From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: [PATCH 09/10] swiotlb: add support for non-coherent DMA Date: Mon, 8 Oct 2018 10:02:45 +0200 Message-ID: <20181008080246.20543-10-hch@lst.de> References: <20181008080246.20543-1-hch@lst.de> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20181008080246.20543-1-hch@lst.de> Sender: linux-kernel-owner@vger.kernel.org To: Will Deacon , Catalin Marinas , Robin Murphy , Konrad Rzeszutek Wilk Cc: linux-arm-kernel@lists.infradead.org, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org List-Id: iommu@lists.linux-foundation.org Handle architectures that are not cache coherent directly in the main swiotlb code by calling arch_sync_dma_for_{device,cpu} in all the right places from the various dma_map/unmap/sync methods when the device is non-coherent. Because swiotlb now uses dma_direct_alloc for the coherent allocation that side is already taken care of by the dma-direct code calling into arch_dma_{alloc,free} for devices that are non-coherent. Signed-off-by: Christoph Hellwig --- kernel/dma/swiotlb.c | 23 +++++++++++++++++------ 1 file changed, 17 insertions(+), 6 deletions(-) diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index 475a41eff3dc..52885b274368 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -21,6 +21,7 @@ #include #include +#include #include #include #include @@ -677,6 +678,10 @@ dma_addr_t swiotlb_map_page(struct device *dev, struct page *page, dma_addr = swiotlb_bounce_page(dev, &phys, size, dir, attrs); } + if (!dev_is_dma_coherent(dev) && + (attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0) + arch_sync_dma_for_device(dev, phys, size, dir); + return dma_addr; } @@ -696,6 +701,10 @@ void swiotlb_unmap_page(struct device *hwdev, dma_addr_t dev_addr, BUG_ON(dir == DMA_NONE); + if (!dev_is_dma_coherent(hwdev) && + (attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0) + arch_sync_dma_for_cpu(hwdev, paddr, size, dir); + if (is_swiotlb_buffer(paddr)) { swiotlb_tbl_unmap_single(hwdev, paddr, size, dir, attrs); return; @@ -732,15 +741,17 @@ swiotlb_sync_single(struct device *hwdev, dma_addr_t dev_addr, BUG_ON(dir == DMA_NONE); - if (is_swiotlb_buffer(paddr)) { + if (!dev_is_dma_coherent(hwdev) && target == SYNC_FOR_CPU) + arch_sync_dma_for_cpu(hwdev, paddr, size, dir); + + if (is_swiotlb_buffer(paddr)) swiotlb_tbl_sync_single(hwdev, paddr, size, dir, target); - return; - } - if (dir != DMA_FROM_DEVICE) - return; + if (!dev_is_dma_coherent(hwdev) && target == SYNC_FOR_DEVICE) + arch_sync_dma_for_device(hwdev, paddr, size, dir); - dma_mark_clean(phys_to_virt(paddr), size); + if (!is_swiotlb_buffer(paddr) && dir == DMA_FROM_DEVICE) + dma_mark_clean(phys_to_virt(paddr), size); } void -- 2.19.0