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
  16 extern void efi_init(void);
  17 extern void efifb_setup_from_dmi(struct screen_info *si, const char *opt);
  18 #else
  19 #define efi_init()
  20 #endif
  21
  22 int efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md);
  23 int 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
  44 efi_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  */
  78 static 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
  85 static 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
 104 static 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
 132 void efi_virtmap_load(void);
 133 void efi_virtmap_unload(void);
 134
 135 static 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 */