2 * Extensible Firmware Interface
4 * Based on Extensible Firmware Interface Specification version 2.4
6 * Copyright (C) 2013, 2014 Linaro Ltd.
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
14 #include <linux/atomic.h>
15 #include <linux/dmi.h>
16 #include <linux/efi.h>
17 #include <linux/export.h>
18 #include <linux/memblock.h>
19 #include <linux/mm_types.h>
20 #include <linux/bootmem.h>
22 #include <linux/of_fdt.h>
23 #include <linux/preempt.h>
24 #include <linux/rbtree.h>
25 #include <linux/rwsem.h>
26 #include <linux/sched.h>
27 #include <linux/slab.h>
28 #include <linux/spinlock.h>
30 #include <asm/cacheflush.h>
32 #include <asm/tlbflush.h>
33 #include <asm/mmu_context.h>
35 #include <asm/pgtable.h>
37 struct efi_memory_map memmap;
39 static u64 efi_system_table;
41 static pgd_t efi_pgd[PTRS_PER_PGD] __page_aligned_bss;
43 static struct mm_struct efi_mm = {
46 .mm_users = ATOMIC_INIT(2),
47 .mm_count = ATOMIC_INIT(1),
48 .mmap_sem = __RWSEM_INITIALIZER(efi_mm.mmap_sem),
49 .page_table_lock = __SPIN_LOCK_UNLOCKED(efi_mm.page_table_lock),
50 .mmlist = LIST_HEAD_INIT(efi_mm.mmlist),
51 INIT_MM_CONTEXT(efi_mm)
54 static int uefi_debug __initdata;
55 static int __init uefi_debug_setup(char *str)
61 early_param("uefi_debug", uefi_debug_setup);
63 static int __init is_normal_ram(efi_memory_desc_t *md)
65 if (md->attribute & EFI_MEMORY_WB)
71 * Translate a EFI virtual address into a physical address: this is necessary,
72 * as some data members of the EFI system table are virtually remapped after
73 * SetVirtualAddressMap() has been called.
75 static phys_addr_t efi_to_phys(unsigned long addr)
77 efi_memory_desc_t *md;
79 for_each_efi_memory_desc(&memmap, md) {
80 if (!(md->attribute & EFI_MEMORY_RUNTIME))
82 if (md->virt_addr == 0)
83 /* no virtual mapping has been installed by the stub */
85 if (md->virt_addr <= addr &&
86 (addr - md->virt_addr) < (md->num_pages << EFI_PAGE_SHIFT))
87 return md->phys_addr + addr - md->virt_addr;
92 static int __init uefi_init(void)
97 char vendor[100] = "unknown";
100 efi.systab = early_memremap(efi_system_table,
101 sizeof(efi_system_table_t));
102 if (efi.systab == NULL) {
103 pr_warn("Unable to map EFI system table.\n");
107 set_bit(EFI_BOOT, &efi.flags);
108 set_bit(EFI_64BIT, &efi.flags);
111 * Verify the EFI Table
113 if (efi.systab->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) {
114 pr_err("System table signature incorrect\n");
118 if ((efi.systab->hdr.revision >> 16) < 2)
119 pr_warn("Warning: EFI system table version %d.%02d, expected 2.00 or greater\n",
120 efi.systab->hdr.revision >> 16,
121 efi.systab->hdr.revision & 0xffff);
123 /* Show what we know for posterity */
124 c16 = early_memremap(efi_to_phys(efi.systab->fw_vendor),
127 for (i = 0; i < (int) sizeof(vendor) - 1 && *c16; ++i)
130 early_memunmap(c16, sizeof(vendor));
133 pr_info("EFI v%u.%.02u by %s\n",
134 efi.systab->hdr.revision >> 16,
135 efi.systab->hdr.revision & 0xffff, vendor);
137 table_size = sizeof(efi_config_table_64_t) * efi.systab->nr_tables;
138 config_tables = early_memremap(efi_to_phys(efi.systab->tables),
141 retval = efi_config_parse_tables(config_tables, efi.systab->nr_tables,
142 sizeof(efi_config_table_64_t), NULL);
144 early_memunmap(config_tables, table_size);
146 early_memunmap(efi.systab, sizeof(efi_system_table_t));
151 * Return true for RAM regions we want to permanently reserve.
153 static __init int is_reserve_region(efi_memory_desc_t *md)
156 case EFI_LOADER_CODE:
157 case EFI_LOADER_DATA:
158 case EFI_BOOT_SERVICES_CODE:
159 case EFI_BOOT_SERVICES_DATA:
160 case EFI_CONVENTIONAL_MEMORY:
165 return is_normal_ram(md);
168 static __init void reserve_regions(void)
170 efi_memory_desc_t *md;
171 u64 paddr, npages, size;
174 pr_info("Processing EFI memory map:\n");
176 for_each_efi_memory_desc(&memmap, md) {
177 paddr = md->phys_addr;
178 npages = md->num_pages;
183 pr_info(" 0x%012llx-0x%012llx %s",
184 paddr, paddr + (npages << EFI_PAGE_SHIFT) - 1,
185 efi_md_typeattr_format(buf, sizeof(buf), md));
188 memrange_efi_to_native(&paddr, &npages);
189 size = npages << PAGE_SHIFT;
191 if (is_normal_ram(md))
192 early_init_dt_add_memory_arch(paddr, size);
194 if (is_reserve_region(md)) {
195 memblock_reserve(paddr, size);
204 set_bit(EFI_MEMMAP, &efi.flags);
207 void __init efi_init(void)
209 struct efi_fdt_params params;
211 /* Grab UEFI information placed in FDT by stub */
212 if (!efi_get_fdt_params(¶ms, uefi_debug))
215 efi_system_table = params.system_table;
217 memblock_reserve(params.mmap & PAGE_MASK,
218 PAGE_ALIGN(params.mmap_size + (params.mmap & ~PAGE_MASK)));
219 memmap.phys_map = (void *)params.mmap;
220 memmap.map = early_memremap(params.mmap, params.mmap_size);
221 memmap.map_end = memmap.map + params.mmap_size;
222 memmap.desc_size = params.desc_size;
223 memmap.desc_version = params.desc_ver;
229 early_memunmap(memmap.map, params.mmap_size);
232 static bool __init efi_virtmap_init(void)
234 efi_memory_desc_t *md;
236 for_each_efi_memory_desc(&memmap, md) {
237 u64 paddr, npages, size;
240 if (!(md->attribute & EFI_MEMORY_RUNTIME))
242 if (md->virt_addr == 0)
245 paddr = md->phys_addr;
246 npages = md->num_pages;
247 memrange_efi_to_native(&paddr, &npages);
248 size = npages << PAGE_SHIFT;
250 pr_info(" EFI remap 0x%016llx => %p\n",
251 md->phys_addr, (void *)md->virt_addr);
254 * Only regions of type EFI_RUNTIME_SERVICES_CODE need to be
255 * executable, everything else can be mapped with the XN bits
258 if (!is_normal_ram(md))
259 prot = __pgprot(PROT_DEVICE_nGnRE);
260 else if (md->type == EFI_RUNTIME_SERVICES_CODE)
261 prot = PAGE_KERNEL_EXEC;
265 create_pgd_mapping(&efi_mm, paddr, md->virt_addr, size, prot);
271 * Enable the UEFI Runtime Services if all prerequisites are in place, i.e.,
272 * non-early mapping of the UEFI system table and virtual mappings for all
273 * EFI_MEMORY_RUNTIME regions.
275 static int __init arm64_enable_runtime_services(void)
279 if (!efi_enabled(EFI_BOOT)) {
280 pr_info("EFI services will not be available.\n");
284 if (efi_runtime_disabled()) {
285 pr_info("EFI runtime services will be disabled.\n");
289 pr_info("Remapping and enabling EFI services.\n");
291 mapsize = memmap.map_end - memmap.map;
292 memmap.map = (__force void *)ioremap_cache((phys_addr_t)memmap.phys_map,
295 pr_err("Failed to remap EFI memory map\n");
298 memmap.map_end = memmap.map + mapsize;
299 efi.memmap = &memmap;
301 efi.systab = (__force void *)ioremap_cache(efi_system_table,
302 sizeof(efi_system_table_t));
304 pr_err("Failed to remap EFI System Table\n");
307 set_bit(EFI_SYSTEM_TABLES, &efi.flags);
309 if (!efi_virtmap_init()) {
310 pr_err("No UEFI virtual mapping was installed -- runtime services will not be available\n");
314 /* Set up runtime services function pointers */
315 efi_native_runtime_setup();
316 set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
318 efi.runtime_version = efi.systab->hdr.revision;
322 early_initcall(arm64_enable_runtime_services);
324 static int __init arm64_dmi_init(void)
327 * On arm64, DMI depends on UEFI, and dmi_scan_machine() needs to
328 * be called early because dmi_id_init(), which is an arch_initcall
329 * itself, depends on dmi_scan_machine() having been called already.
333 dmi_set_dump_stack_arch_desc();
336 core_initcall(arm64_dmi_init);
338 static void efi_set_pgd(struct mm_struct *mm)
341 cpu_set_reserved_ttbr0();
343 cpu_switch_mm(mm->pgd, mm);
346 if (icache_is_aivivt())
347 __flush_icache_all();
350 void efi_virtmap_load(void)
353 efi_set_pgd(&efi_mm);
356 void efi_virtmap_unload(void)
358 efi_set_pgd(current->active_mm);
363 * UpdateCapsule() depends on the system being shutdown via
366 bool efi_poweroff_required(void)
368 return efi_enabled(EFI_RUNTIME_SERVICES);