diff options
Diffstat (limited to 'mm/memblock.c')
-rw-r--r-- | mm/memblock.c | 241 |
1 files changed, 132 insertions, 109 deletions
diff --git a/mm/memblock.c b/mm/memblock.c index 4618fda..a0562d1 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -58,28 +58,6 @@ static unsigned long __init_memblock memblock_addrs_overlap(phys_addr_t base1, p return ((base1 < (base2 + size2)) && (base2 < (base1 + size1))); } -static long __init_memblock memblock_addrs_adjacent(phys_addr_t base1, phys_addr_t size1, - phys_addr_t base2, phys_addr_t size2) -{ - if (base2 == base1 + size1) - return 1; - else if (base1 == base2 + size2) - return -1; - - return 0; -} - -static long __init_memblock memblock_regions_adjacent(struct memblock_type *type, - unsigned long r1, unsigned long r2) -{ - phys_addr_t base1 = type->regions[r1].base; - phys_addr_t size1 = type->regions[r1].size; - phys_addr_t base2 = type->regions[r2].base; - phys_addr_t size2 = type->regions[r2].size; - - return memblock_addrs_adjacent(base1, size1, base2, size2); -} - long __init_memblock memblock_overlaps_region(struct memblock_type *type, phys_addr_t base, phys_addr_t size) { unsigned long i; @@ -206,14 +184,13 @@ static void __init_memblock memblock_remove_region(struct memblock_type *type, u type->regions[i].size = type->regions[i + 1].size; } type->cnt--; -} -/* Assumption: base addr of region 1 < base addr of region 2 */ -static void __init_memblock memblock_coalesce_regions(struct memblock_type *type, - unsigned long r1, unsigned long r2) -{ - type->regions[r1].size += type->regions[r2].size; - memblock_remove_region(type, r2); + /* Special case for empty arrays */ + if (type->cnt == 0) { + type->cnt = 1; + type->regions[0].base = 0; + type->regions[0].size = 0; + } } /* Defined below but needed now */ @@ -276,7 +253,7 @@ static int __init_memblock memblock_double_array(struct memblock_type *type) return 0; /* Add the new reserved region now. Should not fail ! */ - BUG_ON(memblock_add_region(&memblock.reserved, addr, new_size) < 0); + BUG_ON(memblock_add_region(&memblock.reserved, addr, new_size)); /* If the array wasn't our static init one, then free it. We only do * that before SLAB is available as later on, we don't know whether @@ -296,58 +273,99 @@ extern int __init_memblock __weak memblock_memory_can_coalesce(phys_addr_t addr1 return 1; } -static long __init_memblock memblock_add_region(struct memblock_type *type, phys_addr_t base, phys_addr_t size) +static long __init_memblock memblock_add_region(struct memblock_type *type, + phys_addr_t base, phys_addr_t size) { - unsigned long coalesced = 0; - long adjacent, i; - - if ((type->cnt == 1) && (type->regions[0].size == 0)) { - type->regions[0].base = base; - type->regions[0].size = size; - return 0; - } + phys_addr_t end = base + size; + int i, slot = -1; - /* First try and coalesce this MEMBLOCK with another. */ + /* First try and coalesce this MEMBLOCK with others */ for (i = 0; i < type->cnt; i++) { - phys_addr_t rgnbase = type->regions[i].base; - phys_addr_t rgnsize = type->regions[i].size; + struct memblock_region *rgn = &type->regions[i]; + phys_addr_t rend = rgn->base + rgn->size; + + /* Exit if there's no possible hits */ + if (rgn->base > end || rgn->size == 0) + break; - if ((rgnbase == base) && (rgnsize == size)) - /* Already have this region, so we're done */ + /* Check if we are fully enclosed within an existing + * block + */ + if (rgn->base <= base && rend >= end) return 0; - adjacent = memblock_addrs_adjacent(base, size, rgnbase, rgnsize); - /* Check if arch allows coalescing */ - if (adjacent != 0 && type == &memblock.memory && - !memblock_memory_can_coalesce(base, size, rgnbase, rgnsize)) - break; - if (adjacent > 0) { - type->regions[i].base -= size; - type->regions[i].size += size; - coalesced++; - break; - } else if (adjacent < 0) { - type->regions[i].size += size; - coalesced++; - break; + /* Check if we overlap or are adjacent with the bottom + * of a block. + */ + if (base < rgn->base && end >= rgn->base) { + /* If we can't coalesce, create a new block */ + if (!memblock_memory_can_coalesce(base, size, + rgn->base, + rgn->size)) { + /* Overlap & can't coalesce are mutually + * exclusive, if you do that, be prepared + * for trouble + */ + WARN_ON(end != rgn->base); + goto new_block; + } + /* We extend the bottom of the block down to our + * base + */ + rgn->base = base; + rgn->size = rend - base; + + /* Return if we have nothing else to allocate + * (fully coalesced) + */ + if (rend >= end) + return 0; + + /* We continue processing from the end of the + * coalesced block. + */ + base = rend; + size = end - base; + } + + /* Now check if we overlap or are adjacent with the + * top of a block + */ + if (base <= rend && end >= rend) { + /* If we can't coalesce, create a new block */ + if (!memblock_memory_can_coalesce(rgn->base, + rgn->size, + base, size)) { + /* Overlap & can't coalesce are mutually + * exclusive, if you do that, be prepared + * for trouble + */ + WARN_ON(rend != base); + goto new_block; + } + /* We adjust our base down to enclose the + * original block and destroy it. It will be + * part of our new allocation. Since we've + * freed an entry, we know we won't fail + * to allocate one later, so we won't risk + * losing the original block allocation. + */ + size += (base - rgn->base); + base = rgn->base; + memblock_remove_region(type, i--); } } - /* If we plugged a hole, we may want to also coalesce with the - * next region + /* If the array is empty, special case, replace the fake + * filler region and return */ - if ((i < type->cnt - 1) && memblock_regions_adjacent(type, i, i+1) && - ((type != &memblock.memory || memblock_memory_can_coalesce(type->regions[i].base, - type->regions[i].size, - type->regions[i+1].base, - type->regions[i+1].size)))) { - memblock_coalesce_regions(type, i, i+1); - coalesced++; + if ((type->cnt == 1) && (type->regions[0].size == 0)) { + type->regions[0].base = base; + type->regions[0].size = size; + return 0; } - if (coalesced) - return coalesced; - + new_block: /* If we are out of space, we fail. It's too late to resize the array * but then this shouldn't have happened in the first place. */ @@ -362,13 +380,14 @@ static long __init_memblock memblock_add_region(struct memblock_type *type, phys } else { type->regions[i+1].base = base; type->regions[i+1].size = size; + slot = i + 1; break; } } - if (base < type->regions[0].base) { type->regions[0].base = base; type->regions[0].size = size; + slot = 0; } type->cnt++; @@ -376,7 +395,8 @@ static long __init_memblock memblock_add_region(struct memblock_type *type, phys * our allocation and return an error */ if (type->cnt == type->max && memblock_double_array(type)) { - type->cnt--; + BUG_ON(slot < 0); + memblock_remove_region(type, slot); return -1; } @@ -389,52 +409,55 @@ long __init_memblock memblock_add(phys_addr_t base, phys_addr_t size) } -static long __init_memblock __memblock_remove(struct memblock_type *type, phys_addr_t base, phys_addr_t size) +static long __init_memblock __memblock_remove(struct memblock_type *type, + phys_addr_t base, phys_addr_t size) { - phys_addr_t rgnbegin, rgnend; phys_addr_t end = base + size; int i; - rgnbegin = rgnend = 0; /* supress gcc warnings */ - - /* Find the region where (base, size) belongs to */ - for (i=0; i < type->cnt; i++) { - rgnbegin = type->regions[i].base; - rgnend = rgnbegin + type->regions[i].size; + /* Walk through the array for collisions */ + for (i = 0; i < type->cnt; i++) { + struct memblock_region *rgn = &type->regions[i]; + phys_addr_t rend = rgn->base + rgn->size; - if ((rgnbegin <= base) && (end <= rgnend)) + /* Nothing more to do, exit */ + if (rgn->base > end || rgn->size == 0) break; - } - /* Didn't find the region */ - if (i == type->cnt) - return -1; + /* If we fully enclose the block, drop it */ + if (base <= rgn->base && end >= rend) { + memblock_remove_region(type, i--); + continue; + } - /* Check to see if we are removing entire region */ - if ((rgnbegin == base) && (rgnend == end)) { - memblock_remove_region(type, i); - return 0; - } + /* If we are fully enclosed within a block + * then we need to split it and we are done + */ + if (base > rgn->base && end < rend) { + rgn->size = base - rgn->base; + if (!memblock_add_region(type, end, rend - end)) + return 0; + /* Failure to split is bad, we at least + * restore the block before erroring + */ + rgn->size = rend - rgn->base; + WARN_ON(1); + return -1; + } - /* Check to see if region is matching at the front */ - if (rgnbegin == base) { - type->regions[i].base = end; - type->regions[i].size -= size; - return 0; - } + /* Check if we need to trim the bottom of a block */ + if (rgn->base < end && rend > end) { + rgn->size -= end - rgn->base; + rgn->base = end; + break; + } - /* Check to see if the region is matching at the end */ - if (rgnend == end) { - type->regions[i].size -= size; - return 0; - } + /* And check if we need to trim the top of a block */ + if (base < rend) + rgn->size -= rend - base; - /* - * We need to split the entry - adjust the current one to the - * beginging of the hole and add the region after hole. - */ - type->regions[i].size = base - type->regions[i].base; - return memblock_add_region(type, end, rgnend - end); + } + return 0; } long __init_memblock memblock_remove(phys_addr_t base, phys_addr_t size) @@ -467,7 +490,7 @@ phys_addr_t __init __memblock_alloc_base(phys_addr_t size, phys_addr_t align, ph found = memblock_find_base(size, align, 0, max_addr); if (found != MEMBLOCK_ERROR && - memblock_add_region(&memblock.reserved, found, size) >= 0) + !memblock_add_region(&memblock.reserved, found, size)) return found; return 0; @@ -548,7 +571,7 @@ static phys_addr_t __init memblock_alloc_nid_region(struct memblock_region *mp, if (this_nid == nid) { phys_addr_t ret = memblock_find_region(start, this_end, size, align); if (ret != MEMBLOCK_ERROR && - memblock_add_region(&memblock.reserved, ret, size) >= 0) + !memblock_add_region(&memblock.reserved, ret, size)) return ret; } start = this_end; |