From: Navneet Singh <navneet.singh@xxxxxxxxx> 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@xxxxxxxxx> Co-developed-by: Ira Weiny <ira.weiny@xxxxxxxxx> Signed-off-by: Ira Weiny <ira.weiny@xxxxxxxxx> --- Changes: [djiang: Split sysfs docs up] [iweiny: Adjust sysfs docs dates] --- Documentation/ABI/testing/sysfs-bus-cxl | 32 ++++++++++++++++++ drivers/cxl/core/extent.c | 58 +++++++++++++++++++++++++++++++++ 2 files changed, 90 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl index b63ab622515f..64918180a3c9 100644 --- a/Documentation/ABI/testing/sysfs-bus-cxl +++ b/Documentation/ABI/testing/sysfs-bus-cxl @@ -632,3 +632,35 @@ 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 +Date: December, 2024 +KernelVersion: v6.13 +Contact: linux-cxl@xxxxxxxxxxxxxxx +Description: + (RO) [For Dynamic Capacity regions only] 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. Extent offset + within the region. + +What: /sys/bus/cxl/devices/dax_regionX/extentX.Y/length +Date: December, 2024 +KernelVersion: v6.13 +Contact: linux-cxl@xxxxxxxxxxxxxxx +Description: + (RO) [For Dynamic Capacity regions only] 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. Extent length + within the region. + +What: /sys/bus/cxl/devices/dax_regionX/extentX.Y/tag +Date: December, 2024 +KernelVersion: v6.13 +Contact: linux-cxl@xxxxxxxxxxxxxxx +Description: + (RO) [For Dynamic Capacity regions only] 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. Extent tag. diff --git a/drivers/cxl/core/extent.c b/drivers/cxl/core/extent.c index 69a7614ba6a9..a1eb6e8e4f1a 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(®ion_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", ®ion_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(®ion_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) -- 2.46.0