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Diffstat (limited to '')
| -rw-r--r-- | drivers/firmware/efi/arm-runtime.c | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/drivers/firmware/efi/arm-runtime.c b/drivers/firmware/efi/arm-runtime.c new file mode 100644 index 000000000..a00934d26 --- /dev/null +++ b/drivers/firmware/efi/arm-runtime.c @@ -0,0 +1,177 @@ +/* + * 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/dmi.h> +#include <linux/efi.h> +#include <linux/io.h> +#include <linux/memblock.h> +#include <linux/mm_types.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/mmu.h> +#include <asm/pgalloc.h> +#include <asm/pgtable.h> + +extern u64 efi_system_table; + +#ifdef CONFIG_ARM64_PTDUMP_DEBUGFS +#include <asm/ptdump.h> + +static struct ptdump_info efi_ptdump_info = { + .mm = &efi_mm, + .markers = (struct addr_marker[]){ + { 0, "UEFI runtime start" }, + { TASK_SIZE_64, "UEFI runtime end" } + }, + .base_addr = 0, +}; + +static int __init ptdump_init(void) +{ + if (!efi_enabled(EFI_RUNTIME_SERVICES)) + return 0; + + return ptdump_debugfs_register(&efi_ptdump_info, "efi_page_tables"); +} +device_initcall(ptdump_init); + +#endif + +static bool __init efi_virtmap_init(void) +{ + efi_memory_desc_t *md; + bool systab_found; + + efi_mm.pgd = pgd_alloc(&efi_mm); + mm_init_cpumask(&efi_mm); + init_new_context(NULL, &efi_mm); + + systab_found = false; + for_each_efi_memory_desc(md) { + phys_addr_t phys = md->phys_addr; + int ret; + + if (!(md->attribute & EFI_MEMORY_RUNTIME)) + continue; + if (md->virt_addr == 0) + return false; + + ret = efi_create_mapping(&efi_mm, md); + if (ret) { + pr_warn(" EFI remap %pa: failed to create mapping (%d)\n", + &phys, ret); + return false; + } + /* + * If this entry covers the address of the UEFI system table, + * calculate and record its virtual address. + */ + if (efi_system_table >= phys && + efi_system_table < phys + (md->num_pages * EFI_PAGE_SIZE)) { + efi.systab = (void *)(unsigned long)(efi_system_table - + phys + md->virt_addr); + systab_found = true; + } + } + if (!systab_found) { + pr_err("No virtual mapping found for the UEFI System Table\n"); + return false; + } + + if (efi_memattr_apply_permissions(&efi_mm, efi_set_mapping_permissions)) + return false; + + 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 arm_enable_runtime_services(void) +{ + u64 mapsize; + + if (!efi_enabled(EFI_BOOT)) { + pr_info("EFI services will not be available.\n"); + return 0; + } + + efi_memmap_unmap(); + + mapsize = efi.memmap.desc_size * efi.memmap.nr_map; + + if (efi_memmap_init_late(efi.memmap.phys_map, mapsize)) { + pr_err("Failed to remap EFI memory map\n"); + return 0; + } + + if (efi_runtime_disabled()) { + pr_info("EFI runtime services will be disabled.\n"); + return 0; + } + + if (efi_enabled(EFI_RUNTIME_SERVICES)) { + pr_info("EFI runtime services access via paravirt.\n"); + return 0; + } + + pr_info("Remapping and enabling EFI services.\n"); + + if (!efi_virtmap_init()) { + pr_err("UEFI virtual mapping missing or invalid -- runtime services will not be available\n"); + return -ENOMEM; + } + + /* Set up runtime services function pointers */ + efi_native_runtime_setup(); + set_bit(EFI_RUNTIME_SERVICES, &efi.flags); + + return 0; +} +early_initcall(arm_enable_runtime_services); + +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(); +} + + +static int __init arm_dmi_init(void) +{ + /* + * On arm64/ARM, 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(arm_dmi_init); |