arch/x86/include/asm/efi.h

   1 #ifndef _ASM_X86_EFI_H
   2 #define _ASM_X86_EFI_H
   3
   4 #include <asm/fpu/api.h>
   5 #include <asm/pgtable.h>
   6 #include <asm/processor-flags.h>
   7 #include <asm/tlb.h>
   8 #include <asm/nospec-branch.h>
   9
  10 /*
  11  * We map the EFI regions needed for runtime services non-contiguously,
  12  * with preserved alignment on virtual addresses starting from -4G down
  13  * for a total max space of 64G. This way, we provide for stable runtime
  14  * services addresses across kernels so that a kexec'd kernel can still
  15  * use them.
  16  *
  17  * This is the main reason why we're doing stable VA mappings for RT
  18  * services.
  19  *
  20  * This flag is used in conjuction with a chicken bit called
  21  * "efi=old_map" which can be used as a fallback to the old runtime
  22  * services mapping method in case there's some b0rkage with a
  23  * particular EFI implementation (haha, it is hard to hold up the
  24  * sarcasm here...).
  25  */
  26 #define EFI_OLD_MEMMAP          EFI_ARCH_1
  27
  28 #define EFI32_LOADER_SIGNATURE  "EL32"
  29 #define EFI64_LOADER_SIGNATURE  "EL64"
  30
  31 #define MAX_CMDLINE_ADDRESS     UINT_MAX
  32
  33 #define ARCH_EFI_IRQ_FLAGS_MASK X86_EFLAGS_IF
  34
  35 #ifdef CONFIG_X86_32
  36
  37 extern unsigned long asmlinkage efi_call_phys(void *, ...);
  38
  39 #define arch_efi_call_virt_setup()                                      \
  40 ({                                                                      \
  41         kernel_fpu_begin();                                             \
  42         firmware_restrict_branch_speculation_start();                   \
  43 })
  44
  45 #define arch_efi_call_virt_teardown()                                   \
  46 ({                                                                      \
  47         firmware_restrict_branch_speculation_end();                     \
  48         kernel_fpu_end();                                               \
  49 })
  50
  51
  52 /*
  53  * Wrap all the virtual calls in a way that forces the parameters on the stack.
  54  */
  55 #define arch_efi_call_virt(p, f, args...)                               \
  56 ({                                                                      \
  57         ((efi_##f##_t __attribute__((regparm(0)))*) p->f)(args);        \
  58 })
  59
  60 #define efi_ioremap(addr, size, type, attr)     ioremap_cache(addr, size)
  61
  62 #else /* !CONFIG_X86_32 */
  63
  64 #define EFI_LOADER_SIGNATURE    "EL64"
  65
  66 extern u64 asmlinkage efi_call(void *fp, ...);
  67
  68 #define efi_call_phys(f, args...)               efi_call((f), args)
  69
  70 /*
  71  * Scratch space used for switching the pagetable in the EFI stub
  72  */
  73 struct efi_scratch {
  74         u64     r15;
  75         u64     prev_cr3;
  76         pgd_t   *efi_pgt;
  77         bool    use_pgd;
  78         u64     phys_stack;
  79 } __packed;
  80
  81 #define arch_efi_call_virt_setup()                                      \
  82 ({                                                                      \
  83         efi_sync_low_kernel_mappings();                                 \
  84         preempt_disable();                                              \
  85         __kernel_fpu_begin();                                           \
  86         firmware_restrict_branch_speculation_start();                   \
  87                                                                         \
  88         if (efi_scratch.use_pgd) {                                      \
  89                 efi_scratch.prev_cr3 = read_cr3();                      \
  90                 write_cr3((unsigned long)efi_scratch.efi_pgt);          \
  91                 __flush_tlb_all();                                      \
  92         }                                                               \
  93 })
  94
  95 #define arch_efi_call_virt(p, f, args...)                               \
  96         efi_call((void *)p->f, args)                                    \
  97
  98 #define arch_efi_call_virt_teardown()                                   \
  99 ({                                                                      \
 100         if (efi_scratch.use_pgd) {                                      \
 101                 write_cr3(efi_scratch.prev_cr3);                        \
 102                 __flush_tlb_all();                                      \
 103         }                                                               \
 104                                                                         \
 105         firmware_restrict_branch_speculation_end();                     \
 106         __kernel_fpu_end();                                             \
 107         preempt_enable();                                               \
 108 })
 109
 110 extern void __iomem *__init efi_ioremap(unsigned long addr, unsigned long size,
 111                                         u32 type, u64 attribute);
 112
 113 #ifdef CONFIG_KASAN
 114 /*
 115  * CONFIG_KASAN may redefine memset to __memset.  __memset function is present
 116  * only in kernel binary.  Since the EFI stub linked into a separate binary it
 117  * doesn't have __memset().  So we should use standard memset from
 118  * arch/x86/boot/compressed/string.c.  The same applies to memcpy and memmove.
 119  */
 120 #undef memcpy
 121 #undef memset
 122 #undef memmove
 123 #endif
 124
 125 #endif /* CONFIG_X86_32 */
 126
 127 extern struct efi_scratch efi_scratch;
 128 extern void __init efi_set_executable(efi_memory_desc_t *md, bool executable);
 129 extern int __init efi_memblock_x86_reserve_range(void);
 130 extern pgd_t * __init efi_call_phys_prolog(void);
 131 extern void __init efi_call_phys_epilog(pgd_t *save_pgd);
 132 extern void __init efi_print_memmap(void);
 133 extern void __init efi_memory_uc(u64 addr, unsigned long size);
 134 extern void __init efi_map_region(efi_memory_desc_t *md);
 135 extern void __init efi_map_region_fixed(efi_memory_desc_t *md);
 136 extern void efi_sync_low_kernel_mappings(void);
 137 extern int __init efi_alloc_page_tables(void);
 138 extern int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages);
 139 extern void __init old_map_region(efi_memory_desc_t *md);
 140 extern void __init runtime_code_page_mkexec(void);
 141 extern void __init efi_runtime_update_mappings(void);
 142 extern void __init efi_dump_pagetable(void);
 143 extern void __init efi_apply_memmap_quirks(void);
 144 extern int __init efi_reuse_config(u64 tables, int nr_tables);
 145 extern void efi_delete_dummy_variable(void);
 146
 147 struct efi_setup_data {
 148         u64 fw_vendor;
 149         u64 runtime;
 150         u64 tables;
 151         u64 smbios;
 152         u64 reserved[8];
 153 };
 154
 155 extern u64 efi_setup;
 156
 157 #ifdef CONFIG_EFI
 158
 159 static inline bool efi_is_native(void)
 160 {
 161         return IS_ENABLED(CONFIG_X86_64) == efi_enabled(EFI_64BIT);
 162 }
 163
 164 static inline bool efi_runtime_supported(void)
 165 {
 166         if (efi_is_native())
 167                 return true;
 168
 169         if (IS_ENABLED(CONFIG_EFI_MIXED) && !efi_enabled(EFI_OLD_MEMMAP))
 170                 return true;
 171
 172         return false;
 173 }
 174
 175 extern struct console early_efi_console;
 176 extern void parse_efi_setup(u64 phys_addr, u32 data_len);
 177
 178 extern void efifb_setup_from_dmi(struct screen_info *si, const char *opt);
 179
 180 #ifdef CONFIG_EFI_MIXED
 181 extern void efi_thunk_runtime_setup(void);
 182 extern efi_status_t efi_thunk_set_virtual_address_map(
 183         void *phys_set_virtual_address_map,
 184         unsigned long memory_map_size,
 185         unsigned long descriptor_size,
 186         u32 descriptor_version,
 187         efi_memory_desc_t *virtual_map);
 188 #else
 189 static inline void efi_thunk_runtime_setup(void) {}
 190 static inline efi_status_t efi_thunk_set_virtual_address_map(
 191         void *phys_set_virtual_address_map,
 192         unsigned long memory_map_size,
 193         unsigned long descriptor_size,
 194         u32 descriptor_version,
 195         efi_memory_desc_t *virtual_map)
 196 {
 197         return EFI_SUCCESS;
 198 }
 199 #endif /* CONFIG_EFI_MIXED */
 200
 201
 202 /* arch specific definitions used by the stub code */
 203
 204 struct efi_config {
 205         u64 image_handle;
 206         u64 table;
 207         u64 boot_services;
 208         u64 text_output;
 209         efi_status_t (*call)(unsigned long, ...);
 210         bool is64;
 211 } __packed;
 212
 213 __pure const struct efi_config *__efi_early(void);
 214
 215 static inline bool efi_is_64bit(void)
 216 {
 217         if (!IS_ENABLED(CONFIG_X86_64))
 218                 return false;
 219
 220         if (!IS_ENABLED(CONFIG_EFI_MIXED))
 221                 return true;
 222
 223         return __efi_early()->is64;
 224 }
 225
 226 #define efi_call_early(f, ...)                                          \
 227         __efi_early()->call(efi_is_64bit() ?                            \
 228                 ((efi_boot_services_64_t *)(unsigned long)              \
 229                         __efi_early()->boot_services)->f :              \
 230                 ((efi_boot_services_32_t *)(unsigned long)              \
 231                         __efi_early()->boot_services)->f, __VA_ARGS__)
 232
 233 #define __efi_call_early(f, ...)                                        \
 234         __efi_early()->call((unsigned long)f, __VA_ARGS__);
 235
 236 extern bool efi_reboot_required(void);
 237
 238 #else
 239 static inline void parse_efi_setup(u64 phys_addr, u32 data_len) {}
 240 static inline bool efi_reboot_required(void)
 241 {
 242         return false;
 243 }
 244 #endif /* CONFIG_EFI */
 245
 246 #endif /* _ASM_X86_EFI_H */