1/*
2 *  bootmem - A boot-time physical memory allocator and configurator
3 *
4 *  Copyright (C) 1999 Ingo Molnar
5 *                1999 Kanoj Sarcar, SGI
6 *                2008 Johannes Weiner
7 *
8 * Access to this subsystem has to be serialized externally (which is true
9 * for the boot process anyway).
10 */
11#include <linux/init.h>
12#include <linux/pfn.h>
13#include <linux/slab.h>
14#include <linux/bootmem.h>
15#include <linux/export.h>
16#include <linux/kmemleak.h>
17#include <linux/range.h>
18#include <linux/memblock.h>
19#include <linux/bug.h>
20#include <linux/io.h>
21
22#include <asm/processor.h>
23
24#include "internal.h"
25
26#ifndef CONFIG_NEED_MULTIPLE_NODES
27struct pglist_data __refdata contig_page_data = {
28	.bdata = &bootmem_node_data[0]
29};
30EXPORT_SYMBOL(contig_page_data);
31#endif
32
33unsigned long max_low_pfn;
34unsigned long min_low_pfn;
35unsigned long max_pfn;
36
37bootmem_data_t bootmem_node_data[MAX_NUMNODES] __initdata;
38
39static struct list_head bdata_list __initdata = LIST_HEAD_INIT(bdata_list);
40
41static int bootmem_debug;
42
43static int __init bootmem_debug_setup(char *buf)
44{
45	bootmem_debug = 1;
46	return 0;
47}
48early_param("bootmem_debug", bootmem_debug_setup);
49
50#define bdebug(fmt, args...) ({				\
51	if (unlikely(bootmem_debug))			\
52		printk(KERN_INFO			\
53			"bootmem::%s " fmt,		\
54			__func__, ## args);		\
55})
56
57static unsigned long __init bootmap_bytes(unsigned long pages)
58{
59	unsigned long bytes = DIV_ROUND_UP(pages, 8);
60
61	return ALIGN(bytes, sizeof(long));
62}
63
64/**
65 * bootmem_bootmap_pages - calculate bitmap size in pages
66 * @pages: number of pages the bitmap has to represent
67 */
68unsigned long __init bootmem_bootmap_pages(unsigned long pages)
69{
70	unsigned long bytes = bootmap_bytes(pages);
71
72	return PAGE_ALIGN(bytes) >> PAGE_SHIFT;
73}
74
75/*
76 * link bdata in order
77 */
78static void __init link_bootmem(bootmem_data_t *bdata)
79{
80	bootmem_data_t *ent;
81
82	list_for_each_entry(ent, &bdata_list, list) {
83		if (bdata->node_min_pfn < ent->node_min_pfn) {
84			list_add_tail(&bdata->list, &ent->list);
85			return;
86		}
87	}
88
89	list_add_tail(&bdata->list, &bdata_list);
90}
91
92/*
93 * Called once to set up the allocator itself.
94 */
95static unsigned long __init init_bootmem_core(bootmem_data_t *bdata,
96	unsigned long mapstart, unsigned long start, unsigned long end)
97{
98	unsigned long mapsize;
99
100	mminit_validate_memmodel_limits(&start, &end);
101	bdata->node_bootmem_map = phys_to_virt(PFN_PHYS(mapstart));
102	bdata->node_min_pfn = start;
103	bdata->node_low_pfn = end;
104	link_bootmem(bdata);
105
106	/*
107	 * Initially all pages are reserved - setup_arch() has to
108	 * register free RAM areas explicitly.
109	 */
110	mapsize = bootmap_bytes(end - start);
111	memset(bdata->node_bootmem_map, 0xff, mapsize);
112
113	bdebug("nid=%td start=%lx map=%lx end=%lx mapsize=%lx\n",
114		bdata - bootmem_node_data, start, mapstart, end, mapsize);
115
116	return mapsize;
117}
118
119/**
120 * init_bootmem_node - register a node as boot memory
121 * @pgdat: node to register
122 * @freepfn: pfn where the bitmap for this node is to be placed
123 * @startpfn: first pfn on the node
124 * @endpfn: first pfn after the node
125 *
126 * Returns the number of bytes needed to hold the bitmap for this node.
127 */
128unsigned long __init init_bootmem_node(pg_data_t *pgdat, unsigned long freepfn,
129				unsigned long startpfn, unsigned long endpfn)
130{
131	return init_bootmem_core(pgdat->bdata, freepfn, startpfn, endpfn);
132}
133
134/**
135 * init_bootmem - register boot memory
136 * @start: pfn where the bitmap is to be placed
137 * @pages: number of available physical pages
138 *
139 * Returns the number of bytes needed to hold the bitmap.
140 */
141unsigned long __init init_bootmem(unsigned long start, unsigned long pages)
142{
143	max_low_pfn = pages;
144	min_low_pfn = start;
145	return init_bootmem_core(NODE_DATA(0)->bdata, start, 0, pages);
146}
147
148/*
149 * free_bootmem_late - free bootmem pages directly to page allocator
150 * @addr: starting physical address of the range
151 * @size: size of the range in bytes
152 *
153 * This is only useful when the bootmem allocator has already been torn
154 * down, but we are still initializing the system.  Pages are given directly
155 * to the page allocator, no bootmem metadata is updated because it is gone.
156 */
157void __init free_bootmem_late(unsigned long physaddr, unsigned long size)
158{
159	unsigned long cursor, end;
160
161	kmemleak_free_part(__va(physaddr), size);
162
163	cursor = PFN_UP(physaddr);
164	end = PFN_DOWN(physaddr + size);
165
166	for (; cursor < end; cursor++) {
167		__free_pages_bootmem(pfn_to_page(cursor), cursor, 0);
168		totalram_pages++;
169	}
170}
171
172static unsigned long __init free_all_bootmem_core(bootmem_data_t *bdata)
173{
174	struct page *page;
175	unsigned long *map, start, end, pages, cur, count = 0;
176
177	if (!bdata->node_bootmem_map)
178		return 0;
179
180	map = bdata->node_bootmem_map;
181	start = bdata->node_min_pfn;
182	end = bdata->node_low_pfn;
183
184	bdebug("nid=%td start=%lx end=%lx\n",
185		bdata - bootmem_node_data, start, end);
186
187	while (start < end) {
188		unsigned long idx, vec;
189		unsigned shift;
190
191		idx = start - bdata->node_min_pfn;
192		shift = idx & (BITS_PER_LONG - 1);
193		/*
194		 * vec holds at most BITS_PER_LONG map bits,
195		 * bit 0 corresponds to start.
196		 */
197		vec = ~map[idx / BITS_PER_LONG];
198
199		if (shift) {
200			vec >>= shift;
201			if (end - start >= BITS_PER_LONG)
202				vec |= ~map[idx / BITS_PER_LONG + 1] <<
203					(BITS_PER_LONG - shift);
204		}
205		/*
206		 * If we have a properly aligned and fully unreserved
207		 * BITS_PER_LONG block of pages in front of us, free
208		 * it in one go.
209		 */
210		if (IS_ALIGNED(start, BITS_PER_LONG) && vec == ~0UL) {
211			int order = ilog2(BITS_PER_LONG);
212
213			__free_pages_bootmem(pfn_to_page(start), start, order);
214			count += BITS_PER_LONG;
215			start += BITS_PER_LONG;
216		} else {
217			cur = start;
218
219			start = ALIGN(start + 1, BITS_PER_LONG);
220			while (vec && cur != start) {
221				if (vec & 1) {
222					page = pfn_to_page(cur);
223					__free_pages_bootmem(page, cur, 0);
224					count++;
225				}
226				vec >>= 1;
227				++cur;
228			}
229		}
230	}
231
232	cur = bdata->node_min_pfn;
233	page = virt_to_page(bdata->node_bootmem_map);
234	pages = bdata->node_low_pfn - bdata->node_min_pfn;
235	pages = bootmem_bootmap_pages(pages);
236	count += pages;
237	while (pages--)
238		__free_pages_bootmem(page++, cur++, 0);
239
240	bdebug("nid=%td released=%lx\n", bdata - bootmem_node_data, count);
241
242	return count;
243}
244
245static int reset_managed_pages_done __initdata;
246
247void reset_node_managed_pages(pg_data_t *pgdat)
248{
249	struct zone *z;
250
251	for (z = pgdat->node_zones; z < pgdat->node_zones + MAX_NR_ZONES; z++)
252		z->managed_pages = 0;
253}
254
255void __init reset_all_zones_managed_pages(void)
256{
257	struct pglist_data *pgdat;
258
259	if (reset_managed_pages_done)
260		return;
261
262	for_each_online_pgdat(pgdat)
263		reset_node_managed_pages(pgdat);
264
265	reset_managed_pages_done = 1;
266}
267
268/**
269 * free_all_bootmem - release free pages to the buddy allocator
270 *
271 * Returns the number of pages actually released.
272 */
273unsigned long __init free_all_bootmem(void)
274{
275	unsigned long total_pages = 0;
276	bootmem_data_t *bdata;
277
278	reset_all_zones_managed_pages();
279
280	list_for_each_entry(bdata, &bdata_list, list)
281		total_pages += free_all_bootmem_core(bdata);
282
283	totalram_pages += total_pages;
284
285	return total_pages;
286}
287
288static void __init __free(bootmem_data_t *bdata,
289			unsigned long sidx, unsigned long eidx)
290{
291	unsigned long idx;
292
293	bdebug("nid=%td start=%lx end=%lx\n", bdata - bootmem_node_data,
294		sidx + bdata->node_min_pfn,
295		eidx + bdata->node_min_pfn);
296
297	if (bdata->hint_idx > sidx)
298		bdata->hint_idx = sidx;
299
300	for (idx = sidx; idx < eidx; idx++)
301		if (!test_and_clear_bit(idx, bdata->node_bootmem_map))
302			BUG();
303}
304
305static int __init __reserve(bootmem_data_t *bdata, unsigned long sidx,
306			unsigned long eidx, int flags)
307{
308	unsigned long idx;
309	int exclusive = flags & BOOTMEM_EXCLUSIVE;
310
311	bdebug("nid=%td start=%lx end=%lx flags=%x\n",
312		bdata - bootmem_node_data,
313		sidx + bdata->node_min_pfn,
314		eidx + bdata->node_min_pfn,
315		flags);
316
317	for (idx = sidx; idx < eidx; idx++)
318		if (test_and_set_bit(idx, bdata->node_bootmem_map)) {
319			if (exclusive) {
320				__free(bdata, sidx, idx);
321				return -EBUSY;
322			}
323			bdebug("silent double reserve of PFN %lx\n",
324				idx + bdata->node_min_pfn);
325		}
326	return 0;
327}
328
329static int __init mark_bootmem_node(bootmem_data_t *bdata,
330				unsigned long start, unsigned long end,
331				int reserve, int flags)
332{
333	unsigned long sidx, eidx;
334
335	bdebug("nid=%td start=%lx end=%lx reserve=%d flags=%x\n",
336		bdata - bootmem_node_data, start, end, reserve, flags);
337
338	BUG_ON(start < bdata->node_min_pfn);
339	BUG_ON(end > bdata->node_low_pfn);
340
341	sidx = start - bdata->node_min_pfn;
342	eidx = end - bdata->node_min_pfn;
343
344	if (reserve)
345		return __reserve(bdata, sidx, eidx, flags);
346	else
347		__free(bdata, sidx, eidx);
348	return 0;
349}
350
351static int __init mark_bootmem(unsigned long start, unsigned long end,
352				int reserve, int flags)
353{
354	unsigned long pos;
355	bootmem_data_t *bdata;
356
357	pos = start;
358	list_for_each_entry(bdata, &bdata_list, list) {
359		int err;
360		unsigned long max;
361
362		if (pos < bdata->node_min_pfn ||
363		    pos >= bdata->node_low_pfn) {
364			BUG_ON(pos != start);
365			continue;
366		}
367
368		max = min(bdata->node_low_pfn, end);
369
370		err = mark_bootmem_node(bdata, pos, max, reserve, flags);
371		if (reserve && err) {
372			mark_bootmem(start, pos, 0, 0);
373			return err;
374		}
375
376		if (max == end)
377			return 0;
378		pos = bdata->node_low_pfn;
379	}
380	BUG();
381}
382
383/**
384 * free_bootmem_node - mark a page range as usable
385 * @pgdat: node the range resides on
386 * @physaddr: starting address of the range
387 * @size: size of the range in bytes
388 *
389 * Partial pages will be considered reserved and left as they are.
390 *
391 * The range must reside completely on the specified node.
392 */
393void __init free_bootmem_node(pg_data_t *pgdat, unsigned long physaddr,
394			      unsigned long size)
395{
396	unsigned long start, end;
397
398	kmemleak_free_part(__va(physaddr), size);
399
400	start = PFN_UP(physaddr);
401	end = PFN_DOWN(physaddr + size);
402
403	mark_bootmem_node(pgdat->bdata, start, end, 0, 0);
404}
405
406/**
407 * free_bootmem - mark a page range as usable
408 * @addr: starting physical address of the range
409 * @size: size of the range in bytes
410 *
411 * Partial pages will be considered reserved and left as they are.
412 *
413 * The range must be contiguous but may span node boundaries.
414 */
415void __init free_bootmem(unsigned long physaddr, unsigned long size)
416{
417	unsigned long start, end;
418
419	kmemleak_free_part(__va(physaddr), size);
420
421	start = PFN_UP(physaddr);
422	end = PFN_DOWN(physaddr + size);
423
424	mark_bootmem(start, end, 0, 0);
425}
426
427/**
428 * reserve_bootmem_node - mark a page range as reserved
429 * @pgdat: node the range resides on
430 * @physaddr: starting address of the range
431 * @size: size of the range in bytes
432 * @flags: reservation flags (see linux/bootmem.h)
433 *
434 * Partial pages will be reserved.
435 *
436 * The range must reside completely on the specified node.
437 */
438int __init reserve_bootmem_node(pg_data_t *pgdat, unsigned long physaddr,
439				 unsigned long size, int flags)
440{
441	unsigned long start, end;
442
443	start = PFN_DOWN(physaddr);
444	end = PFN_UP(physaddr + size);
445
446	return mark_bootmem_node(pgdat->bdata, start, end, 1, flags);
447}
448
449/**
450 * reserve_bootmem - mark a page range as reserved
451 * @addr: starting address of the range
452 * @size: size of the range in bytes
453 * @flags: reservation flags (see linux/bootmem.h)
454 *
455 * Partial pages will be reserved.
456 *
457 * The range must be contiguous but may span node boundaries.
458 */
459int __init reserve_bootmem(unsigned long addr, unsigned long size,
460			    int flags)
461{
462	unsigned long start, end;
463
464	start = PFN_DOWN(addr);
465	end = PFN_UP(addr + size);
466
467	return mark_bootmem(start, end, 1, flags);
468}
469
470static unsigned long __init align_idx(struct bootmem_data *bdata,
471				      unsigned long idx, unsigned long step)
472{
473	unsigned long base = bdata->node_min_pfn;
474
475	/*
476	 * Align the index with respect to the node start so that the
477	 * combination of both satisfies the requested alignment.
478	 */
479
480	return ALIGN(base + idx, step) - base;
481}
482
483static unsigned long __init align_off(struct bootmem_data *bdata,
484				      unsigned long off, unsigned long align)
485{
486	unsigned long base = PFN_PHYS(bdata->node_min_pfn);
487
488	/* Same as align_idx for byte offsets */
489
490	return ALIGN(base + off, align) - base;
491}
492
493static void * __init alloc_bootmem_bdata(struct bootmem_data *bdata,
494					unsigned long size, unsigned long align,
495					unsigned long goal, unsigned long limit)
496{
497	unsigned long fallback = 0;
498	unsigned long min, max, start, sidx, midx, step;
499
500	bdebug("nid=%td size=%lx [%lu pages] align=%lx goal=%lx limit=%lx\n",
501		bdata - bootmem_node_data, size, PAGE_ALIGN(size) >> PAGE_SHIFT,
502		align, goal, limit);
503
504	BUG_ON(!size);
505	BUG_ON(align & (align - 1));
506	BUG_ON(limit && goal + size > limit);
507
508	if (!bdata->node_bootmem_map)
509		return NULL;
510
511	min = bdata->node_min_pfn;
512	max = bdata->node_low_pfn;
513
514	goal >>= PAGE_SHIFT;
515	limit >>= PAGE_SHIFT;
516
517	if (limit && max > limit)
518		max = limit;
519	if (max <= min)
520		return NULL;
521
522	step = max(align >> PAGE_SHIFT, 1UL);
523
524	if (goal && min < goal && goal < max)
525		start = ALIGN(goal, step);
526	else
527		start = ALIGN(min, step);
528
529	sidx = start - bdata->node_min_pfn;
530	midx = max - bdata->node_min_pfn;
531
532	if (bdata->hint_idx > sidx) {
533		/*
534		 * Handle the valid case of sidx being zero and still
535		 * catch the fallback below.
536		 */
537		fallback = sidx + 1;
538		sidx = align_idx(bdata, bdata->hint_idx, step);
539	}
540
541	while (1) {
542		int merge;
543		void *region;
544		unsigned long eidx, i, start_off, end_off;
545find_block:
546		sidx = find_next_zero_bit(bdata->node_bootmem_map, midx, sidx);
547		sidx = align_idx(bdata, sidx, step);
548		eidx = sidx + PFN_UP(size);
549
550		if (sidx >= midx || eidx > midx)
551			break;
552
553		for (i = sidx; i < eidx; i++)
554			if (test_bit(i, bdata->node_bootmem_map)) {
555				sidx = align_idx(bdata, i, step);
556				if (sidx == i)
557					sidx += step;
558				goto find_block;
559			}
560
561		if (bdata->last_end_off & (PAGE_SIZE - 1) &&
562				PFN_DOWN(bdata->last_end_off) + 1 == sidx)
563			start_off = align_off(bdata, bdata->last_end_off, align);
564		else
565			start_off = PFN_PHYS(sidx);
566
567		merge = PFN_DOWN(start_off) < sidx;
568		end_off = start_off + size;
569
570		bdata->last_end_off = end_off;
571		bdata->hint_idx = PFN_UP(end_off);
572
573		/*
574		 * Reserve the area now:
575		 */
576		if (__reserve(bdata, PFN_DOWN(start_off) + merge,
577				PFN_UP(end_off), BOOTMEM_EXCLUSIVE))
578			BUG();
579
580		region = phys_to_virt(PFN_PHYS(bdata->node_min_pfn) +
581				start_off);
582		memset(region, 0, size);
583		/*
584		 * The min_count is set to 0 so that bootmem allocated blocks
585		 * are never reported as leaks.
586		 */
587		kmemleak_alloc(region, size, 0, 0);
588		return region;
589	}
590
591	if (fallback) {
592		sidx = align_idx(bdata, fallback - 1, step);
593		fallback = 0;
594		goto find_block;
595	}
596
597	return NULL;
598}
599
600static void * __init alloc_bootmem_core(unsigned long size,
601					unsigned long align,
602					unsigned long goal,
603					unsigned long limit)
604{
605	bootmem_data_t *bdata;
606	void *region;
607
608	if (WARN_ON_ONCE(slab_is_available()))
609		return kzalloc(size, GFP_NOWAIT);
610
611	list_for_each_entry(bdata, &bdata_list, list) {
612		if (goal && bdata->node_low_pfn <= PFN_DOWN(goal))
613			continue;
614		if (limit && bdata->node_min_pfn >= PFN_DOWN(limit))
615			break;
616
617		region = alloc_bootmem_bdata(bdata, size, align, goal, limit);
618		if (region)
619			return region;
620	}
621
622	return NULL;
623}
624
625static void * __init ___alloc_bootmem_nopanic(unsigned long size,
626					      unsigned long align,
627					      unsigned long goal,
628					      unsigned long limit)
629{
630	void *ptr;
631
632restart:
633	ptr = alloc_bootmem_core(size, align, goal, limit);
634	if (ptr)
635		return ptr;
636	if (goal) {
637		goal = 0;
638		goto restart;
639	}
640
641	return NULL;
642}
643
644/**
645 * __alloc_bootmem_nopanic - allocate boot memory without panicking
646 * @size: size of the request in bytes
647 * @align: alignment of the region
648 * @goal: preferred starting address of the region
649 *
650 * The goal is dropped if it can not be satisfied and the allocation will
651 * fall back to memory below @goal.
652 *
653 * Allocation may happen on any node in the system.
654 *
655 * Returns NULL on failure.
656 */
657void * __init __alloc_bootmem_nopanic(unsigned long size, unsigned long align,
658					unsigned long goal)
659{
660	unsigned long limit = 0;
661
662	return ___alloc_bootmem_nopanic(size, align, goal, limit);
663}
664
665static void * __init ___alloc_bootmem(unsigned long size, unsigned long align,
666					unsigned long goal, unsigned long limit)
667{
668	void *mem = ___alloc_bootmem_nopanic(size, align, goal, limit);
669
670	if (mem)
671		return mem;
672	/*
673	 * Whoops, we cannot satisfy the allocation request.
674	 */
675	printk(KERN_ALERT "bootmem alloc of %lu bytes failed!\n", size);
676	panic("Out of memory");
677	return NULL;
678}
679
680/**
681 * __alloc_bootmem - allocate boot memory
682 * @size: size of the request in bytes
683 * @align: alignment of the region
684 * @goal: preferred starting address of the region
685 *
686 * The goal is dropped if it can not be satisfied and the allocation will
687 * fall back to memory below @goal.
688 *
689 * Allocation may happen on any node in the system.
690 *
691 * The function panics if the request can not be satisfied.
692 */
693void * __init __alloc_bootmem(unsigned long size, unsigned long align,
694			      unsigned long goal)
695{
696	unsigned long limit = 0;
697
698	return ___alloc_bootmem(size, align, goal, limit);
699}
700
701void * __init ___alloc_bootmem_node_nopanic(pg_data_t *pgdat,
702				unsigned long size, unsigned long align,
703				unsigned long goal, unsigned long limit)
704{
705	void *ptr;
706
707	if (WARN_ON_ONCE(slab_is_available()))
708		return kzalloc(size, GFP_NOWAIT);
709again:
710
711	/* do not panic in alloc_bootmem_bdata() */
712	if (limit && goal + size > limit)
713		limit = 0;
714
715	ptr = alloc_bootmem_bdata(pgdat->bdata, size, align, goal, limit);
716	if (ptr)
717		return ptr;
718
719	ptr = alloc_bootmem_core(size, align, goal, limit);
720	if (ptr)
721		return ptr;
722
723	if (goal) {
724		goal = 0;
725		goto again;
726	}
727
728	return NULL;
729}
730
731void * __init __alloc_bootmem_node_nopanic(pg_data_t *pgdat, unsigned long size,
732				   unsigned long align, unsigned long goal)
733{
734	if (WARN_ON_ONCE(slab_is_available()))
735		return kzalloc_node(size, GFP_NOWAIT, pgdat->node_id);
736
737	return ___alloc_bootmem_node_nopanic(pgdat, size, align, goal, 0);
738}
739
740void * __init ___alloc_bootmem_node(pg_data_t *pgdat, unsigned long size,
741				    unsigned long align, unsigned long goal,
742				    unsigned long limit)
743{
744	void *ptr;
745
746	ptr = ___alloc_bootmem_node_nopanic(pgdat, size, align, goal, 0);
747	if (ptr)
748		return ptr;
749
750	printk(KERN_ALERT "bootmem alloc of %lu bytes failed!\n", size);
751	panic("Out of memory");
752	return NULL;
753}
754
755/**
756 * __alloc_bootmem_node - allocate boot memory from a specific node
757 * @pgdat: node to allocate from
758 * @size: size of the request in bytes
759 * @align: alignment of the region
760 * @goal: preferred starting address of the region
761 *
762 * The goal is dropped if it can not be satisfied and the allocation will
763 * fall back to memory below @goal.
764 *
765 * Allocation may fall back to any node in the system if the specified node
766 * can not hold the requested memory.
767 *
768 * The function panics if the request can not be satisfied.
769 */
770void * __init __alloc_bootmem_node(pg_data_t *pgdat, unsigned long size,
771				   unsigned long align, unsigned long goal)
772{
773	if (WARN_ON_ONCE(slab_is_available()))
774		return kzalloc_node(size, GFP_NOWAIT, pgdat->node_id);
775
776	return  ___alloc_bootmem_node(pgdat, size, align, goal, 0);
777}
778
779void * __init __alloc_bootmem_node_high(pg_data_t *pgdat, unsigned long size,
780				   unsigned long align, unsigned long goal)
781{
782#ifdef MAX_DMA32_PFN
783	unsigned long end_pfn;
784
785	if (WARN_ON_ONCE(slab_is_available()))
786		return kzalloc_node(size, GFP_NOWAIT, pgdat->node_id);
787
788	/* update goal according ...MAX_DMA32_PFN */
789	end_pfn = pgdat_end_pfn(pgdat);
790
791	if (end_pfn > MAX_DMA32_PFN + (128 >> (20 - PAGE_SHIFT)) &&
792	    (goal >> PAGE_SHIFT) < MAX_DMA32_PFN) {
793		void *ptr;
794		unsigned long new_goal;
795
796		new_goal = MAX_DMA32_PFN << PAGE_SHIFT;
797		ptr = alloc_bootmem_bdata(pgdat->bdata, size, align,
798						 new_goal, 0);
799		if (ptr)
800			return ptr;
801	}
802#endif
803
804	return __alloc_bootmem_node(pgdat, size, align, goal);
805
806}
807
808#ifndef ARCH_LOW_ADDRESS_LIMIT
809#define ARCH_LOW_ADDRESS_LIMIT	0xffffffffUL
810#endif
811
812/**
813 * __alloc_bootmem_low - allocate low boot memory
814 * @size: size of the request in bytes
815 * @align: alignment of the region
816 * @goal: preferred starting address of the region
817 *
818 * The goal is dropped if it can not be satisfied and the allocation will
819 * fall back to memory below @goal.
820 *
821 * Allocation may happen on any node in the system.
822 *
823 * The function panics if the request can not be satisfied.
824 */
825void * __init __alloc_bootmem_low(unsigned long size, unsigned long align,
826				  unsigned long goal)
827{
828	return ___alloc_bootmem(size, align, goal, ARCH_LOW_ADDRESS_LIMIT);
829}
830
831void * __init __alloc_bootmem_low_nopanic(unsigned long size,
832					  unsigned long align,
833					  unsigned long goal)
834{
835	return ___alloc_bootmem_nopanic(size, align, goal,
836					ARCH_LOW_ADDRESS_LIMIT);
837}
838
839/**
840 * __alloc_bootmem_low_node - allocate low boot memory from a specific node
841 * @pgdat: node to allocate from
842 * @size: size of the request in bytes
843 * @align: alignment of the region
844 * @goal: preferred starting address of the region
845 *
846 * The goal is dropped if it can not be satisfied and the allocation will
847 * fall back to memory below @goal.
848 *
849 * Allocation may fall back to any node in the system if the specified node
850 * can not hold the requested memory.
851 *
852 * The function panics if the request can not be satisfied.
853 */
854void * __init __alloc_bootmem_low_node(pg_data_t *pgdat, unsigned long size,
855				       unsigned long align, unsigned long goal)
856{
857	if (WARN_ON_ONCE(slab_is_available()))
858		return kzalloc_node(size, GFP_NOWAIT, pgdat->node_id);
859
860	return ___alloc_bootmem_node(pgdat, size, align,
861				     goal, ARCH_LOW_ADDRESS_LIMIT);
862}
863