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