From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753338AbdBTM65 (ORCPT ); Mon, 20 Feb 2017 07:58:57 -0500 Received: from mx0a-0016f401.pphosted.com ([67.231.148.174]:42924 "EHLO mx0b-0016f401.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752194AbdBTM6z (ORCPT ); Mon, 20 Feb 2017 07:58:55 -0500 From: Jisheng Zhang To: , , , , CC: , , , Jisheng Zhang Subject: [PATCH net-next v3 1/4] net: mvneta: avoid getting status from rx_desc as much as possible Date: Mon, 20 Feb 2017 20:53:41 +0800 Message-ID: <20170220125344.3555-2-jszhang@marvell.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20170220125344.3555-1-jszhang@marvell.com> References: <20170220125344.3555-1-jszhang@marvell.com> MIME-Version: 1.0 Content-Type: text/plain X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-02-20_11:,, signatures=0 X-Proofpoint-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=2 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1612050000 definitions=main-1702200127 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In hot code path mvneta_rx_hwbm(), the rx_desc->status is read twice. 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 rx_status to avoid the second reading from uncached memory. Signed-off-by: Jisheng Zhang Suggested-by: Arnd Bergmann Tested-by: Gregory CLEMENT --- drivers/net/ethernet/marvell/mvneta.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c index 61dd4462411c..06df72b8da85 100644 --- a/drivers/net/ethernet/marvell/mvneta.c +++ b/drivers/net/ethernet/marvell/mvneta.c @@ -313,8 +313,8 @@ ((addr >= txq->tso_hdrs_phys) && \ (addr < txq->tso_hdrs_phys + txq->size * TSO_HEADER_SIZE)) -#define MVNETA_RX_GET_BM_POOL_ID(rxd) \ - (((rxd)->status & MVNETA_RXD_BM_POOL_MASK) >> MVNETA_RXD_BM_POOL_SHIFT) +#define MVNETA_RX_GET_BM_POOL_ID(status) \ + (((status) & MVNETA_RXD_BM_POOL_MASK) >> MVNETA_RXD_BM_POOL_SHIFT) struct mvneta_statistic { unsigned short offset; @@ -1900,7 +1900,7 @@ static void mvneta_rxq_drop_pkts(struct mvneta_port *pp, for (i = 0; i < rx_done; i++) { struct mvneta_rx_desc *rx_desc = mvneta_rxq_next_desc_get(rxq); - u8 pool_id = MVNETA_RX_GET_BM_POOL_ID(rx_desc); + u8 pool_id = MVNETA_RX_GET_BM_POOL_ID(rx_desc->status); struct mvneta_bm_pool *bm_pool; bm_pool = &pp->bm_priv->bm_pools[pool_id]; @@ -2075,7 +2075,7 @@ static int mvneta_rx_hwbm(struct mvneta_port *pp, int rx_todo, rx_bytes = rx_desc->data_size - (ETH_FCS_LEN + MVNETA_MH_SIZE); data = (u8 *)(uintptr_t)rx_desc->buf_cookie; phys_addr = rx_desc->buf_phys_addr; - pool_id = MVNETA_RX_GET_BM_POOL_ID(rx_desc); + pool_id = MVNETA_RX_GET_BM_POOL_ID(rx_status); bm_pool = &pp->bm_priv->bm_pools[pool_id]; if (!mvneta_rxq_desc_is_first_last(rx_status) || -- 2.11.0