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-rw-r--r--arch/x86/kernel/e820.c1054
1 files changed, 529 insertions, 525 deletions
diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index b2bbad6ebe4d..6e9b26fa6d05 100644
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -1,49 +1,55 @@
 /*
- * Handle the memory map.
- * The functions here do the job until bootmem takes over.
+ * Low level x86 E820 memory map handling functions.
  *
- *  Getting sanitize_e820_map() in sync with i386 version by applying change:
- *  -  Provisions for empty E820 memory regions (reported by certain BIOSes).
- *     Alex Achenbach <xela@slit.de>, December 2002.
- *  Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
+ * The firmware and bootloader passes us the "E820 table", which is the primary
+ * physical memory layout description available about x86 systems.
  *
+ * The kernel takes the E820 memory layout and optionally modifies it with
+ * quirks and other tweaks, and feeds that into the generic Linux memory
+ * allocation code routines via a platform independent interface (memblock, etc.).
  */
-#include <linux/kernel.h>
-#include <linux/types.h>
-#include <linux/init.h>
 #include <linux/crash_dump.h>
-#include <linux/export.h>
 #include <linux/bootmem.h>
-#include <linux/pfn.h>
 #include <linux/suspend.h>
 #include <linux/acpi.h>
 #include <linux/firmware-map.h>
 #include <linux/memblock.h>
 #include <linux/sort.h>
 
-#include <asm/e820.h>
-#include <asm/proto.h>
+#include <asm/e820/api.h>
 #include <asm/setup.h>
-#include <asm/cpufeature.h>
 
 /*
- * The e820 map is the map that gets modified e.g. with command line parameters
- * and that is also registered with modifications in the kernel resource tree
- * with the iomem_resource as parent.
+ * We organize the E820 table into two main data structures:
  *
- * The e820_saved is directly saved after the BIOS-provided memory map is
- * copied. It doesn't get modified afterwards. It's registered for the
- * /sys/firmware/memmap interface.
+ * - 'e820_table_firmware': the original firmware version passed to us by the
+ *   bootloader - not modified by the kernel. We use this to:
  *
- * That memory map is not modified and is used as base for kexec. The kexec'd
- * kernel should get the same memory map as the firmware provides. Then the
- * user can e.g. boot the original kernel with mem=1G while still booting the
- * next kernel with full memory.
+ *       - inform the user about the firmware's notion of memory layout
+ *         via /sys/firmware/memmap
+ *
+ *       - the hibernation code uses it to generate a kernel-independent MD5
+ *         fingerprint of the physical memory layout of a system.
+ *
+ *       - kexec, which is a bootloader in disguise, uses the original E820
+ *         layout to pass to the kexec-ed kernel. This way the original kernel
+ *         can have a restricted E820 map while the kexec()-ed kexec-kernel
+ *         can have access to full memory - etc.
+ *
+ * - 'e820_table': this is the main E820 table that is massaged by the
+ *   low level x86 platform code, or modified by boot parameters, before
+ *   passed on to higher level MM layers.
+ *
+ * Once the E820 map has been converted to the standard Linux memory layout
+ * information its role stops - modifying it has no effect and does not get
+ * re-propagated. So itsmain role is a temporary bootstrap storage of firmware
+ * specific memory layout data during early bootup.
  */
-static struct e820map initial_e820  __initdata;
-static struct e820map initial_e820_saved  __initdata;
-struct e820map *e820 __refdata = &initial_e820;
-struct e820map *e820_saved __refdata = &initial_e820_saved;
+static struct e820_table e820_table_init		__initdata;
+static struct e820_table e820_table_firmware_init	__initdata;
+
+struct e820_table *e820_table __refdata			= &e820_table_init;
+struct e820_table *e820_table_firmware __refdata	= &e820_table_firmware_init;
 
 /* For PCI or other memory-mapped resources */
 unsigned long pci_mem_start = 0xaeedbabe;
@@ -55,51 +61,53 @@ EXPORT_SYMBOL(pci_mem_start);
  * This function checks if any part of the range <start,end> is mapped
  * with type.
  */
-int
-e820_any_mapped(u64 start, u64 end, unsigned type)
+bool e820__mapped_any(u64 start, u64 end, enum e820_type type)
 {
 	int i;
 
-	for (i = 0; i < e820->nr_map; i++) {
-		struct e820entry *ei = &e820->map[i];
+	for (i = 0; i < e820_table->nr_entries; i++) {
+		struct e820_entry *entry = &e820_table->entries[i];
 
-		if (type && ei->type != type)
+		if (type && entry->type != type)
 			continue;
-		if (ei->addr >= end || ei->addr + ei->size <= start)
+		if (entry->addr >= end || entry->addr + entry->size <= start)
 			continue;
 		return 1;
 	}
 	return 0;
 }
-EXPORT_SYMBOL_GPL(e820_any_mapped);
+EXPORT_SYMBOL_GPL(e820__mapped_any);
 
 /*
- * This function checks if the entire range <start,end> is mapped with type.
+ * This function checks if the entire <start,end> range is mapped with 'type'.
  *
- * Note: this function only works correct if the e820 table is sorted and
- * not-overlapping, which is the case
+ * Note: this function only works correctly once the E820 table is sorted and
+ * not-overlapping (at least for the range specified), which is the case normally.
  */
-int __init e820_all_mapped(u64 start, u64 end, unsigned type)
+bool __init e820__mapped_all(u64 start, u64 end, enum e820_type type)
 {
 	int i;
 
-	for (i = 0; i < e820->nr_map; i++) {
-		struct e820entry *ei = &e820->map[i];
+	for (i = 0; i < e820_table->nr_entries; i++) {
+		struct e820_entry *entry = &e820_table->entries[i];
 
-		if (type && ei->type != type)
+		if (type && entry->type != type)
 			continue;
-		/* is the region (part) in overlap with the current region ?*/
-		if (ei->addr >= end || ei->addr + ei->size <= start)
+
+		/* Is the region (part) in overlap with the current region? */
+		if (entry->addr >= end || entry->addr + entry->size <= start)
 			continue;
 
-		/* if the region is at the beginning of <start,end> we move
-		 * start to the end of the region since it's ok until there
+		/*
+		 * If the region is at the beginning of <start,end> we move
+		 * 'start' to the end of the region since it's ok until there
 		 */
-		if (ei->addr <= start)
-			start = ei->addr + ei->size;
+		if (entry->addr <= start)
+			start = entry->addr + entry->size;
+
 		/*
-		 * if start is now at or beyond end, we're done, full
-		 * coverage
+		 * If 'start' is now at or beyond 'end', we're done, full
+		 * coverage of the desired range exists:
 		 */
 		if (start >= end)
 			return 1;
@@ -108,94 +116,77 @@ int __init e820_all_mapped(u64 start, u64 end, unsigned type)
 }
 
 /*
- * Add a memory region to the kernel e820 map.
+ * Add a memory region to the kernel E820 map.
  */
-static void __init __e820_add_region(struct e820map *e820x, u64 start, u64 size,
-					 int type)
+static void __init __e820__range_add(struct e820_table *table, u64 start, u64 size, enum e820_type type)
 {
-	int x = e820x->nr_map;
+	int x = table->nr_entries;
 
-	if (x >= ARRAY_SIZE(e820x->map)) {
-		printk(KERN_ERR "e820: too many entries; ignoring [mem %#010llx-%#010llx]\n",
-		       (unsigned long long) start,
-		       (unsigned long long) (start + size - 1));
+	if (x >= ARRAY_SIZE(table->entries)) {
+		pr_err("e820: too many entries; ignoring [mem %#010llx-%#010llx]\n", start, start + size - 1);
 		return;
 	}
 
-	e820x->map[x].addr = start;
-	e820x->map[x].size = size;
-	e820x->map[x].type = type;
-	e820x->nr_map++;
+	table->entries[x].addr = start;
+	table->entries[x].size = size;
+	table->entries[x].type = type;
+	table->nr_entries++;
 }
 
-void __init e820_add_region(u64 start, u64 size, int type)
+void __init e820__range_add(u64 start, u64 size, enum e820_type type)
 {
-	__e820_add_region(e820, start, size, type);
+	__e820__range_add(e820_table, start, size, type);
 }
 
-static void __init e820_print_type(u32 type)
+static void __init e820_print_type(enum e820_type type)
 {
 	switch (type) {
-	case E820_RAM:
-	case E820_RESERVED_KERN:
-		printk(KERN_CONT "usable");
-		break;
-	case E820_RESERVED:
-		printk(KERN_CONT "reserved");
-		break;
-	case E820_ACPI:
-		printk(KERN_CONT "ACPI data");
-		break;
-	case E820_NVS:
-		printk(KERN_CONT "ACPI NVS");
-		break;
-	case E820_UNUSABLE:
-		printk(KERN_CONT "unusable");
-		break;
-	case E820_PMEM:
-	case E820_PRAM:
-		printk(KERN_CONT "persistent (type %u)", type);
-		break;
-	default:
-		printk(KERN_CONT "type %u", type);
-		break;
+	case E820_TYPE_RAM:		/* Fall through: */
+	case E820_TYPE_RESERVED_KERN:	pr_cont("usable");			break;
+	case E820_TYPE_RESERVED:	pr_cont("reserved");			break;
+	case E820_TYPE_ACPI:		pr_cont("ACPI data");			break;
+	case E820_TYPE_NVS:		pr_cont("ACPI NVS");			break;
+	case E820_TYPE_UNUSABLE:	pr_cont("unusable");			break;
+	case E820_TYPE_PMEM:		/* Fall through: */
+	case E820_TYPE_PRAM:		pr_cont("persistent (type %u)", type);	break;
+	default:			pr_cont("type %u", type);		break;
 	}
 }
 
-void __init e820_print_map(char *who)
+void __init e820__print_table(char *who)
 {
 	int i;
 
-	for (i = 0; i < e820->nr_map; i++) {
-		printk(KERN_INFO "%s: [mem %#018Lx-%#018Lx] ", who,
-		       (unsigned long long) e820->map[i].addr,
-		       (unsigned long long)
-		       (e820->map[i].addr + e820->map[i].size - 1));
-		e820_print_type(e820->map[i].type);
-		printk(KERN_CONT "\n");
+	for (i = 0; i < e820_table->nr_entries; i++) {
+		pr_info("%s: [mem %#018Lx-%#018Lx] ", who,
+		       e820_table->entries[i].addr,
+		       e820_table->entries[i].addr + e820_table->entries[i].size - 1);
+
+		e820_print_type(e820_table->entries[i].type);
+		pr_cont("\n");
 	}
 }
 
 /*
- * Sanitize the BIOS e820 map.
+ * Sanitize an E820 map.
  *
- * Some e820 responses include overlapping entries. The following
- * replaces the original e820 map with a new one, removing overlaps,
+ * Some E820 layouts include overlapping entries. The following
+ * replaces the original E820 map with a new one, removing overlaps,
  * and resolving conflicting memory types in favor of highest
  * numbered type.
  *
- * The input parameter biosmap points to an array of 'struct
- * e820entry' which on entry has elements in the range [0, *pnr_map)
- * valid, and which has space for up to max_nr_map entries.
- * On return, the resulting sanitized e820 map entries will be in
- * overwritten in the same location, starting at biosmap.
+ * The input parameter 'entries' points to an array of 'struct
+ * e820_entry' which on entry has elements in the range [0, *nr_entries)
+ * valid, and which has space for up to max_nr_entries entries.
+ * On return, the resulting sanitized E820 map entries will be in
+ * overwritten in the same location, starting at 'entries'.
  *
- * The integer pointed to by pnr_map must be valid on entry (the
- * current number of valid entries located at biosmap). If the
- * sanitizing succeeds the *pnr_map will be updated with the new
- * number of valid entries (something no more than max_nr_map).
+ * The integer pointed to by nr_entries must be valid on entry (the
+ * current number of valid entries located at 'entries'). If the
+ * sanitizing succeeds the *nr_entries will be updated with the new
+ * number of valid entries (something no more than max_nr_entries).
  *
- * The return value from sanitize_e820_map() is zero if it
+ * The return value from e820__update_table() is zero if it
  * successfully 'sanitized' the map entries passed in, and is -1
  * if it did nothing, which can happen if either of (1) it was
  * only passed one map entry, or (2) any of the input map entries
@@ -238,10 +229,17 @@ void __init e820_print_map(char *who)
  *	   ______________________4_
  */
 struct change_member {
-	struct e820entry *pbios; /* pointer to original bios entry */
-	unsigned long long addr; /* address for this change point */
+	/* Pointer to the original entry: */
+	struct e820_entry	*entry;
+	/* Address for this change point: */
+	unsigned long long	addr;
 };
 
+static struct change_member	change_point_list[2*E820_MAX_ENTRIES]	__initdata;
+static struct change_member	*change_point[2*E820_MAX_ENTRIES]	__initdata;
+static struct e820_entry	*overlap_list[E820_MAX_ENTRIES]		__initdata;
+static struct e820_entry	new_entries[E820_MAX_ENTRIES]		__initdata;
+
 static int __init cpcompare(const void *a, const void *b)
 {
 	struct change_member * const *app = a, * const *bpp = b;
@@ -249,164 +247,141 @@ static int __init cpcompare(const void *a, const void *b)
 
 	/*
 	 * Inputs are pointers to two elements of change_point[].  If their
-	 * addresses are unequal, their difference dominates.  If the addresses
+	 * addresses are not equal, their difference dominates.  If the addresses
 	 * are equal, then consider one that represents the end of its region
 	 * to be greater than one that does not.
 	 */
 	if (ap->addr != bp->addr)
 		return ap->addr > bp->addr ? 1 : -1;
 
-	return (ap->addr != ap->pbios->addr) - (bp->addr != bp->pbios->addr);
+	return (ap->addr != ap->entry->addr) - (bp->addr != bp->entry->addr);
 }
 
-int __init sanitize_e820_map(struct e820entry *biosmap, int max_nr_map,
-			     u32 *pnr_map)
+int __init e820__update_table(struct e820_table *table)
 {
-	static struct change_member change_point_list[2*E820_X_MAX] __initdata;
-	static struct change_member *change_point[2*E820_X_MAX] __initdata;
-	static struct e820entry *overlap_list[E820_X_MAX] __initdata;
-	static struct e820entry new_bios[E820_X_MAX] __initdata;
-	unsigned long current_type, last_type;
+	struct e820_entry *entries = table->entries;
+	u32 max_nr_entries = ARRAY_SIZE(table->entries);
+	enum e820_type current_type, last_type;
 	unsigned long long last_addr;
-	int chgidx;
-	int overlap_entries;
-	int new_bios_entry;
-	int old_nr, new_nr, chg_nr;
-	int i;
+	u32 new_nr_entries, overlap_entries;
+	u32 i, chg_idx, chg_nr;
 
-	/* if there's only one memory region, don't bother */
-	if (*pnr_map < 2)
+	/* If there's only one memory region, don't bother: */
+	if (table->nr_entries < 2)
 		return -1;
 
-	old_nr = *pnr_map;
-	BUG_ON(old_nr > max_nr_map);
+	table->nr_entries = table->nr_entries;
+	BUG_ON(table->nr_entries > max_nr_entries);
 
-	/* bail out if we find any unreasonable addresses in bios map */
-	for (i = 0; i < old_nr; i++)
-		if (biosmap[i].addr + biosmap[i].size < biosmap[i].addr)
+	/* Bail out if we find any unreasonable addresses in the map: */
+	for (i = 0; i < table->nr_entries; i++) {
+		if (entries[i].addr + entries[i].size < entries[i].addr)
 			return -1;
+	}
 
-	/* create pointers for initial change-point information (for sorting) */
-	for (i = 0; i < 2 * old_nr; i++)
+	/* Create pointers for initial change-point information (for sorting): */
+	for (i = 0; i < 2 * table->nr_entries; i++)
 		change_point[i] = &change_point_list[i];
 
-	/* record all known change-points (starting and ending addresses),
-	   omitting those that are for empty memory regions */
-	chgidx = 0;
-	for (i = 0; i < old_nr; i++)	{
-		if (biosmap[i].size != 0) {
-			change_point[chgidx]->addr = biosmap[i].addr;
-			change_point[chgidx++]->pbios = &biosmap[i];
-			change_point[chgidx]->addr = biosmap[i].addr +
-				biosmap[i].size;
-			change_point[chgidx++]->pbios = &biosmap[i];
+	/*
+	 * Record all known change-points (starting and ending addresses),
+	 * omitting empty memory regions:
+	 */
+	chg_idx = 0;
+	for (i = 0; i < table->nr_entries; i++)	{
+		if (entries[i].size != 0) {
+			change_point[chg_idx]->addr	= entries[i].addr;
+			change_point[chg_idx++]->entry	= &entries[i];
+			change_point[chg_idx]->addr	= entries[i].addr + entries[i].size;
+			change_point[chg_idx++]->entry	= &entries[i];
 		}
 	}
-	chg_nr = chgidx;
-
-	/* sort change-point list by memory addresses (low -> high) */
-	sort(change_point, chg_nr, sizeof *change_point, cpcompare, NULL);
-
-	/* create a new bios memory map, removing overlaps */
-	overlap_entries = 0;	 /* number of entries in the overlap table */
-	new_bios_entry = 0;	 /* index for creating new bios map entries */
-	last_type = 0;		 /* start with undefined memory type */
-	last_addr = 0;		 /* start with 0 as last starting address */
-
-	/* loop through change-points, determining affect on the new bios map */
-	for (chgidx = 0; chgidx < chg_nr; chgidx++) {
-		/* keep track of all overlapping bios entries */
-		if (change_point[chgidx]->addr ==
-		    change_point[chgidx]->pbios->addr) {
-			/*
-			 * add map entry to overlap list (> 1 entry
-			 * implies an overlap)
-			 */
-			overlap_list[overlap_entries++] =
-				change_point[chgidx]->pbios;
+	chg_nr = chg_idx;
+
+	/* Sort change-point list by memory addresses (low -> high): */
+	sort(change_point, chg_nr, sizeof(*change_point), cpcompare, NULL);
+
+	/* Create a new memory map, removing overlaps: */
+	overlap_entries = 0;	 /* Number of entries in the overlap table */
+	new_nr_entries = 0;	 /* Index for creating new map entries */
+	last_type = 0;		 /* Start with undefined memory type */
+	last_addr = 0;		 /* Start with 0 as last starting address */
+
+	/* Loop through change-points, determining effect on the new map: */
+	for (chg_idx = 0; chg_idx < chg_nr; chg_idx++) {
+		/* Keep track of all overlapping entries */
+		if (change_point[chg_idx]->addr == change_point[chg_idx]->entry->addr) {
+			/* Add map entry to overlap list (> 1 entry implies an overlap) */
+			overlap_list[overlap_entries++] = change_point[chg_idx]->entry;
 		} else {
-			/*
-			 * remove entry from list (order independent,
-			 * so swap with last)
-			 */
+			/* Remove entry from list (order independent, so swap with last): */
 			for (i = 0; i < overlap_entries; i++) {
-				if (overlap_list[i] ==
-				    change_point[chgidx]->pbios)
-					overlap_list[i] =
-						overlap_list[overlap_entries-1];
+				if (overlap_list[i] == change_point[chg_idx]->entry)
+					overlap_list[i] = overlap_list[overlap_entries-1];
 			}
 			overlap_entries--;
 		}
 		/*
-		 * if there are overlapping entries, decide which
+		 * If there are overlapping entries, decide which
 		 * "type" to use (larger value takes precedence --
 		 * 1=usable, 2,3,4,4+=unusable)
 		 */
 		current_type = 0;
-		for (i = 0; i < overlap_entries; i++)
+		for (i = 0; i < overlap_entries; i++) {
 			if (overlap_list[i]->type > current_type)
 				current_type = overlap_list[i]->type;
-		/*
-		 * continue building up new bios map based on this
-		 * information
-		 */
-		if (current_type != last_type || current_type == E820_PRAM) {
+		}
+
+		/* Continue building up new map based on this information: */
+		if (current_type != last_type || current_type == E820_TYPE_PRAM) {
 			if (last_type != 0)	 {
-				new_bios[new_bios_entry].size =
-					change_point[chgidx]->addr - last_addr;
-				/*
-				 * move forward only if the new size
-				 * was non-zero
-				 */
-				if (new_bios[new_bios_entry].size != 0)
-					/*
-					 * no more space left for new
-					 * bios entries ?
-					 */
-					if (++new_bios_entry >= max_nr_map)
+				new_entries[new_nr_entries].size = change_point[chg_idx]->addr - last_addr;
+				/* Move forward only if the new size was non-zero: */
+				if (new_entries[new_nr_entries].size != 0)
+					/* No more space left for new entries? */
+					if (++new_nr_entries >= max_nr_entries)
 						break;
 			}
 			if (current_type != 0)	{
-				new_bios[new_bios_entry].addr =
-					change_point[chgidx]->addr;
-				new_bios[new_bios_entry].type = current_type;
-				last_addr = change_point[chgidx]->addr;
+				new_entries[new_nr_entries].addr = change_point[chg_idx]->addr;
+				new_entries[new_nr_entries].type = current_type;
+				last_addr = change_point[chg_idx]->addr;
 			}
 			last_type = current_type;
 		}
 	}
-	/* retain count for new bios entries */
-	new_nr = new_bios_entry;
 
-	/* copy new bios mapping into original location */
-	memcpy(biosmap, new_bios, new_nr * sizeof(struct e820entry));
-	*pnr_map = new_nr;
+	/* Copy the new entries into the original location: */
+	memcpy(entries, new_entries, new_nr_entries*sizeof(*entries));
+	table->nr_entries = new_nr_entries;
 
 	return 0;
 }
 
-static int __init __append_e820_map(struct e820entry *biosmap, int nr_map)
+static int __init __append_e820_table(struct boot_e820_entry *entries, u32 nr_entries)
 {
-	while (nr_map) {
-		u64 start = biosmap->addr;
-		u64 size = biosmap->size;
+	struct boot_e820_entry *entry = entries;
+
+	while (nr_entries) {
+		u64 start = entry->addr;
+		u64 size = entry->size;
 		u64 end = start + size - 1;
-		u32 type = biosmap->type;
+		u32 type = entry->type;
 
-		/* Overflow in 64 bits? Ignore the memory map. */
+		/* Ignore the entry on 64-bit overflow: */
 		if (start > end && likely(size))
 			return -1;
 
-		e820_add_region(start, size, type);
+		e820__range_add(start, size, type);
 
-		biosmap++;
-		nr_map--;
+		entry++;
+		nr_entries--;
 	}
 	return 0;
 }
 
 /*
- * Copy the BIOS e820 map into a safe place.
+ * Copy the BIOS E820 map into a safe place.
  *
  * Sanity-check it while we're at it..
  *
@@ -414,18 +389,17 @@ static int __init __append_e820_map(struct e820entry *biosmap, int nr_map)
  * will have given us a memory map that we can use to properly
  * set up memory.  If we aren't, we'll fake a memory map.
  */
-static int __init append_e820_map(struct e820entry *biosmap, int nr_map)
+static int __init append_e820_table(struct boot_e820_entry *entries, u32 nr_entries)
 {
 	/* Only one memory region (or negative)? Ignore it */
-	if (nr_map < 2)
+	if (nr_entries < 2)
 		return -1;
 
-	return __append_e820_map(biosmap, nr_map);
+	return __append_e820_table(entries, nr_entries);
 }
 
-static u64 __init __e820_update_range(struct e820map *e820x, u64 start,
-					u64 size, unsigned old_type,
-					unsigned new_type)
+static u64 __init
+__e820__range_update(struct e820_table *table, u64 start, u64 size, enum e820_type old_type, enum e820_type new_type)
 {
 	u64 end;
 	unsigned int i;
@@ -437,77 +411,73 @@ static u64 __init __e820_update_range(struct e820map *e820x, u64 start,
 		size = ULLONG_MAX - start;
 
 	end = start + size;
-	printk(KERN_DEBUG "e820: update [mem %#010Lx-%#010Lx] ",
-	       (unsigned long long) start, (unsigned long long) (end - 1));
+	printk(KERN_DEBUG "e820: update [mem %#010Lx-%#010Lx] ", start, end - 1);
 	e820_print_type(old_type);
-	printk(KERN_CONT " ==> ");
+	pr_cont(" ==> ");
 	e820_print_type(new_type);
-	printk(KERN_CONT "\n");
+	pr_cont("\n");
 
-	for (i = 0; i < e820x->nr_map; i++) {
-		struct e820entry *ei = &e820x->map[i];
+	for (i = 0; i < table->nr_entries; i++) {
+		struct e820_entry *entry = &table->entries[i];
 		u64 final_start, final_end;
-		u64 ei_end;
+		u64 entry_end;
 
-		if (ei->type != old_type)
+		if (entry->type != old_type)
 			continue;
 
-		ei_end = ei->addr + ei->size;
-		/* totally covered by new range? */
-		if (ei->addr >= start && ei_end <= end) {
-			ei->type = new_type;
-			real_updated_size += ei->size;
+		entry_end = entry->addr + entry->size;
+
+		/* Completely covered by new range? */
+		if (entry->addr >= start && entry_end <= end) {
+			entry->type = new_type;
+			real_updated_size += entry->size;
 			continue;
 		}
 
-		/* new range is totally covered? */
-		if (ei->addr < start && ei_end > end) {
-			__e820_add_region(e820x, start, size, new_type);
-			__e820_add_region(e820x, end, ei_end - end, ei->type);
-			ei->size = start - ei->addr;
+		/* New range is completely covered? */
+		if (entry->addr < start && entry_end > end) {
+			__e820__range_add(table, start, size, new_type);
+			__e820__range_add(table, end, entry_end - end, entry->type);
+			entry->size = start - entry->addr;
 			real_updated_size += size;
 			continue;
 		}
 
-		/* partially covered */
-		final_start = max(start, ei->addr);
-		final_end = min(end, ei_end);
+		/* Partially covered: */
+		final_start = max(start, entry->addr);
+		final_end = min(end, entry_end);
 		if (final_start >= final_end)
 			continue;
 
-		__e820_add_region(e820x, final_start, final_end - final_start,
-				  new_type);
+		__e820__range_add(table, final_start, final_end - final_start, new_type);
 
 		real_updated_size += final_end - final_start;
 
 		/*
-		 * left range could be head or tail, so need to update
-		 * size at first.
+		 * Left range could be head or tail, so need to update
+		 * its size first:
 		 */
-		ei->size -= final_end - final_start;
-		if (ei->addr < final_start)
+		entry->size -= final_end - final_start;
+		if (entry->addr < final_start)
 			continue;
-		ei->addr = final_end;
+
+		entry->addr = final_end;
 	}
 	return real_updated_size;
 }
 
-u64 __init e820_update_range(u64 start, u64 size, unsigned old_type,
-			     unsigned new_type)
+u64 __init e820__range_update(u64 start, u64 size, enum e820_type old_type, enum e820_type new_type)
 {
-	return __e820_update_range(e820, start, size, old_type, new_type);
+	return __e820__range_update(e820_table, start, size, old_type, new_type);
 }
 
-static u64 __init e820_update_range_saved(u64 start, u64 size,
-					  unsigned old_type, unsigned new_type)
+static u64 __init e820__range_update_firmware(u64 start, u64 size, enum e820_type old_type, enum e820_type  new_type)
 {
-	return __e820_update_range(e820_saved, start, size, old_type,
-				     new_type);
+	return __e820__range_update(e820_table_firmware, start, size, old_type, new_type);
 }
 
-/* make e820 not cover the range */
-u64 __init e820_remove_range(u64 start, u64 size, unsigned old_type,
-			     int checktype)
+/* Remove a range of memory from the E820 table: */
+u64 __init e820__range_remove(u64 start, u64 size, enum e820_type old_type, bool check_type)
 {
 	int i;
 	u64 end;
@@ -517,85 +487,89 @@ u64 __init e820_remove_range(u64 start, u64 size, unsigned old_type,
 		size = ULLONG_MAX - start;
 
 	end = start + size;
-	printk(KERN_DEBUG "e820: remove [mem %#010Lx-%#010Lx] ",
-	       (unsigned long long) start, (unsigned long long) (end - 1));
-	if (checktype)
+	printk(KERN_DEBUG "e820: remove [mem %#010Lx-%#010Lx] ", start, end - 1);
+	if (check_type)
 		e820_print_type(old_type);
-	printk(KERN_CONT "\n");
+	pr_cont("\n");
 
-	for (i = 0; i < e820->nr_map; i++) {
-		struct e820entry *ei = &e820->map[i];
+	for (i = 0; i < e820_table->nr_entries; i++) {
+		struct e820_entry *entry = &e820_table->entries[i];
 		u64 final_start, final_end;
-		u64 ei_end;
+		u64 entry_end;
 
-		if (checktype && ei->type != old_type)
+		if (check_type && entry->type != old_type)
 			continue;
 
-		ei_end = ei->addr + ei->size;
-		/* totally covered? */
-		if (ei->addr >= start && ei_end <= end) {
-			real_removed_size += ei->size;
-			memset(ei, 0, sizeof(struct e820entry));
+		entry_end = entry->addr + entry->size;
+
+		/* Completely covered? */
+		if (entry->addr >= start && entry_end <= end) {
+			real_removed_size += entry->size;
+			memset(entry, 0, sizeof(*entry));
 			continue;
 		}
 
-		/* new range is totally covered? */
-		if (ei->addr < start && ei_end > end) {
-			e820_add_region(end, ei_end - end, ei->type);
-			ei->size = start - ei->addr;
+		/* Is the new range completely covered? */
+		if (entry->addr < start && entry_end > end) {
+			e820__range_add(end, entry_end - end, entry->type);
+			entry->size = start - entry->addr;
 			real_removed_size += size;
 			continue;
 		}
 
-		/* partially covered */
-		final_start = max(start, ei->addr);
-		final_end = min(end, ei_end);
+		/* Partially covered: */
+		final_start = max(start, entry->addr);
+		final_end = min(end, entry_end);
 		if (final_start >= final_end)
 			continue;
+
 		real_removed_size += final_end - final_start;
 
 		/*
-		 * left range could be head or tail, so need to update
-		 * size at first.
+		 * Left range could be head or tail, so need to update
+		 * the size first:
 		 */
-		ei->size -= final_end - final_start;
-		if (ei->addr < final_start)
+		entry->size -= final_end - final_start;
+		if (entry->addr < final_start)
 			continue;
-		ei->addr = final_end;
+
+		entry->addr = final_end;
 	}
 	return real_removed_size;
 }
 
-void __init update_e820(void)
+void __init e820__update_table_print(void)
 {
-	if (sanitize_e820_map(e820->map, ARRAY_SIZE(e820->map), &e820->nr_map))
+	if (e820__update_table(e820_table))
 		return;
-	printk(KERN_INFO "e820: modified physical RAM map:\n");
-	e820_print_map("modified");
+
+	pr_info("e820: modified physical RAM map:\n");
+	e820__print_table("modified");
 }
-static void __init update_e820_saved(void)
+
+static void __init e820__update_table_firmware(void)
 {
-	sanitize_e820_map(e820_saved->map, ARRAY_SIZE(e820_saved->map),
-				&e820_saved->nr_map);
+	e820__update_table(e820_table_firmware);
 }
+
 #define MAX_GAP_END 0x100000000ull
+
 /*
- * Search for a gap in the e820 memory space from 0 to MAX_GAP_END.
+ * Search for a gap in the E820 memory space from 0 to MAX_GAP_END (4GB).
  */
-static int __init e820_search_gap(unsigned long *gapstart,
-		unsigned long *gapsize)
+static int __init e820_search_gap(unsigned long *gapstart, unsigned long *gapsize)
 {
 	unsigned long long last = MAX_GAP_END;
-	int i = e820->nr_map;
+	int i = e820_table->nr_entries;
 	int found = 0;
 
 	while (--i >= 0) {
-		unsigned long long start = e820->map[i].addr;
-		unsigned long long end = start + e820->map[i].size;
+		unsigned long long start = e820_table->entries[i].addr;
+		unsigned long long end = start + e820_table->entries[i].size;
 
 		/*
 		 * Since "last" is at most 4GB, we know we'll
-		 * fit in 32 bits if this condition is true
+		 * fit in 32 bits if this condition is true:
 		 */
 		if (last > end) {
 			unsigned long gap = last - end;
@@ -613,12 +587,14 @@ static int __init e820_search_gap(unsigned long *gapstart,
 }
 
 /*
- * Search for the biggest gap in the low 32 bits of the e820
- * memory space.  We pass this space to PCI to assign MMIO resources
- * for hotplug or unconfigured devices in.
+ * Search for the biggest gap in the low 32 bits of the E820
+ * memory space. We pass this space to the PCI subsystem, so
+ * that it can assign MMIO resources for hotplug or
+ * unconfigured devices in.
+ *
  * Hopefully the BIOS let enough space left.
  */
-__init void e820_setup_gap(void)
+__init void e820__setup_pci_gap(void)
 {
 	unsigned long gapstart, gapsize;
 	int found;
@@ -629,138 +605,143 @@ __init void e820_setup_gap(void)
 	if (!found) {
 #ifdef CONFIG_X86_64
 		gapstart = (max_pfn << PAGE_SHIFT) + 1024*1024;
-		printk(KERN_ERR
-	"e820: cannot find a gap in the 32bit address range\n"
-	"e820: PCI devices with unassigned 32bit BARs may break!\n");
+		pr_err(
+			"e820: Cannot find an available gap in the 32-bit address range\n"
+			"e820: PCI devices with unassigned 32-bit BARs may not work!\n");
 #else
 		gapstart = 0x10000000;
 #endif
 	}
 
 	/*
-	 * e820_reserve_resources_late protect stolen RAM already
+	 * e820__reserve_resources_late() protects stolen RAM already:
 	 */
 	pci_mem_start = gapstart;
 
-	printk(KERN_INFO
-	       "e820: [mem %#010lx-%#010lx] available for PCI devices\n",
-	       gapstart, gapstart + gapsize - 1);
+	pr_info("e820: [mem %#010lx-%#010lx] available for PCI devices\n", gapstart, gapstart + gapsize - 1);
 }
 
 /*
  * Called late during init, in free_initmem().
  *
- * Initial e820 and e820_saved are largish __initdata arrays.
- * Copy them to (usually much smaller) dynamically allocated area.
- * This is done after all tweaks we ever do to them:
- * all functions which modify them are __init functions,
- * they won't exist after this point.
+ * Initial e820_table and e820_table_firmware are largish __initdata arrays.
+ *
+ * Copy them to a (usually much smaller) dynamically allocated area that is
+ * sized precisely after the number of e820 entries.
+ *
+ * This is done after we've performed all the fixes and tweaks to the tables.
+ * All functions which modify them are __init functions, which won't exist
+ * after free_initmem().
  */
-__init void e820_reallocate_tables(void)
+__init void e820__reallocate_tables(void)
 {
-	struct e820map *n;
+	struct e820_table *n;
 	int size;
 
-	size = offsetof(struct e820map, map) + sizeof(struct e820entry) * e820->nr_map;
+	size = offsetof(struct e820_table, entries) + sizeof(struct e820_entry)*e820_table->nr_entries;
 	n = kmalloc(size, GFP_KERNEL);
 	BUG_ON(!n);
-	memcpy(n, e820, size);
-	e820 = n;
+	memcpy(n, e820_table, size);
+	e820_table = n;
 
-	size = offsetof(struct e820map, map) + sizeof(struct e820entry) * e820_saved->nr_map;
+	size = offsetof(struct e820_table, entries) + sizeof(struct e820_entry)*e820_table_firmware->nr_entries;
 	n = kmalloc(size, GFP_KERNEL);
 	BUG_ON(!n);
-	memcpy(n, e820_saved, size);
-	e820_saved = n;
+	memcpy(n, e820_table_firmware, size);
+	e820_table_firmware = n;
 }
 
-/**
- * Because of the size limitation of struct boot_params, only first
- * 128 E820 memory entries are passed to kernel via
- * boot_params.e820_map, others are passed via SETUP_E820_EXT node of
- * linked list of struct setup_data, which is parsed here.
+/*
+ * Because of the small fixed size of struct boot_params, only the first
+ * 128 E820 memory entries are passed to the kernel via boot_params.e820_table,
+ * the remaining (if any) entries are passed via the SETUP_E820_EXT node of
+ * struct setup_data, which is parsed here.
  */
-void __init parse_e820_ext(u64 phys_addr, u32 data_len)
+void __init e820__memory_setup_extended(u64 phys_addr, u32 data_len)
 {
 	int entries;
-	struct e820entry *extmap;
+	struct boot_e820_entry *extmap;
 	struct setup_data *sdata;
 
 	sdata = early_memremap(phys_addr, data_len);
-	entries = sdata->len / sizeof(struct e820entry);
-	extmap = (struct e820entry *)(sdata->data);
-	__append_e820_map(extmap, entries);
-	sanitize_e820_map(e820->map, ARRAY_SIZE(e820->map), &e820->nr_map);
+	entries = sdata->len / sizeof(*extmap);
+	extmap = (struct boot_e820_entry *)(sdata->data);
+
+	__append_e820_table(extmap, entries);
+	e820__update_table(e820_table);
+
 	early_memunmap(sdata, data_len);
-	printk(KERN_INFO "e820: extended physical RAM map:\n");
-	e820_print_map("extended");
+	pr_info("e820: extended physical RAM map:\n");
+	e820__print_table("extended");
 }
 
-#if defined(CONFIG_X86_64) || \
-	(defined(CONFIG_X86_32) && defined(CONFIG_HIBERNATION))
-/**
+/*
  * Find the ranges of physical addresses that do not correspond to
- * e820 RAM areas and mark the corresponding pages as nosave for
- * hibernation (32 bit) or software suspend and suspend to RAM (64 bit).
+ * E820 RAM areas and register the corresponding pages as 'nosave' for
+ * hibernation (32-bit) or software suspend and suspend to RAM (64-bit).
  *
- * This function requires the e820 map to be sorted and without any
+ * This function requires the E820 map to be sorted and without any
  * overlapping entries.
  */
-void __init e820_mark_nosave_regions(unsigned long limit_pfn)
+void __init e820__register_nosave_regions(unsigned long limit_pfn)
 {
 	int i;
 	unsigned long pfn = 0;
 
-	for (i = 0; i < e820->nr_map; i++) {
-		struct e820entry *ei = &e820->map[i];
+	for (i = 0; i < e820_table->nr_entries; i++) {
+		struct e820_entry *entry = &e820_table->entries[i];
 
-		if (pfn < PFN_UP(ei->addr))
-			register_nosave_region(pfn, PFN_UP(ei->addr));
+		if (pfn < PFN_UP(entry->addr))
+			register_nosave_region(pfn, PFN_UP(entry->addr));
 
-		pfn = PFN_DOWN(ei->addr + ei->size);
+		pfn = PFN_DOWN(entry->addr + entry->size);
 
-		if (ei->type != E820_RAM && ei->type != E820_RESERVED_KERN)
-			register_nosave_region(PFN_UP(ei->addr), pfn);
+		if (entry->type != E820_TYPE_RAM && entry->type != E820_TYPE_RESERVED_KERN)
+			register_nosave_region(PFN_UP(entry->addr), pfn);
 
 		if (pfn >= limit_pfn)
 			break;
 	}
 }
-#endif
 
 #ifdef CONFIG_ACPI
-/**
- * Mark ACPI NVS memory region, so that we can save/restore it during
- * hibernation and the subsequent resume.
+/*
+ * Register ACPI NVS memory regions, so that we can save/restore them during
+ * hibernation and the subsequent resume:
  */
-static int __init e820_mark_nvs_memory(void)
+static int __init e820__register_nvs_regions(void)
 {
 	int i;
 
-	for (i = 0; i < e820->nr_map; i++) {
-		struct e820entry *ei = &e820->map[i];
+	for (i = 0; i < e820_table->nr_entries; i++) {
+		struct e820_entry *entry = &e820_table->entries[i];
 
-		if (ei->type == E820_NVS)
-			acpi_nvs_register(ei->addr, ei->size);
+		if (entry->type == E820_TYPE_NVS)
+			acpi_nvs_register(entry->addr, entry->size);
 	}
 
 	return 0;
 }
-core_initcall(e820_mark_nvs_memory);
+core_initcall(e820__register_nvs_regions);
 #endif
 
 /*
- * pre allocated 4k and reserved it in memblock and e820_saved
+ * Allocate the requested number of bytes with the requsted alignment
+ * and return (the physical address) to the caller. Also register this
+ * range in the 'firmware' E820 table as a reserved range.
+ *
+ * This allows kexec to fake a new mptable, as if it came from the real
+ * system.
  */
-u64 __init early_reserve_e820(u64 size, u64 align)
+u64 __init e820__memblock_alloc_reserved(u64 size, u64 align)
 {
 	u64 addr;
 
 	addr = __memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ACCESSIBLE);
 	if (addr) {
-		e820_update_range_saved(addr, size, E820_RAM, E820_RESERVED);
-		printk(KERN_INFO "e820: update e820_saved for early_reserve_e820\n");
-		update_e820_saved();
+		e820__range_update_firmware(addr, size, E820_TYPE_RAM, E820_TYPE_RESERVED);
+		pr_info("e820: update e820_table_firmware for e820__memblock_alloc_reserved()\n");
+		e820__update_table_firmware();
 	}
 
 	return addr;
@@ -779,22 +760,22 @@ u64 __init early_reserve_e820(u64 size, u64 align)
 /*
  * Find the highest page frame number we have available
  */
-static unsigned long __init e820_end_pfn(unsigned long limit_pfn, unsigned type)
+static unsigned long __init e820_end_pfn(unsigned long limit_pfn, enum e820_type type)
 {
 	int i;
 	unsigned long last_pfn = 0;
 	unsigned long max_arch_pfn = MAX_ARCH_PFN;
 
-	for (i = 0; i < e820->nr_map; i++) {
-		struct e820entry *ei = &e820->map[i];
+	for (i = 0; i < e820_table->nr_entries; i++) {
+		struct e820_entry *entry = &e820_table->entries[i];
 		unsigned long start_pfn;
 		unsigned long end_pfn;
 
-		if (ei->type != type)
+		if (entry->type != type)
 			continue;
 
-		start_pfn = ei->addr >> PAGE_SHIFT;
-		end_pfn = (ei->addr + ei->size) >> PAGE_SHIFT;
+		start_pfn = entry->addr >> PAGE_SHIFT;
+		end_pfn = (entry->addr + entry->size) >> PAGE_SHIFT;
 
 		if (start_pfn >= limit_pfn)
 			continue;
@@ -809,18 +790,19 @@ static unsigned long __init e820_end_pfn(unsigned long limit_pfn, unsigned type)
 	if (last_pfn > max_arch_pfn)
 		last_pfn = max_arch_pfn;
 
-	printk(KERN_INFO "e820: last_pfn = %#lx max_arch_pfn = %#lx\n",
+	pr_info("e820: last_pfn = %#lx max_arch_pfn = %#lx\n",
 			 last_pfn, max_arch_pfn);
 	return last_pfn;
 }
-unsigned long __init e820_end_of_ram_pfn(void)
+
+unsigned long __init e820__end_of_ram_pfn(void)
 {
-	return e820_end_pfn(MAX_ARCH_PFN, E820_RAM);
+	return e820_end_pfn(MAX_ARCH_PFN, E820_TYPE_RAM);
 }
 
-unsigned long __init e820_end_of_low_ram_pfn(void)
+unsigned long __init e820__end_of_low_ram_pfn(void)
 {
-	return e820_end_pfn(1UL << (32 - PAGE_SHIFT), E820_RAM);
+	return e820_end_pfn(1UL << (32 - PAGE_SHIFT), E820_TYPE_RAM);
 }
 
 static void __init early_panic(char *msg)
@@ -831,7 +813,7 @@ static void __init early_panic(char *msg)
 
 static int userdef __initdata;
 
-/* "mem=nopentium" disables the 4MB page tables. */
+/* The "mem=nopentium" boot option disables 4MB page tables on 32-bit kernels: */
 static int __init parse_memopt(char *p)
 {
 	u64 mem_size;
@@ -844,17 +826,19 @@ static int __init parse_memopt(char *p)
 		setup_clear_cpu_cap(X86_FEATURE_PSE);
 		return 0;
 #else
-		printk(KERN_WARNING "mem=nopentium ignored! (only supported on x86_32)\n");
+		pr_warn("mem=nopentium ignored! (only supported on x86_32)\n");
 		return -EINVAL;
 #endif
 	}
 
 	userdef = 1;
 	mem_size = memparse(p, &p);
-	/* don't remove all of memory when handling "mem={invalid}" param */
+
+	/* Don't remove all memory when getting "mem={invalid}" parameter: */
 	if (mem_size == 0)
 		return -EINVAL;
-	e820_remove_range(mem_size, ULLONG_MAX - mem_size, E820_RAM, 1);
+
+	e820__range_remove(mem_size, ULLONG_MAX - mem_size, E820_TYPE_RAM, 1);
 
 	return 0;
 }
@@ -872,12 +856,12 @@ static int __init parse_memmap_one(char *p)
 #ifdef CONFIG_CRASH_DUMP
 		/*
 		 * If we are doing a crash dump, we still need to know
-		 * the real mem size before original memory map is
+		 * the real memory size before the original memory map is
 		 * reset.
 		 */
-		saved_max_pfn = e820_end_of_ram_pfn();
+		saved_max_pfn = e820__end_of_ram_pfn();
 #endif
-		e820->nr_map = 0;
+		e820_table->nr_entries = 0;
 		userdef = 1;
 		return 0;
 	}
@@ -890,21 +874,23 @@ static int __init parse_memmap_one(char *p)
 	userdef = 1;
 	if (*p == '@') {
 		start_at = memparse(p+1, &p);
-		e820_add_region(start_at, mem_size, E820_RAM);
+		e820__range_add(start_at, mem_size, E820_TYPE_RAM);
 	} else if (*p == '#') {
 		start_at = memparse(p+1, &p);
-		e820_add_region(start_at, mem_size, E820_ACPI);
+		e820__range_add(start_at, mem_size, E820_TYPE_ACPI);
 	} else if (*p == '$') {
 		start_at = memparse(p+1, &p);
-		e820_add_region(start_at, mem_size, E820_RESERVED);
+		e820__range_add(start_at, mem_size, E820_TYPE_RESERVED);
 	} else if (*p == '!') {
 		start_at = memparse(p+1, &p);
-		e820_add_region(start_at, mem_size, E820_PRAM);
-	} else
-		e820_remove_range(mem_size, ULLONG_MAX - mem_size, E820_RAM, 1);
+		e820__range_add(start_at, mem_size, E820_TYPE_PRAM);
+	} else {
+		e820__range_remove(mem_size, ULLONG_MAX - mem_size, E820_TYPE_RAM, 1);
+	}
 
 	return *p == '\0' ? 0 : -EINVAL;
 }
+
 static int __init parse_memmap_opt(char *str)
 {
 	while (str) {
@@ -921,68 +907,97 @@ static int __init parse_memmap_opt(char *str)
 }
 early_param("memmap", parse_memmap_opt);
 
-void __init finish_e820_parsing(void)
+/*
+ * Reserve all entries from the bootloader's extensible data nodes list,
+ * because if present we are going to use it later on to fetch e820
+ * entries from it:
+ */
+void __init e820__reserve_setup_data(void)
+{
+	struct setup_data *data;
+	u64 pa_data;
+
+	pa_data = boot_params.hdr.setup_data;
+	if (!pa_data)
+		return;
+
+	while (pa_data) {
+		data = early_memremap(pa_data, sizeof(*data));
+		e820__range_update(pa_data, sizeof(*data)+data->len, E820_TYPE_RAM, E820_TYPE_RESERVED_KERN);
+		pa_data = data->next;
+		early_memunmap(data, sizeof(*data));
+	}
+
+	e820__update_table(e820_table);
+
+	memcpy(e820_table_firmware, e820_table, sizeof(*e820_table_firmware));
+
+	pr_info("extended physical RAM map:\n");
+	e820__print_table("reserve setup_data");
+}
+
+/*
+ * Called after parse_early_param(), after early parameters (such as mem=)
+ * have been processed, in which case we already have an E820 table filled in
+ * via the parameter callback function(s), but it's not sorted and printed yet:
+ */
+void __init e820__finish_early_params(void)
 {
 	if (userdef) {
-		if (sanitize_e820_map(e820->map, ARRAY_SIZE(e820->map),
-					&e820->nr_map) < 0)
+		if (e820__update_table(e820_table) < 0)
 			early_panic("Invalid user supplied memory map");
 
-		printk(KERN_INFO "e820: user-defined physical RAM map:\n");
-		e820_print_map("user");
+		pr_info("e820: user-defined physical RAM map:\n");
+		e820__print_table("user");
 	}
 }
 
-static const char *__init e820_type_to_string(int e820_type)
+static const char *__init e820_type_to_string(struct e820_entry *entry)
 {
-	switch (e820_type) {
-	case E820_RESERVED_KERN:
-	case E820_RAM:	return "System RAM";
-	case E820_ACPI:	return "ACPI Tables";
-	case E820_NVS:	return "ACPI Non-volatile Storage";
-	case E820_UNUSABLE:	return "Unusable memory";
-	case E820_PRAM: return "Persistent Memory (legacy)";
-	case E820_PMEM: return "Persistent Memory";
-	default:	return "reserved";
+	switch (entry->type) {
+	case E820_TYPE_RESERVED_KERN:	/* Fall-through: */
+	case E820_TYPE_RAM:		return "System RAM";
+	case E820_TYPE_ACPI:		return "ACPI Tables";
+	case E820_TYPE_NVS:		return "ACPI Non-volatile Storage";
+	case E820_TYPE_UNUSABLE:	return "Unusable memory";
+	case E820_TYPE_PRAM:		return "Persistent Memory (legacy)";
+	case E820_TYPE_PMEM:		return "Persistent Memory";
+	case E820_TYPE_RESERVED:	return "Reserved";
+	default:			return "Unknown E820 type";
 	}
 }
 
-static unsigned long __init e820_type_to_iomem_type(int e820_type)
+static unsigned long __init e820_type_to_iomem_type(struct e820_entry *entry)
 {
-	switch (e820_type) {
-	case E820_RESERVED_KERN:
-	case E820_RAM:
-		return IORESOURCE_SYSTEM_RAM;
-	case E820_ACPI:
-	case E820_NVS:
-	case E820_UNUSABLE:
-	case E820_PRAM:
-	case E820_PMEM:
-	default:
-		return IORESOURCE_MEM;
+	switch (entry->type) {
+	case E820_TYPE_RESERVED_KERN:	/* Fall-through: */
+	case E820_TYPE_RAM:		return IORESOURCE_SYSTEM_RAM;
+	case E820_TYPE_ACPI:		/* Fall-through: */
+	case E820_TYPE_NVS:		/* Fall-through: */
+	case E820_TYPE_UNUSABLE:	/* Fall-through: */
+	case E820_TYPE_PRAM:		/* Fall-through: */
+	case E820_TYPE_PMEM:		/* Fall-through: */
+	case E820_TYPE_RESERVED:	/* Fall-through: */
+	default:			return IORESOURCE_MEM;
 	}
 }
 
-static unsigned long __init e820_type_to_iores_desc(int e820_type)
+static unsigned long __init e820_type_to_iores_desc(struct e820_entry *entry)
 {
-	switch (e820_type) {
-	case E820_ACPI:
-		return IORES_DESC_ACPI_TABLES;
-	case E820_NVS:
-		return IORES_DESC_ACPI_NV_STORAGE;
-	case E820_PMEM:
-		return IORES_DESC_PERSISTENT_MEMORY;
-	case E820_PRAM:
-		return IORES_DESC_PERSISTENT_MEMORY_LEGACY;
-	case E820_RESERVED_KERN:
-	case E820_RAM:
-	case E820_UNUSABLE:
-	default:
-		return IORES_DESC_NONE;
+	switch (entry->type) {
+	case E820_TYPE_ACPI:		return IORES_DESC_ACPI_TABLES;
+	case E820_TYPE_NVS:		return IORES_DESC_ACPI_NV_STORAGE;
+	case E820_TYPE_PMEM:		return IORES_DESC_PERSISTENT_MEMORY;
+	case E820_TYPE_PRAM:		return IORES_DESC_PERSISTENT_MEMORY_LEGACY;
+	case E820_TYPE_RESERVED_KERN:	/* Fall-through: */
+	case E820_TYPE_RAM:		/* Fall-through: */
+	case E820_TYPE_UNUSABLE:	/* Fall-through: */
+	case E820_TYPE_RESERVED:	/* Fall-through: */
+	default:			return IORES_DESC_NONE;
 	}
 }
 
-static bool __init do_mark_busy(u32 type, struct resource *res)
+static bool __init do_mark_busy(enum e820_type type, struct resource *res)
 {
 	/* this is the legacy bios/dos rom-shadow + mmio region */
 	if (res->start < (1ULL<<20))
@@ -993,61 +1008,71 @@ static bool __init do_mark_busy(u32 type, struct resource *res)
 	 * for exclusive use of a driver
 	 */
 	switch (type) {
-	case E820_RESERVED:
-	case E820_PRAM:
-	case E820_PMEM:
+	case E820_TYPE_RESERVED:
+	case E820_TYPE_PRAM:
+	case E820_TYPE_PMEM:
 		return false;
+	case E820_TYPE_RESERVED_KERN:
+	case E820_TYPE_RAM:
+	case E820_TYPE_ACPI:
+	case E820_TYPE_NVS:
+	case E820_TYPE_UNUSABLE:
 	default:
 		return true;
 	}
 }
 
 /*
- * Mark e820 reserved areas as busy for the resource manager.
+ * Mark E820 reserved areas as busy for the resource manager:
  */
+
 static struct resource __initdata *e820_res;
-void __init e820_reserve_resources(void)
+
+void __init e820__reserve_resources(void)
 {
 	int i;
 	struct resource *res;
 	u64 end;
 
-	res = alloc_bootmem(sizeof(struct resource) * e820->nr_map);
+	res = alloc_bootmem(sizeof(*res) * e820_table->nr_entries);
 	e820_res = res;
-	for (i = 0; i < e820->nr_map; i++) {
-		end = e820->map[i].addr + e820->map[i].size - 1;
+
+	for (i = 0; i < e820_table->nr_entries; i++) {
+		struct e820_entry *entry = e820_table->entries + i;
+
+		end = entry->addr + entry->size - 1;
 		if (end != (resource_size_t)end) {
 			res++;
 			continue;
 		}
-		res->name = e820_type_to_string(e820->map[i].type);
-		res->start = e820->map[i].addr;
-		res->end = end;
-
-		res->flags = e820_type_to_iomem_type(e820->map[i].type);
-		res->desc = e820_type_to_iores_desc(e820->map[i].type);
+		res->start = entry->addr;
+		res->end   = end;
+		res->name  = e820_type_to_string(entry);
+		res->flags = e820_type_to_iomem_type(entry);
+		res->desc  = e820_type_to_iores_desc(entry);
 
 		/*
-		 * don't register the region that could be conflicted with
-		 * pci device BAR resource and insert them later in
-		 * pcibios_resource_survey()
+		 * Don't register the region that could be conflicted with
+		 * PCI device BAR resources and insert them later in
+		 * pcibios_resource_survey():
 		 */
-		if (do_mark_busy(e820->map[i].type, res)) {
+		if (do_mark_busy(entry->type, res)) {
 			res->flags |= IORESOURCE_BUSY;
 			insert_resource(&iomem_resource, res);
 		}
 		res++;
 	}
 
-	for (i = 0; i < e820_saved->nr_map; i++) {
-		struct e820entry *entry = &e820_saved->map[i];
-		firmware_map_add_early(entry->addr,
-			entry->addr + entry->size,
-			e820_type_to_string(entry->type));
+	for (i = 0; i < e820_table_firmware->nr_entries; i++) {
+		struct e820_entry *entry = e820_table_firmware->entries + i;
+
+		firmware_map_add_early(entry->addr, entry->addr + entry->size, e820_type_to_string(entry));
 	}
 }
 
-/* How much should we pad RAM ending depending on where it is? */
+/*
+ * How much should we pad the end of RAM, depending on where it is?
+ */
 static unsigned long __init ram_alignment(resource_size_t pos)
 {
 	unsigned long mb = pos >> 20;
@@ -1066,64 +1091,59 @@ static unsigned long __init ram_alignment(resource_size_t pos)
 
 #define MAX_RESOURCE_SIZE ((resource_size_t)-1)
 
-void __init e820_reserve_resources_late(void)
+void __init e820__reserve_resources_late(void)
 {
 	int i;
 	struct resource *res;
 
 	res = e820_res;
-	for (i = 0; i < e820->nr_map; i++) {
+	for (i = 0; i < e820_table->nr_entries; i++) {
 		if (!res->parent && res->end)
 			insert_resource_expand_to_fit(&iomem_resource, res);
 		res++;
 	}
 
 	/*
-	 * Try to bump up RAM regions to reasonable boundaries to
+	 * Try to bump up RAM regions to reasonable boundaries, to
 	 * avoid stolen RAM:
 	 */
-	for (i = 0; i < e820->nr_map; i++) {
-		struct e820entry *entry = &e820->map[i];
+	for (i = 0; i < e820_table->nr_entries; i++) {
+		struct e820_entry *entry = &e820_table->entries[i];
 		u64 start, end;
 
-		if (entry->type != E820_RAM)
+		if (entry->type != E820_TYPE_RAM)
 			continue;
+
 		start = entry->addr + entry->size;
 		end = round_up(start, ram_alignment(start)) - 1;
 		if (end > MAX_RESOURCE_SIZE)
 			end = MAX_RESOURCE_SIZE;
 		if (start >= end)
 			continue;
-		printk(KERN_DEBUG
-		       "e820: reserve RAM buffer [mem %#010llx-%#010llx]\n",
-		       start, end);
-		reserve_region_with_split(&iomem_resource, start, end,
-					  "RAM buffer");
+
+		printk(KERN_DEBUG "e820: reserve RAM buffer [mem %#010llx-%#010llx]\n", start, end);
+		reserve_region_with_split(&iomem_resource, start, end, "RAM buffer");
 	}
 }
 
-char *__init default_machine_specific_memory_setup(void)
+/*
+ * Pass the firmware (bootloader) E820 map to the kernel and process it:
+ */
+char *__init e820__memory_setup_default(void)
 {
 	char *who = "BIOS-e820";
-	u32 new_nr;
+
 	/*
 	 * Try to copy the BIOS-supplied E820-map.
 	 *
 	 * Otherwise fake a memory map; one section from 0k->640k,
 	 * the next section from 1mb->appropriate_mem_k
 	 */
-	new_nr = boot_params.e820_entries;
-	sanitize_e820_map(boot_params.e820_map,
-			ARRAY_SIZE(boot_params.e820_map),
-			&new_nr);
-	boot_params.e820_entries = new_nr;
-	if (append_e820_map(boot_params.e820_map, boot_params.e820_entries)
-	  < 0) {
+	if (append_e820_table(boot_params.e820_table, boot_params.e820_entries) < 0) {
 		u64 mem_size;
 
-		/* compare results from other methods and take the greater */
-		if (boot_params.alt_mem_k
-		    < boot_params.screen_info.ext_mem_k) {
+		/* Compare results from other methods and take the one that gives more RAM: */
+		if (boot_params.alt_mem_k < boot_params.screen_info.ext_mem_k) {
 			mem_size = boot_params.screen_info.ext_mem_k;
 			who = "BIOS-88";
 		} else {
@@ -1131,84 +1151,68 @@ char *__init default_machine_specific_memory_setup(void)
 			who = "BIOS-e801";
 		}
 
-		e820->nr_map = 0;
-		e820_add_region(0, LOWMEMSIZE(), E820_RAM);
-		e820_add_region(HIGH_MEMORY, mem_size << 10, E820_RAM);
+		e820_table->nr_entries = 0;
+		e820__range_add(0, LOWMEMSIZE(), E820_TYPE_RAM);
+		e820__range_add(HIGH_MEMORY, mem_size << 10, E820_TYPE_RAM);
 	}
 
-	/* In case someone cares... */
+	/* We just appended a lot of ranges, sanitize the table: */
+	e820__update_table(e820_table);
+
 	return who;
 }
 
-void __init setup_memory_map(void)
+/*
+ * Calls e820__memory_setup_default() in essence to pick up the firmware/bootloader
+ * E820 map - with an optional platform quirk available for virtual platforms
+ * to override this method of boot environment processing:
+ */
+void __init e820__memory_setup(void)
 {
 	char *who;
 
+	/* This is a firmware interface ABI - make sure we don't break it: */
+	BUILD_BUG_ON(sizeof(struct boot_e820_entry) != 20);
+
 	who = x86_init.resources.memory_setup();
-	memcpy(e820_saved, e820, sizeof(struct e820map));
-	printk(KERN_INFO "e820: BIOS-provided physical RAM map:\n");
-	e820_print_map(who);
+
+	memcpy(e820_table_firmware, e820_table, sizeof(*e820_table_firmware));
+
+	pr_info("e820: BIOS-provided physical RAM map:\n");
+	e820__print_table(who);
 }
 
-void __init memblock_x86_fill(void)
+void __init e820__memblock_setup(void)
 {
 	int i;
 	u64 end;
 
 	/*
-	 * EFI may have more than 128 entries
-	 * We are safe to enable resizing, beause memblock_x86_fill()
-	 * is rather later for x86
+	 * The bootstrap memblock region count maximum is 128 entries
+	 * (INIT_MEMBLOCK_REGIONS), but EFI might pass us more E820 entries
+	 * than that - so allow memblock resizing.
+	 *
+	 * This is safe, because this call happens pretty late during x86 setup,
+	 * so we know about reserved memory regions already. (This is important
+	 * so that memblock resizing does no stomp over reserved areas.)
 	 */
 	memblock_allow_resize();
 
-	for (i = 0; i < e820->nr_map; i++) {
-		struct e820entry *ei = &e820->map[i];
+	for (i = 0; i < e820_table->nr_entries; i++) {
+		struct e820_entry *entry = &e820_table->entries[i];
 
-		end = ei->addr + ei->size;
+		end = entry->addr + entry->size;
 		if (end != (resource_size_t)end)
 			continue;
 
-		if (ei->type != E820_RAM && ei->type != E820_RESERVED_KERN)
+		if (entry->type != E820_TYPE_RAM && entry->type != E820_TYPE_RESERVED_KERN)
 			continue;
 
-		memblock_add(ei->addr, ei->size);
+		memblock_add(entry->addr, entry->size);
 	}
 
-	/* throw away partial pages */
+	/* Throw away partial pages: */
 	memblock_trim_memory(PAGE_SIZE);
 
 	memblock_dump_all();
 }
-
-void __init memblock_find_dma_reserve(void)
-{
-#ifdef CONFIG_X86_64
-	u64 nr_pages = 0, nr_free_pages = 0;
-	unsigned long start_pfn, end_pfn;
-	phys_addr_t start, end;
-	int i;
-	u64 u;
-
-	/*
-	 * need to find out used area below MAX_DMA_PFN
-	 * need to use memblock to get free size in [0, MAX_DMA_PFN]
-	 * at first, and assume boot_mem will not take below MAX_DMA_PFN
-	 */
-	for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, NULL) {
-		start_pfn = min(start_pfn, MAX_DMA_PFN);
-		end_pfn = min(end_pfn, MAX_DMA_PFN);
-		nr_pages += end_pfn - start_pfn;
-	}
-
-	for_each_free_mem_range(u, NUMA_NO_NODE, MEMBLOCK_NONE, &start, &end,
-				NULL) {
-		start_pfn = min_t(unsigned long, PFN_UP(start), MAX_DMA_PFN);
-		end_pfn = min_t(unsigned long, PFN_DOWN(end), MAX_DMA_PFN);
-		if (start_pfn < end_pfn)
-			nr_free_pages += end_pfn - start_pfn;
-	}
-
-	set_dma_reserve(nr_pages - nr_free_pages);
-#endif
-}