From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2AAA3C00A89 for ; Fri, 30 Oct 2020 17:31:07 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id A65DB20756 for ; Fri, 30 Oct 2020 17:31:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="Qt1wxbBQ"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="Fw6dvWMm" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A65DB20756 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:Message-Id:Date:Subject:To:From: Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender :Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References:List-Owner; bh=FIkAKiRzkvuNM2Arlr6Q8+43ZycnCZf3c6hIDU90vOU=; b=Qt1wxbBQxnaISQxV5yT4uzm2U5 1StKYbbg/jI4Ya6idnCw2vveMMRlMP86CkbSGZcfeKyALhetwyxrxrt8+0Hy2iKDoujAM7SA4AUW4 ypzcQgvaDFCpw9LIpzmruBnaVKZaaxbE7s36emcvTcRixl+MqzRGWPwmDq8JPRIvgCMW5NvTptPWb Tn7mXdTfPzCfmnCQU+YNTUXPhgxBzr4ZdE7dP8FRbu+AkvHJs4vaHcnt1+O6lSljn6Mlg93nQSUBj vqx8EitF0QvT4NP7LAZnoHw4ZZfTfwlNevcW1xcDkaL71OWb4zhBju8AdJ420mdcRU/9/HL+q6GKa nJyzNSlA==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kYYEu-0006cl-0Q; Fri, 30 Oct 2020 17:31:00 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kYYCw-0005Zi-3A for linux-nvme@lists.infradead.org; Fri, 30 Oct 2020 17:29:00 +0000 Received: from dhcp-10-100-145-180.wdc.com (unknown [199.255.45.60]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7B27420756; Fri, 30 Oct 2020 17:28:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604078937; bh=NgnDV1e+LsYMq8aEcJWrK2XWaltCZ0Wts8NRdmjOAaY=; h=From:To:Cc:Subject:Date:From; b=Fw6dvWMmSVI4PDuxSb3RC1D7hsQvtGGpOqKhrcuYbeNC+E3g+RvHg5kXs8g0CDzoK WkcEVy0DsEtf18/eQo+bm0ukFAgry6awtajzMdQVi8AQxywxgSbxzrWb5NPDVDQc/k HiuzTIamSbDB3m6zEsDJCg1kMEyQEIxRleodM++0= From: Keith Busch To: linux-nvme@lists.infradead.org, hch@lst.de, sagi@grimberg.me Subject: [PATCH] Revert "nvme-pci: remove last_sq_tail" Date: Fri, 30 Oct 2020 10:28:54 -0700 Message-Id: <20201030172854.1961578-1-kbusch@kernel.org> X-Mailer: git-send-email 2.24.1 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201030_132858_264459_3D8E1A39 X-CRM114-Status: GOOD ( 14.41 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Keith Busch , "B.L. Jones" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org Multiple CPUs may be mapped to the same hctx, allowing mulitple submission contexts to attempt commit_rqs(). We need to verify we're not writing the same doorbell value multiple times since that's a spec violation. Revert commit 54b2fcee1db041a83b52b51752dade6090cf952f. Link: https://bugzilla.redhat.com/show_bug.cgi?id=1878596 Reported-by: "B.L. Jones" Signed-off-by: Keith Busch --- drivers/nvme/host/pci.c | 23 +++++++++++++++++++---- 1 file changed, 19 insertions(+), 4 deletions(-) diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c index df8f3612107f..0578ff253c47 100644 --- a/drivers/nvme/host/pci.c +++ b/drivers/nvme/host/pci.c @@ -198,6 +198,7 @@ struct nvme_queue { u32 q_depth; u16 cq_vector; u16 sq_tail; + u16 last_sq_tail; u16 cq_head; u16 qid; u8 cq_phase; @@ -455,11 +456,24 @@ static int nvme_pci_map_queues(struct blk_mq_tag_set *set) return 0; } -static inline void nvme_write_sq_db(struct nvme_queue *nvmeq) +/* + * Write sq tail if we are asked to, or if the next command would wrap. + */ +static inline void nvme_write_sq_db(struct nvme_queue *nvmeq, bool write_sq) { + if (!write_sq) { + u16 next_tail = nvmeq->sq_tail + 1; + + if (next_tail == nvmeq->q_depth) + next_tail = 0; + if (next_tail != nvmeq->last_sq_tail) + return; + } + if (nvme_dbbuf_update_and_check_event(nvmeq->sq_tail, nvmeq->dbbuf_sq_db, nvmeq->dbbuf_sq_ei)) writel(nvmeq->sq_tail, nvmeq->q_db); + nvmeq->last_sq_tail = nvmeq->sq_tail; } /** @@ -476,8 +490,7 @@ static void nvme_submit_cmd(struct nvme_queue *nvmeq, struct nvme_command *cmd, cmd, sizeof(*cmd)); if (++nvmeq->sq_tail == nvmeq->q_depth) nvmeq->sq_tail = 0; - if (write_sq) - nvme_write_sq_db(nvmeq); + nvme_write_sq_db(nvmeq, write_sq); spin_unlock(&nvmeq->sq_lock); } @@ -486,7 +499,8 @@ static void nvme_commit_rqs(struct blk_mq_hw_ctx *hctx) struct nvme_queue *nvmeq = hctx->driver_data; spin_lock(&nvmeq->sq_lock); - nvme_write_sq_db(nvmeq); + if (nvmeq->sq_tail != nvmeq->last_sq_tail) + nvme_write_sq_db(nvmeq, true); spin_unlock(&nvmeq->sq_lock); } @@ -1496,6 +1510,7 @@ static void nvme_init_queue(struct nvme_queue *nvmeq, u16 qid) struct nvme_dev *dev = nvmeq->dev; nvmeq->sq_tail = 0; + nvmeq->last_sq_tail = 0; nvmeq->cq_head = 0; nvmeq->cq_phase = 1; nvmeq->q_db = &dev->dbs[qid * 2 * dev->db_stride]; -- 2.24.1 _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme