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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A8C0AC433F5 for ; Wed, 10 Nov 2021 00:45:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8A2DB61186 for ; Wed, 10 Nov 2021 00:45:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231431AbhKJAsp (ORCPT ); Tue, 9 Nov 2021 19:48:45 -0500 Received: from mail-pg1-f177.google.com ([209.85.215.177]:39846 "EHLO mail-pg1-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231405AbhKJAso (ORCPT ); Tue, 9 Nov 2021 19:48:44 -0500 Received: by mail-pg1-f177.google.com with SMTP id g184so635840pgc.6 for ; Tue, 09 Nov 2021 16:45:58 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=DXgDe1+Dztca8AnvzuiNKtcmsU9O3EaaKYEgt6dr/+c=; b=PMMor+AedtF7rI58ujm3mg/SmZgyBqiDw2/wJWytuPiWebu1SNabk8rqoGVIig8SnJ c/UtspkrDuR+CM8omo9UQ9GpELcumXe9PaN5/B/Hv46pGiKG+0HPmMva+sXmlWfnrlqt IWQAz4XGoxgN+RQ2uFUwdU06FuxDOPOCQ5GcRVFf366jvxR9YZi/c4hEMumjc/9JeVs7 9gXb2UlY4+ZpDXZ+qqFSj4HjncUOSVmwMkkhen+f99xxxRs5sOsgbJaisZVPeJhj8EU1 QI4sEwCXHGhO7R4ci6S6EzGfYvu4QA7b9Td3SKNqoH08tlEqoQY7ic3IlVUVQ8PodKi+ MARw== X-Gm-Message-State: AOAM530+b7Hk6mKQWZrmP2TpcE8sQ9ouA0oiCLqrEq605ABvvsl90iUq +TcEgVsxuKtP9ZHGr5N7RpA= X-Google-Smtp-Source: ABdhPJyu5jkWq5iVhRipJo4YYw8hDv6DrxXDVvzXNo2p2uGES7wY5AHhr9W3z2hd+G9ybL4pGLkVAA== X-Received: by 2002:a62:31c5:0:b0:447:cd37:61f8 with SMTP id x188-20020a6231c5000000b00447cd3761f8mr95464562pfx.29.1636505157524; Tue, 09 Nov 2021 16:45:57 -0800 (PST) Received: from bvanassche-linux.mtv.corp.google.com ([2620:15c:211:201:a582:6939:6a97:9cbf]) by smtp.gmail.com with ESMTPSA id l17sm21868826pfc.94.2021.11.09.16.45.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 09 Nov 2021 16:45:57 -0800 (PST) From: Bart Van Assche To: "Martin K . Petersen" Cc: linux-scsi@vger.kernel.org, Jaegeuk Kim , Adrian Hunter , Bart Van Assche , "James E.J. Bottomley" , Bean Huo , Can Guo , Stanley Chu , Avri Altman , Asutosh Das Subject: [PATCH 11/11] scsi: ufs: Implement polling support Date: Tue, 9 Nov 2021 16:44:40 -0800 Message-Id: <20211110004440.3389311-12-bvanassche@acm.org> X-Mailer: git-send-email 2.34.0.rc0.344.g81b53c2807-goog In-Reply-To: <20211110004440.3389311-1-bvanassche@acm.org> References: <20211110004440.3389311-1-bvanassche@acm.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org The time spent in io_schedule() is significant when submitting direct I/O to a UFS device. Hence this patch that implements polling support. User space software can enable polling by passing the RWF_HIPRI flag to the preadv2() system call or the IORING_SETUP_IOPOLL flag to the io_uring interface. Signed-off-by: Bart Van Assche --- drivers/scsi/ufs/ufshcd.c | 45 +++++++++++++++++++++++---------------- 1 file changed, 27 insertions(+), 18 deletions(-) diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index 36df89e8a575..70f128f12445 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -5250,6 +5250,31 @@ static void __ufshcd_transfer_req_compl(struct ufs_hba *hba, } } +/* + * Returns > 0 if one or more commands have been completed or 0 if no + * requests have been completed. + */ +static int ufshcd_poll(struct Scsi_Host *shost, unsigned int queue_num) +{ + struct ufs_hba *hba = shost_priv(shost); + unsigned long completed_reqs, flags; + u32 tr_doorbell; + + spin_lock_irqsave(&hba->outstanding_lock, flags); + tr_doorbell = ufshcd_readl(hba, REG_UTP_TRANSFER_REQ_DOOR_BELL); + completed_reqs = ~tr_doorbell & hba->outstanding_reqs; + WARN_ONCE(completed_reqs & ~hba->outstanding_reqs, + "completed: %#lx; outstanding: %#lx\n", completed_reqs, + hba->outstanding_reqs); + hba->outstanding_reqs &= ~completed_reqs; + spin_unlock_irqrestore(&hba->outstanding_lock, flags); + + if (completed_reqs) + __ufshcd_transfer_req_compl(hba, completed_reqs); + + return completed_reqs; +} + /** * ufshcd_transfer_req_compl - handle SCSI and query command completion * @hba: per adapter instance @@ -5260,9 +5285,6 @@ static void __ufshcd_transfer_req_compl(struct ufs_hba *hba, */ static irqreturn_t ufshcd_transfer_req_compl(struct ufs_hba *hba) { - unsigned long completed_reqs, flags; - u32 tr_doorbell; - /* Resetting interrupt aggregation counters first and reading the * DOOR_BELL afterward allows us to handle all the completed requests. * In order to prevent other interrupts starvation the DB is read once @@ -5277,21 +5299,7 @@ static irqreturn_t ufshcd_transfer_req_compl(struct ufs_hba *hba) if (ufs_fail_completion()) return IRQ_HANDLED; - spin_lock_irqsave(&hba->outstanding_lock, flags); - tr_doorbell = ufshcd_readl(hba, REG_UTP_TRANSFER_REQ_DOOR_BELL); - completed_reqs = ~tr_doorbell & hba->outstanding_reqs; - WARN_ONCE(completed_reqs & ~hba->outstanding_reqs, - "completed: %#lx; outstanding: %#lx\n", completed_reqs, - hba->outstanding_reqs); - hba->outstanding_reqs &= ~completed_reqs; - spin_unlock_irqrestore(&hba->outstanding_lock, flags); - - if (completed_reqs) { - __ufshcd_transfer_req_compl(hba, completed_reqs); - return IRQ_HANDLED; - } else { - return IRQ_NONE; - } + return ufshcd_poll(hba->host, 0) ? IRQ_HANDLED : IRQ_NONE; } int __ufshcd_write_ee_control(struct ufs_hba *hba, u32 ee_ctrl_mask) @@ -8112,6 +8120,7 @@ static struct scsi_host_template ufshcd_driver_template = { .name = UFSHCD, .proc_name = UFSHCD, .queuecommand = ufshcd_queuecommand, + .mq_poll = ufshcd_poll, .slave_alloc = ufshcd_slave_alloc, .slave_configure = ufshcd_slave_configure, .slave_destroy = ufshcd_slave_destroy,