Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1 | /* |
Tejun Heo | 88999a8 | 2010-04-09 18:57:01 +0900 | [diff] [blame] | 2 | * mm/percpu.c - percpu memory allocator |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 3 | * |
| 4 | * Copyright (C) 2009 SUSE Linux Products GmbH |
| 5 | * Copyright (C) 2009 Tejun Heo <tj@kernel.org> |
| 6 | * |
Dennis Zhou (Facebook) | 5e81ee3 | 2017-07-24 19:02:20 -0400 | [diff] [blame] | 7 | * Copyright (C) 2017 Facebook Inc. |
| 8 | * Copyright (C) 2017 Dennis Zhou <dennisszhou@gmail.com> |
| 9 | * |
Dennis Zhou (Facebook) | 9c01516 | 2017-07-15 22:23:09 -0400 | [diff] [blame] | 10 | * This file is released under the GPLv2 license. |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 11 | * |
Dennis Zhou (Facebook) | 9c01516 | 2017-07-15 22:23:09 -0400 | [diff] [blame] | 12 | * The percpu allocator handles both static and dynamic areas. Percpu |
| 13 | * areas are allocated in chunks which are divided into units. There is |
| 14 | * a 1-to-1 mapping for units to possible cpus. These units are grouped |
| 15 | * based on NUMA properties of the machine. |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 16 | * |
| 17 | * c0 c1 c2 |
| 18 | * ------------------- ------------------- ------------ |
| 19 | * | u0 | u1 | u2 | u3 | | u0 | u1 | u2 | u3 | | u0 | u1 | u |
| 20 | * ------------------- ...... ------------------- .... ------------ |
| 21 | * |
Dennis Zhou (Facebook) | 9c01516 | 2017-07-15 22:23:09 -0400 | [diff] [blame] | 22 | * Allocation is done by offsets into a unit's address space. Ie., an |
| 23 | * area of 512 bytes at 6k in c1 occupies 512 bytes at 6k in c1:u0, |
| 24 | * c1:u1, c1:u2, etc. On NUMA machines, the mapping may be non-linear |
| 25 | * and even sparse. Access is handled by configuring percpu base |
| 26 | * registers according to the cpu to unit mappings and offsetting the |
| 27 | * base address using pcpu_unit_size. |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 28 | * |
Dennis Zhou (Facebook) | 9c01516 | 2017-07-15 22:23:09 -0400 | [diff] [blame] | 29 | * There is special consideration for the first chunk which must handle |
| 30 | * the static percpu variables in the kernel image as allocation services |
Dennis Zhou (Facebook) | 5e81ee3 | 2017-07-24 19:02:20 -0400 | [diff] [blame] | 31 | * are not online yet. In short, the first chunk is structured like so: |
Dennis Zhou (Facebook) | 9c01516 | 2017-07-15 22:23:09 -0400 | [diff] [blame] | 32 | * |
| 33 | * <Static | [Reserved] | Dynamic> |
| 34 | * |
| 35 | * The static data is copied from the original section managed by the |
| 36 | * linker. The reserved section, if non-zero, primarily manages static |
| 37 | * percpu variables from kernel modules. Finally, the dynamic section |
| 38 | * takes care of normal allocations. |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 39 | * |
Dennis Zhou (Facebook) | 5e81ee3 | 2017-07-24 19:02:20 -0400 | [diff] [blame] | 40 | * The allocator organizes chunks into lists according to free size and |
| 41 | * tries to allocate from the fullest chunk first. Each chunk is managed |
| 42 | * by a bitmap with metadata blocks. The allocation map is updated on |
| 43 | * every allocation and free to reflect the current state while the boundary |
| 44 | * map is only updated on allocation. Each metadata block contains |
| 45 | * information to help mitigate the need to iterate over large portions |
| 46 | * of the bitmap. The reverse mapping from page to chunk is stored in |
| 47 | * the page's index. Lastly, units are lazily backed and grow in unison. |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 48 | * |
Dennis Zhou (Facebook) | 5e81ee3 | 2017-07-24 19:02:20 -0400 | [diff] [blame] | 49 | * There is a unique conversion that goes on here between bytes and bits. |
| 50 | * Each bit represents a fragment of size PCPU_MIN_ALLOC_SIZE. The chunk |
| 51 | * tracks the number of pages it is responsible for in nr_pages. Helper |
| 52 | * functions are used to convert from between the bytes, bits, and blocks. |
| 53 | * All hints are managed in bits unless explicitly stated. |
Dennis Zhou (Facebook) | 9c01516 | 2017-07-15 22:23:09 -0400 | [diff] [blame] | 54 | * |
Masahiro Yamada | 4091fb9 | 2017-02-27 14:29:56 -0800 | [diff] [blame] | 55 | * To use this allocator, arch code should do the following: |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 56 | * |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 57 | * - define __addr_to_pcpu_ptr() and __pcpu_ptr_to_addr() to translate |
Tejun Heo | e010098 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 58 | * regular address to percpu pointer and back if they need to be |
| 59 | * different from the default |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 60 | * |
Tejun Heo | 8d408b4 | 2009-02-24 11:57:21 +0900 | [diff] [blame] | 61 | * - use pcpu_setup_first_chunk() during percpu area initialization to |
| 62 | * setup the first chunk containing the kernel static percpu area |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 63 | */ |
| 64 | |
Joe Perches | 870d4b1 | 2016-03-17 14:19:53 -0700 | [diff] [blame] | 65 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| 66 | |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 67 | #include <linux/bitmap.h> |
| 68 | #include <linux/bootmem.h> |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 69 | #include <linux/err.h> |
Dennis Zhou (Facebook) | ca460b3 | 2017-07-24 19:02:12 -0400 | [diff] [blame] | 70 | #include <linux/lcm.h> |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 71 | #include <linux/list.h> |
Tejun Heo | a530b79 | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 72 | #include <linux/log2.h> |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 73 | #include <linux/mm.h> |
| 74 | #include <linux/module.h> |
| 75 | #include <linux/mutex.h> |
| 76 | #include <linux/percpu.h> |
| 77 | #include <linux/pfn.h> |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 78 | #include <linux/slab.h> |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 79 | #include <linux/spinlock.h> |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 80 | #include <linux/vmalloc.h> |
Tejun Heo | a56dbdd | 2009-03-07 00:44:11 +0900 | [diff] [blame] | 81 | #include <linux/workqueue.h> |
Catalin Marinas | f528f0b | 2011-09-26 17:12:53 +0100 | [diff] [blame] | 82 | #include <linux/kmemleak.h> |
Tejun Heo | e9caf1e | 2018-03-14 08:27:26 -0700 | [diff] [blame] | 83 | #include <linux/sched.h> |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 84 | |
| 85 | #include <asm/cacheflush.h> |
Tejun Heo | e010098 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 86 | #include <asm/sections.h> |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 87 | #include <asm/tlbflush.h> |
Vivek Goyal | 3b034b0 | 2009-11-24 15:50:03 +0900 | [diff] [blame] | 88 | #include <asm/io.h> |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 89 | |
Dennis Zhou | df95e79 | 2017-06-19 19:28:32 -0400 | [diff] [blame] | 90 | #define CREATE_TRACE_POINTS |
| 91 | #include <trace/events/percpu.h> |
| 92 | |
Dennis Zhou | 8fa3ed8 | 2017-06-19 19:28:30 -0400 | [diff] [blame] | 93 | #include "percpu-internal.h" |
| 94 | |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 95 | /* the slots are sorted by free bytes left, 1-31 bytes share the same slot */ |
| 96 | #define PCPU_SLOT_BASE_SHIFT 5 |
| 97 | |
Tejun Heo | 1a4d760 | 2014-09-02 14:46:05 -0400 | [diff] [blame] | 98 | #define PCPU_EMPTY_POP_PAGES_LOW 2 |
| 99 | #define PCPU_EMPTY_POP_PAGES_HIGH 4 |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 100 | |
Tejun Heo | bbddff0 | 2010-09-03 18:22:48 +0200 | [diff] [blame] | 101 | #ifdef CONFIG_SMP |
Tejun Heo | e010098 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 102 | /* default addr <-> pcpu_ptr mapping, override in asm/percpu.h if necessary */ |
| 103 | #ifndef __addr_to_pcpu_ptr |
| 104 | #define __addr_to_pcpu_ptr(addr) \ |
Tejun Heo | 43cf38e | 2010-02-02 14:38:57 +0900 | [diff] [blame] | 105 | (void __percpu *)((unsigned long)(addr) - \ |
| 106 | (unsigned long)pcpu_base_addr + \ |
| 107 | (unsigned long)__per_cpu_start) |
Tejun Heo | e010098 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 108 | #endif |
| 109 | #ifndef __pcpu_ptr_to_addr |
| 110 | #define __pcpu_ptr_to_addr(ptr) \ |
Tejun Heo | 43cf38e | 2010-02-02 14:38:57 +0900 | [diff] [blame] | 111 | (void __force *)((unsigned long)(ptr) + \ |
| 112 | (unsigned long)pcpu_base_addr - \ |
| 113 | (unsigned long)__per_cpu_start) |
Tejun Heo | e010098 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 114 | #endif |
Tejun Heo | bbddff0 | 2010-09-03 18:22:48 +0200 | [diff] [blame] | 115 | #else /* CONFIG_SMP */ |
| 116 | /* on UP, it's always identity mapped */ |
| 117 | #define __addr_to_pcpu_ptr(addr) (void __percpu *)(addr) |
| 118 | #define __pcpu_ptr_to_addr(ptr) (void __force *)(ptr) |
| 119 | #endif /* CONFIG_SMP */ |
Tejun Heo | e010098 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 120 | |
Daniel Micay | 1328710 | 2017-05-10 13:36:37 -0400 | [diff] [blame] | 121 | static int pcpu_unit_pages __ro_after_init; |
| 122 | static int pcpu_unit_size __ro_after_init; |
| 123 | static int pcpu_nr_units __ro_after_init; |
| 124 | static int pcpu_atom_size __ro_after_init; |
Dennis Zhou | 8fa3ed8 | 2017-06-19 19:28:30 -0400 | [diff] [blame] | 125 | int pcpu_nr_slots __ro_after_init; |
Daniel Micay | 1328710 | 2017-05-10 13:36:37 -0400 | [diff] [blame] | 126 | static size_t pcpu_chunk_struct_size __ro_after_init; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 127 | |
Tejun Heo | a855b84 | 2011-11-18 10:55:35 -0800 | [diff] [blame] | 128 | /* cpus with the lowest and highest unit addresses */ |
Daniel Micay | 1328710 | 2017-05-10 13:36:37 -0400 | [diff] [blame] | 129 | static unsigned int pcpu_low_unit_cpu __ro_after_init; |
| 130 | static unsigned int pcpu_high_unit_cpu __ro_after_init; |
Tejun Heo | 2f39e63 | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 131 | |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 132 | /* the address of the first chunk which starts with the kernel static area */ |
Daniel Micay | 1328710 | 2017-05-10 13:36:37 -0400 | [diff] [blame] | 133 | void *pcpu_base_addr __ro_after_init; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 134 | EXPORT_SYMBOL_GPL(pcpu_base_addr); |
| 135 | |
Daniel Micay | 1328710 | 2017-05-10 13:36:37 -0400 | [diff] [blame] | 136 | static const int *pcpu_unit_map __ro_after_init; /* cpu -> unit */ |
| 137 | const unsigned long *pcpu_unit_offsets __ro_after_init; /* cpu -> unit offset */ |
Tejun Heo | 2f39e63 | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 138 | |
Tejun Heo | 6563297 | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 139 | /* group information, used for vm allocation */ |
Daniel Micay | 1328710 | 2017-05-10 13:36:37 -0400 | [diff] [blame] | 140 | static int pcpu_nr_groups __ro_after_init; |
| 141 | static const unsigned long *pcpu_group_offsets __ro_after_init; |
| 142 | static const size_t *pcpu_group_sizes __ro_after_init; |
Tejun Heo | 6563297 | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 143 | |
Tejun Heo | ae9e6bc9 | 2009-04-02 13:19:54 +0900 | [diff] [blame] | 144 | /* |
| 145 | * The first chunk which always exists. Note that unlike other |
| 146 | * chunks, this one can be allocated and mapped in several different |
| 147 | * ways and thus often doesn't live in the vmalloc area. |
| 148 | */ |
Dennis Zhou | 8fa3ed8 | 2017-06-19 19:28:30 -0400 | [diff] [blame] | 149 | struct pcpu_chunk *pcpu_first_chunk __ro_after_init; |
Tejun Heo | ae9e6bc9 | 2009-04-02 13:19:54 +0900 | [diff] [blame] | 150 | |
| 151 | /* |
| 152 | * Optional reserved chunk. This chunk reserves part of the first |
Dennis Zhou (Facebook) | e226670 | 2017-07-24 19:01:59 -0400 | [diff] [blame] | 153 | * chunk and serves it for reserved allocations. When the reserved |
| 154 | * region doesn't exist, the following variable is NULL. |
Tejun Heo | ae9e6bc9 | 2009-04-02 13:19:54 +0900 | [diff] [blame] | 155 | */ |
Dennis Zhou | 8fa3ed8 | 2017-06-19 19:28:30 -0400 | [diff] [blame] | 156 | struct pcpu_chunk *pcpu_reserved_chunk __ro_after_init; |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 157 | |
Dennis Zhou | 8fa3ed8 | 2017-06-19 19:28:30 -0400 | [diff] [blame] | 158 | DEFINE_SPINLOCK(pcpu_lock); /* all internal data structures */ |
Tejun Heo | 6710e59 | 2016-05-25 11:48:25 -0400 | [diff] [blame] | 159 | static DEFINE_MUTEX(pcpu_alloc_mutex); /* chunk create/destroy, [de]pop, map ext */ |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 160 | |
Dennis Zhou | 8fa3ed8 | 2017-06-19 19:28:30 -0400 | [diff] [blame] | 161 | struct list_head *pcpu_slot __ro_after_init; /* chunk list slots */ |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 162 | |
Tejun Heo | 4f996e2 | 2016-05-25 11:48:25 -0400 | [diff] [blame] | 163 | /* chunks which need their map areas extended, protected by pcpu_lock */ |
| 164 | static LIST_HEAD(pcpu_map_extend_chunks); |
| 165 | |
Tejun Heo | b539b87 | 2014-09-02 14:46:05 -0400 | [diff] [blame] | 166 | /* |
| 167 | * The number of empty populated pages, protected by pcpu_lock. The |
| 168 | * reserved chunk doesn't contribute to the count. |
| 169 | */ |
Dennis Zhou (Facebook) | 6b9b6f3 | 2017-07-15 22:23:08 -0400 | [diff] [blame] | 170 | int pcpu_nr_empty_pop_pages; |
Tejun Heo | b539b87 | 2014-09-02 14:46:05 -0400 | [diff] [blame] | 171 | |
Tejun Heo | 1a4d760 | 2014-09-02 14:46:05 -0400 | [diff] [blame] | 172 | /* |
| 173 | * Balance work is used to populate or destroy chunks asynchronously. We |
| 174 | * try to keep the number of populated free pages between |
| 175 | * PCPU_EMPTY_POP_PAGES_LOW and HIGH for atomic allocations and at most one |
| 176 | * empty chunk. |
| 177 | */ |
Tejun Heo | fe6bd8c | 2014-09-02 14:46:05 -0400 | [diff] [blame] | 178 | static void pcpu_balance_workfn(struct work_struct *work); |
| 179 | static DECLARE_WORK(pcpu_balance_work, pcpu_balance_workfn); |
Tejun Heo | 1a4d760 | 2014-09-02 14:46:05 -0400 | [diff] [blame] | 180 | static bool pcpu_async_enabled __read_mostly; |
| 181 | static bool pcpu_atomic_alloc_failed; |
| 182 | |
| 183 | static void pcpu_schedule_balance_work(void) |
| 184 | { |
| 185 | if (pcpu_async_enabled) |
| 186 | schedule_work(&pcpu_balance_work); |
| 187 | } |
Tejun Heo | a56dbdd | 2009-03-07 00:44:11 +0900 | [diff] [blame] | 188 | |
Dennis Zhou (Facebook) | c0ebfdc | 2017-07-24 19:02:05 -0400 | [diff] [blame] | 189 | /** |
Dennis Zhou (Facebook) | 560f2c2 | 2017-07-24 19:02:06 -0400 | [diff] [blame] | 190 | * pcpu_addr_in_chunk - check if the address is served from this chunk |
| 191 | * @chunk: chunk of interest |
| 192 | * @addr: percpu address |
Dennis Zhou (Facebook) | c0ebfdc | 2017-07-24 19:02:05 -0400 | [diff] [blame] | 193 | * |
| 194 | * RETURNS: |
Dennis Zhou (Facebook) | 560f2c2 | 2017-07-24 19:02:06 -0400 | [diff] [blame] | 195 | * True if the address is served from this chunk. |
Dennis Zhou (Facebook) | c0ebfdc | 2017-07-24 19:02:05 -0400 | [diff] [blame] | 196 | */ |
Dennis Zhou (Facebook) | 560f2c2 | 2017-07-24 19:02:06 -0400 | [diff] [blame] | 197 | static bool pcpu_addr_in_chunk(struct pcpu_chunk *chunk, void *addr) |
Tejun Heo | 020ec65 | 2010-04-09 18:57:00 +0900 | [diff] [blame] | 198 | { |
Dennis Zhou (Facebook) | c0ebfdc | 2017-07-24 19:02:05 -0400 | [diff] [blame] | 199 | void *start_addr, *end_addr; |
Tejun Heo | 020ec65 | 2010-04-09 18:57:00 +0900 | [diff] [blame] | 200 | |
Dennis Zhou (Facebook) | 560f2c2 | 2017-07-24 19:02:06 -0400 | [diff] [blame] | 201 | if (!chunk) |
Dennis Zhou (Facebook) | c0ebfdc | 2017-07-24 19:02:05 -0400 | [diff] [blame] | 202 | return false; |
| 203 | |
Dennis Zhou (Facebook) | 560f2c2 | 2017-07-24 19:02:06 -0400 | [diff] [blame] | 204 | start_addr = chunk->base_addr + chunk->start_offset; |
| 205 | end_addr = chunk->base_addr + chunk->nr_pages * PAGE_SIZE - |
| 206 | chunk->end_offset; |
Dennis Zhou (Facebook) | c0ebfdc | 2017-07-24 19:02:05 -0400 | [diff] [blame] | 207 | |
| 208 | return addr >= start_addr && addr < end_addr; |
Tejun Heo | 020ec65 | 2010-04-09 18:57:00 +0900 | [diff] [blame] | 209 | } |
| 210 | |
Tejun Heo | d9b55ee | 2009-02-24 11:57:21 +0900 | [diff] [blame] | 211 | static int __pcpu_size_to_slot(int size) |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 212 | { |
Tejun Heo | cae3aeb | 2009-02-21 16:56:23 +0900 | [diff] [blame] | 213 | int highbit = fls(size); /* size is in bytes */ |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 214 | return max(highbit - PCPU_SLOT_BASE_SHIFT + 2, 1); |
| 215 | } |
| 216 | |
Tejun Heo | d9b55ee | 2009-02-24 11:57:21 +0900 | [diff] [blame] | 217 | static int pcpu_size_to_slot(int size) |
| 218 | { |
| 219 | if (size == pcpu_unit_size) |
| 220 | return pcpu_nr_slots - 1; |
| 221 | return __pcpu_size_to_slot(size); |
| 222 | } |
| 223 | |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 224 | static int pcpu_chunk_slot(const struct pcpu_chunk *chunk) |
| 225 | { |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 226 | if (chunk->free_bytes < PCPU_MIN_ALLOC_SIZE || chunk->contig_bits == 0) |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 227 | return 0; |
| 228 | |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 229 | return pcpu_size_to_slot(chunk->free_bytes); |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 230 | } |
| 231 | |
Tejun Heo | 88999a8 | 2010-04-09 18:57:01 +0900 | [diff] [blame] | 232 | /* set the pointer to a chunk in a page struct */ |
| 233 | static void pcpu_set_page_chunk(struct page *page, struct pcpu_chunk *pcpu) |
| 234 | { |
| 235 | page->index = (unsigned long)pcpu; |
| 236 | } |
| 237 | |
| 238 | /* obtain pointer to a chunk from a page struct */ |
| 239 | static struct pcpu_chunk *pcpu_get_page_chunk(struct page *page) |
| 240 | { |
| 241 | return (struct pcpu_chunk *)page->index; |
| 242 | } |
| 243 | |
| 244 | static int __maybe_unused pcpu_page_idx(unsigned int cpu, int page_idx) |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 245 | { |
Tejun Heo | 2f39e63 | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 246 | return pcpu_unit_map[cpu] * pcpu_unit_pages + page_idx; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 247 | } |
| 248 | |
Dennis Zhou (Facebook) | c0ebfdc | 2017-07-24 19:02:05 -0400 | [diff] [blame] | 249 | static unsigned long pcpu_unit_page_offset(unsigned int cpu, int page_idx) |
| 250 | { |
| 251 | return pcpu_unit_offsets[cpu] + (page_idx << PAGE_SHIFT); |
| 252 | } |
| 253 | |
Tejun Heo | 9983b6f0 | 2010-06-18 11:44:31 +0200 | [diff] [blame] | 254 | static unsigned long pcpu_chunk_addr(struct pcpu_chunk *chunk, |
| 255 | unsigned int cpu, int page_idx) |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 256 | { |
Dennis Zhou (Facebook) | c0ebfdc | 2017-07-24 19:02:05 -0400 | [diff] [blame] | 257 | return (unsigned long)chunk->base_addr + |
| 258 | pcpu_unit_page_offset(cpu, page_idx); |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 259 | } |
| 260 | |
Dennis Zhou (Facebook) | 91e914c | 2017-07-24 19:02:10 -0400 | [diff] [blame] | 261 | static void pcpu_next_unpop(unsigned long *bitmap, int *rs, int *re, int end) |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 262 | { |
Dennis Zhou (Facebook) | 91e914c | 2017-07-24 19:02:10 -0400 | [diff] [blame] | 263 | *rs = find_next_zero_bit(bitmap, end, *rs); |
| 264 | *re = find_next_bit(bitmap, end, *rs + 1); |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 265 | } |
| 266 | |
Dennis Zhou (Facebook) | 91e914c | 2017-07-24 19:02:10 -0400 | [diff] [blame] | 267 | static void pcpu_next_pop(unsigned long *bitmap, int *rs, int *re, int end) |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 268 | { |
Dennis Zhou (Facebook) | 91e914c | 2017-07-24 19:02:10 -0400 | [diff] [blame] | 269 | *rs = find_next_bit(bitmap, end, *rs); |
| 270 | *re = find_next_zero_bit(bitmap, end, *rs + 1); |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 271 | } |
| 272 | |
| 273 | /* |
Dennis Zhou (Facebook) | 91e914c | 2017-07-24 19:02:10 -0400 | [diff] [blame] | 274 | * Bitmap region iterators. Iterates over the bitmap between |
| 275 | * [@start, @end) in @chunk. @rs and @re should be integer variables |
| 276 | * and will be set to start and end index of the current free region. |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 277 | */ |
Dennis Zhou (Facebook) | 91e914c | 2017-07-24 19:02:10 -0400 | [diff] [blame] | 278 | #define pcpu_for_each_unpop_region(bitmap, rs, re, start, end) \ |
| 279 | for ((rs) = (start), pcpu_next_unpop((bitmap), &(rs), &(re), (end)); \ |
| 280 | (rs) < (re); \ |
| 281 | (rs) = (re) + 1, pcpu_next_unpop((bitmap), &(rs), &(re), (end))) |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 282 | |
Dennis Zhou (Facebook) | 91e914c | 2017-07-24 19:02:10 -0400 | [diff] [blame] | 283 | #define pcpu_for_each_pop_region(bitmap, rs, re, start, end) \ |
| 284 | for ((rs) = (start), pcpu_next_pop((bitmap), &(rs), &(re), (end)); \ |
| 285 | (rs) < (re); \ |
| 286 | (rs) = (re) + 1, pcpu_next_pop((bitmap), &(rs), &(re), (end))) |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 287 | |
Dennis Zhou (Facebook) | ca460b3 | 2017-07-24 19:02:12 -0400 | [diff] [blame] | 288 | /* |
| 289 | * The following are helper functions to help access bitmaps and convert |
| 290 | * between bitmap offsets to address offsets. |
| 291 | */ |
| 292 | static unsigned long *pcpu_index_alloc_map(struct pcpu_chunk *chunk, int index) |
| 293 | { |
| 294 | return chunk->alloc_map + |
| 295 | (index * PCPU_BITMAP_BLOCK_BITS / BITS_PER_LONG); |
| 296 | } |
| 297 | |
| 298 | static unsigned long pcpu_off_to_block_index(int off) |
| 299 | { |
| 300 | return off / PCPU_BITMAP_BLOCK_BITS; |
| 301 | } |
| 302 | |
| 303 | static unsigned long pcpu_off_to_block_off(int off) |
| 304 | { |
| 305 | return off & (PCPU_BITMAP_BLOCK_BITS - 1); |
| 306 | } |
| 307 | |
Dennis Zhou (Facebook) | b185cd0 | 2017-07-24 19:02:17 -0400 | [diff] [blame] | 308 | static unsigned long pcpu_block_off_to_off(int index, int off) |
| 309 | { |
| 310 | return index * PCPU_BITMAP_BLOCK_BITS + off; |
| 311 | } |
| 312 | |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 313 | /** |
Dennis Zhou (Facebook) | 525ca84 | 2017-07-24 19:02:18 -0400 | [diff] [blame] | 314 | * pcpu_next_md_free_region - finds the next hint free area |
| 315 | * @chunk: chunk of interest |
| 316 | * @bit_off: chunk offset |
| 317 | * @bits: size of free area |
| 318 | * |
| 319 | * Helper function for pcpu_for_each_md_free_region. It checks |
| 320 | * block->contig_hint and performs aggregation across blocks to find the |
| 321 | * next hint. It modifies bit_off and bits in-place to be consumed in the |
| 322 | * loop. |
| 323 | */ |
| 324 | static void pcpu_next_md_free_region(struct pcpu_chunk *chunk, int *bit_off, |
| 325 | int *bits) |
| 326 | { |
| 327 | int i = pcpu_off_to_block_index(*bit_off); |
| 328 | int block_off = pcpu_off_to_block_off(*bit_off); |
| 329 | struct pcpu_block_md *block; |
| 330 | |
| 331 | *bits = 0; |
| 332 | for (block = chunk->md_blocks + i; i < pcpu_chunk_nr_blocks(chunk); |
| 333 | block++, i++) { |
| 334 | /* handles contig area across blocks */ |
| 335 | if (*bits) { |
| 336 | *bits += block->left_free; |
| 337 | if (block->left_free == PCPU_BITMAP_BLOCK_BITS) |
| 338 | continue; |
| 339 | return; |
| 340 | } |
| 341 | |
| 342 | /* |
| 343 | * This checks three things. First is there a contig_hint to |
| 344 | * check. Second, have we checked this hint before by |
| 345 | * comparing the block_off. Third, is this the same as the |
| 346 | * right contig hint. In the last case, it spills over into |
| 347 | * the next block and should be handled by the contig area |
| 348 | * across blocks code. |
| 349 | */ |
| 350 | *bits = block->contig_hint; |
| 351 | if (*bits && block->contig_hint_start >= block_off && |
| 352 | *bits + block->contig_hint_start < PCPU_BITMAP_BLOCK_BITS) { |
| 353 | *bit_off = pcpu_block_off_to_off(i, |
| 354 | block->contig_hint_start); |
| 355 | return; |
| 356 | } |
Dennis Zhou | 1fa4df3 | 2017-09-27 16:35:00 -0500 | [diff] [blame] | 357 | /* reset to satisfy the second predicate above */ |
| 358 | block_off = 0; |
Dennis Zhou (Facebook) | 525ca84 | 2017-07-24 19:02:18 -0400 | [diff] [blame] | 359 | |
| 360 | *bits = block->right_free; |
| 361 | *bit_off = (i + 1) * PCPU_BITMAP_BLOCK_BITS - block->right_free; |
| 362 | } |
| 363 | } |
| 364 | |
Dennis Zhou (Facebook) | b4c2116 | 2017-07-24 19:02:19 -0400 | [diff] [blame] | 365 | /** |
| 366 | * pcpu_next_fit_region - finds fit areas for a given allocation request |
| 367 | * @chunk: chunk of interest |
| 368 | * @alloc_bits: size of allocation |
| 369 | * @align: alignment of area (max PAGE_SIZE) |
| 370 | * @bit_off: chunk offset |
| 371 | * @bits: size of free area |
| 372 | * |
| 373 | * Finds the next free region that is viable for use with a given size and |
| 374 | * alignment. This only returns if there is a valid area to be used for this |
| 375 | * allocation. block->first_free is returned if the allocation request fits |
| 376 | * within the block to see if the request can be fulfilled prior to the contig |
| 377 | * hint. |
| 378 | */ |
| 379 | static void pcpu_next_fit_region(struct pcpu_chunk *chunk, int alloc_bits, |
| 380 | int align, int *bit_off, int *bits) |
| 381 | { |
| 382 | int i = pcpu_off_to_block_index(*bit_off); |
| 383 | int block_off = pcpu_off_to_block_off(*bit_off); |
| 384 | struct pcpu_block_md *block; |
| 385 | |
| 386 | *bits = 0; |
| 387 | for (block = chunk->md_blocks + i; i < pcpu_chunk_nr_blocks(chunk); |
| 388 | block++, i++) { |
| 389 | /* handles contig area across blocks */ |
| 390 | if (*bits) { |
| 391 | *bits += block->left_free; |
| 392 | if (*bits >= alloc_bits) |
| 393 | return; |
| 394 | if (block->left_free == PCPU_BITMAP_BLOCK_BITS) |
| 395 | continue; |
| 396 | } |
| 397 | |
| 398 | /* check block->contig_hint */ |
| 399 | *bits = ALIGN(block->contig_hint_start, align) - |
| 400 | block->contig_hint_start; |
| 401 | /* |
| 402 | * This uses the block offset to determine if this has been |
| 403 | * checked in the prior iteration. |
| 404 | */ |
| 405 | if (block->contig_hint && |
| 406 | block->contig_hint_start >= block_off && |
| 407 | block->contig_hint >= *bits + alloc_bits) { |
| 408 | *bits += alloc_bits + block->contig_hint_start - |
| 409 | block->first_free; |
| 410 | *bit_off = pcpu_block_off_to_off(i, block->first_free); |
| 411 | return; |
| 412 | } |
Dennis Zhou | 1fa4df3 | 2017-09-27 16:35:00 -0500 | [diff] [blame] | 413 | /* reset to satisfy the second predicate above */ |
| 414 | block_off = 0; |
Dennis Zhou (Facebook) | b4c2116 | 2017-07-24 19:02:19 -0400 | [diff] [blame] | 415 | |
| 416 | *bit_off = ALIGN(PCPU_BITMAP_BLOCK_BITS - block->right_free, |
| 417 | align); |
| 418 | *bits = PCPU_BITMAP_BLOCK_BITS - *bit_off; |
| 419 | *bit_off = pcpu_block_off_to_off(i, *bit_off); |
| 420 | if (*bits >= alloc_bits) |
| 421 | return; |
| 422 | } |
| 423 | |
| 424 | /* no valid offsets were found - fail condition */ |
| 425 | *bit_off = pcpu_chunk_map_bits(chunk); |
| 426 | } |
| 427 | |
Dennis Zhou (Facebook) | 525ca84 | 2017-07-24 19:02:18 -0400 | [diff] [blame] | 428 | /* |
| 429 | * Metadata free area iterators. These perform aggregation of free areas |
| 430 | * based on the metadata blocks and return the offset @bit_off and size in |
Dennis Zhou (Facebook) | b4c2116 | 2017-07-24 19:02:19 -0400 | [diff] [blame] | 431 | * bits of the free area @bits. pcpu_for_each_fit_region only returns when |
| 432 | * a fit is found for the allocation request. |
Dennis Zhou (Facebook) | 525ca84 | 2017-07-24 19:02:18 -0400 | [diff] [blame] | 433 | */ |
| 434 | #define pcpu_for_each_md_free_region(chunk, bit_off, bits) \ |
| 435 | for (pcpu_next_md_free_region((chunk), &(bit_off), &(bits)); \ |
| 436 | (bit_off) < pcpu_chunk_map_bits((chunk)); \ |
| 437 | (bit_off) += (bits) + 1, \ |
| 438 | pcpu_next_md_free_region((chunk), &(bit_off), &(bits))) |
| 439 | |
Dennis Zhou (Facebook) | b4c2116 | 2017-07-24 19:02:19 -0400 | [diff] [blame] | 440 | #define pcpu_for_each_fit_region(chunk, alloc_bits, align, bit_off, bits) \ |
| 441 | for (pcpu_next_fit_region((chunk), (alloc_bits), (align), &(bit_off), \ |
| 442 | &(bits)); \ |
| 443 | (bit_off) < pcpu_chunk_map_bits((chunk)); \ |
| 444 | (bit_off) += (bits), \ |
| 445 | pcpu_next_fit_region((chunk), (alloc_bits), (align), &(bit_off), \ |
| 446 | &(bits))) |
| 447 | |
Dennis Zhou (Facebook) | 525ca84 | 2017-07-24 19:02:18 -0400 | [diff] [blame] | 448 | /** |
Bob Liu | 90459ce0 | 2011-08-04 11:02:33 +0200 | [diff] [blame] | 449 | * pcpu_mem_zalloc - allocate memory |
Tejun Heo | 1880d93 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 450 | * @size: bytes to allocate |
Dennis Zhou | 72682b1 | 2018-02-16 12:07:19 -0600 | [diff] [blame] | 451 | * @gfp: allocation flags |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 452 | * |
Tejun Heo | 1880d93 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 453 | * Allocate @size bytes. If @size is smaller than PAGE_SIZE, |
Dennis Zhou | 72682b1 | 2018-02-16 12:07:19 -0600 | [diff] [blame] | 454 | * kzalloc() is used; otherwise, the equivalent of vzalloc() is used. |
| 455 | * This is to facilitate passing through whitelisted flags. The |
| 456 | * returned memory is always zeroed. |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 457 | * |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 458 | * CONTEXT: |
| 459 | * Does GFP_KERNEL allocation. |
| 460 | * |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 461 | * RETURNS: |
Tejun Heo | 1880d93 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 462 | * Pointer to the allocated area on success, NULL on failure. |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 463 | */ |
Dennis Zhou | 72682b1 | 2018-02-16 12:07:19 -0600 | [diff] [blame] | 464 | static void *pcpu_mem_zalloc(size_t size, gfp_t gfp) |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 465 | { |
Tejun Heo | 099a19d | 2010-06-27 18:50:00 +0200 | [diff] [blame] | 466 | if (WARN_ON_ONCE(!slab_is_available())) |
| 467 | return NULL; |
| 468 | |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 469 | if (size <= PAGE_SIZE) |
Dennis Zhou | 72682b1 | 2018-02-16 12:07:19 -0600 | [diff] [blame] | 470 | return kzalloc(size, gfp | GFP_KERNEL); |
Jesper Juhl | 7af4c09 | 2010-10-30 15:56:54 +0200 | [diff] [blame] | 471 | else |
Dennis Zhou | 72682b1 | 2018-02-16 12:07:19 -0600 | [diff] [blame] | 472 | return __vmalloc(size, gfp | GFP_KERNEL | __GFP_ZERO, |
| 473 | PAGE_KERNEL); |
Tejun Heo | 1880d93 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 474 | } |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 475 | |
Tejun Heo | 1880d93 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 476 | /** |
| 477 | * pcpu_mem_free - free memory |
| 478 | * @ptr: memory to free |
Tejun Heo | 1880d93 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 479 | * |
Bob Liu | 90459ce0 | 2011-08-04 11:02:33 +0200 | [diff] [blame] | 480 | * Free @ptr. @ptr should have been allocated using pcpu_mem_zalloc(). |
Tejun Heo | 1880d93 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 481 | */ |
Tetsuo Handa | 1d5cfdb | 2016-01-22 15:11:02 -0800 | [diff] [blame] | 482 | static void pcpu_mem_free(void *ptr) |
Tejun Heo | 1880d93 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 483 | { |
Tetsuo Handa | 1d5cfdb | 2016-01-22 15:11:02 -0800 | [diff] [blame] | 484 | kvfree(ptr); |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 485 | } |
| 486 | |
| 487 | /** |
| 488 | * pcpu_chunk_relocate - put chunk in the appropriate chunk slot |
| 489 | * @chunk: chunk of interest |
| 490 | * @oslot: the previous slot it was on |
| 491 | * |
| 492 | * This function is called after an allocation or free changed @chunk. |
| 493 | * New slot according to the changed state is determined and @chunk is |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 494 | * moved to the slot. Note that the reserved chunk is never put on |
| 495 | * chunk slots. |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 496 | * |
| 497 | * CONTEXT: |
| 498 | * pcpu_lock. |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 499 | */ |
| 500 | static void pcpu_chunk_relocate(struct pcpu_chunk *chunk, int oslot) |
| 501 | { |
| 502 | int nslot = pcpu_chunk_slot(chunk); |
| 503 | |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 504 | if (chunk != pcpu_reserved_chunk && oslot != nslot) { |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 505 | if (oslot < nslot) |
| 506 | list_move(&chunk->list, &pcpu_slot[nslot]); |
| 507 | else |
| 508 | list_move_tail(&chunk->list, &pcpu_slot[nslot]); |
| 509 | } |
| 510 | } |
| 511 | |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 512 | /** |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 513 | * pcpu_cnt_pop_pages- counts populated backing pages in range |
Tejun Heo | 833af84 | 2009-11-11 15:35:18 +0900 | [diff] [blame] | 514 | * @chunk: chunk of interest |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 515 | * @bit_off: start offset |
| 516 | * @bits: size of area to check |
Tejun Heo | 9f7dcf2 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 517 | * |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 518 | * Calculates the number of populated pages in the region |
| 519 | * [page_start, page_end). This keeps track of how many empty populated |
| 520 | * pages are available and decide if async work should be scheduled. |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 521 | * |
Tejun Heo | 9f7dcf2 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 522 | * RETURNS: |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 523 | * The nr of populated pages. |
Tejun Heo | 9f7dcf2 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 524 | */ |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 525 | static inline int pcpu_cnt_pop_pages(struct pcpu_chunk *chunk, int bit_off, |
| 526 | int bits) |
Tejun Heo | 9f7dcf2 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 527 | { |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 528 | int page_start = PFN_UP(bit_off * PCPU_MIN_ALLOC_SIZE); |
| 529 | int page_end = PFN_DOWN((bit_off + bits) * PCPU_MIN_ALLOC_SIZE); |
| 530 | |
| 531 | if (page_start >= page_end) |
| 532 | return 0; |
| 533 | |
| 534 | /* |
| 535 | * bitmap_weight counts the number of bits set in a bitmap up to |
| 536 | * the specified number of bits. This is counting the populated |
| 537 | * pages up to page_end and then subtracting the populated pages |
| 538 | * up to page_start to count the populated pages in |
| 539 | * [page_start, page_end). |
| 540 | */ |
| 541 | return bitmap_weight(chunk->populated, page_end) - |
| 542 | bitmap_weight(chunk->populated, page_start); |
| 543 | } |
| 544 | |
| 545 | /** |
| 546 | * pcpu_chunk_update - updates the chunk metadata given a free area |
| 547 | * @chunk: chunk of interest |
| 548 | * @bit_off: chunk offset |
| 549 | * @bits: size of free area |
| 550 | * |
Dennis Zhou (Facebook) | 13f9663 | 2017-07-24 19:02:14 -0400 | [diff] [blame] | 551 | * This updates the chunk's contig hint and starting offset given a free area. |
Dennis Zhou (Facebook) | 268625a | 2017-07-24 19:02:15 -0400 | [diff] [blame] | 552 | * Choose the best starting offset if the contig hint is equal. |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 553 | */ |
| 554 | static void pcpu_chunk_update(struct pcpu_chunk *chunk, int bit_off, int bits) |
| 555 | { |
Dennis Zhou (Facebook) | 13f9663 | 2017-07-24 19:02:14 -0400 | [diff] [blame] | 556 | if (bits > chunk->contig_bits) { |
| 557 | chunk->contig_bits_start = bit_off; |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 558 | chunk->contig_bits = bits; |
Dennis Zhou (Facebook) | 268625a | 2017-07-24 19:02:15 -0400 | [diff] [blame] | 559 | } else if (bits == chunk->contig_bits && chunk->contig_bits_start && |
| 560 | (!bit_off || |
| 561 | __ffs(bit_off) > __ffs(chunk->contig_bits_start))) { |
| 562 | /* use the start with the best alignment */ |
| 563 | chunk->contig_bits_start = bit_off; |
Dennis Zhou (Facebook) | 13f9663 | 2017-07-24 19:02:14 -0400 | [diff] [blame] | 564 | } |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 565 | } |
| 566 | |
| 567 | /** |
| 568 | * pcpu_chunk_refresh_hint - updates metadata about a chunk |
| 569 | * @chunk: chunk of interest |
| 570 | * |
Dennis Zhou (Facebook) | 525ca84 | 2017-07-24 19:02:18 -0400 | [diff] [blame] | 571 | * Iterates over the metadata blocks to find the largest contig area. |
| 572 | * It also counts the populated pages and uses the delta to update the |
| 573 | * global count. |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 574 | * |
| 575 | * Updates: |
| 576 | * chunk->contig_bits |
Dennis Zhou (Facebook) | 13f9663 | 2017-07-24 19:02:14 -0400 | [diff] [blame] | 577 | * chunk->contig_bits_start |
Dennis Zhou (Facebook) | 525ca84 | 2017-07-24 19:02:18 -0400 | [diff] [blame] | 578 | * nr_empty_pop_pages (chunk and global) |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 579 | */ |
| 580 | static void pcpu_chunk_refresh_hint(struct pcpu_chunk *chunk) |
| 581 | { |
Dennis Zhou (Facebook) | 525ca84 | 2017-07-24 19:02:18 -0400 | [diff] [blame] | 582 | int bit_off, bits, nr_empty_pop_pages; |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 583 | |
| 584 | /* clear metadata */ |
| 585 | chunk->contig_bits = 0; |
| 586 | |
Dennis Zhou (Facebook) | 525ca84 | 2017-07-24 19:02:18 -0400 | [diff] [blame] | 587 | bit_off = chunk->first_bit; |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 588 | bits = nr_empty_pop_pages = 0; |
Dennis Zhou (Facebook) | 525ca84 | 2017-07-24 19:02:18 -0400 | [diff] [blame] | 589 | pcpu_for_each_md_free_region(chunk, bit_off, bits) { |
| 590 | pcpu_chunk_update(chunk, bit_off, bits); |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 591 | |
Dennis Zhou (Facebook) | 525ca84 | 2017-07-24 19:02:18 -0400 | [diff] [blame] | 592 | nr_empty_pop_pages += pcpu_cnt_pop_pages(chunk, bit_off, bits); |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 593 | } |
| 594 | |
| 595 | /* |
| 596 | * Keep track of nr_empty_pop_pages. |
| 597 | * |
| 598 | * The chunk maintains the previous number of free pages it held, |
| 599 | * so the delta is used to update the global counter. The reserved |
| 600 | * chunk is not part of the free page count as they are populated |
| 601 | * at init and are special to serving reserved allocations. |
| 602 | */ |
| 603 | if (chunk != pcpu_reserved_chunk) |
| 604 | pcpu_nr_empty_pop_pages += |
| 605 | (nr_empty_pop_pages - chunk->nr_empty_pop_pages); |
| 606 | |
| 607 | chunk->nr_empty_pop_pages = nr_empty_pop_pages; |
| 608 | } |
| 609 | |
| 610 | /** |
Dennis Zhou (Facebook) | ca460b3 | 2017-07-24 19:02:12 -0400 | [diff] [blame] | 611 | * pcpu_block_update - updates a block given a free area |
| 612 | * @block: block of interest |
| 613 | * @start: start offset in block |
| 614 | * @end: end offset in block |
| 615 | * |
| 616 | * Updates a block given a known free area. The region [start, end) is |
Dennis Zhou (Facebook) | 268625a | 2017-07-24 19:02:15 -0400 | [diff] [blame] | 617 | * expected to be the entirety of the free area within a block. Chooses |
| 618 | * the best starting offset if the contig hints are equal. |
Dennis Zhou (Facebook) | ca460b3 | 2017-07-24 19:02:12 -0400 | [diff] [blame] | 619 | */ |
| 620 | static void pcpu_block_update(struct pcpu_block_md *block, int start, int end) |
| 621 | { |
| 622 | int contig = end - start; |
| 623 | |
| 624 | block->first_free = min(block->first_free, start); |
| 625 | if (start == 0) |
| 626 | block->left_free = contig; |
| 627 | |
| 628 | if (end == PCPU_BITMAP_BLOCK_BITS) |
| 629 | block->right_free = contig; |
| 630 | |
| 631 | if (contig > block->contig_hint) { |
| 632 | block->contig_hint_start = start; |
| 633 | block->contig_hint = contig; |
Dennis Zhou (Facebook) | 268625a | 2017-07-24 19:02:15 -0400 | [diff] [blame] | 634 | } else if (block->contig_hint_start && contig == block->contig_hint && |
| 635 | (!start || __ffs(start) > __ffs(block->contig_hint_start))) { |
| 636 | /* use the start with the best alignment */ |
| 637 | block->contig_hint_start = start; |
Dennis Zhou (Facebook) | ca460b3 | 2017-07-24 19:02:12 -0400 | [diff] [blame] | 638 | } |
| 639 | } |
| 640 | |
| 641 | /** |
| 642 | * pcpu_block_refresh_hint |
| 643 | * @chunk: chunk of interest |
| 644 | * @index: index of the metadata block |
| 645 | * |
| 646 | * Scans over the block beginning at first_free and updates the block |
| 647 | * metadata accordingly. |
| 648 | */ |
| 649 | static void pcpu_block_refresh_hint(struct pcpu_chunk *chunk, int index) |
| 650 | { |
| 651 | struct pcpu_block_md *block = chunk->md_blocks + index; |
| 652 | unsigned long *alloc_map = pcpu_index_alloc_map(chunk, index); |
| 653 | int rs, re; /* region start, region end */ |
| 654 | |
| 655 | /* clear hints */ |
| 656 | block->contig_hint = 0; |
| 657 | block->left_free = block->right_free = 0; |
| 658 | |
| 659 | /* iterate over free areas and update the contig hints */ |
| 660 | pcpu_for_each_unpop_region(alloc_map, rs, re, block->first_free, |
| 661 | PCPU_BITMAP_BLOCK_BITS) { |
| 662 | pcpu_block_update(block, rs, re); |
| 663 | } |
| 664 | } |
| 665 | |
| 666 | /** |
| 667 | * pcpu_block_update_hint_alloc - update hint on allocation path |
| 668 | * @chunk: chunk of interest |
| 669 | * @bit_off: chunk offset |
| 670 | * @bits: size of request |
Dennis Zhou (Facebook) | fc30433 | 2017-07-24 19:02:16 -0400 | [diff] [blame] | 671 | * |
| 672 | * Updates metadata for the allocation path. The metadata only has to be |
| 673 | * refreshed by a full scan iff the chunk's contig hint is broken. Block level |
| 674 | * scans are required if the block's contig hint is broken. |
Dennis Zhou (Facebook) | ca460b3 | 2017-07-24 19:02:12 -0400 | [diff] [blame] | 675 | */ |
| 676 | static void pcpu_block_update_hint_alloc(struct pcpu_chunk *chunk, int bit_off, |
| 677 | int bits) |
| 678 | { |
| 679 | struct pcpu_block_md *s_block, *e_block, *block; |
| 680 | int s_index, e_index; /* block indexes of the freed allocation */ |
| 681 | int s_off, e_off; /* block offsets of the freed allocation */ |
| 682 | |
| 683 | /* |
| 684 | * Calculate per block offsets. |
| 685 | * The calculation uses an inclusive range, but the resulting offsets |
| 686 | * are [start, end). e_index always points to the last block in the |
| 687 | * range. |
| 688 | */ |
| 689 | s_index = pcpu_off_to_block_index(bit_off); |
| 690 | e_index = pcpu_off_to_block_index(bit_off + bits - 1); |
| 691 | s_off = pcpu_off_to_block_off(bit_off); |
| 692 | e_off = pcpu_off_to_block_off(bit_off + bits - 1) + 1; |
| 693 | |
| 694 | s_block = chunk->md_blocks + s_index; |
| 695 | e_block = chunk->md_blocks + e_index; |
| 696 | |
| 697 | /* |
| 698 | * Update s_block. |
Dennis Zhou (Facebook) | fc30433 | 2017-07-24 19:02:16 -0400 | [diff] [blame] | 699 | * block->first_free must be updated if the allocation takes its place. |
| 700 | * If the allocation breaks the contig_hint, a scan is required to |
| 701 | * restore this hint. |
Dennis Zhou (Facebook) | ca460b3 | 2017-07-24 19:02:12 -0400 | [diff] [blame] | 702 | */ |
Dennis Zhou (Facebook) | fc30433 | 2017-07-24 19:02:16 -0400 | [diff] [blame] | 703 | if (s_off == s_block->first_free) |
| 704 | s_block->first_free = find_next_zero_bit( |
| 705 | pcpu_index_alloc_map(chunk, s_index), |
| 706 | PCPU_BITMAP_BLOCK_BITS, |
| 707 | s_off + bits); |
| 708 | |
| 709 | if (s_off >= s_block->contig_hint_start && |
| 710 | s_off < s_block->contig_hint_start + s_block->contig_hint) { |
| 711 | /* block contig hint is broken - scan to fix it */ |
| 712 | pcpu_block_refresh_hint(chunk, s_index); |
| 713 | } else { |
| 714 | /* update left and right contig manually */ |
| 715 | s_block->left_free = min(s_block->left_free, s_off); |
| 716 | if (s_index == e_index) |
| 717 | s_block->right_free = min_t(int, s_block->right_free, |
| 718 | PCPU_BITMAP_BLOCK_BITS - e_off); |
| 719 | else |
| 720 | s_block->right_free = 0; |
| 721 | } |
Dennis Zhou (Facebook) | ca460b3 | 2017-07-24 19:02:12 -0400 | [diff] [blame] | 722 | |
| 723 | /* |
| 724 | * Update e_block. |
| 725 | */ |
| 726 | if (s_index != e_index) { |
Dennis Zhou (Facebook) | fc30433 | 2017-07-24 19:02:16 -0400 | [diff] [blame] | 727 | /* |
| 728 | * When the allocation is across blocks, the end is along |
| 729 | * the left part of the e_block. |
| 730 | */ |
| 731 | e_block->first_free = find_next_zero_bit( |
| 732 | pcpu_index_alloc_map(chunk, e_index), |
| 733 | PCPU_BITMAP_BLOCK_BITS, e_off); |
| 734 | |
| 735 | if (e_off == PCPU_BITMAP_BLOCK_BITS) { |
| 736 | /* reset the block */ |
| 737 | e_block++; |
| 738 | } else { |
| 739 | if (e_off > e_block->contig_hint_start) { |
| 740 | /* contig hint is broken - scan to fix it */ |
| 741 | pcpu_block_refresh_hint(chunk, e_index); |
| 742 | } else { |
| 743 | e_block->left_free = 0; |
| 744 | e_block->right_free = |
| 745 | min_t(int, e_block->right_free, |
| 746 | PCPU_BITMAP_BLOCK_BITS - e_off); |
| 747 | } |
| 748 | } |
Dennis Zhou (Facebook) | ca460b3 | 2017-07-24 19:02:12 -0400 | [diff] [blame] | 749 | |
| 750 | /* update in-between md_blocks */ |
| 751 | for (block = s_block + 1; block < e_block; block++) { |
| 752 | block->contig_hint = 0; |
| 753 | block->left_free = 0; |
| 754 | block->right_free = 0; |
| 755 | } |
| 756 | } |
| 757 | |
Dennis Zhou (Facebook) | fc30433 | 2017-07-24 19:02:16 -0400 | [diff] [blame] | 758 | /* |
| 759 | * The only time a full chunk scan is required is if the chunk |
| 760 | * contig hint is broken. Otherwise, it means a smaller space |
| 761 | * was used and therefore the chunk contig hint is still correct. |
| 762 | */ |
| 763 | if (bit_off >= chunk->contig_bits_start && |
| 764 | bit_off < chunk->contig_bits_start + chunk->contig_bits) |
| 765 | pcpu_chunk_refresh_hint(chunk); |
Dennis Zhou (Facebook) | ca460b3 | 2017-07-24 19:02:12 -0400 | [diff] [blame] | 766 | } |
| 767 | |
| 768 | /** |
| 769 | * pcpu_block_update_hint_free - updates the block hints on the free path |
| 770 | * @chunk: chunk of interest |
| 771 | * @bit_off: chunk offset |
| 772 | * @bits: size of request |
Dennis Zhou (Facebook) | b185cd0 | 2017-07-24 19:02:17 -0400 | [diff] [blame] | 773 | * |
| 774 | * Updates metadata for the allocation path. This avoids a blind block |
| 775 | * refresh by making use of the block contig hints. If this fails, it scans |
| 776 | * forward and backward to determine the extent of the free area. This is |
| 777 | * capped at the boundary of blocks. |
| 778 | * |
| 779 | * A chunk update is triggered if a page becomes free, a block becomes free, |
| 780 | * or the free spans across blocks. This tradeoff is to minimize iterating |
| 781 | * over the block metadata to update chunk->contig_bits. chunk->contig_bits |
| 782 | * may be off by up to a page, but it will never be more than the available |
| 783 | * space. If the contig hint is contained in one block, it will be accurate. |
Dennis Zhou (Facebook) | ca460b3 | 2017-07-24 19:02:12 -0400 | [diff] [blame] | 784 | */ |
| 785 | static void pcpu_block_update_hint_free(struct pcpu_chunk *chunk, int bit_off, |
| 786 | int bits) |
| 787 | { |
| 788 | struct pcpu_block_md *s_block, *e_block, *block; |
| 789 | int s_index, e_index; /* block indexes of the freed allocation */ |
| 790 | int s_off, e_off; /* block offsets of the freed allocation */ |
Dennis Zhou (Facebook) | b185cd0 | 2017-07-24 19:02:17 -0400 | [diff] [blame] | 791 | int start, end; /* start and end of the whole free area */ |
Dennis Zhou (Facebook) | ca460b3 | 2017-07-24 19:02:12 -0400 | [diff] [blame] | 792 | |
| 793 | /* |
| 794 | * Calculate per block offsets. |
| 795 | * The calculation uses an inclusive range, but the resulting offsets |
| 796 | * are [start, end). e_index always points to the last block in the |
| 797 | * range. |
| 798 | */ |
| 799 | s_index = pcpu_off_to_block_index(bit_off); |
| 800 | e_index = pcpu_off_to_block_index(bit_off + bits - 1); |
| 801 | s_off = pcpu_off_to_block_off(bit_off); |
| 802 | e_off = pcpu_off_to_block_off(bit_off + bits - 1) + 1; |
| 803 | |
| 804 | s_block = chunk->md_blocks + s_index; |
| 805 | e_block = chunk->md_blocks + e_index; |
| 806 | |
Dennis Zhou (Facebook) | b185cd0 | 2017-07-24 19:02:17 -0400 | [diff] [blame] | 807 | /* |
| 808 | * Check if the freed area aligns with the block->contig_hint. |
| 809 | * If it does, then the scan to find the beginning/end of the |
| 810 | * larger free area can be avoided. |
| 811 | * |
| 812 | * start and end refer to beginning and end of the free area |
| 813 | * within each their respective blocks. This is not necessarily |
| 814 | * the entire free area as it may span blocks past the beginning |
| 815 | * or end of the block. |
| 816 | */ |
| 817 | start = s_off; |
| 818 | if (s_off == s_block->contig_hint + s_block->contig_hint_start) { |
| 819 | start = s_block->contig_hint_start; |
| 820 | } else { |
| 821 | /* |
| 822 | * Scan backwards to find the extent of the free area. |
| 823 | * find_last_bit returns the starting bit, so if the start bit |
| 824 | * is returned, that means there was no last bit and the |
| 825 | * remainder of the chunk is free. |
| 826 | */ |
| 827 | int l_bit = find_last_bit(pcpu_index_alloc_map(chunk, s_index), |
| 828 | start); |
| 829 | start = (start == l_bit) ? 0 : l_bit + 1; |
| 830 | } |
| 831 | |
| 832 | end = e_off; |
| 833 | if (e_off == e_block->contig_hint_start) |
| 834 | end = e_block->contig_hint_start + e_block->contig_hint; |
| 835 | else |
| 836 | end = find_next_bit(pcpu_index_alloc_map(chunk, e_index), |
| 837 | PCPU_BITMAP_BLOCK_BITS, end); |
| 838 | |
Dennis Zhou (Facebook) | ca460b3 | 2017-07-24 19:02:12 -0400 | [diff] [blame] | 839 | /* update s_block */ |
Dennis Zhou (Facebook) | b185cd0 | 2017-07-24 19:02:17 -0400 | [diff] [blame] | 840 | e_off = (s_index == e_index) ? end : PCPU_BITMAP_BLOCK_BITS; |
| 841 | pcpu_block_update(s_block, start, e_off); |
Dennis Zhou (Facebook) | ca460b3 | 2017-07-24 19:02:12 -0400 | [diff] [blame] | 842 | |
| 843 | /* freeing in the same block */ |
| 844 | if (s_index != e_index) { |
| 845 | /* update e_block */ |
Dennis Zhou (Facebook) | b185cd0 | 2017-07-24 19:02:17 -0400 | [diff] [blame] | 846 | pcpu_block_update(e_block, 0, end); |
Dennis Zhou (Facebook) | ca460b3 | 2017-07-24 19:02:12 -0400 | [diff] [blame] | 847 | |
| 848 | /* reset md_blocks in the middle */ |
| 849 | for (block = s_block + 1; block < e_block; block++) { |
| 850 | block->first_free = 0; |
| 851 | block->contig_hint_start = 0; |
| 852 | block->contig_hint = PCPU_BITMAP_BLOCK_BITS; |
| 853 | block->left_free = PCPU_BITMAP_BLOCK_BITS; |
| 854 | block->right_free = PCPU_BITMAP_BLOCK_BITS; |
| 855 | } |
| 856 | } |
| 857 | |
Dennis Zhou (Facebook) | b185cd0 | 2017-07-24 19:02:17 -0400 | [diff] [blame] | 858 | /* |
| 859 | * Refresh chunk metadata when the free makes a page free, a block |
| 860 | * free, or spans across blocks. The contig hint may be off by up to |
| 861 | * a page, but if the hint is contained in a block, it will be accurate |
| 862 | * with the else condition below. |
| 863 | */ |
| 864 | if ((ALIGN_DOWN(end, min(PCPU_BITS_PER_PAGE, PCPU_BITMAP_BLOCK_BITS)) > |
| 865 | ALIGN(start, min(PCPU_BITS_PER_PAGE, PCPU_BITMAP_BLOCK_BITS))) || |
| 866 | s_index != e_index) |
| 867 | pcpu_chunk_refresh_hint(chunk); |
| 868 | else |
| 869 | pcpu_chunk_update(chunk, pcpu_block_off_to_off(s_index, start), |
| 870 | s_block->contig_hint); |
Dennis Zhou (Facebook) | ca460b3 | 2017-07-24 19:02:12 -0400 | [diff] [blame] | 871 | } |
| 872 | |
| 873 | /** |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 874 | * pcpu_is_populated - determines if the region is populated |
| 875 | * @chunk: chunk of interest |
| 876 | * @bit_off: chunk offset |
| 877 | * @bits: size of area |
| 878 | * @next_off: return value for the next offset to start searching |
| 879 | * |
| 880 | * For atomic allocations, check if the backing pages are populated. |
| 881 | * |
| 882 | * RETURNS: |
| 883 | * Bool if the backing pages are populated. |
| 884 | * next_index is to skip over unpopulated blocks in pcpu_find_block_fit. |
| 885 | */ |
| 886 | static bool pcpu_is_populated(struct pcpu_chunk *chunk, int bit_off, int bits, |
| 887 | int *next_off) |
| 888 | { |
| 889 | int page_start, page_end, rs, re; |
| 890 | |
| 891 | page_start = PFN_DOWN(bit_off * PCPU_MIN_ALLOC_SIZE); |
| 892 | page_end = PFN_UP((bit_off + bits) * PCPU_MIN_ALLOC_SIZE); |
| 893 | |
| 894 | rs = page_start; |
| 895 | pcpu_next_unpop(chunk->populated, &rs, &re, page_end); |
| 896 | if (rs >= page_end) |
| 897 | return true; |
| 898 | |
| 899 | *next_off = re * PAGE_SIZE / PCPU_MIN_ALLOC_SIZE; |
| 900 | return false; |
| 901 | } |
| 902 | |
| 903 | /** |
| 904 | * pcpu_find_block_fit - finds the block index to start searching |
| 905 | * @chunk: chunk of interest |
| 906 | * @alloc_bits: size of request in allocation units |
| 907 | * @align: alignment of area (max PAGE_SIZE bytes) |
| 908 | * @pop_only: use populated regions only |
| 909 | * |
Dennis Zhou (Facebook) | b4c2116 | 2017-07-24 19:02:19 -0400 | [diff] [blame] | 910 | * Given a chunk and an allocation spec, find the offset to begin searching |
| 911 | * for a free region. This iterates over the bitmap metadata blocks to |
| 912 | * find an offset that will be guaranteed to fit the requirements. It is |
| 913 | * not quite first fit as if the allocation does not fit in the contig hint |
| 914 | * of a block or chunk, it is skipped. This errs on the side of caution |
| 915 | * to prevent excess iteration. Poor alignment can cause the allocator to |
| 916 | * skip over blocks and chunks that have valid free areas. |
| 917 | * |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 918 | * RETURNS: |
| 919 | * The offset in the bitmap to begin searching. |
| 920 | * -1 if no offset is found. |
| 921 | */ |
| 922 | static int pcpu_find_block_fit(struct pcpu_chunk *chunk, int alloc_bits, |
| 923 | size_t align, bool pop_only) |
| 924 | { |
Dennis Zhou (Facebook) | b4c2116 | 2017-07-24 19:02:19 -0400 | [diff] [blame] | 925 | int bit_off, bits, next_off; |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 926 | |
Dennis Zhou (Facebook) | 13f9663 | 2017-07-24 19:02:14 -0400 | [diff] [blame] | 927 | /* |
| 928 | * Check to see if the allocation can fit in the chunk's contig hint. |
| 929 | * This is an optimization to prevent scanning by assuming if it |
| 930 | * cannot fit in the global hint, there is memory pressure and creating |
| 931 | * a new chunk would happen soon. |
| 932 | */ |
| 933 | bit_off = ALIGN(chunk->contig_bits_start, align) - |
| 934 | chunk->contig_bits_start; |
| 935 | if (bit_off + alloc_bits > chunk->contig_bits) |
| 936 | return -1; |
| 937 | |
Dennis Zhou (Facebook) | b4c2116 | 2017-07-24 19:02:19 -0400 | [diff] [blame] | 938 | bit_off = chunk->first_bit; |
| 939 | bits = 0; |
| 940 | pcpu_for_each_fit_region(chunk, alloc_bits, align, bit_off, bits) { |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 941 | if (!pop_only || pcpu_is_populated(chunk, bit_off, bits, |
Dennis Zhou (Facebook) | b4c2116 | 2017-07-24 19:02:19 -0400 | [diff] [blame] | 942 | &next_off)) |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 943 | break; |
| 944 | |
Dennis Zhou (Facebook) | b4c2116 | 2017-07-24 19:02:19 -0400 | [diff] [blame] | 945 | bit_off = next_off; |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 946 | bits = 0; |
| 947 | } |
| 948 | |
| 949 | if (bit_off == pcpu_chunk_map_bits(chunk)) |
| 950 | return -1; |
| 951 | |
| 952 | return bit_off; |
| 953 | } |
| 954 | |
| 955 | /** |
| 956 | * pcpu_alloc_area - allocates an area from a pcpu_chunk |
| 957 | * @chunk: chunk of interest |
| 958 | * @alloc_bits: size of request in allocation units |
| 959 | * @align: alignment of area (max PAGE_SIZE) |
| 960 | * @start: bit_off to start searching |
| 961 | * |
| 962 | * This function takes in a @start offset to begin searching to fit an |
Dennis Zhou (Facebook) | b4c2116 | 2017-07-24 19:02:19 -0400 | [diff] [blame] | 963 | * allocation of @alloc_bits with alignment @align. It needs to scan |
| 964 | * the allocation map because if it fits within the block's contig hint, |
| 965 | * @start will be block->first_free. This is an attempt to fill the |
| 966 | * allocation prior to breaking the contig hint. The allocation and |
| 967 | * boundary maps are updated accordingly if it confirms a valid |
| 968 | * free area. |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 969 | * |
| 970 | * RETURNS: |
| 971 | * Allocated addr offset in @chunk on success. |
| 972 | * -1 if no matching area is found. |
| 973 | */ |
| 974 | static int pcpu_alloc_area(struct pcpu_chunk *chunk, int alloc_bits, |
| 975 | size_t align, int start) |
| 976 | { |
| 977 | size_t align_mask = (align) ? (align - 1) : 0; |
| 978 | int bit_off, end, oslot; |
Tejun Heo | 9f7dcf2 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 979 | |
Tejun Heo | 4f996e2 | 2016-05-25 11:48:25 -0400 | [diff] [blame] | 980 | lockdep_assert_held(&pcpu_lock); |
| 981 | |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 982 | oslot = pcpu_chunk_slot(chunk); |
Tejun Heo | 833af84 | 2009-11-11 15:35:18 +0900 | [diff] [blame] | 983 | |
| 984 | /* |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 985 | * Search to find a fit. |
Tejun Heo | 833af84 | 2009-11-11 15:35:18 +0900 | [diff] [blame] | 986 | */ |
Dennis Zhou (Facebook) | b4c2116 | 2017-07-24 19:02:19 -0400 | [diff] [blame] | 987 | end = start + alloc_bits + PCPU_BITMAP_BLOCK_BITS; |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 988 | bit_off = bitmap_find_next_zero_area(chunk->alloc_map, end, start, |
| 989 | alloc_bits, align_mask); |
| 990 | if (bit_off >= end) |
| 991 | return -1; |
Tejun Heo | 833af84 | 2009-11-11 15:35:18 +0900 | [diff] [blame] | 992 | |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 993 | /* update alloc map */ |
| 994 | bitmap_set(chunk->alloc_map, bit_off, alloc_bits); |
Tejun Heo | 9f7dcf2 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 995 | |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 996 | /* update boundary map */ |
| 997 | set_bit(bit_off, chunk->bound_map); |
| 998 | bitmap_clear(chunk->bound_map, bit_off + 1, alloc_bits - 1); |
| 999 | set_bit(bit_off + alloc_bits, chunk->bound_map); |
Tejun Heo | a16037c | 2014-09-02 14:46:02 -0400 | [diff] [blame] | 1000 | |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 1001 | chunk->free_bytes -= alloc_bits * PCPU_MIN_ALLOC_SIZE; |
Tejun Heo | a16037c | 2014-09-02 14:46:02 -0400 | [diff] [blame] | 1002 | |
Dennis Zhou (Facebook) | 86b442f | 2017-07-24 19:02:13 -0400 | [diff] [blame] | 1003 | /* update first free bit */ |
| 1004 | if (bit_off == chunk->first_bit) |
| 1005 | chunk->first_bit = find_next_zero_bit( |
| 1006 | chunk->alloc_map, |
| 1007 | pcpu_chunk_map_bits(chunk), |
| 1008 | bit_off + alloc_bits); |
| 1009 | |
Dennis Zhou (Facebook) | ca460b3 | 2017-07-24 19:02:12 -0400 | [diff] [blame] | 1010 | pcpu_block_update_hint_alloc(chunk, bit_off, alloc_bits); |
Tejun Heo | a16037c | 2014-09-02 14:46:02 -0400 | [diff] [blame] | 1011 | |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1012 | pcpu_chunk_relocate(chunk, oslot); |
| 1013 | |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 1014 | return bit_off * PCPU_MIN_ALLOC_SIZE; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1015 | } |
| 1016 | |
| 1017 | /** |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 1018 | * pcpu_free_area - frees the corresponding offset |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1019 | * @chunk: chunk of interest |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 1020 | * @off: addr offset into chunk |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1021 | * |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 1022 | * This function determines the size of an allocation to free using |
| 1023 | * the boundary bitmap and clears the allocation map. |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1024 | */ |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 1025 | static void pcpu_free_area(struct pcpu_chunk *chunk, int off) |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1026 | { |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 1027 | int bit_off, bits, end, oslot; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1028 | |
Dennis Zhou | 5ccd30e | 2017-06-19 19:28:29 -0400 | [diff] [blame] | 1029 | lockdep_assert_held(&pcpu_lock); |
Dennis Zhou | 30a5b53 | 2017-06-19 19:28:31 -0400 | [diff] [blame] | 1030 | pcpu_stats_area_dealloc(chunk); |
Dennis Zhou | 5ccd30e | 2017-06-19 19:28:29 -0400 | [diff] [blame] | 1031 | |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 1032 | oslot = pcpu_chunk_slot(chunk); |
Al Viro | 723ad1d | 2014-03-06 21:13:18 -0500 | [diff] [blame] | 1033 | |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 1034 | bit_off = off / PCPU_MIN_ALLOC_SIZE; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1035 | |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 1036 | /* find end index */ |
| 1037 | end = find_next_bit(chunk->bound_map, pcpu_chunk_map_bits(chunk), |
| 1038 | bit_off + 1); |
| 1039 | bits = end - bit_off; |
| 1040 | bitmap_clear(chunk->alloc_map, bit_off, bits); |
Al Viro | 3d331ad | 2014-03-06 20:52:32 -0500 | [diff] [blame] | 1041 | |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 1042 | /* update metadata */ |
| 1043 | chunk->free_bytes += bits * PCPU_MIN_ALLOC_SIZE; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1044 | |
Dennis Zhou (Facebook) | 86b442f | 2017-07-24 19:02:13 -0400 | [diff] [blame] | 1045 | /* update first free bit */ |
| 1046 | chunk->first_bit = min(chunk->first_bit, bit_off); |
| 1047 | |
Dennis Zhou (Facebook) | ca460b3 | 2017-07-24 19:02:12 -0400 | [diff] [blame] | 1048 | pcpu_block_update_hint_free(chunk, bit_off, bits); |
Tejun Heo | b539b87 | 2014-09-02 14:46:05 -0400 | [diff] [blame] | 1049 | |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1050 | pcpu_chunk_relocate(chunk, oslot); |
| 1051 | } |
| 1052 | |
Dennis Zhou (Facebook) | ca460b3 | 2017-07-24 19:02:12 -0400 | [diff] [blame] | 1053 | static void pcpu_init_md_blocks(struct pcpu_chunk *chunk) |
| 1054 | { |
| 1055 | struct pcpu_block_md *md_block; |
| 1056 | |
| 1057 | for (md_block = chunk->md_blocks; |
| 1058 | md_block != chunk->md_blocks + pcpu_chunk_nr_blocks(chunk); |
| 1059 | md_block++) { |
| 1060 | md_block->contig_hint = PCPU_BITMAP_BLOCK_BITS; |
| 1061 | md_block->left_free = PCPU_BITMAP_BLOCK_BITS; |
| 1062 | md_block->right_free = PCPU_BITMAP_BLOCK_BITS; |
| 1063 | } |
| 1064 | } |
| 1065 | |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 1066 | /** |
| 1067 | * pcpu_alloc_first_chunk - creates chunks that serve the first chunk |
| 1068 | * @tmp_addr: the start of the region served |
| 1069 | * @map_size: size of the region served |
| 1070 | * |
| 1071 | * This is responsible for creating the chunks that serve the first chunk. The |
| 1072 | * base_addr is page aligned down of @tmp_addr while the region end is page |
| 1073 | * aligned up. Offsets are kept track of to determine the region served. All |
| 1074 | * this is done to appease the bitmap allocator in avoiding partial blocks. |
| 1075 | * |
| 1076 | * RETURNS: |
| 1077 | * Chunk serving the region at @tmp_addr of @map_size. |
| 1078 | */ |
Dennis Zhou (Facebook) | c0ebfdc | 2017-07-24 19:02:05 -0400 | [diff] [blame] | 1079 | static struct pcpu_chunk * __init pcpu_alloc_first_chunk(unsigned long tmp_addr, |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 1080 | int map_size) |
Dennis Zhou (Facebook) | 10edf5b | 2017-07-24 19:02:02 -0400 | [diff] [blame] | 1081 | { |
| 1082 | struct pcpu_chunk *chunk; |
Dennis Zhou (Facebook) | ca460b3 | 2017-07-24 19:02:12 -0400 | [diff] [blame] | 1083 | unsigned long aligned_addr, lcm_align; |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 1084 | int start_offset, offset_bits, region_size, region_bits; |
Dennis Zhou (Facebook) | c0ebfdc | 2017-07-24 19:02:05 -0400 | [diff] [blame] | 1085 | |
| 1086 | /* region calculations */ |
| 1087 | aligned_addr = tmp_addr & PAGE_MASK; |
| 1088 | |
| 1089 | start_offset = tmp_addr - aligned_addr; |
Dennis Zhou (Facebook) | 6b9d7c8 | 2017-07-24 19:02:03 -0400 | [diff] [blame] | 1090 | |
Dennis Zhou (Facebook) | ca460b3 | 2017-07-24 19:02:12 -0400 | [diff] [blame] | 1091 | /* |
| 1092 | * Align the end of the region with the LCM of PAGE_SIZE and |
| 1093 | * PCPU_BITMAP_BLOCK_SIZE. One of these constants is a multiple of |
| 1094 | * the other. |
| 1095 | */ |
| 1096 | lcm_align = lcm(PAGE_SIZE, PCPU_BITMAP_BLOCK_SIZE); |
| 1097 | region_size = ALIGN(start_offset + map_size, lcm_align); |
Dennis Zhou (Facebook) | 10edf5b | 2017-07-24 19:02:02 -0400 | [diff] [blame] | 1098 | |
Dennis Zhou (Facebook) | c0ebfdc | 2017-07-24 19:02:05 -0400 | [diff] [blame] | 1099 | /* allocate chunk */ |
Dennis Zhou (Facebook) | 8ab16c4 | 2017-07-24 19:02:07 -0400 | [diff] [blame] | 1100 | chunk = memblock_virt_alloc(sizeof(struct pcpu_chunk) + |
| 1101 | BITS_TO_LONGS(region_size >> PAGE_SHIFT), |
| 1102 | 0); |
Dennis Zhou (Facebook) | c0ebfdc | 2017-07-24 19:02:05 -0400 | [diff] [blame] | 1103 | |
Dennis Zhou (Facebook) | 10edf5b | 2017-07-24 19:02:02 -0400 | [diff] [blame] | 1104 | INIT_LIST_HEAD(&chunk->list); |
Dennis Zhou (Facebook) | c0ebfdc | 2017-07-24 19:02:05 -0400 | [diff] [blame] | 1105 | |
| 1106 | chunk->base_addr = (void *)aligned_addr; |
Dennis Zhou (Facebook) | 10edf5b | 2017-07-24 19:02:02 -0400 | [diff] [blame] | 1107 | chunk->start_offset = start_offset; |
Dennis Zhou (Facebook) | 6b9d7c8 | 2017-07-24 19:02:03 -0400 | [diff] [blame] | 1108 | chunk->end_offset = region_size - chunk->start_offset - map_size; |
Dennis Zhou (Facebook) | c0ebfdc | 2017-07-24 19:02:05 -0400 | [diff] [blame] | 1109 | |
Dennis Zhou (Facebook) | 8ab16c4 | 2017-07-24 19:02:07 -0400 | [diff] [blame] | 1110 | chunk->nr_pages = region_size >> PAGE_SHIFT; |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 1111 | region_bits = pcpu_chunk_map_bits(chunk); |
Dennis Zhou (Facebook) | c0ebfdc | 2017-07-24 19:02:05 -0400 | [diff] [blame] | 1112 | |
Dennis Zhou (Facebook) | ca460b3 | 2017-07-24 19:02:12 -0400 | [diff] [blame] | 1113 | chunk->alloc_map = memblock_virt_alloc(BITS_TO_LONGS(region_bits) * |
| 1114 | sizeof(chunk->alloc_map[0]), 0); |
| 1115 | chunk->bound_map = memblock_virt_alloc(BITS_TO_LONGS(region_bits + 1) * |
| 1116 | sizeof(chunk->bound_map[0]), 0); |
| 1117 | chunk->md_blocks = memblock_virt_alloc(pcpu_chunk_nr_blocks(chunk) * |
| 1118 | sizeof(chunk->md_blocks[0]), 0); |
| 1119 | pcpu_init_md_blocks(chunk); |
Dennis Zhou (Facebook) | 10edf5b | 2017-07-24 19:02:02 -0400 | [diff] [blame] | 1120 | |
| 1121 | /* manage populated page bitmap */ |
| 1122 | chunk->immutable = true; |
Dennis Zhou (Facebook) | 8ab16c4 | 2017-07-24 19:02:07 -0400 | [diff] [blame] | 1123 | bitmap_fill(chunk->populated, chunk->nr_pages); |
| 1124 | chunk->nr_populated = chunk->nr_pages; |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 1125 | chunk->nr_empty_pop_pages = |
| 1126 | pcpu_cnt_pop_pages(chunk, start_offset / PCPU_MIN_ALLOC_SIZE, |
| 1127 | map_size / PCPU_MIN_ALLOC_SIZE); |
Dennis Zhou (Facebook) | 10edf5b | 2017-07-24 19:02:02 -0400 | [diff] [blame] | 1128 | |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 1129 | chunk->contig_bits = map_size / PCPU_MIN_ALLOC_SIZE; |
| 1130 | chunk->free_bytes = map_size; |
Dennis Zhou (Facebook) | c0ebfdc | 2017-07-24 19:02:05 -0400 | [diff] [blame] | 1131 | |
| 1132 | if (chunk->start_offset) { |
| 1133 | /* hide the beginning of the bitmap */ |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 1134 | offset_bits = chunk->start_offset / PCPU_MIN_ALLOC_SIZE; |
| 1135 | bitmap_set(chunk->alloc_map, 0, offset_bits); |
| 1136 | set_bit(0, chunk->bound_map); |
| 1137 | set_bit(offset_bits, chunk->bound_map); |
Dennis Zhou (Facebook) | ca460b3 | 2017-07-24 19:02:12 -0400 | [diff] [blame] | 1138 | |
Dennis Zhou (Facebook) | 86b442f | 2017-07-24 19:02:13 -0400 | [diff] [blame] | 1139 | chunk->first_bit = offset_bits; |
| 1140 | |
Dennis Zhou (Facebook) | ca460b3 | 2017-07-24 19:02:12 -0400 | [diff] [blame] | 1141 | pcpu_block_update_hint_alloc(chunk, 0, offset_bits); |
Dennis Zhou (Facebook) | c0ebfdc | 2017-07-24 19:02:05 -0400 | [diff] [blame] | 1142 | } |
| 1143 | |
Dennis Zhou (Facebook) | 6b9d7c8 | 2017-07-24 19:02:03 -0400 | [diff] [blame] | 1144 | if (chunk->end_offset) { |
| 1145 | /* hide the end of the bitmap */ |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 1146 | offset_bits = chunk->end_offset / PCPU_MIN_ALLOC_SIZE; |
| 1147 | bitmap_set(chunk->alloc_map, |
| 1148 | pcpu_chunk_map_bits(chunk) - offset_bits, |
| 1149 | offset_bits); |
| 1150 | set_bit((start_offset + map_size) / PCPU_MIN_ALLOC_SIZE, |
| 1151 | chunk->bound_map); |
| 1152 | set_bit(region_bits, chunk->bound_map); |
Dennis Zhou (Facebook) | 6b9d7c8 | 2017-07-24 19:02:03 -0400 | [diff] [blame] | 1153 | |
Dennis Zhou (Facebook) | ca460b3 | 2017-07-24 19:02:12 -0400 | [diff] [blame] | 1154 | pcpu_block_update_hint_alloc(chunk, pcpu_chunk_map_bits(chunk) |
| 1155 | - offset_bits, offset_bits); |
| 1156 | } |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 1157 | |
Dennis Zhou (Facebook) | 10edf5b | 2017-07-24 19:02:02 -0400 | [diff] [blame] | 1158 | return chunk; |
| 1159 | } |
| 1160 | |
Dennis Zhou | 72682b1 | 2018-02-16 12:07:19 -0600 | [diff] [blame] | 1161 | static struct pcpu_chunk *pcpu_alloc_chunk(gfp_t gfp) |
Tejun Heo | 6081089 | 2010-04-09 18:57:01 +0900 | [diff] [blame] | 1162 | { |
| 1163 | struct pcpu_chunk *chunk; |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 1164 | int region_bits; |
Tejun Heo | 6081089 | 2010-04-09 18:57:01 +0900 | [diff] [blame] | 1165 | |
Dennis Zhou | 72682b1 | 2018-02-16 12:07:19 -0600 | [diff] [blame] | 1166 | chunk = pcpu_mem_zalloc(pcpu_chunk_struct_size, gfp); |
Tejun Heo | 6081089 | 2010-04-09 18:57:01 +0900 | [diff] [blame] | 1167 | if (!chunk) |
| 1168 | return NULL; |
| 1169 | |
Tejun Heo | 6081089 | 2010-04-09 18:57:01 +0900 | [diff] [blame] | 1170 | INIT_LIST_HEAD(&chunk->list); |
Dennis Zhou (Facebook) | c0ebfdc | 2017-07-24 19:02:05 -0400 | [diff] [blame] | 1171 | chunk->nr_pages = pcpu_unit_pages; |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 1172 | region_bits = pcpu_chunk_map_bits(chunk); |
| 1173 | |
| 1174 | chunk->alloc_map = pcpu_mem_zalloc(BITS_TO_LONGS(region_bits) * |
Dennis Zhou | 72682b1 | 2018-02-16 12:07:19 -0600 | [diff] [blame] | 1175 | sizeof(chunk->alloc_map[0]), gfp); |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 1176 | if (!chunk->alloc_map) |
| 1177 | goto alloc_map_fail; |
| 1178 | |
| 1179 | chunk->bound_map = pcpu_mem_zalloc(BITS_TO_LONGS(region_bits + 1) * |
Dennis Zhou | 72682b1 | 2018-02-16 12:07:19 -0600 | [diff] [blame] | 1180 | sizeof(chunk->bound_map[0]), gfp); |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 1181 | if (!chunk->bound_map) |
| 1182 | goto bound_map_fail; |
| 1183 | |
Dennis Zhou (Facebook) | ca460b3 | 2017-07-24 19:02:12 -0400 | [diff] [blame] | 1184 | chunk->md_blocks = pcpu_mem_zalloc(pcpu_chunk_nr_blocks(chunk) * |
Dennis Zhou | 72682b1 | 2018-02-16 12:07:19 -0600 | [diff] [blame] | 1185 | sizeof(chunk->md_blocks[0]), gfp); |
Dennis Zhou (Facebook) | ca460b3 | 2017-07-24 19:02:12 -0400 | [diff] [blame] | 1186 | if (!chunk->md_blocks) |
| 1187 | goto md_blocks_fail; |
| 1188 | |
| 1189 | pcpu_init_md_blocks(chunk); |
| 1190 | |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 1191 | /* init metadata */ |
| 1192 | chunk->contig_bits = region_bits; |
| 1193 | chunk->free_bytes = chunk->nr_pages * PAGE_SIZE; |
Dennis Zhou (Facebook) | c0ebfdc | 2017-07-24 19:02:05 -0400 | [diff] [blame] | 1194 | |
Tejun Heo | 6081089 | 2010-04-09 18:57:01 +0900 | [diff] [blame] | 1195 | return chunk; |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 1196 | |
Dennis Zhou (Facebook) | ca460b3 | 2017-07-24 19:02:12 -0400 | [diff] [blame] | 1197 | md_blocks_fail: |
| 1198 | pcpu_mem_free(chunk->bound_map); |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 1199 | bound_map_fail: |
| 1200 | pcpu_mem_free(chunk->alloc_map); |
| 1201 | alloc_map_fail: |
| 1202 | pcpu_mem_free(chunk); |
| 1203 | |
| 1204 | return NULL; |
Tejun Heo | 6081089 | 2010-04-09 18:57:01 +0900 | [diff] [blame] | 1205 | } |
| 1206 | |
| 1207 | static void pcpu_free_chunk(struct pcpu_chunk *chunk) |
| 1208 | { |
| 1209 | if (!chunk) |
| 1210 | return; |
Mike Rapoport | 54886c9 | 2018-10-07 11:31:51 +0300 | [diff] [blame] | 1211 | pcpu_mem_free(chunk->md_blocks); |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 1212 | pcpu_mem_free(chunk->bound_map); |
| 1213 | pcpu_mem_free(chunk->alloc_map); |
Tetsuo Handa | 1d5cfdb | 2016-01-22 15:11:02 -0800 | [diff] [blame] | 1214 | pcpu_mem_free(chunk); |
Tejun Heo | 6081089 | 2010-04-09 18:57:01 +0900 | [diff] [blame] | 1215 | } |
| 1216 | |
Tejun Heo | b539b87 | 2014-09-02 14:46:05 -0400 | [diff] [blame] | 1217 | /** |
| 1218 | * pcpu_chunk_populated - post-population bookkeeping |
| 1219 | * @chunk: pcpu_chunk which got populated |
| 1220 | * @page_start: the start page |
| 1221 | * @page_end: the end page |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 1222 | * @for_alloc: if this is to populate for allocation |
Tejun Heo | b539b87 | 2014-09-02 14:46:05 -0400 | [diff] [blame] | 1223 | * |
| 1224 | * Pages in [@page_start,@page_end) have been populated to @chunk. Update |
| 1225 | * the bookkeeping information accordingly. Must be called after each |
| 1226 | * successful population. |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 1227 | * |
| 1228 | * If this is @for_alloc, do not increment pcpu_nr_empty_pop_pages because it |
| 1229 | * is to serve an allocation in that area. |
Tejun Heo | b539b87 | 2014-09-02 14:46:05 -0400 | [diff] [blame] | 1230 | */ |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 1231 | static void pcpu_chunk_populated(struct pcpu_chunk *chunk, int page_start, |
| 1232 | int page_end, bool for_alloc) |
Tejun Heo | b539b87 | 2014-09-02 14:46:05 -0400 | [diff] [blame] | 1233 | { |
| 1234 | int nr = page_end - page_start; |
| 1235 | |
| 1236 | lockdep_assert_held(&pcpu_lock); |
| 1237 | |
| 1238 | bitmap_set(chunk->populated, page_start, nr); |
| 1239 | chunk->nr_populated += nr; |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 1240 | |
| 1241 | if (!for_alloc) { |
| 1242 | chunk->nr_empty_pop_pages += nr; |
| 1243 | pcpu_nr_empty_pop_pages += nr; |
| 1244 | } |
Tejun Heo | b539b87 | 2014-09-02 14:46:05 -0400 | [diff] [blame] | 1245 | } |
| 1246 | |
| 1247 | /** |
| 1248 | * pcpu_chunk_depopulated - post-depopulation bookkeeping |
| 1249 | * @chunk: pcpu_chunk which got depopulated |
| 1250 | * @page_start: the start page |
| 1251 | * @page_end: the end page |
| 1252 | * |
| 1253 | * Pages in [@page_start,@page_end) have been depopulated from @chunk. |
| 1254 | * Update the bookkeeping information accordingly. Must be called after |
| 1255 | * each successful depopulation. |
| 1256 | */ |
| 1257 | static void pcpu_chunk_depopulated(struct pcpu_chunk *chunk, |
| 1258 | int page_start, int page_end) |
| 1259 | { |
| 1260 | int nr = page_end - page_start; |
| 1261 | |
| 1262 | lockdep_assert_held(&pcpu_lock); |
| 1263 | |
| 1264 | bitmap_clear(chunk->populated, page_start, nr); |
| 1265 | chunk->nr_populated -= nr; |
Dennis Zhou (Facebook) | 0cecf50 | 2017-07-24 19:02:08 -0400 | [diff] [blame] | 1266 | chunk->nr_empty_pop_pages -= nr; |
Tejun Heo | b539b87 | 2014-09-02 14:46:05 -0400 | [diff] [blame] | 1267 | pcpu_nr_empty_pop_pages -= nr; |
| 1268 | } |
| 1269 | |
Tejun Heo | 9f64553 | 2010-04-09 18:57:01 +0900 | [diff] [blame] | 1270 | /* |
| 1271 | * Chunk management implementation. |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1272 | * |
Tejun Heo | 9f64553 | 2010-04-09 18:57:01 +0900 | [diff] [blame] | 1273 | * To allow different implementations, chunk alloc/free and |
| 1274 | * [de]population are implemented in a separate file which is pulled |
| 1275 | * into this file and compiled together. The following functions |
| 1276 | * should be implemented. |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 1277 | * |
Tejun Heo | 9f64553 | 2010-04-09 18:57:01 +0900 | [diff] [blame] | 1278 | * pcpu_populate_chunk - populate the specified range of a chunk |
| 1279 | * pcpu_depopulate_chunk - depopulate the specified range of a chunk |
| 1280 | * pcpu_create_chunk - create a new chunk |
| 1281 | * pcpu_destroy_chunk - destroy a chunk, always preceded by full depop |
| 1282 | * pcpu_addr_to_page - translate address to physical address |
| 1283 | * pcpu_verify_alloc_info - check alloc_info is acceptable during init |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1284 | */ |
Dennis Zhou | 72682b1 | 2018-02-16 12:07:19 -0600 | [diff] [blame] | 1285 | static int pcpu_populate_chunk(struct pcpu_chunk *chunk, int off, int size, |
| 1286 | gfp_t gfp); |
Tejun Heo | 9f64553 | 2010-04-09 18:57:01 +0900 | [diff] [blame] | 1287 | static void pcpu_depopulate_chunk(struct pcpu_chunk *chunk, int off, int size); |
Dennis Zhou | 72682b1 | 2018-02-16 12:07:19 -0600 | [diff] [blame] | 1288 | static struct pcpu_chunk *pcpu_create_chunk(gfp_t gfp); |
Tejun Heo | 9f64553 | 2010-04-09 18:57:01 +0900 | [diff] [blame] | 1289 | static void pcpu_destroy_chunk(struct pcpu_chunk *chunk); |
| 1290 | static struct page *pcpu_addr_to_page(void *addr); |
| 1291 | static int __init pcpu_verify_alloc_info(const struct pcpu_alloc_info *ai); |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 1292 | |
Tejun Heo | b0c9778 | 2010-04-09 18:57:01 +0900 | [diff] [blame] | 1293 | #ifdef CONFIG_NEED_PER_CPU_KM |
| 1294 | #include "percpu-km.c" |
| 1295 | #else |
Tejun Heo | 9f64553 | 2010-04-09 18:57:01 +0900 | [diff] [blame] | 1296 | #include "percpu-vm.c" |
Tejun Heo | b0c9778 | 2010-04-09 18:57:01 +0900 | [diff] [blame] | 1297 | #endif |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1298 | |
| 1299 | /** |
Tejun Heo | 88999a8 | 2010-04-09 18:57:01 +0900 | [diff] [blame] | 1300 | * pcpu_chunk_addr_search - determine chunk containing specified address |
| 1301 | * @addr: address for which the chunk needs to be determined. |
| 1302 | * |
Dennis Zhou (Facebook) | c0ebfdc | 2017-07-24 19:02:05 -0400 | [diff] [blame] | 1303 | * This is an internal function that handles all but static allocations. |
| 1304 | * Static percpu address values should never be passed into the allocator. |
| 1305 | * |
Tejun Heo | 88999a8 | 2010-04-09 18:57:01 +0900 | [diff] [blame] | 1306 | * RETURNS: |
| 1307 | * The address of the found chunk. |
| 1308 | */ |
| 1309 | static struct pcpu_chunk *pcpu_chunk_addr_search(void *addr) |
| 1310 | { |
Dennis Zhou (Facebook) | c0ebfdc | 2017-07-24 19:02:05 -0400 | [diff] [blame] | 1311 | /* is it in the dynamic region (first chunk)? */ |
Dennis Zhou (Facebook) | 560f2c2 | 2017-07-24 19:02:06 -0400 | [diff] [blame] | 1312 | if (pcpu_addr_in_chunk(pcpu_first_chunk, addr)) |
Tejun Heo | 88999a8 | 2010-04-09 18:57:01 +0900 | [diff] [blame] | 1313 | return pcpu_first_chunk; |
Dennis Zhou (Facebook) | c0ebfdc | 2017-07-24 19:02:05 -0400 | [diff] [blame] | 1314 | |
| 1315 | /* is it in the reserved region? */ |
Dennis Zhou (Facebook) | 560f2c2 | 2017-07-24 19:02:06 -0400 | [diff] [blame] | 1316 | if (pcpu_addr_in_chunk(pcpu_reserved_chunk, addr)) |
Dennis Zhou (Facebook) | c0ebfdc | 2017-07-24 19:02:05 -0400 | [diff] [blame] | 1317 | return pcpu_reserved_chunk; |
Tejun Heo | 88999a8 | 2010-04-09 18:57:01 +0900 | [diff] [blame] | 1318 | |
| 1319 | /* |
| 1320 | * The address is relative to unit0 which might be unused and |
| 1321 | * thus unmapped. Offset the address to the unit space of the |
| 1322 | * current processor before looking it up in the vmalloc |
| 1323 | * space. Note that any possible cpu id can be used here, so |
| 1324 | * there's no need to worry about preemption or cpu hotplug. |
| 1325 | */ |
| 1326 | addr += pcpu_unit_offsets[raw_smp_processor_id()]; |
Tejun Heo | 9f64553 | 2010-04-09 18:57:01 +0900 | [diff] [blame] | 1327 | return pcpu_get_page_chunk(pcpu_addr_to_page(addr)); |
Tejun Heo | 88999a8 | 2010-04-09 18:57:01 +0900 | [diff] [blame] | 1328 | } |
| 1329 | |
| 1330 | /** |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1331 | * pcpu_alloc - the percpu allocator |
Tejun Heo | cae3aeb | 2009-02-21 16:56:23 +0900 | [diff] [blame] | 1332 | * @size: size of area to allocate in bytes |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1333 | * @align: alignment of area (max PAGE_SIZE) |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1334 | * @reserved: allocate from the reserved chunk if available |
Tejun Heo | 5835d96 | 2014-09-02 14:46:04 -0400 | [diff] [blame] | 1335 | * @gfp: allocation flags |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1336 | * |
Tejun Heo | 5835d96 | 2014-09-02 14:46:04 -0400 | [diff] [blame] | 1337 | * Allocate percpu area of @size bytes aligned at @align. If @gfp doesn't |
Daniel Borkmann | 0ea7eee | 2017-10-17 16:55:52 +0200 | [diff] [blame] | 1338 | * contain %GFP_KERNEL, the allocation is atomic. If @gfp has __GFP_NOWARN |
| 1339 | * then no warning will be triggered on invalid or failed allocation |
| 1340 | * requests. |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1341 | * |
| 1342 | * RETURNS: |
| 1343 | * Percpu pointer to the allocated area on success, NULL on failure. |
| 1344 | */ |
Tejun Heo | 5835d96 | 2014-09-02 14:46:04 -0400 | [diff] [blame] | 1345 | static void __percpu *pcpu_alloc(size_t size, size_t align, bool reserved, |
| 1346 | gfp_t gfp) |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1347 | { |
Daniel Borkmann | 0ea7eee | 2017-10-17 16:55:52 +0200 | [diff] [blame] | 1348 | bool is_atomic = (gfp & GFP_KERNEL) != GFP_KERNEL; |
| 1349 | bool do_warn = !(gfp & __GFP_NOWARN); |
Tejun Heo | f2badb0 | 2009-09-29 09:17:58 +0900 | [diff] [blame] | 1350 | static int warn_limit = 10; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1351 | struct pcpu_chunk *chunk; |
Tejun Heo | f2badb0 | 2009-09-29 09:17:58 +0900 | [diff] [blame] | 1352 | const char *err; |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 1353 | int slot, off, cpu, ret; |
Jiri Kosina | 403a91b | 2009-10-29 00:25:59 +0900 | [diff] [blame] | 1354 | unsigned long flags; |
Catalin Marinas | f528f0b | 2011-09-26 17:12:53 +0100 | [diff] [blame] | 1355 | void __percpu *ptr; |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 1356 | size_t bits, bit_align; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1357 | |
Al Viro | 723ad1d | 2014-03-06 21:13:18 -0500 | [diff] [blame] | 1358 | /* |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 1359 | * There is now a minimum allocation size of PCPU_MIN_ALLOC_SIZE, |
| 1360 | * therefore alignment must be a minimum of that many bytes. |
| 1361 | * An allocation may have internal fragmentation from rounding up |
| 1362 | * of up to PCPU_MIN_ALLOC_SIZE - 1 bytes. |
Al Viro | 723ad1d | 2014-03-06 21:13:18 -0500 | [diff] [blame] | 1363 | */ |
Dennis Zhou (Facebook) | d2f3c38 | 2017-07-24 19:02:09 -0400 | [diff] [blame] | 1364 | if (unlikely(align < PCPU_MIN_ALLOC_SIZE)) |
| 1365 | align = PCPU_MIN_ALLOC_SIZE; |
Al Viro | 723ad1d | 2014-03-06 21:13:18 -0500 | [diff] [blame] | 1366 | |
Dennis Zhou (Facebook) | d2f3c38 | 2017-07-24 19:02:09 -0400 | [diff] [blame] | 1367 | size = ALIGN(size, PCPU_MIN_ALLOC_SIZE); |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 1368 | bits = size >> PCPU_MIN_ALLOC_SHIFT; |
| 1369 | bit_align = align >> PCPU_MIN_ALLOC_SHIFT; |
Viro | 2f69fa8 | 2014-03-17 16:01:27 -0400 | [diff] [blame] | 1370 | |
zijun_hu | 3ca45a4 | 2016-10-14 15:12:54 +0800 | [diff] [blame] | 1371 | if (unlikely(!size || size > PCPU_MIN_UNIT_SIZE || align > PAGE_SIZE || |
| 1372 | !is_power_of_2(align))) { |
Daniel Borkmann | 0ea7eee | 2017-10-17 16:55:52 +0200 | [diff] [blame] | 1373 | WARN(do_warn, "illegal size (%zu) or align (%zu) for percpu allocation\n", |
Joe Perches | 756a025 | 2016-03-17 14:19:47 -0700 | [diff] [blame] | 1374 | size, align); |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1375 | return NULL; |
| 1376 | } |
| 1377 | |
Tejun Heo | 6710e59 | 2016-05-25 11:48:25 -0400 | [diff] [blame] | 1378 | if (!is_atomic) |
| 1379 | mutex_lock(&pcpu_alloc_mutex); |
| 1380 | |
Jiri Kosina | 403a91b | 2009-10-29 00:25:59 +0900 | [diff] [blame] | 1381 | spin_lock_irqsave(&pcpu_lock, flags); |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1382 | |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1383 | /* serve reserved allocations from the reserved chunk if available */ |
| 1384 | if (reserved && pcpu_reserved_chunk) { |
| 1385 | chunk = pcpu_reserved_chunk; |
Tejun Heo | 833af84 | 2009-11-11 15:35:18 +0900 | [diff] [blame] | 1386 | |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 1387 | off = pcpu_find_block_fit(chunk, bits, bit_align, is_atomic); |
| 1388 | if (off < 0) { |
Tejun Heo | 833af84 | 2009-11-11 15:35:18 +0900 | [diff] [blame] | 1389 | err = "alloc from reserved chunk failed"; |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 1390 | goto fail_unlock; |
Tejun Heo | f2badb0 | 2009-09-29 09:17:58 +0900 | [diff] [blame] | 1391 | } |
Tejun Heo | 833af84 | 2009-11-11 15:35:18 +0900 | [diff] [blame] | 1392 | |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 1393 | off = pcpu_alloc_area(chunk, bits, bit_align, off); |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1394 | if (off >= 0) |
| 1395 | goto area_found; |
Tejun Heo | 833af84 | 2009-11-11 15:35:18 +0900 | [diff] [blame] | 1396 | |
Tejun Heo | f2badb0 | 2009-09-29 09:17:58 +0900 | [diff] [blame] | 1397 | err = "alloc from reserved chunk failed"; |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 1398 | goto fail_unlock; |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1399 | } |
| 1400 | |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 1401 | restart: |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1402 | /* search through normal chunks */ |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1403 | for (slot = pcpu_size_to_slot(size); slot < pcpu_nr_slots; slot++) { |
| 1404 | list_for_each_entry(chunk, &pcpu_slot[slot], list) { |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 1405 | off = pcpu_find_block_fit(chunk, bits, bit_align, |
| 1406 | is_atomic); |
| 1407 | if (off < 0) |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1408 | continue; |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 1409 | |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 1410 | off = pcpu_alloc_area(chunk, bits, bit_align, off); |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1411 | if (off >= 0) |
| 1412 | goto area_found; |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 1413 | |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1414 | } |
| 1415 | } |
| 1416 | |
Jiri Kosina | 403a91b | 2009-10-29 00:25:59 +0900 | [diff] [blame] | 1417 | spin_unlock_irqrestore(&pcpu_lock, flags); |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 1418 | |
Tejun Heo | b38d08f | 2014-09-02 14:46:02 -0400 | [diff] [blame] | 1419 | /* |
| 1420 | * No space left. Create a new chunk. We don't want multiple |
| 1421 | * tasks to create chunks simultaneously. Serialize and create iff |
| 1422 | * there's still no empty chunk after grabbing the mutex. |
| 1423 | */ |
Dennis Zhou | 11df02b | 2017-06-21 11:51:09 -0400 | [diff] [blame] | 1424 | if (is_atomic) { |
| 1425 | err = "atomic alloc failed, no space left"; |
Tejun Heo | 5835d96 | 2014-09-02 14:46:04 -0400 | [diff] [blame] | 1426 | goto fail; |
Dennis Zhou | 11df02b | 2017-06-21 11:51:09 -0400 | [diff] [blame] | 1427 | } |
Tejun Heo | 5835d96 | 2014-09-02 14:46:04 -0400 | [diff] [blame] | 1428 | |
Tejun Heo | b38d08f | 2014-09-02 14:46:02 -0400 | [diff] [blame] | 1429 | if (list_empty(&pcpu_slot[pcpu_nr_slots - 1])) { |
Dennis Zhou | 72682b1 | 2018-02-16 12:07:19 -0600 | [diff] [blame] | 1430 | chunk = pcpu_create_chunk(0); |
Tejun Heo | b38d08f | 2014-09-02 14:46:02 -0400 | [diff] [blame] | 1431 | if (!chunk) { |
| 1432 | err = "failed to allocate new chunk"; |
| 1433 | goto fail; |
| 1434 | } |
| 1435 | |
| 1436 | spin_lock_irqsave(&pcpu_lock, flags); |
| 1437 | pcpu_chunk_relocate(chunk, -1); |
| 1438 | } else { |
| 1439 | spin_lock_irqsave(&pcpu_lock, flags); |
Tejun Heo | f2badb0 | 2009-09-29 09:17:58 +0900 | [diff] [blame] | 1440 | } |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 1441 | |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 1442 | goto restart; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1443 | |
| 1444 | area_found: |
Dennis Zhou | 30a5b53 | 2017-06-19 19:28:31 -0400 | [diff] [blame] | 1445 | pcpu_stats_area_alloc(chunk, size); |
Jiri Kosina | 403a91b | 2009-10-29 00:25:59 +0900 | [diff] [blame] | 1446 | spin_unlock_irqrestore(&pcpu_lock, flags); |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 1447 | |
Tejun Heo | dca4964 | 2014-09-02 14:46:01 -0400 | [diff] [blame] | 1448 | /* populate if not all pages are already there */ |
Tejun Heo | 5835d96 | 2014-09-02 14:46:04 -0400 | [diff] [blame] | 1449 | if (!is_atomic) { |
Tejun Heo | e04d320 | 2014-09-02 14:46:04 -0400 | [diff] [blame] | 1450 | int page_start, page_end, rs, re; |
Tejun Heo | dca4964 | 2014-09-02 14:46:01 -0400 | [diff] [blame] | 1451 | |
Tejun Heo | e04d320 | 2014-09-02 14:46:04 -0400 | [diff] [blame] | 1452 | page_start = PFN_DOWN(off); |
| 1453 | page_end = PFN_UP(off + size); |
Tejun Heo | b38d08f | 2014-09-02 14:46:02 -0400 | [diff] [blame] | 1454 | |
Dennis Zhou (Facebook) | 91e914c | 2017-07-24 19:02:10 -0400 | [diff] [blame] | 1455 | pcpu_for_each_unpop_region(chunk->populated, rs, re, |
| 1456 | page_start, page_end) { |
Tejun Heo | e04d320 | 2014-09-02 14:46:04 -0400 | [diff] [blame] | 1457 | WARN_ON(chunk->immutable); |
| 1458 | |
Dennis Zhou | 72682b1 | 2018-02-16 12:07:19 -0600 | [diff] [blame] | 1459 | ret = pcpu_populate_chunk(chunk, rs, re, 0); |
Tejun Heo | e04d320 | 2014-09-02 14:46:04 -0400 | [diff] [blame] | 1460 | |
| 1461 | spin_lock_irqsave(&pcpu_lock, flags); |
| 1462 | if (ret) { |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 1463 | pcpu_free_area(chunk, off); |
Tejun Heo | e04d320 | 2014-09-02 14:46:04 -0400 | [diff] [blame] | 1464 | err = "failed to populate"; |
| 1465 | goto fail_unlock; |
| 1466 | } |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 1467 | pcpu_chunk_populated(chunk, rs, re, true); |
Tejun Heo | e04d320 | 2014-09-02 14:46:04 -0400 | [diff] [blame] | 1468 | spin_unlock_irqrestore(&pcpu_lock, flags); |
Tejun Heo | dca4964 | 2014-09-02 14:46:01 -0400 | [diff] [blame] | 1469 | } |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1470 | |
Tejun Heo | e04d320 | 2014-09-02 14:46:04 -0400 | [diff] [blame] | 1471 | mutex_unlock(&pcpu_alloc_mutex); |
| 1472 | } |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 1473 | |
Tejun Heo | 1a4d760 | 2014-09-02 14:46:05 -0400 | [diff] [blame] | 1474 | if (pcpu_nr_empty_pop_pages < PCPU_EMPTY_POP_PAGES_LOW) |
| 1475 | pcpu_schedule_balance_work(); |
| 1476 | |
Tejun Heo | dca4964 | 2014-09-02 14:46:01 -0400 | [diff] [blame] | 1477 | /* clear the areas and return address relative to base address */ |
| 1478 | for_each_possible_cpu(cpu) |
| 1479 | memset((void *)pcpu_chunk_addr(chunk, cpu, 0) + off, 0, size); |
| 1480 | |
Catalin Marinas | f528f0b | 2011-09-26 17:12:53 +0100 | [diff] [blame] | 1481 | ptr = __addr_to_pcpu_ptr(chunk->base_addr + off); |
Larry Finger | 8a8c35f | 2015-06-24 16:58:51 -0700 | [diff] [blame] | 1482 | kmemleak_alloc_percpu(ptr, size, gfp); |
Dennis Zhou | df95e79 | 2017-06-19 19:28:32 -0400 | [diff] [blame] | 1483 | |
| 1484 | trace_percpu_alloc_percpu(reserved, is_atomic, size, align, |
| 1485 | chunk->base_addr, off, ptr); |
| 1486 | |
Catalin Marinas | f528f0b | 2011-09-26 17:12:53 +0100 | [diff] [blame] | 1487 | return ptr; |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 1488 | |
| 1489 | fail_unlock: |
Jiri Kosina | 403a91b | 2009-10-29 00:25:59 +0900 | [diff] [blame] | 1490 | spin_unlock_irqrestore(&pcpu_lock, flags); |
Tejun Heo | b38d08f | 2014-09-02 14:46:02 -0400 | [diff] [blame] | 1491 | fail: |
Dennis Zhou | df95e79 | 2017-06-19 19:28:32 -0400 | [diff] [blame] | 1492 | trace_percpu_alloc_percpu_fail(reserved, is_atomic, size, align); |
| 1493 | |
Daniel Borkmann | 0ea7eee | 2017-10-17 16:55:52 +0200 | [diff] [blame] | 1494 | if (!is_atomic && do_warn && warn_limit) { |
Joe Perches | 870d4b1 | 2016-03-17 14:19:53 -0700 | [diff] [blame] | 1495 | pr_warn("allocation failed, size=%zu align=%zu atomic=%d, %s\n", |
Joe Perches | 598d809 | 2016-03-17 14:19:44 -0700 | [diff] [blame] | 1496 | size, align, is_atomic, err); |
Tejun Heo | f2badb0 | 2009-09-29 09:17:58 +0900 | [diff] [blame] | 1497 | dump_stack(); |
| 1498 | if (!--warn_limit) |
Joe Perches | 870d4b1 | 2016-03-17 14:19:53 -0700 | [diff] [blame] | 1499 | pr_info("limit reached, disable warning\n"); |
Tejun Heo | f2badb0 | 2009-09-29 09:17:58 +0900 | [diff] [blame] | 1500 | } |
Tejun Heo | 1a4d760 | 2014-09-02 14:46:05 -0400 | [diff] [blame] | 1501 | if (is_atomic) { |
| 1502 | /* see the flag handling in pcpu_blance_workfn() */ |
| 1503 | pcpu_atomic_alloc_failed = true; |
| 1504 | pcpu_schedule_balance_work(); |
Tejun Heo | 6710e59 | 2016-05-25 11:48:25 -0400 | [diff] [blame] | 1505 | } else { |
| 1506 | mutex_unlock(&pcpu_alloc_mutex); |
Tejun Heo | 1a4d760 | 2014-09-02 14:46:05 -0400 | [diff] [blame] | 1507 | } |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 1508 | return NULL; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1509 | } |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1510 | |
| 1511 | /** |
Tejun Heo | 5835d96 | 2014-09-02 14:46:04 -0400 | [diff] [blame] | 1512 | * __alloc_percpu_gfp - allocate dynamic percpu area |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1513 | * @size: size of area to allocate in bytes |
| 1514 | * @align: alignment of area (max PAGE_SIZE) |
Tejun Heo | 5835d96 | 2014-09-02 14:46:04 -0400 | [diff] [blame] | 1515 | * @gfp: allocation flags |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1516 | * |
Tejun Heo | 5835d96 | 2014-09-02 14:46:04 -0400 | [diff] [blame] | 1517 | * Allocate zero-filled percpu area of @size bytes aligned at @align. If |
| 1518 | * @gfp doesn't contain %GFP_KERNEL, the allocation doesn't block and can |
Daniel Borkmann | 0ea7eee | 2017-10-17 16:55:52 +0200 | [diff] [blame] | 1519 | * be called from any context but is a lot more likely to fail. If @gfp |
| 1520 | * has __GFP_NOWARN then no warning will be triggered on invalid or failed |
| 1521 | * allocation requests. |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 1522 | * |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1523 | * RETURNS: |
| 1524 | * Percpu pointer to the allocated area on success, NULL on failure. |
| 1525 | */ |
Tejun Heo | 5835d96 | 2014-09-02 14:46:04 -0400 | [diff] [blame] | 1526 | void __percpu *__alloc_percpu_gfp(size_t size, size_t align, gfp_t gfp) |
| 1527 | { |
| 1528 | return pcpu_alloc(size, align, false, gfp); |
| 1529 | } |
| 1530 | EXPORT_SYMBOL_GPL(__alloc_percpu_gfp); |
| 1531 | |
| 1532 | /** |
| 1533 | * __alloc_percpu - allocate dynamic percpu area |
| 1534 | * @size: size of area to allocate in bytes |
| 1535 | * @align: alignment of area (max PAGE_SIZE) |
| 1536 | * |
| 1537 | * Equivalent to __alloc_percpu_gfp(size, align, %GFP_KERNEL). |
| 1538 | */ |
Tejun Heo | 43cf38e | 2010-02-02 14:38:57 +0900 | [diff] [blame] | 1539 | void __percpu *__alloc_percpu(size_t size, size_t align) |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1540 | { |
Tejun Heo | 5835d96 | 2014-09-02 14:46:04 -0400 | [diff] [blame] | 1541 | return pcpu_alloc(size, align, false, GFP_KERNEL); |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1542 | } |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1543 | EXPORT_SYMBOL_GPL(__alloc_percpu); |
| 1544 | |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1545 | /** |
| 1546 | * __alloc_reserved_percpu - allocate reserved percpu area |
| 1547 | * @size: size of area to allocate in bytes |
| 1548 | * @align: alignment of area (max PAGE_SIZE) |
| 1549 | * |
Tejun Heo | 9329ba9 | 2010-09-10 11:01:56 +0200 | [diff] [blame] | 1550 | * Allocate zero-filled percpu area of @size bytes aligned at @align |
| 1551 | * from reserved percpu area if arch has set it up; otherwise, |
| 1552 | * allocation is served from the same dynamic area. Might sleep. |
| 1553 | * Might trigger writeouts. |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1554 | * |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 1555 | * CONTEXT: |
| 1556 | * Does GFP_KERNEL allocation. |
| 1557 | * |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1558 | * RETURNS: |
| 1559 | * Percpu pointer to the allocated area on success, NULL on failure. |
| 1560 | */ |
Tejun Heo | 43cf38e | 2010-02-02 14:38:57 +0900 | [diff] [blame] | 1561 | void __percpu *__alloc_reserved_percpu(size_t size, size_t align) |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1562 | { |
Tejun Heo | 5835d96 | 2014-09-02 14:46:04 -0400 | [diff] [blame] | 1563 | return pcpu_alloc(size, align, true, GFP_KERNEL); |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1564 | } |
| 1565 | |
Tejun Heo | a56dbdd | 2009-03-07 00:44:11 +0900 | [diff] [blame] | 1566 | /** |
Tejun Heo | 1a4d760 | 2014-09-02 14:46:05 -0400 | [diff] [blame] | 1567 | * pcpu_balance_workfn - manage the amount of free chunks and populated pages |
Tejun Heo | a56dbdd | 2009-03-07 00:44:11 +0900 | [diff] [blame] | 1568 | * @work: unused |
| 1569 | * |
Dennis Zhou | 72682b1 | 2018-02-16 12:07:19 -0600 | [diff] [blame] | 1570 | * Reclaim all fully free chunks except for the first one. This is also |
| 1571 | * responsible for maintaining the pool of empty populated pages. However, |
| 1572 | * it is possible that this is called when physical memory is scarce causing |
| 1573 | * OOM killer to be triggered. We should avoid doing so until an actual |
| 1574 | * allocation causes the failure as it is possible that requests can be |
| 1575 | * serviced from already backed regions. |
Tejun Heo | a56dbdd | 2009-03-07 00:44:11 +0900 | [diff] [blame] | 1576 | */ |
Tejun Heo | fe6bd8c | 2014-09-02 14:46:05 -0400 | [diff] [blame] | 1577 | static void pcpu_balance_workfn(struct work_struct *work) |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1578 | { |
Dennis Zhou | 72682b1 | 2018-02-16 12:07:19 -0600 | [diff] [blame] | 1579 | /* gfp flags passed to underlying allocators */ |
| 1580 | const gfp_t gfp = __GFP_NORETRY | __GFP_NOWARN; |
Tejun Heo | fe6bd8c | 2014-09-02 14:46:05 -0400 | [diff] [blame] | 1581 | LIST_HEAD(to_free); |
| 1582 | struct list_head *free_head = &pcpu_slot[pcpu_nr_slots - 1]; |
Tejun Heo | a56dbdd | 2009-03-07 00:44:11 +0900 | [diff] [blame] | 1583 | struct pcpu_chunk *chunk, *next; |
Tejun Heo | 1a4d760 | 2014-09-02 14:46:05 -0400 | [diff] [blame] | 1584 | int slot, nr_to_pop, ret; |
Tejun Heo | a56dbdd | 2009-03-07 00:44:11 +0900 | [diff] [blame] | 1585 | |
Tejun Heo | 1a4d760 | 2014-09-02 14:46:05 -0400 | [diff] [blame] | 1586 | /* |
| 1587 | * There's no reason to keep around multiple unused chunks and VM |
| 1588 | * areas can be scarce. Destroy all free chunks except for one. |
| 1589 | */ |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 1590 | mutex_lock(&pcpu_alloc_mutex); |
| 1591 | spin_lock_irq(&pcpu_lock); |
Tejun Heo | a56dbdd | 2009-03-07 00:44:11 +0900 | [diff] [blame] | 1592 | |
Tejun Heo | fe6bd8c | 2014-09-02 14:46:05 -0400 | [diff] [blame] | 1593 | list_for_each_entry_safe(chunk, next, free_head, list) { |
Tejun Heo | a56dbdd | 2009-03-07 00:44:11 +0900 | [diff] [blame] | 1594 | WARN_ON(chunk->immutable); |
| 1595 | |
| 1596 | /* spare the first one */ |
Tejun Heo | fe6bd8c | 2014-09-02 14:46:05 -0400 | [diff] [blame] | 1597 | if (chunk == list_first_entry(free_head, struct pcpu_chunk, list)) |
Tejun Heo | a56dbdd | 2009-03-07 00:44:11 +0900 | [diff] [blame] | 1598 | continue; |
| 1599 | |
Tejun Heo | fe6bd8c | 2014-09-02 14:46:05 -0400 | [diff] [blame] | 1600 | list_move(&chunk->list, &to_free); |
Tejun Heo | a56dbdd | 2009-03-07 00:44:11 +0900 | [diff] [blame] | 1601 | } |
| 1602 | |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 1603 | spin_unlock_irq(&pcpu_lock); |
Tejun Heo | a56dbdd | 2009-03-07 00:44:11 +0900 | [diff] [blame] | 1604 | |
Tejun Heo | fe6bd8c | 2014-09-02 14:46:05 -0400 | [diff] [blame] | 1605 | list_for_each_entry_safe(chunk, next, &to_free, list) { |
Tejun Heo | a93ace4 | 2014-09-02 14:46:02 -0400 | [diff] [blame] | 1606 | int rs, re; |
Tejun Heo | dca4964 | 2014-09-02 14:46:01 -0400 | [diff] [blame] | 1607 | |
Dennis Zhou (Facebook) | 91e914c | 2017-07-24 19:02:10 -0400 | [diff] [blame] | 1608 | pcpu_for_each_pop_region(chunk->populated, rs, re, 0, |
| 1609 | chunk->nr_pages) { |
Tejun Heo | a93ace4 | 2014-09-02 14:46:02 -0400 | [diff] [blame] | 1610 | pcpu_depopulate_chunk(chunk, rs, re); |
Tejun Heo | b539b87 | 2014-09-02 14:46:05 -0400 | [diff] [blame] | 1611 | spin_lock_irq(&pcpu_lock); |
| 1612 | pcpu_chunk_depopulated(chunk, rs, re); |
| 1613 | spin_unlock_irq(&pcpu_lock); |
Tejun Heo | a93ace4 | 2014-09-02 14:46:02 -0400 | [diff] [blame] | 1614 | } |
Tejun Heo | 6081089 | 2010-04-09 18:57:01 +0900 | [diff] [blame] | 1615 | pcpu_destroy_chunk(chunk); |
Tejun Heo | a56dbdd | 2009-03-07 00:44:11 +0900 | [diff] [blame] | 1616 | } |
Tejun Heo | 971f391 | 2009-08-14 15:00:49 +0900 | [diff] [blame] | 1617 | |
Tejun Heo | 1a4d760 | 2014-09-02 14:46:05 -0400 | [diff] [blame] | 1618 | /* |
| 1619 | * Ensure there are certain number of free populated pages for |
| 1620 | * atomic allocs. Fill up from the most packed so that atomic |
| 1621 | * allocs don't increase fragmentation. If atomic allocation |
| 1622 | * failed previously, always populate the maximum amount. This |
| 1623 | * should prevent atomic allocs larger than PAGE_SIZE from keeping |
| 1624 | * failing indefinitely; however, large atomic allocs are not |
| 1625 | * something we support properly and can be highly unreliable and |
| 1626 | * inefficient. |
| 1627 | */ |
| 1628 | retry_pop: |
| 1629 | if (pcpu_atomic_alloc_failed) { |
| 1630 | nr_to_pop = PCPU_EMPTY_POP_PAGES_HIGH; |
| 1631 | /* best effort anyway, don't worry about synchronization */ |
| 1632 | pcpu_atomic_alloc_failed = false; |
| 1633 | } else { |
| 1634 | nr_to_pop = clamp(PCPU_EMPTY_POP_PAGES_HIGH - |
| 1635 | pcpu_nr_empty_pop_pages, |
| 1636 | 0, PCPU_EMPTY_POP_PAGES_HIGH); |
| 1637 | } |
| 1638 | |
| 1639 | for (slot = pcpu_size_to_slot(PAGE_SIZE); slot < pcpu_nr_slots; slot++) { |
| 1640 | int nr_unpop = 0, rs, re; |
| 1641 | |
| 1642 | if (!nr_to_pop) |
| 1643 | break; |
| 1644 | |
| 1645 | spin_lock_irq(&pcpu_lock); |
| 1646 | list_for_each_entry(chunk, &pcpu_slot[slot], list) { |
Dennis Zhou (Facebook) | 8ab16c4 | 2017-07-24 19:02:07 -0400 | [diff] [blame] | 1647 | nr_unpop = chunk->nr_pages - chunk->nr_populated; |
Tejun Heo | 1a4d760 | 2014-09-02 14:46:05 -0400 | [diff] [blame] | 1648 | if (nr_unpop) |
| 1649 | break; |
| 1650 | } |
| 1651 | spin_unlock_irq(&pcpu_lock); |
| 1652 | |
| 1653 | if (!nr_unpop) |
| 1654 | continue; |
| 1655 | |
| 1656 | /* @chunk can't go away while pcpu_alloc_mutex is held */ |
Dennis Zhou (Facebook) | 91e914c | 2017-07-24 19:02:10 -0400 | [diff] [blame] | 1657 | pcpu_for_each_unpop_region(chunk->populated, rs, re, 0, |
| 1658 | chunk->nr_pages) { |
Tejun Heo | 1a4d760 | 2014-09-02 14:46:05 -0400 | [diff] [blame] | 1659 | int nr = min(re - rs, nr_to_pop); |
| 1660 | |
Dennis Zhou | 72682b1 | 2018-02-16 12:07:19 -0600 | [diff] [blame] | 1661 | ret = pcpu_populate_chunk(chunk, rs, rs + nr, gfp); |
Tejun Heo | 1a4d760 | 2014-09-02 14:46:05 -0400 | [diff] [blame] | 1662 | if (!ret) { |
| 1663 | nr_to_pop -= nr; |
| 1664 | spin_lock_irq(&pcpu_lock); |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 1665 | pcpu_chunk_populated(chunk, rs, rs + nr, false); |
Tejun Heo | 1a4d760 | 2014-09-02 14:46:05 -0400 | [diff] [blame] | 1666 | spin_unlock_irq(&pcpu_lock); |
| 1667 | } else { |
| 1668 | nr_to_pop = 0; |
| 1669 | } |
| 1670 | |
| 1671 | if (!nr_to_pop) |
| 1672 | break; |
| 1673 | } |
| 1674 | } |
| 1675 | |
| 1676 | if (nr_to_pop) { |
| 1677 | /* ran out of chunks to populate, create a new one and retry */ |
Dennis Zhou | 72682b1 | 2018-02-16 12:07:19 -0600 | [diff] [blame] | 1678 | chunk = pcpu_create_chunk(gfp); |
Tejun Heo | 1a4d760 | 2014-09-02 14:46:05 -0400 | [diff] [blame] | 1679 | if (chunk) { |
| 1680 | spin_lock_irq(&pcpu_lock); |
| 1681 | pcpu_chunk_relocate(chunk, -1); |
| 1682 | spin_unlock_irq(&pcpu_lock); |
| 1683 | goto retry_pop; |
| 1684 | } |
| 1685 | } |
| 1686 | |
Tejun Heo | 971f391 | 2009-08-14 15:00:49 +0900 | [diff] [blame] | 1687 | mutex_unlock(&pcpu_alloc_mutex); |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1688 | } |
| 1689 | |
| 1690 | /** |
| 1691 | * free_percpu - free percpu area |
| 1692 | * @ptr: pointer to area to free |
| 1693 | * |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 1694 | * Free percpu area @ptr. |
| 1695 | * |
| 1696 | * CONTEXT: |
| 1697 | * Can be called from atomic context. |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1698 | */ |
Tejun Heo | 43cf38e | 2010-02-02 14:38:57 +0900 | [diff] [blame] | 1699 | void free_percpu(void __percpu *ptr) |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1700 | { |
Andrew Morton | 129182e | 2010-01-08 14:42:39 -0800 | [diff] [blame] | 1701 | void *addr; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1702 | struct pcpu_chunk *chunk; |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 1703 | unsigned long flags; |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 1704 | int off; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1705 | |
| 1706 | if (!ptr) |
| 1707 | return; |
| 1708 | |
Catalin Marinas | f528f0b | 2011-09-26 17:12:53 +0100 | [diff] [blame] | 1709 | kmemleak_free_percpu(ptr); |
| 1710 | |
Andrew Morton | 129182e | 2010-01-08 14:42:39 -0800 | [diff] [blame] | 1711 | addr = __pcpu_ptr_to_addr(ptr); |
| 1712 | |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 1713 | spin_lock_irqsave(&pcpu_lock, flags); |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1714 | |
| 1715 | chunk = pcpu_chunk_addr_search(addr); |
Tejun Heo | bba174f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1716 | off = addr - chunk->base_addr; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1717 | |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 1718 | pcpu_free_area(chunk, off); |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1719 | |
Tejun Heo | a56dbdd | 2009-03-07 00:44:11 +0900 | [diff] [blame] | 1720 | /* if there are more than one fully free chunks, wake up grim reaper */ |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 1721 | if (chunk->free_bytes == pcpu_unit_size) { |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1722 | struct pcpu_chunk *pos; |
| 1723 | |
Tejun Heo | a56dbdd | 2009-03-07 00:44:11 +0900 | [diff] [blame] | 1724 | list_for_each_entry(pos, &pcpu_slot[pcpu_nr_slots - 1], list) |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1725 | if (pos != chunk) { |
Tejun Heo | 1a4d760 | 2014-09-02 14:46:05 -0400 | [diff] [blame] | 1726 | pcpu_schedule_balance_work(); |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1727 | break; |
| 1728 | } |
| 1729 | } |
| 1730 | |
Dennis Zhou | df95e79 | 2017-06-19 19:28:32 -0400 | [diff] [blame] | 1731 | trace_percpu_free_percpu(chunk->base_addr, off, ptr); |
| 1732 | |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 1733 | spin_unlock_irqrestore(&pcpu_lock, flags); |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1734 | } |
| 1735 | EXPORT_SYMBOL_GPL(free_percpu); |
| 1736 | |
Thomas Gleixner | 383776f | 2017-02-27 15:37:36 +0100 | [diff] [blame] | 1737 | bool __is_kernel_percpu_address(unsigned long addr, unsigned long *can_addr) |
| 1738 | { |
| 1739 | #ifdef CONFIG_SMP |
| 1740 | const size_t static_size = __per_cpu_end - __per_cpu_start; |
| 1741 | void __percpu *base = __addr_to_pcpu_ptr(pcpu_base_addr); |
| 1742 | unsigned int cpu; |
| 1743 | |
| 1744 | for_each_possible_cpu(cpu) { |
| 1745 | void *start = per_cpu_ptr(base, cpu); |
| 1746 | void *va = (void *)addr; |
| 1747 | |
| 1748 | if (va >= start && va < start + static_size) { |
Peter Zijlstra | 8ce371f | 2017-03-20 12:26:55 +0100 | [diff] [blame] | 1749 | if (can_addr) { |
Thomas Gleixner | 383776f | 2017-02-27 15:37:36 +0100 | [diff] [blame] | 1750 | *can_addr = (unsigned long) (va - start); |
Peter Zijlstra | 8ce371f | 2017-03-20 12:26:55 +0100 | [diff] [blame] | 1751 | *can_addr += (unsigned long) |
| 1752 | per_cpu_ptr(base, get_boot_cpu_id()); |
| 1753 | } |
Thomas Gleixner | 383776f | 2017-02-27 15:37:36 +0100 | [diff] [blame] | 1754 | return true; |
| 1755 | } |
| 1756 | } |
| 1757 | #endif |
| 1758 | /* on UP, can't distinguish from other static vars, always false */ |
| 1759 | return false; |
| 1760 | } |
| 1761 | |
Vivek Goyal | 3b034b0 | 2009-11-24 15:50:03 +0900 | [diff] [blame] | 1762 | /** |
Tejun Heo | 10fad5e | 2010-03-10 18:57:54 +0900 | [diff] [blame] | 1763 | * is_kernel_percpu_address - test whether address is from static percpu area |
| 1764 | * @addr: address to test |
| 1765 | * |
| 1766 | * Test whether @addr belongs to in-kernel static percpu area. Module |
| 1767 | * static percpu areas are not considered. For those, use |
| 1768 | * is_module_percpu_address(). |
| 1769 | * |
| 1770 | * RETURNS: |
| 1771 | * %true if @addr is from in-kernel static percpu area, %false otherwise. |
| 1772 | */ |
| 1773 | bool is_kernel_percpu_address(unsigned long addr) |
| 1774 | { |
Thomas Gleixner | 383776f | 2017-02-27 15:37:36 +0100 | [diff] [blame] | 1775 | return __is_kernel_percpu_address(addr, NULL); |
Tejun Heo | 10fad5e | 2010-03-10 18:57:54 +0900 | [diff] [blame] | 1776 | } |
| 1777 | |
| 1778 | /** |
Vivek Goyal | 3b034b0 | 2009-11-24 15:50:03 +0900 | [diff] [blame] | 1779 | * per_cpu_ptr_to_phys - convert translated percpu address to physical address |
| 1780 | * @addr: the address to be converted to physical address |
| 1781 | * |
| 1782 | * Given @addr which is dereferenceable address obtained via one of |
| 1783 | * percpu access macros, this function translates it into its physical |
| 1784 | * address. The caller is responsible for ensuring @addr stays valid |
| 1785 | * until this function finishes. |
| 1786 | * |
Dave Young | 67589c7 | 2011-11-23 08:20:53 -0800 | [diff] [blame] | 1787 | * percpu allocator has special setup for the first chunk, which currently |
| 1788 | * supports either embedding in linear address space or vmalloc mapping, |
| 1789 | * and, from the second one, the backing allocator (currently either vm or |
| 1790 | * km) provides translation. |
| 1791 | * |
Yannick Guerrini | bffc437 | 2015-03-06 23:30:42 +0100 | [diff] [blame] | 1792 | * The addr can be translated simply without checking if it falls into the |
Dave Young | 67589c7 | 2011-11-23 08:20:53 -0800 | [diff] [blame] | 1793 | * first chunk. But the current code reflects better how percpu allocator |
| 1794 | * actually works, and the verification can discover both bugs in percpu |
| 1795 | * allocator itself and per_cpu_ptr_to_phys() callers. So we keep current |
| 1796 | * code. |
| 1797 | * |
Vivek Goyal | 3b034b0 | 2009-11-24 15:50:03 +0900 | [diff] [blame] | 1798 | * RETURNS: |
| 1799 | * The physical address for @addr. |
| 1800 | */ |
| 1801 | phys_addr_t per_cpu_ptr_to_phys(void *addr) |
| 1802 | { |
Tejun Heo | 9983b6f0 | 2010-06-18 11:44:31 +0200 | [diff] [blame] | 1803 | void __percpu *base = __addr_to_pcpu_ptr(pcpu_base_addr); |
| 1804 | bool in_first_chunk = false; |
Tejun Heo | a855b84 | 2011-11-18 10:55:35 -0800 | [diff] [blame] | 1805 | unsigned long first_low, first_high; |
Tejun Heo | 9983b6f0 | 2010-06-18 11:44:31 +0200 | [diff] [blame] | 1806 | unsigned int cpu; |
| 1807 | |
| 1808 | /* |
Tejun Heo | a855b84 | 2011-11-18 10:55:35 -0800 | [diff] [blame] | 1809 | * The following test on unit_low/high isn't strictly |
Tejun Heo | 9983b6f0 | 2010-06-18 11:44:31 +0200 | [diff] [blame] | 1810 | * necessary but will speed up lookups of addresses which |
| 1811 | * aren't in the first chunk. |
Dennis Zhou (Facebook) | c0ebfdc | 2017-07-24 19:02:05 -0400 | [diff] [blame] | 1812 | * |
| 1813 | * The address check is against full chunk sizes. pcpu_base_addr |
| 1814 | * points to the beginning of the first chunk including the |
| 1815 | * static region. Assumes good intent as the first chunk may |
| 1816 | * not be full (ie. < pcpu_unit_pages in size). |
Tejun Heo | 9983b6f0 | 2010-06-18 11:44:31 +0200 | [diff] [blame] | 1817 | */ |
Dennis Zhou (Facebook) | c0ebfdc | 2017-07-24 19:02:05 -0400 | [diff] [blame] | 1818 | first_low = (unsigned long)pcpu_base_addr + |
| 1819 | pcpu_unit_page_offset(pcpu_low_unit_cpu, 0); |
| 1820 | first_high = (unsigned long)pcpu_base_addr + |
| 1821 | pcpu_unit_page_offset(pcpu_high_unit_cpu, pcpu_unit_pages); |
Tejun Heo | a855b84 | 2011-11-18 10:55:35 -0800 | [diff] [blame] | 1822 | if ((unsigned long)addr >= first_low && |
| 1823 | (unsigned long)addr < first_high) { |
Tejun Heo | 9983b6f0 | 2010-06-18 11:44:31 +0200 | [diff] [blame] | 1824 | for_each_possible_cpu(cpu) { |
| 1825 | void *start = per_cpu_ptr(base, cpu); |
| 1826 | |
| 1827 | if (addr >= start && addr < start + pcpu_unit_size) { |
| 1828 | in_first_chunk = true; |
| 1829 | break; |
| 1830 | } |
| 1831 | } |
| 1832 | } |
| 1833 | |
| 1834 | if (in_first_chunk) { |
David Howells | eac522e | 2011-03-28 12:53:29 +0100 | [diff] [blame] | 1835 | if (!is_vmalloc_addr(addr)) |
Tejun Heo | 020ec65 | 2010-04-09 18:57:00 +0900 | [diff] [blame] | 1836 | return __pa(addr); |
| 1837 | else |
Eugene Surovegin | 9f57bd4 | 2011-12-15 11:25:59 -0800 | [diff] [blame] | 1838 | return page_to_phys(vmalloc_to_page(addr)) + |
| 1839 | offset_in_page(addr); |
Tejun Heo | 020ec65 | 2010-04-09 18:57:00 +0900 | [diff] [blame] | 1840 | } else |
Eugene Surovegin | 9f57bd4 | 2011-12-15 11:25:59 -0800 | [diff] [blame] | 1841 | return page_to_phys(pcpu_addr_to_page(addr)) + |
| 1842 | offset_in_page(addr); |
Vivek Goyal | 3b034b0 | 2009-11-24 15:50:03 +0900 | [diff] [blame] | 1843 | } |
| 1844 | |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1845 | /** |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1846 | * pcpu_alloc_alloc_info - allocate percpu allocation info |
| 1847 | * @nr_groups: the number of groups |
| 1848 | * @nr_units: the number of units |
Tejun Heo | 033e48f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1849 | * |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1850 | * Allocate ai which is large enough for @nr_groups groups containing |
| 1851 | * @nr_units units. The returned ai's groups[0].cpu_map points to the |
| 1852 | * cpu_map array which is long enough for @nr_units and filled with |
| 1853 | * NR_CPUS. It's the caller's responsibility to initialize cpu_map |
| 1854 | * pointer of other groups. |
Tejun Heo | 033e48f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1855 | * |
| 1856 | * RETURNS: |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1857 | * Pointer to the allocated pcpu_alloc_info on success, NULL on |
| 1858 | * failure. |
Tejun Heo | 033e48f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1859 | */ |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1860 | struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups, |
| 1861 | int nr_units) |
| 1862 | { |
| 1863 | struct pcpu_alloc_info *ai; |
| 1864 | size_t base_size, ai_size; |
| 1865 | void *ptr; |
| 1866 | int unit; |
| 1867 | |
| 1868 | base_size = ALIGN(sizeof(*ai) + nr_groups * sizeof(ai->groups[0]), |
| 1869 | __alignof__(ai->groups[0].cpu_map[0])); |
| 1870 | ai_size = base_size + nr_units * sizeof(ai->groups[0].cpu_map[0]); |
| 1871 | |
Santosh Shilimkar | 999c17e | 2014-01-21 15:50:40 -0800 | [diff] [blame] | 1872 | ptr = memblock_virt_alloc_nopanic(PFN_ALIGN(ai_size), 0); |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1873 | if (!ptr) |
| 1874 | return NULL; |
| 1875 | ai = ptr; |
| 1876 | ptr += base_size; |
| 1877 | |
| 1878 | ai->groups[0].cpu_map = ptr; |
| 1879 | |
| 1880 | for (unit = 0; unit < nr_units; unit++) |
| 1881 | ai->groups[0].cpu_map[unit] = NR_CPUS; |
| 1882 | |
| 1883 | ai->nr_groups = nr_groups; |
| 1884 | ai->__ai_size = PFN_ALIGN(ai_size); |
| 1885 | |
| 1886 | return ai; |
| 1887 | } |
| 1888 | |
| 1889 | /** |
| 1890 | * pcpu_free_alloc_info - free percpu allocation info |
| 1891 | * @ai: pcpu_alloc_info to free |
| 1892 | * |
| 1893 | * Free @ai which was allocated by pcpu_alloc_alloc_info(). |
| 1894 | */ |
| 1895 | void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai) |
| 1896 | { |
Santosh Shilimkar | 999c17e | 2014-01-21 15:50:40 -0800 | [diff] [blame] | 1897 | memblock_free_early(__pa(ai), ai->__ai_size); |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1898 | } |
| 1899 | |
| 1900 | /** |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1901 | * pcpu_dump_alloc_info - print out information about pcpu_alloc_info |
| 1902 | * @lvl: loglevel |
| 1903 | * @ai: allocation info to dump |
| 1904 | * |
| 1905 | * Print out information about @ai using loglevel @lvl. |
| 1906 | */ |
| 1907 | static void pcpu_dump_alloc_info(const char *lvl, |
| 1908 | const struct pcpu_alloc_info *ai) |
Tejun Heo | 033e48f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1909 | { |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1910 | int group_width = 1, cpu_width = 1, width; |
Tejun Heo | 033e48f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1911 | char empty_str[] = "--------"; |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1912 | int alloc = 0, alloc_end = 0; |
| 1913 | int group, v; |
| 1914 | int upa, apl; /* units per alloc, allocs per line */ |
Tejun Heo | 033e48f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1915 | |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1916 | v = ai->nr_groups; |
Tejun Heo | 033e48f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1917 | while (v /= 10) |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1918 | group_width++; |
Tejun Heo | 033e48f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1919 | |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1920 | v = num_possible_cpus(); |
| 1921 | while (v /= 10) |
| 1922 | cpu_width++; |
| 1923 | empty_str[min_t(int, cpu_width, sizeof(empty_str) - 1)] = '\0'; |
Tejun Heo | 033e48f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1924 | |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1925 | upa = ai->alloc_size / ai->unit_size; |
| 1926 | width = upa * (cpu_width + 1) + group_width + 3; |
| 1927 | apl = rounddown_pow_of_two(max(60 / width, 1)); |
Tejun Heo | 033e48f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1928 | |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1929 | printk("%spcpu-alloc: s%zu r%zu d%zu u%zu alloc=%zu*%zu", |
| 1930 | lvl, ai->static_size, ai->reserved_size, ai->dyn_size, |
| 1931 | ai->unit_size, ai->alloc_size / ai->atom_size, ai->atom_size); |
| 1932 | |
| 1933 | for (group = 0; group < ai->nr_groups; group++) { |
| 1934 | const struct pcpu_group_info *gi = &ai->groups[group]; |
| 1935 | int unit = 0, unit_end = 0; |
| 1936 | |
| 1937 | BUG_ON(gi->nr_units % upa); |
| 1938 | for (alloc_end += gi->nr_units / upa; |
| 1939 | alloc < alloc_end; alloc++) { |
| 1940 | if (!(alloc % apl)) { |
Joe Perches | 1170532 | 2016-03-17 14:19:50 -0700 | [diff] [blame] | 1941 | pr_cont("\n"); |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1942 | printk("%spcpu-alloc: ", lvl); |
| 1943 | } |
Joe Perches | 1170532 | 2016-03-17 14:19:50 -0700 | [diff] [blame] | 1944 | pr_cont("[%0*d] ", group_width, group); |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1945 | |
| 1946 | for (unit_end += upa; unit < unit_end; unit++) |
| 1947 | if (gi->cpu_map[unit] != NR_CPUS) |
Joe Perches | 1170532 | 2016-03-17 14:19:50 -0700 | [diff] [blame] | 1948 | pr_cont("%0*d ", |
| 1949 | cpu_width, gi->cpu_map[unit]); |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1950 | else |
Joe Perches | 1170532 | 2016-03-17 14:19:50 -0700 | [diff] [blame] | 1951 | pr_cont("%s ", empty_str); |
Tejun Heo | 033e48f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1952 | } |
Tejun Heo | 033e48f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1953 | } |
Joe Perches | 1170532 | 2016-03-17 14:19:50 -0700 | [diff] [blame] | 1954 | pr_cont("\n"); |
Tejun Heo | 033e48f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1955 | } |
Tejun Heo | 033e48f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1956 | |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1957 | /** |
Tejun Heo | 8d408b4 | 2009-02-24 11:57:21 +0900 | [diff] [blame] | 1958 | * pcpu_setup_first_chunk - initialize the first percpu chunk |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1959 | * @ai: pcpu_alloc_info describing how to percpu area is shaped |
Tejun Heo | 38a6be5 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1960 | * @base_addr: mapped address |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1961 | * |
Tejun Heo | 8d408b4 | 2009-02-24 11:57:21 +0900 | [diff] [blame] | 1962 | * Initialize the first percpu chunk which contains the kernel static |
| 1963 | * perpcu area. This function is to be called from arch percpu area |
Tejun Heo | 38a6be5 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1964 | * setup path. |
Tejun Heo | 8d408b4 | 2009-02-24 11:57:21 +0900 | [diff] [blame] | 1965 | * |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1966 | * @ai contains all information necessary to initialize the first |
| 1967 | * chunk and prime the dynamic percpu allocator. |
Tejun Heo | 8d408b4 | 2009-02-24 11:57:21 +0900 | [diff] [blame] | 1968 | * |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1969 | * @ai->static_size is the size of static percpu area. |
| 1970 | * |
| 1971 | * @ai->reserved_size, if non-zero, specifies the amount of bytes to |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1972 | * reserve after the static area in the first chunk. This reserves |
| 1973 | * the first chunk such that it's available only through reserved |
| 1974 | * percpu allocation. This is primarily used to serve module percpu |
| 1975 | * static areas on architectures where the addressing model has |
| 1976 | * limited offset range for symbol relocations to guarantee module |
| 1977 | * percpu symbols fall inside the relocatable range. |
| 1978 | * |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1979 | * @ai->dyn_size determines the number of bytes available for dynamic |
| 1980 | * allocation in the first chunk. The area between @ai->static_size + |
| 1981 | * @ai->reserved_size + @ai->dyn_size and @ai->unit_size is unused. |
Tejun Heo | 6074d5b | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 1982 | * |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1983 | * @ai->unit_size specifies unit size and must be aligned to PAGE_SIZE |
| 1984 | * and equal to or larger than @ai->static_size + @ai->reserved_size + |
| 1985 | * @ai->dyn_size. |
Tejun Heo | 8d408b4 | 2009-02-24 11:57:21 +0900 | [diff] [blame] | 1986 | * |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1987 | * @ai->atom_size is the allocation atom size and used as alignment |
| 1988 | * for vm areas. |
Tejun Heo | 8d408b4 | 2009-02-24 11:57:21 +0900 | [diff] [blame] | 1989 | * |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1990 | * @ai->alloc_size is the allocation size and always multiple of |
| 1991 | * @ai->atom_size. This is larger than @ai->atom_size if |
| 1992 | * @ai->unit_size is larger than @ai->atom_size. |
| 1993 | * |
| 1994 | * @ai->nr_groups and @ai->groups describe virtual memory layout of |
| 1995 | * percpu areas. Units which should be colocated are put into the |
| 1996 | * same group. Dynamic VM areas will be allocated according to these |
| 1997 | * groupings. If @ai->nr_groups is zero, a single group containing |
| 1998 | * all units is assumed. |
Tejun Heo | 8d408b4 | 2009-02-24 11:57:21 +0900 | [diff] [blame] | 1999 | * |
Tejun Heo | 38a6be5 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 2000 | * The caller should have mapped the first chunk at @base_addr and |
| 2001 | * copied static data to each unit. |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 2002 | * |
Dennis Zhou (Facebook) | c0ebfdc | 2017-07-24 19:02:05 -0400 | [diff] [blame] | 2003 | * The first chunk will always contain a static and a dynamic region. |
| 2004 | * However, the static region is not managed by any chunk. If the first |
| 2005 | * chunk also contains a reserved region, it is served by two chunks - |
| 2006 | * one for the reserved region and one for the dynamic region. They |
| 2007 | * share the same vm, but use offset regions in the area allocation map. |
| 2008 | * The chunk serving the dynamic region is circulated in the chunk slots |
| 2009 | * and available for dynamic allocation like any other chunk. |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 2010 | * |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 2011 | * RETURNS: |
Tejun Heo | fb435d5 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 2012 | * 0 on success, -errno on failure. |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 2013 | */ |
Tejun Heo | fb435d5 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 2014 | int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai, |
| 2015 | void *base_addr) |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 2016 | { |
Dennis Zhou (Facebook) | b9c3944 | 2017-07-24 19:02:01 -0400 | [diff] [blame] | 2017 | size_t size_sum = ai->static_size + ai->reserved_size + ai->dyn_size; |
Dennis Zhou (Facebook) | d2f3c38 | 2017-07-24 19:02:09 -0400 | [diff] [blame] | 2018 | size_t static_size, dyn_size; |
Dennis Zhou (Facebook) | 0c4169c | 2017-07-24 19:02:04 -0400 | [diff] [blame] | 2019 | struct pcpu_chunk *chunk; |
Tejun Heo | 6563297 | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 2020 | unsigned long *group_offsets; |
| 2021 | size_t *group_sizes; |
Tejun Heo | fb435d5 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 2022 | unsigned long *unit_off; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 2023 | unsigned int cpu; |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 2024 | int *unit_map; |
| 2025 | int group, unit, i; |
Dennis Zhou (Facebook) | c0ebfdc | 2017-07-24 19:02:05 -0400 | [diff] [blame] | 2026 | int map_size; |
| 2027 | unsigned long tmp_addr; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 2028 | |
Tejun Heo | 635b75f | 2009-09-24 09:43:11 +0900 | [diff] [blame] | 2029 | #define PCPU_SETUP_BUG_ON(cond) do { \ |
| 2030 | if (unlikely(cond)) { \ |
Joe Perches | 870d4b1 | 2016-03-17 14:19:53 -0700 | [diff] [blame] | 2031 | pr_emerg("failed to initialize, %s\n", #cond); \ |
| 2032 | pr_emerg("cpu_possible_mask=%*pb\n", \ |
Tejun Heo | 807de07 | 2015-02-13 14:37:34 -0800 | [diff] [blame] | 2033 | cpumask_pr_args(cpu_possible_mask)); \ |
Tejun Heo | 635b75f | 2009-09-24 09:43:11 +0900 | [diff] [blame] | 2034 | pcpu_dump_alloc_info(KERN_EMERG, ai); \ |
| 2035 | BUG(); \ |
| 2036 | } \ |
| 2037 | } while (0) |
| 2038 | |
Tejun Heo | 2f39e63 | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 2039 | /* sanity checks */ |
Tejun Heo | 635b75f | 2009-09-24 09:43:11 +0900 | [diff] [blame] | 2040 | PCPU_SETUP_BUG_ON(ai->nr_groups <= 0); |
Tejun Heo | bbddff0 | 2010-09-03 18:22:48 +0200 | [diff] [blame] | 2041 | #ifdef CONFIG_SMP |
Tejun Heo | 635b75f | 2009-09-24 09:43:11 +0900 | [diff] [blame] | 2042 | PCPU_SETUP_BUG_ON(!ai->static_size); |
Alexander Kuleshov | f09f124 | 2015-11-05 18:46:43 -0800 | [diff] [blame] | 2043 | PCPU_SETUP_BUG_ON(offset_in_page(__per_cpu_start)); |
Tejun Heo | bbddff0 | 2010-09-03 18:22:48 +0200 | [diff] [blame] | 2044 | #endif |
Tejun Heo | 635b75f | 2009-09-24 09:43:11 +0900 | [diff] [blame] | 2045 | PCPU_SETUP_BUG_ON(!base_addr); |
Alexander Kuleshov | f09f124 | 2015-11-05 18:46:43 -0800 | [diff] [blame] | 2046 | PCPU_SETUP_BUG_ON(offset_in_page(base_addr)); |
Tejun Heo | 635b75f | 2009-09-24 09:43:11 +0900 | [diff] [blame] | 2047 | PCPU_SETUP_BUG_ON(ai->unit_size < size_sum); |
Alexander Kuleshov | f09f124 | 2015-11-05 18:46:43 -0800 | [diff] [blame] | 2048 | PCPU_SETUP_BUG_ON(offset_in_page(ai->unit_size)); |
Tejun Heo | 635b75f | 2009-09-24 09:43:11 +0900 | [diff] [blame] | 2049 | PCPU_SETUP_BUG_ON(ai->unit_size < PCPU_MIN_UNIT_SIZE); |
Dennis Zhou (Facebook) | ca460b3 | 2017-07-24 19:02:12 -0400 | [diff] [blame] | 2050 | PCPU_SETUP_BUG_ON(!IS_ALIGNED(ai->unit_size, PCPU_BITMAP_BLOCK_SIZE)); |
Tejun Heo | 099a19d | 2010-06-27 18:50:00 +0200 | [diff] [blame] | 2051 | PCPU_SETUP_BUG_ON(ai->dyn_size < PERCPU_DYNAMIC_EARLY_SIZE); |
Dennis Zhou (Facebook) | fb29a2c | 2017-07-24 19:01:58 -0400 | [diff] [blame] | 2052 | PCPU_SETUP_BUG_ON(!ai->dyn_size); |
Dennis Zhou (Facebook) | d2f3c38 | 2017-07-24 19:02:09 -0400 | [diff] [blame] | 2053 | PCPU_SETUP_BUG_ON(!IS_ALIGNED(ai->reserved_size, PCPU_MIN_ALLOC_SIZE)); |
Dennis Zhou (Facebook) | ca460b3 | 2017-07-24 19:02:12 -0400 | [diff] [blame] | 2054 | PCPU_SETUP_BUG_ON(!(IS_ALIGNED(PCPU_BITMAP_BLOCK_SIZE, PAGE_SIZE) || |
| 2055 | IS_ALIGNED(PAGE_SIZE, PCPU_BITMAP_BLOCK_SIZE))); |
Tejun Heo | 9f64553 | 2010-04-09 18:57:01 +0900 | [diff] [blame] | 2056 | PCPU_SETUP_BUG_ON(pcpu_verify_alloc_info(ai) < 0); |
Tejun Heo | 8d408b4 | 2009-02-24 11:57:21 +0900 | [diff] [blame] | 2057 | |
Tejun Heo | 6563297 | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 2058 | /* process group information and build config tables accordingly */ |
Santosh Shilimkar | 999c17e | 2014-01-21 15:50:40 -0800 | [diff] [blame] | 2059 | group_offsets = memblock_virt_alloc(ai->nr_groups * |
| 2060 | sizeof(group_offsets[0]), 0); |
| 2061 | group_sizes = memblock_virt_alloc(ai->nr_groups * |
| 2062 | sizeof(group_sizes[0]), 0); |
| 2063 | unit_map = memblock_virt_alloc(nr_cpu_ids * sizeof(unit_map[0]), 0); |
| 2064 | unit_off = memblock_virt_alloc(nr_cpu_ids * sizeof(unit_off[0]), 0); |
Tejun Heo | 2f39e63 | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 2065 | |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 2066 | for (cpu = 0; cpu < nr_cpu_ids; cpu++) |
Tejun Heo | ffe0d5a | 2009-09-29 09:17:56 +0900 | [diff] [blame] | 2067 | unit_map[cpu] = UINT_MAX; |
Tejun Heo | a855b84 | 2011-11-18 10:55:35 -0800 | [diff] [blame] | 2068 | |
| 2069 | pcpu_low_unit_cpu = NR_CPUS; |
| 2070 | pcpu_high_unit_cpu = NR_CPUS; |
Tejun Heo | 2f39e63 | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 2071 | |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 2072 | for (group = 0, unit = 0; group < ai->nr_groups; group++, unit += i) { |
| 2073 | const struct pcpu_group_info *gi = &ai->groups[group]; |
Tejun Heo | 2f39e63 | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 2074 | |
Tejun Heo | 6563297 | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 2075 | group_offsets[group] = gi->base_offset; |
| 2076 | group_sizes[group] = gi->nr_units * ai->unit_size; |
| 2077 | |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 2078 | for (i = 0; i < gi->nr_units; i++) { |
| 2079 | cpu = gi->cpu_map[i]; |
| 2080 | if (cpu == NR_CPUS) |
| 2081 | continue; |
| 2082 | |
Dan Carpenter | 9f29566 | 2014-10-29 11:45:04 +0300 | [diff] [blame] | 2083 | PCPU_SETUP_BUG_ON(cpu >= nr_cpu_ids); |
Tejun Heo | 635b75f | 2009-09-24 09:43:11 +0900 | [diff] [blame] | 2084 | PCPU_SETUP_BUG_ON(!cpu_possible(cpu)); |
| 2085 | PCPU_SETUP_BUG_ON(unit_map[cpu] != UINT_MAX); |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 2086 | |
| 2087 | unit_map[cpu] = unit + i; |
Tejun Heo | fb435d5 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 2088 | unit_off[cpu] = gi->base_offset + i * ai->unit_size; |
| 2089 | |
Tejun Heo | a855b84 | 2011-11-18 10:55:35 -0800 | [diff] [blame] | 2090 | /* determine low/high unit_cpu */ |
| 2091 | if (pcpu_low_unit_cpu == NR_CPUS || |
| 2092 | unit_off[cpu] < unit_off[pcpu_low_unit_cpu]) |
| 2093 | pcpu_low_unit_cpu = cpu; |
| 2094 | if (pcpu_high_unit_cpu == NR_CPUS || |
| 2095 | unit_off[cpu] > unit_off[pcpu_high_unit_cpu]) |
| 2096 | pcpu_high_unit_cpu = cpu; |
Tejun Heo | 2f39e63 | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 2097 | } |
Tejun Heo | 2f39e63 | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 2098 | } |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 2099 | pcpu_nr_units = unit; |
| 2100 | |
| 2101 | for_each_possible_cpu(cpu) |
Tejun Heo | 635b75f | 2009-09-24 09:43:11 +0900 | [diff] [blame] | 2102 | PCPU_SETUP_BUG_ON(unit_map[cpu] == UINT_MAX); |
| 2103 | |
| 2104 | /* we're done parsing the input, undefine BUG macro and dump config */ |
| 2105 | #undef PCPU_SETUP_BUG_ON |
Tejun Heo | bcbea79 | 2010-12-22 14:19:14 +0100 | [diff] [blame] | 2106 | pcpu_dump_alloc_info(KERN_DEBUG, ai); |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 2107 | |
Tejun Heo | 6563297 | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 2108 | pcpu_nr_groups = ai->nr_groups; |
| 2109 | pcpu_group_offsets = group_offsets; |
| 2110 | pcpu_group_sizes = group_sizes; |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 2111 | pcpu_unit_map = unit_map; |
Tejun Heo | fb435d5 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 2112 | pcpu_unit_offsets = unit_off; |
Tejun Heo | 2f39e63 | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 2113 | |
| 2114 | /* determine basic parameters */ |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 2115 | pcpu_unit_pages = ai->unit_size >> PAGE_SHIFT; |
Tejun Heo | d9b55ee | 2009-02-24 11:57:21 +0900 | [diff] [blame] | 2116 | pcpu_unit_size = pcpu_unit_pages << PAGE_SHIFT; |
Tejun Heo | 6563297 | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 2117 | pcpu_atom_size = ai->atom_size; |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 2118 | pcpu_chunk_struct_size = sizeof(struct pcpu_chunk) + |
| 2119 | BITS_TO_LONGS(pcpu_unit_pages) * sizeof(unsigned long); |
Tejun Heo | cafe881 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 2120 | |
Dennis Zhou | 30a5b53 | 2017-06-19 19:28:31 -0400 | [diff] [blame] | 2121 | pcpu_stats_save_ai(ai); |
| 2122 | |
Tejun Heo | d9b55ee | 2009-02-24 11:57:21 +0900 | [diff] [blame] | 2123 | /* |
| 2124 | * Allocate chunk slots. The additional last slot is for |
| 2125 | * empty chunks. |
| 2126 | */ |
| 2127 | pcpu_nr_slots = __pcpu_size_to_slot(pcpu_unit_size) + 2; |
Santosh Shilimkar | 999c17e | 2014-01-21 15:50:40 -0800 | [diff] [blame] | 2128 | pcpu_slot = memblock_virt_alloc( |
| 2129 | pcpu_nr_slots * sizeof(pcpu_slot[0]), 0); |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 2130 | for (i = 0; i < pcpu_nr_slots; i++) |
| 2131 | INIT_LIST_HEAD(&pcpu_slot[i]); |
| 2132 | |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 2133 | /* |
Dennis Zhou (Facebook) | d2f3c38 | 2017-07-24 19:02:09 -0400 | [diff] [blame] | 2134 | * The end of the static region needs to be aligned with the |
| 2135 | * minimum allocation size as this offsets the reserved and |
| 2136 | * dynamic region. The first chunk ends page aligned by |
| 2137 | * expanding the dynamic region, therefore the dynamic region |
| 2138 | * can be shrunk to compensate while still staying above the |
| 2139 | * configured sizes. |
| 2140 | */ |
| 2141 | static_size = ALIGN(ai->static_size, PCPU_MIN_ALLOC_SIZE); |
| 2142 | dyn_size = ai->dyn_size - (static_size - ai->static_size); |
| 2143 | |
| 2144 | /* |
Dennis Zhou (Facebook) | c0ebfdc | 2017-07-24 19:02:05 -0400 | [diff] [blame] | 2145 | * Initialize first chunk. |
| 2146 | * If the reserved_size is non-zero, this initializes the reserved |
| 2147 | * chunk. If the reserved_size is zero, the reserved chunk is NULL |
| 2148 | * and the dynamic region is initialized here. The first chunk, |
| 2149 | * pcpu_first_chunk, will always point to the chunk that serves |
| 2150 | * the dynamic region. |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 2151 | */ |
Dennis Zhou (Facebook) | d2f3c38 | 2017-07-24 19:02:09 -0400 | [diff] [blame] | 2152 | tmp_addr = (unsigned long)base_addr + static_size; |
| 2153 | map_size = ai->reserved_size ?: dyn_size; |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 2154 | chunk = pcpu_alloc_first_chunk(tmp_addr, map_size); |
Tejun Heo | 61ace7f | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 2155 | |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 2156 | /* init dynamic chunk if necessary */ |
Dennis Zhou (Facebook) | b9c3944 | 2017-07-24 19:02:01 -0400 | [diff] [blame] | 2157 | if (ai->reserved_size) { |
Dennis Zhou (Facebook) | 0c4169c | 2017-07-24 19:02:04 -0400 | [diff] [blame] | 2158 | pcpu_reserved_chunk = chunk; |
Dennis Zhou (Facebook) | b9c3944 | 2017-07-24 19:02:01 -0400 | [diff] [blame] | 2159 | |
Dennis Zhou (Facebook) | d2f3c38 | 2017-07-24 19:02:09 -0400 | [diff] [blame] | 2160 | tmp_addr = (unsigned long)base_addr + static_size + |
Dennis Zhou (Facebook) | c0ebfdc | 2017-07-24 19:02:05 -0400 | [diff] [blame] | 2161 | ai->reserved_size; |
Dennis Zhou (Facebook) | d2f3c38 | 2017-07-24 19:02:09 -0400 | [diff] [blame] | 2162 | map_size = dyn_size; |
Dennis Zhou (Facebook) | 40064ae | 2017-07-12 11:27:32 -0700 | [diff] [blame] | 2163 | chunk = pcpu_alloc_first_chunk(tmp_addr, map_size); |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 2164 | } |
| 2165 | |
Tejun Heo | 2441d15 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 2166 | /* link the first chunk in */ |
Dennis Zhou (Facebook) | 0c4169c | 2017-07-24 19:02:04 -0400 | [diff] [blame] | 2167 | pcpu_first_chunk = chunk; |
Dennis Zhou (Facebook) | 0cecf50 | 2017-07-24 19:02:08 -0400 | [diff] [blame] | 2168 | pcpu_nr_empty_pop_pages = pcpu_first_chunk->nr_empty_pop_pages; |
Tejun Heo | ae9e6bc9 | 2009-04-02 13:19:54 +0900 | [diff] [blame] | 2169 | pcpu_chunk_relocate(pcpu_first_chunk, -1); |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 2170 | |
Dennis Zhou | 30a5b53 | 2017-06-19 19:28:31 -0400 | [diff] [blame] | 2171 | pcpu_stats_chunk_alloc(); |
Dennis Zhou | df95e79 | 2017-06-19 19:28:32 -0400 | [diff] [blame] | 2172 | trace_percpu_create_chunk(base_addr); |
Dennis Zhou | 30a5b53 | 2017-06-19 19:28:31 -0400 | [diff] [blame] | 2173 | |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 2174 | /* we're done */ |
Tejun Heo | bba174f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 2175 | pcpu_base_addr = base_addr; |
Tejun Heo | fb435d5 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 2176 | return 0; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 2177 | } |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 2178 | |
Tejun Heo | bbddff0 | 2010-09-03 18:22:48 +0200 | [diff] [blame] | 2179 | #ifdef CONFIG_SMP |
| 2180 | |
Andi Kleen | 17f3609 | 2012-10-04 17:12:07 -0700 | [diff] [blame] | 2181 | const char * const pcpu_fc_names[PCPU_FC_NR] __initconst = { |
Tejun Heo | f58dc01 | 2009-08-14 15:00:50 +0900 | [diff] [blame] | 2182 | [PCPU_FC_AUTO] = "auto", |
| 2183 | [PCPU_FC_EMBED] = "embed", |
| 2184 | [PCPU_FC_PAGE] = "page", |
Tejun Heo | f58dc01 | 2009-08-14 15:00:50 +0900 | [diff] [blame] | 2185 | }; |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 2186 | |
Tejun Heo | f58dc01 | 2009-08-14 15:00:50 +0900 | [diff] [blame] | 2187 | enum pcpu_fc pcpu_chosen_fc __initdata = PCPU_FC_AUTO; |
| 2188 | |
| 2189 | static int __init percpu_alloc_setup(char *str) |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 2190 | { |
Cyrill Gorcunov | 5479c78 | 2012-11-25 01:17:13 +0400 | [diff] [blame] | 2191 | if (!str) |
| 2192 | return -EINVAL; |
| 2193 | |
Tejun Heo | f58dc01 | 2009-08-14 15:00:50 +0900 | [diff] [blame] | 2194 | if (0) |
| 2195 | /* nada */; |
| 2196 | #ifdef CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK |
| 2197 | else if (!strcmp(str, "embed")) |
| 2198 | pcpu_chosen_fc = PCPU_FC_EMBED; |
| 2199 | #endif |
| 2200 | #ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK |
| 2201 | else if (!strcmp(str, "page")) |
| 2202 | pcpu_chosen_fc = PCPU_FC_PAGE; |
| 2203 | #endif |
Tejun Heo | f58dc01 | 2009-08-14 15:00:50 +0900 | [diff] [blame] | 2204 | else |
Joe Perches | 870d4b1 | 2016-03-17 14:19:53 -0700 | [diff] [blame] | 2205 | pr_warn("unknown allocator %s specified\n", str); |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 2206 | |
Tejun Heo | f58dc01 | 2009-08-14 15:00:50 +0900 | [diff] [blame] | 2207 | return 0; |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 2208 | } |
Tejun Heo | f58dc01 | 2009-08-14 15:00:50 +0900 | [diff] [blame] | 2209 | early_param("percpu_alloc", percpu_alloc_setup); |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 2210 | |
Tejun Heo | 3c9a024 | 2010-09-09 18:00:15 +0200 | [diff] [blame] | 2211 | /* |
| 2212 | * pcpu_embed_first_chunk() is used by the generic percpu setup. |
| 2213 | * Build it if needed by the arch config or the generic setup is going |
| 2214 | * to be used. |
| 2215 | */ |
Tejun Heo | 08fc458 | 2009-08-14 15:00:49 +0900 | [diff] [blame] | 2216 | #if defined(CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK) || \ |
| 2217 | !defined(CONFIG_HAVE_SETUP_PER_CPU_AREA) |
Tejun Heo | 3c9a024 | 2010-09-09 18:00:15 +0200 | [diff] [blame] | 2218 | #define BUILD_EMBED_FIRST_CHUNK |
| 2219 | #endif |
| 2220 | |
| 2221 | /* build pcpu_page_first_chunk() iff needed by the arch config */ |
| 2222 | #if defined(CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK) |
| 2223 | #define BUILD_PAGE_FIRST_CHUNK |
| 2224 | #endif |
| 2225 | |
| 2226 | /* pcpu_build_alloc_info() is used by both embed and page first chunk */ |
| 2227 | #if defined(BUILD_EMBED_FIRST_CHUNK) || defined(BUILD_PAGE_FIRST_CHUNK) |
| 2228 | /** |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 2229 | * pcpu_build_alloc_info - build alloc_info considering distances between CPUs |
| 2230 | * @reserved_size: the size of reserved percpu area in bytes |
| 2231 | * @dyn_size: minimum free size for dynamic allocation in bytes |
| 2232 | * @atom_size: allocation atom size |
| 2233 | * @cpu_distance_fn: callback to determine distance between cpus, optional |
| 2234 | * |
| 2235 | * This function determines grouping of units, their mappings to cpus |
| 2236 | * and other parameters considering needed percpu size, allocation |
| 2237 | * atom size and distances between CPUs. |
| 2238 | * |
Yannick Guerrini | bffc437 | 2015-03-06 23:30:42 +0100 | [diff] [blame] | 2239 | * Groups are always multiples of atom size and CPUs which are of |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 2240 | * LOCAL_DISTANCE both ways are grouped together and share space for |
| 2241 | * units in the same group. The returned configuration is guaranteed |
| 2242 | * to have CPUs on different nodes on different groups and >=75% usage |
| 2243 | * of allocated virtual address space. |
| 2244 | * |
| 2245 | * RETURNS: |
| 2246 | * On success, pointer to the new allocation_info is returned. On |
| 2247 | * failure, ERR_PTR value is returned. |
| 2248 | */ |
| 2249 | static struct pcpu_alloc_info * __init pcpu_build_alloc_info( |
| 2250 | size_t reserved_size, size_t dyn_size, |
| 2251 | size_t atom_size, |
| 2252 | pcpu_fc_cpu_distance_fn_t cpu_distance_fn) |
| 2253 | { |
| 2254 | static int group_map[NR_CPUS] __initdata; |
| 2255 | static int group_cnt[NR_CPUS] __initdata; |
| 2256 | const size_t static_size = __per_cpu_end - __per_cpu_start; |
| 2257 | int nr_groups = 1, nr_units = 0; |
| 2258 | size_t size_sum, min_unit_size, alloc_size; |
| 2259 | int upa, max_upa, uninitialized_var(best_upa); /* units_per_alloc */ |
| 2260 | int last_allocs, group, unit; |
| 2261 | unsigned int cpu, tcpu; |
| 2262 | struct pcpu_alloc_info *ai; |
| 2263 | unsigned int *cpu_map; |
| 2264 | |
| 2265 | /* this function may be called multiple times */ |
| 2266 | memset(group_map, 0, sizeof(group_map)); |
| 2267 | memset(group_cnt, 0, sizeof(group_cnt)); |
| 2268 | |
| 2269 | /* calculate size_sum and ensure dyn_size is enough for early alloc */ |
| 2270 | size_sum = PFN_ALIGN(static_size + reserved_size + |
| 2271 | max_t(size_t, dyn_size, PERCPU_DYNAMIC_EARLY_SIZE)); |
| 2272 | dyn_size = size_sum - static_size - reserved_size; |
| 2273 | |
| 2274 | /* |
| 2275 | * Determine min_unit_size, alloc_size and max_upa such that |
| 2276 | * alloc_size is multiple of atom_size and is the smallest |
Lucas De Marchi | 25985ed | 2011-03-30 22:57:33 -0300 | [diff] [blame] | 2277 | * which can accommodate 4k aligned segments which are equal to |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 2278 | * or larger than min_unit_size. |
| 2279 | */ |
| 2280 | min_unit_size = max_t(size_t, size_sum, PCPU_MIN_UNIT_SIZE); |
| 2281 | |
Dennis Zhou (Facebook) | 9c01516 | 2017-07-15 22:23:09 -0400 | [diff] [blame] | 2282 | /* determine the maximum # of units that can fit in an allocation */ |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 2283 | alloc_size = roundup(min_unit_size, atom_size); |
| 2284 | upa = alloc_size / min_unit_size; |
Alexander Kuleshov | f09f124 | 2015-11-05 18:46:43 -0800 | [diff] [blame] | 2285 | while (alloc_size % upa || (offset_in_page(alloc_size / upa))) |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 2286 | upa--; |
| 2287 | max_upa = upa; |
| 2288 | |
| 2289 | /* group cpus according to their proximity */ |
| 2290 | for_each_possible_cpu(cpu) { |
| 2291 | group = 0; |
| 2292 | next_group: |
| 2293 | for_each_possible_cpu(tcpu) { |
| 2294 | if (cpu == tcpu) |
| 2295 | break; |
| 2296 | if (group_map[tcpu] == group && cpu_distance_fn && |
| 2297 | (cpu_distance_fn(cpu, tcpu) > LOCAL_DISTANCE || |
| 2298 | cpu_distance_fn(tcpu, cpu) > LOCAL_DISTANCE)) { |
| 2299 | group++; |
| 2300 | nr_groups = max(nr_groups, group + 1); |
| 2301 | goto next_group; |
| 2302 | } |
| 2303 | } |
| 2304 | group_map[cpu] = group; |
| 2305 | group_cnt[group]++; |
| 2306 | } |
| 2307 | |
| 2308 | /* |
Dennis Zhou (Facebook) | 9c01516 | 2017-07-15 22:23:09 -0400 | [diff] [blame] | 2309 | * Wasted space is caused by a ratio imbalance of upa to group_cnt. |
| 2310 | * Expand the unit_size until we use >= 75% of the units allocated. |
| 2311 | * Related to atom_size, which could be much larger than the unit_size. |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 2312 | */ |
| 2313 | last_allocs = INT_MAX; |
| 2314 | for (upa = max_upa; upa; upa--) { |
| 2315 | int allocs = 0, wasted = 0; |
| 2316 | |
Alexander Kuleshov | f09f124 | 2015-11-05 18:46:43 -0800 | [diff] [blame] | 2317 | if (alloc_size % upa || (offset_in_page(alloc_size / upa))) |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 2318 | continue; |
| 2319 | |
| 2320 | for (group = 0; group < nr_groups; group++) { |
| 2321 | int this_allocs = DIV_ROUND_UP(group_cnt[group], upa); |
| 2322 | allocs += this_allocs; |
| 2323 | wasted += this_allocs * upa - group_cnt[group]; |
| 2324 | } |
| 2325 | |
| 2326 | /* |
| 2327 | * Don't accept if wastage is over 1/3. The |
| 2328 | * greater-than comparison ensures upa==1 always |
| 2329 | * passes the following check. |
| 2330 | */ |
| 2331 | if (wasted > num_possible_cpus() / 3) |
| 2332 | continue; |
| 2333 | |
| 2334 | /* and then don't consume more memory */ |
| 2335 | if (allocs > last_allocs) |
| 2336 | break; |
| 2337 | last_allocs = allocs; |
| 2338 | best_upa = upa; |
| 2339 | } |
| 2340 | upa = best_upa; |
| 2341 | |
| 2342 | /* allocate and fill alloc_info */ |
| 2343 | for (group = 0; group < nr_groups; group++) |
| 2344 | nr_units += roundup(group_cnt[group], upa); |
| 2345 | |
| 2346 | ai = pcpu_alloc_alloc_info(nr_groups, nr_units); |
| 2347 | if (!ai) |
| 2348 | return ERR_PTR(-ENOMEM); |
| 2349 | cpu_map = ai->groups[0].cpu_map; |
| 2350 | |
| 2351 | for (group = 0; group < nr_groups; group++) { |
| 2352 | ai->groups[group].cpu_map = cpu_map; |
| 2353 | cpu_map += roundup(group_cnt[group], upa); |
| 2354 | } |
| 2355 | |
| 2356 | ai->static_size = static_size; |
| 2357 | ai->reserved_size = reserved_size; |
| 2358 | ai->dyn_size = dyn_size; |
| 2359 | ai->unit_size = alloc_size / upa; |
| 2360 | ai->atom_size = atom_size; |
| 2361 | ai->alloc_size = alloc_size; |
| 2362 | |
| 2363 | for (group = 0, unit = 0; group_cnt[group]; group++) { |
| 2364 | struct pcpu_group_info *gi = &ai->groups[group]; |
| 2365 | |
| 2366 | /* |
| 2367 | * Initialize base_offset as if all groups are located |
| 2368 | * back-to-back. The caller should update this to |
| 2369 | * reflect actual allocation. |
| 2370 | */ |
| 2371 | gi->base_offset = unit * ai->unit_size; |
| 2372 | |
| 2373 | for_each_possible_cpu(cpu) |
| 2374 | if (group_map[cpu] == group) |
| 2375 | gi->cpu_map[gi->nr_units++] = cpu; |
| 2376 | gi->nr_units = roundup(gi->nr_units, upa); |
| 2377 | unit += gi->nr_units; |
| 2378 | } |
| 2379 | BUG_ON(unit != nr_units); |
| 2380 | |
| 2381 | return ai; |
| 2382 | } |
Tejun Heo | 3c9a024 | 2010-09-09 18:00:15 +0200 | [diff] [blame] | 2383 | #endif /* BUILD_EMBED_FIRST_CHUNK || BUILD_PAGE_FIRST_CHUNK */ |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 2384 | |
Tejun Heo | 3c9a024 | 2010-09-09 18:00:15 +0200 | [diff] [blame] | 2385 | #if defined(BUILD_EMBED_FIRST_CHUNK) |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 2386 | /** |
| 2387 | * pcpu_embed_first_chunk - embed the first percpu chunk into bootmem |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 2388 | * @reserved_size: the size of reserved percpu area in bytes |
Tejun Heo | 4ba6ce2 | 2010-06-27 18:49:59 +0200 | [diff] [blame] | 2389 | * @dyn_size: minimum free size for dynamic allocation in bytes |
Tejun Heo | c8826dd | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 2390 | * @atom_size: allocation atom size |
| 2391 | * @cpu_distance_fn: callback to determine distance between cpus, optional |
| 2392 | * @alloc_fn: function to allocate percpu page |
Lucas De Marchi | 25985ed | 2011-03-30 22:57:33 -0300 | [diff] [blame] | 2393 | * @free_fn: function to free percpu page |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 2394 | * |
| 2395 | * This is a helper to ease setting up embedded first percpu chunk and |
| 2396 | * can be called where pcpu_setup_first_chunk() is expected. |
| 2397 | * |
| 2398 | * If this function is used to setup the first chunk, it is allocated |
Tejun Heo | c8826dd | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 2399 | * by calling @alloc_fn and used as-is without being mapped into |
| 2400 | * vmalloc area. Allocations are always whole multiples of @atom_size |
| 2401 | * aligned to @atom_size. |
| 2402 | * |
| 2403 | * This enables the first chunk to piggy back on the linear physical |
| 2404 | * mapping which often uses larger page size. Please note that this |
| 2405 | * can result in very sparse cpu->unit mapping on NUMA machines thus |
| 2406 | * requiring large vmalloc address space. Don't use this allocator if |
| 2407 | * vmalloc space is not orders of magnitude larger than distances |
| 2408 | * between node memory addresses (ie. 32bit NUMA machines). |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 2409 | * |
Tejun Heo | 4ba6ce2 | 2010-06-27 18:49:59 +0200 | [diff] [blame] | 2410 | * @dyn_size specifies the minimum dynamic area size. |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 2411 | * |
| 2412 | * If the needed size is smaller than the minimum or specified unit |
Tejun Heo | c8826dd | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 2413 | * size, the leftover is returned using @free_fn. |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 2414 | * |
| 2415 | * RETURNS: |
Tejun Heo | fb435d5 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 2416 | * 0 on success, -errno on failure. |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 2417 | */ |
Tejun Heo | 4ba6ce2 | 2010-06-27 18:49:59 +0200 | [diff] [blame] | 2418 | int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size, |
Tejun Heo | c8826dd | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 2419 | size_t atom_size, |
| 2420 | pcpu_fc_cpu_distance_fn_t cpu_distance_fn, |
| 2421 | pcpu_fc_alloc_fn_t alloc_fn, |
| 2422 | pcpu_fc_free_fn_t free_fn) |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 2423 | { |
Tejun Heo | c8826dd | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 2424 | void *base = (void *)ULONG_MAX; |
| 2425 | void **areas = NULL; |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 2426 | struct pcpu_alloc_info *ai; |
zijun_hu | 93c76b6b | 2016-10-05 21:19:11 +0800 | [diff] [blame] | 2427 | size_t size_sum, areas_size; |
| 2428 | unsigned long max_distance; |
zijun_hu | 9b73966 | 2016-10-05 21:30:24 +0800 | [diff] [blame] | 2429 | int group, i, highest_group, rc; |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 2430 | |
Tejun Heo | c8826dd | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 2431 | ai = pcpu_build_alloc_info(reserved_size, dyn_size, atom_size, |
| 2432 | cpu_distance_fn); |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 2433 | if (IS_ERR(ai)) |
| 2434 | return PTR_ERR(ai); |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 2435 | |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 2436 | size_sum = ai->static_size + ai->reserved_size + ai->dyn_size; |
Tejun Heo | c8826dd | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 2437 | areas_size = PFN_ALIGN(ai->nr_groups * sizeof(void *)); |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 2438 | |
Santosh Shilimkar | 999c17e | 2014-01-21 15:50:40 -0800 | [diff] [blame] | 2439 | areas = memblock_virt_alloc_nopanic(areas_size, 0); |
Tejun Heo | c8826dd | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 2440 | if (!areas) { |
Tejun Heo | fb435d5 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 2441 | rc = -ENOMEM; |
Tejun Heo | c8826dd | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 2442 | goto out_free; |
Tejun Heo | fa8a709 | 2009-06-22 11:56:24 +0900 | [diff] [blame] | 2443 | } |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 2444 | |
zijun_hu | 9b73966 | 2016-10-05 21:30:24 +0800 | [diff] [blame] | 2445 | /* allocate, copy and determine base address & max_distance */ |
| 2446 | highest_group = 0; |
Tejun Heo | c8826dd | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 2447 | for (group = 0; group < ai->nr_groups; group++) { |
| 2448 | struct pcpu_group_info *gi = &ai->groups[group]; |
| 2449 | unsigned int cpu = NR_CPUS; |
| 2450 | void *ptr; |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 2451 | |
Tejun Heo | c8826dd | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 2452 | for (i = 0; i < gi->nr_units && cpu == NR_CPUS; i++) |
| 2453 | cpu = gi->cpu_map[i]; |
| 2454 | BUG_ON(cpu == NR_CPUS); |
| 2455 | |
| 2456 | /* allocate space for the whole group */ |
| 2457 | ptr = alloc_fn(cpu, gi->nr_units * ai->unit_size, atom_size); |
| 2458 | if (!ptr) { |
| 2459 | rc = -ENOMEM; |
| 2460 | goto out_free_areas; |
| 2461 | } |
Catalin Marinas | f528f0b | 2011-09-26 17:12:53 +0100 | [diff] [blame] | 2462 | /* kmemleak tracks the percpu allocations separately */ |
| 2463 | kmemleak_free(ptr); |
Tejun Heo | c8826dd | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 2464 | areas[group] = ptr; |
| 2465 | |
| 2466 | base = min(ptr, base); |
zijun_hu | 9b73966 | 2016-10-05 21:30:24 +0800 | [diff] [blame] | 2467 | if (ptr > areas[highest_group]) |
| 2468 | highest_group = group; |
| 2469 | } |
| 2470 | max_distance = areas[highest_group] - base; |
| 2471 | max_distance += ai->unit_size * ai->groups[highest_group].nr_units; |
| 2472 | |
| 2473 | /* warn if maximum distance is further than 75% of vmalloc space */ |
| 2474 | if (max_distance > VMALLOC_TOTAL * 3 / 4) { |
| 2475 | pr_warn("max_distance=0x%lx too large for vmalloc space 0x%lx\n", |
| 2476 | max_distance, VMALLOC_TOTAL); |
| 2477 | #ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK |
| 2478 | /* and fail if we have fallback */ |
| 2479 | rc = -EINVAL; |
| 2480 | goto out_free_areas; |
| 2481 | #endif |
Tejun Heo | 42b6428 | 2012-04-27 08:42:53 -0700 | [diff] [blame] | 2482 | } |
| 2483 | |
| 2484 | /* |
| 2485 | * Copy data and free unused parts. This should happen after all |
| 2486 | * allocations are complete; otherwise, we may end up with |
| 2487 | * overlapping groups. |
| 2488 | */ |
| 2489 | for (group = 0; group < ai->nr_groups; group++) { |
| 2490 | struct pcpu_group_info *gi = &ai->groups[group]; |
| 2491 | void *ptr = areas[group]; |
Tejun Heo | c8826dd | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 2492 | |
| 2493 | for (i = 0; i < gi->nr_units; i++, ptr += ai->unit_size) { |
| 2494 | if (gi->cpu_map[i] == NR_CPUS) { |
| 2495 | /* unused unit, free whole */ |
| 2496 | free_fn(ptr, ai->unit_size); |
| 2497 | continue; |
| 2498 | } |
| 2499 | /* copy and return the unused part */ |
| 2500 | memcpy(ptr, __per_cpu_load, ai->static_size); |
| 2501 | free_fn(ptr + size_sum, ai->unit_size - size_sum); |
| 2502 | } |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 2503 | } |
| 2504 | |
Tejun Heo | c8826dd | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 2505 | /* base address is now known, determine group base offsets */ |
Tejun Heo | 6ea529a | 2009-09-24 18:46:01 +0900 | [diff] [blame] | 2506 | for (group = 0; group < ai->nr_groups; group++) { |
Tejun Heo | c8826dd | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 2507 | ai->groups[group].base_offset = areas[group] - base; |
Tejun Heo | 6ea529a | 2009-09-24 18:46:01 +0900 | [diff] [blame] | 2508 | } |
Tejun Heo | c8826dd | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 2509 | |
Joe Perches | 870d4b1 | 2016-03-17 14:19:53 -0700 | [diff] [blame] | 2510 | pr_info("Embedded %zu pages/cpu @%p s%zu r%zu d%zu u%zu\n", |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 2511 | PFN_DOWN(size_sum), base, ai->static_size, ai->reserved_size, |
| 2512 | ai->dyn_size, ai->unit_size); |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 2513 | |
Tejun Heo | fb435d5 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 2514 | rc = pcpu_setup_first_chunk(ai, base); |
Tejun Heo | c8826dd | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 2515 | goto out_free; |
| 2516 | |
| 2517 | out_free_areas: |
| 2518 | for (group = 0; group < ai->nr_groups; group++) |
Michael Holzheu | f851c8d | 2013-09-17 16:57:34 +0200 | [diff] [blame] | 2519 | if (areas[group]) |
| 2520 | free_fn(areas[group], |
| 2521 | ai->groups[group].nr_units * ai->unit_size); |
Tejun Heo | c8826dd | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 2522 | out_free: |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 2523 | pcpu_free_alloc_info(ai); |
Tejun Heo | c8826dd | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 2524 | if (areas) |
Santosh Shilimkar | 999c17e | 2014-01-21 15:50:40 -0800 | [diff] [blame] | 2525 | memblock_free_early(__pa(areas), areas_size); |
Tejun Heo | fb435d5 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 2526 | return rc; |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 2527 | } |
Tejun Heo | 3c9a024 | 2010-09-09 18:00:15 +0200 | [diff] [blame] | 2528 | #endif /* BUILD_EMBED_FIRST_CHUNK */ |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 2529 | |
Tejun Heo | 3c9a024 | 2010-09-09 18:00:15 +0200 | [diff] [blame] | 2530 | #ifdef BUILD_PAGE_FIRST_CHUNK |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 2531 | /** |
Tejun Heo | 00ae406 | 2009-08-14 15:00:49 +0900 | [diff] [blame] | 2532 | * pcpu_page_first_chunk - map the first chunk using PAGE_SIZE pages |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 2533 | * @reserved_size: the size of reserved percpu area in bytes |
| 2534 | * @alloc_fn: function to allocate percpu page, always called with PAGE_SIZE |
Lucas De Marchi | 25985ed | 2011-03-30 22:57:33 -0300 | [diff] [blame] | 2535 | * @free_fn: function to free percpu page, always called with PAGE_SIZE |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 2536 | * @populate_pte_fn: function to populate pte |
| 2537 | * |
Tejun Heo | 00ae406 | 2009-08-14 15:00:49 +0900 | [diff] [blame] | 2538 | * This is a helper to ease setting up page-remapped first percpu |
| 2539 | * chunk and can be called where pcpu_setup_first_chunk() is expected. |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 2540 | * |
| 2541 | * This is the basic allocator. Static percpu area is allocated |
| 2542 | * page-by-page into vmalloc area. |
| 2543 | * |
| 2544 | * RETURNS: |
Tejun Heo | fb435d5 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 2545 | * 0 on success, -errno on failure. |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 2546 | */ |
Tejun Heo | fb435d5 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 2547 | int __init pcpu_page_first_chunk(size_t reserved_size, |
| 2548 | pcpu_fc_alloc_fn_t alloc_fn, |
| 2549 | pcpu_fc_free_fn_t free_fn, |
| 2550 | pcpu_fc_populate_pte_fn_t populate_pte_fn) |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 2551 | { |
Tejun Heo | 8f05a6a | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 2552 | static struct vm_struct vm; |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 2553 | struct pcpu_alloc_info *ai; |
Tejun Heo | 00ae406 | 2009-08-14 15:00:49 +0900 | [diff] [blame] | 2554 | char psize_str[16]; |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 2555 | int unit_pages; |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 2556 | size_t pages_size; |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 2557 | struct page **pages; |
Tejun Heo | fb435d5 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 2558 | int unit, i, j, rc; |
zijun_hu | 8f60660 | 2016-12-12 16:45:02 -0800 | [diff] [blame] | 2559 | int upa; |
| 2560 | int nr_g0_units; |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 2561 | |
Tejun Heo | 00ae406 | 2009-08-14 15:00:49 +0900 | [diff] [blame] | 2562 | snprintf(psize_str, sizeof(psize_str), "%luK", PAGE_SIZE >> 10); |
| 2563 | |
Tejun Heo | 4ba6ce2 | 2010-06-27 18:49:59 +0200 | [diff] [blame] | 2564 | ai = pcpu_build_alloc_info(reserved_size, 0, PAGE_SIZE, NULL); |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 2565 | if (IS_ERR(ai)) |
| 2566 | return PTR_ERR(ai); |
| 2567 | BUG_ON(ai->nr_groups != 1); |
zijun_hu | 8f60660 | 2016-12-12 16:45:02 -0800 | [diff] [blame] | 2568 | upa = ai->alloc_size/ai->unit_size; |
| 2569 | nr_g0_units = roundup(num_possible_cpus(), upa); |
| 2570 | if (unlikely(WARN_ON(ai->groups[0].nr_units != nr_g0_units))) { |
| 2571 | pcpu_free_alloc_info(ai); |
| 2572 | return -EINVAL; |
| 2573 | } |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 2574 | |
| 2575 | unit_pages = ai->unit_size >> PAGE_SHIFT; |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 2576 | |
| 2577 | /* unaligned allocations can't be freed, round up to page size */ |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 2578 | pages_size = PFN_ALIGN(unit_pages * num_possible_cpus() * |
| 2579 | sizeof(pages[0])); |
Santosh Shilimkar | 999c17e | 2014-01-21 15:50:40 -0800 | [diff] [blame] | 2580 | pages = memblock_virt_alloc(pages_size, 0); |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 2581 | |
Tejun Heo | 8f05a6a | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 2582 | /* allocate pages */ |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 2583 | j = 0; |
zijun_hu | 8f60660 | 2016-12-12 16:45:02 -0800 | [diff] [blame] | 2584 | for (unit = 0; unit < num_possible_cpus(); unit++) { |
| 2585 | unsigned int cpu = ai->groups[0].cpu_map[unit]; |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 2586 | for (i = 0; i < unit_pages; i++) { |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 2587 | void *ptr; |
| 2588 | |
Tejun Heo | 3cbc856 | 2009-08-14 15:00:50 +0900 | [diff] [blame] | 2589 | ptr = alloc_fn(cpu, PAGE_SIZE, PAGE_SIZE); |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 2590 | if (!ptr) { |
Joe Perches | 870d4b1 | 2016-03-17 14:19:53 -0700 | [diff] [blame] | 2591 | pr_warn("failed to allocate %s page for cpu%u\n", |
zijun_hu | 8f60660 | 2016-12-12 16:45:02 -0800 | [diff] [blame] | 2592 | psize_str, cpu); |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 2593 | goto enomem; |
| 2594 | } |
Catalin Marinas | f528f0b | 2011-09-26 17:12:53 +0100 | [diff] [blame] | 2595 | /* kmemleak tracks the percpu allocations separately */ |
| 2596 | kmemleak_free(ptr); |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 2597 | pages[j++] = virt_to_page(ptr); |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 2598 | } |
zijun_hu | 8f60660 | 2016-12-12 16:45:02 -0800 | [diff] [blame] | 2599 | } |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 2600 | |
Tejun Heo | 8f05a6a | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 2601 | /* allocate vm area, map the pages and copy static data */ |
| 2602 | vm.flags = VM_ALLOC; |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 2603 | vm.size = num_possible_cpus() * ai->unit_size; |
Tejun Heo | 8f05a6a | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 2604 | vm_area_register_early(&vm, PAGE_SIZE); |
| 2605 | |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 2606 | for (unit = 0; unit < num_possible_cpus(); unit++) { |
Tejun Heo | 1d9d325 | 2009-08-14 15:00:50 +0900 | [diff] [blame] | 2607 | unsigned long unit_addr = |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 2608 | (unsigned long)vm.addr + unit * ai->unit_size; |
Tejun Heo | 8f05a6a | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 2609 | |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 2610 | for (i = 0; i < unit_pages; i++) |
Tejun Heo | 8f05a6a | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 2611 | populate_pte_fn(unit_addr + (i << PAGE_SHIFT)); |
| 2612 | |
| 2613 | /* pte already populated, the following shouldn't fail */ |
Tejun Heo | fb435d5 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 2614 | rc = __pcpu_map_pages(unit_addr, &pages[unit * unit_pages], |
| 2615 | unit_pages); |
| 2616 | if (rc < 0) |
| 2617 | panic("failed to map percpu area, err=%d\n", rc); |
Tejun Heo | 8f05a6a | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 2618 | |
| 2619 | /* |
| 2620 | * FIXME: Archs with virtual cache should flush local |
| 2621 | * cache for the linear mapping here - something |
| 2622 | * equivalent to flush_cache_vmap() on the local cpu. |
| 2623 | * flush_cache_vmap() can't be used as most supporting |
| 2624 | * data structures are not set up yet. |
| 2625 | */ |
| 2626 | |
| 2627 | /* copy static data */ |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 2628 | memcpy((void *)unit_addr, __per_cpu_load, ai->static_size); |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 2629 | } |
| 2630 | |
| 2631 | /* we're ready, commit */ |
Joe Perches | 870d4b1 | 2016-03-17 14:19:53 -0700 | [diff] [blame] | 2632 | pr_info("%d %s pages/cpu @%p s%zu r%zu d%zu\n", |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 2633 | unit_pages, psize_str, vm.addr, ai->static_size, |
| 2634 | ai->reserved_size, ai->dyn_size); |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 2635 | |
Tejun Heo | fb435d5 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 2636 | rc = pcpu_setup_first_chunk(ai, vm.addr); |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 2637 | goto out_free_ar; |
| 2638 | |
| 2639 | enomem: |
| 2640 | while (--j >= 0) |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 2641 | free_fn(page_address(pages[j]), PAGE_SIZE); |
Tejun Heo | fb435d5 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 2642 | rc = -ENOMEM; |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 2643 | out_free_ar: |
Santosh Shilimkar | 999c17e | 2014-01-21 15:50:40 -0800 | [diff] [blame] | 2644 | memblock_free_early(__pa(pages), pages_size); |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 2645 | pcpu_free_alloc_info(ai); |
Tejun Heo | fb435d5 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 2646 | return rc; |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 2647 | } |
Tejun Heo | 3c9a024 | 2010-09-09 18:00:15 +0200 | [diff] [blame] | 2648 | #endif /* BUILD_PAGE_FIRST_CHUNK */ |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 2649 | |
Tejun Heo | bbddff0 | 2010-09-03 18:22:48 +0200 | [diff] [blame] | 2650 | #ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA |
Tejun Heo | 8c4bfc6 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 2651 | /* |
Tejun Heo | bbddff0 | 2010-09-03 18:22:48 +0200 | [diff] [blame] | 2652 | * Generic SMP percpu area setup. |
Tejun Heo | e74e396 | 2009-03-30 19:07:44 +0900 | [diff] [blame] | 2653 | * |
| 2654 | * The embedding helper is used because its behavior closely resembles |
| 2655 | * the original non-dynamic generic percpu area setup. This is |
| 2656 | * important because many archs have addressing restrictions and might |
| 2657 | * fail if the percpu area is located far away from the previous |
| 2658 | * location. As an added bonus, in non-NUMA cases, embedding is |
| 2659 | * generally a good idea TLB-wise because percpu area can piggy back |
| 2660 | * on the physical linear memory mapping which uses large page |
| 2661 | * mappings on applicable archs. |
| 2662 | */ |
Tejun Heo | e74e396 | 2009-03-30 19:07:44 +0900 | [diff] [blame] | 2663 | unsigned long __per_cpu_offset[NR_CPUS] __read_mostly; |
| 2664 | EXPORT_SYMBOL(__per_cpu_offset); |
| 2665 | |
Tejun Heo | c8826dd | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 2666 | static void * __init pcpu_dfl_fc_alloc(unsigned int cpu, size_t size, |
| 2667 | size_t align) |
| 2668 | { |
Santosh Shilimkar | 999c17e | 2014-01-21 15:50:40 -0800 | [diff] [blame] | 2669 | return memblock_virt_alloc_from_nopanic( |
| 2670 | size, align, __pa(MAX_DMA_ADDRESS)); |
Tejun Heo | c8826dd | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 2671 | } |
| 2672 | |
| 2673 | static void __init pcpu_dfl_fc_free(void *ptr, size_t size) |
| 2674 | { |
Santosh Shilimkar | 999c17e | 2014-01-21 15:50:40 -0800 | [diff] [blame] | 2675 | memblock_free_early(__pa(ptr), size); |
Tejun Heo | c8826dd | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 2676 | } |
| 2677 | |
Tejun Heo | e74e396 | 2009-03-30 19:07:44 +0900 | [diff] [blame] | 2678 | void __init setup_per_cpu_areas(void) |
| 2679 | { |
Tejun Heo | e74e396 | 2009-03-30 19:07:44 +0900 | [diff] [blame] | 2680 | unsigned long delta; |
| 2681 | unsigned int cpu; |
Tejun Heo | fb435d5 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 2682 | int rc; |
Tejun Heo | e74e396 | 2009-03-30 19:07:44 +0900 | [diff] [blame] | 2683 | |
| 2684 | /* |
| 2685 | * Always reserve area for module percpu variables. That's |
| 2686 | * what the legacy allocator did. |
| 2687 | */ |
Tejun Heo | fb435d5 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 2688 | rc = pcpu_embed_first_chunk(PERCPU_MODULE_RESERVE, |
Tejun Heo | c8826dd | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 2689 | PERCPU_DYNAMIC_RESERVE, PAGE_SIZE, NULL, |
| 2690 | pcpu_dfl_fc_alloc, pcpu_dfl_fc_free); |
Tejun Heo | fb435d5 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 2691 | if (rc < 0) |
Tejun Heo | bbddff0 | 2010-09-03 18:22:48 +0200 | [diff] [blame] | 2692 | panic("Failed to initialize percpu areas."); |
Tejun Heo | e74e396 | 2009-03-30 19:07:44 +0900 | [diff] [blame] | 2693 | |
| 2694 | delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start; |
| 2695 | for_each_possible_cpu(cpu) |
Tejun Heo | fb435d5 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 2696 | __per_cpu_offset[cpu] = delta + pcpu_unit_offsets[cpu]; |
Tejun Heo | e74e396 | 2009-03-30 19:07:44 +0900 | [diff] [blame] | 2697 | } |
Tejun Heo | bbddff0 | 2010-09-03 18:22:48 +0200 | [diff] [blame] | 2698 | #endif /* CONFIG_HAVE_SETUP_PER_CPU_AREA */ |
| 2699 | |
| 2700 | #else /* CONFIG_SMP */ |
| 2701 | |
| 2702 | /* |
| 2703 | * UP percpu area setup. |
| 2704 | * |
| 2705 | * UP always uses km-based percpu allocator with identity mapping. |
| 2706 | * Static percpu variables are indistinguishable from the usual static |
| 2707 | * variables and don't require any special preparation. |
| 2708 | */ |
| 2709 | void __init setup_per_cpu_areas(void) |
| 2710 | { |
| 2711 | const size_t unit_size = |
| 2712 | roundup_pow_of_two(max_t(size_t, PCPU_MIN_UNIT_SIZE, |
| 2713 | PERCPU_DYNAMIC_RESERVE)); |
| 2714 | struct pcpu_alloc_info *ai; |
| 2715 | void *fc; |
| 2716 | |
| 2717 | ai = pcpu_alloc_alloc_info(1, 1); |
Santosh Shilimkar | 999c17e | 2014-01-21 15:50:40 -0800 | [diff] [blame] | 2718 | fc = memblock_virt_alloc_from_nopanic(unit_size, |
| 2719 | PAGE_SIZE, |
| 2720 | __pa(MAX_DMA_ADDRESS)); |
Tejun Heo | bbddff0 | 2010-09-03 18:22:48 +0200 | [diff] [blame] | 2721 | if (!ai || !fc) |
| 2722 | panic("Failed to allocate memory for percpu areas."); |
Catalin Marinas | 100d13c | 2012-05-09 16:55:19 +0100 | [diff] [blame] | 2723 | /* kmemleak tracks the percpu allocations separately */ |
| 2724 | kmemleak_free(fc); |
Tejun Heo | bbddff0 | 2010-09-03 18:22:48 +0200 | [diff] [blame] | 2725 | |
| 2726 | ai->dyn_size = unit_size; |
| 2727 | ai->unit_size = unit_size; |
| 2728 | ai->atom_size = unit_size; |
| 2729 | ai->alloc_size = unit_size; |
| 2730 | ai->groups[0].nr_units = 1; |
| 2731 | ai->groups[0].cpu_map[0] = 0; |
| 2732 | |
| 2733 | if (pcpu_setup_first_chunk(ai, fc) < 0) |
| 2734 | panic("Failed to initialize percpu areas."); |
| 2735 | } |
| 2736 | |
| 2737 | #endif /* CONFIG_SMP */ |
Tejun Heo | 099a19d | 2010-06-27 18:50:00 +0200 | [diff] [blame] | 2738 | |
| 2739 | /* |
Tejun Heo | 1a4d760 | 2014-09-02 14:46:05 -0400 | [diff] [blame] | 2740 | * Percpu allocator is initialized early during boot when neither slab or |
| 2741 | * workqueue is available. Plug async management until everything is up |
| 2742 | * and running. |
| 2743 | */ |
| 2744 | static int __init percpu_enable_async(void) |
| 2745 | { |
| 2746 | pcpu_async_enabled = true; |
| 2747 | return 0; |
| 2748 | } |
| 2749 | subsys_initcall(percpu_enable_async); |