[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/e820/api.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);

/*
 * 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.
 *
 * However, some boot services regions contain data that is required
 * by drivers, so we need to track which memory ranges can never be
 * freed. This is done by tagging those regions with the
 * EFI_MEMORY_RUNTIME attribute.
 *
 * Any driver that wants to mark a region as reserved must use
 * efi_mem_reserve() which will insert a new EFI memory descriptor
 * into efi.memmap (splitting existing regions if necessary) and tag
 * it with EFI_MEMORY_RUNTIME.
 */
void __init efi_arch_mem_reserve(phys_addr_t addr, u64 size)
{
	phys_addr_t new_phys, new_size;
	struct efi_mem_range mr;
	efi_memory_desc_t md;
	int num_entries;
	void *new;

	if (efi_mem_desc_lookup(addr, &md)) {
		pr_err("Failed to lookup EFI memory descriptor for %pa\n", &addr);
		return;
	}

	if (addr + size > md.phys_addr + (md.num_pages << EFI_PAGE_SHIFT)) {
		pr_err("Region spans EFI memory descriptors, %pa\n", &addr);
		return;
	}

	/* No need to reserve regions that will never be freed. */
	if (md.attribute & EFI_MEMORY_RUNTIME)
		return;

	size += addr % EFI_PAGE_SIZE;
	size = round_up(size, EFI_PAGE_SIZE);
	addr = round_down(addr, EFI_PAGE_SIZE);

	mr.range.start = addr;
	mr.range.end = addr + size - 1;
	mr.attribute = md.attribute | EFI_MEMORY_RUNTIME;

	num_entries = efi_memmap_split_count(&md, &mr.range);
	num_entries += efi.memmap.nr_map;

	new_size = efi.memmap.desc_size * num_entries;

	new_phys = efi_memmap_alloc(num_entries);
	if (!new_phys) {
		pr_err("Could not allocate boot services memmap\n");
		return;
	}

	new = early_memremap(new_phys, new_size);
	if (!new) {
		pr_err("Failed to map new boot services memmap\n");
		return;
	}

	efi_memmap_insert(&efi.memmap, new, &mr);
	early_memunmap(new, new_size);

	efi_memmap_install(new_phys, num_entries);
}

/*
 * 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_TYPE_RESERVED, E820_TYPE_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__mapped_all(start, start+size, E820_TYPE_RAM))
		return false;

	return true;
}

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_TYPE_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)
{
	phys_addr_t new_phys, new_size;
	efi_memory_desc_t *md;
	int num_entries = 0;
	void *new, *new_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) {
			num_entries++;
			continue;
		}

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

	if (!num_entries)
		return;

	new_size = efi.memmap.desc_size * num_entries;
	new_phys = efi_memmap_alloc(num_entries);
	if (!new_phys) {
		pr_err("Failed to allocate new EFI memmap\n");
		return;
	}

	new = memremap(new_phys, new_size, MEMREMAP_WB);
	if (!new) {
		pr_err("Failed to map new EFI memmap\n");
		return;
	}

	/*
	 * Build a new EFI memmap that excludes any boot services
	 * regions that are not tagged EFI_MEMORY_RUNTIME, since those
	 * regions have now been freed.
	 */
	new_md = new;
	for_each_efi_memory_desc(md) {
		if (!(md->attribute & EFI_MEMORY_RUNTIME) &&
		    (md->type == EFI_BOOT_SERVICES_CODE ||
		     md->type == EFI_BOOT_SERVICES_DATA))
			continue;

		memcpy(new_md, md, efi.memmap.desc_size);
		new_md += efi.memmap.desc_size;
	}

	memunmap(new);

	if (efi_memmap_install(new_phys, num_entries)) {
		pr_err("Could not install new EFI memmap\n");
		return;
	}
}

/*
 * 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>
5520b7e7 IM	14
5520b7e7 IM	15	#include <asm/e820/api.h>
eeb9db09 ST	16	#include <asm/efi.h>
	17	#include <asm/uv/uv.h>
	18
	19	#define EFI_MIN_RESERVE 5120
	20
	21	#define EFI_DUMMY_GUID \
	22	EFI_GUID(0x4424ac57, 0xbe4b, 0x47dd, 0x9e, 0x97, 0xed, 0x50, 0xf0, 0x9f, 0x92, 0xa9)
	23
	24	static efi_char16_t efi_dummy_name[6] = { 'D', 'U', 'M', 'M', 'Y', 0 };
	25
	26	static bool efi_no_storage_paranoia;
	27
	28	/*
	29	* Some firmware implementations refuse to boot if there's insufficient
	30	* space in the variable store. The implementation of garbage collection
	31	* in some FW versions causes stale (deleted) variables to take up space
	32	* longer than intended and space is only freed once the store becomes
	33	* almost completely full.
	34	*
	35	* Enabling this option disables the space checks in
	36	* efi_query_variable_store() and forces garbage collection.
	37	*
	38	* Only enable this option if deleting EFI variables does not free up
	39	* space in your variable store, e.g. if despite deleting variables
	40	* you're unable to create new ones.
	41	*/
	42	static int __init setup_storage_paranoia(char *arg)
	43	{
	44	efi_no_storage_paranoia = true;
	45	return 0;
	46	}
	47	early_param("efi_no_storage_paranoia", setup_storage_paranoia);
	48
	49	/*
	50	* Deleting the dummy variable which kicks off garbage collection
	51	*/
	52	void efi_delete_dummy_variable(void)
	53	{
	54	efi.set_variable(efi_dummy_name, &EFI_DUMMY_GUID,
	55	EFI_VARIABLE_NON_VOLATILE \|
	56	EFI_VARIABLE_BOOTSERVICE_ACCESS \|
	57	EFI_VARIABLE_RUNTIME_ACCESS,
	58	0, NULL);
	59	}
	60
ca0e30dc AB	61	/*
	62	* In the nonblocking case we do not attempt to perform garbage
	63	* collection if we do not have enough free space. Rather, we do the
	64	* bare minimum check and give up immediately if the available space
	65	* is below EFI_MIN_RESERVE.
	66	*
	67	* This function is intended to be small and simple because it is
	68	* invoked from crash handler paths.
	69	*/
	70	static efi_status_t
	71	query_variable_store_nonblocking(u32 attributes, unsigned long size)
	72	{
	73	efi_status_t status;
	74	u64 storage_size, remaining_size, max_size;
	75
	76	status = efi.query_variable_info_nonblocking(attributes, &storage_size,
	77	&remaining_size,
	78	&max_size);
	79	if (status != EFI_SUCCESS)
	80	return status;
	81
	82	if (remaining_size - size < EFI_MIN_RESERVE)
	83	return EFI_OUT_OF_RESOURCES;
	84
	85	return EFI_SUCCESS;
	86	}
	87
eeb9db09 ST	88	/*
	89	* Some firmware implementations refuse to boot if there's insufficient space
	90	* in the variable store. Ensure that we never use more than a safe limit.
	91	*
	92	* Return EFI_SUCCESS if it is safe to write 'size' bytes to the variable
	93	* store.
	94	*/
ca0e30dc AB	95	efi_status_t efi_query_variable_store(u32 attributes, unsigned long size,
ca0e30dc AB	96	bool nonblocking)
eeb9db09 ST	97	{
	98	efi_status_t status;
	99	u64 storage_size, remaining_size, max_size;
	100
	101	if (!(attributes & EFI_VARIABLE_NON_VOLATILE))
	102	return 0;
	103
ca0e30dc AB	104	if (nonblocking)
	105	return query_variable_store_nonblocking(attributes, size);
	106
eeb9db09 ST	107	status = efi.query_variable_info(attributes, &storage_size,
	108	&remaining_size, &max_size);
	109	if (status != EFI_SUCCESS)
	110	return status;
	111
	112	/*
	113	* We account for that by refusing the write if permitting it would
	114	* reduce the available space to under 5KB. This figure was provided by
	115	* Samsung, so should be safe.
	116	*/
	117	if ((remaining_size - size < EFI_MIN_RESERVE) &&
	118	!efi_no_storage_paranoia) {
	119
	120	/*
	121	* Triggering garbage collection may require that the firmware
	122	* generate a real EFI_OUT_OF_RESOURCES error. We can force
	123	* that by attempting to use more space than is available.
	124	*/
	125	unsigned long dummy_size = remaining_size + 1024;
	126	void *dummy = kzalloc(dummy_size, GFP_ATOMIC);
	127
	128	if (!dummy)
	129	return EFI_OUT_OF_RESOURCES;
	130
	131	status = efi.set_variable(efi_dummy_name, &EFI_DUMMY_GUID,
	132	EFI_VARIABLE_NON_VOLATILE \|
	133	EFI_VARIABLE_BOOTSERVICE_ACCESS \|
	134	EFI_VARIABLE_RUNTIME_ACCESS,
	135	dummy_size, dummy);
	136
	137	if (status == EFI_SUCCESS) {
	138	/*
	139	* This should have failed, so if it didn't make sure
	140	* that we delete it...
	141	*/
	142	efi_delete_dummy_variable();
	143	}
	144
	145	kfree(dummy);
	146
	147	/*
	148	* The runtime code may now have triggered a garbage collection
	149	* run, so check the variable info again
	150	*/
	151	status = efi.query_variable_info(attributes, &storage_size,
	152	&remaining_size, &max_size);
	153
	154	if (status != EFI_SUCCESS)
	155	return status;
	156
	157	/*
	158	* There still isn't enough room, so return an error
	159	*/
	160	if (remaining_size - size < EFI_MIN_RESERVE)
	161	return EFI_OUT_OF_RESOURCES;
	162	}
	163
	164	return EFI_SUCCESS;
	165	}
	166	EXPORT_SYMBOL_GPL(efi_query_variable_store);
	167
816e7612 MF	168	/*
	169	* The UEFI specification makes it clear that the operating system is
	170	* free to do whatever it wants with boot services code after
	171	* ExitBootServices() has been called. Ignoring this recommendation a
	172	* significant bunch of EFI implementations continue calling into boot
	173	* services code (SetVirtualAddressMap). In order to work around such
	174	* buggy implementations we reserve boot services region during EFI
	175	* init and make sure it stays executable. Then, after
	176	* SetVirtualAddressMap(), it is discarded.
	177	*
	178	* However, some boot services regions contain data that is required
	179	* by drivers, so we need to track which memory ranges can never be
	180	* freed. This is done by tagging those regions with the
	181	* EFI_MEMORY_RUNTIME attribute.
	182	*
	183	* Any driver that wants to mark a region as reserved must use
	184	* efi_mem_reserve() which will insert a new EFI memory descriptor
	185	* into efi.memmap (splitting existing regions if necessary) and tag
	186	* it with EFI_MEMORY_RUNTIME.
	187	*/
	188	void __init efi_arch_mem_reserve(phys_addr_t addr, u64 size)
	189	{
	190	phys_addr_t new_phys, new_size;
	191	struct efi_mem_range mr;
	192	efi_memory_desc_t md;
	193	int num_entries;
	194	void *new;
	195
	196	if (efi_mem_desc_lookup(addr, &md)) {
	197	pr_err("Failed to lookup EFI memory descriptor for %pa\n", &addr);
	198	return;
	199	}
	200
	201	if (addr + size > md.phys_addr + (md.num_pages << EFI_PAGE_SHIFT)) {
	202	pr_err("Region spans EFI memory descriptors, %pa\n", &addr);
	203	return;
	204	}
	205
6f6266a5 OS	206	/* No need to reserve regions that will never be freed. */
	207	if (md.attribute & EFI_MEMORY_RUNTIME)
	208	return;
	209
92dc3350 MF	210	size += addr % EFI_PAGE_SIZE;
	211	size = round_up(size, EFI_PAGE_SIZE);
	212	addr = round_down(addr, EFI_PAGE_SIZE);
	213
816e7612	214	mr.range.start = addr;
92dc3350	215	mr.range.end = addr + size - 1;
816e7612 MF	216	mr.attribute = md.attribute \| EFI_MEMORY_RUNTIME;
	217
	218	num_entries = efi_memmap_split_count(&md, &mr.range);
	219	num_entries += efi.memmap.nr_map;
	220
	221	new_size = efi.memmap.desc_size * num_entries;
	222
20b1e22d	223	new_phys = efi_memmap_alloc(num_entries);
816e7612 MF	224	if (!new_phys) {
	225	pr_err("Could not allocate boot services memmap\n");
	226	return;
	227	}
	228
	229	new = early_memremap(new_phys, new_size);
	230	if (!new) {
	231	pr_err("Failed to map new boot services memmap\n");
	232	return;
	233	}
	234
	235	efi_memmap_insert(&efi.memmap, new, &mr);
	236	early_memunmap(new, new_size);
	237
	238	efi_memmap_install(new_phys, num_entries);
	239	}
	240
452308de MF	241	/*
	242	* Helper function for efi_reserve_boot_services() to figure out if we
	243	* can free regions in efi_free_boot_services().
	244	*
	245	* Use this function to ensure we do not free regions owned by somebody
	246	* else. We must only reserve (and then free) regions:
	247	*
	248	* - Not within any part of the kernel
09821ff1	249	* - Not the BIOS reserved area (E820_TYPE_RESERVED, E820_TYPE_NVS, etc)
452308de MF	250	*/
	251	static bool can_free_region(u64 start, u64 size)
	252	{
	253	if (start + size > __pa_symbol(_text) && start <= __pa_symbol(_end))
	254	return false;
	255
09821ff1	256	if (!e820__mapped_all(start, start+size, E820_TYPE_RAM))
452308de MF	257	return false;
	258
	259	return true;
	260	}
	261
eeb9db09 ST	262	void __init efi_reserve_boot_services(void)
eeb9db09 ST	263	{
78ce248f	264	efi_memory_desc_t *md;
eeb9db09	265
78ce248f	266	for_each_efi_memory_desc(md) {
eeb9db09 ST	267	u64 start = md->phys_addr;
eeb9db09 ST	268	u64 size = md->num_pages << EFI_PAGE_SHIFT;
452308de	269	bool already_reserved;
eeb9db09 ST	270
	271	if (md->type != EFI_BOOT_SERVICES_CODE &&
	272	md->type != EFI_BOOT_SERVICES_DATA)
	273	continue;
452308de MF	274
	275	already_reserved = memblock_is_region_reserved(start, size);
	276
	277	/*
	278	* Because the following memblock_reserve() is paired
	279	* with free_bootmem_late() for this region in
	280	* efi_free_boot_services(), we must be extremely
	281	* careful not to reserve, and subsequently free,
	282	* critical regions of memory (like the kernel image) or
	283	* those regions that somebody else has already
	284	* reserved.
	285	*
	286	* A good example of a critical region that must not be
	287	* freed is page zero (first 4Kb of memory), which may
	288	* contain boot services code/data but is marked
09821ff1	289	* E820_TYPE_RESERVED by trim_bios_range().
452308de MF	290	*/
452308de MF	291	if (!already_reserved) {
eeb9db09	292	memblock_reserve(start, size);
452308de MF	293
	294	/*
	295	* If we are the first to reserve the region, no
	296	* one else cares about it. We own it and can
	297	* free it later.
	298	*/
	299	if (can_free_region(start, size))
	300	continue;
	301	}
	302
	303	/*
	304	* We don't own the region. We must not free it.
	305	*
	306	* Setting this bit for a boot services region really
	307	* doesn't make sense as far as the firmware is
	308	* concerned, but it does provide us with a way to tag
	309	* those regions that must not be paired with
	310	* free_bootmem_late().
	311	*/
	312	md->attribute \|= EFI_MEMORY_RUNTIME;
eeb9db09 ST	313	}
	314	}
	315
	316	void __init efi_free_boot_services(void)
	317	{
816e7612	318	phys_addr_t new_phys, new_size;
78ce248f	319	efi_memory_desc_t *md;
816e7612 MF	320	int num_entries = 0;
816e7612 MF	321	void new, new_md;
eeb9db09	322
78ce248f	323	for_each_efi_memory_desc(md) {
eeb9db09 ST	324	unsigned long long start = md->phys_addr;
eeb9db09 ST	325	unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
5bc653b7	326	size_t rm_size;
eeb9db09 ST	327
eeb9db09 ST	328	if (md->type != EFI_BOOT_SERVICES_CODE &&
816e7612 MF	329	md->type != EFI_BOOT_SERVICES_DATA) {
816e7612 MF	330	num_entries++;
eeb9db09	331	continue;
816e7612	332	}
eeb9db09	333
452308de	334	/* Do not free, someone else owns it: */
816e7612 MF	335	if (md->attribute & EFI_MEMORY_RUNTIME) {
816e7612 MF	336	num_entries++;
eeb9db09	337	continue;
816e7612	338	}
eeb9db09	339
5bc653b7 AL	340	/*
	341	* Nasty quirk: if all sub-1MB memory is used for boot
	342	* services, we can get here without having allocated the
	343	* real mode trampoline. It's too late to hand boot services
	344	* memory back to the memblock allocator, so instead
	345	* try to manually allocate the trampoline if needed.
	346	*
	347	* I've seen this on a Dell XPS 13 9350 with firmware
	348	* 1.4.4 with SGX enabled booting Linux via Fedora 24's
	349	* grub2-efi on a hard disk. (And no, I don't know why
	350	* this happened, but Linux should still try to boot rather
	351	* panicing early.)
	352	*/
	353	rm_size = real_mode_size_needed();
	354	if (rm_size && (start + rm_size) < (1<<20) && size >= rm_size) {
	355	set_real_mode_mem(start, rm_size);
	356	start += rm_size;
	357	size -= rm_size;
	358	}
	359
eeb9db09 ST	360	free_bootmem_late(start, size);
eeb9db09 ST	361	}
816e7612	362
1ea34adb JG	363	if (!num_entries)
	364	return;
	365
816e7612	366	new_size = efi.memmap.desc_size * num_entries;
20b1e22d	367	new_phys = efi_memmap_alloc(num_entries);
816e7612 MF	368	if (!new_phys) {
	369	pr_err("Failed to allocate new EFI memmap\n");
	370	return;
	371	}
	372
	373	new = memremap(new_phys, new_size, MEMREMAP_WB);
	374	if (!new) {
	375	pr_err("Failed to map new EFI memmap\n");
	376	return;
	377	}
	378
	379	/*
	380	* Build a new EFI memmap that excludes any boot services
	381	* regions that are not tagged EFI_MEMORY_RUNTIME, since those
	382	* regions have now been freed.
	383	*/
	384	new_md = new;
	385	for_each_efi_memory_desc(md) {
	386	if (!(md->attribute & EFI_MEMORY_RUNTIME) &&
	387	(md->type == EFI_BOOT_SERVICES_CODE \|\|
	388	md->type == EFI_BOOT_SERVICES_DATA))
	389	continue;
	390
	391	memcpy(new_md, md, efi.memmap.desc_size);
	392	new_md += efi.memmap.desc_size;
	393	}
	394
	395	memunmap(new);
	396
	397	if (efi_memmap_install(new_phys, num_entries)) {
	398	pr_err("Could not install new EFI memmap\n");
	399	return;
	400	}
eeb9db09 ST	401	}
	402
	403	/*
	404	* A number of config table entries get remapped to virtual addresses
	405	* after entering EFI virtual mode. However, the kexec kernel requires
	406	* their physical addresses therefore we pass them via setup_data and
	407	* correct those entries to their respective physical addresses here.
	408	*
	409	* Currently only handles smbios which is necessary for some firmware
	410	* implementation.
	411	*/
	412	int __init efi_reuse_config(u64 tables, int nr_tables)
	413	{
	414	int i, sz, ret = 0;
	415	void p, tablep;
	416	struct efi_setup_data *data;
	417
	418	if (!efi_setup)
	419	return 0;
	420
	421	if (!efi_enabled(EFI_64BIT))
	422	return 0;
	423
	424	data = early_memremap(efi_setup, sizeof(*data));
	425	if (!data) {
	426	ret = -ENOMEM;
	427	goto out;
	428	}
	429
	430	if (!data->smbios)
	431	goto out_memremap;
	432
	433	sz = sizeof(efi_config_table_64_t);
	434
	435	p = tablep = early_memremap(tables, nr_tables * sz);
	436	if (!p) {
	437	pr_err("Could not map Configuration table!\n");
	438	ret = -ENOMEM;
	439	goto out_memremap;
	440	}
	441
	442	for (i = 0; i < efi.systab->nr_tables; i++) {
	443	efi_guid_t guid;
	444
	445	guid = ((efi_config_table_64_t *)p)->guid;
	446
	447	if (!efi_guidcmp(guid, SMBIOS_TABLE_GUID))
	448	((efi_config_table_64_t *)p)->table = data->smbios;
	449	p += sz;
	450	}
98a716b6	451	early_memunmap(tablep, nr_tables * sz);
eeb9db09 ST	452
eeb9db09 ST	453	out_memremap:
98a716b6	454	early_memunmap(data, sizeof(*data));
eeb9db09 ST	455	out:
	456	return ret;
	457	}
	458
d394f2d9 AT	459	static const struct dmi_system_id sgi_uv1_dmi[] = {
	460	{ NULL, "SGI UV1",
	461	{ DMI_MATCH(DMI_PRODUCT_NAME, "Stoutland Platform"),
	462	DMI_MATCH(DMI_PRODUCT_VERSION, "1.0"),
	463	DMI_MATCH(DMI_BIOS_VENDOR, "SGI.COM"),
	464	}
	465	},
	466	{ } /* NULL entry stops DMI scanning */
	467	};
	468
eeb9db09 ST	469	void __init efi_apply_memmap_quirks(void)
	470	{
	471	/*
	472	* Once setup is done earlier, unmap the EFI memory map on mismatched
	473	* firmware/kernel architectures since there is no support for runtime
	474	* services.
	475	*/
	476	if (!efi_runtime_supported()) {
26d7f65f	477	pr_info("Setup done, disabling due to 32/64-bit mismatch\n");
9479c7ce	478	efi_memmap_unmap();
eeb9db09 ST	479	}
eeb9db09 ST	480
d394f2d9 AT	481	/* UV2+ BIOS has a fix for this issue. UV1 still needs the quirk. */
d394f2d9 AT	482	if (dmi_check_system(sgi_uv1_dmi))
eeb9db09 ST	483	set_bit(EFI_OLD_MEMMAP, &efi.flags);
eeb9db09 ST	484	}
44be28e9 MF	485
	486	/*
	487	* For most modern platforms the preferred method of powering off is via
	488	* ACPI. However, there are some that are known to require the use of
	489	* EFI runtime services and for which ACPI does not work at all.
	490	*
	491	* Using EFI is a last resort, to be used only if no other option
	492	* exists.
	493	*/
	494	bool efi_reboot_required(void)
	495	{
	496	if (!acpi_gbl_reduced_hardware)
	497	return false;
	498
	499	efi_reboot_quirk_mode = EFI_RESET_WARM;
	500	return true;
	501	}
	502
	503	bool efi_poweroff_required(void)
	504	{
13737181	505	return acpi_gbl_reduced_hardware \|\| acpi_no_s5;
44be28e9	506	}