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CommitLineData
1da177e4
LT
1/*
2 * linux/mm/bootmem.c
3 *
4 * Copyright (C) 1999 Ingo Molnar
5 * Discontiguous memory support, Kanoj Sarcar, SGI, Nov 1999
6 *
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.
10 */
1da177e4 11#include <linux/init.h>
bbc7b92e 12#include <linux/pfn.h>
1da177e4 13#include <linux/bootmem.h>
1da177e4 14#include <linux/module.h>
e786e86a
FBH
15
16#include <asm/bug.h>
1da177e4 17#include <asm/io.h>
dfd54cbc 18#include <asm/processor.h>
e786e86a 19
1da177e4
LT
20#include "internal.h"
21
22/*
23 * Access to this subsystem has to be serialized externally. (this is
24 * true for the boot process anyway)
25 */
26unsigned long max_low_pfn;
27unsigned long min_low_pfn;
28unsigned long max_pfn;
29
679bc9fb 30static LIST_HEAD(bdata_list);
92aa63a5
VG
31#ifdef CONFIG_CRASH_DUMP
32/*
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.
35 */
36unsigned long saved_max_pfn;
37#endif
38
1da177e4 39/* return the number of _pages_ that will be allocated for the boot bitmap */
f71bf0ca 40unsigned long __init bootmem_bootmap_pages(unsigned long pages)
1da177e4
LT
41{
42 unsigned long mapsize;
43
44 mapsize = (pages+7)/8;
45 mapsize = (mapsize + ~PAGE_MASK) & PAGE_MASK;
46 mapsize >>= PAGE_SHIFT;
47
48 return mapsize;
49}
f71bf0ca 50
679bc9fb
KH
51/*
52 * link bdata in order
53 */
69d49e68 54static void __init link_bootmem(bootmem_data_t *bdata)
679bc9fb
KH
55{
56 bootmem_data_t *ent;
f71bf0ca 57
679bc9fb
KH
58 if (list_empty(&bdata_list)) {
59 list_add(&bdata->list, &bdata_list);
60 return;
61 }
62 /* insert in order */
63 list_for_each_entry(ent, &bdata_list, list) {
64 if (bdata->node_boot_start < ent->node_boot_start) {
65 list_add_tail(&bdata->list, &ent->list);
66 return;
67 }
68 }
69 list_add_tail(&bdata->list, &bdata_list);
679bc9fb
KH
70}
71
bbc7b92e
FBH
72/*
73 * Given an initialised bdata, it returns the size of the boot bitmap
74 */
75static unsigned long __init get_mapsize(bootmem_data_t *bdata)
76{
77 unsigned long mapsize;
78 unsigned long start = PFN_DOWN(bdata->node_boot_start);
79 unsigned long end = bdata->node_low_pfn;
80
81 mapsize = ((end - start) + 7) / 8;
82 return ALIGN(mapsize, sizeof(long));
83}
1da177e4
LT
84
85/*
86 * Called once to set up the allocator itself.
87 */
f71bf0ca 88static unsigned long __init init_bootmem_core(pg_data_t *pgdat,
1da177e4
LT
89 unsigned long mapstart, unsigned long start, unsigned long end)
90{
91 bootmem_data_t *bdata = pgdat->bdata;
bbc7b92e 92 unsigned long mapsize;
1da177e4 93
bbc7b92e
FBH
94 bdata->node_bootmem_map = phys_to_virt(PFN_PHYS(mapstart));
95 bdata->node_boot_start = PFN_PHYS(start);
1da177e4 96 bdata->node_low_pfn = end;
679bc9fb 97 link_bootmem(bdata);
1da177e4
LT
98
99 /*
100 * Initially all pages are reserved - setup_arch() has to
101 * register free RAM areas explicitly.
102 */
bbc7b92e 103 mapsize = get_mapsize(bdata);
1da177e4
LT
104 memset(bdata->node_bootmem_map, 0xff, mapsize);
105
106 return mapsize;
107}
108
109/*
110 * Marks a particular physical memory range as unallocatable. Usable RAM
111 * might be used for boot-time allocations - or it might get added
112 * to the free page pool later on.
113 */
bb0923a6
FBH
114static void __init reserve_bootmem_core(bootmem_data_t *bdata, unsigned long addr,
115 unsigned long size)
1da177e4 116{
bbc7b92e 117 unsigned long sidx, eidx;
1da177e4 118 unsigned long i;
bbc7b92e 119
1da177e4
LT
120 /*
121 * round up, partially reserved pages are considered
122 * fully reserved.
123 */
1da177e4 124 BUG_ON(!size);
bbc7b92e
FBH
125 BUG_ON(PFN_DOWN(addr) >= bdata->node_low_pfn);
126 BUG_ON(PFN_UP(addr + size) > bdata->node_low_pfn);
127
128 sidx = PFN_DOWN(addr - bdata->node_boot_start);
129 eidx = PFN_UP(addr + size - bdata->node_boot_start);
1da177e4
LT
130
131 for (i = sidx; i < eidx; i++)
132 if (test_and_set_bit(i, bdata->node_bootmem_map)) {
133#ifdef CONFIG_DEBUG_BOOTMEM
134 printk("hm, page %08lx reserved twice.\n", i*PAGE_SIZE);
135#endif
136 }
137}
138
bb0923a6
FBH
139static void __init free_bootmem_core(bootmem_data_t *bdata, unsigned long addr,
140 unsigned long size)
1da177e4 141{
bbc7b92e 142 unsigned long sidx, eidx;
1da177e4 143 unsigned long i;
bbc7b92e 144
1da177e4
LT
145 /*
146 * round down end of usable mem, partially free pages are
147 * considered reserved.
148 */
1da177e4 149 BUG_ON(!size);
bbc7b92e 150 BUG_ON(PFN_DOWN(addr + size) > bdata->node_low_pfn);
1da177e4
LT
151
152 if (addr < bdata->last_success)
153 bdata->last_success = addr;
154
155 /*
156 * Round up the beginning of the address.
157 */
bbc7b92e
FBH
158 sidx = PFN_UP(addr) - PFN_DOWN(bdata->node_boot_start);
159 eidx = PFN_DOWN(addr + size - bdata->node_boot_start);
1da177e4
LT
160
161 for (i = sidx; i < eidx; i++) {
162 if (unlikely(!test_and_clear_bit(i, bdata->node_bootmem_map)))
163 BUG();
164 }
165}
166
167/*
168 * We 'merge' subsequent allocations to save space. We might 'lose'
169 * some fraction of a page if allocations cannot be satisfied due to
170 * size constraints on boxes where there is physical RAM space
171 * fragmentation - in these cases (mostly large memory boxes) this
172 * is not a problem.
173 *
174 * On low memory boxes we get it right in 100% of the cases.
175 *
176 * alignment has to be a power of 2 value.
177 *
178 * NOTE: This function is _not_ reentrant.
179 */
267b4801 180void * __init
1da177e4 181__alloc_bootmem_core(struct bootmem_data *bdata, unsigned long size,
281dd25c 182 unsigned long align, unsigned long goal, unsigned long limit)
1da177e4
LT
183{
184 unsigned long offset, remaining_size, areasize, preferred;
bbc7b92e 185 unsigned long i, start = 0, incr, eidx, end_pfn;
1da177e4
LT
186 void *ret;
187
f71bf0ca 188 if (!size) {
1da177e4
LT
189 printk("__alloc_bootmem_core(): zero-sized request\n");
190 BUG();
191 }
192 BUG_ON(align & (align-1));
193
281dd25c
YG
194 if (limit && bdata->node_boot_start >= limit)
195 return NULL;
196
7c309a64
CK
197 /* on nodes without memory - bootmem_map is NULL */
198 if (!bdata->node_bootmem_map)
199 return NULL;
200
bbc7b92e
FBH
201 end_pfn = bdata->node_low_pfn;
202 limit = PFN_DOWN(limit);
281dd25c
YG
203 if (limit && end_pfn > limit)
204 end_pfn = limit;
205
bbc7b92e 206 eidx = end_pfn - PFN_DOWN(bdata->node_boot_start);
1da177e4 207 offset = 0;
bbc7b92e
FBH
208 if (align && (bdata->node_boot_start & (align - 1UL)) != 0)
209 offset = align - (bdata->node_boot_start & (align - 1UL));
210 offset = PFN_DOWN(offset);
1da177e4
LT
211
212 /*
213 * We try to allocate bootmem pages above 'goal'
214 * first, then we try to allocate lower pages.
215 */
bbc7b92e 216 if (goal && goal >= bdata->node_boot_start && PFN_DOWN(goal) < end_pfn) {
1da177e4
LT
217 preferred = goal - bdata->node_boot_start;
218
219 if (bdata->last_success >= preferred)
281dd25c
YG
220 if (!limit || (limit && limit > bdata->last_success))
221 preferred = bdata->last_success;
1da177e4
LT
222 } else
223 preferred = 0;
224
bbc7b92e
FBH
225 preferred = PFN_DOWN(ALIGN(preferred, align)) + offset;
226 areasize = (size + PAGE_SIZE-1) / PAGE_SIZE;
1da177e4
LT
227 incr = align >> PAGE_SHIFT ? : 1;
228
229restart_scan:
230 for (i = preferred; i < eidx; i += incr) {
231 unsigned long j;
232 i = find_next_zero_bit(bdata->node_bootmem_map, eidx, i);
233 i = ALIGN(i, incr);
66d43e98
HM
234 if (i >= eidx)
235 break;
1da177e4
LT
236 if (test_bit(i, bdata->node_bootmem_map))
237 continue;
238 for (j = i + 1; j < i + areasize; ++j) {
239 if (j >= eidx)
240 goto fail_block;
f71bf0ca 241 if (test_bit(j, bdata->node_bootmem_map))
1da177e4
LT
242 goto fail_block;
243 }
244 start = i;
245 goto found;
246 fail_block:
247 i = ALIGN(j, incr);
248 }
249
250 if (preferred > offset) {
251 preferred = offset;
252 goto restart_scan;
253 }
254 return NULL;
255
256found:
bbc7b92e 257 bdata->last_success = PFN_PHYS(start);
1da177e4
LT
258 BUG_ON(start >= eidx);
259
260 /*
261 * Is the next page of the previous allocation-end the start
262 * of this allocation's buffer? If yes then we can 'merge'
263 * the previous partial page with this allocation.
264 */
265 if (align < PAGE_SIZE &&
266 bdata->last_offset && bdata->last_pos+1 == start) {
8c0e33c1 267 offset = ALIGN(bdata->last_offset, align);
1da177e4 268 BUG_ON(offset > PAGE_SIZE);
f71bf0ca 269 remaining_size = PAGE_SIZE - offset;
1da177e4
LT
270 if (size < remaining_size) {
271 areasize = 0;
272 /* last_pos unchanged */
f71bf0ca
FBH
273 bdata->last_offset = offset + size;
274 ret = phys_to_virt(bdata->last_pos * PAGE_SIZE +
275 offset +
276 bdata->node_boot_start);
1da177e4
LT
277 } else {
278 remaining_size = size - remaining_size;
f71bf0ca
FBH
279 areasize = (remaining_size + PAGE_SIZE-1) / PAGE_SIZE;
280 ret = phys_to_virt(bdata->last_pos * PAGE_SIZE +
281 offset +
282 bdata->node_boot_start);
283 bdata->last_pos = start + areasize - 1;
1da177e4
LT
284 bdata->last_offset = remaining_size;
285 }
286 bdata->last_offset &= ~PAGE_MASK;
287 } else {
288 bdata->last_pos = start + areasize - 1;
289 bdata->last_offset = size & ~PAGE_MASK;
290 ret = phys_to_virt(start * PAGE_SIZE + bdata->node_boot_start);
291 }
292
293 /*
294 * Reserve the area now:
295 */
f71bf0ca 296 for (i = start; i < start + areasize; i++)
1da177e4
LT
297 if (unlikely(test_and_set_bit(i, bdata->node_bootmem_map)))
298 BUG();
299 memset(ret, 0, size);
300 return ret;
301}
302
303static unsigned long __init free_all_bootmem_core(pg_data_t *pgdat)
304{
305 struct page *page;
d41dee36 306 unsigned long pfn;
1da177e4
LT
307 bootmem_data_t *bdata = pgdat->bdata;
308 unsigned long i, count, total = 0;
309 unsigned long idx;
310 unsigned long *map;
311 int gofast = 0;
312
313 BUG_ON(!bdata->node_bootmem_map);
314
315 count = 0;
316 /* first extant page of the node */
bbc7b92e
FBH
317 pfn = PFN_DOWN(bdata->node_boot_start);
318 idx = bdata->node_low_pfn - pfn;
1da177e4
LT
319 map = bdata->node_bootmem_map;
320 /* Check physaddr is O(LOG2(BITS_PER_LONG)) page aligned */
321 if (bdata->node_boot_start == 0 ||
322 ffs(bdata->node_boot_start) - PAGE_SHIFT > ffs(BITS_PER_LONG))
323 gofast = 1;
324 for (i = 0; i < idx; ) {
325 unsigned long v = ~map[i / BITS_PER_LONG];
d41dee36 326
1da177e4 327 if (gofast && v == ~0UL) {
a226f6c8 328 int order;
1da177e4 329
d41dee36 330 page = pfn_to_page(pfn);
1da177e4 331 count += BITS_PER_LONG;
1da177e4 332 order = ffs(BITS_PER_LONG) - 1;
a226f6c8 333 __free_pages_bootmem(page, order);
1da177e4
LT
334 i += BITS_PER_LONG;
335 page += BITS_PER_LONG;
336 } else if (v) {
337 unsigned long m;
d41dee36
AW
338
339 page = pfn_to_page(pfn);
1da177e4
LT
340 for (m = 1; m && i < idx; m<<=1, page++, i++) {
341 if (v & m) {
342 count++;
a226f6c8 343 __free_pages_bootmem(page, 0);
1da177e4
LT
344 }
345 }
346 } else {
f71bf0ca 347 i += BITS_PER_LONG;
1da177e4 348 }
d41dee36 349 pfn += BITS_PER_LONG;
1da177e4
LT
350 }
351 total += count;
352
353 /*
354 * Now free the allocator bitmap itself, it's not
355 * needed anymore:
356 */
357 page = virt_to_page(bdata->node_bootmem_map);
358 count = 0;
bbc7b92e
FBH
359 idx = (get_mapsize(bdata) + PAGE_SIZE-1) >> PAGE_SHIFT;
360 for (i = 0; i < idx; i++, page++) {
a226f6c8 361 __free_pages_bootmem(page, 0);
bbc7b92e 362 count++;
1da177e4
LT
363 }
364 total += count;
365 bdata->node_bootmem_map = NULL;
366
367 return total;
368}
369
f71bf0ca 370unsigned long __init init_bootmem_node(pg_data_t *pgdat, unsigned long freepfn,
bb0923a6 371 unsigned long startpfn, unsigned long endpfn)
1da177e4 372{
f71bf0ca 373 return init_bootmem_core(pgdat, freepfn, startpfn, endpfn);
1da177e4
LT
374}
375
f71bf0ca
FBH
376void __init reserve_bootmem_node(pg_data_t *pgdat, unsigned long physaddr,
377 unsigned long size)
1da177e4
LT
378{
379 reserve_bootmem_core(pgdat->bdata, physaddr, size);
380}
381
f71bf0ca
FBH
382void __init free_bootmem_node(pg_data_t *pgdat, unsigned long physaddr,
383 unsigned long size)
1da177e4
LT
384{
385 free_bootmem_core(pgdat->bdata, physaddr, size);
386}
387
f71bf0ca 388unsigned long __init free_all_bootmem_node(pg_data_t *pgdat)
1da177e4 389{
f71bf0ca 390 return free_all_bootmem_core(pgdat);
1da177e4
LT
391}
392
f71bf0ca 393unsigned long __init init_bootmem(unsigned long start, unsigned long pages)
1da177e4
LT
394{
395 max_low_pfn = pages;
396 min_low_pfn = start;
f71bf0ca 397 return init_bootmem_core(NODE_DATA(0), start, 0, pages);
1da177e4
LT
398}
399
400#ifndef CONFIG_HAVE_ARCH_BOOTMEM_NODE
f71bf0ca 401void __init reserve_bootmem(unsigned long addr, unsigned long size)
1da177e4
LT
402{
403 reserve_bootmem_core(NODE_DATA(0)->bdata, addr, size);
404}
405#endif /* !CONFIG_HAVE_ARCH_BOOTMEM_NODE */
406
f71bf0ca 407void __init free_bootmem(unsigned long addr, unsigned long size)
1da177e4
LT
408{
409 free_bootmem_core(NODE_DATA(0)->bdata, addr, size);
410}
411
f71bf0ca 412unsigned long __init free_all_bootmem(void)
1da177e4 413{
f71bf0ca 414 return free_all_bootmem_core(NODE_DATA(0));
1da177e4
LT
415}
416
bb0923a6
FBH
417void * __init __alloc_bootmem_nopanic(unsigned long size, unsigned long align,
418 unsigned long goal)
1da177e4 419{
679bc9fb 420 bootmem_data_t *bdata;
1da177e4
LT
421 void *ptr;
422
f71bf0ca
FBH
423 list_for_each_entry(bdata, &bdata_list, list) {
424 ptr = __alloc_bootmem_core(bdata, size, align, goal, 0);
425 if (ptr)
426 return ptr;
427 }
a8062231
AK
428 return NULL;
429}
1da177e4 430
bb0923a6
FBH
431void * __init __alloc_bootmem(unsigned long size, unsigned long align,
432 unsigned long goal)
a8062231
AK
433{
434 void *mem = __alloc_bootmem_nopanic(size,align,goal);
f71bf0ca 435
a8062231
AK
436 if (mem)
437 return mem;
1da177e4
LT
438 /*
439 * Whoops, we cannot satisfy the allocation request.
440 */
441 printk(KERN_ALERT "bootmem alloc of %lu bytes failed!\n", size);
442 panic("Out of memory");
443 return NULL;
444}
445
281dd25c 446
bb0923a6
FBH
447void * __init __alloc_bootmem_node(pg_data_t *pgdat, unsigned long size,
448 unsigned long align, unsigned long goal)
1da177e4
LT
449{
450 void *ptr;
451
008857c1 452 ptr = __alloc_bootmem_core(pgdat->bdata, size, align, goal, 0);
1da177e4 453 if (ptr)
f71bf0ca 454 return ptr;
1da177e4 455
008857c1 456 return __alloc_bootmem(size, align, goal);
1da177e4
LT
457}
458
dfd54cbc
HC
459#ifndef ARCH_LOW_ADDRESS_LIMIT
460#define ARCH_LOW_ADDRESS_LIMIT 0xffffffffUL
461#endif
008857c1 462
bb0923a6
FBH
463void * __init __alloc_bootmem_low(unsigned long size, unsigned long align,
464 unsigned long goal)
008857c1 465{
679bc9fb 466 bootmem_data_t *bdata;
008857c1
RT
467 void *ptr;
468
f71bf0ca 469 list_for_each_entry(bdata, &bdata_list, list) {
dfd54cbc
HC
470 ptr = __alloc_bootmem_core(bdata, size, align, goal,
471 ARCH_LOW_ADDRESS_LIMIT);
f71bf0ca
FBH
472 if (ptr)
473 return ptr;
474 }
008857c1
RT
475
476 /*
477 * Whoops, we cannot satisfy the allocation request.
478 */
479 printk(KERN_ALERT "low bootmem alloc of %lu bytes failed!\n", size);
480 panic("Out of low memory");
481 return NULL;
482}
483
484void * __init __alloc_bootmem_low_node(pg_data_t *pgdat, unsigned long size,
485 unsigned long align, unsigned long goal)
486{
dfd54cbc
HC
487 return __alloc_bootmem_core(pgdat->bdata, size, align, goal,
488 ARCH_LOW_ADDRESS_LIMIT);
008857c1 489}