arch/x86/include/asm/efi.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _ASM_X86_EFI_H
   3 #define _ASM_X86_EFI_H
   4
   5 #include <asm/fpu/api.h>
   6 #include <asm/pgtable.h>
   7 #include <asm/processor-flags.h>
   8 #include <asm/tlb.h>
   9 #include <asm/nospec-branch.h>
  10
  11 /*
  12  * We map the EFI regions needed for runtime services non-contiguously,
  13  * with preserved alignment on virtual addresses starting from -4G down
  14  * for a total max space of 64G. This way, we provide for stable runtime
  15  * services addresses across kernels so that a kexec'd kernel can still
  16  * use them.
  17  *
  18  * This is the main reason why we're doing stable VA mappings for RT
  19  * services.
  20  *
  21  * This flag is used in conjuction with a chicken bit called
  22  * "efi=old_map" which can be used as a fallback to the old runtime
  23  * services mapping method in case there's some b0rkage with a
  24  * particular EFI implementation (haha, it is hard to hold up the
  25  * sarcasm here...).
  26  */
  27 #define EFI_OLD_MEMMAP          EFI_ARCH_1
  28
  29 #define EFI32_LOADER_SIGNATURE  "EL32"
  30 #define EFI64_LOADER_SIGNATURE  "EL64"
  31
  32 #define MAX_CMDLINE_ADDRESS     UINT_MAX
  33
  34 #define ARCH_EFI_IRQ_FLAGS_MASK X86_EFLAGS_IF
  35
  36 #ifdef CONFIG_X86_32
  37
  38 extern asmlinkage unsigned long efi_call_phys(void *, ...);
  39
  40 #define arch_efi_call_virt_setup()                                      \
  41 ({                                                                      \
  42         kernel_fpu_begin();                                             \
  43         firmware_restrict_branch_speculation_start();                   \
  44 })
  45
  46 #define arch_efi_call_virt_teardown()                                   \
  47 ({                                                                      \
  48         firmware_restrict_branch_speculation_end();                     \
  49         kernel_fpu_end();                                               \
  50 })
  51
  52
  53 /*
  54  * Wrap all the virtual calls in a way that forces the parameters on the stack.
  55  */
  56 #define arch_efi_call_virt(p, f, args...)                               \
  57 ({                                                                      \
  58         ((efi_##f##_t __attribute__((regparm(0)))*) p->f)(args);        \
  59 })
  60
  61 #define efi_ioremap(addr, size, type, attr)     ioremap_cache(addr, size)
  62
  63 #else /* !CONFIG_X86_32 */
  64
  65 #define EFI_LOADER_SIGNATURE    "EL64"
  66
  67 extern asmlinkage u64 efi_call(void *fp, ...);
  68
  69 #define efi_call_phys(f, args...)               efi_call((f), args)
  70
  71 /*
  72  * Scratch space used for switching the pagetable in the EFI stub
  73  */
  74 struct efi_scratch {
  75         u64     r15;
  76         u64     prev_cr3;
  77         pgd_t   *efi_pgt;
  78         bool    use_pgd;
  79         u64     phys_stack;
  80 } __packed;
  81
  82 #define arch_efi_call_virt_setup()                                      \
  83 ({                                                                      \
  84         efi_sync_low_kernel_mappings();                                 \
  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 })
 108
 109 extern void __iomem *__init efi_ioremap(unsigned long addr, unsigned long size,
 110                                         u32 type, u64 attribute);
 111
 112 #ifdef CONFIG_KASAN
 113 /*
 114  * CONFIG_KASAN may redefine memset to __memset.  __memset function is present
 115  * only in kernel binary.  Since the EFI stub linked into a separate binary it
 116  * doesn't have __memset().  So we should use standard memset from
 117  * arch/x86/boot/compressed/string.c.  The same applies to memcpy and memmove.
 118  */
 119 #undef memcpy
 120 #undef memset
 121 #undef memmove
 122 #endif
 123
 124 #endif /* CONFIG_X86_32 */
 125
 126 extern struct efi_scratch efi_scratch;
 127 extern void __init efi_set_executable(efi_memory_desc_t *md, bool executable);
 128 extern int __init efi_memblock_x86_reserve_range(void);
 129 extern pgd_t * __init efi_call_phys_prolog(void);
 130 extern void __init efi_call_phys_epilog(pgd_t *save_pgd);
 131 extern void __init efi_print_memmap(void);
 132 extern void __init efi_memory_uc(u64 addr, unsigned long size);
 133 extern void __init efi_map_region(efi_memory_desc_t *md);
 134 extern void __init efi_map_region_fixed(efi_memory_desc_t *md);
 135 extern void efi_sync_low_kernel_mappings(void);
 136 extern int __init efi_alloc_page_tables(void);
 137 extern int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages);
 138 extern void __init old_map_region(efi_memory_desc_t *md);
 139 extern void __init runtime_code_page_mkexec(void);
 140 extern void __init efi_runtime_update_mappings(void);
 141 extern void __init efi_dump_pagetable(void);
 142 extern void __init efi_apply_memmap_quirks(void);
 143 extern int __init efi_reuse_config(u64 tables, int nr_tables);
 144 extern void efi_delete_dummy_variable(void);
 145
 146 struct efi_setup_data {
 147         u64 fw_vendor;
 148         u64 runtime;
 149         u64 tables;
 150         u64 smbios;
 151         u64 reserved[8];
 152 };
 153
 154 extern u64 efi_setup;
 155
 156 #ifdef CONFIG_EFI
 157
 158 static inline bool efi_is_native(void)
 159 {
 160         return IS_ENABLED(CONFIG_X86_64) == efi_enabled(EFI_64BIT);
 161 }
 162
 163 static inline bool efi_runtime_supported(void)
 164 {
 165         if (efi_is_native())
 166                 return true;
 167
 168         if (IS_ENABLED(CONFIG_EFI_MIXED) && !efi_enabled(EFI_OLD_MEMMAP))
 169                 return true;
 170
 171         return false;
 172 }
 173
 174 extern struct console early_efi_console;
 175 extern void parse_efi_setup(u64 phys_addr, u32 data_len);
 176
 177 extern void efifb_setup_from_dmi(struct screen_info *si, const char *opt);
 178
 179 #ifdef CONFIG_EFI_MIXED
 180 extern void efi_thunk_runtime_setup(void);
 181 extern efi_status_t efi_thunk_set_virtual_address_map(
 182         void *phys_set_virtual_address_map,
 183         unsigned long memory_map_size,
 184         unsigned long descriptor_size,
 185         u32 descriptor_version,
 186         efi_memory_desc_t *virtual_map);
 187 #else
 188 static inline void efi_thunk_runtime_setup(void) {}
 189 static inline efi_status_t efi_thunk_set_virtual_address_map(
 190         void *phys_set_virtual_address_map,
 191         unsigned long memory_map_size,
 192         unsigned long descriptor_size,
 193         u32 descriptor_version,
 194         efi_memory_desc_t *virtual_map)
 195 {
 196         return EFI_SUCCESS;
 197 }
 198 #endif /* CONFIG_EFI_MIXED */
 199
 200
 201 /* arch specific definitions used by the stub code */
 202
 203 struct efi_config {
 204         u64 image_handle;
 205         u64 table;
 206         u64 runtime_services;
 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_table_attr(table, attr, instance)                           \
 227         (efi_is_64bit() ?                                               \
 228                 ((table##_64_t *)(unsigned long)instance)->attr :       \
 229                 ((table##_32_t *)(unsigned long)instance)->attr)
 230
 231 #define efi_call_proto(protocol, f, instance, ...)                      \
 232         __efi_early()->call(efi_table_attr(protocol, f, instance),      \
 233                 instance, ##__VA_ARGS__)
 234
 235 #define efi_call_early(f, ...)                                          \
 236         __efi_early()->call(efi_table_attr(efi_boot_services, f,        \
 237                 __efi_early()->boot_services), __VA_ARGS__)
 238
 239 #define __efi_call_early(f, ...)                                        \
 240         __efi_early()->call((unsigned long)f, __VA_ARGS__);
 241
 242 #define efi_call_runtime(f, ...)                                        \
 243         __efi_early()->call(efi_table_attr(efi_runtime_services, f,     \
 244                 __efi_early()->runtime_services), __VA_ARGS__)
 245
 246 extern bool efi_reboot_required(void);
 247
 248 #else
 249 static inline void parse_efi_setup(u64 phys_addr, u32 data_len) {}
 250 static inline bool efi_reboot_required(void)
 251 {
 252         return false;
 253 }
 254 #endif /* CONFIG_EFI */
 255
 256 #endif /* _ASM_X86_EFI_H */