[PATCH] perf stat: Suppress warning when using cpum_cf events on s390

[Thomas Richter]

Running command perf stat -vv -e cpu_cycles -C0 -- true
displays this warning:

 Attempting to add event pmu 'cpum_cf' with 'cpu_cycles,'
 that may result in non-fatal errors

Make the PMU cpum_cf selectable and avoid this warning.
While at it also fix this warning for PMUs pai_crypto and pai_ext.

Output before:

 #  ./perf stat -vv -e cpu_cycles -C0 -- true
 Using CPUID IBM,3931,704,A01,3.7,002f
 Attempting to add event pmu 'cpum_cf' with 'cpu_cycles,'
   that may result in non-fatal errors
 After aliases, add event pmu 'cpum_cf' with 'event,'
   that may result in non-fatal errors
   cpu_cycles -> cpum_cf/event=0/
 Control descriptor is not initialized
 ------------------------------------------------------------
 perf_event_attr:
  type                             10
  size                             128
  config                           0x1001
  sample_type                      IDENTIFIER
  read_format                      TOTAL_TIME_ENABLED|TOTAL_TIME_RUNNING
  disabled                         1
  inherit                          1
  exclude_guest                    1
 ------------------------------------------------------------
 sys_perf_event_open: pid -1  cpu 0  group_fd -1  flags 0x8 = 3
 cpu_cycles: 0: 290434 2479172 2479172:
 cpu_cycles: 290434 2479172 2479172

 Performance counter stats for 'CPU(s) 0':

           290,434      cpu_cycles

       0.002465617 seconds time elapsed
 #

Now the warning "Attempting to add event pmu 'cpum_cf' ..."
does not show up anymore.

Output after:
 # ./perf stat -vv -e cpu_cycles -C0 -- true
 Using CPUID IBM,3931,704,A01,3.7,002f
 After aliases, add event pmu 'cpum_cf' with 'event,'
   that may result in non-fatal errors
   cpu_cycles -> cpum_cf/event=0/
 Control descriptor is not initialized
 ....

 Performance counter stats for 'CPU(s) 0':

           357,023      cpu_cycles

       0.002454995 seconds time elapsed
 #

Signed-off-by: Thomas Richter <tmricht@xxxxxxxxxxxxx>
---
 tools/perf/arch/s390/util/Build |  1 +
 tools/perf/arch/s390/util/pmu.c | 23 +++++++++++++++++++++++
 2 files changed, 24 insertions(+)
 create mode 100644 tools/perf/arch/s390/util/pmu.c

diff --git a/tools/perf/arch/s390/util/Build b/tools/perf/arch/s390/util/Build
index db6884086997..fa66f15a14ec 100644
--- a/tools/perf/arch/s390/util/Build
+++ b/tools/perf/arch/s390/util/Build
@@ -6,5 +6,6 @@ perf-$(CONFIG_DWARF) += dwarf-regs.o
 perf-$(CONFIG_LIBDW_DWARF_UNWIND) += unwind-libdw.o
 
 perf-y += machine.o
+perf-y += pmu.o
 
 perf-$(CONFIG_AUXTRACE) += auxtrace.o
diff --git a/tools/perf/arch/s390/util/pmu.c b/tools/perf/arch/s390/util/pmu.c
new file mode 100644
index 000000000000..11f03f32e3fd
--- /dev/null
+++ b/tools/perf/arch/s390/util/pmu.c
@@ -0,0 +1,23 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * Copyright IBM Corp. 2023
+ * Author(s): Thomas Richter <tmricht@xxxxxxxxxxxxx>
+ */
+
+#include <string.h>
+
+#include "../../../util/pmu.h"
+
+#define	S390_PMUPAI_CRYPTO	"pai_crypto"
+#define	S390_PMUPAI_EXT		"pai_ext"
+#define	S390_PMUCPUM_CF		"cpum_cf"
+
+struct perf_event_attr *perf_pmu__get_default_config(struct perf_pmu *pmu)
+{
+	if (!strcmp(pmu->name, S390_PMUPAI_CRYPTO) ||
+	    !strcmp(pmu->name, S390_PMUPAI_EXT) ||
+	    !strcmp(pmu->name, S390_PMUCPUM_CF))
+		pmu->selectable = true;
+	return NULL;
+}
-- 
2.39.1