During early boot, if the bottom up mode is set, just try allocating bottom up from the end of kernel image, and if that fails, do normal top down allocation. So in function dma_contiguous_reserve(), we add the above logic. Signed-off-by: Tang Chen <tangchen@xxxxxxxxxxxxxx> Reviewed-by: Zhang Yanfei <zhangyanfei@xxxxxxxxxxxxxx> --- drivers/base/dma-contiguous.c | 17 ++++++++++++++--- 1 files changed, 14 insertions(+), 3 deletions(-) diff --git a/drivers/base/dma-contiguous.c b/drivers/base/dma-contiguous.c index 99802d6..aada945 100644 --- a/drivers/base/dma-contiguous.c +++ b/drivers/base/dma-contiguous.c @@ -228,17 +228,28 @@ int __init dma_contiguous_reserve_area(phys_addr_t size, phys_addr_t base, goto err; } } else { + phys_addr_t addr; + + if (memblock_direction_bottom_up()) { + addr = memblock_alloc_bottom_up( + MEMBLOCK_ALLOC_ACCESSIBLE, + limit, size, alignment); + if (addr) + goto success; + } + /* * Use __memblock_alloc_base() since * memblock_alloc_base() panic()s. */ - phys_addr_t addr = __memblock_alloc_base(size, alignment, limit); + addr = __memblock_alloc_base(size, alignment, limit); if (!addr) { ret = -ENOMEM; goto err; - } else { - base = addr; } + +success: + base = addr; } /* -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html