1 files changed, 70 insertions, 25 deletions

diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index 1db84c0758b7..ad285404ea7f 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -194,7 +194,7 @@ static void __init do_add_efi_memmap(void)
 int __init efi_memblock_x86_reserve_range(void)
 {
 	struct efi_info *e = &boot_params.efi_info;
-	unsigned long pmap;
+	phys_addr_t pmap;
 
 	if (efi_enabled(EFI_PARAVIRT))
 		return 0;
@@ -209,7 +209,7 @@ int __init efi_memblock_x86_reserve_range(void)
 #else
 	pmap = (e->efi_memmap |	((__u64)e->efi_memmap_hi << 32));
 #endif
-	memmap.phys_map		= (void *)pmap;
+	memmap.phys_map		= pmap;
 	memmap.nr_map		= e->efi_memmap_size /
 				  e->efi_memdesc_size;
 	memmap.desc_size	= e->efi_memdesc_size;
@@ -222,7 +222,7 @@ int __init efi_memblock_x86_reserve_range(void)
 	return 0;
 }
 
-static void __init print_efi_memmap(void)
+void __init efi_print_memmap(void)
 {
 #ifdef EFI_DEBUG
 	efi_memory_desc_t *md;
@@ -524,7 +524,7 @@ void __init efi_init(void)
 		return;
 
 	if (efi_enabled(EFI_DBG))
-		print_efi_memmap();
+		efi_print_memmap();
 
 	efi_esrt_init();
 }
@@ -705,6 +705,70 @@ out:
 }
 
 /*
+ * Iterate the EFI memory map in reverse order because the regions
+ * will be mapped top-down. The end result is the same as if we had
+ * mapped things forward, but doesn't require us to change the
+ * existing implementation of efi_map_region().
+ */
+static inline void *efi_map_next_entry_reverse(void *entry)
+{
+	/* Initial call */
+	if (!entry)
+		return memmap.map_end - memmap.desc_size;
+
+	entry -= memmap.desc_size;
+	if (entry < memmap.map)
+		return NULL;
+
+	return entry;
+}
+
+/*
+ * efi_map_next_entry - Return the next EFI memory map descriptor
+ * @entry: Previous EFI memory map descriptor
+ *
+ * This is a helper function to iterate over the EFI memory map, which
+ * we do in different orders depending on the current configuration.
+ *
+ * To begin traversing the memory map @entry must be %NULL.
+ *
+ * Returns %NULL when we reach the end of the memory map.
+ */
+static void *efi_map_next_entry(void *entry)
+{
+	if (!efi_enabled(EFI_OLD_MEMMAP) && efi_enabled(EFI_64BIT)) {
+		/*
+		 * Starting in UEFI v2.5 the EFI_PROPERTIES_TABLE
+		 * config table feature requires us to map all entries
+		 * in the same order as they appear in the EFI memory
+		 * map. That is to say, entry N must have a lower
+		 * virtual address than entry N+1. This is because the
+		 * firmware toolchain leaves relative references in
+		 * the code/data sections, which are split and become
+		 * separate EFI memory regions. Mapping things
+		 * out-of-order leads to the firmware accessing
+		 * unmapped addresses.
+		 *
+		 * Since we need to map things this way whether or not
+		 * the kernel actually makes use of
+		 * EFI_PROPERTIES_TABLE, let's just switch to this
+		 * scheme by default for 64-bit.
+		 */
+		return efi_map_next_entry_reverse(entry);
+	}
+
+	/* Initial call */
+	if (!entry)
+		return memmap.map;
+
+	entry += memmap.desc_size;
+	if (entry >= memmap.map_end)
+		return NULL;
+
+	return entry;
+}
+
+/*
  * Map the efi memory ranges of the runtime services and update new_mmap with
  * virtual addresses.
  */
@@ -714,7 +778,8 @@ static void * __init efi_map_regions(int *count, int *pg_shift)
 	unsigned long left = 0;
 	efi_memory_desc_t *md;
 
-	for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
+	p = NULL;
+	while ((p = efi_map_next_entry(p))) {
 		md = p;
 		if (!(md->attribute & EFI_MEMORY_RUNTIME)) {
 #ifdef CONFIG_X86_64
@@ -952,24 +1017,6 @@ u32 efi_mem_type(unsigned long phys_addr)
 	return 0;
 }
 
-u64 efi_mem_attributes(unsigned long phys_addr)
-{
-	efi_memory_desc_t *md;
-	void *p;
-
-	if (!efi_enabled(EFI_MEMMAP))
-		return 0;
-
-	for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
-		md = p;
-		if ((md->phys_addr <= phys_addr) &&
-		    (phys_addr < (md->phys_addr +
-				  (md->num_pages << EFI_PAGE_SHIFT))))
-			return md->attribute;
-	}
-	return 0;
-}
-
 static int __init arch_parse_efi_cmdline(char *str)
 {
 	if (!str) {
@@ -979,8 +1026,6 @@ static int __init arch_parse_efi_cmdline(char *str)
 
 	if (parse_option_str(str, "old_map"))
 		set_bit(EFI_OLD_MEMMAP, &efi.flags);
-	if (parse_option_str(str, "debug"))
-		set_bit(EFI_DBG, &efi.flags);
 
 	return 0;
 }