| /* |
| * Extensible Firmware Interface |
| * |
| * Based on Extensible Firmware Interface Specification version 2.4 |
| * |
| * Copyright (C) 2013, 2014 Linaro Ltd. |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 as |
| * published by the Free Software Foundation. |
| * |
| */ |
| |
| #include <linux/atomic.h> |
| #include <linux/dmi.h> |
| #include <linux/efi.h> |
| #include <linux/export.h> |
| #include <linux/memblock.h> |
| #include <linux/mm_types.h> |
| #include <linux/bootmem.h> |
| #include <linux/of.h> |
| #include <linux/of_fdt.h> |
| #include <linux/preempt.h> |
| #include <linux/rbtree.h> |
| #include <linux/rwsem.h> |
| #include <linux/sched.h> |
| #include <linux/slab.h> |
| #include <linux/spinlock.h> |
| |
| #include <asm/cacheflush.h> |
| #include <asm/efi.h> |
| #include <asm/tlbflush.h> |
| #include <asm/mmu_context.h> |
| #include <asm/mmu.h> |
| #include <asm/pgtable.h> |
| |
| struct efi_memory_map memmap; |
| |
| static u64 efi_system_table; |
| |
| static pgd_t efi_pgd[PTRS_PER_PGD] __page_aligned_bss; |
| |
| static struct mm_struct efi_mm = { |
| .mm_rb = RB_ROOT, |
| .pgd = efi_pgd, |
| .mm_users = ATOMIC_INIT(2), |
| .mm_count = ATOMIC_INIT(1), |
| .mmap_sem = __RWSEM_INITIALIZER(efi_mm.mmap_sem), |
| .page_table_lock = __SPIN_LOCK_UNLOCKED(efi_mm.page_table_lock), |
| .mmlist = LIST_HEAD_INIT(efi_mm.mmlist), |
| }; |
| |
| static int __init is_normal_ram(efi_memory_desc_t *md) |
| { |
| if (md->attribute & EFI_MEMORY_WB) |
| return 1; |
| return 0; |
| } |
| |
| /* |
| * Translate a EFI virtual address into a physical address: this is necessary, |
| * as some data members of the EFI system table are virtually remapped after |
| * SetVirtualAddressMap() has been called. |
| */ |
| static phys_addr_t efi_to_phys(unsigned long addr) |
| { |
| efi_memory_desc_t *md; |
| |
| for_each_efi_memory_desc(&memmap, md) { |
| if (!(md->attribute & EFI_MEMORY_RUNTIME)) |
| continue; |
| if (md->virt_addr == 0) |
| /* no virtual mapping has been installed by the stub */ |
| break; |
| if (md->virt_addr <= addr && |
| (addr - md->virt_addr) < (md->num_pages << EFI_PAGE_SHIFT)) |
| return md->phys_addr + addr - md->virt_addr; |
| } |
| return addr; |
| } |
| |
| static int __init uefi_init(void) |
| { |
| efi_char16_t *c16; |
| void *config_tables; |
| u64 table_size; |
| char vendor[100] = "unknown"; |
| int i, retval; |
| |
| efi.systab = early_memremap(efi_system_table, |
| sizeof(efi_system_table_t)); |
| if (efi.systab == NULL) { |
| pr_warn("Unable to map EFI system table.\n"); |
| return -ENOMEM; |
| } |
| |
| set_bit(EFI_BOOT, &efi.flags); |
| set_bit(EFI_64BIT, &efi.flags); |
| |
| /* |
| * Verify the EFI Table |
| */ |
| if (efi.systab->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) { |
| pr_err("System table signature incorrect\n"); |
| retval = -EINVAL; |
| goto out; |
| } |
| if ((efi.systab->hdr.revision >> 16) < 2) |
| pr_warn("Warning: EFI system table version %d.%02d, expected 2.00 or greater\n", |
| efi.systab->hdr.revision >> 16, |
| efi.systab->hdr.revision & 0xffff); |
| |
| /* Show what we know for posterity */ |
| c16 = early_memremap(efi_to_phys(efi.systab->fw_vendor), |
| sizeof(vendor) * sizeof(efi_char16_t)); |
| if (c16) { |
| for (i = 0; i < (int) sizeof(vendor) - 1 && *c16; ++i) |
| vendor[i] = c16[i]; |
| vendor[i] = '\0'; |
| early_memunmap(c16, sizeof(vendor) * sizeof(efi_char16_t)); |
| } |
| |
| pr_info("EFI v%u.%.02u by %s\n", |
| efi.systab->hdr.revision >> 16, |
| efi.systab->hdr.revision & 0xffff, vendor); |
| |
| table_size = sizeof(efi_config_table_64_t) * efi.systab->nr_tables; |
| config_tables = early_memremap(efi_to_phys(efi.systab->tables), |
| table_size); |
| |
| retval = efi_config_parse_tables(config_tables, efi.systab->nr_tables, |
| sizeof(efi_config_table_64_t), NULL); |
| |
| early_memunmap(config_tables, table_size); |
| out: |
| early_memunmap(efi.systab, sizeof(efi_system_table_t)); |
| return retval; |
| } |
| |
| /* |
| * Return true for RAM regions we want to permanently reserve. |
| */ |
| static __init int is_reserve_region(efi_memory_desc_t *md) |
| { |
| switch (md->type) { |
| case EFI_LOADER_CODE: |
| case EFI_LOADER_DATA: |
| case EFI_BOOT_SERVICES_CODE: |
| case EFI_BOOT_SERVICES_DATA: |
| case EFI_CONVENTIONAL_MEMORY: |
| case EFI_PERSISTENT_MEMORY: |
| return 0; |
| default: |
| break; |
| } |
| return is_normal_ram(md); |
| } |
| |
| static __init void reserve_regions(void) |
| { |
| efi_memory_desc_t *md; |
| u64 paddr, npages, size; |
| |
| if (efi_enabled(EFI_DBG)) |
| pr_info("Processing EFI memory map:\n"); |
| |
| for_each_efi_memory_desc(&memmap, md) { |
| paddr = md->phys_addr; |
| npages = md->num_pages; |
| |
| if (efi_enabled(EFI_DBG)) { |
| char buf[64]; |
| |
| pr_info(" 0x%012llx-0x%012llx %s", |
| paddr, paddr + (npages << EFI_PAGE_SHIFT) - 1, |
| efi_md_typeattr_format(buf, sizeof(buf), md)); |
| } |
| |
| memrange_efi_to_native(&paddr, &npages); |
| size = npages << PAGE_SHIFT; |
| |
| if (is_normal_ram(md)) |
| early_init_dt_add_memory_arch(paddr, size); |
| |
| if (is_reserve_region(md)) { |
| memblock_reserve(paddr, size); |
| if (efi_enabled(EFI_DBG)) |
| pr_cont("*"); |
| } |
| |
| if (efi_enabled(EFI_DBG)) |
| pr_cont("\n"); |
| } |
| |
| set_bit(EFI_MEMMAP, &efi.flags); |
| } |
| |
| void __init efi_init(void) |
| { |
| struct efi_fdt_params params; |
| |
| /* Grab UEFI information placed in FDT by stub */ |
| if (!efi_get_fdt_params(¶ms)) |
| return; |
| |
| efi_system_table = params.system_table; |
| |
| memblock_reserve(params.mmap & PAGE_MASK, |
| PAGE_ALIGN(params.mmap_size + (params.mmap & ~PAGE_MASK))); |
| memmap.phys_map = params.mmap; |
| memmap.map = early_memremap(params.mmap, params.mmap_size); |
| memmap.map_end = memmap.map + params.mmap_size; |
| memmap.desc_size = params.desc_size; |
| memmap.desc_version = params.desc_ver; |
| |
| if (uefi_init() < 0) |
| return; |
| |
| reserve_regions(); |
| early_memunmap(memmap.map, params.mmap_size); |
| } |
| |
| static bool __init efi_virtmap_init(void) |
| { |
| efi_memory_desc_t *md; |
| |
| init_new_context(NULL, &efi_mm); |
| |
| for_each_efi_memory_desc(&memmap, md) { |
| u64 paddr, npages, size; |
| pgprot_t prot; |
| |
| if (!(md->attribute & EFI_MEMORY_RUNTIME)) |
| continue; |
| if (md->virt_addr == 0) |
| return false; |
| |
| paddr = md->phys_addr; |
| npages = md->num_pages; |
| memrange_efi_to_native(&paddr, &npages); |
| size = npages << PAGE_SHIFT; |
| |
| pr_info(" EFI remap 0x%016llx => %p\n", |
| md->phys_addr, (void *)md->virt_addr); |
| |
| /* |
| * Only regions of type EFI_RUNTIME_SERVICES_CODE need to be |
| * executable, everything else can be mapped with the XN bits |
| * set. |
| */ |
| if (!is_normal_ram(md)) |
| prot = __pgprot(PROT_DEVICE_nGnRE); |
| else if (md->type == EFI_RUNTIME_SERVICES_CODE || |
| !PAGE_ALIGNED(md->phys_addr)) |
| prot = PAGE_KERNEL_EXEC; |
| else |
| prot = PAGE_KERNEL; |
| |
| create_pgd_mapping(&efi_mm, paddr, md->virt_addr, size, |
| __pgprot(pgprot_val(prot) | PTE_NG)); |
| } |
| return true; |
| } |
| |
| /* |
| * Enable the UEFI Runtime Services if all prerequisites are in place, i.e., |
| * non-early mapping of the UEFI system table and virtual mappings for all |
| * EFI_MEMORY_RUNTIME regions. |
| */ |
| static int __init arm64_enable_runtime_services(void) |
| { |
| u64 mapsize; |
| |
| if (!efi_enabled(EFI_BOOT)) { |
| pr_info("EFI services will not be available.\n"); |
| return -1; |
| } |
| |
| if (efi_runtime_disabled()) { |
| pr_info("EFI runtime services will be disabled.\n"); |
| return -1; |
| } |
| |
| pr_info("Remapping and enabling EFI services.\n"); |
| |
| mapsize = memmap.map_end - memmap.map; |
| memmap.map = (__force void *)ioremap_cache(memmap.phys_map, |
| mapsize); |
| if (!memmap.map) { |
| pr_err("Failed to remap EFI memory map\n"); |
| return -1; |
| } |
| memmap.map_end = memmap.map + mapsize; |
| efi.memmap = &memmap; |
| |
| efi.systab = (__force void *)ioremap_cache(efi_system_table, |
| sizeof(efi_system_table_t)); |
| if (!efi.systab) { |
| pr_err("Failed to remap EFI System Table\n"); |
| return -1; |
| } |
| set_bit(EFI_SYSTEM_TABLES, &efi.flags); |
| |
| if (!efi_virtmap_init()) { |
| pr_err("No UEFI virtual mapping was installed -- runtime services will not be available\n"); |
| return -1; |
| } |
| |
| /* Set up runtime services function pointers */ |
| efi_native_runtime_setup(); |
| set_bit(EFI_RUNTIME_SERVICES, &efi.flags); |
| |
| efi.runtime_version = efi.systab->hdr.revision; |
| |
| return 0; |
| } |
| early_initcall(arm64_enable_runtime_services); |
| |
| static int __init arm64_dmi_init(void) |
| { |
| /* |
| * On arm64, DMI depends on UEFI, and dmi_scan_machine() needs to |
| * be called early because dmi_id_init(), which is an arch_initcall |
| * itself, depends on dmi_scan_machine() having been called already. |
| */ |
| dmi_scan_machine(); |
| if (dmi_available) |
| dmi_set_dump_stack_arch_desc(); |
| return 0; |
| } |
| core_initcall(arm64_dmi_init); |
| |
| static void efi_set_pgd(struct mm_struct *mm) |
| { |
| switch_mm(NULL, mm, NULL); |
| } |
| |
| void efi_virtmap_load(void) |
| { |
| preempt_disable(); |
| efi_set_pgd(&efi_mm); |
| } |
| |
| void efi_virtmap_unload(void) |
| { |
| efi_set_pgd(current->active_mm); |
| preempt_enable(); |
| } |
| |
| /* |
| * UpdateCapsule() depends on the system being shutdown via |
| * ResetSystem(). |
| */ |
| bool efi_poweroff_required(void) |
| { |
| return efi_enabled(EFI_RUNTIME_SERVICES); |
| } |