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         preempt_disable();                                              \
  86         __kernel_fpu_begin();                                           \
  87         firmware_restrict_branch_speculation_start();                   \
  88                                                                         \
  89         if (efi_scratch.use_pgd) {                                      \
  90                 efi_scratch.prev_cr3 = __read_cr3();                    \
  91                 write_cr3((unsigned long)efi_scratch.efi_pgt);          \
  92                 __flush_tlb_all();                                      \
  93         }                                                               \
  94 })
  95
  96 #define arch_efi_call_virt(p, f, args...)                               \
  97         efi_call((void *)p->f, args)                                    \
  98
  99 #define arch_efi_call_virt_teardown()                                   \
 100 ({                                                                      \
 101         if (efi_scratch.use_pgd) {                                      \
 102                 write_cr3(efi_scratch.prev_cr3);                        \
 103                 __flush_tlb_all();                                      \
 104         }                                                               \
 105                                                                         \
 106         firmware_restrict_branch_speculation_end();                     \
 107         __kernel_fpu_end();                                             \
 108         preempt_enable();                                               \
 109 })
 110
 111 extern void __iomem *__init efi_ioremap(unsigned long addr, unsigned long size,
 112                                         u32 type, u64 attribute);
 113
 114 #ifdef CONFIG_KASAN
 115 /*
 116  * CONFIG_KASAN may redefine memset to __memset.  __memset function is present
 117  * only in kernel binary.  Since the EFI stub linked into a separate binary it
 118  * doesn't have __memset().  So we should use standard memset from
 119  * arch/x86/boot/compressed/string.c.  The same applies to memcpy and memmove.
 120  */
 121 #undef memcpy
 122 #undef memset
 123 #undef memmove
 124 #endif
 125
 126 #endif /* CONFIG_X86_32 */
 127
 128 extern struct efi_scratch efi_scratch;
 129 extern void __init efi_set_executable(efi_memory_desc_t *md, bool executable);
 130 extern int __init efi_memblock_x86_reserve_range(void);
 131 extern pgd_t * __init efi_call_phys_prolog(void);
 132 extern void __init efi_call_phys_epilog(pgd_t *save_pgd);
 133 extern void __init efi_print_memmap(void);
 134 extern void __init efi_memory_uc(u64 addr, unsigned long size);
 135 extern void __init efi_map_region(efi_memory_desc_t *md);
 136 extern void __init efi_map_region_fixed(efi_memory_desc_t *md);
 137 extern void efi_sync_low_kernel_mappings(void);
 138 extern int __init efi_alloc_page_tables(void);
 139 extern int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages);
 140 extern void __init old_map_region(efi_memory_desc_t *md);
 141 extern void __init runtime_code_page_mkexec(void);
 142 extern void __init efi_runtime_update_mappings(void);
 143 extern void __init efi_dump_pagetable(void);
 144 extern void __init efi_apply_memmap_quirks(void);
 145 extern int __init efi_reuse_config(u64 tables, int nr_tables);
 146 extern void efi_delete_dummy_variable(void);
 147
 148 struct efi_setup_data {
 149         u64 fw_vendor;
 150         u64 runtime;
 151         u64 tables;
 152         u64 smbios;
 153         u64 reserved[8];
 154 };
 155
 156 extern u64 efi_setup;
 157
 158 #ifdef CONFIG_EFI
 159
 160 static inline bool efi_is_native(void)
 161 {
 162         return IS_ENABLED(CONFIG_X86_64) == efi_enabled(EFI_64BIT);
 163 }
 164
 165 static inline bool efi_runtime_supported(void)
 166 {
 167         if (efi_is_native())
 168                 return true;
 169
 170         if (IS_ENABLED(CONFIG_EFI_MIXED) && !efi_enabled(EFI_OLD_MEMMAP))
 171                 return true;
 172
 173         return false;
 174 }
 175
 176 extern struct console early_efi_console;
 177 extern void parse_efi_setup(u64 phys_addr, u32 data_len);
 178
 179 extern void efifb_setup_from_dmi(struct screen_info *si, const char *opt);
 180
 181 #ifdef CONFIG_EFI_MIXED
 182 extern void efi_thunk_runtime_setup(void);
 183 extern efi_status_t efi_thunk_set_virtual_address_map(
 184         void *phys_set_virtual_address_map,
 185         unsigned long memory_map_size,
 186         unsigned long descriptor_size,
 187         u32 descriptor_version,
 188         efi_memory_desc_t *virtual_map);
 189 #else
 190 static inline void efi_thunk_runtime_setup(void) {}
 191 static inline efi_status_t efi_thunk_set_virtual_address_map(
 192         void *phys_set_virtual_address_map,
 193         unsigned long memory_map_size,
 194         unsigned long descriptor_size,
 195         u32 descriptor_version,
 196         efi_memory_desc_t *virtual_map)
 197 {
 198         return EFI_SUCCESS;
 199 }
 200 #endif /* CONFIG_EFI_MIXED */
 201
 202
 203 /* arch specific definitions used by the stub code */
 204
 205 struct efi_config {
 206         u64 image_handle;
 207         u64 table;
 208         u64 runtime_services;
 209         u64 boot_services;
 210         u64 text_output;
 211         efi_status_t (*call)(unsigned long, ...);
 212         bool is64;
 213 } __packed;
 214
 215 __pure const struct efi_config *__efi_early(void);
 216
 217 static inline bool efi_is_64bit(void)
 218 {
 219         if (!IS_ENABLED(CONFIG_X86_64))
 220                 return false;
 221
 222         if (!IS_ENABLED(CONFIG_EFI_MIXED))
 223                 return true;
 224
 225         return __efi_early()->is64;
 226 }
 227
 228 #define efi_table_attr(table, attr, instance)                           \
 229         (efi_is_64bit() ?                                               \
 230                 ((table##_64_t *)(unsigned long)instance)->attr :       \
 231                 ((table##_32_t *)(unsigned long)instance)->attr)
 232
 233 #define efi_call_proto(protocol, f, instance, ...)                      \
 234         __efi_early()->call(efi_table_attr(protocol, f, instance),      \
 235                 instance, ##__VA_ARGS__)
 236
 237 #define efi_call_early(f, ...)                                          \
 238         __efi_early()->call(efi_table_attr(efi_boot_services, f,        \
 239                 __efi_early()->boot_services), __VA_ARGS__)
 240
 241 #define __efi_call_early(f, ...)                                        \
 242         __efi_early()->call((unsigned long)f, __VA_ARGS__);
 243
 244 #define efi_call_runtime(f, ...)                                        \
 245         __efi_early()->call(efi_table_attr(efi_runtime_services, f,     \
 246                 __efi_early()->runtime_services), __VA_ARGS__)
 247
 248 extern bool efi_reboot_required(void);
 249
 250 #else
 251 static inline void parse_efi_setup(u64 phys_addr, u32 data_len) {}
 252 static inline bool efi_reboot_required(void)
 253 {
 254         return false;
 255 }
 256 #endif /* CONFIG_EFI */
 257
 258 #endif /* _ASM_X86_EFI_H */