From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Date: Tue, 22 May 2018 12:04:06 +0000 Subject: [PATCH 01/25] hexagon: remove the sync_single_for_cpu DMA operation Message-Id: <20180522120430.28709-2-hch@lst.de> List-Id: References: <20180522120430.28709-1-hch@lst.de> In-Reply-To: <20180522120430.28709-1-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: iommu@lists.linux-foundation.org Cc: linux-arch@vger.kernel.org, Michal Simek , Greentime Hu , Vincent Chen , linux-alpha@vger.kernel.org, linux-snps-arc@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-c6x-dev@linux-c6x.org, linux-hexagon@vger.kernel.org, linux-m68k@lists.linux-m68k.org, nios2-dev@lists.rocketboards.org, openrisc@lists.librecores.org, linux-parisc@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-xtensa@linux-xtensa.org, linux-kernel@vger.kernel.org hexagon does all the required cache maintainance at dma map time, and none at unmap time. It thus has to implement sync_single_for_device to match the map cace for buffer reuse, but there is no point in doing another invalidation in the sync_single_cpu_case, which in terms of cache maintainance is equivalent to the unmap case. Signed-off-by: Christoph Hellwig --- arch/hexagon/kernel/dma.c | 8 -------- 1 file changed, 8 deletions(-) diff --git a/arch/hexagon/kernel/dma.c b/arch/hexagon/kernel/dma.c index 77459df34e2e..d2b717f352f4 100644 --- a/arch/hexagon/kernel/dma.c +++ b/arch/hexagon/kernel/dma.c @@ -181,13 +181,6 @@ static dma_addr_t hexagon_map_page(struct device *dev, struct page *page, return bus; } -static void hexagon_sync_single_for_cpu(struct device *dev, - dma_addr_t dma_handle, size_t size, - enum dma_data_direction dir) -{ - dma_sync(dma_addr_to_virt(dma_handle), size, dir); -} - static void hexagon_sync_single_for_device(struct device *dev, dma_addr_t dma_handle, size_t size, enum dma_data_direction dir) @@ -205,7 +198,6 @@ const struct dma_map_ops hexagon_dma_ops = { .free = hexagon_free_coherent, .map_sg = hexagon_map_sg, .map_page = hexagon_map_page, - .sync_single_for_cpu = hexagon_sync_single_for_cpu, .sync_single_for_device = hexagon_sync_single_for_device, .mapping_error = hexagon_mapping_error, }; -- 2.17.0