It will return free memory size in specified range. We can not use memory_size - reserved_size here, because some reserved area may not be in the scope of memblock.memory.region. Use memblock.memory.region subtracting memblock.reserved.region to get free range array. then count size of all free ranges. -v2: Ben insist on using _in_range Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx> --- arch/x86/include/asm/memblock.h | 1 + arch/x86/mm/memblock.c | 48 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 49 insertions(+), 0 deletions(-) diff --git a/arch/x86/include/asm/memblock.h b/arch/x86/include/asm/memblock.h index 3a86b10..fc3c230 100644 --- a/arch/x86/include/asm/memblock.h +++ b/arch/x86/include/asm/memblock.h @@ -15,5 +15,6 @@ void memblock_x86_register_active_regions(int nid, unsigned long start_pfn, unsigned long last_pfn); u64 memblock_x86_hole_size(u64 start, u64 end); u64 memblock_x86_find_in_range_node(int nid, u64 start, u64 end, u64 size, u64 align); +u64 memblock_x86_free_memory_in_range(u64 addr, u64 limit); #endif diff --git a/arch/x86/mm/memblock.c b/arch/x86/mm/memblock.c index 723a2fc..0cd94cf 100644 --- a/arch/x86/mm/memblock.c +++ b/arch/x86/mm/memblock.c @@ -211,6 +211,54 @@ void __init memblock_x86_to_bootmem(u64 start, u64 end) } #endif +u64 __init memblock_x86_free_memory_in_range(u64 addr, u64 limit) +{ + int i, count; + struct range *range; + int nr_range; + u64 final_start, final_end; + u64 free_size; + struct memblock_region *r; + + count = (memblock.reserved.cnt + memblock.memory.cnt) * 2; + + range = find_range_array(count); + nr_range = 0; + + addr = PFN_UP(addr); + limit = PFN_DOWN(limit); + + for_each_memblock(memory, r) { + final_start = PFN_UP(r->base); + final_end = PFN_DOWN(r->base + r->size); + if (final_start >= final_end) + continue; + if (final_start >= limit || final_end <= addr) + continue; + + nr_range = add_range(range, count, nr_range, final_start, final_end); + } + subtract_range(range, count, 0, addr); + subtract_range(range, count, limit, -1ULL); + for_each_memblock(reserved, r) { + final_start = PFN_DOWN(r->base); + final_end = PFN_UP(r->base + r->size); + if (final_start >= final_end) + continue; + if (final_start >= limit || final_end <= addr) + continue; + + subtract_range(range, count, final_start, final_end); + } + nr_range = clean_sort_range(range, count); + + free_size = 0; + for (i = 0; i < nr_range; i++) + free_size += range[i].end - range[i].start; + + return free_size << PAGE_SHIFT; +} + void __init memblock_x86_reserve_range(u64 start, u64 end, char *name) { if (start == end) -- 1.6.4.2 -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html