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>
18 #include <asm/processor.h>
22 unsigned long max_low_pfn;
23 unsigned long min_low_pfn;
24 unsigned long max_pfn;
26 #ifdef CONFIG_CRASH_DUMP
28 * If we have booted due to a crash, max_pfn will be a very low value. We need
29 * to know the amount of memory that the previous kernel used.
31 unsigned long saved_max_pfn;
34 bootmem_data_t bootmem_node_data[MAX_NUMNODES] __initdata;
36 static struct list_head bdata_list __initdata = LIST_HEAD_INIT(bdata_list);
38 static int bootmem_debug;
40 static int __init bootmem_debug_setup(char *buf)
45 early_param("bootmem_debug", bootmem_debug_setup);
47 #define bdebug(fmt, args...) ({ \
48 if (unlikely(bootmem_debug)) \
51 __FUNCTION__, ## args); \
54 static unsigned long __init bootmap_bytes(unsigned long pages)
56 unsigned long bytes = (pages + 7) / 8;
58 return ALIGN(bytes, sizeof(long));
62 * bootmem_bootmap_pages - calculate bitmap size in pages
63 * @pages: number of pages the bitmap has to represent
65 unsigned long __init bootmem_bootmap_pages(unsigned long pages)
67 unsigned long bytes = bootmap_bytes(pages);
69 return PAGE_ALIGN(bytes) >> PAGE_SHIFT;
75 static void __init link_bootmem(bootmem_data_t *bdata)
77 struct list_head *iter;
79 list_for_each(iter, &bdata_list) {
82 ent = list_entry(iter, bootmem_data_t, list);
83 if (bdata->node_boot_start < ent->node_boot_start)
86 list_add_tail(&bdata->list, iter);
90 * Called once to set up the allocator itself.
92 static unsigned long __init init_bootmem_core(bootmem_data_t *bdata,
93 unsigned long mapstart, unsigned long start, unsigned long end)
95 unsigned long mapsize;
97 mminit_validate_memmodel_limits(&start, &end);
98 bdata->node_bootmem_map = phys_to_virt(PFN_PHYS(mapstart));
99 bdata->node_boot_start = PFN_PHYS(start);
100 bdata->node_low_pfn = end;
104 * Initially all pages are reserved - setup_arch() has to
105 * register free RAM areas explicitly.
107 mapsize = bootmap_bytes(end - start);
108 memset(bdata->node_bootmem_map, 0xff, mapsize);
110 bdebug("nid=%td start=%lx map=%lx end=%lx mapsize=%lx\n",
111 bdata - bootmem_node_data, start, mapstart, end, mapsize);
117 * init_bootmem_node - register a node as boot memory
118 * @pgdat: node to register
119 * @freepfn: pfn where the bitmap for this node is to be placed
120 * @startpfn: first pfn on the node
121 * @endpfn: first pfn after the node
123 * Returns the number of bytes needed to hold the bitmap for this node.
125 unsigned long __init init_bootmem_node(pg_data_t *pgdat, unsigned long freepfn,
126 unsigned long startpfn, unsigned long endpfn)
128 return init_bootmem_core(pgdat->bdata, freepfn, startpfn, endpfn);
132 * init_bootmem - register boot memory
133 * @start: pfn where the bitmap is to be placed
134 * @pages: number of available physical pages
136 * Returns the number of bytes needed to hold the bitmap.
138 unsigned long __init init_bootmem(unsigned long start, unsigned long pages)
142 return init_bootmem_core(NODE_DATA(0)->bdata, start, 0, pages);
145 static unsigned long __init free_all_bootmem_core(bootmem_data_t *bdata)
149 unsigned long start, end, pages, count = 0;
151 if (!bdata->node_bootmem_map)
154 start = PFN_DOWN(bdata->node_boot_start);
155 end = bdata->node_low_pfn;
158 * If the start is aligned to the machines wordsize, we might
159 * be able to free pages in bulks of that order.
161 aligned = !(start & (BITS_PER_LONG - 1));
163 bdebug("nid=%td start=%lx end=%lx aligned=%d\n",
164 bdata - bootmem_node_data, start, end, aligned);
166 while (start < end) {
167 unsigned long *map, idx, vec;
169 map = bdata->node_bootmem_map;
170 idx = start - PFN_DOWN(bdata->node_boot_start);
171 vec = ~map[idx / BITS_PER_LONG];
173 if (aligned && vec == ~0UL && start + BITS_PER_LONG < end) {
174 int order = ilog2(BITS_PER_LONG);
176 __free_pages_bootmem(pfn_to_page(start), order);
177 count += BITS_PER_LONG;
179 unsigned long off = 0;
181 while (vec && off < BITS_PER_LONG) {
183 page = pfn_to_page(start + off);
184 __free_pages_bootmem(page, 0);
191 start += BITS_PER_LONG;
194 page = virt_to_page(bdata->node_bootmem_map);
195 pages = bdata->node_low_pfn - PFN_DOWN(bdata->node_boot_start);
196 pages = bootmem_bootmap_pages(pages);
199 __free_pages_bootmem(page++, 0);
201 bdebug("nid=%td released=%lx\n", bdata - bootmem_node_data, count);
207 * free_all_bootmem_node - release a node's free pages to the buddy allocator
208 * @pgdat: node to be released
210 * Returns the number of pages actually released.
212 unsigned long __init free_all_bootmem_node(pg_data_t *pgdat)
214 register_page_bootmem_info_node(pgdat);
215 return free_all_bootmem_core(pgdat->bdata);
219 * free_all_bootmem - release free pages to the buddy allocator
221 * Returns the number of pages actually released.
223 unsigned long __init free_all_bootmem(void)
225 return free_all_bootmem_core(NODE_DATA(0)->bdata);
228 static void __init __free(bootmem_data_t *bdata,
229 unsigned long sidx, unsigned long eidx)
233 bdebug("nid=%td start=%lx end=%lx\n", bdata - bootmem_node_data,
234 sidx + PFN_DOWN(bdata->node_boot_start),
235 eidx + PFN_DOWN(bdata->node_boot_start));
237 if (bdata->hint_idx > sidx)
238 bdata->hint_idx = sidx;
240 for (idx = sidx; idx < eidx; idx++)
241 if (!test_and_clear_bit(idx, bdata->node_bootmem_map))
245 static int __init __reserve(bootmem_data_t *bdata, unsigned long sidx,
246 unsigned long eidx, int flags)
249 int exclusive = flags & BOOTMEM_EXCLUSIVE;
251 bdebug("nid=%td start=%lx end=%lx flags=%x\n",
252 bdata - bootmem_node_data,
253 sidx + PFN_DOWN(bdata->node_boot_start),
254 eidx + PFN_DOWN(bdata->node_boot_start),
257 for (idx = sidx; idx < eidx; idx++)
258 if (test_and_set_bit(idx, bdata->node_bootmem_map)) {
260 __free(bdata, sidx, idx);
263 bdebug("silent double reserve of PFN %lx\n",
264 idx + PFN_DOWN(bdata->node_boot_start));
269 static int __init mark_bootmem_node(bootmem_data_t *bdata,
270 unsigned long start, unsigned long end,
271 int reserve, int flags)
273 unsigned long sidx, eidx;
275 bdebug("nid=%td start=%lx end=%lx reserve=%d flags=%x\n",
276 bdata - bootmem_node_data, start, end, reserve, flags);
278 BUG_ON(start < PFN_DOWN(bdata->node_boot_start));
279 BUG_ON(end > bdata->node_low_pfn);
281 sidx = start - PFN_DOWN(bdata->node_boot_start);
282 eidx = end - PFN_DOWN(bdata->node_boot_start);
285 return __reserve(bdata, sidx, eidx, flags);
287 __free(bdata, sidx, eidx);
291 static int __init mark_bootmem(unsigned long start, unsigned long end,
292 int reserve, int flags)
295 bootmem_data_t *bdata;
298 list_for_each_entry(bdata, &bdata_list, list) {
302 if (pos < PFN_DOWN(bdata->node_boot_start)) {
303 BUG_ON(pos != start);
307 max = min(bdata->node_low_pfn, end);
309 err = mark_bootmem_node(bdata, pos, max, reserve, flags);
310 if (reserve && err) {
311 mark_bootmem(start, pos, 0, 0);
317 pos = bdata->node_low_pfn;
323 * free_bootmem_node - mark a page range as usable
324 * @pgdat: node the range resides on
325 * @physaddr: starting address of the range
326 * @size: size of the range in bytes
328 * Partial pages will be considered reserved and left as they are.
330 * The range must reside completely on the specified node.
332 void __init free_bootmem_node(pg_data_t *pgdat, unsigned long physaddr,
335 unsigned long start, end;
337 start = PFN_UP(physaddr);
338 end = PFN_DOWN(physaddr + size);
340 mark_bootmem_node(pgdat->bdata, start, end, 0, 0);
344 * free_bootmem - mark a page range as usable
345 * @addr: starting address of the range
346 * @size: size of the range in bytes
348 * Partial pages will be considered reserved and left as they are.
350 * The range must be contiguous but may span node boundaries.
352 void __init free_bootmem(unsigned long addr, unsigned long size)
354 unsigned long start, end;
356 start = PFN_UP(addr);
357 end = PFN_DOWN(addr + size);
359 mark_bootmem(start, end, 0, 0);
363 * reserve_bootmem_node - mark a page range as reserved
364 * @pgdat: node the range resides on
365 * @physaddr: starting address of the range
366 * @size: size of the range in bytes
367 * @flags: reservation flags (see linux/bootmem.h)
369 * Partial pages will be reserved.
371 * The range must reside completely on the specified node.
373 int __init reserve_bootmem_node(pg_data_t *pgdat, unsigned long physaddr,
374 unsigned long size, int flags)
376 unsigned long start, end;
378 start = PFN_DOWN(physaddr);
379 end = PFN_UP(physaddr + size);
381 return mark_bootmem_node(pgdat->bdata, start, end, 1, flags);
384 #ifndef CONFIG_HAVE_ARCH_BOOTMEM_NODE
386 * reserve_bootmem - mark a page range as usable
387 * @addr: starting address of the range
388 * @size: size of the range in bytes
389 * @flags: reservation flags (see linux/bootmem.h)
391 * Partial pages will be reserved.
393 * The range must be contiguous but may span node boundaries.
395 int __init reserve_bootmem(unsigned long addr, unsigned long size,
398 unsigned long start, end;
400 start = PFN_DOWN(addr);
401 end = PFN_UP(addr + size);
403 return mark_bootmem(start, end, 1, flags);
405 #endif /* !CONFIG_HAVE_ARCH_BOOTMEM_NODE */
407 static void * __init alloc_bootmem_core(struct bootmem_data *bdata,
408 unsigned long size, unsigned long align,
409 unsigned long goal, unsigned long limit)
411 unsigned long fallback = 0;
412 unsigned long min, max, start, sidx, midx, step;
415 BUG_ON(align & (align - 1));
416 BUG_ON(limit && goal + size > limit);
418 if (!bdata->node_bootmem_map)
421 bdebug("nid=%td size=%lx [%lu pages] align=%lx goal=%lx limit=%lx\n",
422 bdata - bootmem_node_data, size, PAGE_ALIGN(size) >> PAGE_SHIFT,
425 min = PFN_DOWN(bdata->node_boot_start);
426 max = bdata->node_low_pfn;
429 limit >>= PAGE_SHIFT;
431 if (limit && max > limit)
436 step = max(align >> PAGE_SHIFT, 1UL);
438 if (goal && min < goal && goal < max)
439 start = ALIGN(goal, step);
441 start = ALIGN(min, step);
443 sidx = start - PFN_DOWN(bdata->node_boot_start);
444 midx = max - PFN_DOWN(bdata->node_boot_start);
446 if (bdata->hint_idx > sidx) {
448 * Handle the valid case of sidx being zero and still
449 * catch the fallback below.
452 sidx = ALIGN(bdata->hint_idx, step);
458 unsigned long eidx, i, start_off, end_off;
460 sidx = find_next_zero_bit(bdata->node_bootmem_map, midx, sidx);
461 sidx = ALIGN(sidx, step);
462 eidx = sidx + PFN_UP(size);
464 if (sidx >= midx || eidx > midx)
467 for (i = sidx; i < eidx; i++)
468 if (test_bit(i, bdata->node_bootmem_map)) {
469 sidx = ALIGN(i, step);
475 if (bdata->last_end_off &&
476 PFN_DOWN(bdata->last_end_off) + 1 == sidx)
477 start_off = ALIGN(bdata->last_end_off, align);
479 start_off = PFN_PHYS(sidx);
481 merge = PFN_DOWN(start_off) < sidx;
482 end_off = start_off + size;
484 bdata->last_end_off = end_off;
485 bdata->hint_idx = PFN_UP(end_off);
488 * Reserve the area now:
490 if (__reserve(bdata, PFN_DOWN(start_off) + merge,
491 PFN_UP(end_off), BOOTMEM_EXCLUSIVE))
494 region = phys_to_virt(bdata->node_boot_start + start_off);
495 memset(region, 0, size);
500 sidx = ALIGN(fallback - 1, step);
508 static void * __init ___alloc_bootmem_nopanic(unsigned long size,
513 bootmem_data_t *bdata;
516 list_for_each_entry(bdata, &bdata_list, list) {
519 if (goal && bdata->node_low_pfn <= PFN_DOWN(goal))
521 if (limit && bdata->node_boot_start >= limit)
524 region = alloc_bootmem_core(bdata, size, align, goal, limit);
538 * __alloc_bootmem_nopanic - allocate boot memory without panicking
539 * @size: size of the request in bytes
540 * @align: alignment of the region
541 * @goal: preferred starting address of the region
543 * The goal is dropped if it can not be satisfied and the allocation will
544 * fall back to memory below @goal.
546 * Allocation may happen on any node in the system.
548 * Returns NULL on failure.
550 void * __init __alloc_bootmem_nopanic(unsigned long size, unsigned long align,
553 return ___alloc_bootmem_nopanic(size, align, goal, 0);
556 static void * __init ___alloc_bootmem(unsigned long size, unsigned long align,
557 unsigned long goal, unsigned long limit)
559 void *mem = ___alloc_bootmem_nopanic(size, align, goal, limit);
564 * Whoops, we cannot satisfy the allocation request.
566 printk(KERN_ALERT "bootmem alloc of %lu bytes failed!\n", size);
567 panic("Out of memory");
572 * __alloc_bootmem - allocate boot memory
573 * @size: size of the request in bytes
574 * @align: alignment of the region
575 * @goal: preferred starting address of the region
577 * The goal is dropped if it can not be satisfied and the allocation will
578 * fall back to memory below @goal.
580 * Allocation may happen on any node in the system.
582 * The function panics if the request can not be satisfied.
584 void * __init __alloc_bootmem(unsigned long size, unsigned long align,
587 return ___alloc_bootmem(size, align, goal, 0);
590 static void * __init ___alloc_bootmem_node(bootmem_data_t *bdata,
591 unsigned long size, unsigned long align,
592 unsigned long goal, unsigned long limit)
596 ptr = alloc_bootmem_core(bdata, size, align, goal, limit);
600 return ___alloc_bootmem(size, align, goal, limit);
604 * __alloc_bootmem_node - allocate boot memory from a specific node
605 * @pgdat: node to allocate from
606 * @size: size of the request in bytes
607 * @align: alignment of the region
608 * @goal: preferred starting address of the region
610 * The goal is dropped if it can not be satisfied and the allocation will
611 * fall back to memory below @goal.
613 * Allocation may fall back to any node in the system if the specified node
614 * can not hold the requested memory.
616 * The function panics if the request can not be satisfied.
618 void * __init __alloc_bootmem_node(pg_data_t *pgdat, unsigned long size,
619 unsigned long align, unsigned long goal)
621 return ___alloc_bootmem_node(pgdat->bdata, size, align, goal, 0);
624 #ifdef CONFIG_SPARSEMEM
626 * alloc_bootmem_section - allocate boot memory from a specific section
627 * @size: size of the request in bytes
628 * @section_nr: sparse map section to allocate from
630 * Return NULL on failure.
632 void * __init alloc_bootmem_section(unsigned long size,
633 unsigned long section_nr)
635 bootmem_data_t *bdata;
636 unsigned long pfn, goal, limit;
638 pfn = section_nr_to_pfn(section_nr);
639 goal = pfn << PAGE_SHIFT;
640 limit = section_nr_to_pfn(section_nr + 1) << PAGE_SHIFT;
641 bdata = &bootmem_node_data[early_pfn_to_nid(pfn)];
643 return alloc_bootmem_core(bdata, size, SMP_CACHE_BYTES, goal, limit);
647 void * __init __alloc_bootmem_node_nopanic(pg_data_t *pgdat, unsigned long size,
648 unsigned long align, unsigned long goal)
652 ptr = alloc_bootmem_core(pgdat->bdata, size, align, goal, 0);
656 return __alloc_bootmem_nopanic(size, align, goal);
659 #ifndef ARCH_LOW_ADDRESS_LIMIT
660 #define ARCH_LOW_ADDRESS_LIMIT 0xffffffffUL
664 * __alloc_bootmem_low - allocate low boot memory
665 * @size: size of the request in bytes
666 * @align: alignment of the region
667 * @goal: preferred starting address of the region
669 * The goal is dropped if it can not be satisfied and the allocation will
670 * fall back to memory below @goal.
672 * Allocation may happen on any node in the system.
674 * The function panics if the request can not be satisfied.
676 void * __init __alloc_bootmem_low(unsigned long size, unsigned long align,
679 return ___alloc_bootmem(size, align, goal, ARCH_LOW_ADDRESS_LIMIT);
683 * __alloc_bootmem_low_node - allocate low boot memory from a specific node
684 * @pgdat: node to allocate from
685 * @size: size of the request in bytes
686 * @align: alignment of the region
687 * @goal: preferred starting address of the region
689 * The goal is dropped if it can not be satisfied and the allocation will
690 * fall back to memory below @goal.
692 * Allocation may fall back to any node in the system if the specified node
693 * can not hold the requested memory.
695 * The function panics if the request can not be satisfied.
697 void * __init __alloc_bootmem_low_node(pg_data_t *pgdat, unsigned long size,
698 unsigned long align, unsigned long goal)
700 return ___alloc_bootmem_node(pgdat->bdata, size, align,
701 goal, ARCH_LOW_ADDRESS_LIMIT);