This adds support for the DMA Contiguous Memory Allocator for intel-iommu. This change enables dma_alloc_coherent() to allocate big contiguous memory.
It is achieved in the same way as nommu_dma_ops currently does, i.e. trying to allocate memory by dma_alloc_from_contiguous() and alloc_pages() is used as a fallback. Cc: Marek Szyprowski <m.szyprow...@samsung.com> Cc: David Woodhouse <dw...@infradead.org> Cc: io...@lists.linux-foundation.org Cc: Thomas Gleixner <t...@linutronix.de> Cc: Ingo Molnar <mi...@redhat.com> Cc: "H. Peter Anvin" <h...@zytor.com> Cc: x...@kernel.org Signed-off-by: Akinobu Mita <akinobu.m...@gmail.com> --- drivers/iommu/intel-iommu.c | 32 ++++++++++++++++++++++++-------- 1 file changed, 24 insertions(+), 8 deletions(-) diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index fd426ca..172c2b0 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -3004,7 +3004,7 @@ static void *intel_alloc_coherent(struct device *hwdev, size_t size, dma_addr_t *dma_handle, gfp_t flags, struct dma_attrs *attrs) { - void *vaddr; + struct page *page = NULL; int order; size = PAGE_ALIGN(size); @@ -3019,17 +3019,31 @@ static void *intel_alloc_coherent(struct device *hwdev, size_t size, flags |= GFP_DMA32; } - vaddr = (void *)__get_free_pages(flags, order); - if (!vaddr) + if (!(flags & GFP_ATOMIC)) { + unsigned int count = size >> PAGE_SHIFT; + + page = dma_alloc_from_contiguous(hwdev, count, order); + if (page && iommu_no_mapping(hwdev) && + page_to_phys(page) + size > hwdev->coherent_dma_mask) { + dma_release_from_contiguous(hwdev, page, count); + page = NULL; + } + } + + if (!page) + page = alloc_pages(flags, order); + if (!page) return NULL; - memset(vaddr, 0, size); + memset(page_address(page), 0, size); - *dma_handle = __intel_map_single(hwdev, virt_to_bus(vaddr), size, + *dma_handle = __intel_map_single(hwdev, page_to_phys(page), size, DMA_BIDIRECTIONAL, hwdev->coherent_dma_mask); if (*dma_handle) - return vaddr; - free_pages((unsigned long)vaddr, order); + return page_address(page); + if (!dma_release_from_contiguous(hwdev, page, size >> PAGE_SHIFT)) + __free_pages(page, order); + return NULL; } @@ -3037,12 +3051,14 @@ static void intel_free_coherent(struct device *hwdev, size_t size, void *vaddr, dma_addr_t dma_handle, struct dma_attrs *attrs) { int order; + struct page *page = virt_to_page(vaddr); size = PAGE_ALIGN(size); order = get_order(size); intel_unmap_page(hwdev, dma_handle, size, DMA_BIDIRECTIONAL, NULL); - free_pages((unsigned long)vaddr, order); + if (!dma_release_from_contiguous(hwdev, page, size >> PAGE_SHIFT)) + __free_pages(page, order); } static void intel_unmap_sg(struct device *hwdev, struct scatterlist *sglist, -- 1.8.3.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/