1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2015 Linaro Ltd <ard.biesheuvel@linaro.org> 4 */ 5 6 #include <linux/efi.h> 7 #include <linux/memblock.h> 8 #include <linux/screen_info.h> 9 10 #include <asm/efi.h> 11 #include <asm/mach/map.h> 12 #include <asm/mmu_context.h> 13 14 static int __init set_permissions(pte_t *ptep, unsigned long addr, void *data) 15 { 16 efi_memory_desc_t *md = data; 17 pte_t pte = *ptep; 18 19 if (md->attribute & EFI_MEMORY_RO) 20 pte = set_pte_bit(pte, __pgprot(L_PTE_RDONLY)); 21 if (md->attribute & EFI_MEMORY_XP) 22 pte = set_pte_bit(pte, __pgprot(L_PTE_XN)); 23 set_pte_ext(ptep, pte, PTE_EXT_NG); 24 return 0; 25 } 26 27 int __init efi_set_mapping_permissions(struct mm_struct *mm, 28 efi_memory_desc_t *md, 29 bool ignored) 30 { 31 unsigned long base, size; 32 33 base = md->virt_addr; 34 size = md->num_pages << EFI_PAGE_SHIFT; 35 36 /* 37 * We can only use apply_to_page_range() if we can guarantee that the 38 * entire region was mapped using pages. This should be the case if the 39 * region does not cover any naturally aligned SECTION_SIZE sized 40 * blocks. 41 */ 42 if (round_down(base + size, SECTION_SIZE) < 43 round_up(base, SECTION_SIZE) + SECTION_SIZE) 44 return apply_to_page_range(mm, base, size, set_permissions, md); 45 46 return 0; 47 } 48 49 int __init efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md) 50 { 51 struct map_desc desc = { 52 .virtual = md->virt_addr, 53 .pfn = __phys_to_pfn(md->phys_addr), 54 .length = md->num_pages * EFI_PAGE_SIZE, 55 }; 56 57 /* 58 * Order is important here: memory regions may have all of the 59 * bits below set (and usually do), so we check them in order of 60 * preference. 61 */ 62 if (md->attribute & EFI_MEMORY_WB) 63 desc.type = MT_MEMORY_RWX; 64 else if (md->attribute & EFI_MEMORY_WT) 65 desc.type = MT_MEMORY_RWX_NONCACHED; 66 else if (md->attribute & EFI_MEMORY_WC) 67 desc.type = MT_DEVICE_WC; 68 else 69 desc.type = MT_DEVICE; 70 71 create_mapping_late(mm, &desc, true); 72 73 /* 74 * If stricter permissions were specified, apply them now. 75 */ 76 if (md->attribute & (EFI_MEMORY_RO | EFI_MEMORY_XP)) 77 return efi_set_mapping_permissions(mm, md, false); 78 return 0; 79 } 80 81 static unsigned long __initdata cpu_state_table = EFI_INVALID_TABLE_ADDR; 82 83 const efi_config_table_type_t efi_arch_tables[] __initconst = { 84 {LINUX_EFI_ARM_CPU_STATE_TABLE_GUID, &cpu_state_table}, 85 {} 86 }; 87 88 static void __init load_cpu_state_table(void) 89 { 90 if (cpu_state_table != EFI_INVALID_TABLE_ADDR) { 91 struct efi_arm_entry_state *state; 92 bool dump_state = true; 93 94 state = early_memremap_ro(cpu_state_table, 95 sizeof(struct efi_arm_entry_state)); 96 if (state == NULL) { 97 pr_warn("Unable to map CPU entry state table.\n"); 98 return; 99 } 100 101 if ((state->sctlr_before_ebs & 1) == 0) 102 pr_warn(FW_BUG "EFI stub was entered with MMU and Dcache disabled, please fix your firmware!\n"); 103 else if ((state->sctlr_after_ebs & 1) == 0) 104 pr_warn(FW_BUG "ExitBootServices() returned with MMU and Dcache disabled, please fix your firmware!\n"); 105 else 106 dump_state = false; 107 108 if (dump_state || efi_enabled(EFI_DBG)) { 109 pr_info("CPSR at EFI stub entry : 0x%08x\n", 110 state->cpsr_before_ebs); 111 pr_info("SCTLR at EFI stub entry : 0x%08x\n", 112 state->sctlr_before_ebs); 113 pr_info("CPSR after ExitBootServices() : 0x%08x\n", 114 state->cpsr_after_ebs); 115 pr_info("SCTLR after ExitBootServices(): 0x%08x\n", 116 state->sctlr_after_ebs); 117 } 118 early_memunmap(state, sizeof(struct efi_arm_entry_state)); 119 } 120 } 121 122 void __init arm_efi_init(void) 123 { 124 efi_init(); 125 126 /* ARM does not permit early mappings to persist across paging_init() */ 127 efi_memmap_unmap(); 128 129 load_cpu_state_table(); 130 } 131