scsi: mpt3sas: Recognize and act on iopriority info

This patch adds support for request iopriority handling in the mpt3sas
layer. This works only when a ATA device is behind the SATL. The ATA
device also has to indicate that it supports command priorities in the
identify information that is pulled from the SATL.

Signed-off-by: Adam Manzanares <adam.manzanares@wdc.com>
Acked-by: Sreekanth Reddy <Sreekanth.Reddy@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 41 insertions, 2 deletions

diff --git a/drivers/scsi/mpt3sas/mpt3sas_ctl.c b/drivers/scsi/mpt3sas/mpt3sas_ctl.c
index 050bd788ad02..95f0f24bac05 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_ctl.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_ctl.c
@@ -3325,8 +3325,6 @@ static DEVICE_ATTR(diag_trigger_mpi, S_IRUGO | S_IWUSR,
 
 /*********** diagnostic trigger suppport *** END ****************************/
 
-
-
 /*****************************************/
 
 struct device_attribute *mpt3sas_host_attrs[] = {
@@ -3402,9 +3400,50 @@ _ctl_device_handle_show(struct device *dev, struct device_attribute *attr,
 }
 static DEVICE_ATTR(sas_device_handle, S_IRUGO, _ctl_device_handle_show, NULL);
 
+/**
+ * _ctl_device_ncq_io_prio_show - send prioritized io commands to device
+ * @dev - pointer to embedded device
+ * @buf - the buffer returned
+ *
+ * A sysfs 'read/write' sdev attribute, only works with SATA
+ */
+static ssize_t
+_ctl_device_ncq_prio_enable_show(struct device *dev,
+				 struct device_attribute *attr, char *buf)
+{
+	struct scsi_device *sdev = to_scsi_device(dev);
+	struct MPT3SAS_DEVICE *sas_device_priv_data = sdev->hostdata;
+
+	return snprintf(buf, PAGE_SIZE, "%d\n",
+			sas_device_priv_data->ncq_prio_enable);
+}
+
+static ssize_t
+_ctl_device_ncq_prio_enable_store(struct device *dev,
+				  struct device_attribute *attr,
+				  const char *buf, size_t count)
+{
+	struct scsi_device *sdev = to_scsi_device(dev);
+	struct MPT3SAS_DEVICE *sas_device_priv_data = sdev->hostdata;
+	bool ncq_prio_enable = 0;
+
+	if (kstrtobool(buf, &ncq_prio_enable))
+		return -EINVAL;
+
+	if (!scsih_ncq_prio_supp(sdev))
+		return -EINVAL;
+
+	sas_device_priv_data->ncq_prio_enable = ncq_prio_enable;
+	return strlen(buf);
+}
+static DEVICE_ATTR(sas_ncq_prio_enable, S_IRUGO | S_IWUSR,
+		   _ctl_device_ncq_prio_enable_show,
+		   _ctl_device_ncq_prio_enable_store);
+
 struct device_attribute *mpt3sas_dev_attrs[] = {
 	&dev_attr_sas_address,
 	&dev_attr_sas_device_handle,
+	&dev_attr_sas_ncq_prio_enable,
 	NULL,
 };