- 根目录:
- arch
- x86
- platform
- efi
- efi.c
/*
* Common EFI (Extensible Firmware Interface) support functions
* Based on Extensible Firmware Interface Specification version 1.0
*
* Copyright (C) 1999 VA Linux Systems
* Copyright (C) 1999 Walt Drummond <drummond@valinux.com>
* Copyright (C) 1999-2002 Hewlett-Packard Co.
* David Mosberger-Tang <davidm@hpl.hp.com>
* Stephane Eranian <eranian@hpl.hp.com>
* Copyright (C) 2005-2008 Intel Co.
* Fenghua Yu <fenghua.yu@intel.com>
* Bibo Mao <bibo.mao@intel.com>
* Chandramouli Narayanan <mouli@linux.intel.com>
* Huang Ying <ying.huang@intel.com>
* Copyright (C) 2013 SuSE Labs
* Borislav Petkov <bp@suse.de> - runtime services VA mapping
*
* Copied from efi_32.c to eliminate the duplicated code between EFI
* 32/64 support code. --ying 2007-10-26
*
* All EFI Runtime Services are not implemented yet as EFI only
* supports physical mode addressing on SoftSDV. This is to be fixed
* in a future version. --drummond 1999-07-20
*
* Implemented EFI runtime services and virtual mode calls. --davidm
*
* Goutham Rao: <goutham.rao@intel.com>
* Skip non-WB memory and ignore empty memory ranges.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/efi.h>
#include <linux/efi-bgrt.h>
#include <linux/export.h>
#include <linux/bootmem.h>
#include <linux/slab.h>
#include <linux/memblock.h>
#include <linux/spinlock.h>
#include <linux/uaccess.h>
#include <linux/time.h>
#include <linux/io.h>
#include <linux/reboot.h>
#include <linux/bcd.h>
#include <asm/setup.h>
#include <asm/efi.h>
#include <asm/time.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
#include <asm/x86_init.h>
#include <asm/rtc.h>
#include <asm/uv/uv.h>
#define EFI_DEBUG
struct efi_memory_map memmap;
static struct efi efi_phys __initdata;
static efi_system_table_t efi_systab __initdata;
static efi_config_table_type_t arch_tables[] __initdata = {
#ifdef CONFIG_X86_UV
{UV_SYSTEM_TABLE_GUID, "UVsystab", &efi.uv_systab},
#endif
{NULL_GUID, NULL, NULL},
};
u64 efi_setup; /* efi setup_data physical address */
static int add_efi_memmap __initdata;
static int __init setup_add_efi_memmap(char *arg)
{
add_efi_memmap = 1;
return 0;
}
early_param("add_efi_memmap", setup_add_efi_memmap);
static efi_status_t __init phys_efi_set_virtual_address_map(
unsigned long memory_map_size,
unsigned long descriptor_size,
u32 descriptor_version,
efi_memory_desc_t *virtual_map)
{
efi_status_t status;
unsigned long flags;
pgd_t *save_pgd;
save_pgd = efi_call_phys_prolog();
/* Disable interrupts around EFI calls: */
local_irq_save(flags);
status = efi_call_phys(efi_phys.set_virtual_address_map,
memory_map_size, descriptor_size,
descriptor_version, virtual_map);
local_irq_restore(flags);
efi_call_phys_epilog(save_pgd);
return status;
}
void efi_get_time(struct timespec *now)
{
efi_status_t status;
efi_time_t eft;
efi_time_cap_t cap;
status = efi.get_time(&eft, &cap);
if (status != EFI_SUCCESS)
pr_err("Oops: efitime: can't read time!\n");
now->tv_sec = mktime(eft.year, eft.month, eft.day, eft.hour,
eft.minute, eft.second);
now->tv_nsec = 0;
}
/*
* Tell the kernel about the EFI memory map. This might include
* more than the max 128 entries that can fit in the e820 legacy
* (zeropage) memory map.
*/
static void __init do_add_efi_memmap(void)
{
void *p;
for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
efi_memory_desc_t *md = p;
unsigned long long start = md->phys_addr;
unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
int e820_type;
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:
if (md->attribute & EFI_MEMORY_WB)
e820_type = E820_RAM;
else
e820_type = E820_RESERVED;
break;
case EFI_ACPI_RECLAIM_MEMORY:
e820_type = E820_ACPI;
break;
case EFI_ACPI_MEMORY_NVS:
e820_type = E820_NVS;
break;
case EFI_UNUSABLE_MEMORY:
e820_type = E820_UNUSABLE;
break;
default:
/*
* EFI_RESERVED_TYPE EFI_RUNTIME_SERVICES_CODE
* EFI_RUNTIME_SERVICES_DATA EFI_MEMORY_MAPPED_IO
* EFI_MEMORY_MAPPED_IO_PORT_SPACE EFI_PAL_CODE
*/
e820_type = E820_RESERVED;
break;
}
e820_add_region(start, size, e820_type);
}
sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
}
int __init efi_memblock_x86_reserve_range(void)
{
struct efi_info *e = &boot_params.efi_info;
unsigned long pmap;
if (efi_enabled(EFI_PARAVIRT))
return 0;
#ifdef CONFIG_X86_32
/* Can't handle data above 4GB at this time */
if (e->efi_memmap_hi) {
pr_err("Memory map is above 4GB, disabling EFI.\n");
return -EINVAL;
}
pmap = e->efi_memmap;
#else
pmap = (e->efi_memmap | ((__u64)e->efi_memmap_hi << 32));
#endif
memmap.phys_map = (void *)pmap;
memmap.nr_map = e->efi_memmap_size /
e->efi_memdesc_size;
memmap.desc_size = e->efi_memdesc_size;
memmap.desc_version = e->efi_memdesc_version;
memblock_reserve(pmap, memmap.nr_map * memmap.desc_size);
efi.memmap = &memmap;
return 0;
}
static void __init print_efi_memmap(void)
{
#ifdef EFI_DEBUG
efi_memory_desc_t *md;
void *p;
int i;
for (p = memmap.map, i = 0;
p < memmap.map_end;
p += memmap.desc_size, i++) {
char buf[64];
md = p;
pr_info("mem%02u: %s range=[0x%016llx-0x%016llx) (%lluMB)\n",
i, efi_md_typeattr_format(buf, sizeof(buf), md),
md->phys_addr,
md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT),
(md->num_pages >> (20 - EFI_PAGE_SHIFT)));
}
#endif /* EFI_DEBUG */
}
void __init efi_unmap_memmap(void)
{
clear_bit(EFI_MEMMAP, &efi.flags);
if (memmap.map) {
early_memunmap(memmap.map, memmap.nr_map * memmap.desc_size);
memmap.map = NULL;
}
}
static int __init efi_systab_init(void *phys)
{
if (efi_enabled(EFI_64BIT)) {
efi_system_table_64_t *systab64;
struct efi_setup_data *data = NULL;
u64 tmp = 0;
if (efi_setup) {
data = early_memremap(efi_setup, sizeof(*data));
if (!data)
return -ENOMEM;
}
systab64 = early_memremap((unsigned long)phys,
sizeof(*systab64));
if (systab64 == NULL) {
pr_err("Couldn't map the system table!\n");
if (data)
early_memunmap(data, sizeof(*data));
return -ENOMEM;
}
efi_systab.hdr = systab64->hdr;
efi_systab.fw_vendor = data ? (unsigned long)data->fw_vendor :
systab64->fw_vendor;
tmp |= data ? data->fw_vendor : systab64->fw_vendor;
efi_systab.fw_revision = systab64->fw_revision;
efi_systab.con_in_handle = systab64->con_in_handle;
tmp |= systab64->con_in_handle;
efi_systab.con_in = systab64->con_in;
tmp |= systab64->con_in;
efi_systab.con_out_handle = systab64->con_out_handle;
tmp |= systab64->con_out_handle;
efi_systab.con_out = systab64->con_out;
tmp |= systab64->con_out;
efi_systab.stderr_handle = systab64->stderr_handle;
tmp |= systab64->stderr_handle;
efi_systab.stderr = systab64->stderr;
tmp |= systab64->stderr;
efi_systab.runtime = data ?
(void *)(unsigned long)data->runtime :
(void *)(unsigned long)systab64->runtime;
tmp |= data ? data->runtime : systab64->runtime;
efi_systab.boottime = (void *)(unsigned long)systab64->boottime;
tmp |= systab64->boottime;
efi_systab.nr_tables = systab64->nr_tables;
efi_systab.tables = data ? (unsigned long)data->tables :
systab64->tables;
tmp |= data ? data->tables : systab64->tables;
early_memunmap(systab64, sizeof(*systab64));
if (data)
early_memunmap(data, sizeof(*data));
#ifdef CONFIG_X86_32
if (tmp >> 32) {
pr_err("EFI data located above 4GB, disabling EFI.\n");
return -EINVAL;
}
#endif
} else {
efi_system_table_32_t *systab32;
systab32 = early_memremap((unsigned long)phys,
sizeof(*systab32));
if (systab32 == NULL) {
pr_err("Couldn't map the system table!\n");
return -ENOMEM;
}
efi_systab.hdr = systab32->hdr;
efi_systab.fw_vendor = systab32->fw_vendor;
efi_systab.fw_revision = systab32->fw_revision;
efi_systab.con_in_handle = systab32->con_in_handle;
efi_systab.con_in = systab32->con_in;
efi_systab.con_out_handle = systab32->con_out_handle;
efi_systab.con_out = systab32->con_out;
efi_systab.stderr_handle = systab32->stderr_handle;
efi_systab.stderr = systab32->stderr;
efi_systab.runtime = (void *)(unsigned long)systab32->runtime;
efi_systab.boottime = (void *)(unsigned long)systab32->boottime;
efi_systab.nr_tables = systab32->nr_tables;
efi_systab.tables = systab32->tables;
early_memunmap(systab32, sizeof(*systab32));
}
efi.systab = &efi_systab;
/*
* Verify the EFI Table
*/
if (efi.systab->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) {
pr_err("System table signature incorrect!\n");
return -EINVAL;
}
if ((efi.systab->hdr.revision >> 16) == 0)
pr_err("Warning: System table version %d.%02d, expected 1.00 or greater!\n",
efi.systab->hdr.revision >> 16,
efi.systab->hdr.revision & 0xffff);
set_bit(EFI_SYSTEM_TABLES, &efi.flags);
return 0;
}
static int __init efi_runtime_init32(void)
{
efi_runtime_services_32_t *runtime;
runtime = early_memremap((unsigned long)efi.systab->runtime,
sizeof(efi_runtime_services_32_t));
if (!runtime) {
pr_err("Could not map the runtime service table!\n");
return -ENOMEM;
}
/*
* We will only need *early* access to the SetVirtualAddressMap
* EFI runtime service. All other runtime services will be called
* via the virtual mapping.
*/
efi_phys.set_virtual_address_map =
(efi_set_virtual_address_map_t *)
(unsigned long)runtime->set_virtual_address_map;
early_memunmap(runtime, sizeof(efi_runtime_services_32_t));
return 0;
}
static int __init efi_runtime_init64(void)
{
efi_runtime_services_64_t *runtime;
runtime = early_memremap((unsigned long)efi.systab->runtime,
sizeof(efi_runtime_services_64_t));
if (!runtime) {
pr_err("Could not map the runtime service table!\n");
return -ENOMEM;
}
/*
* We will only need *early* access to the SetVirtualAddressMap
* EFI runtime service. All other runtime services will be called
* via the virtual mapping.
*/
efi_phys.set_virtual_address_map =
(efi_set_virtual_address_map_t *)
(unsigned long)runtime->set_virtual_address_map;
early_memunmap(runtime, sizeof(efi_runtime_services_64_t));
return 0;
}
static int __init efi_runtime_init(void)
{
int rv;
/*
* Check out the runtime services table. We need to map
* the runtime services table so that we can grab the physical
* address of several of the EFI runtime functions, needed to
* set the firmware into virtual mode.
*
* When EFI_PARAVIRT is in force then we could not map runtime
* service memory region because we do not have direct access to it.
* However, runtime services are available through proxy functions
* (e.g. in case of Xen dom0 EFI implementation they call special
* hypercall which executes relevant EFI functions) and that is why
* they are always enabled.
*/
if (!efi_enabled(EFI_PARAVIRT)) {
if (efi_enabled(EFI_64BIT))
rv = efi_runtime_init64();
else
rv = efi_runtime_init32();
if (rv)
return rv;
}
set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
return 0;
}
static int __init efi_memmap_init(void)
{
if (efi_enabled(EFI_PARAVIRT))
return 0;
/* Map the EFI memory map */
memmap.map = early_memremap((unsigned long)memmap.phys_map,
memmap.nr_map * memmap.desc_size);
if (memmap.map == NULL) {
pr_err("Could not map the memory map!\n");
return -ENOMEM;
}
memmap.map_end = memmap.map + (memmap.nr_map * memmap.desc_size);
if (add_efi_memmap)
do_add_efi_memmap();
set_bit(EFI_MEMMAP, &efi.flags);
return 0;
}
void __init efi_init(void)
{
efi_char16_t *c16;
char vendor[100] = "unknown";
int i = 0;
void *tmp;
#ifdef CONFIG_X86_32
if (boot_params.efi_info.efi_systab_hi ||
boot_params.efi_info.efi_memmap_hi) {
pr_info("Table located above 4GB, disabling EFI.\n");
return;
}
efi_phys.systab = (efi_system_table_t *)boot_params.efi_info.efi_systab;
#else
efi_phys.systab = (efi_system_table_t *)
(boot_params.efi_info.efi_systab |
((__u64)boot_params.efi_info.efi_systab_hi<<32));
#endif
if (efi_systab_init(efi_phys.systab))
return;
efi.config_table = (unsigned long)efi.systab->tables;
efi.fw_vendor = (unsigned long)efi.systab->fw_vendor;
efi.runtime = (unsigned long)efi.systab->runtime;
/*
* Show what we know for posterity
*/
c16 = tmp = early_memremap(efi.systab->fw_vendor, 2);
if (c16) {
for (i = 0; i < sizeof(vendor) - 1 && *c16; ++i)
vendor[i] = *c16++;
vendor[i] = '\0';
} else
pr_err("Could not map the firmware vendor!\n");
early_memunmap(tmp, 2);
pr_info("EFI v%u.%.02u by %s\n",
efi.systab->hdr.revision >> 16,
efi.systab->hdr.revision & 0xffff, vendor);
if (efi_reuse_config(efi.systab->tables, efi.systab->nr_tables))
return;
if (efi_config_init(arch_tables))
return;
/*
* Note: We currently don't support runtime services on an EFI
* that doesn't match the kernel 32/64-bit mode.
*/
if (!efi_runtime_supported())
pr_info("No EFI runtime due to 32/64-bit mismatch with kernel\n");
else {
if (efi_runtime_disabled() || efi_runtime_init())
return;
}
if (efi_memmap_init())
return;
if (efi_enabled(EFI_DBG))
print_efi_memmap();
}
void __init efi_late_init(void)
{
efi_bgrt_init();
}
void __init efi_set_executable(efi_memory_desc_t *md, bool executable)
{
u64 addr, npages;
addr = md->virt_addr;
npages = md->num_pages;
memrange_efi_to_native(&addr, &npages);
if (executable)
set_memory_x(addr, npages);
else
set_memory_nx(addr, npages);
}
void __init runtime_code_page_mkexec(void)
{
efi_memory_desc_t *md;
void *p;
/* Make EFI runtime service code area executable */
for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
md = p;
if (md->type != EFI_RUNTIME_SERVICES_CODE)
continue;
efi_set_executable(md, true);
}
}
void __init efi_memory_uc(u64 addr, unsigned long size)
{
unsigned long page_shift = 1UL << EFI_PAGE_SHIFT;
u64 npages;
npages = round_up(size, page_shift) / page_shift;
memrange_efi_to_native(&addr, &npages);
set_memory_uc(addr, npages);
}
void __init old_map_region(efi_memory_desc_t *md)
{
u64 start_pfn, end_pfn, end;
unsigned long size;
void *va;
start_pfn = PFN_DOWN(md->phys_addr);
size = md->num_pages << PAGE_SHIFT;
end = md->phys_addr + size;
end_pfn = PFN_UP(end);
if (pfn_range_is_mapped(start_pfn, end_pfn)) {
va = __va(md->phys_addr);
if (!(md->attribute & EFI_MEMORY_WB))
efi_memory_uc((u64)(unsigned long)va, size);
} else
va = efi_ioremap(md->phys_addr, size,
md->type, md->attribute);
md->virt_addr = (u64) (unsigned long) va;
if (!va)
pr_err("ioremap of 0x%llX failed!\n",
(unsigned long long)md->phys_addr);
}
/* Merge contiguous regions of the same type and attribute */
static void __init efi_merge_regions(void)
{
void *p;
efi_memory_desc_t *md, *prev_md = NULL;
for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
u64 prev_size;
md = p;
if (!prev_md) {
prev_md = md;
continue;
}
if (prev_md->type != md->type ||
prev_md->attribute != md->attribute) {
prev_md = md;
continue;
}
prev_size = prev_md->num_pages << EFI_PAGE_SHIFT;
if (md->phys_addr == (prev_md->phys_addr + prev_size)) {
prev_md->num_pages += md->num_pages;
md->type = EFI_RESERVED_TYPE;
md->attribute = 0;
continue;
}
prev_md = md;
}
}
static void __init get_systab_virt_addr(efi_memory_desc_t *md)
{
unsigned long size;
u64 end, systab;
size = md->num_pages << EFI_PAGE_SHIFT;
end = md->phys_addr + size;
systab = (u64)(unsigned long)efi_phys.systab;
if (md->phys_addr <= systab && systab < end) {
systab += md->virt_addr - md->phys_addr;
efi.systab = (efi_system_table_t *)(unsigned long)systab;
}
}
static void __init save_runtime_map(void)
{
#ifdef CONFIG_KEXEC
efi_memory_desc_t *md;
void *tmp, *p, *q = NULL;
int count = 0;
if (efi_enabled(EFI_OLD_MEMMAP))
return;
for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
md = p;
if (!(md->attribute & EFI_MEMORY_RUNTIME) ||
(md->type == EFI_BOOT_SERVICES_CODE) ||
(md->type == EFI_BOOT_SERVICES_DATA))
continue;
tmp = krealloc(q, (count + 1) * memmap.desc_size, GFP_KERNEL);
if (!tmp)
goto out;
q = tmp;
memcpy(q + count * memmap.desc_size, md, memmap.desc_size);
count++;
}
efi_runtime_map_setup(q, count, memmap.desc_size);
return;
out:
kfree(q);
pr_err("Error saving runtime map, efi runtime on kexec non-functional!!\n");
#endif
}
static void *realloc_pages(void *old_memmap, int old_shift)
{
void *ret;
ret = (void *)__get_free_pages(GFP_KERNEL, old_shift + 1);
if (!ret)
goto out;
/*
* A first-time allocation doesn't have anything to copy.
*/
if (!old_memmap)
return ret;
memcpy(ret, old_memmap, PAGE_SIZE << old_shift);
out:
free_pages((unsigned long)old_memmap, old_shift);
return ret;
}
/*
* Map the efi memory ranges of the runtime services and update new_mmap with
* virtual addresses.
*/
static void * __init efi_map_regions(int *count, int *pg_shift)
{
void *p, *new_memmap = NULL;
unsigned long left = 0;
efi_memory_desc_t *md;
for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
md = p;
if (!(md->attribute & EFI_MEMORY_RUNTIME)) {
#ifdef CONFIG_X86_64
if (md->type != EFI_BOOT_SERVICES_CODE &&
md->type != EFI_BOOT_SERVICES_DATA)
#endif
continue;
}
efi_map_region(md);
get_systab_virt_addr(md);
if (left < memmap.desc_size) {
new_memmap = realloc_pages(new_memmap, *pg_shift);
if (!new_memmap)
return NULL;
left += PAGE_SIZE << *pg_shift;
(*pg_shift)++;
}
memcpy(new_memmap + (*count * memmap.desc_size), md,
memmap.desc_size);
left -= memmap.desc_size;
(*count)++;
}
return new_memmap;
}
static void __init kexec_enter_virtual_mode(void)
{
#ifdef CONFIG_KEXEC
efi_memory_desc_t *md;
void *p;
efi.systab = NULL;
/*
* We don't do virtual mode, since we don't do runtime services, on
* non-native EFI
*/
if (!efi_is_native()) {
efi_unmap_memmap();
clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
return;
}
/*
* Map efi regions which were passed via setup_data. The virt_addr is a
* fixed addr which was used in first kernel of a kexec boot.
*/
for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
md = p;
efi_map_region_fixed(md); /* FIXME: add error handling */
get_systab_virt_addr(md);
}
save_runtime_map();
BUG_ON(!efi.systab);
efi_sync_low_kernel_mappings();
/*
* Now that EFI is in virtual mode, update the function
* pointers in the runtime service table to the new virtual addresses.
*
* Call EFI services through wrapper functions.
*/
efi.runtime_version = efi_systab.hdr.revision;
efi_native_runtime_setup();
efi.set_virtual_address_map = NULL;
if (efi_enabled(EFI_OLD_MEMMAP) && (__supported_pte_mask & _PAGE_NX))
runtime_code_page_mkexec();
/* clean DUMMY object */
efi_delete_dummy_variable();
#endif
}
/*
* This function will switch the EFI runtime services to virtual mode.
* Essentially, we look through the EFI memmap and map every region that
* has the runtime attribute bit set in its memory descriptor into the
* ->trampoline_pgd page table using a top-down VA allocation scheme.
*
* The old method which used to update that memory descriptor with the
* virtual address obtained from ioremap() is still supported when the
* kernel is booted with efi=old_map on its command line. Same old
* method enabled the runtime services to be called without having to
* thunk back into physical mode for every invocation.
*
* The new method does a pagetable switch in a preemption-safe manner
* so that we're in a different address space when calling a runtime
* function. For function arguments passing we do copy the PGDs of the
* kernel page table into ->trampoline_pgd prior to each call.
*
* Specially for kexec boot, efi runtime maps in previous kernel should
* be passed in via setup_data. In that case runtime ranges will be mapped
* to the same virtual addresses as the first kernel, see
* kexec_enter_virtual_mode().
*/
static void __init __efi_enter_virtual_mode(void)
{
int count = 0, pg_shift = 0;
void *new_memmap = NULL;
efi_status_t status;
efi.systab = NULL;
efi_merge_regions();
new_memmap = efi_map_regions(&count, &pg_shift);
if (!new_memmap) {
pr_err("Error reallocating memory, EFI runtime non-functional!\n");
clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
return;
}
save_runtime_map();
BUG_ON(!efi.systab);
if (efi_setup_page_tables(__pa(new_memmap), 1 << pg_shift)) {
clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
return;
}
efi_sync_low_kernel_mappings();
efi_dump_pagetable();
if (efi_is_native()) {
status = phys_efi_set_virtual_address_map(
memmap.desc_size * count,
memmap.desc_size,
memmap.desc_version,
(efi_memory_desc_t *)__pa(new_memmap));
} else {
status = efi_thunk_set_virtual_address_map(
efi_phys.set_virtual_address_map,
memmap.desc_size * count,
memmap.desc_size,
memmap.desc_version,
(efi_memory_desc_t *)__pa(new_memmap));
}
if (status != EFI_SUCCESS) {
pr_alert("Unable to switch EFI into virtual mode (status=%lx)!\n",
status);
panic("EFI call to SetVirtualAddressMap() failed!");
}
/*
* Now that EFI is in virtual mode, update the function
* pointers in the runtime service table to the new virtual addresses.
*
* Call EFI services through wrapper functions.
*/
efi.runtime_version = efi_systab.hdr.revision;
if (efi_is_native())
efi_native_runtime_setup();
else
efi_thunk_runtime_setup();
efi.set_virtual_address_map = NULL;
efi_runtime_mkexec();
/*
* We mapped the descriptor array into the EFI pagetable above but we're
* not unmapping it here. Here's why:
*
* We're copying select PGDs from the kernel page table to the EFI page
* table and when we do so and make changes to those PGDs like unmapping
* stuff from them, those changes appear in the kernel page table and we
* go boom.
*
* From setup_real_mode():
*
* ...
* trampoline_pgd[0] = init_level4_pgt[pgd_index(__PAGE_OFFSET)].pgd;
*
* In this particular case, our allocation is in PGD 0 of the EFI page
* table but we've copied that PGD from PGD[272] of the EFI page table:
*
* pgd_index(__PAGE_OFFSET = 0xffff880000000000) = 272
*
* where the direct memory mapping in kernel space is.
*
* new_memmap's VA comes from that direct mapping and thus clearing it,
* it would get cleared in the kernel page table too.
*
* efi_cleanup_page_tables(__pa(new_memmap), 1 << pg_shift);
*/
free_pages((unsigned long)new_memmap, pg_shift);
/* clean DUMMY object */
efi_delete_dummy_variable();
}
void __init efi_enter_virtual_mode(void)
{
if (efi_enabled(EFI_PARAVIRT))
return;
if (efi_setup)
kexec_enter_virtual_mode();
else
__efi_enter_virtual_mode();
}
/*
* Convenience functions to obtain memory types and attributes
*/
u32 efi_mem_type(unsigned long phys_addr)
{
efi_memory_desc_t *md;
void *p;
if (!efi_enabled(EFI_MEMMAP))
return 0;
for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
md = p;
if ((md->phys_addr <= phys_addr) &&
(phys_addr < (md->phys_addr +
(md->num_pages << EFI_PAGE_SHIFT))))
return md->type;
}
return 0;
}
u64 efi_mem_attributes(unsigned long phys_addr)
{
efi_memory_desc_t *md;
void *p;
if (!efi_enabled(EFI_MEMMAP))
return 0;
for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
md = p;
if ((md->phys_addr <= phys_addr) &&
(phys_addr < (md->phys_addr +
(md->num_pages << EFI_PAGE_SHIFT))))
return md->attribute;
}
return 0;
}
static int __init arch_parse_efi_cmdline(char *str)
{
if (parse_option_str(str, "old_map"))
set_bit(EFI_OLD_MEMMAP, &efi.flags);
if (parse_option_str(str, "debug"))
set_bit(EFI_DBG, &efi.flags);
return 0;
}
early_param("efi", arch_parse_efi_cmdline);