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789957ef72
Call into the generic memory attributes table support code at the appropriate times during the init sequence so that the UEFI Runtime Services region are mapped according to the strict permissions it specifies. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Leif Lindholm <leif.lindholm@linaro.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Jones <pjones@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/1461614832-17633-15-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
145 lines
3.4 KiB
C
145 lines
3.4 KiB
C
/*
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* Extensible Firmware Interface
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*
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* Based on Extensible Firmware Interface Specification version 2.4
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*
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* Copyright (C) 2013, 2014 Linaro Ltd.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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*/
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#include <linux/efi.h>
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#include <linux/io.h>
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#include <linux/memblock.h>
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#include <linux/mm_types.h>
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#include <linux/preempt.h>
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#include <linux/rbtree.h>
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#include <linux/rwsem.h>
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#include <linux/sched.h>
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#include <linux/slab.h>
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#include <linux/spinlock.h>
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#include <asm/cacheflush.h>
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#include <asm/efi.h>
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#include <asm/mmu.h>
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#include <asm/pgalloc.h>
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#include <asm/pgtable.h>
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extern u64 efi_system_table;
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static struct mm_struct efi_mm = {
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.mm_rb = RB_ROOT,
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.mm_users = ATOMIC_INIT(2),
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.mm_count = ATOMIC_INIT(1),
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.mmap_sem = __RWSEM_INITIALIZER(efi_mm.mmap_sem),
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.page_table_lock = __SPIN_LOCK_UNLOCKED(efi_mm.page_table_lock),
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.mmlist = LIST_HEAD_INIT(efi_mm.mmlist),
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};
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static bool __init efi_virtmap_init(void)
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{
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efi_memory_desc_t *md;
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bool systab_found;
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efi_mm.pgd = pgd_alloc(&efi_mm);
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init_new_context(NULL, &efi_mm);
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systab_found = false;
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for_each_efi_memory_desc(md) {
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phys_addr_t phys = md->phys_addr;
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int ret;
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if (!(md->attribute & EFI_MEMORY_RUNTIME))
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continue;
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if (md->virt_addr == 0)
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return false;
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ret = efi_create_mapping(&efi_mm, md);
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if (!ret) {
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pr_info(" EFI remap %pa => %p\n",
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&phys, (void *)(unsigned long)md->virt_addr);
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} else {
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pr_warn(" EFI remap %pa: failed to create mapping (%d)\n",
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&phys, ret);
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return false;
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}
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/*
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* If this entry covers the address of the UEFI system table,
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* calculate and record its virtual address.
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*/
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if (efi_system_table >= phys &&
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efi_system_table < phys + (md->num_pages * EFI_PAGE_SIZE)) {
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efi.systab = (void *)(unsigned long)(efi_system_table -
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phys + md->virt_addr);
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systab_found = true;
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}
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}
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if (!systab_found) {
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pr_err("No virtual mapping found for the UEFI System Table\n");
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return false;
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}
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if (efi_memattr_apply_permissions(&efi_mm, efi_set_mapping_permissions))
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return false;
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return true;
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}
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/*
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* Enable the UEFI Runtime Services if all prerequisites are in place, i.e.,
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* non-early mapping of the UEFI system table and virtual mappings for all
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* EFI_MEMORY_RUNTIME regions.
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*/
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static int __init arm_enable_runtime_services(void)
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{
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u64 mapsize;
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if (!efi_enabled(EFI_BOOT)) {
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pr_info("EFI services will not be available.\n");
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return 0;
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}
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if (efi_runtime_disabled()) {
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pr_info("EFI runtime services will be disabled.\n");
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return 0;
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}
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pr_info("Remapping and enabling EFI services.\n");
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mapsize = efi.memmap.map_end - efi.memmap.map;
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efi.memmap.map = memremap(efi.memmap.phys_map, mapsize, MEMREMAP_WB);
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if (!efi.memmap.map) {
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pr_err("Failed to remap EFI memory map\n");
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return -ENOMEM;
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}
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efi.memmap.map_end = efi.memmap.map + mapsize;
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if (!efi_virtmap_init()) {
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pr_err("UEFI virtual mapping missing or invalid -- runtime services will not be available\n");
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return -ENOMEM;
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}
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/* Set up runtime services function pointers */
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efi_native_runtime_setup();
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set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
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return 0;
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}
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early_initcall(arm_enable_runtime_services);
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void efi_virtmap_load(void)
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{
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preempt_disable();
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efi_set_pgd(&efi_mm);
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}
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void efi_virtmap_unload(void)
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{
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efi_set_pgd(current->active_mm);
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preempt_enable();
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}
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