scsi: ata: libata-sata: Factor out NCQ Priority configuration helpers

Export libata NCQ Priority configuration helpers to be reused for libsas
managed SATA devices.

Switched locking from spin_lock_irq() to spin_lock_irqsave().  In the
future someone might call these helper functions when interrupts are
disabled. spin_unlock_irq() could lead to a premature re-enabling of
interrupts, whereas spin_unlock_irqrestore() restores the interrupt state
to its condition prior to the spin_lock_irqsave() call.

Acked-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Jason Yan <yanaijie@huawei.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Igor Pylypiv <ipylypiv@google.com>
Link: https://lore.kernel.org/r/20240307214418.3812290-2-ipylypiv@google.com
Reviewed-by: Niklas Cassel <cassel@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/ata/libata-sata.c b/drivers/ata/libata-sata.c
index 0fb1934875f2084a753216cf54ff443aa601361b..a8d773003d74bf44763f1219ef2408038f46b23d 100644 (file)
--- a/drivers/ata/libata-sata.c
+++ b/drivers/ata/libata-sata.c
@@ -848,80 +848,143 @@ 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);
 
-static ssize_t ata_ncq_prio_supported_show(struct device *device,
-                                          struct device_attribute *attr,
-                                          char *buf)
+/**
+ *     ata_ncq_prio_supported - Check if device supports NCQ Priority
+ *     @ap: ATA port of the target device
+ *     @sdev: SCSI device
+ *     @supported: Address of a boolean to store the result
+ *
+ *     Helper to check if device supports NCQ Priority feature.
+ *
+ *     Context: Any context. Takes and releases @ap->lock.
+ *
+ *     Return:
+ *     * %0            - OK. Status is stored into @supported
+ *     * %-ENODEV      - Failed to find the ATA device
+ */
+int ata_ncq_prio_supported(struct ata_port *ap, struct scsi_device *sdev,
+                          bool *supported)
 {
-       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_supported;
+       unsigned long flags;
        int rc = 0;
 
-       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);
+               *supported = 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);
+       bool supported;
+       int rc;
+
+       rc = ata_ncq_prio_supported(ap, sdev, &supported);
+       if (rc)
+               return rc;
 
-       return rc ? rc : sysfs_emit(buf, "%u\n", ncq_prio_supported);
+       return sysfs_emit(buf, "%d\n", supported);
 }
 
 DEVICE_ATTR(ncq_prio_supported, S_IRUGO, ata_ncq_prio_supported_show, NULL);
 EXPORT_SYMBOL_GPL(dev_attr_ncq_prio_supported);
 
-static ssize_t ata_ncq_prio_enable_show(struct device *device,
-                                       struct device_attribute *attr,
-                                       char *buf)
+/**
+ *     ata_ncq_prio_enabled - Check if NCQ Priority is enabled
+ *     @ap: ATA port of the target device
+ *     @sdev: SCSI device
+ *     @enabled: Address of a boolean to store the result
+ *
+ *     Helper to check if NCQ Priority feature is enabled.
+ *
+ *     Context: Any context. Takes and releases @ap->lock.
+ *
+ *     Return:
+ *     * %0            - OK. Status is stored into @enabled
+ *     * %-ENODEV      - Failed to find the ATA device
+ */
+int ata_ncq_prio_enabled(struct ata_port *ap, struct scsi_device *sdev,
+                        bool *enabled)
 {
-       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;
+       unsigned long flags;
        int rc = 0;
 
-       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_enable = dev->flags & ATA_DFLAG_NCQ_PRIO_ENABLED;
-       spin_unlock_irq(ap->lock);
+               *enabled = dev->flags & ATA_DFLAG_NCQ_PRIO_ENABLED;
+       spin_unlock_irqrestore(ap->lock, flags);
 
-       return rc ? rc : sysfs_emit(buf, "%u\n", ncq_prio_enable);
+       return rc;
 }
+EXPORT_SYMBOL_GPL(ata_ncq_prio_enabled);
 
-static ssize_t ata_ncq_prio_enable_store(struct device *device,
-                                        struct device_attribute *attr,
-                                        const char *buf, size_t len)
+static ssize_t ata_ncq_prio_enable_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;
-       long int input;
-       int rc = 0;
+       struct ata_port *ap = ata_shost_to_port(sdev->host);
+       bool enabled;
+       int rc;
 
-       rc = kstrtol(buf, 10, &input);
+       rc = ata_ncq_prio_enabled(ap, sdev, &enabled);
        if (rc)
                return rc;
-       if ((input < 0) || (input > 1))
-               return -EINVAL;
 
-       ap = ata_shost_to_port(sdev->host);
-       dev = ata_scsi_find_dev(ap, sdev);
-       if (unlikely(!dev))
-               return  -ENODEV;
+       return sysfs_emit(buf, "%d\n", enabled);
+}
+
+/**
+ *     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.
+ *
+ *     Context: Any context. Takes and releases @ap->lock.
+ *
+ *     Return:
+ *     * %0            - OK. Status is stored into @enabled
+ *     * %-ENODEV      - Failed to find the ATA device
+ *     * %-EINVAL      - NCQ Priority is not supported or CDL is enabled
+ */
+int ata_ncq_prio_enable(struct ata_port *ap, struct scsi_device *sdev,
+                       bool enable)
+{
+       struct ata_device *dev;
+       unsigned long flags;
+       int rc = 0;
+
+       spin_lock_irqsave(ap->lock, flags);
 
-       spin_lock_irq(ap->lock);
+       dev = ata_scsi_find_dev(ap, sdev);
+       if (!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 +997,30 @@ 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 26d68115afb826b65a9fd11ce329635161e39cca..6dd9a4f9ca7cb5a5d313d18b66807b8a90931180 100644 (file)
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -1157,6 +1157,12 @@ 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,
+                                 bool *supported);
+extern int ata_ncq_prio_enabled(struct ata_port *ap, struct scsi_device *sdev,
+                               bool *enabled);
+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);