Received: by 2002:a05:6a10:f347:0:0:0:0 with SMTP id d7csp3982253pxu; Wed, 9 Dec 2020 05:41:33 -0800 (PST) X-Google-Smtp-Source: ABdhPJyYG4bdUqSOXtDpDeyPldlF/l8gODLbmQfUsPxd9nwPsJ116JrA9mojY6+8k3V9gV+CGFxT X-Received: by 2002:a50:a6de:: with SMTP id f30mr2121156edc.30.1607521293127; Wed, 09 Dec 2020 05:41:33 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1607521293; cv=none; d=google.com; s=arc-20160816; b=hNFdlWBIx1yhVXxavPsvtHoTlTteE0+Cl312RWWDnQXp9DQmkkk/9veQ1bmoFbmG3K zElIjwR5b1QfstgG5SLnKCVYCMvjND8oecjXs5BgDgLfgJ+5BseF2cpHqEL4WbdSXfj6 HSG6HydM+/XbbDfo94vqtLtCyZLFPfGm1pZtU2/JMXAclTNxJCePMHr7RbpS0f/jcafQ dT2a6t7OT8VAODn9CLhr1ysRccmJYsEN4uSWOJ5ZraoWdmF31CVKUXlM5ZHxukP7ovSw WWOzF0/57elJSljqeVjDKplidYqNzEBTsoI+BZkclIW0SEkEdmK7W80veD4cz26EJcKC CnJQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:references:in-reply-to:message-id:date:subject :cc:to:from:ironport-sdr; bh=ME39BoMktcw1KySa7vubMp6u1VEG+HcVGWl/HI6qqtE=; b=H+UHvHKXoNv/bFfaPg9jjRb5SE5ddB3RHH0Pc+OCtzoX1oH6/2uYsJWRGajjUSH11b Ayugju2ozHGwALSTcXIKn1HzwjsmigN4c95f8qIzVClYPidCp9MnHZ0ArG3pdhGKKkt2 AVAKo4WTEcOR+FNHB0f0vnxdOWp92TPJPEy1HCuv9B/jL0gB7LwDBOIJAEcHpItpRncP 0bYsMQE8iHbXXlugK+mvD1zG5Mmt6rfpOv7I7iTArAcUcLwxtMBE3MyCjL8tSTmgq6IZ jB6AOhOLQUSKHYBsrMnvOaBQNbGeWUeXbJCR3Wik4ssR/2lsAP3RzjL8d85QQ4HswQzf n6DA== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id 93si856103edm.94.2020.12.09.05.41.10; Wed, 09 Dec 2020 05:41:33 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732477AbgLINgm (ORCPT + 99 others); Wed, 9 Dec 2020 08:36:42 -0500 Received: from labrats.qualcomm.com ([199.106.110.90]:9670 "EHLO labrats.qualcomm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732473AbgLINgk (ORCPT ); Wed, 9 Dec 2020 08:36:40 -0500 IronPort-SDR: EnG4cFkRdCAyiTvt2miaGM/ot+hX5hJegmxnpVdCCZ2r4zWGONdUypgCjYzi8+VN+F86AiHH86 Tz6mwOR4gf5MUhEcauNn5quod/7V3wimUNq4ONU9+VzSP8vkgF85RKACSSgbwPS2BIaxoxfSWy nNzuOhIqANO4MNxCSTEGzvlnzbHyK7xNajC8OrQY+Yml2orBXMvIeYjlCLc/xfX4oejq8zjJM6 2maX8DUdWX416RLwqqjN2zofuA/pyMozLUTa8g9gSXMj8lc9x6lvJJVo90Tl/h48z5GRJH/OpX ru0= X-IronPort-AV: E=Sophos;i="5.78,405,1599548400"; d="scan'208";a="47569735" Received: from unknown (HELO ironmsg-SD-alpha.qualcomm.com) ([10.53.140.30]) by labrats.qualcomm.com with ESMTP; 09 Dec 2020 05:35:51 -0800 X-QCInternal: smtphost Received: from wsp769891wss.qualcomm.com (HELO stor-presley.qualcomm.com) ([192.168.140.85]) by ironmsg-SD-alpha.qualcomm.com with ESMTP; 09 Dec 2020 05:35:49 -0800 Received: by stor-presley.qualcomm.com (Postfix, from userid 359480) id EBC6A21340; Wed, 9 Dec 2020 05:35:49 -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 1/2] scsi: ufs: Protect some contexts from unexpected clock scaling Date: Wed, 9 Dec 2020 05:35:40 -0800 Message-Id: <1607520942-22254-2-git-send-email-cang@codeaurora.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1607520942-22254-1-git-send-email-cang@codeaurora.org> References: <1607520942-22254-1-git-send-email-cang@codeaurora.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 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; -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project.