diff options
| author | Madhavan Srinivasan <maddy@linux.ibm.com> | 2021-04-08 10:45:03 +0300 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2021-04-14 16:04:19 +0300 |
| commit | 2e2a441d2c0bb639b6fdbb64b15ee0a43599bcec (patch) | |
| tree | 4a41289e05c6b4abce5e817706987ff47caba53e | |
| parent | 59fd366b9bef2d048af763e27cd1622ee5a1dfd4 (diff) | |
| download | linux-2e2a441d2c0bb639b6fdbb64b15ee0a43599bcec.tar.xz | |
powerpc/perf: Infrastructure to support checking of attr.config*
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 fields that are reserved and some specific values for
bit fields are reserved. For ex., MMCRA[61:62] is
Random Sampling Mode (SM) and value of 0b11 for this field
is reserved.
Writing non-zero or invalid values in these fields will
have unknown behaviours.
Patch adds a generic call-back function "check_attr_config"
in "struct power_pmu", to be called in event_init to
check for attr.config* values for a given platform.
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210408074504.248211-1-maddy@linux.ibm.com
| -rw-r--r-- | arch/powerpc/include/asm/perf_event_server.h | 6 | ||||
| -rw-r--r-- | arch/powerpc/perf/core-book3s.c | 11 |
2 files changed, 17 insertions, 0 deletions
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 766f064f00fb..b17358e8dc12 100644 --- a/arch/powerpc/perf/core-book3s.c +++ b/arch/powerpc/perf/core-book3s.c @@ -1963,6 +1963,17 @@ static int power_pmu_event_init(struct perf_event *event) return -ENOENT; } + /* + * PMU config registers have fields that are + * reserved and some specific values for bit fields are reserved. + * For ex., MMCRA[61:62] is Randome Sampling Mode (SM) + * and value of 0b11 to this field is reserved. + * Check for invalid values in attr.config. + */ + if (ppmu->check_attr_config && + ppmu->check_attr_config(event)) + return -EINVAL; + event->hw.config_base = ev; event->hw.idx = 0; |