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
  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
  38extern 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
  67extern 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 */
  74struct 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
 111extern 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
 128extern struct efi_scratch efi_scratch;
 129extern void __init efi_set_executable(efi_memory_desc_t *md, bool executable);
 130extern int __init efi_memblock_x86_reserve_range(void);
 131extern pgd_t * __init efi_call_phys_prolog(void);
 132extern void __init efi_call_phys_epilog(pgd_t *save_pgd);
 133extern void __init efi_print_memmap(void);
 134extern void __init efi_memory_uc(u64 addr, unsigned long size);
 135extern void __init efi_map_region(efi_memory_desc_t *md);
 136extern void __init efi_map_region_fixed(efi_memory_desc_t *md);
 137extern void efi_sync_low_kernel_mappings(void);
 138extern int __init efi_alloc_page_tables(void);
 139extern int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages);
 140extern void __init old_map_region(efi_memory_desc_t *md);
 141extern void __init runtime_code_page_mkexec(void);
 142extern void __init efi_runtime_update_mappings(void);
 143extern void __init efi_dump_pagetable(void);
 144extern void __init efi_apply_memmap_quirks(void);
 145extern int __init efi_reuse_config(u64 tables, int nr_tables);
 146extern void efi_delete_dummy_variable(void);
 147
 148struct efi_setup_data {
 149        u64 fw_vendor;
 150        u64 runtime;
 151        u64 tables;
 152        u64 smbios;
 153        u64 reserved[8];
 154};
 155
 156extern u64 efi_setup;
 157
 158#ifdef CONFIG_EFI
 159
 160static inline bool efi_is_native(void)
 161{
 162        return IS_ENABLED(CONFIG_X86_64) == efi_enabled(EFI_64BIT);
 163}
 164
 165static 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
 176extern struct console early_efi_console;
 177extern void parse_efi_setup(u64 phys_addr, u32 data_len);
 178
 179extern void efifb_setup_from_dmi(struct screen_info *si, const char *opt);
 180
 181#ifdef CONFIG_EFI_MIXED
 182extern void efi_thunk_runtime_setup(void);
 183extern 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
 190static inline void efi_thunk_runtime_setup(void) {}
 191static 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
 205struct 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
 217static 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
 248extern bool efi_reboot_required(void);
 249
 250#else
 251static inline void parse_efi_setup(u64 phys_addr, u32 data_len) {}
 252static inline bool efi_reboot_required(void)
 253{
 254        return false;
 255}
 256#endif /* CONFIG_EFI */
 257
 258#endif /* _ASM_X86_EFI_H */
 259