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(" rmo_size = 0x%llx\n", (unsigned long long)memblock.rmo_size);
53 pr_info(" memory.size = 0x%llx\n", (unsigned long long)memblock.memory.size);
55 memblock_dump(&memblock.memory, "memory");
56 memblock_dump(&memblock.reserved, "reserved");
59 static unsigned long memblock_addrs_overlap(u64 base1, u64 size1, u64 base2,
62 return ((base1 < (base2 + size2)) && (base2 < (base1 + size1)));
65 static long memblock_addrs_adjacent(u64 base1, u64 size1, u64 base2, u64 size2)
67 if (base2 == base1 + size1)
69 else if (base1 == base2 + size2)
75 static long memblock_regions_adjacent(struct memblock_type *type,
76 unsigned long r1, unsigned long r2)
78 u64 base1 = type->regions[r1].base;
79 u64 size1 = type->regions[r1].size;
80 u64 base2 = type->regions[r2].base;
81 u64 size2 = type->regions[r2].size;
83 return memblock_addrs_adjacent(base1, size1, base2, size2);
86 static void memblock_remove_region(struct memblock_type *type, unsigned long r)
90 for (i = r; i < type->cnt - 1; i++) {
91 type->regions[i].base = type->regions[i + 1].base;
92 type->regions[i].size = type->regions[i + 1].size;
97 /* Assumption: base addr of region 1 < base addr of region 2 */
98 static void memblock_coalesce_regions(struct memblock_type *type,
99 unsigned long r1, unsigned long r2)
101 type->regions[r1].size += type->regions[r2].size;
102 memblock_remove_region(type, r2);
105 void __init memblock_init(void)
107 /* Create a dummy zero size MEMBLOCK which will get coalesced away later.
108 * This simplifies the memblock_add() code below...
110 memblock.memory.regions[0].base = 0;
111 memblock.memory.regions[0].size = 0;
112 memblock.memory.cnt = 1;
115 memblock.reserved.regions[0].base = 0;
116 memblock.reserved.regions[0].size = 0;
117 memblock.reserved.cnt = 1;
119 memblock.current_limit = MEMBLOCK_ALLOC_ANYWHERE;
122 void __init memblock_analyze(void)
126 memblock.memory.size = 0;
128 for (i = 0; i < memblock.memory.cnt; i++)
129 memblock.memory.size += memblock.memory.regions[i].size;
132 static long memblock_add_region(struct memblock_type *type, u64 base, u64 size)
134 unsigned long coalesced = 0;
137 if ((type->cnt == 1) && (type->regions[0].size == 0)) {
138 type->regions[0].base = base;
139 type->regions[0].size = size;
143 /* First try and coalesce this MEMBLOCK with another. */
144 for (i = 0; i < type->cnt; i++) {
145 u64 rgnbase = type->regions[i].base;
146 u64 rgnsize = type->regions[i].size;
148 if ((rgnbase == base) && (rgnsize == size))
149 /* Already have this region, so we're done */
152 adjacent = memblock_addrs_adjacent(base, size, rgnbase, rgnsize);
154 type->regions[i].base -= size;
155 type->regions[i].size += size;
158 } else if (adjacent < 0) {
159 type->regions[i].size += size;
165 if ((i < type->cnt - 1) && memblock_regions_adjacent(type, i, i+1)) {
166 memblock_coalesce_regions(type, i, i+1);
172 if (type->cnt >= MAX_MEMBLOCK_REGIONS)
175 /* Couldn't coalesce the MEMBLOCK, so add it to the sorted table. */
176 for (i = type->cnt - 1; i >= 0; i--) {
177 if (base < type->regions[i].base) {
178 type->regions[i+1].base = type->regions[i].base;
179 type->regions[i+1].size = type->regions[i].size;
181 type->regions[i+1].base = base;
182 type->regions[i+1].size = size;
187 if (base < type->regions[0].base) {
188 type->regions[0].base = base;
189 type->regions[0].size = size;
196 long memblock_add(u64 base, u64 size)
198 /* On pSeries LPAR systems, the first MEMBLOCK is our RMO region. */
200 memblock.rmo_size = size;
202 return memblock_add_region(&memblock.memory, base, size);
206 static long __memblock_remove(struct memblock_type *type, u64 base, u64 size)
208 u64 rgnbegin, rgnend;
209 u64 end = base + size;
212 rgnbegin = rgnend = 0; /* supress gcc warnings */
214 /* Find the region where (base, size) belongs to */
215 for (i=0; i < type->cnt; i++) {
216 rgnbegin = type->regions[i].base;
217 rgnend = rgnbegin + type->regions[i].size;
219 if ((rgnbegin <= base) && (end <= rgnend))
223 /* Didn't find the region */
227 /* Check to see if we are removing entire region */
228 if ((rgnbegin == base) && (rgnend == end)) {
229 memblock_remove_region(type, i);
233 /* Check to see if region is matching at the front */
234 if (rgnbegin == base) {
235 type->regions[i].base = end;
236 type->regions[i].size -= size;
240 /* Check to see if the region is matching at the end */
242 type->regions[i].size -= size;
247 * We need to split the entry - adjust the current one to the
248 * beginging of the hole and add the region after hole.
250 type->regions[i].size = base - type->regions[i].base;
251 return memblock_add_region(type, end, rgnend - end);
254 long memblock_remove(u64 base, u64 size)
256 return __memblock_remove(&memblock.memory, base, size);
259 long __init memblock_free(u64 base, u64 size)
261 return __memblock_remove(&memblock.reserved, base, size);
264 long __init memblock_reserve(u64 base, u64 size)
266 struct memblock_type *_rgn = &memblock.reserved;
270 return memblock_add_region(_rgn, base, size);
273 long memblock_overlaps_region(struct memblock_type *type, u64 base, u64 size)
277 for (i = 0; i < type->cnt; i++) {
278 u64 rgnbase = type->regions[i].base;
279 u64 rgnsize = type->regions[i].size;
280 if (memblock_addrs_overlap(base, size, rgnbase, rgnsize))
284 return (i < type->cnt) ? i : -1;
287 static u64 memblock_align_down(u64 addr, u64 size)
289 return addr & ~(size - 1);
292 static u64 memblock_align_up(u64 addr, u64 size)
294 return (addr + (size - 1)) & ~(size - 1);
297 static u64 __init memblock_alloc_region(u64 start, u64 end,
303 base = memblock_align_down((end - size), align);
304 while (start <= base) {
305 j = memblock_overlaps_region(&memblock.reserved, base, size);
307 /* this area isn't reserved, take it */
308 if (memblock_add_region(&memblock.reserved, base, size) < 0)
312 res_base = memblock.reserved.regions[j].base;
315 base = memblock_align_down(res_base - size, align);
321 u64 __weak __init memblock_nid_range(u64 start, u64 end, int *nid)
328 static u64 __init memblock_alloc_nid_region(struct memblock_region *mp,
329 u64 size, u64 align, int nid)
334 end = start + mp->size;
336 start = memblock_align_up(start, align);
337 while (start < end) {
341 this_end = memblock_nid_range(start, end, &this_nid);
342 if (this_nid == nid) {
343 u64 ret = memblock_alloc_region(start, this_end, size, align);
353 u64 __init memblock_alloc_nid(u64 size, u64 align, int nid)
355 struct memblock_type *mem = &memblock.memory;
360 /* We do a bottom-up search for a region with the right
361 * nid since that's easier considering how memblock_nid_range()
364 size = memblock_align_up(size, align);
366 for (i = 0; i < mem->cnt; i++) {
367 u64 ret = memblock_alloc_nid_region(&mem->regions[i],
373 return memblock_alloc(size, align);
376 u64 __init memblock_alloc(u64 size, u64 align)
378 return memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ACCESSIBLE);
381 u64 __init memblock_alloc_base(u64 size, u64 align, u64 max_addr)
385 alloc = __memblock_alloc_base(size, align, max_addr);
388 panic("ERROR: Failed to allocate 0x%llx bytes below 0x%llx.\n",
389 (unsigned long long) size, (unsigned long long) max_addr);
394 u64 __init __memblock_alloc_base(u64 size, u64 align, u64 max_addr)
402 size = memblock_align_up(size, align);
404 /* Pump up max_addr */
405 if (max_addr == MEMBLOCK_ALLOC_ACCESSIBLE)
406 max_addr = memblock.current_limit;
408 /* We do a top-down search, this tends to limit memory
409 * fragmentation by keeping early boot allocs near the
412 for (i = memblock.memory.cnt - 1; i >= 0; i--) {
413 u64 memblockbase = memblock.memory.regions[i].base;
414 u64 memblocksize = memblock.memory.regions[i].size;
416 if (memblocksize < size)
418 base = min(memblockbase + memblocksize, max_addr);
419 res_base = memblock_alloc_region(memblockbase, base, size, align);
420 if (res_base != ~(u64)0)
426 /* You must call memblock_analyze() before this. */
427 u64 __init memblock_phys_mem_size(void)
429 return memblock.memory.size;
432 u64 memblock_end_of_DRAM(void)
434 int idx = memblock.memory.cnt - 1;
436 return (memblock.memory.regions[idx].base + memblock.memory.regions[idx].size);
439 /* You must call memblock_analyze() after this. */
440 void __init memblock_enforce_memory_limit(u64 memory_limit)
444 struct memblock_region *p;
449 /* Truncate the memblock regions to satisfy the memory limit. */
450 limit = memory_limit;
451 for (i = 0; i < memblock.memory.cnt; i++) {
452 if (limit > memblock.memory.regions[i].size) {
453 limit -= memblock.memory.regions[i].size;
457 memblock.memory.regions[i].size = limit;
458 memblock.memory.cnt = i + 1;
462 if (memblock.memory.regions[0].size < memblock.rmo_size)
463 memblock.rmo_size = memblock.memory.regions[0].size;
465 memory_limit = memblock_end_of_DRAM();
467 /* And truncate any reserves above the limit also. */
468 for (i = 0; i < memblock.reserved.cnt; i++) {
469 p = &memblock.reserved.regions[i];
471 if (p->base > memory_limit)
473 else if ((p->base + p->size) > memory_limit)
474 p->size = memory_limit - p->base;
477 memblock_remove_region(&memblock.reserved, i);
483 static int memblock_search(struct memblock_type *type, u64 addr)
485 unsigned int left = 0, right = type->cnt;
488 unsigned int mid = (right + left) / 2;
490 if (addr < type->regions[mid].base)
492 else if (addr >= (type->regions[mid].base +
493 type->regions[mid].size))
497 } while (left < right);
501 int __init memblock_is_reserved(u64 addr)
503 return memblock_search(&memblock.reserved, addr) != -1;
506 int memblock_is_memory(u64 addr)
508 return memblock_search(&memblock.memory, addr) != -1;
511 int memblock_is_region_memory(u64 base, u64 size)
513 int idx = memblock_search(&memblock.reserved, base);
517 return memblock.reserved.regions[idx].base <= base &&
518 (memblock.reserved.regions[idx].base +
519 memblock.reserved.regions[idx].size) >= (base + size);
522 int memblock_is_region_reserved(u64 base, u64 size)
524 return memblock_overlaps_region(&memblock.reserved, base, size) >= 0;
528 void __init memblock_set_current_limit(u64 limit)
530 memblock.current_limit = limit;