From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jisheng Zhang Subject: [PATCH net-next v3 2/4] net: mvneta: avoid getting buf_phys_addr from rx_desc again Date: Mon, 20 Feb 2017 20:53:42 +0800 Message-ID: <20170220125344.3555-3-jszhang@marvell.com> References: <20170220125344.3555-1-jszhang@marvell.com> Mime-Version: 1.0 Content-Type: text/plain Cc: , , , Jisheng Zhang To: , , , , Return-path: In-Reply-To: <20170220125344.3555-1-jszhang@marvell.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org In hot code path mvneta_rx_hwbm(), the rx_desc->buf_phys_addr is read four times. The rx_desc is allocated by dma_alloc_coherent, it's uncacheable if the device isn't cache-coherent, reading from uncached memory is fairly slow. So reuse the read out phys_addr variable to avoid the extra reading from uncached memory. Signed-off-by: Jisheng Zhang Suggested-by: Gregory CLEMENT --- drivers/net/ethernet/marvell/mvneta.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c index 06df72b8da85..a25042801eec 100644 --- a/drivers/net/ethernet/marvell/mvneta.c +++ b/drivers/net/ethernet/marvell/mvneta.c @@ -2082,8 +2082,7 @@ static int mvneta_rx_hwbm(struct mvneta_port *pp, int rx_todo, (rx_status & MVNETA_RXD_ERR_SUMMARY)) { err_drop_frame_ret_pool: /* Return the buffer to the pool */ - mvneta_bm_pool_put_bp(pp->bm_priv, bm_pool, - rx_desc->buf_phys_addr); + mvneta_bm_pool_put_bp(pp->bm_priv, bm_pool, phys_addr); err_drop_frame: dev->stats.rx_errors++; mvneta_rx_error(pp, rx_desc); @@ -2098,7 +2097,7 @@ static int mvneta_rx_hwbm(struct mvneta_port *pp, int rx_todo, goto err_drop_frame_ret_pool; dma_sync_single_range_for_cpu(dev->dev.parent, - rx_desc->buf_phys_addr, + phys_addr, MVNETA_MH_SIZE + NET_SKB_PAD, rx_bytes, DMA_FROM_DEVICE); @@ -2114,8 +2113,7 @@ static int mvneta_rx_hwbm(struct mvneta_port *pp, int rx_todo, rcvd_bytes += rx_bytes; /* Return the buffer to the pool */ - mvneta_bm_pool_put_bp(pp->bm_priv, bm_pool, - rx_desc->buf_phys_addr); + mvneta_bm_pool_put_bp(pp->bm_priv, bm_pool, phys_addr); /* leave the descriptor and buffer untouched */ continue; -- 2.11.0