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