Commit a1c45d3e authored by Robin Murphy's avatar Robin Murphy Committed by Will Deacon
Browse files

perf/arm-cmn: Add sysfs identifier 



Expose a sysfs identifier encapsulating the CMN part number and revision
so that jevents can narrow down a fundamental set of possible events for
calculating metrics. Configuration-dependent aspects - such as whether a
given node type is present, and/or a given node ID is valid - are still
not covered, and in general it's hard to see how userspace could handle
them, so we won't be removing any data or validation logic from the
driver any time soon, but at least it's a step in a useful direction.

Signed-off-by: default avatarRobin Murphy <robin.murphy@arm.com>
Reviewed-and-tested-by: default avatarIlkka Koskinen <ilkka@os.amperecomputing.com>
Tested-by: default avatarJing Zhang <renyu.zj@linux.alibaba.com>
Link: https://lore.kernel.org/r/b8a14c14fcdf028939ebf57849863e8ae01743de.1686588640.git.robin.murphy@arm.com


Signed-off-by: default avatarWill Deacon <will@kernel.org>
parent 7819e05a

drivers/perf/arm-cmn.c

+16 −4
Original line number Diff line number Diff line
@@ -1199,19 +1199,31 @@ static ssize_t arm_cmn_cpumask_show(struct device *dev, 
static struct device_attribute arm_cmn_cpumask_attr =

		__ATTR(cpumask, 0444, arm_cmn_cpumask_show, NULL);



static struct attribute *arm_cmn_cpumask_attrs[] = {

static ssize_t arm_cmn_identifier_show(struct device *dev,

				       struct device_attribute *attr, char *buf)

{

	struct arm_cmn *cmn = to_cmn(dev_get_drvdata(dev));



	return sysfs_emit(buf, "%03x%02x\n", cmn->part, cmn->rev);

}



static struct device_attribute arm_cmn_identifier_attr =

		__ATTR(identifier, 0444, arm_cmn_identifier_show, NULL);



static struct attribute *arm_cmn_other_attrs[] = {

	&arm_cmn_cpumask_attr.attr,

	&arm_cmn_identifier_attr.attr,

	NULL,

};



static const struct attribute_group arm_cmn_cpumask_attr_group = {

	.attrs = arm_cmn_cpumask_attrs,

static const struct attribute_group arm_cmn_other_attrs_group = {

	.attrs = arm_cmn_other_attrs,

};



static const struct attribute_group *arm_cmn_attr_groups[] = {

	&arm_cmn_event_attrs_group,

	&arm_cmn_format_attrs_group,

	&arm_cmn_cpumask_attr_group,

	&arm_cmn_other_attrs_group,

	NULL

};