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* Extensible Firmware Interface
*
* Based on Extensible Firmware Interface Specification version 2.4
*
* Copyright (C) 2013, 2014 Linaro Ltd.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
*/
#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 u64 efi_system_table;
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 int uefi_debug __initdata;
static int __init uefi_debug_setup(char *str)
{
uefi_debug = 1;
return 0;
}
early_param("uefi_debug", uefi_debug_setup);
static int __init is_normal_ram(efi_memory_desc_t *md)
{
if (md->attribute & EFI_MEMORY_WB)
return 1;
return 0;
}
/*
* 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;
efi.systab = early_memremap(efi_system_table,
sizeof(efi_system_table_t));
if (efi.systab == NULL) {
pr_warn("Unable to map EFI system table.\n");
return -ENOMEM;
}
set_bit(EFI_BOOT, &efi.flags);
set_bit(EFI_64BIT, &efi.flags);
/*
* Verify the EFI Table
*/
if (efi.systab->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) {
pr_err("System table signature incorrect\n");
retval = -EINVAL;
goto out;
}
if ((efi.systab->hdr.revision >> 16) < 2)
pr_warn("Warning: EFI system table version %d.%02d, expected 2.00 or greater\n",
efi.systab->hdr.revision >> 16,
efi.systab->hdr.revision & 0xffff);
/* Show what we know for posterity */
c16 = early_memremap(efi_to_phys(efi.systab->fw_vendor),
sizeof(vendor));
if (c16) {
for (i = 0; i < (int) sizeof(vendor) - 1 && *c16; ++i)
vendor[i] = c16[i];
vendor[i] = '\0';
early_memunmap(c16, sizeof(vendor));
}
pr_info("EFI v%u.%.02u by %s\n",
efi.systab->hdr.revision >> 16,
efi.systab->hdr.revision & 0xffff, vendor);
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;
}
/*
* Return true for RAM regions we want to permanently reserve.
*/
static __init int is_reserve_region(efi_memory_desc_t *md)
{
switch (md->type) {
case EFI_LOADER_CODE:
case EFI_LOADER_DATA:
case EFI_BOOT_SERVICES_CODE:
case EFI_BOOT_SERVICES_DATA:
case EFI_CONVENTIONAL_MEMORY:
return 0;
default:
break;
}
return is_normal_ram(md);
}
static __init void reserve_regions(void)
{
efi_memory_desc_t *md;
u64 paddr, npages, size;
if (uefi_debug)
pr_info("Processing EFI memory map:\n");
for_each_efi_memory_desc(&memmap, md) {
paddr = md->phys_addr;
npages = md->num_pages;
if (uefi_debug) {
char buf[64];
pr_info(" 0x%012llx-0x%012llx %s",
paddr, paddr + (npages << EFI_PAGE_SHIFT) - 1,
efi_md_typeattr_format(buf, sizeof(buf), md));
}
memrange_efi_to_native(&paddr, &npages);
size = npages << PAGE_SHIFT;
if (is_normal_ram(md))
early_init_dt_add_memory_arch(paddr, size);
if (is_reserve_region(md)) {
memblock_reserve(paddr, size);
if (uefi_debug)
pr_cont("*");
}
if (uefi_debug)
pr_cont("\n");
}
set_bit(EFI_MEMMAP, &efi.flags);
}
void __init efi_init(void)
{
struct efi_fdt_params params;
/* Grab UEFI information placed in FDT by stub */
if (!efi_get_fdt_params(¶ms, uefi_debug))
return;
efi_system_table = params.system_table;
memblock_reserve(params.mmap & PAGE_MASK,
PAGE_ALIGN(params.mmap_size + (params.mmap & ~PAGE_MASK)));
memmap.phys_map = (void *)params.mmap;
memmap.map = early_memremap(params.mmap, params.mmap_size);
memmap.map_end = memmap.map + params.mmap_size;
memmap.desc_size = params.desc_size;
memmap.desc_version = params.desc_ver;
if (uefi_init() < 0)
return;
reserve_regions();
early_memunmap(memmap.map, params.mmap_size);
}
static bool __init efi_virtmap_init(void)
{
efi_memory_desc_t *md;
for_each_efi_memory_desc(&memmap, md) {
u64 paddr, npages, size;
pgprot_t prot;
if (!(md->attribute & EFI_MEMORY_RUNTIME))
continue;
if (md->virt_addr == 0)
return false;
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);
}
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 arm64_enable_runtime_services(void)
{
u64 mapsize;
if (!efi_enabled(EFI_BOOT)) {
pr_info("EFI services will not be available.\n");
return -1;
}
if (efi_runtime_disabled()) {
pr_info("EFI runtime services will be disabled.\n");
return -1;
}
pr_info("Remapping and enabling EFI services.\n");
mapsize = memmap.map_end - memmap.map;
memmap.map = (__force void *)ioremap_cache((phys_addr_t)memmap.phys_map,
mapsize);
if (!memmap.map) {
pr_err("Failed to remap EFI memory map\n");
return -1;
}
memmap.map_end = memmap.map + mapsize;
efi.memmap = &memmap;
efi.systab = (__force void *)ioremap_cache(efi_system_table,
sizeof(efi_system_table_t));
if (!efi.systab) {
pr_err("Failed to remap EFI System Table\n");
return -1;
}
set_bit(EFI_SYSTEM_TABLES, &efi.flags);
if (!efi_virtmap_init()) {
pr_err("No UEFI virtual mapping was installed -- runtime services will not be available\n");
return -1;
}
/* Set up runtime services function pointers */
efi_native_runtime_setup();
set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
efi.runtime_version = efi.systab->hdr.revision;
return 0;
}
early_initcall(arm64_enable_runtime_services);
static int __init arm64_dmi_init(void)
{
/*
* On arm64, DMI depends on UEFI, and dmi_scan_machine() 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_scan_machine();
if (dmi_available)
dmi_set_dump_stack_arch_desc();
return 0;
}
core_initcall(arm64_dmi_init);
static void efi_set_pgd(struct mm_struct *mm)
{
if (mm == &init_mm)
cpu_set_reserved_ttbr0();
else
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();
}
/*
* UpdateCapsule() depends on the system being shutdown via
* ResetSystem().
*/
bool efi_poweroff_required(void)
{
return efi_enabled(EFI_RUNTIME_SERVICES);
}
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