On Wed, Feb 24, 2021 at 07:58:39PM +0530, Madhavan Srinivasan wrote:
Introduce code to support the checking of attr.config* for
values which are reserved for a given platform.
Performance Monitoring Unit (PMU) configuration registers
have fileds that are reserved and specific values to bit fields
s/fileds/fields/
as reserved. Writing a none zero values in these fields
Should the previous sentences say something like "required values
for specific bit fields" or "specific bit fields that are reserved"?
s/none zero/non-zero/
or writing invalid value to bit fields will have unknown
behaviours.
Patch here add a generic call-back function "check_attr_config"
s/add/adds/ or "This patch adds ..." or just "Add ...".
quoted hunk ↗ jump to hunk
in "struct power_pmu", to be called in event_init to
check for attr.config* values for a given platform.
"check_attr_config" is valid only for raw event type.
Suggested-by: Alexey Kardashevskiy <redacted>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
---
arch/powerpc/include/asm/perf_event_server.h | 6 ++++++
arch/powerpc/perf/core-book3s.c | 12 ++++++++++++
2 files changed, 18 insertions(+)
diff --git a/arch/powerpc/include/asm/perf_event_server.h b/arch/powerpc/include/asm/perf_event_server.h
index 00e7e671bb4b..dde97d7d9253 100644
--- a/arch/powerpc/include/asm/perf_event_server.h
+++ b/arch/powerpc/include/asm/perf_event_server.h
@@ -67,6 +67,12 @@ struct power_pmu {
* the pmu supports extended perf regs capability
*/
int capabilities;
+ /*
+ * Function to check event code for values which are
+ * reserved. Function takes struct perf_event as input,
+ * since event code could be spread in attr.config*
+ */
+ int (*check_attr_config)(struct perf_event *ev);
};
/*diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c
index 6817331e22ff..679d67506299 100644
--- a/arch/powerpc/perf/core-book3s.c
+++ b/arch/powerpc/perf/core-book3s.c
@@ -1958,6 +1958,18 @@ static int power_pmu_event_init(struct perf_event *event)
if (ppmu->blacklist_ev && is_event_blacklisted(ev))
return -EINVAL;
+ /*
+ * PMU config registers have fileds that are
+ * reserved and spacific values to bit fileds be reserved.
s/spacific/specific/
s/fileds/fields/
Same comment about "specific values to bit fields be reserved", and
rewording that to be more clear.
quoted hunk ↗ jump to hunk
+ * This call-back will check the event code for same.
+ *
+ * Event type hardware and hw_cache will not value
+ * invalid values in the event code which is not true
+ * for raw event type.
I confess I don't understand what this means. (But it could be just me!)
quoted hunk ↗ jump to hunk
+ */
+ if (ppmu->check_attr_config &&
+ ppmu->check_attr_config(event))
+ return -EINVAL;
break;
default:
return -ENOENT;
--
PC