arch/arm64/include/asm/efi.h

   1 #ifndef _ASM_EFI_H
   2 #define _ASM_EFI_H
   3
   4 #include <asm/cpufeature.h>
   5 #include <asm/io.h>
   6 #include <asm/mmu_context.h>
   7 #include <asm/neon.h>
   8 #include <asm/ptrace.h>
   9 #include <asm/tlbflush.h>
  10
  11 #ifdef CONFIG_EFI
  12 extern void efi_init(void);
  13 #else
  14 #define efi_init()
  15 #endif
  16
  17 int efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md);
  18 int efi_set_mapping_permissions(struct mm_struct *mm, efi_memory_desc_t *md);
  19
  20 #define arch_efi_call_virt_setup()                                      \
  21 ({                                                                      \
  22         kernel_neon_begin();                                            \
  23         efi_virtmap_load();                                             \
  24 })
  25
  26 #define arch_efi_call_virt(p, f, args...)                               \
  27 ({                                                                      \
  28         efi_##f##_t *__f;                                               \
  29         __f = p->f;                                                     \
  30         __f(args);                                                      \
  31 })
  32
  33 #define arch_efi_call_virt_teardown()                                   \
  34 ({                                                                      \
  35         efi_virtmap_unload();                                           \
  36         kernel_neon_end();                                              \
  37 })
  38
  39 #define ARCH_EFI_IRQ_FLAGS_MASK (PSR_D_BIT | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT)
  40
  41 /* arch specific definitions used by the stub code */
  42
  43 /*
  44  * AArch64 requires the DTB to be 8-byte aligned in the first 512MiB from
  45  * start of kernel and may not cross a 2MiB boundary. We set alignment to
  46  * 2MiB so we know it won't cross a 2MiB boundary.
  47  */
  48 #define EFI_FDT_ALIGN   SZ_2M   /* used by allocate_new_fdt_and_exit_boot() */
  49 #define MAX_FDT_OFFSET  SZ_512M
  50
  51 #define efi_call_early(f, ...)          sys_table_arg->boottime->f(__VA_ARGS__)
  52 #define __efi_call_early(f, ...)        f(__VA_ARGS__)
  53 #define efi_is_64bit()                  (true)
  54
  55 #define efi_call_proto(protocol, f, instance, ...)                      \
  56         ((protocol##_t *)instance)->f(instance, ##__VA_ARGS__)
  57
  58 #define alloc_screen_info(x...)         &screen_info
  59 #define free_screen_info(x...)
  60
  61 static inline void efifb_setup_from_dmi(struct screen_info *si, const char *opt)
  62 {
  63 }
  64
  65 #define EFI_ALLOC_ALIGN         SZ_64K
  66
  67 /*
  68  * On ARM systems, virtually remapped UEFI runtime services are set up in two
  69  * distinct stages:
  70  * - The stub retrieves the final version of the memory map from UEFI, populates
  71  *   the virt_addr fields and calls the SetVirtualAddressMap() [SVAM] runtime
  72  *   service to communicate the new mapping to the firmware (Note that the new
  73  *   mapping is not live at this time)
  74  * - During an early initcall(), the EFI system table is permanently remapped
  75  *   and the virtual remapping of the UEFI Runtime Services regions is loaded
  76  *   into a private set of page tables. If this all succeeds, the Runtime
  77  *   Services are enabled and the EFI_RUNTIME_SERVICES bit set.
  78  */
  79
  80 static inline void efi_set_pgd(struct mm_struct *mm)
  81 {
  82         __switch_mm(mm);
  83
  84         if (system_uses_ttbr0_pan()) {
  85                 if (mm != current->active_mm) {
  86                         /*
  87                          * Update the current thread's saved ttbr0 since it is
  88                          * restored as part of a return from exception. Set
  89                          * the hardware TTBR0_EL1 using cpu_switch_mm()
  90                          * directly to enable potential errata workarounds.
  91                          */
  92                         update_saved_ttbr0(current, mm);
  93                         cpu_switch_mm(mm->pgd, mm);
  94                 } else {
  95                         /*
  96                          * Defer the switch to the current thread's TTBR0_EL1
  97                          * until uaccess_enable(). Restore the current
  98                          * thread's saved ttbr0 corresponding to its active_mm
  99                          * (if different from init_mm).
 100                          */
 101                         cpu_set_reserved_ttbr0();
 102                         if (current->active_mm != &init_mm)
 103                                 update_saved_ttbr0(current, current->active_mm);
 104                 }
 105         }
 106 }
 107
 108 void efi_virtmap_load(void);
 109 void efi_virtmap_unload(void);
 110
 111 #endif /* _ASM_EFI_H */