Ard Biesheuvel | e5bc22a | 2015-11-30 13:28:18 +0100 | [diff] [blame] | 1 | /* |
| 2 | * Extensible Firmware Interface |
| 3 | * |
| 4 | * Based on Extensible Firmware Interface Specification version 2.4 |
| 5 | * |
| 6 | * Copyright (C) 2013, 2014 Linaro Ltd. |
| 7 | * |
| 8 | * This program is free software; you can redistribute it and/or modify |
| 9 | * it under the terms of the GNU General Public License version 2 as |
| 10 | * published by the Free Software Foundation. |
| 11 | * |
| 12 | */ |
| 13 | |
| 14 | #include <linux/efi.h> |
Ard Biesheuvel | f7d9248 | 2015-11-30 13:28:19 +0100 | [diff] [blame] | 15 | #include <linux/io.h> |
Ard Biesheuvel | e5bc22a | 2015-11-30 13:28:18 +0100 | [diff] [blame] | 16 | #include <linux/memblock.h> |
| 17 | #include <linux/mm_types.h> |
| 18 | #include <linux/preempt.h> |
| 19 | #include <linux/rbtree.h> |
| 20 | #include <linux/rwsem.h> |
| 21 | #include <linux/sched.h> |
| 22 | #include <linux/slab.h> |
| 23 | #include <linux/spinlock.h> |
| 24 | |
| 25 | #include <asm/cacheflush.h> |
| 26 | #include <asm/efi.h> |
Ard Biesheuvel | e5bc22a | 2015-11-30 13:28:18 +0100 | [diff] [blame] | 27 | #include <asm/mmu.h> |
Ard Biesheuvel | f7d9248 | 2015-11-30 13:28:19 +0100 | [diff] [blame] | 28 | #include <asm/pgalloc.h> |
Ard Biesheuvel | e5bc22a | 2015-11-30 13:28:18 +0100 | [diff] [blame] | 29 | #include <asm/pgtable.h> |
| 30 | |
Ard Biesheuvel | e5bc22a | 2015-11-30 13:28:18 +0100 | [diff] [blame] | 31 | extern u64 efi_system_table; |
| 32 | |
| 33 | static struct mm_struct efi_mm = { |
| 34 | .mm_rb = RB_ROOT, |
Ard Biesheuvel | e5bc22a | 2015-11-30 13:28:18 +0100 | [diff] [blame] | 35 | .mm_users = ATOMIC_INIT(2), |
| 36 | .mm_count = ATOMIC_INIT(1), |
| 37 | .mmap_sem = __RWSEM_INITIALIZER(efi_mm.mmap_sem), |
| 38 | .page_table_lock = __SPIN_LOCK_UNLOCKED(efi_mm.page_table_lock), |
| 39 | .mmlist = LIST_HEAD_INIT(efi_mm.mmlist), |
| 40 | }; |
| 41 | |
| 42 | static bool __init efi_virtmap_init(void) |
| 43 | { |
| 44 | efi_memory_desc_t *md; |
Ard Biesheuvel | 14c43be | 2016-04-25 21:06:34 +0100 | [diff] [blame] | 45 | bool systab_found; |
Ard Biesheuvel | e5bc22a | 2015-11-30 13:28:18 +0100 | [diff] [blame] | 46 | |
Ard Biesheuvel | f7d9248 | 2015-11-30 13:28:19 +0100 | [diff] [blame] | 47 | efi_mm.pgd = pgd_alloc(&efi_mm); |
Ard Biesheuvel | e5bc22a | 2015-11-30 13:28:18 +0100 | [diff] [blame] | 48 | init_new_context(NULL, &efi_mm); |
| 49 | |
Ard Biesheuvel | 14c43be | 2016-04-25 21:06:34 +0100 | [diff] [blame] | 50 | systab_found = false; |
Matt Fleming | 78ce248 | 2016-04-25 21:06:38 +0100 | [diff] [blame] | 51 | for_each_efi_memory_desc(md) { |
Ard Biesheuvel | f7d9248 | 2015-11-30 13:28:19 +0100 | [diff] [blame] | 52 | phys_addr_t phys = md->phys_addr; |
| 53 | int ret; |
Ard Biesheuvel | e5bc22a | 2015-11-30 13:28:18 +0100 | [diff] [blame] | 54 | |
| 55 | if (!(md->attribute & EFI_MEMORY_RUNTIME)) |
| 56 | continue; |
| 57 | if (md->virt_addr == 0) |
| 58 | return false; |
| 59 | |
Ard Biesheuvel | f7d9248 | 2015-11-30 13:28:19 +0100 | [diff] [blame] | 60 | ret = efi_create_mapping(&efi_mm, md); |
| 61 | if (!ret) { |
| 62 | pr_info(" EFI remap %pa => %p\n", |
| 63 | &phys, (void *)(unsigned long)md->virt_addr); |
| 64 | } else { |
| 65 | pr_warn(" EFI remap %pa: failed to create mapping (%d)\n", |
| 66 | &phys, ret); |
| 67 | return false; |
| 68 | } |
Ard Biesheuvel | 14c43be | 2016-04-25 21:06:34 +0100 | [diff] [blame] | 69 | /* |
| 70 | * If this entry covers the address of the UEFI system table, |
| 71 | * calculate and record its virtual address. |
| 72 | */ |
| 73 | if (efi_system_table >= phys && |
| 74 | efi_system_table < phys + (md->num_pages * EFI_PAGE_SIZE)) { |
| 75 | efi.systab = (void *)(unsigned long)(efi_system_table - |
| 76 | phys + md->virt_addr); |
| 77 | systab_found = true; |
| 78 | } |
Ard Biesheuvel | e5bc22a | 2015-11-30 13:28:18 +0100 | [diff] [blame] | 79 | } |
Ard Biesheuvel | 789957e | 2016-04-25 21:06:46 +0100 | [diff] [blame] | 80 | if (!systab_found) { |
Ard Biesheuvel | 14c43be | 2016-04-25 21:06:34 +0100 | [diff] [blame] | 81 | pr_err("No virtual mapping found for the UEFI System Table\n"); |
Ard Biesheuvel | 789957e | 2016-04-25 21:06:46 +0100 | [diff] [blame] | 82 | return false; |
| 83 | } |
| 84 | |
| 85 | if (efi_memattr_apply_permissions(&efi_mm, efi_set_mapping_permissions)) |
| 86 | return false; |
| 87 | |
| 88 | return true; |
Ard Biesheuvel | e5bc22a | 2015-11-30 13:28:18 +0100 | [diff] [blame] | 89 | } |
| 90 | |
| 91 | /* |
| 92 | * Enable the UEFI Runtime Services if all prerequisites are in place, i.e., |
| 93 | * non-early mapping of the UEFI system table and virtual mappings for all |
| 94 | * EFI_MEMORY_RUNTIME regions. |
| 95 | */ |
Ard Biesheuvel | f7d9248 | 2015-11-30 13:28:19 +0100 | [diff] [blame] | 96 | static int __init arm_enable_runtime_services(void) |
Ard Biesheuvel | e5bc22a | 2015-11-30 13:28:18 +0100 | [diff] [blame] | 97 | { |
| 98 | u64 mapsize; |
| 99 | |
| 100 | if (!efi_enabled(EFI_BOOT)) { |
| 101 | pr_info("EFI services will not be available.\n"); |
| 102 | return 0; |
| 103 | } |
| 104 | |
| 105 | if (efi_runtime_disabled()) { |
| 106 | pr_info("EFI runtime services will be disabled.\n"); |
| 107 | return 0; |
| 108 | } |
| 109 | |
| 110 | pr_info("Remapping and enabling EFI services.\n"); |
| 111 | |
Matt Fleming | 884f4f6 | 2016-04-25 21:06:39 +0100 | [diff] [blame] | 112 | mapsize = efi.memmap.map_end - efi.memmap.map; |
| 113 | |
Ard Biesheuvel | 24d45d1 | 2016-04-25 21:06:41 +0100 | [diff] [blame] | 114 | efi.memmap.map = memremap(efi.memmap.phys_map, mapsize, MEMREMAP_WB); |
Matt Fleming | 884f4f6 | 2016-04-25 21:06:39 +0100 | [diff] [blame] | 115 | if (!efi.memmap.map) { |
Ard Biesheuvel | e5bc22a | 2015-11-30 13:28:18 +0100 | [diff] [blame] | 116 | pr_err("Failed to remap EFI memory map\n"); |
| 117 | return -ENOMEM; |
| 118 | } |
Matt Fleming | 884f4f6 | 2016-04-25 21:06:39 +0100 | [diff] [blame] | 119 | efi.memmap.map_end = efi.memmap.map + mapsize; |
Ard Biesheuvel | e5bc22a | 2015-11-30 13:28:18 +0100 | [diff] [blame] | 120 | |
Ard Biesheuvel | e5bc22a | 2015-11-30 13:28:18 +0100 | [diff] [blame] | 121 | if (!efi_virtmap_init()) { |
Ard Biesheuvel | 14c43be | 2016-04-25 21:06:34 +0100 | [diff] [blame] | 122 | pr_err("UEFI virtual mapping missing or invalid -- runtime services will not be available\n"); |
Ard Biesheuvel | e5bc22a | 2015-11-30 13:28:18 +0100 | [diff] [blame] | 123 | return -ENOMEM; |
| 124 | } |
| 125 | |
| 126 | /* Set up runtime services function pointers */ |
| 127 | efi_native_runtime_setup(); |
| 128 | set_bit(EFI_RUNTIME_SERVICES, &efi.flags); |
| 129 | |
Ard Biesheuvel | e5bc22a | 2015-11-30 13:28:18 +0100 | [diff] [blame] | 130 | return 0; |
| 131 | } |
Ard Biesheuvel | f7d9248 | 2015-11-30 13:28:19 +0100 | [diff] [blame] | 132 | early_initcall(arm_enable_runtime_services); |
Ard Biesheuvel | e5bc22a | 2015-11-30 13:28:18 +0100 | [diff] [blame] | 133 | |
| 134 | void efi_virtmap_load(void) |
| 135 | { |
| 136 | preempt_disable(); |
| 137 | efi_set_pgd(&efi_mm); |
| 138 | } |
| 139 | |
| 140 | void efi_virtmap_unload(void) |
| 141 | { |
| 142 | efi_set_pgd(current->active_mm); |
| 143 | preempt_enable(); |
| 144 | } |