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 #include <asm/mmu_context.h>
  11
  12 /*
  13  * We map the EFI regions needed for runtime services non-contiguously,
  14  * with preserved alignment on virtual addresses starting from -4G down
  15  * for a total max space of 64G. This way, we provide for stable runtime
  16  * services addresses across kernels so that a kexec'd kernel can still
  17  * use them.
  18  *
  19  * This is the main reason why we're doing stable VA mappings for RT
  20  * services.
  21  *
  22  * This flag is used in conjuction with a chicken bit called
  23  * "efi=old_map" which can be used as a fallback to the old runtime
  24  * services mapping method in case there's some b0rkage with a
  25  * particular EFI implementation (haha, it is hard to hold up the
  26  * sarcasm here...).
  27  */
  28 #define EFI_OLD_MEMMAP          EFI_ARCH_1
  29
  30 #define EFI32_LOADER_SIGNATURE  "EL32"
  31 #define EFI64_LOADER_SIGNATURE  "EL64"
  32
  33 #define MAX_CMDLINE_ADDRESS     UINT_MAX
  34
  35 #define ARCH_EFI_IRQ_FLAGS_MASK X86_EFLAGS_IF
  36
  37 #ifdef CONFIG_X86_32
  38
  39 extern asmlinkage unsigned long efi_call_phys(void *, ...);
  40
  41 #define arch_efi_call_virt_setup()                                      \
  42 ({                                                                      \
  43         kernel_fpu_begin();                                             \
  44         firmware_restrict_branch_speculation_start();                   \
  45 })
  46
  47 #define arch_efi_call_virt_teardown()                                   \
  48 ({                                                                      \
  49         firmware_restrict_branch_speculation_end();                     \
  50         kernel_fpu_end();                                               \
  51 })
  52
  53
  54 /*
  55  * Wrap all the virtual calls in a way that forces the parameters on the stack.
  56  */
  57 #define arch_efi_call_virt(p, f, args...)                               \
  58 ({                                                                      \
  59         ((efi_##f##_t __attribute__((regparm(0)))*) p->f)(args);        \
  60 })
  61
  62 #define efi_ioremap(addr, size, type, attr)     ioremap_cache(addr, size)
  63
  64 #else /* !CONFIG_X86_32 */
  65
  66 #define EFI_LOADER_SIGNATURE    "EL64"
  67
  68 extern asmlinkage u64 efi_call(void *fp, ...);
  69
  70 #define efi_call_phys(f, args...)               efi_call((f), args)
  71
  72 /*
  73  * Scratch space used for switching the pagetable in the EFI stub
  74  */
  75 struct efi_scratch {
  76         u64     r15;
  77         u64     prev_cr3;
  78         pgd_t   *efi_pgt;
  79         bool    use_pgd;
  80         u64     phys_stack;
  81 } __packed;
  82
  83 #define arch_efi_call_virt_setup()                                      \
  84 ({                                                                      \
  85         efi_sync_low_kernel_mappings();                                 \
  86         preempt_disable();                                              \
  87         __kernel_fpu_begin();                                           \
  88         firmware_restrict_branch_speculation_start();                   \
  89                                                                         \
  90         if (efi_scratch.use_pgd) {                                      \
  91                 efi_scratch.prev_cr3 = __read_cr3();                    \
  92                 write_cr3((unsigned long)efi_scratch.efi_pgt);          \
  93                 __flush_tlb_all();                                      \
  94         }                                                               \
  95 })
  96
  97 #define arch_efi_call_virt(p, f, args...)                               \
  98         efi_call((void *)p->f, args)                                    \
  99
 100 #define arch_efi_call_virt_teardown()                                   \
 101 ({                                                                      \
 102         if (efi_scratch.use_pgd) {                                      \
 103                 write_cr3(efi_scratch.prev_cr3);                        \
 104                 __flush_tlb_all();                                      \
 105         }                                                               \
 106                                                                         \
 107         firmware_restrict_branch_speculation_end();                     \
 108         __kernel_fpu_end();                                             \
 109         preempt_enable();                                               \
 110 })
 111
 112 extern void __iomem *__init efi_ioremap(unsigned long addr, unsigned long size,
 113                                         u32 type, u64 attribute);
 114
 115 #ifdef CONFIG_KASAN
 116 /*
 117  * CONFIG_KASAN may redefine memset to __memset.  __memset function is present
 118  * only in kernel binary.  Since the EFI stub linked into a separate binary it
 119  * doesn't have __memset().  So we should use standard memset from
 120  * arch/x86/boot/compressed/string.c.  The same applies to memcpy and memmove.
 121  */
 122 #undef memcpy
 123 #undef memset
 124 #undef memmove
 125 #endif
 126
 127 #endif /* CONFIG_X86_32 */
 128
 129 extern struct efi_scratch efi_scratch;
 130 extern void __init efi_set_executable(efi_memory_desc_t *md, bool executable);
 131 extern int __init efi_memblock_x86_reserve_range(void);
 132 extern pgd_t * __init efi_call_phys_prolog(void);
 133 extern void __init efi_call_phys_epilog(pgd_t *save_pgd);
 134 extern void __init efi_print_memmap(void);
 135 extern void __init efi_memory_uc(u64 addr, unsigned long size);
 136 extern void __init efi_map_region(efi_memory_desc_t *md);
 137 extern void __init efi_map_region_fixed(efi_memory_desc_t *md);
 138 extern void efi_sync_low_kernel_mappings(void);
 139 extern int __init efi_alloc_page_tables(void);
 140 extern int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages);
 141 extern void __init old_map_region(efi_memory_desc_t *md);
 142 extern void __init runtime_code_page_mkexec(void);
 143 extern void __init efi_runtime_update_mappings(void);
 144 extern void __init efi_dump_pagetable(void);
 145 extern void __init efi_apply_memmap_quirks(void);
 146 extern int __init efi_reuse_config(u64 tables, int nr_tables);
 147 extern void efi_delete_dummy_variable(void);
 148
 149 struct efi_setup_data {
 150         u64 fw_vendor;
 151         u64 runtime;
 152         u64 tables;
 153         u64 smbios;
 154         u64 reserved[8];
 155 };
 156
 157 extern u64 efi_setup;
 158
 159 #ifdef CONFIG_EFI
 160
 161 static inline bool efi_is_native(void)
 162 {
 163         return IS_ENABLED(CONFIG_X86_64) == efi_enabled(EFI_64BIT);
 164 }
 165
 166 static inline bool efi_runtime_supported(void)
 167 {
 168         if (efi_is_native())
 169                 return true;
 170
 171         if (IS_ENABLED(CONFIG_EFI_MIXED) && !efi_enabled(EFI_OLD_MEMMAP))
 172                 return true;
 173
 174         return false;
 175 }
 176
 177 extern struct console early_efi_console;
 178 extern void parse_efi_setup(u64 phys_addr, u32 data_len);
 179
 180 extern void efifb_setup_from_dmi(struct screen_info *si, const char *opt);
 181
 182 #ifdef CONFIG_EFI_MIXED
 183 extern void efi_thunk_runtime_setup(void);
 184 extern efi_status_t efi_thunk_set_virtual_address_map(
 185         void *phys_set_virtual_address_map,
 186         unsigned long memory_map_size,
 187         unsigned long descriptor_size,
 188         u32 descriptor_version,
 189         efi_memory_desc_t *virtual_map);
 190 #else
 191 static inline void efi_thunk_runtime_setup(void) {}
 192 static inline efi_status_t efi_thunk_set_virtual_address_map(
 193         void *phys_set_virtual_address_map,
 194         unsigned long memory_map_size,
 195         unsigned long descriptor_size,
 196         u32 descriptor_version,
 197         efi_memory_desc_t *virtual_map)
 198 {
 199         return EFI_SUCCESS;
 200 }
 201 #endif /* CONFIG_EFI_MIXED */
 202
 203
 204 /* arch specific definitions used by the stub code */
 205
 206 struct efi_config {
 207         u64 image_handle;
 208         u64 table;
 209         u64 runtime_services;
 210         u64 boot_services;
 211         u64 text_output;
 212         efi_status_t (*call)(unsigned long, ...);
 213         bool is64;
 214 } __packed;
 215
 216 __pure const struct efi_config *__efi_early(void);
 217
 218 static inline bool efi_is_64bit(void)
 219 {
 220         if (!IS_ENABLED(CONFIG_X86_64))
 221                 return false;
 222
 223         if (!IS_ENABLED(CONFIG_EFI_MIXED))
 224                 return true;
 225
 226         return __efi_early()->is64;
 227 }
 228
 229 #define efi_table_attr(table, attr, instance)                           \
 230         (efi_is_64bit() ?                                               \
 231                 ((table##_64_t *)(unsigned long)instance)->attr :       \
 232                 ((table##_32_t *)(unsigned long)instance)->attr)
 233
 234 #define efi_call_proto(protocol, f, instance, ...)                      \
 235         __efi_early()->call(efi_table_attr(protocol, f, instance),      \
 236                 instance, ##__VA_ARGS__)
 237
 238 #define efi_call_early(f, ...)                                          \
 239         __efi_early()->call(efi_table_attr(efi_boot_services, f,        \
 240                 __efi_early()->boot_services), __VA_ARGS__)
 241
 242 #define __efi_call_early(f, ...)                                        \
 243         __efi_early()->call((unsigned long)f, __VA_ARGS__);
 244
 245 #define efi_call_runtime(f, ...)                                        \
 246         __efi_early()->call(efi_table_attr(efi_runtime_services, f,     \
 247                 __efi_early()->runtime_services), __VA_ARGS__)
 248
 249 extern bool efi_reboot_required(void);
 250
 251 #else
 252 static inline void parse_efi_setup(u64 phys_addr, u32 data_len) {}
 253 static inline bool efi_reboot_required(void)
 254 {
 255         return false;
 256 }
 257 #endif /* CONFIG_EFI */
 258
 259 #endif /* _ASM_X86_EFI_H */