[deliverable/linux.git] / arch / x86 / kernel / e820.c

/*
 * 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 <asm/pgtable.h>
#include <asm/page.h>
#include <asm/e820.h>
#include <asm/setup.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 add_memory_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.
 *
 */
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;

	/*
		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_
	*/

	/* 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;
}

/*
 * 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;

	do {
		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;

		add_memory_region(start, size, type);
	} while (biosmap++, --nr_map);
	return 0;
}

u64 __init update_memory_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;
		add_memory_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);
}
Commit	Line	Data
b79cd8f1 YL	1	/*
	2	* Handle the memory map.
	3	* The functions here do the job until bootmem takes over.
	4	*
	5	* Getting sanitize_e820_map() in sync with i386 version by applying change:
	6	* - Provisions for empty E820 memory regions (reported by certain BIOSes).
	7	* Alex Achenbach <xela@slit.de>, December 2002.
	8	* Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
	9	*
	10	*/
	11	#include <linux/kernel.h>
	12	#include <linux/types.h>
	13	#include <linux/init.h>
	14	#include <linux/bootmem.h>
	15	#include <linux/ioport.h>
	16	#include <linux/string.h>
	17	#include <linux/kexec.h>
	18	#include <linux/module.h>
	19	#include <linux/mm.h>
	20	#include <linux/pfn.h>
	21
	22	#include <asm/pgtable.h>
	23	#include <asm/page.h>
	24	#include <asm/e820.h>
	25	#include <asm/setup.h>
	26
	27	struct e820map e820;
	28
	29	/* For PCI or other memory-mapped resources */
	30	unsigned long pci_mem_start = 0xaeedbabe;
	31	#ifdef CONFIG_PCI
	32	EXPORT_SYMBOL(pci_mem_start);
	33	#endif
	34
	35	/*
	36	* This function checks if any part of the range <start,end> is mapped
	37	* with type.
	38	*/
	39	int
	40	e820_any_mapped(u64 start, u64 end, unsigned type)
	41	{
	42	int i;
	43
	44	for (i = 0; i < e820.nr_map; i++) {
	45	struct e820entry *ei = &e820.map[i];
	46
	47	if (type && ei->type != type)
	48	continue;
	49	if (ei->addr >= end \|\| ei->addr + ei->size <= start)
	50	continue;
	51	return 1;
	52	}
	53	return 0;
	54	}
	55	EXPORT_SYMBOL_GPL(e820_any_mapped);
	56
	57	/*
	58	* This function checks if the entire range <start,end> is mapped with type.
	59	*
	60	* Note: this function only works correct if the e820 table is sorted and
	61	* not-overlapping, which is the case
	62	*/
	63	int __init e820_all_mapped(u64 start, u64 end, unsigned type)
	64	{
65	int i;
66
67	for (i = 0; i < e820.nr_map; i++) {
68	struct e820entry *ei = &e820.map[i];
69
70	if (type && ei->type != type)
71	continue;
72	/* is the region (part) in overlap with the current region ?*/
73	if (ei->addr >= end \|\| ei->addr + ei->size <= start)
74	continue;
75
76	/* if the region is at the beginning of <start,end> we move
77	* start to the end of the region since it's ok until there
78	*/
79	if (ei->addr <= start)
80	start = ei->addr + ei->size;
81	/*
82	* if start is now at or beyond end, we're done, full
83	* coverage
84	*/
85	if (start >= end)
86	return 1;
87	}
88	return 0;
89	}
90
91	/*
92	* Add a memory region to the kernel e820 map.
93	*/
94	void __init add_memory_region(u64 start, u64 size, int type)
95	{
96	int x = e820.nr_map;
97
c3965bd1	98	if (x == ARRAY_SIZE(e820.map)) {
b79cd8f1 YL	99	printk(KERN_ERR "Ooops! Too many entries in the memory map!\n");
	100	return;
	101	}
	102
	103	e820.map[x].addr = start;
	104	e820.map[x].size = size;
	105	e820.map[x].type = type;
	106	e820.nr_map++;
	107	}
	108
	109	void __init e820_print_map(char *who)
	110	{
	111	int i;
	112
	113	for (i = 0; i < e820.nr_map; i++) {
	114	printk(KERN_INFO " %s: %016Lx - %016Lx ", who,
	115	(unsigned long long) e820.map[i].addr,
	116	(unsigned long long)
	117	(e820.map[i].addr + e820.map[i].size));
	118	switch (e820.map[i].type) {
	119	case E820_RAM:
	120	printk(KERN_CONT "(usable)\n");
	121	break;
	122	case E820_RESERVED:
	123	printk(KERN_CONT "(reserved)\n");
	124	break;
	125	case E820_ACPI:
	126	printk(KERN_CONT "(ACPI data)\n");
	127	break;
	128	case E820_NVS:
	129	printk(KERN_CONT "(ACPI NVS)\n");
	130	break;
	131	default:
	132	printk(KERN_CONT "type %u\n", e820.map[i].type);
	133	break;
	134	}
	135	}
	136	}
	137
	138	/*
	139	* Sanitize the BIOS e820 map.
	140	*
	141	* Some e820 responses include overlapping entries. The following
	142	* replaces the original e820 map with a new one, removing overlaps.
	143	*
	144	*/
c3965bd1	145	int __init sanitize_e820_map(struct e820entry *biosmap, int max_nr_map,
6e9bcc79	146	int *pnr_map)
b79cd8f1 YL	147	{
	148	struct change_member {
	149	struct e820entry pbios; / pointer to original bios entry */
	150	unsigned long long addr; /* address for this change point */
	151	};
028b7858 PJ	152	static struct change_member change_point_list[2*E820_X_MAX] __initdata;
	153	static struct change_member change_point[2E820_X_MAX] __initdata;
	154	static struct e820entry *overlap_list[E820_X_MAX] __initdata;
	155	static struct e820entry new_bios[E820_X_MAX] __initdata;
b79cd8f1 YL	156	struct change_member *change_tmp;
	157	unsigned long current_type, last_type;
	158	unsigned long long last_addr;
	159	int chgidx, still_changing;
	160	int overlap_entries;
	161	int new_bios_entry;
	162	int old_nr, new_nr, chg_nr;
	163	int i;
	164
	165	/*
	166	Visually we're performing the following
	167	(1,2,3,4 = memory types)...
	168
	169	Sample memory map (w/overlaps):
	170	____22__________________
	171	______________________4_
	172	____1111________________
	173	_44_____________________
	174	11111111________________
	175	____________________33__
	176	___________44___________
	177	__________33333_________
	178	______________22________
	179	___________________2222_
	180	_________111111111______
	181	_____________________11_
	182	_________________4______
	183
	184	Sanitized equivalent (no overlap):
	185	1_______________________
	186	_44_____________________
	187	___1____________________
	188	____22__________________
	189	______11________________
	190	_________1______________
	191	__________3_____________
	192	___________44___________
	193	_____________33_________
	194	_______________2________
	195	________________1_______
	196	_________________4______
	197	___________________2____
	198	____________________33__
	199	______________________4_
	200	*/
	201
	202	/* if there's only one memory region, don't bother */
	203	if (*pnr_map < 2)
	204	return -1;
	205
	206	old_nr = *pnr_map;
6e9bcc79	207	BUG_ON(old_nr > max_nr_map);
b79cd8f1 YL	208
	209	/* bail out if we find any unreasonable addresses in bios map */
	210	for (i = 0; i < old_nr; i++)
	211	if (biosmap[i].addr + biosmap[i].size < biosmap[i].addr)
	212	return -1;
	213
	214	/* create pointers for initial change-point information (for sorting) */
	215	for (i = 0; i < 2 * old_nr; i++)
	216	change_point[i] = &change_point_list[i];
	217
	218	/* record all known change-points (starting and ending addresses),
	219	omitting those that are for empty memory regions */
	220	chgidx = 0;
	221	for (i = 0; i < old_nr; i++) {
	222	if (biosmap[i].size != 0) {
	223	change_point[chgidx]->addr = biosmap[i].addr;
	224	change_point[chgidx++]->pbios = &biosmap[i];
	225	change_point[chgidx]->addr = biosmap[i].addr +
	226	biosmap[i].size;
	227	change_point[chgidx++]->pbios = &biosmap[i];
	228	}
	229	}
	230	chg_nr = chgidx;
	231
	232	/* sort change-point list by memory addresses (low -> high) */
	233	still_changing = 1;
	234	while (still_changing) {
	235	still_changing = 0;
	236	for (i = 1; i < chg_nr; i++) {
	237	unsigned long long curaddr, lastaddr;
	238	unsigned long long curpbaddr, lastpbaddr;
	239
	240	curaddr = change_point[i]->addr;
	241	lastaddr = change_point[i - 1]->addr;
	242	curpbaddr = change_point[i]->pbios->addr;
	243	lastpbaddr = change_point[i - 1]->pbios->addr;
	244
	245	/*
	246	* swap entries, when:
	247	*
	248	* curaddr > lastaddr or
	249	* curaddr == lastaddr and curaddr == curpbaddr and
	250	* lastaddr != lastpbaddr
	251	*/
	252	if (curaddr < lastaddr \|\|
	253	(curaddr == lastaddr && curaddr == curpbaddr &&
	254	lastaddr != lastpbaddr)) {
	255	change_tmp = change_point[i];
	256	change_point[i] = change_point[i-1];
	257	change_point[i-1] = change_tmp;
	258	still_changing = 1;
	259	}
	260	}
	261	}
	262
	263	/* create a new bios memory map, removing overlaps */
	264	overlap_entries = 0; /* number of entries in the overlap table */
	265	new_bios_entry = 0; /* index for creating new bios map entries */
	266	last_type = 0; /* start with undefined memory type */
	267	last_addr = 0; /* start with 0 as last starting address */
	268
	269	/* loop through change-points, determining affect on the new bios map */
	270	for (chgidx = 0; chgidx < chg_nr; chgidx++) {
	271	/* keep track of all overlapping bios entries */
272	if (change_point[chgidx]->addr ==
273	change_point[chgidx]->pbios->addr) {
274	/*
275	* add map entry to overlap list (> 1 entry
276	* implies an overlap)
277	*/
278	overlap_list[overlap_entries++] =
279	change_point[chgidx]->pbios;
280	} else {
281	/*
282	* remove entry from list (order independent,
283	* so swap with last)
284	*/
285	for (i = 0; i < overlap_entries; i++) {
286	if (overlap_list[i] ==
287	change_point[chgidx]->pbios)
288	overlap_list[i] =
289	overlap_list[overlap_entries-1];
290	}
291	overlap_entries--;
292	}
293	/*
294	* if there are overlapping entries, decide which
295	* "type" to use (larger value takes precedence --
296	* 1=usable, 2,3,4,4+=unusable)
297	*/
298	current_type = 0;
299	for (i = 0; i < overlap_entries; i++)
300	if (overlap_list[i]->type > current_type)
301	current_type = overlap_list[i]->type;
302	/*
303	* continue building up new bios map based on this
304	* information
305	*/
306	if (current_type != last_type) {
307	if (last_type != 0) {
308	new_bios[new_bios_entry].size =
309	change_point[chgidx]->addr - last_addr;
310	/*
311	* move forward only if the new size
312	* was non-zero
313	*/
314	if (new_bios[new_bios_entry].size != 0)
315	/*
316	* no more space left for new
317	* bios entries ?
318	*/
c3965bd1	319	if (++new_bios_entry >= max_nr_map)
b79cd8f1 YL	320	break;
	321	}
	322	if (current_type != 0) {
	323	new_bios[new_bios_entry].addr =
	324	change_point[chgidx]->addr;
	325	new_bios[new_bios_entry].type = current_type;
	326	last_addr = change_point[chgidx]->addr;
	327	}
	328	last_type = current_type;
	329	}
	330	}
	331	/* retain count for new bios entries */
	332	new_nr = new_bios_entry;
	333
	334	/* copy new bios mapping into original location */
	335	memcpy(biosmap, new_bios, new_nr * sizeof(struct e820entry));
	336	*pnr_map = new_nr;
	337
	338	return 0;
	339	}
	340
	341	/*
	342	* Copy the BIOS e820 map into a safe place.
	343	*
	344	* Sanity-check it while we're at it..
	345	*
	346	* If we're lucky and live on a modern system, the setup code
	347	* will have given us a memory map that we can use to properly
	348	* set up memory. If we aren't, we'll fake a memory map.
	349	*/
	350	int __init copy_e820_map(struct e820entry *biosmap, int nr_map)
	351	{
	352	/* Only one memory region (or negative)? Ignore it */
	353	if (nr_map < 2)
	354	return -1;
	355
	356	do {
	357	u64 start = biosmap->addr;
	358	u64 size = biosmap->size;
	359	u64 end = start + size;
	360	u32 type = biosmap->type;
	361
	362	/* Overflow in 64 bits? Ignore the memory map. */
	363	if (start > end)
	364	return -1;
	365
	366	add_memory_region(start, size, type);
	367	} while (biosmap++, --nr_map);
	368	return 0;
	369	}
	370
	371	u64 __init update_memory_range(u64 start, u64 size, unsigned old_type,
	372	unsigned new_type)
	373	{
	374	int i;
	375	u64 real_updated_size = 0;
	376
	377	BUG_ON(old_type == new_type);
	378
	379	for (i = 0; i < e820.nr_map; i++) {
	380	struct e820entry *ei = &e820.map[i];
	381	u64 final_start, final_end;
	382	if (ei->type != old_type)
	383	continue;
384	/* totally covered? */
385	if (ei->addr >= start &&
386	(ei->addr + ei->size) <= (start + size)) {
387	ei->type = new_type;
388	real_updated_size += ei->size;
389	continue;
390	}
391	/* partially covered */
392	final_start = max(start, ei->addr);
393	final_end = min(start + size, ei->addr + ei->size);
394	if (final_start >= final_end)
395	continue;
396	add_memory_region(final_start, final_end - final_start,
397	new_type);
398	real_updated_size += final_end - final_start;
399	}
400	return real_updated_size;
401	}
402
403	void __init update_e820(void)
404	{
6e9bcc79	405	int nr_map;
b79cd8f1 YL	406
b79cd8f1 YL	407	nr_map = e820.nr_map;
c3965bd1	408	if (sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &nr_map))
b79cd8f1 YL	409	return;
	410	e820.nr_map = nr_map;
	411	printk(KERN_INFO "modified physical RAM map:\n");
	412	e820_print_map("modified");
	413	}
	414
	415	/*
	416	* Search for the biggest gap in the low 32 bits of the e820
	417	* memory space. We pass this space to PCI to assign MMIO resources
	418	* for hotplug or unconfigured devices in.
	419	* Hopefully the BIOS let enough space left.
	420	*/
	421	__init void e820_setup_gap(void)
	422	{
	423	unsigned long gapstart, gapsize, round;
	424	unsigned long long last;
	425	int i;
	426	int found = 0;
	427
	428	last = 0x100000000ull;
	429	gapstart = 0x10000000;
	430	gapsize = 0x400000;
	431	i = e820.nr_map;
	432	while (--i >= 0) {
	433	unsigned long long start = e820.map[i].addr;
	434	unsigned long long end = start + e820.map[i].size;
	435
	436	/*
	437	* Since "last" is at most 4GB, we know we'll
	438	* fit in 32 bits if this condition is true
	439	*/
	440	if (last > end) {
	441	unsigned long gap = last - end;
	442
	443	if (gap > gapsize) {
	444	gapsize = gap;
	445	gapstart = end;
	446	found = 1;
	447	}
	448	}
	449	if (start < last)
	450	last = start;
	451	}
	452
	453	#ifdef CONFIG_X86_64
	454	if (!found) {
	455	gapstart = (end_pfn << PAGE_SHIFT) + 1024*1024;
	456	printk(KERN_ERR "PCI: Warning: Cannot find a gap in the 32bit "
	457	"address range\n"
	458	KERN_ERR "PCI: Unassigned devices with 32bit resource "
	459	"registers may break!\n");
	460	}
	461	#endif
	462
	463	/*
	464	* See how much we want to round up: start off with
	465	* rounding to the next 1MB area.
	466	*/
	467	round = 0x100000;
	468	while ((gapsize >> 4) > round)
	469	round += round;
	470	/* Fun with two's complement */
	471	pci_mem_start = (gapstart + round) & -round;
	472
473	printk(KERN_INFO
474	"Allocating PCI resources starting at %lx (gap: %lx:%lx)\n",
475	pci_mem_start, gapstart, gapsize);
476	}
477