diff options
Diffstat (limited to 'drivers/firmware/efi/arm-init.c')
| -rw-r--r-- | drivers/firmware/efi/arm-init.c | 209 |
1 files changed, 209 insertions, 0 deletions
diff --git a/drivers/firmware/efi/arm-init.c b/drivers/firmware/efi/arm-init.c new file mode 100644 index 000000000..9e15d571b --- /dev/null +++ b/drivers/firmware/efi/arm-init.c @@ -0,0 +1,209 @@ +/* + * Extensible Firmware Interface + * + * Based on Extensible Firmware Interface Specification version 2.4 + * + * Copyright (C) 2013 - 2015 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/efi.h> +#include <linux/init.h> +#include <linux/memblock.h> +#include <linux/mm_types.h> +#include <linux/of.h> +#include <linux/of_fdt.h> + +#include <asm/efi.h> + +struct efi_memory_map memmap; + +u64 efi_system_table; + +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; + size_t 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); + if (IS_ENABLED(CONFIG_64BIT)) + 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); + if (config_tables == NULL) { + pr_warn("Unable to map EFI config table array.\n"); + retval = -ENOMEM; + goto out; + } + retval = efi_config_parse_tables(config_tables, efi.systab->nr_tables, + sizeof(efi_config_table_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_mark_nomap(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; + + memmap.phys_map = params.mmap; + memmap.map = early_memremap(params.mmap, params.mmap_size); + if (memmap.map == NULL) { + /* + * If we are booting via UEFI, the UEFI memory map is the only + * description of memory we have, so there is little point in + * proceeding if we cannot access it. + */ + panic("Unable to map EFI memory map.\n"); + } + 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); + memblock_mark_nomap(params.mmap & PAGE_MASK, + PAGE_ALIGN(params.mmap_size + + (params.mmap & ~PAGE_MASK))); +} |