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        __efi_rt_asm_wrapper(__f, #f, args);                            \
  35})
  36
  37#define arch_efi_call_virt_teardown()                                   \
  38({                                                                      \
  39        __efi_fpsimd_end();                                             \
  40        efi_virtmap_unload();                                           \
  41})
  42
  43efi_status_t __efi_rt_asm_wrapper(void *, const char *, ...);
  44
  45#define ARCH_EFI_IRQ_FLAGS_MASK (PSR_D_BIT | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT)
  46
  47/*
  48 * Even when Linux uses IRQ priorities for IRQ disabling, EFI does not.
  49 * And EFI shouldn't really play around with priority masking as it is not aware
  50 * which priorities the OS has assigned to its interrupts.
  51 */
  52#define arch_efi_save_flags(state_flags)                \
  53        ((void)((state_flags) = read_sysreg(daif)))
  54
  55#define arch_efi_restore_flags(state_flags)     write_sysreg(state_flags, daif)
  56
  57
  58/* arch specific definitions used by the stub code */
  59
  60/*
  61 * AArch64 requires the DTB to be 8-byte aligned in the first 512MiB from
  62 * start of kernel and may not cross a 2MiB boundary. We set alignment to
  63 * 2MiB so we know it won't cross a 2MiB boundary.
  64 */
  65#define EFI_FDT_ALIGN   SZ_2M   /* used by allocate_new_fdt_and_exit_boot() */
  66
  67/*
  68 * In some configurations (e.g. VMAP_STACK && 64K pages), stacks built into the
  69 * kernel need greater alignment than we require the segments to be padded to.
  70 */
  71#define EFI_KIMG_ALIGN  \
  72        (SEGMENT_ALIGN > THREAD_ALIGN ? SEGMENT_ALIGN : THREAD_ALIGN)
  73
  74/* on arm64, the FDT may be located anywhere in system RAM */
  75static inline unsigned long efi_get_max_fdt_addr(unsigned long dram_base)
  76{
  77        return ULONG_MAX;
  78}
  79
  80/*
  81 * On arm64, we have to ensure that the initrd ends up in the linear region,
  82 * which is a 1 GB aligned region of size '1UL << (VA_BITS_MIN - 1)' that is
  83 * guaranteed to cover the kernel Image.
  84 *
  85 * Since the EFI stub is part of the kernel Image, we can relax the
  86 * usual requirements in Documentation/arm64/booting.rst, which still
  87 * apply to other bootloaders, and are required for some kernel
  88 * configurations.
  89 */
  90static inline unsigned long efi_get_max_initrd_addr(unsigned long dram_base,
  91                                                    unsigned long image_addr)
  92{
  93        return (image_addr & ~(SZ_1G - 1UL)) + (1UL << (VA_BITS_MIN - 1));
  94}
  95
  96#define efi_call_early(f, ...)          sys_table_arg->boottime->f(__VA_ARGS__)
  97#define __efi_call_early(f, ...)        f(__VA_ARGS__)
  98#define efi_call_runtime(f, ...)        sys_table_arg->runtime->f(__VA_ARGS__)
  99#define efi_is_64bit()                  (true)
 100
 101#define efi_table_attr(table, attr, instance)                           \
 102        ((table##_t *)instance)->attr
 103
 104#define efi_call_proto(protocol, f, instance, ...)                      \
 105        ((protocol##_t *)instance)->f(instance, ##__VA_ARGS__)
 106
 107#define alloc_screen_info(x...)         &screen_info
 108
 109static inline void free_screen_info(efi_system_table_t *sys_table_arg,
 110                                    struct screen_info *si)
 111{
 112}
 113
 114/* redeclare as 'hidden' so the compiler will generate relative references */
 115extern struct screen_info screen_info __attribute__((__visibility__("hidden")));
 116
 117static inline void efifb_setup_from_dmi(struct screen_info *si, const char *opt)
 118{
 119}
 120
 121#define EFI_ALLOC_ALIGN         SZ_64K
 122
 123/*
 124 * On ARM systems, virtually remapped UEFI runtime services are set up in two
 125 * distinct stages:
 126 * - The stub retrieves the final version of the memory map from UEFI, populates
 127 *   the virt_addr fields and calls the SetVirtualAddressMap() [SVAM] runtime
 128 *   service to communicate the new mapping to the firmware (Note that the new
 129 *   mapping is not live at this time)
 130 * - During an early initcall(), the EFI system table is permanently remapped
 131 *   and the virtual remapping of the UEFI Runtime Services regions is loaded
 132 *   into a private set of page tables. If this all succeeds, the Runtime
 133 *   Services are enabled and the EFI_RUNTIME_SERVICES bit set.
 134 */
 135
 136static inline void efi_set_pgd(struct mm_struct *mm)
 137{
 138        __switch_mm(mm);
 139
 140        if (system_uses_ttbr0_pan()) {
 141                if (mm != current->active_mm) {
 142                        /*
 143                         * Update the current thread's saved ttbr0 since it is
 144                         * restored as part of a return from exception. Enable
 145                         * access to the valid TTBR0_EL1 and invoke the errata
 146                         * workaround directly since there is no return from
 147                         * exception when invoking the EFI run-time services.
 148                         */
 149                        update_saved_ttbr0(current, mm);
 150                        uaccess_ttbr0_enable();
 151                        post_ttbr_update_workaround();
 152                } else {
 153                        /*
 154                         * Defer the switch to the current thread's TTBR0_EL1
 155                         * until uaccess_enable(). Restore the current
 156                         * thread's saved ttbr0 corresponding to its active_mm
 157                         */
 158                        uaccess_ttbr0_disable();
 159                        update_saved_ttbr0(current, current->active_mm);
 160                }
 161        }
 162}
 163
 164void efi_virtmap_load(void);
 165void efi_virtmap_unload(void);
 166
 167#endif /* _ASM_EFI_H */
 168