From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yongseok Koh Subject: [PATCH v2 1/8] eal: introduce DMA memory barriers Date: Mon, 15 Jan 2018 17:10:43 -0800 Message-ID: <20180116011050.18866-2-yskoh@mellanox.com> References: <20171227042824.33373-1-yskoh@mellanox.com> <20180116011050.18866-1-yskoh@mellanox.com> Mime-Version: 1.0 Content-Type: text/plain Cc: dev@dpdk.org, Yongseok Koh To: adrien.mazarguil@6wind.com, nelio.laranjeiro@6wind.com, jerin.jacob@caviumnetworks.com, jianbo.liu@arm.com Return-path: Received: from EUR01-HE1-obe.outbound.protection.outlook.com (mail-he1eur01on0046.outbound.protection.outlook.com [104.47.0.46]) by dpdk.org (Postfix) with ESMTP id 065EFA48D for ; Tue, 16 Jan 2018 02:12:24 +0100 (CET) In-Reply-To: <20180116011050.18866-1-yskoh@mellanox.com> List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" This commit introduces rte_dma_wmb() and rte_dma_rmb(), in order to guarantee the ordering of coherent shared memory between the CPU and a DMA capable device. Signed-off-by: Yongseok Koh --- lib/librte_eal/common/include/generic/rte_atomic.h | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/lib/librte_eal/common/include/generic/rte_atomic.h b/lib/librte_eal/common/include/generic/rte_atomic.h index 16af5ca57..2e0503ce6 100644 --- a/lib/librte_eal/common/include/generic/rte_atomic.h +++ b/lib/librte_eal/common/include/generic/rte_atomic.h @@ -98,6 +98,24 @@ static inline void rte_io_wmb(void); */ static inline void rte_io_rmb(void); +/** + * Write memory barrier for coherent memory between lcore and IO device + * + * Guarantees that the STORE operations on coherent memory that + * precede the rte_dma_wmb() call are visible to I/O device before the + * STORE operations that follow it. + */ +static inline void rte_dma_wmb(void); + +/** + * Read memory barrier for coherent memory between lcore and IO device + * + * Guarantees that the LOAD operations on coherent memory updated by + * IO device that precede the rte_dma_rmb() call are visible to CPU + * before the LOAD operations that follow it. + */ +static inline void rte_dma_rmb(void); + #endif /* __DOXYGEN__ */ /** -- 2.11.0