lkml.org 
[lkml]   [2018]   [Nov]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 02/24] swiotlb: Skip cache maintenance on map error
    Date
    From: Robin Murphy <robin.murphy@arm.com>

    If swiotlb_bounce_page() failed, calling arch_sync_dma_for_device() may
    lead to such delights as performing cache maintenance on whatever
    address phys_to_virt(SWIOTLB_MAP_ERROR) looks like, which is typically
    outside the kernel memory map and goes about as well as expected.

    Don't do that.

    Fixes: a4a4330db46a ("swiotlb: add support for non-coherent DMA")
    Tested-by: John Stultz <john.stultz@linaro.org>
    Signed-off-by: Robin Murphy <robin.murphy@arm.com>
    Signed-off-by: Christoph Hellwig <hch@lst.de>
    ---
    kernel/dma/swiotlb.c | 3 ++-
    1 file changed, 2 insertions(+), 1 deletion(-)

    diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
    index 5731daa09a32..045930e32c0e 100644
    --- a/kernel/dma/swiotlb.c
    +++ b/kernel/dma/swiotlb.c
    @@ -679,7 +679,8 @@ dma_addr_t swiotlb_map_page(struct device *dev, struct page *page,
    }

    if (!dev_is_dma_coherent(dev) &&
    - (attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0)
    + (attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0 &&
    + dev_addr != DIRECT_MAPPING_ERROR)
    arch_sync_dma_for_device(dev, phys, size, dir);

    return dev_addr;
    --
    2.19.1
    \
     
     \ /
      Last update: 2018-11-22 15:07    [W:2.827 / U:0.008 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site