From patchwork Thu Oct 31 22:55:26 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bart Van Assche X-Patchwork-Id: 11222047 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 5A86A913 for ; Thu, 31 Oct 2019 22:55:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 38FA520873 for ; Thu, 31 Oct 2019 22:55:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728389AbfJaWzj (ORCPT ); Thu, 31 Oct 2019 18:55:39 -0400 Received: from mail-pg1-f194.google.com ([209.85.215.194]:45676 "EHLO mail-pg1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728207AbfJaWzi (ORCPT ); Thu, 31 Oct 2019 18:55:38 -0400 Received: by mail-pg1-f194.google.com with SMTP id r1so5076161pgj.12 for ; Thu, 31 Oct 2019 15:55:37 -0700 (PDT) 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=EEOV50IZRPg32q0FSFfXKmFxs3kNH9cfwbJA85sPBQk=; b=FrpdeyN6Y8dRplfM3tyjLqXc/9cwu3n8QCrP1OK68ni+eQEgNiowzrpzNUPl0dSRnN xTQ/eNi9fvCzfrFmoFm0b9W5ep3dN5N6crONROS3Tp8UNk4j6Z2k43kXvXYXQTbcGIsL ZN4d1+eIvEVut5XAAdG7nEqbvj8PH+l7NNN4sa2K+iQjAfcoiKSnvq6gJJqHtngYYzoD 15u+/mDtSzh3DTAfYw+n/Akkz363r5rEYh9jMaU6Mwf3jcgCPgNz81qS7XabmSj17QXS mK2KUQfd9lpYsOKTp0i3oIF4JxsNSV68xw3Db5tmZLl74v3r4RrDOfKp/Khi4/k6fiO2 tZwg== X-Gm-Message-State: APjAAAXDskYt2in1KHodoAE1KokuGaH0CgG2vy1UNbZZts1prYZM5y+3 TTCTd802ySnrebubG9gqZQM= X-Google-Smtp-Source: APXvYqyO0CRrcbVI5rY8t7goof3GiwmMRcCp/nuJrcRhDL7BV+C/FwbXdUDZOfOyumwVOV3mrbGetw== X-Received: by 2002:a17:90a:26c1:: with SMTP id m59mr10883959pje.101.1572562537216; Thu, 31 Oct 2019 15:55:37 -0700 (PDT) Received: from desktop-bart.svl.corp.google.com ([2620:15c:2cd:202:4308:52a3:24b6:2c60]) by smtp.gmail.com with ESMTPSA id d139sm8391711pfd.162.2019.10.31.15.55.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 31 Oct 2019 15:55:36 -0700 (PDT) From: Bart Van Assche To: "Martin K . Petersen" , "James E . J . Bottomley" Cc: linux-scsi@vger.kernel.org, Christoph Hellwig , Bart Van Assche , Yaniv Gardi , Subhash Jadavani , Stanley Chu , Avri Altman , Tomas Winkler Subject: [PATCH 2/4] ufs: Simplify the clock scaling mechanism implementation Date: Thu, 31 Oct 2019 15:55:26 -0700 Message-Id: <20191031225528.233895-3-bvanassche@acm.org> X-Mailer: git-send-email 2.24.0.rc0.303.g954a862665-goog In-Reply-To: <20191031225528.233895-1-bvanassche@acm.org> References: <20191031225528.233895-1-bvanassche@acm.org> MIME-Version: 1.0 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. Cc: Yaniv Gardi Cc: Subhash Jadavani Cc: Stanley Chu Cc: Avri Altman Cc: Tomas Winkler Signed-off-by: Bart Van Assche --- drivers/scsi/ufs/ufshcd.c | 131 ++++++++++++-------------------------- drivers/scsi/ufs/ufshcd.h | 3 - 2 files changed, 40 insertions(+), 94 deletions(-) diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index da9677fb2d5d..b7e27d86a0ec 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -292,14 +292,46 @@ static inline void ufshcd_disable_irq(struct ufs_hba *hba) static void ufshcd_scsi_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->tag_alloc_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_scsi_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; + bool success = true; + + if (timeout == ULONG_MAX) { + shost_for_each_device(sdev, hba->host) + blk_mq_freeze_queue(sdev->request_queue); + blk_mq_freeze_queue(hba->tag_alloc_queue); + return 0; + } + + shost_for_each_device(sdev, hba->host) + blk_freeze_queue_start(sdev->request_queue); + blk_freeze_queue_start(hba->tag_alloc_queue); + if (blk_mq_freeze_queue_wait_timeout(hba->tag_alloc_queue, + max_t(long, 0, deadline - jiffies)) <= 0) + goto err; + shost_for_each_device(sdev, hba->host) { + if (blk_mq_freeze_queue_wait_timeout(sdev->request_queue, + max_t(long, 0, deadline - jiffies)) <= 0) { + success = false; + break; + } + } + if (!success) { +err: + ufshcd_scsi_unblock_requests(hba); + return -ETIMEDOUT; + } + return 0; } static void ufshcd_add_cmd_upiu_trace(struct ufs_hba *hba, unsigned int tag, @@ -1005,65 +1037,6 @@ 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 @@ -1113,26 +1086,15 @@ 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_scsi_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); } @@ -1562,7 +1524,7 @@ int ufshcd_hold(struct ufs_hba *hba, bool async) */ /* fallthrough */ case CLKS_OFF: - ufshcd_scsi_block_requests(hba); + ufshcd_scsi_block_requests(hba, ULONG_MAX); hba->clk_gating.state = REQ_CLKS_ON; trace_ufshcd_clk_gating(dev_name(hba->dev), hba->clk_gating.state); @@ -2428,9 +2390,6 @@ 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: @@ -2495,7 +2454,6 @@ 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; } @@ -2649,8 +2607,6 @@ 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, @@ -2684,7 +2640,6 @@ 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; } @@ -5483,7 +5438,7 @@ 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); + ufshcd_scsi_block_requests(hba, ULONG_MAX); hba->ufshcd_state = UFSHCD_STATE_EH_SCHEDULED; @@ -5760,8 +5715,6 @@ 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_IN, 0); if (IS_ERR(req)) return PTR_ERR(req); @@ -5840,7 +5793,6 @@ static int ufshcd_issue_devman_upiu_cmd(struct ufs_hba *hba, } blk_put_request(req); - up_read(&hba->clk_scaling_lock); return err; } @@ -8320,8 +8272,6 @@ 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); @@ -8387,7 +8337,6 @@ 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 8fa33fb71237..fd88a9de3519 100644 --- a/drivers/scsi/ufs/ufshcd.h +++ b/drivers/scsi/ufs/ufshcd.h @@ -522,7 +522,6 @@ 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; @@ -728,9 +727,7 @@ 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;