| #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| |
| #include <linux/kernel.h> |
| #include <linux/export.h> |
| #include <linux/init.h> |
| #include <linux/bootmem.h> |
| #include <linux/percpu.h> |
| #include <linux/kexec.h> |
| #include <linux/crash_dump.h> |
| #include <linux/smp.h> |
| #include <linux/topology.h> |
| #include <linux/pfn.h> |
| #include <asm/sections.h> |
| #include <asm/processor.h> |
| #include <asm/desc.h> |
| #include <asm/setup.h> |
| #include <asm/mpspec.h> |
| #include <asm/apicdef.h> |
| #include <asm/highmem.h> |
| #include <asm/proto.h> |
| #include <asm/cpumask.h> |
| #include <asm/cpu.h> |
| #include <asm/stackprotector.h> |
| |
| DEFINE_PER_CPU_READ_MOSTLY(int, cpu_number); |
| EXPORT_PER_CPU_SYMBOL(cpu_number); |
| |
| #ifdef CONFIG_X86_64 |
| #define BOOT_PERCPU_OFFSET ((unsigned long)__per_cpu_load) |
| #else |
| #define BOOT_PERCPU_OFFSET 0 |
| #endif |
| |
| DEFINE_PER_CPU_READ_MOSTLY(unsigned long, this_cpu_off) = BOOT_PERCPU_OFFSET; |
| EXPORT_PER_CPU_SYMBOL(this_cpu_off); |
| |
| unsigned long __per_cpu_offset[NR_CPUS] __ro_after_init = { |
| [0 ... NR_CPUS-1] = BOOT_PERCPU_OFFSET, |
| }; |
| EXPORT_SYMBOL(__per_cpu_offset); |
| |
| /* |
| * On x86_64 symbols referenced from code should be reachable using |
| * 32bit relocations. Reserve space for static percpu variables in |
| * modules so that they are always served from the first chunk which |
| * is located at the percpu segment base. On x86_32, anything can |
| * address anywhere. No need to reserve space in the first chunk. |
| */ |
| #ifdef CONFIG_X86_64 |
| #define PERCPU_FIRST_CHUNK_RESERVE PERCPU_MODULE_RESERVE |
| #else |
| #define PERCPU_FIRST_CHUNK_RESERVE 0 |
| #endif |
| |
| #ifdef CONFIG_X86_32 |
| /** |
| * pcpu_need_numa - determine percpu allocation needs to consider NUMA |
| * |
| * If NUMA is not configured or there is only one NUMA node available, |
| * there is no reason to consider NUMA. This function determines |
| * whether percpu allocation should consider NUMA or not. |
| * |
| * RETURNS: |
| * true if NUMA should be considered; otherwise, false. |
| */ |
| static bool __init pcpu_need_numa(void) |
| { |
| #ifdef CONFIG_NEED_MULTIPLE_NODES |
| pg_data_t *last = NULL; |
| unsigned int cpu; |
| |
| for_each_possible_cpu(cpu) { |
| int node = early_cpu_to_node(cpu); |
| |
| if (node_online(node) && NODE_DATA(node) && |
| last && last != NODE_DATA(node)) |
| return true; |
| |
| last = NODE_DATA(node); |
| } |
| #endif |
| return false; |
| } |
| #endif |
| |
| /** |
| * pcpu_alloc_bootmem - NUMA friendly alloc_bootmem wrapper for percpu |
| * @cpu: cpu to allocate for |
| * @size: size allocation in bytes |
| * @align: alignment |
| * |
| * Allocate @size bytes aligned at @align for cpu @cpu. This wrapper |
| * does the right thing for NUMA regardless of the current |
| * configuration. |
| * |
| * RETURNS: |
| * Pointer to the allocated area on success, NULL on failure. |
| */ |
| static void * __init pcpu_alloc_bootmem(unsigned int cpu, unsigned long size, |
| unsigned long align) |
| { |
| const unsigned long goal = __pa(MAX_DMA_ADDRESS); |
| #ifdef CONFIG_NEED_MULTIPLE_NODES |
| int node = early_cpu_to_node(cpu); |
| void *ptr; |
| |
| if (!node_online(node) || !NODE_DATA(node)) { |
| ptr = __alloc_bootmem_nopanic(size, align, goal); |
| pr_info("cpu %d has no node %d or node-local memory\n", |
| cpu, node); |
| pr_debug("per cpu data for cpu%d %lu bytes at %016lx\n", |
| cpu, size, __pa(ptr)); |
| } else { |
| ptr = __alloc_bootmem_node_nopanic(NODE_DATA(node), |
| size, align, goal); |
| pr_debug("per cpu data for cpu%d %lu bytes on node%d at %016lx\n", |
| cpu, size, node, __pa(ptr)); |
| } |
| return ptr; |
| #else |
| return __alloc_bootmem_nopanic(size, align, goal); |
| #endif |
| } |
| |
| /* |
| * Helpers for first chunk memory allocation |
| */ |
| static void * __init pcpu_fc_alloc(unsigned int cpu, size_t size, size_t align) |
| { |
| return pcpu_alloc_bootmem(cpu, size, align); |
| } |
| |
| static void __init pcpu_fc_free(void *ptr, size_t size) |
| { |
| free_bootmem(__pa(ptr), size); |
| } |
| |
| static int __init pcpu_cpu_distance(unsigned int from, unsigned int to) |
| { |
| #ifdef CONFIG_NEED_MULTIPLE_NODES |
| if (early_cpu_to_node(from) == early_cpu_to_node(to)) |
| return LOCAL_DISTANCE; |
| else |
| return REMOTE_DISTANCE; |
| #else |
| return LOCAL_DISTANCE; |
| #endif |
| } |
| |
| static void __init pcpup_populate_pte(unsigned long addr) |
| { |
| populate_extra_pte(addr); |
| } |
| |
| static inline void setup_percpu_segment(int cpu) |
| { |
| #ifdef CONFIG_X86_32 |
| struct desc_struct gdt; |
| |
| pack_descriptor(&gdt, per_cpu_offset(cpu), 0xFFFFF, |
| 0x2 | DESCTYPE_S, 0x8); |
| gdt.s = 1; |
| write_gdt_entry(get_cpu_gdt_rw(cpu), |
| GDT_ENTRY_PERCPU, &gdt, DESCTYPE_S); |
| #endif |
| } |
| |
| void __init setup_per_cpu_areas(void) |
| { |
| unsigned int cpu; |
| unsigned long delta; |
| int rc; |
| |
| pr_info("NR_CPUS:%d nr_cpumask_bits:%d nr_cpu_ids:%d nr_node_ids:%d\n", |
| NR_CPUS, nr_cpumask_bits, nr_cpu_ids, nr_node_ids); |
| |
| /* |
| * Allocate percpu area. Embedding allocator is our favorite; |
| * however, on NUMA configurations, it can result in very |
| * sparse unit mapping and vmalloc area isn't spacious enough |
| * on 32bit. Use page in that case. |
| */ |
| #ifdef CONFIG_X86_32 |
| if (pcpu_chosen_fc == PCPU_FC_AUTO && pcpu_need_numa()) |
| pcpu_chosen_fc = PCPU_FC_PAGE; |
| #endif |
| rc = -EINVAL; |
| if (pcpu_chosen_fc != PCPU_FC_PAGE) { |
| const size_t dyn_size = PERCPU_MODULE_RESERVE + |
| PERCPU_DYNAMIC_RESERVE - PERCPU_FIRST_CHUNK_RESERVE; |
| size_t atom_size; |
| |
| /* |
| * On 64bit, use PMD_SIZE for atom_size so that embedded |
| * percpu areas are aligned to PMD. This, in the future, |
| * can also allow using PMD mappings in vmalloc area. Use |
| * PAGE_SIZE on 32bit as vmalloc space is highly contended |
| * and large vmalloc area allocs can easily fail. |
| */ |
| #ifdef CONFIG_X86_64 |
| atom_size = PMD_SIZE; |
| #else |
| atom_size = PAGE_SIZE; |
| #endif |
| rc = pcpu_embed_first_chunk(PERCPU_FIRST_CHUNK_RESERVE, |
| dyn_size, atom_size, |
| pcpu_cpu_distance, |
| pcpu_fc_alloc, pcpu_fc_free); |
| if (rc < 0) |
| pr_warning("%s allocator failed (%d), falling back to page size\n", |
| pcpu_fc_names[pcpu_chosen_fc], rc); |
| } |
| if (rc < 0) |
| rc = pcpu_page_first_chunk(PERCPU_FIRST_CHUNK_RESERVE, |
| pcpu_fc_alloc, pcpu_fc_free, |
| pcpup_populate_pte); |
| if (rc < 0) |
| panic("cannot initialize percpu area (err=%d)", rc); |
| |
| /* alrighty, percpu areas up and running */ |
| delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start; |
| for_each_possible_cpu(cpu) { |
| per_cpu_offset(cpu) = delta + pcpu_unit_offsets[cpu]; |
| per_cpu(this_cpu_off, cpu) = per_cpu_offset(cpu); |
| per_cpu(cpu_number, cpu) = cpu; |
| setup_percpu_segment(cpu); |
| setup_stack_canary_segment(cpu); |
| /* |
| * Copy data used in early init routines from the |
| * initial arrays to the per cpu data areas. These |
| * arrays then become expendable and the *_early_ptr's |
| * are zeroed indicating that the static arrays are |
| * gone. |
| */ |
| #ifdef CONFIG_X86_LOCAL_APIC |
| per_cpu(x86_cpu_to_apicid, cpu) = |
| early_per_cpu_map(x86_cpu_to_apicid, cpu); |
| per_cpu(x86_bios_cpu_apicid, cpu) = |
| early_per_cpu_map(x86_bios_cpu_apicid, cpu); |
| per_cpu(x86_cpu_to_acpiid, cpu) = |
| early_per_cpu_map(x86_cpu_to_acpiid, cpu); |
| #endif |
| #ifdef CONFIG_X86_32 |
| per_cpu(x86_cpu_to_logical_apicid, cpu) = |
| early_per_cpu_map(x86_cpu_to_logical_apicid, cpu); |
| #endif |
| #ifdef CONFIG_X86_64 |
| per_cpu(irq_stack_ptr, cpu) = |
| per_cpu(irq_stack_union.irq_stack, cpu) + |
| IRQ_STACK_SIZE; |
| #endif |
| #ifdef CONFIG_NUMA |
| per_cpu(x86_cpu_to_node_map, cpu) = |
| early_per_cpu_map(x86_cpu_to_node_map, cpu); |
| /* |
| * Ensure that the boot cpu numa_node is correct when the boot |
| * cpu is on a node that doesn't have memory installed. |
| * Also cpu_up() will call cpu_to_node() for APs when |
| * MEMORY_HOTPLUG is defined, before per_cpu(numa_node) is set |
| * up later with c_init aka intel_init/amd_init. |
| * So set them all (boot cpu and all APs). |
| */ |
| set_cpu_numa_node(cpu, early_cpu_to_node(cpu)); |
| #endif |
| /* |
| * Up to this point, the boot CPU has been using .init.data |
| * area. Reload any changed state for the boot CPU. |
| */ |
| if (!cpu) |
| switch_to_new_gdt(cpu); |
| } |
| |
| /* indicate the early static arrays will soon be gone */ |
| #ifdef CONFIG_X86_LOCAL_APIC |
| early_per_cpu_ptr(x86_cpu_to_apicid) = NULL; |
| early_per_cpu_ptr(x86_bios_cpu_apicid) = NULL; |
| early_per_cpu_ptr(x86_cpu_to_acpiid) = NULL; |
| #endif |
| #ifdef CONFIG_X86_32 |
| early_per_cpu_ptr(x86_cpu_to_logical_apicid) = NULL; |
| #endif |
| #ifdef CONFIG_NUMA |
| early_per_cpu_ptr(x86_cpu_to_node_map) = NULL; |
| #endif |
| |
| /* Setup node to cpumask map */ |
| setup_node_to_cpumask_map(); |
| |
| /* Setup cpu initialized, callin, callout masks */ |
| setup_cpu_local_masks(); |
| |
| #ifdef CONFIG_X86_32 |
| /* |
| * Sync back kernel address range. We want to make sure that |
| * all kernel mappings, including percpu mappings, are available |
| * in the smpboot asm. We can't reliably pick up percpu |
| * mappings using vmalloc_fault(), because exception dispatch |
| * needs percpu data. |
| */ |
| clone_pgd_range(initial_page_table + KERNEL_PGD_BOUNDARY, |
| swapper_pg_dir + KERNEL_PGD_BOUNDARY, |
| KERNEL_PGD_PTRS); |
| |
| /* |
| * sync back low identity map too. It is used for example |
| * in the 32-bit EFI stub. |
| */ |
| clone_pgd_range(initial_page_table, |
| swapper_pg_dir + KERNEL_PGD_BOUNDARY, |
| min(KERNEL_PGD_PTRS, KERNEL_PGD_BOUNDARY)); |
| #endif |
| } |