xref: /openbmc/linux/mm/memblock.c (revision 95e9fd10)
1 /*
2  * Procedures for maintaining information about logical memory blocks.
3  *
4  * Peter Bergner, IBM Corp.	June 2001.
5  * Copyright (C) 2001 Peter Bergner.
6  *
7  *      This program is free software; you can redistribute it and/or
8  *      modify it under the terms of the GNU General Public License
9  *      as published by the Free Software Foundation; either version
10  *      2 of the License, or (at your option) any later version.
11  */
12 
13 #include <linux/kernel.h>
14 #include <linux/slab.h>
15 #include <linux/init.h>
16 #include <linux/bitops.h>
17 #include <linux/poison.h>
18 #include <linux/pfn.h>
19 #include <linux/debugfs.h>
20 #include <linux/seq_file.h>
21 #include <linux/memblock.h>
22 
23 static struct memblock_region memblock_memory_init_regions[INIT_MEMBLOCK_REGIONS] __initdata_memblock;
24 static struct memblock_region memblock_reserved_init_regions[INIT_MEMBLOCK_REGIONS] __initdata_memblock;
25 
26 struct memblock memblock __initdata_memblock = {
27 	.memory.regions		= memblock_memory_init_regions,
28 	.memory.cnt		= 1,	/* empty dummy entry */
29 	.memory.max		= INIT_MEMBLOCK_REGIONS,
30 
31 	.reserved.regions	= memblock_reserved_init_regions,
32 	.reserved.cnt		= 1,	/* empty dummy entry */
33 	.reserved.max		= INIT_MEMBLOCK_REGIONS,
34 
35 	.current_limit		= MEMBLOCK_ALLOC_ANYWHERE,
36 };
37 
38 int memblock_debug __initdata_memblock;
39 static int memblock_can_resize __initdata_memblock;
40 static int memblock_memory_in_slab __initdata_memblock = 0;
41 static int memblock_reserved_in_slab __initdata_memblock = 0;
42 
43 /* inline so we don't get a warning when pr_debug is compiled out */
44 static inline const char *memblock_type_name(struct memblock_type *type)
45 {
46 	if (type == &memblock.memory)
47 		return "memory";
48 	else if (type == &memblock.reserved)
49 		return "reserved";
50 	else
51 		return "unknown";
52 }
53 
54 /* adjust *@size so that (@base + *@size) doesn't overflow, return new size */
55 static inline phys_addr_t memblock_cap_size(phys_addr_t base, phys_addr_t *size)
56 {
57 	return *size = min(*size, (phys_addr_t)ULLONG_MAX - base);
58 }
59 
60 /*
61  * Address comparison utilities
62  */
63 static unsigned long __init_memblock memblock_addrs_overlap(phys_addr_t base1, phys_addr_t size1,
64 				       phys_addr_t base2, phys_addr_t size2)
65 {
66 	return ((base1 < (base2 + size2)) && (base2 < (base1 + size1)));
67 }
68 
69 static long __init_memblock memblock_overlaps_region(struct memblock_type *type,
70 					phys_addr_t base, phys_addr_t size)
71 {
72 	unsigned long i;
73 
74 	for (i = 0; i < type->cnt; i++) {
75 		phys_addr_t rgnbase = type->regions[i].base;
76 		phys_addr_t rgnsize = type->regions[i].size;
77 		if (memblock_addrs_overlap(base, size, rgnbase, rgnsize))
78 			break;
79 	}
80 
81 	return (i < type->cnt) ? i : -1;
82 }
83 
84 /**
85  * memblock_find_in_range_node - find free area in given range and node
86  * @start: start of candidate range
87  * @end: end of candidate range, can be %MEMBLOCK_ALLOC_{ANYWHERE|ACCESSIBLE}
88  * @size: size of free area to find
89  * @align: alignment of free area to find
90  * @nid: nid of the free area to find, %MAX_NUMNODES for any node
91  *
92  * Find @size free area aligned to @align in the specified range and node.
93  *
94  * RETURNS:
95  * Found address on success, %0 on failure.
96  */
97 phys_addr_t __init_memblock memblock_find_in_range_node(phys_addr_t start,
98 					phys_addr_t end, phys_addr_t size,
99 					phys_addr_t align, int nid)
100 {
101 	phys_addr_t this_start, this_end, cand;
102 	u64 i;
103 
104 	/* pump up @end */
105 	if (end == MEMBLOCK_ALLOC_ACCESSIBLE)
106 		end = memblock.current_limit;
107 
108 	/* avoid allocating the first page */
109 	start = max_t(phys_addr_t, start, PAGE_SIZE);
110 	end = max(start, end);
111 
112 	for_each_free_mem_range_reverse(i, nid, &this_start, &this_end, NULL) {
113 		this_start = clamp(this_start, start, end);
114 		this_end = clamp(this_end, start, end);
115 
116 		if (this_end < size)
117 			continue;
118 
119 		cand = round_down(this_end - size, align);
120 		if (cand >= this_start)
121 			return cand;
122 	}
123 	return 0;
124 }
125 
126 /**
127  * memblock_find_in_range - find free area in given range
128  * @start: start of candidate range
129  * @end: end of candidate range, can be %MEMBLOCK_ALLOC_{ANYWHERE|ACCESSIBLE}
130  * @size: size of free area to find
131  * @align: alignment of free area to find
132  *
133  * Find @size free area aligned to @align in the specified range.
134  *
135  * RETURNS:
136  * Found address on success, %0 on failure.
137  */
138 phys_addr_t __init_memblock memblock_find_in_range(phys_addr_t start,
139 					phys_addr_t end, phys_addr_t size,
140 					phys_addr_t align)
141 {
142 	return memblock_find_in_range_node(start, end, size, align,
143 					   MAX_NUMNODES);
144 }
145 
146 static void __init_memblock memblock_remove_region(struct memblock_type *type, unsigned long r)
147 {
148 	type->total_size -= type->regions[r].size;
149 	memmove(&type->regions[r], &type->regions[r + 1],
150 		(type->cnt - (r + 1)) * sizeof(type->regions[r]));
151 	type->cnt--;
152 
153 	/* Special case for empty arrays */
154 	if (type->cnt == 0) {
155 		WARN_ON(type->total_size != 0);
156 		type->cnt = 1;
157 		type->regions[0].base = 0;
158 		type->regions[0].size = 0;
159 		memblock_set_region_node(&type->regions[0], MAX_NUMNODES);
160 	}
161 }
162 
163 phys_addr_t __init_memblock get_allocated_memblock_reserved_regions_info(
164 					phys_addr_t *addr)
165 {
166 	if (memblock.reserved.regions == memblock_reserved_init_regions)
167 		return 0;
168 
169 	*addr = __pa(memblock.reserved.regions);
170 
171 	return PAGE_ALIGN(sizeof(struct memblock_region) *
172 			  memblock.reserved.max);
173 }
174 
175 /**
176  * memblock_double_array - double the size of the memblock regions array
177  * @type: memblock type of the regions array being doubled
178  * @new_area_start: starting address of memory range to avoid overlap with
179  * @new_area_size: size of memory range to avoid overlap with
180  *
181  * Double the size of the @type regions array. If memblock is being used to
182  * allocate memory for a new reserved regions array and there is a previously
183  * allocated memory range [@new_area_start,@new_area_start+@new_area_size]
184  * waiting to be reserved, ensure the memory used by the new array does
185  * not overlap.
186  *
187  * RETURNS:
188  * 0 on success, -1 on failure.
189  */
190 static int __init_memblock memblock_double_array(struct memblock_type *type,
191 						phys_addr_t new_area_start,
192 						phys_addr_t new_area_size)
193 {
194 	struct memblock_region *new_array, *old_array;
195 	phys_addr_t old_alloc_size, new_alloc_size;
196 	phys_addr_t old_size, new_size, addr;
197 	int use_slab = slab_is_available();
198 	int *in_slab;
199 
200 	/* We don't allow resizing until we know about the reserved regions
201 	 * of memory that aren't suitable for allocation
202 	 */
203 	if (!memblock_can_resize)
204 		return -1;
205 
206 	/* Calculate new doubled size */
207 	old_size = type->max * sizeof(struct memblock_region);
208 	new_size = old_size << 1;
209 	/*
210 	 * We need to allocated new one align to PAGE_SIZE,
211 	 *   so we can free them completely later.
212 	 */
213 	old_alloc_size = PAGE_ALIGN(old_size);
214 	new_alloc_size = PAGE_ALIGN(new_size);
215 
216 	/* Retrieve the slab flag */
217 	if (type == &memblock.memory)
218 		in_slab = &memblock_memory_in_slab;
219 	else
220 		in_slab = &memblock_reserved_in_slab;
221 
222 	/* Try to find some space for it.
223 	 *
224 	 * WARNING: We assume that either slab_is_available() and we use it or
225 	 * we use MEMBLOCK for allocations. That means that this is unsafe to
226 	 * use when bootmem is currently active (unless bootmem itself is
227 	 * implemented on top of MEMBLOCK which isn't the case yet)
228 	 *
229 	 * This should however not be an issue for now, as we currently only
230 	 * call into MEMBLOCK while it's still active, or much later when slab
231 	 * is active for memory hotplug operations
232 	 */
233 	if (use_slab) {
234 		new_array = kmalloc(new_size, GFP_KERNEL);
235 		addr = new_array ? __pa(new_array) : 0;
236 	} else {
237 		/* only exclude range when trying to double reserved.regions */
238 		if (type != &memblock.reserved)
239 			new_area_start = new_area_size = 0;
240 
241 		addr = memblock_find_in_range(new_area_start + new_area_size,
242 						memblock.current_limit,
243 						new_alloc_size, PAGE_SIZE);
244 		if (!addr && new_area_size)
245 			addr = memblock_find_in_range(0,
246 				min(new_area_start, memblock.current_limit),
247 				new_alloc_size, PAGE_SIZE);
248 
249 		new_array = addr ? __va(addr) : 0;
250 	}
251 	if (!addr) {
252 		pr_err("memblock: Failed to double %s array from %ld to %ld entries !\n",
253 		       memblock_type_name(type), type->max, type->max * 2);
254 		return -1;
255 	}
256 
257 	memblock_dbg("memblock: %s is doubled to %ld at [%#010llx-%#010llx]",
258 			memblock_type_name(type), type->max * 2, (u64)addr,
259 			(u64)addr + new_size - 1);
260 
261 	/*
262 	 * Found space, we now need to move the array over before we add the
263 	 * reserved region since it may be our reserved array itself that is
264 	 * full.
265 	 */
266 	memcpy(new_array, type->regions, old_size);
267 	memset(new_array + type->max, 0, old_size);
268 	old_array = type->regions;
269 	type->regions = new_array;
270 	type->max <<= 1;
271 
272 	/* Free old array. We needn't free it if the array is the static one */
273 	if (*in_slab)
274 		kfree(old_array);
275 	else if (old_array != memblock_memory_init_regions &&
276 		 old_array != memblock_reserved_init_regions)
277 		memblock_free(__pa(old_array), old_alloc_size);
278 
279 	/*
280 	 * Reserve the new array if that comes from the memblock.  Otherwise, we
281 	 * needn't do it
282 	 */
283 	if (!use_slab)
284 		BUG_ON(memblock_reserve(addr, new_alloc_size));
285 
286 	/* Update slab flag */
287 	*in_slab = use_slab;
288 
289 	return 0;
290 }
291 
292 /**
293  * memblock_merge_regions - merge neighboring compatible regions
294  * @type: memblock type to scan
295  *
296  * Scan @type and merge neighboring compatible regions.
297  */
298 static void __init_memblock memblock_merge_regions(struct memblock_type *type)
299 {
300 	int i = 0;
301 
302 	/* cnt never goes below 1 */
303 	while (i < type->cnt - 1) {
304 		struct memblock_region *this = &type->regions[i];
305 		struct memblock_region *next = &type->regions[i + 1];
306 
307 		if (this->base + this->size != next->base ||
308 		    memblock_get_region_node(this) !=
309 		    memblock_get_region_node(next)) {
310 			BUG_ON(this->base + this->size > next->base);
311 			i++;
312 			continue;
313 		}
314 
315 		this->size += next->size;
316 		memmove(next, next + 1, (type->cnt - (i + 1)) * sizeof(*next));
317 		type->cnt--;
318 	}
319 }
320 
321 /**
322  * memblock_insert_region - insert new memblock region
323  * @type: memblock type to insert into
324  * @idx: index for the insertion point
325  * @base: base address of the new region
326  * @size: size of the new region
327  *
328  * Insert new memblock region [@base,@base+@size) into @type at @idx.
329  * @type must already have extra room to accomodate the new region.
330  */
331 static void __init_memblock memblock_insert_region(struct memblock_type *type,
332 						   int idx, phys_addr_t base,
333 						   phys_addr_t size, int nid)
334 {
335 	struct memblock_region *rgn = &type->regions[idx];
336 
337 	BUG_ON(type->cnt >= type->max);
338 	memmove(rgn + 1, rgn, (type->cnt - idx) * sizeof(*rgn));
339 	rgn->base = base;
340 	rgn->size = size;
341 	memblock_set_region_node(rgn, nid);
342 	type->cnt++;
343 	type->total_size += size;
344 }
345 
346 /**
347  * memblock_add_region - add new memblock region
348  * @type: memblock type to add new region into
349  * @base: base address of the new region
350  * @size: size of the new region
351  * @nid: nid of the new region
352  *
353  * Add new memblock region [@base,@base+@size) into @type.  The new region
354  * is allowed to overlap with existing ones - overlaps don't affect already
355  * existing regions.  @type is guaranteed to be minimal (all neighbouring
356  * compatible regions are merged) after the addition.
357  *
358  * RETURNS:
359  * 0 on success, -errno on failure.
360  */
361 static int __init_memblock memblock_add_region(struct memblock_type *type,
362 				phys_addr_t base, phys_addr_t size, int nid)
363 {
364 	bool insert = false;
365 	phys_addr_t obase = base;
366 	phys_addr_t end = base + memblock_cap_size(base, &size);
367 	int i, nr_new;
368 
369 	if (!size)
370 		return 0;
371 
372 	/* special case for empty array */
373 	if (type->regions[0].size == 0) {
374 		WARN_ON(type->cnt != 1 || type->total_size);
375 		type->regions[0].base = base;
376 		type->regions[0].size = size;
377 		memblock_set_region_node(&type->regions[0], nid);
378 		type->total_size = size;
379 		return 0;
380 	}
381 repeat:
382 	/*
383 	 * The following is executed twice.  Once with %false @insert and
384 	 * then with %true.  The first counts the number of regions needed
385 	 * to accomodate the new area.  The second actually inserts them.
386 	 */
387 	base = obase;
388 	nr_new = 0;
389 
390 	for (i = 0; i < type->cnt; i++) {
391 		struct memblock_region *rgn = &type->regions[i];
392 		phys_addr_t rbase = rgn->base;
393 		phys_addr_t rend = rbase + rgn->size;
394 
395 		if (rbase >= end)
396 			break;
397 		if (rend <= base)
398 			continue;
399 		/*
400 		 * @rgn overlaps.  If it separates the lower part of new
401 		 * area, insert that portion.
402 		 */
403 		if (rbase > base) {
404 			nr_new++;
405 			if (insert)
406 				memblock_insert_region(type, i++, base,
407 						       rbase - base, nid);
408 		}
409 		/* area below @rend is dealt with, forget about it */
410 		base = min(rend, end);
411 	}
412 
413 	/* insert the remaining portion */
414 	if (base < end) {
415 		nr_new++;
416 		if (insert)
417 			memblock_insert_region(type, i, base, end - base, nid);
418 	}
419 
420 	/*
421 	 * If this was the first round, resize array and repeat for actual
422 	 * insertions; otherwise, merge and return.
423 	 */
424 	if (!insert) {
425 		while (type->cnt + nr_new > type->max)
426 			if (memblock_double_array(type, obase, size) < 0)
427 				return -ENOMEM;
428 		insert = true;
429 		goto repeat;
430 	} else {
431 		memblock_merge_regions(type);
432 		return 0;
433 	}
434 }
435 
436 int __init_memblock memblock_add_node(phys_addr_t base, phys_addr_t size,
437 				       int nid)
438 {
439 	return memblock_add_region(&memblock.memory, base, size, nid);
440 }
441 
442 int __init_memblock memblock_add(phys_addr_t base, phys_addr_t size)
443 {
444 	return memblock_add_region(&memblock.memory, base, size, MAX_NUMNODES);
445 }
446 
447 /**
448  * memblock_isolate_range - isolate given range into disjoint memblocks
449  * @type: memblock type to isolate range for
450  * @base: base of range to isolate
451  * @size: size of range to isolate
452  * @start_rgn: out parameter for the start of isolated region
453  * @end_rgn: out parameter for the end of isolated region
454  *
455  * Walk @type and ensure that regions don't cross the boundaries defined by
456  * [@base,@base+@size).  Crossing regions are split at the boundaries,
457  * which may create at most two more regions.  The index of the first
458  * region inside the range is returned in *@start_rgn and end in *@end_rgn.
459  *
460  * RETURNS:
461  * 0 on success, -errno on failure.
462  */
463 static int __init_memblock memblock_isolate_range(struct memblock_type *type,
464 					phys_addr_t base, phys_addr_t size,
465 					int *start_rgn, int *end_rgn)
466 {
467 	phys_addr_t end = base + memblock_cap_size(base, &size);
468 	int i;
469 
470 	*start_rgn = *end_rgn = 0;
471 
472 	if (!size)
473 		return 0;
474 
475 	/* we'll create at most two more regions */
476 	while (type->cnt + 2 > type->max)
477 		if (memblock_double_array(type, base, size) < 0)
478 			return -ENOMEM;
479 
480 	for (i = 0; i < type->cnt; i++) {
481 		struct memblock_region *rgn = &type->regions[i];
482 		phys_addr_t rbase = rgn->base;
483 		phys_addr_t rend = rbase + rgn->size;
484 
485 		if (rbase >= end)
486 			break;
487 		if (rend <= base)
488 			continue;
489 
490 		if (rbase < base) {
491 			/*
492 			 * @rgn intersects from below.  Split and continue
493 			 * to process the next region - the new top half.
494 			 */
495 			rgn->base = base;
496 			rgn->size -= base - rbase;
497 			type->total_size -= base - rbase;
498 			memblock_insert_region(type, i, rbase, base - rbase,
499 					       memblock_get_region_node(rgn));
500 		} else if (rend > end) {
501 			/*
502 			 * @rgn intersects from above.  Split and redo the
503 			 * current region - the new bottom half.
504 			 */
505 			rgn->base = end;
506 			rgn->size -= end - rbase;
507 			type->total_size -= end - rbase;
508 			memblock_insert_region(type, i--, rbase, end - rbase,
509 					       memblock_get_region_node(rgn));
510 		} else {
511 			/* @rgn is fully contained, record it */
512 			if (!*end_rgn)
513 				*start_rgn = i;
514 			*end_rgn = i + 1;
515 		}
516 	}
517 
518 	return 0;
519 }
520 
521 static int __init_memblock __memblock_remove(struct memblock_type *type,
522 					     phys_addr_t base, phys_addr_t size)
523 {
524 	int start_rgn, end_rgn;
525 	int i, ret;
526 
527 	ret = memblock_isolate_range(type, base, size, &start_rgn, &end_rgn);
528 	if (ret)
529 		return ret;
530 
531 	for (i = end_rgn - 1; i >= start_rgn; i--)
532 		memblock_remove_region(type, i);
533 	return 0;
534 }
535 
536 int __init_memblock memblock_remove(phys_addr_t base, phys_addr_t size)
537 {
538 	return __memblock_remove(&memblock.memory, base, size);
539 }
540 
541 int __init_memblock memblock_free(phys_addr_t base, phys_addr_t size)
542 {
543 	memblock_dbg("   memblock_free: [%#016llx-%#016llx] %pF\n",
544 		     (unsigned long long)base,
545 		     (unsigned long long)base + size,
546 		     (void *)_RET_IP_);
547 
548 	return __memblock_remove(&memblock.reserved, base, size);
549 }
550 
551 int __init_memblock memblock_reserve(phys_addr_t base, phys_addr_t size)
552 {
553 	struct memblock_type *_rgn = &memblock.reserved;
554 
555 	memblock_dbg("memblock_reserve: [%#016llx-%#016llx] %pF\n",
556 		     (unsigned long long)base,
557 		     (unsigned long long)base + size,
558 		     (void *)_RET_IP_);
559 
560 	return memblock_add_region(_rgn, base, size, MAX_NUMNODES);
561 }
562 
563 /**
564  * __next_free_mem_range - next function for for_each_free_mem_range()
565  * @idx: pointer to u64 loop variable
566  * @nid: nid: node selector, %MAX_NUMNODES for all nodes
567  * @out_start: ptr to phys_addr_t for start address of the range, can be %NULL
568  * @out_end: ptr to phys_addr_t for end address of the range, can be %NULL
569  * @out_nid: ptr to int for nid of the range, can be %NULL
570  *
571  * Find the first free area from *@idx which matches @nid, fill the out
572  * parameters, and update *@idx for the next iteration.  The lower 32bit of
573  * *@idx contains index into memory region and the upper 32bit indexes the
574  * areas before each reserved region.  For example, if reserved regions
575  * look like the following,
576  *
577  *	0:[0-16), 1:[32-48), 2:[128-130)
578  *
579  * The upper 32bit indexes the following regions.
580  *
581  *	0:[0-0), 1:[16-32), 2:[48-128), 3:[130-MAX)
582  *
583  * As both region arrays are sorted, the function advances the two indices
584  * in lockstep and returns each intersection.
585  */
586 void __init_memblock __next_free_mem_range(u64 *idx, int nid,
587 					   phys_addr_t *out_start,
588 					   phys_addr_t *out_end, int *out_nid)
589 {
590 	struct memblock_type *mem = &memblock.memory;
591 	struct memblock_type *rsv = &memblock.reserved;
592 	int mi = *idx & 0xffffffff;
593 	int ri = *idx >> 32;
594 
595 	for ( ; mi < mem->cnt; mi++) {
596 		struct memblock_region *m = &mem->regions[mi];
597 		phys_addr_t m_start = m->base;
598 		phys_addr_t m_end = m->base + m->size;
599 
600 		/* only memory regions are associated with nodes, check it */
601 		if (nid != MAX_NUMNODES && nid != memblock_get_region_node(m))
602 			continue;
603 
604 		/* scan areas before each reservation for intersection */
605 		for ( ; ri < rsv->cnt + 1; ri++) {
606 			struct memblock_region *r = &rsv->regions[ri];
607 			phys_addr_t r_start = ri ? r[-1].base + r[-1].size : 0;
608 			phys_addr_t r_end = ri < rsv->cnt ? r->base : ULLONG_MAX;
609 
610 			/* if ri advanced past mi, break out to advance mi */
611 			if (r_start >= m_end)
612 				break;
613 			/* if the two regions intersect, we're done */
614 			if (m_start < r_end) {
615 				if (out_start)
616 					*out_start = max(m_start, r_start);
617 				if (out_end)
618 					*out_end = min(m_end, r_end);
619 				if (out_nid)
620 					*out_nid = memblock_get_region_node(m);
621 				/*
622 				 * The region which ends first is advanced
623 				 * for the next iteration.
624 				 */
625 				if (m_end <= r_end)
626 					mi++;
627 				else
628 					ri++;
629 				*idx = (u32)mi | (u64)ri << 32;
630 				return;
631 			}
632 		}
633 	}
634 
635 	/* signal end of iteration */
636 	*idx = ULLONG_MAX;
637 }
638 
639 /**
640  * __next_free_mem_range_rev - next function for for_each_free_mem_range_reverse()
641  * @idx: pointer to u64 loop variable
642  * @nid: nid: node selector, %MAX_NUMNODES for all nodes
643  * @out_start: ptr to phys_addr_t for start address of the range, can be %NULL
644  * @out_end: ptr to phys_addr_t for end address of the range, can be %NULL
645  * @out_nid: ptr to int for nid of the range, can be %NULL
646  *
647  * Reverse of __next_free_mem_range().
648  */
649 void __init_memblock __next_free_mem_range_rev(u64 *idx, int nid,
650 					   phys_addr_t *out_start,
651 					   phys_addr_t *out_end, int *out_nid)
652 {
653 	struct memblock_type *mem = &memblock.memory;
654 	struct memblock_type *rsv = &memblock.reserved;
655 	int mi = *idx & 0xffffffff;
656 	int ri = *idx >> 32;
657 
658 	if (*idx == (u64)ULLONG_MAX) {
659 		mi = mem->cnt - 1;
660 		ri = rsv->cnt;
661 	}
662 
663 	for ( ; mi >= 0; mi--) {
664 		struct memblock_region *m = &mem->regions[mi];
665 		phys_addr_t m_start = m->base;
666 		phys_addr_t m_end = m->base + m->size;
667 
668 		/* only memory regions are associated with nodes, check it */
669 		if (nid != MAX_NUMNODES && nid != memblock_get_region_node(m))
670 			continue;
671 
672 		/* scan areas before each reservation for intersection */
673 		for ( ; ri >= 0; ri--) {
674 			struct memblock_region *r = &rsv->regions[ri];
675 			phys_addr_t r_start = ri ? r[-1].base + r[-1].size : 0;
676 			phys_addr_t r_end = ri < rsv->cnt ? r->base : ULLONG_MAX;
677 
678 			/* if ri advanced past mi, break out to advance mi */
679 			if (r_end <= m_start)
680 				break;
681 			/* if the two regions intersect, we're done */
682 			if (m_end > r_start) {
683 				if (out_start)
684 					*out_start = max(m_start, r_start);
685 				if (out_end)
686 					*out_end = min(m_end, r_end);
687 				if (out_nid)
688 					*out_nid = memblock_get_region_node(m);
689 
690 				if (m_start >= r_start)
691 					mi--;
692 				else
693 					ri--;
694 				*idx = (u32)mi | (u64)ri << 32;
695 				return;
696 			}
697 		}
698 	}
699 
700 	*idx = ULLONG_MAX;
701 }
702 
703 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
704 /*
705  * Common iterator interface used to define for_each_mem_range().
706  */
707 void __init_memblock __next_mem_pfn_range(int *idx, int nid,
708 				unsigned long *out_start_pfn,
709 				unsigned long *out_end_pfn, int *out_nid)
710 {
711 	struct memblock_type *type = &memblock.memory;
712 	struct memblock_region *r;
713 
714 	while (++*idx < type->cnt) {
715 		r = &type->regions[*idx];
716 
717 		if (PFN_UP(r->base) >= PFN_DOWN(r->base + r->size))
718 			continue;
719 		if (nid == MAX_NUMNODES || nid == r->nid)
720 			break;
721 	}
722 	if (*idx >= type->cnt) {
723 		*idx = -1;
724 		return;
725 	}
726 
727 	if (out_start_pfn)
728 		*out_start_pfn = PFN_UP(r->base);
729 	if (out_end_pfn)
730 		*out_end_pfn = PFN_DOWN(r->base + r->size);
731 	if (out_nid)
732 		*out_nid = r->nid;
733 }
734 
735 /**
736  * memblock_set_node - set node ID on memblock regions
737  * @base: base of area to set node ID for
738  * @size: size of area to set node ID for
739  * @nid: node ID to set
740  *
741  * Set the nid of memblock memory regions in [@base,@base+@size) to @nid.
742  * Regions which cross the area boundaries are split as necessary.
743  *
744  * RETURNS:
745  * 0 on success, -errno on failure.
746  */
747 int __init_memblock memblock_set_node(phys_addr_t base, phys_addr_t size,
748 				      int nid)
749 {
750 	struct memblock_type *type = &memblock.memory;
751 	int start_rgn, end_rgn;
752 	int i, ret;
753 
754 	ret = memblock_isolate_range(type, base, size, &start_rgn, &end_rgn);
755 	if (ret)
756 		return ret;
757 
758 	for (i = start_rgn; i < end_rgn; i++)
759 		type->regions[i].nid = nid;
760 
761 	memblock_merge_regions(type);
762 	return 0;
763 }
764 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
765 
766 static phys_addr_t __init memblock_alloc_base_nid(phys_addr_t size,
767 					phys_addr_t align, phys_addr_t max_addr,
768 					int nid)
769 {
770 	phys_addr_t found;
771 
772 	/* align @size to avoid excessive fragmentation on reserved array */
773 	size = round_up(size, align);
774 
775 	found = memblock_find_in_range_node(0, max_addr, size, align, nid);
776 	if (found && !memblock_reserve(found, size))
777 		return found;
778 
779 	return 0;
780 }
781 
782 phys_addr_t __init memblock_alloc_nid(phys_addr_t size, phys_addr_t align, int nid)
783 {
784 	return memblock_alloc_base_nid(size, align, MEMBLOCK_ALLOC_ACCESSIBLE, nid);
785 }
786 
787 phys_addr_t __init __memblock_alloc_base(phys_addr_t size, phys_addr_t align, phys_addr_t max_addr)
788 {
789 	return memblock_alloc_base_nid(size, align, max_addr, MAX_NUMNODES);
790 }
791 
792 phys_addr_t __init memblock_alloc_base(phys_addr_t size, phys_addr_t align, phys_addr_t max_addr)
793 {
794 	phys_addr_t alloc;
795 
796 	alloc = __memblock_alloc_base(size, align, max_addr);
797 
798 	if (alloc == 0)
799 		panic("ERROR: Failed to allocate 0x%llx bytes below 0x%llx.\n",
800 		      (unsigned long long) size, (unsigned long long) max_addr);
801 
802 	return alloc;
803 }
804 
805 phys_addr_t __init memblock_alloc(phys_addr_t size, phys_addr_t align)
806 {
807 	return memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ACCESSIBLE);
808 }
809 
810 phys_addr_t __init memblock_alloc_try_nid(phys_addr_t size, phys_addr_t align, int nid)
811 {
812 	phys_addr_t res = memblock_alloc_nid(size, align, nid);
813 
814 	if (res)
815 		return res;
816 	return memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ACCESSIBLE);
817 }
818 
819 
820 /*
821  * Remaining API functions
822  */
823 
824 phys_addr_t __init memblock_phys_mem_size(void)
825 {
826 	return memblock.memory.total_size;
827 }
828 
829 /* lowest address */
830 phys_addr_t __init_memblock memblock_start_of_DRAM(void)
831 {
832 	return memblock.memory.regions[0].base;
833 }
834 
835 phys_addr_t __init_memblock memblock_end_of_DRAM(void)
836 {
837 	int idx = memblock.memory.cnt - 1;
838 
839 	return (memblock.memory.regions[idx].base + memblock.memory.regions[idx].size);
840 }
841 
842 void __init memblock_enforce_memory_limit(phys_addr_t limit)
843 {
844 	unsigned long i;
845 	phys_addr_t max_addr = (phys_addr_t)ULLONG_MAX;
846 
847 	if (!limit)
848 		return;
849 
850 	/* find out max address */
851 	for (i = 0; i < memblock.memory.cnt; i++) {
852 		struct memblock_region *r = &memblock.memory.regions[i];
853 
854 		if (limit <= r->size) {
855 			max_addr = r->base + limit;
856 			break;
857 		}
858 		limit -= r->size;
859 	}
860 
861 	/* truncate both memory and reserved regions */
862 	__memblock_remove(&memblock.memory, max_addr, (phys_addr_t)ULLONG_MAX);
863 	__memblock_remove(&memblock.reserved, max_addr, (phys_addr_t)ULLONG_MAX);
864 }
865 
866 static int __init_memblock memblock_search(struct memblock_type *type, phys_addr_t addr)
867 {
868 	unsigned int left = 0, right = type->cnt;
869 
870 	do {
871 		unsigned int mid = (right + left) / 2;
872 
873 		if (addr < type->regions[mid].base)
874 			right = mid;
875 		else if (addr >= (type->regions[mid].base +
876 				  type->regions[mid].size))
877 			left = mid + 1;
878 		else
879 			return mid;
880 	} while (left < right);
881 	return -1;
882 }
883 
884 int __init memblock_is_reserved(phys_addr_t addr)
885 {
886 	return memblock_search(&memblock.reserved, addr) != -1;
887 }
888 
889 int __init_memblock memblock_is_memory(phys_addr_t addr)
890 {
891 	return memblock_search(&memblock.memory, addr) != -1;
892 }
893 
894 /**
895  * memblock_is_region_memory - check if a region is a subset of memory
896  * @base: base of region to check
897  * @size: size of region to check
898  *
899  * Check if the region [@base, @base+@size) is a subset of a memory block.
900  *
901  * RETURNS:
902  * 0 if false, non-zero if true
903  */
904 int __init_memblock memblock_is_region_memory(phys_addr_t base, phys_addr_t size)
905 {
906 	int idx = memblock_search(&memblock.memory, base);
907 	phys_addr_t end = base + memblock_cap_size(base, &size);
908 
909 	if (idx == -1)
910 		return 0;
911 	return memblock.memory.regions[idx].base <= base &&
912 		(memblock.memory.regions[idx].base +
913 		 memblock.memory.regions[idx].size) >= end;
914 }
915 
916 /**
917  * memblock_is_region_reserved - check if a region intersects reserved memory
918  * @base: base of region to check
919  * @size: size of region to check
920  *
921  * Check if the region [@base, @base+@size) intersects a reserved memory block.
922  *
923  * RETURNS:
924  * 0 if false, non-zero if true
925  */
926 int __init_memblock memblock_is_region_reserved(phys_addr_t base, phys_addr_t size)
927 {
928 	memblock_cap_size(base, &size);
929 	return memblock_overlaps_region(&memblock.reserved, base, size) >= 0;
930 }
931 
932 
933 void __init_memblock memblock_set_current_limit(phys_addr_t limit)
934 {
935 	memblock.current_limit = limit;
936 }
937 
938 static void __init_memblock memblock_dump(struct memblock_type *type, char *name)
939 {
940 	unsigned long long base, size;
941 	int i;
942 
943 	pr_info(" %s.cnt  = 0x%lx\n", name, type->cnt);
944 
945 	for (i = 0; i < type->cnt; i++) {
946 		struct memblock_region *rgn = &type->regions[i];
947 		char nid_buf[32] = "";
948 
949 		base = rgn->base;
950 		size = rgn->size;
951 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
952 		if (memblock_get_region_node(rgn) != MAX_NUMNODES)
953 			snprintf(nid_buf, sizeof(nid_buf), " on node %d",
954 				 memblock_get_region_node(rgn));
955 #endif
956 		pr_info(" %s[%#x]\t[%#016llx-%#016llx], %#llx bytes%s\n",
957 			name, i, base, base + size - 1, size, nid_buf);
958 	}
959 }
960 
961 void __init_memblock __memblock_dump_all(void)
962 {
963 	pr_info("MEMBLOCK configuration:\n");
964 	pr_info(" memory size = %#llx reserved size = %#llx\n",
965 		(unsigned long long)memblock.memory.total_size,
966 		(unsigned long long)memblock.reserved.total_size);
967 
968 	memblock_dump(&memblock.memory, "memory");
969 	memblock_dump(&memblock.reserved, "reserved");
970 }
971 
972 void __init memblock_allow_resize(void)
973 {
974 	memblock_can_resize = 1;
975 }
976 
977 static int __init early_memblock(char *p)
978 {
979 	if (p && strstr(p, "debug"))
980 		memblock_debug = 1;
981 	return 0;
982 }
983 early_param("memblock", early_memblock);
984 
985 #if defined(CONFIG_DEBUG_FS) && !defined(CONFIG_ARCH_DISCARD_MEMBLOCK)
986 
987 static int memblock_debug_show(struct seq_file *m, void *private)
988 {
989 	struct memblock_type *type = m->private;
990 	struct memblock_region *reg;
991 	int i;
992 
993 	for (i = 0; i < type->cnt; i++) {
994 		reg = &type->regions[i];
995 		seq_printf(m, "%4d: ", i);
996 		if (sizeof(phys_addr_t) == 4)
997 			seq_printf(m, "0x%08lx..0x%08lx\n",
998 				   (unsigned long)reg->base,
999 				   (unsigned long)(reg->base + reg->size - 1));
1000 		else
1001 			seq_printf(m, "0x%016llx..0x%016llx\n",
1002 				   (unsigned long long)reg->base,
1003 				   (unsigned long long)(reg->base + reg->size - 1));
1004 
1005 	}
1006 	return 0;
1007 }
1008 
1009 static int memblock_debug_open(struct inode *inode, struct file *file)
1010 {
1011 	return single_open(file, memblock_debug_show, inode->i_private);
1012 }
1013 
1014 static const struct file_operations memblock_debug_fops = {
1015 	.open = memblock_debug_open,
1016 	.read = seq_read,
1017 	.llseek = seq_lseek,
1018 	.release = single_release,
1019 };
1020 
1021 static int __init memblock_init_debugfs(void)
1022 {
1023 	struct dentry *root = debugfs_create_dir("memblock", NULL);
1024 	if (!root)
1025 		return -ENXIO;
1026 	debugfs_create_file("memory", S_IRUGO, root, &memblock.memory, &memblock_debug_fops);
1027 	debugfs_create_file("reserved", S_IRUGO, root, &memblock.reserved, &memblock_debug_fops);
1028 
1029 	return 0;
1030 }
1031 __initcall(memblock_init_debugfs);
1032 
1033 #endif /* CONFIG_DEBUG_FS */
1034