mirror of https://gitee.com/openkylin/linux.git
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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