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

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