From patchwork Wed Dec 9 06:58:19 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Can Guo X-Patchwork-Id: 11960631 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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 C64E6C4167B for ; Wed, 9 Dec 2020 07:00:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 949D323A5A for ; Wed, 9 Dec 2020 07:00:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728317AbgLIG7P (ORCPT ); Wed, 9 Dec 2020 01:59:15 -0500 Received: from labrats.qualcomm.com ([199.106.110.90]:3997 "EHLO labrats.qualcomm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728268AbgLIG7O (ORCPT ); Wed, 9 Dec 2020 01:59:14 -0500 IronPort-SDR: GnzSheHhUoKHu791sEvuPm8RzrIShCt1vITB3NHuMYlhK6e0Nr95zOtaRSM2cpfNKtHI/6vQwo iHiTlnDYjIV11aqpuNNo72qNyBpY15dMoevWkpSvAAR/pwNad25WrFOyas6K21rGx+riKUwYHp qbKuDAOJHMGiu7/zdMkofj0ekaln1jgFGRLDmTHrxFApICnTShrcvDp8LXlS4rFbu8637mdjv6 duLb+I5vPAYA9qUDz0f7RU9J0Ty4dOk1Otl+lAK3wezP42W3Qc6yhXsQbrKqaHFDewP41llCrm Lbs= X-IronPort-AV: E=Sophos;i="5.78,404,1599548400"; d="scan'208";a="29331281" Received: from unknown (HELO ironmsg02-sd.qualcomm.com) ([10.53.140.142]) by labrats.qualcomm.com with ESMTP; 08 Dec 2020 22:58:29 -0800 X-QCInternal: smtphost Received: from wsp769891wss.qualcomm.com (HELO stor-presley.qualcomm.com) ([192.168.140.85]) by ironmsg02-sd.qualcomm.com with ESMTP; 08 Dec 2020 22:58:28 -0800 Received: by stor-presley.qualcomm.com (Postfix, from userid 359480) id 5FD51212AC; Tue, 8 Dec 2020 22:58:28 -0800 (PST) From: Can Guo To: asutoshd@codeaurora.org, nguyenb@codeaurora.org, hongwus@codeaurora.org, rnayak@codeaurora.org, linux-scsi@vger.kernel.org, kernel-team@android.com, saravanak@google.com, salyzyn@google.com, cang@codeaurora.org Cc: Alim Akhtar , Avri Altman , "James E.J. Bottomley" , "Martin K. Petersen" , Stanley Chu , Bean Huo , Bart Van Assche , Satya Tangirala , linux-kernel@vger.kernel.org (open list) Subject: [PATCH v1 1/2] scsi: ufs: Protect some contexts from unexpected clock scaling Date: Tue, 8 Dec 2020 22:58:19 -0800 Message-Id: <1607497100-27570-2-git-send-email-cang@codeaurora.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1607497100-27570-1-git-send-email-cang@codeaurora.org> References: <1607497100-27570-1-git-send-email-cang@codeaurora.org> Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org In contexts like suspend, shutdown and error handling, we need to suspend devfreq to make sure these contexts won't be disturbed by clock scaling. However, suspending devfreq is not enough since users can still trigger a clock scaling by manipulating the sysfs node clkscale_enable and devfreq sysfs nodes like min/max_freq and governor. Add one more flag in struct clk_scaling such that these contexts can prevent clock scaling from being invoked through above sysfs nodes. Signed-off-by: Can Guo --- drivers/scsi/ufs/ufshcd.c | 86 ++++++++++++++++++++++++++++------------------- drivers/scsi/ufs/ufshcd.h | 2 ++ 2 files changed, 53 insertions(+), 35 deletions(-) diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index 0c148fc..12266bd 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -1147,12 +1147,18 @@ static int ufshcd_clock_scaling_prepare(struct ufs_hba *hba) */ ufshcd_scsi_block_requests(hba); down_write(&hba->clk_scaling_lock); - if (ufshcd_wait_for_doorbell_clr(hba, DOORBELL_CLR_TOUT_US)) { + if (!hba->clk_scaling.is_allowed || + ufshcd_wait_for_doorbell_clr(hba, DOORBELL_CLR_TOUT_US)) { ret = -EBUSY; up_write(&hba->clk_scaling_lock); ufshcd_scsi_unblock_requests(hba); + goto out; } + /* let's not get into low power until clock scaling is completed */ + ufshcd_hold(hba, false); + +out: return ret; } @@ -1160,6 +1166,7 @@ static void ufshcd_clock_scaling_unprepare(struct ufs_hba *hba) { up_write(&hba->clk_scaling_lock); ufshcd_scsi_unblock_requests(hba); + ufshcd_release(hba); } /** @@ -1175,12 +1182,9 @@ static int ufshcd_devfreq_scale(struct ufs_hba *hba, bool scale_up) { int ret = 0; - /* let's not get into low power until clock scaling is completed */ - ufshcd_hold(hba, false); - ret = ufshcd_clock_scaling_prepare(hba); if (ret) - goto out; + return ret; /* scale down the gear before scaling down clocks */ if (!scale_up) { @@ -1212,8 +1216,6 @@ static int ufshcd_devfreq_scale(struct ufs_hba *hba, bool scale_up) out_unprepare: ufshcd_clock_scaling_unprepare(hba); -out: - ufshcd_release(hba); return ret; } @@ -1294,15 +1296,8 @@ static int ufshcd_devfreq_target(struct device *dev, } spin_unlock_irqrestore(hba->host->host_lock, irq_flags); - pm_runtime_get_noresume(hba->dev); - if (!pm_runtime_active(hba->dev)) { - pm_runtime_put_noidle(hba->dev); - ret = -EAGAIN; - goto out; - } start = ktime_get(); ret = ufshcd_devfreq_scale(hba, scale_up); - pm_runtime_put(hba->dev); trace_ufshcd_profile_clk_scaling(dev_name(hba->dev), (scale_up ? "up" : "down"), @@ -1487,7 +1482,7 @@ static ssize_t ufshcd_clkscale_enable_show(struct device *dev, { struct ufs_hba *hba = dev_get_drvdata(dev); - return snprintf(buf, PAGE_SIZE, "%d\n", hba->clk_scaling.is_allowed); + return snprintf(buf, PAGE_SIZE, "%d\n", hba->clk_scaling.is_enabled); } static ssize_t ufshcd_clkscale_enable_store(struct device *dev, @@ -1496,12 +1491,20 @@ static ssize_t ufshcd_clkscale_enable_store(struct device *dev, struct ufs_hba *hba = dev_get_drvdata(dev); u32 value; int err; + unsigned long flags; + bool update = true; if (kstrtou32(buf, 0, &value)) return -EINVAL; value = !!value; - if (value == hba->clk_scaling.is_allowed) + spin_lock_irqsave(hba->host->host_lock, flags); + if (value == hba->clk_scaling.is_enabled) + update = false; + else + hba->clk_scaling.is_enabled = value; + spin_unlock_irqrestore(hba->host->host_lock, flags); + if (!update) goto out; pm_runtime_get_sync(hba->dev); @@ -1510,8 +1513,6 @@ static ssize_t ufshcd_clkscale_enable_store(struct device *dev, cancel_work_sync(&hba->clk_scaling.suspend_work); cancel_work_sync(&hba->clk_scaling.resume_work); - hba->clk_scaling.is_allowed = value; - if (value) { ufshcd_resume_clkscaling(hba); } else { @@ -1845,8 +1846,6 @@ static void ufshcd_init_clk_scaling(struct ufs_hba *hba) snprintf(wq_name, sizeof(wq_name), "ufs_clkscaling_%d", hba->host->host_no); hba->clk_scaling.workq = create_singlethread_workqueue(wq_name); - - ufshcd_clkscaling_init_sysfs(hba); } static void ufshcd_exit_clk_scaling(struct ufs_hba *hba) @@ -1854,6 +1853,8 @@ static void ufshcd_exit_clk_scaling(struct ufs_hba *hba) if (!ufshcd_is_clkscaling_supported(hba)) return; + if (hba->devfreq) + device_remove_file(hba->dev, &hba->clk_scaling.enable_attr); destroy_workqueue(hba->clk_scaling.workq); ufshcd_devfreq_remove(hba); } @@ -1918,7 +1919,7 @@ static void ufshcd_clk_scaling_start_busy(struct ufs_hba *hba) if (!hba->clk_scaling.active_reqs++) queue_resume_work = true; - if (!hba->clk_scaling.is_allowed || hba->pm_op_in_progress) + if (!hba->clk_scaling.is_enabled || hba->pm_op_in_progress) return; if (queue_resume_work) @@ -4987,7 +4988,8 @@ static void __ufshcd_transfer_req_compl(struct ufs_hba *hba, complete(hba->dev_cmd.complete); } } - if (ufshcd_is_clkscaling_supported(hba)) + if (ufshcd_is_clkscaling_supported(hba) && + hba->clk_scaling.active_reqs > 0) hba->clk_scaling.active_reqs--; } @@ -5650,18 +5652,25 @@ static void ufshcd_err_handling_prepare(struct ufs_hba *hba) ufshcd_vops_resume(hba, UFS_RUNTIME_PM); } else { ufshcd_hold(hba, false); - if (hba->clk_scaling.is_allowed) { + if (hba->clk_scaling.is_enabled) { cancel_work_sync(&hba->clk_scaling.suspend_work); cancel_work_sync(&hba->clk_scaling.resume_work); ufshcd_suspend_clkscaling(hba); } } + down_write(&hba->clk_scaling_lock); + hba->clk_scaling.is_allowed = false; + up_write(&hba->clk_scaling_lock); } static void ufshcd_err_handling_unprepare(struct ufs_hba *hba) { ufshcd_release(hba); - if (hba->clk_scaling.is_allowed) + + down_write(&hba->clk_scaling_lock); + hba->clk_scaling.is_allowed = true; + up_write(&hba->clk_scaling_lock); + if (hba->clk_scaling.is_enabled) ufshcd_resume_clkscaling(hba); pm_runtime_put(hba->dev); } @@ -7620,12 +7629,14 @@ static int ufshcd_add_lus(struct ufs_hba *hba) sizeof(struct ufs_pa_layer_attr)); hba->clk_scaling.saved_pwr_info.is_valid = true; if (!hba->devfreq) { + hba->clk_scaling.is_allowed = true; ret = ufshcd_devfreq_init(hba); if (ret) goto out; - } - hba->clk_scaling.is_allowed = true; + hba->clk_scaling.is_enabled = true; + ufshcd_clkscaling_init_sysfs(hba); + } } ufs_bsg_probe(hba); @@ -8491,11 +8502,14 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op) ufshcd_hold(hba, false); hba->clk_gating.is_suspended = true; - if (hba->clk_scaling.is_allowed) { + if (hba->clk_scaling.is_enabled) { cancel_work_sync(&hba->clk_scaling.suspend_work); cancel_work_sync(&hba->clk_scaling.resume_work); ufshcd_suspend_clkscaling(hba); } + down_write(&hba->clk_scaling_lock); + hba->clk_scaling.is_allowed = false; + up_write(&hba->clk_scaling_lock); if (req_dev_pwr_mode == UFS_ACTIVE_PWR_MODE && req_link_state == UIC_LINK_ACTIVE_STATE) { @@ -8592,8 +8606,6 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op) goto out; set_link_active: - if (hba->clk_scaling.is_allowed) - ufshcd_resume_clkscaling(hba); ufshcd_vreg_set_hpm(hba); if (ufshcd_is_link_hibern8(hba) && !ufshcd_uic_hibern8_exit(hba)) ufshcd_set_link_active(hba); @@ -8603,7 +8615,10 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op) if (!ufshcd_set_dev_pwr_mode(hba, UFS_ACTIVE_PWR_MODE)) ufshcd_disable_auto_bkops(hba); enable_gating: - if (hba->clk_scaling.is_allowed) + down_write(&hba->clk_scaling_lock); + hba->clk_scaling.is_allowed = true; + up_write(&hba->clk_scaling_lock); + if (hba->clk_scaling.is_enabled) ufshcd_resume_clkscaling(hba); hba->clk_gating.is_suspended = false; hba->dev_info.b_rpm_dev_flush_capable = false; @@ -8701,7 +8716,10 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op) hba->clk_gating.is_suspended = false; - if (hba->clk_scaling.is_allowed) + down_write(&hba->clk_scaling_lock); + hba->clk_scaling.is_allowed = true; + up_write(&hba->clk_scaling_lock); + if (hba->clk_scaling.is_enabled) ufshcd_resume_clkscaling(hba); /* Enable Auto-Hibernate if configured */ @@ -8725,8 +8743,6 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op) ufshcd_vreg_set_lpm(hba); disable_irq_and_vops_clks: ufshcd_disable_irq(hba); - if (hba->clk_scaling.is_allowed) - ufshcd_suspend_clkscaling(hba); ufshcd_setup_clocks(hba, false); if (ufshcd_is_clkgating_allowed(hba)) { hba->clk_gating.state = CLKS_OFF; @@ -8915,6 +8931,8 @@ int ufshcd_shutdown(struct ufs_hba *hba) pm_runtime_get_sync(hba->dev); + ufshcd_exit_clk_scaling(hba); + ret = ufshcd_suspend(hba, UFS_SHUTDOWN_PM); out: if (ret) @@ -8944,8 +8962,6 @@ void ufshcd_remove(struct ufs_hba *hba) ufshcd_exit_clk_scaling(hba); ufshcd_exit_clk_gating(hba); - if (ufshcd_is_clkscaling_supported(hba)) - device_remove_file(hba->dev, &hba->clk_scaling.enable_attr); ufshcd_hba_exit(hba); } EXPORT_SYMBOL_GPL(ufshcd_remove); diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h index e0f00a4..9fcecba 100644 --- a/drivers/scsi/ufs/ufshcd.h +++ b/drivers/scsi/ufs/ufshcd.h @@ -382,6 +382,7 @@ struct ufs_saved_pwr_info { * @workq: workqueue to schedule devfreq suspend/resume work * @suspend_work: worker to suspend devfreq * @resume_work: worker to resume devfreq + * @is_enabled: tracks if scaling is currently enabled or not * @is_allowed: tracks if scaling is currently allowed or not * @is_busy_started: tracks if busy period has started or not * @is_suspended: tracks if devfreq is suspended or not @@ -396,6 +397,7 @@ struct ufs_clk_scaling { struct workqueue_struct *workq; struct work_struct suspend_work; struct work_struct resume_work; + bool is_enabled; bool is_allowed; bool is_busy_started; bool is_suspended;