Re: [PATCH v7 2/7] scsi: libsas: Define NCQ Priority sysfs attributes for SATA devices

Niklas Cassel
2024-03-06T10:54:58Z

On Tue, Mar 05, 2024 at 05:22:21PM -0800, Igor Pylypiv wrote:
> Libata sysfs attributes cannot be used for libsas managed SATA devices
> because the ata_port location is different for libsas.
>
> Defined sysfs attributes (visible for SATA devices only):
> - /sys/block/sda/device/ncq_prio_enable
> - /sys/block/sda/device/ncq_prio_supported
>
> The newly defined attributes will pass the correct ata_port to libata
> helper functions.
>
> Reviewed-by: John Garry <john.g.garry@oracle.com>
> Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
> Reviewed-by: Jason Yan <yanaijie@huawei.com>
> Signed-off-by: Igor Pylypiv <ipylypiv@google.com>
> ---
> drivers/scsi/libsas/sas_ata.c | 94 +++++++++++++++++++++++++++++++++++
> include/scsi/sas_ata.h | 6 +++
> 2 files changed, 100 insertions(+)
>
> diff --git a/drivers/scsi/libsas/sas_ata.c b/drivers/scsi/libsas/sas_ata.c
> index 12e2653846e3..04b0bd9a4e01 100644
> --- a/drivers/scsi/libsas/sas_ata.c
> +++ b/drivers/scsi/libsas/sas_ata.c
> @@ -964,3 +964,97 @@ int sas_execute_ata_cmd(struct domain_device *device, u8 *fis, int force_phy_id)
> force_phy_id, &tmf_task);
> }
> EXPORT_SYMBOL_GPL(sas_execute_ata_cmd);
> +
> +static ssize_t sas_ncq_prio_supported_show(struct device *device,
> + struct device_attribute *attr,
> + char *buf)
> +{
> + struct scsi_device *sdev = to_scsi_device(device);
> + struct domain_device *ddev = sdev_to_domain_dev(sdev);
> + bool supported;
> + int rc;
> +
> + /* This attribute shall be visible for SATA devices only */
> + if (WARN_ON_ONCE(!dev_is_sata(ddev)))
> + return -EINVAL;

Like Hannes commented, I don't believe this is needed.

> +
> + rc = ata_ncq_prio_supported(ddev->sata_dev.ap, sdev, &supported);
> + if (rc)
> + return rc;
> +
> + return sysfs_emit(buf, "%d\n", supported);
> +}
> +

While this is a bit different depending on file, the most common way is to
have no blank link before the DEVICE_ATTR().

> +DEVICE_ATTR(ncq_prio_supported, S_IRUGO, sas_ncq_prio_supported_show, NULL);
> +
> +static ssize_t sas_ncq_prio_enable_show(struct device *device,
> + struct device_attribute *attr,
> + char *buf)
> +{
> + struct scsi_device *sdev = to_scsi_device(device);
> + struct domain_device *ddev = sdev_to_domain_dev(sdev);
> + bool enabled;
> + int rc;
> +
> + /* This attribute shall be visible for SATA devices only */
> + if (WARN_ON_ONCE(!dev_is_sata(ddev)))
> + return -EINVAL;
> +
> + rc = ata_ncq_prio_enabled(ddev->sata_dev.ap, sdev, &enabled);
> + if (rc)
> + return rc;
> +
> + return sysfs_emit(buf, "%d\n", enabled);
> +}
> +
> +static ssize_t sas_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 domain_device *ddev = sdev_to_domain_dev(sdev);
> + bool enable;
> + int rc;
> +
> + /* This attribute shall be visible for SATA devices only */
> + if (WARN_ON_ONCE(!dev_is_sata(ddev)))
> + return -EINVAL;
> +
> + rc = kstrtobool(buf, &enable);
> + if (rc)
> + return rc;
> +
> + rc = ata_ncq_prio_enable(ddev->sata_dev.ap, sdev, enable);
> + if (rc)
> + return rc;
> +
> + return len;
> +}
> +
> +DEVICE_ATTR(ncq_prio_enable, S_IRUGO | S_IWUSR,
> + sas_ncq_prio_enable_show, sas_ncq_prio_enable_store);
> +
> +static struct attribute *sas_ata_sdev_attrs[] = {
> + &dev_attr_ncq_prio_supported.attr,
> + &dev_attr_ncq_prio_enable.attr,
> + NULL
> +};
> +
> +static umode_t sas_ata_attr_is_visible(struct kobject *kobj,
> + struct attribute *attr, int i)
> +{
> + struct device *dev = kobj_to_dev(kobj);
> + struct scsi_device *sdev = to_scsi_device(dev);
> + struct domain_device *ddev = sdev_to_domain_dev(sdev);
> +
> + if (!dev_is_sata(ddev))
> + return 0;
> +
> + return attr->mode;
> +}
> +
> +const struct attribute_group sas_ata_sdev_attr_group = {
> + .attrs = sas_ata_sdev_attrs,
> + .is_visible = sas_ata_attr_is_visible,
> +};
> +EXPORT_SYMBOL_GPL(sas_ata_sdev_attr_group);
> diff --git a/include/scsi/sas_ata.h b/include/scsi/sas_ata.h
> index 2f8c719840a6..92e27e7bf088 100644
> --- a/include/scsi/sas_ata.h
> +++ b/include/scsi/sas_ata.h
> @@ -39,6 +39,9 @@ int smp_ata_check_ready_type(struct ata_link *link);
> int sas_discover_sata(struct domain_device *dev);
> int sas_ata_add_dev(struct domain_device *parent, struct ex_phy *phy,
> struct domain_device *child, int phy_id);
> +
> +extern const struct attribute_group sas_ata_sdev_attr_group;
> +
> #else
>
> static inline void sas_ata_disabled_notice(void)
> @@ -123,6 +126,9 @@ static inline int sas_ata_add_dev(struct domain_device *parent, struct ex_phy *p
> sas_ata_disabled_notice();
> return -ENODEV;
> }
> +
> +#define sas_ata_sdev_attr_group ((struct attribute_group) {})
> +
> #endif
>
> #endif /* _SAS_ATA_H_ */
> --
> 2.44.0.278.ge034bb2e1d-goog
>