0cac5c3018
The EFI DT parameters for bare metal are located under /chosen node, while for Xen Dom0 they are located under /hyperviosr/uefi node. These parameters under /chosen and /hyperviosr/uefi are not expected to appear at the same time. Parse these EFI parameters and initialize EFI like the way for bare metal except the runtime services because the runtime services for Xen Dom0 are available through hypercalls and they are always enabled. So it sets the EFI_RUNTIME_SERVICES flag if it finds /hyperviosr/uefi node and bails out in arm_enable_runtime_services() when EFI_RUNTIME_SERVICES flag is set already. Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Leif Lindholm <leif.lindholm@linaro.org> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
150 lines
3.5 KiB
C
150 lines
3.5 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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if (efi_enabled(EFI_RUNTIME_SERVICES)) {
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pr_info("EFI runtime services access via paravirt.\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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