e820.c 32.5 KB
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/*
 * 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>
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#include <linux/suspend.h>
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#include <asm/pgtable.h>
#include <asm/page.h>
#include <asm/e820.h>
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#include <asm/proto.h>
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#include <asm/setup.h>
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#include <asm/trampoline.h>
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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.
 */
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void __init e820_add_region(u64 start, u64 size, int type)
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{
	int x = e820.nr_map;

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	if (x == ARRAY_SIZE(e820.map)) {
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		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
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 * replaces the original e820 map with a new one, removing overlaps,
 * and resolving conflicting memory types in favor of highest
 * numbered type.
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 *
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 * 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_
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 */
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int __init sanitize_e820_map(struct e820entry *biosmap, int max_nr_map,
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				int *pnr_map)
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{
	struct change_member {
		struct e820entry *pbios; /* pointer to original bios entry */
		unsigned long long addr; /* address for this change point */
	};
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	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;
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	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;
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	BUG_ON(old_nr > max_nr_map);
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	/* 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 ?
					 */
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					if (++new_bios_entry >= max_nr_map)
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						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;
}

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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;
}

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/*
 * 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;

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	return __copy_e820_map(biosmap, nr_map);
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}

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u64 __init e820_update_range(u64 start, u64 size, unsigned old_type,
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				unsigned new_type)
{
	int i;
	u64 real_updated_size = 0;

	BUG_ON(old_type == new_type);

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	if (size > (ULLONG_MAX - start))
		size = ULLONG_MAX - start;

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	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;
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		e820_add_region(final_start, final_end - final_start,
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					 new_type);
		real_updated_size += final_end - final_start;
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		ei->size -= final_end - final_start;
		if (ei->addr < final_start)
			continue;
		ei->addr = final_end;
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	}
	return real_updated_size;
}

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/* make e820 not cover the range */
u64 __init e820_remove_range(u64 start, u64 size, unsigned old_type,
			     int checktype)
{
	int i;
	u64 real_removed_size = 0;

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	if (size > (ULLONG_MAX - start))
		size = ULLONG_MAX - start;

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	for (i = 0; i < e820.nr_map; i++) {
		struct e820entry *ei = &e820.map[i];
		u64 final_start, final_end;

		if (checktype && ei->type != old_type)
			continue;
		/* totally covered? */
		if (ei->addr >= start &&
		    (ei->addr + ei->size) <= (start + size)) {
			real_removed_size += ei->size;
			memset(ei, 0, sizeof(struct e820entry));
			continue;
		}
		/* partially covered */
		final_start = max(start, ei->addr);
		final_end = min(start + size, ei->addr + ei->size);
		if (final_start >= final_end)
			continue;
		real_removed_size += final_end - final_start;

		ei->size -= final_end - final_start;
		if (ei->addr < final_start)
			continue;
		ei->addr = final_end;
	}
	return real_removed_size;
}

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void __init update_e820(void)
{
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	int nr_map;
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	nr_map = e820.nr_map;
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	if (sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &nr_map))
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		return;
	e820.nr_map = nr_map;
	printk(KERN_INFO "modified physical RAM map:\n");
	e820_print_map("modified");
}

/*
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 * Search for a gap in the e820 memory space from start_addr to 2^32.
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 */
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__init int e820_search_gap(unsigned long *gapstart, unsigned long *gapsize,
		unsigned long start_addr)
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{
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	unsigned long long last = 0x100000000ull;
	int i = e820.nr_map;
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	int found = 0;

	while (--i >= 0) {
		unsigned long long start = e820.map[i].addr;
		unsigned long long end = start + e820.map[i].size;

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		if (end < start_addr)
			continue;

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		/*
		 * 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;

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			if (gap >= *gapsize) {
				*gapsize = gap;
				*gapstart = end;
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				found = 1;
			}
		}
		if (start < last)
			last = start;
	}
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	return found;
}

/*
 * 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;
	int found;

	gapstart = 0x10000000;
	gapsize = 0x400000;
	found  = e820_search_gap(&gapstart, &gapsize, 0);
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#ifdef CONFIG_X86_64
	if (!found) {
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		gapstart = (max_pfn << PAGE_SHIFT) + 1024*1024;
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		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);
}

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/**
 * 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");
}

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#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
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/*
 * Early reserved memory areas.
 */
#define MAX_EARLY_RES 20

struct early_res {
	u64 start, end;
	char name[16];
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	char overlap_ok;
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};
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
	{}
};

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static int __init find_overlapped_early(u64 start, u64 end)
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{
	int i;
	struct early_res *r;
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	for (i = 0; i < MAX_EARLY_RES && early_res[i].end; i++) {
		r = &early_res[i];
		if (end > r->start && start < r->end)
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			break;
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	}
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	return i;
}

668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754
/*
 * Drop the i-th range from the early reservation map,
 * by copying any higher ranges down one over it, and
 * clearing what had been the last slot.
 */
static void __init drop_range(int i)
{
	int j;

	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;
}

/*
 * Split any existing ranges that:
 *  1) are marked 'overlap_ok', and
 *  2) overlap with the stated range [start, end)
 * into whatever portion (if any) of the existing range is entirely
 * below or entirely above the stated range.  Drop the portion
 * of the existing range that overlaps with the stated range,
 * which will allow the caller of this routine to then add that
 * stated range without conflicting with any existing range.
 */
static void __init drop_overlaps_that_are_ok(u64 start, u64 end)
{
	int i;
	struct early_res *r;
	u64 lower_start, lower_end;
	u64 upper_start, upper_end;
	char name[16];

	for (i = 0; i < MAX_EARLY_RES && early_res[i].end; i++) {
		r = &early_res[i];

		/* Continue past non-overlapping ranges */
		if (end <= r->start || start >= r->end)
			continue;

		/*
		 * Leave non-ok overlaps as is; let caller
		 * panic "Overlapping early reservations"
		 * when it hits this overlap.
		 */
		if (!r->overlap_ok)
			return;

		/*
		 * We have an ok overlap.  We will drop it from the early
		 * reservation map, and add back in any non-overlapping
		 * portions (lower or upper) as separate, overlap_ok,
		 * non-overlapping ranges.
		 */

		/* 1. Note any non-overlapping (lower or upper) ranges. */
		strncpy(name, r->name, sizeof(name) - 1);

		lower_start = lower_end = 0;
		upper_start = upper_end = 0;
		if (r->start < start) {
		 	lower_start = r->start;
			lower_end = start;
		}
		if (r->end > end) {
			upper_start = end;
			upper_end = r->end;
		}

		/* 2. Drop the original ok overlapping range */
		drop_range(i);

		i--;		/* resume for-loop on copied down entry */

		/* 3. Add back in any non-overlapping ranges. */
		if (lower_end)
			reserve_early_overlap_ok(lower_start, lower_end, name);
		if (upper_end)
			reserve_early_overlap_ok(upper_start, upper_end, name);
	}
}

static void __init __reserve_early(u64 start, u64 end, char *name,
						int overlap_ok)
755 756 757 758 759
{
	int i;
	struct early_res *r;

	i = find_overlapped_early(start, end);
760 761 762
	if (i >= MAX_EARLY_RES)
		panic("Too many early reservations");
	r = &early_res[i];
763 764 765 766 767
	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);
768 769
	r->start = start;
	r->end = end;
770
	r->overlap_ok = overlap_ok;
771 772 773 774
	if (name)
		strncpy(r->name, name, sizeof(r->name) - 1);
}

775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814
/*
 * A few early reservtations come here.
 *
 * The 'overlap_ok' in the name of this routine does -not- mean it
 * is ok for these reservations to overlap an earlier reservation.
 * Rather it means that it is ok for subsequent reservations to
 * overlap this one.
 *
 * Use this entry point to reserve early ranges when you are doing
 * so out of "Paranoia", reserving perhaps more memory than you need,
 * just in case, and don't mind a subsequent overlapping reservation
 * that is known to be needed.
 *
 * The drop_overlaps_that_are_ok() call here isn't really needed.
 * It would be needed if we had two colliding 'overlap_ok'
 * reservations, so that the second such would not panic on the
 * overlap with the first.  We don't have any such as of this
 * writing, but might as well tolerate such if it happens in
 * the future.
 */
void __init reserve_early_overlap_ok(u64 start, u64 end, char *name)
{
	drop_overlaps_that_are_ok(start, end);
	__reserve_early(start, end, name, 1);
}

/*
 * Most early reservations come here.
 *
 * We first have drop_overlaps_that_are_ok() drop any pre-existing
 * 'overlap_ok' ranges, so that we can then reserve this memory
 * range without risk of panic'ing on an overlapping overlap_ok
 * early reservation.
 */
void __init reserve_early(u64 start, u64 end, char *name)
{
	drop_overlaps_that_are_ok(start, end);
	__reserve_early(start, end, name, 0);
}

815 816 817
void __init free_early(u64 start, u64 end)
{
	struct early_res *r;
818
	int i;
819

820 821 822
	i = find_overlapped_early(start, end);
	r = &early_res[i];
	if (i >= MAX_EARLY_RES || r->end != end || r->start != start)
823
		panic("free_early on not reserved area: %llx-%llx!",
824
			 start, end - 1);
825

826
	drop_range(i);
827 828 829 830
}

void __init early_res_to_bootmem(u64 start, u64 end)
{
831
	int i, count;
832
	u64 final_start, final_end;
833 834 835 836 837 838 839

	count  = 0;
	for (i = 0; i < MAX_EARLY_RES && early_res[i].end; i++)
		count++;

	printk(KERN_INFO "(%d early reservations) ==> bootmem\n", count);
	for (i = 0; i < count; i++) {
840
		struct early_res *r = &early_res[i];
841 842
		printk(KERN_INFO "  #%d [ %010llx - %010llx ] %16s", i,
			r->start, r->end, r->name);
843 844
		final_start = max(start, r->start);
		final_end = min(end, r->end);
845 846
		if (final_start >= final_end) {
			printk(KERN_CONT "\n");
847
			continue;
848 849 850
		}
		printk(KERN_CONT " ===> [ %010llx - %010llx ]\n",
			final_start, final_end);
851
		reserve_bootmem_generic(final_start, final_end - final_start,
852 853 854 855 856 857 858 859
				BOOTMEM_DEFAULT);
	}
}

/* Check for already reserved areas */
static inline int __init bad_addr(u64 *addrp, u64 size, u64 align)
{
	int i;
860
	u64 addr = *addrp;
861
	int changed = 0;
862
	struct early_res *r;
863
again:
864 865 866 867 868 869
	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;
870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971
	}
	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;

}
Y
Yinghai Lu 已提交
972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989

/*
 * 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);
990
	e820_update_range(addr, sizet, E820_RAM, E820_RESERVED);
Y
Yinghai Lu 已提交
991 992 993 994 995 996
	printk(KERN_INFO "update e820 for early_reserve_e820\n");
	update_e820();

	return addr;
}

997 998 999 1000 1001 1002 1003
#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 */
1004
# define MAX_ARCH_PFN MAXMEM>>PAGE_SHIFT
1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026
#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;

1027
	printk(KERN_INFO "last_pfn = %#lx max_arch_pfn = %#lx\n",
1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105
			 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);
}
1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129

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;
1130 1131 1132
	e820_update_range(mem_size, ULLONG_MAX - mem_size,
		E820_RAM, E820_RESERVED);

1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167
	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);
1168
		e820_add_region(start_at, mem_size, E820_RAM);
1169 1170
	} else if (*p == '#') {
		start_at = memparse(p+1, &p);
1171
		e820_add_region(start_at, mem_size, E820_ACPI);
1172 1173
	} else if (*p == '$') {
		start_at = memparse(p+1, &p);
1174
		e820_add_region(start_at, mem_size, E820_RESERVED);
1175 1176
	} else {
		end_user_pfn = (mem_size >> PAGE_SHIFT);
1177 1178
		e820_update_range(mem_size, ULLONG_MAX - mem_size,
			E820_RAM, E820_RESERVED);
1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196
	}
	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");
	}
}
1197 1198 1199 1200 1201 1202 1203 1204

/*
 * Mark e820 reserved areas as busy for the resource manager.
 */
void __init e820_reserve_resources(void)
{
	int i;
	struct resource *res;
1205
	u64 end;
1206 1207 1208 1209 1210 1211 1212 1213 1214

	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";
		}
1215
		end = e820.map[i].addr + e820.map[i].size - 1;
1216
#ifndef CONFIG_RESOURCES_64BIT
1217
		if (end > 0x100000000ULL) {
1218 1219 1220 1221
			res++;
			continue;
		}
#endif
1222 1223 1224
		res->start = e820.map[i].addr;
		res->end = end;

1225 1226 1227 1228 1229 1230
		res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
		insert_resource(&iomem_resource, res);
		res++;
	}
}

1231
char *__init default_machine_specific_memory_setup(void)
1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246
{
	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) {
1247
		u64 mem_size;
1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267

		/* 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;
}

1268 1269 1270 1271 1272
char *__init __attribute__((weak)) machine_specific_memory_setup(void)
{
	return default_machine_specific_memory_setup();
}

1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288
/* 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;
1289

1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304
	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