From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id 96A7AA09EF; Mon, 21 Dec 2020 15:24:31 +0100 (CET) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 4D794CC17; Mon, 21 Dec 2020 15:23:54 +0100 (CET) Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by dpdk.org (Postfix) with ESMTP id BEC6BCBB4 for ; Mon, 21 Dec 2020 15:23:52 +0100 (CET) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 317F01FB; Mon, 21 Dec 2020 06:23:51 -0800 (PST) Received: from net-arm-thunderx2-03.shanghai.arm.com (net-arm-thunderx2-03.shanghai.arm.com [10.169.208.206]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 0D5983F6CF; Mon, 21 Dec 2020 06:23:48 -0800 (PST) From: Joyce Kong To: maxime.coquelin@redhat.com, chenbo.xia@intel.com, honnappa.nagarahalli@arm.com, ruifeng.wang@arm.com Cc: dev@dpdk.org, nd@arm.com Date: Mon, 21 Dec 2020 22:23:19 +0800 Message-Id: <20201221142321.51606-3-joyce.kong@arm.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201221142321.51606-1-joyce.kong@arm.com> References: <20201221142321.51606-1-joyce.kong@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Subject: [dpdk-dev] [PATCH v1 2/4] net/virtio: replace smp barrier with IO barrier X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" Replace rte_smp_wmb/rmb with rte_io_wmb/rmb as they are the same on x86 and ppc platforms. Then, for function virtqueue_fetch_flags_packed/ virtqueue_store_flags_packed, the if and else branch are still identical for the platforms except Arm. Signed-off-by: Joyce Kong Reviewed-by: Ruifeng Wang --- drivers/net/virtio/virtqueue.h | 27 +++++++++++++-------------- 1 file changed, 13 insertions(+), 14 deletions(-) diff --git a/drivers/net/virtio/virtqueue.h b/drivers/net/virtio/virtqueue.h index 42c4c9882..ac3d9e750 100644 --- a/drivers/net/virtio/virtqueue.h +++ b/drivers/net/virtio/virtqueue.h @@ -66,16 +66,15 @@ virtqueue_fetch_flags_packed(struct vring_packed_desc *dp, uint16_t flags; if (weak_barriers) { -/* x86 prefers to using rte_smp_rmb over __atomic_load_n as it reports +/* x86 prefers to using rte_io_rmb over __atomic_load_n as it reports * a better perf(~1.5%), which comes from the saved branch by the compiler. - * The if and else branch are identical with the smp and io barriers both - * defined as compiler barriers on x86. + * The if and else branch are identical on the platforms except Arm. */ -#ifdef RTE_ARCH_X86_64 - flags = dp->flags; - rte_smp_rmb(); -#else +#ifdef RTE_ARCH_ARM flags = __atomic_load_n(&dp->flags, __ATOMIC_ACQUIRE); +#else + flags = dp->flags; + rte_io_rmb(); #endif } else { flags = dp->flags; @@ -90,22 +89,22 @@ virtqueue_store_flags_packed(struct vring_packed_desc *dp, uint16_t flags, uint8_t weak_barriers) { if (weak_barriers) { -/* x86 prefers to using rte_smp_wmb over __atomic_store_n as it reports +/* x86 prefers to using rte_io_wmb over __atomic_store_n as it reports * a better perf(~1.5%), which comes from the saved branch by the compiler. - * The if and else branch are identical with the smp and io barriers both - * defined as compiler barriers on x86. + * The if and else branch are identical on the platforms except Arm. */ -#ifdef RTE_ARCH_X86_64 - rte_smp_wmb(); - dp->flags = flags; -#else +#ifdef RTE_ARCH_ARM __atomic_store_n(&dp->flags, flags, __ATOMIC_RELEASE); +#else + rte_io_wmb(); + dp->flags = flags; #endif } else { rte_io_wmb(); dp->flags = flags; } } + #ifdef RTE_PMD_PACKET_PREFETCH #define rte_packet_prefetch(p) rte_prefetch1(p) #else -- 2.29.2