xref: /openbmc/linux/mm/memblock.c (revision c0605cd6)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Procedures for maintaining information about logical memory blocks.
4  *
5  * Peter Bergner, IBM Corp.	June 2001.
6  * Copyright (C) 2001 Peter Bergner.
7  */
8 
9 #include <linux/kernel.h>
10 #include <linux/slab.h>
11 #include <linux/init.h>
12 #include <linux/bitops.h>
13 #include <linux/poison.h>
14 #include <linux/pfn.h>
15 #include <linux/debugfs.h>
16 #include <linux/kmemleak.h>
17 #include <linux/seq_file.h>
18 #include <linux/memblock.h>
19 
20 #include <asm/sections.h>
21 #include <linux/io.h>
22 
23 #include "internal.h"
24 
25 #define INIT_MEMBLOCK_REGIONS			128
26 #define INIT_PHYSMEM_REGIONS			4
27 
28 #ifndef INIT_MEMBLOCK_RESERVED_REGIONS
29 # define INIT_MEMBLOCK_RESERVED_REGIONS		INIT_MEMBLOCK_REGIONS
30 #endif
31 
32 #ifndef INIT_MEMBLOCK_MEMORY_REGIONS
33 #define INIT_MEMBLOCK_MEMORY_REGIONS		INIT_MEMBLOCK_REGIONS
34 #endif
35 
36 /**
37  * DOC: memblock overview
38  *
39  * Memblock is a method of managing memory regions during the early
40  * boot period when the usual kernel memory allocators are not up and
41  * running.
42  *
43  * Memblock views the system memory as collections of contiguous
44  * regions. There are several types of these collections:
45  *
46  * * ``memory`` - describes the physical memory available to the
47  *   kernel; this may differ from the actual physical memory installed
48  *   in the system, for instance when the memory is restricted with
49  *   ``mem=`` command line parameter
50  * * ``reserved`` - describes the regions that were allocated
51  * * ``physmem`` - describes the actual physical memory available during
52  *   boot regardless of the possible restrictions and memory hot(un)plug;
53  *   the ``physmem`` type is only available on some architectures.
54  *
55  * Each region is represented by struct memblock_region that
56  * defines the region extents, its attributes and NUMA node id on NUMA
57  * systems. Every memory type is described by the struct memblock_type
58  * which contains an array of memory regions along with
59  * the allocator metadata. The "memory" and "reserved" types are nicely
60  * wrapped with struct memblock. This structure is statically
61  * initialized at build time. The region arrays are initially sized to
62  * %INIT_MEMBLOCK_MEMORY_REGIONS for "memory" and
63  * %INIT_MEMBLOCK_RESERVED_REGIONS for "reserved". The region array
64  * for "physmem" is initially sized to %INIT_PHYSMEM_REGIONS.
65  * The memblock_allow_resize() enables automatic resizing of the region
66  * arrays during addition of new regions. This feature should be used
67  * with care so that memory allocated for the region array will not
68  * overlap with areas that should be reserved, for example initrd.
69  *
70  * The early architecture setup should tell memblock what the physical
71  * memory layout is by using memblock_add() or memblock_add_node()
72  * functions. The first function does not assign the region to a NUMA
73  * node and it is appropriate for UMA systems. Yet, it is possible to
74  * use it on NUMA systems as well and assign the region to a NUMA node
75  * later in the setup process using memblock_set_node(). The
76  * memblock_add_node() performs such an assignment directly.
77  *
78  * Once memblock is setup the memory can be allocated using one of the
79  * API variants:
80  *
81  * * memblock_phys_alloc*() - these functions return the **physical**
82  *   address of the allocated memory
83  * * memblock_alloc*() - these functions return the **virtual** address
84  *   of the allocated memory.
85  *
86  * Note, that both API variants use implicit assumptions about allowed
87  * memory ranges and the fallback methods. Consult the documentation
88  * of memblock_alloc_internal() and memblock_alloc_range_nid()
89  * functions for more elaborate description.
90  *
91  * As the system boot progresses, the architecture specific mem_init()
92  * function frees all the memory to the buddy page allocator.
93  *
94  * Unless an architecture enables %CONFIG_ARCH_KEEP_MEMBLOCK, the
95  * memblock data structures (except "physmem") will be discarded after the
96  * system initialization completes.
97  */
98 
99 #ifndef CONFIG_NUMA
100 struct pglist_data __refdata contig_page_data;
101 EXPORT_SYMBOL(contig_page_data);
102 #endif
103 
104 unsigned long max_low_pfn;
105 unsigned long min_low_pfn;
106 unsigned long max_pfn;
107 unsigned long long max_possible_pfn;
108 
109 static struct memblock_region memblock_memory_init_regions[INIT_MEMBLOCK_MEMORY_REGIONS] __initdata_memblock;
110 static struct memblock_region memblock_reserved_init_regions[INIT_MEMBLOCK_RESERVED_REGIONS] __initdata_memblock;
111 #ifdef CONFIG_HAVE_MEMBLOCK_PHYS_MAP
112 static struct memblock_region memblock_physmem_init_regions[INIT_PHYSMEM_REGIONS];
113 #endif
114 
115 struct memblock memblock __initdata_memblock = {
116 	.memory.regions		= memblock_memory_init_regions,
117 	.memory.cnt		= 1,	/* empty dummy entry */
118 	.memory.max		= INIT_MEMBLOCK_MEMORY_REGIONS,
119 	.memory.name		= "memory",
120 
121 	.reserved.regions	= memblock_reserved_init_regions,
122 	.reserved.cnt		= 1,	/* empty dummy entry */
123 	.reserved.max		= INIT_MEMBLOCK_RESERVED_REGIONS,
124 	.reserved.name		= "reserved",
125 
126 	.bottom_up		= false,
127 	.current_limit		= MEMBLOCK_ALLOC_ANYWHERE,
128 };
129 
130 #ifdef CONFIG_HAVE_MEMBLOCK_PHYS_MAP
131 struct memblock_type physmem = {
132 	.regions		= memblock_physmem_init_regions,
133 	.cnt			= 1,	/* empty dummy entry */
134 	.max			= INIT_PHYSMEM_REGIONS,
135 	.name			= "physmem",
136 };
137 #endif
138 
139 /*
140  * keep a pointer to &memblock.memory in the text section to use it in
141  * __next_mem_range() and its helpers.
142  *  For architectures that do not keep memblock data after init, this
143  * pointer will be reset to NULL at memblock_discard()
144  */
145 static __refdata struct memblock_type *memblock_memory = &memblock.memory;
146 
147 #define for_each_memblock_type(i, memblock_type, rgn)			\
148 	for (i = 0, rgn = &memblock_type->regions[0];			\
149 	     i < memblock_type->cnt;					\
150 	     i++, rgn = &memblock_type->regions[i])
151 
152 #define memblock_dbg(fmt, ...)						\
153 	do {								\
154 		if (memblock_debug)					\
155 			pr_info(fmt, ##__VA_ARGS__);			\
156 	} while (0)
157 
158 static int memblock_debug __initdata_memblock;
159 static bool system_has_some_mirror __initdata_memblock = false;
160 static int memblock_can_resize __initdata_memblock;
161 static int memblock_memory_in_slab __initdata_memblock = 0;
162 static int memblock_reserved_in_slab __initdata_memblock = 0;
163 
164 static enum memblock_flags __init_memblock choose_memblock_flags(void)
165 {
166 	return system_has_some_mirror ? MEMBLOCK_MIRROR : MEMBLOCK_NONE;
167 }
168 
169 /* adjust *@size so that (@base + *@size) doesn't overflow, return new size */
170 static inline phys_addr_t memblock_cap_size(phys_addr_t base, phys_addr_t *size)
171 {
172 	return *size = min(*size, PHYS_ADDR_MAX - base);
173 }
174 
175 /*
176  * Address comparison utilities
177  */
178 static unsigned long __init_memblock memblock_addrs_overlap(phys_addr_t base1, phys_addr_t size1,
179 				       phys_addr_t base2, phys_addr_t size2)
180 {
181 	return ((base1 < (base2 + size2)) && (base2 < (base1 + size1)));
182 }
183 
184 bool __init_memblock memblock_overlaps_region(struct memblock_type *type,
185 					phys_addr_t base, phys_addr_t size)
186 {
187 	unsigned long i;
188 
189 	memblock_cap_size(base, &size);
190 
191 	for (i = 0; i < type->cnt; i++)
192 		if (memblock_addrs_overlap(base, size, type->regions[i].base,
193 					   type->regions[i].size))
194 			break;
195 	return i < type->cnt;
196 }
197 
198 /**
199  * __memblock_find_range_bottom_up - find free area utility in bottom-up
200  * @start: start of candidate range
201  * @end: end of candidate range, can be %MEMBLOCK_ALLOC_ANYWHERE or
202  *       %MEMBLOCK_ALLOC_ACCESSIBLE
203  * @size: size of free area to find
204  * @align: alignment of free area to find
205  * @nid: nid of the free area to find, %NUMA_NO_NODE for any node
206  * @flags: pick from blocks based on memory attributes
207  *
208  * Utility called from memblock_find_in_range_node(), find free area bottom-up.
209  *
210  * Return:
211  * Found address on success, 0 on failure.
212  */
213 static phys_addr_t __init_memblock
214 __memblock_find_range_bottom_up(phys_addr_t start, phys_addr_t end,
215 				phys_addr_t size, phys_addr_t align, int nid,
216 				enum memblock_flags flags)
217 {
218 	phys_addr_t this_start, this_end, cand;
219 	u64 i;
220 
221 	for_each_free_mem_range(i, nid, flags, &this_start, &this_end, NULL) {
222 		this_start = clamp(this_start, start, end);
223 		this_end = clamp(this_end, start, end);
224 
225 		cand = round_up(this_start, align);
226 		if (cand < this_end && this_end - cand >= size)
227 			return cand;
228 	}
229 
230 	return 0;
231 }
232 
233 /**
234  * __memblock_find_range_top_down - find free area utility, in top-down
235  * @start: start of candidate range
236  * @end: end of candidate range, can be %MEMBLOCK_ALLOC_ANYWHERE or
237  *       %MEMBLOCK_ALLOC_ACCESSIBLE
238  * @size: size of free area to find
239  * @align: alignment of free area to find
240  * @nid: nid of the free area to find, %NUMA_NO_NODE for any node
241  * @flags: pick from blocks based on memory attributes
242  *
243  * Utility called from memblock_find_in_range_node(), find free area top-down.
244  *
245  * Return:
246  * Found address on success, 0 on failure.
247  */
248 static phys_addr_t __init_memblock
249 __memblock_find_range_top_down(phys_addr_t start, phys_addr_t end,
250 			       phys_addr_t size, phys_addr_t align, int nid,
251 			       enum memblock_flags flags)
252 {
253 	phys_addr_t this_start, this_end, cand;
254 	u64 i;
255 
256 	for_each_free_mem_range_reverse(i, nid, flags, &this_start, &this_end,
257 					NULL) {
258 		this_start = clamp(this_start, start, end);
259 		this_end = clamp(this_end, start, end);
260 
261 		if (this_end < size)
262 			continue;
263 
264 		cand = round_down(this_end - size, align);
265 		if (cand >= this_start)
266 			return cand;
267 	}
268 
269 	return 0;
270 }
271 
272 /**
273  * memblock_find_in_range_node - find free area in given range and node
274  * @size: size of free area to find
275  * @align: alignment of free area to find
276  * @start: start of candidate range
277  * @end: end of candidate range, can be %MEMBLOCK_ALLOC_ANYWHERE or
278  *       %MEMBLOCK_ALLOC_ACCESSIBLE
279  * @nid: nid of the free area to find, %NUMA_NO_NODE for any node
280  * @flags: pick from blocks based on memory attributes
281  *
282  * Find @size free area aligned to @align in the specified range and node.
283  *
284  * Return:
285  * Found address on success, 0 on failure.
286  */
287 static phys_addr_t __init_memblock memblock_find_in_range_node(phys_addr_t size,
288 					phys_addr_t align, phys_addr_t start,
289 					phys_addr_t end, int nid,
290 					enum memblock_flags flags)
291 {
292 	/* pump up @end */
293 	if (end == MEMBLOCK_ALLOC_ACCESSIBLE ||
294 	    end == MEMBLOCK_ALLOC_NOLEAKTRACE)
295 		end = memblock.current_limit;
296 
297 	/* avoid allocating the first page */
298 	start = max_t(phys_addr_t, start, PAGE_SIZE);
299 	end = max(start, end);
300 
301 	if (memblock_bottom_up())
302 		return __memblock_find_range_bottom_up(start, end, size, align,
303 						       nid, flags);
304 	else
305 		return __memblock_find_range_top_down(start, end, size, align,
306 						      nid, flags);
307 }
308 
309 /**
310  * memblock_find_in_range - find free area in given range
311  * @start: start of candidate range
312  * @end: end of candidate range, can be %MEMBLOCK_ALLOC_ANYWHERE or
313  *       %MEMBLOCK_ALLOC_ACCESSIBLE
314  * @size: size of free area to find
315  * @align: alignment of free area to find
316  *
317  * Find @size free area aligned to @align in the specified range.
318  *
319  * Return:
320  * Found address on success, 0 on failure.
321  */
322 static phys_addr_t __init_memblock memblock_find_in_range(phys_addr_t start,
323 					phys_addr_t end, phys_addr_t size,
324 					phys_addr_t align)
325 {
326 	phys_addr_t ret;
327 	enum memblock_flags flags = choose_memblock_flags();
328 
329 again:
330 	ret = memblock_find_in_range_node(size, align, start, end,
331 					    NUMA_NO_NODE, flags);
332 
333 	if (!ret && (flags & MEMBLOCK_MIRROR)) {
334 		pr_warn_ratelimited("Could not allocate %pap bytes of mirrored memory\n",
335 			&size);
336 		flags &= ~MEMBLOCK_MIRROR;
337 		goto again;
338 	}
339 
340 	return ret;
341 }
342 
343 static void __init_memblock memblock_remove_region(struct memblock_type *type, unsigned long r)
344 {
345 	type->total_size -= type->regions[r].size;
346 	memmove(&type->regions[r], &type->regions[r + 1],
347 		(type->cnt - (r + 1)) * sizeof(type->regions[r]));
348 	type->cnt--;
349 
350 	/* Special case for empty arrays */
351 	if (type->cnt == 0) {
352 		WARN_ON(type->total_size != 0);
353 		type->cnt = 1;
354 		type->regions[0].base = 0;
355 		type->regions[0].size = 0;
356 		type->regions[0].flags = 0;
357 		memblock_set_region_node(&type->regions[0], MAX_NUMNODES);
358 	}
359 }
360 
361 #ifndef CONFIG_ARCH_KEEP_MEMBLOCK
362 /**
363  * memblock_discard - discard memory and reserved arrays if they were allocated
364  */
365 void __init memblock_discard(void)
366 {
367 	phys_addr_t addr, size;
368 
369 	if (memblock.reserved.regions != memblock_reserved_init_regions) {
370 		addr = __pa(memblock.reserved.regions);
371 		size = PAGE_ALIGN(sizeof(struct memblock_region) *
372 				  memblock.reserved.max);
373 		if (memblock_reserved_in_slab)
374 			kfree(memblock.reserved.regions);
375 		else
376 			memblock_free_late(addr, size);
377 	}
378 
379 	if (memblock.memory.regions != memblock_memory_init_regions) {
380 		addr = __pa(memblock.memory.regions);
381 		size = PAGE_ALIGN(sizeof(struct memblock_region) *
382 				  memblock.memory.max);
383 		if (memblock_memory_in_slab)
384 			kfree(memblock.memory.regions);
385 		else
386 			memblock_free_late(addr, size);
387 	}
388 
389 	memblock_memory = NULL;
390 }
391 #endif
392 
393 /**
394  * memblock_double_array - double the size of the memblock regions array
395  * @type: memblock type of the regions array being doubled
396  * @new_area_start: starting address of memory range to avoid overlap with
397  * @new_area_size: size of memory range to avoid overlap with
398  *
399  * Double the size of the @type regions array. If memblock is being used to
400  * allocate memory for a new reserved regions array and there is a previously
401  * allocated memory range [@new_area_start, @new_area_start + @new_area_size]
402  * waiting to be reserved, ensure the memory used by the new array does
403  * not overlap.
404  *
405  * Return:
406  * 0 on success, -1 on failure.
407  */
408 static int __init_memblock memblock_double_array(struct memblock_type *type,
409 						phys_addr_t new_area_start,
410 						phys_addr_t new_area_size)
411 {
412 	struct memblock_region *new_array, *old_array;
413 	phys_addr_t old_alloc_size, new_alloc_size;
414 	phys_addr_t old_size, new_size, addr, new_end;
415 	int use_slab = slab_is_available();
416 	int *in_slab;
417 
418 	/* We don't allow resizing until we know about the reserved regions
419 	 * of memory that aren't suitable for allocation
420 	 */
421 	if (!memblock_can_resize)
422 		return -1;
423 
424 	/* Calculate new doubled size */
425 	old_size = type->max * sizeof(struct memblock_region);
426 	new_size = old_size << 1;
427 	/*
428 	 * We need to allocated new one align to PAGE_SIZE,
429 	 *   so we can free them completely later.
430 	 */
431 	old_alloc_size = PAGE_ALIGN(old_size);
432 	new_alloc_size = PAGE_ALIGN(new_size);
433 
434 	/* Retrieve the slab flag */
435 	if (type == &memblock.memory)
436 		in_slab = &memblock_memory_in_slab;
437 	else
438 		in_slab = &memblock_reserved_in_slab;
439 
440 	/* Try to find some space for it */
441 	if (use_slab) {
442 		new_array = kmalloc(new_size, GFP_KERNEL);
443 		addr = new_array ? __pa(new_array) : 0;
444 	} else {
445 		/* only exclude range when trying to double reserved.regions */
446 		if (type != &memblock.reserved)
447 			new_area_start = new_area_size = 0;
448 
449 		addr = memblock_find_in_range(new_area_start + new_area_size,
450 						memblock.current_limit,
451 						new_alloc_size, PAGE_SIZE);
452 		if (!addr && new_area_size)
453 			addr = memblock_find_in_range(0,
454 				min(new_area_start, memblock.current_limit),
455 				new_alloc_size, PAGE_SIZE);
456 
457 		new_array = addr ? __va(addr) : NULL;
458 	}
459 	if (!addr) {
460 		pr_err("memblock: Failed to double %s array from %ld to %ld entries !\n",
461 		       type->name, type->max, type->max * 2);
462 		return -1;
463 	}
464 
465 	new_end = addr + new_size - 1;
466 	memblock_dbg("memblock: %s is doubled to %ld at [%pa-%pa]",
467 			type->name, type->max * 2, &addr, &new_end);
468 
469 	/*
470 	 * Found space, we now need to move the array over before we add the
471 	 * reserved region since it may be our reserved array itself that is
472 	 * full.
473 	 */
474 	memcpy(new_array, type->regions, old_size);
475 	memset(new_array + type->max, 0, old_size);
476 	old_array = type->regions;
477 	type->regions = new_array;
478 	type->max <<= 1;
479 
480 	/* Free old array. We needn't free it if the array is the static one */
481 	if (*in_slab)
482 		kfree(old_array);
483 	else if (old_array != memblock_memory_init_regions &&
484 		 old_array != memblock_reserved_init_regions)
485 		memblock_free(old_array, old_alloc_size);
486 
487 	/*
488 	 * Reserve the new array if that comes from the memblock.  Otherwise, we
489 	 * needn't do it
490 	 */
491 	if (!use_slab)
492 		BUG_ON(memblock_reserve(addr, new_alloc_size));
493 
494 	/* Update slab flag */
495 	*in_slab = use_slab;
496 
497 	return 0;
498 }
499 
500 /**
501  * memblock_merge_regions - merge neighboring compatible regions
502  * @type: memblock type to scan
503  *
504  * Scan @type and merge neighboring compatible regions.
505  */
506 static void __init_memblock memblock_merge_regions(struct memblock_type *type)
507 {
508 	int i = 0;
509 
510 	/* cnt never goes below 1 */
511 	while (i < type->cnt - 1) {
512 		struct memblock_region *this = &type->regions[i];
513 		struct memblock_region *next = &type->regions[i + 1];
514 
515 		if (this->base + this->size != next->base ||
516 		    memblock_get_region_node(this) !=
517 		    memblock_get_region_node(next) ||
518 		    this->flags != next->flags) {
519 			BUG_ON(this->base + this->size > next->base);
520 			i++;
521 			continue;
522 		}
523 
524 		this->size += next->size;
525 		/* move forward from next + 1, index of which is i + 2 */
526 		memmove(next, next + 1, (type->cnt - (i + 2)) * sizeof(*next));
527 		type->cnt--;
528 	}
529 }
530 
531 /**
532  * memblock_insert_region - insert new memblock region
533  * @type:	memblock type to insert into
534  * @idx:	index for the insertion point
535  * @base:	base address of the new region
536  * @size:	size of the new region
537  * @nid:	node id of the new region
538  * @flags:	flags of the new region
539  *
540  * Insert new memblock region [@base, @base + @size) into @type at @idx.
541  * @type must already have extra room to accommodate the new region.
542  */
543 static void __init_memblock memblock_insert_region(struct memblock_type *type,
544 						   int idx, phys_addr_t base,
545 						   phys_addr_t size,
546 						   int nid,
547 						   enum memblock_flags flags)
548 {
549 	struct memblock_region *rgn = &type->regions[idx];
550 
551 	BUG_ON(type->cnt >= type->max);
552 	memmove(rgn + 1, rgn, (type->cnt - idx) * sizeof(*rgn));
553 	rgn->base = base;
554 	rgn->size = size;
555 	rgn->flags = flags;
556 	memblock_set_region_node(rgn, nid);
557 	type->cnt++;
558 	type->total_size += size;
559 }
560 
561 /**
562  * memblock_add_range - add new memblock region
563  * @type: memblock type to add new region into
564  * @base: base address of the new region
565  * @size: size of the new region
566  * @nid: nid of the new region
567  * @flags: flags of the new region
568  *
569  * Add new memblock region [@base, @base + @size) into @type.  The new region
570  * is allowed to overlap with existing ones - overlaps don't affect already
571  * existing regions.  @type is guaranteed to be minimal (all neighbouring
572  * compatible regions are merged) after the addition.
573  *
574  * Return:
575  * 0 on success, -errno on failure.
576  */
577 static int __init_memblock memblock_add_range(struct memblock_type *type,
578 				phys_addr_t base, phys_addr_t size,
579 				int nid, enum memblock_flags flags)
580 {
581 	bool insert = false;
582 	phys_addr_t obase = base;
583 	phys_addr_t end = base + memblock_cap_size(base, &size);
584 	int idx, nr_new;
585 	struct memblock_region *rgn;
586 
587 	if (!size)
588 		return 0;
589 
590 	/* special case for empty array */
591 	if (type->regions[0].size == 0) {
592 		WARN_ON(type->cnt != 1 || type->total_size);
593 		type->regions[0].base = base;
594 		type->regions[0].size = size;
595 		type->regions[0].flags = flags;
596 		memblock_set_region_node(&type->regions[0], nid);
597 		type->total_size = size;
598 		return 0;
599 	}
600 
601 	/*
602 	 * The worst case is when new range overlaps all existing regions,
603 	 * then we'll need type->cnt + 1 empty regions in @type. So if
604 	 * type->cnt * 2 + 1 is less than type->max, we know
605 	 * that there is enough empty regions in @type, and we can insert
606 	 * regions directly.
607 	 */
608 	if (type->cnt * 2 + 1 < type->max)
609 		insert = true;
610 
611 repeat:
612 	/*
613 	 * The following is executed twice.  Once with %false @insert and
614 	 * then with %true.  The first counts the number of regions needed
615 	 * to accommodate the new area.  The second actually inserts them.
616 	 */
617 	base = obase;
618 	nr_new = 0;
619 
620 	for_each_memblock_type(idx, type, rgn) {
621 		phys_addr_t rbase = rgn->base;
622 		phys_addr_t rend = rbase + rgn->size;
623 
624 		if (rbase >= end)
625 			break;
626 		if (rend <= base)
627 			continue;
628 		/*
629 		 * @rgn overlaps.  If it separates the lower part of new
630 		 * area, insert that portion.
631 		 */
632 		if (rbase > base) {
633 #ifdef CONFIG_NUMA
634 			WARN_ON(nid != memblock_get_region_node(rgn));
635 #endif
636 			WARN_ON(flags != rgn->flags);
637 			nr_new++;
638 			if (insert)
639 				memblock_insert_region(type, idx++, base,
640 						       rbase - base, nid,
641 						       flags);
642 		}
643 		/* area below @rend is dealt with, forget about it */
644 		base = min(rend, end);
645 	}
646 
647 	/* insert the remaining portion */
648 	if (base < end) {
649 		nr_new++;
650 		if (insert)
651 			memblock_insert_region(type, idx, base, end - base,
652 					       nid, flags);
653 	}
654 
655 	if (!nr_new)
656 		return 0;
657 
658 	/*
659 	 * If this was the first round, resize array and repeat for actual
660 	 * insertions; otherwise, merge and return.
661 	 */
662 	if (!insert) {
663 		while (type->cnt + nr_new > type->max)
664 			if (memblock_double_array(type, obase, size) < 0)
665 				return -ENOMEM;
666 		insert = true;
667 		goto repeat;
668 	} else {
669 		memblock_merge_regions(type);
670 		return 0;
671 	}
672 }
673 
674 /**
675  * memblock_add_node - add new memblock region within a NUMA node
676  * @base: base address of the new region
677  * @size: size of the new region
678  * @nid: nid of the new region
679  * @flags: flags of the new region
680  *
681  * Add new memblock region [@base, @base + @size) to the "memory"
682  * type. See memblock_add_range() description for mode details
683  *
684  * Return:
685  * 0 on success, -errno on failure.
686  */
687 int __init_memblock memblock_add_node(phys_addr_t base, phys_addr_t size,
688 				      int nid, enum memblock_flags flags)
689 {
690 	phys_addr_t end = base + size - 1;
691 
692 	memblock_dbg("%s: [%pa-%pa] nid=%d flags=%x %pS\n", __func__,
693 		     &base, &end, nid, flags, (void *)_RET_IP_);
694 
695 	return memblock_add_range(&memblock.memory, base, size, nid, flags);
696 }
697 
698 /**
699  * memblock_add - add new memblock region
700  * @base: base address of the new region
701  * @size: size of the new region
702  *
703  * Add new memblock region [@base, @base + @size) to the "memory"
704  * type. See memblock_add_range() description for mode details
705  *
706  * Return:
707  * 0 on success, -errno on failure.
708  */
709 int __init_memblock memblock_add(phys_addr_t base, phys_addr_t size)
710 {
711 	phys_addr_t end = base + size - 1;
712 
713 	memblock_dbg("%s: [%pa-%pa] %pS\n", __func__,
714 		     &base, &end, (void *)_RET_IP_);
715 
716 	return memblock_add_range(&memblock.memory, base, size, MAX_NUMNODES, 0);
717 }
718 
719 /**
720  * memblock_isolate_range - isolate given range into disjoint memblocks
721  * @type: memblock type to isolate range for
722  * @base: base of range to isolate
723  * @size: size of range to isolate
724  * @start_rgn: out parameter for the start of isolated region
725  * @end_rgn: out parameter for the end of isolated region
726  *
727  * Walk @type and ensure that regions don't cross the boundaries defined by
728  * [@base, @base + @size).  Crossing regions are split at the boundaries,
729  * which may create at most two more regions.  The index of the first
730  * region inside the range is returned in *@start_rgn and end in *@end_rgn.
731  *
732  * Return:
733  * 0 on success, -errno on failure.
734  */
735 static int __init_memblock memblock_isolate_range(struct memblock_type *type,
736 					phys_addr_t base, phys_addr_t size,
737 					int *start_rgn, int *end_rgn)
738 {
739 	phys_addr_t end = base + memblock_cap_size(base, &size);
740 	int idx;
741 	struct memblock_region *rgn;
742 
743 	*start_rgn = *end_rgn = 0;
744 
745 	if (!size)
746 		return 0;
747 
748 	/* we'll create at most two more regions */
749 	while (type->cnt + 2 > type->max)
750 		if (memblock_double_array(type, base, size) < 0)
751 			return -ENOMEM;
752 
753 	for_each_memblock_type(idx, type, rgn) {
754 		phys_addr_t rbase = rgn->base;
755 		phys_addr_t rend = rbase + rgn->size;
756 
757 		if (rbase >= end)
758 			break;
759 		if (rend <= base)
760 			continue;
761 
762 		if (rbase < base) {
763 			/*
764 			 * @rgn intersects from below.  Split and continue
765 			 * to process the next region - the new top half.
766 			 */
767 			rgn->base = base;
768 			rgn->size -= base - rbase;
769 			type->total_size -= base - rbase;
770 			memblock_insert_region(type, idx, rbase, base - rbase,
771 					       memblock_get_region_node(rgn),
772 					       rgn->flags);
773 		} else if (rend > end) {
774 			/*
775 			 * @rgn intersects from above.  Split and redo the
776 			 * current region - the new bottom half.
777 			 */
778 			rgn->base = end;
779 			rgn->size -= end - rbase;
780 			type->total_size -= end - rbase;
781 			memblock_insert_region(type, idx--, rbase, end - rbase,
782 					       memblock_get_region_node(rgn),
783 					       rgn->flags);
784 		} else {
785 			/* @rgn is fully contained, record it */
786 			if (!*end_rgn)
787 				*start_rgn = idx;
788 			*end_rgn = idx + 1;
789 		}
790 	}
791 
792 	return 0;
793 }
794 
795 static int __init_memblock memblock_remove_range(struct memblock_type *type,
796 					  phys_addr_t base, phys_addr_t size)
797 {
798 	int start_rgn, end_rgn;
799 	int i, ret;
800 
801 	ret = memblock_isolate_range(type, base, size, &start_rgn, &end_rgn);
802 	if (ret)
803 		return ret;
804 
805 	for (i = end_rgn - 1; i >= start_rgn; i--)
806 		memblock_remove_region(type, i);
807 	return 0;
808 }
809 
810 int __init_memblock memblock_remove(phys_addr_t base, phys_addr_t size)
811 {
812 	phys_addr_t end = base + size - 1;
813 
814 	memblock_dbg("%s: [%pa-%pa] %pS\n", __func__,
815 		     &base, &end, (void *)_RET_IP_);
816 
817 	return memblock_remove_range(&memblock.memory, base, size);
818 }
819 
820 /**
821  * memblock_free - free boot memory allocation
822  * @ptr: starting address of the  boot memory allocation
823  * @size: size of the boot memory block in bytes
824  *
825  * Free boot memory block previously allocated by memblock_alloc_xx() API.
826  * The freeing memory will not be released to the buddy allocator.
827  */
828 void __init_memblock memblock_free(void *ptr, size_t size)
829 {
830 	if (ptr)
831 		memblock_phys_free(__pa(ptr), size);
832 }
833 
834 /**
835  * memblock_phys_free - free boot memory block
836  * @base: phys starting address of the  boot memory block
837  * @size: size of the boot memory block in bytes
838  *
839  * Free boot memory block previously allocated by memblock_alloc_xx() API.
840  * The freeing memory will not be released to the buddy allocator.
841  */
842 int __init_memblock memblock_phys_free(phys_addr_t base, phys_addr_t size)
843 {
844 	phys_addr_t end = base + size - 1;
845 
846 	memblock_dbg("%s: [%pa-%pa] %pS\n", __func__,
847 		     &base, &end, (void *)_RET_IP_);
848 
849 	kmemleak_free_part_phys(base, size);
850 	return memblock_remove_range(&memblock.reserved, base, size);
851 }
852 
853 int __init_memblock memblock_reserve(phys_addr_t base, phys_addr_t size)
854 {
855 	phys_addr_t end = base + size - 1;
856 
857 	memblock_dbg("%s: [%pa-%pa] %pS\n", __func__,
858 		     &base, &end, (void *)_RET_IP_);
859 
860 	return memblock_add_range(&memblock.reserved, base, size, MAX_NUMNODES, 0);
861 }
862 
863 #ifdef CONFIG_HAVE_MEMBLOCK_PHYS_MAP
864 int __init_memblock memblock_physmem_add(phys_addr_t base, phys_addr_t size)
865 {
866 	phys_addr_t end = base + size - 1;
867 
868 	memblock_dbg("%s: [%pa-%pa] %pS\n", __func__,
869 		     &base, &end, (void *)_RET_IP_);
870 
871 	return memblock_add_range(&physmem, base, size, MAX_NUMNODES, 0);
872 }
873 #endif
874 
875 /**
876  * memblock_setclr_flag - set or clear flag for a memory region
877  * @base: base address of the region
878  * @size: size of the region
879  * @set: set or clear the flag
880  * @flag: the flag to update
881  *
882  * This function isolates region [@base, @base + @size), and sets/clears flag
883  *
884  * Return: 0 on success, -errno on failure.
885  */
886 static int __init_memblock memblock_setclr_flag(phys_addr_t base,
887 				phys_addr_t size, int set, int flag)
888 {
889 	struct memblock_type *type = &memblock.memory;
890 	int i, ret, start_rgn, end_rgn;
891 
892 	ret = memblock_isolate_range(type, base, size, &start_rgn, &end_rgn);
893 	if (ret)
894 		return ret;
895 
896 	for (i = start_rgn; i < end_rgn; i++) {
897 		struct memblock_region *r = &type->regions[i];
898 
899 		if (set)
900 			r->flags |= flag;
901 		else
902 			r->flags &= ~flag;
903 	}
904 
905 	memblock_merge_regions(type);
906 	return 0;
907 }
908 
909 /**
910  * memblock_mark_hotplug - Mark hotpluggable memory with flag MEMBLOCK_HOTPLUG.
911  * @base: the base phys addr of the region
912  * @size: the size of the region
913  *
914  * Return: 0 on success, -errno on failure.
915  */
916 int __init_memblock memblock_mark_hotplug(phys_addr_t base, phys_addr_t size)
917 {
918 	return memblock_setclr_flag(base, size, 1, MEMBLOCK_HOTPLUG);
919 }
920 
921 /**
922  * memblock_clear_hotplug - Clear flag MEMBLOCK_HOTPLUG for a specified region.
923  * @base: the base phys addr of the region
924  * @size: the size of the region
925  *
926  * Return: 0 on success, -errno on failure.
927  */
928 int __init_memblock memblock_clear_hotplug(phys_addr_t base, phys_addr_t size)
929 {
930 	return memblock_setclr_flag(base, size, 0, MEMBLOCK_HOTPLUG);
931 }
932 
933 /**
934  * memblock_mark_mirror - Mark mirrored memory with flag MEMBLOCK_MIRROR.
935  * @base: the base phys addr of the region
936  * @size: the size of the region
937  *
938  * Return: 0 on success, -errno on failure.
939  */
940 int __init_memblock memblock_mark_mirror(phys_addr_t base, phys_addr_t size)
941 {
942 	if (!mirrored_kernelcore)
943 		return 0;
944 
945 	system_has_some_mirror = true;
946 
947 	return memblock_setclr_flag(base, size, 1, MEMBLOCK_MIRROR);
948 }
949 
950 /**
951  * memblock_mark_nomap - Mark a memory region with flag MEMBLOCK_NOMAP.
952  * @base: the base phys addr of the region
953  * @size: the size of the region
954  *
955  * The memory regions marked with %MEMBLOCK_NOMAP will not be added to the
956  * direct mapping of the physical memory. These regions will still be
957  * covered by the memory map. The struct page representing NOMAP memory
958  * frames in the memory map will be PageReserved()
959  *
960  * Note: if the memory being marked %MEMBLOCK_NOMAP was allocated from
961  * memblock, the caller must inform kmemleak to ignore that memory
962  *
963  * Return: 0 on success, -errno on failure.
964  */
965 int __init_memblock memblock_mark_nomap(phys_addr_t base, phys_addr_t size)
966 {
967 	return memblock_setclr_flag(base, size, 1, MEMBLOCK_NOMAP);
968 }
969 
970 /**
971  * memblock_clear_nomap - Clear flag MEMBLOCK_NOMAP for a specified region.
972  * @base: the base phys addr of the region
973  * @size: the size of the region
974  *
975  * Return: 0 on success, -errno on failure.
976  */
977 int __init_memblock memblock_clear_nomap(phys_addr_t base, phys_addr_t size)
978 {
979 	return memblock_setclr_flag(base, size, 0, MEMBLOCK_NOMAP);
980 }
981 
982 static bool should_skip_region(struct memblock_type *type,
983 			       struct memblock_region *m,
984 			       int nid, int flags)
985 {
986 	int m_nid = memblock_get_region_node(m);
987 
988 	/* we never skip regions when iterating memblock.reserved or physmem */
989 	if (type != memblock_memory)
990 		return false;
991 
992 	/* only memory regions are associated with nodes, check it */
993 	if (nid != NUMA_NO_NODE && nid != m_nid)
994 		return true;
995 
996 	/* skip hotpluggable memory regions if needed */
997 	if (movable_node_is_enabled() && memblock_is_hotpluggable(m) &&
998 	    !(flags & MEMBLOCK_HOTPLUG))
999 		return true;
1000 
1001 	/* if we want mirror memory skip non-mirror memory regions */
1002 	if ((flags & MEMBLOCK_MIRROR) && !memblock_is_mirror(m))
1003 		return true;
1004 
1005 	/* skip nomap memory unless we were asked for it explicitly */
1006 	if (!(flags & MEMBLOCK_NOMAP) && memblock_is_nomap(m))
1007 		return true;
1008 
1009 	/* skip driver-managed memory unless we were asked for it explicitly */
1010 	if (!(flags & MEMBLOCK_DRIVER_MANAGED) && memblock_is_driver_managed(m))
1011 		return true;
1012 
1013 	return false;
1014 }
1015 
1016 /**
1017  * __next_mem_range - next function for for_each_free_mem_range() etc.
1018  * @idx: pointer to u64 loop variable
1019  * @nid: node selector, %NUMA_NO_NODE for all nodes
1020  * @flags: pick from blocks based on memory attributes
1021  * @type_a: pointer to memblock_type from where the range is taken
1022  * @type_b: pointer to memblock_type which excludes memory from being taken
1023  * @out_start: ptr to phys_addr_t for start address of the range, can be %NULL
1024  * @out_end: ptr to phys_addr_t for end address of the range, can be %NULL
1025  * @out_nid: ptr to int for nid of the range, can be %NULL
1026  *
1027  * Find the first area from *@idx which matches @nid, fill the out
1028  * parameters, and update *@idx for the next iteration.  The lower 32bit of
1029  * *@idx contains index into type_a and the upper 32bit indexes the
1030  * areas before each region in type_b.	For example, if type_b regions
1031  * look like the following,
1032  *
1033  *	0:[0-16), 1:[32-48), 2:[128-130)
1034  *
1035  * The upper 32bit indexes the following regions.
1036  *
1037  *	0:[0-0), 1:[16-32), 2:[48-128), 3:[130-MAX)
1038  *
1039  * As both region arrays are sorted, the function advances the two indices
1040  * in lockstep and returns each intersection.
1041  */
1042 void __next_mem_range(u64 *idx, int nid, enum memblock_flags flags,
1043 		      struct memblock_type *type_a,
1044 		      struct memblock_type *type_b, phys_addr_t *out_start,
1045 		      phys_addr_t *out_end, int *out_nid)
1046 {
1047 	int idx_a = *idx & 0xffffffff;
1048 	int idx_b = *idx >> 32;
1049 
1050 	if (WARN_ONCE(nid == MAX_NUMNODES,
1051 	"Usage of MAX_NUMNODES is deprecated. Use NUMA_NO_NODE instead\n"))
1052 		nid = NUMA_NO_NODE;
1053 
1054 	for (; idx_a < type_a->cnt; idx_a++) {
1055 		struct memblock_region *m = &type_a->regions[idx_a];
1056 
1057 		phys_addr_t m_start = m->base;
1058 		phys_addr_t m_end = m->base + m->size;
1059 		int	    m_nid = memblock_get_region_node(m);
1060 
1061 		if (should_skip_region(type_a, m, nid, flags))
1062 			continue;
1063 
1064 		if (!type_b) {
1065 			if (out_start)
1066 				*out_start = m_start;
1067 			if (out_end)
1068 				*out_end = m_end;
1069 			if (out_nid)
1070 				*out_nid = m_nid;
1071 			idx_a++;
1072 			*idx = (u32)idx_a | (u64)idx_b << 32;
1073 			return;
1074 		}
1075 
1076 		/* scan areas before each reservation */
1077 		for (; idx_b < type_b->cnt + 1; idx_b++) {
1078 			struct memblock_region *r;
1079 			phys_addr_t r_start;
1080 			phys_addr_t r_end;
1081 
1082 			r = &type_b->regions[idx_b];
1083 			r_start = idx_b ? r[-1].base + r[-1].size : 0;
1084 			r_end = idx_b < type_b->cnt ?
1085 				r->base : PHYS_ADDR_MAX;
1086 
1087 			/*
1088 			 * if idx_b advanced past idx_a,
1089 			 * break out to advance idx_a
1090 			 */
1091 			if (r_start >= m_end)
1092 				break;
1093 			/* if the two regions intersect, we're done */
1094 			if (m_start < r_end) {
1095 				if (out_start)
1096 					*out_start =
1097 						max(m_start, r_start);
1098 				if (out_end)
1099 					*out_end = min(m_end, r_end);
1100 				if (out_nid)
1101 					*out_nid = m_nid;
1102 				/*
1103 				 * The region which ends first is
1104 				 * advanced for the next iteration.
1105 				 */
1106 				if (m_end <= r_end)
1107 					idx_a++;
1108 				else
1109 					idx_b++;
1110 				*idx = (u32)idx_a | (u64)idx_b << 32;
1111 				return;
1112 			}
1113 		}
1114 	}
1115 
1116 	/* signal end of iteration */
1117 	*idx = ULLONG_MAX;
1118 }
1119 
1120 /**
1121  * __next_mem_range_rev - generic next function for for_each_*_range_rev()
1122  *
1123  * @idx: pointer to u64 loop variable
1124  * @nid: node selector, %NUMA_NO_NODE for all nodes
1125  * @flags: pick from blocks based on memory attributes
1126  * @type_a: pointer to memblock_type from where the range is taken
1127  * @type_b: pointer to memblock_type which excludes memory from being taken
1128  * @out_start: ptr to phys_addr_t for start address of the range, can be %NULL
1129  * @out_end: ptr to phys_addr_t for end address of the range, can be %NULL
1130  * @out_nid: ptr to int for nid of the range, can be %NULL
1131  *
1132  * Finds the next range from type_a which is not marked as unsuitable
1133  * in type_b.
1134  *
1135  * Reverse of __next_mem_range().
1136  */
1137 void __init_memblock __next_mem_range_rev(u64 *idx, int nid,
1138 					  enum memblock_flags flags,
1139 					  struct memblock_type *type_a,
1140 					  struct memblock_type *type_b,
1141 					  phys_addr_t *out_start,
1142 					  phys_addr_t *out_end, int *out_nid)
1143 {
1144 	int idx_a = *idx & 0xffffffff;
1145 	int idx_b = *idx >> 32;
1146 
1147 	if (WARN_ONCE(nid == MAX_NUMNODES, "Usage of MAX_NUMNODES is deprecated. Use NUMA_NO_NODE instead\n"))
1148 		nid = NUMA_NO_NODE;
1149 
1150 	if (*idx == (u64)ULLONG_MAX) {
1151 		idx_a = type_a->cnt - 1;
1152 		if (type_b != NULL)
1153 			idx_b = type_b->cnt;
1154 		else
1155 			idx_b = 0;
1156 	}
1157 
1158 	for (; idx_a >= 0; idx_a--) {
1159 		struct memblock_region *m = &type_a->regions[idx_a];
1160 
1161 		phys_addr_t m_start = m->base;
1162 		phys_addr_t m_end = m->base + m->size;
1163 		int m_nid = memblock_get_region_node(m);
1164 
1165 		if (should_skip_region(type_a, m, nid, flags))
1166 			continue;
1167 
1168 		if (!type_b) {
1169 			if (out_start)
1170 				*out_start = m_start;
1171 			if (out_end)
1172 				*out_end = m_end;
1173 			if (out_nid)
1174 				*out_nid = m_nid;
1175 			idx_a--;
1176 			*idx = (u32)idx_a | (u64)idx_b << 32;
1177 			return;
1178 		}
1179 
1180 		/* scan areas before each reservation */
1181 		for (; idx_b >= 0; idx_b--) {
1182 			struct memblock_region *r;
1183 			phys_addr_t r_start;
1184 			phys_addr_t r_end;
1185 
1186 			r = &type_b->regions[idx_b];
1187 			r_start = idx_b ? r[-1].base + r[-1].size : 0;
1188 			r_end = idx_b < type_b->cnt ?
1189 				r->base : PHYS_ADDR_MAX;
1190 			/*
1191 			 * if idx_b advanced past idx_a,
1192 			 * break out to advance idx_a
1193 			 */
1194 
1195 			if (r_end <= m_start)
1196 				break;
1197 			/* if the two regions intersect, we're done */
1198 			if (m_end > r_start) {
1199 				if (out_start)
1200 					*out_start = max(m_start, r_start);
1201 				if (out_end)
1202 					*out_end = min(m_end, r_end);
1203 				if (out_nid)
1204 					*out_nid = m_nid;
1205 				if (m_start >= r_start)
1206 					idx_a--;
1207 				else
1208 					idx_b--;
1209 				*idx = (u32)idx_a | (u64)idx_b << 32;
1210 				return;
1211 			}
1212 		}
1213 	}
1214 	/* signal end of iteration */
1215 	*idx = ULLONG_MAX;
1216 }
1217 
1218 /*
1219  * Common iterator interface used to define for_each_mem_pfn_range().
1220  */
1221 void __init_memblock __next_mem_pfn_range(int *idx, int nid,
1222 				unsigned long *out_start_pfn,
1223 				unsigned long *out_end_pfn, int *out_nid)
1224 {
1225 	struct memblock_type *type = &memblock.memory;
1226 	struct memblock_region *r;
1227 	int r_nid;
1228 
1229 	while (++*idx < type->cnt) {
1230 		r = &type->regions[*idx];
1231 		r_nid = memblock_get_region_node(r);
1232 
1233 		if (PFN_UP(r->base) >= PFN_DOWN(r->base + r->size))
1234 			continue;
1235 		if (nid == MAX_NUMNODES || nid == r_nid)
1236 			break;
1237 	}
1238 	if (*idx >= type->cnt) {
1239 		*idx = -1;
1240 		return;
1241 	}
1242 
1243 	if (out_start_pfn)
1244 		*out_start_pfn = PFN_UP(r->base);
1245 	if (out_end_pfn)
1246 		*out_end_pfn = PFN_DOWN(r->base + r->size);
1247 	if (out_nid)
1248 		*out_nid = r_nid;
1249 }
1250 
1251 /**
1252  * memblock_set_node - set node ID on memblock regions
1253  * @base: base of area to set node ID for
1254  * @size: size of area to set node ID for
1255  * @type: memblock type to set node ID for
1256  * @nid: node ID to set
1257  *
1258  * Set the nid of memblock @type regions in [@base, @base + @size) to @nid.
1259  * Regions which cross the area boundaries are split as necessary.
1260  *
1261  * Return:
1262  * 0 on success, -errno on failure.
1263  */
1264 int __init_memblock memblock_set_node(phys_addr_t base, phys_addr_t size,
1265 				      struct memblock_type *type, int nid)
1266 {
1267 #ifdef CONFIG_NUMA
1268 	int start_rgn, end_rgn;
1269 	int i, ret;
1270 
1271 	ret = memblock_isolate_range(type, base, size, &start_rgn, &end_rgn);
1272 	if (ret)
1273 		return ret;
1274 
1275 	for (i = start_rgn; i < end_rgn; i++)
1276 		memblock_set_region_node(&type->regions[i], nid);
1277 
1278 	memblock_merge_regions(type);
1279 #endif
1280 	return 0;
1281 }
1282 
1283 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1284 /**
1285  * __next_mem_pfn_range_in_zone - iterator for for_each_*_range_in_zone()
1286  *
1287  * @idx: pointer to u64 loop variable
1288  * @zone: zone in which all of the memory blocks reside
1289  * @out_spfn: ptr to ulong for start pfn of the range, can be %NULL
1290  * @out_epfn: ptr to ulong for end pfn of the range, can be %NULL
1291  *
1292  * This function is meant to be a zone/pfn specific wrapper for the
1293  * for_each_mem_range type iterators. Specifically they are used in the
1294  * deferred memory init routines and as such we were duplicating much of
1295  * this logic throughout the code. So instead of having it in multiple
1296  * locations it seemed like it would make more sense to centralize this to
1297  * one new iterator that does everything they need.
1298  */
1299 void __init_memblock
1300 __next_mem_pfn_range_in_zone(u64 *idx, struct zone *zone,
1301 			     unsigned long *out_spfn, unsigned long *out_epfn)
1302 {
1303 	int zone_nid = zone_to_nid(zone);
1304 	phys_addr_t spa, epa;
1305 
1306 	__next_mem_range(idx, zone_nid, MEMBLOCK_NONE,
1307 			 &memblock.memory, &memblock.reserved,
1308 			 &spa, &epa, NULL);
1309 
1310 	while (*idx != U64_MAX) {
1311 		unsigned long epfn = PFN_DOWN(epa);
1312 		unsigned long spfn = PFN_UP(spa);
1313 
1314 		/*
1315 		 * Verify the end is at least past the start of the zone and
1316 		 * that we have at least one PFN to initialize.
1317 		 */
1318 		if (zone->zone_start_pfn < epfn && spfn < epfn) {
1319 			/* if we went too far just stop searching */
1320 			if (zone_end_pfn(zone) <= spfn) {
1321 				*idx = U64_MAX;
1322 				break;
1323 			}
1324 
1325 			if (out_spfn)
1326 				*out_spfn = max(zone->zone_start_pfn, spfn);
1327 			if (out_epfn)
1328 				*out_epfn = min(zone_end_pfn(zone), epfn);
1329 
1330 			return;
1331 		}
1332 
1333 		__next_mem_range(idx, zone_nid, MEMBLOCK_NONE,
1334 				 &memblock.memory, &memblock.reserved,
1335 				 &spa, &epa, NULL);
1336 	}
1337 
1338 	/* signal end of iteration */
1339 	if (out_spfn)
1340 		*out_spfn = ULONG_MAX;
1341 	if (out_epfn)
1342 		*out_epfn = 0;
1343 }
1344 
1345 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1346 
1347 /**
1348  * memblock_alloc_range_nid - allocate boot memory block
1349  * @size: size of memory block to be allocated in bytes
1350  * @align: alignment of the region and block's size
1351  * @start: the lower bound of the memory region to allocate (phys address)
1352  * @end: the upper bound of the memory region to allocate (phys address)
1353  * @nid: nid of the free area to find, %NUMA_NO_NODE for any node
1354  * @exact_nid: control the allocation fall back to other nodes
1355  *
1356  * The allocation is performed from memory region limited by
1357  * memblock.current_limit if @end == %MEMBLOCK_ALLOC_ACCESSIBLE.
1358  *
1359  * If the specified node can not hold the requested memory and @exact_nid
1360  * is false, the allocation falls back to any node in the system.
1361  *
1362  * For systems with memory mirroring, the allocation is attempted first
1363  * from the regions with mirroring enabled and then retried from any
1364  * memory region.
1365  *
1366  * In addition, function using kmemleak_alloc_phys for allocated boot
1367  * memory block, it is never reported as leaks.
1368  *
1369  * Return:
1370  * Physical address of allocated memory block on success, %0 on failure.
1371  */
1372 phys_addr_t __init memblock_alloc_range_nid(phys_addr_t size,
1373 					phys_addr_t align, phys_addr_t start,
1374 					phys_addr_t end, int nid,
1375 					bool exact_nid)
1376 {
1377 	enum memblock_flags flags = choose_memblock_flags();
1378 	phys_addr_t found;
1379 
1380 	if (WARN_ONCE(nid == MAX_NUMNODES, "Usage of MAX_NUMNODES is deprecated. Use NUMA_NO_NODE instead\n"))
1381 		nid = NUMA_NO_NODE;
1382 
1383 	if (!align) {
1384 		/* Can't use WARNs this early in boot on powerpc */
1385 		dump_stack();
1386 		align = SMP_CACHE_BYTES;
1387 	}
1388 
1389 again:
1390 	found = memblock_find_in_range_node(size, align, start, end, nid,
1391 					    flags);
1392 	if (found && !memblock_reserve(found, size))
1393 		goto done;
1394 
1395 	if (nid != NUMA_NO_NODE && !exact_nid) {
1396 		found = memblock_find_in_range_node(size, align, start,
1397 						    end, NUMA_NO_NODE,
1398 						    flags);
1399 		if (found && !memblock_reserve(found, size))
1400 			goto done;
1401 	}
1402 
1403 	if (flags & MEMBLOCK_MIRROR) {
1404 		flags &= ~MEMBLOCK_MIRROR;
1405 		pr_warn_ratelimited("Could not allocate %pap bytes of mirrored memory\n",
1406 			&size);
1407 		goto again;
1408 	}
1409 
1410 	return 0;
1411 
1412 done:
1413 	/*
1414 	 * Skip kmemleak for those places like kasan_init() and
1415 	 * early_pgtable_alloc() due to high volume.
1416 	 */
1417 	if (end != MEMBLOCK_ALLOC_NOLEAKTRACE)
1418 		/*
1419 		 * Memblock allocated blocks are never reported as
1420 		 * leaks. This is because many of these blocks are
1421 		 * only referred via the physical address which is
1422 		 * not looked up by kmemleak.
1423 		 */
1424 		kmemleak_alloc_phys(found, size, 0);
1425 
1426 	return found;
1427 }
1428 
1429 /**
1430  * memblock_phys_alloc_range - allocate a memory block inside specified range
1431  * @size: size of memory block to be allocated in bytes
1432  * @align: alignment of the region and block's size
1433  * @start: the lower bound of the memory region to allocate (physical address)
1434  * @end: the upper bound of the memory region to allocate (physical address)
1435  *
1436  * Allocate @size bytes in the between @start and @end.
1437  *
1438  * Return: physical address of the allocated memory block on success,
1439  * %0 on failure.
1440  */
1441 phys_addr_t __init memblock_phys_alloc_range(phys_addr_t size,
1442 					     phys_addr_t align,
1443 					     phys_addr_t start,
1444 					     phys_addr_t end)
1445 {
1446 	memblock_dbg("%s: %llu bytes align=0x%llx from=%pa max_addr=%pa %pS\n",
1447 		     __func__, (u64)size, (u64)align, &start, &end,
1448 		     (void *)_RET_IP_);
1449 	return memblock_alloc_range_nid(size, align, start, end, NUMA_NO_NODE,
1450 					false);
1451 }
1452 
1453 /**
1454  * memblock_phys_alloc_try_nid - allocate a memory block from specified NUMA node
1455  * @size: size of memory block to be allocated in bytes
1456  * @align: alignment of the region and block's size
1457  * @nid: nid of the free area to find, %NUMA_NO_NODE for any node
1458  *
1459  * Allocates memory block from the specified NUMA node. If the node
1460  * has no available memory, attempts to allocated from any node in the
1461  * system.
1462  *
1463  * Return: physical address of the allocated memory block on success,
1464  * %0 on failure.
1465  */
1466 phys_addr_t __init memblock_phys_alloc_try_nid(phys_addr_t size, phys_addr_t align, int nid)
1467 {
1468 	return memblock_alloc_range_nid(size, align, 0,
1469 					MEMBLOCK_ALLOC_ACCESSIBLE, nid, false);
1470 }
1471 
1472 /**
1473  * memblock_alloc_internal - allocate boot memory block
1474  * @size: size of memory block to be allocated in bytes
1475  * @align: alignment of the region and block's size
1476  * @min_addr: the lower bound of the memory region to allocate (phys address)
1477  * @max_addr: the upper bound of the memory region to allocate (phys address)
1478  * @nid: nid of the free area to find, %NUMA_NO_NODE for any node
1479  * @exact_nid: control the allocation fall back to other nodes
1480  *
1481  * Allocates memory block using memblock_alloc_range_nid() and
1482  * converts the returned physical address to virtual.
1483  *
1484  * The @min_addr limit is dropped if it can not be satisfied and the allocation
1485  * will fall back to memory below @min_addr. Other constraints, such
1486  * as node and mirrored memory will be handled again in
1487  * memblock_alloc_range_nid().
1488  *
1489  * Return:
1490  * Virtual address of allocated memory block on success, NULL on failure.
1491  */
1492 static void * __init memblock_alloc_internal(
1493 				phys_addr_t size, phys_addr_t align,
1494 				phys_addr_t min_addr, phys_addr_t max_addr,
1495 				int nid, bool exact_nid)
1496 {
1497 	phys_addr_t alloc;
1498 
1499 	/*
1500 	 * Detect any accidental use of these APIs after slab is ready, as at
1501 	 * this moment memblock may be deinitialized already and its
1502 	 * internal data may be destroyed (after execution of memblock_free_all)
1503 	 */
1504 	if (WARN_ON_ONCE(slab_is_available()))
1505 		return kzalloc_node(size, GFP_NOWAIT, nid);
1506 
1507 	if (max_addr > memblock.current_limit)
1508 		max_addr = memblock.current_limit;
1509 
1510 	alloc = memblock_alloc_range_nid(size, align, min_addr, max_addr, nid,
1511 					exact_nid);
1512 
1513 	/* retry allocation without lower limit */
1514 	if (!alloc && min_addr)
1515 		alloc = memblock_alloc_range_nid(size, align, 0, max_addr, nid,
1516 						exact_nid);
1517 
1518 	if (!alloc)
1519 		return NULL;
1520 
1521 	return phys_to_virt(alloc);
1522 }
1523 
1524 /**
1525  * memblock_alloc_exact_nid_raw - allocate boot memory block on the exact node
1526  * without zeroing memory
1527  * @size: size of memory block to be allocated in bytes
1528  * @align: alignment of the region and block's size
1529  * @min_addr: the lower bound of the memory region from where the allocation
1530  *	  is preferred (phys address)
1531  * @max_addr: the upper bound of the memory region from where the allocation
1532  *	      is preferred (phys address), or %MEMBLOCK_ALLOC_ACCESSIBLE to
1533  *	      allocate only from memory limited by memblock.current_limit value
1534  * @nid: nid of the free area to find, %NUMA_NO_NODE for any node
1535  *
1536  * Public function, provides additional debug information (including caller
1537  * info), if enabled. Does not zero allocated memory.
1538  *
1539  * Return:
1540  * Virtual address of allocated memory block on success, NULL on failure.
1541  */
1542 void * __init memblock_alloc_exact_nid_raw(
1543 			phys_addr_t size, phys_addr_t align,
1544 			phys_addr_t min_addr, phys_addr_t max_addr,
1545 			int nid)
1546 {
1547 	memblock_dbg("%s: %llu bytes align=0x%llx nid=%d from=%pa max_addr=%pa %pS\n",
1548 		     __func__, (u64)size, (u64)align, nid, &min_addr,
1549 		     &max_addr, (void *)_RET_IP_);
1550 
1551 	return memblock_alloc_internal(size, align, min_addr, max_addr, nid,
1552 				       true);
1553 }
1554 
1555 /**
1556  * memblock_alloc_try_nid_raw - allocate boot memory block without zeroing
1557  * memory and without panicking
1558  * @size: size of memory block to be allocated in bytes
1559  * @align: alignment of the region and block's size
1560  * @min_addr: the lower bound of the memory region from where the allocation
1561  *	  is preferred (phys address)
1562  * @max_addr: the upper bound of the memory region from where the allocation
1563  *	      is preferred (phys address), or %MEMBLOCK_ALLOC_ACCESSIBLE to
1564  *	      allocate only from memory limited by memblock.current_limit value
1565  * @nid: nid of the free area to find, %NUMA_NO_NODE for any node
1566  *
1567  * Public function, provides additional debug information (including caller
1568  * info), if enabled. Does not zero allocated memory, does not panic if request
1569  * cannot be satisfied.
1570  *
1571  * Return:
1572  * Virtual address of allocated memory block on success, NULL on failure.
1573  */
1574 void * __init memblock_alloc_try_nid_raw(
1575 			phys_addr_t size, phys_addr_t align,
1576 			phys_addr_t min_addr, phys_addr_t max_addr,
1577 			int nid)
1578 {
1579 	memblock_dbg("%s: %llu bytes align=0x%llx nid=%d from=%pa max_addr=%pa %pS\n",
1580 		     __func__, (u64)size, (u64)align, nid, &min_addr,
1581 		     &max_addr, (void *)_RET_IP_);
1582 
1583 	return memblock_alloc_internal(size, align, min_addr, max_addr, nid,
1584 				       false);
1585 }
1586 
1587 /**
1588  * memblock_alloc_try_nid - allocate boot memory block
1589  * @size: size of memory block to be allocated in bytes
1590  * @align: alignment of the region and block's size
1591  * @min_addr: the lower bound of the memory region from where the allocation
1592  *	  is preferred (phys address)
1593  * @max_addr: the upper bound of the memory region from where the allocation
1594  *	      is preferred (phys address), or %MEMBLOCK_ALLOC_ACCESSIBLE to
1595  *	      allocate only from memory limited by memblock.current_limit value
1596  * @nid: nid of the free area to find, %NUMA_NO_NODE for any node
1597  *
1598  * Public function, provides additional debug information (including caller
1599  * info), if enabled. This function zeroes the allocated memory.
1600  *
1601  * Return:
1602  * Virtual address of allocated memory block on success, NULL on failure.
1603  */
1604 void * __init memblock_alloc_try_nid(
1605 			phys_addr_t size, phys_addr_t align,
1606 			phys_addr_t min_addr, phys_addr_t max_addr,
1607 			int nid)
1608 {
1609 	void *ptr;
1610 
1611 	memblock_dbg("%s: %llu bytes align=0x%llx nid=%d from=%pa max_addr=%pa %pS\n",
1612 		     __func__, (u64)size, (u64)align, nid, &min_addr,
1613 		     &max_addr, (void *)_RET_IP_);
1614 	ptr = memblock_alloc_internal(size, align,
1615 					   min_addr, max_addr, nid, false);
1616 	if (ptr)
1617 		memset(ptr, 0, size);
1618 
1619 	return ptr;
1620 }
1621 
1622 /**
1623  * memblock_free_late - free pages directly to buddy allocator
1624  * @base: phys starting address of the  boot memory block
1625  * @size: size of the boot memory block in bytes
1626  *
1627  * This is only useful when the memblock allocator has already been torn
1628  * down, but we are still initializing the system.  Pages are released directly
1629  * to the buddy allocator.
1630  */
1631 void __init memblock_free_late(phys_addr_t base, phys_addr_t size)
1632 {
1633 	phys_addr_t cursor, end;
1634 
1635 	end = base + size - 1;
1636 	memblock_dbg("%s: [%pa-%pa] %pS\n",
1637 		     __func__, &base, &end, (void *)_RET_IP_);
1638 	kmemleak_free_part_phys(base, size);
1639 	cursor = PFN_UP(base);
1640 	end = PFN_DOWN(base + size);
1641 
1642 	for (; cursor < end; cursor++) {
1643 		memblock_free_pages(pfn_to_page(cursor), cursor, 0);
1644 		totalram_pages_inc();
1645 	}
1646 }
1647 
1648 /*
1649  * Remaining API functions
1650  */
1651 
1652 phys_addr_t __init_memblock memblock_phys_mem_size(void)
1653 {
1654 	return memblock.memory.total_size;
1655 }
1656 
1657 phys_addr_t __init_memblock memblock_reserved_size(void)
1658 {
1659 	return memblock.reserved.total_size;
1660 }
1661 
1662 /* lowest address */
1663 phys_addr_t __init_memblock memblock_start_of_DRAM(void)
1664 {
1665 	return memblock.memory.regions[0].base;
1666 }
1667 
1668 phys_addr_t __init_memblock memblock_end_of_DRAM(void)
1669 {
1670 	int idx = memblock.memory.cnt - 1;
1671 
1672 	return (memblock.memory.regions[idx].base + memblock.memory.regions[idx].size);
1673 }
1674 
1675 static phys_addr_t __init_memblock __find_max_addr(phys_addr_t limit)
1676 {
1677 	phys_addr_t max_addr = PHYS_ADDR_MAX;
1678 	struct memblock_region *r;
1679 
1680 	/*
1681 	 * translate the memory @limit size into the max address within one of
1682 	 * the memory memblock regions, if the @limit exceeds the total size
1683 	 * of those regions, max_addr will keep original value PHYS_ADDR_MAX
1684 	 */
1685 	for_each_mem_region(r) {
1686 		if (limit <= r->size) {
1687 			max_addr = r->base + limit;
1688 			break;
1689 		}
1690 		limit -= r->size;
1691 	}
1692 
1693 	return max_addr;
1694 }
1695 
1696 void __init memblock_enforce_memory_limit(phys_addr_t limit)
1697 {
1698 	phys_addr_t max_addr;
1699 
1700 	if (!limit)
1701 		return;
1702 
1703 	max_addr = __find_max_addr(limit);
1704 
1705 	/* @limit exceeds the total size of the memory, do nothing */
1706 	if (max_addr == PHYS_ADDR_MAX)
1707 		return;
1708 
1709 	/* truncate both memory and reserved regions */
1710 	memblock_remove_range(&memblock.memory, max_addr,
1711 			      PHYS_ADDR_MAX);
1712 	memblock_remove_range(&memblock.reserved, max_addr,
1713 			      PHYS_ADDR_MAX);
1714 }
1715 
1716 void __init memblock_cap_memory_range(phys_addr_t base, phys_addr_t size)
1717 {
1718 	int start_rgn, end_rgn;
1719 	int i, ret;
1720 
1721 	if (!size)
1722 		return;
1723 
1724 	if (!memblock_memory->total_size) {
1725 		pr_warn("%s: No memory registered yet\n", __func__);
1726 		return;
1727 	}
1728 
1729 	ret = memblock_isolate_range(&memblock.memory, base, size,
1730 						&start_rgn, &end_rgn);
1731 	if (ret)
1732 		return;
1733 
1734 	/* remove all the MAP regions */
1735 	for (i = memblock.memory.cnt - 1; i >= end_rgn; i--)
1736 		if (!memblock_is_nomap(&memblock.memory.regions[i]))
1737 			memblock_remove_region(&memblock.memory, i);
1738 
1739 	for (i = start_rgn - 1; i >= 0; i--)
1740 		if (!memblock_is_nomap(&memblock.memory.regions[i]))
1741 			memblock_remove_region(&memblock.memory, i);
1742 
1743 	/* truncate the reserved regions */
1744 	memblock_remove_range(&memblock.reserved, 0, base);
1745 	memblock_remove_range(&memblock.reserved,
1746 			base + size, PHYS_ADDR_MAX);
1747 }
1748 
1749 void __init memblock_mem_limit_remove_map(phys_addr_t limit)
1750 {
1751 	phys_addr_t max_addr;
1752 
1753 	if (!limit)
1754 		return;
1755 
1756 	max_addr = __find_max_addr(limit);
1757 
1758 	/* @limit exceeds the total size of the memory, do nothing */
1759 	if (max_addr == PHYS_ADDR_MAX)
1760 		return;
1761 
1762 	memblock_cap_memory_range(0, max_addr);
1763 }
1764 
1765 static int __init_memblock memblock_search(struct memblock_type *type, phys_addr_t addr)
1766 {
1767 	unsigned int left = 0, right = type->cnt;
1768 
1769 	do {
1770 		unsigned int mid = (right + left) / 2;
1771 
1772 		if (addr < type->regions[mid].base)
1773 			right = mid;
1774 		else if (addr >= (type->regions[mid].base +
1775 				  type->regions[mid].size))
1776 			left = mid + 1;
1777 		else
1778 			return mid;
1779 	} while (left < right);
1780 	return -1;
1781 }
1782 
1783 bool __init_memblock memblock_is_reserved(phys_addr_t addr)
1784 {
1785 	return memblock_search(&memblock.reserved, addr) != -1;
1786 }
1787 
1788 bool __init_memblock memblock_is_memory(phys_addr_t addr)
1789 {
1790 	return memblock_search(&memblock.memory, addr) != -1;
1791 }
1792 
1793 bool __init_memblock memblock_is_map_memory(phys_addr_t addr)
1794 {
1795 	int i = memblock_search(&memblock.memory, addr);
1796 
1797 	if (i == -1)
1798 		return false;
1799 	return !memblock_is_nomap(&memblock.memory.regions[i]);
1800 }
1801 
1802 int __init_memblock memblock_search_pfn_nid(unsigned long pfn,
1803 			 unsigned long *start_pfn, unsigned long *end_pfn)
1804 {
1805 	struct memblock_type *type = &memblock.memory;
1806 	int mid = memblock_search(type, PFN_PHYS(pfn));
1807 
1808 	if (mid == -1)
1809 		return -1;
1810 
1811 	*start_pfn = PFN_DOWN(type->regions[mid].base);
1812 	*end_pfn = PFN_DOWN(type->regions[mid].base + type->regions[mid].size);
1813 
1814 	return memblock_get_region_node(&type->regions[mid]);
1815 }
1816 
1817 /**
1818  * memblock_is_region_memory - check if a region is a subset of memory
1819  * @base: base of region to check
1820  * @size: size of region to check
1821  *
1822  * Check if the region [@base, @base + @size) is a subset of a memory block.
1823  *
1824  * Return:
1825  * 0 if false, non-zero if true
1826  */
1827 bool __init_memblock memblock_is_region_memory(phys_addr_t base, phys_addr_t size)
1828 {
1829 	int idx = memblock_search(&memblock.memory, base);
1830 	phys_addr_t end = base + memblock_cap_size(base, &size);
1831 
1832 	if (idx == -1)
1833 		return false;
1834 	return (memblock.memory.regions[idx].base +
1835 		 memblock.memory.regions[idx].size) >= end;
1836 }
1837 
1838 /**
1839  * memblock_is_region_reserved - check if a region intersects reserved memory
1840  * @base: base of region to check
1841  * @size: size of region to check
1842  *
1843  * Check if the region [@base, @base + @size) intersects a reserved
1844  * memory block.
1845  *
1846  * Return:
1847  * True if they intersect, false if not.
1848  */
1849 bool __init_memblock memblock_is_region_reserved(phys_addr_t base, phys_addr_t size)
1850 {
1851 	return memblock_overlaps_region(&memblock.reserved, base, size);
1852 }
1853 
1854 void __init_memblock memblock_trim_memory(phys_addr_t align)
1855 {
1856 	phys_addr_t start, end, orig_start, orig_end;
1857 	struct memblock_region *r;
1858 
1859 	for_each_mem_region(r) {
1860 		orig_start = r->base;
1861 		orig_end = r->base + r->size;
1862 		start = round_up(orig_start, align);
1863 		end = round_down(orig_end, align);
1864 
1865 		if (start == orig_start && end == orig_end)
1866 			continue;
1867 
1868 		if (start < end) {
1869 			r->base = start;
1870 			r->size = end - start;
1871 		} else {
1872 			memblock_remove_region(&memblock.memory,
1873 					       r - memblock.memory.regions);
1874 			r--;
1875 		}
1876 	}
1877 }
1878 
1879 void __init_memblock memblock_set_current_limit(phys_addr_t limit)
1880 {
1881 	memblock.current_limit = limit;
1882 }
1883 
1884 phys_addr_t __init_memblock memblock_get_current_limit(void)
1885 {
1886 	return memblock.current_limit;
1887 }
1888 
1889 static void __init_memblock memblock_dump(struct memblock_type *type)
1890 {
1891 	phys_addr_t base, end, size;
1892 	enum memblock_flags flags;
1893 	int idx;
1894 	struct memblock_region *rgn;
1895 
1896 	pr_info(" %s.cnt  = 0x%lx\n", type->name, type->cnt);
1897 
1898 	for_each_memblock_type(idx, type, rgn) {
1899 		char nid_buf[32] = "";
1900 
1901 		base = rgn->base;
1902 		size = rgn->size;
1903 		end = base + size - 1;
1904 		flags = rgn->flags;
1905 #ifdef CONFIG_NUMA
1906 		if (memblock_get_region_node(rgn) != MAX_NUMNODES)
1907 			snprintf(nid_buf, sizeof(nid_buf), " on node %d",
1908 				 memblock_get_region_node(rgn));
1909 #endif
1910 		pr_info(" %s[%#x]\t[%pa-%pa], %pa bytes%s flags: %#x\n",
1911 			type->name, idx, &base, &end, &size, nid_buf, flags);
1912 	}
1913 }
1914 
1915 static void __init_memblock __memblock_dump_all(void)
1916 {
1917 	pr_info("MEMBLOCK configuration:\n");
1918 	pr_info(" memory size = %pa reserved size = %pa\n",
1919 		&memblock.memory.total_size,
1920 		&memblock.reserved.total_size);
1921 
1922 	memblock_dump(&memblock.memory);
1923 	memblock_dump(&memblock.reserved);
1924 #ifdef CONFIG_HAVE_MEMBLOCK_PHYS_MAP
1925 	memblock_dump(&physmem);
1926 #endif
1927 }
1928 
1929 void __init_memblock memblock_dump_all(void)
1930 {
1931 	if (memblock_debug)
1932 		__memblock_dump_all();
1933 }
1934 
1935 void __init memblock_allow_resize(void)
1936 {
1937 	memblock_can_resize = 1;
1938 }
1939 
1940 static int __init early_memblock(char *p)
1941 {
1942 	if (p && strstr(p, "debug"))
1943 		memblock_debug = 1;
1944 	return 0;
1945 }
1946 early_param("memblock", early_memblock);
1947 
1948 static void __init free_memmap(unsigned long start_pfn, unsigned long end_pfn)
1949 {
1950 	struct page *start_pg, *end_pg;
1951 	phys_addr_t pg, pgend;
1952 
1953 	/*
1954 	 * Convert start_pfn/end_pfn to a struct page pointer.
1955 	 */
1956 	start_pg = pfn_to_page(start_pfn - 1) + 1;
1957 	end_pg = pfn_to_page(end_pfn - 1) + 1;
1958 
1959 	/*
1960 	 * Convert to physical addresses, and round start upwards and end
1961 	 * downwards.
1962 	 */
1963 	pg = PAGE_ALIGN(__pa(start_pg));
1964 	pgend = __pa(end_pg) & PAGE_MASK;
1965 
1966 	/*
1967 	 * If there are free pages between these, free the section of the
1968 	 * memmap array.
1969 	 */
1970 	if (pg < pgend)
1971 		memblock_phys_free(pg, pgend - pg);
1972 }
1973 
1974 /*
1975  * The mem_map array can get very big.  Free the unused area of the memory map.
1976  */
1977 static void __init free_unused_memmap(void)
1978 {
1979 	unsigned long start, end, prev_end = 0;
1980 	int i;
1981 
1982 	if (!IS_ENABLED(CONFIG_HAVE_ARCH_PFN_VALID) ||
1983 	    IS_ENABLED(CONFIG_SPARSEMEM_VMEMMAP))
1984 		return;
1985 
1986 	/*
1987 	 * This relies on each bank being in address order.
1988 	 * The banks are sorted previously in bootmem_init().
1989 	 */
1990 	for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, NULL) {
1991 #ifdef CONFIG_SPARSEMEM
1992 		/*
1993 		 * Take care not to free memmap entries that don't exist
1994 		 * due to SPARSEMEM sections which aren't present.
1995 		 */
1996 		start = min(start, ALIGN(prev_end, PAGES_PER_SECTION));
1997 #endif
1998 		/*
1999 		 * Align down here since many operations in VM subsystem
2000 		 * presume that there are no holes in the memory map inside
2001 		 * a pageblock
2002 		 */
2003 		start = pageblock_start_pfn(start);
2004 
2005 		/*
2006 		 * If we had a previous bank, and there is a space
2007 		 * between the current bank and the previous, free it.
2008 		 */
2009 		if (prev_end && prev_end < start)
2010 			free_memmap(prev_end, start);
2011 
2012 		/*
2013 		 * Align up here since many operations in VM subsystem
2014 		 * presume that there are no holes in the memory map inside
2015 		 * a pageblock
2016 		 */
2017 		prev_end = pageblock_align(end);
2018 	}
2019 
2020 #ifdef CONFIG_SPARSEMEM
2021 	if (!IS_ALIGNED(prev_end, PAGES_PER_SECTION)) {
2022 		prev_end = pageblock_align(end);
2023 		free_memmap(prev_end, ALIGN(prev_end, PAGES_PER_SECTION));
2024 	}
2025 #endif
2026 }
2027 
2028 static void __init __free_pages_memory(unsigned long start, unsigned long end)
2029 {
2030 	int order;
2031 
2032 	while (start < end) {
2033 		order = min(MAX_ORDER - 1UL, __ffs(start));
2034 
2035 		while (start + (1UL << order) > end)
2036 			order--;
2037 
2038 		memblock_free_pages(pfn_to_page(start), start, order);
2039 
2040 		start += (1UL << order);
2041 	}
2042 }
2043 
2044 static unsigned long __init __free_memory_core(phys_addr_t start,
2045 				 phys_addr_t end)
2046 {
2047 	unsigned long start_pfn = PFN_UP(start);
2048 	unsigned long end_pfn = min_t(unsigned long,
2049 				      PFN_DOWN(end), max_low_pfn);
2050 
2051 	if (start_pfn >= end_pfn)
2052 		return 0;
2053 
2054 	__free_pages_memory(start_pfn, end_pfn);
2055 
2056 	return end_pfn - start_pfn;
2057 }
2058 
2059 static void __init memmap_init_reserved_pages(void)
2060 {
2061 	struct memblock_region *region;
2062 	phys_addr_t start, end;
2063 	u64 i;
2064 
2065 	/* initialize struct pages for the reserved regions */
2066 	for_each_reserved_mem_range(i, &start, &end)
2067 		reserve_bootmem_region(start, end);
2068 
2069 	/* and also treat struct pages for the NOMAP regions as PageReserved */
2070 	for_each_mem_region(region) {
2071 		if (memblock_is_nomap(region)) {
2072 			start = region->base;
2073 			end = start + region->size;
2074 			reserve_bootmem_region(start, end);
2075 		}
2076 	}
2077 }
2078 
2079 static unsigned long __init free_low_memory_core_early(void)
2080 {
2081 	unsigned long count = 0;
2082 	phys_addr_t start, end;
2083 	u64 i;
2084 
2085 	memblock_clear_hotplug(0, -1);
2086 
2087 	memmap_init_reserved_pages();
2088 
2089 	/*
2090 	 * We need to use NUMA_NO_NODE instead of NODE_DATA(0)->node_id
2091 	 *  because in some case like Node0 doesn't have RAM installed
2092 	 *  low ram will be on Node1
2093 	 */
2094 	for_each_free_mem_range(i, NUMA_NO_NODE, MEMBLOCK_NONE, &start, &end,
2095 				NULL)
2096 		count += __free_memory_core(start, end);
2097 
2098 	return count;
2099 }
2100 
2101 static int reset_managed_pages_done __initdata;
2102 
2103 void reset_node_managed_pages(pg_data_t *pgdat)
2104 {
2105 	struct zone *z;
2106 
2107 	for (z = pgdat->node_zones; z < pgdat->node_zones + MAX_NR_ZONES; z++)
2108 		atomic_long_set(&z->managed_pages, 0);
2109 }
2110 
2111 void __init reset_all_zones_managed_pages(void)
2112 {
2113 	struct pglist_data *pgdat;
2114 
2115 	if (reset_managed_pages_done)
2116 		return;
2117 
2118 	for_each_online_pgdat(pgdat)
2119 		reset_node_managed_pages(pgdat);
2120 
2121 	reset_managed_pages_done = 1;
2122 }
2123 
2124 /**
2125  * memblock_free_all - release free pages to the buddy allocator
2126  */
2127 void __init memblock_free_all(void)
2128 {
2129 	unsigned long pages;
2130 
2131 	free_unused_memmap();
2132 	reset_all_zones_managed_pages();
2133 
2134 	pages = free_low_memory_core_early();
2135 	totalram_pages_add(pages);
2136 }
2137 
2138 #if defined(CONFIG_DEBUG_FS) && defined(CONFIG_ARCH_KEEP_MEMBLOCK)
2139 
2140 static int memblock_debug_show(struct seq_file *m, void *private)
2141 {
2142 	struct memblock_type *type = m->private;
2143 	struct memblock_region *reg;
2144 	int i;
2145 	phys_addr_t end;
2146 
2147 	for (i = 0; i < type->cnt; i++) {
2148 		reg = &type->regions[i];
2149 		end = reg->base + reg->size - 1;
2150 
2151 		seq_printf(m, "%4d: ", i);
2152 		seq_printf(m, "%pa..%pa\n", &reg->base, &end);
2153 	}
2154 	return 0;
2155 }
2156 DEFINE_SHOW_ATTRIBUTE(memblock_debug);
2157 
2158 static int __init memblock_init_debugfs(void)
2159 {
2160 	struct dentry *root = debugfs_create_dir("memblock", NULL);
2161 
2162 	debugfs_create_file("memory", 0444, root,
2163 			    &memblock.memory, &memblock_debug_fops);
2164 	debugfs_create_file("reserved", 0444, root,
2165 			    &memblock.reserved, &memblock_debug_fops);
2166 #ifdef CONFIG_HAVE_MEMBLOCK_PHYS_MAP
2167 	debugfs_create_file("physmem", 0444, root, &physmem,
2168 			    &memblock_debug_fops);
2169 #endif
2170 
2171 	return 0;
2172 }
2173 __initcall(memblock_init_debugfs);
2174 
2175 #endif /* CONFIG_DEBUG_FS */
2176