From 572e2cd74fcfa218cdcc463fa216a05814888f2d Mon Sep 17 00:00:00 2001 From: "John W. Linville" Date: Fri, 8 Mar 2024 14:59:29 -0700 Subject: [PATCH] cxl/region: Add sysfs attribute for locality attributes of CXL regions JIRA: https://issues.redhat.com/browse/RHEL-54609 Add read/write latencies and bandwidth sysfs attributes for the enabled CXL region. The bandwidth is the aggregated bandwidth of all devices that contribute to the CXL region. The latency is the worst latency of the device amongst all the devices that contribute to the CXL region. Reviewed-by: Jonathan Cameron Tested-by: Jonathan Cameron Signed-off-by: Dave Jiang Link: https://lore.kernel.org/r/20240308220055.2172956-11-dave.jiang@intel.com Signed-off-by: Dan Williams (cherry picked from commit c20eaf44113eac090b0d77fa2036143a836b9f56) Signed-off-by: John W. Linville --- Documentation/ABI/testing/sysfs-bus-cxl | 34 +++++++++ drivers/cxl/core/region.c | 94 +++++++++++++++++++++++++ 2 files changed, 128 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl index 80563ba7f417..5384f92360d6 100644 --- a/Documentation/ABI/testing/sysfs-bus-cxl +++ b/Documentation/ABI/testing/sysfs-bus-cxl @@ -554,3 +554,37 @@ 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. diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c index 0afeaee520ce..98ec71fa0b11 100644 --- a/drivers/cxl/core/region.c +++ b/drivers/cxl/core/region.c @@ -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, };