powerpc/hv-24x7: Add sysfs files inside hv-24x7 device to show cpumask

Patch here adds a cpumask attr to hv_24x7 pmu along with ABI documentation.

Primary use to expose the cpumask is for the perf tool which has the
capability to parse the driver sysfs folder and understand the
cpumask file. Having cpumask file will reduce the number of perf command
line parameters (will avoid "-C" option in the perf tool
command line). It can also notify the user which is
the current cpu used to retrieve the counter data.

command:# cat /sys/devices/hv_24x7/interface/cpumask
0

Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
Reviewed-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200709051836.723765-3-kjain@linux.ibm.com
This commit is contained in:
Kajol Jain 2020-07-09 10:48:36 +05:30 committed by Michael Ellerman
parent 1a8f0886a6
commit 792f73f747
2 changed files with 15 additions and 0 deletions

View File

@ -43,6 +43,13 @@ Description: read only
This sysfs interface exposes the number of cores per chip
present in the system.
What: /sys/devices/hv_24x7/interface/cpumask
Date: July 2020
Contact: Linux on PowerPC Developer List <linuxppc-dev@lists.ozlabs.org>
Description: read only
This sysfs file exposes the cpumask which is designated to make
HCALLs to retrieve hv-24x7 pmu event counter data.
What: /sys/bus/event_source/devices/hv_24x7/event_descs/<event-name>
Date: February 2014
Contact: Linux on PowerPC Developer List <linuxppc-dev@lists.ozlabs.org>

View File

@ -448,6 +448,12 @@ static ssize_t device_show_string(struct device *dev,
return sprintf(buf, "%s\n", (char *)d->var);
}
static ssize_t cpumask_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
return cpumap_print_to_pagebuf(true, buf, &hv_24x7_cpumask);
}
static ssize_t sockets_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
@ -1115,6 +1121,7 @@ static DEVICE_ATTR_RO(domains);
static DEVICE_ATTR_RO(sockets);
static DEVICE_ATTR_RO(chipspersocket);
static DEVICE_ATTR_RO(coresperchip);
static DEVICE_ATTR_RO(cpumask);
static struct bin_attribute *if_bin_attrs[] = {
&bin_attr_catalog,
@ -1128,6 +1135,7 @@ static struct attribute *if_attrs[] = {
&dev_attr_sockets.attr,
&dev_attr_chipspersocket.attr,
&dev_attr_coresperchip.attr,
&dev_attr_cpumask.attr,
NULL,
};