Root/mm/bootmem.c

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
20#include <asm/bug.h>
21#include <asm/io.h>
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), 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, 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), order);
214            count += BITS_PER_LONG;
215            start += BITS_PER_LONG;
216        } else {
217            unsigned long 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, 0);
224                    count++;
225                }
226                vec >>= 1;
227                ++cur;
228            }
229        }
230    }
231
232    page = virt_to_page(bdata->node_bootmem_map);
233    pages = bdata->node_low_pfn - bdata->node_min_pfn;
234    pages = bootmem_bootmap_pages(pages);
235    count += pages;
236    while (pages--)
237        __free_pages_bootmem(page++, 0);
238
239    bdebug("nid=%td released=%lx\n", bdata - bootmem_node_data, count);
240
241    return count;
242}
243
244static int reset_managed_pages_done __initdata;
245
246static inline void __init reset_node_managed_pages(pg_data_t *pgdat)
247{
248    struct zone *z;
249
250    if (reset_managed_pages_done)
251        return;
252
253    for (z = pgdat->node_zones; z < pgdat->node_zones + MAX_NR_ZONES; z++)
254        z->managed_pages = 0;
255}
256
257void __init reset_all_zones_managed_pages(void)
258{
259    struct pglist_data *pgdat;
260
261    for_each_online_pgdat(pgdat)
262        reset_node_managed_pages(pgdat);
263    reset_managed_pages_done = 1;
264}
265
266/**
267 * free_all_bootmem - release free pages to the buddy allocator
268 *
269 * Returns the number of pages actually released.
270 */
271unsigned long __init free_all_bootmem(void)
272{
273    unsigned long total_pages = 0;
274    bootmem_data_t *bdata;
275
276    reset_all_zones_managed_pages();
277
278    list_for_each_entry(bdata, &bdata_list, list)
279        total_pages += free_all_bootmem_core(bdata);
280
281    totalram_pages += total_pages;
282
283    return total_pages;
284}
285
286static void __init __free(bootmem_data_t *bdata,
287            unsigned long sidx, unsigned long eidx)
288{
289    unsigned long idx;
290
291    bdebug("nid=%td start=%lx end=%lx\n", bdata - bootmem_node_data,
292        sidx + bdata->node_min_pfn,
293        eidx + bdata->node_min_pfn);
294
295    if (bdata->hint_idx > sidx)
296        bdata->hint_idx = sidx;
297
298    for (idx = sidx; idx < eidx; idx++)
299        if (!test_and_clear_bit(idx, bdata->node_bootmem_map))
300            BUG();
301}
302
303static int __init __reserve(bootmem_data_t *bdata, unsigned long sidx,
304            unsigned long eidx, int flags)
305{
306    unsigned long idx;
307    int exclusive = flags & BOOTMEM_EXCLUSIVE;
308
309    bdebug("nid=%td start=%lx end=%lx flags=%x\n",
310        bdata - bootmem_node_data,
311        sidx + bdata->node_min_pfn,
312        eidx + bdata->node_min_pfn,
313        flags);
314
315    for (idx = sidx; idx < eidx; idx++)
316        if (test_and_set_bit(idx, bdata->node_bootmem_map)) {
317            if (exclusive) {
318                __free(bdata, sidx, idx);
319                return -EBUSY;
320            }
321            bdebug("silent double reserve of PFN %lx\n",
322                idx + bdata->node_min_pfn);
323        }
324    return 0;
325}
326
327static int __init mark_bootmem_node(bootmem_data_t *bdata,
328                unsigned long start, unsigned long end,
329                int reserve, int flags)
330{
331    unsigned long sidx, eidx;
332
333    bdebug("nid=%td start=%lx end=%lx reserve=%d flags=%x\n",
334        bdata - bootmem_node_data, start, end, reserve, flags);
335
336    BUG_ON(start < bdata->node_min_pfn);
337    BUG_ON(end > bdata->node_low_pfn);
338
339    sidx = start - bdata->node_min_pfn;
340    eidx = end - bdata->node_min_pfn;
341
342    if (reserve)
343        return __reserve(bdata, sidx, eidx, flags);
344    else
345        __free(bdata, sidx, eidx);
346    return 0;
347}
348
349static int __init mark_bootmem(unsigned long start, unsigned long end,
350                int reserve, int flags)
351{
352    unsigned long pos;
353    bootmem_data_t *bdata;
354
355    pos = start;
356    list_for_each_entry(bdata, &bdata_list, list) {
357        int err;
358        unsigned long max;
359
360        if (pos < bdata->node_min_pfn ||
361            pos >= bdata->node_low_pfn) {
362            BUG_ON(pos != start);
363            continue;
364        }
365
366        max = min(bdata->node_low_pfn, end);
367
368        err = mark_bootmem_node(bdata, pos, max, reserve, flags);
369        if (reserve && err) {
370            mark_bootmem(start, pos, 0, 0);
371            return err;
372        }
373
374        if (max == end)
375            return 0;
376        pos = bdata->node_low_pfn;
377    }
378    BUG();
379}
380
381/**
382 * free_bootmem_node - mark a page range as usable
383 * @pgdat: node the range resides on
384 * @physaddr: starting address of the range
385 * @size: size of the range in bytes
386 *
387 * Partial pages will be considered reserved and left as they are.
388 *
389 * The range must reside completely on the specified node.
390 */
391void __init free_bootmem_node(pg_data_t *pgdat, unsigned long physaddr,
392                  unsigned long size)
393{
394    unsigned long start, end;
395
396    kmemleak_free_part(__va(physaddr), size);
397
398    start = PFN_UP(physaddr);
399    end = PFN_DOWN(physaddr + size);
400
401    mark_bootmem_node(pgdat->bdata, start, end, 0, 0);
402}
403
404/**
405 * free_bootmem - mark a page range as usable
406 * @addr: starting physical address of the range
407 * @size: size of the range in bytes
408 *
409 * Partial pages will be considered reserved and left as they are.
410 *
411 * The range must be contiguous but may span node boundaries.
412 */
413void __init free_bootmem(unsigned long physaddr, unsigned long size)
414{
415    unsigned long start, end;
416
417    kmemleak_free_part(__va(physaddr), size);
418
419    start = PFN_UP(physaddr);
420    end = PFN_DOWN(physaddr + size);
421
422    mark_bootmem(start, end, 0, 0);
423}
424
425/**
426 * reserve_bootmem_node - mark a page range as reserved
427 * @pgdat: node the range resides on
428 * @physaddr: starting address of the range
429 * @size: size of the range in bytes
430 * @flags: reservation flags (see linux/bootmem.h)
431 *
432 * Partial pages will be reserved.
433 *
434 * The range must reside completely on the specified node.
435 */
436int __init reserve_bootmem_node(pg_data_t *pgdat, unsigned long physaddr,
437                 unsigned long size, int flags)
438{
439    unsigned long start, end;
440
441    start = PFN_DOWN(physaddr);
442    end = PFN_UP(physaddr + size);
443
444    return mark_bootmem_node(pgdat->bdata, start, end, 1, flags);
445}
446
447/**
448 * reserve_bootmem - mark a page range as reserved
449 * @addr: starting address of the range
450 * @size: size of the range in bytes
451 * @flags: reservation flags (see linux/bootmem.h)
452 *
453 * Partial pages will be reserved.
454 *
455 * The range must be contiguous but may span node boundaries.
456 */
457int __init reserve_bootmem(unsigned long addr, unsigned long size,
458                int flags)
459{
460    unsigned long start, end;
461
462    start = PFN_DOWN(addr);
463    end = PFN_UP(addr + size);
464
465    return mark_bootmem(start, end, 1, flags);
466}
467
468static unsigned long __init align_idx(struct bootmem_data *bdata,
469                      unsigned long idx, unsigned long step)
470{
471    unsigned long base = bdata->node_min_pfn;
472
473    /*
474     * Align the index with respect to the node start so that the
475     * combination of both satisfies the requested alignment.
476     */
477
478    return ALIGN(base + idx, step) - base;
479}
480
481static unsigned long __init align_off(struct bootmem_data *bdata,
482                      unsigned long off, unsigned long align)
483{
484    unsigned long base = PFN_PHYS(bdata->node_min_pfn);
485
486    /* Same as align_idx for byte offsets */
487
488    return ALIGN(base + off, align) - base;
489}
490
491static void * __init alloc_bootmem_bdata(struct bootmem_data *bdata,
492                    unsigned long size, unsigned long align,
493                    unsigned long goal, unsigned long limit)
494{
495    unsigned long fallback = 0;
496    unsigned long min, max, start, sidx, midx, step;
497
498    bdebug("nid=%td size=%lx [%lu pages] align=%lx goal=%lx limit=%lx\n",
499        bdata - bootmem_node_data, size, PAGE_ALIGN(size) >> PAGE_SHIFT,
500        align, goal, limit);
501
502    BUG_ON(!size);
503    BUG_ON(align & (align - 1));
504    BUG_ON(limit && goal + size > limit);
505
506    if (!bdata->node_bootmem_map)
507        return NULL;
508
509    min = bdata->node_min_pfn;
510    max = bdata->node_low_pfn;
511
512    goal >>= PAGE_SHIFT;
513    limit >>= PAGE_SHIFT;
514
515    if (limit && max > limit)
516        max = limit;
517    if (max <= min)
518        return NULL;
519
520    step = max(align >> PAGE_SHIFT, 1UL);
521
522    if (goal && min < goal && goal < max)
523        start = ALIGN(goal, step);
524    else
525        start = ALIGN(min, step);
526
527    sidx = start - bdata->node_min_pfn;
528    midx = max - bdata->node_min_pfn;
529
530    if (bdata->hint_idx > sidx) {
531        /*
532         * Handle the valid case of sidx being zero and still
533         * catch the fallback below.
534         */
535        fallback = sidx + 1;
536        sidx = align_idx(bdata, bdata->hint_idx, step);
537    }
538
539    while (1) {
540        int merge;
541        void *region;
542        unsigned long eidx, i, start_off, end_off;
543find_block:
544        sidx = find_next_zero_bit(bdata->node_bootmem_map, midx, sidx);
545        sidx = align_idx(bdata, sidx, step);
546        eidx = sidx + PFN_UP(size);
547
548        if (sidx >= midx || eidx > midx)
549            break;
550
551        for (i = sidx; i < eidx; i++)
552            if (test_bit(i, bdata->node_bootmem_map)) {
553                sidx = align_idx(bdata, i, step);
554                if (sidx == i)
555                    sidx += step;
556                goto find_block;
557            }
558
559        if (bdata->last_end_off & (PAGE_SIZE - 1) &&
560                PFN_DOWN(bdata->last_end_off) + 1 == sidx)
561            start_off = align_off(bdata, bdata->last_end_off, align);
562        else
563            start_off = PFN_PHYS(sidx);
564
565        merge = PFN_DOWN(start_off) < sidx;
566        end_off = start_off + size;
567
568        bdata->last_end_off = end_off;
569        bdata->hint_idx = PFN_UP(end_off);
570
571        /*
572         * Reserve the area now:
573         */
574        if (__reserve(bdata, PFN_DOWN(start_off) + merge,
575                PFN_UP(end_off), BOOTMEM_EXCLUSIVE))
576            BUG();
577
578        region = phys_to_virt(PFN_PHYS(bdata->node_min_pfn) +
579                start_off);
580        memset(region, 0, size);
581        /*
582         * The min_count is set to 0 so that bootmem allocated blocks
583         * are never reported as leaks.
584         */
585        kmemleak_alloc(region, size, 0, 0);
586        return region;
587    }
588
589    if (fallback) {
590        sidx = align_idx(bdata, fallback - 1, step);
591        fallback = 0;
592        goto find_block;
593    }
594
595    return NULL;
596}
597
598static void * __init alloc_bootmem_core(unsigned long size,
599                    unsigned long align,
600                    unsigned long goal,
601                    unsigned long limit)
602{
603    bootmem_data_t *bdata;
604    void *region;
605
606    if (WARN_ON_ONCE(slab_is_available()))
607        return kzalloc(size, GFP_NOWAIT);
608
609    list_for_each_entry(bdata, &bdata_list, list) {
610        if (goal && bdata->node_low_pfn <= PFN_DOWN(goal))
611            continue;
612        if (limit && bdata->node_min_pfn >= PFN_DOWN(limit))
613            break;
614
615        region = alloc_bootmem_bdata(bdata, size, align, goal, limit);
616        if (region)
617            return region;
618    }
619
620    return NULL;
621}
622
623static void * __init ___alloc_bootmem_nopanic(unsigned long size,
624                          unsigned long align,
625                          unsigned long goal,
626                          unsigned long limit)
627{
628    void *ptr;
629
630restart:
631    ptr = alloc_bootmem_core(size, align, goal, limit);
632    if (ptr)
633        return ptr;
634    if (goal) {
635        goal = 0;
636        goto restart;
637    }
638
639    return NULL;
640}
641
642/**
643 * __alloc_bootmem_nopanic - allocate boot memory without panicking
644 * @size: size of the request in bytes
645 * @align: alignment of the region
646 * @goal: preferred starting address of the region
647 *
648 * The goal is dropped if it can not be satisfied and the allocation will
649 * fall back to memory below @goal.
650 *
651 * Allocation may happen on any node in the system.
652 *
653 * Returns NULL on failure.
654 */
655void * __init __alloc_bootmem_nopanic(unsigned long size, unsigned long align,
656                    unsigned long goal)
657{
658    unsigned long limit = 0;
659
660    return ___alloc_bootmem_nopanic(size, align, goal, limit);
661}
662
663static void * __init ___alloc_bootmem(unsigned long size, unsigned long align,
664                    unsigned long goal, unsigned long limit)
665{
666    void *mem = ___alloc_bootmem_nopanic(size, align, goal, limit);
667
668    if (mem)
669        return mem;
670    /*
671     * Whoops, we cannot satisfy the allocation request.
672     */
673    printk(KERN_ALERT "bootmem alloc of %lu bytes failed!\n", size);
674    panic("Out of memory");
675    return NULL;
676}
677
678/**
679 * __alloc_bootmem - allocate boot memory
680 * @size: size of the request in bytes
681 * @align: alignment of the region
682 * @goal: preferred starting address of the region
683 *
684 * The goal is dropped if it can not be satisfied and the allocation will
685 * fall back to memory below @goal.
686 *
687 * Allocation may happen on any node in the system.
688 *
689 * The function panics if the request can not be satisfied.
690 */
691void * __init __alloc_bootmem(unsigned long size, unsigned long align,
692                  unsigned long goal)
693{
694    unsigned long limit = 0;
695
696    return ___alloc_bootmem(size, align, goal, limit);
697}
698
699void * __init ___alloc_bootmem_node_nopanic(pg_data_t *pgdat,
700                unsigned long size, unsigned long align,
701                unsigned long goal, unsigned long limit)
702{
703    void *ptr;
704
705    if (WARN_ON_ONCE(slab_is_available()))
706        return kzalloc(size, GFP_NOWAIT);
707again:
708
709    /* do not panic in alloc_bootmem_bdata() */
710    if (limit && goal + size > limit)
711        limit = 0;
712
713    ptr = alloc_bootmem_bdata(pgdat->bdata, size, align, goal, limit);
714    if (ptr)
715        return ptr;
716
717    ptr = alloc_bootmem_core(size, align, goal, limit);
718    if (ptr)
719        return ptr;
720
721    if (goal) {
722        goal = 0;
723        goto again;
724    }
725
726    return NULL;
727}
728
729void * __init __alloc_bootmem_node_nopanic(pg_data_t *pgdat, unsigned long size,
730                   unsigned long align, unsigned long goal)
731{
732    if (WARN_ON_ONCE(slab_is_available()))
733        return kzalloc_node(size, GFP_NOWAIT, pgdat->node_id);
734
735    return ___alloc_bootmem_node_nopanic(pgdat, size, align, goal, 0);
736}
737
738void * __init ___alloc_bootmem_node(pg_data_t *pgdat, unsigned long size,
739                    unsigned long align, unsigned long goal,
740                    unsigned long limit)
741{
742    void *ptr;
743
744    ptr = ___alloc_bootmem_node_nopanic(pgdat, size, align, goal, 0);
745    if (ptr)
746        return ptr;
747
748    printk(KERN_ALERT "bootmem alloc of %lu bytes failed!\n", size);
749    panic("Out of memory");
750    return NULL;
751}
752
753/**
754 * __alloc_bootmem_node - allocate boot memory from a specific node
755 * @pgdat: node to allocate from
756 * @size: size of the request in bytes
757 * @align: alignment of the region
758 * @goal: preferred starting address of the region
759 *
760 * The goal is dropped if it can not be satisfied and the allocation will
761 * fall back to memory below @goal.
762 *
763 * Allocation may fall back to any node in the system if the specified node
764 * can not hold the requested memory.
765 *
766 * The function panics if the request can not be satisfied.
767 */
768void * __init __alloc_bootmem_node(pg_data_t *pgdat, unsigned long size,
769                   unsigned long align, unsigned long goal)
770{
771    if (WARN_ON_ONCE(slab_is_available()))
772        return kzalloc_node(size, GFP_NOWAIT, pgdat->node_id);
773
774    return ___alloc_bootmem_node(pgdat, size, align, goal, 0);
775}
776
777void * __init __alloc_bootmem_node_high(pg_data_t *pgdat, unsigned long size,
778                   unsigned long align, unsigned long goal)
779{
780#ifdef MAX_DMA32_PFN
781    unsigned long end_pfn;
782
783    if (WARN_ON_ONCE(slab_is_available()))
784        return kzalloc_node(size, GFP_NOWAIT, pgdat->node_id);
785
786    /* update goal according ...MAX_DMA32_PFN */
787    end_pfn = pgdat_end_pfn(pgdat);
788
789    if (end_pfn > MAX_DMA32_PFN + (128 >> (20 - PAGE_SHIFT)) &&
790        (goal >> PAGE_SHIFT) < MAX_DMA32_PFN) {
791        void *ptr;
792        unsigned long new_goal;
793
794        new_goal = MAX_DMA32_PFN << PAGE_SHIFT;
795        ptr = alloc_bootmem_bdata(pgdat->bdata, size, align,
796                         new_goal, 0);
797        if (ptr)
798            return ptr;
799    }
800#endif
801
802    return __alloc_bootmem_node(pgdat, size, align, goal);
803
804}
805
806#ifndef ARCH_LOW_ADDRESS_LIMIT
807#define ARCH_LOW_ADDRESS_LIMIT 0xffffffffUL
808#endif
809
810/**
811 * __alloc_bootmem_low - allocate low boot memory
812 * @size: size of the request in bytes
813 * @align: alignment of the region
814 * @goal: preferred starting address of the region
815 *
816 * The goal is dropped if it can not be satisfied and the allocation will
817 * fall back to memory below @goal.
818 *
819 * Allocation may happen on any node in the system.
820 *
821 * The function panics if the request can not be satisfied.
822 */
823void * __init __alloc_bootmem_low(unsigned long size, unsigned long align,
824                  unsigned long goal)
825{
826    return ___alloc_bootmem(size, align, goal, ARCH_LOW_ADDRESS_LIMIT);
827}
828
829void * __init __alloc_bootmem_low_nopanic(unsigned long size,
830                      unsigned long align,
831                      unsigned long goal)
832{
833    return ___alloc_bootmem_nopanic(size, align, goal,
834                    ARCH_LOW_ADDRESS_LIMIT);
835}
836
837/**
838 * __alloc_bootmem_low_node - allocate low boot memory from a specific node
839 * @pgdat: node to allocate from
840 * @size: size of the request in bytes
841 * @align: alignment of the region
842 * @goal: preferred starting address of the region
843 *
844 * The goal is dropped if it can not be satisfied and the allocation will
845 * fall back to memory below @goal.
846 *
847 * Allocation may fall back to any node in the system if the specified node
848 * can not hold the requested memory.
849 *
850 * The function panics if the request can not be satisfied.
851 */
852void * __init __alloc_bootmem_low_node(pg_data_t *pgdat, unsigned long size,
853                       unsigned long align, unsigned long goal)
854{
855    if (WARN_ON_ONCE(slab_is_available()))
856        return kzalloc_node(size, GFP_NOWAIT, pgdat->node_id);
857
858    return ___alloc_bootmem_node(pgdat, size, align,
859                     goal, ARCH_LOW_ADDRESS_LIMIT);
860}
861

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