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(pg_data_t *pgdat,
91 unsigned long mapstart, unsigned long start, unsigned long end)
93 bootmem_data_t *bdata = pgdat->bdata;
94 unsigned long mapsize;
96 mminit_validate_memmodel_limits(&start, &end);
97 bdata->node_bootmem_map = phys_to_virt(PFN_PHYS(mapstart));
98 bdata->node_boot_start = PFN_PHYS(start);
99 bdata->node_low_pfn = end;
103 * Initially all pages are reserved - setup_arch() has to
104 * register free RAM areas explicitly.
106 mapsize = get_mapsize(bdata);
107 memset(bdata->node_bootmem_map, 0xff, mapsize);
113 * Marks a particular physical memory range as unallocatable. Usable RAM
114 * might be used for boot-time allocations - or it might get added
115 * to the free page pool later on.
117 static int __init can_reserve_bootmem_core(bootmem_data_t *bdata,
118 unsigned long addr, unsigned long size, int flags)
120 unsigned long sidx, eidx;
125 /* out of range, don't hold other */
126 if (addr + size < bdata->node_boot_start ||
127 PFN_DOWN(addr) > bdata->node_low_pfn)
131 * Round up to index to the range.
133 if (addr > bdata->node_boot_start)
134 sidx= PFN_DOWN(addr - bdata->node_boot_start);
138 eidx = PFN_UP(addr + size - bdata->node_boot_start);
139 if (eidx > bdata->node_low_pfn - PFN_DOWN(bdata->node_boot_start))
140 eidx = bdata->node_low_pfn - PFN_DOWN(bdata->node_boot_start);
142 for (i = sidx; i < eidx; i++) {
143 if (test_bit(i, bdata->node_bootmem_map)) {
144 if (flags & BOOTMEM_EXCLUSIVE)
153 static void __init reserve_bootmem_core(bootmem_data_t *bdata,
154 unsigned long addr, unsigned long size, int flags)
156 unsigned long sidx, eidx;
162 if (addr + size < bdata->node_boot_start ||
163 PFN_DOWN(addr) > bdata->node_low_pfn)
167 * Round up to index to the range.
169 if (addr > bdata->node_boot_start)
170 sidx= PFN_DOWN(addr - bdata->node_boot_start);
174 eidx = PFN_UP(addr + size - bdata->node_boot_start);
175 if (eidx > bdata->node_low_pfn - PFN_DOWN(bdata->node_boot_start))
176 eidx = bdata->node_low_pfn - PFN_DOWN(bdata->node_boot_start);
178 for (i = sidx; i < eidx; i++) {
179 if (test_and_set_bit(i, bdata->node_bootmem_map)) {
180 #ifdef CONFIG_DEBUG_BOOTMEM
181 printk("hm, page %08lx reserved twice.\n", i*PAGE_SIZE);
187 static void __init free_bootmem_core(bootmem_data_t *bdata, unsigned long addr,
190 unsigned long sidx, eidx;
196 if (addr + size < bdata->node_boot_start ||
197 PFN_DOWN(addr) > bdata->node_low_pfn)
200 * round down end of usable mem, partially free pages are
201 * considered reserved.
204 if (addr >= bdata->node_boot_start && addr < bdata->last_success)
205 bdata->last_success = addr;
208 * Round up to index to the range.
210 if (PFN_UP(addr) > PFN_DOWN(bdata->node_boot_start))
211 sidx = PFN_UP(addr) - PFN_DOWN(bdata->node_boot_start);
215 eidx = PFN_DOWN(addr + size - bdata->node_boot_start);
216 if (eidx > bdata->node_low_pfn - PFN_DOWN(bdata->node_boot_start))
217 eidx = bdata->node_low_pfn - PFN_DOWN(bdata->node_boot_start);
219 for (i = sidx; i < eidx; i++) {
220 if (unlikely(!test_and_clear_bit(i, bdata->node_bootmem_map)))
226 * We 'merge' subsequent allocations to save space. We might 'lose'
227 * some fraction of a page if allocations cannot be satisfied due to
228 * size constraints on boxes where there is physical RAM space
229 * fragmentation - in these cases (mostly large memory boxes) this
232 * On low memory boxes we get it right in 100% of the cases.
234 * alignment has to be a power of 2 value.
236 * NOTE: This function is _not_ reentrant.
239 __alloc_bootmem_core(struct bootmem_data *bdata, unsigned long size,
240 unsigned long align, unsigned long goal, unsigned long limit)
242 unsigned long areasize, preferred;
243 unsigned long i, start = 0, incr, eidx, end_pfn;
245 unsigned long node_boot_start;
246 void *node_bootmem_map;
249 printk("__alloc_bootmem_core(): zero-sized request\n");
252 BUG_ON(align & (align-1));
254 /* on nodes without memory - bootmem_map is NULL */
255 if (!bdata->node_bootmem_map)
258 /* bdata->node_boot_start is supposed to be (12+6)bits alignment on x86_64 ? */
259 node_boot_start = bdata->node_boot_start;
260 node_bootmem_map = bdata->node_bootmem_map;
262 node_boot_start = ALIGN(bdata->node_boot_start, align);
263 if (node_boot_start > bdata->node_boot_start)
264 node_bootmem_map = (unsigned long *)bdata->node_bootmem_map +
265 PFN_DOWN(node_boot_start - bdata->node_boot_start)/BITS_PER_LONG;
268 if (limit && node_boot_start >= limit)
271 end_pfn = bdata->node_low_pfn;
272 limit = PFN_DOWN(limit);
273 if (limit && end_pfn > limit)
276 eidx = end_pfn - PFN_DOWN(node_boot_start);
279 * We try to allocate bootmem pages above 'goal'
280 * first, then we try to allocate lower pages.
283 if (goal && PFN_DOWN(goal) < end_pfn) {
284 if (goal > node_boot_start)
285 preferred = goal - node_boot_start;
287 if (bdata->last_success > node_boot_start &&
288 bdata->last_success - node_boot_start >= preferred)
289 if (!limit || (limit && limit > bdata->last_success))
290 preferred = bdata->last_success - node_boot_start;
293 preferred = PFN_DOWN(ALIGN(preferred, align));
294 areasize = (size + PAGE_SIZE-1) / PAGE_SIZE;
295 incr = align >> PAGE_SHIFT ? : 1;
298 for (i = preferred; i < eidx;) {
301 i = find_next_zero_bit(node_bootmem_map, eidx, i);
305 if (test_bit(i, node_bootmem_map)) {
309 for (j = i + 1; j < i + areasize; ++j) {
312 if (test_bit(j, node_bootmem_map))
330 bdata->last_success = PFN_PHYS(start) + node_boot_start;
331 BUG_ON(start >= eidx);
334 * Is the next page of the previous allocation-end the start
335 * of this allocation's buffer? If yes then we can 'merge'
336 * the previous partial page with this allocation.
338 if (align < PAGE_SIZE &&
339 bdata->last_offset && bdata->last_pos+1 == start) {
340 unsigned long offset, remaining_size;
341 offset = ALIGN(bdata->last_offset, align);
342 BUG_ON(offset > PAGE_SIZE);
343 remaining_size = PAGE_SIZE - offset;
344 if (size < remaining_size) {
346 /* last_pos unchanged */
347 bdata->last_offset = offset + size;
348 ret = phys_to_virt(bdata->last_pos * PAGE_SIZE +
349 offset + node_boot_start);
351 remaining_size = size - remaining_size;
352 areasize = (remaining_size + PAGE_SIZE-1) / PAGE_SIZE;
353 ret = phys_to_virt(bdata->last_pos * PAGE_SIZE +
354 offset + node_boot_start);
355 bdata->last_pos = start + areasize - 1;
356 bdata->last_offset = remaining_size;
358 bdata->last_offset &= ~PAGE_MASK;
360 bdata->last_pos = start + areasize - 1;
361 bdata->last_offset = size & ~PAGE_MASK;
362 ret = phys_to_virt(start * PAGE_SIZE + node_boot_start);
366 * Reserve the area now:
368 for (i = start; i < start + areasize; i++)
369 if (unlikely(test_and_set_bit(i, node_bootmem_map)))
371 memset(ret, 0, size);
375 static unsigned long __init free_all_bootmem_core(pg_data_t *pgdat)
379 bootmem_data_t *bdata = pgdat->bdata;
380 unsigned long i, count, total = 0;
385 BUG_ON(!bdata->node_bootmem_map);
388 /* first extant page of the node */
389 pfn = PFN_DOWN(bdata->node_boot_start);
390 idx = bdata->node_low_pfn - pfn;
391 map = bdata->node_bootmem_map;
392 /* Check physaddr is O(LOG2(BITS_PER_LONG)) page aligned */
393 if (bdata->node_boot_start == 0 ||
394 ffs(bdata->node_boot_start) - PAGE_SHIFT > ffs(BITS_PER_LONG))
396 for (i = 0; i < idx; ) {
397 unsigned long v = ~map[i / BITS_PER_LONG];
399 if (gofast && v == ~0UL) {
402 page = pfn_to_page(pfn);
403 count += BITS_PER_LONG;
404 order = ffs(BITS_PER_LONG) - 1;
405 __free_pages_bootmem(page, order);
407 page += BITS_PER_LONG;
411 page = pfn_to_page(pfn);
412 for (m = 1; m && i < idx; m<<=1, page++, i++) {
415 __free_pages_bootmem(page, 0);
421 pfn += BITS_PER_LONG;
426 * Now free the allocator bitmap itself, it's not
429 page = virt_to_page(bdata->node_bootmem_map);
431 idx = (get_mapsize(bdata) + PAGE_SIZE-1) >> PAGE_SHIFT;
432 for (i = 0; i < idx; i++, page++) {
433 __free_pages_bootmem(page, 0);
437 bdata->node_bootmem_map = NULL;
442 unsigned long __init init_bootmem_node(pg_data_t *pgdat, unsigned long freepfn,
443 unsigned long startpfn, unsigned long endpfn)
445 return init_bootmem_core(pgdat, freepfn, startpfn, endpfn);
448 int __init reserve_bootmem_node(pg_data_t *pgdat, unsigned long physaddr,
449 unsigned long size, int flags)
453 ret = can_reserve_bootmem_core(pgdat->bdata, physaddr, size, flags);
456 reserve_bootmem_core(pgdat->bdata, physaddr, size, flags);
461 void __init free_bootmem_node(pg_data_t *pgdat, unsigned long physaddr,
464 free_bootmem_core(pgdat->bdata, physaddr, size);
467 unsigned long __init free_all_bootmem_node(pg_data_t *pgdat)
469 register_page_bootmem_info_node(pgdat);
470 return free_all_bootmem_core(pgdat);
473 unsigned long __init init_bootmem(unsigned long start, unsigned long pages)
477 return init_bootmem_core(NODE_DATA(0), start, 0, pages);
480 #ifndef CONFIG_HAVE_ARCH_BOOTMEM_NODE
481 int __init reserve_bootmem(unsigned long addr, unsigned long size,
484 bootmem_data_t *bdata;
487 list_for_each_entry(bdata, &bdata_list, list) {
488 ret = can_reserve_bootmem_core(bdata, addr, size, flags);
492 list_for_each_entry(bdata, &bdata_list, list)
493 reserve_bootmem_core(bdata, addr, size, flags);
497 #endif /* !CONFIG_HAVE_ARCH_BOOTMEM_NODE */
499 void __init free_bootmem(unsigned long addr, unsigned long size)
501 bootmem_data_t *bdata;
502 list_for_each_entry(bdata, &bdata_list, list)
503 free_bootmem_core(bdata, addr, size);
506 unsigned long __init free_all_bootmem(void)
508 return free_all_bootmem_core(NODE_DATA(0));
511 void * __init __alloc_bootmem_nopanic(unsigned long size, unsigned long align,
514 bootmem_data_t *bdata;
517 list_for_each_entry(bdata, &bdata_list, list) {
518 ptr = __alloc_bootmem_core(bdata, size, align, goal, 0);
525 void * __init __alloc_bootmem(unsigned long size, unsigned long align,
528 void *mem = __alloc_bootmem_nopanic(size,align,goal);
533 * Whoops, we cannot satisfy the allocation request.
535 printk(KERN_ALERT "bootmem alloc of %lu bytes failed!\n", size);
536 panic("Out of memory");
541 void * __init __alloc_bootmem_node(pg_data_t *pgdat, unsigned long size,
542 unsigned long align, unsigned long goal)
546 ptr = __alloc_bootmem_core(pgdat->bdata, size, align, goal, 0);
550 return __alloc_bootmem(size, align, goal);
553 #ifdef CONFIG_SPARSEMEM
554 void * __init alloc_bootmem_section(unsigned long size,
555 unsigned long section_nr)
558 unsigned long limit, goal, start_nr, end_nr, pfn;
559 struct pglist_data *pgdat;
561 pfn = section_nr_to_pfn(section_nr);
562 goal = PFN_PHYS(pfn);
563 limit = PFN_PHYS(section_nr_to_pfn(section_nr + 1)) - 1;
564 pgdat = NODE_DATA(early_pfn_to_nid(pfn));
565 ptr = __alloc_bootmem_core(pgdat->bdata, size, SMP_CACHE_BYTES, goal,
571 start_nr = pfn_to_section_nr(PFN_DOWN(__pa(ptr)));
572 end_nr = pfn_to_section_nr(PFN_DOWN(__pa(ptr) + size));
573 if (start_nr != section_nr || end_nr != section_nr) {
574 printk(KERN_WARNING "alloc_bootmem failed on section %ld.\n",
576 free_bootmem_core(pgdat->bdata, __pa(ptr), size);
584 #ifndef ARCH_LOW_ADDRESS_LIMIT
585 #define ARCH_LOW_ADDRESS_LIMIT 0xffffffffUL
588 void * __init __alloc_bootmem_low(unsigned long size, unsigned long align,
591 bootmem_data_t *bdata;
594 list_for_each_entry(bdata, &bdata_list, list) {
595 ptr = __alloc_bootmem_core(bdata, size, align, goal,
596 ARCH_LOW_ADDRESS_LIMIT);
602 * Whoops, we cannot satisfy the allocation request.
604 printk(KERN_ALERT "low bootmem alloc of %lu bytes failed!\n", size);
605 panic("Out of low memory");
609 void * __init __alloc_bootmem_low_node(pg_data_t *pgdat, unsigned long size,
610 unsigned long align, unsigned long goal)
612 return __alloc_bootmem_core(pgdat->bdata, size, align, goal,
613 ARCH_LOW_ADDRESS_LIMIT);