diff mbox

[v5,4/4] ata: ATA Command Priority Disabled By Default

Message ID 1476399631-5799-5-git-send-email-adam.manzanares@hgst.com (mailing list archive)
State New, archived
Headers show

Commit Message

Adam Manzanares Oct. 13, 2016, 11 p.m. UTC 
Add a sysfs entry to turn on priority information being passed
to a ATA device. By default this feature is turned off.

This patch depends on ata: Enabling ATA Command Priorities

Signed-off-by: Adam Manzanares <adam.manzanares@wdc.com>
---
 drivers/ata/libahci.c     |  1 +
 drivers/ata/libata-core.c |  2 +-
 drivers/ata/libata-scsi.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/libata.h    |  8 ++++++
 4 files changed, 78 insertions(+), 1 deletion(-)

Comments

Tejun Heo Oct. 13, 2016, 11:22 p.m. UTC | #1 
Hello, Adam.

Sorry about late reply.  Was on vacation.

On Thu, Oct 13, 2016 at 04:00:31PM -0700, Adam Manzanares wrote:
> Add a sysfs entry to turn on priority information being passed
> to a ATA device. By default this feature is turned off.
> 
> This patch depends on ata: Enabling ATA Command Priorities

Looks generally good but can we please use a device attribute name
which is more specific - ie. enable_ncq_prio?

Thanks.
Adam Manzanares Oct. 13, 2016, 11:37 p.m. UTC | #2 
Hello Tejun,

The 10/13/2016 19:22, Tejun Heo wrote:
> Hello, Adam.
> 
> Sorry about late reply.  Was on vacation.

NP I was on vacation at the end of the week last week.

> 
> On Thu, Oct 13, 2016 at 04:00:31PM -0700, Adam Manzanares wrote:
> > Add a sysfs entry to turn on priority information being passed
> > to a ATA device. By default this feature is turned off.
> > 
> > This patch depends on ata: Enabling ATA Command Priorities
> 
> Looks generally good but can we please use a device attribute name
> which is more specific - ie. enable_ncq_prio?

Will do, I'll also double check the naming scheme of functions and variables 
also. The functions that check if the device has the ncq prio capability might
be too similar to the function that checks if the device attribute is 
enabled.

> 
> Thanks.
> 
> -- 
> tejun

Take care,
Adam
--
To unsubscribe from this list: send the line "unsubscribe linux-block" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
diff mbox

Patch

diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c
index dcf2c72..383adf7 100644
--- a/drivers/ata/libahci.c
+++ b/drivers/ata/libahci.c
@@ -140,6 +140,7 @@  EXPORT_SYMBOL_GPL(ahci_shost_attrs);
 struct device_attribute *ahci_sdev_attrs[] = {
 	&dev_attr_sw_activity,
 	&dev_attr_unload_heads,
+	&dev_attr_enable_prio,
 	NULL
 };
 EXPORT_SYMBOL_GPL(ahci_sdev_attrs);
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 181b530..d0cf987 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -787,7 +787,7 @@  int ata_build_rw_tf(struct ata_taskfile *tf, struct ata_device *dev,
 		if (tf->flags & ATA_TFLAG_FUA)
 			tf->device |= 1 << 7;
 
-		if (ata_ncq_prio_enabled(dev)) {
+		if (ata_ncq_prio_enabled(dev) && ata_prio_enabled(dev)) {
 			if (class == IOPRIO_CLASS_RT)
 				tf->hob_nsect |= ATA_PRIO_HIGH <<
 						 ATA_SHIFT_PRIO;
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 18629e8..10ba118 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -271,6 +271,73 @@  DEVICE_ATTR(unload_heads, S_IRUGO | S_IWUSR,
 	    ata_scsi_park_show, ata_scsi_park_store);
 EXPORT_SYMBOL_GPL(dev_attr_unload_heads);
 
+static ssize_t ata_enable_prio_show(struct device *device,
+				    struct device_attribute *attr, char *buf)
+{
+	struct scsi_device *sdev = to_scsi_device(device);
+	struct ata_port *ap;
+	struct ata_device *dev;
+	int rc = 0;
+	int enable_prio;
+
+	ap = ata_shost_to_port(sdev->host);
+
+	spin_lock_irq(ap->lock);
+	dev = ata_scsi_find_dev(ap, sdev);
+	if (!dev) {
+		rc = -ENODEV;
+		goto unlock;
+	}
+
+	enable_prio = ata_prio_enabled(dev);
+
+unlock:
+	spin_unlock_irq(ap->lock);
+
+	return rc ? rc : snprintf(buf, 20, "%u\n", enable_prio);
+}
+
+static ssize_t ata_enable_prio_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;
+	struct ata_device *dev;
+	long int input;
+	unsigned long flags;
+	int rc;
+
+	rc = kstrtol(buf, 10, &input);
+	if (rc)
+		return rc;
+	if ((input < 0) || (input > 1))
+		return -EINVAL;
+
+	ap = ata_shost_to_port(sdev->host);
+
+	spin_lock_irqsave(ap->lock, flags);
+	dev = ata_scsi_find_dev(ap, sdev);
+	if (unlikely(!dev)) {
+		rc = -ENODEV;
+		goto unlock;
+	}
+
+	if (input)
+		dev->flags |= ATA_DFLAG_ENABLE_PRIO;
+	else
+		dev->flags &= ~ATA_DFLAG_ENABLE_PRIO;
+
+unlock:
+	spin_unlock_irqrestore(ap->lock, flags);
+
+	return rc ? rc : len;
+}
+
+DEVICE_ATTR(enable_prio, S_IRUGO | S_IWUSR,
+	    ata_enable_prio_show, ata_enable_prio_store);
+EXPORT_SYMBOL_GPL(dev_attr_enable_prio);
+
 void ata_scsi_set_sense(struct ata_device *dev, struct scsi_cmnd *cmd,
 			u8 sk, u8 asc, u8 ascq)
 {
@@ -402,6 +469,7 @@  EXPORT_SYMBOL_GPL(dev_attr_sw_activity);
 
 struct device_attribute *ata_common_sdev_attrs[] = {
 	&dev_attr_unload_heads,
+	&dev_attr_enable_prio,
 	NULL
 };
 EXPORT_SYMBOL_GPL(ata_common_sdev_attrs);
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 244f261..c8acb16 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -166,6 +166,7 @@  enum {
 	ATA_DFLAG_UNLOCK_HPA	= (1 << 18), /* unlock HPA */
 	ATA_DFLAG_NCQ_SEND_RECV = (1 << 19), /* device supports NCQ SEND and RECV */
 	ATA_DFLAG_NCQ_PRIO	= (1 << 20), /* device supports NCQ priority */
+	ATA_DFLAG_ENABLE_PRIO	= (1 << 21), /* User enable device priority */
 	ATA_DFLAG_INIT_MASK	= (1 << 24) - 1,
 
 	ATA_DFLAG_DETACH	= (1 << 24),
@@ -544,6 +545,7 @@  typedef void (*ata_postreset_fn_t)(struct ata_link *link, unsigned int *classes)
 
 extern struct device_attribute dev_attr_link_power_management_policy;
 extern struct device_attribute dev_attr_unload_heads;
+extern struct device_attribute dev_attr_enable_prio;
 extern struct device_attribute dev_attr_em_message_type;
 extern struct device_attribute dev_attr_em_message;
 extern struct device_attribute dev_attr_sw_activity;
@@ -1627,6 +1629,12 @@  static inline int ata_ncq_prio_enabled(struct ata_device *dev)
 	return (dev->flags & ATA_DFLAG_NCQ_PRIO) == ATA_DFLAG_NCQ_PRIO;
 }
 
+static inline int ata_prio_enabled(struct ata_device *dev)
+{
+	return ((dev->flags & ATA_DFLAG_ENABLE_PRIO) ==
+		 ATA_DFLAG_ENABLE_PRIO);
+}
+
 static inline bool ata_fpdma_dsm_supported(struct ata_device *dev)
 {
 	return (dev->flags & ATA_DFLAG_NCQ_SEND_RECV) &&