diff options
Diffstat (limited to 'arch/arm64/kernel/efi.c')
-rw-r--r-- | arch/arm64/kernel/efi.c | 230 |
1 files changed, 127 insertions, 103 deletions
diff --git a/arch/arm64/kernel/efi.c b/arch/arm64/kernel/efi.c index 2bb4347d0edf..755e545144ea 100644 --- a/arch/arm64/kernel/efi.c +++ b/arch/arm64/kernel/efi.c @@ -11,25 +11,31 @@ * */ +#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 efi_runtime_services_t *runtime; - static u64 efi_system_table; static int uefi_debug __initdata; @@ -69,9 +75,33 @@ static void __init efi_setup_idmap(void) } } +/* + * 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; @@ -99,7 +129,7 @@ static int __init uefi_init(void) efi.systab->hdr.revision & 0xffff); /* Show what we know for posterity */ - c16 = early_memremap(efi.systab->fw_vendor, + c16 = early_memremap(efi_to_phys(efi.systab->fw_vendor), sizeof(vendor)); if (c16) { for (i = 0; i < (int) sizeof(vendor) - 1 && *c16; ++i) @@ -112,8 +142,14 @@ static int __init uefi_init(void) efi.systab->hdr.revision >> 16, efi.systab->hdr.revision & 0xffff, vendor); - retval = efi_config_init(NULL); + 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; @@ -329,51 +365,14 @@ void __init efi_idmap_init(void) early_memunmap(memmap.map, memmap.map_end - memmap.map); } -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 + * 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_enter_virtual_mode(void) +static int __init arm64_enable_runtime_services(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"); @@ -395,81 +394,30 @@ static int __init arm64_enter_virtual_mode(void) 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)) - goto err_unmap; - ++count; - } - - efi.systab = (__force void *)efi_lookup_mapped_addr(efi_system_table); + efi.systab = (__force void *)ioremap_cache(efi_system_table, + sizeof(efi_system_table_t)); if (!efi.systab) { - /* - * If we have no virtual mapping for the System Table at this - * point, the memory map doesn't cover the physical offset where - * it resides. This means the System Table will be inaccessible - * to Runtime Services themselves once the virtual mapping is - * installed. - */ - pr_err("Failed to remap EFI System Table -- buggy firmware?\n"); - goto err_unmap; + pr_err("Failed to remap EFI System Table\n"); + return -1; } 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); + if (!efi_enabled(EFI_VIRTMAP)) { + pr_err("No UEFI virtual mapping was installed -- runtime services will not be available\n"); return -1; } /* Set up runtime services function pointers */ - runtime = efi.systab->runtime; efi_native_runtime_setup(); set_bit(EFI_RUNTIME_SERVICES, &efi.flags); efi.runtime_version = efi.systab->hdr.revision; return 0; - -err_unmap: - /* unmap all mappings that succeeded: there are 'count' of those */ - for (virt_md = virtmap; count--; virt_md += memmap.desc_size) { - md = virt_md; - iounmap((__force void __iomem *)md->virt_addr); - } - kfree(virtmap); - return -1; } -early_initcall(arm64_enter_virtual_mode); +early_initcall(arm64_enable_runtime_services); static int __init arm64_dmi_init(void) { @@ -484,3 +432,79 @@ static int __init arm64_dmi_init(void) return 0; } core_initcall(arm64_dmi_init); + +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 void efi_set_pgd(struct mm_struct *mm) +{ + 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(); +} + +void __init efi_virtmap_init(void) +{ + efi_memory_desc_t *md; + + if (!efi_enabled(EFI_BOOT)) + return; + + for_each_efi_memory_desc(&memmap, md) { + u64 paddr, npages, size; + pgprot_t prot; + + if (!(md->attribute & EFI_MEMORY_RUNTIME)) + continue; + if (WARN(md->virt_addr == 0, + "UEFI virtual mapping incomplete or missing -- no entry found for 0x%llx\n", + md->phys_addr)) + return; + + 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); + } + set_bit(EFI_VIRTMAP, &efi.flags); +} |