diff mbox

[RESEND,v3,1/2] scsi: ufs: Use DEVICE_ATTR_RW macros and sdev_attrs structure

Message ID 20170726145503.15339-2-michalx.potomski@intel.com (mailing list archive)
State Deferred, archived
Headers show

Commit Message

Potomski, MichalX July 26, 2017, 2:55 p.m. UTC 
From: Michał Potomski <michalx.potomski@intel.com>

Previous implementation was obsolete and needed to be updated.
Additionally device_create_file() call occurs after a UFS device
has been made visible in sysfs and hence will cause trouble
(race condition) if a udev rule tries to set this attribute
from inside a rule that is triggered by device creation.

Signed-off-by: Michał Potomski <michalx.potomski@intel.com>
---
 drivers/scsi/ufs/ufshcd.c | 232 ++++++++++++++++++++--------------------------
 1 file changed, 103 insertions(+), 129 deletions(-)

Comments

Bart Van Assche July 26, 2017, 3:17 p.m. UTC | #1 
On Wed, 2017-07-26 at 16:55 +0200, Michal Potomski wrote:
> Previous implementation was obsolete and needed to be updated.
> Additionally device_create_file() call occurs after a UFS device
> has been made visible in sysfs and hence will cause trouble
> (race condition) if a udev rule tries to set this attribute
> from inside a rule that is triggered by device creation.

Hello Michal,

Thank you for having done this work!

> +static ssize_t rpm_lvl_show(struct device *dev,
> +		struct device_attribute *attr, char *buf)
> +{
> +	struct ufs_hba *hba = dev_get_drvdata(dev);
> +	int curr_len;
> +	u8 lvl;
> +
> +	curr_len = snprintf(buf, PAGE_SIZE,
> +			    "\nCurrent Runtime PM level [%d] => dev_state [%s] link_state [%s]\n",
> +			    hba->rpm_lvl,
> +			    ufschd_ufs_dev_pwr_mode_to_string(
> +				ufs_pm_lvl_states[hba->rpm_lvl].dev_state),
> +			    ufschd_uic_link_state_to_string(
> +				ufs_pm_lvl_states[hba->rpm_lvl].link_state));
> +
> +	curr_len += snprintf((buf + curr_len), (PAGE_SIZE - curr_len),
> +			     "\nAll available Runtime PM levels info:\n");
> +	for (lvl = UFS_PM_LVL_0; lvl < UFS_PM_LVL_MAX; lvl++)
> +		curr_len += snprintf((buf + curr_len), (PAGE_SIZE - curr_len),
> +				     "\tRuntime PM level [%d] => dev_state [%s] link_state [%s]\n",
> +				    lvl,
> +				    ufschd_ufs_dev_pwr_mode_to_string(
> +					ufs_pm_lvl_states[lvl].dev_state),
> +				    ufschd_uic_link_state_to_string(
> +					ufs_pm_lvl_states[lvl].link_state));
> +
> +	return curr_len;
> +}

I am aware that this code is existing code that has been moved up. But are
the UFS contributors aware that this kind of output violates the sysfs rules?
Please consider either to move this attribute to debugfs (the one value per
file rule only applies to sysfs and configfs) or to split it into multiple
sysfs attributes if that is possible without breaking existing user space
applications. A quote from
https://www.kernel.org/doc/Documentation/filesystems/sysfs.txt: "Attributes
should be ASCII text files, preferably with only one value per file. It is
noted that it may not be efficient to contain only one value per file, so it
is socially acceptable to express an array of values of the same type."

Anyway, since this patch is an improvement compared to the current code base:

Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
diff mbox

Patch

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 5bc9dc14e075..5e0fee6ab0db 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -6490,6 +6490,108 @@  static enum blk_eh_timer_return ufshcd_eh_timed_out(struct scsi_cmnd *scmd)
 	return found ? BLK_EH_NOT_HANDLED : BLK_EH_RESET_TIMER;
 }
 
+static inline ssize_t ufshcd_pm_lvl_store(struct device *dev,
+					   struct device_attribute *attr,
+					   const char *buf, size_t count,
+					   bool rpm)
+{
+	struct ufs_hba *hba = dev_get_drvdata(dev);
+	unsigned long flags, value;
+
+	if (kstrtoul(buf, 0, &value))
+		return -EINVAL;
+
+	if (value >= UFS_PM_LVL_MAX)
+		return -EINVAL;
+
+	spin_lock_irqsave(hba->host->host_lock, flags);
+	if (rpm)
+		hba->rpm_lvl = value;
+	else
+		hba->spm_lvl = value;
+	spin_unlock_irqrestore(hba->host->host_lock, flags);
+	return count;
+}
+
+static ssize_t rpm_lvl_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct ufs_hba *hba = dev_get_drvdata(dev);
+	int curr_len;
+	u8 lvl;
+
+	curr_len = snprintf(buf, PAGE_SIZE,
+			    "\nCurrent Runtime PM level [%d] => dev_state [%s] link_state [%s]\n",
+			    hba->rpm_lvl,
+			    ufschd_ufs_dev_pwr_mode_to_string(
+				ufs_pm_lvl_states[hba->rpm_lvl].dev_state),
+			    ufschd_uic_link_state_to_string(
+				ufs_pm_lvl_states[hba->rpm_lvl].link_state));
+
+	curr_len += snprintf((buf + curr_len), (PAGE_SIZE - curr_len),
+			     "\nAll available Runtime PM levels info:\n");
+	for (lvl = UFS_PM_LVL_0; lvl < UFS_PM_LVL_MAX; lvl++)
+		curr_len += snprintf((buf + curr_len), (PAGE_SIZE - curr_len),
+				     "\tRuntime PM level [%d] => dev_state [%s] link_state [%s]\n",
+				    lvl,
+				    ufschd_ufs_dev_pwr_mode_to_string(
+					ufs_pm_lvl_states[lvl].dev_state),
+				    ufschd_uic_link_state_to_string(
+					ufs_pm_lvl_states[lvl].link_state));
+
+	return curr_len;
+}
+
+static ssize_t rpm_lvl_store(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t count)
+{
+	return ufshcd_pm_lvl_store(dev, attr, buf, count, true);
+}
+
+static ssize_t spm_lvl_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct ufs_hba *hba = dev_get_drvdata(dev);
+	int curr_len;
+	u8 lvl;
+
+	curr_len = snprintf(buf, PAGE_SIZE,
+			    "\nCurrent System PM level [%d] => dev_state [%s] link_state [%s]\n",
+			    hba->spm_lvl,
+			    ufschd_ufs_dev_pwr_mode_to_string(
+				ufs_pm_lvl_states[hba->spm_lvl].dev_state),
+			    ufschd_uic_link_state_to_string(
+				ufs_pm_lvl_states[hba->spm_lvl].link_state));
+
+	curr_len += snprintf((buf + curr_len), (PAGE_SIZE - curr_len),
+			     "\nAll available System PM levels info:\n");
+	for (lvl = UFS_PM_LVL_0; lvl < UFS_PM_LVL_MAX; lvl++)
+		curr_len += snprintf((buf + curr_len), (PAGE_SIZE - curr_len),
+				     "\tSystem PM level [%d] => dev_state [%s] link_state [%s]\n",
+				    lvl,
+				    ufschd_ufs_dev_pwr_mode_to_string(
+					ufs_pm_lvl_states[lvl].dev_state),
+				    ufschd_uic_link_state_to_string(
+					ufs_pm_lvl_states[lvl].link_state));
+
+	return curr_len;
+}
+
+static ssize_t spm_lvl_store(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t count)
+{
+	return ufshcd_pm_lvl_store(dev, attr, buf, count, false);
+}
+
+static DEVICE_ATTR_RW(rpm_lvl);
+static DEVICE_ATTR_RW(spm_lvl);
+
+static struct device_attribute *ufshcd_dev_attrs[] = {
+	&dev_attr_rpm_lvl,
+	&dev_attr_spm_lvl,
+	NULL,
+};
+
 static struct scsi_host_template ufshcd_driver_template = {
 	.module			= THIS_MODULE,
 	.name			= UFSHCD,
@@ -6509,6 +6611,7 @@  static struct scsi_host_template ufshcd_driver_template = {
 	.can_queue		= UFSHCD_CAN_QUEUE,
 	.max_host_blocked	= 1,
 	.track_queue_depth	= 1,
+	.sdev_attrs		= ufshcd_dev_attrs,
 };
 
 static int ufshcd_config_vreg_load(struct device *dev, struct ufs_vreg *vreg,
@@ -7578,133 +7681,6 @@  int ufshcd_runtime_idle(struct ufs_hba *hba)
 }
 EXPORT_SYMBOL(ufshcd_runtime_idle);
 
-static inline ssize_t ufshcd_pm_lvl_store(struct device *dev,
-					   struct device_attribute *attr,
-					   const char *buf, size_t count,
-					   bool rpm)
-{
-	struct ufs_hba *hba = dev_get_drvdata(dev);
-	unsigned long flags, value;
-
-	if (kstrtoul(buf, 0, &value))
-		return -EINVAL;
-
-	if (value >= UFS_PM_LVL_MAX)
-		return -EINVAL;
-
-	spin_lock_irqsave(hba->host->host_lock, flags);
-	if (rpm)
-		hba->rpm_lvl = value;
-	else
-		hba->spm_lvl = value;
-	spin_unlock_irqrestore(hba->host->host_lock, flags);
-	return count;
-}
-
-static ssize_t ufshcd_rpm_lvl_show(struct device *dev,
-		struct device_attribute *attr, char *buf)
-{
-	struct ufs_hba *hba = dev_get_drvdata(dev);
-	int curr_len;
-	u8 lvl;
-
-	curr_len = snprintf(buf, PAGE_SIZE,
-			    "\nCurrent Runtime PM level [%d] => dev_state [%s] link_state [%s]\n",
-			    hba->rpm_lvl,
-			    ufschd_ufs_dev_pwr_mode_to_string(
-				ufs_pm_lvl_states[hba->rpm_lvl].dev_state),
-			    ufschd_uic_link_state_to_string(
-				ufs_pm_lvl_states[hba->rpm_lvl].link_state));
-
-	curr_len += snprintf((buf + curr_len), (PAGE_SIZE - curr_len),
-			     "\nAll available Runtime PM levels info:\n");
-	for (lvl = UFS_PM_LVL_0; lvl < UFS_PM_LVL_MAX; lvl++)
-		curr_len += snprintf((buf + curr_len), (PAGE_SIZE - curr_len),
-				     "\tRuntime PM level [%d] => dev_state [%s] link_state [%s]\n",
-				    lvl,
-				    ufschd_ufs_dev_pwr_mode_to_string(
-					ufs_pm_lvl_states[lvl].dev_state),
-				    ufschd_uic_link_state_to_string(
-					ufs_pm_lvl_states[lvl].link_state));
-
-	return curr_len;
-}
-
-static ssize_t ufshcd_rpm_lvl_store(struct device *dev,
-		struct device_attribute *attr, const char *buf, size_t count)
-{
-	return ufshcd_pm_lvl_store(dev, attr, buf, count, true);
-}
-
-static void ufshcd_add_rpm_lvl_sysfs_nodes(struct ufs_hba *hba)
-{
-	hba->rpm_lvl_attr.show = ufshcd_rpm_lvl_show;
-	hba->rpm_lvl_attr.store = ufshcd_rpm_lvl_store;
-	sysfs_attr_init(&hba->rpm_lvl_attr.attr);
-	hba->rpm_lvl_attr.attr.name = "rpm_lvl";
-	hba->rpm_lvl_attr.attr.mode = 0644;
-	if (device_create_file(hba->dev, &hba->rpm_lvl_attr))
-		dev_err(hba->dev, "Failed to create sysfs for rpm_lvl\n");
-}
-
-static ssize_t ufshcd_spm_lvl_show(struct device *dev,
-		struct device_attribute *attr, char *buf)
-{
-	struct ufs_hba *hba = dev_get_drvdata(dev);
-	int curr_len;
-	u8 lvl;
-
-	curr_len = snprintf(buf, PAGE_SIZE,
-			    "\nCurrent System PM level [%d] => dev_state [%s] link_state [%s]\n",
-			    hba->spm_lvl,
-			    ufschd_ufs_dev_pwr_mode_to_string(
-				ufs_pm_lvl_states[hba->spm_lvl].dev_state),
-			    ufschd_uic_link_state_to_string(
-				ufs_pm_lvl_states[hba->spm_lvl].link_state));
-
-	curr_len += snprintf((buf + curr_len), (PAGE_SIZE - curr_len),
-			     "\nAll available System PM levels info:\n");
-	for (lvl = UFS_PM_LVL_0; lvl < UFS_PM_LVL_MAX; lvl++)
-		curr_len += snprintf((buf + curr_len), (PAGE_SIZE - curr_len),
-				     "\tSystem PM level [%d] => dev_state [%s] link_state [%s]\n",
-				    lvl,
-				    ufschd_ufs_dev_pwr_mode_to_string(
-					ufs_pm_lvl_states[lvl].dev_state),
-				    ufschd_uic_link_state_to_string(
-					ufs_pm_lvl_states[lvl].link_state));
-
-	return curr_len;
-}
-
-static ssize_t ufshcd_spm_lvl_store(struct device *dev,
-		struct device_attribute *attr, const char *buf, size_t count)
-{
-	return ufshcd_pm_lvl_store(dev, attr, buf, count, false);
-}
-
-static void ufshcd_add_spm_lvl_sysfs_nodes(struct ufs_hba *hba)
-{
-	hba->spm_lvl_attr.show = ufshcd_spm_lvl_show;
-	hba->spm_lvl_attr.store = ufshcd_spm_lvl_store;
-	sysfs_attr_init(&hba->spm_lvl_attr.attr);
-	hba->spm_lvl_attr.attr.name = "spm_lvl";
-	hba->spm_lvl_attr.attr.mode = 0644;
-	if (device_create_file(hba->dev, &hba->spm_lvl_attr))
-		dev_err(hba->dev, "Failed to create sysfs for spm_lvl\n");
-}
-
-static inline void ufshcd_add_sysfs_nodes(struct ufs_hba *hba)
-{
-	ufshcd_add_rpm_lvl_sysfs_nodes(hba);
-	ufshcd_add_spm_lvl_sysfs_nodes(hba);
-}
-
-static inline void ufshcd_remove_sysfs_nodes(struct ufs_hba *hba)
-{
-	device_remove_file(hba->dev, &hba->rpm_lvl_attr);
-	device_remove_file(hba->dev, &hba->spm_lvl_attr);
-}
-
 /**
  * ufshcd_shutdown - shutdown routine
  * @hba: per adapter instance
@@ -7742,7 +7718,6 @@  EXPORT_SYMBOL(ufshcd_shutdown);
  */
 void ufshcd_remove(struct ufs_hba *hba)
 {
-	ufshcd_remove_sysfs_nodes(hba);
 	scsi_remove_host(hba->host);
 	/* disable interrupts */
 	ufshcd_disable_intr(hba, hba->intr_mask);
@@ -7989,7 +7964,6 @@  int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq)
 	ufshcd_set_ufs_dev_active(hba);
 
 	async_schedule(ufshcd_async_scan, hba);
-	ufshcd_add_sysfs_nodes(hba);
 
 	return 0;