2 * Low level x86 E820 memory map handling functions.
4 * The firmware and bootloader passes us the "E820 table", which is the primary
5 * physical memory layout description available about x86 systems.
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.).
11 #include <linux/crash_dump.h>
12 #include <linux/memblock.h>
13 #include <linux/suspend.h>
14 #include <linux/acpi.h>
15 #include <linux/firmware-map.h>
16 #include <linux/sort.h>
18 #include <asm/e820/api.h>
19 #include <asm/setup.h>
22 * We organize the E820 table into three main data structures:
24 * - 'e820_table_firmware': the original firmware version passed to us by the
25 * bootloader - not modified by the kernel. It is composed of two parts:
26 * the first 128 E820 memory entries in boot_params.e820_table and the remaining
27 * (if any) entries of the SETUP_E820_EXT nodes. We use this to:
29 * - inform the user about the firmware's notion of memory layout
30 * via /sys/firmware/memmap
32 * - the hibernation code uses it to generate a kernel-independent MD5
33 * fingerprint of the physical memory layout of a system.
35 * - 'e820_table_kexec': a slightly modified (by the kernel) firmware version
36 * passed to us by the bootloader - the major difference between
37 * e820_table_firmware[] and this one is that, the latter marks the setup_data
38 * list created by the EFI boot stub as reserved, so that kexec can reuse the
39 * setup_data information in the second kernel. Besides, e820_table_kexec[]
40 * might also be modified by the kexec itself to fake a mptable.
43 * - kexec, which is a bootloader in disguise, uses the original E820
44 * layout to pass to the kexec-ed kernel. This way the original kernel
45 * can have a restricted E820 map while the kexec()-ed kexec-kernel
46 * can have access to full memory - etc.
48 * - 'e820_table': this is the main E820 table that is massaged by the
49 * low level x86 platform code, or modified by boot parameters, before
50 * passed on to higher level MM layers.
52 * Once the E820 map has been converted to the standard Linux memory layout
53 * information its role stops - modifying it has no effect and does not get
54 * re-propagated. So itsmain role is a temporary bootstrap storage of firmware
55 * specific memory layout data during early bootup.
57 static struct e820_table e820_table_init __initdata;
58 static struct e820_table e820_table_kexec_init __initdata;
59 static struct e820_table e820_table_firmware_init __initdata;
61 struct e820_table *e820_table __refdata = &e820_table_init;
62 struct e820_table *e820_table_kexec __refdata = &e820_table_kexec_init;
63 struct e820_table *e820_table_firmware __refdata = &e820_table_firmware_init;
65 /* For PCI or other memory-mapped resources */
66 unsigned long pci_mem_start = 0xaeedbabe;
68 EXPORT_SYMBOL(pci_mem_start);
72 * This function checks if any part of the range <start,end> is mapped
75 bool e820__mapped_any(u64 start, u64 end, enum e820_type type)
79 for (i = 0; i < e820_table->nr_entries; i++) {
80 struct e820_entry *entry = &e820_table->entries[i];
82 if (type && entry->type != type)
84 if (entry->addr >= end || entry->addr + entry->size <= start)
90 EXPORT_SYMBOL_GPL(e820__mapped_any);
93 * This function checks if the entire <start,end> range is mapped with 'type'.
95 * Note: this function only works correctly once the E820 table is sorted and
96 * not-overlapping (at least for the range specified), which is the case normally.
98 static struct e820_entry *__e820__mapped_all(u64 start, u64 end,
103 for (i = 0; i < e820_table->nr_entries; i++) {
104 struct e820_entry *entry = &e820_table->entries[i];
106 if (type && entry->type != type)
109 /* Is the region (part) in overlap with the current region? */
110 if (entry->addr >= end || entry->addr + entry->size <= start)
114 * If the region is at the beginning of <start,end> we move
115 * 'start' to the end of the region since it's ok until there
117 if (entry->addr <= start)
118 start = entry->addr + entry->size;
121 * If 'start' is now at or beyond 'end', we're done, full
122 * coverage of the desired range exists:
132 * This function checks if the entire range <start,end> is mapped with type.
134 bool __init e820__mapped_all(u64 start, u64 end, enum e820_type type)
136 return __e820__mapped_all(start, end, type);
140 * This function returns the type associated with the range <start,end>.
142 int e820__get_entry_type(u64 start, u64 end)
144 struct e820_entry *entry = __e820__mapped_all(start, end, 0);
146 return entry ? entry->type : -EINVAL;
150 * Add a memory region to the kernel E820 map.
152 static void __init __e820__range_add(struct e820_table *table, u64 start, u64 size, enum e820_type type)
154 int x = table->nr_entries;
156 if (x >= ARRAY_SIZE(table->entries)) {
157 pr_err("too many entries; ignoring [mem %#010llx-%#010llx]\n",
158 start, start + size - 1);
162 table->entries[x].addr = start;
163 table->entries[x].size = size;
164 table->entries[x].type = type;
168 void __init e820__range_add(u64 start, u64 size, enum e820_type type)
170 __e820__range_add(e820_table, start, size, type);
173 static void __init e820_print_type(enum e820_type 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;
188 void __init e820__print_table(char *who)
192 for (i = 0; i < e820_table->nr_entries; i++) {
193 pr_info("%s: [mem %#018Lx-%#018Lx] ",
195 e820_table->entries[i].addr,
196 e820_table->entries[i].addr + e820_table->entries[i].size - 1);
198 e820_print_type(e820_table->entries[i].type);
204 * Sanitize an E820 map.
206 * Some E820 layouts include overlapping entries. The following
207 * replaces the original E820 map with a new one, removing overlaps,
208 * and resolving conflicting memory types in favor of highest
211 * The input parameter 'entries' points to an array of 'struct
212 * e820_entry' which on entry has elements in the range [0, *nr_entries)
213 * valid, and which has space for up to max_nr_entries entries.
214 * On return, the resulting sanitized E820 map entries will be in
215 * overwritten in the same location, starting at 'entries'.
217 * The integer pointed to by nr_entries must be valid on entry (the
218 * current number of valid entries located at 'entries'). If the
219 * sanitizing succeeds the *nr_entries will be updated with the new
220 * number of valid entries (something no more than max_nr_entries).
222 * The return value from e820__update_table() is zero if it
223 * successfully 'sanitized' the map entries passed in, and is -1
224 * if it did nothing, which can happen if either of (1) it was
225 * only passed one map entry, or (2) any of the input map entries
226 * were invalid (start + size < start, meaning that the size was
227 * so big the described memory range wrapped around through zero.)
229 * Visually we're performing the following
230 * (1,2,3,4 = memory types)...
232 * Sample memory map (w/overlaps):
233 * ____22__________________
234 * ______________________4_
235 * ____1111________________
236 * _44_____________________
237 * 11111111________________
238 * ____________________33__
239 * ___________44___________
240 * __________33333_________
241 * ______________22________
242 * ___________________2222_
243 * _________111111111______
244 * _____________________11_
245 * _________________4______
247 * Sanitized equivalent (no overlap):
248 * 1_______________________
249 * _44_____________________
250 * ___1____________________
251 * ____22__________________
252 * ______11________________
253 * _________1______________
254 * __________3_____________
255 * ___________44___________
256 * _____________33_________
257 * _______________2________
258 * ________________1_______
259 * _________________4______
260 * ___________________2____
261 * ____________________33__
262 * ______________________4_
264 struct change_member {
265 /* Pointer to the original entry: */
266 struct e820_entry *entry;
267 /* Address for this change point: */
268 unsigned long long addr;
271 static struct change_member change_point_list[2*E820_MAX_ENTRIES] __initdata;
272 static struct change_member *change_point[2*E820_MAX_ENTRIES] __initdata;
273 static struct e820_entry *overlap_list[E820_MAX_ENTRIES] __initdata;
274 static struct e820_entry new_entries[E820_MAX_ENTRIES] __initdata;
276 static int __init cpcompare(const void *a, const void *b)
278 struct change_member * const *app = a, * const *bpp = b;
279 const struct change_member *ap = *app, *bp = *bpp;
282 * Inputs are pointers to two elements of change_point[]. If their
283 * addresses are not equal, their difference dominates. If the addresses
284 * are equal, then consider one that represents the end of its region
285 * to be greater than one that does not.
287 if (ap->addr != bp->addr)
288 return ap->addr > bp->addr ? 1 : -1;
290 return (ap->addr != ap->entry->addr) - (bp->addr != bp->entry->addr);
293 int __init e820__update_table(struct e820_table *table)
295 struct e820_entry *entries = table->entries;
296 u32 max_nr_entries = ARRAY_SIZE(table->entries);
297 enum e820_type current_type, last_type;
298 unsigned long long last_addr;
299 u32 new_nr_entries, overlap_entries;
300 u32 i, chg_idx, chg_nr;
302 /* If there's only one memory region, don't bother: */
303 if (table->nr_entries < 2)
306 BUG_ON(table->nr_entries > max_nr_entries);
308 /* Bail out if we find any unreasonable addresses in the map: */
309 for (i = 0; i < table->nr_entries; i++) {
310 if (entries[i].addr + entries[i].size < entries[i].addr)
314 /* Create pointers for initial change-point information (for sorting): */
315 for (i = 0; i < 2 * table->nr_entries; i++)
316 change_point[i] = &change_point_list[i];
319 * Record all known change-points (starting and ending addresses),
320 * omitting empty memory regions:
323 for (i = 0; i < table->nr_entries; i++) {
324 if (entries[i].size != 0) {
325 change_point[chg_idx]->addr = entries[i].addr;
326 change_point[chg_idx++]->entry = &entries[i];
327 change_point[chg_idx]->addr = entries[i].addr + entries[i].size;
328 change_point[chg_idx++]->entry = &entries[i];
333 /* Sort change-point list by memory addresses (low -> high): */
334 sort(change_point, chg_nr, sizeof(*change_point), cpcompare, NULL);
336 /* Create a new memory map, removing overlaps: */
337 overlap_entries = 0; /* Number of entries in the overlap table */
338 new_nr_entries = 0; /* Index for creating new map entries */
339 last_type = 0; /* Start with undefined memory type */
340 last_addr = 0; /* Start with 0 as last starting address */
342 /* Loop through change-points, determining effect on the new map: */
343 for (chg_idx = 0; chg_idx < chg_nr; chg_idx++) {
344 /* Keep track of all overlapping entries */
345 if (change_point[chg_idx]->addr == change_point[chg_idx]->entry->addr) {
346 /* Add map entry to overlap list (> 1 entry implies an overlap) */
347 overlap_list[overlap_entries++] = change_point[chg_idx]->entry;
349 /* Remove entry from list (order independent, so swap with last): */
350 for (i = 0; i < overlap_entries; i++) {
351 if (overlap_list[i] == change_point[chg_idx]->entry)
352 overlap_list[i] = overlap_list[overlap_entries-1];
357 * If there are overlapping entries, decide which
358 * "type" to use (larger value takes precedence --
359 * 1=usable, 2,3,4,4+=unusable)
362 for (i = 0; i < overlap_entries; i++) {
363 if (overlap_list[i]->type > current_type)
364 current_type = overlap_list[i]->type;
367 /* Continue building up new map based on this information: */
368 if (current_type != last_type || current_type == E820_TYPE_PRAM) {
369 if (last_type != 0) {
370 new_entries[new_nr_entries].size = change_point[chg_idx]->addr - last_addr;
371 /* Move forward only if the new size was non-zero: */
372 if (new_entries[new_nr_entries].size != 0)
373 /* No more space left for new entries? */
374 if (++new_nr_entries >= max_nr_entries)
377 if (current_type != 0) {
378 new_entries[new_nr_entries].addr = change_point[chg_idx]->addr;
379 new_entries[new_nr_entries].type = current_type;
380 last_addr = change_point[chg_idx]->addr;
382 last_type = current_type;
386 /* Copy the new entries into the original location: */
387 memcpy(entries, new_entries, new_nr_entries*sizeof(*entries));
388 table->nr_entries = new_nr_entries;
393 static int __init __append_e820_table(struct boot_e820_entry *entries, u32 nr_entries)
395 struct boot_e820_entry *entry = entries;
398 u64 start = entry->addr;
399 u64 size = entry->size;
400 u64 end = start + size - 1;
401 u32 type = entry->type;
403 /* Ignore the entry on 64-bit overflow: */
404 if (start > end && likely(size))
407 e820__range_add(start, size, type);
416 * Copy the BIOS E820 map into a safe place.
418 * Sanity-check it while we're at it..
420 * If we're lucky and live on a modern system, the setup code
421 * will have given us a memory map that we can use to properly
422 * set up memory. If we aren't, we'll fake a memory map.
424 static int __init append_e820_table(struct boot_e820_entry *entries, u32 nr_entries)
426 /* Only one memory region (or negative)? Ignore it */
430 return __append_e820_table(entries, nr_entries);
434 __e820__range_update(struct e820_table *table, u64 start, u64 size, enum e820_type old_type, enum e820_type new_type)
438 u64 real_updated_size = 0;
440 BUG_ON(old_type == new_type);
442 if (size > (ULLONG_MAX - start))
443 size = ULLONG_MAX - start;
446 printk(KERN_DEBUG "e820: update [mem %#010Lx-%#010Lx] ", start, end - 1);
447 e820_print_type(old_type);
449 e820_print_type(new_type);
452 for (i = 0; i < table->nr_entries; i++) {
453 struct e820_entry *entry = &table->entries[i];
454 u64 final_start, final_end;
457 if (entry->type != old_type)
460 entry_end = entry->addr + entry->size;
462 /* Completely covered by new range? */
463 if (entry->addr >= start && entry_end <= end) {
464 entry->type = new_type;
465 real_updated_size += entry->size;
469 /* New range is completely covered? */
470 if (entry->addr < start && entry_end > end) {
471 __e820__range_add(table, start, size, new_type);
472 __e820__range_add(table, end, entry_end - end, entry->type);
473 entry->size = start - entry->addr;
474 real_updated_size += size;
478 /* Partially covered: */
479 final_start = max(start, entry->addr);
480 final_end = min(end, entry_end);
481 if (final_start >= final_end)
484 __e820__range_add(table, final_start, final_end - final_start, new_type);
486 real_updated_size += final_end - final_start;
489 * Left range could be head or tail, so need to update
492 entry->size -= final_end - final_start;
493 if (entry->addr < final_start)
496 entry->addr = final_end;
498 return real_updated_size;
501 u64 __init e820__range_update(u64 start, u64 size, enum e820_type old_type, enum e820_type new_type)
503 return __e820__range_update(e820_table, start, size, old_type, new_type);
506 static u64 __init e820__range_update_kexec(u64 start, u64 size, enum e820_type old_type, enum e820_type new_type)
508 return __e820__range_update(e820_table_kexec, start, size, old_type, new_type);
511 /* Remove a range of memory from the E820 table: */
512 u64 __init e820__range_remove(u64 start, u64 size, enum e820_type old_type, bool check_type)
516 u64 real_removed_size = 0;
518 if (size > (ULLONG_MAX - start))
519 size = ULLONG_MAX - start;
522 printk(KERN_DEBUG "e820: remove [mem %#010Lx-%#010Lx] ", start, end - 1);
524 e820_print_type(old_type);
527 for (i = 0; i < e820_table->nr_entries; i++) {
528 struct e820_entry *entry = &e820_table->entries[i];
529 u64 final_start, final_end;
532 if (check_type && entry->type != old_type)
535 entry_end = entry->addr + entry->size;
537 /* Completely covered? */
538 if (entry->addr >= start && entry_end <= end) {
539 real_removed_size += entry->size;
540 memset(entry, 0, sizeof(*entry));
544 /* Is the new range completely covered? */
545 if (entry->addr < start && entry_end > end) {
546 e820__range_add(end, entry_end - end, entry->type);
547 entry->size = start - entry->addr;
548 real_removed_size += size;
552 /* Partially covered: */
553 final_start = max(start, entry->addr);
554 final_end = min(end, entry_end);
555 if (final_start >= final_end)
558 real_removed_size += final_end - final_start;
561 * Left range could be head or tail, so need to update
564 entry->size -= final_end - final_start;
565 if (entry->addr < final_start)
568 entry->addr = final_end;
570 return real_removed_size;
573 void __init e820__update_table_print(void)
575 if (e820__update_table(e820_table))
578 pr_info("modified physical RAM map:\n");
579 e820__print_table("modified");
582 static void __init e820__update_table_kexec(void)
584 e820__update_table(e820_table_kexec);
587 #define MAX_GAP_END 0x100000000ull
590 * Search for a gap in the E820 memory space from 0 to MAX_GAP_END (4GB).
592 static int __init e820_search_gap(unsigned long *gapstart, unsigned long *gapsize)
594 unsigned long long last = MAX_GAP_END;
595 int i = e820_table->nr_entries;
599 unsigned long long start = e820_table->entries[i].addr;
600 unsigned long long end = start + e820_table->entries[i].size;
603 * Since "last" is at most 4GB, we know we'll
604 * fit in 32 bits if this condition is true:
607 unsigned long gap = last - end;
609 if (gap >= *gapsize) {
622 * Search for the biggest gap in the low 32 bits of the E820
623 * memory space. We pass this space to the PCI subsystem, so
624 * that it can assign MMIO resources for hotplug or
625 * unconfigured devices in.
627 * Hopefully the BIOS let enough space left.
629 __init void e820__setup_pci_gap(void)
631 unsigned long gapstart, gapsize;
635 found = e820_search_gap(&gapstart, &gapsize);
639 gapstart = (max_pfn << PAGE_SHIFT) + 1024*1024;
640 pr_err("Cannot find an available gap in the 32-bit address range\n");
641 pr_err("PCI devices with unassigned 32-bit BARs may not work!\n");
643 gapstart = 0x10000000;
648 * e820__reserve_resources_late() protects stolen RAM already:
650 pci_mem_start = gapstart;
652 pr_info("[mem %#010lx-%#010lx] available for PCI devices\n",
653 gapstart, gapstart + gapsize - 1);
657 * Called late during init, in free_initmem().
659 * Initial e820_table and e820_table_kexec are largish __initdata arrays.
661 * Copy them to a (usually much smaller) dynamically allocated area that is
662 * sized precisely after the number of e820 entries.
664 * This is done after we've performed all the fixes and tweaks to the tables.
665 * All functions which modify them are __init functions, which won't exist
666 * after free_initmem().
668 __init void e820__reallocate_tables(void)
670 struct e820_table *n;
673 size = offsetof(struct e820_table, entries) + sizeof(struct e820_entry)*e820_table->nr_entries;
674 n = kmalloc(size, GFP_KERNEL);
676 memcpy(n, e820_table, size);
679 size = offsetof(struct e820_table, entries) + sizeof(struct e820_entry)*e820_table_kexec->nr_entries;
680 n = kmalloc(size, GFP_KERNEL);
682 memcpy(n, e820_table_kexec, size);
683 e820_table_kexec = n;
685 size = offsetof(struct e820_table, entries) + sizeof(struct e820_entry)*e820_table_firmware->nr_entries;
686 n = kmalloc(size, GFP_KERNEL);
688 memcpy(n, e820_table_firmware, size);
689 e820_table_firmware = n;
693 * Because of the small fixed size of struct boot_params, only the first
694 * 128 E820 memory entries are passed to the kernel via boot_params.e820_table,
695 * the remaining (if any) entries are passed via the SETUP_E820_EXT node of
696 * struct setup_data, which is parsed here.
698 void __init e820__memory_setup_extended(u64 phys_addr, u32 data_len)
701 struct boot_e820_entry *extmap;
702 struct setup_data *sdata;
704 sdata = early_memremap(phys_addr, data_len);
705 entries = sdata->len / sizeof(*extmap);
706 extmap = (struct boot_e820_entry *)(sdata->data);
708 __append_e820_table(extmap, entries);
709 e820__update_table(e820_table);
711 memcpy(e820_table_kexec, e820_table, sizeof(*e820_table_kexec));
712 memcpy(e820_table_firmware, e820_table, sizeof(*e820_table_firmware));
714 early_memunmap(sdata, data_len);
715 pr_info("extended physical RAM map:\n");
716 e820__print_table("extended");
720 * Find the ranges of physical addresses that do not correspond to
721 * E820 RAM areas and register the corresponding pages as 'nosave' for
722 * hibernation (32-bit) or software suspend and suspend to RAM (64-bit).
724 * This function requires the E820 map to be sorted and without any
725 * overlapping entries.
727 void __init e820__register_nosave_regions(unsigned long limit_pfn)
730 unsigned long pfn = 0;
732 for (i = 0; i < e820_table->nr_entries; i++) {
733 struct e820_entry *entry = &e820_table->entries[i];
735 if (pfn < PFN_UP(entry->addr))
736 register_nosave_region(pfn, PFN_UP(entry->addr));
738 pfn = PFN_DOWN(entry->addr + entry->size);
740 if (entry->type != E820_TYPE_RAM && entry->type != E820_TYPE_RESERVED_KERN)
741 register_nosave_region(PFN_UP(entry->addr), pfn);
743 if (pfn >= limit_pfn)
750 * Register ACPI NVS memory regions, so that we can save/restore them during
751 * hibernation and the subsequent resume:
753 static int __init e820__register_nvs_regions(void)
757 for (i = 0; i < e820_table->nr_entries; i++) {
758 struct e820_entry *entry = &e820_table->entries[i];
760 if (entry->type == E820_TYPE_NVS)
761 acpi_nvs_register(entry->addr, entry->size);
766 core_initcall(e820__register_nvs_regions);
770 * Allocate the requested number of bytes with the requsted alignment
771 * and return (the physical address) to the caller. Also register this
772 * range in the 'kexec' E820 table as a reserved range.
774 * This allows kexec to fake a new mptable, as if it came from the real
777 u64 __init e820__memblock_alloc_reserved(u64 size, u64 align)
781 addr = __memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ACCESSIBLE);
783 e820__range_update_kexec(addr, size, E820_TYPE_RAM, E820_TYPE_RESERVED);
784 pr_info("update e820_table_kexec for e820__memblock_alloc_reserved()\n");
785 e820__update_table_kexec();
792 # ifdef CONFIG_X86_PAE
793 # define MAX_ARCH_PFN (1ULL<<(36-PAGE_SHIFT))
795 # define MAX_ARCH_PFN (1ULL<<(32-PAGE_SHIFT))
797 #else /* CONFIG_X86_32 */
798 # define MAX_ARCH_PFN MAXMEM>>PAGE_SHIFT
802 * Find the highest page frame number we have available
804 static unsigned long __init e820_end_pfn(unsigned long limit_pfn, enum e820_type type)
807 unsigned long last_pfn = 0;
808 unsigned long max_arch_pfn = MAX_ARCH_PFN;
810 for (i = 0; i < e820_table->nr_entries; i++) {
811 struct e820_entry *entry = &e820_table->entries[i];
812 unsigned long start_pfn;
813 unsigned long end_pfn;
815 if (entry->type != type)
818 start_pfn = entry->addr >> PAGE_SHIFT;
819 end_pfn = (entry->addr + entry->size) >> PAGE_SHIFT;
821 if (start_pfn >= limit_pfn)
823 if (end_pfn > limit_pfn) {
824 last_pfn = limit_pfn;
827 if (end_pfn > last_pfn)
831 if (last_pfn > max_arch_pfn)
832 last_pfn = max_arch_pfn;
834 pr_info("last_pfn = %#lx max_arch_pfn = %#lx\n",
835 last_pfn, max_arch_pfn);
839 unsigned long __init e820__end_of_ram_pfn(void)
841 return e820_end_pfn(MAX_ARCH_PFN, E820_TYPE_RAM);
844 unsigned long __init e820__end_of_low_ram_pfn(void)
846 return e820_end_pfn(1UL << (32 - PAGE_SHIFT), E820_TYPE_RAM);
849 static void __init early_panic(char *msg)
855 static int userdef __initdata;
857 /* The "mem=nopentium" boot option disables 4MB page tables on 32-bit kernels: */
858 static int __init parse_memopt(char *p)
865 if (!strcmp(p, "nopentium")) {
867 setup_clear_cpu_cap(X86_FEATURE_PSE);
870 pr_warn("mem=nopentium ignored! (only supported on x86_32)\n");
876 mem_size = memparse(p, &p);
878 /* Don't remove all memory when getting "mem={invalid}" parameter: */
882 e820__range_remove(mem_size, ULLONG_MAX - mem_size, E820_TYPE_RAM, 1);
886 early_param("mem", parse_memopt);
888 static int __init parse_memmap_one(char *p)
891 u64 start_at, mem_size;
896 if (!strncmp(p, "exactmap", 8)) {
897 #ifdef CONFIG_CRASH_DUMP
899 * If we are doing a crash dump, we still need to know
900 * the real memory size before the original memory map is
903 saved_max_pfn = e820__end_of_ram_pfn();
905 e820_table->nr_entries = 0;
911 mem_size = memparse(p, &p);
917 start_at = memparse(p+1, &p);
918 e820__range_add(start_at, mem_size, E820_TYPE_RAM);
919 } else if (*p == '#') {
920 start_at = memparse(p+1, &p);
921 e820__range_add(start_at, mem_size, E820_TYPE_ACPI);
922 } else if (*p == '$') {
923 start_at = memparse(p+1, &p);
924 e820__range_add(start_at, mem_size, E820_TYPE_RESERVED);
925 } else if (*p == '!') {
926 start_at = memparse(p+1, &p);
927 e820__range_add(start_at, mem_size, E820_TYPE_PRAM);
928 } else if (*p == '%') {
929 enum e820_type from = 0, to = 0;
931 start_at = memparse(p + 1, &p);
933 from = simple_strtoull(p + 1, &p, 0);
935 to = simple_strtoull(p + 1, &p, 0);
939 e820__range_update(start_at, mem_size, from, to);
941 e820__range_add(start_at, mem_size, to);
943 e820__range_remove(start_at, mem_size, from, 1);
945 e820__range_remove(start_at, mem_size, 0, 0);
947 e820__range_remove(mem_size, ULLONG_MAX - mem_size, E820_TYPE_RAM, 1);
950 return *p == '\0' ? 0 : -EINVAL;
953 static int __init parse_memmap_opt(char *str)
956 char *k = strchr(str, ',');
961 parse_memmap_one(str);
967 early_param("memmap", parse_memmap_opt);
970 * Reserve all entries from the bootloader's extensible data nodes list,
971 * because if present we are going to use it later on to fetch e820
974 void __init e820__reserve_setup_data(void)
976 struct setup_data *data;
979 pa_data = boot_params.hdr.setup_data;
984 data = early_memremap(pa_data, sizeof(*data));
985 e820__range_update(pa_data, sizeof(*data)+data->len, E820_TYPE_RAM, E820_TYPE_RESERVED_KERN);
986 e820__range_update_kexec(pa_data, sizeof(*data)+data->len, E820_TYPE_RAM, E820_TYPE_RESERVED_KERN);
987 pa_data = data->next;
988 early_memunmap(data, sizeof(*data));
991 e820__update_table(e820_table);
992 e820__update_table(e820_table_kexec);
994 pr_info("extended physical RAM map:\n");
995 e820__print_table("reserve setup_data");
999 * Called after parse_early_param(), after early parameters (such as mem=)
1000 * have been processed, in which case we already have an E820 table filled in
1001 * via the parameter callback function(s), but it's not sorted and printed yet:
1003 void __init e820__finish_early_params(void)
1006 if (e820__update_table(e820_table) < 0)
1007 early_panic("Invalid user supplied memory map");
1009 pr_info("user-defined physical RAM map:\n");
1010 e820__print_table("user");
1014 static const char *__init e820_type_to_string(struct e820_entry *entry)
1016 switch (entry->type) {
1017 case E820_TYPE_RESERVED_KERN: /* Fall-through: */
1018 case E820_TYPE_RAM: return "System RAM";
1019 case E820_TYPE_ACPI: return "ACPI Tables";
1020 case E820_TYPE_NVS: return "ACPI Non-volatile Storage";
1021 case E820_TYPE_UNUSABLE: return "Unusable memory";
1022 case E820_TYPE_PRAM: return "Persistent Memory (legacy)";
1023 case E820_TYPE_PMEM: return "Persistent Memory";
1024 case E820_TYPE_RESERVED: return "Reserved";
1025 default: return "Unknown E820 type";
1029 static unsigned long __init e820_type_to_iomem_type(struct e820_entry *entry)
1031 switch (entry->type) {
1032 case E820_TYPE_RESERVED_KERN: /* Fall-through: */
1033 case E820_TYPE_RAM: return IORESOURCE_SYSTEM_RAM;
1034 case E820_TYPE_ACPI: /* Fall-through: */
1035 case E820_TYPE_NVS: /* Fall-through: */
1036 case E820_TYPE_UNUSABLE: /* Fall-through: */
1037 case E820_TYPE_PRAM: /* Fall-through: */
1038 case E820_TYPE_PMEM: /* Fall-through: */
1039 case E820_TYPE_RESERVED: /* Fall-through: */
1040 default: return IORESOURCE_MEM;
1044 static unsigned long __init e820_type_to_iores_desc(struct e820_entry *entry)
1046 switch (entry->type) {
1047 case E820_TYPE_ACPI: return IORES_DESC_ACPI_TABLES;
1048 case E820_TYPE_NVS: return IORES_DESC_ACPI_NV_STORAGE;
1049 case E820_TYPE_PMEM: return IORES_DESC_PERSISTENT_MEMORY;
1050 case E820_TYPE_PRAM: return IORES_DESC_PERSISTENT_MEMORY_LEGACY;
1051 case E820_TYPE_RESERVED_KERN: /* Fall-through: */
1052 case E820_TYPE_RAM: /* Fall-through: */
1053 case E820_TYPE_UNUSABLE: /* Fall-through: */
1054 case E820_TYPE_RESERVED: /* Fall-through: */
1055 default: return IORES_DESC_NONE;
1059 static bool __init do_mark_busy(enum e820_type type, struct resource *res)
1061 /* this is the legacy bios/dos rom-shadow + mmio region */
1062 if (res->start < (1ULL<<20))
1066 * Treat persistent memory like device memory, i.e. reserve it
1067 * for exclusive use of a driver
1070 case E820_TYPE_RESERVED:
1071 case E820_TYPE_PRAM:
1072 case E820_TYPE_PMEM:
1074 case E820_TYPE_RESERVED_KERN:
1076 case E820_TYPE_ACPI:
1078 case E820_TYPE_UNUSABLE:
1085 * Mark E820 reserved areas as busy for the resource manager:
1088 static struct resource __initdata *e820_res;
1090 void __init e820__reserve_resources(void)
1093 struct resource *res;
1096 res = memblock_alloc(sizeof(*res) * e820_table->nr_entries,
1100 for (i = 0; i < e820_table->nr_entries; i++) {
1101 struct e820_entry *entry = e820_table->entries + i;
1103 end = entry->addr + entry->size - 1;
1104 if (end != (resource_size_t)end) {
1108 res->start = entry->addr;
1110 res->name = e820_type_to_string(entry);
1111 res->flags = e820_type_to_iomem_type(entry);
1112 res->desc = e820_type_to_iores_desc(entry);
1115 * Don't register the region that could be conflicted with
1116 * PCI device BAR resources and insert them later in
1117 * pcibios_resource_survey():
1119 if (do_mark_busy(entry->type, res)) {
1120 res->flags |= IORESOURCE_BUSY;
1121 insert_resource(&iomem_resource, res);
1126 /* Expose the bootloader-provided memory layout to the sysfs. */
1127 for (i = 0; i < e820_table_firmware->nr_entries; i++) {
1128 struct e820_entry *entry = e820_table_firmware->entries + i;
1130 firmware_map_add_early(entry->addr, entry->addr + entry->size, e820_type_to_string(entry));
1135 * How much should we pad the end of RAM, depending on where it is?
1137 static unsigned long __init ram_alignment(resource_size_t pos)
1139 unsigned long mb = pos >> 20;
1141 /* To 64kB in the first megabyte */
1145 /* To 1MB in the first 16MB */
1149 /* To 64MB for anything above that */
1150 return 64*1024*1024;
1153 #define MAX_RESOURCE_SIZE ((resource_size_t)-1)
1155 void __init e820__reserve_resources_late(void)
1158 struct resource *res;
1161 for (i = 0; i < e820_table->nr_entries; i++) {
1162 if (!res->parent && res->end)
1163 insert_resource_expand_to_fit(&iomem_resource, res);
1168 * Try to bump up RAM regions to reasonable boundaries, to
1171 for (i = 0; i < e820_table->nr_entries; i++) {
1172 struct e820_entry *entry = &e820_table->entries[i];
1175 if (entry->type != E820_TYPE_RAM)
1178 start = entry->addr + entry->size;
1179 end = round_up(start, ram_alignment(start)) - 1;
1180 if (end > MAX_RESOURCE_SIZE)
1181 end = MAX_RESOURCE_SIZE;
1185 printk(KERN_DEBUG "e820: reserve RAM buffer [mem %#010llx-%#010llx]\n", start, end);
1186 reserve_region_with_split(&iomem_resource, start, end, "RAM buffer");
1191 * Pass the firmware (bootloader) E820 map to the kernel and process it:
1193 char *__init e820__memory_setup_default(void)
1195 char *who = "BIOS-e820";
1198 * Try to copy the BIOS-supplied E820-map.
1200 * Otherwise fake a memory map; one section from 0k->640k,
1201 * the next section from 1mb->appropriate_mem_k
1203 if (append_e820_table(boot_params.e820_table, boot_params.e820_entries) < 0) {
1206 /* Compare results from other methods and take the one that gives more RAM: */
1207 if (boot_params.alt_mem_k < boot_params.screen_info.ext_mem_k) {
1208 mem_size = boot_params.screen_info.ext_mem_k;
1211 mem_size = boot_params.alt_mem_k;
1215 e820_table->nr_entries = 0;
1216 e820__range_add(0, LOWMEMSIZE(), E820_TYPE_RAM);
1217 e820__range_add(HIGH_MEMORY, mem_size << 10, E820_TYPE_RAM);
1220 /* We just appended a lot of ranges, sanitize the table: */
1221 e820__update_table(e820_table);
1227 * Calls e820__memory_setup_default() in essence to pick up the firmware/bootloader
1228 * E820 map - with an optional platform quirk available for virtual platforms
1229 * to override this method of boot environment processing:
1231 void __init e820__memory_setup(void)
1235 /* This is a firmware interface ABI - make sure we don't break it: */
1236 BUILD_BUG_ON(sizeof(struct boot_e820_entry) != 20);
1238 who = x86_init.resources.memory_setup();
1240 memcpy(e820_table_kexec, e820_table, sizeof(*e820_table_kexec));
1241 memcpy(e820_table_firmware, e820_table, sizeof(*e820_table_firmware));
1243 pr_info("BIOS-provided physical RAM map:\n");
1244 e820__print_table(who);
1247 void __init e820__memblock_setup(void)
1253 * The bootstrap memblock region count maximum is 128 entries
1254 * (INIT_MEMBLOCK_REGIONS), but EFI might pass us more E820 entries
1255 * than that - so allow memblock resizing.
1257 * This is safe, because this call happens pretty late during x86 setup,
1258 * so we know about reserved memory regions already. (This is important
1259 * so that memblock resizing does no stomp over reserved areas.)
1261 memblock_allow_resize();
1263 for (i = 0; i < e820_table->nr_entries; i++) {
1264 struct e820_entry *entry = &e820_table->entries[i];
1266 end = entry->addr + entry->size;
1267 if (end != (resource_size_t)end)
1270 if (entry->type != E820_TYPE_RAM && entry->type != E820_TYPE_RESERVED_KERN)
1273 memblock_add(entry->addr, entry->size);
1276 /* Throw away partial pages: */
1277 memblock_trim_memory(PAGE_SIZE);
1279 memblock_dump_all();