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1/*
2 * Handle the memory map.
3 * The functions here do the job until bootmem takes over.
4 *
5 * Getting sanitize_e820_map() in sync with i386 version by applying change:
6 * - Provisions for empty E820 memory regions (reported by certain BIOSes).
7 * Alex Achenbach <xela@slit.de>, December 2002.
8 * Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
9 *
10 */
11#include <linux/kernel.h>
12#include <linux/types.h>
13#include <linux/init.h>
14#include <linux/crash_dump.h>
15#include <linux/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>
23
24#include <asm/e820.h>
25#include <asm/proto.h>
26#include <asm/setup.h>
27
28/*
29 * The e820 map is the map that gets modified e.g. with command line parameters
30 * and that is also registered with modifications in the kernel resource tree
31 * with the iomem_resource as parent.
32 *
33 * The e820_saved is directly saved after the BIOS-provided memory map is
34 * copied. It doesn't get modified afterwards. It's registered for the
35 * /sys/firmware/memmap interface.
36 *
37 * That memory map is not modified and is used as base for kexec. The kexec'd
38 * kernel should get the same memory map as the firmware provides. Then the
39 * user can e.g. boot the original kernel with mem=1G while still booting the
40 * next kernel with full memory.
41 */
42struct e820map e820;
43struct e820map e820_saved;
44
45/* For PCI or other memory-mapped resources */
46unsigned long pci_mem_start = 0xaeedbabe;
47#ifdef CONFIG_PCI
48EXPORT_SYMBOL(pci_mem_start);
49#endif
50
51/*
52 * This function checks if any part of the range <start,end> is mapped
53 * with type.
54 */
55int
56e820_any_mapped(u64 start, u64 end, unsigned type)
57{
58 int i;
59
60 for (i = 0; i < e820.nr_map; i++) {
61 struct e820entry *ei = &e820.map[i];
62
63 if (type && ei->type != type)
64 continue;
65 if (ei->addr >= end || ei->addr + ei->size <= start)
66 continue;
67 return 1;
68 }
69 return 0;
70}
71EXPORT_SYMBOL_GPL(e820_any_mapped);
72
73/*
74 * This function checks if the entire range <start,end> is mapped with type.
75 *
76 * Note: this function only works correct if the e820 table is sorted and
77 * not-overlapping, which is the case
78 */
79int __init e820_all_mapped(u64 start, u64 end, unsigned type)
80{
81 int i;
82
83 for (i = 0; i < e820.nr_map; i++) {
84 struct e820entry *ei = &e820.map[i];
85
86 if (type && ei->type != type)
87 continue;
88 /* is the region (part) in overlap with the current region ?*/
89 if (ei->addr >= end || ei->addr + ei->size <= start)
90 continue;
91
92 /* if the region is at the beginning of <start,end> we move
93 * start to the end of the region since it's ok until there
94 */
95 if (ei->addr <= start)
96 start = ei->addr + ei->size;
97 /*
98 * if start is now at or beyond end, we're done, full
99 * coverage
100 */
101 if (start >= end)
102 return 1;
103 }
104 return 0;
105}
106
107/*
108 * Add a memory region to the kernel e820 map.
109 */
110static void __init __e820_add_region(struct e820map *e820x, u64 start, u64 size,
111 int type)
112{
113 int x = e820x->nr_map;
114
115 if (x >= ARRAY_SIZE(e820x->map)) {
116 printk(KERN_ERR "e820: too many entries; ignoring [mem %#010llx-%#010llx]\n",
117 (unsigned long long) start,
118 (unsigned long long) (start + size - 1));
119 return;
120 }
121
122 e820x->map[x].addr = start;
123 e820x->map[x].size = size;
124 e820x->map[x].type = type;
125 e820x->nr_map++;
126}
127
128void __init e820_add_region(u64 start, u64 size, int type)
129{
130 __e820_add_region(&e820, start, size, type);
131}
132
133static void __init e820_print_type(u32 type)
134{
135 switch (type) {
136 case E820_RAM:
137 case E820_RESERVED_KERN:
138 printk(KERN_CONT "usable");
139 break;
140 case E820_RESERVED:
141 printk(KERN_CONT "reserved");
142 break;
143 case E820_ACPI:
144 printk(KERN_CONT "ACPI data");
145 break;
146 case E820_NVS:
147 printk(KERN_CONT "ACPI NVS");
148 break;
149 case E820_UNUSABLE:
150 printk(KERN_CONT "unusable");
151 break;
152 default:
153 printk(KERN_CONT "type %u", type);
154 break;
155 }
156}
157
158void __init e820_print_map(char *who)
159{
160 int i;
161
162 for (i = 0; i < e820.nr_map; i++) {
163 printk(KERN_INFO "%s: [mem %#018Lx-%#018Lx] ", who,
164 (unsigned long long) e820.map[i].addr,
165 (unsigned long long)
166 (e820.map[i].addr + e820.map[i].size - 1));
167 e820_print_type(e820.map[i].type);
168 printk(KERN_CONT "\n");
169 }
170}
171
172/*
173 * Sanitize the BIOS e820 map.
174 *
175 * Some e820 responses include overlapping entries. The following
176 * replaces the original e820 map with a new one, removing overlaps,
177 * and resolving conflicting memory types in favor of highest
178 * numbered type.
179 *
180 * The input parameter biosmap points to an array of 'struct
181 * e820entry' which on entry has elements in the range [0, *pnr_map)
182 * valid, and which has space for up to max_nr_map entries.
183 * On return, the resulting sanitized e820 map entries will be in
184 * overwritten in the same location, starting at biosmap.
185 *
186 * The integer pointed to by pnr_map must be valid on entry (the
187 * current number of valid entries located at biosmap) and will
188 * be updated on return, with the new number of valid entries
189 * (something no more than max_nr_map.)
190 *
191 * The return value from sanitize_e820_map() is zero if it
192 * successfully 'sanitized' the map entries passed in, and is -1
193 * if it did nothing, which can happen if either of (1) it was
194 * only passed one map entry, or (2) any of the input map entries
195 * were invalid (start + size < start, meaning that the size was
196 * so big the described memory range wrapped around through zero.)
197 *
198 * Visually we're performing the following
199 * (1,2,3,4 = memory types)...
200 *
201 * Sample memory map (w/overlaps):
202 * ____22__________________
203 * ______________________4_
204 * ____1111________________
205 * _44_____________________
206 * 11111111________________
207 * ____________________33__
208 * ___________44___________
209 * __________33333_________
210 * ______________22________
211 * ___________________2222_
212 * _________111111111______
213 * _____________________11_
214 * _________________4______
215 *
216 * Sanitized equivalent (no overlap):
217 * 1_______________________
218 * _44_____________________
219 * ___1____________________
220 * ____22__________________
221 * ______11________________
222 * _________1______________
223 * __________3_____________
224 * ___________44___________
225 * _____________33_________
226 * _______________2________
227 * ________________1_______
228 * _________________4______
229 * ___________________2____
230 * ____________________33__
231 * ______________________4_
232 */
233struct change_member {
234 struct e820entry *pbios; /* pointer to original bios entry */
235 unsigned long long addr; /* address for this change point */
236};
237
238static int __init cpcompare(const void *a, const void *b)
239{
240 struct change_member * const *app = a, * const *bpp = b;
241 const struct change_member *ap = *app, *bp = *bpp;
242
243 /*
244 * Inputs are pointers to two elements of change_point[]. If their
245 * addresses are unequal, their difference dominates. If the addresses
246 * are equal, then consider one that represents the end of its region
247 * to be greater than one that does not.
248 */
249 if (ap->addr != bp->addr)
250 return ap->addr > bp->addr ? 1 : -1;
251
252 return (ap->addr != ap->pbios->addr) - (bp->addr != bp->pbios->addr);
253}
254
255int __init sanitize_e820_map(struct e820entry *biosmap, int max_nr_map,
256 u32 *pnr_map)
257{
258 static struct change_member change_point_list[2*E820_X_MAX] __initdata;
259 static struct change_member *change_point[2*E820_X_MAX] __initdata;
260 static struct e820entry *overlap_list[E820_X_MAX] __initdata;
261 static struct e820entry new_bios[E820_X_MAX] __initdata;
262 unsigned long current_type, last_type;
263 unsigned long long last_addr;
264 int chgidx;
265 int overlap_entries;
266 int new_bios_entry;
267 int old_nr, new_nr, chg_nr;
268 int i;
269
270 /* if there's only one memory region, don't bother */
271 if (*pnr_map < 2)
272 return -1;
273
274 old_nr = *pnr_map;
275 BUG_ON(old_nr > max_nr_map);
276
277 /* bail out if we find any unreasonable addresses in bios map */
278 for (i = 0; i < old_nr; i++)
279 if (biosmap[i].addr + biosmap[i].size < biosmap[i].addr)
280 return -1;
281
282 /* create pointers for initial change-point information (for sorting) */
283 for (i = 0; i < 2 * old_nr; i++)
284 change_point[i] = &change_point_list[i];
285
286 /* record all known change-points (starting and ending addresses),
287 omitting those that are for empty memory regions */
288 chgidx = 0;
289 for (i = 0; i < old_nr; i++) {
290 if (biosmap[i].size != 0) {
291 change_point[chgidx]->addr = biosmap[i].addr;
292 change_point[chgidx++]->pbios = &biosmap[i];
293 change_point[chgidx]->addr = biosmap[i].addr +
294 biosmap[i].size;
295 change_point[chgidx++]->pbios = &biosmap[i];
296 }
297 }
298 chg_nr = chgidx;
299
300 /* sort change-point list by memory addresses (low -> high) */
301 sort(change_point, chg_nr, sizeof *change_point, cpcompare, NULL);
302
303 /* create a new bios memory map, removing overlaps */
304 overlap_entries = 0; /* number of entries in the overlap table */
305 new_bios_entry = 0; /* index for creating new bios map entries */
306 last_type = 0; /* start with undefined memory type */
307 last_addr = 0; /* start with 0 as last starting address */
308
309 /* loop through change-points, determining affect on the new bios map */
310 for (chgidx = 0; chgidx < chg_nr; chgidx++) {
311 /* keep track of all overlapping bios entries */
312 if (change_point[chgidx]->addr ==
313 change_point[chgidx]->pbios->addr) {
314 /*
315 * add map entry to overlap list (> 1 entry
316 * implies an overlap)
317 */
318 overlap_list[overlap_entries++] =
319 change_point[chgidx]->pbios;
320 } else {
321 /*
322 * remove entry from list (order independent,
323 * so swap with last)
324 */
325 for (i = 0; i < overlap_entries; i++) {
326 if (overlap_list[i] ==
327 change_point[chgidx]->pbios)
328 overlap_list[i] =
329 overlap_list[overlap_entries-1];
330 }
331 overlap_entries--;
332 }
333 /*
334 * if there are overlapping entries, decide which
335 * "type" to use (larger value takes precedence --
336 * 1=usable, 2,3,4,4+=unusable)
337 */
338 current_type = 0;
339 for (i = 0; i < overlap_entries; i++)
340 if (overlap_list[i]->type > current_type)
341 current_type = overlap_list[i]->type;
342 /*
343 * continue building up new bios map based on this
344 * information
345 */
346 if (current_type != last_type) {
347 if (last_type != 0) {
348 new_bios[new_bios_entry].size =
349 change_point[chgidx]->addr - last_addr;
350 /*
351 * move forward only if the new size
352 * was non-zero
353 */
354 if (new_bios[new_bios_entry].size != 0)
355 /*
356 * no more space left for new
357 * bios entries ?
358 */
359 if (++new_bios_entry >= max_nr_map)
360 break;
361 }
362 if (current_type != 0) {
363 new_bios[new_bios_entry].addr =
364 change_point[chgidx]->addr;
365 new_bios[new_bios_entry].type = current_type;
366 last_addr = change_point[chgidx]->addr;
367 }
368 last_type = current_type;
369 }
370 }
371 /* retain count for new bios entries */
372 new_nr = new_bios_entry;
373
374 /* copy new bios mapping into original location */
375 memcpy(biosmap, new_bios, new_nr * sizeof(struct e820entry));
376 *pnr_map = new_nr;
377
378 return 0;
379}
380
381static int __init __append_e820_map(struct e820entry *biosmap, int nr_map)
382{
383 while (nr_map) {
384 u64 start = biosmap->addr;
385 u64 size = biosmap->size;
386 u64 end = start + size;
387 u32 type = biosmap->type;
388
389 /* Overflow in 64 bits? Ignore the memory map. */
390 if (start > end)
391 return -1;
392
393 e820_add_region(start, size, type);
394
395 biosmap++;
396 nr_map--;
397 }
398 return 0;
399}
400
401/*
402 * Copy the BIOS e820 map into a safe place.
403 *
404 * Sanity-check it while we're at it..
405 *
406 * If we're lucky and live on a modern system, the setup code
407 * will have given us a memory map that we can use to properly
408 * set up memory. If we aren't, we'll fake a memory map.
409 */
410static int __init append_e820_map(struct e820entry *biosmap, int nr_map)
411{
412 /* Only one memory region (or negative)? Ignore it */
413 if (nr_map < 2)
414 return -1;
415
416 return __append_e820_map(biosmap, nr_map);
417}
418
419static u64 __init __e820_update_range(struct e820map *e820x, u64 start,
420 u64 size, unsigned old_type,
421 unsigned new_type)
422{
423 u64 end;
424 unsigned int i;
425 u64 real_updated_size = 0;
426
427 BUG_ON(old_type == new_type);
428
429 if (size > (ULLONG_MAX - start))
430 size = ULLONG_MAX - start;
431
432 end = start + size;
433 printk(KERN_DEBUG "e820: update [mem %#010Lx-%#010Lx] ",
434 (unsigned long long) start, (unsigned long long) (end - 1));
435 e820_print_type(old_type);
436 printk(KERN_CONT " ==> ");
437 e820_print_type(new_type);
438 printk(KERN_CONT "\n");
439
440 for (i = 0; i < e820x->nr_map; i++) {
441 struct e820entry *ei = &e820x->map[i];
442 u64 final_start, final_end;
443 u64 ei_end;
444
445 if (ei->type != old_type)
446 continue;
447
448 ei_end = ei->addr + ei->size;
449 /* totally covered by new range? */
450 if (ei->addr >= start && ei_end <= end) {
451 ei->type = new_type;
452 real_updated_size += ei->size;
453 continue;
454 }
455
456 /* new range is totally covered? */
457 if (ei->addr < start && ei_end > end) {
458 __e820_add_region(e820x, start, size, new_type);
459 __e820_add_region(e820x, end, ei_end - end, ei->type);
460 ei->size = start - ei->addr;
461 real_updated_size += size;
462 continue;
463 }
464
465 /* partially covered */
466 final_start = max(start, ei->addr);
467 final_end = min(end, ei_end);
468 if (final_start >= final_end)
469 continue;
470
471 __e820_add_region(e820x, final_start, final_end - final_start,
472 new_type);
473
474 real_updated_size += final_end - final_start;
475
476 /*
477 * left range could be head or tail, so need to update
478 * size at first.
479 */
480 ei->size -= final_end - final_start;
481 if (ei->addr < final_start)
482 continue;
483 ei->addr = final_end;
484 }
485 return real_updated_size;
486}
487
488u64 __init e820_update_range(u64 start, u64 size, unsigned old_type,
489 unsigned new_type)
490{
491 return __e820_update_range(&e820, start, size, old_type, new_type);
492}
493
494static u64 __init e820_update_range_saved(u64 start, u64 size,
495 unsigned old_type, unsigned new_type)
496{
497 return __e820_update_range(&e820_saved, start, size, old_type,
498 new_type);
499}
500
501/* make e820 not cover the range */
502u64 __init e820_remove_range(u64 start, u64 size, unsigned old_type,
503 int checktype)
504{
505 int i;
506 u64 end;
507 u64 real_removed_size = 0;
508
509 if (size > (ULLONG_MAX - start))
510 size = ULLONG_MAX - start;
511
512 end = start + size;
513 printk(KERN_DEBUG "e820: remove [mem %#010Lx-%#010Lx] ",
514 (unsigned long long) start, (unsigned long long) (end - 1));
515 if (checktype)
516 e820_print_type(old_type);
517 printk(KERN_CONT "\n");
518
519 for (i = 0; i < e820.nr_map; i++) {
520 struct e820entry *ei = &e820.map[i];
521 u64 final_start, final_end;
522 u64 ei_end;
523
524 if (checktype && ei->type != old_type)
525 continue;
526
527 ei_end = ei->addr + ei->size;
528 /* totally covered? */
529 if (ei->addr >= start && ei_end <= end) {
530 real_removed_size += ei->size;
531 memset(ei, 0, sizeof(struct e820entry));
532 continue;
533 }
534
535 /* new range is totally covered? */
536 if (ei->addr < start && ei_end > end) {
537 e820_add_region(end, ei_end - end, ei->type);
538 ei->size = start - ei->addr;
539 real_removed_size += size;
540 continue;
541 }
542
543 /* partially covered */
544 final_start = max(start, ei->addr);
545 final_end = min(end, ei_end);
546 if (final_start >= final_end)
547 continue;
548 real_removed_size += final_end - final_start;
549
550 /*
551 * left range could be head or tail, so need to update
552 * size at first.
553 */
554 ei->size -= final_end - final_start;
555 if (ei->addr < final_start)
556 continue;
557 ei->addr = final_end;
558 }
559 return real_removed_size;
560}
561
562void __init update_e820(void)
563{
564 u32 nr_map;
565
566 nr_map = e820.nr_map;
567 if (sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &nr_map))
568 return;
569 e820.nr_map = nr_map;
570 printk(KERN_INFO "e820: modified physical RAM map:\n");
571 e820_print_map("modified");
572}
573static void __init update_e820_saved(void)
574{
575 u32 nr_map;
576
577 nr_map = e820_saved.nr_map;
578 if (sanitize_e820_map(e820_saved.map, ARRAY_SIZE(e820_saved.map), &nr_map))
579 return;
580 e820_saved.nr_map = nr_map;
581}
582#define MAX_GAP_END 0x100000000ull
583/*
584 * Search for a gap in the e820 memory space from start_addr to end_addr.
585 */
586__init int e820_search_gap(unsigned long *gapstart, unsigned long *gapsize,
587 unsigned long start_addr, unsigned long long end_addr)
588{
589 unsigned long long last;
590 int i = e820.nr_map;
591 int found = 0;
592
593 last = (end_addr && end_addr < MAX_GAP_END) ? end_addr : MAX_GAP_END;
594
595 while (--i >= 0) {
596 unsigned long long start = e820.map[i].addr;
597 unsigned long long end = start + e820.map[i].size;
598
599 if (end < start_addr)
600 continue;
601
602 /*
603 * Since "last" is at most 4GB, we know we'll
604 * fit in 32 bits if this condition is true
605 */
606 if (last > end) {
607 unsigned long gap = last - end;
608
609 if (gap >= *gapsize) {
610 *gapsize = gap;
611 *gapstart = end;
612 found = 1;
613 }
614 }
615 if (start < last)
616 last = start;
617 }
618 return found;
619}
620
621/*
622 * Search for the biggest gap in the low 32 bits of the e820
623 * memory space. We pass this space to PCI to assign MMIO resources
624 * for hotplug or unconfigured devices in.
625 * Hopefully the BIOS let enough space left.
626 */
627__init void e820_setup_gap(void)
628{
629 unsigned long gapstart, gapsize;
630 int found;
631
632 gapstart = 0x10000000;
633 gapsize = 0x400000;
634 found = e820_search_gap(&gapstart, &gapsize, 0, MAX_GAP_END);
635
636#ifdef CONFIG_X86_64
637 if (!found) {
638 gapstart = (max_pfn << PAGE_SHIFT) + 1024*1024;
639 printk(KERN_ERR
640 "e820: cannot find a gap in the 32bit address range\n"
641 "e820: PCI devices with unassigned 32bit BARs may break!\n");
642 }
643#endif
644
645 /*
646 * e820_reserve_resources_late protect stolen RAM already
647 */
648 pci_mem_start = gapstart;
649
650 printk(KERN_INFO
651 "e820: [mem %#010lx-%#010lx] available for PCI devices\n",
652 gapstart, gapstart + gapsize - 1);
653}
654
655/**
656 * Because of the size limitation of struct boot_params, only first
657 * 128 E820 memory entries are passed to kernel via
658 * boot_params.e820_map, others are passed via SETUP_E820_EXT node of
659 * linked list of struct setup_data, which is parsed here.
660 */
661void __init parse_e820_ext(struct setup_data *sdata)
662{
663 int entries;
664 struct e820entry *extmap;
665
666 entries = sdata->len / sizeof(struct e820entry);
667 extmap = (struct e820entry *)(sdata->data);
668 __append_e820_map(extmap, entries);
669 sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
670 printk(KERN_INFO "e820: extended physical RAM map:\n");
671 e820_print_map("extended");
672}
673
674#if defined(CONFIG_X86_64) || \
675 (defined(CONFIG_X86_32) && defined(CONFIG_HIBERNATION))
676/**
677 * Find the ranges of physical addresses that do not correspond to
678 * e820 RAM areas and mark the corresponding pages as nosave for
679 * hibernation (32 bit) or software suspend and suspend to RAM (64 bit).
680 *
681 * This function requires the e820 map to be sorted and without any
682 * overlapping entries and assumes the first e820 area to be RAM.
683 */
684void __init e820_mark_nosave_regions(unsigned long limit_pfn)
685{
686 int i;
687 unsigned long pfn;
688
689 pfn = PFN_DOWN(e820.map[0].addr + e820.map[0].size);
690 for (i = 1; i < e820.nr_map; i++) {
691 struct e820entry *ei = &e820.map[i];
692
693 if (pfn < PFN_UP(ei->addr))
694 register_nosave_region(pfn, PFN_UP(ei->addr));
695
696 pfn = PFN_DOWN(ei->addr + ei->size);
697 if (ei->type != E820_RAM && ei->type != E820_RESERVED_KERN)
698 register_nosave_region(PFN_UP(ei->addr), pfn);
699
700 if (pfn >= limit_pfn)
701 break;
702 }
703}
704#endif
705
706#ifdef CONFIG_ACPI
707/**
708 * Mark ACPI NVS memory region, so that we can save/restore it during
709 * hibernation and the subsequent resume.
710 */
711static int __init e820_mark_nvs_memory(void)
712{
713 int i;
714
715 for (i = 0; i < e820.nr_map; i++) {
716 struct e820entry *ei = &e820.map[i];
717
718 if (ei->type == E820_NVS)
719 acpi_nvs_register(ei->addr, ei->size);
720 }
721
722 return 0;
723}
724core_initcall(e820_mark_nvs_memory);
725#endif
726
727/*
728 * pre allocated 4k and reserved it in memblock and e820_saved
729 */
730u64 __init early_reserve_e820(u64 size, u64 align)
731{
732 u64 addr;
733
734 addr = __memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ACCESSIBLE);
735 if (addr) {
736 e820_update_range_saved(addr, size, E820_RAM, E820_RESERVED);
737 printk(KERN_INFO "e820: update e820_saved for early_reserve_e820\n");
738 update_e820_saved();
739 }
740
741 return addr;
742}
743
744#ifdef CONFIG_X86_32
745# ifdef CONFIG_X86_PAE
746# define MAX_ARCH_PFN (1ULL<<(36-PAGE_SHIFT))
747# else
748# define MAX_ARCH_PFN (1ULL<<(32-PAGE_SHIFT))
749# endif
750#else /* CONFIG_X86_32 */
751# define MAX_ARCH_PFN MAXMEM>>PAGE_SHIFT
752#endif
753
754/*
755 * Find the highest page frame number we have available
756 */
757static unsigned long __init e820_end_pfn(unsigned long limit_pfn, unsigned type)
758{
759 int i;
760 unsigned long last_pfn = 0;
761 unsigned long max_arch_pfn = MAX_ARCH_PFN;
762
763 for (i = 0; i < e820.nr_map; i++) {
764 struct e820entry *ei = &e820.map[i];
765 unsigned long start_pfn;
766 unsigned long end_pfn;
767
768 if (ei->type != type)
769 continue;
770
771 start_pfn = ei->addr >> PAGE_SHIFT;
772 end_pfn = (ei->addr + ei->size) >> PAGE_SHIFT;
773
774 if (start_pfn >= limit_pfn)
775 continue;
776 if (end_pfn > limit_pfn) {
777 last_pfn = limit_pfn;
778 break;
779 }
780 if (end_pfn > last_pfn)
781 last_pfn = end_pfn;
782 }
783
784 if (last_pfn > max_arch_pfn)
785 last_pfn = max_arch_pfn;
786
787 printk(KERN_INFO "e820: last_pfn = %#lx max_arch_pfn = %#lx\n",
788 last_pfn, max_arch_pfn);
789 return last_pfn;
790}
791unsigned long __init e820_end_of_ram_pfn(void)
792{
793 return e820_end_pfn(MAX_ARCH_PFN, E820_RAM);
794}
795
796unsigned long __init e820_end_of_low_ram_pfn(void)
797{
798 return e820_end_pfn(1UL<<(32 - PAGE_SHIFT), E820_RAM);
799}
800
801static void early_panic(char *msg)
802{
803 early_printk(msg);
804 panic(msg);
805}
806
807static int userdef __initdata;
808
809/* "mem=nopentium" disables the 4MB page tables. */
810static int __init parse_memopt(char *p)
811{
812 u64 mem_size;
813
814 if (!p)
815 return -EINVAL;
816
817 if (!strcmp(p, "nopentium")) {
818#ifdef CONFIG_X86_32
819 setup_clear_cpu_cap(X86_FEATURE_PSE);
820 return 0;
821#else
822 printk(KERN_WARNING "mem=nopentium ignored! (only supported on x86_32)\n");
823 return -EINVAL;
824#endif
825 }
826
827 userdef = 1;
828 mem_size = memparse(p, &p);
829 /* don't remove all of memory when handling "mem={invalid}" param */
830 if (mem_size == 0)
831 return -EINVAL;
832 e820_remove_range(mem_size, ULLONG_MAX - mem_size, E820_RAM, 1);
833
834 return 0;
835}
836early_param("mem", parse_memopt);
837
838static int __init parse_memmap_opt(char *p)
839{
840 char *oldp;
841 u64 start_at, mem_size;
842
843 if (!p)
844 return -EINVAL;
845
846 if (!strncmp(p, "exactmap", 8)) {
847#ifdef CONFIG_CRASH_DUMP
848 /*
849 * If we are doing a crash dump, we still need to know
850 * the real mem size before original memory map is
851 * reset.
852 */
853 saved_max_pfn = e820_end_of_ram_pfn();
854#endif
855 e820.nr_map = 0;
856 userdef = 1;
857 return 0;
858 }
859
860 oldp = p;
861 mem_size = memparse(p, &p);
862 if (p == oldp)
863 return -EINVAL;
864
865 userdef = 1;
866 if (*p == '@') {
867 start_at = memparse(p+1, &p);
868 e820_add_region(start_at, mem_size, E820_RAM);
869 } else if (*p == '#') {
870 start_at = memparse(p+1, &p);
871 e820_add_region(start_at, mem_size, E820_ACPI);
872 } else if (*p == '$') {
873 start_at = memparse(p+1, &p);
874 e820_add_region(start_at, mem_size, E820_RESERVED);
875 } else
876 e820_remove_range(mem_size, ULLONG_MAX - mem_size, E820_RAM, 1);
877
878 return *p == '\0' ? 0 : -EINVAL;
879}
880early_param("memmap", parse_memmap_opt);
881
882void __init finish_e820_parsing(void)
883{
884 if (userdef) {
885 u32 nr = e820.nr_map;
886
887 if (sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &nr) < 0)
888 early_panic("Invalid user supplied memory map");
889 e820.nr_map = nr;
890
891 printk(KERN_INFO "e820: user-defined physical RAM map:\n");
892 e820_print_map("user");
893 }
894}
895
896static inline const char *e820_type_to_string(int e820_type)
897{
898 switch (e820_type) {
899 case E820_RESERVED_KERN:
900 case E820_RAM: return "System RAM";
901 case E820_ACPI: return "ACPI Tables";
902 case E820_NVS: return "ACPI Non-volatile Storage";
903 case E820_UNUSABLE: return "Unusable memory";
904 default: return "reserved";
905 }
906}
907
908/*
909 * Mark e820 reserved areas as busy for the resource manager.
910 */
911static struct resource __initdata *e820_res;
912void __init e820_reserve_resources(void)
913{
914 int i;
915 struct resource *res;
916 u64 end;
917
918 res = alloc_bootmem(sizeof(struct resource) * e820.nr_map);
919 e820_res = res;
920 for (i = 0; i < e820.nr_map; i++) {
921 end = e820.map[i].addr + e820.map[i].size - 1;
922 if (end != (resource_size_t)end) {
923 res++;
924 continue;
925 }
926 res->name = e820_type_to_string(e820.map[i].type);
927 res->start = e820.map[i].addr;
928 res->end = end;
929
930 res->flags = IORESOURCE_MEM;
931
932 /*
933 * don't register the region that could be conflicted with
934 * pci device BAR resource and insert them later in
935 * pcibios_resource_survey()
936 */
937 if (e820.map[i].type != E820_RESERVED || res->start < (1ULL<<20)) {
938 res->flags |= IORESOURCE_BUSY;
939 insert_resource(&iomem_resource, res);
940 }
941 res++;
942 }
943
944 for (i = 0; i < e820_saved.nr_map; i++) {
945 struct e820entry *entry = &e820_saved.map[i];
946 firmware_map_add_early(entry->addr,
947 entry->addr + entry->size - 1,
948 e820_type_to_string(entry->type));
949 }
950}
951
952/* How much should we pad RAM ending depending on where it is? */
953static unsigned long ram_alignment(resource_size_t pos)
954{
955 unsigned long mb = pos >> 20;
956
957 /* To 64kB in the first megabyte */
958 if (!mb)
959 return 64*1024;
960
961 /* To 1MB in the first 16MB */
962 if (mb < 16)
963 return 1024*1024;
964
965 /* To 64MB for anything above that */
966 return 64*1024*1024;
967}
968
969#define MAX_RESOURCE_SIZE ((resource_size_t)-1)
970
971void __init e820_reserve_resources_late(void)
972{
973 int i;
974 struct resource *res;
975
976 res = e820_res;
977 for (i = 0; i < e820.nr_map; i++) {
978 if (!res->parent && res->end)
979 insert_resource_expand_to_fit(&iomem_resource, res);
980 res++;
981 }
982
983 /*
984 * Try to bump up RAM regions to reasonable boundaries to
985 * avoid stolen RAM:
986 */
987 for (i = 0; i < e820.nr_map; i++) {
988 struct e820entry *entry = &e820.map[i];
989 u64 start, end;
990
991 if (entry->type != E820_RAM)
992 continue;
993 start = entry->addr + entry->size;
994 end = round_up(start, ram_alignment(start)) - 1;
995 if (end > MAX_RESOURCE_SIZE)
996 end = MAX_RESOURCE_SIZE;
997 if (start >= end)
998 continue;
999 printk(KERN_DEBUG
1000 "e820: reserve RAM buffer [mem %#010llx-%#010llx]\n",
1001 start, end);
1002 reserve_region_with_split(&iomem_resource, start, end,
1003 "RAM buffer");
1004 }
1005}
1006
1007char *__init default_machine_specific_memory_setup(void)
1008{
1009 char *who = "BIOS-e820";
1010 u32 new_nr;
1011 /*
1012 * Try to copy the BIOS-supplied E820-map.
1013 *
1014 * Otherwise fake a memory map; one section from 0k->640k,
1015 * the next section from 1mb->appropriate_mem_k
1016 */
1017 new_nr = boot_params.e820_entries;
1018 sanitize_e820_map(boot_params.e820_map,
1019 ARRAY_SIZE(boot_params.e820_map),
1020 &new_nr);
1021 boot_params.e820_entries = new_nr;
1022 if (append_e820_map(boot_params.e820_map, boot_params.e820_entries)
1023 < 0) {
1024 u64 mem_size;
1025
1026 /* compare results from other methods and take the greater */
1027 if (boot_params.alt_mem_k
1028 < boot_params.screen_info.ext_mem_k) {
1029 mem_size = boot_params.screen_info.ext_mem_k;
1030 who = "BIOS-88";
1031 } else {
1032 mem_size = boot_params.alt_mem_k;
1033 who = "BIOS-e801";
1034 }
1035
1036 e820.nr_map = 0;
1037 e820_add_region(0, LOWMEMSIZE(), E820_RAM);
1038 e820_add_region(HIGH_MEMORY, mem_size << 10, E820_RAM);
1039 }
1040
1041 /* In case someone cares... */
1042 return who;
1043}
1044
1045void __init setup_memory_map(void)
1046{
1047 char *who;
1048
1049 who = x86_init.resources.memory_setup();
1050 memcpy(&e820_saved, &e820, sizeof(struct e820map));
1051 printk(KERN_INFO "e820: BIOS-provided physical RAM map:\n");
1052 e820_print_map(who);
1053}
1054
1055void __init memblock_x86_fill(void)
1056{
1057 int i;
1058 u64 end;
1059
1060 /*
1061 * EFI may have more than 128 entries
1062 * We are safe to enable resizing, beause memblock_x86_fill()
1063 * is rather later for x86
1064 */
1065 memblock_allow_resize();
1066
1067 for (i = 0; i < e820.nr_map; i++) {
1068 struct e820entry *ei = &e820.map[i];
1069
1070 end = ei->addr + ei->size;
1071 if (end != (resource_size_t)end)
1072 continue;
1073
1074 if (ei->type != E820_RAM && ei->type != E820_RESERVED_KERN)
1075 continue;
1076
1077 memblock_add(ei->addr, ei->size);
1078 }
1079
1080 memblock_dump_all();
1081}
1082
1083void __init memblock_find_dma_reserve(void)
1084{
1085#ifdef CONFIG_X86_64
1086 u64 nr_pages = 0, nr_free_pages = 0;
1087 unsigned long start_pfn, end_pfn;
1088 phys_addr_t start, end;
1089 int i;
1090 u64 u;
1091
1092 /*
1093 * need to find out used area below MAX_DMA_PFN
1094 * need to use memblock to get free size in [0, MAX_DMA_PFN]
1095 * at first, and assume boot_mem will not take below MAX_DMA_PFN
1096 */
1097 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, NULL) {
1098 start_pfn = min_t(unsigned long, start_pfn, MAX_DMA_PFN);
1099 end_pfn = min_t(unsigned long, end_pfn, MAX_DMA_PFN);
1100 nr_pages += end_pfn - start_pfn;
1101 }
1102
1103 for_each_free_mem_range(u, MAX_NUMNODES, &start, &end, NULL) {
1104 start_pfn = min_t(unsigned long, PFN_UP(start), MAX_DMA_PFN);
1105 end_pfn = min_t(unsigned long, PFN_DOWN(end), MAX_DMA_PFN);
1106 if (start_pfn < end_pfn)
1107 nr_free_pages += end_pfn - start_pfn;
1108 }
1109
1110 set_dma_reserve(nr_pages - nr_free_pages);
1111#endif
1112}
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Low level x86 E820 memory map handling functions.
4 *
5 * The firmware and bootloader passes us the "E820 table", which is the primary
6 * physical memory layout description available about x86 systems.
7 *
8 * The kernel takes the E820 memory layout and optionally modifies it with
9 * quirks and other tweaks, and feeds that into the generic Linux memory
10 * allocation code routines via a platform independent interface (memblock, etc.).
11 */
12#include <linux/crash_dump.h>
13#include <linux/memblock.h>
14#include <linux/suspend.h>
15#include <linux/acpi.h>
16#include <linux/firmware-map.h>
17#include <linux/sort.h>
18#include <linux/memory_hotplug.h>
19
20#include <asm/e820/api.h>
21#include <asm/setup.h>
22
23/*
24 * We organize the E820 table into three main data structures:
25 *
26 * - 'e820_table_firmware': the original firmware version passed to us by the
27 * bootloader - not modified by the kernel. It is composed of two parts:
28 * the first 128 E820 memory entries in boot_params.e820_table and the remaining
29 * (if any) entries of the SETUP_E820_EXT nodes. We use this to:
30 *
31 * - inform the user about the firmware's notion of memory layout
32 * via /sys/firmware/memmap
33 *
34 * - the hibernation code uses it to generate a kernel-independent CRC32
35 * checksum of the physical memory layout of a system.
36 *
37 * - 'e820_table_kexec': a slightly modified (by the kernel) firmware version
38 * passed to us by the bootloader - the major difference between
39 * e820_table_firmware[] and this one is that, the latter marks the setup_data
40 * list created by the EFI boot stub as reserved, so that kexec can reuse the
41 * setup_data information in the second kernel. Besides, e820_table_kexec[]
42 * might also be modified by the kexec itself to fake a mptable.
43 * We use this to:
44 *
45 * - kexec, which is a bootloader in disguise, uses the original E820
46 * layout to pass to the kexec-ed kernel. This way the original kernel
47 * can have a restricted E820 map while the kexec()-ed kexec-kernel
48 * can have access to full memory - etc.
49 *
50 * - 'e820_table': this is the main E820 table that is massaged by the
51 * low level x86 platform code, or modified by boot parameters, before
52 * passed on to higher level MM layers.
53 *
54 * Once the E820 map has been converted to the standard Linux memory layout
55 * information its role stops - modifying it has no effect and does not get
56 * re-propagated. So its main role is a temporary bootstrap storage of firmware
57 * specific memory layout data during early bootup.
58 */
59static struct e820_table e820_table_init __initdata;
60static struct e820_table e820_table_kexec_init __initdata;
61static struct e820_table e820_table_firmware_init __initdata;
62
63struct e820_table *e820_table __refdata = &e820_table_init;
64struct e820_table *e820_table_kexec __refdata = &e820_table_kexec_init;
65struct e820_table *e820_table_firmware __refdata = &e820_table_firmware_init;
66
67/* For PCI or other memory-mapped resources */
68unsigned long pci_mem_start = 0xaeedbabe;
69#ifdef CONFIG_PCI
70EXPORT_SYMBOL(pci_mem_start);
71#endif
72
73/*
74 * This function checks if any part of the range <start,end> is mapped
75 * with type.
76 */
77static bool _e820__mapped_any(struct e820_table *table,
78 u64 start, u64 end, enum e820_type type)
79{
80 int i;
81
82 for (i = 0; i < table->nr_entries; i++) {
83 struct e820_entry *entry = &table->entries[i];
84
85 if (type && entry->type != type)
86 continue;
87 if (entry->addr >= end || entry->addr + entry->size <= start)
88 continue;
89 return true;
90 }
91 return false;
92}
93
94bool e820__mapped_raw_any(u64 start, u64 end, enum e820_type type)
95{
96 return _e820__mapped_any(e820_table_firmware, start, end, type);
97}
98EXPORT_SYMBOL_GPL(e820__mapped_raw_any);
99
100bool e820__mapped_any(u64 start, u64 end, enum e820_type type)
101{
102 return _e820__mapped_any(e820_table, start, end, type);
103}
104EXPORT_SYMBOL_GPL(e820__mapped_any);
105
106/*
107 * This function checks if the entire <start,end> range is mapped with 'type'.
108 *
109 * Note: this function only works correctly once the E820 table is sorted and
110 * not-overlapping (at least for the range specified), which is the case normally.
111 */
112static struct e820_entry *__e820__mapped_all(u64 start, u64 end,
113 enum e820_type type)
114{
115 int i;
116
117 for (i = 0; i < e820_table->nr_entries; i++) {
118 struct e820_entry *entry = &e820_table->entries[i];
119
120 if (type && entry->type != type)
121 continue;
122
123 /* Is the region (part) in overlap with the current region? */
124 if (entry->addr >= end || entry->addr + entry->size <= start)
125 continue;
126
127 /*
128 * If the region is at the beginning of <start,end> we move
129 * 'start' to the end of the region since it's ok until there
130 */
131 if (entry->addr <= start)
132 start = entry->addr + entry->size;
133
134 /*
135 * If 'start' is now at or beyond 'end', we're done, full
136 * coverage of the desired range exists:
137 */
138 if (start >= end)
139 return entry;
140 }
141
142 return NULL;
143}
144
145/*
146 * This function checks if the entire range <start,end> is mapped with type.
147 */
148bool __init e820__mapped_all(u64 start, u64 end, enum e820_type type)
149{
150 return __e820__mapped_all(start, end, type);
151}
152
153/*
154 * This function returns the type associated with the range <start,end>.
155 */
156int e820__get_entry_type(u64 start, u64 end)
157{
158 struct e820_entry *entry = __e820__mapped_all(start, end, 0);
159
160 return entry ? entry->type : -EINVAL;
161}
162
163/*
164 * Add a memory region to the kernel E820 map.
165 */
166static void __init __e820__range_add(struct e820_table *table, u64 start, u64 size, enum e820_type type)
167{
168 int x = table->nr_entries;
169
170 if (x >= ARRAY_SIZE(table->entries)) {
171 pr_err("too many entries; ignoring [mem %#010llx-%#010llx]\n",
172 start, start + size - 1);
173 return;
174 }
175
176 table->entries[x].addr = start;
177 table->entries[x].size = size;
178 table->entries[x].type = type;
179 table->nr_entries++;
180}
181
182void __init e820__range_add(u64 start, u64 size, enum e820_type type)
183{
184 __e820__range_add(e820_table, start, size, type);
185}
186
187static void __init e820_print_type(enum e820_type type)
188{
189 switch (type) {
190 case E820_TYPE_RAM: /* Fall through: */
191 case E820_TYPE_RESERVED_KERN: pr_cont("usable"); break;
192 case E820_TYPE_RESERVED: pr_cont("reserved"); break;
193 case E820_TYPE_SOFT_RESERVED: pr_cont("soft reserved"); break;
194 case E820_TYPE_ACPI: pr_cont("ACPI data"); break;
195 case E820_TYPE_NVS: pr_cont("ACPI NVS"); break;
196 case E820_TYPE_UNUSABLE: pr_cont("unusable"); break;
197 case E820_TYPE_PMEM: /* Fall through: */
198 case E820_TYPE_PRAM: pr_cont("persistent (type %u)", type); break;
199 default: pr_cont("type %u", type); break;
200 }
201}
202
203void __init e820__print_table(char *who)
204{
205 int i;
206
207 for (i = 0; i < e820_table->nr_entries; i++) {
208 pr_info("%s: [mem %#018Lx-%#018Lx] ",
209 who,
210 e820_table->entries[i].addr,
211 e820_table->entries[i].addr + e820_table->entries[i].size - 1);
212
213 e820_print_type(e820_table->entries[i].type);
214 pr_cont("\n");
215 }
216}
217
218/*
219 * Sanitize an E820 map.
220 *
221 * Some E820 layouts include overlapping entries. The following
222 * replaces the original E820 map with a new one, removing overlaps,
223 * and resolving conflicting memory types in favor of highest
224 * numbered type.
225 *
226 * The input parameter 'entries' points to an array of 'struct
227 * e820_entry' which on entry has elements in the range [0, *nr_entries)
228 * valid, and which has space for up to max_nr_entries entries.
229 * On return, the resulting sanitized E820 map entries will be in
230 * overwritten in the same location, starting at 'entries'.
231 *
232 * The integer pointed to by nr_entries must be valid on entry (the
233 * current number of valid entries located at 'entries'). If the
234 * sanitizing succeeds the *nr_entries will be updated with the new
235 * number of valid entries (something no more than max_nr_entries).
236 *
237 * The return value from e820__update_table() is zero if it
238 * successfully 'sanitized' the map entries passed in, and is -1
239 * if it did nothing, which can happen if either of (1) it was
240 * only passed one map entry, or (2) any of the input map entries
241 * were invalid (start + size < start, meaning that the size was
242 * so big the described memory range wrapped around through zero.)
243 *
244 * Visually we're performing the following
245 * (1,2,3,4 = memory types)...
246 *
247 * Sample memory map (w/overlaps):
248 * ____22__________________
249 * ______________________4_
250 * ____1111________________
251 * _44_____________________
252 * 11111111________________
253 * ____________________33__
254 * ___________44___________
255 * __________33333_________
256 * ______________22________
257 * ___________________2222_
258 * _________111111111______
259 * _____________________11_
260 * _________________4______
261 *
262 * Sanitized equivalent (no overlap):
263 * 1_______________________
264 * _44_____________________
265 * ___1____________________
266 * ____22__________________
267 * ______11________________
268 * _________1______________
269 * __________3_____________
270 * ___________44___________
271 * _____________33_________
272 * _______________2________
273 * ________________1_______
274 * _________________4______
275 * ___________________2____
276 * ____________________33__
277 * ______________________4_
278 */
279struct change_member {
280 /* Pointer to the original entry: */
281 struct e820_entry *entry;
282 /* Address for this change point: */
283 unsigned long long addr;
284};
285
286static struct change_member change_point_list[2*E820_MAX_ENTRIES] __initdata;
287static struct change_member *change_point[2*E820_MAX_ENTRIES] __initdata;
288static struct e820_entry *overlap_list[E820_MAX_ENTRIES] __initdata;
289static struct e820_entry new_entries[E820_MAX_ENTRIES] __initdata;
290
291static int __init cpcompare(const void *a, const void *b)
292{
293 struct change_member * const *app = a, * const *bpp = b;
294 const struct change_member *ap = *app, *bp = *bpp;
295
296 /*
297 * Inputs are pointers to two elements of change_point[]. If their
298 * addresses are not equal, their difference dominates. If the addresses
299 * are equal, then consider one that represents the end of its region
300 * to be greater than one that does not.
301 */
302 if (ap->addr != bp->addr)
303 return ap->addr > bp->addr ? 1 : -1;
304
305 return (ap->addr != ap->entry->addr) - (bp->addr != bp->entry->addr);
306}
307
308static bool e820_nomerge(enum e820_type type)
309{
310 /*
311 * These types may indicate distinct platform ranges aligned to
312 * numa node, protection domain, performance domain, or other
313 * boundaries. Do not merge them.
314 */
315 if (type == E820_TYPE_PRAM)
316 return true;
317 if (type == E820_TYPE_SOFT_RESERVED)
318 return true;
319 return false;
320}
321
322int __init e820__update_table(struct e820_table *table)
323{
324 struct e820_entry *entries = table->entries;
325 u32 max_nr_entries = ARRAY_SIZE(table->entries);
326 enum e820_type current_type, last_type;
327 unsigned long long last_addr;
328 u32 new_nr_entries, overlap_entries;
329 u32 i, chg_idx, chg_nr;
330
331 /* If there's only one memory region, don't bother: */
332 if (table->nr_entries < 2)
333 return -1;
334
335 BUG_ON(table->nr_entries > max_nr_entries);
336
337 /* Bail out if we find any unreasonable addresses in the map: */
338 for (i = 0; i < table->nr_entries; i++) {
339 if (entries[i].addr + entries[i].size < entries[i].addr)
340 return -1;
341 }
342
343 /* Create pointers for initial change-point information (for sorting): */
344 for (i = 0; i < 2 * table->nr_entries; i++)
345 change_point[i] = &change_point_list[i];
346
347 /*
348 * Record all known change-points (starting and ending addresses),
349 * omitting empty memory regions:
350 */
351 chg_idx = 0;
352 for (i = 0; i < table->nr_entries; i++) {
353 if (entries[i].size != 0) {
354 change_point[chg_idx]->addr = entries[i].addr;
355 change_point[chg_idx++]->entry = &entries[i];
356 change_point[chg_idx]->addr = entries[i].addr + entries[i].size;
357 change_point[chg_idx++]->entry = &entries[i];
358 }
359 }
360 chg_nr = chg_idx;
361
362 /* Sort change-point list by memory addresses (low -> high): */
363 sort(change_point, chg_nr, sizeof(*change_point), cpcompare, NULL);
364
365 /* Create a new memory map, removing overlaps: */
366 overlap_entries = 0; /* Number of entries in the overlap table */
367 new_nr_entries = 0; /* Index for creating new map entries */
368 last_type = 0; /* Start with undefined memory type */
369 last_addr = 0; /* Start with 0 as last starting address */
370
371 /* Loop through change-points, determining effect on the new map: */
372 for (chg_idx = 0; chg_idx < chg_nr; chg_idx++) {
373 /* Keep track of all overlapping entries */
374 if (change_point[chg_idx]->addr == change_point[chg_idx]->entry->addr) {
375 /* Add map entry to overlap list (> 1 entry implies an overlap) */
376 overlap_list[overlap_entries++] = change_point[chg_idx]->entry;
377 } else {
378 /* Remove entry from list (order independent, so swap with last): */
379 for (i = 0; i < overlap_entries; i++) {
380 if (overlap_list[i] == change_point[chg_idx]->entry)
381 overlap_list[i] = overlap_list[overlap_entries-1];
382 }
383 overlap_entries--;
384 }
385 /*
386 * If there are overlapping entries, decide which
387 * "type" to use (larger value takes precedence --
388 * 1=usable, 2,3,4,4+=unusable)
389 */
390 current_type = 0;
391 for (i = 0; i < overlap_entries; i++) {
392 if (overlap_list[i]->type > current_type)
393 current_type = overlap_list[i]->type;
394 }
395
396 /* Continue building up new map based on this information: */
397 if (current_type != last_type || e820_nomerge(current_type)) {
398 if (last_type) {
399 new_entries[new_nr_entries].size = change_point[chg_idx]->addr - last_addr;
400 /* Move forward only if the new size was non-zero: */
401 if (new_entries[new_nr_entries].size != 0)
402 /* No more space left for new entries? */
403 if (++new_nr_entries >= max_nr_entries)
404 break;
405 }
406 if (current_type) {
407 new_entries[new_nr_entries].addr = change_point[chg_idx]->addr;
408 new_entries[new_nr_entries].type = current_type;
409 last_addr = change_point[chg_idx]->addr;
410 }
411 last_type = current_type;
412 }
413 }
414
415 /* Copy the new entries into the original location: */
416 memcpy(entries, new_entries, new_nr_entries*sizeof(*entries));
417 table->nr_entries = new_nr_entries;
418
419 return 0;
420}
421
422static int __init __append_e820_table(struct boot_e820_entry *entries, u32 nr_entries)
423{
424 struct boot_e820_entry *entry = entries;
425
426 while (nr_entries) {
427 u64 start = entry->addr;
428 u64 size = entry->size;
429 u64 end = start + size - 1;
430 u32 type = entry->type;
431
432 /* Ignore the entry on 64-bit overflow: */
433 if (start > end && likely(size))
434 return -1;
435
436 e820__range_add(start, size, type);
437
438 entry++;
439 nr_entries--;
440 }
441 return 0;
442}
443
444/*
445 * Copy the BIOS E820 map into a safe place.
446 *
447 * Sanity-check it while we're at it..
448 *
449 * If we're lucky and live on a modern system, the setup code
450 * will have given us a memory map that we can use to properly
451 * set up memory. If we aren't, we'll fake a memory map.
452 */
453static int __init append_e820_table(struct boot_e820_entry *entries, u32 nr_entries)
454{
455 /* Only one memory region (or negative)? Ignore it */
456 if (nr_entries < 2)
457 return -1;
458
459 return __append_e820_table(entries, nr_entries);
460}
461
462static u64 __init
463__e820__range_update(struct e820_table *table, u64 start, u64 size, enum e820_type old_type, enum e820_type new_type)
464{
465 u64 end;
466 unsigned int i;
467 u64 real_updated_size = 0;
468
469 BUG_ON(old_type == new_type);
470
471 if (size > (ULLONG_MAX - start))
472 size = ULLONG_MAX - start;
473
474 end = start + size;
475 printk(KERN_DEBUG "e820: update [mem %#010Lx-%#010Lx] ", start, end - 1);
476 e820_print_type(old_type);
477 pr_cont(" ==> ");
478 e820_print_type(new_type);
479 pr_cont("\n");
480
481 for (i = 0; i < table->nr_entries; i++) {
482 struct e820_entry *entry = &table->entries[i];
483 u64 final_start, final_end;
484 u64 entry_end;
485
486 if (entry->type != old_type)
487 continue;
488
489 entry_end = entry->addr + entry->size;
490
491 /* Completely covered by new range? */
492 if (entry->addr >= start && entry_end <= end) {
493 entry->type = new_type;
494 real_updated_size += entry->size;
495 continue;
496 }
497
498 /* New range is completely covered? */
499 if (entry->addr < start && entry_end > end) {
500 __e820__range_add(table, start, size, new_type);
501 __e820__range_add(table, end, entry_end - end, entry->type);
502 entry->size = start - entry->addr;
503 real_updated_size += size;
504 continue;
505 }
506
507 /* Partially covered: */
508 final_start = max(start, entry->addr);
509 final_end = min(end, entry_end);
510 if (final_start >= final_end)
511 continue;
512
513 __e820__range_add(table, final_start, final_end - final_start, new_type);
514
515 real_updated_size += final_end - final_start;
516
517 /*
518 * Left range could be head or tail, so need to update
519 * its size first:
520 */
521 entry->size -= final_end - final_start;
522 if (entry->addr < final_start)
523 continue;
524
525 entry->addr = final_end;
526 }
527 return real_updated_size;
528}
529
530u64 __init e820__range_update(u64 start, u64 size, enum e820_type old_type, enum e820_type new_type)
531{
532 return __e820__range_update(e820_table, start, size, old_type, new_type);
533}
534
535u64 __init e820__range_update_table(struct e820_table *t, u64 start, u64 size,
536 enum e820_type old_type, enum e820_type new_type)
537{
538 return __e820__range_update(t, start, size, old_type, new_type);
539}
540
541/* Remove a range of memory from the E820 table: */
542u64 __init e820__range_remove(u64 start, u64 size, enum e820_type old_type, bool check_type)
543{
544 int i;
545 u64 end;
546 u64 real_removed_size = 0;
547
548 if (size > (ULLONG_MAX - start))
549 size = ULLONG_MAX - start;
550
551 end = start + size;
552 printk(KERN_DEBUG "e820: remove [mem %#010Lx-%#010Lx] ", start, end - 1);
553 if (check_type)
554 e820_print_type(old_type);
555 pr_cont("\n");
556
557 for (i = 0; i < e820_table->nr_entries; i++) {
558 struct e820_entry *entry = &e820_table->entries[i];
559 u64 final_start, final_end;
560 u64 entry_end;
561
562 if (check_type && entry->type != old_type)
563 continue;
564
565 entry_end = entry->addr + entry->size;
566
567 /* Completely covered? */
568 if (entry->addr >= start && entry_end <= end) {
569 real_removed_size += entry->size;
570 memset(entry, 0, sizeof(*entry));
571 continue;
572 }
573
574 /* Is the new range completely covered? */
575 if (entry->addr < start && entry_end > end) {
576 e820__range_add(end, entry_end - end, entry->type);
577 entry->size = start - entry->addr;
578 real_removed_size += size;
579 continue;
580 }
581
582 /* Partially covered: */
583 final_start = max(start, entry->addr);
584 final_end = min(end, entry_end);
585 if (final_start >= final_end)
586 continue;
587
588 real_removed_size += final_end - final_start;
589
590 /*
591 * Left range could be head or tail, so need to update
592 * the size first:
593 */
594 entry->size -= final_end - final_start;
595 if (entry->addr < final_start)
596 continue;
597
598 entry->addr = final_end;
599 }
600 return real_removed_size;
601}
602
603void __init e820__update_table_print(void)
604{
605 if (e820__update_table(e820_table))
606 return;
607
608 pr_info("modified physical RAM map:\n");
609 e820__print_table("modified");
610}
611
612static void __init e820__update_table_kexec(void)
613{
614 e820__update_table(e820_table_kexec);
615}
616
617#define MAX_GAP_END 0x100000000ull
618
619/*
620 * Search for a gap in the E820 memory space from 0 to MAX_GAP_END (4GB).
621 */
622static int __init e820_search_gap(unsigned long *gapstart, unsigned long *gapsize)
623{
624 unsigned long long last = MAX_GAP_END;
625 int i = e820_table->nr_entries;
626 int found = 0;
627
628 while (--i >= 0) {
629 unsigned long long start = e820_table->entries[i].addr;
630 unsigned long long end = start + e820_table->entries[i].size;
631
632 /*
633 * Since "last" is at most 4GB, we know we'll
634 * fit in 32 bits if this condition is true:
635 */
636 if (last > end) {
637 unsigned long gap = last - end;
638
639 if (gap >= *gapsize) {
640 *gapsize = gap;
641 *gapstart = end;
642 found = 1;
643 }
644 }
645 if (start < last)
646 last = start;
647 }
648 return found;
649}
650
651/*
652 * Search for the biggest gap in the low 32 bits of the E820
653 * memory space. We pass this space to the PCI subsystem, so
654 * that it can assign MMIO resources for hotplug or
655 * unconfigured devices in.
656 *
657 * Hopefully the BIOS let enough space left.
658 */
659__init void e820__setup_pci_gap(void)
660{
661 unsigned long gapstart, gapsize;
662 int found;
663
664 gapsize = 0x400000;
665 found = e820_search_gap(&gapstart, &gapsize);
666
667 if (!found) {
668#ifdef CONFIG_X86_64
669 gapstart = (max_pfn << PAGE_SHIFT) + 1024*1024;
670 pr_err("Cannot find an available gap in the 32-bit address range\n");
671 pr_err("PCI devices with unassigned 32-bit BARs may not work!\n");
672#else
673 gapstart = 0x10000000;
674#endif
675 }
676
677 /*
678 * e820__reserve_resources_late() protects stolen RAM already:
679 */
680 pci_mem_start = gapstart;
681
682 pr_info("[mem %#010lx-%#010lx] available for PCI devices\n",
683 gapstart, gapstart + gapsize - 1);
684}
685
686/*
687 * Called late during init, in free_initmem().
688 *
689 * Initial e820_table and e820_table_kexec are largish __initdata arrays.
690 *
691 * Copy them to a (usually much smaller) dynamically allocated area that is
692 * sized precisely after the number of e820 entries.
693 *
694 * This is done after we've performed all the fixes and tweaks to the tables.
695 * All functions which modify them are __init functions, which won't exist
696 * after free_initmem().
697 */
698__init void e820__reallocate_tables(void)
699{
700 struct e820_table *n;
701 int size;
702
703 size = offsetof(struct e820_table, entries) + sizeof(struct e820_entry)*e820_table->nr_entries;
704 n = kmemdup(e820_table, size, GFP_KERNEL);
705 BUG_ON(!n);
706 e820_table = n;
707
708 size = offsetof(struct e820_table, entries) + sizeof(struct e820_entry)*e820_table_kexec->nr_entries;
709 n = kmemdup(e820_table_kexec, size, GFP_KERNEL);
710 BUG_ON(!n);
711 e820_table_kexec = n;
712
713 size = offsetof(struct e820_table, entries) + sizeof(struct e820_entry)*e820_table_firmware->nr_entries;
714 n = kmemdup(e820_table_firmware, size, GFP_KERNEL);
715 BUG_ON(!n);
716 e820_table_firmware = n;
717}
718
719/*
720 * Because of the small fixed size of struct boot_params, only the first
721 * 128 E820 memory entries are passed to the kernel via boot_params.e820_table,
722 * the remaining (if any) entries are passed via the SETUP_E820_EXT node of
723 * struct setup_data, which is parsed here.
724 */
725void __init e820__memory_setup_extended(u64 phys_addr, u32 data_len)
726{
727 int entries;
728 struct boot_e820_entry *extmap;
729 struct setup_data *sdata;
730
731 sdata = early_memremap(phys_addr, data_len);
732 entries = sdata->len / sizeof(*extmap);
733 extmap = (struct boot_e820_entry *)(sdata->data);
734
735 __append_e820_table(extmap, entries);
736 e820__update_table(e820_table);
737
738 memcpy(e820_table_kexec, e820_table, sizeof(*e820_table_kexec));
739 memcpy(e820_table_firmware, e820_table, sizeof(*e820_table_firmware));
740
741 early_memunmap(sdata, data_len);
742 pr_info("extended physical RAM map:\n");
743 e820__print_table("extended");
744}
745
746/*
747 * Find the ranges of physical addresses that do not correspond to
748 * E820 RAM areas and register the corresponding pages as 'nosave' for
749 * hibernation (32-bit) or software suspend and suspend to RAM (64-bit).
750 *
751 * This function requires the E820 map to be sorted and without any
752 * overlapping entries.
753 */
754void __init e820__register_nosave_regions(unsigned long limit_pfn)
755{
756 int i;
757 unsigned long pfn = 0;
758
759 for (i = 0; i < e820_table->nr_entries; i++) {
760 struct e820_entry *entry = &e820_table->entries[i];
761
762 if (pfn < PFN_UP(entry->addr))
763 register_nosave_region(pfn, PFN_UP(entry->addr));
764
765 pfn = PFN_DOWN(entry->addr + entry->size);
766
767 if (entry->type != E820_TYPE_RAM && entry->type != E820_TYPE_RESERVED_KERN)
768 register_nosave_region(PFN_UP(entry->addr), pfn);
769
770 if (pfn >= limit_pfn)
771 break;
772 }
773}
774
775#ifdef CONFIG_ACPI
776/*
777 * Register ACPI NVS memory regions, so that we can save/restore them during
778 * hibernation and the subsequent resume:
779 */
780static int __init e820__register_nvs_regions(void)
781{
782 int i;
783
784 for (i = 0; i < e820_table->nr_entries; i++) {
785 struct e820_entry *entry = &e820_table->entries[i];
786
787 if (entry->type == E820_TYPE_NVS)
788 acpi_nvs_register(entry->addr, entry->size);
789 }
790
791 return 0;
792}
793core_initcall(e820__register_nvs_regions);
794#endif
795
796/*
797 * Allocate the requested number of bytes with the requested alignment
798 * and return (the physical address) to the caller. Also register this
799 * range in the 'kexec' E820 table as a reserved range.
800 *
801 * This allows kexec to fake a new mptable, as if it came from the real
802 * system.
803 */
804u64 __init e820__memblock_alloc_reserved(u64 size, u64 align)
805{
806 u64 addr;
807
808 addr = memblock_phys_alloc(size, align);
809 if (addr) {
810 e820__range_update_table(e820_table_kexec, addr, size, E820_TYPE_RAM, E820_TYPE_RESERVED);
811 pr_info("update e820_table_kexec for e820__memblock_alloc_reserved()\n");
812 e820__update_table_kexec();
813 }
814
815 return addr;
816}
817
818#ifdef CONFIG_X86_32
819# ifdef CONFIG_X86_PAE
820# define MAX_ARCH_PFN (1ULL<<(36-PAGE_SHIFT))
821# else
822# define MAX_ARCH_PFN (1ULL<<(32-PAGE_SHIFT))
823# endif
824#else /* CONFIG_X86_32 */
825# define MAX_ARCH_PFN MAXMEM>>PAGE_SHIFT
826#endif
827
828/*
829 * Find the highest page frame number we have available
830 */
831static unsigned long __init e820__end_ram_pfn(unsigned long limit_pfn)
832{
833 int i;
834 unsigned long last_pfn = 0;
835 unsigned long max_arch_pfn = MAX_ARCH_PFN;
836
837 for (i = 0; i < e820_table->nr_entries; i++) {
838 struct e820_entry *entry = &e820_table->entries[i];
839 unsigned long start_pfn;
840 unsigned long end_pfn;
841
842 if (entry->type != E820_TYPE_RAM &&
843 entry->type != E820_TYPE_ACPI)
844 continue;
845
846 start_pfn = entry->addr >> PAGE_SHIFT;
847 end_pfn = (entry->addr + entry->size) >> PAGE_SHIFT;
848
849 if (start_pfn >= limit_pfn)
850 continue;
851 if (end_pfn > limit_pfn) {
852 last_pfn = limit_pfn;
853 break;
854 }
855 if (end_pfn > last_pfn)
856 last_pfn = end_pfn;
857 }
858
859 if (last_pfn > max_arch_pfn)
860 last_pfn = max_arch_pfn;
861
862 pr_info("last_pfn = %#lx max_arch_pfn = %#lx\n",
863 last_pfn, max_arch_pfn);
864 return last_pfn;
865}
866
867unsigned long __init e820__end_of_ram_pfn(void)
868{
869 return e820__end_ram_pfn(MAX_ARCH_PFN);
870}
871
872unsigned long __init e820__end_of_low_ram_pfn(void)
873{
874 return e820__end_ram_pfn(1UL << (32 - PAGE_SHIFT));
875}
876
877static void __init early_panic(char *msg)
878{
879 early_printk(msg);
880 panic(msg);
881}
882
883static int userdef __initdata;
884
885/* The "mem=nopentium" boot option disables 4MB page tables on 32-bit kernels: */
886static int __init parse_memopt(char *p)
887{
888 u64 mem_size;
889
890 if (!p)
891 return -EINVAL;
892
893 if (!strcmp(p, "nopentium")) {
894#ifdef CONFIG_X86_32
895 setup_clear_cpu_cap(X86_FEATURE_PSE);
896 return 0;
897#else
898 pr_warn("mem=nopentium ignored! (only supported on x86_32)\n");
899 return -EINVAL;
900#endif
901 }
902
903 userdef = 1;
904 mem_size = memparse(p, &p);
905
906 /* Don't remove all memory when getting "mem={invalid}" parameter: */
907 if (mem_size == 0)
908 return -EINVAL;
909
910 e820__range_remove(mem_size, ULLONG_MAX - mem_size, E820_TYPE_RAM, 1);
911
912#ifdef CONFIG_MEMORY_HOTPLUG
913 max_mem_size = mem_size;
914#endif
915
916 return 0;
917}
918early_param("mem", parse_memopt);
919
920static int __init parse_memmap_one(char *p)
921{
922 char *oldp;
923 u64 start_at, mem_size;
924
925 if (!p)
926 return -EINVAL;
927
928 if (!strncmp(p, "exactmap", 8)) {
929 e820_table->nr_entries = 0;
930 userdef = 1;
931 return 0;
932 }
933
934 oldp = p;
935 mem_size = memparse(p, &p);
936 if (p == oldp)
937 return -EINVAL;
938
939 userdef = 1;
940 if (*p == '@') {
941 start_at = memparse(p+1, &p);
942 e820__range_add(start_at, mem_size, E820_TYPE_RAM);
943 } else if (*p == '#') {
944 start_at = memparse(p+1, &p);
945 e820__range_add(start_at, mem_size, E820_TYPE_ACPI);
946 } else if (*p == '$') {
947 start_at = memparse(p+1, &p);
948 e820__range_add(start_at, mem_size, E820_TYPE_RESERVED);
949 } else if (*p == '!') {
950 start_at = memparse(p+1, &p);
951 e820__range_add(start_at, mem_size, E820_TYPE_PRAM);
952 } else if (*p == '%') {
953 enum e820_type from = 0, to = 0;
954
955 start_at = memparse(p + 1, &p);
956 if (*p == '-')
957 from = simple_strtoull(p + 1, &p, 0);
958 if (*p == '+')
959 to = simple_strtoull(p + 1, &p, 0);
960 if (*p != '\0')
961 return -EINVAL;
962 if (from && to)
963 e820__range_update(start_at, mem_size, from, to);
964 else if (to)
965 e820__range_add(start_at, mem_size, to);
966 else if (from)
967 e820__range_remove(start_at, mem_size, from, 1);
968 else
969 e820__range_remove(start_at, mem_size, 0, 0);
970 } else {
971 e820__range_remove(mem_size, ULLONG_MAX - mem_size, E820_TYPE_RAM, 1);
972 }
973
974 return *p == '\0' ? 0 : -EINVAL;
975}
976
977static int __init parse_memmap_opt(char *str)
978{
979 while (str) {
980 char *k = strchr(str, ',');
981
982 if (k)
983 *k++ = 0;
984
985 parse_memmap_one(str);
986 str = k;
987 }
988
989 return 0;
990}
991early_param("memmap", parse_memmap_opt);
992
993/*
994 * Reserve all entries from the bootloader's extensible data nodes list,
995 * because if present we are going to use it later on to fetch e820
996 * entries from it:
997 */
998void __init e820__reserve_setup_data(void)
999{
1000 struct setup_indirect *indirect;
1001 struct setup_data *data;
1002 u64 pa_data, pa_next;
1003 u32 len;
1004
1005 pa_data = boot_params.hdr.setup_data;
1006 if (!pa_data)
1007 return;
1008
1009 while (pa_data) {
1010 data = early_memremap(pa_data, sizeof(*data));
1011 if (!data) {
1012 pr_warn("e820: failed to memremap setup_data entry\n");
1013 return;
1014 }
1015
1016 len = sizeof(*data);
1017 pa_next = data->next;
1018
1019 e820__range_update(pa_data, sizeof(*data)+data->len, E820_TYPE_RAM, E820_TYPE_RESERVED_KERN);
1020
1021 if (data->type == SETUP_INDIRECT) {
1022 len += data->len;
1023 early_memunmap(data, sizeof(*data));
1024 data = early_memremap(pa_data, len);
1025 if (!data) {
1026 pr_warn("e820: failed to memremap indirect setup_data\n");
1027 return;
1028 }
1029
1030 indirect = (struct setup_indirect *)data->data;
1031
1032 if (indirect->type != SETUP_INDIRECT)
1033 e820__range_update(indirect->addr, indirect->len,
1034 E820_TYPE_RAM, E820_TYPE_RESERVED_KERN);
1035 }
1036
1037 pa_data = pa_next;
1038 early_memunmap(data, len);
1039 }
1040
1041 e820__update_table(e820_table);
1042
1043 pr_info("extended physical RAM map:\n");
1044 e820__print_table("reserve setup_data");
1045}
1046
1047/*
1048 * Called after parse_early_param(), after early parameters (such as mem=)
1049 * have been processed, in which case we already have an E820 table filled in
1050 * via the parameter callback function(s), but it's not sorted and printed yet:
1051 */
1052void __init e820__finish_early_params(void)
1053{
1054 if (userdef) {
1055 if (e820__update_table(e820_table) < 0)
1056 early_panic("Invalid user supplied memory map");
1057
1058 pr_info("user-defined physical RAM map:\n");
1059 e820__print_table("user");
1060 }
1061}
1062
1063static const char *__init e820_type_to_string(struct e820_entry *entry)
1064{
1065 switch (entry->type) {
1066 case E820_TYPE_RESERVED_KERN: /* Fall-through: */
1067 case E820_TYPE_RAM: return "System RAM";
1068 case E820_TYPE_ACPI: return "ACPI Tables";
1069 case E820_TYPE_NVS: return "ACPI Non-volatile Storage";
1070 case E820_TYPE_UNUSABLE: return "Unusable memory";
1071 case E820_TYPE_PRAM: return "Persistent Memory (legacy)";
1072 case E820_TYPE_PMEM: return "Persistent Memory";
1073 case E820_TYPE_RESERVED: return "Reserved";
1074 case E820_TYPE_SOFT_RESERVED: return "Soft Reserved";
1075 default: return "Unknown E820 type";
1076 }
1077}
1078
1079static unsigned long __init e820_type_to_iomem_type(struct e820_entry *entry)
1080{
1081 switch (entry->type) {
1082 case E820_TYPE_RESERVED_KERN: /* Fall-through: */
1083 case E820_TYPE_RAM: return IORESOURCE_SYSTEM_RAM;
1084 case E820_TYPE_ACPI: /* Fall-through: */
1085 case E820_TYPE_NVS: /* Fall-through: */
1086 case E820_TYPE_UNUSABLE: /* Fall-through: */
1087 case E820_TYPE_PRAM: /* Fall-through: */
1088 case E820_TYPE_PMEM: /* Fall-through: */
1089 case E820_TYPE_RESERVED: /* Fall-through: */
1090 case E820_TYPE_SOFT_RESERVED: /* Fall-through: */
1091 default: return IORESOURCE_MEM;
1092 }
1093}
1094
1095static unsigned long __init e820_type_to_iores_desc(struct e820_entry *entry)
1096{
1097 switch (entry->type) {
1098 case E820_TYPE_ACPI: return IORES_DESC_ACPI_TABLES;
1099 case E820_TYPE_NVS: return IORES_DESC_ACPI_NV_STORAGE;
1100 case E820_TYPE_PMEM: return IORES_DESC_PERSISTENT_MEMORY;
1101 case E820_TYPE_PRAM: return IORES_DESC_PERSISTENT_MEMORY_LEGACY;
1102 case E820_TYPE_RESERVED: return IORES_DESC_RESERVED;
1103 case E820_TYPE_SOFT_RESERVED: return IORES_DESC_SOFT_RESERVED;
1104 case E820_TYPE_RESERVED_KERN: /* Fall-through: */
1105 case E820_TYPE_RAM: /* Fall-through: */
1106 case E820_TYPE_UNUSABLE: /* Fall-through: */
1107 default: return IORES_DESC_NONE;
1108 }
1109}
1110
1111static bool __init do_mark_busy(enum e820_type type, struct resource *res)
1112{
1113 /* this is the legacy bios/dos rom-shadow + mmio region */
1114 if (res->start < (1ULL<<20))
1115 return true;
1116
1117 /*
1118 * Treat persistent memory and other special memory ranges like
1119 * device memory, i.e. reserve it for exclusive use of a driver
1120 */
1121 switch (type) {
1122 case E820_TYPE_RESERVED:
1123 case E820_TYPE_SOFT_RESERVED:
1124 case E820_TYPE_PRAM:
1125 case E820_TYPE_PMEM:
1126 return false;
1127 case E820_TYPE_RESERVED_KERN:
1128 case E820_TYPE_RAM:
1129 case E820_TYPE_ACPI:
1130 case E820_TYPE_NVS:
1131 case E820_TYPE_UNUSABLE:
1132 default:
1133 return true;
1134 }
1135}
1136
1137/*
1138 * Mark E820 reserved areas as busy for the resource manager:
1139 */
1140
1141static struct resource __initdata *e820_res;
1142
1143void __init e820__reserve_resources(void)
1144{
1145 int i;
1146 struct resource *res;
1147 u64 end;
1148
1149 res = memblock_alloc(sizeof(*res) * e820_table->nr_entries,
1150 SMP_CACHE_BYTES);
1151 if (!res)
1152 panic("%s: Failed to allocate %zu bytes\n", __func__,
1153 sizeof(*res) * e820_table->nr_entries);
1154 e820_res = res;
1155
1156 for (i = 0; i < e820_table->nr_entries; i++) {
1157 struct e820_entry *entry = e820_table->entries + i;
1158
1159 end = entry->addr + entry->size - 1;
1160 if (end != (resource_size_t)end) {
1161 res++;
1162 continue;
1163 }
1164 res->start = entry->addr;
1165 res->end = end;
1166 res->name = e820_type_to_string(entry);
1167 res->flags = e820_type_to_iomem_type(entry);
1168 res->desc = e820_type_to_iores_desc(entry);
1169
1170 /*
1171 * Don't register the region that could be conflicted with
1172 * PCI device BAR resources and insert them later in
1173 * pcibios_resource_survey():
1174 */
1175 if (do_mark_busy(entry->type, res)) {
1176 res->flags |= IORESOURCE_BUSY;
1177 insert_resource(&iomem_resource, res);
1178 }
1179 res++;
1180 }
1181
1182 /* Expose the bootloader-provided memory layout to the sysfs. */
1183 for (i = 0; i < e820_table_firmware->nr_entries; i++) {
1184 struct e820_entry *entry = e820_table_firmware->entries + i;
1185
1186 firmware_map_add_early(entry->addr, entry->addr + entry->size, e820_type_to_string(entry));
1187 }
1188}
1189
1190/*
1191 * How much should we pad the end of RAM, depending on where it is?
1192 */
1193static unsigned long __init ram_alignment(resource_size_t pos)
1194{
1195 unsigned long mb = pos >> 20;
1196
1197 /* To 64kB in the first megabyte */
1198 if (!mb)
1199 return 64*1024;
1200
1201 /* To 1MB in the first 16MB */
1202 if (mb < 16)
1203 return 1024*1024;
1204
1205 /* To 64MB for anything above that */
1206 return 64*1024*1024;
1207}
1208
1209#define MAX_RESOURCE_SIZE ((resource_size_t)-1)
1210
1211void __init e820__reserve_resources_late(void)
1212{
1213 int i;
1214 struct resource *res;
1215
1216 res = e820_res;
1217 for (i = 0; i < e820_table->nr_entries; i++) {
1218 if (!res->parent && res->end)
1219 insert_resource_expand_to_fit(&iomem_resource, res);
1220 res++;
1221 }
1222
1223 /*
1224 * Try to bump up RAM regions to reasonable boundaries, to
1225 * avoid stolen RAM:
1226 */
1227 for (i = 0; i < e820_table->nr_entries; i++) {
1228 struct e820_entry *entry = &e820_table->entries[i];
1229 u64 start, end;
1230
1231 if (entry->type != E820_TYPE_RAM)
1232 continue;
1233
1234 start = entry->addr + entry->size;
1235 end = round_up(start, ram_alignment(start)) - 1;
1236 if (end > MAX_RESOURCE_SIZE)
1237 end = MAX_RESOURCE_SIZE;
1238 if (start >= end)
1239 continue;
1240
1241 printk(KERN_DEBUG "e820: reserve RAM buffer [mem %#010llx-%#010llx]\n", start, end);
1242 reserve_region_with_split(&iomem_resource, start, end, "RAM buffer");
1243 }
1244}
1245
1246/*
1247 * Pass the firmware (bootloader) E820 map to the kernel and process it:
1248 */
1249char *__init e820__memory_setup_default(void)
1250{
1251 char *who = "BIOS-e820";
1252
1253 /*
1254 * Try to copy the BIOS-supplied E820-map.
1255 *
1256 * Otherwise fake a memory map; one section from 0k->640k,
1257 * the next section from 1mb->appropriate_mem_k
1258 */
1259 if (append_e820_table(boot_params.e820_table, boot_params.e820_entries) < 0) {
1260 u64 mem_size;
1261
1262 /* Compare results from other methods and take the one that gives more RAM: */
1263 if (boot_params.alt_mem_k < boot_params.screen_info.ext_mem_k) {
1264 mem_size = boot_params.screen_info.ext_mem_k;
1265 who = "BIOS-88";
1266 } else {
1267 mem_size = boot_params.alt_mem_k;
1268 who = "BIOS-e801";
1269 }
1270
1271 e820_table->nr_entries = 0;
1272 e820__range_add(0, LOWMEMSIZE(), E820_TYPE_RAM);
1273 e820__range_add(HIGH_MEMORY, mem_size << 10, E820_TYPE_RAM);
1274 }
1275
1276 /* We just appended a lot of ranges, sanitize the table: */
1277 e820__update_table(e820_table);
1278
1279 return who;
1280}
1281
1282/*
1283 * Calls e820__memory_setup_default() in essence to pick up the firmware/bootloader
1284 * E820 map - with an optional platform quirk available for virtual platforms
1285 * to override this method of boot environment processing:
1286 */
1287void __init e820__memory_setup(void)
1288{
1289 char *who;
1290
1291 /* This is a firmware interface ABI - make sure we don't break it: */
1292 BUILD_BUG_ON(sizeof(struct boot_e820_entry) != 20);
1293
1294 who = x86_init.resources.memory_setup();
1295
1296 memcpy(e820_table_kexec, e820_table, sizeof(*e820_table_kexec));
1297 memcpy(e820_table_firmware, e820_table, sizeof(*e820_table_firmware));
1298
1299 pr_info("BIOS-provided physical RAM map:\n");
1300 e820__print_table(who);
1301}
1302
1303void __init e820__memblock_setup(void)
1304{
1305 int i;
1306 u64 end;
1307
1308 /*
1309 * The bootstrap memblock region count maximum is 128 entries
1310 * (INIT_MEMBLOCK_REGIONS), but EFI might pass us more E820 entries
1311 * than that - so allow memblock resizing.
1312 *
1313 * This is safe, because this call happens pretty late during x86 setup,
1314 * so we know about reserved memory regions already. (This is important
1315 * so that memblock resizing does no stomp over reserved areas.)
1316 */
1317 memblock_allow_resize();
1318
1319 for (i = 0; i < e820_table->nr_entries; i++) {
1320 struct e820_entry *entry = &e820_table->entries[i];
1321
1322 end = entry->addr + entry->size;
1323 if (end != (resource_size_t)end)
1324 continue;
1325
1326 if (entry->type == E820_TYPE_SOFT_RESERVED)
1327 memblock_reserve(entry->addr, entry->size);
1328
1329 if (entry->type != E820_TYPE_RAM && entry->type != E820_TYPE_RESERVED_KERN)
1330 continue;
1331
1332 memblock_add(entry->addr, entry->size);
1333 }
1334
1335 /* Throw away partial pages: */
1336 memblock_trim_memory(PAGE_SIZE);
1337
1338 memblock_dump_all();
1339}