diff options
Diffstat (limited to 'arch/arm64/kernel/efi.c')
| -rw-r--r-- | arch/arm64/kernel/efi.c | 369 |
1 files changed, 369 insertions, 0 deletions
diff --git a/arch/arm64/kernel/efi.c b/arch/arm64/kernel/efi.c new file mode 100644 index 000000000..ab21e0d58 --- /dev/null +++ b/arch/arm64/kernel/efi.c @@ -0,0 +1,369 @@ +/* + * 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), + INIT_MM_CONTEXT(efi_mm) +}; + +static int uefi_debug __initdata; +static int __init uefi_debug_setup(char *str) +{ + uefi_debug = 1; + + return 0; +} +early_param("uefi_debug", uefi_debug_setup); + +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)); + if (c16) { + for (i = 0; i < (int) sizeof(vendor) - 1 && *c16; ++i) + vendor[i] = c16[i]; + vendor[i] = '\0'; + early_memunmap(c16, sizeof(vendor)); + } + + 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: + 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 (uefi_debug) + pr_info("Processing EFI memory map:\n"); + + for_each_efi_memory_desc(&memmap, md) { + paddr = md->phys_addr; + npages = md->num_pages; + + if (uefi_debug) { + 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 (uefi_debug) + pr_cont("*"); + } + + if (uefi_debug) + 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, uefi_debug)) + 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 = (void *)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; + + 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) + prot = PAGE_KERNEL_EXEC; + else + prot = PAGE_KERNEL; + + create_pgd_mapping(&efi_mm, paddr, md->virt_addr, size, prot); + } + 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((phys_addr_t)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) +{ + if (mm == &init_mm) + cpu_set_reserved_ttbr0(); + else + cpu_switch_mm(mm->pgd, mm); + + flush_tlb_all(); + if (icache_is_aivivt()) + __flush_icache_all(); +} + +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); +} |