diff mbox series

[v5,2/7] scsi: libsas: Define NCQ Priority sysfs attributes for SATA devices

Message ID 20240305005103.1849325-3-ipylypiv@google.com
State New
Headers show
Series NCQ Priority sysfs sttributes for libsas | expand

Commit Message

Igor Pylypiv March 5, 2024, 12:50 a.m. UTC
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>
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(+)

Comments

Jason Yan March 5, 2024, 2:44 a.m. UTC | #1
On 2024/3/5 8:50, 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>
> 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(+)

Reviewed-by: Jason Yan <yanaijie@huawei.com>
John Garry March 5, 2024, 11:29 a.m. UTC | #2
On 05/03/2024 00:50, Igor Pylypiv wrote:
>   
>   static inline void sas_ata_disabled_notice(void)
> @@ -123,6 +125,10 @@ static inline int sas_ata_add_dev(struct domain_device *parent, struct ex_phy *p
>   	sas_ata_disabled_notice();
>   	return -ENODEV;
>   }
> +
> +static const struct attribute_group sas_ata_sdev_attr_group = {
> +	.attrs = NULL,
> +};

I just noticed a build issue.

With CONFIG_SCSI_SAS_ATA not set, I get this for W=1 build:

In file included from drivers/scsi/hisi_sas/hisi_sas.h:29,
                 from drivers/scsi/hisi_sas/hisi_sas_v1_hw.c:7:
./include/scsi/sas_ata.h:129:37: error: ‘sas_ata_sdev_attr_group’
defined but not used [-Werror=unused-const-variable=]
  129 | static const struct attribute_group sas_ata_sdev_attr_group = {

I suppose that marking sas_ata_sdev_attr_group as __maybe_unused is ok, 
but less than ideal. The linker should strip it out of files when unused.

I think that this is also ok:

#define sas_ata_sdev_attr_group (struct attribute_group) {}

The compiler here will create a empty structure and have 
&sas_ata_sdev_attr_group point at it.

Thanks,
John
Igor Pylypiv March 5, 2024, 11:58 p.m. UTC | #3
On Tue, Mar 05, 2024 at 11:29:11AM +0000, John Garry wrote:
> On 05/03/2024 00:50, Igor Pylypiv wrote:
> >   static inline void sas_ata_disabled_notice(void)
> > @@ -123,6 +125,10 @@ static inline int sas_ata_add_dev(struct domain_device *parent, struct ex_phy *p
> >   	sas_ata_disabled_notice();
> >   	return -ENODEV;
> >   }
> > +
> > +static const struct attribute_group sas_ata_sdev_attr_group = {
> > +	.attrs = NULL,
> > +};
> 
> I just noticed a build issue.
> 
> With CONFIG_SCSI_SAS_ATA not set, I get this for W=1 build:
> 
> In file included from drivers/scsi/hisi_sas/hisi_sas.h:29,
>                 from drivers/scsi/hisi_sas/hisi_sas_v1_hw.c:7:
> ./include/scsi/sas_ata.h:129:37: error: ‘sas_ata_sdev_attr_group’
> defined but not used [-Werror=unused-const-variable=]
>  129 | static const struct attribute_group sas_ata_sdev_attr_group = {

Thanks for catching this, John!
For some reason I only get this warning with gcc but not with clang.

> 
> I suppose that marking sas_ata_sdev_attr_group as __maybe_unused is ok, but
> less than ideal. The linker should strip it out of files when unused.

Looks like adding the __maybe_unused attribute is a prefferred way since
it is mentioned in the Linux kernel coding style:
https://www.kernel.org/doc/html/v6.7/process/coding-style.html#conditional-compilation

Added the __maybe_unused attribute in v6. Thank you!

> 
> I think that this is also ok:
> 
> #define sas_ata_sdev_attr_group (struct attribute_group) {}
> 
> The compiler here will create a empty structure and have
> &sas_ata_sdev_attr_group point at it.
> 
> Thanks,
> John
diff mbox series

Patch

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;
+
+	rc = ata_ncq_prio_supported(ddev->sata_dev.ap, sdev, &supported);
+	if (rc)
+		return rc;
+
+	return sysfs_emit(buf, "%d\n", supported);
+}
+
+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..cded782fdf33 100644
--- a/include/scsi/sas_ata.h
+++ b/include/scsi/sas_ata.h
@@ -39,6 +39,8 @@  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 +125,10 @@  static inline int sas_ata_add_dev(struct domain_device *parent, struct ex_phy *p
 	sas_ata_disabled_notice();
 	return -ENODEV;
 }
+
+static const struct attribute_group sas_ata_sdev_attr_group = {
+	.attrs = NULL,
+};
 #endif
 
 #endif /* _SAS_ATA_H_ */