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v4.10.11
   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/crash_dump.h>
  15#include <linux/export.h>
  16#include <linux/bootmem.h>
  17#include <linux/pfn.h>
  18#include <linux/suspend.h>
  19#include <linux/acpi.h>
  20#include <linux/firmware-map.h>
  21#include <linux/memblock.h>
  22#include <linux/sort.h>
  23
  24#include <asm/e820.h>
  25#include <asm/proto.h>
  26#include <asm/setup.h>
  27#include <asm/cpufeature.h>
  28
  29/*
  30 * The e820 map is the map that gets modified e.g. with command line parameters
  31 * and that is also registered with modifications in the kernel resource tree
  32 * with the iomem_resource as parent.
  33 *
  34 * The e820_saved is directly saved after the BIOS-provided memory map is
  35 * copied. It doesn't get modified afterwards. It's registered for the
  36 * /sys/firmware/memmap interface.
  37 *
  38 * That memory map is not modified and is used as base for kexec. The kexec'd
  39 * kernel should get the same memory map as the firmware provides. Then the
  40 * user can e.g. boot the original kernel with mem=1G while still booting the
  41 * next kernel with full memory.
  42 */
  43static struct e820map initial_e820  __initdata;
  44static struct e820map initial_e820_saved  __initdata;
  45struct e820map *e820 __refdata = &initial_e820;
  46struct e820map *e820_saved __refdata = &initial_e820_saved;
  47
  48/* For PCI or other memory-mapped resources */
  49unsigned long pci_mem_start = 0xaeedbabe;
  50#ifdef CONFIG_PCI
  51EXPORT_SYMBOL(pci_mem_start);
  52#endif
  53
  54/*
  55 * This function checks if any part of the range <start,end> is mapped
  56 * with type.
  57 */
  58int
  59e820_any_mapped(u64 start, u64 end, unsigned type)
  60{
  61	int i;
  62
  63	for (i = 0; i < e820->nr_map; i++) {
  64		struct e820entry *ei = &e820->map[i];
  65
  66		if (type && ei->type != type)
  67			continue;
  68		if (ei->addr >= end || ei->addr + ei->size <= start)
  69			continue;
  70		return 1;
  71	}
  72	return 0;
  73}
  74EXPORT_SYMBOL_GPL(e820_any_mapped);
  75
  76/*
  77 * This function checks if the entire range <start,end> is mapped with type.
  78 *
  79 * Note: this function only works correct if the e820 table is sorted and
  80 * not-overlapping, which is the case
  81 */
  82int __init e820_all_mapped(u64 start, u64 end, unsigned type)
  83{
  84	int i;
  85
  86	for (i = 0; i < e820->nr_map; i++) {
  87		struct e820entry *ei = &e820->map[i];
  88
  89		if (type && ei->type != type)
  90			continue;
  91		/* is the region (part) in overlap with the current region ?*/
  92		if (ei->addr >= end || ei->addr + ei->size <= start)
  93			continue;
  94
  95		/* if the region is at the beginning of <start,end> we move
  96		 * start to the end of the region since it's ok until there
  97		 */
  98		if (ei->addr <= start)
  99			start = ei->addr + ei->size;
 100		/*
 101		 * if start is now at or beyond end, we're done, full
 102		 * coverage
 103		 */
 104		if (start >= end)
 105			return 1;
 106	}
 107	return 0;
 108}
 109
 110/*
 111 * Add a memory region to the kernel e820 map.
 112 */
 113static void __init __e820_add_region(struct e820map *e820x, u64 start, u64 size,
 114					 int type)
 115{
 116	int x = e820x->nr_map;
 117
 118	if (x >= ARRAY_SIZE(e820x->map)) {
 119		printk(KERN_ERR "e820: too many entries; ignoring [mem %#010llx-%#010llx]\n",
 120		       (unsigned long long) start,
 121		       (unsigned long long) (start + size - 1));
 122		return;
 123	}
 124
 125	e820x->map[x].addr = start;
 126	e820x->map[x].size = size;
 127	e820x->map[x].type = type;
 128	e820x->nr_map++;
 129}
 130
 131void __init e820_add_region(u64 start, u64 size, int type)
 132{
 133	__e820_add_region(e820, start, size, type);
 134}
 135
 136static void __init e820_print_type(u32 type)
 137{
 138	switch (type) {
 139	case E820_RAM:
 140	case E820_RESERVED_KERN:
 141		printk(KERN_CONT "usable");
 142		break;
 143	case E820_RESERVED:
 144		printk(KERN_CONT "reserved");
 145		break;
 146	case E820_ACPI:
 147		printk(KERN_CONT "ACPI data");
 148		break;
 149	case E820_NVS:
 150		printk(KERN_CONT "ACPI NVS");
 151		break;
 152	case E820_UNUSABLE:
 153		printk(KERN_CONT "unusable");
 154		break;
 155	case E820_PMEM:
 156	case E820_PRAM:
 157		printk(KERN_CONT "persistent (type %u)", type);
 158		break;
 159	default:
 160		printk(KERN_CONT "type %u", type);
 161		break;
 162	}
 163}
 164
 165void __init e820_print_map(char *who)
 166{
 167	int i;
 168
 169	for (i = 0; i < e820->nr_map; i++) {
 170		printk(KERN_INFO "%s: [mem %#018Lx-%#018Lx] ", who,
 171		       (unsigned long long) e820->map[i].addr,
 172		       (unsigned long long)
 173		       (e820->map[i].addr + e820->map[i].size - 1));
 174		e820_print_type(e820->map[i].type);
 175		printk(KERN_CONT "\n");
 176	}
 177}
 178
 179/*
 180 * Sanitize the BIOS e820 map.
 181 *
 182 * Some e820 responses include overlapping entries. The following
 183 * replaces the original e820 map with a new one, removing overlaps,
 184 * and resolving conflicting memory types in favor of highest
 185 * numbered type.
 186 *
 187 * The input parameter biosmap points to an array of 'struct
 188 * e820entry' which on entry has elements in the range [0, *pnr_map)
 189 * valid, and which has space for up to max_nr_map entries.
 190 * On return, the resulting sanitized e820 map entries will be in
 191 * overwritten in the same location, starting at biosmap.
 192 *
 193 * The integer pointed to by pnr_map must be valid on entry (the
 194 * current number of valid entries located at biosmap). If the
 195 * sanitizing succeeds the *pnr_map will be updated with the new
 196 * number of valid entries (something no more than max_nr_map).
 197 *
 198 * The return value from sanitize_e820_map() is zero if it
 199 * successfully 'sanitized' the map entries passed in, and is -1
 200 * if it did nothing, which can happen if either of (1) it was
 201 * only passed one map entry, or (2) any of the input map entries
 202 * were invalid (start + size < start, meaning that the size was
 203 * so big the described memory range wrapped around through zero.)
 204 *
 205 *	Visually we're performing the following
 206 *	(1,2,3,4 = memory types)...
 207 *
 208 *	Sample memory map (w/overlaps):
 209 *	   ____22__________________
 210 *	   ______________________4_
 211 *	   ____1111________________
 212 *	   _44_____________________
 213 *	   11111111________________
 214 *	   ____________________33__
 215 *	   ___________44___________
 216 *	   __________33333_________
 217 *	   ______________22________
 218 *	   ___________________2222_
 219 *	   _________111111111______
 220 *	   _____________________11_
 221 *	   _________________4______
 222 *
 223 *	Sanitized equivalent (no overlap):
 224 *	   1_______________________
 225 *	   _44_____________________
 226 *	   ___1____________________
 227 *	   ____22__________________
 228 *	   ______11________________
 229 *	   _________1______________
 230 *	   __________3_____________
 231 *	   ___________44___________
 232 *	   _____________33_________
 233 *	   _______________2________
 234 *	   ________________1_______
 235 *	   _________________4______
 236 *	   ___________________2____
 237 *	   ____________________33__
 238 *	   ______________________4_
 239 */
 240struct change_member {
 241	struct e820entry *pbios; /* pointer to original bios entry */
 242	unsigned long long addr; /* address for this change point */
 243};
 244
 245static int __init cpcompare(const void *a, const void *b)
 246{
 247	struct change_member * const *app = a, * const *bpp = b;
 248	const struct change_member *ap = *app, *bp = *bpp;
 249
 250	/*
 251	 * Inputs are pointers to two elements of change_point[].  If their
 252	 * addresses are unequal, their difference dominates.  If the addresses
 253	 * are equal, then consider one that represents the end of its region
 254	 * to be greater than one that does not.
 255	 */
 256	if (ap->addr != bp->addr)
 257		return ap->addr > bp->addr ? 1 : -1;
 258
 259	return (ap->addr != ap->pbios->addr) - (bp->addr != bp->pbios->addr);
 260}
 261
 262int __init sanitize_e820_map(struct e820entry *biosmap, int max_nr_map,
 263			     u32 *pnr_map)
 264{
 265	static struct change_member change_point_list[2*E820_X_MAX] __initdata;
 266	static struct change_member *change_point[2*E820_X_MAX] __initdata;
 267	static struct e820entry *overlap_list[E820_X_MAX] __initdata;
 268	static struct e820entry new_bios[E820_X_MAX] __initdata;
 269	unsigned long current_type, last_type;
 270	unsigned long long last_addr;
 271	int chgidx;
 272	int overlap_entries;
 273	int new_bios_entry;
 274	int old_nr, new_nr, chg_nr;
 275	int i;
 276
 277	/* if there's only one memory region, don't bother */
 278	if (*pnr_map < 2)
 279		return -1;
 280
 281	old_nr = *pnr_map;
 282	BUG_ON(old_nr > max_nr_map);
 283
 284	/* bail out if we find any unreasonable addresses in bios map */
 285	for (i = 0; i < old_nr; i++)
 286		if (biosmap[i].addr + biosmap[i].size < biosmap[i].addr)
 287			return -1;
 288
 289	/* create pointers for initial change-point information (for sorting) */
 290	for (i = 0; i < 2 * old_nr; i++)
 291		change_point[i] = &change_point_list[i];
 292
 293	/* record all known change-points (starting and ending addresses),
 294	   omitting those that are for empty memory regions */
 295	chgidx = 0;
 296	for (i = 0; i < old_nr; i++)	{
 297		if (biosmap[i].size != 0) {
 298			change_point[chgidx]->addr = biosmap[i].addr;
 299			change_point[chgidx++]->pbios = &biosmap[i];
 300			change_point[chgidx]->addr = biosmap[i].addr +
 301				biosmap[i].size;
 302			change_point[chgidx++]->pbios = &biosmap[i];
 303		}
 304	}
 305	chg_nr = chgidx;
 306
 307	/* sort change-point list by memory addresses (low -> high) */
 308	sort(change_point, chg_nr, sizeof *change_point, cpcompare, NULL);
 309
 310	/* create a new bios memory map, removing overlaps */
 311	overlap_entries = 0;	 /* number of entries in the overlap table */
 312	new_bios_entry = 0;	 /* index for creating new bios map entries */
 313	last_type = 0;		 /* start with undefined memory type */
 314	last_addr = 0;		 /* start with 0 as last starting address */
 315
 316	/* loop through change-points, determining affect on the new bios map */
 317	for (chgidx = 0; chgidx < chg_nr; chgidx++) {
 318		/* keep track of all overlapping bios entries */
 319		if (change_point[chgidx]->addr ==
 320		    change_point[chgidx]->pbios->addr) {
 321			/*
 322			 * add map entry to overlap list (> 1 entry
 323			 * implies an overlap)
 324			 */
 325			overlap_list[overlap_entries++] =
 326				change_point[chgidx]->pbios;
 327		} else {
 328			/*
 329			 * remove entry from list (order independent,
 330			 * so swap with last)
 331			 */
 332			for (i = 0; i < overlap_entries; i++) {
 333				if (overlap_list[i] ==
 334				    change_point[chgidx]->pbios)
 335					overlap_list[i] =
 336						overlap_list[overlap_entries-1];
 337			}
 338			overlap_entries--;
 339		}
 340		/*
 341		 * if there are overlapping entries, decide which
 342		 * "type" to use (larger value takes precedence --
 343		 * 1=usable, 2,3,4,4+=unusable)
 344		 */
 345		current_type = 0;
 346		for (i = 0; i < overlap_entries; i++)
 347			if (overlap_list[i]->type > current_type)
 348				current_type = overlap_list[i]->type;
 349		/*
 350		 * continue building up new bios map based on this
 351		 * information
 352		 */
 353		if (current_type != last_type || current_type == E820_PRAM) {
 354			if (last_type != 0)	 {
 355				new_bios[new_bios_entry].size =
 356					change_point[chgidx]->addr - last_addr;
 357				/*
 358				 * move forward only if the new size
 359				 * was non-zero
 360				 */
 361				if (new_bios[new_bios_entry].size != 0)
 362					/*
 363					 * no more space left for new
 364					 * bios entries ?
 365					 */
 366					if (++new_bios_entry >= max_nr_map)
 367						break;
 368			}
 369			if (current_type != 0)	{
 370				new_bios[new_bios_entry].addr =
 371					change_point[chgidx]->addr;
 372				new_bios[new_bios_entry].type = current_type;
 373				last_addr = change_point[chgidx]->addr;
 374			}
 375			last_type = current_type;
 376		}
 377	}
 378	/* retain count for new bios entries */
 379	new_nr = new_bios_entry;
 380
 381	/* copy new bios mapping into original location */
 382	memcpy(biosmap, new_bios, new_nr * sizeof(struct e820entry));
 383	*pnr_map = new_nr;
 384
 385	return 0;
 386}
 387
 388static int __init __append_e820_map(struct e820entry *biosmap, int nr_map)
 389{
 390	while (nr_map) {
 391		u64 start = biosmap->addr;
 392		u64 size = biosmap->size;
 393		u64 end = start + size - 1;
 394		u32 type = biosmap->type;
 395
 396		/* Overflow in 64 bits? Ignore the memory map. */
 397		if (start > end && likely(size))
 398			return -1;
 399
 400		e820_add_region(start, size, type);
 401
 402		biosmap++;
 403		nr_map--;
 404	}
 405	return 0;
 406}
 407
 408/*
 409 * Copy the BIOS e820 map into a safe place.
 410 *
 411 * Sanity-check it while we're at it..
 412 *
 413 * If we're lucky and live on a modern system, the setup code
 414 * will have given us a memory map that we can use to properly
 415 * set up memory.  If we aren't, we'll fake a memory map.
 416 */
 417static int __init append_e820_map(struct e820entry *biosmap, int nr_map)
 418{
 419	/* Only one memory region (or negative)? Ignore it */
 420	if (nr_map < 2)
 421		return -1;
 422
 423	return __append_e820_map(biosmap, nr_map);
 424}
 425
 426static u64 __init __e820_update_range(struct e820map *e820x, u64 start,
 427					u64 size, unsigned old_type,
 428					unsigned new_type)
 429{
 430	u64 end;
 431	unsigned int i;
 432	u64 real_updated_size = 0;
 433
 434	BUG_ON(old_type == new_type);
 435
 436	if (size > (ULLONG_MAX - start))
 437		size = ULLONG_MAX - start;
 438
 439	end = start + size;
 440	printk(KERN_DEBUG "e820: update [mem %#010Lx-%#010Lx] ",
 441	       (unsigned long long) start, (unsigned long long) (end - 1));
 442	e820_print_type(old_type);
 443	printk(KERN_CONT " ==> ");
 444	e820_print_type(new_type);
 445	printk(KERN_CONT "\n");
 446
 447	for (i = 0; i < e820x->nr_map; i++) {
 448		struct e820entry *ei = &e820x->map[i];
 449		u64 final_start, final_end;
 450		u64 ei_end;
 451
 452		if (ei->type != old_type)
 453			continue;
 454
 455		ei_end = ei->addr + ei->size;
 456		/* totally covered by new range? */
 457		if (ei->addr >= start && ei_end <= end) {
 458			ei->type = new_type;
 459			real_updated_size += ei->size;
 460			continue;
 461		}
 462
 463		/* new range is totally covered? */
 464		if (ei->addr < start && ei_end > end) {
 465			__e820_add_region(e820x, start, size, new_type);
 466			__e820_add_region(e820x, end, ei_end - end, ei->type);
 467			ei->size = start - ei->addr;
 468			real_updated_size += size;
 469			continue;
 470		}
 471
 472		/* partially covered */
 473		final_start = max(start, ei->addr);
 474		final_end = min(end, ei_end);
 475		if (final_start >= final_end)
 476			continue;
 477
 478		__e820_add_region(e820x, final_start, final_end - final_start,
 479				  new_type);
 480
 481		real_updated_size += final_end - final_start;
 482
 483		/*
 484		 * left range could be head or tail, so need to update
 485		 * size at first.
 486		 */
 487		ei->size -= final_end - final_start;
 488		if (ei->addr < final_start)
 489			continue;
 490		ei->addr = final_end;
 491	}
 492	return real_updated_size;
 493}
 494
 495u64 __init e820_update_range(u64 start, u64 size, unsigned old_type,
 496			     unsigned new_type)
 497{
 498	return __e820_update_range(e820, start, size, old_type, new_type);
 499}
 500
 501static u64 __init e820_update_range_saved(u64 start, u64 size,
 502					  unsigned old_type, unsigned new_type)
 503{
 504	return __e820_update_range(e820_saved, start, size, old_type,
 505				     new_type);
 506}
 507
 508/* make e820 not cover the range */
 509u64 __init e820_remove_range(u64 start, u64 size, unsigned old_type,
 510			     int checktype)
 511{
 512	int i;
 513	u64 end;
 514	u64 real_removed_size = 0;
 515
 516	if (size > (ULLONG_MAX - start))
 517		size = ULLONG_MAX - start;
 518
 519	end = start + size;
 520	printk(KERN_DEBUG "e820: remove [mem %#010Lx-%#010Lx] ",
 521	       (unsigned long long) start, (unsigned long long) (end - 1));
 522	if (checktype)
 523		e820_print_type(old_type);
 524	printk(KERN_CONT "\n");
 525
 526	for (i = 0; i < e820->nr_map; i++) {
 527		struct e820entry *ei = &e820->map[i];
 528		u64 final_start, final_end;
 529		u64 ei_end;
 530
 531		if (checktype && ei->type != old_type)
 532			continue;
 533
 534		ei_end = ei->addr + ei->size;
 535		/* totally covered? */
 536		if (ei->addr >= start && ei_end <= end) {
 537			real_removed_size += ei->size;
 538			memset(ei, 0, sizeof(struct e820entry));
 539			continue;
 540		}
 541
 542		/* new range is totally covered? */
 543		if (ei->addr < start && ei_end > end) {
 544			e820_add_region(end, ei_end - end, ei->type);
 545			ei->size = start - ei->addr;
 546			real_removed_size += size;
 547			continue;
 548		}
 549
 550		/* partially covered */
 551		final_start = max(start, ei->addr);
 552		final_end = min(end, ei_end);
 553		if (final_start >= final_end)
 554			continue;
 555		real_removed_size += final_end - final_start;
 556
 557		/*
 558		 * left range could be head or tail, so need to update
 559		 * size at first.
 560		 */
 561		ei->size -= final_end - final_start;
 562		if (ei->addr < final_start)
 563			continue;
 564		ei->addr = final_end;
 565	}
 566	return real_removed_size;
 567}
 568
 569void __init update_e820(void)
 570{
 571	if (sanitize_e820_map(e820->map, ARRAY_SIZE(e820->map), &e820->nr_map))
 572		return;
 573	printk(KERN_INFO "e820: modified physical RAM map:\n");
 574	e820_print_map("modified");
 575}
 576static void __init update_e820_saved(void)
 577{
 578	sanitize_e820_map(e820_saved->map, ARRAY_SIZE(e820_saved->map),
 579				&e820_saved->nr_map);
 580}
 581#define MAX_GAP_END 0x100000000ull
 582/*
 583 * Search for a gap in the e820 memory space from start_addr to end_addr.
 584 */
 585__init int e820_search_gap(unsigned long *gapstart, unsigned long *gapsize,
 586		unsigned long start_addr, unsigned long long end_addr)
 587{
 588	unsigned long long last;
 589	int i = e820->nr_map;
 590	int found = 0;
 591
 592	last = (end_addr && end_addr < MAX_GAP_END) ? end_addr : MAX_GAP_END;
 593
 594	while (--i >= 0) {
 595		unsigned long long start = e820->map[i].addr;
 596		unsigned long long end = start + e820->map[i].size;
 597
 598		if (end < start_addr)
 599			continue;
 600
 601		/*
 602		 * Since "last" is at most 4GB, we know we'll
 603		 * fit in 32 bits if this condition is true
 604		 */
 605		if (last > end) {
 606			unsigned long gap = last - end;
 607
 608			if (gap >= *gapsize) {
 609				*gapsize = gap;
 610				*gapstart = end;
 611				found = 1;
 612			}
 613		}
 614		if (start < last)
 615			last = start;
 616	}
 617	return found;
 618}
 619
 620/*
 621 * Search for the biggest gap in the low 32 bits of the e820
 622 * memory space.  We pass this space to PCI to assign MMIO resources
 623 * for hotplug or unconfigured devices in.
 624 * Hopefully the BIOS let enough space left.
 625 */
 626__init void e820_setup_gap(void)
 627{
 628	unsigned long gapstart, gapsize;
 629	int found;
 630
 631	gapstart = 0x10000000;
 632	gapsize = 0x400000;
 633	found  = e820_search_gap(&gapstart, &gapsize, 0, MAX_GAP_END);
 634
 635#ifdef CONFIG_X86_64
 636	if (!found) {
 637		gapstart = (max_pfn << PAGE_SHIFT) + 1024*1024;
 638		printk(KERN_ERR
 639	"e820: cannot find a gap in the 32bit address range\n"
 640	"e820: PCI devices with unassigned 32bit BARs may break!\n");
 641	}
 642#endif
 643
 644	/*
 645	 * e820_reserve_resources_late protect stolen RAM already
 646	 */
 647	pci_mem_start = gapstart;
 648
 649	printk(KERN_INFO
 650	       "e820: [mem %#010lx-%#010lx] available for PCI devices\n",
 651	       gapstart, gapstart + gapsize - 1);
 652}
 653
 654/*
 655 * Called late during init, in free_initmem().
 656 *
 657 * Initial e820 and e820_saved are largish __initdata arrays.
 658 * Copy them to (usually much smaller) dynamically allocated area.
 659 * This is done after all tweaks we ever do to them:
 660 * all functions which modify them are __init functions,
 661 * they won't exist after this point.
 662 */
 663__init void e820_reallocate_tables(void)
 664{
 665	struct e820map *n;
 666	int size;
 667
 668	size = offsetof(struct e820map, map) + sizeof(struct e820entry) * e820->nr_map;
 669	n = kmalloc(size, GFP_KERNEL);
 670	BUG_ON(!n);
 671	memcpy(n, e820, size);
 672	e820 = n;
 673
 674	size = offsetof(struct e820map, map) + sizeof(struct e820entry) * e820_saved->nr_map;
 675	n = kmalloc(size, GFP_KERNEL);
 676	BUG_ON(!n);
 677	memcpy(n, e820_saved, size);
 678	e820_saved = n;
 679}
 680
 681/**
 682 * Because of the size limitation of struct boot_params, only first
 683 * 128 E820 memory entries are passed to kernel via
 684 * boot_params.e820_map, others are passed via SETUP_E820_EXT node of
 685 * linked list of struct setup_data, which is parsed here.
 686 */
 687void __init parse_e820_ext(u64 phys_addr, u32 data_len)
 688{
 689	int entries;
 690	struct e820entry *extmap;
 691	struct setup_data *sdata;
 692
 693	sdata = early_memremap(phys_addr, data_len);
 694	entries = sdata->len / sizeof(struct e820entry);
 695	extmap = (struct e820entry *)(sdata->data);
 696	__append_e820_map(extmap, entries);
 697	sanitize_e820_map(e820->map, ARRAY_SIZE(e820->map), &e820->nr_map);
 698	early_memunmap(sdata, data_len);
 699	printk(KERN_INFO "e820: extended physical RAM map:\n");
 700	e820_print_map("extended");
 701}
 702
 703#if defined(CONFIG_X86_64) || \
 704	(defined(CONFIG_X86_32) && defined(CONFIG_HIBERNATION))
 705/**
 706 * Find the ranges of physical addresses that do not correspond to
 707 * e820 RAM areas and mark the corresponding pages as nosave for
 708 * hibernation (32 bit) or software suspend and suspend to RAM (64 bit).
 709 *
 710 * This function requires the e820 map to be sorted and without any
 711 * overlapping entries.
 712 */
 713void __init e820_mark_nosave_regions(unsigned long limit_pfn)
 714{
 715	int i;
 716	unsigned long pfn = 0;
 717
 718	for (i = 0; i < e820->nr_map; i++) {
 719		struct e820entry *ei = &e820->map[i];
 720
 721		if (pfn < PFN_UP(ei->addr))
 722			register_nosave_region(pfn, PFN_UP(ei->addr));
 723
 724		pfn = PFN_DOWN(ei->addr + ei->size);
 725
 726		if (ei->type != E820_RAM && ei->type != E820_RESERVED_KERN)
 727			register_nosave_region(PFN_UP(ei->addr), pfn);
 728
 729		if (pfn >= limit_pfn)
 730			break;
 731	}
 732}
 733#endif
 734
 735#ifdef CONFIG_ACPI
 736/**
 737 * Mark ACPI NVS memory region, so that we can save/restore it during
 738 * hibernation and the subsequent resume.
 739 */
 740static int __init e820_mark_nvs_memory(void)
 741{
 742	int i;
 743
 744	for (i = 0; i < e820->nr_map; i++) {
 745		struct e820entry *ei = &e820->map[i];
 746
 747		if (ei->type == E820_NVS)
 748			acpi_nvs_register(ei->addr, ei->size);
 749	}
 750
 751	return 0;
 752}
 753core_initcall(e820_mark_nvs_memory);
 754#endif
 755
 756/*
 757 * pre allocated 4k and reserved it in memblock and e820_saved
 758 */
 759u64 __init early_reserve_e820(u64 size, u64 align)
 760{
 761	u64 addr;
 762
 763	addr = __memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ACCESSIBLE);
 764	if (addr) {
 765		e820_update_range_saved(addr, size, E820_RAM, E820_RESERVED);
 766		printk(KERN_INFO "e820: update e820_saved for early_reserve_e820\n");
 767		update_e820_saved();
 768	}
 769
 770	return addr;
 771}
 772
 773#ifdef CONFIG_X86_32
 774# ifdef CONFIG_X86_PAE
 775#  define MAX_ARCH_PFN		(1ULL<<(36-PAGE_SHIFT))
 776# else
 777#  define MAX_ARCH_PFN		(1ULL<<(32-PAGE_SHIFT))
 778# endif
 779#else /* CONFIG_X86_32 */
 780# define MAX_ARCH_PFN MAXMEM>>PAGE_SHIFT
 781#endif
 782
 783/*
 784 * Find the highest page frame number we have available
 785 */
 786static unsigned long __init e820_end_pfn(unsigned long limit_pfn, unsigned type)
 787{
 788	int i;
 789	unsigned long last_pfn = 0;
 790	unsigned long max_arch_pfn = MAX_ARCH_PFN;
 791
 792	for (i = 0; i < e820->nr_map; i++) {
 793		struct e820entry *ei = &e820->map[i];
 794		unsigned long start_pfn;
 795		unsigned long end_pfn;
 796
 797		if (ei->type != type)
 
 
 
 
 798			continue;
 799
 800		start_pfn = ei->addr >> PAGE_SHIFT;
 801		end_pfn = (ei->addr + ei->size) >> PAGE_SHIFT;
 802
 803		if (start_pfn >= limit_pfn)
 804			continue;
 805		if (end_pfn > limit_pfn) {
 806			last_pfn = limit_pfn;
 807			break;
 808		}
 809		if (end_pfn > last_pfn)
 810			last_pfn = end_pfn;
 811	}
 812
 813	if (last_pfn > max_arch_pfn)
 814		last_pfn = max_arch_pfn;
 815
 816	printk(KERN_INFO "e820: last_pfn = %#lx max_arch_pfn = %#lx\n",
 817			 last_pfn, max_arch_pfn);
 818	return last_pfn;
 819}
 820unsigned long __init e820_end_of_ram_pfn(void)
 821{
 822	return e820_end_pfn(MAX_ARCH_PFN, E820_RAM);
 823}
 824
 825unsigned long __init e820_end_of_low_ram_pfn(void)
 826{
 827	return e820_end_pfn(1UL << (32 - PAGE_SHIFT), E820_RAM);
 828}
 829
 830static void __init early_panic(char *msg)
 831{
 832	early_printk(msg);
 833	panic(msg);
 834}
 835
 836static int userdef __initdata;
 837
 838/* "mem=nopentium" disables the 4MB page tables. */
 839static int __init parse_memopt(char *p)
 840{
 841	u64 mem_size;
 842
 843	if (!p)
 844		return -EINVAL;
 845
 846	if (!strcmp(p, "nopentium")) {
 847#ifdef CONFIG_X86_32
 848		setup_clear_cpu_cap(X86_FEATURE_PSE);
 849		return 0;
 850#else
 851		printk(KERN_WARNING "mem=nopentium ignored! (only supported on x86_32)\n");
 852		return -EINVAL;
 853#endif
 854	}
 855
 856	userdef = 1;
 857	mem_size = memparse(p, &p);
 858	/* don't remove all of memory when handling "mem={invalid}" param */
 859	if (mem_size == 0)
 860		return -EINVAL;
 861	e820_remove_range(mem_size, ULLONG_MAX - mem_size, E820_RAM, 1);
 862
 863	return 0;
 864}
 865early_param("mem", parse_memopt);
 866
 867static int __init parse_memmap_one(char *p)
 868{
 869	char *oldp;
 870	u64 start_at, mem_size;
 871
 872	if (!p)
 873		return -EINVAL;
 874
 875	if (!strncmp(p, "exactmap", 8)) {
 876#ifdef CONFIG_CRASH_DUMP
 877		/*
 878		 * If we are doing a crash dump, we still need to know
 879		 * the real mem size before original memory map is
 880		 * reset.
 881		 */
 882		saved_max_pfn = e820_end_of_ram_pfn();
 883#endif
 884		e820->nr_map = 0;
 885		userdef = 1;
 886		return 0;
 887	}
 888
 889	oldp = p;
 890	mem_size = memparse(p, &p);
 891	if (p == oldp)
 892		return -EINVAL;
 893
 894	userdef = 1;
 895	if (*p == '@') {
 896		start_at = memparse(p+1, &p);
 897		e820_add_region(start_at, mem_size, E820_RAM);
 898	} else if (*p == '#') {
 899		start_at = memparse(p+1, &p);
 900		e820_add_region(start_at, mem_size, E820_ACPI);
 901	} else if (*p == '$') {
 902		start_at = memparse(p+1, &p);
 903		e820_add_region(start_at, mem_size, E820_RESERVED);
 904	} else if (*p == '!') {
 905		start_at = memparse(p+1, &p);
 906		e820_add_region(start_at, mem_size, E820_PRAM);
 907	} else
 908		e820_remove_range(mem_size, ULLONG_MAX - mem_size, E820_RAM, 1);
 909
 910	return *p == '\0' ? 0 : -EINVAL;
 911}
 912static int __init parse_memmap_opt(char *str)
 913{
 914	while (str) {
 915		char *k = strchr(str, ',');
 916
 917		if (k)
 918			*k++ = 0;
 919
 920		parse_memmap_one(str);
 921		str = k;
 922	}
 923
 924	return 0;
 925}
 926early_param("memmap", parse_memmap_opt);
 927
 928void __init finish_e820_parsing(void)
 929{
 930	if (userdef) {
 931		if (sanitize_e820_map(e820->map, ARRAY_SIZE(e820->map),
 932					&e820->nr_map) < 0)
 933			early_panic("Invalid user supplied memory map");
 934
 935		printk(KERN_INFO "e820: user-defined physical RAM map:\n");
 936		e820_print_map("user");
 937	}
 938}
 939
 940static const char *__init e820_type_to_string(int e820_type)
 941{
 942	switch (e820_type) {
 943	case E820_RESERVED_KERN:
 944	case E820_RAM:	return "System RAM";
 945	case E820_ACPI:	return "ACPI Tables";
 946	case E820_NVS:	return "ACPI Non-volatile Storage";
 947	case E820_UNUSABLE:	return "Unusable memory";
 948	case E820_PRAM: return "Persistent Memory (legacy)";
 949	case E820_PMEM: return "Persistent Memory";
 950	default:	return "reserved";
 951	}
 952}
 953
 954static unsigned long __init e820_type_to_iomem_type(int e820_type)
 955{
 956	switch (e820_type) {
 957	case E820_RESERVED_KERN:
 958	case E820_RAM:
 959		return IORESOURCE_SYSTEM_RAM;
 960	case E820_ACPI:
 961	case E820_NVS:
 962	case E820_UNUSABLE:
 963	case E820_PRAM:
 964	case E820_PMEM:
 965	default:
 966		return IORESOURCE_MEM;
 967	}
 968}
 969
 970static unsigned long __init e820_type_to_iores_desc(int e820_type)
 971{
 972	switch (e820_type) {
 973	case E820_ACPI:
 974		return IORES_DESC_ACPI_TABLES;
 975	case E820_NVS:
 976		return IORES_DESC_ACPI_NV_STORAGE;
 977	case E820_PMEM:
 978		return IORES_DESC_PERSISTENT_MEMORY;
 979	case E820_PRAM:
 980		return IORES_DESC_PERSISTENT_MEMORY_LEGACY;
 981	case E820_RESERVED_KERN:
 982	case E820_RAM:
 983	case E820_UNUSABLE:
 984	default:
 985		return IORES_DESC_NONE;
 986	}
 987}
 988
 989static bool __init do_mark_busy(u32 type, struct resource *res)
 990{
 991	/* this is the legacy bios/dos rom-shadow + mmio region */
 992	if (res->start < (1ULL<<20))
 993		return true;
 994
 995	/*
 996	 * Treat persistent memory like device memory, i.e. reserve it
 997	 * for exclusive use of a driver
 998	 */
 999	switch (type) {
1000	case E820_RESERVED:
1001	case E820_PRAM:
1002	case E820_PMEM:
1003		return false;
1004	default:
1005		return true;
1006	}
1007}
1008
1009/*
1010 * Mark e820 reserved areas as busy for the resource manager.
1011 */
1012static struct resource __initdata *e820_res;
1013void __init e820_reserve_resources(void)
1014{
1015	int i;
1016	struct resource *res;
1017	u64 end;
1018
1019	res = alloc_bootmem(sizeof(struct resource) * e820->nr_map);
1020	e820_res = res;
1021	for (i = 0; i < e820->nr_map; i++) {
1022		end = e820->map[i].addr + e820->map[i].size - 1;
1023		if (end != (resource_size_t)end) {
1024			res++;
1025			continue;
1026		}
1027		res->name = e820_type_to_string(e820->map[i].type);
1028		res->start = e820->map[i].addr;
1029		res->end = end;
1030
1031		res->flags = e820_type_to_iomem_type(e820->map[i].type);
1032		res->desc = e820_type_to_iores_desc(e820->map[i].type);
1033
1034		/*
1035		 * don't register the region that could be conflicted with
1036		 * pci device BAR resource and insert them later in
1037		 * pcibios_resource_survey()
1038		 */
1039		if (do_mark_busy(e820->map[i].type, res)) {
1040			res->flags |= IORESOURCE_BUSY;
1041			insert_resource(&iomem_resource, res);
1042		}
1043		res++;
1044	}
1045
1046	for (i = 0; i < e820_saved->nr_map; i++) {
1047		struct e820entry *entry = &e820_saved->map[i];
1048		firmware_map_add_early(entry->addr,
1049			entry->addr + entry->size,
1050			e820_type_to_string(entry->type));
1051	}
1052}
1053
1054/* How much should we pad RAM ending depending on where it is? */
1055static unsigned long __init ram_alignment(resource_size_t pos)
1056{
1057	unsigned long mb = pos >> 20;
1058
1059	/* To 64kB in the first megabyte */
1060	if (!mb)
1061		return 64*1024;
1062
1063	/* To 1MB in the first 16MB */
1064	if (mb < 16)
1065		return 1024*1024;
1066
1067	/* To 64MB for anything above that */
1068	return 64*1024*1024;
1069}
1070
1071#define MAX_RESOURCE_SIZE ((resource_size_t)-1)
1072
1073void __init e820_reserve_resources_late(void)
1074{
1075	int i;
1076	struct resource *res;
1077
1078	res = e820_res;
1079	for (i = 0; i < e820->nr_map; i++) {
1080		if (!res->parent && res->end)
1081			insert_resource_expand_to_fit(&iomem_resource, res);
1082		res++;
1083	}
1084
1085	/*
1086	 * Try to bump up RAM regions to reasonable boundaries to
1087	 * avoid stolen RAM:
1088	 */
1089	for (i = 0; i < e820->nr_map; i++) {
1090		struct e820entry *entry = &e820->map[i];
1091		u64 start, end;
1092
1093		if (entry->type != E820_RAM)
1094			continue;
1095		start = entry->addr + entry->size;
1096		end = round_up(start, ram_alignment(start)) - 1;
1097		if (end > MAX_RESOURCE_SIZE)
1098			end = MAX_RESOURCE_SIZE;
1099		if (start >= end)
1100			continue;
1101		printk(KERN_DEBUG
1102		       "e820: reserve RAM buffer [mem %#010llx-%#010llx]\n",
1103		       start, end);
1104		reserve_region_with_split(&iomem_resource, start, end,
1105					  "RAM buffer");
1106	}
1107}
1108
1109char *__init default_machine_specific_memory_setup(void)
1110{
1111	char *who = "BIOS-e820";
1112	u32 new_nr;
1113	/*
1114	 * Try to copy the BIOS-supplied E820-map.
1115	 *
1116	 * Otherwise fake a memory map; one section from 0k->640k,
1117	 * the next section from 1mb->appropriate_mem_k
1118	 */
1119	new_nr = boot_params.e820_entries;
1120	sanitize_e820_map(boot_params.e820_map,
1121			ARRAY_SIZE(boot_params.e820_map),
1122			&new_nr);
1123	boot_params.e820_entries = new_nr;
1124	if (append_e820_map(boot_params.e820_map, boot_params.e820_entries)
1125	  < 0) {
1126		u64 mem_size;
1127
1128		/* compare results from other methods and take the greater */
1129		if (boot_params.alt_mem_k
1130		    < boot_params.screen_info.ext_mem_k) {
1131			mem_size = boot_params.screen_info.ext_mem_k;
1132			who = "BIOS-88";
1133		} else {
1134			mem_size = boot_params.alt_mem_k;
1135			who = "BIOS-e801";
1136		}
1137
1138		e820->nr_map = 0;
1139		e820_add_region(0, LOWMEMSIZE(), E820_RAM);
1140		e820_add_region(HIGH_MEMORY, mem_size << 10, E820_RAM);
1141	}
1142
1143	/* In case someone cares... */
1144	return who;
1145}
1146
1147void __init setup_memory_map(void)
1148{
1149	char *who;
1150
1151	who = x86_init.resources.memory_setup();
1152	memcpy(e820_saved, e820, sizeof(struct e820map));
1153	printk(KERN_INFO "e820: BIOS-provided physical RAM map:\n");
1154	e820_print_map(who);
1155}
1156
1157void __init memblock_x86_fill(void)
1158{
1159	int i;
1160	u64 end;
1161
1162	/*
1163	 * EFI may have more than 128 entries
1164	 * We are safe to enable resizing, beause memblock_x86_fill()
1165	 * is rather later for x86
1166	 */
1167	memblock_allow_resize();
1168
1169	for (i = 0; i < e820->nr_map; i++) {
1170		struct e820entry *ei = &e820->map[i];
1171
1172		end = ei->addr + ei->size;
1173		if (end != (resource_size_t)end)
1174			continue;
1175
1176		if (ei->type != E820_RAM && ei->type != E820_RESERVED_KERN)
1177			continue;
1178
1179		memblock_add(ei->addr, ei->size);
1180	}
1181
1182	/* throw away partial pages */
1183	memblock_trim_memory(PAGE_SIZE);
1184
1185	memblock_dump_all();
1186}
1187
1188void __init memblock_find_dma_reserve(void)
1189{
1190#ifdef CONFIG_X86_64
1191	u64 nr_pages = 0, nr_free_pages = 0;
1192	unsigned long start_pfn, end_pfn;
1193	phys_addr_t start, end;
1194	int i;
1195	u64 u;
1196
1197	/*
1198	 * need to find out used area below MAX_DMA_PFN
1199	 * need to use memblock to get free size in [0, MAX_DMA_PFN]
1200	 * at first, and assume boot_mem will not take below MAX_DMA_PFN
1201	 */
1202	for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, NULL) {
1203		start_pfn = min(start_pfn, MAX_DMA_PFN);
1204		end_pfn = min(end_pfn, MAX_DMA_PFN);
1205		nr_pages += end_pfn - start_pfn;
1206	}
1207
1208	for_each_free_mem_range(u, NUMA_NO_NODE, MEMBLOCK_NONE, &start, &end,
1209				NULL) {
1210		start_pfn = min_t(unsigned long, PFN_UP(start), MAX_DMA_PFN);
1211		end_pfn = min_t(unsigned long, PFN_DOWN(end), MAX_DMA_PFN);
1212		if (start_pfn < end_pfn)
1213			nr_free_pages += end_pfn - start_pfn;
1214	}
1215
1216	set_dma_reserve(nr_pages - nr_free_pages);
1217#endif
1218}
v4.6
   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/crash_dump.h>
  15#include <linux/export.h>
  16#include <linux/bootmem.h>
  17#include <linux/pfn.h>
  18#include <linux/suspend.h>
  19#include <linux/acpi.h>
  20#include <linux/firmware-map.h>
  21#include <linux/memblock.h>
  22#include <linux/sort.h>
  23
  24#include <asm/e820.h>
  25#include <asm/proto.h>
  26#include <asm/setup.h>
  27#include <asm/cpufeature.h>
  28
  29/*
  30 * The e820 map is the map that gets modified e.g. with command line parameters
  31 * and that is also registered with modifications in the kernel resource tree
  32 * with the iomem_resource as parent.
  33 *
  34 * The e820_saved is directly saved after the BIOS-provided memory map is
  35 * copied. It doesn't get modified afterwards. It's registered for the
  36 * /sys/firmware/memmap interface.
  37 *
  38 * That memory map is not modified and is used as base for kexec. The kexec'd
  39 * kernel should get the same memory map as the firmware provides. Then the
  40 * user can e.g. boot the original kernel with mem=1G while still booting the
  41 * next kernel with full memory.
  42 */
  43struct e820map e820;
  44struct e820map e820_saved;
 
 
  45
  46/* For PCI or other memory-mapped resources */
  47unsigned long pci_mem_start = 0xaeedbabe;
  48#ifdef CONFIG_PCI
  49EXPORT_SYMBOL(pci_mem_start);
  50#endif
  51
  52/*
  53 * This function checks if any part of the range <start,end> is mapped
  54 * with type.
  55 */
  56int
  57e820_any_mapped(u64 start, u64 end, unsigned type)
  58{
  59	int i;
  60
  61	for (i = 0; i < e820.nr_map; i++) {
  62		struct e820entry *ei = &e820.map[i];
  63
  64		if (type && ei->type != type)
  65			continue;
  66		if (ei->addr >= end || ei->addr + ei->size <= start)
  67			continue;
  68		return 1;
  69	}
  70	return 0;
  71}
  72EXPORT_SYMBOL_GPL(e820_any_mapped);
  73
  74/*
  75 * This function checks if the entire range <start,end> is mapped with type.
  76 *
  77 * Note: this function only works correct if the e820 table is sorted and
  78 * not-overlapping, which is the case
  79 */
  80int __init e820_all_mapped(u64 start, u64 end, unsigned type)
  81{
  82	int i;
  83
  84	for (i = 0; i < e820.nr_map; i++) {
  85		struct e820entry *ei = &e820.map[i];
  86
  87		if (type && ei->type != type)
  88			continue;
  89		/* is the region (part) in overlap with the current region ?*/
  90		if (ei->addr >= end || ei->addr + ei->size <= start)
  91			continue;
  92
  93		/* if the region is at the beginning of <start,end> we move
  94		 * start to the end of the region since it's ok until there
  95		 */
  96		if (ei->addr <= start)
  97			start = ei->addr + ei->size;
  98		/*
  99		 * if start is now at or beyond end, we're done, full
 100		 * coverage
 101		 */
 102		if (start >= end)
 103			return 1;
 104	}
 105	return 0;
 106}
 107
 108/*
 109 * Add a memory region to the kernel e820 map.
 110 */
 111static void __init __e820_add_region(struct e820map *e820x, u64 start, u64 size,
 112					 int type)
 113{
 114	int x = e820x->nr_map;
 115
 116	if (x >= ARRAY_SIZE(e820x->map)) {
 117		printk(KERN_ERR "e820: too many entries; ignoring [mem %#010llx-%#010llx]\n",
 118		       (unsigned long long) start,
 119		       (unsigned long long) (start + size - 1));
 120		return;
 121	}
 122
 123	e820x->map[x].addr = start;
 124	e820x->map[x].size = size;
 125	e820x->map[x].type = type;
 126	e820x->nr_map++;
 127}
 128
 129void __init e820_add_region(u64 start, u64 size, int type)
 130{
 131	__e820_add_region(&e820, start, size, type);
 132}
 133
 134static void __init e820_print_type(u32 type)
 135{
 136	switch (type) {
 137	case E820_RAM:
 138	case E820_RESERVED_KERN:
 139		printk(KERN_CONT "usable");
 140		break;
 141	case E820_RESERVED:
 142		printk(KERN_CONT "reserved");
 143		break;
 144	case E820_ACPI:
 145		printk(KERN_CONT "ACPI data");
 146		break;
 147	case E820_NVS:
 148		printk(KERN_CONT "ACPI NVS");
 149		break;
 150	case E820_UNUSABLE:
 151		printk(KERN_CONT "unusable");
 152		break;
 153	case E820_PMEM:
 154	case E820_PRAM:
 155		printk(KERN_CONT "persistent (type %u)", type);
 156		break;
 157	default:
 158		printk(KERN_CONT "type %u", type);
 159		break;
 160	}
 161}
 162
 163void __init e820_print_map(char *who)
 164{
 165	int i;
 166
 167	for (i = 0; i < e820.nr_map; i++) {
 168		printk(KERN_INFO "%s: [mem %#018Lx-%#018Lx] ", who,
 169		       (unsigned long long) e820.map[i].addr,
 170		       (unsigned long long)
 171		       (e820.map[i].addr + e820.map[i].size - 1));
 172		e820_print_type(e820.map[i].type);
 173		printk(KERN_CONT "\n");
 174	}
 175}
 176
 177/*
 178 * Sanitize the BIOS e820 map.
 179 *
 180 * Some e820 responses include overlapping entries. The following
 181 * replaces the original e820 map with a new one, removing overlaps,
 182 * and resolving conflicting memory types in favor of highest
 183 * numbered type.
 184 *
 185 * The input parameter biosmap points to an array of 'struct
 186 * e820entry' which on entry has elements in the range [0, *pnr_map)
 187 * valid, and which has space for up to max_nr_map entries.
 188 * On return, the resulting sanitized e820 map entries will be in
 189 * overwritten in the same location, starting at biosmap.
 190 *
 191 * The integer pointed to by pnr_map must be valid on entry (the
 192 * current number of valid entries located at biosmap). If the
 193 * sanitizing succeeds the *pnr_map will be updated with the new
 194 * number of valid entries (something no more than max_nr_map).
 195 *
 196 * The return value from sanitize_e820_map() is zero if it
 197 * successfully 'sanitized' the map entries passed in, and is -1
 198 * if it did nothing, which can happen if either of (1) it was
 199 * only passed one map entry, or (2) any of the input map entries
 200 * were invalid (start + size < start, meaning that the size was
 201 * so big the described memory range wrapped around through zero.)
 202 *
 203 *	Visually we're performing the following
 204 *	(1,2,3,4 = memory types)...
 205 *
 206 *	Sample memory map (w/overlaps):
 207 *	   ____22__________________
 208 *	   ______________________4_
 209 *	   ____1111________________
 210 *	   _44_____________________
 211 *	   11111111________________
 212 *	   ____________________33__
 213 *	   ___________44___________
 214 *	   __________33333_________
 215 *	   ______________22________
 216 *	   ___________________2222_
 217 *	   _________111111111______
 218 *	   _____________________11_
 219 *	   _________________4______
 220 *
 221 *	Sanitized equivalent (no overlap):
 222 *	   1_______________________
 223 *	   _44_____________________
 224 *	   ___1____________________
 225 *	   ____22__________________
 226 *	   ______11________________
 227 *	   _________1______________
 228 *	   __________3_____________
 229 *	   ___________44___________
 230 *	   _____________33_________
 231 *	   _______________2________
 232 *	   ________________1_______
 233 *	   _________________4______
 234 *	   ___________________2____
 235 *	   ____________________33__
 236 *	   ______________________4_
 237 */
 238struct change_member {
 239	struct e820entry *pbios; /* pointer to original bios entry */
 240	unsigned long long addr; /* address for this change point */
 241};
 242
 243static int __init cpcompare(const void *a, const void *b)
 244{
 245	struct change_member * const *app = a, * const *bpp = b;
 246	const struct change_member *ap = *app, *bp = *bpp;
 247
 248	/*
 249	 * Inputs are pointers to two elements of change_point[].  If their
 250	 * addresses are unequal, their difference dominates.  If the addresses
 251	 * are equal, then consider one that represents the end of its region
 252	 * to be greater than one that does not.
 253	 */
 254	if (ap->addr != bp->addr)
 255		return ap->addr > bp->addr ? 1 : -1;
 256
 257	return (ap->addr != ap->pbios->addr) - (bp->addr != bp->pbios->addr);
 258}
 259
 260int __init sanitize_e820_map(struct e820entry *biosmap, int max_nr_map,
 261			     u32 *pnr_map)
 262{
 263	static struct change_member change_point_list[2*E820_X_MAX] __initdata;
 264	static struct change_member *change_point[2*E820_X_MAX] __initdata;
 265	static struct e820entry *overlap_list[E820_X_MAX] __initdata;
 266	static struct e820entry new_bios[E820_X_MAX] __initdata;
 267	unsigned long current_type, last_type;
 268	unsigned long long last_addr;
 269	int chgidx;
 270	int overlap_entries;
 271	int new_bios_entry;
 272	int old_nr, new_nr, chg_nr;
 273	int i;
 274
 275	/* if there's only one memory region, don't bother */
 276	if (*pnr_map < 2)
 277		return -1;
 278
 279	old_nr = *pnr_map;
 280	BUG_ON(old_nr > max_nr_map);
 281
 282	/* bail out if we find any unreasonable addresses in bios map */
 283	for (i = 0; i < old_nr; i++)
 284		if (biosmap[i].addr + biosmap[i].size < biosmap[i].addr)
 285			return -1;
 286
 287	/* create pointers for initial change-point information (for sorting) */
 288	for (i = 0; i < 2 * old_nr; i++)
 289		change_point[i] = &change_point_list[i];
 290
 291	/* record all known change-points (starting and ending addresses),
 292	   omitting those that are for empty memory regions */
 293	chgidx = 0;
 294	for (i = 0; i < old_nr; i++)	{
 295		if (biosmap[i].size != 0) {
 296			change_point[chgidx]->addr = biosmap[i].addr;
 297			change_point[chgidx++]->pbios = &biosmap[i];
 298			change_point[chgidx]->addr = biosmap[i].addr +
 299				biosmap[i].size;
 300			change_point[chgidx++]->pbios = &biosmap[i];
 301		}
 302	}
 303	chg_nr = chgidx;
 304
 305	/* sort change-point list by memory addresses (low -> high) */
 306	sort(change_point, chg_nr, sizeof *change_point, cpcompare, NULL);
 307
 308	/* create a new bios memory map, removing overlaps */
 309	overlap_entries = 0;	 /* number of entries in the overlap table */
 310	new_bios_entry = 0;	 /* index for creating new bios map entries */
 311	last_type = 0;		 /* start with undefined memory type */
 312	last_addr = 0;		 /* start with 0 as last starting address */
 313
 314	/* loop through change-points, determining affect on the new bios map */
 315	for (chgidx = 0; chgidx < chg_nr; chgidx++) {
 316		/* keep track of all overlapping bios entries */
 317		if (change_point[chgidx]->addr ==
 318		    change_point[chgidx]->pbios->addr) {
 319			/*
 320			 * add map entry to overlap list (> 1 entry
 321			 * implies an overlap)
 322			 */
 323			overlap_list[overlap_entries++] =
 324				change_point[chgidx]->pbios;
 325		} else {
 326			/*
 327			 * remove entry from list (order independent,
 328			 * so swap with last)
 329			 */
 330			for (i = 0; i < overlap_entries; i++) {
 331				if (overlap_list[i] ==
 332				    change_point[chgidx]->pbios)
 333					overlap_list[i] =
 334						overlap_list[overlap_entries-1];
 335			}
 336			overlap_entries--;
 337		}
 338		/*
 339		 * if there are overlapping entries, decide which
 340		 * "type" to use (larger value takes precedence --
 341		 * 1=usable, 2,3,4,4+=unusable)
 342		 */
 343		current_type = 0;
 344		for (i = 0; i < overlap_entries; i++)
 345			if (overlap_list[i]->type > current_type)
 346				current_type = overlap_list[i]->type;
 347		/*
 348		 * continue building up new bios map based on this
 349		 * information
 350		 */
 351		if (current_type != last_type || current_type == E820_PRAM) {
 352			if (last_type != 0)	 {
 353				new_bios[new_bios_entry].size =
 354					change_point[chgidx]->addr - last_addr;
 355				/*
 356				 * move forward only if the new size
 357				 * was non-zero
 358				 */
 359				if (new_bios[new_bios_entry].size != 0)
 360					/*
 361					 * no more space left for new
 362					 * bios entries ?
 363					 */
 364					if (++new_bios_entry >= max_nr_map)
 365						break;
 366			}
 367			if (current_type != 0)	{
 368				new_bios[new_bios_entry].addr =
 369					change_point[chgidx]->addr;
 370				new_bios[new_bios_entry].type = current_type;
 371				last_addr = change_point[chgidx]->addr;
 372			}
 373			last_type = current_type;
 374		}
 375	}
 376	/* retain count for new bios entries */
 377	new_nr = new_bios_entry;
 378
 379	/* copy new bios mapping into original location */
 380	memcpy(biosmap, new_bios, new_nr * sizeof(struct e820entry));
 381	*pnr_map = new_nr;
 382
 383	return 0;
 384}
 385
 386static int __init __append_e820_map(struct e820entry *biosmap, int nr_map)
 387{
 388	while (nr_map) {
 389		u64 start = biosmap->addr;
 390		u64 size = biosmap->size;
 391		u64 end = start + size;
 392		u32 type = biosmap->type;
 393
 394		/* Overflow in 64 bits? Ignore the memory map. */
 395		if (start > end)
 396			return -1;
 397
 398		e820_add_region(start, size, type);
 399
 400		biosmap++;
 401		nr_map--;
 402	}
 403	return 0;
 404}
 405
 406/*
 407 * Copy the BIOS e820 map into a safe place.
 408 *
 409 * Sanity-check it while we're at it..
 410 *
 411 * If we're lucky and live on a modern system, the setup code
 412 * will have given us a memory map that we can use to properly
 413 * set up memory.  If we aren't, we'll fake a memory map.
 414 */
 415static int __init append_e820_map(struct e820entry *biosmap, int nr_map)
 416{
 417	/* Only one memory region (or negative)? Ignore it */
 418	if (nr_map < 2)
 419		return -1;
 420
 421	return __append_e820_map(biosmap, nr_map);
 422}
 423
 424static u64 __init __e820_update_range(struct e820map *e820x, u64 start,
 425					u64 size, unsigned old_type,
 426					unsigned new_type)
 427{
 428	u64 end;
 429	unsigned int i;
 430	u64 real_updated_size = 0;
 431
 432	BUG_ON(old_type == new_type);
 433
 434	if (size > (ULLONG_MAX - start))
 435		size = ULLONG_MAX - start;
 436
 437	end = start + size;
 438	printk(KERN_DEBUG "e820: update [mem %#010Lx-%#010Lx] ",
 439	       (unsigned long long) start, (unsigned long long) (end - 1));
 440	e820_print_type(old_type);
 441	printk(KERN_CONT " ==> ");
 442	e820_print_type(new_type);
 443	printk(KERN_CONT "\n");
 444
 445	for (i = 0; i < e820x->nr_map; i++) {
 446		struct e820entry *ei = &e820x->map[i];
 447		u64 final_start, final_end;
 448		u64 ei_end;
 449
 450		if (ei->type != old_type)
 451			continue;
 452
 453		ei_end = ei->addr + ei->size;
 454		/* totally covered by new range? */
 455		if (ei->addr >= start && ei_end <= end) {
 456			ei->type = new_type;
 457			real_updated_size += ei->size;
 458			continue;
 459		}
 460
 461		/* new range is totally covered? */
 462		if (ei->addr < start && ei_end > end) {
 463			__e820_add_region(e820x, start, size, new_type);
 464			__e820_add_region(e820x, end, ei_end - end, ei->type);
 465			ei->size = start - ei->addr;
 466			real_updated_size += size;
 467			continue;
 468		}
 469
 470		/* partially covered */
 471		final_start = max(start, ei->addr);
 472		final_end = min(end, ei_end);
 473		if (final_start >= final_end)
 474			continue;
 475
 476		__e820_add_region(e820x, final_start, final_end - final_start,
 477				  new_type);
 478
 479		real_updated_size += final_end - final_start;
 480
 481		/*
 482		 * left range could be head or tail, so need to update
 483		 * size at first.
 484		 */
 485		ei->size -= final_end - final_start;
 486		if (ei->addr < final_start)
 487			continue;
 488		ei->addr = final_end;
 489	}
 490	return real_updated_size;
 491}
 492
 493u64 __init e820_update_range(u64 start, u64 size, unsigned old_type,
 494			     unsigned new_type)
 495{
 496	return __e820_update_range(&e820, start, size, old_type, new_type);
 497}
 498
 499static u64 __init e820_update_range_saved(u64 start, u64 size,
 500					  unsigned old_type, unsigned new_type)
 501{
 502	return __e820_update_range(&e820_saved, start, size, old_type,
 503				     new_type);
 504}
 505
 506/* make e820 not cover the range */
 507u64 __init e820_remove_range(u64 start, u64 size, unsigned old_type,
 508			     int checktype)
 509{
 510	int i;
 511	u64 end;
 512	u64 real_removed_size = 0;
 513
 514	if (size > (ULLONG_MAX - start))
 515		size = ULLONG_MAX - start;
 516
 517	end = start + size;
 518	printk(KERN_DEBUG "e820: remove [mem %#010Lx-%#010Lx] ",
 519	       (unsigned long long) start, (unsigned long long) (end - 1));
 520	if (checktype)
 521		e820_print_type(old_type);
 522	printk(KERN_CONT "\n");
 523
 524	for (i = 0; i < e820.nr_map; i++) {
 525		struct e820entry *ei = &e820.map[i];
 526		u64 final_start, final_end;
 527		u64 ei_end;
 528
 529		if (checktype && ei->type != old_type)
 530			continue;
 531
 532		ei_end = ei->addr + ei->size;
 533		/* totally covered? */
 534		if (ei->addr >= start && ei_end <= end) {
 535			real_removed_size += ei->size;
 536			memset(ei, 0, sizeof(struct e820entry));
 537			continue;
 538		}
 539
 540		/* new range is totally covered? */
 541		if (ei->addr < start && ei_end > end) {
 542			e820_add_region(end, ei_end - end, ei->type);
 543			ei->size = start - ei->addr;
 544			real_removed_size += size;
 545			continue;
 546		}
 547
 548		/* partially covered */
 549		final_start = max(start, ei->addr);
 550		final_end = min(end, ei_end);
 551		if (final_start >= final_end)
 552			continue;
 553		real_removed_size += final_end - final_start;
 554
 555		/*
 556		 * left range could be head or tail, so need to update
 557		 * size at first.
 558		 */
 559		ei->size -= final_end - final_start;
 560		if (ei->addr < final_start)
 561			continue;
 562		ei->addr = final_end;
 563	}
 564	return real_removed_size;
 565}
 566
 567void __init update_e820(void)
 568{
 569	if (sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map))
 570		return;
 571	printk(KERN_INFO "e820: modified physical RAM map:\n");
 572	e820_print_map("modified");
 573}
 574static void __init update_e820_saved(void)
 575{
 576	sanitize_e820_map(e820_saved.map, ARRAY_SIZE(e820_saved.map),
 577				&e820_saved.nr_map);
 578}
 579#define MAX_GAP_END 0x100000000ull
 580/*
 581 * Search for a gap in the e820 memory space from start_addr to end_addr.
 582 */
 583__init int e820_search_gap(unsigned long *gapstart, unsigned long *gapsize,
 584		unsigned long start_addr, unsigned long long end_addr)
 585{
 586	unsigned long long last;
 587	int i = e820.nr_map;
 588	int found = 0;
 589
 590	last = (end_addr && end_addr < MAX_GAP_END) ? end_addr : MAX_GAP_END;
 591
 592	while (--i >= 0) {
 593		unsigned long long start = e820.map[i].addr;
 594		unsigned long long end = start + e820.map[i].size;
 595
 596		if (end < start_addr)
 597			continue;
 598
 599		/*
 600		 * Since "last" is at most 4GB, we know we'll
 601		 * fit in 32 bits if this condition is true
 602		 */
 603		if (last > end) {
 604			unsigned long gap = last - end;
 605
 606			if (gap >= *gapsize) {
 607				*gapsize = gap;
 608				*gapstart = end;
 609				found = 1;
 610			}
 611		}
 612		if (start < last)
 613			last = start;
 614	}
 615	return found;
 616}
 617
 618/*
 619 * Search for the biggest gap in the low 32 bits of the e820
 620 * memory space.  We pass this space to PCI to assign MMIO resources
 621 * for hotplug or unconfigured devices in.
 622 * Hopefully the BIOS let enough space left.
 623 */
 624__init void e820_setup_gap(void)
 625{
 626	unsigned long gapstart, gapsize;
 627	int found;
 628
 629	gapstart = 0x10000000;
 630	gapsize = 0x400000;
 631	found  = e820_search_gap(&gapstart, &gapsize, 0, MAX_GAP_END);
 632
 633#ifdef CONFIG_X86_64
 634	if (!found) {
 635		gapstart = (max_pfn << PAGE_SHIFT) + 1024*1024;
 636		printk(KERN_ERR
 637	"e820: cannot find a gap in the 32bit address range\n"
 638	"e820: PCI devices with unassigned 32bit BARs may break!\n");
 639	}
 640#endif
 641
 642	/*
 643	 * e820_reserve_resources_late protect stolen RAM already
 644	 */
 645	pci_mem_start = gapstart;
 646
 647	printk(KERN_INFO
 648	       "e820: [mem %#010lx-%#010lx] available for PCI devices\n",
 649	       gapstart, gapstart + gapsize - 1);
 650}
 651
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 652/**
 653 * Because of the size limitation of struct boot_params, only first
 654 * 128 E820 memory entries are passed to kernel via
 655 * boot_params.e820_map, others are passed via SETUP_E820_EXT node of
 656 * linked list of struct setup_data, which is parsed here.
 657 */
 658void __init parse_e820_ext(u64 phys_addr, u32 data_len)
 659{
 660	int entries;
 661	struct e820entry *extmap;
 662	struct setup_data *sdata;
 663
 664	sdata = early_memremap(phys_addr, data_len);
 665	entries = sdata->len / sizeof(struct e820entry);
 666	extmap = (struct e820entry *)(sdata->data);
 667	__append_e820_map(extmap, entries);
 668	sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
 669	early_memunmap(sdata, data_len);
 670	printk(KERN_INFO "e820: extended physical RAM map:\n");
 671	e820_print_map("extended");
 672}
 673
 674#if defined(CONFIG_X86_64) || \
 675	(defined(CONFIG_X86_32) && defined(CONFIG_HIBERNATION))
 676/**
 677 * Find the ranges of physical addresses that do not correspond to
 678 * e820 RAM areas and mark the corresponding pages as nosave for
 679 * hibernation (32 bit) or software suspend and suspend to RAM (64 bit).
 680 *
 681 * This function requires the e820 map to be sorted and without any
 682 * overlapping entries.
 683 */
 684void __init e820_mark_nosave_regions(unsigned long limit_pfn)
 685{
 686	int i;
 687	unsigned long pfn = 0;
 688
 689	for (i = 0; i < e820.nr_map; i++) {
 690		struct e820entry *ei = &e820.map[i];
 691
 692		if (pfn < PFN_UP(ei->addr))
 693			register_nosave_region(pfn, PFN_UP(ei->addr));
 694
 695		pfn = PFN_DOWN(ei->addr + ei->size);
 696
 697		if (ei->type != E820_RAM && ei->type != E820_RESERVED_KERN)
 698			register_nosave_region(PFN_UP(ei->addr), pfn);
 699
 700		if (pfn >= limit_pfn)
 701			break;
 702	}
 703}
 704#endif
 705
 706#ifdef CONFIG_ACPI
 707/**
 708 * Mark ACPI NVS memory region, so that we can save/restore it during
 709 * hibernation and the subsequent resume.
 710 */
 711static int __init e820_mark_nvs_memory(void)
 712{
 713	int i;
 714
 715	for (i = 0; i < e820.nr_map; i++) {
 716		struct e820entry *ei = &e820.map[i];
 717
 718		if (ei->type == E820_NVS)
 719			acpi_nvs_register(ei->addr, ei->size);
 720	}
 721
 722	return 0;
 723}
 724core_initcall(e820_mark_nvs_memory);
 725#endif
 726
 727/*
 728 * pre allocated 4k and reserved it in memblock and e820_saved
 729 */
 730u64 __init early_reserve_e820(u64 size, u64 align)
 731{
 732	u64 addr;
 733
 734	addr = __memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ACCESSIBLE);
 735	if (addr) {
 736		e820_update_range_saved(addr, size, E820_RAM, E820_RESERVED);
 737		printk(KERN_INFO "e820: update e820_saved for early_reserve_e820\n");
 738		update_e820_saved();
 739	}
 740
 741	return addr;
 742}
 743
 744#ifdef CONFIG_X86_32
 745# ifdef CONFIG_X86_PAE
 746#  define MAX_ARCH_PFN		(1ULL<<(36-PAGE_SHIFT))
 747# else
 748#  define MAX_ARCH_PFN		(1ULL<<(32-PAGE_SHIFT))
 749# endif
 750#else /* CONFIG_X86_32 */
 751# define MAX_ARCH_PFN MAXMEM>>PAGE_SHIFT
 752#endif
 753
 754/*
 755 * Find the highest page frame number we have available
 756 */
 757static unsigned long __init e820_end_pfn(unsigned long limit_pfn)
 758{
 759	int i;
 760	unsigned long last_pfn = 0;
 761	unsigned long max_arch_pfn = MAX_ARCH_PFN;
 762
 763	for (i = 0; i < e820.nr_map; i++) {
 764		struct e820entry *ei = &e820.map[i];
 765		unsigned long start_pfn;
 766		unsigned long end_pfn;
 767
 768		/*
 769		 * Persistent memory is accounted as ram for purposes of
 770		 * establishing max_pfn and mem_map.
 771		 */
 772		if (ei->type != E820_RAM && ei->type != E820_PRAM)
 773			continue;
 774
 775		start_pfn = ei->addr >> PAGE_SHIFT;
 776		end_pfn = (ei->addr + ei->size) >> PAGE_SHIFT;
 777
 778		if (start_pfn >= limit_pfn)
 779			continue;
 780		if (end_pfn > limit_pfn) {
 781			last_pfn = limit_pfn;
 782			break;
 783		}
 784		if (end_pfn > last_pfn)
 785			last_pfn = end_pfn;
 786	}
 787
 788	if (last_pfn > max_arch_pfn)
 789		last_pfn = max_arch_pfn;
 790
 791	printk(KERN_INFO "e820: last_pfn = %#lx max_arch_pfn = %#lx\n",
 792			 last_pfn, max_arch_pfn);
 793	return last_pfn;
 794}
 795unsigned long __init e820_end_of_ram_pfn(void)
 796{
 797	return e820_end_pfn(MAX_ARCH_PFN);
 798}
 799
 800unsigned long __init e820_end_of_low_ram_pfn(void)
 801{
 802	return e820_end_pfn(1UL << (32-PAGE_SHIFT));
 803}
 804
 805static void early_panic(char *msg)
 806{
 807	early_printk(msg);
 808	panic(msg);
 809}
 810
 811static int userdef __initdata;
 812
 813/* "mem=nopentium" disables the 4MB page tables. */
 814static int __init parse_memopt(char *p)
 815{
 816	u64 mem_size;
 817
 818	if (!p)
 819		return -EINVAL;
 820
 821	if (!strcmp(p, "nopentium")) {
 822#ifdef CONFIG_X86_32
 823		setup_clear_cpu_cap(X86_FEATURE_PSE);
 824		return 0;
 825#else
 826		printk(KERN_WARNING "mem=nopentium ignored! (only supported on x86_32)\n");
 827		return -EINVAL;
 828#endif
 829	}
 830
 831	userdef = 1;
 832	mem_size = memparse(p, &p);
 833	/* don't remove all of memory when handling "mem={invalid}" param */
 834	if (mem_size == 0)
 835		return -EINVAL;
 836	e820_remove_range(mem_size, ULLONG_MAX - mem_size, E820_RAM, 1);
 837
 838	return 0;
 839}
 840early_param("mem", parse_memopt);
 841
 842static int __init parse_memmap_one(char *p)
 843{
 844	char *oldp;
 845	u64 start_at, mem_size;
 846
 847	if (!p)
 848		return -EINVAL;
 849
 850	if (!strncmp(p, "exactmap", 8)) {
 851#ifdef CONFIG_CRASH_DUMP
 852		/*
 853		 * If we are doing a crash dump, we still need to know
 854		 * the real mem size before original memory map is
 855		 * reset.
 856		 */
 857		saved_max_pfn = e820_end_of_ram_pfn();
 858#endif
 859		e820.nr_map = 0;
 860		userdef = 1;
 861		return 0;
 862	}
 863
 864	oldp = p;
 865	mem_size = memparse(p, &p);
 866	if (p == oldp)
 867		return -EINVAL;
 868
 869	userdef = 1;
 870	if (*p == '@') {
 871		start_at = memparse(p+1, &p);
 872		e820_add_region(start_at, mem_size, E820_RAM);
 873	} else if (*p == '#') {
 874		start_at = memparse(p+1, &p);
 875		e820_add_region(start_at, mem_size, E820_ACPI);
 876	} else if (*p == '$') {
 877		start_at = memparse(p+1, &p);
 878		e820_add_region(start_at, mem_size, E820_RESERVED);
 879	} else if (*p == '!') {
 880		start_at = memparse(p+1, &p);
 881		e820_add_region(start_at, mem_size, E820_PRAM);
 882	} else
 883		e820_remove_range(mem_size, ULLONG_MAX - mem_size, E820_RAM, 1);
 884
 885	return *p == '\0' ? 0 : -EINVAL;
 886}
 887static int __init parse_memmap_opt(char *str)
 888{
 889	while (str) {
 890		char *k = strchr(str, ',');
 891
 892		if (k)
 893			*k++ = 0;
 894
 895		parse_memmap_one(str);
 896		str = k;
 897	}
 898
 899	return 0;
 900}
 901early_param("memmap", parse_memmap_opt);
 902
 903void __init finish_e820_parsing(void)
 904{
 905	if (userdef) {
 906		if (sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map),
 907					&e820.nr_map) < 0)
 908			early_panic("Invalid user supplied memory map");
 909
 910		printk(KERN_INFO "e820: user-defined physical RAM map:\n");
 911		e820_print_map("user");
 912	}
 913}
 914
 915static const char *e820_type_to_string(int e820_type)
 916{
 917	switch (e820_type) {
 918	case E820_RESERVED_KERN:
 919	case E820_RAM:	return "System RAM";
 920	case E820_ACPI:	return "ACPI Tables";
 921	case E820_NVS:	return "ACPI Non-volatile Storage";
 922	case E820_UNUSABLE:	return "Unusable memory";
 923	case E820_PRAM: return "Persistent Memory (legacy)";
 924	case E820_PMEM: return "Persistent Memory";
 925	default:	return "reserved";
 926	}
 927}
 928
 929static unsigned long e820_type_to_iomem_type(int e820_type)
 930{
 931	switch (e820_type) {
 932	case E820_RESERVED_KERN:
 933	case E820_RAM:
 934		return IORESOURCE_SYSTEM_RAM;
 935	case E820_ACPI:
 936	case E820_NVS:
 937	case E820_UNUSABLE:
 938	case E820_PRAM:
 939	case E820_PMEM:
 940	default:
 941		return IORESOURCE_MEM;
 942	}
 943}
 944
 945static unsigned long e820_type_to_iores_desc(int e820_type)
 946{
 947	switch (e820_type) {
 948	case E820_ACPI:
 949		return IORES_DESC_ACPI_TABLES;
 950	case E820_NVS:
 951		return IORES_DESC_ACPI_NV_STORAGE;
 952	case E820_PMEM:
 953		return IORES_DESC_PERSISTENT_MEMORY;
 954	case E820_PRAM:
 955		return IORES_DESC_PERSISTENT_MEMORY_LEGACY;
 956	case E820_RESERVED_KERN:
 957	case E820_RAM:
 958	case E820_UNUSABLE:
 959	default:
 960		return IORES_DESC_NONE;
 961	}
 962}
 963
 964static bool do_mark_busy(u32 type, struct resource *res)
 965{
 966	/* this is the legacy bios/dos rom-shadow + mmio region */
 967	if (res->start < (1ULL<<20))
 968		return true;
 969
 970	/*
 971	 * Treat persistent memory like device memory, i.e. reserve it
 972	 * for exclusive use of a driver
 973	 */
 974	switch (type) {
 975	case E820_RESERVED:
 976	case E820_PRAM:
 977	case E820_PMEM:
 978		return false;
 979	default:
 980		return true;
 981	}
 982}
 983
 984/*
 985 * Mark e820 reserved areas as busy for the resource manager.
 986 */
 987static struct resource __initdata *e820_res;
 988void __init e820_reserve_resources(void)
 989{
 990	int i;
 991	struct resource *res;
 992	u64 end;
 993
 994	res = alloc_bootmem(sizeof(struct resource) * e820.nr_map);
 995	e820_res = res;
 996	for (i = 0; i < e820.nr_map; i++) {
 997		end = e820.map[i].addr + e820.map[i].size - 1;
 998		if (end != (resource_size_t)end) {
 999			res++;
1000			continue;
1001		}
1002		res->name = e820_type_to_string(e820.map[i].type);
1003		res->start = e820.map[i].addr;
1004		res->end = end;
1005
1006		res->flags = e820_type_to_iomem_type(e820.map[i].type);
1007		res->desc = e820_type_to_iores_desc(e820.map[i].type);
1008
1009		/*
1010		 * don't register the region that could be conflicted with
1011		 * pci device BAR resource and insert them later in
1012		 * pcibios_resource_survey()
1013		 */
1014		if (do_mark_busy(e820.map[i].type, res)) {
1015			res->flags |= IORESOURCE_BUSY;
1016			insert_resource(&iomem_resource, res);
1017		}
1018		res++;
1019	}
1020
1021	for (i = 0; i < e820_saved.nr_map; i++) {
1022		struct e820entry *entry = &e820_saved.map[i];
1023		firmware_map_add_early(entry->addr,
1024			entry->addr + entry->size,
1025			e820_type_to_string(entry->type));
1026	}
1027}
1028
1029/* How much should we pad RAM ending depending on where it is? */
1030static unsigned long ram_alignment(resource_size_t pos)
1031{
1032	unsigned long mb = pos >> 20;
1033
1034	/* To 64kB in the first megabyte */
1035	if (!mb)
1036		return 64*1024;
1037
1038	/* To 1MB in the first 16MB */
1039	if (mb < 16)
1040		return 1024*1024;
1041
1042	/* To 64MB for anything above that */
1043	return 64*1024*1024;
1044}
1045
1046#define MAX_RESOURCE_SIZE ((resource_size_t)-1)
1047
1048void __init e820_reserve_resources_late(void)
1049{
1050	int i;
1051	struct resource *res;
1052
1053	res = e820_res;
1054	for (i = 0; i < e820.nr_map; i++) {
1055		if (!res->parent && res->end)
1056			insert_resource_expand_to_fit(&iomem_resource, res);
1057		res++;
1058	}
1059
1060	/*
1061	 * Try to bump up RAM regions to reasonable boundaries to
1062	 * avoid stolen RAM:
1063	 */
1064	for (i = 0; i < e820.nr_map; i++) {
1065		struct e820entry *entry = &e820.map[i];
1066		u64 start, end;
1067
1068		if (entry->type != E820_RAM)
1069			continue;
1070		start = entry->addr + entry->size;
1071		end = round_up(start, ram_alignment(start)) - 1;
1072		if (end > MAX_RESOURCE_SIZE)
1073			end = MAX_RESOURCE_SIZE;
1074		if (start >= end)
1075			continue;
1076		printk(KERN_DEBUG
1077		       "e820: reserve RAM buffer [mem %#010llx-%#010llx]\n",
1078		       start, end);
1079		reserve_region_with_split(&iomem_resource, start, end,
1080					  "RAM buffer");
1081	}
1082}
1083
1084char *__init default_machine_specific_memory_setup(void)
1085{
1086	char *who = "BIOS-e820";
1087	u32 new_nr;
1088	/*
1089	 * Try to copy the BIOS-supplied E820-map.
1090	 *
1091	 * Otherwise fake a memory map; one section from 0k->640k,
1092	 * the next section from 1mb->appropriate_mem_k
1093	 */
1094	new_nr = boot_params.e820_entries;
1095	sanitize_e820_map(boot_params.e820_map,
1096			ARRAY_SIZE(boot_params.e820_map),
1097			&new_nr);
1098	boot_params.e820_entries = new_nr;
1099	if (append_e820_map(boot_params.e820_map, boot_params.e820_entries)
1100	  < 0) {
1101		u64 mem_size;
1102
1103		/* compare results from other methods and take the greater */
1104		if (boot_params.alt_mem_k
1105		    < boot_params.screen_info.ext_mem_k) {
1106			mem_size = boot_params.screen_info.ext_mem_k;
1107			who = "BIOS-88";
1108		} else {
1109			mem_size = boot_params.alt_mem_k;
1110			who = "BIOS-e801";
1111		}
1112
1113		e820.nr_map = 0;
1114		e820_add_region(0, LOWMEMSIZE(), E820_RAM);
1115		e820_add_region(HIGH_MEMORY, mem_size << 10, E820_RAM);
1116	}
1117
1118	/* In case someone cares... */
1119	return who;
1120}
1121
1122void __init setup_memory_map(void)
1123{
1124	char *who;
1125
1126	who = x86_init.resources.memory_setup();
1127	memcpy(&e820_saved, &e820, sizeof(struct e820map));
1128	printk(KERN_INFO "e820: BIOS-provided physical RAM map:\n");
1129	e820_print_map(who);
1130}
1131
1132void __init memblock_x86_fill(void)
1133{
1134	int i;
1135	u64 end;
1136
1137	/*
1138	 * EFI may have more than 128 entries
1139	 * We are safe to enable resizing, beause memblock_x86_fill()
1140	 * is rather later for x86
1141	 */
1142	memblock_allow_resize();
1143
1144	for (i = 0; i < e820.nr_map; i++) {
1145		struct e820entry *ei = &e820.map[i];
1146
1147		end = ei->addr + ei->size;
1148		if (end != (resource_size_t)end)
1149			continue;
1150
1151		if (ei->type != E820_RAM && ei->type != E820_RESERVED_KERN)
1152			continue;
1153
1154		memblock_add(ei->addr, ei->size);
1155	}
1156
1157	/* throw away partial pages */
1158	memblock_trim_memory(PAGE_SIZE);
1159
1160	memblock_dump_all();
1161}
1162
1163void __init memblock_find_dma_reserve(void)
1164{
1165#ifdef CONFIG_X86_64
1166	u64 nr_pages = 0, nr_free_pages = 0;
1167	unsigned long start_pfn, end_pfn;
1168	phys_addr_t start, end;
1169	int i;
1170	u64 u;
1171
1172	/*
1173	 * need to find out used area below MAX_DMA_PFN
1174	 * need to use memblock to get free size in [0, MAX_DMA_PFN]
1175	 * at first, and assume boot_mem will not take below MAX_DMA_PFN
1176	 */
1177	for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, NULL) {
1178		start_pfn = min(start_pfn, MAX_DMA_PFN);
1179		end_pfn = min(end_pfn, MAX_DMA_PFN);
1180		nr_pages += end_pfn - start_pfn;
1181	}
1182
1183	for_each_free_mem_range(u, NUMA_NO_NODE, MEMBLOCK_NONE, &start, &end,
1184				NULL) {
1185		start_pfn = min_t(unsigned long, PFN_UP(start), MAX_DMA_PFN);
1186		end_pfn = min_t(unsigned long, PFN_DOWN(end), MAX_DMA_PFN);
1187		if (start_pfn < end_pfn)
1188			nr_free_pages += end_pfn - start_pfn;
1189	}
1190
1191	set_dma_reserve(nr_pages - nr_free_pages);
1192#endif
1193}