writeback: do not remove bdi from bdi_list
[linux/fpc-iii.git] / mm / memblock.c
blob3024eb30fc273ea11e076878047a07d798d6b936
1 /*
2 * Procedures for maintaining information about logical memory blocks.
4 * Peter Bergner, IBM Corp. June 2001.
5 * Copyright (C) 2001 Peter Bergner.
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
13 #include <linux/kernel.h>
14 #include <linux/init.h>
15 #include <linux/bitops.h>
16 #include <linux/memblock.h>
18 #define MEMBLOCK_ALLOC_ANYWHERE 0
20 struct memblock memblock;
22 static int memblock_debug;
24 static int __init early_memblock(char *p)
26 if (p && strstr(p, "debug"))
27 memblock_debug = 1;
28 return 0;
30 early_param("memblock", early_memblock);
32 static void memblock_dump(struct memblock_region *region, char *name)
34 unsigned long long base, size;
35 int i;
37 pr_info(" %s.cnt = 0x%lx\n", name, region->cnt);
39 for (i = 0; i < region->cnt; i++) {
40 base = region->region[i].base;
41 size = region->region[i].size;
43 pr_info(" %s[0x%x]\t0x%016llx - 0x%016llx, 0x%llx bytes\n",
44 name, i, base, base + size - 1, size);
48 void memblock_dump_all(void)
50 if (!memblock_debug)
51 return;
53 pr_info("MEMBLOCK configuration:\n");
54 pr_info(" rmo_size = 0x%llx\n", (unsigned long long)memblock.rmo_size);
55 pr_info(" memory.size = 0x%llx\n", (unsigned long long)memblock.memory.size);
57 memblock_dump(&memblock.memory, "memory");
58 memblock_dump(&memblock.reserved, "reserved");
61 static unsigned long memblock_addrs_overlap(u64 base1, u64 size1, u64 base2,
62 u64 size2)
64 return ((base1 < (base2 + size2)) && (base2 < (base1 + size1)));
67 static long memblock_addrs_adjacent(u64 base1, u64 size1, u64 base2, u64 size2)
69 if (base2 == base1 + size1)
70 return 1;
71 else if (base1 == base2 + size2)
72 return -1;
74 return 0;
77 static long memblock_regions_adjacent(struct memblock_region *rgn,
78 unsigned long r1, unsigned long r2)
80 u64 base1 = rgn->region[r1].base;
81 u64 size1 = rgn->region[r1].size;
82 u64 base2 = rgn->region[r2].base;
83 u64 size2 = rgn->region[r2].size;
85 return memblock_addrs_adjacent(base1, size1, base2, size2);
88 static void memblock_remove_region(struct memblock_region *rgn, unsigned long r)
90 unsigned long i;
92 for (i = r; i < rgn->cnt - 1; i++) {
93 rgn->region[i].base = rgn->region[i + 1].base;
94 rgn->region[i].size = rgn->region[i + 1].size;
96 rgn->cnt--;
99 /* Assumption: base addr of region 1 < base addr of region 2 */
100 static void memblock_coalesce_regions(struct memblock_region *rgn,
101 unsigned long r1, unsigned long r2)
103 rgn->region[r1].size += rgn->region[r2].size;
104 memblock_remove_region(rgn, r2);
107 void __init memblock_init(void)
109 /* Create a dummy zero size MEMBLOCK which will get coalesced away later.
110 * This simplifies the memblock_add() code below...
112 memblock.memory.region[0].base = 0;
113 memblock.memory.region[0].size = 0;
114 memblock.memory.cnt = 1;
116 /* Ditto. */
117 memblock.reserved.region[0].base = 0;
118 memblock.reserved.region[0].size = 0;
119 memblock.reserved.cnt = 1;
122 void __init memblock_analyze(void)
124 int i;
126 memblock.memory.size = 0;
128 for (i = 0; i < memblock.memory.cnt; i++)
129 memblock.memory.size += memblock.memory.region[i].size;
132 static long memblock_add_region(struct memblock_region *rgn, u64 base, u64 size)
134 unsigned long coalesced = 0;
135 long adjacent, i;
137 if ((rgn->cnt == 1) && (rgn->region[0].size == 0)) {
138 rgn->region[0].base = base;
139 rgn->region[0].size = size;
140 return 0;
143 /* First try and coalesce this MEMBLOCK with another. */
144 for (i = 0; i < rgn->cnt; i++) {
145 u64 rgnbase = rgn->region[i].base;
146 u64 rgnsize = rgn->region[i].size;
148 if ((rgnbase == base) && (rgnsize == size))
149 /* Already have this region, so we're done */
150 return 0;
152 adjacent = memblock_addrs_adjacent(base, size, rgnbase, rgnsize);
153 if (adjacent > 0) {
154 rgn->region[i].base -= size;
155 rgn->region[i].size += size;
156 coalesced++;
157 break;
158 } else if (adjacent < 0) {
159 rgn->region[i].size += size;
160 coalesced++;
161 break;
165 if ((i < rgn->cnt - 1) && memblock_regions_adjacent(rgn, i, i+1)) {
166 memblock_coalesce_regions(rgn, i, i+1);
167 coalesced++;
170 if (coalesced)
171 return coalesced;
172 if (rgn->cnt >= MAX_MEMBLOCK_REGIONS)
173 return -1;
175 /* Couldn't coalesce the MEMBLOCK, so add it to the sorted table. */
176 for (i = rgn->cnt - 1; i >= 0; i--) {
177 if (base < rgn->region[i].base) {
178 rgn->region[i+1].base = rgn->region[i].base;
179 rgn->region[i+1].size = rgn->region[i].size;
180 } else {
181 rgn->region[i+1].base = base;
182 rgn->region[i+1].size = size;
183 break;
187 if (base < rgn->region[0].base) {
188 rgn->region[0].base = base;
189 rgn->region[0].size = size;
191 rgn->cnt++;
193 return 0;
196 long memblock_add(u64 base, u64 size)
198 struct memblock_region *_rgn = &memblock.memory;
200 /* On pSeries LPAR systems, the first MEMBLOCK is our RMO region. */
201 if (base == 0)
202 memblock.rmo_size = size;
204 return memblock_add_region(_rgn, base, size);
208 static long __memblock_remove(struct memblock_region *rgn, u64 base, u64 size)
210 u64 rgnbegin, rgnend;
211 u64 end = base + size;
212 int i;
214 rgnbegin = rgnend = 0; /* supress gcc warnings */
216 /* Find the region where (base, size) belongs to */
217 for (i=0; i < rgn->cnt; i++) {
218 rgnbegin = rgn->region[i].base;
219 rgnend = rgnbegin + rgn->region[i].size;
221 if ((rgnbegin <= base) && (end <= rgnend))
222 break;
225 /* Didn't find the region */
226 if (i == rgn->cnt)
227 return -1;
229 /* Check to see if we are removing entire region */
230 if ((rgnbegin == base) && (rgnend == end)) {
231 memblock_remove_region(rgn, i);
232 return 0;
235 /* Check to see if region is matching at the front */
236 if (rgnbegin == base) {
237 rgn->region[i].base = end;
238 rgn->region[i].size -= size;
239 return 0;
242 /* Check to see if the region is matching at the end */
243 if (rgnend == end) {
244 rgn->region[i].size -= size;
245 return 0;
249 * We need to split the entry - adjust the current one to the
250 * beginging of the hole and add the region after hole.
252 rgn->region[i].size = base - rgn->region[i].base;
253 return memblock_add_region(rgn, end, rgnend - end);
256 long memblock_remove(u64 base, u64 size)
258 return __memblock_remove(&memblock.memory, base, size);
261 long __init memblock_free(u64 base, u64 size)
263 return __memblock_remove(&memblock.reserved, base, size);
266 long __init memblock_reserve(u64 base, u64 size)
268 struct memblock_region *_rgn = &memblock.reserved;
270 BUG_ON(0 == size);
272 return memblock_add_region(_rgn, base, size);
275 long memblock_overlaps_region(struct memblock_region *rgn, u64 base, u64 size)
277 unsigned long i;
279 for (i = 0; i < rgn->cnt; i++) {
280 u64 rgnbase = rgn->region[i].base;
281 u64 rgnsize = rgn->region[i].size;
282 if (memblock_addrs_overlap(base, size, rgnbase, rgnsize))
283 break;
286 return (i < rgn->cnt) ? i : -1;
289 static u64 memblock_align_down(u64 addr, u64 size)
291 return addr & ~(size - 1);
294 static u64 memblock_align_up(u64 addr, u64 size)
296 return (addr + (size - 1)) & ~(size - 1);
299 static u64 __init memblock_alloc_nid_unreserved(u64 start, u64 end,
300 u64 size, u64 align)
302 u64 base, res_base;
303 long j;
305 base = memblock_align_down((end - size), align);
306 while (start <= base) {
307 j = memblock_overlaps_region(&memblock.reserved, base, size);
308 if (j < 0) {
309 /* this area isn't reserved, take it */
310 if (memblock_add_region(&memblock.reserved, base, size) < 0)
311 base = ~(u64)0;
312 return base;
314 res_base = memblock.reserved.region[j].base;
315 if (res_base < size)
316 break;
317 base = memblock_align_down(res_base - size, align);
320 return ~(u64)0;
323 static u64 __init memblock_alloc_nid_region(struct memblock_property *mp,
324 u64 (*nid_range)(u64, u64, int *),
325 u64 size, u64 align, int nid)
327 u64 start, end;
329 start = mp->base;
330 end = start + mp->size;
332 start = memblock_align_up(start, align);
333 while (start < end) {
334 u64 this_end;
335 int this_nid;
337 this_end = nid_range(start, end, &this_nid);
338 if (this_nid == nid) {
339 u64 ret = memblock_alloc_nid_unreserved(start, this_end,
340 size, align);
341 if (ret != ~(u64)0)
342 return ret;
344 start = this_end;
347 return ~(u64)0;
350 u64 __init memblock_alloc_nid(u64 size, u64 align, int nid,
351 u64 (*nid_range)(u64 start, u64 end, int *nid))
353 struct memblock_region *mem = &memblock.memory;
354 int i;
356 BUG_ON(0 == size);
358 size = memblock_align_up(size, align);
360 for (i = 0; i < mem->cnt; i++) {
361 u64 ret = memblock_alloc_nid_region(&mem->region[i],
362 nid_range,
363 size, align, nid);
364 if (ret != ~(u64)0)
365 return ret;
368 return memblock_alloc(size, align);
371 u64 __init memblock_alloc(u64 size, u64 align)
373 return memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ANYWHERE);
376 u64 __init memblock_alloc_base(u64 size, u64 align, u64 max_addr)
378 u64 alloc;
380 alloc = __memblock_alloc_base(size, align, max_addr);
382 if (alloc == 0)
383 panic("ERROR: Failed to allocate 0x%llx bytes below 0x%llx.\n",
384 (unsigned long long) size, (unsigned long long) max_addr);
386 return alloc;
389 u64 __init __memblock_alloc_base(u64 size, u64 align, u64 max_addr)
391 long i, j;
392 u64 base = 0;
393 u64 res_base;
395 BUG_ON(0 == size);
397 size = memblock_align_up(size, align);
399 /* On some platforms, make sure we allocate lowmem */
400 /* Note that MEMBLOCK_REAL_LIMIT may be MEMBLOCK_ALLOC_ANYWHERE */
401 if (max_addr == MEMBLOCK_ALLOC_ANYWHERE)
402 max_addr = MEMBLOCK_REAL_LIMIT;
404 for (i = memblock.memory.cnt - 1; i >= 0; i--) {
405 u64 memblockbase = memblock.memory.region[i].base;
406 u64 memblocksize = memblock.memory.region[i].size;
408 if (memblocksize < size)
409 continue;
410 if (max_addr == MEMBLOCK_ALLOC_ANYWHERE)
411 base = memblock_align_down(memblockbase + memblocksize - size, align);
412 else if (memblockbase < max_addr) {
413 base = min(memblockbase + memblocksize, max_addr);
414 base = memblock_align_down(base - size, align);
415 } else
416 continue;
418 while (base && memblockbase <= base) {
419 j = memblock_overlaps_region(&memblock.reserved, base, size);
420 if (j < 0) {
421 /* this area isn't reserved, take it */
422 if (memblock_add_region(&memblock.reserved, base, size) < 0)
423 return 0;
424 return base;
426 res_base = memblock.reserved.region[j].base;
427 if (res_base < size)
428 break;
429 base = memblock_align_down(res_base - size, align);
432 return 0;
435 /* You must call memblock_analyze() before this. */
436 u64 __init memblock_phys_mem_size(void)
438 return memblock.memory.size;
441 u64 memblock_end_of_DRAM(void)
443 int idx = memblock.memory.cnt - 1;
445 return (memblock.memory.region[idx].base + memblock.memory.region[idx].size);
448 /* You must call memblock_analyze() after this. */
449 void __init memblock_enforce_memory_limit(u64 memory_limit)
451 unsigned long i;
452 u64 limit;
453 struct memblock_property *p;
455 if (!memory_limit)
456 return;
458 /* Truncate the memblock regions to satisfy the memory limit. */
459 limit = memory_limit;
460 for (i = 0; i < memblock.memory.cnt; i++) {
461 if (limit > memblock.memory.region[i].size) {
462 limit -= memblock.memory.region[i].size;
463 continue;
466 memblock.memory.region[i].size = limit;
467 memblock.memory.cnt = i + 1;
468 break;
471 if (memblock.memory.region[0].size < memblock.rmo_size)
472 memblock.rmo_size = memblock.memory.region[0].size;
474 memory_limit = memblock_end_of_DRAM();
476 /* And truncate any reserves above the limit also. */
477 for (i = 0; i < memblock.reserved.cnt; i++) {
478 p = &memblock.reserved.region[i];
480 if (p->base > memory_limit)
481 p->size = 0;
482 else if ((p->base + p->size) > memory_limit)
483 p->size = memory_limit - p->base;
485 if (p->size == 0) {
486 memblock_remove_region(&memblock.reserved, i);
487 i--;
492 int __init memblock_is_reserved(u64 addr)
494 int i;
496 for (i = 0; i < memblock.reserved.cnt; i++) {
497 u64 upper = memblock.reserved.region[i].base +
498 memblock.reserved.region[i].size - 1;
499 if ((addr >= memblock.reserved.region[i].base) && (addr <= upper))
500 return 1;
502 return 0;
505 int memblock_is_region_reserved(u64 base, u64 size)
507 return memblock_overlaps_region(&memblock.reserved, base, size);
511 * Given a <base, len>, find which memory regions belong to this range.
512 * Adjust the request and return a contiguous chunk.
514 int memblock_find(struct memblock_property *res)
516 int i;
517 u64 rstart, rend;
519 rstart = res->base;
520 rend = rstart + res->size - 1;
522 for (i = 0; i < memblock.memory.cnt; i++) {
523 u64 start = memblock.memory.region[i].base;
524 u64 end = start + memblock.memory.region[i].size - 1;
526 if (start > rend)
527 return -1;
529 if ((end >= rstart) && (start < rend)) {
530 /* adjust the request */
531 if (rstart < start)
532 rstart = start;
533 if (rend > end)
534 rend = end;
535 res->base = rstart;
536 res->size = rend - rstart + 1;
537 return 0;
540 return -1;