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v4.17
   1/*
   2 * Low level x86 E820 memory map handling functions.
 
   3 *
   4 * The firmware and bootloader passes us the "E820 table", which is the primary
   5 * physical memory layout description available about x86 systems.
 
 
   6 *
   7 * The kernel takes the E820 memory layout and optionally modifies it with
   8 * quirks and other tweaks, and feeds that into the generic Linux memory
   9 * allocation code routines via a platform independent interface (memblock, etc.).
  10 */
 
 
 
  11#include <linux/crash_dump.h>
  12#include <linux/bootmem.h>
 
  13#include <linux/suspend.h>
  14#include <linux/acpi.h>
  15#include <linux/firmware-map.h>
  16#include <linux/memblock.h>
  17#include <linux/sort.h>
  18
  19#include <asm/e820/api.h>
 
  20#include <asm/setup.h>
  21
  22/*
  23 * We organize the E820 table into three main data structures:
  24 *
  25 * - 'e820_table_firmware': the original firmware version passed to us by the
  26 *   bootloader - not modified by the kernel. It is composed of two parts:
  27 *   the first 128 E820 memory entries in boot_params.e820_table and the remaining
  28 *   (if any) entries of the SETUP_E820_EXT nodes. We use this to:
  29 *
  30 *       - inform the user about the firmware's notion of memory layout
  31 *         via /sys/firmware/memmap
  32 *
  33 *       - the hibernation code uses it to generate a kernel-independent MD5
  34 *         fingerprint of the physical memory layout of a system.
  35 *
  36 * - 'e820_table_kexec': a slightly modified (by the kernel) firmware version
  37 *   passed to us by the bootloader - the major difference between
  38 *   e820_table_firmware[] and this one is that, the latter marks the setup_data
  39 *   list created by the EFI boot stub as reserved, so that kexec can reuse the
  40 *   setup_data information in the second kernel. Besides, e820_table_kexec[]
  41 *   might also be modified by the kexec itself to fake a mptable.
  42 *   We use this to:
  43 *
  44 *       - kexec, which is a bootloader in disguise, uses the original E820
  45 *         layout to pass to the kexec-ed kernel. This way the original kernel
  46 *         can have a restricted E820 map while the kexec()-ed kexec-kernel
  47 *         can have access to full memory - etc.
  48 *
  49 * - 'e820_table': this is the main E820 table that is massaged by the
  50 *   low level x86 platform code, or modified by boot parameters, before
  51 *   passed on to higher level MM layers.
  52 *
  53 * Once the E820 map has been converted to the standard Linux memory layout
  54 * information its role stops - modifying it has no effect and does not get
  55 * re-propagated. So itsmain role is a temporary bootstrap storage of firmware
  56 * specific memory layout data during early bootup.
  57 */
  58static struct e820_table e820_table_init		__initdata;
  59static struct e820_table e820_table_kexec_init		__initdata;
  60static struct e820_table e820_table_firmware_init	__initdata;
  61
  62struct e820_table *e820_table __refdata			= &e820_table_init;
  63struct e820_table *e820_table_kexec __refdata		= &e820_table_kexec_init;
  64struct e820_table *e820_table_firmware __refdata	= &e820_table_firmware_init;
  65
  66/* For PCI or other memory-mapped resources */
  67unsigned long pci_mem_start = 0xaeedbabe;
  68#ifdef CONFIG_PCI
  69EXPORT_SYMBOL(pci_mem_start);
  70#endif
  71
  72/*
  73 * This function checks if any part of the range <start,end> is mapped
  74 * with type.
  75 */
  76bool e820__mapped_any(u64 start, u64 end, enum e820_type type)
 
  77{
  78	int i;
  79
  80	for (i = 0; i < e820_table->nr_entries; i++) {
  81		struct e820_entry *entry = &e820_table->entries[i];
  82
  83		if (type && entry->type != type)
  84			continue;
  85		if (entry->addr >= end || entry->addr + entry->size <= start)
  86			continue;
  87		return 1;
  88	}
  89	return 0;
  90}
  91EXPORT_SYMBOL_GPL(e820__mapped_any);
  92
  93/*
  94 * This function checks if the entire <start,end> range is mapped with 'type'.
  95 *
  96 * Note: this function only works correctly once the E820 table is sorted and
  97 * not-overlapping (at least for the range specified), which is the case normally.
  98 */
  99static struct e820_entry *__e820__mapped_all(u64 start, u64 end,
 100					     enum e820_type type)
 101{
 102	int i;
 103
 104	for (i = 0; i < e820_table->nr_entries; i++) {
 105		struct e820_entry *entry = &e820_table->entries[i];
 106
 107		if (type && entry->type != type)
 108			continue;
 109
 110		/* Is the region (part) in overlap with the current region? */
 111		if (entry->addr >= end || entry->addr + entry->size <= start)
 112			continue;
 113
 114		/*
 115		 * If the region is at the beginning of <start,end> we move
 116		 * 'start' to the end of the region since it's ok until there
 117		 */
 118		if (entry->addr <= start)
 119			start = entry->addr + entry->size;
 120
 121		/*
 122		 * If 'start' is now at or beyond 'end', we're done, full
 123		 * coverage of the desired range exists:
 124		 */
 125		if (start >= end)
 126			return entry;
 127	}
 128
 129	return NULL;
 130}
 131
 132/*
 133 * This function checks if the entire range <start,end> is mapped with type.
 134 */
 135bool __init e820__mapped_all(u64 start, u64 end, enum e820_type type)
 136{
 137	return __e820__mapped_all(start, end, type);
 138}
 139
 140/*
 141 * This function returns the type associated with the range <start,end>.
 142 */
 143int e820__get_entry_type(u64 start, u64 end)
 144{
 145	struct e820_entry *entry = __e820__mapped_all(start, end, 0);
 146
 147	return entry ? entry->type : -EINVAL;
 148}
 149
 150/*
 151 * Add a memory region to the kernel E820 map.
 152 */
 153static void __init __e820__range_add(struct e820_table *table, u64 start, u64 size, enum e820_type type)
 
 154{
 155	int x = table->nr_entries;
 156
 157	if (x >= ARRAY_SIZE(table->entries)) {
 158		pr_err("e820: too many entries; ignoring [mem %#010llx-%#010llx]\n", start, start + size - 1);
 159		return;
 160	}
 161
 162	table->entries[x].addr = start;
 163	table->entries[x].size = size;
 164	table->entries[x].type = type;
 165	table->nr_entries++;
 166}
 167
 168void __init e820__range_add(u64 start, u64 size, enum e820_type type)
 169{
 170	__e820__range_add(e820_table, start, size, type);
 171}
 172
 173static void __init e820_print_type(enum e820_type type)
 174{
 175	switch (type) {
 176	case E820_TYPE_RAM:		/* Fall through: */
 177	case E820_TYPE_RESERVED_KERN:	pr_cont("usable");			break;
 178	case E820_TYPE_RESERVED:	pr_cont("reserved");			break;
 179	case E820_TYPE_ACPI:		pr_cont("ACPI data");			break;
 180	case E820_TYPE_NVS:		pr_cont("ACPI NVS");			break;
 181	case E820_TYPE_UNUSABLE:	pr_cont("unusable");			break;
 182	case E820_TYPE_PMEM:		/* Fall through: */
 183	case E820_TYPE_PRAM:		pr_cont("persistent (type %u)", type);	break;
 184	default:			pr_cont("type %u", type);		break;
 
 
 
 
 
 
 
 
 
 
 185	}
 186}
 187
 188void __init e820__print_table(char *who)
 189{
 190	int i;
 191
 192	for (i = 0; i < e820_table->nr_entries; i++) {
 193		pr_info("%s: [mem %#018Lx-%#018Lx] ", who,
 194		       e820_table->entries[i].addr,
 195		       e820_table->entries[i].addr + e820_table->entries[i].size - 1);
 196
 197		e820_print_type(e820_table->entries[i].type);
 198		pr_cont("\n");
 199	}
 200}
 201
 202/*
 203 * Sanitize an E820 map.
 204 *
 205 * Some E820 layouts include overlapping entries. The following
 206 * replaces the original E820 map with a new one, removing overlaps,
 207 * and resolving conflicting memory types in favor of highest
 208 * numbered type.
 209 *
 210 * The input parameter 'entries' points to an array of 'struct
 211 * e820_entry' which on entry has elements in the range [0, *nr_entries)
 212 * valid, and which has space for up to max_nr_entries entries.
 213 * On return, the resulting sanitized E820 map entries will be in
 214 * overwritten in the same location, starting at 'entries'.
 215 *
 216 * The integer pointed to by nr_entries must be valid on entry (the
 217 * current number of valid entries located at 'entries'). If the
 218 * sanitizing succeeds the *nr_entries will be updated with the new
 219 * number of valid entries (something no more than max_nr_entries).
 220 *
 221 * The return value from e820__update_table() is zero if it
 222 * successfully 'sanitized' the map entries passed in, and is -1
 223 * if it did nothing, which can happen if either of (1) it was
 224 * only passed one map entry, or (2) any of the input map entries
 225 * were invalid (start + size < start, meaning that the size was
 226 * so big the described memory range wrapped around through zero.)
 227 *
 228 *	Visually we're performing the following
 229 *	(1,2,3,4 = memory types)...
 230 *
 231 *	Sample memory map (w/overlaps):
 232 *	   ____22__________________
 233 *	   ______________________4_
 234 *	   ____1111________________
 235 *	   _44_____________________
 236 *	   11111111________________
 237 *	   ____________________33__
 238 *	   ___________44___________
 239 *	   __________33333_________
 240 *	   ______________22________
 241 *	   ___________________2222_
 242 *	   _________111111111______
 243 *	   _____________________11_
 244 *	   _________________4______
 245 *
 246 *	Sanitized equivalent (no overlap):
 247 *	   1_______________________
 248 *	   _44_____________________
 249 *	   ___1____________________
 250 *	   ____22__________________
 251 *	   ______11________________
 252 *	   _________1______________
 253 *	   __________3_____________
 254 *	   ___________44___________
 255 *	   _____________33_________
 256 *	   _______________2________
 257 *	   ________________1_______
 258 *	   _________________4______
 259 *	   ___________________2____
 260 *	   ____________________33__
 261 *	   ______________________4_
 262 */
 263struct change_member {
 264	/* Pointer to the original entry: */
 265	struct e820_entry	*entry;
 266	/* Address for this change point: */
 267	unsigned long long	addr;
 268};
 269
 270static struct change_member	change_point_list[2*E820_MAX_ENTRIES]	__initdata;
 271static struct change_member	*change_point[2*E820_MAX_ENTRIES]	__initdata;
 272static struct e820_entry	*overlap_list[E820_MAX_ENTRIES]		__initdata;
 273static struct e820_entry	new_entries[E820_MAX_ENTRIES]		__initdata;
 274
 275static int __init cpcompare(const void *a, const void *b)
 276{
 277	struct change_member * const *app = a, * const *bpp = b;
 278	const struct change_member *ap = *app, *bp = *bpp;
 279
 280	/*
 281	 * Inputs are pointers to two elements of change_point[].  If their
 282	 * addresses are not equal, their difference dominates.  If the addresses
 283	 * are equal, then consider one that represents the end of its region
 284	 * to be greater than one that does not.
 285	 */
 286	if (ap->addr != bp->addr)
 287		return ap->addr > bp->addr ? 1 : -1;
 288
 289	return (ap->addr != ap->entry->addr) - (bp->addr != bp->entry->addr);
 290}
 291
 292int __init e820__update_table(struct e820_table *table)
 293{
 294	struct e820_entry *entries = table->entries;
 295	u32 max_nr_entries = ARRAY_SIZE(table->entries);
 296	enum e820_type current_type, last_type;
 
 
 
 
 
 
 
 297	unsigned long long last_addr;
 298	u32 new_nr_entries, overlap_entries;
 299	u32 i, chg_idx, chg_nr;
 
 
 
 300
 301	/* If there's only one memory region, don't bother: */
 302	if (table->nr_entries < 2)
 303		return -1;
 304
 305	BUG_ON(table->nr_entries > max_nr_entries);
 
 306
 307	/* Bail out if we find any unreasonable addresses in the map: */
 308	for (i = 0; i < table->nr_entries; i++) {
 309		if (entries[i].addr + entries[i].size < entries[i].addr)
 310			return -1;
 311	}
 312
 313	/* Create pointers for initial change-point information (for sorting): */
 314	for (i = 0; i < 2 * table->nr_entries; i++)
 315		change_point[i] = &change_point_list[i];
 316
 317	/*
 318	 * Record all known change-points (starting and ending addresses),
 319	 * omitting empty memory regions:
 320	 */
 321	chg_idx = 0;
 322	for (i = 0; i < table->nr_entries; i++)	{
 323		if (entries[i].size != 0) {
 324			change_point[chg_idx]->addr	= entries[i].addr;
 325			change_point[chg_idx++]->entry	= &entries[i];
 326			change_point[chg_idx]->addr	= entries[i].addr + entries[i].size;
 327			change_point[chg_idx++]->entry	= &entries[i];
 328		}
 329	}
 330	chg_nr = chg_idx;
 331
 332	/* Sort change-point list by memory addresses (low -> high): */
 333	sort(change_point, chg_nr, sizeof(*change_point), cpcompare, NULL);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 334
 335	/* Create a new memory map, removing overlaps: */
 336	overlap_entries = 0;	 /* Number of entries in the overlap table */
 337	new_nr_entries = 0;	 /* Index for creating new map entries */
 338	last_type = 0;		 /* Start with undefined memory type */
 339	last_addr = 0;		 /* Start with 0 as last starting address */
 340
 341	/* Loop through change-points, determining effect on the new map: */
 342	for (chg_idx = 0; chg_idx < chg_nr; chg_idx++) {
 343		/* Keep track of all overlapping entries */
 344		if (change_point[chg_idx]->addr == change_point[chg_idx]->entry->addr) {
 345			/* Add map entry to overlap list (> 1 entry implies an overlap) */
 346			overlap_list[overlap_entries++] = change_point[chg_idx]->entry;
 
 
 
 
 
 347		} else {
 348			/* Remove entry from list (order independent, so swap with last): */
 
 
 
 349			for (i = 0; i < overlap_entries; i++) {
 350				if (overlap_list[i] == change_point[chg_idx]->entry)
 351					overlap_list[i] = overlap_list[overlap_entries-1];
 
 
 352			}
 353			overlap_entries--;
 354		}
 355		/*
 356		 * If there are overlapping entries, decide which
 357		 * "type" to use (larger value takes precedence --
 358		 * 1=usable, 2,3,4,4+=unusable)
 359		 */
 360		current_type = 0;
 361		for (i = 0; i < overlap_entries; i++) {
 362			if (overlap_list[i]->type > current_type)
 363				current_type = overlap_list[i]->type;
 364		}
 365
 366		/* Continue building up new map based on this information: */
 367		if (current_type != last_type || current_type == E820_TYPE_PRAM) {
 
 368			if (last_type != 0)	 {
 369				new_entries[new_nr_entries].size = change_point[chg_idx]->addr - last_addr;
 370				/* Move forward only if the new size was non-zero: */
 371				if (new_entries[new_nr_entries].size != 0)
 372					/* No more space left for new entries? */
 373					if (++new_nr_entries >= max_nr_entries)
 
 
 
 
 
 
 
 374						break;
 375			}
 376			if (current_type != 0)	{
 377				new_entries[new_nr_entries].addr = change_point[chg_idx]->addr;
 378				new_entries[new_nr_entries].type = current_type;
 379				last_addr = change_point[chg_idx]->addr;
 
 380			}
 381			last_type = current_type;
 382		}
 383	}
 
 
 384
 385	/* Copy the new entries into the original location: */
 386	memcpy(entries, new_entries, new_nr_entries*sizeof(*entries));
 387	table->nr_entries = new_nr_entries;
 388
 389	return 0;
 390}
 391
 392static int __init __append_e820_table(struct boot_e820_entry *entries, u32 nr_entries)
 393{
 394	struct boot_e820_entry *entry = entries;
 395
 396	while (nr_entries) {
 397		u64 start = entry->addr;
 398		u64 size = entry->size;
 399		u64 end = start + size - 1;
 400		u32 type = entry->type;
 401
 402		/* Ignore the entry on 64-bit overflow: */
 403		if (start > end && likely(size))
 404			return -1;
 405
 406		e820__range_add(start, size, type);
 407
 408		entry++;
 409		nr_entries--;
 410	}
 411	return 0;
 412}
 413
 414/*
 415 * Copy the BIOS E820 map into a safe place.
 416 *
 417 * Sanity-check it while we're at it..
 418 *
 419 * If we're lucky and live on a modern system, the setup code
 420 * will have given us a memory map that we can use to properly
 421 * set up memory.  If we aren't, we'll fake a memory map.
 422 */
 423static int __init append_e820_table(struct boot_e820_entry *entries, u32 nr_entries)
 424{
 425	/* Only one memory region (or negative)? Ignore it */
 426	if (nr_entries < 2)
 427		return -1;
 428
 429	return __append_e820_table(entries, nr_entries);
 430}
 431
 432static u64 __init
 433__e820__range_update(struct e820_table *table, u64 start, u64 size, enum e820_type old_type, enum e820_type new_type)
 
 434{
 435	u64 end;
 436	unsigned int i;
 437	u64 real_updated_size = 0;
 438
 439	BUG_ON(old_type == new_type);
 440
 441	if (size > (ULLONG_MAX - start))
 442		size = ULLONG_MAX - start;
 443
 444	end = start + size;
 445	printk(KERN_DEBUG "e820: update [mem %#010Lx-%#010Lx] ", start, end - 1);
 
 
 446	e820_print_type(old_type);
 447	pr_cont(" ==> ");
 448	e820_print_type(new_type);
 449	pr_cont("\n");
 450
 451	for (i = 0; i < table->nr_entries; i++) {
 452		struct e820_entry *entry = &table->entries[i];
 453		u64 final_start, final_end;
 454		u64 entry_end;
 455
 456		if (entry->type != old_type)
 457			continue;
 458
 459		entry_end = entry->addr + entry->size;
 460
 461		/* Completely covered by new range? */
 462		if (entry->addr >= start && entry_end <= end) {
 463			entry->type = new_type;
 464			real_updated_size += entry->size;
 465			continue;
 466		}
 467
 468		/* New range is completely covered? */
 469		if (entry->addr < start && entry_end > end) {
 470			__e820__range_add(table, start, size, new_type);
 471			__e820__range_add(table, end, entry_end - end, entry->type);
 472			entry->size = start - entry->addr;
 473			real_updated_size += size;
 474			continue;
 475		}
 476
 477		/* Partially covered: */
 478		final_start = max(start, entry->addr);
 479		final_end = min(end, entry_end);
 480		if (final_start >= final_end)
 481			continue;
 482
 483		__e820__range_add(table, final_start, final_end - final_start, new_type);
 
 484
 485		real_updated_size += final_end - final_start;
 486
 487		/*
 488		 * Left range could be head or tail, so need to update
 489		 * its size first:
 490		 */
 491		entry->size -= final_end - final_start;
 492		if (entry->addr < final_start)
 493			continue;
 494
 495		entry->addr = final_end;
 496	}
 497	return real_updated_size;
 498}
 499
 500u64 __init e820__range_update(u64 start, u64 size, enum e820_type old_type, enum e820_type new_type)
 
 501{
 502	return __e820__range_update(e820_table, start, size, old_type, new_type);
 503}
 504
 505static u64 __init e820__range_update_kexec(u64 start, u64 size, enum e820_type old_type, enum e820_type  new_type)
 
 506{
 507	return __e820__range_update(e820_table_kexec, start, size, old_type, new_type);
 
 508}
 509
 510/* Remove a range of memory from the E820 table: */
 511u64 __init e820__range_remove(u64 start, u64 size, enum e820_type old_type, bool check_type)
 
 512{
 513	int i;
 514	u64 end;
 515	u64 real_removed_size = 0;
 516
 517	if (size > (ULLONG_MAX - start))
 518		size = ULLONG_MAX - start;
 519
 520	end = start + size;
 521	printk(KERN_DEBUG "e820: remove [mem %#010Lx-%#010Lx] ", start, end - 1);
 522	if (check_type)
 
 
 523		e820_print_type(old_type);
 524	pr_cont("\n");
 525
 526	for (i = 0; i < e820_table->nr_entries; i++) {
 527		struct e820_entry *entry = &e820_table->entries[i];
 528		u64 final_start, final_end;
 529		u64 entry_end;
 530
 531		if (check_type && entry->type != old_type)
 532			continue;
 533
 534		entry_end = entry->addr + entry->size;
 535
 536		/* Completely covered? */
 537		if (entry->addr >= start && entry_end <= end) {
 538			real_removed_size += entry->size;
 539			memset(entry, 0, sizeof(*entry));
 540			continue;
 541		}
 542
 543		/* Is the new range completely covered? */
 544		if (entry->addr < start && entry_end > end) {
 545			e820__range_add(end, entry_end - end, entry->type);
 546			entry->size = start - entry->addr;
 547			real_removed_size += size;
 548			continue;
 549		}
 550
 551		/* Partially covered: */
 552		final_start = max(start, entry->addr);
 553		final_end = min(end, entry_end);
 554		if (final_start >= final_end)
 555			continue;
 556
 557		real_removed_size += final_end - final_start;
 558
 559		/*
 560		 * Left range could be head or tail, so need to update
 561		 * the size first:
 562		 */
 563		entry->size -= final_end - final_start;
 564		if (entry->addr < final_start)
 565			continue;
 566
 567		entry->addr = final_end;
 568	}
 569	return real_removed_size;
 570}
 571
 572void __init e820__update_table_print(void)
 573{
 574	if (e820__update_table(e820_table))
 575		return;
 576
 577	pr_info("e820: modified physical RAM map:\n");
 578	e820__print_table("modified");
 
 
 
 
 579}
 580
 581static void __init e820__update_table_kexec(void)
 582{
 583	e820__update_table(e820_table_kexec);
 584}
 585
 
 
 
 
 
 586#define MAX_GAP_END 0x100000000ull
 587
 588/*
 589 * Search for a gap in the E820 memory space from 0 to MAX_GAP_END (4GB).
 590 */
 591static int __init e820_search_gap(unsigned long *gapstart, unsigned long *gapsize)
 
 592{
 593	unsigned long long last = MAX_GAP_END;
 594	int i = e820_table->nr_entries;
 595	int found = 0;
 596
 
 
 597	while (--i >= 0) {
 598		unsigned long long start = e820_table->entries[i].addr;
 599		unsigned long long end = start + e820_table->entries[i].size;
 
 
 
 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 the PCI subsystem, so
 623 * that it can assign MMIO resources for hotplug or
 624 * unconfigured devices in.
 625 *
 626 * Hopefully the BIOS let enough space left.
 627 */
 628__init void e820__setup_pci_gap(void)
 629{
 630	unsigned long gapstart, gapsize;
 631	int found;
 632
 
 633	gapsize = 0x400000;
 634	found  = e820_search_gap(&gapstart, &gapsize);
 635
 636	if (!found) {
 637#ifdef CONFIG_X86_64
 
 638		gapstart = (max_pfn << PAGE_SHIFT) + 1024*1024;
 639		pr_err(
 640			"e820: Cannot find an available gap in the 32-bit address range\n"
 641			"e820: PCI devices with unassigned 32-bit BARs may not work!\n");
 642#else
 643		gapstart = 0x10000000;
 644#endif
 645	}
 
 646
 647	/*
 648	 * e820__reserve_resources_late() protects stolen RAM already:
 649	 */
 650	pci_mem_start = gapstart;
 651
 652	pr_info("e820: [mem %#010lx-%#010lx] available for PCI devices\n", gapstart, gapstart + gapsize - 1);
 653}
 654
 655/*
 656 * Called late during init, in free_initmem().
 657 *
 658 * Initial e820_table and e820_table_kexec are largish __initdata arrays.
 659 *
 660 * Copy them to a (usually much smaller) dynamically allocated area that is
 661 * sized precisely after the number of e820 entries.
 662 *
 663 * This is done after we've performed all the fixes and tweaks to the tables.
 664 * All functions which modify them are __init functions, which won't exist
 665 * after free_initmem().
 666 */
 667__init void e820__reallocate_tables(void)
 668{
 669	struct e820_table *n;
 670	int size;
 671
 672	size = offsetof(struct e820_table, entries) + sizeof(struct e820_entry)*e820_table->nr_entries;
 673	n = kmalloc(size, GFP_KERNEL);
 674	BUG_ON(!n);
 675	memcpy(n, e820_table, size);
 676	e820_table = n;
 677
 678	size = offsetof(struct e820_table, entries) + sizeof(struct e820_entry)*e820_table_kexec->nr_entries;
 679	n = kmalloc(size, GFP_KERNEL);
 680	BUG_ON(!n);
 681	memcpy(n, e820_table_kexec, size);
 682	e820_table_kexec = n;
 683
 684	size = offsetof(struct e820_table, entries) + sizeof(struct e820_entry)*e820_table_firmware->nr_entries;
 685	n = kmalloc(size, GFP_KERNEL);
 686	BUG_ON(!n);
 687	memcpy(n, e820_table_firmware, size);
 688	e820_table_firmware = n;
 689}
 690
 691/*
 692 * Because of the small fixed size of struct boot_params, only the first
 693 * 128 E820 memory entries are passed to the kernel via boot_params.e820_table,
 694 * the remaining (if any) entries are passed via the SETUP_E820_EXT node of
 695 * struct setup_data, which is parsed here.
 696 */
 697void __init e820__memory_setup_extended(u64 phys_addr, u32 data_len)
 698{
 699	int entries;
 700	struct boot_e820_entry *extmap;
 701	struct setup_data *sdata;
 702
 703	sdata = early_memremap(phys_addr, data_len);
 704	entries = sdata->len / sizeof(*extmap);
 705	extmap = (struct boot_e820_entry *)(sdata->data);
 706
 707	__append_e820_table(extmap, entries);
 708	e820__update_table(e820_table);
 709
 710	memcpy(e820_table_kexec, e820_table, sizeof(*e820_table_kexec));
 711	memcpy(e820_table_firmware, e820_table, sizeof(*e820_table_firmware));
 712
 713	early_memunmap(sdata, data_len);
 714	pr_info("e820: extended physical RAM map:\n");
 715	e820__print_table("extended");
 716}
 717
 718/*
 
 
 719 * Find the ranges of physical addresses that do not correspond to
 720 * E820 RAM areas and register the corresponding pages as 'nosave' for
 721 * hibernation (32-bit) or software suspend and suspend to RAM (64-bit).
 722 *
 723 * This function requires the E820 map to be sorted and without any
 724 * overlapping entries.
 725 */
 726void __init e820__register_nosave_regions(unsigned long limit_pfn)
 727{
 728	int i;
 729	unsigned long pfn = 0;
 730
 731	for (i = 0; i < e820_table->nr_entries; i++) {
 732		struct e820_entry *entry = &e820_table->entries[i];
 733
 734		if (pfn < PFN_UP(entry->addr))
 735			register_nosave_region(pfn, PFN_UP(entry->addr));
 736
 737		pfn = PFN_DOWN(entry->addr + entry->size);
 738
 739		if (entry->type != E820_TYPE_RAM && entry->type != E820_TYPE_RESERVED_KERN)
 740			register_nosave_region(PFN_UP(entry->addr), pfn);
 
 
 
 
 
 
 
 
 741
 742		if (pfn >= limit_pfn)
 743			break;
 744	}
 745}
 
 746
 747#ifdef CONFIG_ACPI
 748/*
 749 * Register ACPI NVS memory regions, so that we can save/restore them during
 750 * hibernation and the subsequent resume:
 751 */
 752static int __init e820__register_nvs_regions(void)
 753{
 754	int i;
 755
 756	for (i = 0; i < e820_table->nr_entries; i++) {
 757		struct e820_entry *entry = &e820_table->entries[i];
 758
 759		if (entry->type == E820_TYPE_NVS)
 760			acpi_nvs_register(entry->addr, entry->size);
 761	}
 762
 763	return 0;
 764}
 765core_initcall(e820__register_nvs_regions);
 766#endif
 767
 768/*
 769 * Allocate the requested number of bytes with the requsted alignment
 770 * and return (the physical address) to the caller. Also register this
 771 * range in the 'kexec' E820 table as a reserved range.
 772 *
 773 * This allows kexec to fake a new mptable, as if it came from the real
 774 * system.
 775 */
 776u64 __init e820__memblock_alloc_reserved(u64 size, u64 align)
 777{
 
 778	u64 addr;
 
 779
 780	addr = __memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ACCESSIBLE);
 781	if (addr) {
 782		e820__range_update_kexec(addr, size, E820_TYPE_RAM, E820_TYPE_RESERVED);
 783		pr_info("e820: update e820_table_kexec for e820__memblock_alloc_reserved()\n");
 784		e820__update_table_kexec();
 
 785	}
 786
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 787	return addr;
 788}
 789
 790#ifdef CONFIG_X86_32
 791# ifdef CONFIG_X86_PAE
 792#  define MAX_ARCH_PFN		(1ULL<<(36-PAGE_SHIFT))
 793# else
 794#  define MAX_ARCH_PFN		(1ULL<<(32-PAGE_SHIFT))
 795# endif
 796#else /* CONFIG_X86_32 */
 797# define MAX_ARCH_PFN MAXMEM>>PAGE_SHIFT
 798#endif
 799
 800/*
 801 * Find the highest page frame number we have available
 802 */
 803static unsigned long __init e820_end_pfn(unsigned long limit_pfn, enum e820_type type)
 804{
 805	int i;
 806	unsigned long last_pfn = 0;
 807	unsigned long max_arch_pfn = MAX_ARCH_PFN;
 808
 809	for (i = 0; i < e820_table->nr_entries; i++) {
 810		struct e820_entry *entry = &e820_table->entries[i];
 811		unsigned long start_pfn;
 812		unsigned long end_pfn;
 813
 814		if (entry->type != type)
 815			continue;
 816
 817		start_pfn = entry->addr >> PAGE_SHIFT;
 818		end_pfn = (entry->addr + entry->size) >> PAGE_SHIFT;
 819
 820		if (start_pfn >= limit_pfn)
 821			continue;
 822		if (end_pfn > limit_pfn) {
 823			last_pfn = limit_pfn;
 824			break;
 825		}
 826		if (end_pfn > last_pfn)
 827			last_pfn = end_pfn;
 828	}
 829
 830	if (last_pfn > max_arch_pfn)
 831		last_pfn = max_arch_pfn;
 832
 833	pr_info("e820: last_pfn = %#lx max_arch_pfn = %#lx\n",
 834			 last_pfn, max_arch_pfn);
 835	return last_pfn;
 836}
 837
 838unsigned long __init e820__end_of_ram_pfn(void)
 839{
 840	return e820_end_pfn(MAX_ARCH_PFN, E820_TYPE_RAM);
 841}
 842
 843unsigned long __init e820__end_of_low_ram_pfn(void)
 844{
 845	return e820_end_pfn(1UL << (32 - PAGE_SHIFT), E820_TYPE_RAM);
 846}
 847
 848static void __init early_panic(char *msg)
 849{
 850	early_printk(msg);
 851	panic(msg);
 852}
 853
 854static int userdef __initdata;
 855
 856/* The "mem=nopentium" boot option disables 4MB page tables on 32-bit kernels: */
 857static int __init parse_memopt(char *p)
 858{
 859	u64 mem_size;
 860
 861	if (!p)
 862		return -EINVAL;
 863
 864	if (!strcmp(p, "nopentium")) {
 865#ifdef CONFIG_X86_32
 866		setup_clear_cpu_cap(X86_FEATURE_PSE);
 867		return 0;
 868#else
 869		pr_warn("mem=nopentium ignored! (only supported on x86_32)\n");
 870		return -EINVAL;
 871#endif
 872	}
 873
 874	userdef = 1;
 875	mem_size = memparse(p, &p);
 876
 877	/* Don't remove all memory when getting "mem={invalid}" parameter: */
 878	if (mem_size == 0)
 879		return -EINVAL;
 880
 881	e820__range_remove(mem_size, ULLONG_MAX - mem_size, E820_TYPE_RAM, 1);
 882
 883	return 0;
 884}
 885early_param("mem", parse_memopt);
 886
 887static int __init parse_memmap_one(char *p)
 888{
 889	char *oldp;
 890	u64 start_at, mem_size;
 891
 892	if (!p)
 893		return -EINVAL;
 894
 895	if (!strncmp(p, "exactmap", 8)) {
 896#ifdef CONFIG_CRASH_DUMP
 897		/*
 898		 * If we are doing a crash dump, we still need to know
 899		 * the real memory size before the original memory map is
 900		 * reset.
 901		 */
 902		saved_max_pfn = e820__end_of_ram_pfn();
 903#endif
 904		e820_table->nr_entries = 0;
 905		userdef = 1;
 906		return 0;
 907	}
 908
 909	oldp = p;
 910	mem_size = memparse(p, &p);
 911	if (p == oldp)
 912		return -EINVAL;
 913
 914	userdef = 1;
 915	if (*p == '@') {
 916		start_at = memparse(p+1, &p);
 917		e820__range_add(start_at, mem_size, E820_TYPE_RAM);
 918	} else if (*p == '#') {
 919		start_at = memparse(p+1, &p);
 920		e820__range_add(start_at, mem_size, E820_TYPE_ACPI);
 921	} else if (*p == '$') {
 922		start_at = memparse(p+1, &p);
 923		e820__range_add(start_at, mem_size, E820_TYPE_RESERVED);
 924	} else if (*p == '!') {
 925		start_at = memparse(p+1, &p);
 926		e820__range_add(start_at, mem_size, E820_TYPE_PRAM);
 927	} else if (*p == '%') {
 928		enum e820_type from = 0, to = 0;
 929
 930		start_at = memparse(p + 1, &p);
 931		if (*p == '-')
 932			from = simple_strtoull(p + 1, &p, 0);
 933		if (*p == '+')
 934			to = simple_strtoull(p + 1, &p, 0);
 935		if (*p != '\0')
 936			return -EINVAL;
 937		if (from && to)
 938			e820__range_update(start_at, mem_size, from, to);
 939		else if (to)
 940			e820__range_add(start_at, mem_size, to);
 941		else if (from)
 942			e820__range_remove(start_at, mem_size, from, 1);
 943		else
 944			e820__range_remove(start_at, mem_size, 0, 0);
 945	} else {
 946		e820__range_remove(mem_size, ULLONG_MAX - mem_size, E820_TYPE_RAM, 1);
 947	}
 948
 949	return *p == '\0' ? 0 : -EINVAL;
 950}
 951
 952static int __init parse_memmap_opt(char *str)
 953{
 954	while (str) {
 955		char *k = strchr(str, ',');
 956
 957		if (k)
 958			*k++ = 0;
 959
 960		parse_memmap_one(str);
 961		str = k;
 962	}
 963
 964	return 0;
 965}
 966early_param("memmap", parse_memmap_opt);
 967
 968/*
 969 * Reserve all entries from the bootloader's extensible data nodes list,
 970 * because if present we are going to use it later on to fetch e820
 971 * entries from it:
 972 */
 973void __init e820__reserve_setup_data(void)
 974{
 975	struct setup_data *data;
 976	u64 pa_data;
 977
 978	pa_data = boot_params.hdr.setup_data;
 979	if (!pa_data)
 980		return;
 981
 982	while (pa_data) {
 983		data = early_memremap(pa_data, sizeof(*data));
 984		e820__range_update(pa_data, sizeof(*data)+data->len, E820_TYPE_RAM, E820_TYPE_RESERVED_KERN);
 985		e820__range_update_kexec(pa_data, sizeof(*data)+data->len, E820_TYPE_RAM, E820_TYPE_RESERVED_KERN);
 986		pa_data = data->next;
 987		early_memunmap(data, sizeof(*data));
 988	}
 989
 990	e820__update_table(e820_table);
 991	e820__update_table(e820_table_kexec);
 992
 993	pr_info("extended physical RAM map:\n");
 994	e820__print_table("reserve setup_data");
 995}
 996
 997/*
 998 * Called after parse_early_param(), after early parameters (such as mem=)
 999 * have been processed, in which case we already have an E820 table filled in
1000 * via the parameter callback function(s), but it's not sorted and printed yet:
1001 */
1002void __init e820__finish_early_params(void)
1003{
1004	if (userdef) {
1005		if (e820__update_table(e820_table) < 0)
1006			early_panic("Invalid user supplied memory map");
1007
1008		pr_info("e820: user-defined physical RAM map:\n");
1009		e820__print_table("user");
1010	}
1011}
1012
1013static const char *__init e820_type_to_string(struct e820_entry *entry)
1014{
1015	switch (entry->type) {
1016	case E820_TYPE_RESERVED_KERN:	/* Fall-through: */
1017	case E820_TYPE_RAM:		return "System RAM";
1018	case E820_TYPE_ACPI:		return "ACPI Tables";
1019	case E820_TYPE_NVS:		return "ACPI Non-volatile Storage";
1020	case E820_TYPE_UNUSABLE:	return "Unusable memory";
1021	case E820_TYPE_PRAM:		return "Persistent Memory (legacy)";
1022	case E820_TYPE_PMEM:		return "Persistent Memory";
1023	case E820_TYPE_RESERVED:	return "Reserved";
1024	default:			return "Unknown E820 type";
1025	}
1026}
1027
1028static unsigned long __init e820_type_to_iomem_type(struct e820_entry *entry)
1029{
1030	switch (entry->type) {
1031	case E820_TYPE_RESERVED_KERN:	/* Fall-through: */
1032	case E820_TYPE_RAM:		return IORESOURCE_SYSTEM_RAM;
1033	case E820_TYPE_ACPI:		/* Fall-through: */
1034	case E820_TYPE_NVS:		/* Fall-through: */
1035	case E820_TYPE_UNUSABLE:	/* Fall-through: */
1036	case E820_TYPE_PRAM:		/* Fall-through: */
1037	case E820_TYPE_PMEM:		/* Fall-through: */
1038	case E820_TYPE_RESERVED:	/* Fall-through: */
1039	default:			return IORESOURCE_MEM;
1040	}
1041}
1042
1043static unsigned long __init e820_type_to_iores_desc(struct e820_entry *entry)
1044{
1045	switch (entry->type) {
1046	case E820_TYPE_ACPI:		return IORES_DESC_ACPI_TABLES;
1047	case E820_TYPE_NVS:		return IORES_DESC_ACPI_NV_STORAGE;
1048	case E820_TYPE_PMEM:		return IORES_DESC_PERSISTENT_MEMORY;
1049	case E820_TYPE_PRAM:		return IORES_DESC_PERSISTENT_MEMORY_LEGACY;
1050	case E820_TYPE_RESERVED_KERN:	/* Fall-through: */
1051	case E820_TYPE_RAM:		/* Fall-through: */
1052	case E820_TYPE_UNUSABLE:	/* Fall-through: */
1053	case E820_TYPE_RESERVED:	/* Fall-through: */
1054	default:			return IORES_DESC_NONE;
1055	}
1056}
1057
1058static bool __init do_mark_busy(enum e820_type type, struct resource *res)
1059{
1060	/* this is the legacy bios/dos rom-shadow + mmio region */
1061	if (res->start < (1ULL<<20))
1062		return true;
1063
1064	/*
1065	 * Treat persistent memory like device memory, i.e. reserve it
1066	 * for exclusive use of a driver
1067	 */
1068	switch (type) {
1069	case E820_TYPE_RESERVED:
1070	case E820_TYPE_PRAM:
1071	case E820_TYPE_PMEM:
1072		return false;
1073	case E820_TYPE_RESERVED_KERN:
1074	case E820_TYPE_RAM:
1075	case E820_TYPE_ACPI:
1076	case E820_TYPE_NVS:
1077	case E820_TYPE_UNUSABLE:
1078	default:
1079		return true;
1080	}
1081}
1082
1083/*
1084 * Mark E820 reserved areas as busy for the resource manager:
1085 */
1086
1087static struct resource __initdata *e820_res;
1088
1089void __init e820__reserve_resources(void)
1090{
1091	int i;
1092	struct resource *res;
1093	u64 end;
1094
1095	res = alloc_bootmem(sizeof(*res) * e820_table->nr_entries);
1096	e820_res = res;
1097
1098	for (i = 0; i < e820_table->nr_entries; i++) {
1099		struct e820_entry *entry = e820_table->entries + i;
1100
1101		end = entry->addr + entry->size - 1;
1102		if (end != (resource_size_t)end) {
1103			res++;
1104			continue;
1105		}
1106		res->start = entry->addr;
1107		res->end   = end;
1108		res->name  = e820_type_to_string(entry);
1109		res->flags = e820_type_to_iomem_type(entry);
1110		res->desc  = e820_type_to_iores_desc(entry);
1111
1112		/*
1113		 * Don't register the region that could be conflicted with
1114		 * PCI device BAR resources and insert them later in
1115		 * pcibios_resource_survey():
1116		 */
1117		if (do_mark_busy(entry->type, res)) {
1118			res->flags |= IORESOURCE_BUSY;
1119			insert_resource(&iomem_resource, res);
1120		}
1121		res++;
1122	}
1123
1124	/* Expose the bootloader-provided memory layout to the sysfs. */
1125	for (i = 0; i < e820_table_firmware->nr_entries; i++) {
1126		struct e820_entry *entry = e820_table_firmware->entries + i;
1127
1128		firmware_map_add_early(entry->addr, entry->addr + entry->size, e820_type_to_string(entry));
1129	}
1130}
1131
1132/*
1133 * How much should we pad the end of RAM, depending on where it is?
1134 */
1135static unsigned long __init ram_alignment(resource_size_t pos)
1136{
1137	unsigned long mb = pos >> 20;
1138
1139	/* To 64kB in the first megabyte */
1140	if (!mb)
1141		return 64*1024;
1142
1143	/* To 1MB in the first 16MB */
1144	if (mb < 16)
1145		return 1024*1024;
1146
1147	/* To 64MB for anything above that */
1148	return 64*1024*1024;
1149}
1150
1151#define MAX_RESOURCE_SIZE ((resource_size_t)-1)
1152
1153void __init e820__reserve_resources_late(void)
1154{
1155	int i;
1156	struct resource *res;
1157
1158	res = e820_res;
1159	for (i = 0; i < e820_table->nr_entries; i++) {
1160		if (!res->parent && res->end)
1161			insert_resource_expand_to_fit(&iomem_resource, res);
1162		res++;
1163	}
1164
1165	/*
1166	 * Try to bump up RAM regions to reasonable boundaries, to
1167	 * avoid stolen RAM:
1168	 */
1169	for (i = 0; i < e820_table->nr_entries; i++) {
1170		struct e820_entry *entry = &e820_table->entries[i];
1171		u64 start, end;
1172
1173		if (entry->type != E820_TYPE_RAM)
1174			continue;
1175
1176		start = entry->addr + entry->size;
1177		end = round_up(start, ram_alignment(start)) - 1;
1178		if (end > MAX_RESOURCE_SIZE)
1179			end = MAX_RESOURCE_SIZE;
1180		if (start >= end)
1181			continue;
1182
1183		printk(KERN_DEBUG "e820: reserve RAM buffer [mem %#010llx-%#010llx]\n", start, end);
1184		reserve_region_with_split(&iomem_resource, start, end, "RAM buffer");
 
1185	}
1186}
1187
1188/*
1189 * Pass the firmware (bootloader) E820 map to the kernel and process it:
1190 */
1191char *__init e820__memory_setup_default(void)
1192{
1193	char *who = "BIOS-e820";
1194
1195	/*
1196	 * Try to copy the BIOS-supplied E820-map.
1197	 *
1198	 * Otherwise fake a memory map; one section from 0k->640k,
1199	 * the next section from 1mb->appropriate_mem_k
1200	 */
1201	if (append_e820_table(boot_params.e820_table, boot_params.e820_entries) < 0) {
 
 
 
 
 
 
1202		u64 mem_size;
1203
1204		/* Compare results from other methods and take the one that gives more RAM: */
1205		if (boot_params.alt_mem_k < boot_params.screen_info.ext_mem_k) {
 
1206			mem_size = boot_params.screen_info.ext_mem_k;
1207			who = "BIOS-88";
1208		} else {
1209			mem_size = boot_params.alt_mem_k;
1210			who = "BIOS-e801";
1211		}
1212
1213		e820_table->nr_entries = 0;
1214		e820__range_add(0, LOWMEMSIZE(), E820_TYPE_RAM);
1215		e820__range_add(HIGH_MEMORY, mem_size << 10, E820_TYPE_RAM);
1216	}
1217
1218	/* We just appended a lot of ranges, sanitize the table: */
1219	e820__update_table(e820_table);
1220
1221	return who;
1222}
1223
1224/*
1225 * Calls e820__memory_setup_default() in essence to pick up the firmware/bootloader
1226 * E820 map - with an optional platform quirk available for virtual platforms
1227 * to override this method of boot environment processing:
1228 */
1229void __init e820__memory_setup(void)
1230{
1231	char *who;
1232
1233	/* This is a firmware interface ABI - make sure we don't break it: */
1234	BUILD_BUG_ON(sizeof(struct boot_e820_entry) != 20);
1235
1236	who = x86_init.resources.memory_setup();
1237
1238	memcpy(e820_table_kexec, e820_table, sizeof(*e820_table_kexec));
1239	memcpy(e820_table_firmware, e820_table, sizeof(*e820_table_firmware));
1240
1241	pr_info("e820: BIOS-provided physical RAM map:\n");
1242	e820__print_table(who);
1243}
1244
1245void __init e820__memblock_setup(void)
1246{
1247	int i;
1248	u64 end;
1249
1250	/*
1251	 * The bootstrap memblock region count maximum is 128 entries
1252	 * (INIT_MEMBLOCK_REGIONS), but EFI might pass us more E820 entries
1253	 * than that - so allow memblock resizing.
1254	 *
1255	 * This is safe, because this call happens pretty late during x86 setup,
1256	 * so we know about reserved memory regions already. (This is important
1257	 * so that memblock resizing does no stomp over reserved areas.)
1258	 */
1259	memblock_allow_resize();
1260
1261	for (i = 0; i < e820_table->nr_entries; i++) {
1262		struct e820_entry *entry = &e820_table->entries[i];
1263
1264		end = entry->addr + entry->size;
1265		if (end != (resource_size_t)end)
1266			continue;
1267
1268		if (entry->type != E820_TYPE_RAM && entry->type != E820_TYPE_RESERVED_KERN)
1269			continue;
1270
1271		memblock_add(entry->addr, entry->size);
1272	}
1273
1274	/* Throw away partial pages: */
1275	memblock_trim_memory(PAGE_SIZE);
1276
1277	memblock_dump_all();
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1278}
v3.1
   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/bootmem.h>
  16#include <linux/pfn.h>
  17#include <linux/suspend.h>
  18#include <linux/acpi.h>
  19#include <linux/firmware-map.h>
  20#include <linux/memblock.h>
 
  21
  22#include <asm/e820.h>
  23#include <asm/proto.h>
  24#include <asm/setup.h>
  25
  26/*
  27 * The e820 map is the map that gets modified e.g. with command line parameters
  28 * and that is also registered with modifications in the kernel resource tree
  29 * with the iomem_resource as parent.
  30 *
  31 * The e820_saved is directly saved after the BIOS-provided memory map is
  32 * copied. It doesn't get modified afterwards. It's registered for the
  33 * /sys/firmware/memmap interface.
  34 *
  35 * That memory map is not modified and is used as base for kexec. The kexec'd
  36 * kernel should get the same memory map as the firmware provides. Then the
  37 * user can e.g. boot the original kernel with mem=1G while still booting the
  38 * next kernel with full memory.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  39 */
  40struct e820map e820;
  41struct e820map e820_saved;
 
 
 
 
 
  42
  43/* For PCI or other memory-mapped resources */
  44unsigned long pci_mem_start = 0xaeedbabe;
  45#ifdef CONFIG_PCI
  46EXPORT_SYMBOL(pci_mem_start);
  47#endif
  48
  49/*
  50 * This function checks if any part of the range <start,end> is mapped
  51 * with type.
  52 */
  53int
  54e820_any_mapped(u64 start, u64 end, unsigned type)
  55{
  56	int i;
  57
  58	for (i = 0; i < e820.nr_map; i++) {
  59		struct e820entry *ei = &e820.map[i];
  60
  61		if (type && ei->type != type)
  62			continue;
  63		if (ei->addr >= end || ei->addr + ei->size <= start)
  64			continue;
  65		return 1;
  66	}
  67	return 0;
  68}
  69EXPORT_SYMBOL_GPL(e820_any_mapped);
  70
  71/*
  72 * This function checks if the entire range <start,end> is mapped with type.
  73 *
  74 * Note: this function only works correct if the e820 table is sorted and
  75 * not-overlapping, which is the case
  76 */
  77int __init e820_all_mapped(u64 start, u64 end, unsigned type)
 
  78{
  79	int i;
  80
  81	for (i = 0; i < e820.nr_map; i++) {
  82		struct e820entry *ei = &e820.map[i];
  83
  84		if (type && ei->type != type)
  85			continue;
  86		/* is the region (part) in overlap with the current region ?*/
  87		if (ei->addr >= end || ei->addr + ei->size <= start)
 
  88			continue;
  89
  90		/* if the region is at the beginning of <start,end> we move
  91		 * start to the end of the region since it's ok until there
 
  92		 */
  93		if (ei->addr <= start)
  94			start = ei->addr + ei->size;
 
  95		/*
  96		 * if start is now at or beyond end, we're done, full
  97		 * coverage
  98		 */
  99		if (start >= end)
 100			return 1;
 101	}
 102	return 0;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 103}
 104
 105/*
 106 * Add a memory region to the kernel e820 map.
 107 */
 108static void __init __e820_add_region(struct e820map *e820x, u64 start, u64 size,
 109					 int type)
 110{
 111	int x = e820x->nr_map;
 112
 113	if (x >= ARRAY_SIZE(e820x->map)) {
 114		printk(KERN_ERR "Ooops! Too many entries in the memory map!\n");
 115		return;
 116	}
 117
 118	e820x->map[x].addr = start;
 119	e820x->map[x].size = size;
 120	e820x->map[x].type = type;
 121	e820x->nr_map++;
 122}
 123
 124void __init e820_add_region(u64 start, u64 size, int type)
 125{
 126	__e820_add_region(&e820, start, size, type);
 127}
 128
 129static void __init e820_print_type(u32 type)
 130{
 131	switch (type) {
 132	case E820_RAM:
 133	case E820_RESERVED_KERN:
 134		printk(KERN_CONT "(usable)");
 135		break;
 136	case E820_RESERVED:
 137		printk(KERN_CONT "(reserved)");
 138		break;
 139	case E820_ACPI:
 140		printk(KERN_CONT "(ACPI data)");
 141		break;
 142	case E820_NVS:
 143		printk(KERN_CONT "(ACPI NVS)");
 144		break;
 145	case E820_UNUSABLE:
 146		printk(KERN_CONT "(unusable)");
 147		break;
 148	default:
 149		printk(KERN_CONT "type %u", type);
 150		break;
 151	}
 152}
 153
 154void __init e820_print_map(char *who)
 155{
 156	int i;
 157
 158	for (i = 0; i < e820.nr_map; i++) {
 159		printk(KERN_INFO " %s: %016Lx - %016Lx ", who,
 160		       (unsigned long long) e820.map[i].addr,
 161		       (unsigned long long)
 162		       (e820.map[i].addr + e820.map[i].size));
 163		e820_print_type(e820.map[i].type);
 164		printk(KERN_CONT "\n");
 165	}
 166}
 167
 168/*
 169 * Sanitize the BIOS e820 map.
 170 *
 171 * Some e820 responses include overlapping entries. The following
 172 * replaces the original e820 map with a new one, removing overlaps,
 173 * and resolving conflicting memory types in favor of highest
 174 * numbered type.
 175 *
 176 * The input parameter biosmap points to an array of 'struct
 177 * e820entry' which on entry has elements in the range [0, *pnr_map)
 178 * valid, and which has space for up to max_nr_map entries.
 179 * On return, the resulting sanitized e820 map entries will be in
 180 * overwritten in the same location, starting at biosmap.
 181 *
 182 * The integer pointed to by pnr_map must be valid on entry (the
 183 * current number of valid entries located at biosmap) and will
 184 * be updated on return, with the new number of valid entries
 185 * (something no more than max_nr_map.)
 186 *
 187 * The return value from sanitize_e820_map() is zero if it
 188 * successfully 'sanitized' the map entries passed in, and is -1
 189 * if it did nothing, which can happen if either of (1) it was
 190 * only passed one map entry, or (2) any of the input map entries
 191 * were invalid (start + size < start, meaning that the size was
 192 * so big the described memory range wrapped around through zero.)
 193 *
 194 *	Visually we're performing the following
 195 *	(1,2,3,4 = memory types)...
 196 *
 197 *	Sample memory map (w/overlaps):
 198 *	   ____22__________________
 199 *	   ______________________4_
 200 *	   ____1111________________
 201 *	   _44_____________________
 202 *	   11111111________________
 203 *	   ____________________33__
 204 *	   ___________44___________
 205 *	   __________33333_________
 206 *	   ______________22________
 207 *	   ___________________2222_
 208 *	   _________111111111______
 209 *	   _____________________11_
 210 *	   _________________4______
 211 *
 212 *	Sanitized equivalent (no overlap):
 213 *	   1_______________________
 214 *	   _44_____________________
 215 *	   ___1____________________
 216 *	   ____22__________________
 217 *	   ______11________________
 218 *	   _________1______________
 219 *	   __________3_____________
 220 *	   ___________44___________
 221 *	   _____________33_________
 222 *	   _______________2________
 223 *	   ________________1_______
 224 *	   _________________4______
 225 *	   ___________________2____
 226 *	   ____________________33__
 227 *	   ______________________4_
 228 */
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 229
 230int __init sanitize_e820_map(struct e820entry *biosmap, int max_nr_map,
 231			     u32 *pnr_map)
 
 
 232{
 233	struct change_member {
 234		struct e820entry *pbios; /* pointer to original bios entry */
 235		unsigned long long addr; /* address for this change point */
 236	};
 237	static struct change_member change_point_list[2*E820_X_MAX] __initdata;
 238	static struct change_member *change_point[2*E820_X_MAX] __initdata;
 239	static struct e820entry *overlap_list[E820_X_MAX] __initdata;
 240	static struct e820entry new_bios[E820_X_MAX] __initdata;
 241	struct change_member *change_tmp;
 242	unsigned long current_type, last_type;
 243	unsigned long long last_addr;
 244	int chgidx, still_changing;
 245	int overlap_entries;
 246	int new_bios_entry;
 247	int old_nr, new_nr, chg_nr;
 248	int i;
 249
 250	/* if there's only one memory region, don't bother */
 251	if (*pnr_map < 2)
 252		return -1;
 253
 254	old_nr = *pnr_map;
 255	BUG_ON(old_nr > max_nr_map);
 256
 257	/* bail out if we find any unreasonable addresses in bios map */
 258	for (i = 0; i < old_nr; i++)
 259		if (biosmap[i].addr + biosmap[i].size < biosmap[i].addr)
 260			return -1;
 
 261
 262	/* create pointers for initial change-point information (for sorting) */
 263	for (i = 0; i < 2 * old_nr; i++)
 264		change_point[i] = &change_point_list[i];
 265
 266	/* record all known change-points (starting and ending addresses),
 267	   omitting those that are for empty memory regions */
 268	chgidx = 0;
 269	for (i = 0; i < old_nr; i++)	{
 270		if (biosmap[i].size != 0) {
 271			change_point[chgidx]->addr = biosmap[i].addr;
 272			change_point[chgidx++]->pbios = &biosmap[i];
 273			change_point[chgidx]->addr = biosmap[i].addr +
 274				biosmap[i].size;
 275			change_point[chgidx++]->pbios = &biosmap[i];
 
 276		}
 277	}
 278	chg_nr = chgidx;
 279
 280	/* sort change-point list by memory addresses (low -> high) */
 281	still_changing = 1;
 282	while (still_changing)	{
 283		still_changing = 0;
 284		for (i = 1; i < chg_nr; i++)  {
 285			unsigned long long curaddr, lastaddr;
 286			unsigned long long curpbaddr, lastpbaddr;
 287
 288			curaddr = change_point[i]->addr;
 289			lastaddr = change_point[i - 1]->addr;
 290			curpbaddr = change_point[i]->pbios->addr;
 291			lastpbaddr = change_point[i - 1]->pbios->addr;
 292
 293			/*
 294			 * swap entries, when:
 295			 *
 296			 * curaddr > lastaddr or
 297			 * curaddr == lastaddr and curaddr == curpbaddr and
 298			 * lastaddr != lastpbaddr
 299			 */
 300			if (curaddr < lastaddr ||
 301			    (curaddr == lastaddr && curaddr == curpbaddr &&
 302			     lastaddr != lastpbaddr)) {
 303				change_tmp = change_point[i];
 304				change_point[i] = change_point[i-1];
 305				change_point[i-1] = change_tmp;
 306				still_changing = 1;
 307			}
 308		}
 309	}
 310
 311	/* create a new bios memory map, removing overlaps */
 312	overlap_entries = 0;	 /* number of entries in the overlap table */
 313	new_bios_entry = 0;	 /* index for creating new bios map entries */
 314	last_type = 0;		 /* start with undefined memory type */
 315	last_addr = 0;		 /* start with 0 as last starting address */
 316
 317	/* loop through change-points, determining affect on the new bios map */
 318	for (chgidx = 0; chgidx < chg_nr; chgidx++) {
 319		/* keep track of all overlapping bios entries */
 320		if (change_point[chgidx]->addr ==
 321		    change_point[chgidx]->pbios->addr) {
 322			/*
 323			 * add map entry to overlap list (> 1 entry
 324			 * implies an overlap)
 325			 */
 326			overlap_list[overlap_entries++] =
 327				change_point[chgidx]->pbios;
 328		} else {
 329			/*
 330			 * remove entry from list (order independent,
 331			 * so swap with last)
 332			 */
 333			for (i = 0; i < overlap_entries; i++) {
 334				if (overlap_list[i] ==
 335				    change_point[chgidx]->pbios)
 336					overlap_list[i] =
 337						overlap_list[overlap_entries-1];
 338			}
 339			overlap_entries--;
 340		}
 341		/*
 342		 * if there are overlapping entries, decide which
 343		 * "type" to use (larger value takes precedence --
 344		 * 1=usable, 2,3,4,4+=unusable)
 345		 */
 346		current_type = 0;
 347		for (i = 0; i < overlap_entries; i++)
 348			if (overlap_list[i]->type > current_type)
 349				current_type = overlap_list[i]->type;
 350		/*
 351		 * continue building up new bios map based on this
 352		 * information
 353		 */
 354		if (current_type != last_type)	{
 355			if (last_type != 0)	 {
 356				new_bios[new_bios_entry].size =
 357					change_point[chgidx]->addr - last_addr;
 358				/*
 359				 * move forward only if the new size
 360				 * was non-zero
 361				 */
 362				if (new_bios[new_bios_entry].size != 0)
 363					/*
 364					 * no more space left for new
 365					 * bios entries ?
 366					 */
 367					if (++new_bios_entry >= max_nr_map)
 368						break;
 369			}
 370			if (current_type != 0)	{
 371				new_bios[new_bios_entry].addr =
 372					change_point[chgidx]->addr;
 373				new_bios[new_bios_entry].type = current_type;
 374				last_addr = change_point[chgidx]->addr;
 375			}
 376			last_type = current_type;
 377		}
 378	}
 379	/* retain count for new bios entries */
 380	new_nr = new_bios_entry;
 381
 382	/* copy new bios mapping into original location */
 383	memcpy(biosmap, new_bios, new_nr * sizeof(struct e820entry));
 384	*pnr_map = new_nr;
 385
 386	return 0;
 387}
 388
 389static int __init __append_e820_map(struct e820entry *biosmap, int nr_map)
 390{
 391	while (nr_map) {
 392		u64 start = biosmap->addr;
 393		u64 size = biosmap->size;
 394		u64 end = start + size;
 395		u32 type = biosmap->type;
 
 
 396
 397		/* Overflow in 64 bits? Ignore the memory map. */
 398		if (start > end)
 399			return -1;
 400
 401		e820_add_region(start, size, type);
 402
 403		biosmap++;
 404		nr_map--;
 405	}
 406	return 0;
 407}
 408
 409/*
 410 * Copy the BIOS e820 map into a safe place.
 411 *
 412 * Sanity-check it while we're at it..
 413 *
 414 * If we're lucky and live on a modern system, the setup code
 415 * will have given us a memory map that we can use to properly
 416 * set up memory.  If we aren't, we'll fake a memory map.
 417 */
 418static int __init append_e820_map(struct e820entry *biosmap, int nr_map)
 419{
 420	/* Only one memory region (or negative)? Ignore it */
 421	if (nr_map < 2)
 422		return -1;
 423
 424	return __append_e820_map(biosmap, nr_map);
 425}
 426
 427static u64 __init __e820_update_range(struct e820map *e820x, u64 start,
 428					u64 size, unsigned old_type,
 429					unsigned new_type)
 430{
 431	u64 end;
 432	unsigned int i;
 433	u64 real_updated_size = 0;
 434
 435	BUG_ON(old_type == new_type);
 436
 437	if (size > (ULLONG_MAX - start))
 438		size = ULLONG_MAX - start;
 439
 440	end = start + size;
 441	printk(KERN_DEBUG "e820 update range: %016Lx - %016Lx ",
 442		       (unsigned long long) start,
 443		       (unsigned long long) end);
 444	e820_print_type(old_type);
 445	printk(KERN_CONT " ==> ");
 446	e820_print_type(new_type);
 447	printk(KERN_CONT "\n");
 448
 449	for (i = 0; i < e820x->nr_map; i++) {
 450		struct e820entry *ei = &e820x->map[i];
 451		u64 final_start, final_end;
 452		u64 ei_end;
 453
 454		if (ei->type != old_type)
 455			continue;
 456
 457		ei_end = ei->addr + ei->size;
 458		/* totally covered by new range? */
 459		if (ei->addr >= start && ei_end <= end) {
 460			ei->type = new_type;
 461			real_updated_size += ei->size;
 
 462			continue;
 463		}
 464
 465		/* new range is totally covered? */
 466		if (ei->addr < start && ei_end > end) {
 467			__e820_add_region(e820x, start, size, new_type);
 468			__e820_add_region(e820x, end, ei_end - end, ei->type);
 469			ei->size = start - ei->addr;
 470			real_updated_size += size;
 471			continue;
 472		}
 473
 474		/* partially covered */
 475		final_start = max(start, ei->addr);
 476		final_end = min(end, ei_end);
 477		if (final_start >= final_end)
 478			continue;
 479
 480		__e820_add_region(e820x, final_start, final_end - final_start,
 481				  new_type);
 482
 483		real_updated_size += final_end - final_start;
 484
 485		/*
 486		 * left range could be head or tail, so need to update
 487		 * size at first.
 488		 */
 489		ei->size -= final_end - final_start;
 490		if (ei->addr < final_start)
 491			continue;
 492		ei->addr = final_end;
 
 493	}
 494	return real_updated_size;
 495}
 496
 497u64 __init e820_update_range(u64 start, u64 size, unsigned old_type,
 498			     unsigned new_type)
 499{
 500	return __e820_update_range(&e820, start, size, old_type, new_type);
 501}
 502
 503static u64 __init e820_update_range_saved(u64 start, u64 size,
 504					  unsigned old_type, unsigned new_type)
 505{
 506	return __e820_update_range(&e820_saved, start, size, old_type,
 507				     new_type);
 508}
 509
 510/* make e820 not cover the range */
 511u64 __init e820_remove_range(u64 start, u64 size, unsigned old_type,
 512			     int checktype)
 513{
 514	int i;
 515	u64 end;
 516	u64 real_removed_size = 0;
 517
 518	if (size > (ULLONG_MAX - start))
 519		size = ULLONG_MAX - start;
 520
 521	end = start + size;
 522	printk(KERN_DEBUG "e820 remove range: %016Lx - %016Lx ",
 523		       (unsigned long long) start,
 524		       (unsigned long long) end);
 525	if (checktype)
 526		e820_print_type(old_type);
 527	printk(KERN_CONT "\n");
 528
 529	for (i = 0; i < e820.nr_map; i++) {
 530		struct e820entry *ei = &e820.map[i];
 531		u64 final_start, final_end;
 532		u64 ei_end;
 533
 534		if (checktype && ei->type != old_type)
 535			continue;
 536
 537		ei_end = ei->addr + ei->size;
 538		/* totally covered? */
 539		if (ei->addr >= start && ei_end <= end) {
 540			real_removed_size += ei->size;
 541			memset(ei, 0, sizeof(struct e820entry));
 
 542			continue;
 543		}
 544
 545		/* new range is totally covered? */
 546		if (ei->addr < start && ei_end > end) {
 547			e820_add_region(end, ei_end - end, ei->type);
 548			ei->size = start - ei->addr;
 549			real_removed_size += size;
 550			continue;
 551		}
 552
 553		/* partially covered */
 554		final_start = max(start, ei->addr);
 555		final_end = min(end, ei_end);
 556		if (final_start >= final_end)
 557			continue;
 
 558		real_removed_size += final_end - final_start;
 559
 560		/*
 561		 * left range could be head or tail, so need to update
 562		 * size at first.
 563		 */
 564		ei->size -= final_end - final_start;
 565		if (ei->addr < final_start)
 566			continue;
 567		ei->addr = final_end;
 
 568	}
 569	return real_removed_size;
 570}
 571
 572void __init update_e820(void)
 573{
 574	u32 nr_map;
 
 575
 576	nr_map = e820.nr_map;
 577	if (sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &nr_map))
 578		return;
 579	e820.nr_map = nr_map;
 580	printk(KERN_INFO "modified physical RAM map:\n");
 581	e820_print_map("modified");
 582}
 583static void __init update_e820_saved(void)
 
 584{
 585	u32 nr_map;
 
 586
 587	nr_map = e820_saved.nr_map;
 588	if (sanitize_e820_map(e820_saved.map, ARRAY_SIZE(e820_saved.map), &nr_map))
 589		return;
 590	e820_saved.nr_map = nr_map;
 591}
 592#define MAX_GAP_END 0x100000000ull
 
 593/*
 594 * Search for a gap in the e820 memory space from start_addr to end_addr.
 595 */
 596__init int e820_search_gap(unsigned long *gapstart, unsigned long *gapsize,
 597		unsigned long start_addr, unsigned long long end_addr)
 598{
 599	unsigned long long last;
 600	int i = e820.nr_map;
 601	int found = 0;
 602
 603	last = (end_addr && end_addr < MAX_GAP_END) ? end_addr : MAX_GAP_END;
 604
 605	while (--i >= 0) {
 606		unsigned long long start = e820.map[i].addr;
 607		unsigned long long end = start + e820.map[i].size;
 608
 609		if (end < start_addr)
 610			continue;
 611
 612		/*
 613		 * Since "last" is at most 4GB, we know we'll
 614		 * fit in 32 bits if this condition is true
 615		 */
 616		if (last > end) {
 617			unsigned long gap = last - end;
 618
 619			if (gap >= *gapsize) {
 620				*gapsize = gap;
 621				*gapstart = end;
 622				found = 1;
 623			}
 624		}
 625		if (start < last)
 626			last = start;
 627	}
 628	return found;
 629}
 630
 631/*
 632 * Search for the biggest gap in the low 32 bits of the e820
 633 * memory space.  We pass this space to PCI to assign MMIO resources
 634 * for hotplug or unconfigured devices in.
 
 
 635 * Hopefully the BIOS let enough space left.
 636 */
 637__init void e820_setup_gap(void)
 638{
 639	unsigned long gapstart, gapsize;
 640	int found;
 641
 642	gapstart = 0x10000000;
 643	gapsize = 0x400000;
 644	found  = e820_search_gap(&gapstart, &gapsize, 0, MAX_GAP_END);
 645
 
 646#ifdef CONFIG_X86_64
 647	if (!found) {
 648		gapstart = (max_pfn << PAGE_SHIFT) + 1024*1024;
 649		printk(KERN_ERR
 650	"PCI: Warning: Cannot find a gap in the 32bit address range\n"
 651	"PCI: Unassigned devices with 32bit resource registers may break!\n");
 
 
 
 652	}
 653#endif
 654
 655	/*
 656	 * e820_reserve_resources_late protect stolen RAM already
 657	 */
 658	pci_mem_start = gapstart;
 659
 660	printk(KERN_INFO
 661	       "Allocating PCI resources starting at %lx (gap: %lx:%lx)\n",
 662	       pci_mem_start, gapstart, gapsize);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 663}
 664
 665/**
 666 * Because of the size limitation of struct boot_params, only first
 667 * 128 E820 memory entries are passed to kernel via
 668 * boot_params.e820_map, others are passed via SETUP_E820_EXT node of
 669 * linked list of struct setup_data, which is parsed here.
 670 */
 671void __init parse_e820_ext(struct setup_data *sdata)
 672{
 673	int entries;
 674	struct e820entry *extmap;
 
 675
 676	entries = sdata->len / sizeof(struct e820entry);
 677	extmap = (struct e820entry *)(sdata->data);
 678	__append_e820_map(extmap, entries);
 679	sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
 680	printk(KERN_INFO "extended physical RAM map:\n");
 681	e820_print_map("extended");
 
 
 
 
 
 
 
 682}
 683
 684#if defined(CONFIG_X86_64) || \
 685	(defined(CONFIG_X86_32) && defined(CONFIG_HIBERNATION))
 686/**
 687 * Find the ranges of physical addresses that do not correspond to
 688 * e820 RAM areas and mark the corresponding pages as nosave for
 689 * hibernation (32 bit) or software suspend and suspend to RAM (64 bit).
 690 *
 691 * This function requires the e820 map to be sorted and without any
 692 * overlapping entries and assumes the first e820 area to be RAM.
 693 */
 694void __init e820_mark_nosave_regions(unsigned long limit_pfn)
 695{
 696	int i;
 697	unsigned long pfn;
 
 
 
 
 
 
 
 
 698
 699	pfn = PFN_DOWN(e820.map[0].addr + e820.map[0].size);
 700	for (i = 1; i < e820.nr_map; i++) {
 701		struct e820entry *ei = &e820.map[i];
 702
 703		if (pfn < PFN_UP(ei->addr))
 704			register_nosave_region(pfn, PFN_UP(ei->addr));
 705
 706		pfn = PFN_DOWN(ei->addr + ei->size);
 707		if (ei->type != E820_RAM && ei->type != E820_RESERVED_KERN)
 708			register_nosave_region(PFN_UP(ei->addr), pfn);
 709
 710		if (pfn >= limit_pfn)
 711			break;
 712	}
 713}
 714#endif
 715
 716#ifdef CONFIG_HIBERNATION
 717/**
 718 * Mark ACPI NVS memory region, so that we can save/restore it during
 719 * hibernation and the subsequent resume.
 720 */
 721static int __init e820_mark_nvs_memory(void)
 722{
 723	int i;
 724
 725	for (i = 0; i < e820.nr_map; i++) {
 726		struct e820entry *ei = &e820.map[i];
 727
 728		if (ei->type == E820_NVS)
 729			suspend_nvs_register(ei->addr, ei->size);
 730	}
 731
 732	return 0;
 733}
 734core_initcall(e820_mark_nvs_memory);
 735#endif
 736
 737/*
 738 * pre allocated 4k and reserved it in memblock and e820_saved
 
 
 
 
 
 739 */
 740u64 __init early_reserve_e820(u64 startt, u64 sizet, u64 align)
 741{
 742	u64 size = 0;
 743	u64 addr;
 744	u64 start;
 745
 746	for (start = startt; ; start += size) {
 747		start = memblock_x86_find_in_range_size(start, &size, align);
 748		if (start == MEMBLOCK_ERROR)
 749			return 0;
 750		if (size >= sizet)
 751			break;
 752	}
 753
 754#ifdef CONFIG_X86_32
 755	if (start >= MAXMEM)
 756		return 0;
 757	if (start + size > MAXMEM)
 758		size = MAXMEM - start;
 759#endif
 760
 761	addr = round_down(start + size - sizet, align);
 762	if (addr < start)
 763		return 0;
 764	memblock_x86_reserve_range(addr, addr + sizet, "new next");
 765	e820_update_range_saved(addr, sizet, E820_RAM, E820_RESERVED);
 766	printk(KERN_INFO "update e820_saved for early_reserve_e820\n");
 767	update_e820_saved();
 768
 769	return addr;
 770}
 771
 772#ifdef CONFIG_X86_32
 773# ifdef CONFIG_X86_PAE
 774#  define MAX_ARCH_PFN		(1ULL<<(36-PAGE_SHIFT))
 775# else
 776#  define MAX_ARCH_PFN		(1ULL<<(32-PAGE_SHIFT))
 777# endif
 778#else /* CONFIG_X86_32 */
 779# define MAX_ARCH_PFN MAXMEM>>PAGE_SHIFT
 780#endif
 781
 782/*
 783 * Find the highest page frame number we have available
 784 */
 785static unsigned long __init e820_end_pfn(unsigned long limit_pfn, unsigned type)
 786{
 787	int i;
 788	unsigned long last_pfn = 0;
 789	unsigned long max_arch_pfn = MAX_ARCH_PFN;
 790
 791	for (i = 0; i < e820.nr_map; i++) {
 792		struct e820entry *ei = &e820.map[i];
 793		unsigned long start_pfn;
 794		unsigned long end_pfn;
 795
 796		if (ei->type != type)
 797			continue;
 798
 799		start_pfn = ei->addr >> PAGE_SHIFT;
 800		end_pfn = (ei->addr + ei->size) >> PAGE_SHIFT;
 801
 802		if (start_pfn >= limit_pfn)
 803			continue;
 804		if (end_pfn > limit_pfn) {
 805			last_pfn = limit_pfn;
 806			break;
 807		}
 808		if (end_pfn > last_pfn)
 809			last_pfn = end_pfn;
 810	}
 811
 812	if (last_pfn > max_arch_pfn)
 813		last_pfn = max_arch_pfn;
 814
 815	printk(KERN_INFO "last_pfn = %#lx max_arch_pfn = %#lx\n",
 816			 last_pfn, max_arch_pfn);
 817	return last_pfn;
 818}
 819unsigned long __init e820_end_of_ram_pfn(void)
 
 820{
 821	return e820_end_pfn(MAX_ARCH_PFN, E820_RAM);
 822}
 823
 824unsigned long __init e820_end_of_low_ram_pfn(void)
 825{
 826	return e820_end_pfn(1UL<<(32 - PAGE_SHIFT), E820_RAM);
 827}
 828
 829static void early_panic(char *msg)
 830{
 831	early_printk(msg);
 832	panic(msg);
 833}
 834
 835static int userdef __initdata;
 836
 837/* "mem=nopentium" disables the 4MB page tables. */
 838static int __init parse_memopt(char *p)
 839{
 840	u64 mem_size;
 841
 842	if (!p)
 843		return -EINVAL;
 844
 845	if (!strcmp(p, "nopentium")) {
 846#ifdef CONFIG_X86_32
 847		setup_clear_cpu_cap(X86_FEATURE_PSE);
 848		return 0;
 849#else
 850		printk(KERN_WARNING "mem=nopentium ignored! (only supported on x86_32)\n");
 851		return -EINVAL;
 852#endif
 853	}
 854
 855	userdef = 1;
 856	mem_size = memparse(p, &p);
 857	/* don't remove all of memory when handling "mem={invalid}" param */
 
 858	if (mem_size == 0)
 859		return -EINVAL;
 860	e820_remove_range(mem_size, ULLONG_MAX - mem_size, E820_RAM, 1);
 
 861
 862	return 0;
 863}
 864early_param("mem", parse_memopt);
 865
 866static int __init parse_memmap_opt(char *p)
 867{
 868	char *oldp;
 869	u64 start_at, mem_size;
 870
 871	if (!p)
 872		return -EINVAL;
 873
 874	if (!strncmp(p, "exactmap", 8)) {
 875#ifdef CONFIG_CRASH_DUMP
 876		/*
 877		 * If we are doing a crash dump, we still need to know
 878		 * the real mem size before original memory map is
 879		 * reset.
 880		 */
 881		saved_max_pfn = e820_end_of_ram_pfn();
 882#endif
 883		e820.nr_map = 0;
 884		userdef = 1;
 885		return 0;
 886	}
 887
 888	oldp = p;
 889	mem_size = memparse(p, &p);
 890	if (p == oldp)
 891		return -EINVAL;
 892
 893	userdef = 1;
 894	if (*p == '@') {
 895		start_at = memparse(p+1, &p);
 896		e820_add_region(start_at, mem_size, E820_RAM);
 897	} else if (*p == '#') {
 898		start_at = memparse(p+1, &p);
 899		e820_add_region(start_at, mem_size, E820_ACPI);
 900	} else if (*p == '$') {
 901		start_at = memparse(p+1, &p);
 902		e820_add_region(start_at, mem_size, E820_RESERVED);
 903	} else
 904		e820_remove_range(mem_size, ULLONG_MAX - mem_size, E820_RAM, 1);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 905
 906	return *p == '\0' ? 0 : -EINVAL;
 907}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 908early_param("memmap", parse_memmap_opt);
 909
 910void __init finish_e820_parsing(void)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 911{
 912	if (userdef) {
 913		u32 nr = e820.nr_map;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 914
 915		if (sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &nr) < 0)
 916			early_panic("Invalid user supplied memory map");
 917		e820.nr_map = nr;
 
 
 
 
 
 
 
 
 
 
 
 918
 919		printk(KERN_INFO "user-defined physical RAM map:\n");
 920		e820_print_map("user");
 
 
 
 
 
 
 
 
 
 
 921	}
 922}
 923
 924static inline const char *e820_type_to_string(int e820_type)
 925{
 926	switch (e820_type) {
 927	case E820_RESERVED_KERN:
 928	case E820_RAM:	return "System RAM";
 929	case E820_ACPI:	return "ACPI Tables";
 930	case E820_NVS:	return "ACPI Non-volatile Storage";
 931	case E820_UNUSABLE:	return "Unusable memory";
 932	default:	return "reserved";
 
 
 
 
 
 
 
 
 
 
 
 
 
 933	}
 934}
 935
 936/*
 937 * Mark e820 reserved areas as busy for the resource manager.
 938 */
 
 939static struct resource __initdata *e820_res;
 940void __init e820_reserve_resources(void)
 
 941{
 942	int i;
 943	struct resource *res;
 944	u64 end;
 945
 946	res = alloc_bootmem(sizeof(struct resource) * e820.nr_map);
 947	e820_res = res;
 948	for (i = 0; i < e820.nr_map; i++) {
 949		end = e820.map[i].addr + e820.map[i].size - 1;
 
 
 
 950		if (end != (resource_size_t)end) {
 951			res++;
 952			continue;
 953		}
 954		res->name = e820_type_to_string(e820.map[i].type);
 955		res->start = e820.map[i].addr;
 956		res->end = end;
 957
 958		res->flags = IORESOURCE_MEM;
 959
 960		/*
 961		 * don't register the region that could be conflicted with
 962		 * pci device BAR resource and insert them later in
 963		 * pcibios_resource_survey()
 964		 */
 965		if (e820.map[i].type != E820_RESERVED || res->start < (1ULL<<20)) {
 966			res->flags |= IORESOURCE_BUSY;
 967			insert_resource(&iomem_resource, res);
 968		}
 969		res++;
 970	}
 971
 972	for (i = 0; i < e820_saved.nr_map; i++) {
 973		struct e820entry *entry = &e820_saved.map[i];
 974		firmware_map_add_early(entry->addr,
 975			entry->addr + entry->size - 1,
 976			e820_type_to_string(entry->type));
 977	}
 978}
 979
 980/* How much should we pad RAM ending depending on where it is? */
 981static unsigned long ram_alignment(resource_size_t pos)
 
 
 982{
 983	unsigned long mb = pos >> 20;
 984
 985	/* To 64kB in the first megabyte */
 986	if (!mb)
 987		return 64*1024;
 988
 989	/* To 1MB in the first 16MB */
 990	if (mb < 16)
 991		return 1024*1024;
 992
 993	/* To 64MB for anything above that */
 994	return 64*1024*1024;
 995}
 996
 997#define MAX_RESOURCE_SIZE ((resource_size_t)-1)
 998
 999void __init e820_reserve_resources_late(void)
1000{
1001	int i;
1002	struct resource *res;
1003
1004	res = e820_res;
1005	for (i = 0; i < e820.nr_map; i++) {
1006		if (!res->parent && res->end)
1007			insert_resource_expand_to_fit(&iomem_resource, res);
1008		res++;
1009	}
1010
1011	/*
1012	 * Try to bump up RAM regions to reasonable boundaries to
1013	 * avoid stolen RAM:
1014	 */
1015	for (i = 0; i < e820.nr_map; i++) {
1016		struct e820entry *entry = &e820.map[i];
1017		u64 start, end;
1018
1019		if (entry->type != E820_RAM)
1020			continue;
 
1021		start = entry->addr + entry->size;
1022		end = round_up(start, ram_alignment(start)) - 1;
1023		if (end > MAX_RESOURCE_SIZE)
1024			end = MAX_RESOURCE_SIZE;
1025		if (start >= end)
1026			continue;
1027		printk(KERN_DEBUG "reserve RAM buffer: %016llx - %016llx ",
1028			       start, end);
1029		reserve_region_with_split(&iomem_resource, start, end,
1030					  "RAM buffer");
1031	}
1032}
1033
1034char *__init default_machine_specific_memory_setup(void)
 
 
 
1035{
1036	char *who = "BIOS-e820";
1037	u32 new_nr;
1038	/*
1039	 * Try to copy the BIOS-supplied E820-map.
1040	 *
1041	 * Otherwise fake a memory map; one section from 0k->640k,
1042	 * the next section from 1mb->appropriate_mem_k
1043	 */
1044	new_nr = boot_params.e820_entries;
1045	sanitize_e820_map(boot_params.e820_map,
1046			ARRAY_SIZE(boot_params.e820_map),
1047			&new_nr);
1048	boot_params.e820_entries = new_nr;
1049	if (append_e820_map(boot_params.e820_map, boot_params.e820_entries)
1050	  < 0) {
1051		u64 mem_size;
1052
1053		/* compare results from other methods and take the greater */
1054		if (boot_params.alt_mem_k
1055		    < boot_params.screen_info.ext_mem_k) {
1056			mem_size = boot_params.screen_info.ext_mem_k;
1057			who = "BIOS-88";
1058		} else {
1059			mem_size = boot_params.alt_mem_k;
1060			who = "BIOS-e801";
1061		}
1062
1063		e820.nr_map = 0;
1064		e820_add_region(0, LOWMEMSIZE(), E820_RAM);
1065		e820_add_region(HIGH_MEMORY, mem_size << 10, E820_RAM);
1066	}
1067
1068	/* In case someone cares... */
 
 
1069	return who;
1070}
1071
1072void __init setup_memory_map(void)
 
 
 
 
 
1073{
1074	char *who;
1075
 
 
 
1076	who = x86_init.resources.memory_setup();
1077	memcpy(&e820_saved, &e820, sizeof(struct e820map));
1078	printk(KERN_INFO "BIOS-provided physical RAM map:\n");
1079	e820_print_map(who);
 
 
 
1080}
1081
1082void __init memblock_x86_fill(void)
1083{
1084	int i;
1085	u64 end;
1086
1087	/*
1088	 * EFI may have more than 128 entries
1089	 * We are safe to enable resizing, beause memblock_x86_fill()
1090	 * is rather later for x86
 
 
 
 
1091	 */
1092	memblock_can_resize = 1;
1093
1094	for (i = 0; i < e820.nr_map; i++) {
1095		struct e820entry *ei = &e820.map[i];
1096
1097		end = ei->addr + ei->size;
1098		if (end != (resource_size_t)end)
1099			continue;
1100
1101		if (ei->type != E820_RAM && ei->type != E820_RESERVED_KERN)
1102			continue;
1103
1104		memblock_add(ei->addr, ei->size);
1105	}
1106
1107	memblock_analyze();
 
 
1108	memblock_dump_all();
1109}
1110
1111void __init memblock_find_dma_reserve(void)
1112{
1113#ifdef CONFIG_X86_64
1114	u64 free_size_pfn;
1115	u64 mem_size_pfn;
1116	/*
1117	 * need to find out used area below MAX_DMA_PFN
1118	 * need to use memblock to get free size in [0, MAX_DMA_PFN]
1119	 * at first, and assume boot_mem will not take below MAX_DMA_PFN
1120	 */
1121	mem_size_pfn = memblock_x86_memory_in_range(0, MAX_DMA_PFN << PAGE_SHIFT) >> PAGE_SHIFT;
1122	free_size_pfn = memblock_x86_free_memory_in_range(0, MAX_DMA_PFN << PAGE_SHIFT) >> PAGE_SHIFT;
1123	set_dma_reserve(mem_size_pfn - free_size_pfn);
1124#endif
1125}