Merge branch 'x86/mpparse' into x86/devel

Conflicts:

	arch/x86/Kconfig
	arch/x86/kernel/io_apic_32.c
	arch/x86/kernel/setup_64.c
	arch/x86/mm/init_32.c

Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 1105 insertions, 0 deletions

diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
new file mode 100644
index 000000000000..7b613d2efb04
--- /dev/null
+++ b/arch/x86/kernel/e820.c
@@ -0,0 +1,1105 @@
+/*
+ * Handle the memory map.
+ * The functions here do the job until bootmem takes over.
+ *
+ *  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>
+ *
+ */
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/bootmem.h>
+#include <linux/ioport.h>
+#include <linux/string.h>
+#include <linux/kexec.h>
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/pfn.h>
+#include <linux/suspend.h>
+
+#include <asm/pgtable.h>
+#include <asm/page.h>
+#include <asm/e820.h>
+#include <asm/proto.h>
+#include <asm/setup.h>
+#include <asm/trampoline.h>
+
+struct e820map e820;
+
+/* For PCI or other memory-mapped resources */
+unsigned long pci_mem_start = 0xaeedbabe;
+#ifdef CONFIG_PCI
+EXPORT_SYMBOL(pci_mem_start);
+#endif
+
+/*
+ * 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)
+{
+	int i;
+
+	for (i = 0; i < e820.nr_map; i++) {
+		struct e820entry *ei = &e820.map[i];
+
+		if (type && ei->type != type)
+			continue;
+		if (ei->addr >= end || ei->addr + ei->size <= start)
+			continue;
+		return 1;
+	}
+	return 0;
+}
+EXPORT_SYMBOL_GPL(e820_any_mapped);
+
+/*
+ * This function checks if the entire range <start,end> is mapped with type.
+ *
+ * Note: this function only works correct if the e820 table is sorted and
+ * not-overlapping, which is the case
+ */
+int __init e820_all_mapped(u64 start, u64 end, unsigned type)
+{
+	int i;
+
+	for (i = 0; i < e820.nr_map; i++) {
+		struct e820entry *ei = &e820.map[i];
+
+		if (type && ei->type != type)
+			continue;
+		/* is the region (part) in overlap with the current region ?*/
+		if (ei->addr >= end || ei->addr + ei->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 (ei->addr <= start)
+			start = ei->addr + ei->size;
+		/*
+		 * if start is now at or beyond end, we're done, full
+		 * coverage
+		 */
+		if (start >= end)
+			return 1;
+	}
+	return 0;
+}
+
+/*
+ * Add a memory region to the kernel e820 map.
+ */
+void __init e820_add_region(u64 start, u64 size, int type)
+{
+	int x = e820.nr_map;
+
+	if (x == ARRAY_SIZE(e820.map)) {
+		printk(KERN_ERR "Ooops! Too many entries in the memory map!\n");
+		return;
+	}
+
+	e820.map[x].addr = start;
+	e820.map[x].size = size;
+	e820.map[x].type = type;
+	e820.nr_map++;
+}
+
+void __init e820_print_map(char *who)
+{
+	int i;
+
+	for (i = 0; i < e820.nr_map; i++) {
+		printk(KERN_INFO " %s: %016Lx - %016Lx ", who,
+		       (unsigned long long) e820.map[i].addr,
+		       (unsigned long long)
+		       (e820.map[i].addr + e820.map[i].size));
+		switch (e820.map[i].type) {
+		case E820_RAM:
+			printk(KERN_CONT "(usable)\n");
+			break;
+		case E820_RESERVED:
+			printk(KERN_CONT "(reserved)\n");
+			break;
+		case E820_ACPI:
+			printk(KERN_CONT "(ACPI data)\n");
+			break;
+		case E820_NVS:
+			printk(KERN_CONT "(ACPI NVS)\n");
+			break;
+		default:
+			printk(KERN_CONT "type %u\n", e820.map[i].type);
+			break;
+		}
+	}
+}
+
+/*
+ * Sanitize the BIOS e820 map.
+ *
+ * Some e820 responses 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 integer pointed to by pnr_map must be valid on entry (the
+ * current number of valid entries located at biosmap) and will
+ * be updated on return, with the new number of valid entries
+ * (something no more than max_nr_map.)
+ *
+ * The return value from sanitize_e820_map() 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
+ * were invalid (start + size < start, meaning that the size was
+ * so big the described memory range wrapped around through zero.)
+ *
+ *	Visually we're performing the following
+ *	(1,2,3,4 = memory types)...
+ *
+ *	Sample memory map (w/overlaps):
+ *	   ____22__________________
+ *	   ______________________4_
+ *	   ____1111________________
+ *	   _44_____________________
+ *	   11111111________________
+ *	   ____________________33__
+ *	   ___________44___________
+ *	   __________33333_________
+ *	   ______________22________
+ *	   ___________________2222_
+ *	   _________111111111______
+ *	   _____________________11_
+ *	   _________________4______
+ *
+ *	Sanitized equivalent (no overlap):
+ *	   1_______________________
+ *	   _44_____________________
+ *	   ___1____________________
+ *	   ____22__________________
+ *	   ______11________________
+ *	   _________1______________
+ *	   __________3_____________
+ *	   ___________44___________
+ *	   _____________33_________
+ *	   _______________2________
+ *	   ________________1_______
+ *	   _________________4______
+ *	   ___________________2____
+ *	   ____________________33__
+ *	   ______________________4_
+ */
+
+int __init sanitize_e820_map(struct e820entry *biosmap, int max_nr_map,
+				int *pnr_map)
+{
+	struct change_member {
+		struct e820entry *pbios; /* pointer to original bios entry */
+		unsigned long long addr; /* address for this change point */
+	};
+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;
+	struct change_member *change_tmp;
+	unsigned long current_type, last_type;
+	unsigned long long last_addr;
+	int chgidx, still_changing;
+	int overlap_entries;
+	int new_bios_entry;
+	int old_nr, new_nr, chg_nr;
+	int i;
+
+	/* if there's only one memory region, don't bother */
+	if (*pnr_map < 2)
+		return -1;
+
+	old_nr = *pnr_map;
+	BUG_ON(old_nr > max_nr_map);
+
+	/* 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)
+			return -1;
+
+	/* create pointers for initial change-point information (for sorting) */
+	for (i = 0; i < 2 * old_nr; 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];
+		}
+	}
+	chg_nr = chgidx;
+
+	/* sort change-point list by memory addresses (low -> high) */
+	still_changing = 1;
+	while (still_changing)	{
+		still_changing = 0;
+		for (i = 1; i < chg_nr; i++)  {
+			unsigned long long curaddr, lastaddr;
+			unsigned long long curpbaddr, lastpbaddr;
+
+			curaddr = change_point[i]->addr;
+			lastaddr = change_point[i - 1]->addr;
+			curpbaddr = change_point[i]->pbios->addr;
+			lastpbaddr = change_point[i - 1]->pbios->addr;
+
+			/*
+			 * swap entries, when:
+			 *
+			 * curaddr > lastaddr or
+			 * curaddr == lastaddr and curaddr == curpbaddr and
+			 * lastaddr != lastpbaddr
+			 */
+			if (curaddr < lastaddr ||
+			    (curaddr == lastaddr && curaddr == curpbaddr &&
+			     lastaddr != lastpbaddr)) {
+				change_tmp = change_point[i];
+				change_point[i] = change_point[i-1];
+				change_point[i-1] = change_tmp;
+				still_changing = 1;
+			}
+		}
+	}
+
+	/* 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;
+		} else {
+			/*
+			 * 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];
+			}
+			overlap_entries--;
+		}
+		/*
+		 * 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++)
+			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)	{
+			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)
+						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;
+			}
+			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;
+
+	return 0;
+}
+
+static int __init __copy_e820_map(struct e820entry *biosmap, int nr_map)
+{
+	while (nr_map) {
+		u64 start = biosmap->addr;
+		u64 size = biosmap->size;
+		u64 end = start + size;
+		u32 type = biosmap->type;
+
+		/* Overflow in 64 bits? Ignore the memory map. */
+		if (start > end)
+			return -1;
+
+		e820_add_region(start, size, type);
+
+		biosmap++;
+		nr_map--;
+	}
+	return 0;
+}
+
+/*
+ * Copy the BIOS e820 map into a safe place.
+ *
+ * Sanity-check it while we're at it..
+ *
+ * If we're lucky and live on a modern system, the setup code
+ * 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.
+ */
+int __init copy_e820_map(struct e820entry *biosmap, int nr_map)
+{
+	/* Only one memory region (or negative)? Ignore it */
+	if (nr_map < 2)
+		return -1;
+
+	return __copy_e820_map(biosmap, nr_map);
+}
+
+u64 __init e820_update_range(u64 start, u64 size, unsigned old_type,
+				unsigned new_type)
+{
+	int i;
+	u64 real_updated_size = 0;
+
+	BUG_ON(old_type == new_type);
+
+	for (i = 0; i < e820.nr_map; i++) {
+		struct e820entry *ei = &e820.map[i];
+		u64 final_start, final_end;
+		if (ei->type != old_type)
+			continue;
+		/* totally covered? */
+		if (ei->addr >= start &&
+		    (ei->addr + ei->size) <= (start + size)) {
+			ei->type = new_type;
+			real_updated_size += ei->size;
+			continue;
+		}
+		/* partially covered */
+		final_start = max(start, ei->addr);
+		final_end = min(start + size, ei->addr + ei->size);
+		if (final_start >= final_end)
+			continue;
+		e820_add_region(final_start, final_end - final_start,
+					 new_type);
+		real_updated_size += final_end - final_start;
+	}
+	return real_updated_size;
+}
+
+void __init update_e820(void)
+{
+	int nr_map;
+
+	nr_map = e820.nr_map;
+	if (sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &nr_map))
+		return;
+	e820.nr_map = nr_map;
+	printk(KERN_INFO "modified physical RAM map:\n");
+	e820_print_map("modified");
+}
+
+/*
+ * 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.
+ * Hopefully the BIOS let enough space left.
+ */
+__init void e820_setup_gap(void)
+{
+	unsigned long gapstart, gapsize, round;
+	unsigned long long last;
+	int i;
+	int found = 0;
+
+	last = 0x100000000ull;
+	gapstart = 0x10000000;
+	gapsize = 0x400000;
+	i = e820.nr_map;
+	while (--i >= 0) {
+		unsigned long long start = e820.map[i].addr;
+		unsigned long long end = start + e820.map[i].size;
+
+		/*
+		 * Since "last" is at most 4GB, we know we'll
+		 * fit in 32 bits if this condition is true
+		 */
+		if (last > end) {
+			unsigned long gap = last - end;
+
+			if (gap > gapsize) {
+				gapsize = gap;
+				gapstart = end;
+				found = 1;
+			}
+		}
+		if (start < last)
+			last = start;
+	}
+
+#ifdef CONFIG_X86_64
+	if (!found) {
+		gapstart = (end_pfn << PAGE_SHIFT) + 1024*1024;
+		printk(KERN_ERR "PCI: Warning: Cannot find a gap in the 32bit "
+		       "address range\n"
+		       KERN_ERR "PCI: Unassigned devices with 32bit resource "
+		       "registers may break!\n");
+	}
+#endif
+
+	/*
+	 * See how much we want to round up: start off with
+	 * rounding to the next 1MB area.
+	 */
+	round = 0x100000;
+	while ((gapsize >> 4) > round)
+		round += round;
+	/* Fun with two's complement */
+	pci_mem_start = (gapstart + round) & -round;
+
+	printk(KERN_INFO
+	       "Allocating PCI resources starting at %lx (gap: %lx:%lx)\n",
+	       pci_mem_start, gapstart, gapsize);
+}
+
+/**
+ * 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.
+ */
+void __init parse_e820_ext(struct setup_data *sdata, unsigned long pa_data)
+{
+	u32 map_len;
+	int entries;
+	struct e820entry *extmap;
+
+	entries = sdata->len / sizeof(struct e820entry);
+	map_len = sdata->len + sizeof(struct setup_data);
+	if (map_len > PAGE_SIZE)
+		sdata = early_ioremap(pa_data, map_len);
+	extmap = (struct e820entry *)(sdata->data);
+	__copy_e820_map(extmap, entries);
+	sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
+	if (map_len > PAGE_SIZE)
+		early_iounmap(sdata, map_len);
+	printk(KERN_INFO "extended physical RAM map:\n");
+	e820_print_map("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).
+ *
+ * This function requires the e820 map to be sorted and without any
+ * overlapping entries and assumes the first e820 area to be RAM.
+ */
+void __init e820_mark_nosave_regions(unsigned long limit_pfn)
+{
+	int i;
+	unsigned long pfn;
+
+	pfn = PFN_DOWN(e820.map[0].addr + e820.map[0].size);
+	for (i = 1; i < e820.nr_map; i++) {
+		struct e820entry *ei = &e820.map[i];
+
+		if (pfn < PFN_UP(ei->addr))
+			register_nosave_region(pfn, PFN_UP(ei->addr));
+
+		pfn = PFN_DOWN(ei->addr + ei->size);
+		if (ei->type != E820_RAM)
+			register_nosave_region(PFN_UP(ei->addr), pfn);
+
+		if (pfn >= limit_pfn)
+			break;
+	}
+}
+#endif
+
+/*
+ * Early reserved memory areas.
+ */
+#define MAX_EARLY_RES 20
+
+struct early_res {
+	u64 start, end;
+	char name[16];
+};
+static struct early_res early_res[MAX_EARLY_RES] __initdata = {
+	{ 0, PAGE_SIZE, "BIOS data page" },	/* BIOS data page */
+#if defined(CONFIG_X86_64) && defined(CONFIG_X86_TRAMPOLINE)
+	{ TRAMPOLINE_BASE, TRAMPOLINE_BASE + 2 * PAGE_SIZE, "TRAMPOLINE" },
+#endif
+#if defined(CONFIG_X86_32) && defined(CONFIG_SMP)
+	/*
+	 * But first pinch a few for the stack/trampoline stuff
+	 * FIXME: Don't need the extra page at 4K, but need to fix
+	 * trampoline before removing it. (see the GDT stuff)
+	 */
+	{ PAGE_SIZE, PAGE_SIZE + PAGE_SIZE, "EX TRAMPOLINE" },
+	/*
+	 * Has to be in very low memory so we can execute
+	 * real-mode AP code.
+	 */
+	{ TRAMPOLINE_BASE, TRAMPOLINE_BASE + PAGE_SIZE, "TRAMPOLINE" },
+#endif
+	{}
+};
+
+static int __init find_overlapped_early(u64 start, u64 end)
+{
+	int i;
+	struct early_res *r;
+
+	for (i = 0; i < MAX_EARLY_RES && early_res[i].end; i++) {
+		r = &early_res[i];
+		if (end > r->start && start < r->end)
+			break;
+	}
+
+	return i;
+}
+
+void __init reserve_early(u64 start, u64 end, char *name)
+{
+	int i;
+	struct early_res *r;
+
+	i = find_overlapped_early(start, end);
+	if (i >= MAX_EARLY_RES)
+		panic("Too many early reservations");
+	r = &early_res[i];
+	if (r->end)
+		panic("Overlapping early reservations "
+		      "%llx-%llx %s to %llx-%llx %s\n",
+		      start, end - 1, name?name:"", r->start,
+		      r->end - 1, r->name);
+	r->start = start;
+	r->end = end;
+	if (name)
+		strncpy(r->name, name, sizeof(r->name) - 1);
+}
+
+void __init free_early(u64 start, u64 end)
+{
+	struct early_res *r;
+	int i, j;
+
+	i = find_overlapped_early(start, end);
+	r = &early_res[i];
+	if (i >= MAX_EARLY_RES || r->end != end || r->start != start)
+		panic("free_early on not reserved area: %llx-%llx!",
+			 start, end - 1);
+
+	for (j = i + 1; j < MAX_EARLY_RES && early_res[j].end; j++)
+		;
+
+	memmove(&early_res[i], &early_res[i + 1],
+	       (j - 1 - i) * sizeof(struct early_res));
+
+	early_res[j - 1].end = 0;
+}
+
+void __init early_res_to_bootmem(u64 start, u64 end)
+{
+	int i;
+	u64 final_start, final_end;
+	for (i = 0; i < MAX_EARLY_RES && early_res[i].end; i++) {
+		struct early_res *r = &early_res[i];
+		final_start = max(start, r->start);
+		final_end = min(end, r->end);
+		if (final_start >= final_end)
+			continue;
+		printk(KERN_INFO "  early res: %d [%llx-%llx] %s\n", i,
+			final_start, final_end - 1, r->name);
+		reserve_bootmem_generic(final_start, final_end - final_start,
+				BOOTMEM_DEFAULT);
+	}
+}
+
+/* Check for already reserved areas */
+static inline int __init bad_addr(u64 *addrp, u64 size, u64 align)
+{
+	int i;
+	u64 addr = *addrp;
+	int changed = 0;
+	struct early_res *r;
+again:
+	i = find_overlapped_early(addr, addr + size);
+	r = &early_res[i];
+	if (i < MAX_EARLY_RES && r->end) {
+		*addrp = addr = round_up(r->end, align);
+		changed = 1;
+		goto again;
+	}
+	return changed;
+}
+
+/* Check for already reserved areas */
+static inline int __init bad_addr_size(u64 *addrp, u64 *sizep, u64 align)
+{
+	int i;
+	u64 addr = *addrp, last;
+	u64 size = *sizep;
+	int changed = 0;
+again:
+	last = addr + size;
+	for (i = 0; i < MAX_EARLY_RES && early_res[i].end; i++) {
+		struct early_res *r = &early_res[i];
+		if (last > r->start && addr < r->start) {
+			size = r->start - addr;
+			changed = 1;
+			goto again;
+		}
+		if (last > r->end && addr < r->end) {
+			addr = round_up(r->end, align);
+			size = last - addr;
+			changed = 1;
+			goto again;
+		}
+		if (last <= r->end && addr >= r->start) {
+			(*sizep)++;
+			return 0;
+		}
+	}
+	if (changed) {
+		*addrp = addr;
+		*sizep = size;
+	}
+	return changed;
+}
+
+/*
+ * Find a free area with specified alignment in a specific range.
+ */
+u64 __init find_e820_area(u64 start, u64 end, u64 size, u64 align)
+{
+	int i;
+
+	for (i = 0; i < e820.nr_map; i++) {
+		struct e820entry *ei = &e820.map[i];
+		u64 addr, last;
+		u64 ei_last;
+
+		if (ei->type != E820_RAM)
+			continue;
+		addr = round_up(ei->addr, align);
+		ei_last = ei->addr + ei->size;
+		if (addr < start)
+			addr = round_up(start, align);
+		if (addr >= ei_last)
+			continue;
+		while (bad_addr(&addr, size, align) && addr+size <= ei_last)
+			;
+		last = addr + size;
+		if (last > ei_last)
+			continue;
+		if (last > end)
+			continue;
+		return addr;
+	}
+	return -1ULL;
+}
+
+/*
+ * Find next free range after *start
+ */
+u64 __init find_e820_area_size(u64 start, u64 *sizep, u64 align)
+{
+	int i;
+
+	for (i = 0; i < e820.nr_map; i++) {
+		struct e820entry *ei = &e820.map[i];
+		u64 addr, last;
+		u64 ei_last;
+
+		if (ei->type != E820_RAM)
+			continue;
+		addr = round_up(ei->addr, align);
+		ei_last = ei->addr + ei->size;
+		if (addr < start)
+			addr = round_up(start, align);
+		if (addr >= ei_last)
+			continue;
+		*sizep = ei_last - addr;
+		while (bad_addr_size(&addr, sizep, align) &&
+			addr + *sizep <= ei_last)
+			;
+		last = addr + *sizep;
+		if (last > ei_last)
+			continue;
+		return addr;
+	}
+	return -1UL;
+
+}
+
+/*
+ * pre allocated 4k and reserved it in e820
+ */
+u64 __init early_reserve_e820(u64 startt, u64 sizet, u64 align)
+{
+	u64 size = 0;
+	u64 addr;
+	u64 start;
+
+	start = startt;
+	while (size < sizet)
+		start = find_e820_area_size(start, &size, align);
+
+	if (size < sizet)
+		return 0;
+
+	addr = round_down(start + size - sizet, align);
+	e820_update_range(addr, sizet, E820_RAM, E820_RESERVED);
+	printk(KERN_INFO "update e820 for early_reserve_e820\n");
+	update_e820();
+
+	return addr;
+}
+
+#ifdef CONFIG_X86_32
+# ifdef CONFIG_X86_PAE
+#  define MAX_ARCH_PFN		(1ULL<<(36-PAGE_SHIFT))
+# else
+#  define MAX_ARCH_PFN		(1ULL<<(32-PAGE_SHIFT))
+# endif
+#else /* CONFIG_X86_32 */
+# define MAX_ARCH_PFN MAXMEM>>PAGE_SHIFT
+#endif
+
+/*
+ * Last pfn which the user wants to use.
+ */
+unsigned long __initdata end_user_pfn = MAX_ARCH_PFN;
+
+/*
+ * Find the highest page frame number we have available
+ */
+unsigned long __init e820_end_of_ram(void)
+{
+	unsigned long last_pfn;
+	unsigned long max_arch_pfn = MAX_ARCH_PFN;
+
+	last_pfn = find_max_pfn_with_active_regions();
+
+	if (last_pfn > max_arch_pfn)
+		last_pfn = max_arch_pfn;
+	if (last_pfn > end_user_pfn)
+		last_pfn = end_user_pfn;
+
+	printk(KERN_INFO "last_pfn = %lu max_arch_pfn = %lu\n",
+			 last_pfn, max_arch_pfn);
+	return last_pfn;
+}
+
+/*
+ * Finds an active region in the address range from start_pfn to last_pfn and
+ * returns its range in ei_startpfn and ei_endpfn for the e820 entry.
+ */
+int __init e820_find_active_region(const struct e820entry *ei,
+				  unsigned long start_pfn,
+				  unsigned long last_pfn,
+				  unsigned long *ei_startpfn,
+				  unsigned long *ei_endpfn)
+{
+	u64 align = PAGE_SIZE;
+
+	*ei_startpfn = round_up(ei->addr, align) >> PAGE_SHIFT;
+	*ei_endpfn = round_down(ei->addr + ei->size, align) >> PAGE_SHIFT;
+
+	/* Skip map entries smaller than a page */
+	if (*ei_startpfn >= *ei_endpfn)
+		return 0;
+
+	/* Skip if map is outside the node */
+	if (ei->type != E820_RAM || *ei_endpfn <= start_pfn ||
+				    *ei_startpfn >= last_pfn)
+		return 0;
+
+	/* Check for overlaps */
+	if (*ei_startpfn < start_pfn)
+		*ei_startpfn = start_pfn;
+	if (*ei_endpfn > last_pfn)
+		*ei_endpfn = last_pfn;
+
+	/* Obey end_user_pfn to save on memmap */
+	if (*ei_startpfn >= end_user_pfn)
+		return 0;
+	if (*ei_endpfn > end_user_pfn)
+		*ei_endpfn = end_user_pfn;
+
+	return 1;
+}
+
+/* Walk the e820 map and register active regions within a node */
+void __init e820_register_active_regions(int nid, unsigned long start_pfn,
+					 unsigned long last_pfn)
+{
+	unsigned long ei_startpfn;
+	unsigned long ei_endpfn;
+	int i;
+
+	for (i = 0; i < e820.nr_map; i++)
+		if (e820_find_active_region(&e820.map[i],
+					    start_pfn, last_pfn,
+					    &ei_startpfn, &ei_endpfn))
+			add_active_range(nid, ei_startpfn, ei_endpfn);
+}
+
+/*
+ * Find the hole size (in bytes) in the memory range.
+ * @start: starting address of the memory range to scan
+ * @end: ending address of the memory range to scan
+ */
+u64 __init e820_hole_size(u64 start, u64 end)
+{
+	unsigned long start_pfn = start >> PAGE_SHIFT;
+	unsigned long last_pfn = end >> PAGE_SHIFT;
+	unsigned long ei_startpfn, ei_endpfn, ram = 0;
+	int i;
+
+	for (i = 0; i < e820.nr_map; i++) {
+		if (e820_find_active_region(&e820.map[i],
+					    start_pfn, last_pfn,
+					    &ei_startpfn, &ei_endpfn))
+			ram += ei_endpfn - ei_startpfn;
+	}
+	return end - start - ((u64)ram << PAGE_SHIFT);
+}
+
+static void early_panic(char *msg)
+{
+	early_printk(msg);
+	panic(msg);
+}
+
+/* "mem=nopentium" disables the 4MB page tables. */
+static int __init parse_memopt(char *p)
+{
+	u64 mem_size;
+
+	if (!p)
+		return -EINVAL;
+
+#ifdef CONFIG_X86_32
+	if (!strcmp(p, "nopentium")) {
+		setup_clear_cpu_cap(X86_FEATURE_PSE);
+		return 0;
+	}
+#endif
+
+	mem_size = memparse(p, &p);
+	end_user_pfn = mem_size>>PAGE_SHIFT;
+	return 0;
+}
+early_param("mem", parse_memopt);
+
+static int userdef __initdata;
+
+static int __init parse_memmap_opt(char *p)
+{
+	char *oldp;
+	u64 start_at, mem_size;
+
+	if (!strcmp(p, "exactmap")) {
+#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
+		 * reset.
+		 */
+		e820_register_active_regions(0, 0, -1UL);
+		saved_max_pfn = e820_end_of_ram();
+		remove_all_active_ranges();
+#endif
+		e820.nr_map = 0;
+		userdef = 1;
+		return 0;
+	}
+
+	oldp = p;
+	mem_size = memparse(p, &p);
+	if (p == oldp)
+		return -EINVAL;
+
+	userdef = 1;
+	if (*p == '@') {
+		start_at = memparse(p+1, &p);
+		e820_add_region(start_at, mem_size, E820_RAM);
+	} else if (*p == '#') {
+		start_at = memparse(p+1, &p);
+		e820_add_region(start_at, mem_size, E820_ACPI);
+	} else if (*p == '$') {
+		start_at = memparse(p+1, &p);
+		e820_add_region(start_at, mem_size, E820_RESERVED);
+	} else {
+		end_user_pfn = (mem_size >> PAGE_SHIFT);
+	}
+	return *p == '\0' ? 0 : -EINVAL;
+}
+early_param("memmap", parse_memmap_opt);
+
+void __init finish_e820_parsing(void)
+{
+	if (userdef) {
+		int nr = e820.nr_map;
+
+		if (sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &nr) < 0)
+			early_panic("Invalid user supplied memory map");
+		e820.nr_map = nr;
+
+		printk(KERN_INFO "user-defined physical RAM map:\n");
+		e820_print_map("user");
+	}
+}
+
+/*
+ * Mark e820 reserved areas as busy for the resource manager.
+ */
+void __init e820_reserve_resources(void)
+{
+	int i;
+	struct resource *res;
+
+	res = alloc_bootmem_low(sizeof(struct resource) * e820.nr_map);
+	for (i = 0; i < e820.nr_map; i++) {
+		switch (e820.map[i].type) {
+		case E820_RAM:	res->name = "System RAM"; break;
+		case E820_ACPI:	res->name = "ACPI Tables"; break;
+		case E820_NVS:	res->name = "ACPI Non-volatile Storage"; break;
+		default:	res->name = "reserved";
+		}
+		res->start = e820.map[i].addr;
+		res->end = res->start + e820.map[i].size - 1;
+#ifndef CONFIG_RESOURCES_64BIT
+		if (res->end > 0x100000000ULL) {
+			res++;
+			continue;
+		}
+#endif
+		res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
+		insert_resource(&iomem_resource, res);
+		res++;
+	}
+}
+
+char *__init default_machine_specific_memory_setup(void)
+{
+	char *who = "BIOS-e820";
+	int 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 (copy_e820_map(boot_params.e820_map, 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) {
+			mem_size = boot_params.screen_info.ext_mem_k;
+			who = "BIOS-88";
+		} else {
+			mem_size = boot_params.alt_mem_k;
+			who = "BIOS-e801";
+		}
+
+		e820.nr_map = 0;
+		e820_add_region(0, LOWMEMSIZE(), E820_RAM);
+		e820_add_region(HIGH_MEMORY, mem_size << 10, E820_RAM);
+	}
+
+	/* In case someone cares... */
+	return who;
+}
+
+char *__init __attribute__((weak)) machine_specific_memory_setup(void)
+{
+	return default_machine_specific_memory_setup();
+}
+
+/* Overridden in paravirt.c if CONFIG_PARAVIRT */
+char * __init __attribute__((weak)) memory_setup(void)
+{
+	return machine_specific_memory_setup();
+}
+
+void __init setup_memory_map(void)
+{
+	printk(KERN_INFO "BIOS-provided physical RAM map:\n");
+	e820_print_map(memory_setup());
+}
+
+#ifdef CONFIG_X86_64
+int __init arch_get_ram_range(int slot, u64 *addr, u64 *size)
+{
+	int i;
+
+	if (slot < 0 || slot >= e820.nr_map)
+		return -1;
+	for (i = slot; i < e820.nr_map; i++) {
+		if (e820.map[i].type != E820_RAM)
+			continue;
+		break;
+	}
+	if (i == e820.nr_map || e820.map[i].addr > (max_pfn << PAGE_SHIFT))
+		return -1;
+	*addr = e820.map[i].addr;
+	*size = min_t(u64, e820.map[i].size + e820.map[i].addr,
+		max_pfn << PAGE_SHIFT) - *addr;
+	return i + 1;
+}
+#endif