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/kernel.h>
12 #include <linux/types.h>
13 #include <linux/init.h>
14 #include <linux/crash_dump.h>
15 #include <linux/export.h>
16 #include <linux/bootmem.h>
17 #include <linux/pfn.h>
18 #include <linux/suspend.h>
19 #include <linux/acpi.h>
20 #include <linux/firmware-map.h>
21 #include <linux/memblock.h>
22 #include <linux/sort.h>
24 #include <asm/e820/api.h>
25 #include <asm/proto.h>
26 #include <asm/setup.h>
27 #include <asm/cpufeature.h>
30 * We organize the E820 table into two main data structures:
32 * - 'e820_table_firmware': the original firmware version passed to us by the
33 * bootloader - not modified by the kernel. We use this to:
35 * - inform the user about the firmware's notion of memory layout
36 * via /sys/firmware/memmap
38 * - the hibernation code uses it to generate a kernel-independent MD5
39 * fingerprint of the physical memory layout of a system.
41 * - kexec, which is a bootloader in disguise, uses the original E820
42 * layout to pass to the kexec-ed kernel. This way the original kernel
43 * can have a restricted E820 map while the kexec()-ed kexec-kernel
44 * can have access to full memory - etc.
46 * - 'e820_table': this is the main E820 table that is massaged by the
47 * low level x86 platform code, or modified by boot parameters, before
48 * passed on to higher level MM layers.
50 * Once the E820 map has been converted to the standard Linux memory layout
51 * information its role stops - modifying it has no effect and does not get
52 * re-propagated. So itsmain role is a temporary bootstrap storage of firmware
53 * specific memory layout data during early bootup.
55 static struct e820_table e820_table_init __initdata;
56 static struct e820_table e820_table_firmware_init __initdata;
58 struct e820_table *e820_table __refdata = &e820_table_init;
59 struct e820_table *e820_table_firmware __refdata = &e820_table_firmware_init;
61 /* For PCI or other memory-mapped resources */
62 unsigned long pci_mem_start = 0xaeedbabe;
64 EXPORT_SYMBOL(pci_mem_start);
68 * This function checks if any part of the range <start,end> is mapped
71 int e820__mapped_any(u64 start, u64 end, enum e820_type type)
75 for (i = 0; i < e820_table->nr_entries; i++) {
76 struct e820_entry *entry = &e820_table->entries[i];
78 if (type && entry->type != type)
80 if (entry->addr >= end || entry->addr + entry->size <= start)
86 EXPORT_SYMBOL_GPL(e820__mapped_any);
89 * This function checks if the entire <start,end> range is mapped with 'type'.
91 * Note: this function only works correctly once the E820 table is sorted and
92 * not-overlapping (at least for the range specified), which is the case normally.
94 int __init e820__mapped_all(u64 start, u64 end, enum e820_type type)
98 for (i = 0; i < e820_table->nr_entries; i++) {
99 struct e820_entry *entry = &e820_table->entries[i];
101 if (type && entry->type != type)
104 /* Is the region (part) in overlap with the current region? */
105 if (entry->addr >= end || entry->addr + entry->size <= start)
109 * If the region is at the beginning of <start,end> we move
110 * 'start' to the end of the region since it's ok until there
112 if (entry->addr <= start)
113 start = entry->addr + entry->size;
116 * If 'start' is now at or beyond 'end', we're done, full
117 * coverage of the desired range exists:
126 * Add a memory region to the kernel E820 map.
128 static void __init __e820__range_add(struct e820_table *table, u64 start, u64 size, enum e820_type type)
130 int x = table->nr_entries;
132 if (x >= ARRAY_SIZE(table->entries)) {
133 pr_err("e820: too many entries; ignoring [mem %#010llx-%#010llx]\n", start, start + size - 1);
137 table->entries[x].addr = start;
138 table->entries[x].size = size;
139 table->entries[x].type = type;
143 void __init e820__range_add(u64 start, u64 size, enum e820_type type)
145 __e820__range_add(e820_table, start, size, type);
148 static void __init e820_print_type(enum e820_type type)
151 case E820_TYPE_RAM: /* Fall through: */
152 case E820_TYPE_RESERVED_KERN: pr_cont("usable"); break;
153 case E820_TYPE_RESERVED: pr_cont("reserved"); break;
154 case E820_TYPE_ACPI: pr_cont("ACPI data"); break;
155 case E820_TYPE_NVS: pr_cont("ACPI NVS"); break;
156 case E820_TYPE_UNUSABLE: pr_cont("unusable"); break;
157 case E820_TYPE_PMEM: /* Fall through: */
158 case E820_TYPE_PRAM: pr_cont("persistent (type %u)", type); break;
159 default: pr_cont("type %u", type); break;
163 void __init e820__print_table(char *who)
167 for (i = 0; i < e820_table->nr_entries; i++) {
168 pr_info("%s: [mem %#018Lx-%#018Lx] ", who,
169 e820_table->entries[i].addr,
170 e820_table->entries[i].addr + e820_table->entries[i].size - 1);
172 e820_print_type(e820_table->entries[i].type);
178 * Sanitize the BIOS E820 map.
180 * Some E820 responses include overlapping entries. The following
181 * replaces the original E820 map with a new one, removing overlaps,
182 * and resolving conflicting memory types in favor of highest
185 * The input parameter biosmap points to an array of 'struct
186 * e820_entry' which on entry has elements in the range [0, *pnr_map)
187 * valid, and which has space for up to max_nr_map entries.
188 * On return, the resulting sanitized E820 map entries will be in
189 * overwritten in the same location, starting at biosmap.
191 * The integer pointed to by pnr_map must be valid on entry (the
192 * current number of valid entries located at biosmap). If the
193 * sanitizing succeeds the *pnr_map will be updated with the new
194 * number of valid entries (something no more than max_nr_map).
196 * The return value from e820__update_table() is zero if it
197 * successfully 'sanitized' the map entries passed in, and is -1
198 * if it did nothing, which can happen if either of (1) it was
199 * only passed one map entry, or (2) any of the input map entries
200 * were invalid (start + size < start, meaning that the size was
201 * so big the described memory range wrapped around through zero.)
203 * Visually we're performing the following
204 * (1,2,3,4 = memory types)...
206 * Sample memory map (w/overlaps):
207 * ____22__________________
208 * ______________________4_
209 * ____1111________________
210 * _44_____________________
211 * 11111111________________
212 * ____________________33__
213 * ___________44___________
214 * __________33333_________
215 * ______________22________
216 * ___________________2222_
217 * _________111111111______
218 * _____________________11_
219 * _________________4______
221 * Sanitized equivalent (no overlap):
222 * 1_______________________
223 * _44_____________________
224 * ___1____________________
225 * ____22__________________
226 * ______11________________
227 * _________1______________
228 * __________3_____________
229 * ___________44___________
230 * _____________33_________
231 * _______________2________
232 * ________________1_______
233 * _________________4______
234 * ___________________2____
235 * ____________________33__
236 * ______________________4_
238 struct change_member {
239 /* Pointer to the original BIOS entry: */
240 struct e820_entry *pbios;
241 /* Address for this change point: */
242 unsigned long long addr;
245 static int __init cpcompare(const void *a, const void *b)
247 struct change_member * const *app = a, * const *bpp = b;
248 const struct change_member *ap = *app, *bp = *bpp;
251 * Inputs are pointers to two elements of change_point[]. If their
252 * addresses are not equal, their difference dominates. If the addresses
253 * are equal, then consider one that represents the end of its region
254 * to be greater than one that does not.
256 if (ap->addr != bp->addr)
257 return ap->addr > bp->addr ? 1 : -1;
259 return (ap->addr != ap->pbios->addr) - (bp->addr != bp->pbios->addr);
262 int __init e820__update_table(struct e820_entry *biosmap, int max_nr_map, u32 *pnr_map)
264 static struct change_member change_point_list[2*E820_X_MAX] __initdata;
265 static struct change_member *change_point[2*E820_X_MAX] __initdata;
266 static struct e820_entry *overlap_list[E820_X_MAX] __initdata;
267 static struct e820_entry new_bios[E820_X_MAX] __initdata;
268 enum e820_type current_type, last_type;
269 unsigned long long last_addr;
273 int old_nr, new_nr, chg_nr;
276 /* If there's only one memory region, don't bother: */
281 BUG_ON(old_nr > max_nr_map);
283 /* Bail out if we find any unreasonable addresses in the BIOS map: */
284 for (i = 0; i < old_nr; i++) {
285 if (biosmap[i].addr + biosmap[i].size < biosmap[i].addr)
289 /* Create pointers for initial change-point information (for sorting): */
290 for (i = 0; i < 2 * old_nr; i++)
291 change_point[i] = &change_point_list[i];
294 * Record all known change-points (starting and ending addresses),
295 * omitting empty memory regions:
298 for (i = 0; i < old_nr; i++) {
299 if (biosmap[i].size != 0) {
300 change_point[chgidx]->addr = biosmap[i].addr;
301 change_point[chgidx++]->pbios = &biosmap[i];
302 change_point[chgidx]->addr = biosmap[i].addr + biosmap[i].size;
303 change_point[chgidx++]->pbios = &biosmap[i];
308 /* Sort change-point list by memory addresses (low -> high): */
309 sort(change_point, chg_nr, sizeof *change_point, cpcompare, NULL);
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 */
317 /* Loop through change-points, determining effect 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 == change_point[chgidx]->pbios->addr) {
321 /* Add map entry to overlap list (> 1 entry implies an overlap) */
322 overlap_list[overlap_entries++] = change_point[chgidx]->pbios;
324 /* Remove entry from list (order independent, so swap with last): */
325 for (i = 0; i < overlap_entries; i++) {
326 if (overlap_list[i] == change_point[chgidx]->pbios)
327 overlap_list[i] = overlap_list[overlap_entries-1];
332 * If there are overlapping entries, decide which
333 * "type" to use (larger value takes precedence --
334 * 1=usable, 2,3,4,4+=unusable)
337 for (i = 0; i < overlap_entries; i++) {
338 if (overlap_list[i]->type > current_type)
339 current_type = overlap_list[i]->type;
342 /* Continue building up new BIOS map based on this information: */
343 if (current_type != last_type || current_type == E820_TYPE_PRAM) {
344 if (last_type != 0) {
345 new_bios[new_bios_entry].size = change_point[chgidx]->addr - last_addr;
346 /* Move forward only if the new size was non-zero: */
347 if (new_bios[new_bios_entry].size != 0)
348 /* No more space left for new BIOS entries? */
349 if (++new_bios_entry >= max_nr_map)
352 if (current_type != 0) {
353 new_bios[new_bios_entry].addr = change_point[chgidx]->addr;
354 new_bios[new_bios_entry].type = current_type;
355 last_addr = change_point[chgidx]->addr;
357 last_type = current_type;
361 /* Retain count for new BIOS entries: */
362 new_nr = new_bios_entry;
364 /* Copy new BIOS mapping into the original location: */
365 memcpy(biosmap, new_bios, new_nr*sizeof(struct e820_entry));
371 static int __init __append_e820_table(struct e820_entry *biosmap, int nr_map)
374 u64 start = biosmap->addr;
375 u64 size = biosmap->size;
376 u64 end = start + size - 1;
377 u32 type = biosmap->type;
379 /* Ignore the entry on 64-bit overflow: */
380 if (start > end && likely(size))
383 e820__range_add(start, size, type);
392 * Copy the BIOS E820 map into a safe place.
394 * Sanity-check it while we're at it..
396 * If we're lucky and live on a modern system, the setup code
397 * will have given us a memory map that we can use to properly
398 * set up memory. If we aren't, we'll fake a memory map.
400 static int __init append_e820_table(struct e820_entry *biosmap, int nr_map)
402 /* Only one memory region (or negative)? Ignore it */
406 return __append_e820_table(biosmap, nr_map);
410 __e820__range_update(struct e820_table *table, u64 start, u64 size, enum e820_type old_type, enum e820_type new_type)
414 u64 real_updated_size = 0;
416 BUG_ON(old_type == new_type);
418 if (size > (ULLONG_MAX - start))
419 size = ULLONG_MAX - start;
422 pr_debug("e820: update [mem %#010Lx-%#010Lx] ", start, end - 1);
423 e820_print_type(old_type);
425 e820_print_type(new_type);
428 for (i = 0; i < table->nr_entries; i++) {
429 struct e820_entry *entry = &table->entries[i];
430 u64 final_start, final_end;
433 if (entry->type != old_type)
436 entry_end = entry->addr + entry->size;
438 /* Completely covered by new range? */
439 if (entry->addr >= start && entry_end <= end) {
440 entry->type = new_type;
441 real_updated_size += entry->size;
445 /* New range is completely covered? */
446 if (entry->addr < start && entry_end > end) {
447 __e820__range_add(table, start, size, new_type);
448 __e820__range_add(table, end, entry_end - end, entry->type);
449 entry->size = start - entry->addr;
450 real_updated_size += size;
454 /* Partially covered: */
455 final_start = max(start, entry->addr);
456 final_end = min(end, entry_end);
457 if (final_start >= final_end)
460 __e820__range_add(table, final_start, final_end - final_start, new_type);
462 real_updated_size += final_end - final_start;
465 * Left range could be head or tail, so need to update
468 entry->size -= final_end - final_start;
469 if (entry->addr < final_start)
472 entry->addr = final_end;
474 return real_updated_size;
477 u64 __init e820__range_update(u64 start, u64 size, enum e820_type old_type, enum e820_type new_type)
479 return __e820__range_update(e820_table, start, size, old_type, new_type);
482 static u64 __init e820__range_update_firmware(u64 start, u64 size, enum e820_type old_type, enum e820_type new_type)
484 return __e820__range_update(e820_table_firmware, start, size, old_type, new_type);
487 /* Remove a range of memory from the E820 table: */
488 u64 __init e820__range_remove(u64 start, u64 size, enum e820_type old_type, int checktype)
492 u64 real_removed_size = 0;
494 if (size > (ULLONG_MAX - start))
495 size = ULLONG_MAX - start;
498 pr_debug("e820: remove [mem %#010Lx-%#010Lx] ", start, end - 1);
500 e820_print_type(old_type);
503 for (i = 0; i < e820_table->nr_entries; i++) {
504 struct e820_entry *entry = &e820_table->entries[i];
505 u64 final_start, final_end;
508 if (checktype && entry->type != old_type)
511 entry_end = entry->addr + entry->size;
513 /* Completely covered? */
514 if (entry->addr >= start && entry_end <= end) {
515 real_removed_size += entry->size;
516 memset(entry, 0, sizeof(struct e820_entry));
520 /* Is the new range completely covered? */
521 if (entry->addr < start && entry_end > end) {
522 e820__range_add(end, entry_end - end, entry->type);
523 entry->size = start - entry->addr;
524 real_removed_size += size;
528 /* Partially covered: */
529 final_start = max(start, entry->addr);
530 final_end = min(end, entry_end);
531 if (final_start >= final_end)
534 real_removed_size += final_end - final_start;
537 * Left range could be head or tail, so need to update
540 entry->size -= final_end - final_start;
541 if (entry->addr < final_start)
544 entry->addr = final_end;
546 return real_removed_size;
549 void __init e820__update_table_print(void)
551 if (e820__update_table(e820_table->entries, ARRAY_SIZE(e820_table->entries), &e820_table->nr_entries))
554 pr_info("e820: modified physical RAM map:\n");
555 e820__print_table("modified");
558 static void __init e820__update_table_firmware(void)
560 e820__update_table(e820_table_firmware->entries, ARRAY_SIZE(e820_table_firmware->entries), &e820_table_firmware->nr_entries);
563 #define MAX_GAP_END 0x100000000ull
566 * Search for a gap in the E820 memory space from 0 to MAX_GAP_END (4GB).
568 static int __init e820_search_gap(unsigned long *gapstart, unsigned long *gapsize)
570 unsigned long long last = MAX_GAP_END;
571 int i = e820_table->nr_entries;
575 unsigned long long start = e820_table->entries[i].addr;
576 unsigned long long end = start + e820_table->entries[i].size;
579 * Since "last" is at most 4GB, we know we'll
580 * fit in 32 bits if this condition is true:
583 unsigned long gap = last - end;
585 if (gap >= *gapsize) {
598 * Search for the biggest gap in the low 32 bits of the E820
599 * memory space. We pass this space to the PCI subsystem, so
600 * that it can assign MMIO resources for hotplug or
601 * unconfigured devices in.
603 * Hopefully the BIOS let enough space left.
605 __init void e820__setup_pci_gap(void)
607 unsigned long gapstart, gapsize;
611 found = e820_search_gap(&gapstart, &gapsize);
615 gapstart = (max_pfn << PAGE_SHIFT) + 1024*1024;
617 "e820: Cannot find an available gap in the 32-bit address range\n"
618 "e820: PCI devices with unassigned 32-bit BARs may not work!\n");
620 gapstart = 0x10000000;
625 * e820_reserve_resources_late protect stolen RAM already
627 pci_mem_start = gapstart;
629 pr_info("e820: [mem %#010lx-%#010lx] available for PCI devices\n", gapstart, gapstart + gapsize - 1);
633 * Called late during init, in free_initmem().
635 * Initial e820_table and e820_table_firmware are largish __initdata arrays.
637 * Copy them to a (usually much smaller) dynamically allocated area that is
638 * sized precisely after the number of e820 entries.
640 * This is done after we've performed all the fixes and tweaks to the tables.
641 * All functions which modify them are __init functions, which won't exist
642 * after free_initmem().
644 __init void e820_reallocate_tables(void)
646 struct e820_table *n;
649 size = offsetof(struct e820_table, entries) + sizeof(struct e820_entry)*e820_table->nr_entries;
650 n = kmalloc(size, GFP_KERNEL);
652 memcpy(n, e820_table, size);
655 size = offsetof(struct e820_table, entries) + sizeof(struct e820_entry)*e820_table_firmware->nr_entries;
656 n = kmalloc(size, GFP_KERNEL);
658 memcpy(n, e820_table_firmware, size);
659 e820_table_firmware = n;
663 * Because of the small fixed size of struct boot_params, only the first
664 * 128 E820 memory entries are passed to the kernel via boot_params.e820_table,
665 * the remaining (if any) entries are passed via the SETUP_E820_EXT node of
666 * struct setup_data, which is parsed here.
668 void __init e820__memory_setup_extended(u64 phys_addr, u32 data_len)
671 struct e820_entry *extmap;
672 struct setup_data *sdata;
674 sdata = early_memremap(phys_addr, data_len);
675 entries = sdata->len / sizeof(struct e820_entry);
676 extmap = (struct e820_entry *)(sdata->data);
678 __append_e820_table(extmap, entries);
679 e820__update_table(e820_table->entries, ARRAY_SIZE(e820_table->entries), &e820_table->nr_entries);
681 early_memunmap(sdata, data_len);
682 pr_info("e820: extended physical RAM map:\n");
683 e820__print_table("extended");
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).
691 * This function requires the E820 map to be sorted and without any
692 * overlapping entries.
694 void __init e820_mark_nosave_regions(unsigned long limit_pfn)
697 unsigned long pfn = 0;
699 for (i = 0; i < e820_table->nr_entries; i++) {
700 struct e820_entry *entry = &e820_table->entries[i];
702 if (pfn < PFN_UP(entry->addr))
703 register_nosave_region(pfn, PFN_UP(entry->addr));
705 pfn = PFN_DOWN(entry->addr + entry->size);
707 if (entry->type != E820_TYPE_RAM && entry->type != E820_TYPE_RESERVED_KERN)
708 register_nosave_region(PFN_UP(entry->addr), pfn);
710 if (pfn >= limit_pfn)
717 * Register ACPI NVS memory regions, so that we can save/restore them during
718 * hibernation and the subsequent resume:
720 static int __init e820_mark_nvs_memory(void)
724 for (i = 0; i < e820_table->nr_entries; i++) {
725 struct e820_entry *entry = &e820_table->entries[i];
727 if (entry->type == E820_TYPE_NVS)
728 acpi_nvs_register(entry->addr, entry->size);
733 core_initcall(e820_mark_nvs_memory);
737 * Allocate the requested number of bytes with the requsted alignment
738 * and return (the physical address) to the caller. Also register this
739 * range in the 'firmware' E820 table as a reserved range.
741 * This allows kexec to fake a new mptable, as if it came from the real
744 u64 __init e820__memblock_alloc_reserved(u64 size, u64 align)
748 addr = __memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ACCESSIBLE);
750 e820__range_update_firmware(addr, size, E820_TYPE_RAM, E820_TYPE_RESERVED);
751 pr_info("e820: update e820_table_firmware for e820__memblock_alloc_reserved()\n");
752 e820__update_table_firmware();
759 # ifdef CONFIG_X86_PAE
760 # define MAX_ARCH_PFN (1ULL<<(36-PAGE_SHIFT))
762 # define MAX_ARCH_PFN (1ULL<<(32-PAGE_SHIFT))
764 #else /* CONFIG_X86_32 */
765 # define MAX_ARCH_PFN MAXMEM>>PAGE_SHIFT
769 * Find the highest page frame number we have available
771 static unsigned long __init e820_end_pfn(unsigned long limit_pfn, enum e820_type type)
774 unsigned long last_pfn = 0;
775 unsigned long max_arch_pfn = MAX_ARCH_PFN;
777 for (i = 0; i < e820_table->nr_entries; i++) {
778 struct e820_entry *entry = &e820_table->entries[i];
779 unsigned long start_pfn;
780 unsigned long end_pfn;
782 if (entry->type != type)
785 start_pfn = entry->addr >> PAGE_SHIFT;
786 end_pfn = (entry->addr + entry->size) >> PAGE_SHIFT;
788 if (start_pfn >= limit_pfn)
790 if (end_pfn > limit_pfn) {
791 last_pfn = limit_pfn;
794 if (end_pfn > last_pfn)
798 if (last_pfn > max_arch_pfn)
799 last_pfn = max_arch_pfn;
801 pr_info("e820: last_pfn = %#lx max_arch_pfn = %#lx\n",
802 last_pfn, max_arch_pfn);
806 unsigned long __init e820_end_of_ram_pfn(void)
808 return e820_end_pfn(MAX_ARCH_PFN, E820_TYPE_RAM);
811 unsigned long __init e820_end_of_low_ram_pfn(void)
813 return e820_end_pfn(1UL << (32 - PAGE_SHIFT), E820_TYPE_RAM);
816 static void __init early_panic(char *msg)
822 static int userdef __initdata;
824 /* The "mem=nopentium" boot option disables 4MB page tables on 32-bit kernels: */
825 static int __init parse_memopt(char *p)
832 if (!strcmp(p, "nopentium")) {
834 setup_clear_cpu_cap(X86_FEATURE_PSE);
837 pr_warn("mem=nopentium ignored! (only supported on x86_32)\n");
843 mem_size = memparse(p, &p);
845 /* Don't remove all memory when getting "mem={invalid}" parameter: */
849 e820__range_remove(mem_size, ULLONG_MAX - mem_size, E820_TYPE_RAM, 1);
853 early_param("mem", parse_memopt);
855 static int __init parse_memmap_one(char *p)
858 u64 start_at, mem_size;
863 if (!strncmp(p, "exactmap", 8)) {
864 #ifdef CONFIG_CRASH_DUMP
866 * If we are doing a crash dump, we still need to know
867 * the real memory size before the original memory map is
870 saved_max_pfn = e820_end_of_ram_pfn();
872 e820_table->nr_entries = 0;
878 mem_size = memparse(p, &p);
884 start_at = memparse(p+1, &p);
885 e820__range_add(start_at, mem_size, E820_TYPE_RAM);
886 } else if (*p == '#') {
887 start_at = memparse(p+1, &p);
888 e820__range_add(start_at, mem_size, E820_TYPE_ACPI);
889 } else if (*p == '$') {
890 start_at = memparse(p+1, &p);
891 e820__range_add(start_at, mem_size, E820_TYPE_RESERVED);
892 } else if (*p == '!') {
893 start_at = memparse(p+1, &p);
894 e820__range_add(start_at, mem_size, E820_TYPE_PRAM);
896 e820__range_remove(mem_size, ULLONG_MAX - mem_size, E820_TYPE_RAM, 1);
899 return *p == '\0' ? 0 : -EINVAL;
902 static int __init parse_memmap_opt(char *str)
905 char *k = strchr(str, ',');
910 parse_memmap_one(str);
916 early_param("memmap", parse_memmap_opt);
918 void __init e820_reserve_setup_data(void)
920 struct setup_data *data;
923 pa_data = boot_params.hdr.setup_data;
928 data = early_memremap(pa_data, sizeof(*data));
929 e820__range_update(pa_data, sizeof(*data)+data->len, E820_TYPE_RAM, E820_TYPE_RESERVED_KERN);
930 pa_data = data->next;
931 early_memunmap(data, sizeof(*data));
934 e820__update_table(e820_table->entries, ARRAY_SIZE(e820_table->entries), &e820_table->nr_entries);
935 memcpy(e820_table_firmware, e820_table, sizeof(struct e820_table));
936 printk(KERN_INFO "extended physical RAM map:\n");
937 e820__print_table("reserve setup_data");
941 * Called after parse_early_param(), after early parameters (such as mem=)
942 * have been processed, in which case we already have an E820 table filled in
943 * via the parameter callback function(s), but it's not sorted and printed yet:
945 void __init e820__finish_early_params(void)
948 if (e820__update_table(e820_table->entries, ARRAY_SIZE(e820_table->entries), &e820_table->nr_entries) < 0)
949 early_panic("Invalid user supplied memory map");
951 pr_info("e820: user-defined physical RAM map:\n");
952 e820__print_table("user");
956 static const char *__init e820_type_to_string(struct e820_entry *entry)
958 switch (entry->type) {
959 case E820_TYPE_RESERVED_KERN: /* Fall-through: */
960 case E820_TYPE_RAM: return "System RAM";
961 case E820_TYPE_ACPI: return "ACPI Tables";
962 case E820_TYPE_NVS: return "ACPI Non-volatile Storage";
963 case E820_TYPE_UNUSABLE: return "Unusable memory";
964 case E820_TYPE_PRAM: return "Persistent Memory (legacy)";
965 case E820_TYPE_PMEM: return "Persistent Memory";
966 default: return "Reserved";
970 static unsigned long __init e820_type_to_iomem_type(struct e820_entry *entry)
972 switch (entry->type) {
973 case E820_TYPE_RESERVED_KERN: /* Fall-through: */
974 case E820_TYPE_RAM: return IORESOURCE_SYSTEM_RAM;
975 case E820_TYPE_ACPI: /* Fall-through: */
976 case E820_TYPE_NVS: /* Fall-through: */
977 case E820_TYPE_UNUSABLE: /* Fall-through: */
978 case E820_TYPE_PRAM: /* Fall-through: */
979 case E820_TYPE_PMEM: /* Fall-through: */
980 default: return IORESOURCE_MEM;
984 static unsigned long __init e820_type_to_iores_desc(struct e820_entry *entry)
986 switch (entry->type) {
987 case E820_TYPE_ACPI: return IORES_DESC_ACPI_TABLES;
988 case E820_TYPE_NVS: return IORES_DESC_ACPI_NV_STORAGE;
989 case E820_TYPE_PMEM: return IORES_DESC_PERSISTENT_MEMORY;
990 case E820_TYPE_PRAM: return IORES_DESC_PERSISTENT_MEMORY_LEGACY;
991 case E820_TYPE_RESERVED_KERN: /* Fall-through: */
992 case E820_TYPE_RAM: /* Fall-through: */
993 case E820_TYPE_UNUSABLE: /* Fall-through: */
994 default: return IORES_DESC_NONE;
998 static bool __init do_mark_busy(u32 type, struct resource *res)
1000 /* this is the legacy bios/dos rom-shadow + mmio region */
1001 if (res->start < (1ULL<<20))
1005 * Treat persistent memory like device memory, i.e. reserve it
1006 * for exclusive use of a driver
1009 case E820_TYPE_RESERVED:
1010 case E820_TYPE_PRAM:
1011 case E820_TYPE_PMEM:
1019 * Mark E820 reserved areas as busy for the resource manager:
1022 static struct resource __initdata *e820_res;
1024 void __init e820_reserve_resources(void)
1027 struct resource *res;
1030 res = alloc_bootmem(sizeof(*res) * e820_table->nr_entries);
1033 for (i = 0; i < e820_table->nr_entries; i++) {
1034 struct e820_entry *entry = e820_table->entries + i;
1036 end = entry->addr + entry->size - 1;
1037 if (end != (resource_size_t)end) {
1041 res->start = entry->addr;
1043 res->name = e820_type_to_string(entry);
1044 res->flags = e820_type_to_iomem_type(entry);
1045 res->desc = e820_type_to_iores_desc(entry);
1048 * don't register the region that could be conflicted with
1049 * pci device BAR resource and insert them later in
1050 * pcibios_resource_survey()
1052 if (do_mark_busy(entry->type, res)) {
1053 res->flags |= IORESOURCE_BUSY;
1054 insert_resource(&iomem_resource, res);
1059 for (i = 0; i < e820_table_firmware->nr_entries; i++) {
1060 struct e820_entry *entry = e820_table_firmware->entries + i;
1062 firmware_map_add_early(entry->addr, entry->addr + entry->size, e820_type_to_string(entry));
1066 /* How much should we pad RAM ending depending on where it is? */
1067 static unsigned long __init ram_alignment(resource_size_t pos)
1069 unsigned long mb = pos >> 20;
1071 /* To 64kB in the first megabyte */
1075 /* To 1MB in the first 16MB */
1079 /* To 64MB for anything above that */
1080 return 64*1024*1024;
1083 #define MAX_RESOURCE_SIZE ((resource_size_t)-1)
1085 void __init e820_reserve_resources_late(void)
1088 struct resource *res;
1091 for (i = 0; i < e820_table->nr_entries; i++) {
1092 if (!res->parent && res->end)
1093 insert_resource_expand_to_fit(&iomem_resource, res);
1098 * Try to bump up RAM regions to reasonable boundaries, to
1101 for (i = 0; i < e820_table->nr_entries; i++) {
1102 struct e820_entry *entry = &e820_table->entries[i];
1105 if (entry->type != E820_TYPE_RAM)
1108 start = entry->addr + entry->size;
1109 end = round_up(start, ram_alignment(start)) - 1;
1110 if (end > MAX_RESOURCE_SIZE)
1111 end = MAX_RESOURCE_SIZE;
1115 pr_debug("e820: reserve RAM buffer [mem %#010llx-%#010llx]\n", start, end);
1116 reserve_region_with_split(&iomem_resource, start, end, "RAM buffer");
1121 * Pass the firmware (bootloader) E820 map to the kernel and process it:
1123 char *__init e820__memory_setup_default(void)
1125 char *who = "BIOS-e820";
1129 * Try to copy the BIOS-supplied E820-map.
1131 * Otherwise fake a memory map; one section from 0k->640k,
1132 * the next section from 1mb->appropriate_mem_k
1134 new_nr = boot_params.e820_entries;
1135 e820__update_table(boot_params.e820_table, ARRAY_SIZE(boot_params.e820_table), &new_nr);
1136 boot_params.e820_entries = new_nr;
1138 if (append_e820_table(boot_params.e820_table, boot_params.e820_entries) < 0) {
1141 /* Compare results from other methods and take the one that gives more RAM: */
1142 if (boot_params.alt_mem_k < boot_params.screen_info.ext_mem_k) {
1143 mem_size = boot_params.screen_info.ext_mem_k;
1146 mem_size = boot_params.alt_mem_k;
1150 e820_table->nr_entries = 0;
1151 e820__range_add(0, LOWMEMSIZE(), E820_TYPE_RAM);
1152 e820__range_add(HIGH_MEMORY, mem_size << 10, E820_TYPE_RAM);
1159 * Calls e820__memory_setup_default() in essence to pick up the firmware/bootloader
1160 * E820 map - with an optional platform quirk available for virtual platforms
1161 * to override this method of boot environment processing:
1163 void __init e820__memory_setup(void)
1167 /* This is a firmware interface ABI - make sure we don't break it: */
1168 BUILD_BUG_ON(sizeof(struct e820_entry) != 20);
1170 who = x86_init.resources.memory_setup();
1172 memcpy(e820_table_firmware, e820_table, sizeof(struct e820_table));
1174 pr_info("e820: BIOS-provided physical RAM map:\n");
1175 e820__print_table(who);
1178 void __init e820__memblock_setup(void)
1184 * The bootstrap memblock region count maximum is 128 entries
1185 * (INIT_MEMBLOCK_REGIONS), but EFI might pass us more E820 entries
1186 * than that - so allow memblock resizing.
1188 * This is safe, because this call happens pretty late during x86 setup,
1189 * so we know about reserved memory regions already. (This is important
1190 * so that memblock resizing does no stomp over reserved areas.)
1192 memblock_allow_resize();
1194 for (i = 0; i < e820_table->nr_entries; i++) {
1195 struct e820_entry *entry = &e820_table->entries[i];
1197 end = entry->addr + entry->size;
1198 if (end != (resource_size_t)end)
1201 if (entry->type != E820_TYPE_RAM && entry->type != E820_TYPE_RESERVED_KERN)
1204 memblock_add(entry->addr, entry->size);
1207 /* Throw away partial pages: */
1208 memblock_trim_memory(PAGE_SIZE);
1210 memblock_dump_all();