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
  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 asmlinkage unsigned long efi_call_phys(void *, ...);
  38
  39 #define arch_efi_call_virt_setup()      kernel_fpu_begin()
  40 #define arch_efi_call_virt_teardown()   kernel_fpu_end()
  41
  42 /*
  43  * Wrap all the virtual calls in a way that forces the parameters on the stack.
  44  */
  45 #define arch_efi_call_virt(p, f, args...)                               \
  46 ({                                                                      \
  47         ((efi_##f##_t __attribute__((regparm(0)))*) p->f)(args);        \
  48 })
  49
  50 #define efi_ioremap(addr, size, type, attr)     ioremap_cache(addr, size)
  51
  52 #else /* !CONFIG_X86_32 */
  53
  54 #define EFI_LOADER_SIGNATURE    "EL64"
  55
  56 extern asmlinkage u64 efi_call(void *fp, ...);
  57
  58 #define efi_call_phys(f, args...)               efi_call((f), args)
  59
  60 /*
  61  * Scratch space used for switching the pagetable in the EFI stub
  62  */
  63 struct efi_scratch {
  64         u64     r15;
  65         u64     prev_cr3;
  66         pgd_t   *efi_pgt;
  67         bool    use_pgd;
  68         u64     phys_stack;
  69 } __packed;
  70
  71 #define arch_efi_call_virt_setup()                                      \
  72 ({                                                                      \
  73         efi_sync_low_kernel_mappings();                                 \
  74         preempt_disable();                                              \
  75         __kernel_fpu_begin();                                           \
  76                                                                         \
  77         if (efi_scratch.use_pgd) {                                      \
  78                 efi_scratch.prev_cr3 = __read_cr3();                    \
  79                 write_cr3((unsigned long)efi_scratch.efi_pgt);          \
  80                 __flush_tlb_all();                                      \
  81         }                                                               \
  82 })
  83
  84 #define arch_efi_call_virt(p, f, args...)                               \
  85         efi_call((void *)p->f, args)                                    \
  86
  87 #define arch_efi_call_virt_teardown()                                   \
  88 ({                                                                      \
  89         if (efi_scratch.use_pgd) {                                      \
  90                 write_cr3(efi_scratch.prev_cr3);                        \
  91                 __flush_tlb_all();                                      \
  92         }                                                               \
  93                                                                         \
  94         __kernel_fpu_end();                                             \
  95         preempt_enable();                                               \
  96 })
  97
  98 extern void __iomem *__init efi_ioremap(unsigned long addr, unsigned long size,
  99                                         u32 type, u64 attribute);
 100
 101 #ifdef CONFIG_KASAN
 102 /*
 103  * CONFIG_KASAN may redefine memset to __memset.  __memset function is present
 104  * only in kernel binary.  Since the EFI stub linked into a separate binary it
 105  * doesn't have __memset().  So we should use standard memset from
 106  * arch/x86/boot/compressed/string.c.  The same applies to memcpy and memmove.
 107  */
 108 #undef memcpy
 109 #undef memset
 110 #undef memmove
 111 #endif
 112
 113 #endif /* CONFIG_X86_32 */
 114
 115 extern struct efi_scratch efi_scratch;
 116 extern void __init efi_set_executable(efi_memory_desc_t *md, bool executable);
 117 extern int __init efi_memblock_x86_reserve_range(void);
 118 extern pgd_t * __init efi_call_phys_prolog(void);
 119 extern void __init efi_call_phys_epilog(pgd_t *save_pgd);
 120 extern void __init efi_print_memmap(void);
 121 extern void __init efi_memory_uc(u64 addr, unsigned long size);
 122 extern void __init efi_map_region(efi_memory_desc_t *md);
 123 extern void __init efi_map_region_fixed(efi_memory_desc_t *md);
 124 extern void efi_sync_low_kernel_mappings(void);
 125 extern int __init efi_alloc_page_tables(void);
 126 extern int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages);
 127 extern void __init old_map_region(efi_memory_desc_t *md);
 128 extern void __init runtime_code_page_mkexec(void);
 129 extern void __init efi_runtime_update_mappings(void);
 130 extern void __init efi_dump_pagetable(void);
 131 extern void __init efi_apply_memmap_quirks(void);
 132 extern int __init efi_reuse_config(u64 tables, int nr_tables);
 133 extern void efi_delete_dummy_variable(void);
 134
 135 struct efi_setup_data {
 136         u64 fw_vendor;
 137         u64 runtime;
 138         u64 tables;
 139         u64 smbios;
 140         u64 reserved[8];
 141 };
 142
 143 extern u64 efi_setup;
 144
 145 #ifdef CONFIG_EFI
 146
 147 static inline bool efi_is_native(void)
 148 {
 149         return IS_ENABLED(CONFIG_X86_64) == efi_enabled(EFI_64BIT);
 150 }
 151
 152 static inline bool efi_runtime_supported(void)
 153 {
 154         if (efi_is_native())
 155                 return true;
 156
 157         if (IS_ENABLED(CONFIG_EFI_MIXED) && !efi_enabled(EFI_OLD_MEMMAP))
 158                 return true;
 159
 160         return false;
 161 }
 162
 163 extern struct console early_efi_console;
 164 extern void parse_efi_setup(u64 phys_addr, u32 data_len);
 165
 166 extern void efifb_setup_from_dmi(struct screen_info *si, const char *opt);
 167
 168 #ifdef CONFIG_EFI_MIXED
 169 extern void efi_thunk_runtime_setup(void);
 170 extern efi_status_t efi_thunk_set_virtual_address_map(
 171         void *phys_set_virtual_address_map,
 172         unsigned long memory_map_size,
 173         unsigned long descriptor_size,
 174         u32 descriptor_version,
 175         efi_memory_desc_t *virtual_map);
 176 #else
 177 static inline void efi_thunk_runtime_setup(void) {}
 178 static inline efi_status_t efi_thunk_set_virtual_address_map(
 179         void *phys_set_virtual_address_map,
 180         unsigned long memory_map_size,
 181         unsigned long descriptor_size,
 182         u32 descriptor_version,
 183         efi_memory_desc_t *virtual_map)
 184 {
 185         return EFI_SUCCESS;
 186 }
 187 #endif /* CONFIG_EFI_MIXED */
 188
 189
 190 /* arch specific definitions used by the stub code */
 191
 192 struct efi_config {
 193         u64 image_handle;
 194         u64 table;
 195         u64 runtime_services;
 196         u64 boot_services;
 197         u64 text_output;
 198         efi_status_t (*call)(unsigned long, ...);
 199         bool is64;
 200 } __packed;
 201
 202 __pure const struct efi_config *__efi_early(void);
 203
 204 static inline bool efi_is_64bit(void)
 205 {
 206         if (!IS_ENABLED(CONFIG_X86_64))
 207                 return false;
 208
 209         if (!IS_ENABLED(CONFIG_EFI_MIXED))
 210                 return true;
 211
 212         return __efi_early()->is64;
 213 }
 214
 215 #define efi_table_attr(table, attr, instance)                           \
 216         (efi_is_64bit() ?                                               \
 217                 ((table##_64_t *)(unsigned long)instance)->attr :       \
 218                 ((table##_32_t *)(unsigned long)instance)->attr)
 219
 220 #define efi_call_proto(protocol, f, instance, ...)                      \
 221         __efi_early()->call(efi_table_attr(protocol, f, instance),      \
 222                 instance, ##__VA_ARGS__)
 223
 224 #define efi_call_early(f, ...)                                          \
 225         __efi_early()->call(efi_table_attr(efi_boot_services, f,        \
 226                 __efi_early()->boot_services), __VA_ARGS__)
 227
 228 #define __efi_call_early(f, ...)                                        \
 229         __efi_early()->call((unsigned long)f, __VA_ARGS__);
 230
 231 #define efi_call_runtime(f, ...)                                        \
 232         __efi_early()->call(efi_table_attr(efi_runtime_services, f,     \
 233                 __efi_early()->runtime_services), __VA_ARGS__)
 234
 235 extern bool efi_reboot_required(void);
 236
 237 #else
 238 static inline void parse_efi_setup(u64 phys_addr, u32 data_len) {}
 239 static inline bool efi_reboot_required(void)
 240 {
 241         return false;
 242 }
 243 #endif /* CONFIG_EFI */
 244
 245 #endif /* _ASM_X86_EFI_H */