[PATCH 1/4] openrisc: remove the sync_single_for_cpu DMA operation

From: Christoph Hellwig
Date: Thu Jul 19 2018 - 09:02:42 EST


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@xxxxxx>
---
arch/openrisc/kernel/dma.c | 15 ---------------
1 file changed, 15 deletions(-)

diff --git a/arch/openrisc/kernel/dma.c b/arch/openrisc/kernel/dma.c
index ec7fd45704d2..47601274abf7 100644
--- a/arch/openrisc/kernel/dma.c
+++ b/arch/openrisc/kernel/dma.c
@@ -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);
--
2.18.0