xref: /openbmc/linux/arch/x86/kernel/e820.c (revision 615c36f5)
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 
23 #include <asm/e820.h>
24 #include <asm/proto.h>
25 #include <asm/setup.h>
26 
27 /*
28  * The e820 map is the map that gets modified e.g. with command line parameters
29  * and that is also registered with modifications in the kernel resource tree
30  * with the iomem_resource as parent.
31  *
32  * The e820_saved is directly saved after the BIOS-provided memory map is
33  * copied. It doesn't get modified afterwards. It's registered for the
34  * /sys/firmware/memmap interface.
35  *
36  * That memory map is not modified and is used as base for kexec. The kexec'd
37  * kernel should get the same memory map as the firmware provides. Then the
38  * user can e.g. boot the original kernel with mem=1G while still booting the
39  * next kernel with full memory.
40  */
41 struct e820map e820;
42 struct e820map e820_saved;
43 
44 /* For PCI or other memory-mapped resources */
45 unsigned long pci_mem_start = 0xaeedbabe;
46 #ifdef CONFIG_PCI
47 EXPORT_SYMBOL(pci_mem_start);
48 #endif
49 
50 /*
51  * This function checks if any part of the range <start,end> is mapped
52  * with type.
53  */
54 int
55 e820_any_mapped(u64 start, u64 end, unsigned type)
56 {
57 	int i;
58 
59 	for (i = 0; i < e820.nr_map; i++) {
60 		struct e820entry *ei = &e820.map[i];
61 
62 		if (type && ei->type != type)
63 			continue;
64 		if (ei->addr >= end || ei->addr + ei->size <= start)
65 			continue;
66 		return 1;
67 	}
68 	return 0;
69 }
70 EXPORT_SYMBOL_GPL(e820_any_mapped);
71 
72 /*
73  * This function checks if the entire range <start,end> is mapped with type.
74  *
75  * Note: this function only works correct if the e820 table is sorted and
76  * not-overlapping, which is the case
77  */
78 int __init e820_all_mapped(u64 start, u64 end, unsigned type)
79 {
80 	int i;
81 
82 	for (i = 0; i < e820.nr_map; i++) {
83 		struct e820entry *ei = &e820.map[i];
84 
85 		if (type && ei->type != type)
86 			continue;
87 		/* is the region (part) in overlap with the current region ?*/
88 		if (ei->addr >= end || ei->addr + ei->size <= start)
89 			continue;
90 
91 		/* if the region is at the beginning of <start,end> we move
92 		 * start to the end of the region since it's ok until there
93 		 */
94 		if (ei->addr <= start)
95 			start = ei->addr + ei->size;
96 		/*
97 		 * if start is now at or beyond end, we're done, full
98 		 * coverage
99 		 */
100 		if (start >= end)
101 			return 1;
102 	}
103 	return 0;
104 }
105 
106 /*
107  * Add a memory region to the kernel e820 map.
108  */
109 static void __init __e820_add_region(struct e820map *e820x, u64 start, u64 size,
110 					 int type)
111 {
112 	int x = e820x->nr_map;
113 
114 	if (x >= ARRAY_SIZE(e820x->map)) {
115 		printk(KERN_ERR "Ooops! Too many entries in the memory map!\n");
116 		return;
117 	}
118 
119 	e820x->map[x].addr = start;
120 	e820x->map[x].size = size;
121 	e820x->map[x].type = type;
122 	e820x->nr_map++;
123 }
124 
125 void __init e820_add_region(u64 start, u64 size, int type)
126 {
127 	__e820_add_region(&e820, start, size, type);
128 }
129 
130 static void __init e820_print_type(u32 type)
131 {
132 	switch (type) {
133 	case E820_RAM:
134 	case E820_RESERVED_KERN:
135 		printk(KERN_CONT "(usable)");
136 		break;
137 	case E820_RESERVED:
138 		printk(KERN_CONT "(reserved)");
139 		break;
140 	case E820_ACPI:
141 		printk(KERN_CONT "(ACPI data)");
142 		break;
143 	case E820_NVS:
144 		printk(KERN_CONT "(ACPI NVS)");
145 		break;
146 	case E820_UNUSABLE:
147 		printk(KERN_CONT "(unusable)");
148 		break;
149 	default:
150 		printk(KERN_CONT "type %u", type);
151 		break;
152 	}
153 }
154 
155 void __init e820_print_map(char *who)
156 {
157 	int i;
158 
159 	for (i = 0; i < e820.nr_map; i++) {
160 		printk(KERN_INFO " %s: %016Lx - %016Lx ", who,
161 		       (unsigned long long) e820.map[i].addr,
162 		       (unsigned long long)
163 		       (e820.map[i].addr + e820.map[i].size));
164 		e820_print_type(e820.map[i].type);
165 		printk(KERN_CONT "\n");
166 	}
167 }
168 
169 /*
170  * Sanitize the BIOS e820 map.
171  *
172  * Some e820 responses include overlapping entries. The following
173  * replaces the original e820 map with a new one, removing overlaps,
174  * and resolving conflicting memory types in favor of highest
175  * numbered type.
176  *
177  * The input parameter biosmap points to an array of 'struct
178  * e820entry' which on entry has elements in the range [0, *pnr_map)
179  * valid, and which has space for up to max_nr_map entries.
180  * On return, the resulting sanitized e820 map entries will be in
181  * overwritten in the same location, starting at biosmap.
182  *
183  * The integer pointed to by pnr_map must be valid on entry (the
184  * current number of valid entries located at biosmap) and will
185  * be updated on return, with the new number of valid entries
186  * (something no more than max_nr_map.)
187  *
188  * The return value from sanitize_e820_map() is zero if it
189  * successfully 'sanitized' the map entries passed in, and is -1
190  * if it did nothing, which can happen if either of (1) it was
191  * only passed one map entry, or (2) any of the input map entries
192  * were invalid (start + size < start, meaning that the size was
193  * so big the described memory range wrapped around through zero.)
194  *
195  *	Visually we're performing the following
196  *	(1,2,3,4 = memory types)...
197  *
198  *	Sample memory map (w/overlaps):
199  *	   ____22__________________
200  *	   ______________________4_
201  *	   ____1111________________
202  *	   _44_____________________
203  *	   11111111________________
204  *	   ____________________33__
205  *	   ___________44___________
206  *	   __________33333_________
207  *	   ______________22________
208  *	   ___________________2222_
209  *	   _________111111111______
210  *	   _____________________11_
211  *	   _________________4______
212  *
213  *	Sanitized equivalent (no overlap):
214  *	   1_______________________
215  *	   _44_____________________
216  *	   ___1____________________
217  *	   ____22__________________
218  *	   ______11________________
219  *	   _________1______________
220  *	   __________3_____________
221  *	   ___________44___________
222  *	   _____________33_________
223  *	   _______________2________
224  *	   ________________1_______
225  *	   _________________4______
226  *	   ___________________2____
227  *	   ____________________33__
228  *	   ______________________4_
229  */
230 
231 int __init sanitize_e820_map(struct e820entry *biosmap, int max_nr_map,
232 			     u32 *pnr_map)
233 {
234 	struct change_member {
235 		struct e820entry *pbios; /* pointer to original bios entry */
236 		unsigned long long addr; /* address for this change point */
237 	};
238 	static struct change_member change_point_list[2*E820_X_MAX] __initdata;
239 	static struct change_member *change_point[2*E820_X_MAX] __initdata;
240 	static struct e820entry *overlap_list[E820_X_MAX] __initdata;
241 	static struct e820entry new_bios[E820_X_MAX] __initdata;
242 	struct change_member *change_tmp;
243 	unsigned long current_type, last_type;
244 	unsigned long long last_addr;
245 	int chgidx, still_changing;
246 	int overlap_entries;
247 	int new_bios_entry;
248 	int old_nr, new_nr, chg_nr;
249 	int i;
250 
251 	/* if there's only one memory region, don't bother */
252 	if (*pnr_map < 2)
253 		return -1;
254 
255 	old_nr = *pnr_map;
256 	BUG_ON(old_nr > max_nr_map);
257 
258 	/* bail out if we find any unreasonable addresses in bios map */
259 	for (i = 0; i < old_nr; i++)
260 		if (biosmap[i].addr + biosmap[i].size < biosmap[i].addr)
261 			return -1;
262 
263 	/* create pointers for initial change-point information (for sorting) */
264 	for (i = 0; i < 2 * old_nr; i++)
265 		change_point[i] = &change_point_list[i];
266 
267 	/* record all known change-points (starting and ending addresses),
268 	   omitting those that are for empty memory regions */
269 	chgidx = 0;
270 	for (i = 0; i < old_nr; i++)	{
271 		if (biosmap[i].size != 0) {
272 			change_point[chgidx]->addr = biosmap[i].addr;
273 			change_point[chgidx++]->pbios = &biosmap[i];
274 			change_point[chgidx]->addr = biosmap[i].addr +
275 				biosmap[i].size;
276 			change_point[chgidx++]->pbios = &biosmap[i];
277 		}
278 	}
279 	chg_nr = chgidx;
280 
281 	/* sort change-point list by memory addresses (low -> high) */
282 	still_changing = 1;
283 	while (still_changing)	{
284 		still_changing = 0;
285 		for (i = 1; i < chg_nr; i++)  {
286 			unsigned long long curaddr, lastaddr;
287 			unsigned long long curpbaddr, lastpbaddr;
288 
289 			curaddr = change_point[i]->addr;
290 			lastaddr = change_point[i - 1]->addr;
291 			curpbaddr = change_point[i]->pbios->addr;
292 			lastpbaddr = change_point[i - 1]->pbios->addr;
293 
294 			/*
295 			 * swap entries, when:
296 			 *
297 			 * curaddr > lastaddr or
298 			 * curaddr == lastaddr and curaddr == curpbaddr and
299 			 * lastaddr != lastpbaddr
300 			 */
301 			if (curaddr < lastaddr ||
302 			    (curaddr == lastaddr && curaddr == curpbaddr &&
303 			     lastaddr != lastpbaddr)) {
304 				change_tmp = change_point[i];
305 				change_point[i] = change_point[i-1];
306 				change_point[i-1] = change_tmp;
307 				still_changing = 1;
308 			}
309 		}
310 	}
311 
312 	/* create a new bios memory map, removing overlaps */
313 	overlap_entries = 0;	 /* number of entries in the overlap table */
314 	new_bios_entry = 0;	 /* index for creating new bios map entries */
315 	last_type = 0;		 /* start with undefined memory type */
316 	last_addr = 0;		 /* start with 0 as last starting address */
317 
318 	/* loop through change-points, determining affect on the new bios map */
319 	for (chgidx = 0; chgidx < chg_nr; chgidx++) {
320 		/* keep track of all overlapping bios entries */
321 		if (change_point[chgidx]->addr ==
322 		    change_point[chgidx]->pbios->addr) {
323 			/*
324 			 * add map entry to overlap list (> 1 entry
325 			 * implies an overlap)
326 			 */
327 			overlap_list[overlap_entries++] =
328 				change_point[chgidx]->pbios;
329 		} else {
330 			/*
331 			 * remove entry from list (order independent,
332 			 * so swap with last)
333 			 */
334 			for (i = 0; i < overlap_entries; i++) {
335 				if (overlap_list[i] ==
336 				    change_point[chgidx]->pbios)
337 					overlap_list[i] =
338 						overlap_list[overlap_entries-1];
339 			}
340 			overlap_entries--;
341 		}
342 		/*
343 		 * if there are overlapping entries, decide which
344 		 * "type" to use (larger value takes precedence --
345 		 * 1=usable, 2,3,4,4+=unusable)
346 		 */
347 		current_type = 0;
348 		for (i = 0; i < overlap_entries; i++)
349 			if (overlap_list[i]->type > current_type)
350 				current_type = overlap_list[i]->type;
351 		/*
352 		 * continue building up new bios map based on this
353 		 * information
354 		 */
355 		if (current_type != last_type)	{
356 			if (last_type != 0)	 {
357 				new_bios[new_bios_entry].size =
358 					change_point[chgidx]->addr - last_addr;
359 				/*
360 				 * move forward only if the new size
361 				 * was non-zero
362 				 */
363 				if (new_bios[new_bios_entry].size != 0)
364 					/*
365 					 * no more space left for new
366 					 * bios entries ?
367 					 */
368 					if (++new_bios_entry >= max_nr_map)
369 						break;
370 			}
371 			if (current_type != 0)	{
372 				new_bios[new_bios_entry].addr =
373 					change_point[chgidx]->addr;
374 				new_bios[new_bios_entry].type = current_type;
375 				last_addr = change_point[chgidx]->addr;
376 			}
377 			last_type = current_type;
378 		}
379 	}
380 	/* retain count for new bios entries */
381 	new_nr = new_bios_entry;
382 
383 	/* copy new bios mapping into original location */
384 	memcpy(biosmap, new_bios, new_nr * sizeof(struct e820entry));
385 	*pnr_map = new_nr;
386 
387 	return 0;
388 }
389 
390 static int __init __append_e820_map(struct e820entry *biosmap, int nr_map)
391 {
392 	while (nr_map) {
393 		u64 start = biosmap->addr;
394 		u64 size = biosmap->size;
395 		u64 end = start + size;
396 		u32 type = biosmap->type;
397 
398 		/* Overflow in 64 bits? Ignore the memory map. */
399 		if (start > end)
400 			return -1;
401 
402 		e820_add_region(start, size, type);
403 
404 		biosmap++;
405 		nr_map--;
406 	}
407 	return 0;
408 }
409 
410 /*
411  * Copy the BIOS e820 map into a safe place.
412  *
413  * Sanity-check it while we're at it..
414  *
415  * If we're lucky and live on a modern system, the setup code
416  * will have given us a memory map that we can use to properly
417  * set up memory.  If we aren't, we'll fake a memory map.
418  */
419 static int __init append_e820_map(struct e820entry *biosmap, int nr_map)
420 {
421 	/* Only one memory region (or negative)? Ignore it */
422 	if (nr_map < 2)
423 		return -1;
424 
425 	return __append_e820_map(biosmap, nr_map);
426 }
427 
428 static u64 __init __e820_update_range(struct e820map *e820x, u64 start,
429 					u64 size, unsigned old_type,
430 					unsigned new_type)
431 {
432 	u64 end;
433 	unsigned int i;
434 	u64 real_updated_size = 0;
435 
436 	BUG_ON(old_type == new_type);
437 
438 	if (size > (ULLONG_MAX - start))
439 		size = ULLONG_MAX - start;
440 
441 	end = start + size;
442 	printk(KERN_DEBUG "e820 update range: %016Lx - %016Lx ",
443 		       (unsigned long long) start,
444 		       (unsigned long long) end);
445 	e820_print_type(old_type);
446 	printk(KERN_CONT " ==> ");
447 	e820_print_type(new_type);
448 	printk(KERN_CONT "\n");
449 
450 	for (i = 0; i < e820x->nr_map; i++) {
451 		struct e820entry *ei = &e820x->map[i];
452 		u64 final_start, final_end;
453 		u64 ei_end;
454 
455 		if (ei->type != old_type)
456 			continue;
457 
458 		ei_end = ei->addr + ei->size;
459 		/* totally covered by new range? */
460 		if (ei->addr >= start && ei_end <= end) {
461 			ei->type = new_type;
462 			real_updated_size += ei->size;
463 			continue;
464 		}
465 
466 		/* new range is totally covered? */
467 		if (ei->addr < start && ei_end > end) {
468 			__e820_add_region(e820x, start, size, new_type);
469 			__e820_add_region(e820x, end, ei_end - end, ei->type);
470 			ei->size = start - ei->addr;
471 			real_updated_size += size;
472 			continue;
473 		}
474 
475 		/* partially covered */
476 		final_start = max(start, ei->addr);
477 		final_end = min(end, ei_end);
478 		if (final_start >= final_end)
479 			continue;
480 
481 		__e820_add_region(e820x, final_start, final_end - final_start,
482 				  new_type);
483 
484 		real_updated_size += final_end - final_start;
485 
486 		/*
487 		 * left range could be head or tail, so need to update
488 		 * size at first.
489 		 */
490 		ei->size -= final_end - final_start;
491 		if (ei->addr < final_start)
492 			continue;
493 		ei->addr = final_end;
494 	}
495 	return real_updated_size;
496 }
497 
498 u64 __init e820_update_range(u64 start, u64 size, unsigned old_type,
499 			     unsigned new_type)
500 {
501 	return __e820_update_range(&e820, start, size, old_type, new_type);
502 }
503 
504 static u64 __init e820_update_range_saved(u64 start, u64 size,
505 					  unsigned old_type, unsigned new_type)
506 {
507 	return __e820_update_range(&e820_saved, start, size, old_type,
508 				     new_type);
509 }
510 
511 /* make e820 not cover the range */
512 u64 __init e820_remove_range(u64 start, u64 size, unsigned old_type,
513 			     int checktype)
514 {
515 	int i;
516 	u64 end;
517 	u64 real_removed_size = 0;
518 
519 	if (size > (ULLONG_MAX - start))
520 		size = ULLONG_MAX - start;
521 
522 	end = start + size;
523 	printk(KERN_DEBUG "e820 remove range: %016Lx - %016Lx ",
524 		       (unsigned long long) start,
525 		       (unsigned long long) end);
526 	if (checktype)
527 		e820_print_type(old_type);
528 	printk(KERN_CONT "\n");
529 
530 	for (i = 0; i < e820.nr_map; i++) {
531 		struct e820entry *ei = &e820.map[i];
532 		u64 final_start, final_end;
533 		u64 ei_end;
534 
535 		if (checktype && ei->type != old_type)
536 			continue;
537 
538 		ei_end = ei->addr + ei->size;
539 		/* totally covered? */
540 		if (ei->addr >= start && ei_end <= end) {
541 			real_removed_size += ei->size;
542 			memset(ei, 0, sizeof(struct e820entry));
543 			continue;
544 		}
545 
546 		/* new range is totally covered? */
547 		if (ei->addr < start && ei_end > end) {
548 			e820_add_region(end, ei_end - end, ei->type);
549 			ei->size = start - ei->addr;
550 			real_removed_size += size;
551 			continue;
552 		}
553 
554 		/* partially covered */
555 		final_start = max(start, ei->addr);
556 		final_end = min(end, ei_end);
557 		if (final_start >= final_end)
558 			continue;
559 		real_removed_size += final_end - final_start;
560 
561 		/*
562 		 * left range could be head or tail, so need to update
563 		 * size at first.
564 		 */
565 		ei->size -= final_end - final_start;
566 		if (ei->addr < final_start)
567 			continue;
568 		ei->addr = final_end;
569 	}
570 	return real_removed_size;
571 }
572 
573 void __init update_e820(void)
574 {
575 	u32 nr_map;
576 
577 	nr_map = e820.nr_map;
578 	if (sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &nr_map))
579 		return;
580 	e820.nr_map = nr_map;
581 	printk(KERN_INFO "modified physical RAM map:\n");
582 	e820_print_map("modified");
583 }
584 static void __init update_e820_saved(void)
585 {
586 	u32 nr_map;
587 
588 	nr_map = e820_saved.nr_map;
589 	if (sanitize_e820_map(e820_saved.map, ARRAY_SIZE(e820_saved.map), &nr_map))
590 		return;
591 	e820_saved.nr_map = nr_map;
592 }
593 #define MAX_GAP_END 0x100000000ull
594 /*
595  * Search for a gap in the e820 memory space from start_addr to end_addr.
596  */
597 __init int e820_search_gap(unsigned long *gapstart, unsigned long *gapsize,
598 		unsigned long start_addr, unsigned long long end_addr)
599 {
600 	unsigned long long last;
601 	int i = e820.nr_map;
602 	int found = 0;
603 
604 	last = (end_addr && end_addr < MAX_GAP_END) ? end_addr : MAX_GAP_END;
605 
606 	while (--i >= 0) {
607 		unsigned long long start = e820.map[i].addr;
608 		unsigned long long end = start + e820.map[i].size;
609 
610 		if (end < start_addr)
611 			continue;
612 
613 		/*
614 		 * Since "last" is at most 4GB, we know we'll
615 		 * fit in 32 bits if this condition is true
616 		 */
617 		if (last > end) {
618 			unsigned long gap = last - end;
619 
620 			if (gap >= *gapsize) {
621 				*gapsize = gap;
622 				*gapstart = end;
623 				found = 1;
624 			}
625 		}
626 		if (start < last)
627 			last = start;
628 	}
629 	return found;
630 }
631 
632 /*
633  * Search for the biggest gap in the low 32 bits of the e820
634  * memory space.  We pass this space to PCI to assign MMIO resources
635  * for hotplug or unconfigured devices in.
636  * Hopefully the BIOS let enough space left.
637  */
638 __init void e820_setup_gap(void)
639 {
640 	unsigned long gapstart, gapsize;
641 	int found;
642 
643 	gapstart = 0x10000000;
644 	gapsize = 0x400000;
645 	found  = e820_search_gap(&gapstart, &gapsize, 0, MAX_GAP_END);
646 
647 #ifdef CONFIG_X86_64
648 	if (!found) {
649 		gapstart = (max_pfn << PAGE_SHIFT) + 1024*1024;
650 		printk(KERN_ERR
651 	"PCI: Warning: Cannot find a gap in the 32bit address range\n"
652 	"PCI: Unassigned devices with 32bit resource registers may break!\n");
653 	}
654 #endif
655 
656 	/*
657 	 * e820_reserve_resources_late protect stolen RAM already
658 	 */
659 	pci_mem_start = gapstart;
660 
661 	printk(KERN_INFO
662 	       "Allocating PCI resources starting at %lx (gap: %lx:%lx)\n",
663 	       pci_mem_start, gapstart, gapsize);
664 }
665 
666 /**
667  * Because of the size limitation of struct boot_params, only first
668  * 128 E820 memory entries are passed to kernel via
669  * boot_params.e820_map, others are passed via SETUP_E820_EXT node of
670  * linked list of struct setup_data, which is parsed here.
671  */
672 void __init parse_e820_ext(struct setup_data *sdata)
673 {
674 	int entries;
675 	struct e820entry *extmap;
676 
677 	entries = sdata->len / sizeof(struct e820entry);
678 	extmap = (struct e820entry *)(sdata->data);
679 	__append_e820_map(extmap, entries);
680 	sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
681 	printk(KERN_INFO "extended physical RAM map:\n");
682 	e820_print_map("extended");
683 }
684 
685 #if defined(CONFIG_X86_64) || \
686 	(defined(CONFIG_X86_32) && defined(CONFIG_HIBERNATION))
687 /**
688  * Find the ranges of physical addresses that do not correspond to
689  * e820 RAM areas and mark the corresponding pages as nosave for
690  * hibernation (32 bit) or software suspend and suspend to RAM (64 bit).
691  *
692  * This function requires the e820 map to be sorted and without any
693  * overlapping entries and assumes the first e820 area to be RAM.
694  */
695 void __init e820_mark_nosave_regions(unsigned long limit_pfn)
696 {
697 	int i;
698 	unsigned long pfn;
699 
700 	pfn = PFN_DOWN(e820.map[0].addr + e820.map[0].size);
701 	for (i = 1; i < e820.nr_map; i++) {
702 		struct e820entry *ei = &e820.map[i];
703 
704 		if (pfn < PFN_UP(ei->addr))
705 			register_nosave_region(pfn, PFN_UP(ei->addr));
706 
707 		pfn = PFN_DOWN(ei->addr + ei->size);
708 		if (ei->type != E820_RAM && ei->type != E820_RESERVED_KERN)
709 			register_nosave_region(PFN_UP(ei->addr), pfn);
710 
711 		if (pfn >= limit_pfn)
712 			break;
713 	}
714 }
715 #endif
716 
717 #ifdef CONFIG_HIBERNATION
718 /**
719  * Mark ACPI NVS memory region, so that we can save/restore it during
720  * hibernation and the subsequent resume.
721  */
722 static int __init e820_mark_nvs_memory(void)
723 {
724 	int i;
725 
726 	for (i = 0; i < e820.nr_map; i++) {
727 		struct e820entry *ei = &e820.map[i];
728 
729 		if (ei->type == E820_NVS)
730 			suspend_nvs_register(ei->addr, ei->size);
731 	}
732 
733 	return 0;
734 }
735 core_initcall(e820_mark_nvs_memory);
736 #endif
737 
738 /*
739  * pre allocated 4k and reserved it in memblock and e820_saved
740  */
741 u64 __init early_reserve_e820(u64 startt, u64 sizet, u64 align)
742 {
743 	u64 size = 0;
744 	u64 addr;
745 	u64 start;
746 
747 	for (start = startt; ; start += size) {
748 		start = memblock_x86_find_in_range_size(start, &size, align);
749 		if (start == MEMBLOCK_ERROR)
750 			return 0;
751 		if (size >= sizet)
752 			break;
753 	}
754 
755 #ifdef CONFIG_X86_32
756 	if (start >= MAXMEM)
757 		return 0;
758 	if (start + size > MAXMEM)
759 		size = MAXMEM - start;
760 #endif
761 
762 	addr = round_down(start + size - sizet, align);
763 	if (addr < start)
764 		return 0;
765 	memblock_x86_reserve_range(addr, addr + sizet, "new next");
766 	e820_update_range_saved(addr, sizet, E820_RAM, E820_RESERVED);
767 	printk(KERN_INFO "update e820_saved for early_reserve_e820\n");
768 	update_e820_saved();
769 
770 	return addr;
771 }
772 
773 #ifdef CONFIG_X86_32
774 # ifdef CONFIG_X86_PAE
775 #  define MAX_ARCH_PFN		(1ULL<<(36-PAGE_SHIFT))
776 # else
777 #  define MAX_ARCH_PFN		(1ULL<<(32-PAGE_SHIFT))
778 # endif
779 #else /* CONFIG_X86_32 */
780 # define MAX_ARCH_PFN MAXMEM>>PAGE_SHIFT
781 #endif
782 
783 /*
784  * Find the highest page frame number we have available
785  */
786 static unsigned long __init e820_end_pfn(unsigned long limit_pfn, unsigned type)
787 {
788 	int i;
789 	unsigned long last_pfn = 0;
790 	unsigned long max_arch_pfn = MAX_ARCH_PFN;
791 
792 	for (i = 0; i < e820.nr_map; i++) {
793 		struct e820entry *ei = &e820.map[i];
794 		unsigned long start_pfn;
795 		unsigned long end_pfn;
796 
797 		if (ei->type != type)
798 			continue;
799 
800 		start_pfn = ei->addr >> PAGE_SHIFT;
801 		end_pfn = (ei->addr + ei->size) >> PAGE_SHIFT;
802 
803 		if (start_pfn >= limit_pfn)
804 			continue;
805 		if (end_pfn > limit_pfn) {
806 			last_pfn = limit_pfn;
807 			break;
808 		}
809 		if (end_pfn > last_pfn)
810 			last_pfn = end_pfn;
811 	}
812 
813 	if (last_pfn > max_arch_pfn)
814 		last_pfn = max_arch_pfn;
815 
816 	printk(KERN_INFO "last_pfn = %#lx max_arch_pfn = %#lx\n",
817 			 last_pfn, max_arch_pfn);
818 	return last_pfn;
819 }
820 unsigned long __init e820_end_of_ram_pfn(void)
821 {
822 	return e820_end_pfn(MAX_ARCH_PFN, E820_RAM);
823 }
824 
825 unsigned long __init e820_end_of_low_ram_pfn(void)
826 {
827 	return e820_end_pfn(1UL<<(32 - PAGE_SHIFT), E820_RAM);
828 }
829 
830 static void early_panic(char *msg)
831 {
832 	early_printk(msg);
833 	panic(msg);
834 }
835 
836 static int userdef __initdata;
837 
838 /* "mem=nopentium" disables the 4MB page tables. */
839 static int __init parse_memopt(char *p)
840 {
841 	u64 mem_size;
842 
843 	if (!p)
844 		return -EINVAL;
845 
846 	if (!strcmp(p, "nopentium")) {
847 #ifdef CONFIG_X86_32
848 		setup_clear_cpu_cap(X86_FEATURE_PSE);
849 		return 0;
850 #else
851 		printk(KERN_WARNING "mem=nopentium ignored! (only supported on x86_32)\n");
852 		return -EINVAL;
853 #endif
854 	}
855 
856 	userdef = 1;
857 	mem_size = memparse(p, &p);
858 	/* don't remove all of memory when handling "mem={invalid}" param */
859 	if (mem_size == 0)
860 		return -EINVAL;
861 	e820_remove_range(mem_size, ULLONG_MAX - mem_size, E820_RAM, 1);
862 
863 	return 0;
864 }
865 early_param("mem", parse_memopt);
866 
867 static int __init parse_memmap_opt(char *p)
868 {
869 	char *oldp;
870 	u64 start_at, mem_size;
871 
872 	if (!p)
873 		return -EINVAL;
874 
875 	if (!strncmp(p, "exactmap", 8)) {
876 #ifdef CONFIG_CRASH_DUMP
877 		/*
878 		 * If we are doing a crash dump, we still need to know
879 		 * the real mem size before original memory map is
880 		 * reset.
881 		 */
882 		saved_max_pfn = e820_end_of_ram_pfn();
883 #endif
884 		e820.nr_map = 0;
885 		userdef = 1;
886 		return 0;
887 	}
888 
889 	oldp = p;
890 	mem_size = memparse(p, &p);
891 	if (p == oldp)
892 		return -EINVAL;
893 
894 	userdef = 1;
895 	if (*p == '@') {
896 		start_at = memparse(p+1, &p);
897 		e820_add_region(start_at, mem_size, E820_RAM);
898 	} else if (*p == '#') {
899 		start_at = memparse(p+1, &p);
900 		e820_add_region(start_at, mem_size, E820_ACPI);
901 	} else if (*p == '$') {
902 		start_at = memparse(p+1, &p);
903 		e820_add_region(start_at, mem_size, E820_RESERVED);
904 	} else
905 		e820_remove_range(mem_size, ULLONG_MAX - mem_size, E820_RAM, 1);
906 
907 	return *p == '\0' ? 0 : -EINVAL;
908 }
909 early_param("memmap", parse_memmap_opt);
910 
911 void __init finish_e820_parsing(void)
912 {
913 	if (userdef) {
914 		u32 nr = e820.nr_map;
915 
916 		if (sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &nr) < 0)
917 			early_panic("Invalid user supplied memory map");
918 		e820.nr_map = nr;
919 
920 		printk(KERN_INFO "user-defined physical RAM map:\n");
921 		e820_print_map("user");
922 	}
923 }
924 
925 static inline const char *e820_type_to_string(int e820_type)
926 {
927 	switch (e820_type) {
928 	case E820_RESERVED_KERN:
929 	case E820_RAM:	return "System RAM";
930 	case E820_ACPI:	return "ACPI Tables";
931 	case E820_NVS:	return "ACPI Non-volatile Storage";
932 	case E820_UNUSABLE:	return "Unusable memory";
933 	default:	return "reserved";
934 	}
935 }
936 
937 /*
938  * Mark e820 reserved areas as busy for the resource manager.
939  */
940 static struct resource __initdata *e820_res;
941 void __init e820_reserve_resources(void)
942 {
943 	int i;
944 	struct resource *res;
945 	u64 end;
946 
947 	res = alloc_bootmem(sizeof(struct resource) * e820.nr_map);
948 	e820_res = res;
949 	for (i = 0; i < e820.nr_map; i++) {
950 		end = e820.map[i].addr + e820.map[i].size - 1;
951 		if (end != (resource_size_t)end) {
952 			res++;
953 			continue;
954 		}
955 		res->name = e820_type_to_string(e820.map[i].type);
956 		res->start = e820.map[i].addr;
957 		res->end = end;
958 
959 		res->flags = IORESOURCE_MEM;
960 
961 		/*
962 		 * don't register the region that could be conflicted with
963 		 * pci device BAR resource and insert them later in
964 		 * pcibios_resource_survey()
965 		 */
966 		if (e820.map[i].type != E820_RESERVED || res->start < (1ULL<<20)) {
967 			res->flags |= IORESOURCE_BUSY;
968 			insert_resource(&iomem_resource, res);
969 		}
970 		res++;
971 	}
972 
973 	for (i = 0; i < e820_saved.nr_map; i++) {
974 		struct e820entry *entry = &e820_saved.map[i];
975 		firmware_map_add_early(entry->addr,
976 			entry->addr + entry->size - 1,
977 			e820_type_to_string(entry->type));
978 	}
979 }
980 
981 /* How much should we pad RAM ending depending on where it is? */
982 static unsigned long ram_alignment(resource_size_t pos)
983 {
984 	unsigned long mb = pos >> 20;
985 
986 	/* To 64kB in the first megabyte */
987 	if (!mb)
988 		return 64*1024;
989 
990 	/* To 1MB in the first 16MB */
991 	if (mb < 16)
992 		return 1024*1024;
993 
994 	/* To 64MB for anything above that */
995 	return 64*1024*1024;
996 }
997 
998 #define MAX_RESOURCE_SIZE ((resource_size_t)-1)
999 
1000 void __init e820_reserve_resources_late(void)
1001 {
1002 	int i;
1003 	struct resource *res;
1004 
1005 	res = e820_res;
1006 	for (i = 0; i < e820.nr_map; i++) {
1007 		if (!res->parent && res->end)
1008 			insert_resource_expand_to_fit(&iomem_resource, res);
1009 		res++;
1010 	}
1011 
1012 	/*
1013 	 * Try to bump up RAM regions to reasonable boundaries to
1014 	 * avoid stolen RAM:
1015 	 */
1016 	for (i = 0; i < e820.nr_map; i++) {
1017 		struct e820entry *entry = &e820.map[i];
1018 		u64 start, end;
1019 
1020 		if (entry->type != E820_RAM)
1021 			continue;
1022 		start = entry->addr + entry->size;
1023 		end = round_up(start, ram_alignment(start)) - 1;
1024 		if (end > MAX_RESOURCE_SIZE)
1025 			end = MAX_RESOURCE_SIZE;
1026 		if (start >= end)
1027 			continue;
1028 		printk(KERN_DEBUG "reserve RAM buffer: %016llx - %016llx ",
1029 			       start, end);
1030 		reserve_region_with_split(&iomem_resource, start, end,
1031 					  "RAM buffer");
1032 	}
1033 }
1034 
1035 char *__init default_machine_specific_memory_setup(void)
1036 {
1037 	char *who = "BIOS-e820";
1038 	u32 new_nr;
1039 	/*
1040 	 * Try to copy the BIOS-supplied E820-map.
1041 	 *
1042 	 * Otherwise fake a memory map; one section from 0k->640k,
1043 	 * the next section from 1mb->appropriate_mem_k
1044 	 */
1045 	new_nr = boot_params.e820_entries;
1046 	sanitize_e820_map(boot_params.e820_map,
1047 			ARRAY_SIZE(boot_params.e820_map),
1048 			&new_nr);
1049 	boot_params.e820_entries = new_nr;
1050 	if (append_e820_map(boot_params.e820_map, boot_params.e820_entries)
1051 	  < 0) {
1052 		u64 mem_size;
1053 
1054 		/* compare results from other methods and take the greater */
1055 		if (boot_params.alt_mem_k
1056 		    < boot_params.screen_info.ext_mem_k) {
1057 			mem_size = boot_params.screen_info.ext_mem_k;
1058 			who = "BIOS-88";
1059 		} else {
1060 			mem_size = boot_params.alt_mem_k;
1061 			who = "BIOS-e801";
1062 		}
1063 
1064 		e820.nr_map = 0;
1065 		e820_add_region(0, LOWMEMSIZE(), E820_RAM);
1066 		e820_add_region(HIGH_MEMORY, mem_size << 10, E820_RAM);
1067 	}
1068 
1069 	/* In case someone cares... */
1070 	return who;
1071 }
1072 
1073 void __init setup_memory_map(void)
1074 {
1075 	char *who;
1076 
1077 	who = x86_init.resources.memory_setup();
1078 	memcpy(&e820_saved, &e820, sizeof(struct e820map));
1079 	printk(KERN_INFO "BIOS-provided physical RAM map:\n");
1080 	e820_print_map(who);
1081 }
1082 
1083 void __init memblock_x86_fill(void)
1084 {
1085 	int i;
1086 	u64 end;
1087 
1088 	/*
1089 	 * EFI may have more than 128 entries
1090 	 * We are safe to enable resizing, beause memblock_x86_fill()
1091 	 * is rather later for x86
1092 	 */
1093 	memblock_can_resize = 1;
1094 
1095 	for (i = 0; i < e820.nr_map; i++) {
1096 		struct e820entry *ei = &e820.map[i];
1097 
1098 		end = ei->addr + ei->size;
1099 		if (end != (resource_size_t)end)
1100 			continue;
1101 
1102 		if (ei->type != E820_RAM && ei->type != E820_RESERVED_KERN)
1103 			continue;
1104 
1105 		memblock_add(ei->addr, ei->size);
1106 	}
1107 
1108 	memblock_analyze();
1109 	memblock_dump_all();
1110 }
1111 
1112 void __init memblock_find_dma_reserve(void)
1113 {
1114 #ifdef CONFIG_X86_64
1115 	u64 free_size_pfn;
1116 	u64 mem_size_pfn;
1117 	/*
1118 	 * need to find out used area below MAX_DMA_PFN
1119 	 * need to use memblock to get free size in [0, MAX_DMA_PFN]
1120 	 * at first, and assume boot_mem will not take below MAX_DMA_PFN
1121 	 */
1122 	mem_size_pfn = memblock_x86_memory_in_range(0, MAX_DMA_PFN << PAGE_SHIFT) >> PAGE_SHIFT;
1123 	free_size_pfn = memblock_x86_free_memory_in_range(0, MAX_DMA_PFN << PAGE_SHIFT) >> PAGE_SHIFT;
1124 	set_dma_reserve(mem_size_pfn - free_size_pfn);
1125 #endif
1126 }
1127