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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, 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 6F960C43331 for ; Tue, 12 Nov 2019 17:37:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 47997214E0 for ; Tue, 12 Nov 2019 17:37:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727068AbfKLRh6 (ORCPT ); Tue, 12 Nov 2019 12:37:58 -0500 Received: from mail-pg1-f195.google.com ([209.85.215.195]:40086 "EHLO mail-pg1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726912AbfKLRh5 (ORCPT ); Tue, 12 Nov 2019 12:37:57 -0500 Received: by mail-pg1-f195.google.com with SMTP id 15so12303415pgt.7 for ; Tue, 12 Nov 2019 09:37:57 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=RiRLRVszdgbsqnBw0pFkgvYhCnhFTFUd+1RCHFnT5+U=; b=m0ATz80zYPBdMM3TaElZ+V1rl8juPcXwXucpoDinQL2xjRi9lumftDU2Bau4vM0RaH ZTyxOFUYsbQfELSr6yqxGY5gw14AOF35s5Gt9X9SAJqeX94GY/Q9N111pZAI8jC4DDPd 1axk+Y5kWdKGcWy3BAjsPAaXJvmI109Ft6K2BBu/aO+5qrs/dwfClpZDSP2fVZ0DELfm 1Fl6Yhi8FZjCcNUAihr2zUvnJ1csiyWCpihLTkqTx7zPHcNEsnpDQbhyAwMwBP3GM2NO rUwvbeOWqA8rk63HHM6qweSxvhFqKgDFxzM03EPw5auF7E2SMowt+pNvTJCWnllPq9gx TBag== X-Gm-Message-State: APjAAAU7WGKKOFlFImb8ivadb858qLuuyrezChYCJ6UZOGxQYexztv8T 3LQsGGBFP1wiiR8hBbzzHY4= X-Google-Smtp-Source: APXvYqyBaKgrPv9tREd2bkCZHZ4yYnx9LJjKgN5fVVWRtWnlOLbvR6hoP/QBkM6XEQY/TFx+Kv9csw== X-Received: by 2002:a17:90a:d818:: with SMTP id a24mr7928574pjv.40.1573580276834; Tue, 12 Nov 2019 09:37:56 -0800 (PST) Received: from desktop-bart.svl.corp.google.com ([2620:15c:2cd:202:4308:52a3:24b6:2c60]) by smtp.gmail.com with ESMTPSA id w19sm12930969pga.83.2019.11.12.09.37.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 12 Nov 2019 09:37:56 -0800 (PST) From: Bart Van Assche To: "Martin K . Petersen" , "James E . J . Bottomley" Cc: Bean Huo , Avri Altman , Asutosh Das , Vignesh Raghavendra , Can Guo , linux-scsi@vger.kernel.org, Bart Van Assche , Stanley Chu , Tomas Winkler Subject: [PATCH v5 4/4] ufs: Simplify the clock scaling mechanism implementation Date: Tue, 12 Nov 2019 09:37:43 -0800 Message-Id: <20191112173743.141503-5-bvanassche@acm.org> X-Mailer: git-send-email 2.24.0.rc1.363.gb1bccd3e3d-goog In-Reply-To: <20191112173743.141503-1-bvanassche@acm.org> References: <20191112173743.141503-1-bvanassche@acm.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org Scaling the clock is only safe while no commands are in progress. Use blk_mq_{un,}freeze_queue() to block submission of new commands and to wait for ongoing commands to complete. Remove "_scsi" from the name of the functions that block and unblock requests since these functions now block both SCSI commands and non-SCSI commands. Cc: Bean Huo Cc: Avri Altman Cc: Stanley Chu Cc: Tomas Winkler Signed-off-by: Bart Van Assche --- drivers/scsi/ufs/ufshcd.c | 141 +++++++++++++------------------------- drivers/scsi/ufs/ufshcd.h | 3 - 2 files changed, 46 insertions(+), 98 deletions(-) diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index 810b997f55fc..717ba24a2d40 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -290,16 +290,50 @@ static inline void ufshcd_disable_irq(struct ufs_hba *hba) } } -static void ufshcd_scsi_unblock_requests(struct ufs_hba *hba) +static void ufshcd_unblock_requests(struct ufs_hba *hba) { - if (atomic_dec_and_test(&hba->scsi_block_reqs_cnt)) - scsi_unblock_requests(hba->host); + struct scsi_device *sdev; + + blk_mq_unfreeze_queue(hba->tmf_queue); + blk_mq_unfreeze_queue(hba->cmd_queue); + shost_for_each_device(sdev, hba->host) + blk_mq_unfreeze_queue(sdev->request_queue); } -static void ufshcd_scsi_block_requests(struct ufs_hba *hba) +static int ufshcd_block_requests(struct ufs_hba *hba, unsigned long timeout) { - if (atomic_inc_return(&hba->scsi_block_reqs_cnt) == 1) - scsi_block_requests(hba->host); + struct scsi_device *sdev; + unsigned long deadline = jiffies + timeout; + + if (timeout == ULONG_MAX) { + shost_for_each_device(sdev, hba->host) + blk_mq_freeze_queue(sdev->request_queue); + blk_mq_freeze_queue(hba->cmd_queue); + blk_mq_freeze_queue(hba->tmf_queue); + return 0; + } + + shost_for_each_device(sdev, hba->host) + blk_freeze_queue_start(sdev->request_queue); + blk_freeze_queue_start(hba->cmd_queue); + blk_freeze_queue_start(hba->tmf_queue); + shost_for_each_device(sdev, hba->host) { + if (blk_mq_freeze_queue_wait_timeout(sdev->request_queue, + max_t(long, 0, deadline - jiffies)) <= 0) { + goto err; + } + } + if (blk_mq_freeze_queue_wait_timeout(hba->cmd_queue, + max_t(long, 0, deadline - jiffies)) <= 0) + goto err; + if (blk_mq_freeze_queue_wait_timeout(hba->tmf_queue, + max_t(long, 0, deadline - jiffies)) <= 0) + goto err; + return 0; + +err: + ufshcd_unblock_requests(hba); + return -ETIMEDOUT; } static void ufshcd_add_cmd_upiu_trace(struct ufs_hba *hba, unsigned int tag, @@ -971,65 +1005,6 @@ static bool ufshcd_is_devfreq_scaling_required(struct ufs_hba *hba, return false; } -static int ufshcd_wait_for_doorbell_clr(struct ufs_hba *hba, - u64 wait_timeout_us) -{ - unsigned long flags; - int ret = 0; - u32 tm_doorbell; - u32 tr_doorbell; - bool timeout = false, do_last_check = false; - ktime_t start; - - ufshcd_hold(hba, false); - spin_lock_irqsave(hba->host->host_lock, flags); - /* - * Wait for all the outstanding tasks/transfer requests. - * Verify by checking the doorbell registers are clear. - */ - start = ktime_get(); - do { - if (hba->ufshcd_state != UFSHCD_STATE_OPERATIONAL) { - ret = -EBUSY; - goto out; - } - - tm_doorbell = ufshcd_readl(hba, REG_UTP_TASK_REQ_DOOR_BELL); - tr_doorbell = ufshcd_readl(hba, REG_UTP_TRANSFER_REQ_DOOR_BELL); - if (!tm_doorbell && !tr_doorbell) { - timeout = false; - break; - } else if (do_last_check) { - break; - } - - spin_unlock_irqrestore(hba->host->host_lock, flags); - schedule(); - if (ktime_to_us(ktime_sub(ktime_get(), start)) > - wait_timeout_us) { - timeout = true; - /* - * We might have scheduled out for long time so make - * sure to check if doorbells are cleared by this time - * or not. - */ - do_last_check = true; - } - spin_lock_irqsave(hba->host->host_lock, flags); - } while (tm_doorbell || tr_doorbell); - - if (timeout) { - dev_err(hba->dev, - "%s: timedout waiting for doorbell to clear (tm=0x%x, tr=0x%x)\n", - __func__, tm_doorbell, tr_doorbell); - ret = -EBUSY; - } -out: - spin_unlock_irqrestore(hba->host->host_lock, flags); - ufshcd_release(hba); - return ret; -} - /** * ufshcd_scale_gear - scale up/down UFS gear * @hba: per adapter instance @@ -1079,27 +1054,16 @@ static int ufshcd_scale_gear(struct ufs_hba *hba, bool scale_up) static int ufshcd_clock_scaling_prepare(struct ufs_hba *hba) { - #define DOORBELL_CLR_TOUT_US (1000 * 1000) /* 1 sec */ - int ret = 0; /* * make sure that there are no outstanding requests when * clock scaling is in progress */ - ufshcd_scsi_block_requests(hba); - down_write(&hba->clk_scaling_lock); - if (ufshcd_wait_for_doorbell_clr(hba, DOORBELL_CLR_TOUT_US)) { - ret = -EBUSY; - up_write(&hba->clk_scaling_lock); - ufshcd_scsi_unblock_requests(hba); - } - - return ret; + return ufshcd_block_requests(hba, HZ); } static void ufshcd_clock_scaling_unprepare(struct ufs_hba *hba) { - up_write(&hba->clk_scaling_lock); - ufshcd_scsi_unblock_requests(hba); + ufshcd_unblock_requests(hba); } /** @@ -1471,7 +1435,7 @@ static void ufshcd_ungate_work(struct work_struct *work) hba->clk_gating.is_suspended = false; } unblock_reqs: - ufshcd_scsi_unblock_requests(hba); + ufshcd_unblock_requests(hba); } /** @@ -1528,7 +1492,7 @@ int ufshcd_hold(struct ufs_hba *hba, bool async) */ /* fallthrough */ case CLKS_OFF: - ufshcd_scsi_block_requests(hba); + ufshcd_block_requests(hba, ULONG_MAX); hba->clk_gating.state = REQ_CLKS_ON; trace_ufshcd_clk_gating(dev_name(hba->dev), hba->clk_gating.state); @@ -2395,9 +2359,6 @@ static int ufshcd_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd) BUG(); } - if (!down_read_trylock(&hba->clk_scaling_lock)) - return SCSI_MLQUEUE_HOST_BUSY; - spin_lock_irqsave(hba->host->host_lock, flags); switch (hba->ufshcd_state) { case UFSHCD_STATE_OPERATIONAL: @@ -2463,7 +2424,6 @@ static int ufshcd_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd) out_unlock: spin_unlock_irqrestore(hba->host->host_lock, flags); out: - up_read(&hba->clk_scaling_lock); return err; } @@ -2617,8 +2577,6 @@ static int ufshcd_exec_dev_cmd(struct ufs_hba *hba, struct completion wait; unsigned long flags; - down_read(&hba->clk_scaling_lock); - /* * Get free slot, sleep if slots are unavailable. * Even though we use wait_event() which sleeps indefinitely, @@ -2654,7 +2612,6 @@ static int ufshcd_exec_dev_cmd(struct ufs_hba *hba, out_put_tag: blk_put_request(req); - up_read(&hba->clk_scaling_lock); return err; } @@ -5342,7 +5299,7 @@ static void ufshcd_err_handler(struct work_struct *work) spin_unlock_irqrestore(hba->host->host_lock, flags); if (starget) scsi_target_unblock(&starget->dev, SDEV_RUNNING); - ufshcd_scsi_unblock_requests(hba); + scsi_unblock_requests(hba->host); ufshcd_release(hba); pm_runtime_put_sync(hba->dev); } @@ -5466,7 +5423,7 @@ static void ufshcd_check_errors(struct ufs_hba *hba) /* handle fatal errors only when link is functional */ if (hba->ufshcd_state == UFSHCD_STATE_OPERATIONAL) { /* block commands from scsi mid-layer */ - ufshcd_scsi_block_requests(hba); + scsi_block_requests(hba->host); hba->ufshcd_state = UFSHCD_STATE_EH_SCHEDULED; @@ -5772,8 +5729,6 @@ static int ufshcd_issue_devman_upiu_cmd(struct ufs_hba *hba, unsigned long flags; u32 upiu_flags; - down_read(&hba->clk_scaling_lock); - req = blk_get_request(q, REQ_OP_DRV_OUT, 0); if (IS_ERR(req)) return PTR_ERR(req); @@ -5853,7 +5808,6 @@ static int ufshcd_issue_devman_upiu_cmd(struct ufs_hba *hba, } blk_put_request(req); - up_read(&hba->clk_scaling_lock); return err; } @@ -8322,8 +8276,6 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq) /* Initialize mutex for device management commands */ mutex_init(&hba->dev_cmd.lock); - init_rwsem(&hba->clk_scaling_lock); - ufshcd_init_clk_gating(hba); ufshcd_init_clk_scaling(hba); @@ -8410,7 +8362,6 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq) /* Hold auto suspend until async scan completes */ pm_runtime_get_sync(dev); - atomic_set(&hba->scsi_block_reqs_cnt, 0); /* * We are assuming that device wasn't put in sleep/power-down * state exclusively during the boot stage before kernel. diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h index 5865e16f53a6..c44bfcdb26a3 100644 --- a/drivers/scsi/ufs/ufshcd.h +++ b/drivers/scsi/ufs/ufshcd.h @@ -520,7 +520,6 @@ struct ufs_stats { * @urgent_bkops_lvl: keeps track of urgent bkops level for device * @is_urgent_bkops_lvl_checked: keeps track if the urgent bkops level for * device is known or not. - * @scsi_block_reqs_cnt: reference counting for scsi block requests */ struct ufs_hba { void __iomem *mmio_base; @@ -724,9 +723,7 @@ struct ufs_hba { enum bkops_status urgent_bkops_lvl; bool is_urgent_bkops_lvl_checked; - struct rw_semaphore clk_scaling_lock; struct ufs_desc_size desc_size; - atomic_t scsi_block_reqs_cnt; struct device bsg_dev; struct request_queue *bsg_queue;