diff options
| author | Christoph Hellwig <hch@lst.de> | 2018-01-09 23:40:57 +0100 |
|---|---|---|
| committer | Christoph Hellwig <hch@lst.de> | 2018-01-15 09:35:13 +0100 |
| commit | 95f183916d4b0bc1943684948ecdd2469f1aa978 (patch) | |
| tree | 4f35e71033398e1ac96e90454a84f1ad2402492e /lib | |
| parent | c61e9637340e1d0672c6f0c0b11aa81d7262c49d (diff) | |
| download | linux-95f183916d4b0bc1943684948ecdd2469f1aa978.tar.bz2 | |
dma-direct: retry allocations using GFP_DMA for small masks
If an attempt to allocate memory succeeded, but isn't inside the
supported DMA mask, retry the allocation with GFP_DMA set as a
last resort.
Based on the x86 code, but an off by one error in what is now
dma_coherent_ok has been fixed vs the x86 code.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/dma-direct.c | 25 |
1 files changed, 24 insertions, 1 deletions
diff --git a/lib/dma-direct.c b/lib/dma-direct.c index 8f76032ebc3c..4e43c2bb7f5f 100644 --- a/lib/dma-direct.c +++ b/lib/dma-direct.c @@ -35,6 +35,11 @@ check_addr(struct device *dev, dma_addr_t dma_addr, size_t size, return true; } +static bool dma_coherent_ok(struct device *dev, phys_addr_t phys, size_t size) +{ + return phys_to_dma(dev, phys) + size - 1 <= dev->coherent_dma_mask; +} + static void *dma_direct_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs) { @@ -48,11 +53,29 @@ static void *dma_direct_alloc(struct device *dev, size_t size, if (dev->coherent_dma_mask <= DMA_BIT_MASK(32) && !(gfp & GFP_DMA)) gfp |= GFP_DMA32; +again: /* CMA can be used only in the context which permits sleeping */ - if (gfpflags_allow_blocking(gfp)) + if (gfpflags_allow_blocking(gfp)) { page = dma_alloc_from_contiguous(dev, count, page_order, gfp); + if (page && !dma_coherent_ok(dev, page_to_phys(page), size)) { + dma_release_from_contiguous(dev, page, count); + page = NULL; + } + } if (!page) page = alloc_pages_node(dev_to_node(dev), gfp, page_order); + + if (page && !dma_coherent_ok(dev, page_to_phys(page), size)) { + __free_pages(page, page_order); + page = NULL; + + if (dev->coherent_dma_mask < DMA_BIT_MASK(32) && + !(gfp & GFP_DMA)) { + gfp = (gfp & ~GFP_DMA32) | GFP_DMA; + goto again; + } + } + if (!page) return NULL; |