Merge tag 'efi-next' of git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi into efi/core

Pull EFI updates from Matt Fleming:

"* Refactor the EFI memory map code into architecture neutral files
   and allow drivers to permanently reserve EFI boot services regions
   on x86, as well as ARM/arm64 - Matt Fleming

 * Add ARM support for the EFI esrt driver - Ard Biesheuvel

 * Make the EFI runtime services and efivar API interruptible by
   swapping spinlocks for semaphores - Sylvain Chouleur

 * Provide the EFI identity mapping for kexec which allows kexec to
   work on SGI/UV platforms with requiring the "noefi" kernel command
   line parameter - Alex Thorlton

 * Add debugfs node to dump EFI page tables on arm64 - Ard Biesheuvel

 * Merge the EFI test driver being carried out of tree until now in
   the FWTS project - Ivan Hu

 * Expand the list of flags for classifying EFI regions as "RAM" on
   arm64 so we align with the UEFI spec - Ard Biesheuvel

 * Optimise out the EFI mixed mode if it's unsupported (CONFIG_X86_32)
   or disabled (CONFIG_EFI_MIXED=n) and switch the early EFI boot
   services function table for direct calls, alleviating us from
   having to maintain the custom function table - Lukas Wunner

 * Miscellaneous cleanups and fixes"

Signed-off-by: Ingo Molnar <mingo@kernel.org>

17 files changed, 1472 insertions, 310 deletions

diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig
index 6394152f648f..c981be17d3c0 100644
--- a/drivers/firmware/efi/Kconfig
+++ b/drivers/firmware/efi/Kconfig
@@ -112,6 +112,23 @@ config EFI_CAPSULE_LOADER
 
 	  Most users should say N.
 
+config EFI_TEST
+	tristate "EFI Runtime Service Tests Support"
+	depends on EFI
+	default n
+	help
+	  This driver uses the efi.<service> function pointers directly instead
+	  of going through the efivar API, because it is not trying to test the
+	  kernel subsystem, just for testing the UEFI runtime service
+	  interfaces which are provided by the firmware. This driver is used
+	  by the Firmware Test Suite (FWTS) for testing the UEFI runtime
+	  interfaces readiness of the firmware.
+	  Details for FWTS are available from:
+	  <https://wiki.ubuntu.com/FirmwareTestSuite>
+
+	  Say Y here to enable the runtime services support via /dev/efi_test.
+	  If unsure, say N.
+
 endmenu
 
 config UEFI_CPER
diff --git a/drivers/firmware/efi/Makefile b/drivers/firmware/efi/Makefile
index a219640f881f..c8a439f6d715 100644
--- a/drivers/firmware/efi/Makefile
+++ b/drivers/firmware/efi/Makefile
@@ -10,7 +10,7 @@
 KASAN_SANITIZE_runtime-wrappers.o	:= n
 
 obj-$(CONFIG_EFI)			+= efi.o vars.o reboot.o memattr.o
-obj-$(CONFIG_EFI)			+= capsule.o
+obj-$(CONFIG_EFI)			+= capsule.o memmap.o
 obj-$(CONFIG_EFI_VARS)			+= efivars.o
 obj-$(CONFIG_EFI_ESRT)			+= esrt.o
 obj-$(CONFIG_EFI_VARS_PSTORE)		+= efi-pstore.o
@@ -20,6 +20,7 @@ obj-$(CONFIG_EFI_RUNTIME_WRAPPERS)	+= runtime-wrappers.o
 obj-$(CONFIG_EFI_STUB)			+= libstub/
 obj-$(CONFIG_EFI_FAKE_MEMMAP)		+= fake_mem.o
 obj-$(CONFIG_EFI_BOOTLOADER_CONTROL)	+= efibc.o
+obj-$(CONFIG_EFI_TEST)			+= test/
 
 arm-obj-$(CONFIG_EFI)			:= arm-init.o arm-runtime.o
 obj-$(CONFIG_ARM)			+= $(arm-obj-y)
diff --git a/drivers/firmware/efi/arm-init.c b/drivers/firmware/efi/arm-init.c
index c49d50e68aee..8efe13075c92 100644
--- a/drivers/firmware/efi/arm-init.c
+++ b/drivers/firmware/efi/arm-init.c
@@ -26,9 +26,9 @@
 
 u64 efi_system_table;
 
-static int __init is_normal_ram(efi_memory_desc_t *md)
+static int __init is_memory(efi_memory_desc_t *md)
 {
-	if (md->attribute & EFI_MEMORY_WB)
+	if (md->attribute & (EFI_MEMORY_WB|EFI_MEMORY_WT|EFI_MEMORY_WC))
 		return 1;
 	return 0;
 }
@@ -152,9 +152,9 @@ out:
 }
 
 /*
- * Return true for RAM regions we want to permanently reserve.
+ * Return true for regions that can be used as System RAM.
  */
-static __init int is_reserve_region(efi_memory_desc_t *md)
+static __init int is_usable_memory(efi_memory_desc_t *md)
 {
 	switch (md->type) {
 	case EFI_LOADER_CODE:
@@ -163,18 +163,22 @@ static __init int is_reserve_region(efi_memory_desc_t *md)
 	case EFI_BOOT_SERVICES_DATA:
 	case EFI_CONVENTIONAL_MEMORY:
 	case EFI_PERSISTENT_MEMORY:
-		return 0;
+		/*
+		 * According to the spec, these regions are no longer reserved
+		 * after calling ExitBootServices(). However, we can only use
+		 * them as System RAM if they can be mapped writeback cacheable.
+		 */
+		return (md->attribute & EFI_MEMORY_WB);
 	default:
 		break;
 	}
-	return is_normal_ram(md);
+	return false;
 }
 
 static __init void reserve_regions(void)
 {
 	efi_memory_desc_t *md;
 	u64 paddr, npages, size;
-	int resv;
 
 	if (efi_enabled(EFI_DBG))
 		pr_info("Processing EFI memory map:\n");
@@ -191,32 +195,29 @@ static __init void reserve_regions(void)
 		paddr = md->phys_addr;
 		npages = md->num_pages;
 
-		resv = is_reserve_region(md);
 		if (efi_enabled(EFI_DBG)) {
 			char buf[64];
 
-			pr_info("  0x%012llx-0x%012llx %s%s\n",
+			pr_info("  0x%012llx-0x%012llx %s\n",
 				paddr, paddr + (npages << EFI_PAGE_SHIFT) - 1,
-				efi_md_typeattr_format(buf, sizeof(buf), md),
-				resv ? "*" : "");
+				efi_md_typeattr_format(buf, sizeof(buf), md));
 		}
 
 		memrange_efi_to_native(&paddr, &npages);
 		size = npages << PAGE_SHIFT;
 
-		if (is_normal_ram(md))
+		if (is_memory(md)) {
 			early_init_dt_add_memory_arch(paddr, size);
 
-		if (resv)
-			memblock_mark_nomap(paddr, size);
-
+			if (!is_usable_memory(md))
+				memblock_mark_nomap(paddr, size);
+		}
 	}
-
-	set_bit(EFI_MEMMAP, &efi.flags);
 }
 
 void __init efi_init(void)
 {
+	struct efi_memory_map_data data;
 	struct efi_fdt_params params;
 
 	/* Grab UEFI information placed in FDT by stub */
@@ -225,9 +226,12 @@ void __init efi_init(void)
 
 	efi_system_table = params.system_table;
 
-	efi.memmap.phys_map = params.mmap;
-	efi.memmap.map = early_memremap_ro(params.mmap, params.mmap_size);
-	if (efi.memmap.map == NULL) {
+	data.desc_version = params.desc_ver;
+	data.desc_size = params.desc_size;
+	data.size = params.mmap_size;
+	data.phys_map = params.mmap;
+
+	if (efi_memmap_init_early(&data) < 0) {
 		/*
 		* If we are booting via UEFI, the UEFI memory map is the only
 		* description of memory we have, so there is little point in
@@ -235,9 +239,6 @@ void __init efi_init(void)
 		*/
 		panic("Unable to map EFI memory map.\n");
 	}
-	efi.memmap.map_end = efi.memmap.map + params.mmap_size;
-	efi.memmap.desc_size = params.desc_size;
-	efi.memmap.desc_version = params.desc_ver;
 
 	WARN(efi.memmap.desc_version != 1,
 	     "Unexpected EFI_MEMORY_DESCRIPTOR version %ld",
@@ -248,7 +249,8 @@ void __init efi_init(void)
 
 	reserve_regions();
 	efi_memattr_init();
-	early_memunmap(efi.memmap.map, params.mmap_size);
+	efi_esrt_init();
+	efi_memmap_unmap();
 
 	memblock_reserve(params.mmap & PAGE_MASK,
 			 PAGE_ALIGN(params.mmap_size +
diff --git a/drivers/firmware/efi/arm-runtime.c b/drivers/firmware/efi/arm-runtime.c
index c394b81fe452..7c75a8d9091a 100644
--- a/drivers/firmware/efi/arm-runtime.c
+++ b/drivers/firmware/efi/arm-runtime.c
@@ -39,6 +39,26 @@ static struct mm_struct efi_mm = {
 	.mmlist			= LIST_HEAD_INIT(efi_mm.mmlist),
 };
 
+#ifdef CONFIG_ARM64_PTDUMP
+#include <asm/ptdump.h>
+
+static struct ptdump_info efi_ptdump_info = {
+	.mm		= &efi_mm,
+	.markers	= (struct addr_marker[]){
+		{ 0,		"UEFI runtime start" },
+		{ TASK_SIZE_64,	"UEFI runtime end" }
+	},
+	.base_addr	= 0,
+};
+
+static int __init ptdump_init(void)
+{
+	return ptdump_register(&efi_ptdump_info, "efi_page_tables");
+}
+device_initcall(ptdump_init);
+
+#endif
+
 static bool __init efi_virtmap_init(void)
 {
 	efi_memory_desc_t *md;
@@ -114,14 +134,12 @@ static int __init arm_enable_runtime_services(void)
 
 	pr_info("Remapping and enabling EFI services.\n");
 
-	mapsize = efi.memmap.map_end - efi.memmap.map;
+	mapsize = efi.memmap.desc_size * efi.memmap.nr_map;
 
-	efi.memmap.map = memremap(efi.memmap.phys_map, mapsize, MEMREMAP_WB);
-	if (!efi.memmap.map) {
+	if (efi_memmap_init_late(efi.memmap.phys_map, mapsize)) {
 		pr_err("Failed to remap EFI memory map\n");
 		return -ENOMEM;
 	}
-	efi.memmap.map_end = efi.memmap.map + mapsize;
 
 	if (!efi_virtmap_init()) {
 		pr_err("UEFI virtual mapping missing or invalid -- runtime services will not be available\n");
diff --git a/drivers/firmware/efi/efi-pstore.c b/drivers/firmware/efi/efi-pstore.c
index 30a24d09ea6c..1c33d7469e4a 100644
--- a/drivers/firmware/efi/efi-pstore.c
+++ b/drivers/firmware/efi/efi-pstore.c
@@ -125,16 +125,19 @@ static void efi_pstore_scan_sysfs_enter(struct efivar_entry *pos,
  * @entry: deleting entry
  * @turn_off_scanning: Check if a scanning flag should be turned off
  */
-static inline void __efi_pstore_scan_sysfs_exit(struct efivar_entry *entry,
+static inline int __efi_pstore_scan_sysfs_exit(struct efivar_entry *entry,
 						bool turn_off_scanning)
 {
 	if (entry->deleting) {
 		list_del(&entry->list);
 		efivar_entry_iter_end();
 		efivar_unregister(entry);
-		efivar_entry_iter_begin();
+		if (efivar_entry_iter_begin())
+			return -EINTR;
 	} else if (turn_off_scanning)
 		entry->scanning = false;
+
+	return 0;
 }
 
 /**
@@ -144,13 +147,18 @@ static inline void __efi_pstore_scan_sysfs_exit(struct efivar_entry *entry,
  * @head: list head
  * @stop: a flag checking if scanning will stop
  */
-static void efi_pstore_scan_sysfs_exit(struct efivar_entry *pos,
+static int efi_pstore_scan_sysfs_exit(struct efivar_entry *pos,
 				       struct efivar_entry *next,
 				       struct list_head *head, bool stop)
 {
-	__efi_pstore_scan_sysfs_exit(pos, true);
+	int ret = __efi_pstore_scan_sysfs_exit(pos, true);
+
+	if (ret)
+		return ret;
+
 	if (stop)
-		__efi_pstore_scan_sysfs_exit(next, &next->list != head);
+		ret = __efi_pstore_scan_sysfs_exit(next, &next->list != head);
+	return ret;
 }
 
 /**
@@ -172,13 +180,17 @@ static int efi_pstore_sysfs_entry_iter(void *data, struct efivar_entry **pos)
 	struct efivar_entry *entry, *n;
 	struct list_head *head = &efivar_sysfs_list;
 	int size = 0;
+	int ret;
 
 	if (!*pos) {
 		list_for_each_entry_safe(entry, n, head, list) {
 			efi_pstore_scan_sysfs_enter(entry, n, head);
 
 			size = efi_pstore_read_func(entry, data);
-			efi_pstore_scan_sysfs_exit(entry, n, head, size < 0);
+			ret = efi_pstore_scan_sysfs_exit(entry, n, head,
+							 size < 0);
+			if (ret)
+				return ret;
 			if (size)
 				break;
 		}
@@ -190,7 +202,9 @@ static int efi_pstore_sysfs_entry_iter(void *data, struct efivar_entry **pos)
 		efi_pstore_scan_sysfs_enter((*pos), n, head);
 
 		size = efi_pstore_read_func((*pos), data);
-		efi_pstore_scan_sysfs_exit((*pos), n, head, size < 0);
+		ret = efi_pstore_scan_sysfs_exit((*pos), n, head, size < 0);
+		if (ret)
+			return ret;
 		if (size)
 			break;
 	}
@@ -232,7 +246,10 @@ static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type,
 	if (!*data.buf)
 		return -ENOMEM;
 
-	efivar_entry_iter_begin();
+	if (efivar_entry_iter_begin()) {
+		kfree(*data.buf);
+		return -EINTR;
+	}
 	size = efi_pstore_sysfs_entry_iter(&data,
 					   (struct efivar_entry **)&psi->data);
 	efivar_entry_iter_end();
@@ -347,7 +364,8 @@ static int efi_pstore_erase(enum pstore_type_id type, u64 id, int count,
 	edata.time = time;
 	edata.name = efi_name;
 
-	efivar_entry_iter_begin();
+	if (efivar_entry_iter_begin())
+		return -EINTR;
 	found = __efivar_entry_iter(efi_pstore_erase_func, &efivar_sysfs_list, &edata, &entry);
 
 	if (found && !entry->scanning) {
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 7dd2e2d37231..1ac199cd75e7 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -27,6 +27,7 @@
 #include <linux/slab.h>
 #include <linux/acpi.h>
 #include <linux/ucs2_string.h>
+#include <linux/memblock.h>
 
 #include <asm/early_ioremap.h>
 
@@ -347,56 +348,31 @@ subsys_initcall(efisubsys_init);
 
 /*
  * Find the efi memory descriptor for a given physical address.  Given a
- * physicall address, determine if it exists within an EFI Memory Map entry,
+ * physical address, determine if it exists within an EFI Memory Map entry,
  * 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)
 {
-	struct efi_memory_map *map = &efi.memmap;
-	phys_addr_t p, e;
+	efi_memory_desc_t *md;
 
 	if (!efi_enabled(EFI_MEMMAP)) {
 		pr_err_once("EFI_MEMMAP is not enabled.\n");
 		return -EINVAL;
 	}
 
-	if (!map) {
-		pr_err_once("efi.memmap is not set.\n");
-		return -EINVAL;
-	}
 	if (!out_md) {
 		pr_err_once("out_md is null.\n");
 		return -EINVAL;
         }
-	if (WARN_ON_ONCE(!map->phys_map))
-		return -EINVAL;
-	if (WARN_ON_ONCE(map->nr_map == 0) || WARN_ON_ONCE(map->desc_size == 0))
-		return -EINVAL;
 
-	e = map->phys_map + map->nr_map * map->desc_size;
-	for (p = map->phys_map; p < e; p += map->desc_size) {
-		efi_memory_desc_t *md;
+	for_each_efi_memory_desc(md) {
 		u64 size;
 		u64 end;
 
-		/*
-		 * If a driver calls this after efi_free_boot_services,
-		 * ->map will be NULL, and the target may also not be mapped.
-		 * So just always get our own virtual map on the CPU.
-		 *
-		 */
-		md = early_memremap(p, sizeof (*md));
-		if (!md) {
-			pr_err_once("early_memremap(%pa, %zu) failed.\n",
-				    &p, sizeof (*md));
-			return -ENOMEM;
-		}
-
 		if (!(md->attribute & EFI_MEMORY_RUNTIME) &&
 		    md->type != EFI_BOOT_SERVICES_DATA &&
 		    md->type != EFI_RUNTIME_SERVICES_DATA) {
-			early_memunmap(md, sizeof (*md));
 			continue;
 		}
 
@@ -404,11 +380,8 @@ int __init efi_mem_desc_lookup(u64 phys_addr, efi_memory_desc_t *out_md)
 		end = md->phys_addr + size;
 		if (phys_addr >= md->phys_addr && phys_addr < end) {
 			memcpy(out_md, md, sizeof(*out_md));
-			early_memunmap(md, sizeof (*md));
 			return 0;
 		}
-
-		early_memunmap(md, sizeof (*md));
 	}
 	pr_err_once("requested map not found.\n");
 	return -ENOENT;
@@ -424,6 +397,35 @@ u64 __init efi_mem_desc_end(efi_memory_desc_t *md)
 	return end;
 }
 
+void __init __weak efi_arch_mem_reserve(phys_addr_t addr, u64 size) {}
+
+/**
+ * efi_mem_reserve - Reserve an EFI memory region
+ * @addr: Physical address to reserve
+ * @size: Size of reservation
+ *
+ * Mark a region as reserved from general kernel allocation and
+ * prevent it being released by efi_free_boot_services().
+ *
+ * This function should be called drivers once they've parsed EFI
+ * configuration tables to figure out where their data lives, e.g.
+ * efi_esrt_init().
+ */
+void __init efi_mem_reserve(phys_addr_t addr, u64 size)
+{
+	if (!memblock_is_region_reserved(addr, size))
+		memblock_reserve(addr, size);
+
+	/*
+	 * Some architectures (x86) reserve all boot services ranges
+	 * until efi_free_boot_services() because of buggy firmware
+	 * implementations. This means the above memblock_reserve() is
+	 * superfluous on x86 and instead what it needs to do is
+	 * ensure the @start, @size is not freed.
+	 */
+	efi_arch_mem_reserve(addr, size);
+}
+
 static __initdata efi_config_table_type_t common_tables[] = {
 	{ACPI_20_TABLE_GUID, "ACPI 2.0", &efi.acpi20},
 	{ACPI_TABLE_GUID, "ACPI", &efi.acpi},
@@ -811,6 +813,9 @@ int efi_status_to_err(efi_status_t status)
 	case EFI_NOT_FOUND:
 		err = -ENOENT;
 		break;
+	case EFI_ABORTED:
+		err = -EINTR;
+		break;
 	default:
 		err = -EINVAL;
 	}
diff --git a/drivers/firmware/efi/efivars.c b/drivers/firmware/efi/efivars.c
index 116b244dee68..3e626fd9bd4e 100644
--- a/drivers/firmware/efi/efivars.c
+++ b/drivers/firmware/efi/efivars.c
@@ -510,7 +510,8 @@ static ssize_t efivar_delete(struct file *filp, struct kobject *kobj,
 		vendor = del_var->VendorGuid;
 	}
 
-	efivar_entry_iter_begin();
+	if (efivar_entry_iter_begin())
+		return -EINTR;
 	entry = efivar_entry_find(name, vendor, &efivar_sysfs_list, true);
 	if (!entry)
 		err = -EINVAL;
@@ -575,7 +576,10 @@ efivar_create_sysfs_entry(struct efivar_entry *new_var)
 		return ret;
 
 	kobject_uevent(&new_var->kobj, KOBJ_ADD);
-	efivar_entry_add(new_var, &efivar_sysfs_list);
+	if (efivar_entry_add(new_var, &efivar_sysfs_list)) {
+		efivar_unregister(new_var);
+		return -EINTR;
+	}
 
 	return 0;
 }
@@ -690,7 +694,10 @@ static int efivars_sysfs_callback(efi_char16_t *name, efi_guid_t vendor,
 
 static int efivar_sysfs_destroy(struct efivar_entry *entry, void *data)
 {
-	efivar_entry_remove(entry);
+	int err = efivar_entry_remove(entry);
+
+	if (err)
+		return err;
 	efivar_unregister(entry);
 	return 0;
 }
@@ -698,7 +705,14 @@ static int efivar_sysfs_destroy(struct efivar_entry *entry, void *data)
 static void efivars_sysfs_exit(void)
 {
 	/* Remove all entries and destroy */
-	__efivar_entry_iter(efivar_sysfs_destroy, &efivar_sysfs_list, NULL, NULL);
+	int err;
+
+	err = __efivar_entry_iter(efivar_sysfs_destroy, &efivar_sysfs_list,
+				  NULL, NULL);
+	if (err) {
+		pr_err("efivars: Failed to destroy sysfs entries\n");
+		return;
+	}
 
 	if (efivars_new_var)
 		sysfs_remove_bin_file(&efivars_kset->kobj, efivars_new_var);
diff --git a/drivers/firmware/efi/esrt.c b/drivers/firmware/efi/esrt.c
index 75feb3f5829b..14914074f716 100644
--- a/drivers/firmware/efi/esrt.c
+++ b/drivers/firmware/efi/esrt.c
@@ -16,6 +16,7 @@
 #include <linux/device.h>
 #include <linux/efi.h>
 #include <linux/init.h>
+#include <linux/io.h>
 #include <linux/kernel.h>
 #include <linux/kobject.h>
 #include <linux/list.h>
@@ -235,7 +236,7 @@ static struct attribute_group esrt_attr_group = {
 };
 
 /*
- * remap the table, copy it to kmalloced pages, and unmap it.
+ * remap the table, validate it, mark it reserved and unmap it.
  */
 void __init efi_esrt_init(void)
 {
@@ -335,7 +336,7 @@ void __init efi_esrt_init(void)
 
 	end = esrt_data + size;
 	pr_info("Reserving ESRT space from %pa to %pa.\n", &esrt_data, &end);
-	memblock_reserve(esrt_data, esrt_data_size);
+	efi_mem_reserve(esrt_data, esrt_data_size);
 
 	pr_debug("esrt-init: loaded.\n");
 err_memunmap:
@@ -382,28 +383,18 @@ static void cleanup_entry_list(void)
 static int __init esrt_sysfs_init(void)
 {
 	int error;
-	struct efi_system_resource_table __iomem *ioesrt;
 
 	pr_debug("esrt-sysfs: loading.\n");
 	if (!esrt_data || !esrt_data_size)
 		return -ENOSYS;
 
-	ioesrt = ioremap(esrt_data, esrt_data_size);
-	if (!ioesrt) {
-		pr_err("ioremap(%pa, %zu) failed.\n", &esrt_data,
-		       esrt_data_size);
-		return -ENOMEM;
-	}
-
-	esrt = kmalloc(esrt_data_size, GFP_KERNEL);
+	esrt = memremap(esrt_data, esrt_data_size, MEMREMAP_WB);
 	if (!esrt) {
-		pr_err("kmalloc failed. (wanted %zu bytes)\n", esrt_data_size);
-		iounmap(ioesrt);
+		pr_err("memremap(%pa, %zu) failed.\n", &esrt_data,
+		       esrt_data_size);
 		return -ENOMEM;
 	}
 
-	memcpy_fromio(esrt, ioesrt, esrt_data_size);
-
 	esrt_kobj = kobject_create_and_add("esrt", efi_kobj);
 	if (!esrt_kobj) {
 		pr_err("Firmware table registration failed.\n");
@@ -429,8 +420,6 @@ static int __init esrt_sysfs_init(void)
 	if (error)
 		goto err_cleanup_list;
 
-	memblock_remove(esrt_data, esrt_data_size);
-
 	pr_debug("esrt-sysfs: loaded.\n");
 
 	return 0;
diff --git a/drivers/firmware/efi/fake_mem.c b/drivers/firmware/efi/fake_mem.c
index 48430aba13c1..520a40e5e0e4 100644
--- a/drivers/firmware/efi/fake_mem.c
+++ b/drivers/firmware/efi/fake_mem.c
@@ -35,17 +35,13 @@
 
 #define EFI_MAX_FAKEMEM CONFIG_EFI_MAX_FAKE_MEM
 
-struct fake_mem {
-	struct range range;
-	u64 attribute;
-};
-static struct fake_mem fake_mems[EFI_MAX_FAKEMEM];
+static struct efi_mem_range fake_mems[EFI_MAX_FAKEMEM];
 static int nr_fake_mem;
 
 static int __init cmp_fake_mem(const void *x1, const void *x2)
 {
-	const struct fake_mem *m1 = x1;
-	const struct fake_mem *m2 = x2;
+	const struct efi_mem_range *m1 = x1;
+	const struct efi_mem_range *m2 = x2;
 
 	if (m1->range.start < m2->range.start)
 		return -1;
@@ -56,40 +52,21 @@ static int __init cmp_fake_mem(const void *x1, const void *x2)
 
 void __init efi_fake_memmap(void)
 {
-	u64 start, end, m_start, m_end, m_attr;
 	int new_nr_map = efi.memmap.nr_map;
 	efi_memory_desc_t *md;
 	phys_addr_t new_memmap_phy;
 	void *new_memmap;
-	void *old, *new;
 	int i;
 
-	if (!nr_fake_mem || !efi_enabled(EFI_MEMMAP))
+	if (!nr_fake_mem)
 		return;
 
 	/* count up the number of EFI memory descriptor */
-	for_each_efi_memory_desc(md) {
-		start = md->phys_addr;
-		end = start + (md->num_pages << EFI_PAGE_SHIFT) - 1;
-
-		for (i = 0; i < nr_fake_mem; i++) {
-			/* modifying range */
-			m_start = fake_mems[i].range.start;
-			m_end = fake_mems[i].range.end;
-
-			if (m_start <= start) {
-				/* split into 2 parts */
-				if (start < m_end && m_end < end)
-					new_nr_map++;
-			}
-			if (start < m_start && m_start < end) {
-				/* split into 3 parts */
-				if (m_end < end)
-					new_nr_map += 2;
-				/* split into 2 parts */
-				if (end <= m_end)
-					new_nr_map++;
-			}
+	for (i = 0; i < nr_fake_mem; i++) {
+		for_each_efi_memory_desc(md) {
+			struct range *r = &fake_mems[i].range;
+
+			new_nr_map += efi_memmap_split_count(md, r);
 		}
 	}
 
@@ -107,85 +84,13 @@ void __init efi_fake_memmap(void)
 		return;
 	}
 
-	for (old = efi.memmap.map, new = new_memmap;
-	     old < efi.memmap.map_end;
-	     old += efi.memmap.desc_size, new += efi.memmap.desc_size) {
-
-		/* copy original EFI memory descriptor */
-		memcpy(new, old, efi.memmap.desc_size);
-		md = new;
-		start = md->phys_addr;
-		end = md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT) - 1;
-
-		for (i = 0; i < nr_fake_mem; i++) {
-			/* modifying range */
-			m_start = fake_mems[i].range.start;
-			m_end = fake_mems[i].range.end;
-			m_attr = fake_mems[i].attribute;
-
-			if (m_start <= start && end <= m_end)
-				md->attribute |= m_attr;
-
-			if (m_start <= start &&
-			    (start < m_end && m_end < end)) {
-				/* first part */
-				md->attribute |= m_attr;
-				md->num_pages = (m_end - md->phys_addr + 1) >>
-					EFI_PAGE_SHIFT;
-				/* latter part */
-				new += efi.memmap.desc_size;
-				memcpy(new, old, efi.memmap.desc_size);
-				md = new;
-				md->phys_addr = m_end + 1;
-				md->num_pages = (end - md->phys_addr + 1) >>
-					EFI_PAGE_SHIFT;
-			}
-
-			if ((start < m_start && m_start < end) && m_end < end) {
-				/* first part */
-				md->num_pages = (m_start - md->phys_addr) >>
-					EFI_PAGE_SHIFT;
-				/* middle part */
-				new += efi.memmap.desc_size;
-				memcpy(new, old, efi.memmap.desc_size);
-				md = new;
-				md->attribute |= m_attr;
-				md->phys_addr = m_start;
-				md->num_pages = (m_end - m_start + 1) >>
-					EFI_PAGE_SHIFT;
-				/* last part */
-				new += efi.memmap.desc_size;
-				memcpy(new, old, efi.memmap.desc_size);
-				md = new;
-				md->phys_addr = m_end + 1;
-				md->num_pages = (end - m_end) >>
-					EFI_PAGE_SHIFT;
-			}
-
-			if ((start < m_start && m_start < end) &&
-			    (end <= m_end)) {
-				/* first part */
-				md->num_pages = (m_start - md->phys_addr) >>
-					EFI_PAGE_SHIFT;
-				/* latter part */
-				new += efi.memmap.desc_size;
-				memcpy(new, old, efi.memmap.desc_size);
-				md = new;
-				md->phys_addr = m_start;
-				md->num_pages = (end - md->phys_addr + 1) >>
-					EFI_PAGE_SHIFT;
-				md->attribute |= m_attr;
-			}
-		}
-	}
+	for (i = 0; i < nr_fake_mem; i++)
+		efi_memmap_insert(&efi.memmap, new_memmap, &fake_mems[i]);
 
 	/* swap into new EFI memmap */
-	efi_unmap_memmap();
-	efi.memmap.map = new_memmap;
-	efi.memmap.phys_map = new_memmap_phy;
-	efi.memmap.nr_map = new_nr_map;
-	efi.memmap.map_end = efi.memmap.map + efi.memmap.nr_map * efi.memmap.desc_size;
-	set_bit(EFI_MEMMAP, &efi.flags);
+	early_memunmap(new_memmap, efi.memmap.desc_size * new_nr_map);
+
+	efi_memmap_install(new_memmap_phy, new_nr_map);
 
 	/* print new EFI memmap */
 	efi_print_memmap();
@@ -223,7 +128,7 @@ static int __init setup_fake_mem(char *p)
 			p++;
 	}
 
-	sort(fake_mems, nr_fake_mem, sizeof(struct fake_mem),
+	sort(fake_mems, nr_fake_mem, sizeof(struct efi_mem_range),
 	     cmp_fake_mem, NULL);
 
 	for (i = 0; i < nr_fake_mem; i++)
diff --git a/drivers/firmware/efi/memmap.c b/drivers/firmware/efi/memmap.c
new file mode 100644
index 000000000000..cd96086fd851
--- /dev/null
+++ b/drivers/firmware/efi/memmap.c
@@ -0,0 +1,292 @@
+/*
+ * Common EFI memory map functions.
+ */
+
+#define pr_fmt(fmt) "efi: " fmt
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/efi.h>
+#include <linux/io.h>
+#include <asm/early_ioremap.h>
+
+/**
+ * __efi_memmap_init - Common code for mapping the EFI memory map
+ * @data: EFI memory map data
+ * @late: Use early or late mapping function?
+ *
+ * This function takes care of figuring out which function to use to
+ * map the EFI memory map in efi.memmap based on how far into the boot
+ * we are.
+ *
+ * During bootup @late should be %false since we only have access to
+ * the early_memremap*() functions as the vmalloc space isn't setup.
+ * Once the kernel is fully booted we can fallback to the more robust
+ * memremap*() API.
+ *
+ * Returns zero on success, a negative error code on failure.
+ */
+static int __init
+__efi_memmap_init(struct efi_memory_map_data *data, bool late)
+{
+	struct efi_memory_map map;
+	phys_addr_t phys_map;
+
+	if (efi_enabled(EFI_PARAVIRT))
+		return 0;
+
+	phys_map = data->phys_map;
+
+	if (late)
+		map.map = memremap(phys_map, data->size, MEMREMAP_WB);
+	else
+		map.map = early_memremap(phys_map, data->size);
+
+	if (!map.map) {
+		pr_err("Could not map the memory map!\n");
+		return -ENOMEM;
+	}
+
+	map.phys_map = data->phys_map;
+	map.nr_map = data->size / data->desc_size;
+	map.map_end = map.map + data->size;
+
+	map.desc_version = data->desc_version;
+	map.desc_size = data->desc_size;
+	map.late = late;
+
+	set_bit(EFI_MEMMAP, &efi.flags);
+
+	efi.memmap = map;
+
+	return 0;
+}
+
+/**
+ * efi_memmap_init_early - Map the EFI memory map data structure
+ * @data: EFI memory map data
+ *
+ * Use early_memremap() to map the passed in EFI memory map and assign
+ * it to efi.memmap.
+ */
+int __init efi_memmap_init_early(struct efi_memory_map_data *data)
+{
+	/* Cannot go backwards */
+	WARN_ON(efi.memmap.late);
+
+	return __efi_memmap_init(data, false);
+}
+
+void __init efi_memmap_unmap(void)
+{
+	if (!efi.memmap.late) {
+		unsigned long size;
+
+		size = efi.memmap.desc_size * efi.memmap.nr_map;
+		early_memunmap(efi.memmap.map, size);
+	} else {
+		memunmap(efi.memmap.map);
+	}
+
+	efi.memmap.map = NULL;
+	clear_bit(EFI_MEMMAP, &efi.flags);
+}
+
+/**
+ * efi_memmap_init_late - Map efi.memmap with memremap()
+ * @phys_addr: Physical address of the new EFI memory map
+ * @size: Size in bytes of the new EFI memory map
+ *
+ * Setup a mapping of the EFI memory map using ioremap_cache(). This
+ * function should only be called once the vmalloc space has been
+ * setup and is therefore not suitable for calling during early EFI
+ * initialise, e.g. in efi_init(). Additionally, it expects
+ * efi_memmap_init_early() to have already been called.
+ *
+ * The reason there are two EFI memmap initialisation
+ * (efi_memmap_init_early() and this late version) is because the
+ * early EFI memmap should be explicitly unmapped once EFI
+ * initialisation is complete as the fixmap space used to map the EFI
+ * memmap (via early_memremap()) is a scarce resource.
+ *
+ * This late mapping is intended to persist for the duration of
+ * runtime so that things like efi_mem_desc_lookup() and
+ * efi_mem_attributes() always work.
+ *
+ * Returns zero on success, a negative error code on failure.
+ */
+int __init efi_memmap_init_late(phys_addr_t addr, unsigned long size)
+{
+	struct efi_memory_map_data data = {
+		.phys_map = addr,
+		.size = size,
+	};
+
+	/* Did we forget to unmap the early EFI memmap? */
+	WARN_ON(efi.memmap.map);
+
+	/* Were we already called? */
+	WARN_ON(efi.memmap.late);
+
+	/*
+	 * It makes no sense to allow callers to register different
+	 * values for the following fields. Copy them out of the
+	 * existing early EFI memmap.
+	 */
+	data.desc_version = efi.memmap.desc_version;
+	data.desc_size = efi.memmap.desc_size;
+
+	return __efi_memmap_init(&data, true);
+}
+
+/**
+ * efi_memmap_install - Install a new EFI memory map in efi.memmap
+ * @addr: Physical address of the memory map
+ * @nr_map: Number of entries in the memory map
+ *
+ * Unlike efi_memmap_init_*(), this functio