diff mbox series

[v3,1/7] ata: libata-sata: Factor out NCQ Priority configuration helpers

Message ID 20240302201636.1228331-2-ipylypiv@google.com (mailing list archive)
State Superseded
Headers show
Series NCQ Priority sysfs sttributes for libsas | expand

Commit Message

Igor Pylypiv March 2, 2024, 8:16 p.m. UTC 
Export libata NCQ Priority configuration helpers to be reused
for libsas managed SATA devices.

Signed-off-by: Igor Pylypiv <ipylypiv@google.com>
---
 drivers/ata/libata-sata.c | 139 +++++++++++++++++++++++++++-----------
 include/linux/libata.h    |   4 ++
 2 files changed, 103 insertions(+), 40 deletions(-)

Comments

John Garry March 4, 2024, 8:34 a.m. UTC | #1 
On 02/03/2024 20:16, Igor Pylypiv wrote:
> Export libata NCQ Priority configuration helpers to be reused
> for libsas managed SATA devices.
> 
> Signed-off-by: Igor Pylypiv <ipylypiv@google.com>

This looks ok. Some small code comments below, though.

> ---
>   drivers/ata/libata-sata.c | 139 +++++++++++++++++++++++++++-----------
>   include/linux/libata.h    |   4 ++
>   2 files changed, 103 insertions(+), 40 deletions(-)
> 
> diff --git a/drivers/ata/libata-sata.c b/drivers/ata/libata-sata.c
> index 0fb1934875f2..a8d5e36d5211 100644
> --- a/drivers/ata/libata-sata.c
> +++ b/drivers/ata/libata-sata.c
> @@ -848,29 +848,73 @@ DEVICE_ATTR(link_power_management_policy, S_IRUGO | S_IWUSR,
>   	    ata_scsi_lpm_show, ata_scsi_lpm_store);
>   EXPORT_SYMBOL_GPL(dev_attr_link_power_management_policy);
>   
> +/**
> + *	ata_ncq_prio_supported - Check if device supports NCQ Priority
> + *	@ap: ATA port of the target device
> + *	@sdev: SCSI device
> + *
> + *	Helper to check if device supports NCQ Priority feature,
> + *	usable with both libsas and libata.
> + */
> +int ata_ncq_prio_supported(struct ata_port *ap, struct scsi_device *sdev)
> +{
> +	struct ata_device *dev;
> +	unsigned long flags;
> +	int rc;
> +
> +	spin_lock_irqsave(ap->lock, flags);
> +	dev = ata_scsi_find_dev(ap, sdev);
> +	if (!dev)
> +		rc = -ENODEV;
> +	else
> +		rc = !!(dev->flags & ATA_DFLAG_NCQ_PRIO);
> +	spin_unlock_irqrestore(ap->lock, flags);
> +	return rc;
> +}

I'm not the biggest fan of functions which effectively return both a 
boolean and an error code.

I like this patten more:

int ata_ncq_prio_supported(struct ata_port *ap, struct scsi_device 
*sdev, bool *supported)
{
	...
	if (rc)
		return rc;
	*supported = true/false.
	return 0;
}

No big deal, though.

> +EXPORT_SYMBOL_GPL(ata_ncq_prio_supported);
> +
>   static ssize_t ata_ncq_prio_supported_show(struct device *device,
>   					   struct device_attribute *attr,
>   					   char *buf)
>   {
>   	struct scsi_device *sdev = to_scsi_device(device);
>   	struct ata_port *ap = ata_shost_to_port(sdev->host);
> +	int rc;
> +
> +	rc = ata_ncq_prio_supported(ap, sdev);
> +	if (rc < 0)
> +		return rc;
> +
> +	return sysfs_emit(buf, "%d\n", rc);
> +}
> +
> +DEVICE_ATTR(ncq_prio_supported, S_IRUGO, ata_ncq_prio_supported_show, NULL);
> +EXPORT_SYMBOL_GPL(dev_attr_ncq_prio_supported);
> +
> +/**
> + *	ata_ncq_prio_enabled - Check if NCQ Priority is enabled
> + *	@ap: ATA port of the target device
> + *	@sdev: SCSI device
> + *
> + *	Helper to check if NCQ Priority feature is enabled,
> + *	usable with both libsas and libata.

It's usable by anything which uses libata, really. For the moment that 
is libsas and libata.

> + */
> +int ata_ncq_prio_enabled(struct ata_port *ap, struct scsi_device *sdev)
> +{
>   	struct ata_device *dev;
> -	bool ncq_prio_supported;
> -	int rc = 0;
> +	unsigned long flags;
> +	int rc;
>   
> -	spin_lock_irq(ap->lock);
> +	spin_lock_irqsave(ap->lock, flags);
>   	dev = ata_scsi_find_dev(ap, sdev);
>   	if (!dev)
>   		rc = -ENODEV;
>   	else
> -		ncq_prio_supported = dev->flags & ATA_DFLAG_NCQ_PRIO;
> -	spin_unlock_irq(ap->lock);
> -
> -	return rc ? rc : sysfs_emit(buf, "%u\n", ncq_prio_supported);
> +		rc = !!(dev->flags & ATA_DFLAG_NCQ_PRIO_ENABLED);
> +	spin_unlock_irqrestore(ap->lock, flags);
> +	return rc;
>   }
> -
> -DEVICE_ATTR(ncq_prio_supported, S_IRUGO, ata_ncq_prio_supported_show, NULL);
> -EXPORT_SYMBOL_GPL(dev_attr_ncq_prio_supported);
> +EXPORT_SYMBOL_GPL(ata_ncq_prio_enabled);
>   
>   static ssize_t ata_ncq_prio_enable_show(struct device *device,
>   					struct device_attribute *attr,
> @@ -878,50 +922,45 @@ static ssize_t ata_ncq_prio_enable_show(struct device *device,
>   {
>   	struct scsi_device *sdev = to_scsi_device(device);
>   	struct ata_port *ap = ata_shost_to_port(sdev->host);
> -	struct ata_device *dev;
> -	bool ncq_prio_enable;
> -	int rc = 0;
> +	int rc;
>   
> -	spin_lock_irq(ap->lock);
> -	dev = ata_scsi_find_dev(ap, sdev);
> -	if (!dev)
> -		rc = -ENODEV;
> -	else
> -		ncq_prio_enable = dev->flags & ATA_DFLAG_NCQ_PRIO_ENABLED;
> -	spin_unlock_irq(ap->lock);
> +	rc = ata_ncq_prio_enabled(ap, sdev);
> +	if (rc < 0)
> +		return rc;
>   
> -	return rc ? rc : sysfs_emit(buf, "%u\n", ncq_prio_enable);
> +	return sysfs_emit(buf, "%d\n", rc);
>   }
>   
> -static ssize_t ata_ncq_prio_enable_store(struct device *device,
> -					 struct device_attribute *attr,
> -					 const char *buf, size_t len)
> +/**
> + *	ata_ncq_prio_enable - Enable/disable NCQ Priority
> + *	@ap: ATA port of the target device
> + *	@sdev: SCSI device
> + *	@enable: true - enable NCQ Priority, false - disable NCQ Priority
> + *
> + *	Helper to enable/disable NCQ Priority feature, usable with both
> + *	libsas and libata.
> + */
> +int ata_ncq_prio_enable(struct ata_port *ap, struct scsi_device *sdev,
> +			bool enable)
>   {
> -	struct scsi_device *sdev = to_scsi_device(device);
> -	struct ata_port *ap;
>   	struct ata_device *dev;
> -	long int input;
> +	unsigned long flags;
>   	int rc = 0;
>   
> -	rc = kstrtol(buf, 10, &input);
> -	if (rc)
> -		return rc;
> -	if ((input < 0) || (input > 1))
> -		return -EINVAL;
> +	spin_lock_irqsave(ap->lock, flags);
>   
> -	ap = ata_shost_to_port(sdev->host);
>   	dev = ata_scsi_find_dev(ap, sdev);
> -	if (unlikely(!dev))
> -		return  -ENODEV;
> -
> -	spin_lock_irq(ap->lock);
> +	if (unlikely(!dev)) {

no need for unlikely() - this is not fathpath

> +		rc = -ENODEV;
> +		goto unlock;
> +	}
>   
>   	if (!(dev->flags & ATA_DFLAG_NCQ_PRIO)) {
>   		rc = -EINVAL;
>   		goto unlock;
Igor Pylypiv March 4, 2024, 10:15 p.m. UTC | #2 
On Mon, Mar 04, 2024 at 08:34:52AM +0000, John Garry wrote:
> On 02/03/2024 20:16, Igor Pylypiv wrote:
> > Export libata NCQ Priority configuration helpers to be reused
> > for libsas managed SATA devices.
> > 
> > Signed-off-by: Igor Pylypiv <ipylypiv@google.com>
> 
> This looks ok. Some small code comments below, though.
> 
> > ---
> >   drivers/ata/libata-sata.c | 139 +++++++++++++++++++++++++++-----------
> >   include/linux/libata.h    |   4 ++
> >   2 files changed, 103 insertions(+), 40 deletions(-)
> > 
> > diff --git a/drivers/ata/libata-sata.c b/drivers/ata/libata-sata.c
> > index 0fb1934875f2..a8d5e36d5211 100644
> > --- a/drivers/ata/libata-sata.c
> > +++ b/drivers/ata/libata-sata.c
> > @@ -848,29 +848,73 @@ DEVICE_ATTR(link_power_management_policy, S_IRUGO | S_IWUSR,
> >   	    ata_scsi_lpm_show, ata_scsi_lpm_store);
> >   EXPORT_SYMBOL_GPL(dev_attr_link_power_management_policy);
> > +/**
> > + *	ata_ncq_prio_supported - Check if device supports NCQ Priority
> > + *	@ap: ATA port of the target device
> > + *	@sdev: SCSI device
> > + *
> > + *	Helper to check if device supports NCQ Priority feature,
> > + *	usable with both libsas and libata.
> > + */
> > +int ata_ncq_prio_supported(struct ata_port *ap, struct scsi_device *sdev)
> > +{
> > +	struct ata_device *dev;
> > +	unsigned long flags;
> > +	int rc;
> > +
> > +	spin_lock_irqsave(ap->lock, flags);
> > +	dev = ata_scsi_find_dev(ap, sdev);
> > +	if (!dev)
> > +		rc = -ENODEV;
> > +	else
> > +		rc = !!(dev->flags & ATA_DFLAG_NCQ_PRIO);
> > +	spin_unlock_irqrestore(ap->lock, flags);
> > +	return rc;
> > +}
> 
> I'm not the biggest fan of functions which effectively return both a boolean
> and an error code.
> 
> I like this patten more:
> 
> int ata_ncq_prio_supported(struct ata_port *ap, struct scsi_device *sdev,
> bool *supported)
> {
> 	...
> 	if (rc)
> 		return rc;
> 	*supported = true/false.
> 	return 0;
> }
> 
> No big deal, though.

Thanks for the review, John. Separating out an error code and a boolean
makes the code a bit more readable. Sent out v4 with the changes.

> 
> > +EXPORT_SYMBOL_GPL(ata_ncq_prio_supported);
> > +
> >   static ssize_t ata_ncq_prio_supported_show(struct device *device,
> >   					   struct device_attribute *attr,
> >   					   char *buf)
> >   {
> >   	struct scsi_device *sdev = to_scsi_device(device);
> >   	struct ata_port *ap = ata_shost_to_port(sdev->host);
> > +	int rc;
> > +
> > +	rc = ata_ncq_prio_supported(ap, sdev);
> > +	if (rc < 0)
> > +		return rc;
> > +
> > +	return sysfs_emit(buf, "%d\n", rc);
> > +}
> > +
> > +DEVICE_ATTR(ncq_prio_supported, S_IRUGO, ata_ncq_prio_supported_show, NULL);
> > +EXPORT_SYMBOL_GPL(dev_attr_ncq_prio_supported);
> > +
> > +/**
> > + *	ata_ncq_prio_enabled - Check if NCQ Priority is enabled
> > + *	@ap: ATA port of the target device
> > + *	@sdev: SCSI device
> > + *
> > + *	Helper to check if NCQ Priority feature is enabled,
> > + *	usable with both libsas and libata.
> 
> It's usable by anything which uses libata, really. For the moment that is
> libsas and libata.
> 
> > + */
> > +int ata_ncq_prio_enabled(struct ata_port *ap, struct scsi_device *sdev)
> > +{
> >   	struct ata_device *dev;
> > -	bool ncq_prio_supported;
> > -	int rc = 0;
> > +	unsigned long flags;
> > +	int rc;
> > -	spin_lock_irq(ap->lock);
> > +	spin_lock_irqsave(ap->lock, flags);
> >   	dev = ata_scsi_find_dev(ap, sdev);
> >   	if (!dev)
> >   		rc = -ENODEV;
> >   	else
> > -		ncq_prio_supported = dev->flags & ATA_DFLAG_NCQ_PRIO;
> > -	spin_unlock_irq(ap->lock);
> > -
> > -	return rc ? rc : sysfs_emit(buf, "%u\n", ncq_prio_supported);
> > +		rc = !!(dev->flags & ATA_DFLAG_NCQ_PRIO_ENABLED);
> > +	spin_unlock_irqrestore(ap->lock, flags);
> > +	return rc;
> >   }
> > -
> > -DEVICE_ATTR(ncq_prio_supported, S_IRUGO, ata_ncq_prio_supported_show, NULL);
> > -EXPORT_SYMBOL_GPL(dev_attr_ncq_prio_supported);
> > +EXPORT_SYMBOL_GPL(ata_ncq_prio_enabled);
> >   static ssize_t ata_ncq_prio_enable_show(struct device *device,
> >   					struct device_attribute *attr,
> > @@ -878,50 +922,45 @@ static ssize_t ata_ncq_prio_enable_show(struct device *device,
> >   {
> >   	struct scsi_device *sdev = to_scsi_device(device);
> >   	struct ata_port *ap = ata_shost_to_port(sdev->host);
> > -	struct ata_device *dev;
> > -	bool ncq_prio_enable;
> > -	int rc = 0;
> > +	int rc;
> > -	spin_lock_irq(ap->lock);
> > -	dev = ata_scsi_find_dev(ap, sdev);
> > -	if (!dev)
> > -		rc = -ENODEV;
> > -	else
> > -		ncq_prio_enable = dev->flags & ATA_DFLAG_NCQ_PRIO_ENABLED;
> > -	spin_unlock_irq(ap->lock);
> > +	rc = ata_ncq_prio_enabled(ap, sdev);
> > +	if (rc < 0)
> > +		return rc;
> > -	return rc ? rc : sysfs_emit(buf, "%u\n", ncq_prio_enable);
> > +	return sysfs_emit(buf, "%d\n", rc);
> >   }
> > -static ssize_t ata_ncq_prio_enable_store(struct device *device,
> > -					 struct device_attribute *attr,
> > -					 const char *buf, size_t len)
> > +/**
> > + *	ata_ncq_prio_enable - Enable/disable NCQ Priority
> > + *	@ap: ATA port of the target device
> > + *	@sdev: SCSI device
> > + *	@enable: true - enable NCQ Priority, false - disable NCQ Priority
> > + *
> > + *	Helper to enable/disable NCQ Priority feature, usable with both
> > + *	libsas and libata.
> > + */
> > +int ata_ncq_prio_enable(struct ata_port *ap, struct scsi_device *sdev,
> > +			bool enable)
> >   {
> > -	struct scsi_device *sdev = to_scsi_device(device);
> > -	struct ata_port *ap;
> >   	struct ata_device *dev;
> > -	long int input;
> > +	unsigned long flags;
> >   	int rc = 0;
> > -	rc = kstrtol(buf, 10, &input);
> > -	if (rc)
> > -		return rc;
> > -	if ((input < 0) || (input > 1))
> > -		return -EINVAL;
> > +	spin_lock_irqsave(ap->lock, flags);
> > -	ap = ata_shost_to_port(sdev->host);
> >   	dev = ata_scsi_find_dev(ap, sdev);
> > -	if (unlikely(!dev))
> > -		return  -ENODEV;
> > -
> > -	spin_lock_irq(ap->lock);
> > +	if (unlikely(!dev)) {
> 
> no need for unlikely() - this is not fathpath
> 
> > +		rc = -ENODEV;
> > +		goto unlock;
> > +	}
> >   	if (!(dev->flags & ATA_DFLAG_NCQ_PRIO)) {
> >   		rc = -EINVAL;
> >   		goto unlock;
>
diff mbox series

Patch

diff --git a/drivers/ata/libata-sata.c b/drivers/ata/libata-sata.c
index 0fb1934875f2..a8d5e36d5211 100644
--- a/drivers/ata/libata-sata.c
+++ b/drivers/ata/libata-sata.c
@@ -848,29 +848,73 @@  DEVICE_ATTR(link_power_management_policy, S_IRUGO | S_IWUSR,
 	    ata_scsi_lpm_show, ata_scsi_lpm_store);
 EXPORT_SYMBOL_GPL(dev_attr_link_power_management_policy);
 
+/**
+ *	ata_ncq_prio_supported - Check if device supports NCQ Priority
+ *	@ap: ATA port of the target device
+ *	@sdev: SCSI device
+ *
+ *	Helper to check if device supports NCQ Priority feature,
+ *	usable with both libsas and libata.
+ */
+int ata_ncq_prio_supported(struct ata_port *ap, struct scsi_device *sdev)
+{
+	struct ata_device *dev;
+	unsigned long flags;
+	int rc;
+
+	spin_lock_irqsave(ap->lock, flags);
+	dev = ata_scsi_find_dev(ap, sdev);
+	if (!dev)
+		rc = -ENODEV;
+	else
+		rc = !!(dev->flags & ATA_DFLAG_NCQ_PRIO);
+	spin_unlock_irqrestore(ap->lock, flags);
+	return rc;
+}
+EXPORT_SYMBOL_GPL(ata_ncq_prio_supported);
+
 static ssize_t ata_ncq_prio_supported_show(struct device *device,
 					   struct device_attribute *attr,
 					   char *buf)
 {
 	struct scsi_device *sdev = to_scsi_device(device);
 	struct ata_port *ap = ata_shost_to_port(sdev->host);
+	int rc;
+
+	rc = ata_ncq_prio_supported(ap, sdev);
+	if (rc < 0)
+		return rc;
+
+	return sysfs_emit(buf, "%d\n", rc);
+}
+
+DEVICE_ATTR(ncq_prio_supported, S_IRUGO, ata_ncq_prio_supported_show, NULL);
+EXPORT_SYMBOL_GPL(dev_attr_ncq_prio_supported);
+
+/**
+ *	ata_ncq_prio_enabled - Check if NCQ Priority is enabled
+ *	@ap: ATA port of the target device
+ *	@sdev: SCSI device
+ *
+ *	Helper to check if NCQ Priority feature is enabled,
+ *	usable with both libsas and libata.
+ */
+int ata_ncq_prio_enabled(struct ata_port *ap, struct scsi_device *sdev)
+{
 	struct ata_device *dev;
-	bool ncq_prio_supported;
-	int rc = 0;
+	unsigned long flags;
+	int rc;
 
-	spin_lock_irq(ap->lock);
+	spin_lock_irqsave(ap->lock, flags);
 	dev = ata_scsi_find_dev(ap, sdev);
 	if (!dev)
 		rc = -ENODEV;
 	else
-		ncq_prio_supported = dev->flags & ATA_DFLAG_NCQ_PRIO;
-	spin_unlock_irq(ap->lock);
-
-	return rc ? rc : sysfs_emit(buf, "%u\n", ncq_prio_supported);
+		rc = !!(dev->flags & ATA_DFLAG_NCQ_PRIO_ENABLED);
+	spin_unlock_irqrestore(ap->lock, flags);
+	return rc;
 }
-
-DEVICE_ATTR(ncq_prio_supported, S_IRUGO, ata_ncq_prio_supported_show, NULL);
-EXPORT_SYMBOL_GPL(dev_attr_ncq_prio_supported);
+EXPORT_SYMBOL_GPL(ata_ncq_prio_enabled);
 
 static ssize_t ata_ncq_prio_enable_show(struct device *device,
 					struct device_attribute *attr,
@@ -878,50 +922,45 @@  static ssize_t ata_ncq_prio_enable_show(struct device *device,
 {
 	struct scsi_device *sdev = to_scsi_device(device);
 	struct ata_port *ap = ata_shost_to_port(sdev->host);
-	struct ata_device *dev;
-	bool ncq_prio_enable;
-	int rc = 0;
+	int rc;
 
-	spin_lock_irq(ap->lock);
-	dev = ata_scsi_find_dev(ap, sdev);
-	if (!dev)
-		rc = -ENODEV;
-	else
-		ncq_prio_enable = dev->flags & ATA_DFLAG_NCQ_PRIO_ENABLED;
-	spin_unlock_irq(ap->lock);
+	rc = ata_ncq_prio_enabled(ap, sdev);
+	if (rc < 0)
+		return rc;
 
-	return rc ? rc : sysfs_emit(buf, "%u\n", ncq_prio_enable);
+	return sysfs_emit(buf, "%d\n", rc);
 }
 
-static ssize_t ata_ncq_prio_enable_store(struct device *device,
-					 struct device_attribute *attr,
-					 const char *buf, size_t len)
+/**
+ *	ata_ncq_prio_enable - Enable/disable NCQ Priority
+ *	@ap: ATA port of the target device
+ *	@sdev: SCSI device
+ *	@enable: true - enable NCQ Priority, false - disable NCQ Priority
+ *
+ *	Helper to enable/disable NCQ Priority feature, usable with both
+ *	libsas and libata.
+ */
+int ata_ncq_prio_enable(struct ata_port *ap, struct scsi_device *sdev,
+			bool enable)
 {
-	struct scsi_device *sdev = to_scsi_device(device);
-	struct ata_port *ap;
 	struct ata_device *dev;
-	long int input;
+	unsigned long flags;
 	int rc = 0;
 
-	rc = kstrtol(buf, 10, &input);
-	if (rc)
-		return rc;
-	if ((input < 0) || (input > 1))
-		return -EINVAL;
+	spin_lock_irqsave(ap->lock, flags);
 
-	ap = ata_shost_to_port(sdev->host);
 	dev = ata_scsi_find_dev(ap, sdev);
-	if (unlikely(!dev))
-		return  -ENODEV;
-
-	spin_lock_irq(ap->lock);
+	if (unlikely(!dev)) {
+		rc = -ENODEV;
+		goto unlock;
+	}
 
 	if (!(dev->flags & ATA_DFLAG_NCQ_PRIO)) {
 		rc = -EINVAL;
 		goto unlock;
 	}
 
-	if (input) {
+	if (enable) {
 		if (dev->flags & ATA_DFLAG_CDL_ENABLED) {
 			ata_dev_err(dev,
 				"CDL must be disabled to enable NCQ priority\n");
@@ -934,9 +973,29 @@  static ssize_t ata_ncq_prio_enable_store(struct device *device,
 	}
 
 unlock:
-	spin_unlock_irq(ap->lock);
+	spin_unlock_irqrestore(ap->lock, flags);
+	return rc;
+}
+EXPORT_SYMBOL_GPL(ata_ncq_prio_enable);
+
+static ssize_t ata_ncq_prio_enable_store(struct device *device,
+					 struct device_attribute *attr,
+					 const char *buf, size_t len)
+{
+	struct scsi_device *sdev = to_scsi_device(device);
+	struct ata_port *ap = ata_shost_to_port(sdev->host);
+	bool enable;
+	int rc;
+
+	rc = kstrtobool(buf, &enable);
+	if (rc)
+		return rc;
+
+	rc = ata_ncq_prio_enable(ap, sdev, enable);
+	if (rc)
+		return rc;
 
-	return rc ? rc : len;
+	return len;
 }
 
 DEVICE_ATTR(ncq_prio_enable, S_IRUGO | S_IWUSR,
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 26d68115afb8..f3ff2bf3ec6b 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -1157,6 +1157,10 @@  extern int ata_scsi_change_queue_depth(struct scsi_device *sdev,
 				       int queue_depth);
 extern int ata_change_queue_depth(struct ata_port *ap, struct scsi_device *sdev,
 				  int queue_depth);
+extern int ata_ncq_prio_supported(struct ata_port *ap, struct scsi_device *sdev);
+extern int ata_ncq_prio_enabled(struct ata_port *ap, struct scsi_device *sdev);
+extern int ata_ncq_prio_enable(struct ata_port *ap, struct scsi_device *sdev,
+			       bool enable);
 extern struct ata_device *ata_dev_pair(struct ata_device *adev);
 extern int ata_do_set_mode(struct ata_link *link, struct ata_device **r_failed_dev);
 extern void ata_scsi_port_error_handler(struct Scsi_Host *host, struct ata_port *ap);