openrisc: remove the sync_single_for_cpu DMA operation (1902cbcc) · Commits · 戴 / test

openrisc 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 <hch@lst.de> Signed-off-by:

Stafford Horne <shorne@gmail.com>

arch/openrisc/kernel/dma.c

+0 −15

Original line number	Diff line number	Diff line
		@@ -208,20 +208,6 @@ or1k_unmap_sg(struct device dev, struct scatterlist sg,
		}
		}

		static void
		or1k_sync_single_for_cpu(struct device *dev,
		dma_addr_t dma_handle, size_t size,
		enum dma_data_direction dir)
		{
		unsigned long cl;
		dma_addr_t addr = dma_handle;
		struct cpuinfo_or1k *cpuinfo = &cpuinfo_or1k[smp_processor_id()];

		/* Invalidate the dcache for the requested range */
		for (cl = addr; cl < addr + size; cl += cpuinfo->dcache_block_size)
		mtspr(SPR_DCBIR, cl);
		}

		static void
		or1k_sync_single_for_device(struct device *dev,
		dma_addr_t dma_handle, size_t size,
		@@ -243,7 +229,6 @@ const struct dma_map_ops or1k_dma_map_ops = {
		.unmap_page = or1k_unmap_page,
		.map_sg = or1k_map_sg,
		.unmap_sg = or1k_unmap_sg,
		.sync_single_for_cpu = or1k_sync_single_for_cpu,
		.sync_single_for_device = or1k_sync_single_for_device,
		};
		EXPORT_SYMBOL(or1k_dma_map_ops);

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