diff mbox series

[v2,2/2] scsi: ufs: core: Introduce a new clock_scaling lock

Message ID 20241029102938.685835-3-avri.altman@wdc.com
State New
Headers show
Series Untie the host lock entanglement - part 2 | expand

Commit Message

Avri Altman Oct. 29, 2024, 10:29 a.m. UTC 
Introduce a new clock scaling lock to serialize access to some of the
clock scaling members instead of the host_lock. here also, simplify the
code with the guard() macro and co.

Signed-off-by: Avri Altman <avri.altman@wdc.com>
---
 drivers/ufs/core/ufshcd.c | 126 +++++++++++++++++---------------------
 include/ufs/ufshcd.h      |  16 +++--
 2 files changed, 65 insertions(+), 77 deletions(-)

Comments

Bart Van Assche Oct. 29, 2024, 7:19 p.m. UTC | #1 
On 10/29/24 3:29 AM, Avri Altman wrote:
> Introduce a new clock scaling lock to serialize access to some of the
> clock scaling members instead of the host_lock. here also, simplify the
> code with the guard() macro and co.

This patch looks fine to me, hence:

Reviewed-by: Bart Van Assche <bvanassche@acm.org>
diff mbox series

Patch

diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index 3373debe7b94..e574910adba5 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -1447,16 +1447,14 @@  static void ufshcd_clk_scaling_suspend_work(struct work_struct *work)
 {
 	struct ufs_hba *hba = container_of(work, struct ufs_hba,
 					   clk_scaling.suspend_work);
-	unsigned long irq_flags;
 
-	spin_lock_irqsave(hba->host->host_lock, irq_flags);
-	if (hba->clk_scaling.active_reqs || hba->clk_scaling.is_suspended) {
-		spin_unlock_irqrestore(hba->host->host_lock, irq_flags);
-		return;
+	scoped_guard(spinlock_irqsave, &hba->clk_scaling.lock) {
+		if (hba->clk_scaling.active_reqs || hba->clk_scaling.is_suspended)
+			return;
+
+		hba->clk_scaling.is_suspended = true;
+		hba->clk_scaling.window_start_t = 0;
 	}
-	hba->clk_scaling.is_suspended = true;
-	hba->clk_scaling.window_start_t = 0;
-	spin_unlock_irqrestore(hba->host->host_lock, irq_flags);
 
 	devfreq_suspend_device(hba->devfreq);
 }
@@ -1465,15 +1463,12 @@  static void ufshcd_clk_scaling_resume_work(struct work_struct *work)
 {
 	struct ufs_hba *hba = container_of(work, struct ufs_hba,
 					   clk_scaling.resume_work);
-	unsigned long irq_flags;
 
-	spin_lock_irqsave(hba->host->host_lock, irq_flags);
-	if (!hba->clk_scaling.is_suspended) {
-		spin_unlock_irqrestore(hba->host->host_lock, irq_flags);
-		return;
+	scoped_guard(spinlock_irqsave, &hba->clk_scaling.lock) {
+		if (!hba->clk_scaling.is_suspended)
+			return;
+		hba->clk_scaling.is_suspended = false;
 	}
-	hba->clk_scaling.is_suspended = false;
-	spin_unlock_irqrestore(hba->host->host_lock, irq_flags);
 
 	devfreq_resume_device(hba->devfreq);
 }
@@ -1487,7 +1482,6 @@  static int ufshcd_devfreq_target(struct device *dev,
 	bool scale_up = false, sched_clk_scaling_suspend_work = false;
 	struct list_head *clk_list = &hba->clk_list_head;
 	struct ufs_clk_info *clki;
-	unsigned long irq_flags;
 
 	if (!ufshcd_is_clkscaling_supported(hba))
 		return -EINVAL;
@@ -1508,43 +1502,37 @@  static int ufshcd_devfreq_target(struct device *dev,
 		*freq =	(unsigned long) clk_round_rate(clki->clk, *freq);
 	}
 
-	spin_lock_irqsave(hba->host->host_lock, irq_flags);
-	if (ufshcd_eh_in_progress(hba)) {
-		spin_unlock_irqrestore(hba->host->host_lock, irq_flags);
-		return 0;
-	}
+	scoped_guard(spinlock_irqsave, &hba->clk_scaling.lock) {
+		if (ufshcd_eh_in_progress(hba))
+			return 0;
 
-	/* Skip scaling clock when clock scaling is suspended */
-	if (hba->clk_scaling.is_suspended) {
-		spin_unlock_irqrestore(hba->host->host_lock, irq_flags);
-		dev_warn(hba->dev, "clock scaling is suspended, skip");
-		return 0;
-	}
+		/* Skip scaling clock when clock scaling is suspended */
+		if (hba->clk_scaling.is_suspended) {
+			dev_warn(hba->dev, "clock scaling is suspended, skip");
+			return 0;
+		}
 
-	if (!hba->clk_scaling.active_reqs)
-		sched_clk_scaling_suspend_work = true;
+		if (!hba->clk_scaling.active_reqs)
+			sched_clk_scaling_suspend_work = true;
 
-	if (list_empty(clk_list)) {
-		spin_unlock_irqrestore(hba->host->host_lock, irq_flags);
-		goto out;
-	}
+		if (list_empty(clk_list))
+			goto out;
 
-	/* Decide based on the target or rounded-off frequency and update */
-	if (hba->use_pm_opp)
-		scale_up = *freq > hba->clk_scaling.target_freq;
-	else
-		scale_up = *freq == clki->max_freq;
+		/* Decide based on the target or rounded-off frequency and update */
+		if (hba->use_pm_opp)
+			scale_up = *freq > hba->clk_scaling.target_freq;
+		else
+			scale_up = *freq == clki->max_freq;
 
-	if (!hba->use_pm_opp && !scale_up)
-		*freq = clki->min_freq;
+		if (!hba->use_pm_opp && !scale_up)
+			*freq = clki->min_freq;
 
-	/* Update the frequency */
-	if (!ufshcd_is_devfreq_scaling_required(hba, *freq, scale_up)) {
-		spin_unlock_irqrestore(hba->host->host_lock, irq_flags);
-		ret = 0;
-		goto out; /* no state change required */
+		/* Update the frequency */
+		if (!ufshcd_is_devfreq_scaling_required(hba, *freq, scale_up)) {
+			ret = 0;
+			goto out; /* no state change required */
+		}
 	}
-	spin_unlock_irqrestore(hba->host->host_lock, irq_flags);
 
 	start = ktime_get();
 	ret = ufshcd_devfreq_scale(hba, *freq, scale_up);
@@ -1569,7 +1557,6 @@  static int ufshcd_devfreq_get_dev_status(struct device *dev,
 {
 	struct ufs_hba *hba = dev_get_drvdata(dev);
 	struct ufs_clk_scaling *scaling = &hba->clk_scaling;
-	unsigned long flags;
 	ktime_t curr_t;
 
 	if (!ufshcd_is_clkscaling_supported(hba))
@@ -1577,7 +1564,8 @@  static int ufshcd_devfreq_get_dev_status(struct device *dev,
 
 	memset(stat, 0, sizeof(*stat));
 
-	spin_lock_irqsave(hba->host->host_lock, flags);
+	guard(spinlock_irqsave)(&hba->clk_scaling.lock);
+
 	curr_t = ktime_get();
 	if (!scaling->window_start_t)
 		goto start_window;
@@ -1613,7 +1601,7 @@  static int ufshcd_devfreq_get_dev_status(struct device *dev,
 		scaling->busy_start_t = 0;
 		scaling->is_busy_started = false;
 	}
-	spin_unlock_irqrestore(hba->host->host_lock, flags);
+
 	return 0;
 }
 
@@ -1677,19 +1665,18 @@  static void ufshcd_devfreq_remove(struct ufs_hba *hba)
 
 static void ufshcd_suspend_clkscaling(struct ufs_hba *hba)
 {
-	unsigned long flags;
 	bool suspend = false;
 
 	cancel_work_sync(&hba->clk_scaling.suspend_work);
 	cancel_work_sync(&hba->clk_scaling.resume_work);
 
-	spin_lock_irqsave(hba->host->host_lock, flags);
-	if (!hba->clk_scaling.is_suspended) {
-		suspend = true;
-		hba->clk_scaling.is_suspended = true;
-		hba->clk_scaling.window_start_t = 0;
+	scoped_guard(spinlock_irqsave, &hba->clk_scaling.lock) {
+		if (!hba->clk_scaling.is_suspended) {
+			suspend = true;
+			hba->clk_scaling.is_suspended = true;
+			hba->clk_scaling.window_start_t = 0;
+		}
 	}
-	spin_unlock_irqrestore(hba->host->host_lock, flags);
 
 	if (suspend)
 		devfreq_suspend_device(hba->devfreq);
@@ -1697,15 +1684,14 @@  static void ufshcd_suspend_clkscaling(struct ufs_hba *hba)
 
 static void ufshcd_resume_clkscaling(struct ufs_hba *hba)
 {
-	unsigned long flags;
 	bool resume = false;
 
-	spin_lock_irqsave(hba->host->host_lock, flags);
-	if (hba->clk_scaling.is_suspended) {
-		resume = true;
-		hba->clk_scaling.is_suspended = false;
+	scoped_guard(spinlock_irqsave, &hba->clk_scaling.lock) {
+		if (hba->clk_scaling.is_suspended) {
+			resume = true;
+			hba->clk_scaling.is_suspended = false;
+		}
 	}
-	spin_unlock_irqrestore(hba->host->host_lock, flags);
 
 	if (resume)
 		devfreq_resume_device(hba->devfreq);
@@ -1791,6 +1777,8 @@  static void ufshcd_init_clk_scaling(struct ufs_hba *hba)
 	INIT_WORK(&hba->clk_scaling.resume_work,
 		  ufshcd_clk_scaling_resume_work);
 
+	spin_lock_init(&hba->clk_scaling.lock);
+
 	hba->clk_scaling.workq = alloc_ordered_workqueue(
 		"ufs_clkscaling_%d", WQ_MEM_RECLAIM, hba->host->host_no);
 
@@ -2139,19 +2127,17 @@  static void ufshcd_clk_scaling_start_busy(struct ufs_hba *hba)
 {
 	bool queue_resume_work = false;
 	ktime_t curr_t = ktime_get();
-	unsigned long flags;
 
 	if (!ufshcd_is_clkscaling_supported(hba))
 		return;
 
-	spin_lock_irqsave(hba->host->host_lock, flags);
+	guard(spinlock_irqsave)(&hba->clk_scaling.lock);
+
 	if (!hba->clk_scaling.active_reqs++)
 		queue_resume_work = true;
 
-	if (!hba->clk_scaling.is_enabled || hba->pm_op_in_progress) {
-		spin_unlock_irqrestore(hba->host->host_lock, flags);
+	if (!hba->clk_scaling.is_enabled || hba->pm_op_in_progress)
 		return;
-	}
 
 	if (queue_resume_work)
 		queue_work(hba->clk_scaling.workq,
@@ -2167,18 +2153,17 @@  static void ufshcd_clk_scaling_start_busy(struct ufs_hba *hba)
 		hba->clk_scaling.busy_start_t = curr_t;
 		hba->clk_scaling.is_busy_started = true;
 	}
-	spin_unlock_irqrestore(hba->host->host_lock, flags);
 }
 
 static void ufshcd_clk_scaling_update_busy(struct ufs_hba *hba)
 {
 	struct ufs_clk_scaling *scaling = &hba->clk_scaling;
-	unsigned long flags;
 
 	if (!ufshcd_is_clkscaling_supported(hba))
 		return;
 
-	spin_lock_irqsave(hba->host->host_lock, flags);
+	guard(spinlock_irqsave)(&hba->clk_scaling.lock);
+
 	hba->clk_scaling.active_reqs--;
 	if (!scaling->active_reqs && scaling->is_busy_started) {
 		scaling->tot_busy_t += ktime_to_us(ktime_sub(ktime_get(),
@@ -2186,7 +2171,6 @@  static void ufshcd_clk_scaling_update_busy(struct ufs_hba *hba)
 		scaling->busy_start_t = 0;
 		scaling->is_busy_started = false;
 	}
-	spin_unlock_irqrestore(hba->host->host_lock, flags);
 }
 
 static inline int ufshcd_monitor_opcode2dir(u8 opcode)
diff --git a/include/ufs/ufshcd.h b/include/ufs/ufshcd.h
index 3d42532efbd1..1125b260aef9 100644
--- a/include/ufs/ufshcd.h
+++ b/include/ufs/ufshcd.h
@@ -434,6 +434,10 @@  struct ufs_clk_gating {
 
 /**
  * struct ufs_clk_scaling - UFS clock scaling related data
+ * @workq: workqueue to schedule devfreq suspend/resume work
+ * @suspend_work: worker to suspend devfreq
+ * @resume_work: worker to resume devfreq
+ * @lock: serialize access to some struct ufs_clk_scaling members
  * @active_reqs: number of requests that are pending. If this is zero when
  * devfreq ->target() function is called then schedule "suspend_work" to
  * suspend devfreq.
@@ -443,9 +447,6 @@  struct ufs_clk_gating {
  * @enable_attr: sysfs attribute to enable/disable clock scaling
  * @saved_pwr_info: UFS power mode may also be changed during scaling and this
  * one keeps track of previous power mode.
- * @workq: workqueue to schedule devfreq suspend/resume work
- * @suspend_work: worker to suspend devfreq
- * @resume_work: worker to resume devfreq
  * @target_freq: frequency requested by devfreq framework
  * @min_gear: lowest HS gear to scale down to
  * @is_enabled: tracks if scaling is currently enabled or not, controlled by
@@ -457,15 +458,18 @@  struct ufs_clk_gating {
  * @is_suspended: tracks if devfreq is suspended or not
  */
 struct ufs_clk_scaling {
+	struct workqueue_struct *workq;
+	struct work_struct suspend_work;
+	struct work_struct resume_work;
+
+	spinlock_t lock;
+
 	int active_reqs;
 	unsigned long tot_busy_t;
 	ktime_t window_start_t;
 	ktime_t busy_start_t;
 	struct device_attribute enable_attr;
 	struct ufs_pa_layer_attr saved_pwr_info;
-	struct workqueue_struct *workq;
-	struct work_struct suspend_work;
-	struct work_struct resume_work;
 	unsigned long target_freq;
 	u32 min_gear;
 	bool is_enabled;