2 * Handle the memory map.
3 * The functions here do the job until bootmem takes over.
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>
11 #include <linux/kernel.h>
12 #include <linux/types.h>
13 #include <linux/init.h>
14 #include <linux/bootmem.h>
15 #include <linux/ioport.h>
16 #include <linux/string.h>
17 #include <linux/kexec.h>
18 #include <linux/module.h>
20 #include <linux/suspend.h>
21 #include <linux/pfn.h>
23 #include <asm/pgtable.h>
26 #include <asm/proto.h>
27 #include <asm/setup.h>
28 #include <asm/sections.h>
29 #include <asm/kdebug.h>
34 * PFN of last memory page.
36 unsigned long end_pfn;
39 * end_pfn only includes RAM, while end_pfn_map includes all e820 entries.
40 * The direct mapping extends to end_pfn_map, so that we can directly access
41 * apertures, ACPI and other tables without having to play with fixmaps.
43 unsigned long end_pfn_map;
46 * Last pfn which the user wants to use.
48 static unsigned long __initdata end_user_pfn = MAXMEM>>PAGE_SHIFT;
51 * Early reserved memory areas.
53 #define MAX_EARLY_RES 20
56 unsigned long start, end;
58 static struct early_res early_res[MAX_EARLY_RES] __initdata = {
59 { 0, PAGE_SIZE }, /* BIOS data page */
61 { SMP_TRAMPOLINE_BASE, SMP_TRAMPOLINE_BASE + 2*PAGE_SIZE },
66 void __init reserve_early(unsigned long start, unsigned long end)
70 for (i = 0; i < MAX_EARLY_RES && early_res[i].end; i++) {
72 if (end > r->start && start < r->end)
73 panic("Overlapping early reservations %lx-%lx to %lx-%lx\n",
74 start, end, r->start, r->end);
76 if (i >= MAX_EARLY_RES)
77 panic("Too many early reservations");
83 void __init early_res_to_bootmem(void)
86 for (i = 0; i < MAX_EARLY_RES && early_res[i].end; i++) {
87 struct early_res *r = &early_res[i];
88 reserve_bootmem_generic(r->start, r->end - r->start);
92 /* Check for already reserved areas */
93 static inline int bad_addr(unsigned long *addrp, unsigned long size)
96 unsigned long addr = *addrp, last;
100 for (i = 0; i < MAX_EARLY_RES && early_res[i].end; i++) {
101 struct early_res *r = &early_res[i];
102 if (last >= r->start && addr < r->end) {
103 *addrp = addr = r->end;
112 * This function checks if any part of the range <start,end> is mapped
116 e820_any_mapped(unsigned long start, unsigned long end, unsigned type)
120 for (i = 0; i < e820.nr_map; i++) {
121 struct e820entry *ei = &e820.map[i];
123 if (type && ei->type != type)
125 if (ei->addr >= end || ei->addr + ei->size <= start)
131 EXPORT_SYMBOL_GPL(e820_any_mapped);
134 * This function checks if the entire range <start,end> is mapped with type.
136 * Note: this function only works correct if the e820 table is sorted and
137 * not-overlapping, which is the case
139 int __init e820_all_mapped(unsigned long start, unsigned long end,
144 for (i = 0; i < e820.nr_map; i++) {
145 struct e820entry *ei = &e820.map[i];
147 if (type && ei->type != type)
149 /* is the region (part) in overlap with the current region ?*/
150 if (ei->addr >= end || ei->addr + ei->size <= start)
153 /* if the region is at the beginning of <start,end> we move
154 * start to the end of the region since it's ok until there
156 if (ei->addr <= start)
157 start = ei->addr + ei->size;
159 * if start is now at or beyond end, we're done, full
169 * Find a free area in a specific range.
171 unsigned long __init find_e820_area(unsigned long start, unsigned long end,
176 for (i = 0; i < e820.nr_map; i++) {
177 struct e820entry *ei = &e820.map[i];
178 unsigned long addr = ei->addr, last;
180 if (ei->type != E820_RAM)
184 if (addr > ei->addr + ei->size)
186 while (bad_addr(&addr, size) && addr+size <= ei->addr+ei->size)
188 last = PAGE_ALIGN(addr) + size;
189 if (last > ei->addr + ei->size)
199 * Find the highest page frame number we have available
201 unsigned long __init e820_end_of_ram(void)
203 unsigned long end_pfn;
205 end_pfn = find_max_pfn_with_active_regions();
207 if (end_pfn > end_pfn_map)
208 end_pfn_map = end_pfn;
209 if (end_pfn_map > MAXMEM>>PAGE_SHIFT)
210 end_pfn_map = MAXMEM>>PAGE_SHIFT;
211 if (end_pfn > end_user_pfn)
212 end_pfn = end_user_pfn;
213 if (end_pfn > end_pfn_map)
214 end_pfn = end_pfn_map;
216 printk(KERN_INFO "end_pfn_map = %lu\n", end_pfn_map);
221 * Mark e820 reserved areas as busy for the resource manager.
223 void __init e820_reserve_resources(struct resource *code_resource,
224 struct resource *data_resource, struct resource *bss_resource)
227 for (i = 0; i < e820.nr_map; i++) {
228 struct resource *res;
229 res = alloc_bootmem_low(sizeof(struct resource));
230 switch (e820.map[i].type) {
231 case E820_RAM: res->name = "System RAM"; break;
232 case E820_ACPI: res->name = "ACPI Tables"; break;
233 case E820_NVS: res->name = "ACPI Non-volatile Storage"; break;
234 default: res->name = "reserved";
236 res->start = e820.map[i].addr;
237 res->end = res->start + e820.map[i].size - 1;
238 res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
239 request_resource(&iomem_resource, res);
240 if (e820.map[i].type == E820_RAM) {
242 * We don't know which RAM region contains kernel data,
243 * so we try it repeatedly and let the resource manager
246 request_resource(res, code_resource);
247 request_resource(res, data_resource);
248 request_resource(res, bss_resource);
250 if (crashk_res.start != crashk_res.end)
251 request_resource(res, &crashk_res);
258 * Find the ranges of physical addresses that do not correspond to
259 * e820 RAM areas and mark the corresponding pages as nosave for software
260 * suspend and suspend to RAM.
262 * This function requires the e820 map to be sorted and without any
263 * overlapping entries and assumes the first e820 area to be RAM.
265 void __init e820_mark_nosave_regions(void)
270 paddr = round_down(e820.map[0].addr + e820.map[0].size, PAGE_SIZE);
271 for (i = 1; i < e820.nr_map; i++) {
272 struct e820entry *ei = &e820.map[i];
274 if (paddr < ei->addr)
275 register_nosave_region(PFN_DOWN(paddr),
278 paddr = round_down(ei->addr + ei->size, PAGE_SIZE);
279 if (ei->type != E820_RAM)
280 register_nosave_region(PFN_UP(ei->addr),
283 if (paddr >= (end_pfn << PAGE_SHIFT))
289 * Finds an active region in the address range from start_pfn to end_pfn and
290 * returns its range in ei_startpfn and ei_endpfn for the e820 entry.
292 static int __init e820_find_active_region(const struct e820entry *ei,
293 unsigned long start_pfn,
294 unsigned long end_pfn,
295 unsigned long *ei_startpfn,
296 unsigned long *ei_endpfn)
298 *ei_startpfn = round_up(ei->addr, PAGE_SIZE) >> PAGE_SHIFT;
299 *ei_endpfn = round_down(ei->addr + ei->size, PAGE_SIZE) >> PAGE_SHIFT;
301 /* Skip map entries smaller than a page */
302 if (*ei_startpfn >= *ei_endpfn)
305 /* Check if end_pfn_map should be updated */
306 if (ei->type != E820_RAM && *ei_endpfn > end_pfn_map)
307 end_pfn_map = *ei_endpfn;
309 /* Skip if map is outside the node */
310 if (ei->type != E820_RAM || *ei_endpfn <= start_pfn ||
311 *ei_startpfn >= end_pfn)
314 /* Check for overlaps */
315 if (*ei_startpfn < start_pfn)
316 *ei_startpfn = start_pfn;
317 if (*ei_endpfn > end_pfn)
318 *ei_endpfn = end_pfn;
320 /* Obey end_user_pfn to save on memmap */
321 if (*ei_startpfn >= end_user_pfn)
323 if (*ei_endpfn > end_user_pfn)
324 *ei_endpfn = end_user_pfn;
329 /* Walk the e820 map and register active regions within a node */
331 e820_register_active_regions(int nid, unsigned long start_pfn,
332 unsigned long end_pfn)
334 unsigned long ei_startpfn;
335 unsigned long ei_endpfn;
338 for (i = 0; i < e820.nr_map; i++)
339 if (e820_find_active_region(&e820.map[i],
341 &ei_startpfn, &ei_endpfn))
342 add_active_range(nid, ei_startpfn, ei_endpfn);
346 * Add a memory region to the kernel e820 map.
348 void __init add_memory_region(unsigned long start, unsigned long size, int type)
353 printk(KERN_ERR "Ooops! Too many entries in the memory map!\n");
357 e820.map[x].addr = start;
358 e820.map[x].size = size;
359 e820.map[x].type = type;
364 * Find the hole size (in bytes) in the memory range.
365 * @start: starting address of the memory range to scan
366 * @end: ending address of the memory range to scan
368 unsigned long __init e820_hole_size(unsigned long start, unsigned long end)
370 unsigned long start_pfn = start >> PAGE_SHIFT;
371 unsigned long end_pfn = end >> PAGE_SHIFT;
372 unsigned long ei_startpfn, ei_endpfn, ram = 0;
375 for (i = 0; i < e820.nr_map; i++) {
376 if (e820_find_active_region(&e820.map[i],
378 &ei_startpfn, &ei_endpfn))
379 ram += ei_endpfn - ei_startpfn;
381 return end - start - (ram << PAGE_SHIFT);
384 static void __init e820_print_map(char *who)
388 for (i = 0; i < e820.nr_map; i++) {
389 printk(KERN_INFO " %s: %016Lx - %016Lx ", who,
390 (unsigned long long) e820.map[i].addr,
392 (e820.map[i].addr + e820.map[i].size));
393 switch (e820.map[i].type) {
395 printk(KERN_CONT "(usable)\n");
398 printk(KERN_CONT "(reserved)\n");
401 printk(KERN_CONT "(ACPI data)\n");
404 printk(KERN_CONT "(ACPI NVS)\n");
407 printk(KERN_CONT "type %u\n", e820.map[i].type);
414 * Sanitize the BIOS e820 map.
416 * Some e820 responses include overlapping entries. The following
417 * replaces the original e820 map with a new one, removing overlaps.
420 static int __init sanitize_e820_map(struct e820entry *biosmap, char *pnr_map)
422 struct change_member {
423 struct e820entry *pbios; /* pointer to original bios entry */
424 unsigned long long addr; /* address for this change point */
426 static struct change_member change_point_list[2*E820MAX] __initdata;
427 static struct change_member *change_point[2*E820MAX] __initdata;
428 static struct e820entry *overlap_list[E820MAX] __initdata;
429 static struct e820entry new_bios[E820MAX] __initdata;
430 struct change_member *change_tmp;
431 unsigned long current_type, last_type;
432 unsigned long long last_addr;
433 int chgidx, still_changing;
436 int old_nr, new_nr, chg_nr;
440 Visually we're performing the following
441 (1,2,3,4 = memory types)...
443 Sample memory map (w/overlaps):
444 ____22__________________
445 ______________________4_
446 ____1111________________
447 _44_____________________
448 11111111________________
449 ____________________33__
450 ___________44___________
451 __________33333_________
452 ______________22________
453 ___________________2222_
454 _________111111111______
455 _____________________11_
456 _________________4______
458 Sanitized equivalent (no overlap):
459 1_______________________
460 _44_____________________
461 ___1____________________
462 ____22__________________
463 ______11________________
464 _________1______________
465 __________3_____________
466 ___________44___________
467 _____________33_________
468 _______________2________
469 ________________1_______
470 _________________4______
471 ___________________2____
472 ____________________33__
473 ______________________4_
476 /* if there's only one memory region, don't bother */
482 /* bail out if we find any unreasonable addresses in bios map */
483 for (i = 0; i < old_nr; i++)
484 if (biosmap[i].addr + biosmap[i].size < biosmap[i].addr)
487 /* create pointers for initial change-point information (for sorting) */
488 for (i = 0; i < 2 * old_nr; i++)
489 change_point[i] = &change_point_list[i];
491 /* record all known change-points (starting and ending addresses),
492 omitting those that are for empty memory regions */
494 for (i = 0; i < old_nr; i++) {
495 if (biosmap[i].size != 0) {
496 change_point[chgidx]->addr = biosmap[i].addr;
497 change_point[chgidx++]->pbios = &biosmap[i];
498 change_point[chgidx]->addr = biosmap[i].addr +
500 change_point[chgidx++]->pbios = &biosmap[i];
505 /* sort change-point list by memory addresses (low -> high) */
507 while (still_changing) {
509 for (i = 1; i < chg_nr; i++) {
510 unsigned long long curaddr, lastaddr;
511 unsigned long long curpbaddr, lastpbaddr;
513 curaddr = change_point[i]->addr;
514 lastaddr = change_point[i - 1]->addr;
515 curpbaddr = change_point[i]->pbios->addr;
516 lastpbaddr = change_point[i - 1]->pbios->addr;
519 * swap entries, when:
521 * curaddr > lastaddr or
522 * curaddr == lastaddr and curaddr == curpbaddr and
523 * lastaddr != lastpbaddr
525 if (curaddr < lastaddr ||
526 (curaddr == lastaddr && curaddr == curpbaddr &&
527 lastaddr != lastpbaddr)) {
528 change_tmp = change_point[i];
529 change_point[i] = change_point[i-1];
530 change_point[i-1] = change_tmp;
536 /* create a new bios memory map, removing overlaps */
537 overlap_entries = 0; /* number of entries in the overlap table */
538 new_bios_entry = 0; /* index for creating new bios map entries */
539 last_type = 0; /* start with undefined memory type */
540 last_addr = 0; /* start with 0 as last starting address */
542 /* loop through change-points, determining affect on the new bios map */
543 for (chgidx = 0; chgidx < chg_nr; chgidx++) {
544 /* keep track of all overlapping bios entries */
545 if (change_point[chgidx]->addr ==
546 change_point[chgidx]->pbios->addr) {
548 * add map entry to overlap list (> 1 entry
549 * implies an overlap)
551 overlap_list[overlap_entries++] =
552 change_point[chgidx]->pbios;
555 * remove entry from list (order independent,
558 for (i = 0; i < overlap_entries; i++) {
559 if (overlap_list[i] ==
560 change_point[chgidx]->pbios)
562 overlap_list[overlap_entries-1];
567 * if there are overlapping entries, decide which
568 * "type" to use (larger value takes precedence --
569 * 1=usable, 2,3,4,4+=unusable)
572 for (i = 0; i < overlap_entries; i++)
573 if (overlap_list[i]->type > current_type)
574 current_type = overlap_list[i]->type;
576 * continue building up new bios map based on this
579 if (current_type != last_type) {
580 if (last_type != 0) {
581 new_bios[new_bios_entry].size =
582 change_point[chgidx]->addr - last_addr;
584 * move forward only if the new size
587 if (new_bios[new_bios_entry].size != 0)
589 * no more space left for new
592 if (++new_bios_entry >= E820MAX)
595 if (current_type != 0) {
596 new_bios[new_bios_entry].addr =
597 change_point[chgidx]->addr;
598 new_bios[new_bios_entry].type = current_type;
599 last_addr = change_point[chgidx]->addr;
601 last_type = current_type;
604 /* retain count for new bios entries */
605 new_nr = new_bios_entry;
607 /* copy new bios mapping into original location */
608 memcpy(biosmap, new_bios, new_nr * sizeof(struct e820entry));
615 * Copy the BIOS e820 map into a safe place.
617 * Sanity-check it while we're at it..
619 * If we're lucky and live on a modern system, the setup code
620 * will have given us a memory map that we can use to properly
621 * set up memory. If we aren't, we'll fake a memory map.
623 static int __init copy_e820_map(struct e820entry *biosmap, int nr_map)
625 /* Only one memory region (or negative)? Ignore it */
630 unsigned long start = biosmap->addr;
631 unsigned long size = biosmap->size;
632 unsigned long end = start + size;
633 unsigned long type = biosmap->type;
635 /* Overflow in 64 bits? Ignore the memory map. */
639 add_memory_region(start, size, type);
640 } while (biosmap++, --nr_map);
644 static void early_panic(char *msg)
650 /* We're not void only for x86 32-bit compat */
651 char * __init machine_specific_memory_setup(void)
653 char *who = "BIOS-e820";
655 * Try to copy the BIOS-supplied E820-map.
657 * Otherwise fake a memory map; one section from 0k->640k,
658 * the next section from 1mb->appropriate_mem_k
660 sanitize_e820_map(boot_params.e820_map, &boot_params.e820_entries);
661 if (copy_e820_map(boot_params.e820_map, boot_params.e820_entries) < 0)
662 early_panic("Cannot find a valid memory map");
663 printk(KERN_INFO "BIOS-provided physical RAM map:\n");
666 /* In case someone cares... */
670 static int __init parse_memopt(char *p)
674 end_user_pfn = memparse(p, &p);
675 end_user_pfn >>= PAGE_SHIFT;
678 early_param("mem", parse_memopt);
680 static int userdef __initdata;
682 static int __init parse_memmap_opt(char *p)
685 unsigned long long start_at, mem_size;
687 if (!strcmp(p, "exactmap")) {
688 #ifdef CONFIG_CRASH_DUMP
690 * If we are doing a crash dump, we still need to know
691 * the real mem size before original memory map is
694 e820_register_active_regions(0, 0, -1UL);
695 saved_max_pfn = e820_end_of_ram();
696 remove_all_active_ranges();
705 mem_size = memparse(p, &p);
711 start_at = memparse(p+1, &p);
712 add_memory_region(start_at, mem_size, E820_RAM);
713 } else if (*p == '#') {
714 start_at = memparse(p+1, &p);
715 add_memory_region(start_at, mem_size, E820_ACPI);
716 } else if (*p == '$') {
717 start_at = memparse(p+1, &p);
718 add_memory_region(start_at, mem_size, E820_RESERVED);
720 end_user_pfn = (mem_size >> PAGE_SHIFT);
722 return *p == '\0' ? 0 : -EINVAL;
724 early_param("memmap", parse_memmap_opt);
726 void __init finish_e820_parsing(void)
729 char nr = e820.nr_map;
731 if (sanitize_e820_map(e820.map, &nr) < 0)
732 early_panic("Invalid user supplied memory map");
735 printk(KERN_INFO "user-defined physical RAM map:\n");
736 e820_print_map("user");
740 void __init update_e820(void)
744 nr_map = e820.nr_map;
745 if (sanitize_e820_map(e820.map, &nr_map))
747 e820.nr_map = nr_map;
748 printk(KERN_INFO "modified physical RAM map:\n");
749 e820_print_map("modified");
752 unsigned long pci_mem_start = 0xaeedbabe;
753 EXPORT_SYMBOL(pci_mem_start);
756 * Search for the biggest gap in the low 32 bits of the e820
757 * memory space. We pass this space to PCI to assign MMIO resources
758 * for hotplug or unconfigured devices in.
759 * Hopefully the BIOS let enough space left.
761 __init void e820_setup_gap(void)
763 unsigned long gapstart, gapsize, round;
768 last = 0x100000000ull;
769 gapstart = 0x10000000;
773 unsigned long long start = e820.map[i].addr;
774 unsigned long long end = start + e820.map[i].size;
777 * Since "last" is at most 4GB, we know we'll
778 * fit in 32 bits if this condition is true
781 unsigned long gap = last - end;
794 gapstart = (end_pfn << PAGE_SHIFT) + 1024*1024;
795 printk(KERN_ERR "PCI: Warning: Cannot find a gap in the 32bit "
797 KERN_ERR "PCI: Unassigned devices with 32bit resource "
798 "registers may break!\n");
802 * See how much we want to round up: start off with
803 * rounding to the next 1MB area.
806 while ((gapsize >> 4) > round)
808 /* Fun with two's complement */
809 pci_mem_start = (gapstart + round) & -round;
812 "Allocating PCI resources starting at %lx (gap: %lx:%lx)\n",
813 pci_mem_start, gapstart, gapsize);
816 int __init arch_get_ram_range(int slot, u64 *addr, u64 *size)
820 if (slot < 0 || slot >= e820.nr_map)
822 for (i = slot; i < e820.nr_map; i++) {
823 if (e820.map[i].type != E820_RAM)
827 if (i == e820.nr_map || e820.map[i].addr > (max_pfn << PAGE_SHIFT))
829 *addr = e820.map[i].addr;
830 *size = min_t(u64, e820.map[i].size + e820.map[i].addr,
831 max_pfn << PAGE_SHIFT) - *addr;