Merge branch 'next' into efi-next-merge

Conflicts:
	arch/x86/boot/compressed/eboot.c

9 files changed, 122 insertions, 101 deletions

diff --git a/arch/arm64/kernel/efi.c b/arch/arm64/kernel/efi.c
index 03aaa99e1ea0..95c49ebc660d 100644
--- a/arch/arm64/kernel/efi.c
+++ b/arch/arm64/kernel/efi.c
@@ -89,7 +89,8 @@ static int __init uefi_init(void)
 	 */
 	if (efi.systab->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) {
 		pr_err("System table signature incorrect\n");
-		return -EINVAL;
+		retval = -EINVAL;
+		goto out;
 	}
 	if ((efi.systab->hdr.revision >> 16) < 2)
 		pr_warn("Warning: EFI system table version %d.%02d, expected 2.00 or greater\n",
@@ -103,6 +104,7 @@ static int __init uefi_init(void)
 		for (i = 0; i < (int) sizeof(vendor) - 1 && *c16; ++i)
 			vendor[i] = c16[i];
 		vendor[i] = '\0';
+		early_memunmap(c16, sizeof(vendor));
 	}
 
 	pr_info("EFI v%u.%.02u by %s\n",
@@ -113,29 +115,11 @@ static int __init uefi_init(void)
 	if (retval == 0)
 		set_bit(EFI_CONFIG_TABLES, &efi.flags);
 
-	early_memunmap(c16, sizeof(vendor));
+out:
 	early_memunmap(efi.systab,  sizeof(efi_system_table_t));
-
 	return retval;
 }
 
-static __initdata char memory_type_name[][32] = {
-	{"Reserved"},
-	{"Loader Code"},
-	{"Loader Data"},
-	{"Boot Code"},
-	{"Boot Data"},
-	{"Runtime Code"},
-	{"Runtime Data"},
-	{"Conventional Memory"},
-	{"Unusable Memory"},
-	{"ACPI Reclaim Memory"},
-	{"ACPI Memory NVS"},
-	{"Memory Mapped I/O"},
-	{"MMIO Port Space"},
-	{"PAL Code"},
-};
-
 /*
  * Return true for RAM regions we want to permanently reserve.
  */
@@ -166,10 +150,13 @@ static __init void reserve_regions(void)
 		paddr = md->phys_addr;
 		npages = md->num_pages;
 
-		if (uefi_debug)
-			pr_info("  0x%012llx-0x%012llx [%s]",
+		if (uefi_debug) {
+			char buf[64];
+
+			pr_info("  0x%012llx-0x%012llx %s",
 				paddr, paddr + (npages << EFI_PAGE_SHIFT) - 1,
-				memory_type_name[md->type]);
+				efi_md_typeattr_format(buf, sizeof(buf), md));
+		}
 
 		memrange_efi_to_native(&paddr, &npages);
 		size = npages << PAGE_SHIFT;
@@ -393,11 +380,16 @@ static int __init arm64_enter_virtual_mode(void)
 		return -1;
 	}
 
-	pr_info("Remapping and enabling EFI services.\n");
-
-	/* replace early memmap mapping with permanent mapping */
 	mapsize = memmap.map_end - memmap.map;
 	early_memunmap(memmap.map, mapsize);
+
+	if (efi_runtime_disabled()) {
+		pr_info("EFI runtime services will be disabled.\n");
+		return -1;
+	}
+
+	pr_info("Remapping and enabling EFI services.\n");
+	/* replace early memmap mapping with permanent mapping */
 	memmap.map = (__force void *)ioremap_cache((phys_addr_t)memmap.phys_map,
 						   mapsize);
 	memmap.map_end = memmap.map + mapsize;
diff --git a/arch/ia64/kernel/efi.c b/arch/ia64/kernel/efi.c
index 741b99c1a0b1..c52d7540dc05 100644
--- a/arch/ia64/kernel/efi.c
+++ b/arch/ia64/kernel/efi.c
@@ -568,6 +568,7 @@ efi_init (void)
 		{
 			const char *unit;
 			unsigned long size;
+			char buf[64];
 
 			md = p;
 			size = md->num_pages << EFI_PAGE_SHIFT;
@@ -586,9 +587,10 @@ efi_init (void)
 				unit = "KB";
 			}
 
-			printk("mem%02d: type=%2u, attr=0x%016lx, "
+			printk("mem%02d: %s "
 			       "range=[0x%016lx-0x%016lx) (%4lu%s)\n",
-			       i, md->type, md->attribute, md->phys_addr,
+			       i, efi_md_typeattr_format(buf, sizeof(buf), md),
+			       md->phys_addr,
 			       md->phys_addr + efi_md_size(md), size, unit);
 		}
 	}
diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c
index de8eebd6f67c..1acf605a646d 100644
--- a/arch/x86/boot/compressed/eboot.c
+++ b/arch/x86/boot/compressed/eboot.c
@@ -330,8 +330,10 @@ __setup_efi_pci32(efi_pci_io_protocol_32 *pci, struct pci_setup_rom **__rom)
 	size = pci->romsize + sizeof(*rom);
 
 	status = efi_call_early(allocate_pool, EFI_LOADER_DATA, size, &rom);
-	if (status != EFI_SUCCESS)
+	if (status != EFI_SUCCESS) {
+		efi_printk(sys_table, "Failed to alloc mem for rom\n");
 		return status;
+	}
 
 	memset(rom, 0, sizeof(*rom));
 
@@ -344,14 +346,18 @@ __setup_efi_pci32(efi_pci_io_protocol_32 *pci, struct pci_setup_rom **__rom)
 	status = efi_early->call(pci->pci.read, pci, EfiPciIoWidthUint16,
 				 PCI_VENDOR_ID, 1, &(rom->vendor));
 
-	if (status != EFI_SUCCESS)
+	if (status != EFI_SUCCESS) {
+		efi_printk(sys_table, "Failed to read rom->vendor\n");
 		goto free_struct;
+	}
 
 	status = efi_early->call(pci->pci.read, pci, EfiPciIoWidthUint16,
 				 PCI_DEVICE_ID, 1, &(rom->devid));
 
-	if (status != EFI_SUCCESS)
+	if (status != EFI_SUCCESS) {
+		efi_printk(sys_table, "Failed to read rom->devid\n");
 		goto free_struct;
+	}
 
 	status = efi_early->call(pci->get_location, pci, &(rom->segment),
 				 &(rom->bus), &(rom->device), &(rom->function));
@@ -432,8 +438,10 @@ __setup_efi_pci64(efi_pci_io_protocol_64 *pci, struct pci_setup_rom **__rom)
 	size = pci->romsize + sizeof(*rom);
 
 	status = efi_call_early(allocate_pool, EFI_LOADER_DATA, size, &rom);
-	if (status != EFI_SUCCESS)
+	if (status != EFI_SUCCESS) {
+		efi_printk(sys_table, "Failed to alloc mem for rom\n");
 		return status;
+	}
 
 	rom->data.type = SETUP_PCI;
 	rom->data.len = size - sizeof(struct setup_data);
@@ -444,14 +452,18 @@ __setup_efi_pci64(efi_pci_io_protocol_64 *pci, struct pci_setup_rom **__rom)
 	status = efi_early->call(pci->pci.read, pci, EfiPciIoWidthUint16,
 				 PCI_VENDOR_ID, 1, &(rom->vendor));
 
-	if (status != EFI_SUCCESS)
+	if (status != EFI_SUCCESS) {
+		efi_printk(sys_table, "Failed to read rom->vendor\n");
 		goto free_struct;
+	}
 
 	status = efi_early->call(pci->pci.read, pci, EfiPciIoWidthUint16,
 				 PCI_DEVICE_ID, 1, &(rom->devid));
 
-	if (status != EFI_SUCCESS)
+	if (status != EFI_SUCCESS) {
+		efi_printk(sys_table, "Failed to read rom->devid\n");
 		goto free_struct;
+	}
 
 	status = efi_early->call(pci->get_location, pci, &(rom->segment),
 				 &(rom->bus), &(rom->device), &(rom->function));
@@ -538,8 +550,10 @@ static void setup_efi_pci(struct boot_params *params)
 					EFI_LOADER_DATA,
 					size, (void **)&pci_handle);
 
-		if (status != EFI_SUCCESS)
+		if (status != EFI_SUCCESS) {
+			efi_printk(sys_table, "Failed to alloc mem for pci_handle\n");
 			return;
+		}
 
 		status = efi_call_early(locate_handle,
 					EFI_LOCATE_BY_PROTOCOL, &pci_proto,
@@ -1105,6 +1119,10 @@ struct boot_params *make_boot_params(struct efi_config *c)
 
 	memset(sdt, 0, sizeof(*sdt));
 
+	status = efi_parse_options(cmdline_ptr);
+	if (status != EFI_SUCCESS)
+		goto fail2;
+
 	status = handle_cmdline_files(sys_table, image,
 				      (char *)(unsigned long)hdr->cmd_line_ptr,
 				      "initrd=", hdr->initrd_addr_max,
diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h
index 0ec241ede5a2..9b11757975d0 100644
--- a/arch/x86/include/asm/efi.h
+++ b/arch/x86/include/asm/efi.h
@@ -81,24 +81,23 @@ extern u64 asmlinkage efi_call(void *fp, ...);
  */
 #define __efi_call_virt(f, args...) efi_call_virt(f, args)
 
-extern void __iomem *efi_ioremap(unsigned long addr, unsigned long size,
-				 u32 type, u64 attribute);
+extern void __iomem *__init efi_ioremap(unsigned long addr, unsigned long size,
+					u32 type, u64 attribute);
 
 #endif /* CONFIG_X86_32 */
 
-extern int add_efi_memmap;
 extern struct efi_scratch efi_scratch;
-extern void efi_set_executable(efi_memory_desc_t *md, bool executable);
-extern int efi_memblock_x86_reserve_range(void);
-extern void efi_call_phys_prelog(void);
-extern void efi_call_phys_epilog(void);
-extern void efi_unmap_memmap(void);
-extern void efi_memory_uc(u64 addr, unsigned long size);
+extern void __init efi_set_executable(efi_memory_desc_t *md, bool executable);
+extern int __init efi_memblock_x86_reserve_range(void);
+extern void __init efi_call_phys_prolog(void);
+extern void __init efi_call_phys_epilog(void);
+extern void __init efi_unmap_memmap(void);
+extern void __init efi_memory_uc(u64 addr, unsigned long size);
 extern void __init efi_map_region(efi_memory_desc_t *md);
 extern void __init efi_map_region_fixed(efi_memory_desc_t *md);
 extern void efi_sync_low_kernel_mappings(void);
-extern int efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages);
-extern void efi_cleanup_page_tables(unsigned long pa_memmap, unsigned num_pages);
+extern int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages);
+extern void __init efi_cleanup_page_tables(unsigned long pa_memmap, unsigned num_pages);
 extern void __init old_map_region(efi_memory_desc_t *md);
 extern void __init runtime_code_page_mkexec(void);
 extern void __init efi_runtime_mkexec(void);
@@ -162,16 +161,6 @@ static inline efi_status_t efi_thunk_set_virtual_address_map(
 extern bool efi_reboot_required(void);
 
 #else
-/*
- * IF EFI is not configured, have the EFI calls return -ENOSYS.
- */
-#define efi_call0(_f)					(-ENOSYS)
-#define efi_call1(_f, _a1)				(-ENOSYS)
-#define efi_call2(_f, _a1, _a2)				(-ENOSYS)
-#define efi_call3(_f, _a1, _a2, _a3)			(-ENOSYS)
-#define efi_call4(_f, _a1, _a2, _a3, _a4)		(-ENOSYS)
-#define efi_call5(_f, _a1, _a2, _a3, _a4, _a5)		(-ENOSYS)
-#define efi_call6(_f, _a1, _a2, _a3, _a4, _a5, _a6)	(-ENOSYS)
 static inline void parse_efi_setup(u64 phys_addr, u32 data_len) {}
 static inline bool efi_reboot_required(void)
 {
diff --git a/arch/x86/platform/efi/efi-bgrt.c b/arch/x86/platform/efi/efi-bgrt.c
index f15103dff4b4..d143d216d52b 100644
--- a/arch/x86/platform/efi/efi-bgrt.c
+++ b/arch/x86/platform/efi/efi-bgrt.c
@@ -40,20 +40,40 @@ void __init efi_bgrt_init(void)
 	if (ACPI_FAILURE(status))
 		return;
 
-	if (bgrt_tab->header.length < sizeof(*bgrt_tab))
+	if (bgrt_tab->header.length < sizeof(*bgrt_tab)) {
+		pr_err("Ignoring BGRT: invalid length %u (expected %zu)\n",
+		       bgrt_tab->header.length, sizeof(*bgrt_tab));
 		return;
-	if (bgrt_tab->version != 1 || bgrt_tab->status != 1)
+	}
+	if (bgrt_tab->version != 1) {
+		pr_err("Ignoring BGRT: invalid version %u (expected 1)\n",
+		       bgrt_tab->version);
+		return;
+	}
+	if (bgrt_tab->status != 1) {
+		pr_err("Ignoring BGRT: invalid status %u (expected 1)\n",
+		       bgrt_tab->status);
+		return;
+	}
+	if (bgrt_tab->image_type != 0) {
+		pr_err("Ignoring BGRT: invalid image type %u (expected 0)\n",
+		       bgrt_tab->image_type);
 		return;
-	if (bgrt_tab->image_type != 0 || !bgrt_tab->image_address)
+	}
+	if (!bgrt_tab->image_address) {
+		pr_err("Ignoring BGRT: null image address\n");
 		return;
+	}
 
 	image = efi_lookup_mapped_addr(bgrt_tab->image_address);
 	if (!image) {
 		image = early_memremap(bgrt_tab->image_address,
 				       sizeof(bmp_header));
 		ioremapped = true;
-		if (!image)
+		if (!image) {
+			pr_err("Ignoring BGRT: failed to map image header memory\n");
 			return;
+		}
 	}
 
 	memcpy_fromio(&bmp_header, image, sizeof(bmp_header));
@@ -61,14 +81,18 @@ void __init efi_bgrt_init(void)
 		early_iounmap(image, sizeof(bmp_header));
 	bgrt_image_size = bmp_header.size;
 
-	bgrt_image = kmalloc(bgrt_image_size, GFP_KERNEL);
-	if (!bgrt_image)
+	bgrt_image = kmalloc(bgrt_image_size, GFP_KERNEL | __GFP_NOWARN);
+	if (!bgrt_image) {
+		pr_err("Ignoring BGRT: failed to allocate memory for image (wanted %zu bytes)\n",
+		       bgrt_image_size);
 		return;
+	}
 
 	if (ioremapped) {
 		image = early_memremap(bgrt_tab->image_address,
 				       bmp_header.size);
 		if (!image) {
+			pr_err("Ignoring BGRT: failed to map image memory\n");
 			kfree(bgrt_image);
 			bgrt_image = NULL;
 			return;
diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index 850da94fef30..dbc8627a5cdf 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -70,17 +70,7 @@ static efi_config_table_type_t arch_tables[] __initdata = {
 
 u64 efi_setup;		/* efi setup_data physical address */
 
-static bool disable_runtime __initdata = false;
-static int __init setup_noefi(char *arg)
-{
-	disable_runtime = true;
-	return 0;
-}
-early_param("noefi", setup_noefi);
-
-int add_efi_memmap;
-EXPORT_SYMBOL(add_efi_memmap);
-
+static int add_efi_memmap __initdata;
 static int __init setup_add_efi_memmap(char *arg)
 {
 	add_efi_memmap = 1;
@@ -96,7 +86,7 @@ static efi_status_t __init phys_efi_set_virtual_address_map(
 {
 	efi_status_t status;
 
-	efi_call_phys_prelog();
+	efi_call_phys_prolog();
 	status = efi_call_phys(efi_phys.set_virtual_address_map,
 			       memory_map_size, descriptor_size,
 			       descriptor_version, virtual_map);
@@ -210,9 +200,12 @@ static void __init print_efi_memmap(void)
 	for (p = memmap.map, i = 0;
 	     p < memmap.map_end;
 	     p += memmap.desc_size, i++) {
+		char buf[64];
+
 		md = p;
-		pr_info("mem%02u: type=%u, attr=0x%llx, range=[0x%016llx-0x%016llx) (%lluMB)\n",
-			i, md->type, md->attribute, md->phys_addr,
+		pr_info("mem%02u: %s range=[0x%016llx-0x%016llx) (%lluMB)\n",
+			i, efi_md_typeattr_format(buf, sizeof(buf), md),
+			md->phys_addr,
 			md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT),
 			(md->num_pages >> (20 - EFI_PAGE_SHIFT)));
 	}
@@ -344,9 +337,9 @@ static int __init efi_runtime_init32(void)
 	}
 
 	/*
-	 * We will only need *early* access to the following two
-	 * EFI runtime services before set_virtual_address_map
-	 * is invoked.
+	 * We will only need *early* access to the SetVirtualAddressMap
+	 * EFI runtime service. All other runtime services will be called
+	 * via the virtual mapping.
 	 */
 	efi_phys.set_virtual_address_map =
 			(efi_set_virtual_address_map_t *)
@@ -368,9 +361,9 @@ static int __init efi_runtime_init64(void)
 	}
 
 	/*
-	 * We will only need *early* access to the following two
-	 * EFI runtime services before set_virtual_address_map
-	 * is invoked.
+	 * We will only need *early* access to the SetVirtualAddressMap
+	 * EFI runtime service. All other runtime services will be called
+	 * via the virtual mapping.
 	 */
 	efi_phys.set_virtual_address_map =
 			(efi_set_virtual_address_map_t *)
@@ -492,7 +485,7 @@ void __init efi_init(void)
 	if (!efi_runtime_supported())
 		pr_info("No EFI runtime due to 32/64-bit mismatch with kernel\n");
 	else {
-		if (disable_runtime || efi_runtime_init())
+		if (efi_runtime_disabled() || efi_runtime_init())
 			return;
 	}
 	if (efi_memmap_init())
@@ -537,7 +530,7 @@ void __init runtime_code_page_mkexec(void)
 	}
 }
 
-void efi_memory_uc(u64 addr, unsigned long size)
+void __init efi_memory_uc(u64 addr, unsigned long size)
 {
 	unsigned long page_shift = 1UL << EFI_PAGE_SHIFT;
 	u64 npages;
@@ -732,6 +725,7 @@ static void __init kexec_enter_virtual_mode(void)
 	 */
 	if (!efi_is_native()) {
 		efi_unmap_memmap();
+		clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
 		return;
 	}
 
@@ -805,6 +799,7 @@ static void __init __efi_enter_virtual_mode(void)
 	new_memmap = efi_map_regions(&count, &pg_shift);
 	if (!new_memmap) {
 		pr_err("Error reallocating memory, EFI runtime non-functional!\n");
+		clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
 		return;
 	}
 
@@ -812,8 +807,10 @@ static void __init __efi_enter_virtual_mode(void)
 
 	BUG_ON(!efi.systab);
 
-	if (efi_setup_page_tables(__pa(new_memmap), 1 << pg_shift))
+	if (efi_setup_page_tables(__pa(new_memmap), 1 << pg_shift)) {
+		clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
 		return;
+	}
 
 	efi_sync_low_kernel_mappings();
 	efi_dump_pagetable();
@@ -938,14 +935,11 @@ u64 efi_mem_attributes(unsigned long phys_addr)
 	return 0;
 }
 
-static int __init parse_efi_cmdline(char *str)
+static int __init arch_parse_efi_cmdline(char *str)
 {
-	if (*str == '=')
-		str++;
-
-	if (!strncmp(str, "old_map", 7))
+	if (parse_option_str(str, "old_map"))
 		set_bit(EFI_OLD_MEMMAP, &efi.flags);
 
 	return 0;
 }
-early_param("efi", parse_efi_cmdline);
+early_param("efi", arch_parse_efi_cmdline);
diff --git a/arch/x86/platform/efi/efi_32.c b/arch/x86/platform/efi/efi_32.c
index 9ee3491e31fb..40e7cda52936 100644
--- a/arch/x86/platform/efi/efi_32.c
+++ b/arch/x86/platform/efi/efi_32.c
@@ -33,7 +33,7 @@
 
 /*
  * To make EFI call EFI runtime service in physical addressing mode we need
- * prelog/epilog before/after the invocation to disable interrupt, to
+ * prolog/epilog before/after the invocation to disable interrupt, to
  * claim EFI runtime service handler exclusively and to duplicate a memory in
  * low memory space say 0 - 3G.
  */
@@ -41,11 +41,13 @@ static unsigned long efi_rt_eflags;
 
 void efi_sync_low_kernel_mappings(void) {}
 void __init efi_dump_pagetable(void) {}
-int efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages)
+int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages)
 {
 	return 0;
 }
-void efi_cleanup_page_tables(unsigned long pa_memmap, unsigned num_pages) {}
+void __init efi_cleanup_page_tables(unsigned long pa_memmap, unsigned num_pages)
+{
+}
 
 void __init efi_map_region(efi_memory_desc_t *md)
 {
@@ -55,7 +57,7 @@ void __init efi_map_region(efi_memory_desc_t *md)
 void __init efi_map_region_fixed(efi_memory_desc_t *md) {}
 void __init parse_efi_setup(u64 phys_addr, u32 data_len) {}
 
-void efi_call_phys_prelog(void)
+void __init efi_call_phys_prolog(void)
 {
 	struct desc_ptr gdt_descr;
 
@@ -69,7 +71,7 @@ void efi_call_phys_prelog(void)
 	load_gdt(&gdt_descr);
 }
 
-void efi_call_phys_epilog(void)
+void __init efi_call_phys_epilog(void)
 {
 	struct desc_ptr gdt_descr;
 
diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c
index 290d397e1dd9..35aecb6042fb 100644
--- a/arch/x86/platform/efi/efi_64.c
+++ b/arch/x86/platform/efi/efi_64.c
@@ -79,7 +79,7 @@ static void __init early_code_mapping_set_exec(int executable)
 	}
 }
 
-void __init efi_call_phys_prelog(void)
+void __init efi_call_phys_prolog(void)
 {
 	unsigned long vaddress;
 	int pgd;
@@ -139,7 +139,7 @@ void efi_sync_low_kernel_mappings(void)
 		sizeof(pgd_t) * num_pgds);
 }
 
-int efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages)
+int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages)
 {
 	unsigned long text;
 	struct page *page;
@@ -192,7 +192,7 @@ int efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages)
 	return 0;
 }
 
-void efi_cleanup_page_tables(unsigned long pa_memmap, unsigned num_pages)
+void __init efi_cleanup_page_tables(unsigned long pa_memmap, unsigned num_pages)
 {
 	pgd_t *pgd = (pgd_t *)__va(real_mode_header->trampoline_pgd);
 
diff --git a/arch/x86/platform/efi/efi_stub_32.S b/arch/x86/platform/efi/efi_stub_32.S
index fbe66e626c09..040192b50d02 100644
--- a/arch/x86/platform/efi/efi_stub_32.S
+++ b/arch/x86/platform/efi/efi_stub_32.S
@@ -27,13 +27,13 @@ ENTRY(efi_call_phys)
 	 * set to 0x0010, DS and SS have been set to 0x0018. In EFI, I found
 	 * the values of these registers are the same. And, the corresponding
 	 * GDT entries are identical. So I will do nothing about segment reg
-	 * and GDT, but change GDT base register in prelog and epilog.
+	 * and GDT, but change GDT base register in prolog and epilog.
 	 */
 
 	/*
 	 * 1. Now I am running with EIP = <physical address> + PAGE_OFFSET.
 	 * But to make it smoothly switch from virtual mode to flat mode.
-	 * The mapping of lower virtual memory has been created in prelog and
+	 * The mapping of lower virtual memory has been created in prolog and
 	 * epilog.
 	 */
 	movl	$1f, %edx