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/arch/x86/kernel/e820.c

https://gitlab.com/Team-OSE-old/SimpleKernel
C | 1111 lines | 710 code | 145 blank | 256 comment | 147 complexity | 831d7be81945fda0b6bc4744394058b1 MD5 | raw file
   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
  28/*
  29 * The e820 map is the map that gets modified e.g. with command line parameters
  30 * and that is also registered with modifications in the kernel resource tree
  31 * with the iomem_resource as parent.
  32 *
  33 * The e820_saved is directly saved after the BIOS-provided memory map is
  34 * copied. It doesn't get modified afterwards. It's registered for the
  35 * /sys/firmware/memmap interface.
  36 *
  37 * That memory map is not modified and is used as base for kexec. The kexec'd
  38 * kernel should get the same memory map as the firmware provides. Then the
  39 * user can e.g. boot the original kernel with mem=1G while still booting the
  40 * next kernel with full memory.
  41 */
  42struct e820map e820;
  43struct e820map e820_saved;
  44
  45/* For PCI or other memory-mapped resources */
  46unsigned long pci_mem_start = 0xaeedbabe;
  47#ifdef CONFIG_PCI
  48EXPORT_SYMBOL(pci_mem_start);
  49#endif
  50
  51/*
  52 * This function checks if any part of the range <start,end> is mapped
  53 * with type.
  54 */
  55int
  56e820_any_mapped(u64 start, u64 end, unsigned type)
  57{
  58	int i;
  59
  60	for (i = 0; i < e820.nr_map; i++) {
  61		struct e820entry *ei = &e820.map[i];
  62
  63		if (type && ei->type != type)
  64			continue;
  65		if (ei->addr >= end || ei->addr + ei->size <= start)
  66			continue;
  67		return 1;
  68	}
  69	return 0;
  70}
  71EXPORT_SYMBOL_GPL(e820_any_mapped);
  72
  73/*
  74 * This function checks if the entire range <start,end> is mapped with type.
  75 *
  76 * Note: this function only works correct if the e820 table is sorted and
  77 * not-overlapping, which is the case
  78 */
  79int __init e820_all_mapped(u64 start, u64 end, unsigned type)
  80{
  81	int i;
  82
  83	for (i = 0; i < e820.nr_map; i++) {
  84		struct e820entry *ei = &e820.map[i];
  85
  86		if (type && ei->type != type)
  87			continue;
  88		/* is the region (part) in overlap with the current region ?*/
  89		if (ei->addr >= end || ei->addr + ei->size <= start)
  90			continue;
  91
  92		/* if the region is at the beginning of <start,end> we move
  93		 * start to the end of the region since it's ok until there
  94		 */
  95		if (ei->addr <= start)
  96			start = ei->addr + ei->size;
  97		/*
  98		 * if start is now at or beyond end, we're done, full
  99		 * coverage
 100		 */
 101		if (start >= end)
 102			return 1;
 103	}
 104	return 0;
 105}
 106
 107/*
 108 * Add a memory region to the kernel e820 map.
 109 */
 110static void __init __e820_add_region(struct e820map *e820x, u64 start, u64 size,
 111					 int type)
 112{
 113	int x = e820x->nr_map;
 114
 115	if (x >= ARRAY_SIZE(e820x->map)) {
 116		printk(KERN_ERR "Ooops! Too many entries in the memory map!\n");
 117		return;
 118	}
 119
 120	e820x->map[x].addr = start;
 121	e820x->map[x].size = size;
 122	e820x->map[x].type = type;
 123	e820x->nr_map++;
 124}
 125
 126void __init e820_add_region(u64 start, u64 size, int type)
 127{
 128	__e820_add_region(&e820, start, size, type);
 129}
 130
 131static void __init e820_print_type(u32 type)
 132{
 133	switch (type) {
 134	case E820_RAM:
 135	case E820_RESERVED_KERN:
 136		printk(KERN_CONT "(usable)");
 137		break;
 138	case E820_RESERVED:
 139		printk(KERN_CONT "(reserved)");
 140		break;
 141	case E820_ACPI:
 142		printk(KERN_CONT "(ACPI data)");
 143		break;
 144	case E820_NVS:
 145		printk(KERN_CONT "(ACPI NVS)");
 146		break;
 147	case E820_UNUSABLE:
 148		printk(KERN_CONT "(unusable)");
 149		break;
 150	default:
 151		printk(KERN_CONT "type %u", type);
 152		break;
 153	}
 154}
 155
 156void __init e820_print_map(char *who)
 157{
 158	int i;
 159
 160	for (i = 0; i < e820.nr_map; i++) {
 161		printk(KERN_INFO " %s: %016Lx - %016Lx ", who,
 162		       (unsigned long long) e820.map[i].addr,
 163		       (unsigned long long)
 164		       (e820.map[i].addr + e820.map[i].size));
 165		e820_print_type(e820.map[i].type);
 166		printk(KERN_CONT "\n");
 167	}
 168}
 169
 170/*
 171 * Sanitize the BIOS e820 map.
 172 *
 173 * Some e820 responses include overlapping entries. The following
 174 * replaces the original e820 map with a new one, removing overlaps,
 175 * and resolving conflicting memory types in favor of highest
 176 * numbered type.
 177 *
 178 * The input parameter biosmap points to an array of 'struct
 179 * e820entry' which on entry has elements in the range [0, *pnr_map)
 180 * valid, and which has space for up to max_nr_map entries.
 181 * On return, the resulting sanitized e820 map entries will be in
 182 * overwritten in the same location, starting at biosmap.
 183 *
 184 * The integer pointed to by pnr_map must be valid on entry (the
 185 * current number of valid entries located at biosmap) and will
 186 * be updated on return, with the new number of valid entries
 187 * (something no more than max_nr_map.)
 188 *
 189 * The return value from sanitize_e820_map() is zero if it
 190 * successfully 'sanitized' the map entries passed in, and is -1
 191 * if it did nothing, which can happen if either of (1) it was
 192 * only passed one map entry, or (2) any of the input map entries
 193 * were invalid (start + size < start, meaning that the size was
 194 * so big the described memory range wrapped around through zero.)
 195 *
 196 *	Visually we're performing the following
 197 *	(1,2,3,4 = memory types)...
 198 *
 199 *	Sample memory map (w/overlaps):
 200 *	   ____22__________________
 201 *	   ______________________4_
 202 *	   ____1111________________
 203 *	   _44_____________________
 204 *	   11111111________________
 205 *	   ____________________33__
 206 *	   ___________44___________
 207 *	   __________33333_________
 208 *	   ______________22________
 209 *	   ___________________2222_
 210 *	   _________111111111______
 211 *	   _____________________11_
 212 *	   _________________4______
 213 *
 214 *	Sanitized equivalent (no overlap):
 215 *	   1_______________________
 216 *	   _44_____________________
 217 *	   ___1____________________
 218 *	   ____22__________________
 219 *	   ______11________________
 220 *	   _________1______________
 221 *	   __________3_____________
 222 *	   ___________44___________
 223 *	   _____________33_________
 224 *	   _______________2________
 225 *	   ________________1_______
 226 *	   _________________4______
 227 *	   ___________________2____
 228 *	   ____________________33__
 229 *	   ______________________4_
 230 */
 231struct change_member {
 232	struct e820entry *pbios; /* pointer to original bios entry */
 233	unsigned long long addr; /* address for this change point */
 234};
 235
 236static int __init cpcompare(const void *a, const void *b)
 237{
 238	struct change_member * const *app = a, * const *bpp = b;
 239	const struct change_member *ap = *app, *bp = *bpp;
 240
 241	/*
 242	 * Inputs are pointers to two elements of change_point[].  If their
 243	 * addresses are unequal, their difference dominates.  If the addresses
 244	 * are equal, then consider one that represents the end of its region
 245	 * to be greater than one that does not.
 246	 */
 247	if (ap->addr != bp->addr)
 248		return ap->addr > bp->addr ? 1 : -1;
 249
 250	return (ap->addr != ap->pbios->addr) - (bp->addr != bp->pbios->addr);
 251}
 252
 253int __init sanitize_e820_map(struct e820entry *biosmap, int max_nr_map,
 254			     u32 *pnr_map)
 255{
 256	static struct change_member change_point_list[2*E820_X_MAX] __initdata;
 257	static struct change_member *change_point[2*E820_X_MAX] __initdata;
 258	static struct e820entry *overlap_list[E820_X_MAX] __initdata;
 259	static struct e820entry new_bios[E820_X_MAX] __initdata;
 260	unsigned long current_type, last_type;
 261	unsigned long long last_addr;
 262	int chgidx;
 263	int overlap_entries;
 264	int new_bios_entry;
 265	int old_nr, new_nr, chg_nr;
 266	int i;
 267
 268	/* if there's only one memory region, don't bother */
 269	if (*pnr_map < 2)
 270		return -1;
 271
 272	old_nr = *pnr_map;
 273	BUG_ON(old_nr > max_nr_map);
 274
 275	/* bail out if we find any unreasonable addresses in bios map */
 276	for (i = 0; i < old_nr; i++)
 277		if (biosmap[i].addr + biosmap[i].size < biosmap[i].addr)
 278			return -1;
 279
 280	/* create pointers for initial change-point information (for sorting) */
 281	for (i = 0; i < 2 * old_nr; i++)
 282		change_point[i] = &change_point_list[i];
 283
 284	/* record all known change-points (starting and ending addresses),
 285	   omitting those that are for empty memory regions */
 286	chgidx = 0;
 287	for (i = 0; i < old_nr; i++)	{
 288		if (biosmap[i].size != 0) {
 289			change_point[chgidx]->addr = biosmap[i].addr;
 290			change_point[chgidx++]->pbios = &biosmap[i];
 291			change_point[chgidx]->addr = biosmap[i].addr +
 292				biosmap[i].size;
 293			change_point[chgidx++]->pbios = &biosmap[i];
 294		}
 295	}
 296	chg_nr = chgidx;
 297
 298	/* sort change-point list by memory addresses (low -> high) */
 299	sort(change_point, chg_nr, sizeof *change_point, cpcompare, NULL);
 300
 301	/* create a new bios memory map, removing overlaps */
 302	overlap_entries = 0;	 /* number of entries in the overlap table */
 303	new_bios_entry = 0;	 /* index for creating new bios map entries */
 304	last_type = 0;		 /* start with undefined memory type */
 305	last_addr = 0;		 /* start with 0 as last starting address */
 306
 307	/* loop through change-points, determining affect on the new bios map */
 308	for (chgidx = 0; chgidx < chg_nr; chgidx++) {
 309		/* keep track of all overlapping bios entries */
 310		if (change_point[chgidx]->addr ==
 311		    change_point[chgidx]->pbios->addr) {
 312			/*
 313			 * add map entry to overlap list (> 1 entry
 314			 * implies an overlap)
 315			 */
 316			overlap_list[overlap_entries++] =
 317				change_point[chgidx]->pbios;
 318		} else {
 319			/*
 320			 * remove entry from list (order independent,
 321			 * so swap with last)
 322			 */
 323			for (i = 0; i < overlap_entries; i++) {
 324				if (overlap_list[i] ==
 325				    change_point[chgidx]->pbios)
 326					overlap_list[i] =
 327						overlap_list[overlap_entries-1];
 328			}
 329			overlap_entries--;
 330		}
 331		/*
 332		 * if there are overlapping entries, decide which
 333		 * "type" to use (larger value takes precedence --
 334		 * 1=usable, 2,3,4,4+=unusable)
 335		 */
 336		current_type = 0;
 337		for (i = 0; i < overlap_entries; i++)
 338			if (overlap_list[i]->type > current_type)
 339				current_type = overlap_list[i]->type;
 340		/*
 341		 * continue building up new bios map based on this
 342		 * information
 343		 */
 344		if (current_type != last_type)	{
 345			if (last_type != 0)	 {
 346				new_bios[new_bios_entry].size =
 347					change_point[chgidx]->addr - last_addr;
 348				/*
 349				 * move forward only if the new size
 350				 * was non-zero
 351				 */
 352				if (new_bios[new_bios_entry].size != 0)
 353					/*
 354					 * no more space left for new
 355					 * bios entries ?
 356					 */
 357					if (++new_bios_entry >= max_nr_map)
 358						break;
 359			}
 360			if (current_type != 0)	{
 361				new_bios[new_bios_entry].addr =
 362					change_point[chgidx]->addr;
 363				new_bios[new_bios_entry].type = current_type;
 364				last_addr = change_point[chgidx]->addr;
 365			}
 366			last_type = current_type;
 367		}
 368	}
 369	/* retain count for new bios entries */
 370	new_nr = new_bios_entry;
 371
 372	/* copy new bios mapping into original location */
 373	memcpy(biosmap, new_bios, new_nr * sizeof(struct e820entry));
 374	*pnr_map = new_nr;
 375
 376	return 0;
 377}
 378
 379static int __init __append_e820_map(struct e820entry *biosmap, int nr_map)
 380{
 381	while (nr_map) {
 382		u64 start = biosmap->addr;
 383		u64 size = biosmap->size;
 384		u64 end = start + size;
 385		u32 type = biosmap->type;
 386
 387		/* Overflow in 64 bits? Ignore the memory map. */
 388		if (start > end)
 389			return -1;
 390
 391		e820_add_region(start, size, type);
 392
 393		biosmap++;
 394		nr_map--;
 395	}
 396	return 0;
 397}
 398
 399/*
 400 * Copy the BIOS e820 map into a safe place.
 401 *
 402 * Sanity-check it while we're at it..
 403 *
 404 * If we're lucky and live on a modern system, the setup code
 405 * will have given us a memory map that we can use to properly
 406 * set up memory.  If we aren't, we'll fake a memory map.
 407 */
 408static int __init append_e820_map(struct e820entry *biosmap, int nr_map)
 409{
 410	/* Only one memory region (or negative)? Ignore it */
 411	if (nr_map < 2)
 412		return -1;
 413
 414	return __append_e820_map(biosmap, nr_map);
 415}
 416
 417static u64 __init __e820_update_range(struct e820map *e820x, u64 start,
 418					u64 size, unsigned old_type,
 419					unsigned new_type)
 420{
 421	u64 end;
 422	unsigned int i;
 423	u64 real_updated_size = 0;
 424
 425	BUG_ON(old_type == new_type);
 426
 427	if (size > (ULLONG_MAX - start))
 428		size = ULLONG_MAX - start;
 429
 430	end = start + size;
 431	printk(KERN_DEBUG "e820 update range: %016Lx - %016Lx ",
 432		       (unsigned long long) start,
 433		       (unsigned long long) end);
 434	e820_print_type(old_type);
 435	printk(KERN_CONT " ==> ");
 436	e820_print_type(new_type);
 437	printk(KERN_CONT "\n");
 438
 439	for (i = 0; i < e820x->nr_map; i++) {
 440		struct e820entry *ei = &e820x->map[i];
 441		u64 final_start, final_end;
 442		u64 ei_end;
 443
 444		if (ei->type != old_type)
 445			continue;
 446
 447		ei_end = ei->addr + ei->size;
 448		/* totally covered by new range? */
 449		if (ei->addr >= start && ei_end <= end) {
 450			ei->type = new_type;
 451			real_updated_size += ei->size;
 452			continue;
 453		}
 454
 455		/* new range is totally covered? */
 456		if (ei->addr < start && ei_end > end) {
 457			__e820_add_region(e820x, start, size, new_type);
 458			__e820_add_region(e820x, end, ei_end - end, ei->type);
 459			ei->size = start - ei->addr;
 460			real_updated_size += size;
 461			continue;
 462		}
 463
 464		/* partially covered */
 465		final_start = max(start, ei->addr);
 466		final_end = min(end, ei_end);
 467		if (final_start >= final_end)
 468			continue;
 469
 470		__e820_add_region(e820x, final_start, final_end - final_start,
 471				  new_type);
 472
 473		real_updated_size += final_end - final_start;
 474
 475		/*
 476		 * left range could be head or tail, so need to update
 477		 * size at first.
 478		 */
 479		ei->size -= final_end - final_start;
 480		if (ei->addr < final_start)
 481			continue;
 482		ei->addr = final_end;
 483	}
 484	return real_updated_size;
 485}
 486
 487u64 __init e820_update_range(u64 start, u64 size, unsigned old_type,
 488			     unsigned new_type)
 489{
 490	return __e820_update_range(&e820, start, size, old_type, new_type);
 491}
 492
 493static u64 __init e820_update_range_saved(u64 start, u64 size,
 494					  unsigned old_type, unsigned new_type)
 495{
 496	return __e820_update_range(&e820_saved, start, size, old_type,
 497				     new_type);
 498}
 499
 500/* make e820 not cover the range */
 501u64 __init e820_remove_range(u64 start, u64 size, unsigned old_type,
 502			     int checktype)
 503{
 504	int i;
 505	u64 end;
 506	u64 real_removed_size = 0;
 507
 508	if (size > (ULLONG_MAX - start))
 509		size = ULLONG_MAX - start;
 510
 511	end = start + size;
 512	printk(KERN_DEBUG "e820 remove range: %016Lx - %016Lx ",
 513		       (unsigned long long) start,
 514		       (unsigned long long) end);
 515	if (checktype)
 516		e820_print_type(old_type);
 517	printk(KERN_CONT "\n");
 518
 519	for (i = 0; i < e820.nr_map; i++) {
 520		struct e820entry *ei = &e820.map[i];
 521		u64 final_start, final_end;
 522		u64 ei_end;
 523
 524		if (checktype && ei->type != old_type)
 525			continue;
 526
 527		ei_end = ei->addr + ei->size;
 528		/* totally covered? */
 529		if (ei->addr >= start && ei_end <= end) {
 530			real_removed_size += ei->size;
 531			memset(ei, 0, sizeof(struct e820entry));
 532			continue;
 533		}
 534
 535		/* new range is totally covered? */
 536		if (ei->addr < start && ei_end > end) {
 537			e820_add_region(end, ei_end - end, ei->type);
 538			ei->size = start - ei->addr;
 539			real_removed_size += size;
 540			continue;
 541		}
 542
 543		/* partially covered */
 544		final_start = max(start, ei->addr);
 545		final_end = min(end, ei_end);
 546		if (final_start >= final_end)
 547			continue;
 548		real_removed_size += final_end - final_start;
 549
 550		/*
 551		 * left range could be head or tail, so need to update
 552		 * size at first.
 553		 */
 554		ei->size -= final_end - final_start;
 555		if (ei->addr < final_start)
 556			continue;
 557		ei->addr = final_end;
 558	}
 559	return real_removed_size;
 560}
 561
 562void __init update_e820(void)
 563{
 564	u32 nr_map;
 565
 566	nr_map = e820.nr_map;
 567	if (sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &nr_map))
 568		return;
 569	e820.nr_map = nr_map;
 570	printk(KERN_INFO "modified physical RAM map:\n");
 571	e820_print_map("modified");
 572}
 573static void __init update_e820_saved(void)
 574{
 575	u32 nr_map;
 576
 577	nr_map = e820_saved.nr_map;
 578	if (sanitize_e820_map(e820_saved.map, ARRAY_SIZE(e820_saved.map), &nr_map))
 579		return;
 580	e820_saved.nr_map = nr_map;
 581}
 582#define MAX_GAP_END 0x100000000ull
 583/*
 584 * Search for a gap in the e820 memory space from start_addr to end_addr.
 585 */
 586__init int e820_search_gap(unsigned long *gapstart, unsigned long *gapsize,
 587		unsigned long start_addr, unsigned long long end_addr)
 588{
 589	unsigned long long last;
 590	int i = e820.nr_map;
 591	int found = 0;
 592
 593	last = (end_addr && end_addr < MAX_GAP_END) ? end_addr : MAX_GAP_END;
 594
 595	while (--i >= 0) {
 596		unsigned long long start = e820.map[i].addr;
 597		unsigned long long end = start + e820.map[i].size;
 598
 599		if (end < start_addr)
 600			continue;
 601
 602		/*
 603		 * Since "last" is at most 4GB, we know we'll
 604		 * fit in 32 bits if this condition is true
 605		 */
 606		if (last > end) {
 607			unsigned long gap = last - end;
 608
 609			if (gap >= *gapsize) {
 610				*gapsize = gap;
 611				*gapstart = end;
 612				found = 1;
 613			}
 614		}
 615		if (start < last)
 616			last = start;
 617	}
 618	return found;
 619}
 620
 621/*
 622 * Search for the biggest gap in the low 32 bits of the e820
 623 * memory space.  We pass this space to PCI to assign MMIO resources
 624 * for hotplug or unconfigured devices in.
 625 * Hopefully the BIOS let enough space left.
 626 */
 627__init void e820_setup_gap(void)
 628{
 629	unsigned long gapstart, gapsize;
 630	int found;
 631
 632	gapstart = 0x10000000;
 633	gapsize = 0x400000;
 634	found  = e820_search_gap(&gapstart, &gapsize, 0, MAX_GAP_END);
 635
 636#ifdef CONFIG_X86_64
 637	if (!found) {
 638		gapstart = (max_pfn << PAGE_SHIFT) + 1024*1024;
 639		printk(KERN_ERR
 640	"PCI: Warning: Cannot find a gap in the 32bit address range\n"
 641	"PCI: Unassigned devices with 32bit resource registers may break!\n");
 642	}
 643#endif
 644
 645	/*
 646	 * e820_reserve_resources_late protect stolen RAM already
 647	 */
 648	pci_mem_start = gapstart;
 649
 650	printk(KERN_INFO
 651	       "Allocating PCI resources starting at %lx (gap: %lx:%lx)\n",
 652	       pci_mem_start, gapstart, gapsize);
 653}
 654
 655/**
 656 * Because of the size limitation of struct boot_params, only first
 657 * 128 E820 memory entries are passed to kernel via
 658 * boot_params.e820_map, others are passed via SETUP_E820_EXT node of
 659 * linked list of struct setup_data, which is parsed here.
 660 */
 661void __init parse_e820_ext(struct setup_data *sdata)
 662{
 663	int entries;
 664	struct e820entry *extmap;
 665
 666	entries = sdata->len / sizeof(struct e820entry);
 667	extmap = (struct e820entry *)(sdata->data);
 668	__append_e820_map(extmap, entries);
 669	sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
 670	printk(KERN_INFO "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 and assumes the first e820 area to be RAM.
 683 */
 684void __init e820_mark_nosave_regions(unsigned long limit_pfn)
 685{
 686	int i;
 687	unsigned long pfn;
 688
 689	pfn = PFN_DOWN(e820.map[0].addr + e820.map[0].size);
 690	for (i = 1; i < e820.nr_map; i++) {
 691		struct e820entry *ei = &e820.map[i];
 692
 693		if (pfn < PFN_UP(ei->addr))
 694			register_nosave_region(pfn, PFN_UP(ei->addr));
 695
 696		pfn = PFN_DOWN(ei->addr + ei->size);
 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 "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, unsigned type)
 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		if (ei->type != type)
 769			continue;
 770
 771		start_pfn = ei->addr >> PAGE_SHIFT;
 772		end_pfn = (ei->addr + ei->size) >> PAGE_SHIFT;
 773
 774		if (start_pfn >= limit_pfn)
 775			continue;
 776		if (end_pfn > limit_pfn) {
 777			last_pfn = limit_pfn;
 778			break;
 779		}
 780		if (end_pfn > last_pfn)
 781			last_pfn = end_pfn;
 782	}
 783
 784	if (last_pfn > max_arch_pfn)
 785		last_pfn = max_arch_pfn;
 786
 787	printk(KERN_INFO "last_pfn = %#lx max_arch_pfn = %#lx\n",
 788			 last_pfn, max_arch_pfn);
 789	return last_pfn;
 790}
 791unsigned long __init e820_end_of_ram_pfn(void)
 792{
 793	return e820_end_pfn(MAX_ARCH_PFN, E820_RAM);
 794}
 795
 796unsigned long __init e820_end_of_low_ram_pfn(void)
 797{
 798	return e820_end_pfn(1UL<<(32 - PAGE_SHIFT), E820_RAM);
 799}
 800
 801static void early_panic(char *msg)
 802{
 803	early_printk(msg);
 804	panic(msg);
 805}
 806
 807static int userdef __initdata;
 808
 809/* "mem=nopentium" disables the 4MB page tables. */
 810static int __init parse_memopt(char *p)
 811{
 812	u64 mem_size;
 813
 814	if (!p)
 815		return -EINVAL;
 816
 817	if (!strcmp(p, "nopentium")) {
 818#ifdef CONFIG_X86_32
 819		setup_clear_cpu_cap(X86_FEATURE_PSE);
 820		return 0;
 821#else
 822		printk(KERN_WARNING "mem=nopentium ignored! (only supported on x86_32)\n");
 823		return -EINVAL;
 824#endif
 825	}
 826
 827	userdef = 1;
 828	mem_size = memparse(p, &p);
 829	/* don't remove all of memory when handling "mem={invalid}" param */
 830	if (mem_size == 0)
 831		return -EINVAL;
 832	e820_remove_range(mem_size, ULLONG_MAX - mem_size, E820_RAM, 1);
 833
 834	return 0;
 835}
 836early_param("mem", parse_memopt);
 837
 838static int __init parse_memmap_opt(char *p)
 839{
 840	char *oldp;
 841	u64 start_at, mem_size;
 842
 843	if (!p)
 844		return -EINVAL;
 845
 846	if (!strncmp(p, "exactmap", 8)) {
 847#ifdef CONFIG_CRASH_DUMP
 848		/*
 849		 * If we are doing a crash dump, we still need to know
 850		 * the real mem size before original memory map is
 851		 * reset.
 852		 */
 853		saved_max_pfn = e820_end_of_ram_pfn();
 854#endif
 855		e820.nr_map = 0;
 856		userdef = 1;
 857		return 0;
 858	}
 859
 860	oldp = p;
 861	mem_size = memparse(p, &p);
 862	if (p == oldp)
 863		return -EINVAL;
 864
 865	userdef = 1;
 866	if (*p == '@') {
 867		start_at = memparse(p+1, &p);
 868		e820_add_region(start_at, mem_size, E820_RAM);
 869	} else if (*p == '#') {
 870		start_at = memparse(p+1, &p);
 871		e820_add_region(start_at, mem_size, E820_ACPI);
 872	} else if (*p == '$') {
 873		start_at = memparse(p+1, &p);
 874		e820_add_region(start_at, mem_size, E820_RESERVED);
 875	} else
 876		e820_remove_range(mem_size, ULLONG_MAX - mem_size, E820_RAM, 1);
 877
 878	return *p == '\0' ? 0 : -EINVAL;
 879}
 880early_param("memmap", parse_memmap_opt);
 881
 882void __init finish_e820_parsing(void)
 883{
 884	if (userdef) {
 885		u32 nr = e820.nr_map;
 886
 887		if (sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &nr) < 0)
 888			early_panic("Invalid user supplied memory map");
 889		e820.nr_map = nr;
 890
 891		printk(KERN_INFO "user-defined physical RAM map:\n");
 892		e820_print_map("user");
 893	}
 894}
 895
 896static inline const char *e820_type_to_string(int e820_type)
 897{
 898	switch (e820_type) {
 899	case E820_RESERVED_KERN:
 900	case E820_RAM:	return "System RAM";
 901	case E820_ACPI:	return "ACPI Tables";
 902	case E820_NVS:	return "ACPI Non-volatile Storage";
 903	case E820_UNUSABLE:	return "Unusable memory";
 904	default:	return "reserved";
 905	}
 906}
 907
 908/*
 909 * Mark e820 reserved areas as busy for the resource manager.
 910 */
 911static struct resource __initdata *e820_res;
 912void __init e820_reserve_resources(void)
 913{
 914	int i;
 915	struct resource *res;
 916	u64 end;
 917
 918	res = alloc_bootmem(sizeof(struct resource) * e820.nr_map);
 919	e820_res = res;
 920	for (i = 0; i < e820.nr_map; i++) {
 921		end = e820.map[i].addr + e820.map[i].size - 1;
 922		if (end != (resource_size_t)end) {
 923			res++;
 924			continue;
 925		}
 926		res->name = e820_type_to_string(e820.map[i].type);
 927		res->start = e820.map[i].addr;
 928		res->end = end;
 929
 930		res->flags = IORESOURCE_MEM;
 931
 932		/*
 933		 * don't register the region that could be conflicted with
 934		 * pci device BAR resource and insert them later in
 935		 * pcibios_resource_survey()
 936		 */
 937		if (e820.map[i].type != E820_RESERVED || res->start < (1ULL<<20)) {
 938			res->flags |= IORESOURCE_BUSY;
 939			insert_resource(&iomem_resource, res);
 940		}
 941		res++;
 942	}
 943
 944	for (i = 0; i < e820_saved.nr_map; i++) {
 945		struct e820entry *entry = &e820_saved.map[i];
 946		firmware_map_add_early(entry->addr,
 947			entry->addr + entry->size - 1,
 948			e820_type_to_string(entry->type));
 949	}
 950}
 951
 952/* How much should we pad RAM ending depending on where it is? */
 953static unsigned long ram_alignment(resource_size_t pos)
 954{
 955	unsigned long mb = pos >> 20;
 956
 957	/* To 64kB in the first megabyte */
 958	if (!mb)
 959		return 64*1024;
 960
 961	/* To 1MB in the first 16MB */
 962	if (mb < 16)
 963		return 1024*1024;
 964
 965	/* To 64MB for anything above that */
 966	return 64*1024*1024;
 967}
 968
 969#define MAX_RESOURCE_SIZE ((resource_size_t)-1)
 970
 971void __init e820_reserve_resources_late(void)
 972{
 973	int i;
 974	struct resource *res;
 975
 976	res = e820_res;
 977	for (i = 0; i < e820.nr_map; i++) {
 978		if (!res->parent && res->end)
 979			insert_resource_expand_to_fit(&iomem_resource, res);
 980		res++;
 981	}
 982
 983	/*
 984	 * Try to bump up RAM regions to reasonable boundaries to
 985	 * avoid stolen RAM:
 986	 */
 987	for (i = 0; i < e820.nr_map; i++) {
 988		struct e820entry *entry = &e820.map[i];
 989		u64 start, end;
 990
 991		if (entry->type != E820_RAM)
 992			continue;
 993		start = entry->addr + entry->size;
 994		end = round_up(start, ram_alignment(start)) - 1;
 995		if (end > MAX_RESOURCE_SIZE)
 996			end = MAX_RESOURCE_SIZE;
 997		if (start >= end)
 998			continue;
 999		printk(KERN_DEBUG "reserve RAM buffer: %016llx - %016llx ",
1000			       start, end);
1001		reserve_region_with_split(&iomem_resource, start, end,
1002					  "RAM buffer");
1003	}
1004}
1005
1006char *__init default_machine_specific_memory_setup(void)
1007{
1008	char *who = "BIOS-e820";
1009	u32 new_nr;
1010	/*
1011	 * Try to copy the BIOS-supplied E820-map.
1012	 *
1013	 * Otherwise fake a memory map; one section from 0k->640k,
1014	 * the next section from 1mb->appropriate_mem_k
1015	 */
1016	new_nr = boot_params.e820_entries;
1017	sanitize_e820_map(boot_params.e820_map,
1018			ARRAY_SIZE(boot_params.e820_map),
1019			&new_nr);
1020	boot_params.e820_entries = new_nr;
1021	if (append_e820_map(boot_params.e820_map, boot_params.e820_entries)
1022	  < 0) {
1023		u64 mem_size;
1024
1025		/* compare results from other methods and take the greater */
1026		if (boot_params.alt_mem_k
1027		    < boot_params.screen_info.ext_mem_k) {
1028			mem_size = boot_params.screen_info.ext_mem_k;
1029			who = "BIOS-88";
1030		} else {
1031			mem_size = boot_params.alt_mem_k;
1032			who = "BIOS-e801";
1033		}
1034
1035		e820.nr_map = 0;
1036		e820_add_region(0, LOWMEMSIZE(), E820_RAM);
1037		e820_add_region(HIGH_MEMORY, mem_size << 10, E820_RAM);
1038	}
1039
1040	/* In case someone cares... */
1041	return who;
1042}
1043
1044void __init setup_memory_map(void)
1045{
1046	char *who;
1047
1048	who = x86_init.resources.memory_setup();
1049	memcpy(&e820_saved, &e820, sizeof(struct e820map));
1050	printk(KERN_INFO "BIOS-provided physical RAM map:\n");
1051	e820_print_map(who);
1052}
1053
1054void __init memblock_x86_fill(void)
1055{
1056	int i;
1057	u64 end;
1058
1059	/*
1060	 * EFI may have more than 128 entries
1061	 * We are safe to enable resizing, beause memblock_x86_fill()
1062	 * is rather later for x86
1063	 */
1064	memblock_allow_resize();
1065
1066	for (i = 0; i < e820.nr_map; i++) {
1067		struct e820entry *ei = &e820.map[i];
1068
1069		end = ei->addr + ei->size;
1070		if (end != (resource_size_t)end)
1071			continue;
1072
1073		if (ei->type != E820_RAM && ei->type != E820_RESERVED_KERN)
1074			continue;
1075
1076		memblock_add(ei->addr, ei->size);
1077	}
1078
1079	memblock_dump_all();
1080}
1081
1082void __init memblock_find_dma_reserve(void)
1083{
1084#ifdef CONFIG_X86_64
1085	u64 nr_pages = 0, nr_free_pages = 0;
1086	unsigned long start_pfn, end_pfn;
1087	phys_addr_t start, end;
1088	int i;
1089	u64 u;
1090
1091	/*
1092	 * need to find out used area below MAX_DMA_PFN
1093	 * need to use memblock to get free size in [0, MAX_DMA_PFN]
1094	 * at first, and assume boot_mem will not take below MAX_DMA_PFN
1095	 */
1096	for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, NULL) {
1097		start_pfn = min_t(unsigned long, start_pfn, MAX_DMA_PFN);
1098		end_pfn = min_t(unsigned long, end_pfn, MAX_DMA_PFN);
1099		nr_pages += end_pfn - start_pfn;
1100	}
1101
1102	for_each_free_mem_range(u, MAX_NUMNODES, &start, &end, NULL) {
1103		start_pfn = min_t(unsigned long, PFN_UP(start), MAX_DMA_PFN);
1104		end_pfn = min_t(unsigned long, PFN_DOWN(end), MAX_DMA_PFN);
1105		if (start_pfn < end_pfn)
1106			nr_free_pages += end_pfn - start_pfn;
1107	}
1108
1109	set_dma_reserve(nr_pages - nr_free_pages);
1110#endif
1111}