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WSL2-Linux-Kernel/arch/x86/platform/efi/efi.c

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26 KiB
C
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// SPDX-License-Identifier: GPL-2.0
/*
* 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/memblock.h>
#include <linux/slab.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/e820/api.h>
#include <asm/time.h>
#include <asm/set_memory.h>
#include <asm/tlbflush.h>
#include <asm/x86_init.h>
#include <asm/uv/uv.h>
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 __init efi_find_mirror(void)
{
efi_memory_desc_t *md;
u64 mirror_size = 0, total_size = 0;
for_each_efi_memory_desc(md) {
unsigned long long start = md->phys_addr;
unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
total_size += size;
if (md->attribute & EFI_MEMORY_MORE_RELIABLE) {
memblock_mark_mirror(start, size);
mirror_size += size;
}
}
if (mirror_size)
pr_info("Memory: %lldM/%lldM mirrored memory\n",
mirror_size>>20, total_size>>20);
}
/*
* 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)
{
efi_memory_desc_t *md;
for_each_efi_memory_desc(md) {
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_TYPE_RAM;
else
e820_type = E820_TYPE_RESERVED;
break;
case EFI_ACPI_RECLAIM_MEMORY:
e820_type = E820_TYPE_ACPI;
break;
case EFI_ACPI_MEMORY_NVS:
e820_type = E820_TYPE_NVS;
break;
case EFI_UNUSABLE_MEMORY:
e820_type = E820_TYPE_UNUSABLE;
break;
case EFI_PERSISTENT_MEMORY:
e820_type = E820_TYPE_PMEM;
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_TYPE_RESERVED;
break;
}
e820__range_add(start, size, e820_type);
}
e820__update_table(e820_table);
}
int __init efi_memblock_x86_reserve_range(void)
{
struct efi_info *e = &boot_params.efi_info;
struct efi_memory_map_data data;
phys_addr_t pmap;
int rv;
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
data.phys_map = pmap;
data.size = e->efi_memmap_size;
data.desc_size = e->efi_memdesc_size;
data.desc_version = e->efi_memdesc_version;
rv = efi_memmap_init_early(&data);
if (rv)
return rv;
if (add_efi_memmap)
do_add_efi_memmap();
WARN(efi.memmap.desc_version != 1,
"Unexpected EFI_MEMORY_DESCRIPTOR version %ld",
efi.memmap.desc_version);
memblock_reserve(pmap, efi.memmap.nr_map * efi.memmap.desc_size);
return 0;
}
#define OVERFLOW_ADDR_SHIFT (64 - EFI_PAGE_SHIFT)
#define OVERFLOW_ADDR_MASK (U64_MAX << OVERFLOW_ADDR_SHIFT)
#define U64_HIGH_BIT (~(U64_MAX >> 1))
static bool __init efi_memmap_entry_valid(const efi_memory_desc_t *md, int i)
{
u64 end = (md->num_pages << EFI_PAGE_SHIFT) + md->phys_addr - 1;
u64 end_hi = 0;
char buf[64];
if (md->num_pages == 0) {
end = 0;
} else if (md->num_pages > EFI_PAGES_MAX ||
EFI_PAGES_MAX - md->num_pages <
(md->phys_addr >> EFI_PAGE_SHIFT)) {
end_hi = (md->num_pages & OVERFLOW_ADDR_MASK)
>> OVERFLOW_ADDR_SHIFT;
if ((md->phys_addr & U64_HIGH_BIT) && !(end & U64_HIGH_BIT))
end_hi += 1;
} else {
return true;
}
pr_warn_once(FW_BUG "Invalid EFI memory map entries:\n");
if (end_hi) {
pr_warn("mem%02u: %s range=[0x%016llx-0x%llx%016llx] (invalid)\n",
i, efi_md_typeattr_format(buf, sizeof(buf), md),
md->phys_addr, end_hi, end);
} else {
pr_warn("mem%02u: %s range=[0x%016llx-0x%016llx] (invalid)\n",
i, efi_md_typeattr_format(buf, sizeof(buf), md),
md->phys_addr, end);
}
return false;
}
static void __init efi_clean_memmap(void)
{
efi_memory_desc_t *out = efi.memmap.map;
const efi_memory_desc_t *in = out;
const efi_memory_desc_t *end = efi.memmap.map_end;
int i, n_removal;
for (i = n_removal = 0; in < end; i++) {
if (efi_memmap_entry_valid(in, i)) {
if (out != in)
memcpy(out, in, efi.memmap.desc_size);
out = (void *)out + efi.memmap.desc_size;
} else {
n_removal++;
}
in = (void *)in + efi.memmap.desc_size;
}
if (n_removal > 0) {
u64 size = efi.memmap.nr_map - n_removal;
pr_warn("Removing %d invalid memory map entries.\n", n_removal);
efi_memmap_install(efi.memmap.phys_map, size);
}
}
void __init efi_print_memmap(void)
{
efi_memory_desc_t *md;
int i = 0;
for_each_efi_memory_desc(md) {
char buf[64];
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) - 1,
(md->num_pages >> (20 - EFI_PAGE_SHIFT)));
}
}
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);
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;
}
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()) {
efi_memmap_unmap();
return;
}
}
efi_clean_memmap();
if (efi_enabled(EFI_DBG))
efi_print_memmap();
}
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;
/* Make EFI runtime service code area executable */
for_each_efi_memory_desc(md) {
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)
{
efi_memory_desc_t *md, *prev_md = NULL;
for_each_efi_memory_desc(md) {
u64 prev_size;
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 *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;
}
/*
* Iterate the EFI memory map in reverse order because the regions
* will be mapped top-down. The end result is the same as if we had
* mapped things forward, but doesn't require us to change the
* existing implementation of efi_map_region().
*/
static inline void *efi_map_next_entry_reverse(void *entry)
{
/* Initial call */
if (!entry)
return efi.memmap.map_end - efi.memmap.desc_size;
entry -= efi.memmap.desc_size;
if (entry < efi.memmap.map)
return NULL;
return entry;
}
/*
* efi_map_next_entry - Return the next EFI memory map descriptor
* @entry: Previous EFI memory map descriptor
*
* This is a helper function to iterate over the EFI memory map, which
* we do in different orders depending on the current configuration.
*
* To begin traversing the memory map @entry must be %NULL.
*
* Returns %NULL when we reach the end of the memory map.
*/
static void *efi_map_next_entry(void *entry)
{
if (!efi_enabled(EFI_OLD_MEMMAP) && efi_enabled(EFI_64BIT)) {
/*
* Starting in UEFI v2.5 the EFI_PROPERTIES_TABLE
* config table feature requires us to map all entries
* in the same order as they appear in the EFI memory
* map. That is to say, entry N must have a lower
* virtual address than entry N+1. This is because the
* firmware toolchain leaves relative references in
* the code/data sections, which are split and become
* separate EFI memory regions. Mapping things
* out-of-order leads to the firmware accessing
* unmapped addresses.
*
* Since we need to map things this way whether or not
* the kernel actually makes use of
* EFI_PROPERTIES_TABLE, let's just switch to this
* scheme by default for 64-bit.
*/
return efi_map_next_entry_reverse(entry);
}
/* Initial call */
if (!entry)
return efi.memmap.map;
entry += efi.memmap.desc_size;
if (entry >= efi.memmap.map_end)
return NULL;
return entry;
}
static bool should_map_region(efi_memory_desc_t *md)
{
/*
* Runtime regions always require runtime mappings (obviously).
*/
if (md->attribute & EFI_MEMORY_RUNTIME)
return true;
/*
* 32-bit EFI doesn't suffer from the bug that requires us to
* reserve boot services regions, and mixed mode support
* doesn't exist for 32-bit kernels.
*/
if (IS_ENABLED(CONFIG_X86_32))
return false;
/*
* Map all of RAM so that we can access arguments in the 1:1
* mapping when making EFI runtime calls.
*/
if (IS_ENABLED(CONFIG_EFI_MIXED) && !efi_is_native()) {
if (md->type == EFI_CONVENTIONAL_MEMORY ||
md->type == EFI_LOADER_DATA ||
md->type == EFI_LOADER_CODE)
return true;
}
/*
* Map boot services regions as a workaround for buggy
* firmware that accesses them even when they shouldn't.
*
* See efi_{reserve,free}_boot_services().
*/
if (md->type == EFI_BOOT_SERVICES_CODE ||
md->type == EFI_BOOT_SERVICES_DATA)
return true;
return false;
}
/*
* 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;
unsigned long desc_size;
efi_memory_desc_t *md;
desc_size = efi.memmap.desc_size;
p = NULL;
while ((p = efi_map_next_entry(p))) {
md = p;
if (!should_map_region(md))
continue;
efi_map_region(md);
get_systab_virt_addr(md);
if (left < 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 * desc_size), md, desc_size);
left -= desc_size;
(*count)++;
}
return new_memmap;
}
static void __init kexec_enter_virtual_mode(void)
{
#ifdef CONFIG_KEXEC_CORE
efi_memory_desc_t *md;
unsigned int num_pages;
efi.systab = NULL;
/*
* We don't do virtual mode, since we don't do runtime services, on
* non-native EFI. With efi=old_map, we don't do runtime services in
* kexec kernel because in the initial boot something else might
* have been mapped at these virtual addresses.
*/
if (!efi_is_native() || efi_enabled(EFI_OLD_MEMMAP)) {
efi_memmap_unmap();
clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
return;
}
if (efi_alloc_page_tables()) {
pr_err("Failed to allocate EFI page tables\n");
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_each_efi_memory_desc(md) {
efi_map_region_fixed(md); /* FIXME: add error handling */
get_systab_virt_addr(md);
}
/*
* Unregister the early EFI memmap from efi_init() and install
* the new EFI memory map.
*/
efi_memmap_unmap();
if (efi_memmap_init_late(efi.memmap.phys_map,
efi.memmap.desc_size * efi.memmap.nr_map)) {
pr_err("Failed to remap late EFI memory map\n");
clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
return;
}
BUG_ON(!efi.systab);
num_pages = ALIGN(efi.memmap.nr_map * efi.memmap.desc_size, PAGE_SIZE);
num_pages >>= PAGE_SHIFT;
if (efi_setup_page_tables(efi.memmap.phys_map, num_pages)) {
clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
return;
}
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
* efi_pgd page table.
*
* 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 PUDs of the
* kernel page table into efi_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;
unsigned long pa;
efi.systab = NULL;
if (efi_alloc_page_tables()) {
pr_err("Failed to allocate EFI page tables\n");
clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
return;
}
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;
}
pa = __pa(new_memmap);
/*
* Unregister the early EFI memmap from efi_init() and install
* the new EFI memory map that we are about to pass to the
* firmware via SetVirtualAddressMap().
*/
efi_memmap_unmap();
if (efi_memmap_init_late(pa, efi.memmap.desc_size * count)) {
pr_err("Failed to remap late EFI memory map\n");
clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
return;
}
if (efi_enabled(EFI_DBG)) {
pr_info("EFI runtime memory map:\n");
efi_print_memmap();
}
BUG_ON(!efi.systab);
if (efi_setup_page_tables(pa, 1 << pg_shift)) {
clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
return;
}
efi_sync_low_kernel_mappings();
if (efi_is_native()) {
status = phys_efi_set_virtual_address_map(
efi.memmap.desc_size * count,
efi.memmap.desc_size,
efi.memmap.desc_version,
(efi_memory_desc_t *)pa);
} else {
status = efi_thunk_set_virtual_address_map(
efi_phys.set_virtual_address_map,
efi.memmap.desc_size * count,
efi.memmap.desc_size,
efi.memmap.desc_version,
(efi_memory_desc_t *)pa);
}
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;
/*
* Apply more restrictive page table mapping attributes now that
* SVAM() has been called and the firmware has performed all
* necessary relocation fixups for the new virtual addresses.
*/
efi_runtime_update_mappings();
/* 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();
efi_dump_pagetable();
}
static int __init arch_parse_efi_cmdline(char *str)
{
if (!str) {
pr_warn("need at least one option\n");
return -EINVAL;
}
if (parse_option_str(str, "old_map"))
set_bit(EFI_OLD_MEMMAP, &efi.flags);
return 0;
}
early_param("efi", arch_parse_efi_cmdline);
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