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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  */
42 struct e820map e820;
43 struct e820map e820_saved;
44 
45 /* For PCI or other memory-mapped resources */
46 unsigned long pci_mem_start = 0xaeedbabe;
47 #ifdef CONFIG_PCI
48 EXPORT_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  */
55 int
e820_any_mapped(u64 start,u64 end,unsigned type)56 e820_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 }
71 EXPORT_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  */
e820_all_mapped(u64 start,u64 end,unsigned type)79 int __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  */
__e820_add_region(struct e820map * e820x,u64 start,u64 size,int type)110 static 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 
e820_add_region(u64 start,u64 size,int type)128 void __init e820_add_region(u64 start, u64 size, int type)
129 {
130 	__e820_add_region(&e820, start, size, type);
131 }
132 
e820_print_type(u32 type)133 static 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 
e820_print_map(char * who)158 void __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  */
233 struct change_member {
234 	struct e820entry *pbios; /* pointer to original bios entry */
235 	unsigned long long addr; /* address for this change point */
236 };
237 
cpcompare(const void * a,const void * b)238 static 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 
sanitize_e820_map(struct e820entry * biosmap,int max_nr_map,u32 * pnr_map)255 int __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 
__append_e820_map(struct e820entry * biosmap,int nr_map)381 static 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  */
append_e820_map(struct e820entry * biosmap,int nr_map)410 static 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 
__e820_update_range(struct e820map * e820x,u64 start,u64 size,unsigned old_type,unsigned new_type)419 static 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 
e820_update_range(u64 start,u64 size,unsigned old_type,unsigned new_type)488 u64 __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 
e820_update_range_saved(u64 start,u64 size,unsigned old_type,unsigned new_type)494 static 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 */
e820_remove_range(u64 start,u64 size,unsigned old_type,int checktype)502 u64 __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 
update_e820(void)562 void __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 }
update_e820_saved(void)573 static 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  */
e820_search_gap(unsigned long * gapstart,unsigned long * gapsize,unsigned long start_addr,unsigned long long end_addr)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  */
e820_setup_gap(void)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  */
parse_e820_ext(u64 phys_addr,u32 data_len)661 void __init parse_e820_ext(u64 phys_addr, u32 data_len)
662 {
663 	int entries;
664 	struct e820entry *extmap;
665 	struct setup_data *sdata;
666 
667 	sdata = early_memremap(phys_addr, data_len);
668 	entries = sdata->len / sizeof(struct e820entry);
669 	extmap = (struct e820entry *)(sdata->data);
670 	__append_e820_map(extmap, entries);
671 	sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
672 	early_iounmap(sdata, data_len);
673 	printk(KERN_INFO "e820: extended physical RAM map:\n");
674 	e820_print_map("extended");
675 }
676 
677 #if defined(CONFIG_X86_64) || \
678 	(defined(CONFIG_X86_32) && defined(CONFIG_HIBERNATION))
679 /**
680  * Find the ranges of physical addresses that do not correspond to
681  * e820 RAM areas and mark the corresponding pages as nosave for
682  * hibernation (32 bit) or software suspend and suspend to RAM (64 bit).
683  *
684  * This function requires the e820 map to be sorted and without any
685  * overlapping entries.
686  */
e820_mark_nosave_regions(unsigned long limit_pfn)687 void __init e820_mark_nosave_regions(unsigned long limit_pfn)
688 {
689 	int i;
690 	unsigned long pfn = 0;
691 
692 	for (i = 0; i < e820.nr_map; i++) {
693 		struct e820entry *ei = &e820.map[i];
694 
695 		if (pfn < PFN_UP(ei->addr))
696 			register_nosave_region(pfn, PFN_UP(ei->addr));
697 
698 		pfn = PFN_DOWN(ei->addr + ei->size);
699 		if (ei->type != E820_RAM && ei->type != E820_RESERVED_KERN)
700 			register_nosave_region(PFN_UP(ei->addr), pfn);
701 
702 		if (pfn >= limit_pfn)
703 			break;
704 	}
705 }
706 #endif
707 
708 #ifdef CONFIG_ACPI
709 /**
710  * Mark ACPI NVS memory region, so that we can save/restore it during
711  * hibernation and the subsequent resume.
712  */
e820_mark_nvs_memory(void)713 static int __init e820_mark_nvs_memory(void)
714 {
715 	int i;
716 
717 	for (i = 0; i < e820.nr_map; i++) {
718 		struct e820entry *ei = &e820.map[i];
719 
720 		if (ei->type == E820_NVS)
721 			acpi_nvs_register(ei->addr, ei->size);
722 	}
723 
724 	return 0;
725 }
726 core_initcall(e820_mark_nvs_memory);
727 #endif
728 
729 /*
730  * pre allocated 4k and reserved it in memblock and e820_saved
731  */
early_reserve_e820(u64 size,u64 align)732 u64 __init early_reserve_e820(u64 size, u64 align)
733 {
734 	u64 addr;
735 
736 	addr = __memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ACCESSIBLE);
737 	if (addr) {
738 		e820_update_range_saved(addr, size, E820_RAM, E820_RESERVED);
739 		printk(KERN_INFO "e820: update e820_saved for early_reserve_e820\n");
740 		update_e820_saved();
741 	}
742 
743 	return addr;
744 }
745 
746 #ifdef CONFIG_X86_32
747 # ifdef CONFIG_X86_PAE
748 #  define MAX_ARCH_PFN		(1ULL<<(36-PAGE_SHIFT))
749 # else
750 #  define MAX_ARCH_PFN		(1ULL<<(32-PAGE_SHIFT))
751 # endif
752 #else /* CONFIG_X86_32 */
753 # define MAX_ARCH_PFN MAXMEM>>PAGE_SHIFT
754 #endif
755 
756 /*
757  * Find the highest page frame number we have available
758  */
e820_end_pfn(unsigned long limit_pfn,unsigned type)759 static unsigned long __init e820_end_pfn(unsigned long limit_pfn, unsigned type)
760 {
761 	int i;
762 	unsigned long last_pfn = 0;
763 	unsigned long max_arch_pfn = MAX_ARCH_PFN;
764 
765 	for (i = 0; i < e820.nr_map; i++) {
766 		struct e820entry *ei = &e820.map[i];
767 		unsigned long start_pfn;
768 		unsigned long end_pfn;
769 
770 		if (ei->type != type)
771 			continue;
772 
773 		start_pfn = ei->addr >> PAGE_SHIFT;
774 		end_pfn = (ei->addr + ei->size) >> PAGE_SHIFT;
775 
776 		if (start_pfn >= limit_pfn)
777 			continue;
778 		if (end_pfn > limit_pfn) {
779 			last_pfn = limit_pfn;
780 			break;
781 		}
782 		if (end_pfn > last_pfn)
783 			last_pfn = end_pfn;
784 	}
785 
786 	if (last_pfn > max_arch_pfn)
787 		last_pfn = max_arch_pfn;
788 
789 	printk(KERN_INFO "e820: last_pfn = %#lx max_arch_pfn = %#lx\n",
790 			 last_pfn, max_arch_pfn);
791 	return last_pfn;
792 }
e820_end_of_ram_pfn(void)793 unsigned long __init e820_end_of_ram_pfn(void)
794 {
795 	return e820_end_pfn(MAX_ARCH_PFN, E820_RAM);
796 }
797 
e820_end_of_low_ram_pfn(void)798 unsigned long __init e820_end_of_low_ram_pfn(void)
799 {
800 	return e820_end_pfn(1UL<<(32 - PAGE_SHIFT), E820_RAM);
801 }
802 
early_panic(char * msg)803 static void early_panic(char *msg)
804 {
805 	early_printk(msg);
806 	panic(msg);
807 }
808 
809 static int userdef __initdata;
810 
811 /* "mem=nopentium" disables the 4MB page tables. */
parse_memopt(char * p)812 static int __init parse_memopt(char *p)
813 {
814 	u64 mem_size;
815 
816 	if (!p)
817 		return -EINVAL;
818 
819 	if (!strcmp(p, "nopentium")) {
820 #ifdef CONFIG_X86_32
821 		setup_clear_cpu_cap(X86_FEATURE_PSE);
822 		return 0;
823 #else
824 		printk(KERN_WARNING "mem=nopentium ignored! (only supported on x86_32)\n");
825 		return -EINVAL;
826 #endif
827 	}
828 
829 	userdef = 1;
830 	mem_size = memparse(p, &p);
831 	/* don't remove all of memory when handling "mem={invalid}" param */
832 	if (mem_size == 0)
833 		return -EINVAL;
834 	e820_remove_range(mem_size, ULLONG_MAX - mem_size, E820_RAM, 1);
835 
836 	return 0;
837 }
838 early_param("mem", parse_memopt);
839 
parse_memmap_one(char * p)840 static int __init parse_memmap_one(char *p)
841 {
842 	char *oldp;
843 	u64 start_at, mem_size;
844 
845 	if (!p)
846 		return -EINVAL;
847 
848 	if (!strncmp(p, "exactmap", 8)) {
849 #ifdef CONFIG_CRASH_DUMP
850 		/*
851 		 * If we are doing a crash dump, we still need to know
852 		 * the real mem size before original memory map is
853 		 * reset.
854 		 */
855 		saved_max_pfn = e820_end_of_ram_pfn();
856 #endif
857 		e820.nr_map = 0;
858 		userdef = 1;
859 		return 0;
860 	}
861 
862 	oldp = p;
863 	mem_size = memparse(p, &p);
864 	if (p == oldp)
865 		return -EINVAL;
866 
867 	userdef = 1;
868 	if (*p == '@') {
869 		start_at = memparse(p+1, &p);
870 		e820_add_region(start_at, mem_size, E820_RAM);
871 	} else if (*p == '#') {
872 		start_at = memparse(p+1, &p);
873 		e820_add_region(start_at, mem_size, E820_ACPI);
874 	} else if (*p == '$') {
875 		start_at = memparse(p+1, &p);
876 		e820_add_region(start_at, mem_size, E820_RESERVED);
877 	} else
878 		e820_remove_range(mem_size, ULLONG_MAX - mem_size, E820_RAM, 1);
879 
880 	return *p == '\0' ? 0 : -EINVAL;
881 }
parse_memmap_opt(char * str)882 static int __init parse_memmap_opt(char *str)
883 {
884 	while (str) {
885 		char *k = strchr(str, ',');
886 
887 		if (k)
888 			*k++ = 0;
889 
890 		parse_memmap_one(str);
891 		str = k;
892 	}
893 
894 	return 0;
895 }
896 early_param("memmap", parse_memmap_opt);
897 
finish_e820_parsing(void)898 void __init finish_e820_parsing(void)
899 {
900 	if (userdef) {
901 		u32 nr = e820.nr_map;
902 
903 		if (sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &nr) < 0)
904 			early_panic("Invalid user supplied memory map");
905 		e820.nr_map = nr;
906 
907 		printk(KERN_INFO "e820: user-defined physical RAM map:\n");
908 		e820_print_map("user");
909 	}
910 }
911 
e820_type_to_string(int e820_type)912 static inline const char *e820_type_to_string(int e820_type)
913 {
914 	switch (e820_type) {
915 	case E820_RESERVED_KERN:
916 	case E820_RAM:	return "System RAM";
917 	case E820_ACPI:	return "ACPI Tables";
918 	case E820_NVS:	return "ACPI Non-volatile Storage";
919 	case E820_UNUSABLE:	return "Unusable memory";
920 	default:	return "reserved";
921 	}
922 }
923 
924 /*
925  * Mark e820 reserved areas as busy for the resource manager.
926  */
927 static struct resource __initdata *e820_res;
e820_reserve_resources(void)928 void __init e820_reserve_resources(void)
929 {
930 	int i;
931 	struct resource *res;
932 	u64 end;
933 
934 	res = alloc_bootmem(sizeof(struct resource) * e820.nr_map);
935 	e820_res = res;
936 	for (i = 0; i < e820.nr_map; i++) {
937 		end = e820.map[i].addr + e820.map[i].size - 1;
938 		if (end != (resource_size_t)end) {
939 			res++;
940 			continue;
941 		}
942 		res->name = e820_type_to_string(e820.map[i].type);
943 		res->start = e820.map[i].addr;
944 		res->end = end;
945 
946 		res->flags = IORESOURCE_MEM;
947 
948 		/*
949 		 * don't register the region that could be conflicted with
950 		 * pci device BAR resource and insert them later in
951 		 * pcibios_resource_survey()
952 		 */
953 		if (e820.map[i].type != E820_RESERVED || res->start < (1ULL<<20)) {
954 			res->flags |= IORESOURCE_BUSY;
955 			insert_resource(&iomem_resource, res);
956 		}
957 		res++;
958 	}
959 
960 	for (i = 0; i < e820_saved.nr_map; i++) {
961 		struct e820entry *entry = &e820_saved.map[i];
962 		firmware_map_add_early(entry->addr,
963 			entry->addr + entry->size,
964 			e820_type_to_string(entry->type));
965 	}
966 }
967 
968 /* How much should we pad RAM ending depending on where it is? */
ram_alignment(resource_size_t pos)969 static unsigned long ram_alignment(resource_size_t pos)
970 {
971 	unsigned long mb = pos >> 20;
972 
973 	/* To 64kB in the first megabyte */
974 	if (!mb)
975 		return 64*1024;
976 
977 	/* To 1MB in the first 16MB */
978 	if (mb < 16)
979 		return 1024*1024;
980 
981 	/* To 64MB for anything above that */
982 	return 64*1024*1024;
983 }
984 
985 #define MAX_RESOURCE_SIZE ((resource_size_t)-1)
986 
e820_reserve_resources_late(void)987 void __init e820_reserve_resources_late(void)
988 {
989 	int i;
990 	struct resource *res;
991 
992 	res = e820_res;
993 	for (i = 0; i < e820.nr_map; i++) {
994 		if (!res->parent && res->end)
995 			insert_resource_expand_to_fit(&iomem_resource, res);
996 		res++;
997 	}
998 
999 	/*
1000 	 * Try to bump up RAM regions to reasonable boundaries to
1001 	 * avoid stolen RAM:
1002 	 */
1003 	for (i = 0; i < e820.nr_map; i++) {
1004 		struct e820entry *entry = &e820.map[i];
1005 		u64 start, end;
1006 
1007 		if (entry->type != E820_RAM)
1008 			continue;
1009 		start = entry->addr + entry->size;
1010 		end = round_up(start, ram_alignment(start)) - 1;
1011 		if (end > MAX_RESOURCE_SIZE)
1012 			end = MAX_RESOURCE_SIZE;
1013 		if (start >= end)
1014 			continue;
1015 		printk(KERN_DEBUG
1016 		       "e820: reserve RAM buffer [mem %#010llx-%#010llx]\n",
1017 		       start, end);
1018 		reserve_region_with_split(&iomem_resource, start, end,
1019 					  "RAM buffer");
1020 	}
1021 }
1022 
default_machine_specific_memory_setup(void)1023 char *__init default_machine_specific_memory_setup(void)
1024 {
1025 	char *who = "BIOS-e820";
1026 	u32 new_nr;
1027 	/*
1028 	 * Try to copy the BIOS-supplied E820-map.
1029 	 *
1030 	 * Otherwise fake a memory map; one section from 0k->640k,
1031 	 * the next section from 1mb->appropriate_mem_k
1032 	 */
1033 	new_nr = boot_params.e820_entries;
1034 	sanitize_e820_map(boot_params.e820_map,
1035 			ARRAY_SIZE(boot_params.e820_map),
1036 			&new_nr);
1037 	boot_params.e820_entries = new_nr;
1038 	if (append_e820_map(boot_params.e820_map, boot_params.e820_entries)
1039 	  < 0) {
1040 		u64 mem_size;
1041 
1042 		/* compare results from other methods and take the greater */
1043 		if (boot_params.alt_mem_k
1044 		    < boot_params.screen_info.ext_mem_k) {
1045 			mem_size = boot_params.screen_info.ext_mem_k;
1046 			who = "BIOS-88";
1047 		} else {
1048 			mem_size = boot_params.alt_mem_k;
1049 			who = "BIOS-e801";
1050 		}
1051 
1052 		e820.nr_map = 0;
1053 		e820_add_region(0, LOWMEMSIZE(), E820_RAM);
1054 		e820_add_region(HIGH_MEMORY, mem_size << 10, E820_RAM);
1055 	}
1056 
1057 	/* In case someone cares... */
1058 	return who;
1059 }
1060 
setup_memory_map(void)1061 void __init setup_memory_map(void)
1062 {
1063 	char *who;
1064 
1065 	who = x86_init.resources.memory_setup();
1066 	memcpy(&e820_saved, &e820, sizeof(struct e820map));
1067 	printk(KERN_INFO "e820: BIOS-provided physical RAM map:\n");
1068 	e820_print_map(who);
1069 }
1070 
memblock_x86_fill(void)1071 void __init memblock_x86_fill(void)
1072 {
1073 	int i;
1074 	u64 end;
1075 
1076 	/*
1077 	 * EFI may have more than 128 entries
1078 	 * We are safe to enable resizing, beause memblock_x86_fill()
1079 	 * is rather later for x86
1080 	 */
1081 	memblock_allow_resize();
1082 
1083 	for (i = 0; i < e820.nr_map; i++) {
1084 		struct e820entry *ei = &e820.map[i];
1085 
1086 		end = ei->addr + ei->size;
1087 		if (end != (resource_size_t)end)
1088 			continue;
1089 
1090 		if (ei->type != E820_RAM && ei->type != E820_RESERVED_KERN)
1091 			continue;
1092 
1093 		memblock_add(ei->addr, ei->size);
1094 	}
1095 
1096 	/* throw away partial pages */
1097 	memblock_trim_memory(PAGE_SIZE);
1098 
1099 	memblock_dump_all();
1100 }
1101 
memblock_find_dma_reserve(void)1102 void __init memblock_find_dma_reserve(void)
1103 {
1104 #ifdef CONFIG_X86_64
1105 	u64 nr_pages = 0, nr_free_pages = 0;
1106 	unsigned long start_pfn, end_pfn;
1107 	phys_addr_t start, end;
1108 	int i;
1109 	u64 u;
1110 
1111 	/*
1112 	 * need to find out used area below MAX_DMA_PFN
1113 	 * need to use memblock to get free size in [0, MAX_DMA_PFN]
1114 	 * at first, and assume boot_mem will not take below MAX_DMA_PFN
1115 	 */
1116 	for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, NULL) {
1117 		start_pfn = min_t(unsigned long, start_pfn, MAX_DMA_PFN);
1118 		end_pfn = min_t(unsigned long, end_pfn, MAX_DMA_PFN);
1119 		nr_pages += end_pfn - start_pfn;
1120 	}
1121 
1122 	for_each_free_mem_range(u, NUMA_NO_NODE, &start, &end, NULL) {
1123 		start_pfn = min_t(unsigned long, PFN_UP(start), MAX_DMA_PFN);
1124 		end_pfn = min_t(unsigned long, PFN_DOWN(end), MAX_DMA_PFN);
1125 		if (start_pfn < end_pfn)
1126 			nr_free_pages += end_pfn - start_pfn;
1127 	}
1128 
1129 	set_dma_reserve(nr_pages - nr_free_pages);
1130 #endif
1131 }
1132