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);
  17extern void efifb_setup_from_dmi(struct screen_info *si, const char *opt);
  18#else
  19#define efi_init()
  20#endif
  21
  22int efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md);
  23int efi_set_mapping_permissions(struct mm_struct *mm, efi_memory_desc_t *md);
  24
  25#define arch_efi_call_virt_setup()                                      \
  26({                                                                      \
  27        efi_virtmap_load();                                             \
  28        __efi_fpsimd_begin();                                           \
  29})
  30
  31#define arch_efi_call_virt(p, f, args...)                               \
  32({                                                                      \
  33        efi_##f##_t *__f;                                               \
  34        __f = p->f;                                                     \
  35        __efi_rt_asm_wrapper(__f, #f, args);                            \
  36})
  37
  38#define arch_efi_call_virt_teardown()                                   \
  39({                                                                      \
  40        __efi_fpsimd_end();                                             \
  41        efi_virtmap_unload();                                           \
  42})
  43
  44efi_status_t __efi_rt_asm_wrapper(void *, const char *, ...);
  45
  46#define ARCH_EFI_IRQ_FLAGS_MASK (PSR_D_BIT | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT)
  47
  48/*
  49 * Even when Linux uses IRQ priorities for IRQ disabling, EFI does not.
  50 * And EFI shouldn't really play around with priority masking as it is not aware
  51 * which priorities the OS has assigned to its interrupts.
  52 */
  53#define arch_efi_save_flags(state_flags)                \
  54        ((void)((state_flags) = read_sysreg(daif)))
  55
  56#define arch_efi_restore_flags(state_flags)     write_sysreg(state_flags, daif)
  57
  58
  59/* arch specific definitions used by the stub code */
  60
  61/*
  62 * In some configurations (e.g. VMAP_STACK && 64K pages), stacks built into the
  63 * kernel need greater alignment than we require the segments to be padded to.
  64 */
  65#define EFI_KIMG_ALIGN  \
  66        (SEGMENT_ALIGN > THREAD_ALIGN ? SEGMENT_ALIGN : THREAD_ALIGN)
  67
  68/*
  69 * On arm64, we have to ensure that the initrd ends up in the linear region,
  70 * which is a 1 GB aligned region of size '1UL << (VA_BITS_MIN - 1)' that is
  71 * guaranteed to cover the kernel Image.
  72 *
  73 * Since the EFI stub is part of the kernel Image, we can relax the
  74 * usual requirements in Documentation/arm64/booting.rst, which still
  75 * apply to other bootloaders, and are required for some kernel
  76 * configurations.
  77 */
  78static inline unsigned long efi_get_max_initrd_addr(unsigned long image_addr)
  79{
  80        return (image_addr & ~(SZ_1G - 1UL)) + (1UL << (VA_BITS_MIN - 1));
  81}
  82
  83#define alloc_screen_info(x...)         &screen_info
  84
  85static inline void free_screen_info(struct screen_info *si)
  86{
  87}
  88
  89#define EFI_ALLOC_ALIGN         SZ_64K
  90
  91/*
  92 * On ARM systems, virtually remapped UEFI runtime services are set up in two
  93 * distinct stages:
  94 * - The stub retrieves the final version of the memory map from UEFI, populates
  95 *   the virt_addr fields and calls the SetVirtualAddressMap() [SVAM] runtime
  96 *   service to communicate the new mapping to the firmware (Note that the new
  97 *   mapping is not live at this time)
  98 * - During an early initcall(), the EFI system table is permanently remapped
  99 *   and the virtual remapping of the UEFI Runtime Services regions is loaded
 100 *   into a private set of page tables. If this all succeeds, the Runtime
 101 *   Services are enabled and the EFI_RUNTIME_SERVICES bit set.
 102 */
 103
 104static inline void efi_set_pgd(struct mm_struct *mm)
 105{
 106        __switch_mm(mm);
 107
 108        if (system_uses_ttbr0_pan()) {
 109                if (mm != current->active_mm) {
 110                        /*
 111                         * Update the current thread's saved ttbr0 since it is
 112                         * restored as part of a return from exception. Enable
 113                         * access to the valid TTBR0_EL1 and invoke the errata
 114                         * workaround directly since there is no return from
 115                         * exception when invoking the EFI run-time services.
 116                         */
 117                        update_saved_ttbr0(current, mm);
 118                        uaccess_ttbr0_enable();
 119                        post_ttbr_update_workaround();
 120                } else {
 121                        /*
 122                         * Defer the switch to the current thread's TTBR0_EL1
 123                         * until uaccess_enable(). Restore the current
 124                         * thread's saved ttbr0 corresponding to its active_mm
 125                         */
 126                        uaccess_ttbr0_disable();
 127                        update_saved_ttbr0(current, current->active_mm);
 128                }
 129        }
 130}
 131
 132void efi_virtmap_load(void);
 133void efi_virtmap_unload(void);
 134
 135static inline void efi_capsule_flush_cache_range(void *addr, int size)
 136{
 137        dcache_clean_inval_poc((unsigned long)addr, (unsigned long)addr + size);
 138}
 139
 140#endif /* _ASM_EFI_H */
 141