@@ -552,3 +552,37 @@ Description:
attribute is only visible for devices supporting the
capability. The retrieved errors are logged as kernel
events when cxl_poison event tracing is enabled.
+
+
+What: /sys/bus/cxl/devices/regionZ/accessY/read_bandwidth
+ /sys/bus/cxl/devices/regionZ/accessY/write_banwidth
+Date: Jan, 2024
+KernelVersion: v6.9
+Contact: linux-cxl@vger.kernel.org
+Description:
+ (RO) The aggregated read or write bandwidth of the region. The
+ number is the accumulated read or write bandwidth of all CXL memory
+ devices that contributes to the region in MB/s. It is
+ identical data that should appear in
+ /sys/devices/system/node/nodeX/accessY/initiators/read_bandwidth or
+ /sys/devices/system/node/nodeX/accessY/initiators/write_bandwidth.
+ 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/regionZ/accessY/read_latency
+ /sys/bus/cxl/devices/regionZ/accessY/write_latency
+Date: Jan, 2024
+KernelVersion: v6.9
+Contact: linux-cxl@vger.kernel.org
+Description:
+ (RO) The read or write latency of the region. The number is
+ the worst read or write latency of all CXL memory devices that
+ contributes to the region in nanoseconds. It is identical data
+ that should appear in
+ /sys/devices/system/node/nodeX/accessY/initiators/read_latency or
+ /sys/devices/system/node/nodeX/accessY/initiators/write_latency.
+ See Documentation/ABI/stable/sysfs-devices-node. access0 provides
+ the number to the closest initiator and access1 provides the
+ number to the closest CPU.
@@ -30,6 +30,98 @@
static struct cxl_region *to_cxl_region(struct device *dev);
+#define __ACCESS_ATTR_RO(_level, _name) { \
+ .attr = { .name = __stringify(_name), .mode = 0444 }, \
+ .show = _name##_access##_level##_show, \
+}
+
+#define ACCESS_DEVICE_ATTR_RO(level, name) \
+ struct device_attribute dev_attr_access##level##_##name = __ACCESS_ATTR_RO(level, name)
+
+#define ACCESS_ATTR_RO(level, attrib) \
+static ssize_t attrib##_access##level##_show(struct device *dev, \
+ struct device_attribute *attr, \
+ char *buf) \
+{ \
+ struct cxl_region *cxlr = to_cxl_region(dev); \
+ \
+ if (cxlr->coord[level].attrib == 0) \
+ return -ENOENT; \
+ \
+ return sysfs_emit(buf, "%u\n", cxlr->coord[level].attrib); \
+} \
+static ACCESS_DEVICE_ATTR_RO(level, attrib)
+
+ACCESS_ATTR_RO(0, read_bandwidth);
+ACCESS_ATTR_RO(0, read_latency);
+ACCESS_ATTR_RO(0, write_bandwidth);
+ACCESS_ATTR_RO(0, write_latency);
+
+#define ACCESS_ATTR_DECLARE(level, attrib) \
+ (&dev_attr_access##level##_##attrib.attr)
+
+static struct attribute *access0_coordinate_attrs[] = {
+ ACCESS_ATTR_DECLARE(0, read_bandwidth),
+ ACCESS_ATTR_DECLARE(0, write_bandwidth),
+ ACCESS_ATTR_DECLARE(0, read_latency),
+ ACCESS_ATTR_DECLARE(0, write_latency),
+ NULL
+};
+
+ACCESS_ATTR_RO(1, read_bandwidth);
+ACCESS_ATTR_RO(1, read_latency);
+ACCESS_ATTR_RO(1, write_bandwidth);
+ACCESS_ATTR_RO(1, write_latency);
+
+static struct attribute *access1_coordinate_attrs[] = {
+ ACCESS_ATTR_DECLARE(1, read_bandwidth),
+ ACCESS_ATTR_DECLARE(1, write_bandwidth),
+ ACCESS_ATTR_DECLARE(1, read_latency),
+ ACCESS_ATTR_DECLARE(1, write_latency),
+ NULL
+};
+
+#define ACCESS_VISIBLE(level) \
+static umode_t cxl_region_access##level##_coordinate_visible( \
+ struct kobject *kobj, struct attribute *a, int n) \
+{ \
+ struct device *dev = kobj_to_dev(kobj); \
+ struct cxl_region *cxlr = to_cxl_region(dev); \
+ \
+ if (a == &dev_attr_access##level##_read_latency.attr && \
+ cxlr->coord[level].read_latency == 0) \
+ return 0; \
+ \
+ if (a == &dev_attr_access##level##_write_latency.attr && \
+ cxlr->coord[level].write_latency == 0) \
+ return 0; \
+ \
+ if (a == &dev_attr_access##level##_read_bandwidth.attr && \
+ cxlr->coord[level].read_bandwidth == 0) \
+ return 0; \
+ \
+ if (a == &dev_attr_access##level##_write_bandwidth.attr && \
+ cxlr->coord[level].write_bandwidth == 0) \
+ return 0; \
+ \
+ return a->mode; \
+}
+
+ACCESS_VISIBLE(0);
+ACCESS_VISIBLE(1);
+
+static const struct attribute_group cxl_region_access0_coordinate_group = {
+ .name = "access0",
+ .attrs = access0_coordinate_attrs,
+ .is_visible = cxl_region_access0_coordinate_visible,
+};
+
+static const struct attribute_group cxl_region_access1_coordinate_group = {
+ .name = "access1",
+ .attrs = access1_coordinate_attrs,
+ .is_visible = cxl_region_access1_coordinate_visible,
+};
+
static ssize_t uuid_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
@@ -2069,6 +2161,8 @@ static const struct attribute_group *region_groups[] = {
&cxl_base_attribute_group,
&cxl_region_group,
&cxl_region_target_group,
+ &cxl_region_access0_coordinate_group,
+ &cxl_region_access1_coordinate_group,
NULL,
};