From d2cd563ba82c424083b78e0ce97d68bfb04d1242 Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Tue, 6 Jul 2010 15:39:14 -0700 Subject: memblock: Add arch function to control coalescing of memblock memory regions Some archs such as ARM want to avoid coalescing accross things such as the lowmem/highmem boundary or similar. This provides the option to control it via an arch callback for which a weak default is provided which always allows coalescing. Signed-off-by: Benjamin Herrenschmidt --- mm/memblock.c | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) (limited to 'mm') diff --git a/mm/memblock.c b/mm/memblock.c index 0787790b1ce..8715f09434d 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -241,6 +241,12 @@ static int memblock_double_array(struct memblock_type *type) return 0; } +extern int __weak memblock_memory_can_coalesce(phys_addr_t addr1, phys_addr_t size1, + phys_addr_t addr2, phys_addr_t size2) +{ + return 1; +} + static long memblock_add_region(struct memblock_type *type, phys_addr_t base, phys_addr_t size) { unsigned long coalesced = 0; @@ -262,6 +268,10 @@ static long memblock_add_region(struct memblock_type *type, phys_addr_t base, ph 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; @@ -274,7 +284,14 @@ static long memblock_add_region(struct memblock_type *type, phys_addr_t base, ph } } - if ((i < type->cnt - 1) && memblock_regions_adjacent(type, i, i+1)) { + /* If we plugged a hole, we may want to also coalesce with the + * next region + */ + 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++; } -- cgit v1.2.3-18-g5258