[mirror_ubuntu-artful-kernel.git] / arch / x86 / platform / efi / quirks.c

#define pr_fmt(fmt) "efi: " fmt

#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/time.h>
#include <linux/types.h>
#include <linux/efi.h>
#include <linux/slab.h>
#include <linux/memblock.h>
#include <linux/bootmem.h>
#include <linux/acpi.h>
#include <linux/dmi.h>
#include <asm/efi.h>
#include <asm/uv/uv.h>

#define EFI_MIN_RESERVE 5120

#define EFI_DUMMY_GUID \
	EFI_GUID(0x4424ac57, 0xbe4b, 0x47dd, 0x9e, 0x97, 0xed, 0x50, 0xf0, 0x9f, 0x92, 0xa9)

static efi_char16_t efi_dummy_name[6] = { 'D', 'U', 'M', 'M', 'Y', 0 };

static bool efi_no_storage_paranoia;

/*
 * Some firmware implementations refuse to boot if there's insufficient
 * space in the variable store. The implementation of garbage collection
 * in some FW versions causes stale (deleted) variables to take up space
 * longer than intended and space is only freed once the store becomes
 * almost completely full.
 *
 * Enabling this option disables the space checks in
 * efi_query_variable_store() and forces garbage collection.
 *
 * Only enable this option if deleting EFI variables does not free up
 * space in your variable store, e.g. if despite deleting variables
 * you're unable to create new ones.
 */
static int __init setup_storage_paranoia(char *arg)
{
	efi_no_storage_paranoia = true;
	return 0;
}
early_param("efi_no_storage_paranoia", setup_storage_paranoia);

/*
 * Deleting the dummy variable which kicks off garbage collection
*/
void efi_delete_dummy_variable(void)
{
	efi.set_variable(efi_dummy_name, &EFI_DUMMY_GUID,
			 EFI_VARIABLE_NON_VOLATILE |
			 EFI_VARIABLE_BOOTSERVICE_ACCESS |
			 EFI_VARIABLE_RUNTIME_ACCESS,
			 0, NULL);
}

/*
 * In the nonblocking case we do not attempt to perform garbage
 * collection if we do not have enough free space. Rather, we do the
 * bare minimum check and give up immediately if the available space
 * is below EFI_MIN_RESERVE.
 *
 * This function is intended to be small and simple because it is
 * invoked from crash handler paths.
 */
static efi_status_t
query_variable_store_nonblocking(u32 attributes, unsigned long size)
{
	efi_status_t status;
	u64 storage_size, remaining_size, max_size;

	status = efi.query_variable_info_nonblocking(attributes, &storage_size,
						     &remaining_size,
						     &max_size);
	if (status != EFI_SUCCESS)
		return status;

	if (remaining_size - size < EFI_MIN_RESERVE)
		return EFI_OUT_OF_RESOURCES;

	return EFI_SUCCESS;
}

/*
 * Some firmware implementations refuse to boot if there's insufficient space
 * in the variable store. Ensure that we never use more than a safe limit.
 *
 * Return EFI_SUCCESS if it is safe to write 'size' bytes to the variable
 * store.
 */
efi_status_t efi_query_variable_store(u32 attributes, unsigned long size,
				      bool nonblocking)
{
	efi_status_t status;
	u64 storage_size, remaining_size, max_size;

	if (!(attributes & EFI_VARIABLE_NON_VOLATILE))
		return 0;

	if (nonblocking)
		return query_variable_store_nonblocking(attributes, size);

	status = efi.query_variable_info(attributes, &storage_size,
					 &remaining_size, &max_size);
	if (status != EFI_SUCCESS)
		return status;

	/*
	 * We account for that by refusing the write if permitting it would
	 * reduce the available space to under 5KB. This figure was provided by
	 * Samsung, so should be safe.
	 */
	if ((remaining_size - size < EFI_MIN_RESERVE) &&
		!efi_no_storage_paranoia) {

		/*
		 * Triggering garbage collection may require that the firmware
		 * generate a real EFI_OUT_OF_RESOURCES error. We can force
		 * that by attempting to use more space than is available.
		 */
		unsigned long dummy_size = remaining_size + 1024;
		void *dummy = kzalloc(dummy_size, GFP_ATOMIC);

		if (!dummy)
			return EFI_OUT_OF_RESOURCES;

		status = efi.set_variable(efi_dummy_name, &EFI_DUMMY_GUID,
					  EFI_VARIABLE_NON_VOLATILE |
					  EFI_VARIABLE_BOOTSERVICE_ACCESS |
					  EFI_VARIABLE_RUNTIME_ACCESS,
					  dummy_size, dummy);

		if (status == EFI_SUCCESS) {
			/*
			 * This should have failed, so if it didn't make sure
			 * that we delete it...
			 */
			efi_delete_dummy_variable();
		}

		kfree(dummy);

		/*
		 * The runtime code may now have triggered a garbage collection
		 * run, so check the variable info again
		 */
		status = efi.query_variable_info(attributes, &storage_size,
						 &remaining_size, &max_size);

		if (status != EFI_SUCCESS)
			return status;

		/*
		 * There still isn't enough room, so return an error
		 */
		if (remaining_size - size < EFI_MIN_RESERVE)
			return EFI_OUT_OF_RESOURCES;
	}

	return EFI_SUCCESS;
}
EXPORT_SYMBOL_GPL(efi_query_variable_store);

/*
 * Helper function for efi_reserve_boot_services() to figure out if we
 * can free regions in efi_free_boot_services().
 *
 * Use this function to ensure we do not free regions owned by somebody
 * else. We must only reserve (and then free) regions:
 *
 * - Not within any part of the kernel
 * - Not the BIOS reserved area (E820_RESERVED, E820_NVS, etc)
 */
static bool can_free_region(u64 start, u64 size)
{
	if (start + size > __pa_symbol(_text) && start <= __pa_symbol(_end))
		return false;

	if (!e820_all_mapped(start, start+size, E820_RAM))
		return false;

	return true;
}

/*
 * The UEFI specification makes it clear that the operating system is free to do
 * whatever it wants with boot services code after ExitBootServices() has been
 * called. Ignoring this recommendation a significant bunch of EFI implementations 
 * continue calling into boot services code (SetVirtualAddressMap). In order to 
 * work around such buggy implementations we reserve boot services region during 
 * EFI init and make sure it stays executable. Then, after SetVirtualAddressMap(), it
* is discarded.
*/
void __init efi_reserve_boot_services(void)
{
	efi_memory_desc_t *md;

	for_each_efi_memory_desc(md) {
		u64 start = md->phys_addr;
		u64 size = md->num_pages << EFI_PAGE_SHIFT;
		bool already_reserved;

		if (md->type != EFI_BOOT_SERVICES_CODE &&
		    md->type != EFI_BOOT_SERVICES_DATA)
			continue;

		already_reserved = memblock_is_region_reserved(start, size);

		/*
		 * Because the following memblock_reserve() is paired
		 * with free_bootmem_late() for this region in
		 * efi_free_boot_services(), we must be extremely
		 * careful not to reserve, and subsequently free,
		 * critical regions of memory (like the kernel image) or
		 * those regions that somebody else has already
		 * reserved.
		 *
		 * A good example of a critical region that must not be
		 * freed is page zero (first 4Kb of memory), which may
		 * contain boot services code/data but is marked
		 * E820_RESERVED by trim_bios_range().
		 */
		if (!already_reserved) {
			memblock_reserve(start, size);

			/*
			 * If we are the first to reserve the region, no
			 * one else cares about it. We own it and can
			 * free it later.
			 */
			if (can_free_region(start, size))
				continue;
		}

		/*
		 * We don't own the region. We must not free it.
		 *
		 * Setting this bit for a boot services region really
		 * doesn't make sense as far as the firmware is
		 * concerned, but it does provide us with a way to tag
		 * those regions that must not be paired with
		 * free_bootmem_late().
		 */
		md->attribute |= EFI_MEMORY_RUNTIME;
	}
}

void __init efi_free_boot_services(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;
		size_t rm_size;

		if (md->type != EFI_BOOT_SERVICES_CODE &&
		    md->type != EFI_BOOT_SERVICES_DATA)
			continue;

		/* Do not free, someone else owns it: */
		if (md->attribute & EFI_MEMORY_RUNTIME)
			continue;

		/*
		 * Nasty quirk: if all sub-1MB memory is used for boot
		 * services, we can get here without having allocated the
		 * real mode trampoline.  It's too late to hand boot services
		 * memory back to the memblock allocator, so instead
		 * try to manually allocate the trampoline if needed.
		 *
		 * I've seen this on a Dell XPS 13 9350 with firmware
		 * 1.4.4 with SGX enabled booting Linux via Fedora 24's
		 * grub2-efi on a hard disk.  (And no, I don't know why
		 * this happened, but Linux should still try to boot rather
		 * panicing early.)
		 */
		rm_size = real_mode_size_needed();
		if (rm_size && (start + rm_size) < (1<<20) && size >= rm_size) {
			set_real_mode_mem(start, rm_size);
			start += rm_size;
			size -= rm_size;
		}

		free_bootmem_late(start, size);
	}
}

/*
 * A number of config table entries get remapped to virtual addresses
 * after entering EFI virtual mode. However, the kexec kernel requires
 * their physical addresses therefore we pass them via setup_data and
 * correct those entries to their respective physical addresses here.
 *
 * Currently only handles smbios which is necessary for some firmware
 * implementation.
 */
int __init efi_reuse_config(u64 tables, int nr_tables)
{
	int i, sz, ret = 0;
	void *p, *tablep;
	struct efi_setup_data *data;

	if (!efi_setup)
		return 0;

	if (!efi_enabled(EFI_64BIT))
		return 0;

	data = early_memremap(efi_setup, sizeof(*data));
	if (!data) {
		ret = -ENOMEM;
		goto out;
	}

	if (!data->smbios)
		goto out_memremap;

	sz = sizeof(efi_config_table_64_t);

	p = tablep = early_memremap(tables, nr_tables * sz);
	if (!p) {
		pr_err("Could not map Configuration table!\n");
		ret = -ENOMEM;
		goto out_memremap;
	}

	for (i = 0; i < efi.systab->nr_tables; i++) {
		efi_guid_t guid;

		guid = ((efi_config_table_64_t *)p)->guid;

		if (!efi_guidcmp(guid, SMBIOS_TABLE_GUID))
			((efi_config_table_64_t *)p)->table = data->smbios;
		p += sz;
	}
	early_memunmap(tablep, nr_tables * sz);

out_memremap:
	early_memunmap(data, sizeof(*data));
out:
	return ret;
}

static const struct dmi_system_id sgi_uv1_dmi[] = {
	{ NULL, "SGI UV1",
		{	DMI_MATCH(DMI_PRODUCT_NAME,	"Stoutland Platform"),
			DMI_MATCH(DMI_PRODUCT_VERSION,	"1.0"),
			DMI_MATCH(DMI_BIOS_VENDOR,	"SGI.COM"),
		}
	},
	{ } /* NULL entry stops DMI scanning */
};

void __init efi_apply_memmap_quirks(void)
{
	/*
	 * Once setup is done earlier, unmap the EFI memory map on mismatched
	 * firmware/kernel architectures since there is no support for runtime
	 * services.
	 */
	if (!efi_runtime_supported()) {
		pr_info("Setup done, disabling due to 32/64-bit mismatch\n");
		efi_memmap_unmap();
	}

	/* UV2+ BIOS has a fix for this issue.  UV1 still needs the quirk. */
	if (dmi_check_system(sgi_uv1_dmi))
		set_bit(EFI_OLD_MEMMAP, &efi.flags);
}

/*
 * For most modern platforms the preferred method of powering off is via
 * ACPI. However, there are some that are known to require the use of
 * EFI runtime services and for which ACPI does not work at all.
 *
 * Using EFI is a last resort, to be used only if no other option
 * exists.
 */
bool efi_reboot_required(void)
{
	if (!acpi_gbl_reduced_hardware)
		return false;

	efi_reboot_quirk_mode = EFI_RESET_WARM;
	return true;
}

bool efi_poweroff_required(void)
{
	return acpi_gbl_reduced_hardware || acpi_no_s5;
}
Commit	Line	Data
26d7f65f MF	1	#define pr_fmt(fmt) "efi: " fmt
26d7f65f MF	2
eeb9db09 ST	3	#include <linux/init.h>
	4	#include <linux/kernel.h>
	5	#include <linux/string.h>
	6	#include <linux/time.h>
	7	#include <linux/types.h>
	8	#include <linux/efi.h>
	9	#include <linux/slab.h>
	10	#include <linux/memblock.h>
	11	#include <linux/bootmem.h>
44be28e9	12	#include <linux/acpi.h>
d394f2d9	13	#include <linux/dmi.h>
eeb9db09 ST	14	#include <asm/efi.h>
	15	#include <asm/uv/uv.h>
	16
	17	#define EFI_MIN_RESERVE 5120
	18
	19	#define EFI_DUMMY_GUID \
	20	EFI_GUID(0x4424ac57, 0xbe4b, 0x47dd, 0x9e, 0x97, 0xed, 0x50, 0xf0, 0x9f, 0x92, 0xa9)
	21
	22	static efi_char16_t efi_dummy_name[6] = { 'D', 'U', 'M', 'M', 'Y', 0 };
	23
	24	static bool efi_no_storage_paranoia;
	25
	26	/*
	27	* Some firmware implementations refuse to boot if there's insufficient
	28	* space in the variable store. The implementation of garbage collection
	29	* in some FW versions causes stale (deleted) variables to take up space
	30	* longer than intended and space is only freed once the store becomes
	31	* almost completely full.
	32	*
	33	* Enabling this option disables the space checks in
	34	* efi_query_variable_store() and forces garbage collection.
	35	*
	36	* Only enable this option if deleting EFI variables does not free up
	37	* space in your variable store, e.g. if despite deleting variables
	38	* you're unable to create new ones.
	39	*/
	40	static int __init setup_storage_paranoia(char *arg)
	41	{
	42	efi_no_storage_paranoia = true;
	43	return 0;
	44	}
	45	early_param("efi_no_storage_paranoia", setup_storage_paranoia);
	46
	47	/*
	48	* Deleting the dummy variable which kicks off garbage collection
	49	*/
	50	void efi_delete_dummy_variable(void)
	51	{
	52	efi.set_variable(efi_dummy_name, &EFI_DUMMY_GUID,
	53	EFI_VARIABLE_NON_VOLATILE \|
	54	EFI_VARIABLE_BOOTSERVICE_ACCESS \|
	55	EFI_VARIABLE_RUNTIME_ACCESS,
	56	0, NULL);
	57	}
	58
ca0e30dc AB	59	/*
	60	* In the nonblocking case we do not attempt to perform garbage
	61	* collection if we do not have enough free space. Rather, we do the
	62	* bare minimum check and give up immediately if the available space
	63	* is below EFI_MIN_RESERVE.
	64	*
	65	* This function is intended to be small and simple because it is
	66	* invoked from crash handler paths.
	67	*/
	68	static efi_status_t
	69	query_variable_store_nonblocking(u32 attributes, unsigned long size)
	70	{
	71	efi_status_t status;
	72	u64 storage_size, remaining_size, max_size;
	73
	74	status = efi.query_variable_info_nonblocking(attributes, &storage_size,
	75	&remaining_size,
	76	&max_size);
	77	if (status != EFI_SUCCESS)
	78	return status;
	79
	80	if (remaining_size - size < EFI_MIN_RESERVE)
	81	return EFI_OUT_OF_RESOURCES;
	82
	83	return EFI_SUCCESS;
	84	}
	85
eeb9db09 ST	86	/*
	87	* Some firmware implementations refuse to boot if there's insufficient space
	88	* in the variable store. Ensure that we never use more than a safe limit.
	89	*
	90	* Return EFI_SUCCESS if it is safe to write 'size' bytes to the variable
	91	* store.
	92	*/
ca0e30dc AB	93	efi_status_t efi_query_variable_store(u32 attributes, unsigned long size,
ca0e30dc AB	94	bool nonblocking)
eeb9db09 ST	95	{
	96	efi_status_t status;
	97	u64 storage_size, remaining_size, max_size;
	98
	99	if (!(attributes & EFI_VARIABLE_NON_VOLATILE))
	100	return 0;
	101
ca0e30dc AB	102	if (nonblocking)
	103	return query_variable_store_nonblocking(attributes, size);
	104
eeb9db09 ST	105	status = efi.query_variable_info(attributes, &storage_size,
	106	&remaining_size, &max_size);
	107	if (status != EFI_SUCCESS)
	108	return status;
	109
	110	/*
	111	* We account for that by refusing the write if permitting it would
	112	* reduce the available space to under 5KB. This figure was provided by
	113	* Samsung, so should be safe.
	114	*/
	115	if ((remaining_size - size < EFI_MIN_RESERVE) &&
	116	!efi_no_storage_paranoia) {
	117
	118	/*
	119	* Triggering garbage collection may require that the firmware
	120	* generate a real EFI_OUT_OF_RESOURCES error. We can force
	121	* that by attempting to use more space than is available.
	122	*/
	123	unsigned long dummy_size = remaining_size + 1024;
	124	void *dummy = kzalloc(dummy_size, GFP_ATOMIC);
	125
	126	if (!dummy)
	127	return EFI_OUT_OF_RESOURCES;
	128
	129	status = efi.set_variable(efi_dummy_name, &EFI_DUMMY_GUID,
	130	EFI_VARIABLE_NON_VOLATILE \|
	131	EFI_VARIABLE_BOOTSERVICE_ACCESS \|
	132	EFI_VARIABLE_RUNTIME_ACCESS,
	133	dummy_size, dummy);
	134
	135	if (status == EFI_SUCCESS) {
	136	/*
	137	* This should have failed, so if it didn't make sure
	138	* that we delete it...
	139	*/
	140	efi_delete_dummy_variable();
	141	}
	142
	143	kfree(dummy);
	144
	145	/*
	146	* The runtime code may now have triggered a garbage collection
	147	* run, so check the variable info again
	148	*/
	149	status = efi.query_variable_info(attributes, &storage_size,
	150	&remaining_size, &max_size);
	151
	152	if (status != EFI_SUCCESS)
	153	return status;
	154
	155	/*
	156	* There still isn't enough room, so return an error
	157	*/
	158	if (remaining_size - size < EFI_MIN_RESERVE)
	159	return EFI_OUT_OF_RESOURCES;
	160	}
	161
	162	return EFI_SUCCESS;
	163	}
	164	EXPORT_SYMBOL_GPL(efi_query_variable_store);
	165
452308de MF	166	/*
	167	* Helper function for efi_reserve_boot_services() to figure out if we
	168	* can free regions in efi_free_boot_services().
	169	*
	170	* Use this function to ensure we do not free regions owned by somebody
	171	* else. We must only reserve (and then free) regions:
	172	*
	173	* - Not within any part of the kernel
	174	* - Not the BIOS reserved area (E820_RESERVED, E820_NVS, etc)
	175	*/
	176	static bool can_free_region(u64 start, u64 size)
	177	{
	178	if (start + size > __pa_symbol(_text) && start <= __pa_symbol(_end))
	179	return false;
	180
	181	if (!e820_all_mapped(start, start+size, E820_RAM))
	182	return false;
	183
	184	return true;
	185	}
	186
eeb9db09 ST	187	/*
	188	* The UEFI specification makes it clear that the operating system is free to do
	189	* whatever it wants with boot services code after ExitBootServices() has been
	190	* called. Ignoring this recommendation a significant bunch of EFI implementations
	191	* continue calling into boot services code (SetVirtualAddressMap). In order to
	192	* work around such buggy implementations we reserve boot services region during
	193	* EFI init and make sure it stays executable. Then, after SetVirtualAddressMap(), it
	194	* is discarded.
	195	*/
	196	void __init efi_reserve_boot_services(void)
	197	{
78ce248f	198	efi_memory_desc_t *md;
eeb9db09	199
78ce248f	200	for_each_efi_memory_desc(md) {
eeb9db09 ST	201	u64 start = md->phys_addr;
eeb9db09 ST	202	u64 size = md->num_pages << EFI_PAGE_SHIFT;
452308de	203	bool already_reserved;
eeb9db09 ST	204
	205	if (md->type != EFI_BOOT_SERVICES_CODE &&
	206	md->type != EFI_BOOT_SERVICES_DATA)
	207	continue;
452308de MF	208
	209	already_reserved = memblock_is_region_reserved(start, size);
	210
	211	/*
	212	* Because the following memblock_reserve() is paired
	213	* with free_bootmem_late() for this region in
	214	* efi_free_boot_services(), we must be extremely
	215	* careful not to reserve, and subsequently free,
	216	* critical regions of memory (like the kernel image) or
	217	* those regions that somebody else has already
	218	* reserved.
	219	*
	220	* A good example of a critical region that must not be
	221	* freed is page zero (first 4Kb of memory), which may
	222	* contain boot services code/data but is marked
	223	* E820_RESERVED by trim_bios_range().
	224	*/
	225	if (!already_reserved) {
eeb9db09	226	memblock_reserve(start, size);
452308de MF	227
	228	/*
	229	* If we are the first to reserve the region, no
	230	* one else cares about it. We own it and can
	231	* free it later.
	232	*/
	233	if (can_free_region(start, size))
	234	continue;
	235	}
	236
	237	/*
	238	* We don't own the region. We must not free it.
	239	*
	240	* Setting this bit for a boot services region really
	241	* doesn't make sense as far as the firmware is
	242	* concerned, but it does provide us with a way to tag
	243	* those regions that must not be paired with
	244	* free_bootmem_late().
	245	*/
	246	md->attribute \|= EFI_MEMORY_RUNTIME;
eeb9db09 ST	247	}
	248	}
	249
	250	void __init efi_free_boot_services(void)
	251	{
78ce248f	252	efi_memory_desc_t *md;
eeb9db09	253
78ce248f	254	for_each_efi_memory_desc(md) {
eeb9db09 ST	255	unsigned long long start = md->phys_addr;
eeb9db09 ST	256	unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
5bc653b7	257	size_t rm_size;
eeb9db09 ST	258
	259	if (md->type != EFI_BOOT_SERVICES_CODE &&
	260	md->type != EFI_BOOT_SERVICES_DATA)
	261	continue;
	262
452308de MF	263	/* Do not free, someone else owns it: */
452308de MF	264	if (md->attribute & EFI_MEMORY_RUNTIME)
eeb9db09 ST	265	continue;
eeb9db09 ST	266
5bc653b7 AL	267	/*
	268	* Nasty quirk: if all sub-1MB memory is used for boot
	269	* services, we can get here without having allocated the
	270	* real mode trampoline. It's too late to hand boot services
	271	* memory back to the memblock allocator, so instead
	272	* try to manually allocate the trampoline if needed.
	273	*
	274	* I've seen this on a Dell XPS 13 9350 with firmware
	275	* 1.4.4 with SGX enabled booting Linux via Fedora 24's
	276	* grub2-efi on a hard disk. (And no, I don't know why
	277	* this happened, but Linux should still try to boot rather
	278	* panicing early.)
	279	*/
	280	rm_size = real_mode_size_needed();
	281	if (rm_size && (start + rm_size) < (1<<20) && size >= rm_size) {
	282	set_real_mode_mem(start, rm_size);
	283	start += rm_size;
	284	size -= rm_size;
	285	}
	286
eeb9db09 ST	287	free_bootmem_late(start, size);
eeb9db09 ST	288	}
eeb9db09 ST	289	}
	290
	291	/*
	292	* A number of config table entries get remapped to virtual addresses
	293	* after entering EFI virtual mode. However, the kexec kernel requires
	294	* their physical addresses therefore we pass them via setup_data and
	295	* correct those entries to their respective physical addresses here.
	296	*
	297	* Currently only handles smbios which is necessary for some firmware
	298	* implementation.
	299	*/
	300	int __init efi_reuse_config(u64 tables, int nr_tables)
	301	{
	302	int i, sz, ret = 0;
	303	void p, tablep;
	304	struct efi_setup_data *data;
	305
	306	if (!efi_setup)
	307	return 0;
	308
	309	if (!efi_enabled(EFI_64BIT))
	310	return 0;
	311
	312	data = early_memremap(efi_setup, sizeof(*data));
	313	if (!data) {
	314	ret = -ENOMEM;
	315	goto out;
	316	}
	317
	318	if (!data->smbios)
	319	goto out_memremap;
	320
	321	sz = sizeof(efi_config_table_64_t);
	322
	323	p = tablep = early_memremap(tables, nr_tables * sz);
	324	if (!p) {
	325	pr_err("Could not map Configuration table!\n");
	326	ret = -ENOMEM;
	327	goto out_memremap;
	328	}
	329
	330	for (i = 0; i < efi.systab->nr_tables; i++) {
	331	efi_guid_t guid;
	332
	333	guid = ((efi_config_table_64_t *)p)->guid;
	334
	335	if (!efi_guidcmp(guid, SMBIOS_TABLE_GUID))
	336	((efi_config_table_64_t *)p)->table = data->smbios;
	337	p += sz;
	338	}
98a716b6	339	early_memunmap(tablep, nr_tables * sz);
eeb9db09 ST	340
eeb9db09 ST	341	out_memremap:
98a716b6	342	early_memunmap(data, sizeof(*data));
eeb9db09 ST	343	out:
	344	return ret;
	345	}
	346
d394f2d9 AT	347	static const struct dmi_system_id sgi_uv1_dmi[] = {
	348	{ NULL, "SGI UV1",
	349	{ DMI_MATCH(DMI_PRODUCT_NAME, "Stoutland Platform"),
	350	DMI_MATCH(DMI_PRODUCT_VERSION, "1.0"),
	351	DMI_MATCH(DMI_BIOS_VENDOR, "SGI.COM"),
	352	}
	353	},
	354	{ } /* NULL entry stops DMI scanning */
	355	};
	356
eeb9db09 ST	357	void __init efi_apply_memmap_quirks(void)
	358	{
	359	/*
	360	* Once setup is done earlier, unmap the EFI memory map on mismatched
	361	* firmware/kernel architectures since there is no support for runtime
	362	* services.
	363	*/
	364	if (!efi_runtime_supported()) {
26d7f65f	365	pr_info("Setup done, disabling due to 32/64-bit mismatch\n");
9479c7ce	366	efi_memmap_unmap();
eeb9db09 ST	367	}
eeb9db09 ST	368
d394f2d9 AT	369	/* UV2+ BIOS has a fix for this issue. UV1 still needs the quirk. */
d394f2d9 AT	370	if (dmi_check_system(sgi_uv1_dmi))
eeb9db09 ST	371	set_bit(EFI_OLD_MEMMAP, &efi.flags);
eeb9db09 ST	372	}
44be28e9 MF	373
	374	/*
	375	* For most modern platforms the preferred method of powering off is via
	376	* ACPI. However, there are some that are known to require the use of
	377	* EFI runtime services and for which ACPI does not work at all.
	378	*
	379	* Using EFI is a last resort, to be used only if no other option
	380	* exists.
	381	*/
	382	bool efi_reboot_required(void)
	383	{
	384	if (!acpi_gbl_reduced_hardware)
	385	return false;
	386
	387	efi_reboot_quirk_mode = EFI_RESET_WARM;
	388	return true;
	389	}
	390
	391	bool efi_poweroff_required(void)
	392	{
13737181	393	return acpi_gbl_reduced_hardware \|\| acpi_no_s5;
44be28e9	394	}