diff options
Diffstat (limited to 'arch/arm64/kernel/efi.c')
| -rw-r--r-- | arch/arm64/kernel/efi.c | 469 |
1 files changed, 469 insertions, 0 deletions
diff --git a/arch/arm64/kernel/efi.c b/arch/arm64/kernel/efi.c new file mode 100644 index 00000000000..14db1f6e8d7 --- /dev/null +++ b/arch/arm64/kernel/efi.c @@ -0,0 +1,469 @@ +/* + * 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/efi.h> +#include <linux/export.h> +#include <linux/memblock.h> +#include <linux/bootmem.h> +#include <linux/of.h> +#include <linux/of_fdt.h> +#include <linux/sched.h> +#include <linux/slab.h> + +#include <asm/cacheflush.h> +#include <asm/efi.h> +#include <asm/tlbflush.h> +#include <asm/mmu_context.h> + +struct efi_memory_map memmap; + +static efi_runtime_services_t *runtime; + +static u64 efi_system_table; + +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; +} + +static void __init efi_setup_idmap(void) +{ + struct memblock_region *r; + efi_memory_desc_t *md; + u64 paddr, npages, size; + + for_each_memblock(memory, r) + create_id_mapping(r->base, r->size, 0); + + /* map runtime io spaces */ + for_each_efi_memory_desc(&memmap, md) { + if (!(md->attribute & EFI_MEMORY_RUNTIME) || is_normal_ram(md)) + continue; + paddr = md->phys_addr; + npages = md->num_pages; + memrange_efi_to_native(&paddr, &npages); + size = npages << PAGE_SHIFT; + create_id_mapping(paddr, size, 1); + } +} + +static int __init uefi_init(void) +{ + efi_char16_t *c16; + 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"); + return -EINVAL; + } + 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.systab->fw_vendor, + sizeof(vendor)); + if (c16) { + for (i = 0; i < (int) sizeof(vendor) - 1 && *c16; ++i) + vendor[i] = c16[i]; + vendor[i] = '\0'; + } + + pr_info("EFI v%u.%.02u by %s\n", + efi.systab->hdr.revision >> 16, + efi.systab->hdr.revision & 0xffff, vendor); + + retval = efi_config_init(NULL); + if (retval == 0) + set_bit(EFI_CONFIG_TABLES, &efi.flags); + + early_memunmap(c16, sizeof(vendor)); + early_memunmap(efi.systab, sizeof(efi_system_table_t)); + + return retval; +} + +static __initdata char memory_type_name[][32] = { + {"Reserved"}, + {"Loader Code"}, + {"Loader Data"}, + {"Boot Code"}, + {"Boot Data"}, + {"Runtime Code"}, + {"Runtime Data"}, + {"Conventional Memory"}, + {"Unusable Memory"}, + {"ACPI Reclaim Memory"}, + {"ACPI Memory NVS"}, + {"Memory Mapped I/O"}, + {"MMIO Port Space"}, + {"PAL Code"}, +}; + +/* + * Return true for RAM regions we want to permanently reserve. + */ +static __init int is_reserve_region(efi_memory_desc_t *md) +{ + if (!is_normal_ram(md)) + return 0; + + if (md->attribute & EFI_MEMORY_RUNTIME) + return 1; + + if (md->type == EFI_ACPI_RECLAIM_MEMORY || + md->type == EFI_RESERVED_TYPE) + return 1; + + return 0; +} + +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) + pr_info(" 0x%012llx-0x%012llx [%s]", + paddr, paddr + (npages << EFI_PAGE_SHIFT) - 1, + memory_type_name[md->type]); + + 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) || + md->type == EFI_BOOT_SERVICES_CODE || + md->type == EFI_BOOT_SERVICES_DATA) { + memblock_reserve(paddr, size); + if (uefi_debug) + pr_cont("*"); + } + + if (uefi_debug) + pr_cont("\n"); + } +} + + +static u64 __init free_one_region(u64 start, u64 end) +{ + u64 size = end - start; + + if (uefi_debug) + pr_info(" EFI freeing: 0x%012llx-0x%012llx\n", start, end - 1); + + free_bootmem_late(start, size); + return size; +} + +static u64 __init free_region(u64 start, u64 end) +{ + u64 map_start, map_end, total = 0; + + if (end <= start) + return total; + + map_start = (u64)memmap.phys_map; + map_end = PAGE_ALIGN(map_start + (memmap.map_end - memmap.map)); + map_start &= PAGE_MASK; + + if (start < map_end && end > map_start) { + /* region overlaps UEFI memmap */ + if (start < map_start) + total += free_one_region(start, map_start); + + if (map_end < end) + total += free_one_region(map_end, end); + } else + total += free_one_region(start, end); + + return total; +} + +static void __init free_boot_services(void) +{ + u64 total_freed = 0; + u64 keep_end, free_start, free_end; + efi_memory_desc_t *md; + + /* + * If kernel uses larger pages than UEFI, we have to be careful + * not to inadvertantly free memory we want to keep if there is + * overlap at the kernel page size alignment. We do not want to + * free is_reserve_region() memory nor the UEFI memmap itself. + * + * The memory map is sorted, so we keep track of the end of + * any previous region we want to keep, remember any region + * we want to free and defer freeing it until we encounter + * the next region we want to keep. This way, before freeing + * it, we can clip it as needed to avoid freeing memory we + * want to keep for UEFI. + */ + + keep_end = 0; + free_start = 0; + + for_each_efi_memory_desc(&memmap, md) { + u64 paddr, npages, size; + + if (is_reserve_region(md)) { + /* + * We don't want to free any memory from this region. + */ + if (free_start) { + /* adjust free_end then free region */ + if (free_end > md->phys_addr) + free_end -= PAGE_SIZE; + total_freed += free_region(free_start, free_end); + free_start = 0; + } + keep_end = md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT); + continue; + } + + if (md->type != EFI_BOOT_SERVICES_CODE && + md->type != EFI_BOOT_SERVICES_DATA) { + /* no need to free this region */ + continue; + } + + /* + * We want to free memory from this region. + */ + paddr = md->phys_addr; + npages = md->num_pages; + memrange_efi_to_native(&paddr, &npages); + size = npages << PAGE_SHIFT; + + if (free_start) { + if (paddr <= free_end) + free_end = paddr + size; + else { + total_freed += free_region(free_start, free_end); + free_start = paddr; + free_end = paddr + size; + } + } else { + free_start = paddr; + free_end = paddr + size; + } + if (free_start < keep_end) { + free_start += PAGE_SIZE; + if (free_start >= free_end) + free_start = 0; + } + } + if (free_start) + total_freed += free_region(free_start, free_end); + + if (total_freed) + pr_info("Freed 0x%llx bytes of EFI boot services memory", + total_freed); +} + +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(); +} + +void __init efi_idmap_init(void) +{ + if (!efi_enabled(EFI_BOOT)) + return; + + /* boot time idmap_pg_dir is incomplete, so fill in missing parts */ + efi_setup_idmap(); +} + +static int __init remap_region(efi_memory_desc_t *md, void **new) +{ + u64 paddr, vaddr, npages, size; + + paddr = md->phys_addr; + npages = md->num_pages; + memrange_efi_to_native(&paddr, &npages); + size = npages << PAGE_SHIFT; + + if (is_normal_ram(md)) + vaddr = (__force u64)ioremap_cache(paddr, size); + else + vaddr = (__force u64)ioremap(paddr, size); + + if (!vaddr) { + pr_err("Unable to remap 0x%llx pages @ %p\n", + npages, (void *)paddr); + return 0; + } + + /* adjust for any rounding when EFI and system pagesize differs */ + md->virt_addr = vaddr + (md->phys_addr - paddr); + + if (uefi_debug) + pr_info(" EFI remap 0x%012llx => %p\n", + md->phys_addr, (void *)md->virt_addr); + + memcpy(*new, md, memmap.desc_size); + *new += memmap.desc_size; + + return 1; +} + +/* + * Switch UEFI from an identity map to a kernel virtual map + */ +static int __init arm64_enter_virtual_mode(void) +{ + efi_memory_desc_t *md; + phys_addr_t virtmap_phys; + void *virtmap, *virt_md; + efi_status_t status; + u64 mapsize; + int count = 0; + unsigned long flags; + + if (!efi_enabled(EFI_BOOT)) { + pr_info("EFI services will not be available.\n"); + return -1; + } + + pr_info("Remapping and enabling EFI services.\n"); + + /* replace early memmap mapping with permanent mapping */ + mapsize = memmap.map_end - memmap.map; + early_memunmap(memmap.map, mapsize); + memmap.map = (__force void *)ioremap_cache((phys_addr_t)memmap.phys_map, + mapsize); + memmap.map_end = memmap.map + mapsize; + + efi.memmap = &memmap; + + /* Map the runtime regions */ + virtmap = kmalloc(mapsize, GFP_KERNEL); + if (!virtmap) { + pr_err("Failed to allocate EFI virtual memmap\n"); + return -1; + } + virtmap_phys = virt_to_phys(virtmap); + virt_md = virtmap; + + for_each_efi_memory_desc(&memmap, md) { + if (!(md->attribute & EFI_MEMORY_RUNTIME)) + continue; + if (remap_region(md, &virt_md)) + ++count; + } + + efi.systab = (__force void *)efi_lookup_mapped_addr(efi_system_table); + if (efi.systab) + set_bit(EFI_SYSTEM_TABLES, &efi.flags); + + local_irq_save(flags); + cpu_switch_mm(idmap_pg_dir, &init_mm); + + /* Call SetVirtualAddressMap with the physical address of the map */ + runtime = efi.systab->runtime; + efi.set_virtual_address_map = runtime->set_virtual_address_map; + + status = efi.set_virtual_address_map(count * memmap.desc_size, + memmap.desc_size, + memmap.desc_version, + (efi_memory_desc_t *)virtmap_phys); + cpu_set_reserved_ttbr0(); + flush_tlb_all(); + local_irq_restore(flags); + + kfree(virtmap); + + free_boot_services(); + + if (status != EFI_SUCCESS) { + pr_err("Failed to set EFI virtual address map! [%lx]\n", + status); + return -1; + } + + /* Set up runtime services function pointers */ + runtime = efi.systab->runtime; + efi.get_time = runtime->get_time; + efi.set_time = runtime->set_time; + efi.get_wakeup_time = runtime->get_wakeup_time; + efi.set_wakeup_time = runtime->set_wakeup_time; + efi.get_variable = runtime->get_variable; + efi.get_next_variable = runtime->get_next_variable; + efi.set_variable = runtime->set_variable; + efi.query_variable_info = runtime->query_variable_info; + efi.update_capsule = runtime->update_capsule; + efi.query_capsule_caps = runtime->query_capsule_caps; + efi.get_next_high_mono_count = runtime->get_next_high_mono_count; + efi.reset_system = runtime->reset_system; + + set_bit(EFI_RUNTIME_SERVICES, &efi.flags); + + return 0; +} +early_initcall(arm64_enter_virtual_mode); |