xref: /openbmc/linux/mm/memblock.c (revision cf028200)
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 __init_memblock const char *
45 memblock_type_name(struct memblock_type *type)
46 {
47 	if (type == &memblock.memory)
48 		return "memory";
49 	else if (type == &memblock.reserved)
50 		return "reserved";
51 	else
52 		return "unknown";
53 }
54 
55 /* adjust *@size so that (@base + *@size) doesn't overflow, return new size */
56 static inline phys_addr_t memblock_cap_size(phys_addr_t base, phys_addr_t *size)
57 {
58 	return *size = min(*size, (phys_addr_t)ULLONG_MAX - base);
59 }
60 
61 /*
62  * Address comparison utilities
63  */
64 static unsigned long __init_memblock memblock_addrs_overlap(phys_addr_t base1, phys_addr_t size1,
65 				       phys_addr_t base2, phys_addr_t size2)
66 {
67 	return ((base1 < (base2 + size2)) && (base2 < (base1 + size1)));
68 }
69 
70 static long __init_memblock memblock_overlaps_region(struct memblock_type *type,
71 					phys_addr_t base, phys_addr_t size)
72 {
73 	unsigned long i;
74 
75 	for (i = 0; i < type->cnt; i++) {
76 		phys_addr_t rgnbase = type->regions[i].base;
77 		phys_addr_t rgnsize = type->regions[i].size;
78 		if (memblock_addrs_overlap(base, size, rgnbase, rgnsize))
79 			break;
80 	}
81 
82 	return (i < type->cnt) ? i : -1;
83 }
84 
85 /**
86  * memblock_find_in_range_node - find free area in given range and node
87  * @start: start of candidate range
88  * @end: end of candidate range, can be %MEMBLOCK_ALLOC_{ANYWHERE|ACCESSIBLE}
89  * @size: size of free area to find
90  * @align: alignment of free area to find
91  * @nid: nid of the free area to find, %MAX_NUMNODES for any node
92  *
93  * Find @size free area aligned to @align in the specified range and node.
94  *
95  * RETURNS:
96  * Found address on success, %0 on failure.
97  */
98 phys_addr_t __init_memblock memblock_find_in_range_node(phys_addr_t start,
99 					phys_addr_t end, phys_addr_t size,
100 					phys_addr_t align, int nid)
101 {
102 	phys_addr_t this_start, this_end, cand;
103 	u64 i;
104 
105 	/* pump up @end */
106 	if (end == MEMBLOCK_ALLOC_ACCESSIBLE)
107 		end = memblock.current_limit;
108 
109 	/* avoid allocating the first page */
110 	start = max_t(phys_addr_t, start, PAGE_SIZE);
111 	end = max(start, end);
112 
113 	for_each_free_mem_range_reverse(i, nid, &this_start, &this_end, NULL) {
114 		this_start = clamp(this_start, start, end);
115 		this_end = clamp(this_end, start, end);
116 
117 		if (this_end < size)
118 			continue;
119 
120 		cand = round_down(this_end - size, align);
121 		if (cand >= this_start)
122 			return cand;
123 	}
124 	return 0;
125 }
126 
127 /**
128  * memblock_find_in_range - find free area in given range
129  * @start: start of candidate range
130  * @end: end of candidate range, can be %MEMBLOCK_ALLOC_{ANYWHERE|ACCESSIBLE}
131  * @size: size of free area to find
132  * @align: alignment of free area to find
133  *
134  * Find @size free area aligned to @align in the specified range.
135  *
136  * RETURNS:
137  * Found address on success, %0 on failure.
138  */
139 phys_addr_t __init_memblock memblock_find_in_range(phys_addr_t start,
140 					phys_addr_t end, phys_addr_t size,
141 					phys_addr_t align)
142 {
143 	return memblock_find_in_range_node(start, end, size, align,
144 					   MAX_NUMNODES);
145 }
146 
147 static void __init_memblock memblock_remove_region(struct memblock_type *type, unsigned long r)
148 {
149 	type->total_size -= type->regions[r].size;
150 	memmove(&type->regions[r], &type->regions[r + 1],
151 		(type->cnt - (r + 1)) * sizeof(type->regions[r]));
152 	type->cnt--;
153 
154 	/* Special case for empty arrays */
155 	if (type->cnt == 0) {
156 		WARN_ON(type->total_size != 0);
157 		type->cnt = 1;
158 		type->regions[0].base = 0;
159 		type->regions[0].size = 0;
160 		memblock_set_region_node(&type->regions[0], MAX_NUMNODES);
161 	}
162 }
163 
164 phys_addr_t __init_memblock get_allocated_memblock_reserved_regions_info(
165 					phys_addr_t *addr)
166 {
167 	if (memblock.reserved.regions == memblock_reserved_init_regions)
168 		return 0;
169 
170 	*addr = __pa(memblock.reserved.regions);
171 
172 	return PAGE_ALIGN(sizeof(struct memblock_region) *
173 			  memblock.reserved.max);
174 }
175 
176 /**
177  * memblock_double_array - double the size of the memblock regions array
178  * @type: memblock type of the regions array being doubled
179  * @new_area_start: starting address of memory range to avoid overlap with
180  * @new_area_size: size of memory range to avoid overlap with
181  *
182  * Double the size of the @type regions array. If memblock is being used to
183  * allocate memory for a new reserved regions array and there is a previously
184  * allocated memory range [@new_area_start,@new_area_start+@new_area_size]
185  * waiting to be reserved, ensure the memory used by the new array does
186  * not overlap.
187  *
188  * RETURNS:
189  * 0 on success, -1 on failure.
190  */
191 static int __init_memblock memblock_double_array(struct memblock_type *type,
192 						phys_addr_t new_area_start,
193 						phys_addr_t new_area_size)
194 {
195 	struct memblock_region *new_array, *old_array;
196 	phys_addr_t old_alloc_size, new_alloc_size;
197 	phys_addr_t old_size, new_size, addr;
198 	int use_slab = slab_is_available();
199 	int *in_slab;
200 
201 	/* We don't allow resizing until we know about the reserved regions
202 	 * of memory that aren't suitable for allocation
203 	 */
204 	if (!memblock_can_resize)
205 		return -1;
206 
207 	/* Calculate new doubled size */
208 	old_size = type->max * sizeof(struct memblock_region);
209 	new_size = old_size << 1;
210 	/*
211 	 * We need to allocated new one align to PAGE_SIZE,
212 	 *   so we can free them completely later.
213 	 */
214 	old_alloc_size = PAGE_ALIGN(old_size);
215 	new_alloc_size = PAGE_ALIGN(new_size);
216 
217 	/* Retrieve the slab flag */
218 	if (type == &memblock.memory)
219 		in_slab = &memblock_memory_in_slab;
220 	else
221 		in_slab = &memblock_reserved_in_slab;
222 
223 	/* Try to find some space for it.
224 	 *
225 	 * WARNING: We assume that either slab_is_available() and we use it or
226 	 * we use MEMBLOCK for allocations. That means that this is unsafe to
227 	 * use when bootmem is currently active (unless bootmem itself is
228 	 * implemented on top of MEMBLOCK which isn't the case yet)
229 	 *
230 	 * This should however not be an issue for now, as we currently only
231 	 * call into MEMBLOCK while it's still active, or much later when slab
232 	 * is active for memory hotplug operations
233 	 */
234 	if (use_slab) {
235 		new_array = kmalloc(new_size, GFP_KERNEL);
236 		addr = new_array ? __pa(new_array) : 0;
237 	} else {
238 		/* only exclude range when trying to double reserved.regions */
239 		if (type != &memblock.reserved)
240 			new_area_start = new_area_size = 0;
241 
242 		addr = memblock_find_in_range(new_area_start + new_area_size,
243 						memblock.current_limit,
244 						new_alloc_size, PAGE_SIZE);
245 		if (!addr && new_area_size)
246 			addr = memblock_find_in_range(0,
247 				min(new_area_start, memblock.current_limit),
248 				new_alloc_size, PAGE_SIZE);
249 
250 		new_array = addr ? __va(addr) : NULL;
251 	}
252 	if (!addr) {
253 		pr_err("memblock: Failed to double %s array from %ld to %ld entries !\n",
254 		       memblock_type_name(type), type->max, type->max * 2);
255 		return -1;
256 	}
257 
258 	memblock_dbg("memblock: %s is doubled to %ld at [%#010llx-%#010llx]",
259 			memblock_type_name(type), type->max * 2, (u64)addr,
260 			(u64)addr + new_size - 1);
261 
262 	/*
263 	 * Found space, we now need to move the array over before we add the
264 	 * reserved region since it may be our reserved array itself that is
265 	 * full.
266 	 */
267 	memcpy(new_array, type->regions, old_size);
268 	memset(new_array + type->max, 0, old_size);
269 	old_array = type->regions;
270 	type->regions = new_array;
271 	type->max <<= 1;
272 
273 	/* Free old array. We needn't free it if the array is the static one */
274 	if (*in_slab)
275 		kfree(old_array);
276 	else if (old_array != memblock_memory_init_regions &&
277 		 old_array != memblock_reserved_init_regions)
278 		memblock_free(__pa(old_array), old_alloc_size);
279 
280 	/*
281 	 * Reserve the new array if that comes from the memblock.  Otherwise, we
282 	 * needn't do it
283 	 */
284 	if (!use_slab)
285 		BUG_ON(memblock_reserve(addr, new_alloc_size));
286 
287 	/* Update slab flag */
288 	*in_slab = use_slab;
289 
290 	return 0;
291 }
292 
293 /**
294  * memblock_merge_regions - merge neighboring compatible regions
295  * @type: memblock type to scan
296  *
297  * Scan @type and merge neighboring compatible regions.
298  */
299 static void __init_memblock memblock_merge_regions(struct memblock_type *type)
300 {
301 	int i = 0;
302 
303 	/* cnt never goes below 1 */
304 	while (i < type->cnt - 1) {
305 		struct memblock_region *this = &type->regions[i];
306 		struct memblock_region *next = &type->regions[i + 1];
307 
308 		if (this->base + this->size != next->base ||
309 		    memblock_get_region_node(this) !=
310 		    memblock_get_region_node(next)) {
311 			BUG_ON(this->base + this->size > next->base);
312 			i++;
313 			continue;
314 		}
315 
316 		this->size += next->size;
317 		memmove(next, next + 1, (type->cnt - (i + 1)) * sizeof(*next));
318 		type->cnt--;
319 	}
320 }
321 
322 /**
323  * memblock_insert_region - insert new memblock region
324  * @type: memblock type to insert into
325  * @idx: index for the insertion point
326  * @base: base address of the new region
327  * @size: size of the new region
328  *
329  * Insert new memblock region [@base,@base+@size) into @type at @idx.
330  * @type must already have extra room to accomodate the new region.
331  */
332 static void __init_memblock memblock_insert_region(struct memblock_type *type,
333 						   int idx, phys_addr_t base,
334 						   phys_addr_t size, int nid)
335 {
336 	struct memblock_region *rgn = &type->regions[idx];
337 
338 	BUG_ON(type->cnt >= type->max);
339 	memmove(rgn + 1, rgn, (type->cnt - idx) * sizeof(*rgn));
340 	rgn->base = base;
341 	rgn->size = size;
342 	memblock_set_region_node(rgn, nid);
343 	type->cnt++;
344 	type->total_size += size;
345 }
346 
347 /**
348  * memblock_add_region - add new memblock region
349  * @type: memblock type to add new region into
350  * @base: base address of the new region
351  * @size: size of the new region
352  * @nid: nid of the new region
353  *
354  * Add new memblock region [@base,@base+@size) into @type.  The new region
355  * is allowed to overlap with existing ones - overlaps don't affect already
356  * existing regions.  @type is guaranteed to be minimal (all neighbouring
357  * compatible regions are merged) after the addition.
358  *
359  * RETURNS:
360  * 0 on success, -errno on failure.
361  */
362 static int __init_memblock memblock_add_region(struct memblock_type *type,
363 				phys_addr_t base, phys_addr_t size, int nid)
364 {
365 	bool insert = false;
366 	phys_addr_t obase = base;
367 	phys_addr_t end = base + memblock_cap_size(base, &size);
368 	int i, nr_new;
369 
370 	if (!size)
371 		return 0;
372 
373 	/* special case for empty array */
374 	if (type->regions[0].size == 0) {
375 		WARN_ON(type->cnt != 1 || type->total_size);
376 		type->regions[0].base = base;
377 		type->regions[0].size = size;
378 		memblock_set_region_node(&type->regions[0], nid);
379 		type->total_size = size;
380 		return 0;
381 	}
382 repeat:
383 	/*
384 	 * The following is executed twice.  Once with %false @insert and
385 	 * then with %true.  The first counts the number of regions needed
386 	 * to accomodate the new area.  The second actually inserts them.
387 	 */
388 	base = obase;
389 	nr_new = 0;
390 
391 	for (i = 0; i < type->cnt; i++) {
392 		struct memblock_region *rgn = &type->regions[i];
393 		phys_addr_t rbase = rgn->base;
394 		phys_addr_t rend = rbase + rgn->size;
395 
396 		if (rbase >= end)
397 			break;
398 		if (rend <= base)
399 			continue;
400 		/*
401 		 * @rgn overlaps.  If it separates the lower part of new
402 		 * area, insert that portion.
403 		 */
404 		if (rbase > base) {
405 			nr_new++;
406 			if (insert)
407 				memblock_insert_region(type, i++, base,
408 						       rbase - base, nid);
409 		}
410 		/* area below @rend is dealt with, forget about it */
411 		base = min(rend, end);
412 	}
413 
414 	/* insert the remaining portion */
415 	if (base < end) {
416 		nr_new++;
417 		if (insert)
418 			memblock_insert_region(type, i, base, end - base, nid);
419 	}
420 
421 	/*
422 	 * If this was the first round, resize array and repeat for actual
423 	 * insertions; otherwise, merge and return.
424 	 */
425 	if (!insert) {
426 		while (type->cnt + nr_new > type->max)
427 			if (memblock_double_array(type, obase, size) < 0)
428 				return -ENOMEM;
429 		insert = true;
430 		goto repeat;
431 	} else {
432 		memblock_merge_regions(type);
433 		return 0;
434 	}
435 }
436 
437 int __init_memblock memblock_add_node(phys_addr_t base, phys_addr_t size,
438 				       int nid)
439 {
440 	return memblock_add_region(&memblock.memory, base, size, nid);
441 }
442 
443 int __init_memblock memblock_add(phys_addr_t base, phys_addr_t size)
444 {
445 	return memblock_add_region(&memblock.memory, base, size, MAX_NUMNODES);
446 }
447 
448 /**
449  * memblock_isolate_range - isolate given range into disjoint memblocks
450  * @type: memblock type to isolate range for
451  * @base: base of range to isolate
452  * @size: size of range to isolate
453  * @start_rgn: out parameter for the start of isolated region
454  * @end_rgn: out parameter for the end of isolated region
455  *
456  * Walk @type and ensure that regions don't cross the boundaries defined by
457  * [@base,@base+@size).  Crossing regions are split at the boundaries,
458  * which may create at most two more regions.  The index of the first
459  * region inside the range is returned in *@start_rgn and end in *@end_rgn.
460  *
461  * RETURNS:
462  * 0 on success, -errno on failure.
463  */
464 static int __init_memblock memblock_isolate_range(struct memblock_type *type,
465 					phys_addr_t base, phys_addr_t size,
466 					int *start_rgn, int *end_rgn)
467 {
468 	phys_addr_t end = base + memblock_cap_size(base, &size);
469 	int i;
470 
471 	*start_rgn = *end_rgn = 0;
472 
473 	if (!size)
474 		return 0;
475 
476 	/* we'll create at most two more regions */
477 	while (type->cnt + 2 > type->max)
478 		if (memblock_double_array(type, base, size) < 0)
479 			return -ENOMEM;
480 
481 	for (i = 0; i < type->cnt; i++) {
482 		struct memblock_region *rgn = &type->regions[i];
483 		phys_addr_t rbase = rgn->base;
484 		phys_addr_t rend = rbase + rgn->size;
485 
486 		if (rbase >= end)
487 			break;
488 		if (rend <= base)
489 			continue;
490 
491 		if (rbase < base) {
492 			/*
493 			 * @rgn intersects from below.  Split and continue
494 			 * to process the next region - the new top half.
495 			 */
496 			rgn->base = base;
497 			rgn->size -= base - rbase;
498 			type->total_size -= base - rbase;
499 			memblock_insert_region(type, i, rbase, base - rbase,
500 					       memblock_get_region_node(rgn));
501 		} else if (rend > end) {
502 			/*
503 			 * @rgn intersects from above.  Split and redo the
504 			 * current region - the new bottom half.
505 			 */
506 			rgn->base = end;
507 			rgn->size -= end - rbase;
508 			type->total_size -= end - rbase;
509 			memblock_insert_region(type, i--, rbase, end - rbase,
510 					       memblock_get_region_node(rgn));
511 		} else {
512 			/* @rgn is fully contained, record it */
513 			if (!*end_rgn)
514 				*start_rgn = i;
515 			*end_rgn = i + 1;
516 		}
517 	}
518 
519 	return 0;
520 }
521 
522 static int __init_memblock __memblock_remove(struct memblock_type *type,
523 					     phys_addr_t base, phys_addr_t size)
524 {
525 	int start_rgn, end_rgn;
526 	int i, ret;
527 
528 	ret = memblock_isolate_range(type, base, size, &start_rgn, &end_rgn);
529 	if (ret)
530 		return ret;
531 
532 	for (i = end_rgn - 1; i >= start_rgn; i--)
533 		memblock_remove_region(type, i);
534 	return 0;
535 }
536 
537 int __init_memblock memblock_remove(phys_addr_t base, phys_addr_t size)
538 {
539 	return __memblock_remove(&memblock.memory, base, size);
540 }
541 
542 int __init_memblock memblock_free(phys_addr_t base, phys_addr_t size)
543 {
544 	memblock_dbg("   memblock_free: [%#016llx-%#016llx] %pF\n",
545 		     (unsigned long long)base,
546 		     (unsigned long long)base + size,
547 		     (void *)_RET_IP_);
548 
549 	return __memblock_remove(&memblock.reserved, base, size);
550 }
551 
552 int __init_memblock memblock_reserve(phys_addr_t base, phys_addr_t size)
553 {
554 	struct memblock_type *_rgn = &memblock.reserved;
555 
556 	memblock_dbg("memblock_reserve: [%#016llx-%#016llx] %pF\n",
557 		     (unsigned long long)base,
558 		     (unsigned long long)base + size,
559 		     (void *)_RET_IP_);
560 
561 	return memblock_add_region(_rgn, base, size, MAX_NUMNODES);
562 }
563 
564 /**
565  * __next_free_mem_range - next function for for_each_free_mem_range()
566  * @idx: pointer to u64 loop variable
567  * @nid: nid: node selector, %MAX_NUMNODES for all nodes
568  * @out_start: ptr to phys_addr_t for start address of the range, can be %NULL
569  * @out_end: ptr to phys_addr_t for end address of the range, can be %NULL
570  * @out_nid: ptr to int for nid of the range, can be %NULL
571  *
572  * Find the first free area from *@idx which matches @nid, fill the out
573  * parameters, and update *@idx for the next iteration.  The lower 32bit of
574  * *@idx contains index into memory region and the upper 32bit indexes the
575  * areas before each reserved region.  For example, if reserved regions
576  * look like the following,
577  *
578  *	0:[0-16), 1:[32-48), 2:[128-130)
579  *
580  * The upper 32bit indexes the following regions.
581  *
582  *	0:[0-0), 1:[16-32), 2:[48-128), 3:[130-MAX)
583  *
584  * As both region arrays are sorted, the function advances the two indices
585  * in lockstep and returns each intersection.
586  */
587 void __init_memblock __next_free_mem_range(u64 *idx, int nid,
588 					   phys_addr_t *out_start,
589 					   phys_addr_t *out_end, int *out_nid)
590 {
591 	struct memblock_type *mem = &memblock.memory;
592 	struct memblock_type *rsv = &memblock.reserved;
593 	int mi = *idx & 0xffffffff;
594 	int ri = *idx >> 32;
595 
596 	for ( ; mi < mem->cnt; mi++) {
597 		struct memblock_region *m = &mem->regions[mi];
598 		phys_addr_t m_start = m->base;
599 		phys_addr_t m_end = m->base + m->size;
600 
601 		/* only memory regions are associated with nodes, check it */
602 		if (nid != MAX_NUMNODES && nid != memblock_get_region_node(m))
603 			continue;
604 
605 		/* scan areas before each reservation for intersection */
606 		for ( ; ri < rsv->cnt + 1; ri++) {
607 			struct memblock_region *r = &rsv->regions[ri];
608 			phys_addr_t r_start = ri ? r[-1].base + r[-1].size : 0;
609 			phys_addr_t r_end = ri < rsv->cnt ? r->base : ULLONG_MAX;
610 
611 			/* if ri advanced past mi, break out to advance mi */
612 			if (r_start >= m_end)
613 				break;
614 			/* if the two regions intersect, we're done */
615 			if (m_start < r_end) {
616 				if (out_start)
617 					*out_start = max(m_start, r_start);
618 				if (out_end)
619 					*out_end = min(m_end, r_end);
620 				if (out_nid)
621 					*out_nid = memblock_get_region_node(m);
622 				/*
623 				 * The region which ends first is advanced
624 				 * for the next iteration.
625 				 */
626 				if (m_end <= r_end)
627 					mi++;
628 				else
629 					ri++;
630 				*idx = (u32)mi | (u64)ri << 32;
631 				return;
632 			}
633 		}
634 	}
635 
636 	/* signal end of iteration */
637 	*idx = ULLONG_MAX;
638 }
639 
640 /**
641  * __next_free_mem_range_rev - next function for for_each_free_mem_range_reverse()
642  * @idx: pointer to u64 loop variable
643  * @nid: nid: node selector, %MAX_NUMNODES for all nodes
644  * @out_start: ptr to phys_addr_t for start address of the range, can be %NULL
645  * @out_end: ptr to phys_addr_t for end address of the range, can be %NULL
646  * @out_nid: ptr to int for nid of the range, can be %NULL
647  *
648  * Reverse of __next_free_mem_range().
649  */
650 void __init_memblock __next_free_mem_range_rev(u64 *idx, int nid,
651 					   phys_addr_t *out_start,
652 					   phys_addr_t *out_end, int *out_nid)
653 {
654 	struct memblock_type *mem = &memblock.memory;
655 	struct memblock_type *rsv = &memblock.reserved;
656 	int mi = *idx & 0xffffffff;
657 	int ri = *idx >> 32;
658 
659 	if (*idx == (u64)ULLONG_MAX) {
660 		mi = mem->cnt - 1;
661 		ri = rsv->cnt;
662 	}
663 
664 	for ( ; mi >= 0; mi--) {
665 		struct memblock_region *m = &mem->regions[mi];
666 		phys_addr_t m_start = m->base;
667 		phys_addr_t m_end = m->base + m->size;
668 
669 		/* only memory regions are associated with nodes, check it */
670 		if (nid != MAX_NUMNODES && nid != memblock_get_region_node(m))
671 			continue;
672 
673 		/* scan areas before each reservation for intersection */
674 		for ( ; ri >= 0; ri--) {
675 			struct memblock_region *r = &rsv->regions[ri];
676 			phys_addr_t r_start = ri ? r[-1].base + r[-1].size : 0;
677 			phys_addr_t r_end = ri < rsv->cnt ? r->base : ULLONG_MAX;
678 
679 			/* if ri advanced past mi, break out to advance mi */
680 			if (r_end <= m_start)
681 				break;
682 			/* if the two regions intersect, we're done */
683 			if (m_end > r_start) {
684 				if (out_start)
685 					*out_start = max(m_start, r_start);
686 				if (out_end)
687 					*out_end = min(m_end, r_end);
688 				if (out_nid)
689 					*out_nid = memblock_get_region_node(m);
690 
691 				if (m_start >= r_start)
692 					mi--;
693 				else
694 					ri--;
695 				*idx = (u32)mi | (u64)ri << 32;
696 				return;
697 			}
698 		}
699 	}
700 
701 	*idx = ULLONG_MAX;
702 }
703 
704 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
705 /*
706  * Common iterator interface used to define for_each_mem_range().
707  */
708 void __init_memblock __next_mem_pfn_range(int *idx, int nid,
709 				unsigned long *out_start_pfn,
710 				unsigned long *out_end_pfn, int *out_nid)
711 {
712 	struct memblock_type *type = &memblock.memory;
713 	struct memblock_region *r;
714 
715 	while (++*idx < type->cnt) {
716 		r = &type->regions[*idx];
717 
718 		if (PFN_UP(r->base) >= PFN_DOWN(r->base + r->size))
719 			continue;
720 		if (nid == MAX_NUMNODES || nid == r->nid)
721 			break;
722 	}
723 	if (*idx >= type->cnt) {
724 		*idx = -1;
725 		return;
726 	}
727 
728 	if (out_start_pfn)
729 		*out_start_pfn = PFN_UP(r->base);
730 	if (out_end_pfn)
731 		*out_end_pfn = PFN_DOWN(r->base + r->size);
732 	if (out_nid)
733 		*out_nid = r->nid;
734 }
735 
736 /**
737  * memblock_set_node - set node ID on memblock regions
738  * @base: base of area to set node ID for
739  * @size: size of area to set node ID for
740  * @nid: node ID to set
741  *
742  * Set the nid of memblock memory regions in [@base,@base+@size) to @nid.
743  * Regions which cross the area boundaries are split as necessary.
744  *
745  * RETURNS:
746  * 0 on success, -errno on failure.
747  */
748 int __init_memblock memblock_set_node(phys_addr_t base, phys_addr_t size,
749 				      int nid)
750 {
751 	struct memblock_type *type = &memblock.memory;
752 	int start_rgn, end_rgn;
753 	int i, ret;
754 
755 	ret = memblock_isolate_range(type, base, size, &start_rgn, &end_rgn);
756 	if (ret)
757 		return ret;
758 
759 	for (i = start_rgn; i < end_rgn; i++)
760 		memblock_set_region_node(&type->regions[i], nid);
761 
762 	memblock_merge_regions(type);
763 	return 0;
764 }
765 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
766 
767 static phys_addr_t __init memblock_alloc_base_nid(phys_addr_t size,
768 					phys_addr_t align, phys_addr_t max_addr,
769 					int nid)
770 {
771 	phys_addr_t found;
772 
773 	/* align @size to avoid excessive fragmentation on reserved array */
774 	size = round_up(size, align);
775 
776 	found = memblock_find_in_range_node(0, max_addr, size, align, nid);
777 	if (found && !memblock_reserve(found, size))
778 		return found;
779 
780 	return 0;
781 }
782 
783 phys_addr_t __init memblock_alloc_nid(phys_addr_t size, phys_addr_t align, int nid)
784 {
785 	return memblock_alloc_base_nid(size, align, MEMBLOCK_ALLOC_ACCESSIBLE, nid);
786 }
787 
788 phys_addr_t __init __memblock_alloc_base(phys_addr_t size, phys_addr_t align, phys_addr_t max_addr)
789 {
790 	return memblock_alloc_base_nid(size, align, max_addr, MAX_NUMNODES);
791 }
792 
793 phys_addr_t __init memblock_alloc_base(phys_addr_t size, phys_addr_t align, phys_addr_t max_addr)
794 {
795 	phys_addr_t alloc;
796 
797 	alloc = __memblock_alloc_base(size, align, max_addr);
798 
799 	if (alloc == 0)
800 		panic("ERROR: Failed to allocate 0x%llx bytes below 0x%llx.\n",
801 		      (unsigned long long) size, (unsigned long long) max_addr);
802 
803 	return alloc;
804 }
805 
806 phys_addr_t __init memblock_alloc(phys_addr_t size, phys_addr_t align)
807 {
808 	return memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ACCESSIBLE);
809 }
810 
811 phys_addr_t __init memblock_alloc_try_nid(phys_addr_t size, phys_addr_t align, int nid)
812 {
813 	phys_addr_t res = memblock_alloc_nid(size, align, nid);
814 
815 	if (res)
816 		return res;
817 	return memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ACCESSIBLE);
818 }
819 
820 
821 /*
822  * Remaining API functions
823  */
824 
825 phys_addr_t __init memblock_phys_mem_size(void)
826 {
827 	return memblock.memory.total_size;
828 }
829 
830 /* lowest address */
831 phys_addr_t __init_memblock memblock_start_of_DRAM(void)
832 {
833 	return memblock.memory.regions[0].base;
834 }
835 
836 phys_addr_t __init_memblock memblock_end_of_DRAM(void)
837 {
838 	int idx = memblock.memory.cnt - 1;
839 
840 	return (memblock.memory.regions[idx].base + memblock.memory.regions[idx].size);
841 }
842 
843 void __init memblock_enforce_memory_limit(phys_addr_t limit)
844 {
845 	unsigned long i;
846 	phys_addr_t max_addr = (phys_addr_t)ULLONG_MAX;
847 
848 	if (!limit)
849 		return;
850 
851 	/* find out max address */
852 	for (i = 0; i < memblock.memory.cnt; i++) {
853 		struct memblock_region *r = &memblock.memory.regions[i];
854 
855 		if (limit <= r->size) {
856 			max_addr = r->base + limit;
857 			break;
858 		}
859 		limit -= r->size;
860 	}
861 
862 	/* truncate both memory and reserved regions */
863 	__memblock_remove(&memblock.memory, max_addr, (phys_addr_t)ULLONG_MAX);
864 	__memblock_remove(&memblock.reserved, max_addr, (phys_addr_t)ULLONG_MAX);
865 }
866 
867 static int __init_memblock memblock_search(struct memblock_type *type, phys_addr_t addr)
868 {
869 	unsigned int left = 0, right = type->cnt;
870 
871 	do {
872 		unsigned int mid = (right + left) / 2;
873 
874 		if (addr < type->regions[mid].base)
875 			right = mid;
876 		else if (addr >= (type->regions[mid].base +
877 				  type->regions[mid].size))
878 			left = mid + 1;
879 		else
880 			return mid;
881 	} while (left < right);
882 	return -1;
883 }
884 
885 int __init memblock_is_reserved(phys_addr_t addr)
886 {
887 	return memblock_search(&memblock.reserved, addr) != -1;
888 }
889 
890 int __init_memblock memblock_is_memory(phys_addr_t addr)
891 {
892 	return memblock_search(&memblock.memory, addr) != -1;
893 }
894 
895 /**
896  * memblock_is_region_memory - check if a region is a subset of memory
897  * @base: base of region to check
898  * @size: size of region to check
899  *
900  * Check if the region [@base, @base+@size) is a subset of a memory block.
901  *
902  * RETURNS:
903  * 0 if false, non-zero if true
904  */
905 int __init_memblock memblock_is_region_memory(phys_addr_t base, phys_addr_t size)
906 {
907 	int idx = memblock_search(&memblock.memory, base);
908 	phys_addr_t end = base + memblock_cap_size(base, &size);
909 
910 	if (idx == -1)
911 		return 0;
912 	return memblock.memory.regions[idx].base <= base &&
913 		(memblock.memory.regions[idx].base +
914 		 memblock.memory.regions[idx].size) >= end;
915 }
916 
917 /**
918  * memblock_is_region_reserved - check if a region intersects reserved memory
919  * @base: base of region to check
920  * @size: size of region to check
921  *
922  * Check if the region [@base, @base+@size) intersects a reserved memory block.
923  *
924  * RETURNS:
925  * 0 if false, non-zero if true
926  */
927 int __init_memblock memblock_is_region_reserved(phys_addr_t base, phys_addr_t size)
928 {
929 	memblock_cap_size(base, &size);
930 	return memblock_overlaps_region(&memblock.reserved, base, size) >= 0;
931 }
932 
933 void __init_memblock memblock_trim_memory(phys_addr_t align)
934 {
935 	int i;
936 	phys_addr_t start, end, orig_start, orig_end;
937 	struct memblock_type *mem = &memblock.memory;
938 
939 	for (i = 0; i < mem->cnt; i++) {
940 		orig_start = mem->regions[i].base;
941 		orig_end = mem->regions[i].base + mem->regions[i].size;
942 		start = round_up(orig_start, align);
943 		end = round_down(orig_end, align);
944 
945 		if (start == orig_start && end == orig_end)
946 			continue;
947 
948 		if (start < end) {
949 			mem->regions[i].base = start;
950 			mem->regions[i].size = end - start;
951 		} else {
952 			memblock_remove_region(mem, i);
953 			i--;
954 		}
955 	}
956 }
957 
958 void __init_memblock memblock_set_current_limit(phys_addr_t limit)
959 {
960 	memblock.current_limit = limit;
961 }
962 
963 static void __init_memblock memblock_dump(struct memblock_type *type, char *name)
964 {
965 	unsigned long long base, size;
966 	int i;
967 
968 	pr_info(" %s.cnt  = 0x%lx\n", name, type->cnt);
969 
970 	for (i = 0; i < type->cnt; i++) {
971 		struct memblock_region *rgn = &type->regions[i];
972 		char nid_buf[32] = "";
973 
974 		base = rgn->base;
975 		size = rgn->size;
976 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
977 		if (memblock_get_region_node(rgn) != MAX_NUMNODES)
978 			snprintf(nid_buf, sizeof(nid_buf), " on node %d",
979 				 memblock_get_region_node(rgn));
980 #endif
981 		pr_info(" %s[%#x]\t[%#016llx-%#016llx], %#llx bytes%s\n",
982 			name, i, base, base + size - 1, size, nid_buf);
983 	}
984 }
985 
986 void __init_memblock __memblock_dump_all(void)
987 {
988 	pr_info("MEMBLOCK configuration:\n");
989 	pr_info(" memory size = %#llx reserved size = %#llx\n",
990 		(unsigned long long)memblock.memory.total_size,
991 		(unsigned long long)memblock.reserved.total_size);
992 
993 	memblock_dump(&memblock.memory, "memory");
994 	memblock_dump(&memblock.reserved, "reserved");
995 }
996 
997 void __init memblock_allow_resize(void)
998 {
999 	memblock_can_resize = 1;
1000 }
1001 
1002 static int __init early_memblock(char *p)
1003 {
1004 	if (p && strstr(p, "debug"))
1005 		memblock_debug = 1;
1006 	return 0;
1007 }
1008 early_param("memblock", early_memblock);
1009 
1010 #if defined(CONFIG_DEBUG_FS) && !defined(CONFIG_ARCH_DISCARD_MEMBLOCK)
1011 
1012 static int memblock_debug_show(struct seq_file *m, void *private)
1013 {
1014 	struct memblock_type *type = m->private;
1015 	struct memblock_region *reg;
1016 	int i;
1017 
1018 	for (i = 0; i < type->cnt; i++) {
1019 		reg = &type->regions[i];
1020 		seq_printf(m, "%4d: ", i);
1021 		if (sizeof(phys_addr_t) == 4)
1022 			seq_printf(m, "0x%08lx..0x%08lx\n",
1023 				   (unsigned long)reg->base,
1024 				   (unsigned long)(reg->base + reg->size - 1));
1025 		else
1026 			seq_printf(m, "0x%016llx..0x%016llx\n",
1027 				   (unsigned long long)reg->base,
1028 				   (unsigned long long)(reg->base + reg->size - 1));
1029 
1030 	}
1031 	return 0;
1032 }
1033 
1034 static int memblock_debug_open(struct inode *inode, struct file *file)
1035 {
1036 	return single_open(file, memblock_debug_show, inode->i_private);
1037 }
1038 
1039 static const struct file_operations memblock_debug_fops = {
1040 	.open = memblock_debug_open,
1041 	.read = seq_read,
1042 	.llseek = seq_lseek,
1043 	.release = single_release,
1044 };
1045 
1046 static int __init memblock_init_debugfs(void)
1047 {
1048 	struct dentry *root = debugfs_create_dir("memblock", NULL);
1049 	if (!root)
1050 		return -ENXIO;
1051 	debugfs_create_file("memory", S_IRUGO, root, &memblock.memory, &memblock_debug_fops);
1052 	debugfs_create_file("reserved", S_IRUGO, root, &memblock.reserved, &memblock_debug_fops);
1053 
1054 	return 0;
1055 }
1056 __initcall(memblock_init_debugfs);
1057 
1058 #endif /* CONFIG_DEBUG_FS */
1059