diff mbox series

[v3,19/25] cxl/region/extent: Expose region extent information in sysfs

Message ID 20240816-dcd-type2-upstream-v3-19-7c9b96cba6d7@intel.com (mailing list archive)
State New, archived
Headers show
Series DCD: Add support for Dynamic Capacity Devices (DCD) | expand

Commit Message

Ira Weiny Aug. 16, 2024, 2:44 p.m. UTC 
From: Navneet Singh <navneet.singh@intel.com>

Extent information can be helpful to the user to coordinate memory usage
with the external orchestrator and FM.

Expose the details of region extents by creating the following
sysfs entries.

        /sys/bus/cxl/devices/dax_regionX/extentX.Y
        /sys/bus/cxl/devices/dax_regionX/extentX.Y/offset
        /sys/bus/cxl/devices/dax_regionX/extentX.Y/length
        /sys/bus/cxl/devices/dax_regionX/extentX.Y/tag

Signed-off-by: Navneet Singh <navneet.singh@intel.com>
Co-developed-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>

---
Changes:
[iweiny: split this out]
[Jonathan: add documentation for extent sysfs]
[Jonathan/djbw: s/label/tag]
[Jonathan/djbw: treat tag as uuid]
[djbw: use __ATTRIBUTE_GROUPS]
[djbw: make tag invisible if it is empty]
[djbw/iweiny: use conventional id names for extents; extentX.Y]
---
 Documentation/ABI/testing/sysfs-bus-cxl | 13 ++++++++
 drivers/cxl/core/extent.c               | 58 +++++++++++++++++++++++++++++++++
 2 files changed, 71 insertions(+)

Comments

Dave Jiang Aug. 19, 2024, 7:05 p.m. UTC | #1 
On 8/16/24 7:44 AM, ira.weiny@intel.com wrote:
> From: Navneet Singh <navneet.singh@intel.com>
> 
> Extent information can be helpful to the user to coordinate memory usage
> with the external orchestrator and FM.
> 
> Expose the details of region extents by creating the following
> sysfs entries.
> 
>         /sys/bus/cxl/devices/dax_regionX/extentX.Y
>         /sys/bus/cxl/devices/dax_regionX/extentX.Y/offset
>         /sys/bus/cxl/devices/dax_regionX/extentX.Y/length
>         /sys/bus/cxl/devices/dax_regionX/extentX.Y/tag
> 
> Signed-off-by: Navneet Singh <navneet.singh@intel.com>
> Co-developed-by: Ira Weiny <ira.weiny@intel.com>
> Signed-off-by: Ira Weiny <ira.weiny@intel.com>
> 
> ---
> Changes:
> [iweiny: split this out]
> [Jonathan: add documentation for extent sysfs]
> [Jonathan/djbw: s/label/tag]
> [Jonathan/djbw: treat tag as uuid]
> [djbw: use __ATTRIBUTE_GROUPS]
> [djbw: make tag invisible if it is empty]
> [djbw/iweiny: use conventional id names for extents; extentX.Y]
> ---
>  Documentation/ABI/testing/sysfs-bus-cxl | 13 ++++++++
>  drivers/cxl/core/extent.c               | 58 +++++++++++++++++++++++++++++++++
>  2 files changed, 71 insertions(+)
> 
> diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl
> index 3a5ee88e551b..e97e6a73c960 100644
> --- a/Documentation/ABI/testing/sysfs-bus-cxl
> +++ b/Documentation/ABI/testing/sysfs-bus-cxl
> @@ -599,3 +599,16 @@ Description:
>  		See Documentation/ABI/stable/sysfs-devices-node. access0 provides
>  		the number to the closest initiator and access1 provides the
>  		number to the closest CPU.
> +
> +What:		/sys/bus/cxl/devices/dax_regionX/extentX.Y/offset
> +		/sys/bus/cxl/devices/dax_regionX/extentX.Y/length
> +		/sys/bus/cxl/devices/dax_regionX/extentX.Y/tag

I wonder consider an entry for each with their own descriptions, which seems to be the standard practice.

DJ

> +Date:		October, 2024
> +KernelVersion:	v6.12
> +Contact:	linux-cxl@vger.kernel.org
> +Description:
> +		(RO) [For Dynamic Capacity regions only]  Extent offset and
> +		length within the region.  Users can use the extent information
> +		to create DAX devices on specific extents.  This is done by
> +		creating and destroying DAX devices in specific sequences and
> +		looking at the mappings created.
> diff --git a/drivers/cxl/core/extent.c b/drivers/cxl/core/extent.c
> index 34456594cdc3..d7d526a51e2b 100644
> --- a/drivers/cxl/core/extent.c
> +++ b/drivers/cxl/core/extent.c
> @@ -6,6 +6,63 @@
>  
>  #include "core.h"
>  
> +static ssize_t offset_show(struct device *dev, struct device_attribute *attr,
> +			   char *buf)
> +{
> +	struct region_extent *region_extent = to_region_extent(dev);
> +
> +	return sysfs_emit(buf, "%#llx\n", region_extent->hpa_range.start);
> +}
> +static DEVICE_ATTR_RO(offset);
> +
> +static ssize_t length_show(struct device *dev, struct device_attribute *attr,
> +			   char *buf)
> +{
> +	struct region_extent *region_extent = to_region_extent(dev);
> +	u64 length = range_len(&region_extent->hpa_range);
> +
> +	return sysfs_emit(buf, "%#llx\n", length);
> +}
> +static DEVICE_ATTR_RO(length);
> +
> +static ssize_t tag_show(struct device *dev, struct device_attribute *attr,
> +			char *buf)
> +{
> +	struct region_extent *region_extent = to_region_extent(dev);
> +
> +	return sysfs_emit(buf, "%pUb\n", &region_extent->tag);
> +}
> +static DEVICE_ATTR_RO(tag);
> +
> +static struct attribute *region_extent_attrs[] = {
> +	&dev_attr_offset.attr,
> +	&dev_attr_length.attr,
> +	&dev_attr_tag.attr,
> +	NULL,
> +};
> +
> +static uuid_t empty_tag = { 0 };
> +
> +static umode_t region_extent_visible(struct kobject *kobj,
> +				     struct attribute *a, int n)
> +{
> +	struct device *dev = kobj_to_dev(kobj);
> +	struct region_extent *region_extent = to_region_extent(dev);
> +
> +	if (a == &dev_attr_tag.attr &&
> +	    uuid_equal(&region_extent->tag, &empty_tag))
> +		return 0;
> +
> +	return a->mode;
> +}
> +
> +static const struct attribute_group region_extent_attribute_group = {
> +	.attrs = region_extent_attrs,
> +	.is_visible = region_extent_visible,
> +};
> +
> +__ATTRIBUTE_GROUPS(region_extent_attribute);
> +
>  static void cxled_release_extent(struct cxl_endpoint_decoder *cxled,
>  				 struct cxled_extent *ed_extent)
>  {
> @@ -44,6 +101,7 @@ static void region_extent_release(struct device *dev)
>  static const struct device_type region_extent_type = {
>  	.name = "extent",
>  	.release = region_extent_release,
> +	.groups = region_extent_attribute_groups,
>  };
>  
>  bool is_region_extent(struct device *dev)
>
Ira Weiny Aug. 23, 2024, 2:58 a.m. UTC | #2 
Dave Jiang wrote:
> 
> 
> On 8/16/24 7:44 AM, ira.weiny@intel.com wrote:
> > From: Navneet Singh <navneet.singh@intel.com>
> > 
> > Extent information can be helpful to the user to coordinate memory usage
> > with the external orchestrator and FM.
> > 
> > Expose the details of region extents by creating the following
> > sysfs entries.
> > 
> >         /sys/bus/cxl/devices/dax_regionX/extentX.Y
> >         /sys/bus/cxl/devices/dax_regionX/extentX.Y/offset
> >         /sys/bus/cxl/devices/dax_regionX/extentX.Y/length
> >         /sys/bus/cxl/devices/dax_regionX/extentX.Y/tag
> > 
> > Signed-off-by: Navneet Singh <navneet.singh@intel.com>
> > Co-developed-by: Ira Weiny <ira.weiny@intel.com>
> > Signed-off-by: Ira Weiny <ira.weiny@intel.com>
> > 
> > ---
> > Changes:
> > [iweiny: split this out]
> > [Jonathan: add documentation for extent sysfs]
> > [Jonathan/djbw: s/label/tag]
> > [Jonathan/djbw: treat tag as uuid]
> > [djbw: use __ATTRIBUTE_GROUPS]
> > [djbw: make tag invisible if it is empty]
> > [djbw/iweiny: use conventional id names for extents; extentX.Y]
> > ---
> >  Documentation/ABI/testing/sysfs-bus-cxl | 13 ++++++++
> >  drivers/cxl/core/extent.c               | 58 +++++++++++++++++++++++++++++++++
> >  2 files changed, 71 insertions(+)
> > 
> > diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl
> > index 3a5ee88e551b..e97e6a73c960 100644
> > --- a/Documentation/ABI/testing/sysfs-bus-cxl
> > +++ b/Documentation/ABI/testing/sysfs-bus-cxl
> > @@ -599,3 +599,16 @@ Description:
> >  		See Documentation/ABI/stable/sysfs-devices-node. access0 provides
> >  		the number to the closest initiator and access1 provides the
> >  		number to the closest CPU.
> > +
> > +What:		/sys/bus/cxl/devices/dax_regionX/extentX.Y/offset
> > +		/sys/bus/cxl/devices/dax_regionX/extentX.Y/length
> > +		/sys/bus/cxl/devices/dax_regionX/extentX.Y/tag
> 
> I wonder consider an entry for each with their own descriptions, which seems to be the standard practice.

:-/  Except kind of for the access'.

What:           /sys/bus/cxl/devices/regionZ/accessY/read_bandwidth
                /sys/bus/cxl/devices/regionZ/accessY/write_banwidth

What:           /sys/bus/cxl/devices/regionZ/accessY/read_latency
                /sys/bus/cxl/devices/regionZ/accessY/write_latency

But I think you have a point.

Ira

> 
> DJ
> 

[snip]
Jonathan Cameron Aug. 23, 2024, 5:17 p.m. UTC | #3 
On Thu, 22 Aug 2024 21:58:02 -0500
Ira Weiny <ira.weiny@intel.com> wrote:

> Dave Jiang wrote:
> > 
> > 
> > On 8/16/24 7:44 AM, ira.weiny@intel.com wrote:  
> > > From: Navneet Singh <navneet.singh@intel.com>
> > > 
> > > Extent information can be helpful to the user to coordinate memory usage
> > > with the external orchestrator and FM.
> > > 
> > > Expose the details of region extents by creating the following
> > > sysfs entries.
> > > 
> > >         /sys/bus/cxl/devices/dax_regionX/extentX.Y
> > >         /sys/bus/cxl/devices/dax_regionX/extentX.Y/offset
> > >         /sys/bus/cxl/devices/dax_regionX/extentX.Y/length
> > >         /sys/bus/cxl/devices/dax_regionX/extentX.Y/tag
> > > 
> > > Signed-off-by: Navneet Singh <navneet.singh@intel.com>
> > > Co-developed-by: Ira Weiny <ira.weiny@intel.com>
> > > Signed-off-by: Ira Weiny <ira.weiny@intel.com>
> > > 
> > > ---
> > > Changes:
> > > [iweiny: split this out]
> > > [Jonathan: add documentation for extent sysfs]
> > > [Jonathan/djbw: s/label/tag]
> > > [Jonathan/djbw: treat tag as uuid]
> > > [djbw: use __ATTRIBUTE_GROUPS]
> > > [djbw: make tag invisible if it is empty]
> > > [djbw/iweiny: use conventional id names for extents; extentX.Y]
> > > ---
> > >  Documentation/ABI/testing/sysfs-bus-cxl | 13 ++++++++
> > >  drivers/cxl/core/extent.c               | 58 +++++++++++++++++++++++++++++++++
> > >  2 files changed, 71 insertions(+)
> > > 
> > > diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl
> > > index 3a5ee88e551b..e97e6a73c960 100644
> > > --- a/Documentation/ABI/testing/sysfs-bus-cxl
> > > +++ b/Documentation/ABI/testing/sysfs-bus-cxl
> > > @@ -599,3 +599,16 @@ Description:
> > >  		See Documentation/ABI/stable/sysfs-devices-node. access0 provides
> > >  		the number to the closest initiator and access1 provides the
> > >  		number to the closest CPU.
> > > +
> > > +What:		/sys/bus/cxl/devices/dax_regionX/extentX.Y/offset
> > > +		/sys/bus/cxl/devices/dax_regionX/extentX.Y/length
> > > +		/sys/bus/cxl/devices/dax_regionX/extentX.Y/tag  
> > 
> > I wonder consider an entry for each with their own descriptions, which seems to be the standard practice.  
> 
> :-/  Except kind of for the access'.
> 
> What:           /sys/bus/cxl/devices/regionZ/accessY/read_bandwidth
>                 /sys/bus/cxl/devices/regionZ/accessY/write_banwidth
> 
> What:           /sys/bus/cxl/devices/regionZ/accessY/read_latency
>                 /sys/bus/cxl/devices/regionZ/accessY/write_latency
> 
> But I think you have a point.

It's a balance between complexity and repetition.

E.g. https://elixir.bootlin.com/linux/v6.11-rc4/source/Documentation/ABI/testing/sysfs-bus-iio#L427
is one of these files I know far too well. That would be a lot
of very boring repetition and that doc is long enough without breaking them up.

Here there are only 3 and a good bit of description differs so
probably good to split up.

Less so for bandwidth and latency cases.

Jonathan

> 
> Ira
> 
> > 
> > DJ
> >   
> 
> [snip]
>
Jonathan Cameron Aug. 23, 2024, 5:19 p.m. UTC | #4 
On Fri, 16 Aug 2024 09:44:27 -0500
ira.weiny@intel.com wrote:

> From: Navneet Singh <navneet.singh@intel.com>
> 
> Extent information can be helpful to the user to coordinate memory usage
> with the external orchestrator and FM.
> 
> Expose the details of region extents by creating the following
> sysfs entries.
> 
>         /sys/bus/cxl/devices/dax_regionX/extentX.Y
>         /sys/bus/cxl/devices/dax_regionX/extentX.Y/offset
>         /sys/bus/cxl/devices/dax_regionX/extentX.Y/length
>         /sys/bus/cxl/devices/dax_regionX/extentX.Y/tag
> 
> Signed-off-by: Navneet Singh <navneet.singh@intel.com>
> Co-developed-by: Ira Weiny <ira.weiny@intel.com>
> Signed-off-by: Ira Weiny <ira.weiny@intel.com>
> 
LGTM with or without the docs split.
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Fan Ni Aug. 28, 2024, 5:44 p.m. UTC | #5 
On Fri, Aug 16, 2024 at 09:44:27AM -0500, ira.weiny@intel.com wrote:
> From: Navneet Singh <navneet.singh@intel.com>
> 
> Extent information can be helpful to the user to coordinate memory usage
> with the external orchestrator and FM.
> 
> Expose the details of region extents by creating the following
> sysfs entries.
> 
>         /sys/bus/cxl/devices/dax_regionX/extentX.Y
>         /sys/bus/cxl/devices/dax_regionX/extentX.Y/offset
>         /sys/bus/cxl/devices/dax_regionX/extentX.Y/length
>         /sys/bus/cxl/devices/dax_regionX/extentX.Y/tag
> 
> Signed-off-by: Navneet Singh <navneet.singh@intel.com>
> Co-developed-by: Ira Weiny <ira.weiny@intel.com>
> Signed-off-by: Ira Weiny <ira.weiny@intel.com>

Reviewed-by: Fan Ni <fan.ni@samsung.com>

> 
> ---
> Changes:
> [iweiny: split this out]
> [Jonathan: add documentation for extent sysfs]
> [Jonathan/djbw: s/label/tag]
> [Jonathan/djbw: treat tag as uuid]
> [djbw: use __ATTRIBUTE_GROUPS]
> [djbw: make tag invisible if it is empty]
> [djbw/iweiny: use conventional id names for extents; extentX.Y]
> ---
>  Documentation/ABI/testing/sysfs-bus-cxl | 13 ++++++++
>  drivers/cxl/core/extent.c               | 58 +++++++++++++++++++++++++++++++++
>  2 files changed, 71 insertions(+)
> 
> diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl
> index 3a5ee88e551b..e97e6a73c960 100644
> --- a/Documentation/ABI/testing/sysfs-bus-cxl
> +++ b/Documentation/ABI/testing/sysfs-bus-cxl
> @@ -599,3 +599,16 @@ Description:
>  		See Documentation/ABI/stable/sysfs-devices-node. access0 provides
>  		the number to the closest initiator and access1 provides the
>  		number to the closest CPU.
> +
> +What:		/sys/bus/cxl/devices/dax_regionX/extentX.Y/offset
> +		/sys/bus/cxl/devices/dax_regionX/extentX.Y/length
> +		/sys/bus/cxl/devices/dax_regionX/extentX.Y/tag
> +Date:		October, 2024
> +KernelVersion:	v6.12
> +Contact:	linux-cxl@vger.kernel.org
> +Description:
> +		(RO) [For Dynamic Capacity regions only]  Extent offset and
> +		length within the region.  Users can use the extent information
> +		to create DAX devices on specific extents.  This is done by
> +		creating and destroying DAX devices in specific sequences and
> +		looking at the mappings created.
> diff --git a/drivers/cxl/core/extent.c b/drivers/cxl/core/extent.c
> index 34456594cdc3..d7d526a51e2b 100644
> --- a/drivers/cxl/core/extent.c
> +++ b/drivers/cxl/core/extent.c
> @@ -6,6 +6,63 @@
>  
>  #include "core.h"
>  
> +static ssize_t offset_show(struct device *dev, struct device_attribute *attr,
> +			   char *buf)
> +{
> +	struct region_extent *region_extent = to_region_extent(dev);
> +
> +	return sysfs_emit(buf, "%#llx\n", region_extent->hpa_range.start);
> +}
> +static DEVICE_ATTR_RO(offset);
> +
> +static ssize_t length_show(struct device *dev, struct device_attribute *attr,
> +			   char *buf)
> +{
> +	struct region_extent *region_extent = to_region_extent(dev);
> +	u64 length = range_len(&region_extent->hpa_range);
> +
> +	return sysfs_emit(buf, "%#llx\n", length);
> +}
> +static DEVICE_ATTR_RO(length);
> +
> +static ssize_t tag_show(struct device *dev, struct device_attribute *attr,
> +			char *buf)
> +{
> +	struct region_extent *region_extent = to_region_extent(dev);
> +
> +	return sysfs_emit(buf, "%pUb\n", &region_extent->tag);
> +}
> +static DEVICE_ATTR_RO(tag);
> +
> +static struct attribute *region_extent_attrs[] = {
> +	&dev_attr_offset.attr,
> +	&dev_attr_length.attr,
> +	&dev_attr_tag.attr,
> +	NULL,
> +};
> +
> +static uuid_t empty_tag = { 0 };
> +
> +static umode_t region_extent_visible(struct kobject *kobj,
> +				     struct attribute *a, int n)
> +{
> +	struct device *dev = kobj_to_dev(kobj);
> +	struct region_extent *region_extent = to_region_extent(dev);
> +
> +	if (a == &dev_attr_tag.attr &&
> +	    uuid_equal(&region_extent->tag, &empty_tag))
> +		return 0;
> +
> +	return a->mode;
> +}
> +
> +static const struct attribute_group region_extent_attribute_group = {
> +	.attrs = region_extent_attrs,
> +	.is_visible = region_extent_visible,
> +};
> +
> +__ATTRIBUTE_GROUPS(region_extent_attribute);
> +
>  static void cxled_release_extent(struct cxl_endpoint_decoder *cxled,
>  				 struct cxled_extent *ed_extent)
>  {
> @@ -44,6 +101,7 @@ static void region_extent_release(struct device *dev)
>  static const struct device_type region_extent_type = {
>  	.name = "extent",
>  	.release = region_extent_release,
> +	.groups = region_extent_attribute_groups,
>  };
>  
>  bool is_region_extent(struct device *dev)
> 
> -- 
> 2.45.2
>
diff mbox series

Patch

diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl
index 3a5ee88e551b..e97e6a73c960 100644
--- a/Documentation/ABI/testing/sysfs-bus-cxl
+++ b/Documentation/ABI/testing/sysfs-bus-cxl
@@ -599,3 +599,16 @@  Description:
 		See Documentation/ABI/stable/sysfs-devices-node. access0 provides
 		the number to the closest initiator and access1 provides the
 		number to the closest CPU.
+
+What:		/sys/bus/cxl/devices/dax_regionX/extentX.Y/offset
+		/sys/bus/cxl/devices/dax_regionX/extentX.Y/length
+		/sys/bus/cxl/devices/dax_regionX/extentX.Y/tag
+Date:		October, 2024
+KernelVersion:	v6.12
+Contact:	linux-cxl@vger.kernel.org
+Description:
+		(RO) [For Dynamic Capacity regions only]  Extent offset and
+		length within the region.  Users can use the extent information
+		to create DAX devices on specific extents.  This is done by
+		creating and destroying DAX devices in specific sequences and
+		looking at the mappings created.
diff --git a/drivers/cxl/core/extent.c b/drivers/cxl/core/extent.c
index 34456594cdc3..d7d526a51e2b 100644
--- a/drivers/cxl/core/extent.c
+++ b/drivers/cxl/core/extent.c
@@ -6,6 +6,63 @@ 
 
 #include "core.h"
 
+static ssize_t offset_show(struct device *dev, struct device_attribute *attr,
+			   char *buf)
+{
+	struct region_extent *region_extent = to_region_extent(dev);
+
+	return sysfs_emit(buf, "%#llx\n", region_extent->hpa_range.start);
+}
+static DEVICE_ATTR_RO(offset);
+
+static ssize_t length_show(struct device *dev, struct device_attribute *attr,
+			   char *buf)
+{
+	struct region_extent *region_extent = to_region_extent(dev);
+	u64 length = range_len(&region_extent->hpa_range);
+
+	return sysfs_emit(buf, "%#llx\n", length);
+}
+static DEVICE_ATTR_RO(length);
+
+static ssize_t tag_show(struct device *dev, struct device_attribute *attr,
+			char *buf)
+{
+	struct region_extent *region_extent = to_region_extent(dev);
+
+	return sysfs_emit(buf, "%pUb\n", &region_extent->tag);
+}
+static DEVICE_ATTR_RO(tag);
+
+static struct attribute *region_extent_attrs[] = {
+	&dev_attr_offset.attr,
+	&dev_attr_length.attr,
+	&dev_attr_tag.attr,
+	NULL,
+};
+
+static uuid_t empty_tag = { 0 };
+
+static umode_t region_extent_visible(struct kobject *kobj,
+				     struct attribute *a, int n)
+{
+	struct device *dev = kobj_to_dev(kobj);
+	struct region_extent *region_extent = to_region_extent(dev);
+
+	if (a == &dev_attr_tag.attr &&
+	    uuid_equal(&region_extent->tag, &empty_tag))
+		return 0;
+
+	return a->mode;
+}
+
+static const struct attribute_group region_extent_attribute_group = {
+	.attrs = region_extent_attrs,
+	.is_visible = region_extent_visible,
+};
+
+__ATTRIBUTE_GROUPS(region_extent_attribute);
+
 static void cxled_release_extent(struct cxl_endpoint_decoder *cxled,
 				 struct cxled_extent *ed_extent)
 {
@@ -44,6 +101,7 @@  static void region_extent_release(struct device *dev)
 static const struct device_type region_extent_type = {
 	.name = "extent",
 	.release = region_extent_release,
+	.groups = region_extent_attribute_groups,
 };
 
 bool is_region_extent(struct device *dev)