Merge branch 'efi-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull EFI updates from Thomas Gleixner:
 "The EFI pile:

   - Make mixed mode UEFI runtime service invocations mutually
     exclusive, as mandated by the UEFI spec

   - Perform UEFI runtime services calls from a work queue so the calls
     into the firmware occur from a kernel thread

   - Honor the UEFI memory map attributes for live memory regions
     configured by UEFI as a framebuffer. This works around a coherency
     problem with KVM guests running on ARM.

   - Cleanups, improvements and fixes all over the place"

* 'efi-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efivars: Call guid_parse() against guid_t type of variable
  efi/cper: Use consistent types for UUIDs
  efi/x86: Replace references to efi_early->is64 with efi_is_64bit()
  efi: Deduplicate efi_open_volume()
  efi/x86: Add missing NULL initialization in UGA draw protocol discovery
  efi/x86: Merge 32-bit and 64-bit UGA draw protocol setup routines
  efi/x86: Align efi_uga_draw_protocol typedef names to convention
  efi/x86: Merge the setup_efi_pci32() and setup_efi_pci64() routines
  efi/x86: Prevent reentrant firmware calls in mixed mode
  efi/esrt: Only call efi_mem_reserve() for boot services memory
  fbdev/efifb: Honour UEFI memory map attributes when mapping the FB
  efi: Drop type and attribute checks in efi_mem_desc_lookup()
  efi/libstub/arm: Add opt-in Kconfig option for the DTB loader
  efi: Remove the declaration of efi_late_init() as the function is unused
  efi/cper: Avoid using get_seconds()
  efi: Use a work queue to invoke EFI Runtime Services
  efi/x86: Use non-blocking SetVariable() for efi_delete_dummy_variable()
  efi/x86: Clean up the eboot code

arch/arm/include/asm/efi.h

@@ -58,6 +58,9 @@ void efi_virtmap_unload(void);
 #define efi_call_runtime(f, ...)	sys_table_arg->runtime->f(__VA_ARGS__)
 #define efi_is_64bit()			(false)
 
+#define efi_table_attr(table, attr, instance)				\
+	((table##_t *)instance)->attr
+
 #define efi_call_proto(protocol, f, instance, ...)			\
 	((protocol##_t *)instance)->f(instance, ##__VA_ARGS__)
 

arch/arm64/include/asm/efi.h

@@ -87,6 +87,9 @@ static inline unsigned long efi_get_max_initrd_addr(unsigned long dram_base,
 #define efi_call_runtime(f, ...)	sys_table_arg->runtime->f(__VA_ARGS__)
 #define efi_is_64bit()			(true)
 
+#define efi_table_attr(table, attr, instance)				\
+	((table##_t *)instance)->attr
+
 #define efi_call_proto(protocol, f, instance, ...)			\
 	((protocol##_t *)instance)->f(instance, ##__VA_ARGS__)
 

arch/x86/boot/compressed/eboot.h

@@ -12,22 +12,22 @@
 
 #define DESC_TYPE_CODE_DATA	(1 << 0)
 
-struct efi_uga_draw_protocol_32 {
+typedef struct {
 	u32 get_mode;
 	u32 set_mode;
 	u32 blt;
-};
+} efi_uga_draw_protocol_32_t;
 
-struct efi_uga_draw_protocol_64 {
+typedef struct {
 	u64 get_mode;
 	u64 set_mode;
 	u64 blt;
-};
+} efi_uga_draw_protocol_64_t;
 
-struct efi_uga_draw_protocol {
+typedef struct {
 	void *get_mode;
 	void *set_mode;
 	void *blt;
-};
+} efi_uga_draw_protocol_t;
 
 #endif /* BOOT_COMPRESSED_EBOOT_H */

arch/x86/platform/efi/efi_64.c

@@ -636,6 +636,8 @@ void efi_switch_mm(struct mm_struct *mm)
 #ifdef CONFIG_EFI_MIXED
 extern efi_status_t efi64_thunk(u32, ...);
 
+static DEFINE_SPINLOCK(efi_runtime_lock);
+
 #define runtime_service32(func)						 \
 ({									 \
 	u32 table = (u32)(unsigned long)efi.systab;			 \
@@ -657,17 +659,14 @@ extern efi_status_t efi64_thunk(u32, ...);
 #define efi_thunk(f, ...)						\
 ({									\
 	efi_status_t __s;						\
-	unsigned long __flags;						\
 	u32 __func;							\
 									\
-	local_irq_save(__flags);					\
 	arch_efi_call_virt_setup();					\
 									\
 	__func = runtime_service32(f);					\
 	__s = efi64_thunk(__func, __VA_ARGS__);				\
 									\
 	arch_efi_call_virt_teardown();					\
-	local_irq_restore(__flags);					\
 									\
 	__s;								\
 })
@@ -702,14 +701,17 @@ static efi_status_t efi_thunk_get_time(efi_time_t *tm, efi_time_cap_t *tc)
 {
 	efi_status_t status;
 	u32 phys_tm, phys_tc;
+	unsigned long flags;
 
 	spin_lock(&rtc_lock);
+	spin_lock_irqsave(&efi_runtime_lock, flags);
 
 	phys_tm = virt_to_phys_or_null(tm);
 	phys_tc = virt_to_phys_or_null(tc);
 
 	status = efi_thunk(get_time, phys_tm, phys_tc);
 
+	spin_unlock_irqrestore(&efi_runtime_lock, flags);
 	spin_unlock(&rtc_lock);
 
 	return status;
@@ -719,13 +721,16 @@ static efi_status_t efi_thunk_set_time(efi_time_t *tm)
 {
 	efi_status_t status;
 	u32 phys_tm;
+	unsigned long flags;
 
 	spin_lock(&rtc_lock);
+	spin_lock_irqsave(&efi_runtime_lock, flags);
 
 	phys_tm = virt_to_phys_or_null(tm);
 
 	status = efi_thunk(set_time, phys_tm);
 
+	spin_unlock_irqrestore(&efi_runtime_lock, flags);
 	spin_unlock(&rtc_lock);
 
 	return status;
@@ -737,8 +742,10 @@ efi_thunk_get_wakeup_time(efi_bool_t *enabled, efi_bool_t *pending,
 {
 	efi_status_t status;
 	u32 phys_enabled, phys_pending, phys_tm;
+	unsigned long flags;
 
 	spin_lock(&rtc_lock);
+	spin_lock_irqsave(&efi_runtime_lock, flags);
 
 	phys_enabled = virt_to_phys_or_null(enabled);
 	phys_pending = virt_to_phys_or_null(pending);
@@ -747,6 +754,7 @@ efi_thunk_get_wakeup_time(efi_bool_t *enabled, efi_bool_t *pending,
 	status = efi_thunk(get_wakeup_time, phys_enabled,
 			     phys_pending, phys_tm);
 
+	spin_unlock_irqrestore(&efi_runtime_lock, flags);
 	spin_unlock(&rtc_lock);
 
 	return status;
@@ -757,13 +765,16 @@ efi_thunk_set_wakeup_time(efi_bool_t enabled, efi_time_t *tm)
 {
 	efi_status_t status;
 	u32 phys_tm;
+	unsigned long flags;
 
 	spin_lock(&rtc_lock);
+	spin_lock_irqsave(&efi_runtime_lock, flags);
 
 	phys_tm = virt_to_phys_or_null(tm);
 
 	status = efi_thunk(set_wakeup_time, enabled, phys_tm);
 
+	spin_unlock_irqrestore(&efi_runtime_lock, flags);
 	spin_unlock(&rtc_lock);
 
 	return status;
@@ -781,6 +792,9 @@ efi_thunk_get_variable(efi_char16_t *name, efi_guid_t *vendor,
 	efi_status_t status;
 	u32 phys_name, phys_vendor, phys_attr;
 	u32 phys_data_size, phys_data;
+	unsigned long flags;
+
+	spin_lock_irqsave(&efi_runtime_lock, flags);
 
 	phys_data_size = virt_to_phys_or_null(data_size);
 	phys_vendor = virt_to_phys_or_null(vendor);
@@ -791,6 +805,8 @@ efi_thunk_get_variable(efi_char16_t *name, efi_guid_t *vendor,
 	status = efi_thunk(get_variable, phys_name, phys_vendor,
 			   phys_attr, phys_data_size, phys_data);
 
+	spin_unlock_irqrestore(&efi_runtime_lock, flags);
+
 	return status;
 }
 
@@ -800,6 +816,9 @@ efi_thunk_set_variable(efi_char16_t *name, efi_guid_t *vendor,
 {
 	u32 phys_name, phys_vendor, phys_data;
 	efi_status_t status;
+	unsigned long flags;
+
+	spin_lock_irqsave(&efi_runtime_lock, flags);
 
 	phys_name = virt_to_phys_or_null_size(name, efi_name_size(name));
 	phys_vendor = virt_to_phys_or_null(vendor);
@@ -809,6 +828,33 @@ efi_thunk_set_variable(efi_char16_t *name, efi_guid_t *vendor,
 	status = efi_thunk(set_variable, phys_name, phys_vendor,
 			   attr, data_size, phys_data);
 
+	spin_unlock_irqrestore(&efi_runtime_lock, flags);
+
+	return status;
+}
+
+static efi_status_t
+efi_thunk_set_variable_nonblocking(efi_char16_t *name, efi_guid_t *vendor,
+				   u32 attr, unsigned long data_size,
+				   void *data)
+{
+	u32 phys_name, phys_vendor, phys_data;
+	efi_status_t status;
+	unsigned long flags;
+
+	if (!spin_trylock_irqsave(&efi_runtime_lock, flags))
+		return EFI_NOT_READY;
+
+	phys_name = virt_to_phys_or_null_size(name, efi_name_size(name));
+	phys_vendor = virt_to_phys_or_null(vendor);
+	phys_data = virt_to_phys_or_null_size(data, data_size);
+
+	/* If data_size is > sizeof(u32) we've got problems */
+	status = efi_thunk(set_variable, phys_name, phys_vendor,
+			   attr, data_size, phys_data);
+
+	spin_unlock_irqrestore(&efi_runtime_lock, flags);
+
 	return status;
 }
 
@@ -819,6 +865,9 @@ efi_thunk_get_next_variable(unsigned long *name_size,
 {
 	efi_status_t status;
 	u32 phys_name_size, phys_name, phys_vendor;
+	unsigned long flags;
+
+	spin_lock_irqsave(&efi_runtime_lock, flags);
 
 	phys_name_size = virt_to_phys_or_null(name_size);
 	phys_vendor = virt_to_phys_or_null(vendor);
@@ -827,6 +876,8 @@ efi_thunk_get_next_variable(unsigned long *name_size,
 	status = efi_thunk(get_next_variable, phys_name_size,
 			   phys_name, phys_vendor);
 
+	spin_unlock_irqrestore(&efi_runtime_lock, flags);
+
 	return status;
 }
 
@@ -835,10 +886,15 @@ efi_thunk_get_next_high_mono_count(u32 *count)
 {
 	efi_status_t status;
 	u32 phys_count;
+	unsigned long flags;
+
+	spin_lock_irqsave(&efi_runtime_lock, flags);
 
 	phys_count = virt_to_phys_or_null(count);
 	status = efi_thunk(get_next_high_mono_count, phys_count);
 
+	spin_unlock_irqrestore(&efi_runtime_lock, flags);
+
 	return status;
 }
 
@@ -847,10 +903,15 @@ efi_thunk_reset_system(int reset_type, efi_status_t status,
 		       unsigned long data_size, efi_char16_t *data)
 {
 	u32 phys_data;
+	unsigned long flags;
+
+	spin_lock_irqsave(&efi_runtime_lock, flags);
 
 	phys_data = virt_to_phys_or_null_size(data, data_size);
 
 	efi_thunk(reset_system, reset_type, status, data_size, phys_data);
+
+	spin_unlock_irqrestore(&efi_runtime_lock, flags);
 }
 
 static efi_status_t
@@ -872,10 +933,40 @@ efi_thunk_query_variable_info(u32 attr, u64 *storage_space,
 {
 	efi_status_t status;
 	u32 phys_storage, phys_remaining, phys_max;
+	unsigned long flags;
+
+	if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
+		return EFI_UNSUPPORTED;
+
+	spin_lock_irqsave(&efi_runtime_lock, flags);
+
+	phys_storage = virt_to_phys_or_null(storage_space);
+	phys_remaining = virt_to_phys_or_null(remaining_space);
+	phys_max = virt_to_phys_or_null(max_variable_size);
+
+	status = efi_thunk(query_variable_info, attr, phys_storage,
+			   phys_remaining, phys_max);
+
+	spin_unlock_irqrestore(&efi_runtime_lock, flags);
+
+	return status;
+}
+
+static efi_status_t
+efi_thunk_query_variable_info_nonblocking(u32 attr, u64 *storage_space,
+					  u64 *remaining_space,
+					  u64 *max_variable_size)
+{
+	efi_status_t status;
+	u32 phys_storage, phys_remaining, phys_max;
+	unsigned long flags;
 
 	if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
 		return EFI_UNSUPPORTED;
 
+	if (!spin_trylock_irqsave(&efi_runtime_lock, flags))
+		return EFI_NOT_READY;
+
 	phys_storage = virt_to_phys_or_null(storage_space);
 	phys_remaining = virt_to_phys_or_null(remaining_space);
 	phys_max = virt_to_phys_or_null(max_variable_size);
@@ -883,6 +974,8 @@ efi_thunk_query_variable_info(u32 attr, u64 *storage_space,
 	status = efi_thunk(query_variable_info, attr, phys_storage,
 			   phys_remaining, phys_max);
 
+	spin_unlock_irqrestore(&efi_runtime_lock, flags);
+
 	return status;
 }
 
@@ -908,9 +1001,11 @@ void efi_thunk_runtime_setup(void)
 	efi.get_variable = efi_thunk_get_variable;
 	efi.get_next_variable = efi_thunk_get_next_variable;
 	efi.set_variable = efi_thunk_set_variable;
+	efi.set_variable_nonblocking = efi_thunk_set_variable_nonblocking;
 	efi.get_next_high_mono_count = efi_thunk_get_next_high_mono_count;
 	efi.reset_system = efi_thunk_reset_system;
 	efi.query_variable_info = efi_thunk_query_variable_info;
+	efi.query_variable_info_nonblocking = efi_thunk_query_variable_info_nonblocking;
 	efi.update_capsule = efi_thunk_update_capsule;
 	efi.query_capsule_caps = efi_thunk_query_capsule_caps;
 }

arch/x86/platform/efi/quirks.c

@@ -105,12 +105,11 @@ early_param("efi_no_storage_paranoia", setup_storage_paranoia);
 */
 void efi_delete_dummy_variable(void)
 {
-	efi.set_variable((efi_char16_t *)efi_dummy_name,
+	efi.set_variable_nonblocking((efi_char16_t *)efi_dummy_name,
 				     &EFI_DUMMY_GUID,
 				     EFI_VARIABLE_NON_VOLATILE |
 				     EFI_VARIABLE_BOOTSERVICE_ACCESS |
-			 EFI_VARIABLE_RUNTIME_ACCESS,
-			 0, NULL);
+				     EFI_VARIABLE_RUNTIME_ACCESS, 0, NULL);
 }
 
 /*
@@ -249,7 +248,8 @@ void __init efi_arch_mem_reserve(phys_addr_t addr, u64 size)
 	int num_entries;
 	void *new;
 
-	if (efi_mem_desc_lookup(addr, &md)) {
+	if (efi_mem_desc_lookup(addr, &md) ||
+	    md.type != EFI_BOOT_SERVICES_DATA) {
 		pr_err("Failed to lookup EFI memory descriptor for %pa\n", &addr);
 		return;
 	}

drivers/firmware/efi/Kconfig

@@ -87,6 +87,18 @@ config EFI_RUNTIME_WRAPPERS
 config EFI_ARMSTUB
 	bool
 
+config EFI_ARMSTUB_DTB_LOADER
+	bool "Enable the DTB loader"
+	depends on EFI_ARMSTUB
+	help
+	  Select this config option to add support for the dtb= command
+	  line parameter, allowing a device tree blob to be loaded into
+	  memory from the EFI System Partition by the stub.
+
+	  The device tree is typically provided by the platform or by
+	  the bootloader, so this option is mostly for development
+	  purposes only.
+
 config EFI_BOOTLOADER_CONTROL
 	tristate "EFI Bootloader Control"
 	depends on EFI_VARS

drivers/firmware/efi/cper.c

@@ -48,8 +48,21 @@ u64 cper_next_record_id(void)
 {
 	static atomic64_t seq;
 
-	if (!atomic64_read(&seq))
-		atomic64_set(&seq, ((u64)get_seconds()) << 32);
+	if (!atomic64_read(&seq)) {
+		time64_t time = ktime_get_real_seconds();
+
+		/*
+		 * This code is unlikely to still be needed in year 2106,
+		 * but just in case, let's use a few more bits for timestamps
+		 * after y2038 to be sure they keep increasing monotonically
+		 * for the next few hundred years...
+		 */
+		if (time < 0x80000000)
+			atomic64_set(&seq, (ktime_get_real_seconds()) << 32);
+		else
+			atomic64_set(&seq, 0x8000000000000000ull |
+					   ktime_get_real_seconds() << 24);
+	}
 
 	return atomic64_inc_return(&seq);
 }
@@ -459,7 +472,7 @@ cper_estatus_print_section(const char *pfx, struct acpi_hest_generic_data *gdata
 		else
 			goto err_section_too_small;
 #if defined(CONFIG_ARM64) || defined(CONFIG_ARM)
-	} else if (!uuid_le_cmp(*sec_type, CPER_SEC_PROC_ARM)) {
+	} else if (guid_equal(sec_type, &CPER_SEC_PROC_ARM)) {
 		struct cper_sec_proc_arm *arm_err = acpi_hest_get_payload(gdata);
 
 		printk("%ssection_type: ARM processor error\n", newpfx);

drivers/firmware/efi/efi.c

@@ -84,6 +84,8 @@ struct mm_struct efi_mm = {
 	.mmlist			= LIST_HEAD_INIT(efi_mm.mmlist),
 };
 
+struct workqueue_struct *efi_rts_wq;
+
 static bool disable_runtime;
 static int __init setup_noefi(char *arg)
 {
@@ -337,6 +339,18 @@ static int __init efisubsys_init(void)
 	if (!efi_enabled(EFI_BOOT))
 		return 0;
 
+	/*
+	 * Since we process only one efi_runtime_service() at a time, an
+	 * ordered workqueue (which creates only one execution context)
+	 * should suffice all our needs.
+	 */
+	efi_rts_wq = alloc_ordered_workqueue("efi_rts_wq", 0);
+	if (!efi_rts_wq) {
+		pr_err("Creating efi_rts_wq failed, EFI runtime services disabled.\n");
+		clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
+		return 0;
+	}
+
 	/* We register the efi directory at /sys/firmware/efi */
 	efi_kobj = kobject_create_and_add("efi", firmware_kobj);
 	if (!efi_kobj) {
@@ -388,7 +402,7 @@ subsys_initcall(efisubsys_init);
  * and if so, populate the supplied memory descriptor with the appropriate
  * data.
  */
-int __init efi_mem_desc_lookup(u64 phys_addr, efi_memory_desc_t *out_md)
+int efi_mem_desc_lookup(u64 phys_addr, efi_memory_desc_t *out_md)
 {
 	efi_memory_desc_t *md;
 
@@ -406,12 +420,6 @@ int __init efi_mem_desc_lookup(u64 phys_addr, efi_memory_desc_t *out_md)
 		u64 size;
 		u64 end;
 
-		if (!(md->attribute & EFI_MEMORY_RUNTIME) &&
-		    md->type != EFI_BOOT_SERVICES_DATA &&
-		    md->type != EFI_RUNTIME_SERVICES_DATA) {
-			continue;
-		}
-
 		size = md->num_pages << EFI_PAGE_SHIFT;
 		end = md->phys_addr + size;
 		if (phys_addr >= md->phys_addr && phys_addr < end) {

drivers/firmware/efi/esrt.c

@@ -250,7 +250,10 @@ void __init efi_esrt_init(void)
 		return;
 
 	rc = efi_mem_desc_lookup(efi.esrt, &md);
-	if (rc < 0) {
+	if (rc < 0 ||
+	    (!(md.attribute & EFI_MEMORY_RUNTIME) &&
+	     md.type != EFI_BOOT_SERVICES_DATA &&
+	     md.type != EFI_RUNTIME_SERVICES_DATA)) {
 		pr_warn("ESRT header is not in the memory map.\n");
 		return;
 	}
@@ -326,6 +329,7 @@ void __init efi_esrt_init(void)
 
 	end = esrt_data + size;
 	pr_info("Reserving ESRT space from %pa to %pa.\n", &esrt_data, &end);
+	if (md.type == EFI_BOOT_SERVICES_DATA)
 		efi_mem_reserve(esrt_data, esrt_data_size);
 
 	pr_debug("esrt-init: loaded.\n");

drivers/firmware/efi/libstub/arm-stub.c

@@ -40,31 +40,6 @@
 
 static u64 virtmap_base = EFI_RT_VIRTUAL_BASE;
 
-efi_status_t efi_open_volume(efi_system_table_t *sys_table_arg,
-			     void *__image, void **__fh)
-{
-	efi_file_io_interface_t *io;
-	efi_loaded_image_t *image = __image;
-	efi_file_handle_t *fh;
-	efi_guid_t fs_proto = EFI_FILE_SYSTEM_GUID;
-	efi_status_t status;
-	void *handle = (void *)(unsigned long)image->device_handle;
-
-	status = sys_table_arg->boottime->handle_protocol(handle,
-				 &fs_proto, (void **)&io);
-	if (status != EFI_SUCCESS) {
-		efi_printk(sys_table_arg, "Failed to handle fs_proto\n");
-		return status;
-	}
-
-	status = io->open_volume(io, &fh);
-	if (status != EFI_SUCCESS)
-		efi_printk(sys_table_arg, "Failed to open volume\n");
-
-	*__fh = fh;
-	return status;
-}
-
 void efi_char16_printk(efi_system_table_t *sys_table_arg,
 			      efi_char16_t *str)
 {
@@ -202,8 +177,9 @@ unsigned long efi_entry(void *handle, efi_system_table_t *sys_table,
 	 * 'dtb=' unless UEFI Secure Boot is disabled.  We assume that secure
 	 * boot is enabled if we can't determine its state.
 	 */
-	if (secure_boot != efi_secureboot_mode_disabled &&
-	    strstr(cmdline_ptr, "dtb=")) {
+	if (!IS_ENABLED(CONFIG_EFI_ARMSTUB_DTB_LOADER) ||
+	     secure_boot != efi_secureboot_mode_disabled) {
+		if (strstr(cmdline_ptr, "dtb="))
 			pr_efi(sys_table, "Ignoring DTB from command line.\n");
 	} else {
 		status = handle_cmdline_files(sys_table, image, cmdline_ptr,

drivers/firmware/efi/libstub/efi-stub-helper.c

@@ -413,6 +413,34 @@ static efi_status_t efi_file_close(void *handle)
 	return efi_call_proto(efi_file_handle, close, handle);
 }
 
+static efi_status_t efi_open_volume(efi_system_table_t *sys_table_arg,
+				    efi_loaded_image_t *image,
+				    efi_file_handle_t **__fh)
+{
+	efi_file_io_interface_t *io;
+	efi_file_handle_t *fh;
+	efi_guid_t fs_proto = EFI_FILE_SYSTEM_GUID;
+	efi_status_t status;
+	void *handle = (void *)(unsigned long)efi_table_attr(efi_loaded_image,
+							     device_handle,
+							     image);
+
+	status = efi_call_early(handle_protocol, handle,
+				&fs_proto, (void **)&io);
+	if (status != EFI_SUCCESS) {
+		efi_printk(sys_table_arg, "Failed to handle fs_proto\n");
+		return status;
+	}
+
+	status = efi_call_proto(efi_file_io_interface, open_volume, io, &fh);
+	if (status != EFI_SUCCESS)
+		efi_printk(sys_table_arg, "Failed to open volume\n");
+	else
+		*__fh = fh;
+
+	return status;
+}
+
 /*
  * Parse the ASCII string 'cmdline' for EFI options, denoted by the efi=
  * option, e.g. efi=nochunk.
@@ -563,8 +591,7 @@ efi_status_t handle_cmdline_files(efi_system_table_t *sys_table_arg,
 
 		/* Only open the volume once. */
 		if (!i) {
-			status = efi_open_volume(sys_table_arg, image,
-						 (void **)&fh);
+			status = efi_open_volume(sys_table_arg, image, &fh);
 			if (status != EFI_SUCCESS)
 				goto free_files;
 		}

drivers/firmware/efi/libstub/efistub.h

@@ -36,9 +36,6 @@ extern int __pure is_quiet(void);
 
 void efi_char16_printk(efi_system_table_t *, efi_char16_t *);
 
-efi_status_t efi_open_volume(efi_system_table_t *sys_table_arg, void *__image,
-			     void **__fh);
-
 unsigned long get_dram_base(efi_system_table_t *sys_table_arg);
 
 efi_status_t allocate_new_fdt_and_exit_boot(efi_system_table_t *sys_table,

drivers/firmware/efi/runtime-wrappers.c

 /*
  * runtime-wrappers.c - Runtime Services function call wrappers
  *
+ * Implementation summary:
+ * -----------------------
+ * 1. When user/kernel thread requests to execute efi_runtime_service(),
+ * enqueue work to efi_rts_wq.
+ * 2. Caller thread waits for completion until the work is finished
+ * because it's dependent on the return status and execution of
+ * efi_runtime_service().
+ * For instance, get_variable() and get_next_variable().
+ *
  * Copyright (C) 2014 Linaro Ltd. <ard.biesheuvel@linaro.org>
  *
  * Split off from arch/x86/platform/efi/efi.c
@@ -22,6 +31,9 @@
 #include <linux/mutex.h>
 #include <linux/semaphore.h>
 #include <linux/stringify.h>
+#include <linux/workqueue.h>
+#include <linux/completion.h>
+
 #include <asm/efi.h>
 
 /*
@@ -33,6 +45,76 @@
 #define __efi_call_virt(f, args...) \
 	__efi_call_virt_pointer(efi.systab->runtime, f, args)
 
+/* efi_runtime_service() function identifiers */
+enum efi_rts_ids {
+	GET_TIME,
+	SET_TIME,
+	GET_WAKEUP_TIME,
+	SET_WAKEUP_TIME,
+	GET_VARIABLE,
+	GET_NEXT_VARIABLE,
+	SET_VARIABLE,
+	QUERY_VARIABLE_INFO,
+	GET_NEXT_HIGH_MONO_COUNT,
+	UPDATE_CAPSULE,
+	QUERY_CAPSULE_CAPS,
+};
+
+/*
+ * efi_runtime_work:	Details of EFI Runtime Service work
+ * @arg<1-5>:		EFI Runtime Service function arguments
+ * @status:		Status of executing EFI Runtime Service
+ * @efi_rts_id:		EFI Runtime Service function identifier
+ * @efi_rts_comp:	Struct used for handling completions
+ */
+struct efi_runtime_work {
+	void *arg1;
+	void *arg2;
+	void *arg3;
+	void *arg4;
+	void *arg5;
+	efi_status_t status;
+	struct work_struct work;
+	enum efi_rts_ids efi_rts_id;
+	struct completion efi_rts_comp;
+};
+
+/*
+ * efi_queue_work:	Queue efi_runtime_service() and wait until it's done
+ * @rts:		efi_runtime_service() function identifier
+ * @rts_arg<1-5>:	efi_runtime_service() function arguments
+ *
+ * Accesses to efi_runtime_services() are serialized by a binary
+ * semaphore (efi_runtime_lock) and caller waits until the work is
+ * finished, hence _only_ one work is queued at a time and the caller
+ * thread waits for completion.
+ */
+#define efi_queue_work(_rts, _arg1, _arg2, _arg3, _arg4, _arg5)		\
+({									\
+	struct efi_runtime_work efi_rts_work;				\
+	efi_rts_work.status = EFI_ABORTED;				\
+									\
+	init_completion(&efi_rts_work.efi_rts_comp);			\
+	INIT_WORK_ONSTACK(&efi_rts_work.work, efi_call_rts);		\
+	efi_rts_work.arg1 = _arg1;					\
+	efi_rts_work.arg2 = _arg2;					\
+	efi_rts_work.arg3 = _arg3;					\
+	efi_rts_work.arg4 = _arg4;					\
+	efi_rts_work.arg5 = _arg5;					\
+	efi_rts_work.efi_rts_id = _rts;					\
+									\
+	/*								\
+	 * queue_work() returns 0 if work was already on queue,         \
+	 * _ideally_ this should never happen.                          \
+	 */								\
+	if (queue_work(efi_rts_wq, &efi_rts_work.work))			\
+		wait_for_completion(&efi_rts_work.efi_rts_comp);	\
+	else								\
+		pr_err("Failed to queue work to efi_rts_wq.\n");	\
+									\
+	efi_rts_work.status;						\
+})
+
 void efi_call_virt_check_flags(unsigned long flags, const char *call)
 {
 	unsigned long cur_flags, mismatch;
@@ -90,13 +172,98 @@ void efi_call_virt_check_flags(unsigned long flags, const char *call)
  */
 static DEFINE_SEMAPHORE(efi_runtime_lock);
 
+/*
+ * Calls the appropriate efi_runtime_service() with the appropriate
+ * arguments.
+ *
+ * Semantics followed by efi_call_rts() to understand efi_runtime_work:
+ * 1. If argument was a pointer, recast it from void pointer to original
+ * pointer type.
+ * 2. If argument was a value, recast it from void pointer to original
+ * pointer type and dereference it.
+ */
+static void efi_call_rts(struct work_struct *work)
+{
+	struct efi_runtime_work *efi_rts_work;
+	void *arg1, *arg2, *arg3, *arg4, *arg5;
+	efi_status_t status = EFI_NOT_FOUND;
+
+	efi_rts_work = container_of(work, struct efi_runtime_work, work);
+	arg1 = efi_rts_work->arg1;
+	arg2 = efi_rts_work->arg2;
+	arg3 = efi_rts_work->arg3;
+	arg4 = efi_rts_work->arg4;
+	arg5 = efi_rts_work->arg5;
+
+	switch (efi_rts_work->efi_rts_id) {
+	case GET_TIME:
+		status = efi_call_virt(get_time, (efi_time_t *)arg1,
+				       (efi_time_cap_t *)arg2);
+		break;
+	case SET_TIME:
+		status = efi_call_virt(set_time, (efi_time_t *)arg1);
+		break;
+	case GET_WAKEUP_TIME:
+		status = efi_call_virt(get_wakeup_time, (efi_bool_t *)arg1,
+				       (efi_bool_t *)arg2, (efi_time_t *)arg3);
+		break;
+	case SET_WAKEUP_TIME:
+		status = efi_call_virt(set_wakeup_time, *(efi_bool_t *)arg1,
+				       (efi_time_t *)arg2);
+		break;
+	case GET_VARIABLE:
+		status = efi_call_virt(get_variable, (efi_char16_t *)arg1,
+				       (efi_guid_t *)arg2, (u32 *)arg3,
+				       (unsigned long *)arg4, (void *)arg5);
+		break;
+	case GET_NEXT_VARIABLE:
+		status = efi_call_virt(get_next_variable, (unsigned long *)arg1,
+				       (efi_char16_t *)arg2,
+				       (efi_guid_t *)arg3);
+		break;
+	case SET_VARIABLE:
+		status = efi_call_virt(set_variable, (efi_char16_t *)arg1,
+				       (efi_guid_t *)arg2, *(u32 *)arg3,
+				       *(unsigned long *)arg4, (void *)arg5);
+		break;
+	case QUERY_VARIABLE_INFO:
+		status = efi_call_virt(query_variable_info, *(u32 *)arg1,
+				       (u64 *)arg2, (u64 *)arg3, (u64 *)arg4);
+		break;
+	case GET_NEXT_HIGH_MONO_COUNT:
+		status = efi_call_virt(get_next_high_mono_count, (u32 *)arg1);
+		break;
+	case UPDATE_CAPSULE:
+		status = efi_call_virt(update_capsule,
+				       (efi_capsule_header_t **)arg1,
+				       *(unsigned long *)arg2,
+				       *(unsigned long *)arg3);
+		break;
+	case QUERY_CAPSULE_CAPS:
+		status = efi_call_virt(query_capsule_caps,
+				       (efi_capsule_header_t **)arg1,
+				       *(unsigned long *)arg2, (u64 *)arg3,
+				       (int *)arg4);
+		break;
+	default:
+		/*
+		 * Ideally, we should never reach here because a caller of this
+		 * function should have put the right efi_runtime_service()
+		 * function identifier into efi_rts_work->efi_rts_id
+		 */
+		pr_err("Requested executing invalid EFI Runtime Service.\n");
+	}
+	efi_rts_work->status = status;
+	complete(&efi_rts_work->efi_rts_comp);
+}
+
 static efi_status_t virt_efi_get_time(efi_time_t *tm, efi_time_cap_t *tc)
 {
 	efi_status_t status;
 
 	if (down_interruptible(&efi_runtime_lock))
 		return EFI_ABORTED;
-	status = efi_call_virt(get_time, tm, tc);
+	status = efi_queue_work(GET_TIME, tm, tc, NULL, NULL, NULL);
 	up(&efi_runtime_lock);
 	return status;
 }
@@ -107,7 +274,7 @@ static efi_status_t virt_efi_set_time(efi_time_t *tm)
 
 	if (down_interruptible(&efi_runtime_lock))
 		return EFI_ABORTED;
-	status = efi_call_virt(set_time, tm);
+	status = efi_queue_work(SET_TIME, tm, NULL, NULL, NULL, NULL);
 	up(&efi_runtime_lock);
 	return status;
 }
@@ -120,7 +287,8 @@ static efi_status_t virt_efi_get_wakeup_time(efi_bool_t *enabled,
 
 	if (down_interruptible(&efi_runtime_lock))
 		return EFI_ABORTED;
-	status = efi_call_virt(get_wakeup_time, enabled, pending, tm);
+	status = efi_queue_work(GET_WAKEUP_TIME, enabled, pending, tm, NULL,
+				NULL);
 	up(&efi_runtime_lock);
 	return status;
 }
@@ -131,7 +299,8 @@ static efi_status_t virt_efi_set_wakeup_time(efi_bool_t enabled, efi_time_t *tm)
 
 	if (down_interruptible(&efi_runtime_lock))
 		return EFI_ABORTED;
-	status = efi_call_virt(set_wakeup_time, enabled, tm);
+	status = efi_queue_work(SET_WAKEUP_TIME, &enabled, tm, NULL, NULL,
+				NULL);
 	up(&efi_runtime_lock);
 	return status;
 }
@@ -146,7 +315,7 @@ static efi_status_t virt_efi_get_variable(efi_char16_t *name,
 
 	if (down_interruptible(&efi_runtime_lock))
 		return EFI_ABORTED;
-	status = efi_call_virt(get_variable, name, vendor, attr, data_size,
+	status = efi_queue_work(GET_VARIABLE, name, vendor, attr, data_size,
 				data);
 	up(&efi_runtime_lock);
 	return status;
@@ -160,7 +329,8 @@ static efi_status_t virt_efi_get_next_variable(unsigned long *name_size,
 
 	if (down_interruptible(&efi_runtime_lock))
 		return EFI_ABORTED;
-	status = efi_call_virt(get_next_variable, name_size, name, vendor);
+	status = efi_queue_work(GET_NEXT_VARIABLE, name_size, name, vendor,
+				NULL, NULL);
 	up(&efi_runtime_lock);
 	return status;
 }
@@ -175,7 +345,7 @@ static efi_status_t virt_efi_set_variable(efi_char16_t *name,
 
 	if (down_interruptible(&efi_runtime_lock))
 		return EFI_ABORTED;
-	status = efi_call_virt(set_variable, name, vendor, attr, data_size,
+	status = efi_queue_work(SET_VARIABLE, name, vendor, &attr, &data_size,
 				data);
 	up(&efi_runtime_lock);
 	return status;
@@ -210,8 +380,8 @@ static efi_status_t virt_efi_query_variable_info(u32 attr,
 
 	if (down_interruptible(&efi_runtime_lock))
 		return EFI_ABORTED;
-	status = efi_call_virt(query_variable_info, attr, storage_space,
-			       remaining_space, max_variable_size);
+	status = efi_queue_work(QUERY_VARIABLE_INFO, &attr, storage_space,
+				remaining_space, max_variable_size, NULL);
 	up(&efi_runtime_lock);
 	return status;
 }
@@ -242,7 +412,8 @@ static efi_status_t virt_efi_get_next_high_mono_count(u32 *count)
 
 	if (down_interruptible(&efi_runtime_lock))
 		return EFI_ABORTED;
-	status = efi_call_virt(get_next_high_mono_count, count);
+	status = efi_queue_work(GET_NEXT_HIGH_MONO_COUNT, count, NULL, NULL,
+				NULL, NULL);
 	up(&efi_runtime_lock);
 	return status;
 }
@@ -272,7 +443,8 @@ static efi_status_t virt_efi_update_capsule(efi_capsule_header_t **capsules,
 
 	if (down_interruptible(&efi_runtime_lock))
 		return EFI_ABORTED;
-	status = efi_call_virt(update_capsule, capsules, count, sg_list);
+	status = efi_queue_work(UPDATE_CAPSULE, capsules, &count, &sg_list,
+				NULL, NULL);
 	up(&efi_runtime_lock);
 	return status;
 }
@@ -289,8 +461,8 @@ static efi_status_t virt_efi_query_capsule_caps(efi_capsule_header_t **capsules,
 
 	if (down_interruptible(&efi_runtime_lock))
 		return EFI_ABORTED;
-	status = efi_call_virt(query_capsule_caps, capsules, count, max_size,
-			       reset_type);
+	status = efi_queue_work(QUERY_CAPSULE_CAPS, capsules, &count,
+				max_size, reset_type, NULL);
 	up(&efi_runtime_lock);
 	return status;
 }

drivers/video/fbdev/efifb.c

@@ -20,7 +20,7 @@
 #include <drm/drm_connector.h>  /* For DRM_MODE_PANEL_ORIENTATION_* */
 
 static bool request_mem_succeeded = false;
-static bool nowc = false;
+static u64 mem_flags = EFI_MEMORY_WC | EFI_MEMORY_UC;
 
 static struct fb_var_screeninfo efifb_defined = {
 	.activate		= FB_ACTIVATE_NOW,
@@ -68,8 +68,12 @@ static int efifb_setcolreg(unsigned regno, unsigned red, unsigned green,
 
 static void efifb_destroy(struct fb_info *info)
 {
-	if (info->screen_base)
+	if (info->screen_base) {
+		if (mem_flags & (EFI_MEMORY_UC | EFI_MEMORY_WC))
 			iounmap(info->screen_base);
+		else
+			memunmap(info->screen_base);
+	}
 	if (request_mem_succeeded)
 		release_mem_region(info->apertures->ranges[0].base,
 				   info->apertures->ranges[0].size);
@@ -104,7 +108,7 @@ static int efifb_setup(char *options)
 			else if (!strncmp(this_opt, "width:", 6))
 				screen_info.lfb_width = simple_strtoul(this_opt+6, NULL, 0);
 			else if (!strcmp(this_opt, "nowc"))
-				nowc = true;
+				mem_flags &= ~EFI_MEMORY_WC;
 		}
 	}
 
@@ -164,6 +168,7 @@ static int efifb_probe(struct platform_device *dev)
 	unsigned int size_remap;
 	unsigned int size_total;
 	char *option = NULL;
+	efi_memory_desc_t md;
 
 	if (screen_info.orig_video_isVGA != VIDEO_TYPE_EFI || pci_dev_disabled)
 		return -ENODEV;
@@ -272,12 +277,35 @@ static int efifb_probe(struct platform_device *dev)
 	info->apertures->ranges[0].base = efifb_fix.smem_start;
 	info->apertures->ranges[0].size = size_remap;
 
-	if (nowc)
-		info->screen_base = ioremap(efifb_fix.smem_start, efifb_fix.smem_len);
-	else
-		info->screen_base = ioremap_wc(efifb_fix.smem_start, efifb_fix.smem_len);
+	if (!efi_mem_desc_lookup(efifb_fix.smem_start, &md)) {
+		if ((efifb_fix.smem_start + efifb_fix.smem_len) >
+		    (md.phys_addr + (md.num_pages << EFI_PAGE_SHIFT))) {
+			pr_err("efifb: video memory @ 0x%lx spans multiple EFI memory regions\n",
+			       efifb_fix.smem_start);
+			err = -EIO;
+			goto err_release_fb;
+		}
+		/*
+		 * If the UEFI memory map covers the efifb region, we may only
+		 * remap it using the attributes the memory map prescribes.
+		 */
+		mem_flags |= EFI_MEMORY_WT | EFI_MEMORY_WB;
+		mem_flags &= md.attribute;
+	}
+	if (mem_flags & EFI_MEMORY_WC)
+		info->screen_base = ioremap_wc(efifb_fix.smem_start,
+					       efifb_fix.smem_len);
+	else if (mem_flags & EFI_MEMORY_UC)
+		info->screen_base = ioremap(efifb_fix.smem_start,
+					    efifb_fix.smem_len);
+	else if (mem_flags & EFI_MEMORY_WT)
+		info->screen_base = memremap(efifb_fix.smem_start,
+					     efifb_fix.smem_len, MEMREMAP_WT);
+	else if (mem_flags & EFI_MEMORY_WB)
+		info->screen_base = memremap(efifb_fix.smem_start,
+					     efifb_fix.smem_len, MEMREMAP_WB);
 	if (!info->screen_base) {
-		pr_err("efifb: abort, cannot ioremap video memory 0x%x @ 0x%lx\n",
+		pr_err("efifb: abort, cannot remap video memory 0x%x @ 0x%lx\n",
 			efifb_fix.smem_len, efifb_fix.smem_start);
 		err = -EIO;
 		goto err_release_fb;
@@ -371,7 +399,10 @@ static int efifb_probe(struct platform_device *dev)
 err_groups:
 	sysfs_remove_groups(&dev->dev.kobj, efifb_groups);
 err_unmap:
+	if (mem_flags & (EFI_MEMORY_UC | EFI_MEMORY_WC))
 		iounmap(info->screen_base);
+	else
+		memunmap(info->screen_base);
 err_release_fb:
 	framebuffer_release(info);
 err_release_mem:

fs/efivarfs/inode.c

@@ -86,7 +86,9 @@ static int efivarfs_create(struct inode *dir, struct dentry *dentry,
 	/* length of the variable name itself: remove GUID and separator */
 	namelen = dentry->d_name.len - EFI_VARIABLE_GUID_LEN - 1;
 
-	uuid_le_to_bin(dentry->d_name.name + namelen + 1, &var->var.VendorGuid);
+	err = guid_parse(dentry->d_name.name + namelen + 1, &var->var.VendorGuid);
+	if (err)
+		goto out;
 
 	if (efivar_variable_is_removable(var->var.VendorGuid,
 					 dentry->d_name.name, namelen))

include/linux/efi.h

@@ -894,6 +894,16 @@ typedef struct _efi_file_handle {
 	void *flush;
 } efi_file_handle_t;
 
+typedef struct {
+	u64 revision;
+	u32 open_volume;
+} efi_file_io_interface_32_t;
+
+typedef struct {
+	u64 revision;
+	u64 open_volume;
+} efi_file_io_interface_64_t;
+
 typedef struct _efi_file_io_interface {
 	u64 revision;
 	int (*open_volume)(struct _efi_file_io_interface *,
@@ -988,14 +998,12 @@ extern void efi_memmap_walk (efi_freemem_callback_t callback, void *arg);
 extern void efi_gettimeofday (struct timespec64 *ts);
 extern void efi_enter_virtual_mode (void);	/* switch EFI to virtual mode, if possible */
 #ifdef CONFIG_X86
-extern void efi_late_init(void);
 extern void efi_free_boot_services(void);
 extern efi_status_t efi_query_variable_store(u32 attributes,
 					     unsigned long size,
 					     bool nonblocking);
 extern void efi_find_mirror(void);
 #else
-static inline void efi_late_init(void) {}
 static inline void efi_free_boot_services(void) {}
 
 static inline efi_status_t efi_query_variable_store(u32 attributes,
@@ -1651,4 +1659,7 @@ struct linux_efi_tpm_eventlog {
 
 extern int efi_tpm_eventlog_init(void);
 
+/* Workqueue to queue EFI Runtime Services */
+extern struct workqueue_struct *efi_rts_wq;
+
 #endif /* _LINUX_EFI_H */