LXR linux/arch/arm64/include/asm/efi.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef _ASM_EFI_H
   3#define _ASM_EFI_H
   4
   5#include <asm/boot.h>
   6#include <asm/cpufeature.h>
   7#include <asm/fpsimd.h>
   8#include <asm/io.h>
   9#include <asm/memory.h>
  10#include <asm/mmu_context.h>
  11#include <asm/neon.h>
  12#include <asm/ptrace.h>
  13#include <asm/tlbflush.h>
  14
  15#ifdef CONFIG_EFI
  16extern void efi_init(void);
  17#else
  18#define efi_init()
  19#endif
  20
  21int efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md);
  22int efi_set_mapping_permissions(struct mm_struct *mm, efi_memory_desc_t *md);
  23
  24#define arch_efi_call_virt_setup()                                      \
  25({                                                                      \
  26        efi_virtmap_load();                                             \
  27        __efi_fpsimd_begin();                                           \
  28})
  29
  30#define arch_efi_call_virt(p, f, args...)                               \
  31({                                                                      \
  32        efi_##f##_t *__f;                                               \
  33        __f = p->f;                                                     \
  34        __f(args);                                                      \
  35})
  36
  37#define arch_efi_call_virt_teardown()                                   \
  38({                                                                      \
  39        __efi_fpsimd_end();                                             \
  40        efi_virtmap_unload();                                           \
  41})
  42
  43#define ARCH_EFI_IRQ_FLAGS_MASK (PSR_D_BIT | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT)
  44
  45/* arch specific definitions used by the stub code */
  46
  47/*
  48 * AArch64 requires the DTB to be 8-byte aligned in the first 512MiB from
  49 * start of kernel and may not cross a 2MiB boundary. We set alignment to
  50 * 2MiB so we know it won't cross a 2MiB boundary.
  51 */
  52#define EFI_FDT_ALIGN   SZ_2M   /* used by allocate_new_fdt_and_exit_boot() */
  53
  54/*
  55 * In some configurations (e.g. VMAP_STACK && 64K pages), stacks built into the
  56 * kernel need greater alignment than we require the segments to be padded to.
  57 */
  58#define EFI_KIMG_ALIGN  \
  59        (SEGMENT_ALIGN > THREAD_ALIGN ? SEGMENT_ALIGN : THREAD_ALIGN)
  60
  61/* on arm64, the FDT may be located anywhere in system RAM */
  62static inline unsigned long efi_get_max_fdt_addr(unsigned long dram_base)
  63{
  64        return ULONG_MAX;
  65}
  66
  67/*
  68 * On arm64, we have to ensure that the initrd ends up in the linear region,
  69 * which is a 1 GB aligned region of size '1UL << (VA_BITS - 1)' that is
  70 * guaranteed to cover the kernel Image.
  71 *
  72 * Since the EFI stub is part of the kernel Image, we can relax the
  73 * usual requirements in Documentation/arm64/booting.txt, which still
  74 * apply to other bootloaders, and are required for some kernel
  75 * configurations.
  76 */
  77static inline unsigned long efi_get_max_initrd_addr(unsigned long dram_base,
  78                                                    unsigned long image_addr)
  79{
  80        return (image_addr & ~(SZ_1G - 1UL)) + (1UL << (VA_BITS - 1));
  81}
  82
  83#define efi_call_early(f, ...)          sys_table_arg->boottime->f(__VA_ARGS__)
  84#define __efi_call_early(f, ...)        f(__VA_ARGS__)
  85#define efi_call_runtime(f, ...)        sys_table_arg->runtime->f(__VA_ARGS__)
  86#define efi_is_64bit()                  (true)
  87
  88#define efi_call_proto(protocol, f, instance, ...)                      \
  89        ((protocol##_t *)instance)->f(instance, ##__VA_ARGS__)
  90
  91#define alloc_screen_info(x...)         &screen_info
  92#define free_screen_info(x...)
  93
  94/* redeclare as 'hidden' so the compiler will generate relative references */
  95extern struct screen_info screen_info __attribute__((__visibility__("hidden")));
  96
  97static inline void efifb_setup_from_dmi(struct screen_info *si, const char *opt)
  98{
  99}
 100
 101#define EFI_ALLOC_ALIGN         SZ_64K
 102
 103/*
 104 * On ARM systems, virtually remapped UEFI runtime services are set up in two
 105 * distinct stages:
 106 * - The stub retrieves the final version of the memory map from UEFI, populates
 107 *   the virt_addr fields and calls the SetVirtualAddressMap() [SVAM] runtime
 108 *   service to communicate the new mapping to the firmware (Note that the new
 109 *   mapping is not live at this time)
 110 * - During an early initcall(), the EFI system table is permanently remapped
 111 *   and the virtual remapping of the UEFI Runtime Services regions is loaded
 112 *   into a private set of page tables. If this all succeeds, the Runtime
 113 *   Services are enabled and the EFI_RUNTIME_SERVICES bit set.
 114 */
 115
 116static inline void efi_set_pgd(struct mm_struct *mm)
 117{
 118        __switch_mm(mm);
 119
 120        if (system_uses_ttbr0_pan()) {
 121                if (mm != current->active_mm) {
 122                        /*
 123                         * Update the current thread's saved ttbr0 since it is
 124                         * restored as part of a return from exception. Set
 125                         * the hardware TTBR0_EL1 using cpu_switch_mm()
 126                         * directly to enable potential errata workarounds.
 127                         */
 128                        update_saved_ttbr0(current, mm);
 129                        cpu_switch_mm(mm->pgd, mm);
 130                } else {
 131                        /*
 132                         * Defer the switch to the current thread's TTBR0_EL1
 133                         * until uaccess_enable(). Restore the current
 134                         * thread's saved ttbr0 corresponding to its active_mm
 135                         * (if different from init_mm).
 136                         */
 137                        cpu_set_reserved_ttbr0();
 138                        if (current->active_mm != &init_mm)
 139                                update_saved_ttbr0(current, current->active_mm);
 140                }
 141        }
 142}
 143
 144void efi_virtmap_load(void);
 145void efi_virtmap_unload(void);
 146
 147#endif /* _ASM_EFI_H */
 148