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 /* 48 * Even when Linux uses IRQ priorities for IRQ disabling, EFI does not. 49 * And EFI shouldn't really play around with priority masking as it is not aware 50 * which priorities the OS has assigned to its interrupts. 51 */ 52 #define arch_efi_save_flags(state_flags) \ 53 ((void)((state_flags) = read_sysreg(daif))) 54 55 #define arch_efi_restore_flags(state_flags) write_sysreg(state_flags, daif) 56 57 58 /* arch specific definitions used by the stub code */ 59 60 /* 61 * In some configurations (e.g. VMAP_STACK && 64K pages), stacks built into the 62 * kernel need greater alignment than we require the segments to be padded to. 63 */ 64 #define EFI_KIMG_ALIGN \ 65 (SEGMENT_ALIGN > THREAD_ALIGN ? SEGMENT_ALIGN : THREAD_ALIGN) 66 67 /* on arm64, the FDT may be located anywhere in system RAM */ 68 static inline unsigned long efi_get_max_fdt_addr(unsigned long dram_base) 69 { 70 return ULONG_MAX; 71 } 72 73 /* 74 * On arm64, we have to ensure that the initrd ends up in the linear region, 75 * which is a 1 GB aligned region of size '1UL << (VA_BITS_MIN - 1)' that is 76 * guaranteed to cover the kernel Image. 77 * 78 * Since the EFI stub is part of the kernel Image, we can relax the 79 * usual requirements in Documentation/arm64/booting.rst, which still 80 * apply to other bootloaders, and are required for some kernel 81 * configurations. 82 */ 83 static inline unsigned long efi_get_max_initrd_addr(unsigned long dram_base, 84 unsigned long image_addr) 85 { 86 return (image_addr & ~(SZ_1G - 1UL)) + (1UL << (VA_BITS_MIN - 1)); 87 } 88 89 #define alloc_screen_info(x...) &screen_info 90 91 static inline void free_screen_info(struct screen_info *si) 92 { 93 } 94 95 static inline void efifb_setup_from_dmi(struct screen_info *si, const char *opt) 96 { 97 } 98 99 #define EFI_ALLOC_ALIGN SZ_64K 100 101 /* 102 * On ARM systems, virtually remapped UEFI runtime services are set up in two 103 * distinct stages: 104 * - The stub retrieves the final version of the memory map from UEFI, populates 105 * the virt_addr fields and calls the SetVirtualAddressMap() [SVAM] runtime 106 * service to communicate the new mapping to the firmware (Note that the new 107 * mapping is not live at this time) 108 * - During an early initcall(), the EFI system table is permanently remapped 109 * and the virtual remapping of the UEFI Runtime Services regions is loaded 110 * into a private set of page tables. If this all succeeds, the Runtime 111 * Services are enabled and the EFI_RUNTIME_SERVICES bit set. 112 */ 113 114 static inline void efi_set_pgd(struct mm_struct *mm) 115 { 116 __switch_mm(mm); 117 118 if (system_uses_ttbr0_pan()) { 119 if (mm != current->active_mm) { 120 /* 121 * Update the current thread's saved ttbr0 since it is 122 * restored as part of a return from exception. Enable 123 * access to the valid TTBR0_EL1 and invoke the errata 124 * workaround directly since there is no return from 125 * exception when invoking the EFI run-time services. 126 */ 127 update_saved_ttbr0(current, mm); 128 uaccess_ttbr0_enable(); 129 post_ttbr_update_workaround(); 130 } else { 131 /* 132 * Defer the switch to the current thread's TTBR0_EL1 133 * until uaccess_enable(). Restore the current 134 * thread's saved ttbr0 corresponding to its active_mm 135 */ 136 uaccess_ttbr0_disable(); 137 update_saved_ttbr0(current, current->active_mm); 138 } 139 } 140 } 141 142 void efi_virtmap_load(void); 143 void efi_virtmap_unload(void); 144 145 #endif /* _ASM_EFI_H */ 146