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 18 bool efi_runtime_fixup_exception(struct pt_regs *regs, const char *msg); 19 #else 20 #define efi_init() 21 22 static inline 23 bool efi_runtime_fixup_exception(struct pt_regs *regs, const char *msg) 24 { 25 return false; 26 } 27 #endif 28 29 int efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md); 30 int efi_set_mapping_permissions(struct mm_struct *mm, efi_memory_desc_t *md, 31 bool has_bti); 32 33 #define arch_efi_call_virt_setup() \ 34 ({ \ 35 efi_virtmap_load(); \ 36 __efi_fpsimd_begin(); \ 37 raw_spin_lock(&efi_rt_lock); \ 38 }) 39 40 #undef arch_efi_call_virt 41 #define arch_efi_call_virt(p, f, args...) \ 42 __efi_rt_asm_wrapper((p)->f, #f, args) 43 44 #define arch_efi_call_virt_teardown() \ 45 ({ \ 46 raw_spin_unlock(&efi_rt_lock); \ 47 __efi_fpsimd_end(); \ 48 efi_virtmap_unload(); \ 49 }) 50 51 extern raw_spinlock_t efi_rt_lock; 52 extern u64 *efi_rt_stack_top; 53 efi_status_t __efi_rt_asm_wrapper(void *, const char *, ...); 54 55 /* 56 * efi_rt_stack_top[-1] contains the value the stack pointer had before 57 * switching to the EFI runtime stack. 58 */ 59 #define current_in_efi() \ 60 (!preemptible() && efi_rt_stack_top != NULL && \ 61 on_task_stack(current, READ_ONCE(efi_rt_stack_top[-1]), 1)) 62 63 #define ARCH_EFI_IRQ_FLAGS_MASK (PSR_D_BIT | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT) 64 65 /* 66 * Even when Linux uses IRQ priorities for IRQ disabling, EFI does not. 67 * And EFI shouldn't really play around with priority masking as it is not aware 68 * which priorities the OS has assigned to its interrupts. 69 */ 70 #define arch_efi_save_flags(state_flags) \ 71 ((void)((state_flags) = read_sysreg(daif))) 72 73 #define arch_efi_restore_flags(state_flags) write_sysreg(state_flags, daif) 74 75 76 /* arch specific definitions used by the stub code */ 77 78 /* 79 * In some configurations (e.g. VMAP_STACK && 64K pages), stacks built into the 80 * kernel need greater alignment than we require the segments to be padded to. 81 */ 82 #define EFI_KIMG_ALIGN \ 83 (SEGMENT_ALIGN > THREAD_ALIGN ? SEGMENT_ALIGN : THREAD_ALIGN) 84 85 /* 86 * On arm64, we have to ensure that the initrd ends up in the linear region, 87 * which is a 1 GB aligned region of size '1UL << (VA_BITS_MIN - 1)' that is 88 * guaranteed to cover the kernel Image. 89 * 90 * Since the EFI stub is part of the kernel Image, we can relax the 91 * usual requirements in Documentation/arch/arm64/booting.rst, which still 92 * apply to other bootloaders, and are required for some kernel 93 * configurations. 94 */ 95 static inline unsigned long efi_get_max_initrd_addr(unsigned long image_addr) 96 { 97 return (image_addr & ~(SZ_1G - 1UL)) + (1UL << (VA_BITS_MIN - 1)); 98 } 99 100 static inline unsigned long efi_get_kimg_min_align(void) 101 { 102 extern bool efi_nokaslr; 103 104 /* 105 * Although relocatable kernels can fix up the misalignment with 106 * respect to MIN_KIMG_ALIGN, the resulting virtual text addresses are 107 * subtly out of sync with those recorded in the vmlinux when kaslr is 108 * disabled but the image required relocation anyway. Therefore retain 109 * 2M alignment if KASLR was explicitly disabled, even if it was not 110 * going to be activated to begin with. 111 */ 112 return efi_nokaslr ? MIN_KIMG_ALIGN : EFI_KIMG_ALIGN; 113 } 114 115 #define EFI_ALLOC_ALIGN SZ_64K 116 #define EFI_ALLOC_LIMIT ((1UL << 48) - 1) 117 118 extern unsigned long primary_entry_offset(void); 119 120 /* 121 * On ARM systems, virtually remapped UEFI runtime services are set up in two 122 * distinct stages: 123 * - The stub retrieves the final version of the memory map from UEFI, populates 124 * the virt_addr fields and calls the SetVirtualAddressMap() [SVAM] runtime 125 * service to communicate the new mapping to the firmware (Note that the new 126 * mapping is not live at this time) 127 * - During an early initcall(), the EFI system table is permanently remapped 128 * and the virtual remapping of the UEFI Runtime Services regions is loaded 129 * into a private set of page tables. If this all succeeds, the Runtime 130 * Services are enabled and the EFI_RUNTIME_SERVICES bit set. 131 */ 132 133 static inline void efi_set_pgd(struct mm_struct *mm) 134 { 135 __switch_mm(mm); 136 137 if (system_uses_ttbr0_pan()) { 138 if (mm != current->active_mm) { 139 /* 140 * Update the current thread's saved ttbr0 since it is 141 * restored as part of a return from exception. Enable 142 * access to the valid TTBR0_EL1 and invoke the errata 143 * workaround directly since there is no return from 144 * exception when invoking the EFI run-time services. 145 */ 146 update_saved_ttbr0(current, mm); 147 uaccess_ttbr0_enable(); 148 post_ttbr_update_workaround(); 149 } else { 150 /* 151 * Defer the switch to the current thread's TTBR0_EL1 152 * until uaccess_enable(). Restore the current 153 * thread's saved ttbr0 corresponding to its active_mm 154 */ 155 uaccess_ttbr0_disable(); 156 update_saved_ttbr0(current, current->active_mm); 157 } 158 } 159 } 160 161 void efi_virtmap_load(void); 162 void efi_virtmap_unload(void); 163 164 static inline void efi_capsule_flush_cache_range(void *addr, int size) 165 { 166 dcache_clean_inval_poc((unsigned long)addr, (unsigned long)addr + size); 167 } 168 169 efi_status_t efi_handle_corrupted_x18(efi_status_t s, const char *f); 170 171 #endif /* _ASM_EFI_H */ 172