linux/arch/arm64/kernel/efi.c

474 lines
11 KiB
C

/*
* 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/efi.h>
#include <linux/export.h>
#include <linux/memblock.h>
#include <linux/bootmem.h>
#include <linux/of.h>
#include <linux/of_fdt.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <asm/cacheflush.h>
#include <asm/efi.h>
#include <asm/tlbflush.h>
#include <asm/mmu_context.h>
struct efi_memory_map memmap;
static efi_runtime_services_t *runtime;
static u64 efi_system_table;
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;
}
static void __init efi_setup_idmap(void)
{
struct memblock_region *r;
efi_memory_desc_t *md;
u64 paddr, npages, size;
for_each_memblock(memory, r)
create_id_mapping(r->base, r->size, 0);
/* map runtime io spaces */
for_each_efi_memory_desc(&memmap, md) {
if (!(md->attribute & EFI_MEMORY_RUNTIME) || is_normal_ram(md))
continue;
paddr = md->phys_addr;
npages = md->num_pages;
memrange_efi_to_native(&paddr, &npages);
size = npages << PAGE_SHIFT;
create_id_mapping(paddr, size, 1);
}
}
static int __init uefi_init(void)
{
efi_char16_t *c16;
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.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);
retval = efi_config_init(NULL);
if (retval == 0)
set_bit(EFI_CONFIG_TABLES, &efi.flags);
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)
{
if (!is_normal_ram(md))
return 0;
if (md->attribute & EFI_MEMORY_RUNTIME)
return 1;
if (md->type == EFI_ACPI_RECLAIM_MEMORY ||
md->type == EFI_RESERVED_TYPE)
return 1;
return 0;
}
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) ||
md->type == EFI_BOOT_SERVICES_CODE ||
md->type == EFI_BOOT_SERVICES_DATA) {
memblock_reserve(paddr, size);
if (uefi_debug)
pr_cont("*");
}
if (uefi_debug)
pr_cont("\n");
}
set_bit(EFI_MEMMAP, &efi.flags);
}
static u64 __init free_one_region(u64 start, u64 end)
{
u64 size = end - start;
if (uefi_debug)
pr_info(" EFI freeing: 0x%012llx-0x%012llx\n", start, end - 1);
free_bootmem_late(start, size);
return size;
}
static u64 __init free_region(u64 start, u64 end)
{
u64 map_start, map_end, total = 0;
if (end <= start)
return total;
map_start = (u64)memmap.phys_map;
map_end = PAGE_ALIGN(map_start + (memmap.map_end - memmap.map));
map_start &= PAGE_MASK;
if (start < map_end && end > map_start) {
/* region overlaps UEFI memmap */
if (start < map_start)
total += free_one_region(start, map_start);
if (map_end < end)
total += free_one_region(map_end, end);
} else
total += free_one_region(start, end);
return total;
}
static void __init free_boot_services(void)
{
u64 total_freed = 0;
u64 keep_end, free_start, free_end;
efi_memory_desc_t *md;
/*
* If kernel uses larger pages than UEFI, we have to be careful
* not to inadvertantly free memory we want to keep if there is
* overlap at the kernel page size alignment. We do not want to
* free is_reserve_region() memory nor the UEFI memmap itself.
*
* The memory map is sorted, so we keep track of the end of
* any previous region we want to keep, remember any region
* we want to free and defer freeing it until we encounter
* the next region we want to keep. This way, before freeing
* it, we can clip it as needed to avoid freeing memory we
* want to keep for UEFI.
*/
keep_end = 0;
free_start = 0;
for_each_efi_memory_desc(&memmap, md) {
u64 paddr, npages, size;
if (is_reserve_region(md)) {
/*
* We don't want to free any memory from this region.
*/
if (free_start) {
/* adjust free_end then free region */
if (free_end > md->phys_addr)
free_end -= PAGE_SIZE;
total_freed += free_region(free_start, free_end);
free_start = 0;
}
keep_end = md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT);
continue;
}
if (md->type != EFI_BOOT_SERVICES_CODE &&
md->type != EFI_BOOT_SERVICES_DATA) {
/* no need to free this region */
continue;
}
/*
* We want to free memory from this region.
*/
paddr = md->phys_addr;
npages = md->num_pages;
memrange_efi_to_native(&paddr, &npages);
size = npages << PAGE_SHIFT;
if (free_start) {
if (paddr <= free_end)
free_end = paddr + size;
else {
total_freed += free_region(free_start, free_end);
free_start = paddr;
free_end = paddr + size;
}
} else {
free_start = paddr;
free_end = paddr + size;
}
if (free_start < keep_end) {
free_start += PAGE_SIZE;
if (free_start >= free_end)
free_start = 0;
}
}
if (free_start)
total_freed += free_region(free_start, free_end);
if (total_freed)
pr_info("Freed 0x%llx bytes of EFI boot services memory",
total_freed);
}
void __init efi_init(void)
{
struct efi_fdt_params params;
/* Grab UEFI information placed in FDT by stub */
if (!efi_get_fdt_params(&params, 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();
}
void __init efi_idmap_init(void)
{
if (!efi_enabled(EFI_BOOT))
return;
/* boot time idmap_pg_dir is incomplete, so fill in missing parts */
efi_setup_idmap();
}
static int __init remap_region(efi_memory_desc_t *md, void **new)
{
u64 paddr, vaddr, npages, size;
paddr = md->phys_addr;
npages = md->num_pages;
memrange_efi_to_native(&paddr, &npages);
size = npages << PAGE_SHIFT;
if (is_normal_ram(md))
vaddr = (__force u64)ioremap_cache(paddr, size);
else
vaddr = (__force u64)ioremap(paddr, size);
if (!vaddr) {
pr_err("Unable to remap 0x%llx pages @ %p\n",
npages, (void *)paddr);
return 0;
}
/* adjust for any rounding when EFI and system pagesize differs */
md->virt_addr = vaddr + (md->phys_addr - paddr);
if (uefi_debug)
pr_info(" EFI remap 0x%012llx => %p\n",
md->phys_addr, (void *)md->virt_addr);
memcpy(*new, md, memmap.desc_size);
*new += memmap.desc_size;
return 1;
}
/*
* Switch UEFI from an identity map to a kernel virtual map
*/
static int __init arm64_enter_virtual_mode(void)
{
efi_memory_desc_t *md;
phys_addr_t virtmap_phys;
void *virtmap, *virt_md;
efi_status_t status;
u64 mapsize;
int count = 0;
unsigned long flags;
if (!efi_enabled(EFI_BOOT)) {
pr_info("EFI services will not be available.\n");
return -1;
}
mapsize = memmap.map_end - memmap.map;
early_memunmap(memmap.map, mapsize);
if (efi_runtime_disabled()) {
pr_info("EFI runtime services will be disabled.\n");
return -1;
}
pr_info("Remapping and enabling EFI services.\n");
/* replace early memmap mapping with permanent mapping */
memmap.map = (__force void *)ioremap_cache((phys_addr_t)memmap.phys_map,
mapsize);
memmap.map_end = memmap.map + mapsize;
efi.memmap = &memmap;
/* Map the runtime regions */
virtmap = kmalloc(mapsize, GFP_KERNEL);
if (!virtmap) {
pr_err("Failed to allocate EFI virtual memmap\n");
return -1;
}
virtmap_phys = virt_to_phys(virtmap);
virt_md = virtmap;
for_each_efi_memory_desc(&memmap, md) {
if (!(md->attribute & EFI_MEMORY_RUNTIME))
continue;
if (!remap_region(md, &virt_md))
goto err_unmap;
++count;
}
efi.systab = (__force void *)efi_lookup_mapped_addr(efi_system_table);
if (!efi.systab) {
/*
* If we have no virtual mapping for the System Table at this
* point, the memory map doesn't cover the physical offset where
* it resides. This means the System Table will be inaccessible
* to Runtime Services themselves once the virtual mapping is
* installed.
*/
pr_err("Failed to remap EFI System Table -- buggy firmware?\n");
goto err_unmap;
}
set_bit(EFI_SYSTEM_TABLES, &efi.flags);
local_irq_save(flags);
cpu_switch_mm(idmap_pg_dir, &init_mm);
/* Call SetVirtualAddressMap with the physical address of the map */
runtime = efi.systab->runtime;
efi.set_virtual_address_map = runtime->set_virtual_address_map;
status = efi.set_virtual_address_map(count * memmap.desc_size,
memmap.desc_size,
memmap.desc_version,
(efi_memory_desc_t *)virtmap_phys);
cpu_set_reserved_ttbr0();
flush_tlb_all();
local_irq_restore(flags);
kfree(virtmap);
free_boot_services();
if (status != EFI_SUCCESS) {
pr_err("Failed to set EFI virtual address map! [%lx]\n",
status);
return -1;
}
/* Set up runtime services function pointers */
runtime = efi.systab->runtime;
efi_native_runtime_setup();
set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
efi.runtime_version = efi.systab->hdr.revision;
return 0;
err_unmap:
/* unmap all mappings that succeeded: there are 'count' of those */
for (virt_md = virtmap; count--; virt_md += memmap.desc_size) {
md = virt_md;
iounmap((__force void __iomem *)md->virt_addr);
}
kfree(virtmap);
return -1;
}
early_initcall(arm64_enter_virtual_mode);