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Thu, 22 Mar 2018 16:26:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1521736016; bh=PGLaKXGmKlIUzhwmOqVi79a4k9rslAyuE0MyI3mwmdY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MA2VCt8QF+EHDuCd3YZ80eoOIITWyGR5bjPNA3KNMFf8UH7toQ849fEBNSh97sNje MUX8D/ECjosbVvyp9nII9086txm3D4ls5viPcTwD7Qa2gopOqb7UGu62b8UU4hKDBV D2J5jzeDBsVE1pmAhcGize1tnU5sprozneKpHCwI= DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 1BF3460C64 Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=okaya@codeaurora.org From: Sinan Kaya To: linux-rdma@vger.kernel.org, timur@codeaurora.org, sulrich@codeaurora.org Subject: [PATCH v5 1/3] RDMA/bnxt_re: Eliminate duplicate barriers on weakly-ordered archs Date: Thu, 22 Mar 2018 12:26:47 -0400 Message-Id: <1521736009-23387-2-git-send-email-okaya@codeaurora.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1521736009-23387-1-git-send-email-okaya@codeaurora.org> References: <1521736009-23387-1-git-send-email-okaya@codeaurora.org> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20180322_092705_321783_B60E0179 X-CRM114-Status: GOOD ( 11.80 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Selvin Xavier , Sriharsha Basavapatna , linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, Somnath Kotur , Sinan Kaya , Jason Gunthorpe , Doug Ledford , Devesh Sharma , linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP Code includes wmb() followed by writel(). writel() already has a barrier on some architectures like arm64. This ends up CPU observing two barriers back to back before executing the register write. Since code already has an explicit barrier call, changing writel() to writel_relaxed(). Signed-off-by: Sinan Kaya --- drivers/infiniband/hw/bnxt_re/qplib_rcfw.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c b/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c index 8329ec6..10f9a26 100644 --- a/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c +++ b/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c @@ -181,10 +181,11 @@ static int __send_message(struct bnxt_qplib_rcfw *rcfw, struct cmdq_base *req, /* ring CMDQ DB */ wmb(); - writel(cmdq_prod, rcfw->cmdq_bar_reg_iomem + - rcfw->cmdq_bar_reg_prod_off); - writel(RCFW_CMDQ_TRIG_VAL, rcfw->cmdq_bar_reg_iomem + - rcfw->cmdq_bar_reg_trig_off); + writel_relaxed(cmdq_prod, rcfw->cmdq_bar_reg_iomem + + rcfw->cmdq_bar_reg_prod_off); + writel_relaxed(RCFW_CMDQ_TRIG_VAL, rcfw->cmdq_bar_reg_iomem + + rcfw->cmdq_bar_reg_trig_off); + mmiowb(); done: spin_unlock_irqrestore(&cmdq->lock, flags); /* Return the CREQ response pointer */