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 <asm/efi.h> 9 #include <asm/mach/map.h> 10 #include <asm/mmu_context.h> 11 12 static int __init set_permissions(pte_t *ptep, unsigned long addr, void *data) 13 { 14 efi_memory_desc_t *md = data; 15 pte_t pte = *ptep; 16 17 if (md->attribute & EFI_MEMORY_RO) 18 pte = set_pte_bit(pte, __pgprot(L_PTE_RDONLY)); 19 if (md->attribute & EFI_MEMORY_XP) 20 pte = set_pte_bit(pte, __pgprot(L_PTE_XN)); 21 set_pte_ext(ptep, pte, PTE_EXT_NG); 22 return 0; 23 } 24 25 int __init efi_set_mapping_permissions(struct mm_struct *mm, 26 efi_memory_desc_t *md, 27 bool ignored) 28 { 29 unsigned long base, size; 30 31 base = md->virt_addr; 32 size = md->num_pages << EFI_PAGE_SHIFT; 33 34 /* 35 * We can only use apply_to_page_range() if we can guarantee that the 36 * entire region was mapped using pages. This should be the case if the 37 * region does not cover any naturally aligned SECTION_SIZE sized 38 * blocks. 39 */ 40 if (round_down(base + size, SECTION_SIZE) < 41 round_up(base, SECTION_SIZE) + SECTION_SIZE) 42 return apply_to_page_range(mm, base, size, set_permissions, md); 43 44 return 0; 45 } 46 47 int __init efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md) 48 { 49 struct map_desc desc = { 50 .virtual = md->virt_addr, 51 .pfn = __phys_to_pfn(md->phys_addr), 52 .length = md->num_pages * EFI_PAGE_SIZE, 53 }; 54 55 /* 56 * Order is important here: memory regions may have all of the 57 * bits below set (and usually do), so we check them in order of 58 * preference. 59 */ 60 if (md->attribute & EFI_MEMORY_WB) 61 desc.type = MT_MEMORY_RWX; 62 else if (md->attribute & EFI_MEMORY_WT) 63 desc.type = MT_MEMORY_RWX_NONCACHED; 64 else if (md->attribute & EFI_MEMORY_WC) 65 desc.type = MT_DEVICE_WC; 66 else 67 desc.type = MT_DEVICE; 68 69 create_mapping_late(mm, &desc, true); 70 71 /* 72 * If stricter permissions were specified, apply them now. 73 */ 74 if (md->attribute & (EFI_MEMORY_RO | EFI_MEMORY_XP)) 75 return efi_set_mapping_permissions(mm, md, false); 76 return 0; 77 } 78 79 static unsigned long __initdata cpu_state_table = EFI_INVALID_TABLE_ADDR; 80 81 const efi_config_table_type_t efi_arch_tables[] __initconst = { 82 {LINUX_EFI_ARM_CPU_STATE_TABLE_GUID, &cpu_state_table}, 83 {} 84 }; 85 86 static void __init load_cpu_state_table(void) 87 { 88 if (cpu_state_table != EFI_INVALID_TABLE_ADDR) { 89 struct efi_arm_entry_state *state; 90 bool dump_state = true; 91 92 state = early_memremap_ro(cpu_state_table, 93 sizeof(struct efi_arm_entry_state)); 94 if (state == NULL) { 95 pr_warn("Unable to map CPU entry state table.\n"); 96 return; 97 } 98 99 if ((state->sctlr_before_ebs & 1) == 0) 100 pr_warn(FW_BUG "EFI stub was entered with MMU and Dcache disabled, please fix your firmware!\n"); 101 else if ((state->sctlr_after_ebs & 1) == 0) 102 pr_warn(FW_BUG "ExitBootServices() returned with MMU and Dcache disabled, please fix your firmware!\n"); 103 else 104 dump_state = false; 105 106 if (dump_state || efi_enabled(EFI_DBG)) { 107 pr_info("CPSR at EFI stub entry : 0x%08x\n", 108 state->cpsr_before_ebs); 109 pr_info("SCTLR at EFI stub entry : 0x%08x\n", 110 state->sctlr_before_ebs); 111 pr_info("CPSR after ExitBootServices() : 0x%08x\n", 112 state->cpsr_after_ebs); 113 pr_info("SCTLR after ExitBootServices(): 0x%08x\n", 114 state->sctlr_after_ebs); 115 } 116 early_memunmap(state, sizeof(struct efi_arm_entry_state)); 117 } 118 } 119 120 void __init arm_efi_init(void) 121 { 122 efi_init(); 123 124 if (screen_info.orig_video_isVGA == VIDEO_TYPE_EFI) { 125 /* dummycon on ARM needs non-zero values for columns/lines */ 126 screen_info.orig_video_cols = 80; 127 screen_info.orig_video_lines = 25; 128 } 129 130 /* ARM does not permit early mappings to persist across paging_init() */ 131 efi_memmap_unmap(); 132 133 load_cpu_state_table(); 134 } 135