[PATCH 04/43] memblock: Implement memblock_is_memory and memblock_is_region_memory
in [Kernel]
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From: Benjamin Herrenschmidt on 6 Aug 2010 01:30 To make it fast, we steal ARM's binary search for memblock_is_memory() and we use that to also the replace existing implementation of memblock_is_reserved(). Signed-off-by: Benjamin Herrenschmidt <benh(a)kernel.crashing.org> --- include/linux/memblock.h | 2 ++ mm/memblock.c | 42 ++++++++++++++++++++++++++++++++++-------- 2 files changed, 36 insertions(+), 8 deletions(-) diff --git a/include/linux/memblock.h b/include/linux/memblock.h index 4b69313..47bceb1 100644 --- a/include/linux/memblock.h +++ b/include/linux/memblock.h @@ -56,6 +56,8 @@ extern u64 __init __memblock_alloc_base(u64 size, extern u64 __init memblock_phys_mem_size(void); extern u64 memblock_end_of_DRAM(void); extern void __init memblock_enforce_memory_limit(u64 memory_limit); +extern int memblock_is_memory(u64 addr); +extern int memblock_is_region_memory(u64 base, u64 size); extern int __init memblock_is_reserved(u64 addr); extern int memblock_is_region_reserved(u64 base, u64 size); extern int memblock_find(struct memblock_region *res); diff --git a/mm/memblock.c b/mm/memblock.c index 6f407cc..aa88c62 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -487,17 +487,43 @@ void __init memblock_enforce_memory_limit(u64 memory_limit) } } +static int memblock_search(struct memblock_type *type, u64 addr) +{ + unsigned int left = 0, right = type->cnt; + + do { + unsigned int mid = (right + left) / 2; + + if (addr < type->regions[mid].base) + right = mid; + else if (addr >= (type->regions[mid].base + + type->regions[mid].size)) + left = mid + 1; + else + return mid; + } while (left < right); + return -1; +} + int __init memblock_is_reserved(u64 addr) { - int i; + return memblock_search(&memblock.reserved, addr) != -1; +} - for (i = 0; i < memblock.reserved.cnt; i++) { - u64 upper = memblock.reserved.regions[i].base + - memblock.reserved.regions[i].size - 1; - if ((addr >= memblock.reserved.regions[i].base) && (addr <= upper)) - return 1; - } - return 0; +int memblock_is_memory(u64 addr) +{ + return memblock_search(&memblock.memory, addr) != -1; +} + +int memblock_is_region_memory(u64 base, u64 size) +{ + int idx = memblock_search(&memblock.reserved, base); + + if (idx == -1) + return 0; + return memblock.reserved.regions[idx].base <= base && + (memblock.reserved.regions[idx].base + + memblock.reserved.regions[idx].size) >= (base + size); } int memblock_is_region_reserved(u64 base, u64 size) -- 1.7.0.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |