The DMA engine supports memory copy, RAID5 XOR, RAID6 PQ, and other computations. But the bandwidth of the entire DMA engine is shared among all channels. This patch re-configures operations availability such that one can achieve maximum performance for XOR and PQ computation by removing the memory offload operations. Signed-off-by: Rameshwar Prasad Sahu <rsahu@xxxxxxx> --- drivers/dma/xgene-dma.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/dma/xgene-dma.c b/drivers/dma/xgene-dma.c index 8d57b1b..2998fcb 100644 --- a/drivers/dma/xgene-dma.c +++ b/drivers/dma/xgene-dma.c @@ -154,6 +154,7 @@ #define XGENE_DMA_MAX_XOR_SRC 5 #define XGENE_DMA_16K_BUFFER_LEN_CODE 0x0 #define XGENE_DMA_INVALID_LEN_CODE 0x7800000000000000ULL +#undef XGENE_DMA_MEMCPY_ENABLE /* X-Gene DMA descriptor error codes */ #define ERR_DESC_AXI 0x01 @@ -1707,7 +1708,9 @@ static void xgene_dma_set_caps(struct xgene_dma_chan *chan, dma_cap_zero(dma_dev->cap_mask); /* Set DMA device capability */ +#ifdef XGENE_DMA_MEMCPY_ENABLE dma_cap_set(DMA_MEMCPY, dma_dev->cap_mask); +#endif dma_cap_set(DMA_SG, dma_dev->cap_mask); /* Basically here, the X-Gene SoC DMA engine channel 0 supports XOR -- 1.8.2.1 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
