2 * bootmem - A boot-time physical memory allocator and configurator
4 * Copyright (C) 1999 Ingo Molnar
5 * 1999 Kanoj Sarcar, SGI
8 * Access to this subsystem has to be serialized externally (which is true
9 * for the boot process anyway).
11 #include <linux/init.h>
12 #include <linux/pfn.h>
13 #include <linux/bootmem.h>
14 #include <linux/module.h>
15 #include <linux/kmemleak.h>
19 #include <asm/processor.h>
23 unsigned long max_low_pfn
;
24 unsigned long min_low_pfn
;
25 unsigned long max_pfn
;
27 #ifdef CONFIG_CRASH_DUMP
29 * If we have booted due to a crash, max_pfn will be a very low value. We need
30 * to know the amount of memory that the previous kernel used.
32 unsigned long saved_max_pfn
;
35 bootmem_data_t bootmem_node_data
[MAX_NUMNODES
] __initdata
;
37 static struct list_head bdata_list __initdata
= LIST_HEAD_INIT(bdata_list
);
39 static int bootmem_debug
;
41 static int __init
bootmem_debug_setup(char *buf
)
46 early_param("bootmem_debug", bootmem_debug_setup
);
48 #define bdebug(fmt, args...) ({ \
49 if (unlikely(bootmem_debug)) \
55 static unsigned long __init
bootmap_bytes(unsigned long pages
)
57 unsigned long bytes
= (pages
+ 7) / 8;
59 return ALIGN(bytes
, sizeof(long));
63 * bootmem_bootmap_pages - calculate bitmap size in pages
64 * @pages: number of pages the bitmap has to represent
66 unsigned long __init
bootmem_bootmap_pages(unsigned long pages
)
68 unsigned long bytes
= bootmap_bytes(pages
);
70 return PAGE_ALIGN(bytes
) >> PAGE_SHIFT
;
76 static void __init
link_bootmem(bootmem_data_t
*bdata
)
78 struct list_head
*iter
;
80 list_for_each(iter
, &bdata_list
) {
83 ent
= list_entry(iter
, bootmem_data_t
, list
);
84 if (bdata
->node_min_pfn
< ent
->node_min_pfn
)
87 list_add_tail(&bdata
->list
, iter
);
91 * Called once to set up the allocator itself.
93 static unsigned long __init
init_bootmem_core(bootmem_data_t
*bdata
,
94 unsigned long mapstart
, unsigned long start
, unsigned long end
)
96 unsigned long mapsize
;
98 mminit_validate_memmodel_limits(&start
, &end
);
99 bdata
->node_bootmem_map
= phys_to_virt(PFN_PHYS(mapstart
));
100 bdata
->node_min_pfn
= start
;
101 bdata
->node_low_pfn
= end
;
105 * Initially all pages are reserved - setup_arch() has to
106 * register free RAM areas explicitly.
108 mapsize
= bootmap_bytes(end
- start
);
109 memset(bdata
->node_bootmem_map
, 0xff, mapsize
);
111 bdebug("nid=%td start=%lx map=%lx end=%lx mapsize=%lx\n",
112 bdata
- bootmem_node_data
, start
, mapstart
, end
, mapsize
);
118 * init_bootmem_node - register a node as boot memory
119 * @pgdat: node to register
120 * @freepfn: pfn where the bitmap for this node is to be placed
121 * @startpfn: first pfn on the node
122 * @endpfn: first pfn after the node
124 * Returns the number of bytes needed to hold the bitmap for this node.
126 unsigned long __init
init_bootmem_node(pg_data_t
*pgdat
, unsigned long freepfn
,
127 unsigned long startpfn
, unsigned long endpfn
)
129 return init_bootmem_core(pgdat
->bdata
, freepfn
, startpfn
, endpfn
);
133 * init_bootmem - register boot memory
134 * @start: pfn where the bitmap is to be placed
135 * @pages: number of available physical pages
137 * Returns the number of bytes needed to hold the bitmap.
139 unsigned long __init
init_bootmem(unsigned long start
, unsigned long pages
)
143 return init_bootmem_core(NODE_DATA(0)->bdata
, start
, 0, pages
);
147 * free_bootmem_late - free bootmem pages directly to page allocator
148 * @addr: starting address of the range
149 * @size: size of the range in bytes
151 * This is only useful when the bootmem allocator has already been torn
152 * down, but we are still initializing the system. Pages are given directly
153 * to the page allocator, no bootmem metadata is updated because it is gone.
155 void __init
free_bootmem_late(unsigned long addr
, unsigned long size
)
157 unsigned long cursor
, end
;
159 kmemleak_free_part(__va(addr
), size
);
161 cursor
= PFN_UP(addr
);
162 end
= PFN_DOWN(addr
+ size
);
164 for (; cursor
< end
; cursor
++) {
165 __free_pages_bootmem(pfn_to_page(cursor
), 0);
170 static unsigned long __init
free_all_bootmem_core(bootmem_data_t
*bdata
)
174 unsigned long start
, end
, pages
, count
= 0;
176 if (!bdata
->node_bootmem_map
)
179 start
= bdata
->node_min_pfn
;
180 end
= bdata
->node_low_pfn
;
183 * If the start is aligned to the machines wordsize, we might
184 * be able to free pages in bulks of that order.
186 aligned
= !(start
& (BITS_PER_LONG
- 1));
188 bdebug("nid=%td start=%lx end=%lx aligned=%d\n",
189 bdata
- bootmem_node_data
, start
, end
, aligned
);
191 while (start
< end
) {
192 unsigned long *map
, idx
, vec
;
194 map
= bdata
->node_bootmem_map
;
195 idx
= start
- bdata
->node_min_pfn
;
196 vec
= ~map
[idx
/ BITS_PER_LONG
];
198 if (aligned
&& vec
== ~0UL && start
+ BITS_PER_LONG
< end
) {
199 int order
= ilog2(BITS_PER_LONG
);
201 __free_pages_bootmem(pfn_to_page(start
), order
);
202 count
+= BITS_PER_LONG
;
204 unsigned long off
= 0;
206 while (vec
&& off
< BITS_PER_LONG
) {
208 page
= pfn_to_page(start
+ off
);
209 __free_pages_bootmem(page
, 0);
216 start
+= BITS_PER_LONG
;
219 page
= virt_to_page(bdata
->node_bootmem_map
);
220 pages
= bdata
->node_low_pfn
- bdata
->node_min_pfn
;
221 pages
= bootmem_bootmap_pages(pages
);
224 __free_pages_bootmem(page
++, 0);
226 bdebug("nid=%td released=%lx\n", bdata
- bootmem_node_data
, count
);
232 * free_all_bootmem_node - release a node's free pages to the buddy allocator
233 * @pgdat: node to be released
235 * Returns the number of pages actually released.
237 unsigned long __init
free_all_bootmem_node(pg_data_t
*pgdat
)
239 register_page_bootmem_info_node(pgdat
);
240 return free_all_bootmem_core(pgdat
->bdata
);
244 * free_all_bootmem - release free pages to the buddy allocator
246 * Returns the number of pages actually released.
248 unsigned long __init
free_all_bootmem(void)
250 return free_all_bootmem_core(NODE_DATA(0)->bdata
);
253 static void __init
__free(bootmem_data_t
*bdata
,
254 unsigned long sidx
, unsigned long eidx
)
258 bdebug("nid=%td start=%lx end=%lx\n", bdata
- bootmem_node_data
,
259 sidx
+ bdata
->node_min_pfn
,
260 eidx
+ bdata
->node_min_pfn
);
262 if (bdata
->hint_idx
> sidx
)
263 bdata
->hint_idx
= sidx
;
265 for (idx
= sidx
; idx
< eidx
; idx
++)
266 if (!test_and_clear_bit(idx
, bdata
->node_bootmem_map
))
270 static int __init
__reserve(bootmem_data_t
*bdata
, unsigned long sidx
,
271 unsigned long eidx
, int flags
)
274 int exclusive
= flags
& BOOTMEM_EXCLUSIVE
;
276 bdebug("nid=%td start=%lx end=%lx flags=%x\n",
277 bdata
- bootmem_node_data
,
278 sidx
+ bdata
->node_min_pfn
,
279 eidx
+ bdata
->node_min_pfn
,
282 for (idx
= sidx
; idx
< eidx
; idx
++)
283 if (test_and_set_bit(idx
, bdata
->node_bootmem_map
)) {
285 __free(bdata
, sidx
, idx
);
288 bdebug("silent double reserve of PFN %lx\n",
289 idx
+ bdata
->node_min_pfn
);
294 static int __init
mark_bootmem_node(bootmem_data_t
*bdata
,
295 unsigned long start
, unsigned long end
,
296 int reserve
, int flags
)
298 unsigned long sidx
, eidx
;
300 bdebug("nid=%td start=%lx end=%lx reserve=%d flags=%x\n",
301 bdata
- bootmem_node_data
, start
, end
, reserve
, flags
);
303 BUG_ON(start
< bdata
->node_min_pfn
);
304 BUG_ON(end
> bdata
->node_low_pfn
);
306 sidx
= start
- bdata
->node_min_pfn
;
307 eidx
= end
- bdata
->node_min_pfn
;
310 return __reserve(bdata
, sidx
, eidx
, flags
);
312 __free(bdata
, sidx
, eidx
);
316 static int __init
mark_bootmem(unsigned long start
, unsigned long end
,
317 int reserve
, int flags
)
320 bootmem_data_t
*bdata
;
323 list_for_each_entry(bdata
, &bdata_list
, list
) {
327 if (pos
< bdata
->node_min_pfn
||
328 pos
>= bdata
->node_low_pfn
) {
329 BUG_ON(pos
!= start
);
333 max
= min(bdata
->node_low_pfn
, end
);
335 err
= mark_bootmem_node(bdata
, pos
, max
, reserve
, flags
);
336 if (reserve
&& err
) {
337 mark_bootmem(start
, pos
, 0, 0);
343 pos
= bdata
->node_low_pfn
;
349 * free_bootmem_node - mark a page range as usable
350 * @pgdat: node the range resides on
351 * @physaddr: starting address of the range
352 * @size: size of the range in bytes
354 * Partial pages will be considered reserved and left as they are.
356 * The range must reside completely on the specified node.
358 void __init
free_bootmem_node(pg_data_t
*pgdat
, unsigned long physaddr
,
361 unsigned long start
, end
;
363 kmemleak_free_part(__va(physaddr
), size
);
365 start
= PFN_UP(physaddr
);
366 end
= PFN_DOWN(physaddr
+ size
);
368 mark_bootmem_node(pgdat
->bdata
, start
, end
, 0, 0);
372 * free_bootmem - mark a page range as usable
373 * @addr: starting address of the range
374 * @size: size of the range in bytes
376 * Partial pages will be considered reserved and left as they are.
378 * The range must be contiguous but may span node boundaries.
380 void __init
free_bootmem(unsigned long addr
, unsigned long size
)
382 unsigned long start
, end
;
384 kmemleak_free_part(__va(addr
), size
);
386 start
= PFN_UP(addr
);
387 end
= PFN_DOWN(addr
+ size
);
389 mark_bootmem(start
, end
, 0, 0);
393 * reserve_bootmem_node - mark a page range as reserved
394 * @pgdat: node the range resides on
395 * @physaddr: starting address of the range
396 * @size: size of the range in bytes
397 * @flags: reservation flags (see linux/bootmem.h)
399 * Partial pages will be reserved.
401 * The range must reside completely on the specified node.
403 int __init
reserve_bootmem_node(pg_data_t
*pgdat
, unsigned long physaddr
,
404 unsigned long size
, int flags
)
406 unsigned long start
, end
;
408 start
= PFN_DOWN(physaddr
);
409 end
= PFN_UP(physaddr
+ size
);
411 return mark_bootmem_node(pgdat
->bdata
, start
, end
, 1, flags
);
415 * reserve_bootmem - mark a page range as usable
416 * @addr: starting address of the range
417 * @size: size of the range in bytes
418 * @flags: reservation flags (see linux/bootmem.h)
420 * Partial pages will be reserved.
422 * The range must be contiguous but may span node boundaries.
424 int __init
reserve_bootmem(unsigned long addr
, unsigned long size
,
427 unsigned long start
, end
;
429 start
= PFN_DOWN(addr
);
430 end
= PFN_UP(addr
+ size
);
432 return mark_bootmem(start
, end
, 1, flags
);
435 static unsigned long __init
align_idx(struct bootmem_data
*bdata
,
436 unsigned long idx
, unsigned long step
)
438 unsigned long base
= bdata
->node_min_pfn
;
441 * Align the index with respect to the node start so that the
442 * combination of both satisfies the requested alignment.
445 return ALIGN(base
+ idx
, step
) - base
;
448 static unsigned long __init
align_off(struct bootmem_data
*bdata
,
449 unsigned long off
, unsigned long align
)
451 unsigned long base
= PFN_PHYS(bdata
->node_min_pfn
);
453 /* Same as align_idx for byte offsets */
455 return ALIGN(base
+ off
, align
) - base
;
458 static void * __init
alloc_bootmem_core(struct bootmem_data
*bdata
,
459 unsigned long size
, unsigned long align
,
460 unsigned long goal
, unsigned long limit
)
462 unsigned long fallback
= 0;
463 unsigned long min
, max
, start
, sidx
, midx
, step
;
465 bdebug("nid=%td size=%lx [%lu pages] align=%lx goal=%lx limit=%lx\n",
466 bdata
- bootmem_node_data
, size
, PAGE_ALIGN(size
) >> PAGE_SHIFT
,
470 BUG_ON(align
& (align
- 1));
471 BUG_ON(limit
&& goal
+ size
> limit
);
473 if (!bdata
->node_bootmem_map
)
476 min
= bdata
->node_min_pfn
;
477 max
= bdata
->node_low_pfn
;
480 limit
>>= PAGE_SHIFT
;
482 if (limit
&& max
> limit
)
487 step
= max(align
>> PAGE_SHIFT
, 1UL);
489 if (goal
&& min
< goal
&& goal
< max
)
490 start
= ALIGN(goal
, step
);
492 start
= ALIGN(min
, step
);
494 sidx
= start
- bdata
->node_min_pfn
;
495 midx
= max
- bdata
->node_min_pfn
;
497 if (bdata
->hint_idx
> sidx
) {
499 * Handle the valid case of sidx being zero and still
500 * catch the fallback below.
503 sidx
= align_idx(bdata
, bdata
->hint_idx
, step
);
509 unsigned long eidx
, i
, start_off
, end_off
;
511 sidx
= find_next_zero_bit(bdata
->node_bootmem_map
, midx
, sidx
);
512 sidx
= align_idx(bdata
, sidx
, step
);
513 eidx
= sidx
+ PFN_UP(size
);
515 if (sidx
>= midx
|| eidx
> midx
)
518 for (i
= sidx
; i
< eidx
; i
++)
519 if (test_bit(i
, bdata
->node_bootmem_map
)) {
520 sidx
= align_idx(bdata
, i
, step
);
526 if (bdata
->last_end_off
& (PAGE_SIZE
- 1) &&
527 PFN_DOWN(bdata
->last_end_off
) + 1 == sidx
)
528 start_off
= align_off(bdata
, bdata
->last_end_off
, align
);
530 start_off
= PFN_PHYS(sidx
);
532 merge
= PFN_DOWN(start_off
) < sidx
;
533 end_off
= start_off
+ size
;
535 bdata
->last_end_off
= end_off
;
536 bdata
->hint_idx
= PFN_UP(end_off
);
539 * Reserve the area now:
541 if (__reserve(bdata
, PFN_DOWN(start_off
) + merge
,
542 PFN_UP(end_off
), BOOTMEM_EXCLUSIVE
))
545 region
= phys_to_virt(PFN_PHYS(bdata
->node_min_pfn
) +
547 memset(region
, 0, size
);
549 * The min_count is set to 0 so that bootmem allocated blocks
550 * are never reported as leaks.
552 kmemleak_alloc(region
, size
, 0, 0);
557 sidx
= align_idx(bdata
, fallback
- 1, step
);
565 static void * __init
alloc_arch_preferred_bootmem(bootmem_data_t
*bdata
,
566 unsigned long size
, unsigned long align
,
567 unsigned long goal
, unsigned long limit
)
569 if (WARN_ON_ONCE(slab_is_available()))
570 return kzalloc(size
, GFP_NOWAIT
);
572 #ifdef CONFIG_HAVE_ARCH_BOOTMEM
574 bootmem_data_t
*p_bdata
;
576 p_bdata
= bootmem_arch_preferred_node(bdata
, size
, align
,
579 return alloc_bootmem_core(p_bdata
, size
, align
,
586 static void * __init
___alloc_bootmem_nopanic(unsigned long size
,
591 bootmem_data_t
*bdata
;
595 region
= alloc_arch_preferred_bootmem(NULL
, size
, align
, goal
, limit
);
599 list_for_each_entry(bdata
, &bdata_list
, list
) {
600 if (goal
&& bdata
->node_low_pfn
<= PFN_DOWN(goal
))
602 if (limit
&& bdata
->node_min_pfn
>= PFN_DOWN(limit
))
605 region
= alloc_bootmem_core(bdata
, size
, align
, goal
, limit
);
619 * __alloc_bootmem_nopanic - allocate boot memory without panicking
620 * @size: size of the request in bytes
621 * @align: alignment of the region
622 * @goal: preferred starting address of the region
624 * The goal is dropped if it can not be satisfied and the allocation will
625 * fall back to memory below @goal.
627 * Allocation may happen on any node in the system.
629 * Returns NULL on failure.
631 void * __init
__alloc_bootmem_nopanic(unsigned long size
, unsigned long align
,
634 return ___alloc_bootmem_nopanic(size
, align
, goal
, 0);
637 static void * __init
___alloc_bootmem(unsigned long size
, unsigned long align
,
638 unsigned long goal
, unsigned long limit
)
640 void *mem
= ___alloc_bootmem_nopanic(size
, align
, goal
, limit
);
645 * Whoops, we cannot satisfy the allocation request.
647 printk(KERN_ALERT
"bootmem alloc of %lu bytes failed!\n", size
);
648 panic("Out of memory");
653 * __alloc_bootmem - allocate boot memory
654 * @size: size of the request in bytes
655 * @align: alignment of the region
656 * @goal: preferred starting address of the region
658 * The goal is dropped if it can not be satisfied and the allocation will
659 * fall back to memory below @goal.
661 * Allocation may happen on any node in the system.
663 * The function panics if the request can not be satisfied.
665 void * __init
__alloc_bootmem(unsigned long size
, unsigned long align
,
668 return ___alloc_bootmem(size
, align
, goal
, 0);
671 static void * __init
___alloc_bootmem_node(bootmem_data_t
*bdata
,
672 unsigned long size
, unsigned long align
,
673 unsigned long goal
, unsigned long limit
)
677 ptr
= alloc_arch_preferred_bootmem(bdata
, size
, align
, goal
, limit
);
681 ptr
= alloc_bootmem_core(bdata
, size
, align
, goal
, limit
);
685 return ___alloc_bootmem(size
, align
, goal
, limit
);
689 * __alloc_bootmem_node - allocate boot memory from a specific node
690 * @pgdat: node to allocate from
691 * @size: size of the request in bytes
692 * @align: alignment of the region
693 * @goal: preferred starting address of the region
695 * The goal is dropped if it can not be satisfied and the allocation will
696 * fall back to memory below @goal.
698 * Allocation may fall back to any node in the system if the specified node
699 * can not hold the requested memory.
701 * The function panics if the request can not be satisfied.
703 void * __init
__alloc_bootmem_node(pg_data_t
*pgdat
, unsigned long size
,
704 unsigned long align
, unsigned long goal
)
706 if (WARN_ON_ONCE(slab_is_available()))
707 return kzalloc_node(size
, GFP_NOWAIT
, pgdat
->node_id
);
709 return ___alloc_bootmem_node(pgdat
->bdata
, size
, align
, goal
, 0);
712 #ifdef CONFIG_SPARSEMEM
714 * alloc_bootmem_section - allocate boot memory from a specific section
715 * @size: size of the request in bytes
716 * @section_nr: sparse map section to allocate from
718 * Return NULL on failure.
720 void * __init
alloc_bootmem_section(unsigned long size
,
721 unsigned long section_nr
)
723 bootmem_data_t
*bdata
;
724 unsigned long pfn
, goal
, limit
;
726 pfn
= section_nr_to_pfn(section_nr
);
727 goal
= pfn
<< PAGE_SHIFT
;
728 limit
= section_nr_to_pfn(section_nr
+ 1) << PAGE_SHIFT
;
729 bdata
= &bootmem_node_data
[early_pfn_to_nid(pfn
)];
731 return alloc_bootmem_core(bdata
, size
, SMP_CACHE_BYTES
, goal
, limit
);
735 void * __init
__alloc_bootmem_node_nopanic(pg_data_t
*pgdat
, unsigned long size
,
736 unsigned long align
, unsigned long goal
)
740 if (WARN_ON_ONCE(slab_is_available()))
741 return kzalloc_node(size
, GFP_NOWAIT
, pgdat
->node_id
);
743 ptr
= alloc_arch_preferred_bootmem(pgdat
->bdata
, size
, align
, goal
, 0);
747 ptr
= alloc_bootmem_core(pgdat
->bdata
, size
, align
, goal
, 0);
751 return __alloc_bootmem_nopanic(size
, align
, goal
);
754 #ifndef ARCH_LOW_ADDRESS_LIMIT
755 #define ARCH_LOW_ADDRESS_LIMIT 0xffffffffUL
759 * __alloc_bootmem_low - allocate low boot memory
760 * @size: size of the request in bytes
761 * @align: alignment of the region
762 * @goal: preferred starting address of the region
764 * The goal is dropped if it can not be satisfied and the allocation will
765 * fall back to memory below @goal.
767 * Allocation may happen on any node in the system.
769 * The function panics if the request can not be satisfied.
771 void * __init
__alloc_bootmem_low(unsigned long size
, unsigned long align
,
774 return ___alloc_bootmem(size
, align
, goal
, ARCH_LOW_ADDRESS_LIMIT
);
778 * __alloc_bootmem_low_node - allocate low boot memory from a specific node
779 * @pgdat: node to allocate from
780 * @size: size of the request in bytes
781 * @align: alignment of the region
782 * @goal: preferred starting address of the region
784 * The goal is dropped if it can not be satisfied and the allocation will
785 * fall back to memory below @goal.
787 * Allocation may fall back to any node in the system if the specified node
788 * can not hold the requested memory.
790 * The function panics if the request can not be satisfied.
792 void * __init
__alloc_bootmem_low_node(pg_data_t
*pgdat
, unsigned long size
,
793 unsigned long align
, unsigned long goal
)
795 if (WARN_ON_ONCE(slab_is_available()))
796 return kzalloc_node(size
, GFP_NOWAIT
, pgdat
->node_id
);
798 return ___alloc_bootmem_node(pgdat
->bdata
, size
, align
,
799 goal
, ARCH_LOW_ADDRESS_LIMIT
);