LXR linux/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 conjunction 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
  39extern 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
  68extern asmlinkage u64 efi_call(void *fp, ...);
  69
  70#define efi_call_phys(f, args...)               efi_call((f), args)
  71
  72/*
  73 * struct efi_scratch - Scratch space used while switching to/from efi_mm
  74 * @phys_stack: stack used during EFI Mixed Mode
  75 * @prev_mm:    store/restore stolen mm_struct while switching to/from efi_mm
  76 */
  77struct efi_scratch {
  78        u64                     phys_stack;
  79        struct mm_struct        *prev_mm;
  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_enabled(EFI_OLD_MEMMAP))                               \
  89                efi_switch_mm(&efi_mm);                                 \
  90})
  91
  92#define arch_efi_call_virt(p, f, args...)                               \
  93        efi_call((void *)p->f, args)                                    \
  94
  95#define arch_efi_call_virt_teardown()                                   \
  96({                                                                      \
  97        if (!efi_enabled(EFI_OLD_MEMMAP))                               \
  98                efi_switch_mm(efi_scratch.prev_mm);                     \
  99                                                                        \
 100        firmware_restrict_branch_speculation_end();                     \
 101        kernel_fpu_end();                                               \
 102})
 103
 104extern void __iomem *__init efi_ioremap(unsigned long addr, unsigned long size,
 105                                        u32 type, u64 attribute);
 106
 107#ifdef CONFIG_KASAN
 108/*
 109 * CONFIG_KASAN may redefine memset to __memset.  __memset function is present
 110 * only in kernel binary.  Since the EFI stub linked into a separate binary it
 111 * doesn't have __memset().  So we should use standard memset from
 112 * arch/x86/boot/compressed/string.c.  The same applies to memcpy and memmove.
 113 */
 114#undef memcpy
 115#undef memset
 116#undef memmove
 117#endif
 118
 119#endif /* CONFIG_X86_32 */
 120
 121extern struct efi_scratch efi_scratch;
 122extern void __init efi_set_executable(efi_memory_desc_t *md, bool executable);
 123extern int __init efi_memblock_x86_reserve_range(void);
 124extern pgd_t * __init efi_call_phys_prolog(void);
 125extern void __init efi_call_phys_epilog(pgd_t *save_pgd);
 126extern void __init efi_print_memmap(void);
 127extern void __init efi_memory_uc(u64 addr, unsigned long size);
 128extern void __init efi_map_region(efi_memory_desc_t *md);
 129extern void __init efi_map_region_fixed(efi_memory_desc_t *md);
 130extern void efi_sync_low_kernel_mappings(void);
 131extern int __init efi_alloc_page_tables(void);
 132extern int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages);
 133extern void __init old_map_region(efi_memory_desc_t *md);
 134extern void __init runtime_code_page_mkexec(void);
 135extern void __init efi_runtime_update_mappings(void);
 136extern void __init efi_dump_pagetable(void);
 137extern void __init efi_apply_memmap_quirks(void);
 138extern int __init efi_reuse_config(u64 tables, int nr_tables);
 139extern void efi_delete_dummy_variable(void);
 140extern void efi_switch_mm(struct mm_struct *mm);
 141extern void efi_recover_from_page_fault(unsigned long phys_addr);
 142extern void efi_free_boot_services(void);
 143extern void efi_reserve_boot_services(void);
 144
 145struct efi_setup_data {
 146        u64 fw_vendor;
 147        u64 runtime;
 148        u64 tables;
 149        u64 smbios;
 150        u64 reserved[8];
 151};
 152
 153extern u64 efi_setup;
 154
 155#ifdef CONFIG_EFI
 156
 157static inline bool efi_is_native(void)
 158{
 159        return IS_ENABLED(CONFIG_X86_64) == efi_enabled(EFI_64BIT);
 160}
 161
 162static inline bool efi_runtime_supported(void)
 163{
 164        if (efi_is_native())
 165                return true;
 166
 167        if (IS_ENABLED(CONFIG_EFI_MIXED) && !efi_enabled(EFI_OLD_MEMMAP))
 168                return true;
 169
 170        return false;
 171}
 172
 173extern void parse_efi_setup(u64 phys_addr, u32 data_len);
 174
 175extern void efifb_setup_from_dmi(struct screen_info *si, const char *opt);
 176
 177#ifdef CONFIG_EFI_MIXED
 178extern void efi_thunk_runtime_setup(void);
 179extern efi_status_t efi_thunk_set_virtual_address_map(
 180        void *phys_set_virtual_address_map,
 181        unsigned long memory_map_size,
 182        unsigned long descriptor_size,
 183        u32 descriptor_version,
 184        efi_memory_desc_t *virtual_map);
 185#else
 186static inline void efi_thunk_runtime_setup(void) {}
 187static inline efi_status_t efi_thunk_set_virtual_address_map(
 188        void *phys_set_virtual_address_map,
 189        unsigned long memory_map_size,
 190        unsigned long descriptor_size,
 191        u32 descriptor_version,
 192        efi_memory_desc_t *virtual_map)
 193{
 194        return EFI_SUCCESS;
 195}
 196#endif /* CONFIG_EFI_MIXED */
 197
 198
 199/* arch specific definitions used by the stub code */
 200
 201struct efi_config {
 202        u64 image_handle;
 203        u64 table;
 204        u64 runtime_services;
 205        u64 boot_services;
 206        u64 text_output;
 207        efi_status_t (*call)(unsigned long, ...);
 208        bool is64;
 209} __packed;
 210
 211__pure const struct efi_config *__efi_early(void);
 212
 213static inline bool efi_is_64bit(void)
 214{
 215        if (!IS_ENABLED(CONFIG_X86_64))
 216                return false;
 217
 218        if (!IS_ENABLED(CONFIG_EFI_MIXED))
 219                return true;
 220
 221        return __efi_early()->is64;
 222}
 223
 224#define efi_table_attr(table, attr, instance)                           \
 225        (efi_is_64bit() ?                                               \
 226                ((table##_64_t *)(unsigned long)instance)->attr :       \
 227                ((table##_32_t *)(unsigned long)instance)->attr)
 228
 229#define efi_call_proto(protocol, f, instance, ...)                      \
 230        __efi_early()->call(efi_table_attr(protocol, f, instance),      \
 231                instance, ##__VA_ARGS__)
 232
 233#define efi_call_early(f, ...)                                          \
 234        __efi_early()->call(efi_table_attr(efi_boot_services, f,        \
 235                __efi_early()->boot_services), __VA_ARGS__)
 236
 237#define __efi_call_early(f, ...)                                        \
 238        __efi_early()->call((unsigned long)f, __VA_ARGS__);
 239
 240#define efi_call_runtime(f, ...)                                        \
 241        __efi_early()->call(efi_table_attr(efi_runtime_services, f,     \
 242                __efi_early()->runtime_services), __VA_ARGS__)
 243
 244extern bool efi_reboot_required(void);
 245
 246#else
 247static inline void parse_efi_setup(u64 phys_addr, u32 data_len) {}
 248static inline bool efi_reboot_required(void)
 249{
 250        return false;
 251}
 252#endif /* CONFIG_EFI */
 253
 254#endif /* _ASM_X86_EFI_H */
 255