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 #else
  18 #define efi_init()
  19 #endif
  20
  21 int efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md);
  22 int 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
  43 efi_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 /* arch specific definitions used by the stub code */
  48
  49 /*
  50  * AArch64 requires the DTB to be 8-byte aligned in the first 512MiB from
  51  * start of kernel and may not cross a 2MiB boundary. We set alignment to
  52  * 2MiB so we know it won't cross a 2MiB boundary.
  53  */
  54 #define EFI_FDT_ALIGN   SZ_2M   /* used by allocate_new_fdt_and_exit_boot() */
  55
  56 /*
  57  * In some configurations (e.g. VMAP_STACK && 64K pages), stacks built into the
  58  * kernel need greater alignment than we require the segments to be padded to.
  59  */
  60 #define EFI_KIMG_ALIGN  \
  61         (SEGMENT_ALIGN > THREAD_ALIGN ? SEGMENT_ALIGN : THREAD_ALIGN)
  62
  63 /* on arm64, the FDT may be located anywhere in system RAM */
  64 static inline unsigned long efi_get_max_fdt_addr(unsigned long dram_base)
  65 {
  66         return ULONG_MAX;
  67 }
  68
  69 /*
  70  * On arm64, we have to ensure that the initrd ends up in the linear region,
  71  * which is a 1 GB aligned region of size '1UL << (VA_BITS - 1)' that is
  72  * guaranteed to cover the kernel Image.
  73  *
  74  * Since the EFI stub is part of the kernel Image, we can relax the
  75  * usual requirements in Documentation/arm64/booting.txt, which still
  76  * apply to other bootloaders, and are required for some kernel
  77  * configurations.
  78  */
  79 static inline unsigned long efi_get_max_initrd_addr(unsigned long dram_base,
  80                                                     unsigned long image_addr)
  81 {
  82         return (image_addr & ~(SZ_1G - 1UL)) + (1UL << (VA_BITS - 1));
  83 }
  84
  85 #define efi_call_early(f, ...)          sys_table_arg->boottime->f(__VA_ARGS__)
  86 #define __efi_call_early(f, ...)        f(__VA_ARGS__)
  87 #define efi_call_runtime(f, ...)        sys_table_arg->runtime->f(__VA_ARGS__)
  88 #define efi_is_64bit()                  (true)
  89
  90 #define efi_call_proto(protocol, f, instance, ...)                      \
  91         ((protocol##_t *)instance)->f(instance, ##__VA_ARGS__)
  92
  93 #define alloc_screen_info(x...)         &screen_info
  94 #define free_screen_info(x...)
  95
  96 /* redeclare as 'hidden' so the compiler will generate relative references */
  97 extern struct screen_info screen_info __attribute__((__visibility__("hidden")));
  98
  99 static inline void efifb_setup_from_dmi(struct screen_info *si, const char *opt)
 100 {
 101 }
 102
 103 #define EFI_ALLOC_ALIGN         SZ_64K
 104
 105 /*
 106  * On ARM systems, virtually remapped UEFI runtime services are set up in two
 107  * distinct stages:
 108  * - The stub retrieves the final version of the memory map from UEFI, populates
 109  *   the virt_addr fields and calls the SetVirtualAddressMap() [SVAM] runtime
 110  *   service to communicate the new mapping to the firmware (Note that the new
 111  *   mapping is not live at this time)
 112  * - During an early initcall(), the EFI system table is permanently remapped
 113  *   and the virtual remapping of the UEFI Runtime Services regions is loaded
 114  *   into a private set of page tables. If this all succeeds, the Runtime
 115  *   Services are enabled and the EFI_RUNTIME_SERVICES bit set.
 116  */
 117
 118 static inline void efi_set_pgd(struct mm_struct *mm)
 119 {
 120         __switch_mm(mm);
 121
 122         if (system_uses_ttbr0_pan()) {
 123                 if (mm != current->active_mm) {
 124                         /*
 125                          * Update the current thread's saved ttbr0 since it is
 126                          * restored as part of a return from exception. Enable
 127                          * access to the valid TTBR0_EL1 and invoke the errata
 128                          * workaround directly since there is no return from
 129                          * exception when invoking the EFI run-time services.
 130                          */
 131                         update_saved_ttbr0(current, mm);
 132                         uaccess_ttbr0_enable();
 133                         post_ttbr_update_workaround();
 134                 } else {
 135                         /*
 136                          * Defer the switch to the current thread's TTBR0_EL1
 137                          * until uaccess_enable(). Restore the current
 138                          * thread's saved ttbr0 corresponding to its active_mm
 139                          */
 140                         uaccess_ttbr0_disable();
 141                         update_saved_ttbr0(current, current->active_mm);
 142                 }
 143         }
 144 }
 145
 146 void efi_virtmap_load(void);
 147 void efi_virtmap_unload(void);
 148
 149 #endif /* _ASM_EFI_H */