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 struct memblock memblock;
20 static int memblock_debug;
22 static int __init early_memblock(char *p)
24 if (p && strstr(p, "debug"))
28 early_param("memblock", early_memblock);
30 static void memblock_dump(struct memblock_type *region, char *name)
32 unsigned long long base, size;
35 pr_info(" %s.cnt = 0x%lx\n", name, region->cnt);
37 for (i = 0; i < region->cnt; i++) {
38 base = region->regions[i].base;
39 size = region->regions[i].size;
41 pr_info(" %s[0x%x]\t0x%016llx - 0x%016llx, 0x%llx bytes\n",
42 name, i, base, base + size - 1, size);
46 void memblock_dump_all(void)
51 pr_info("MEMBLOCK configuration:\n");
52 pr_info(" memory.size = 0x%llx\n", (unsigned long long)memblock.memory.size);
54 memblock_dump(&memblock.memory, "memory");
55 memblock_dump(&memblock.reserved, "reserved");
58 static unsigned long memblock_addrs_overlap(u64 base1, u64 size1, u64 base2,
61 return ((base1 < (base2 + size2)) && (base2 < (base1 + size1)));
64 static long memblock_addrs_adjacent(u64 base1, u64 size1, u64 base2, u64 size2)
66 if (base2 == base1 + size1)
68 else if (base1 == base2 + size2)
74 static long memblock_regions_adjacent(struct memblock_type *type,
75 unsigned long r1, unsigned long r2)
77 u64 base1 = type->regions[r1].base;
78 u64 size1 = type->regions[r1].size;
79 u64 base2 = type->regions[r2].base;
80 u64 size2 = type->regions[r2].size;
82 return memblock_addrs_adjacent(base1, size1, base2, size2);
85 static void memblock_remove_region(struct memblock_type *type, unsigned long r)
89 for (i = r; i < type->cnt - 1; i++) {
90 type->regions[i].base = type->regions[i + 1].base;
91 type->regions[i].size = type->regions[i + 1].size;
96 /* Assumption: base addr of region 1 < base addr of region 2 */
97 static void memblock_coalesce_regions(struct memblock_type *type,
98 unsigned long r1, unsigned long r2)
100 type->regions[r1].size += type->regions[r2].size;
101 memblock_remove_region(type, r2);
104 void __init memblock_init(void)
106 /* Create a dummy zero size MEMBLOCK which will get coalesced away later.
107 * This simplifies the memblock_add() code below...
109 memblock.memory.regions[0].base = 0;
110 memblock.memory.regions[0].size = 0;
111 memblock.memory.cnt = 1;
114 memblock.reserved.regions[0].base = 0;
115 memblock.reserved.regions[0].size = 0;
116 memblock.reserved.cnt = 1;
118 memblock.current_limit = MEMBLOCK_ALLOC_ANYWHERE;
121 void __init memblock_analyze(void)
125 memblock.memory.size = 0;
127 for (i = 0; i < memblock.memory.cnt; i++)
128 memblock.memory.size += memblock.memory.regions[i].size;
131 static long memblock_add_region(struct memblock_type *type, u64 base, u64 size)
133 unsigned long coalesced = 0;
136 if ((type->cnt == 1) && (type->regions[0].size == 0)) {
137 type->regions[0].base = base;
138 type->regions[0].size = size;
142 /* First try and coalesce this MEMBLOCK with another. */
143 for (i = 0; i < type->cnt; i++) {
144 u64 rgnbase = type->regions[i].base;
145 u64 rgnsize = type->regions[i].size;
147 if ((rgnbase == base) && (rgnsize == size))
148 /* Already have this region, so we're done */
151 adjacent = memblock_addrs_adjacent(base, size, rgnbase, rgnsize);
153 type->regions[i].base -= size;
154 type->regions[i].size += size;
157 } else if (adjacent < 0) {
158 type->regions[i].size += size;
164 if ((i < type->cnt - 1) && memblock_regions_adjacent(type, i, i+1)) {
165 memblock_coalesce_regions(type, i, i+1);
171 if (type->cnt >= MAX_MEMBLOCK_REGIONS)
174 /* Couldn't coalesce the MEMBLOCK, so add it to the sorted table. */
175 for (i = type->cnt - 1; i >= 0; i--) {
176 if (base < type->regions[i].base) {
177 type->regions[i+1].base = type->regions[i].base;
178 type->regions[i+1].size = type->regions[i].size;
180 type->regions[i+1].base = base;
181 type->regions[i+1].size = size;
186 if (base < type->regions[0].base) {
187 type->regions[0].base = base;
188 type->regions[0].size = size;
195 long memblock_add(u64 base, u64 size)
197 return memblock_add_region(&memblock.memory, base, size);
201 static long __memblock_remove(struct memblock_type *type, u64 base, u64 size)
203 u64 rgnbegin, rgnend;
204 u64 end = base + size;
207 rgnbegin = rgnend = 0; /* supress gcc warnings */
209 /* Find the region where (base, size) belongs to */
210 for (i=0; i < type->cnt; i++) {
211 rgnbegin = type->regions[i].base;
212 rgnend = rgnbegin + type->regions[i].size;
214 if ((rgnbegin <= base) && (end <= rgnend))
218 /* Didn't find the region */
222 /* Check to see if we are removing entire region */
223 if ((rgnbegin == base) && (rgnend == end)) {
224 memblock_remove_region(type, i);
228 /* Check to see if region is matching at the front */
229 if (rgnbegin == base) {
230 type->regions[i].base = end;
231 type->regions[i].size -= size;
235 /* Check to see if the region is matching at the end */
237 type->regions[i].size -= size;
242 * We need to split the entry - adjust the current one to the
243 * beginging of the hole and add the region after hole.
245 type->regions[i].size = base - type->regions[i].base;
246 return memblock_add_region(type, end, rgnend - end);
249 long memblock_remove(u64 base, u64 size)
251 return __memblock_remove(&memblock.memory, base, size);
254 long __init memblock_free(u64 base, u64 size)
256 return __memblock_remove(&memblock.reserved, base, size);
259 long __init memblock_reserve(u64 base, u64 size)
261 struct memblock_type *_rgn = &memblock.reserved;
265 return memblock_add_region(_rgn, base, size);
268 long memblock_overlaps_region(struct memblock_type *type, u64 base, u64 size)
272 for (i = 0; i < type->cnt; i++) {
273 u64 rgnbase = type->regions[i].base;
274 u64 rgnsize = type->regions[i].size;
275 if (memblock_addrs_overlap(base, size, rgnbase, rgnsize))
279 return (i < type->cnt) ? i : -1;
282 static u64 memblock_align_down(u64 addr, u64 size)
284 return addr & ~(size - 1);
287 static u64 memblock_align_up(u64 addr, u64 size)
289 return (addr + (size - 1)) & ~(size - 1);
292 static u64 __init memblock_alloc_region(u64 start, u64 end,
298 base = memblock_align_down((end - size), align);
299 while (start <= base) {
300 j = memblock_overlaps_region(&memblock.reserved, base, size);
302 /* this area isn't reserved, take it */
303 if (memblock_add_region(&memblock.reserved, base, size) < 0)
307 res_base = memblock.reserved.regions[j].base;
310 base = memblock_align_down(res_base - size, align);
316 u64 __weak __init memblock_nid_range(u64 start, u64 end, int *nid)
323 static u64 __init memblock_alloc_nid_region(struct memblock_region *mp,
324 u64 size, u64 align, int nid)
329 end = start + mp->size;
331 start = memblock_align_up(start, align);
332 while (start < end) {
336 this_end = memblock_nid_range(start, end, &this_nid);
337 if (this_nid == nid) {
338 u64 ret = memblock_alloc_region(start, this_end, size, align);
348 u64 __init memblock_alloc_nid(u64 size, u64 align, int nid)
350 struct memblock_type *mem = &memblock.memory;
355 /* We do a bottom-up search for a region with the right
356 * nid since that's easier considering how memblock_nid_range()
359 size = memblock_align_up(size, align);
361 for (i = 0; i < mem->cnt; i++) {
362 u64 ret = memblock_alloc_nid_region(&mem->regions[i],
368 return memblock_alloc(size, align);
371 u64 __init memblock_alloc(u64 size, u64 align)
373 return memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ACCESSIBLE);
376 u64 __init memblock_alloc_base(u64 size, u64 align, u64 max_addr)
380 alloc = __memblock_alloc_base(size, align, max_addr);
383 panic("ERROR: Failed to allocate 0x%llx bytes below 0x%llx.\n",
384 (unsigned long long) size, (unsigned long long) max_addr);
389 u64 __init __memblock_alloc_base(u64 size, u64 align, u64 max_addr)
397 size = memblock_align_up(size, align);
399 /* Pump up max_addr */
400 if (max_addr == MEMBLOCK_ALLOC_ACCESSIBLE)
401 max_addr = memblock.current_limit;
403 /* We do a top-down search, this tends to limit memory
404 * fragmentation by keeping early boot allocs near the
407 for (i = memblock.memory.cnt - 1; i >= 0; i--) {
408 u64 memblockbase = memblock.memory.regions[i].base;
409 u64 memblocksize = memblock.memory.regions[i].size;
411 if (memblocksize < size)
413 base = min(memblockbase + memblocksize, max_addr);
414 res_base = memblock_alloc_region(memblockbase, base, size, align);
415 if (res_base != ~(u64)0)
421 /* You must call memblock_analyze() before this. */
422 u64 __init memblock_phys_mem_size(void)
424 return memblock.memory.size;
427 u64 memblock_end_of_DRAM(void)
429 int idx = memblock.memory.cnt - 1;
431 return (memblock.memory.regions[idx].base + memblock.memory.regions[idx].size);
434 /* You must call memblock_analyze() after this. */
435 void __init memblock_enforce_memory_limit(u64 memory_limit)
439 struct memblock_region *p;
444 /* Truncate the memblock regions to satisfy the memory limit. */
445 limit = memory_limit;
446 for (i = 0; i < memblock.memory.cnt; i++) {
447 if (limit > memblock.memory.regions[i].size) {
448 limit -= memblock.memory.regions[i].size;
452 memblock.memory.regions[i].size = limit;
453 memblock.memory.cnt = i + 1;
457 memory_limit = memblock_end_of_DRAM();
459 /* And truncate any reserves above the limit also. */
460 for (i = 0; i < memblock.reserved.cnt; i++) {
461 p = &memblock.reserved.regions[i];
463 if (p->base > memory_limit)
465 else if ((p->base + p->size) > memory_limit)
466 p->size = memory_limit - p->base;
469 memblock_remove_region(&memblock.reserved, i);
475 static int memblock_search(struct memblock_type *type, u64 addr)
477 unsigned int left = 0, right = type->cnt;
480 unsigned int mid = (right + left) / 2;
482 if (addr < type->regions[mid].base)
484 else if (addr >= (type->regions[mid].base +
485 type->regions[mid].size))
489 } while (left < right);
493 int __init memblock_is_reserved(u64 addr)
495 return memblock_search(&memblock.reserved, addr) != -1;
498 int memblock_is_memory(u64 addr)
500 return memblock_search(&memblock.memory, addr) != -1;
503 int memblock_is_region_memory(u64 base, u64 size)
505 int idx = memblock_search(&memblock.reserved, base);
509 return memblock.reserved.regions[idx].base <= base &&
510 (memblock.reserved.regions[idx].base +
511 memblock.reserved.regions[idx].size) >= (base + size);
514 int memblock_is_region_reserved(u64 base, u64 size)
516 return memblock_overlaps_region(&memblock.reserved, base, size) >= 0;
520 void __init memblock_set_current_limit(u64 limit)
522 memblock.current_limit = limit;