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>
21 #include <asm/pgtable.h>
24 #include <asm/proto.h>
25 #include <asm/bootsetup.h>
26 #include <asm/sections.h>
31 * PFN of last memory page.
33 unsigned long end_pfn;
34 EXPORT_SYMBOL(end_pfn);
37 * end_pfn only includes RAM, while end_pfn_map includes all e820 entries.
38 * The direct mapping extends to end_pfn_map, so that we can directly access
39 * apertures, ACPI and other tables without having to play with fixmaps.
41 unsigned long end_pfn_map;
44 * Last pfn which the user wants to use.
46 static unsigned long __initdata end_user_pfn = MAXMEM>>PAGE_SHIFT;
48 extern struct resource code_resource, data_resource;
50 /* Check for some hardcoded bad areas that early boot is not allowed to touch */
51 static inline int bad_addr(unsigned long *addrp, unsigned long size)
53 unsigned long addr = *addrp, last = addr + size;
55 /* various gunk below that needed for SMP startup */
57 *addrp = PAGE_ALIGN(0x8000);
61 /* direct mapping tables of the kernel */
62 if (last >= table_start<<PAGE_SHIFT && addr < table_end<<PAGE_SHIFT) {
63 *addrp = PAGE_ALIGN(table_end << PAGE_SHIFT);
68 #ifdef CONFIG_BLK_DEV_INITRD
69 if (LOADER_TYPE && INITRD_START && last >= INITRD_START &&
70 addr < INITRD_START+INITRD_SIZE) {
71 *addrp = PAGE_ALIGN(INITRD_START + INITRD_SIZE);
76 if (last >= __pa_symbol(&_text) && addr < __pa_symbol(&_end)) {
77 *addrp = PAGE_ALIGN(__pa_symbol(&_end));
81 if (last >= ebda_addr && addr < ebda_addr + ebda_size) {
82 *addrp = PAGE_ALIGN(ebda_addr + ebda_size);
87 /* NUMA memory to node map */
88 if (last >= nodemap_addr && addr < nodemap_addr + nodemap_size) {
89 *addrp = nodemap_addr + nodemap_size;
93 /* XXX ramdisk image here? */
98 * This function checks if any part of the range <start,end> is mapped
102 e820_any_mapped(unsigned long start, unsigned long end, unsigned type)
105 for (i = 0; i < e820.nr_map; i++) {
106 struct e820entry *ei = &e820.map[i];
107 if (type && ei->type != type)
109 if (ei->addr >= end || ei->addr + ei->size <= start)
115 EXPORT_SYMBOL_GPL(e820_any_mapped);
118 * This function checks if the entire range <start,end> is mapped with type.
120 * Note: this function only works correct if the e820 table is sorted and
121 * not-overlapping, which is the case
123 int __init e820_all_mapped(unsigned long start, unsigned long end, unsigned type)
126 for (i = 0; i < e820.nr_map; i++) {
127 struct e820entry *ei = &e820.map[i];
128 if (type && ei->type != type)
130 /* is the region (part) in overlap with the current region ?*/
131 if (ei->addr >= end || ei->addr + ei->size <= start)
134 /* if the region is at the beginning of <start,end> we move
135 * start to the end of the region since it's ok until there
137 if (ei->addr <= start)
138 start = ei->addr + ei->size;
139 /* if start is now at or beyond end, we're done, full coverage */
141 return 1; /* we're done */
147 * Find a free area in a specific range.
149 unsigned long __init find_e820_area(unsigned long start, unsigned long end, unsigned size)
152 for (i = 0; i < e820.nr_map; i++) {
153 struct e820entry *ei = &e820.map[i];
154 unsigned long addr = ei->addr, last;
155 if (ei->type != E820_RAM)
159 if (addr > ei->addr + ei->size)
161 while (bad_addr(&addr, size) && addr+size <= ei->addr+ei->size)
163 last = PAGE_ALIGN(addr) + size;
164 if (last > ei->addr + ei->size)
174 * Find the highest page frame number we have available
176 unsigned long __init e820_end_of_ram(void)
178 unsigned long end_pfn = 0;
179 end_pfn = find_max_pfn_with_active_regions();
181 if (end_pfn > end_pfn_map)
182 end_pfn_map = end_pfn;
183 if (end_pfn_map > MAXMEM>>PAGE_SHIFT)
184 end_pfn_map = MAXMEM>>PAGE_SHIFT;
185 if (end_pfn > end_user_pfn)
186 end_pfn = end_user_pfn;
187 if (end_pfn > end_pfn_map)
188 end_pfn = end_pfn_map;
190 printk("end_pfn_map = %lu\n", end_pfn_map);
195 * Find the hole size in the range.
197 unsigned long __init e820_hole_size(unsigned long start, unsigned long end)
199 unsigned long ram = 0;
202 for (i = 0; i < e820.nr_map; i++) {
203 struct e820entry *ei = &e820.map[i];
204 unsigned long last, addr;
206 if (ei->type != E820_RAM ||
207 ei->addr+ei->size <= start ||
211 addr = round_up(ei->addr, PAGE_SIZE);
215 last = round_down(ei->addr + ei->size, PAGE_SIZE);
222 return ((end - start) - ram);
226 * Mark e820 reserved areas as busy for the resource manager.
228 void __init e820_reserve_resources(void)
231 for (i = 0; i < e820.nr_map; i++) {
232 struct resource *res;
233 res = alloc_bootmem_low(sizeof(struct resource));
234 switch (e820.map[i].type) {
235 case E820_RAM: res->name = "System RAM"; break;
236 case E820_ACPI: res->name = "ACPI Tables"; break;
237 case E820_NVS: res->name = "ACPI Non-volatile Storage"; break;
238 default: res->name = "reserved";
240 res->start = e820.map[i].addr;
241 res->end = res->start + e820.map[i].size - 1;
242 res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
243 request_resource(&iomem_resource, res);
244 if (e820.map[i].type == E820_RAM) {
246 * We don't know which RAM region contains kernel data,
247 * so we try it repeatedly and let the resource manager
250 request_resource(res, &code_resource);
251 request_resource(res, &data_resource);
253 request_resource(res, &crashk_res);
259 /* Mark pages corresponding to given address range as nosave */
261 e820_mark_nosave_range(unsigned long start, unsigned long end)
263 unsigned long pfn, max_pfn;
268 printk("Nosave address range: %016lx - %016lx\n", start, end);
269 max_pfn = end >> PAGE_SHIFT;
270 for (pfn = start >> PAGE_SHIFT; pfn < max_pfn; pfn++)
272 SetPageNosave(pfn_to_page(pfn));
276 * Find the ranges of physical addresses that do not correspond to
277 * e820 RAM areas and mark the corresponding pages as nosave for software
278 * suspend and suspend to RAM.
280 * This function requires the e820 map to be sorted and without any
281 * overlapping entries and assumes the first e820 area to be RAM.
283 void __init e820_mark_nosave_regions(void)
288 paddr = round_down(e820.map[0].addr + e820.map[0].size, PAGE_SIZE);
289 for (i = 1; i < e820.nr_map; i++) {
290 struct e820entry *ei = &e820.map[i];
292 if (paddr < ei->addr)
293 e820_mark_nosave_range(paddr,
294 round_up(ei->addr, PAGE_SIZE));
296 paddr = round_down(ei->addr + ei->size, PAGE_SIZE);
297 if (ei->type != E820_RAM)
298 e820_mark_nosave_range(round_up(ei->addr, PAGE_SIZE),
301 if (paddr >= (end_pfn << PAGE_SHIFT))
306 /* Walk the e820 map and register active regions within a node */
308 e820_register_active_regions(int nid, unsigned long start_pfn,
309 unsigned long end_pfn)
312 unsigned long ei_startpfn, ei_endpfn;
313 for (i = 0; i < e820.nr_map; i++) {
314 struct e820entry *ei = &e820.map[i];
315 ei_startpfn = round_up(ei->addr, PAGE_SIZE) >> PAGE_SHIFT;
316 ei_endpfn = round_down(ei->addr + ei->size, PAGE_SIZE)
319 /* Skip map entries smaller than a page */
320 if (ei_startpfn >= ei_endpfn)
323 /* Check if end_pfn_map should be updated */
324 if (ei->type != E820_RAM && ei_endpfn > end_pfn_map)
325 end_pfn_map = ei_endpfn;
327 /* Skip if map is outside the node */
328 if (ei->type != E820_RAM ||
329 ei_endpfn <= start_pfn ||
330 ei_startpfn >= end_pfn)
333 /* Check for overlaps */
334 if (ei_startpfn < start_pfn)
335 ei_startpfn = start_pfn;
336 if (ei_endpfn > end_pfn)
339 /* Obey end_user_pfn to save on memmap */
340 if (ei_startpfn >= end_user_pfn)
342 if (ei_endpfn > end_user_pfn)
343 ei_endpfn = end_user_pfn;
345 add_active_range(nid, ei_startpfn, ei_endpfn);
350 * Add a memory region to the kernel e820 map.
352 void __init add_memory_region(unsigned long start, unsigned long size, int type)
357 printk(KERN_ERR "Ooops! Too many entries in the memory map!\n");
361 e820.map[x].addr = start;
362 e820.map[x].size = size;
363 e820.map[x].type = type;
367 void __init e820_print_map(char *who)
371 for (i = 0; i < e820.nr_map; i++) {
372 printk(" %s: %016Lx - %016Lx ", who,
373 (unsigned long long) e820.map[i].addr,
374 (unsigned long long) (e820.map[i].addr + e820.map[i].size));
375 switch (e820.map[i].type) {
376 case E820_RAM: printk("(usable)\n");
379 printk("(reserved)\n");
382 printk("(ACPI data)\n");
385 printk("(ACPI NVS)\n");
387 default: printk("type %u\n", e820.map[i].type);
394 * Sanitize the BIOS e820 map.
396 * Some e820 responses include overlapping entries. The following
397 * replaces the original e820 map with a new one, removing overlaps.
400 static int __init sanitize_e820_map(struct e820entry * biosmap, char * pnr_map)
402 struct change_member {
403 struct e820entry *pbios; /* pointer to original bios entry */
404 unsigned long long addr; /* address for this change point */
406 static struct change_member change_point_list[2*E820MAX] __initdata;
407 static struct change_member *change_point[2*E820MAX] __initdata;
408 static struct e820entry *overlap_list[E820MAX] __initdata;
409 static struct e820entry new_bios[E820MAX] __initdata;
410 struct change_member *change_tmp;
411 unsigned long current_type, last_type;
412 unsigned long long last_addr;
413 int chgidx, still_changing;
416 int old_nr, new_nr, chg_nr;
420 Visually we're performing the following (1,2,3,4 = memory types)...
422 Sample memory map (w/overlaps):
423 ____22__________________
424 ______________________4_
425 ____1111________________
426 _44_____________________
427 11111111________________
428 ____________________33__
429 ___________44___________
430 __________33333_________
431 ______________22________
432 ___________________2222_
433 _________111111111______
434 _____________________11_
435 _________________4______
437 Sanitized equivalent (no overlap):
438 1_______________________
439 _44_____________________
440 ___1____________________
441 ____22__________________
442 ______11________________
443 _________1______________
444 __________3_____________
445 ___________44___________
446 _____________33_________
447 _______________2________
448 ________________1_______
449 _________________4______
450 ___________________2____
451 ____________________33__
452 ______________________4_
455 /* if there's only one memory region, don't bother */
461 /* bail out if we find any unreasonable addresses in bios map */
462 for (i=0; i<old_nr; i++)
463 if (biosmap[i].addr + biosmap[i].size < biosmap[i].addr)
466 /* create pointers for initial change-point information (for sorting) */
467 for (i=0; i < 2*old_nr; i++)
468 change_point[i] = &change_point_list[i];
470 /* record all known change-points (starting and ending addresses),
471 omitting those that are for empty memory regions */
473 for (i=0; i < old_nr; i++) {
474 if (biosmap[i].size != 0) {
475 change_point[chgidx]->addr = biosmap[i].addr;
476 change_point[chgidx++]->pbios = &biosmap[i];
477 change_point[chgidx]->addr = biosmap[i].addr + biosmap[i].size;
478 change_point[chgidx++]->pbios = &biosmap[i];
483 /* sort change-point list by memory addresses (low -> high) */
485 while (still_changing) {
487 for (i=1; i < chg_nr; i++) {
488 /* if <current_addr> > <last_addr>, swap */
489 /* or, if current=<start_addr> & last=<end_addr>, swap */
490 if ((change_point[i]->addr < change_point[i-1]->addr) ||
491 ((change_point[i]->addr == change_point[i-1]->addr) &&
492 (change_point[i]->addr == change_point[i]->pbios->addr) &&
493 (change_point[i-1]->addr != change_point[i-1]->pbios->addr))
496 change_tmp = change_point[i];
497 change_point[i] = change_point[i-1];
498 change_point[i-1] = change_tmp;
504 /* create a new bios memory map, removing overlaps */
505 overlap_entries=0; /* number of entries in the overlap table */
506 new_bios_entry=0; /* index for creating new bios map entries */
507 last_type = 0; /* start with undefined memory type */
508 last_addr = 0; /* start with 0 as last starting address */
509 /* loop through change-points, determining affect on the new bios map */
510 for (chgidx=0; chgidx < chg_nr; chgidx++)
512 /* keep track of all overlapping bios entries */
513 if (change_point[chgidx]->addr == change_point[chgidx]->pbios->addr)
515 /* add map entry to overlap list (> 1 entry implies an overlap) */
516 overlap_list[overlap_entries++]=change_point[chgidx]->pbios;
520 /* remove entry from list (order independent, so swap with last) */
521 for (i=0; i<overlap_entries; i++)
523 if (overlap_list[i] == change_point[chgidx]->pbios)
524 overlap_list[i] = overlap_list[overlap_entries-1];
528 /* if there are overlapping entries, decide which "type" to use */
529 /* (larger value takes precedence -- 1=usable, 2,3,4,4+=unusable) */
531 for (i=0; i<overlap_entries; i++)
532 if (overlap_list[i]->type > current_type)
533 current_type = overlap_list[i]->type;
534 /* continue building up new bios map based on this information */
535 if (current_type != last_type) {
536 if (last_type != 0) {
537 new_bios[new_bios_entry].size =
538 change_point[chgidx]->addr - last_addr;
539 /* move forward only if the new size was non-zero */
540 if (new_bios[new_bios_entry].size != 0)
541 if (++new_bios_entry >= E820MAX)
542 break; /* no more space left for new bios entries */
544 if (current_type != 0) {
545 new_bios[new_bios_entry].addr = change_point[chgidx]->addr;
546 new_bios[new_bios_entry].type = current_type;
547 last_addr=change_point[chgidx]->addr;
549 last_type = current_type;
552 new_nr = new_bios_entry; /* retain count for new bios entries */
554 /* copy new bios mapping into original location */
555 memcpy(biosmap, new_bios, new_nr*sizeof(struct e820entry));
562 * Copy the BIOS e820 map into a safe place.
564 * Sanity-check it while we're at it..
566 * If we're lucky and live on a modern system, the setup code
567 * will have given us a memory map that we can use to properly
568 * set up memory. If we aren't, we'll fake a memory map.
570 static int __init copy_e820_map(struct e820entry * biosmap, int nr_map)
572 /* Only one memory region (or negative)? Ignore it */
577 unsigned long start = biosmap->addr;
578 unsigned long size = biosmap->size;
579 unsigned long end = start + size;
580 unsigned long type = biosmap->type;
582 /* Overflow in 64 bits? Ignore the memory map. */
586 add_memory_region(start, size, type);
587 } while (biosmap++,--nr_map);
591 void early_panic(char *msg)
597 void __init setup_memory_region(void)
600 * Try to copy the BIOS-supplied E820-map.
602 * Otherwise fake a memory map; one section from 0k->640k,
603 * the next section from 1mb->appropriate_mem_k
605 sanitize_e820_map(E820_MAP, &E820_MAP_NR);
606 if (copy_e820_map(E820_MAP, E820_MAP_NR) < 0)
607 early_panic("Cannot find a valid memory map");
608 printk(KERN_INFO "BIOS-provided physical RAM map:\n");
609 e820_print_map("BIOS-e820");
612 static int __init parse_memopt(char *p)
616 end_user_pfn = memparse(p, &p);
617 end_user_pfn >>= PAGE_SHIFT;
620 early_param("mem", parse_memopt);
622 static int userdef __initdata;
624 static int __init parse_memmap_opt(char *p)
627 unsigned long long start_at, mem_size;
629 if (!strcmp(p, "exactmap")) {
630 #ifdef CONFIG_CRASH_DUMP
631 /* If we are doing a crash dump, we
632 * still need to know the real mem
633 * size before original memory map is
636 e820_register_active_regions(0, 0, -1UL);
637 saved_max_pfn = e820_end_of_ram();
638 remove_all_active_ranges();
647 mem_size = memparse(p, &p);
651 start_at = memparse(p+1, &p);
652 add_memory_region(start_at, mem_size, E820_RAM);
653 } else if (*p == '#') {
654 start_at = memparse(p+1, &p);
655 add_memory_region(start_at, mem_size, E820_ACPI);
656 } else if (*p == '$') {
657 start_at = memparse(p+1, &p);
658 add_memory_region(start_at, mem_size, E820_RESERVED);
660 end_user_pfn = (mem_size >> PAGE_SHIFT);
662 return *p == '\0' ? 0 : -EINVAL;
664 early_param("memmap", parse_memmap_opt);
666 void __init finish_e820_parsing(void)
669 printk(KERN_INFO "user-defined physical RAM map:\n");
670 e820_print_map("user");
674 unsigned long pci_mem_start = 0xaeedbabe;
675 EXPORT_SYMBOL(pci_mem_start);
678 * Search for the biggest gap in the low 32 bits of the e820
679 * memory space. We pass this space to PCI to assign MMIO resources
680 * for hotplug or unconfigured devices in.
681 * Hopefully the BIOS let enough space left.
683 __init void e820_setup_gap(void)
685 unsigned long gapstart, gapsize, round;
690 last = 0x100000000ull;
691 gapstart = 0x10000000;
695 unsigned long long start = e820.map[i].addr;
696 unsigned long long end = start + e820.map[i].size;
699 * Since "last" is at most 4GB, we know we'll
700 * fit in 32 bits if this condition is true
703 unsigned long gap = last - end;
716 gapstart = (end_pfn << PAGE_SHIFT) + 1024*1024;
717 printk(KERN_ERR "PCI: Warning: Cannot find a gap in the 32bit address range\n"
718 KERN_ERR "PCI: Unassigned devices with 32bit resource registers may break!\n");
722 * See how much we want to round up: start off with
723 * rounding to the next 1MB area.
726 while ((gapsize >> 4) > round)
728 /* Fun with two's complement */
729 pci_mem_start = (gapstart + round) & -round;
731 printk(KERN_INFO "Allocating PCI resources starting at %lx (gap: %lx:%lx)\n",
732 pci_mem_start, gapstart, gapsize);