On Fri, Apr 19, 2024 at 04:49:13PM +0100, Will Deacon wrote: > On Mon, Apr 15, 2024 at 02:13:15PM +0800, Xu Yang wrote: > > In current design, the user of perf app needs to input counter ID to count > > events. However, this is not user-friendly since the user needs to lookup > > the map table to find the counter. Instead of letting the user to input > > the counter, let this driver to manage the counters in this patch. > > > > This will be implemented by: > > 1. allocate counter 0 for cycle event. > > 2. find unused counter from 1-10 for reference events. > > 3. allocate specific counter for counter-specific events. > > > > In this patch, counter attr will be kept for back-compatible but all the > > value passed down by counter=<n> will be ignored. To mark counter-specific > > events, counter ID will be encoded into perf_pmu_events_attr.id. > > > > Reviewed-by: Frank Li <Frank.Li@xxxxxxx> > > Signed-off-by: Xu Yang <xu.yang_2@xxxxxxx> > > > > --- > > Changes in v6: > > - new patch > > Changes in v7: > > - no changes > > Changes in v8: > > - add Rb tag > > Changes in v9: > > - keep 'counter' attr for back-compatible > > Changes in v10: > > - add some explanation about 'counter' attr in commit message > > --- > > drivers/perf/fsl_imx9_ddr_perf.c | 168 ++++++++++++++++++------------- > > 1 file changed, 100 insertions(+), 68 deletions(-) > > [...] > > > @@ -245,8 +249,8 @@ static const struct attribute_group ddr_perf_events_attr_group = { > > .attrs = ddr_perf_events_attrs, > > }; > > > > -PMU_FORMAT_ATTR(event, "config:0-7"); > > -PMU_FORMAT_ATTR(counter, "config:8-15"); > > +PMU_FORMAT_ATTR(event, "config:0-15"); > > +PMU_FORMAT_ATTR(counter, "config:16-23"); > > Although these mappings are advertised in sysfs, I don't think we can > change them because userspace could be relying on them. I also can't > find any examples of other PMU drivers in the kernel changing these > mappings after being merged, so please keep tthem the same. > > If you need to expand the properties to be 16-bit, then you'll need to > split them into 2x8-bit fields. I just see tools/perf/tests/pmu.c: { "krava01", "config:0-1,62-63\n", } So I supposed "config:" supported below format PMU_FORMAT_ATTR(event, "config:0-7,16-19"); I just want to confim with you because I have not found other perf driver using such format yet. Frank > > Will