linux/drivers/firmware/efi/arm-runtime.c

173 lines
3.7 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Extensible Firmware Interface
*
* Based on Extensible Firmware Interface Specification version 2.4
*
* Copyright (C) 2013, 2014 Linaro Ltd.
*/
#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" },
{ DEFAULT_MAP_WINDOW_64, "UEFI runtime end" },
{ -1, NULL }
},
.base_addr = 0,
};
static int __init ptdump_init(void)
{
if (efi_enabled(EFI_RUNTIME_SERVICES))
ptdump_debugfs_register(&efi_ptdump_info, "efi_page_tables");
return 0;
}
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_setup() 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_setup();
return 0;
}
core_initcall(arm_dmi_init);