4 * Copyright (C) 1999 Ingo Molnar
5 * Discontiguous memory support, Kanoj Sarcar, SGI, Nov 1999
7 * simple boot-time physical memory area allocator and
8 * free memory collector. It's used to deal with reserved
9 * system memory and memory holes as well.
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>
23 * Access to this subsystem has to be serialized externally. (this is
24 * true for the boot process anyway)
26 unsigned long max_low_pfn;
27 unsigned long min_low_pfn;
28 unsigned long max_pfn;
30 static LIST_HEAD(bdata_list);
31 #ifdef CONFIG_CRASH_DUMP
33 * If we have booted due to a crash, max_pfn will be a very low value. We need
34 * to know the amount of memory that the previous kernel used.
36 unsigned long saved_max_pfn;
39 bootmem_data_t bootmem_node_data[MAX_NUMNODES] __initdata;
41 /* return the number of _pages_ that will be allocated for the boot bitmap */
42 unsigned long __init bootmem_bootmap_pages(unsigned long pages)
44 unsigned long mapsize;
46 mapsize = (pages+7)/8;
47 mapsize = (mapsize + ~PAGE_MASK) & PAGE_MASK;
48 mapsize >>= PAGE_SHIFT;
56 static void __init link_bootmem(bootmem_data_t *bdata)
60 if (list_empty(&bdata_list)) {
61 list_add(&bdata->list, &bdata_list);
65 list_for_each_entry(ent, &bdata_list, list) {
66 if (bdata->node_boot_start < ent->node_boot_start) {
67 list_add_tail(&bdata->list, &ent->list);
71 list_add_tail(&bdata->list, &bdata_list);
75 * Given an initialised bdata, it returns the size of the boot bitmap
77 static unsigned long __init get_mapsize(bootmem_data_t *bdata)
79 unsigned long mapsize;
80 unsigned long start = PFN_DOWN(bdata->node_boot_start);
81 unsigned long end = bdata->node_low_pfn;
83 mapsize = ((end - start) + 7) / 8;
84 return ALIGN(mapsize, sizeof(long));
88 * Called once to set up the allocator itself.
90 static unsigned long __init init_bootmem_core(bootmem_data_t *bdata,
91 unsigned long mapstart, unsigned long start, unsigned long end)
93 unsigned long mapsize;
95 mminit_validate_memmodel_limits(&start, &end);
96 bdata->node_bootmem_map = phys_to_virt(PFN_PHYS(mapstart));
97 bdata->node_boot_start = PFN_PHYS(start);
98 bdata->node_low_pfn = end;
102 * Initially all pages are reserved - setup_arch() has to
103 * register free RAM areas explicitly.
105 mapsize = get_mapsize(bdata);
106 memset(bdata->node_bootmem_map, 0xff, mapsize);
112 * Marks a particular physical memory range as unallocatable. Usable RAM
113 * might be used for boot-time allocations - or it might get added
114 * to the free page pool later on.
116 static int __init can_reserve_bootmem_core(bootmem_data_t *bdata,
117 unsigned long addr, unsigned long size, int flags)
119 unsigned long sidx, eidx;
124 /* out of range, don't hold other */
125 if (addr + size < bdata->node_boot_start ||
126 PFN_DOWN(addr) > bdata->node_low_pfn)
130 * Round up to index to the range.
132 if (addr > bdata->node_boot_start)
133 sidx= PFN_DOWN(addr - bdata->node_boot_start);
137 eidx = PFN_UP(addr + size - bdata->node_boot_start);
138 if (eidx > bdata->node_low_pfn - PFN_DOWN(bdata->node_boot_start))
139 eidx = bdata->node_low_pfn - PFN_DOWN(bdata->node_boot_start);
141 for (i = sidx; i < eidx; i++) {
142 if (test_bit(i, bdata->node_bootmem_map)) {
143 if (flags & BOOTMEM_EXCLUSIVE)
152 static void __init reserve_bootmem_core(bootmem_data_t *bdata,
153 unsigned long addr, unsigned long size, int flags)
155 unsigned long sidx, eidx;
161 if (addr + size < bdata->node_boot_start ||
162 PFN_DOWN(addr) > bdata->node_low_pfn)
166 * Round up to index to the range.
168 if (addr > bdata->node_boot_start)
169 sidx= PFN_DOWN(addr - bdata->node_boot_start);
173 eidx = PFN_UP(addr + size - bdata->node_boot_start);
174 if (eidx > bdata->node_low_pfn - PFN_DOWN(bdata->node_boot_start))
175 eidx = bdata->node_low_pfn - PFN_DOWN(bdata->node_boot_start);
177 for (i = sidx; i < eidx; i++) {
178 if (test_and_set_bit(i, bdata->node_bootmem_map)) {
179 #ifdef CONFIG_DEBUG_BOOTMEM
180 printk("hm, page %08lx reserved twice.\n", i*PAGE_SIZE);
186 static void __init free_bootmem_core(bootmem_data_t *bdata, unsigned long addr,
189 unsigned long sidx, eidx;
195 if (addr + size < bdata->node_boot_start ||
196 PFN_DOWN(addr) > bdata->node_low_pfn)
199 * round down end of usable mem, partially free pages are
200 * considered reserved.
203 if (addr >= bdata->node_boot_start && addr < bdata->last_success)
204 bdata->last_success = addr;
207 * Round up to index to the range.
209 if (PFN_UP(addr) > PFN_DOWN(bdata->node_boot_start))
210 sidx = PFN_UP(addr) - PFN_DOWN(bdata->node_boot_start);
214 eidx = PFN_DOWN(addr + size - bdata->node_boot_start);
215 if (eidx > bdata->node_low_pfn - PFN_DOWN(bdata->node_boot_start))
216 eidx = bdata->node_low_pfn - PFN_DOWN(bdata->node_boot_start);
218 for (i = sidx; i < eidx; i++) {
219 if (unlikely(!test_and_clear_bit(i, bdata->node_bootmem_map)))
225 * We 'merge' subsequent allocations to save space. We might 'lose'
226 * some fraction of a page if allocations cannot be satisfied due to
227 * size constraints on boxes where there is physical RAM space
228 * fragmentation - in these cases (mostly large memory boxes) this
231 * On low memory boxes we get it right in 100% of the cases.
233 * alignment has to be a power of 2 value.
235 * NOTE: This function is _not_ reentrant.
238 alloc_bootmem_core(struct bootmem_data *bdata, unsigned long size,
239 unsigned long align, unsigned long goal, unsigned long limit)
241 unsigned long areasize, preferred;
242 unsigned long i, start = 0, incr, eidx, end_pfn;
244 unsigned long node_boot_start;
245 void *node_bootmem_map;
248 printk("alloc_bootmem_core(): zero-sized request\n");
251 BUG_ON(align & (align-1));
253 /* on nodes without memory - bootmem_map is NULL */
254 if (!bdata->node_bootmem_map)
257 /* bdata->node_boot_start is supposed to be (12+6)bits alignment on x86_64 ? */
258 node_boot_start = bdata->node_boot_start;
259 node_bootmem_map = bdata->node_bootmem_map;
261 node_boot_start = ALIGN(bdata->node_boot_start, align);
262 if (node_boot_start > bdata->node_boot_start)
263 node_bootmem_map = (unsigned long *)bdata->node_bootmem_map +
264 PFN_DOWN(node_boot_start - bdata->node_boot_start)/BITS_PER_LONG;
267 if (limit && node_boot_start >= limit)
270 end_pfn = bdata->node_low_pfn;
271 limit = PFN_DOWN(limit);
272 if (limit && end_pfn > limit)
275 eidx = end_pfn - PFN_DOWN(node_boot_start);
278 * We try to allocate bootmem pages above 'goal'
279 * first, then we try to allocate lower pages.
282 if (goal && PFN_DOWN(goal) < end_pfn) {
283 if (goal > node_boot_start)
284 preferred = goal - node_boot_start;
286 if (bdata->last_success > node_boot_start &&
287 bdata->last_success - node_boot_start >= preferred)
288 if (!limit || (limit && limit > bdata->last_success))
289 preferred = bdata->last_success - node_boot_start;
292 preferred = PFN_DOWN(ALIGN(preferred, align));
293 areasize = (size + PAGE_SIZE-1) / PAGE_SIZE;
294 incr = align >> PAGE_SHIFT ? : 1;
297 for (i = preferred; i < eidx;) {
300 i = find_next_zero_bit(node_bootmem_map, eidx, i);
304 if (test_bit(i, node_bootmem_map)) {
308 for (j = i + 1; j < i + areasize; ++j) {
311 if (test_bit(j, node_bootmem_map))
329 bdata->last_success = PFN_PHYS(start) + node_boot_start;
330 BUG_ON(start >= eidx);
333 * Is the next page of the previous allocation-end the start
334 * of this allocation's buffer? If yes then we can 'merge'
335 * the previous partial page with this allocation.
337 if (align < PAGE_SIZE &&
338 bdata->last_offset && bdata->last_pos+1 == start) {
339 unsigned long offset, remaining_size;
340 offset = ALIGN(bdata->last_offset, align);
341 BUG_ON(offset > PAGE_SIZE);
342 remaining_size = PAGE_SIZE - offset;
343 if (size < remaining_size) {
345 /* last_pos unchanged */
346 bdata->last_offset = offset + size;
347 ret = phys_to_virt(bdata->last_pos * PAGE_SIZE +
348 offset + node_boot_start);
350 remaining_size = size - remaining_size;
351 areasize = (remaining_size + PAGE_SIZE-1) / PAGE_SIZE;
352 ret = phys_to_virt(bdata->last_pos * PAGE_SIZE +
353 offset + node_boot_start);
354 bdata->last_pos = start + areasize - 1;
355 bdata->last_offset = remaining_size;
357 bdata->last_offset &= ~PAGE_MASK;
359 bdata->last_pos = start + areasize - 1;
360 bdata->last_offset = size & ~PAGE_MASK;
361 ret = phys_to_virt(start * PAGE_SIZE + node_boot_start);
365 * Reserve the area now:
367 for (i = start; i < start + areasize; i++)
368 if (unlikely(test_and_set_bit(i, node_bootmem_map)))
370 memset(ret, 0, size);
374 static unsigned long __init free_all_bootmem_core(bootmem_data_t *bdata)
378 unsigned long i, count;
383 BUG_ON(!bdata->node_bootmem_map);
386 /* first extant page of the node */
387 pfn = PFN_DOWN(bdata->node_boot_start);
388 idx = bdata->node_low_pfn - pfn;
389 map = bdata->node_bootmem_map;
391 * Check if we are aligned to BITS_PER_LONG pages. If so, we might
392 * be able to free page orders of that size at once.
394 if (!(pfn & (BITS_PER_LONG-1)))
397 for (i = 0; i < idx; ) {
398 unsigned long v = ~map[i / BITS_PER_LONG];
400 if (gofast && v == ~0UL) {
403 page = pfn_to_page(pfn);
404 count += BITS_PER_LONG;
405 order = ffs(BITS_PER_LONG) - 1;
406 __free_pages_bootmem(page, order);
408 page += BITS_PER_LONG;
412 page = pfn_to_page(pfn);
413 for (m = 1; m && i < idx; m<<=1, page++, i++) {
416 __free_pages_bootmem(page, 0);
422 pfn += BITS_PER_LONG;
426 * Now free the allocator bitmap itself, it's not
429 page = virt_to_page(bdata->node_bootmem_map);
430 idx = (get_mapsize(bdata) + PAGE_SIZE-1) >> PAGE_SHIFT;
431 for (i = 0; i < idx; i++, page++)
432 __free_pages_bootmem(page, 0);
434 bdata->node_bootmem_map = NULL;
439 unsigned long __init init_bootmem_node(pg_data_t *pgdat, unsigned long freepfn,
440 unsigned long startpfn, unsigned long endpfn)
442 return init_bootmem_core(pgdat->bdata, freepfn, startpfn, endpfn);
445 int __init reserve_bootmem_node(pg_data_t *pgdat, unsigned long physaddr,
446 unsigned long size, int flags)
450 ret = can_reserve_bootmem_core(pgdat->bdata, physaddr, size, flags);
453 reserve_bootmem_core(pgdat->bdata, physaddr, size, flags);
458 void __init free_bootmem_node(pg_data_t *pgdat, unsigned long physaddr,
461 free_bootmem_core(pgdat->bdata, physaddr, size);
464 unsigned long __init free_all_bootmem_node(pg_data_t *pgdat)
466 register_page_bootmem_info_node(pgdat);
467 return free_all_bootmem_core(pgdat->bdata);
470 unsigned long __init init_bootmem(unsigned long start, unsigned long pages)
474 return init_bootmem_core(NODE_DATA(0)->bdata, start, 0, pages);
477 #ifndef CONFIG_HAVE_ARCH_BOOTMEM_NODE
478 int __init reserve_bootmem(unsigned long addr, unsigned long size,
481 bootmem_data_t *bdata;
484 list_for_each_entry(bdata, &bdata_list, list) {
485 ret = can_reserve_bootmem_core(bdata, addr, size, flags);
489 list_for_each_entry(bdata, &bdata_list, list)
490 reserve_bootmem_core(bdata, addr, size, flags);
494 #endif /* !CONFIG_HAVE_ARCH_BOOTMEM_NODE */
496 void __init free_bootmem(unsigned long addr, unsigned long size)
498 bootmem_data_t *bdata;
499 list_for_each_entry(bdata, &bdata_list, list)
500 free_bootmem_core(bdata, addr, size);
503 unsigned long __init free_all_bootmem(void)
505 return free_all_bootmem_core(NODE_DATA(0)->bdata);
508 void * __init __alloc_bootmem_nopanic(unsigned long size, unsigned long align,
511 bootmem_data_t *bdata;
514 list_for_each_entry(bdata, &bdata_list, list) {
515 ptr = alloc_bootmem_core(bdata, size, align, goal, 0);
522 void * __init __alloc_bootmem(unsigned long size, unsigned long align,
525 void *mem = __alloc_bootmem_nopanic(size,align,goal);
530 * Whoops, we cannot satisfy the allocation request.
532 printk(KERN_ALERT "bootmem alloc of %lu bytes failed!\n", size);
533 panic("Out of memory");
538 void * __init __alloc_bootmem_node(pg_data_t *pgdat, unsigned long size,
539 unsigned long align, unsigned long goal)
543 ptr = alloc_bootmem_core(pgdat->bdata, size, align, goal, 0);
547 return __alloc_bootmem(size, align, goal);
550 #ifdef CONFIG_SPARSEMEM
551 void * __init alloc_bootmem_section(unsigned long size,
552 unsigned long section_nr)
555 unsigned long limit, goal, start_nr, end_nr, pfn;
556 struct pglist_data *pgdat;
558 pfn = section_nr_to_pfn(section_nr);
559 goal = PFN_PHYS(pfn);
560 limit = PFN_PHYS(section_nr_to_pfn(section_nr + 1)) - 1;
561 pgdat = NODE_DATA(early_pfn_to_nid(pfn));
562 ptr = alloc_bootmem_core(pgdat->bdata, size, SMP_CACHE_BYTES, goal,
568 start_nr = pfn_to_section_nr(PFN_DOWN(__pa(ptr)));
569 end_nr = pfn_to_section_nr(PFN_DOWN(__pa(ptr) + size));
570 if (start_nr != section_nr || end_nr != section_nr) {
571 printk(KERN_WARNING "alloc_bootmem failed on section %ld.\n",
573 free_bootmem_core(pgdat->bdata, __pa(ptr), size);
581 #ifndef ARCH_LOW_ADDRESS_LIMIT
582 #define ARCH_LOW_ADDRESS_LIMIT 0xffffffffUL
585 void * __init __alloc_bootmem_low(unsigned long size, unsigned long align,
588 bootmem_data_t *bdata;
591 list_for_each_entry(bdata, &bdata_list, list) {
592 ptr = alloc_bootmem_core(bdata, size, align, goal,
593 ARCH_LOW_ADDRESS_LIMIT);
599 * Whoops, we cannot satisfy the allocation request.
601 printk(KERN_ALERT "low bootmem alloc of %lu bytes failed!\n", size);
602 panic("Out of low memory");
606 void * __init __alloc_bootmem_low_node(pg_data_t *pgdat, unsigned long size,
607 unsigned long align, unsigned long goal)
609 return alloc_bootmem_core(pgdat->bdata, size, align, goal,
610 ARCH_LOW_ADDRESS_LIMIT);