perf cpuid: Introduce a platform specific cpuid compare function

The function get_cpuid_str() is called by perf_pmu__getcpuid() and on
s390 returns a complete description of the CPU and its capabilities,
which is a comma separated list.

To map the CPU type with the value defined in the
pmu-events/arch/s390/mapfile.csv, introduce an architecture specific
cpuid compare function named strcmp_cpuid_str()

The currently used regex algorithm is defined as the weak default and
will be used if no platform specific one is defined. This matches the
current behavior.

Signed-off-by: Thomas Richter <tmricht@linux.vnet.ibm.com>
Reviewed-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Link: http://lkml.kernel.org/r/20180213151419.80737-3-tmricht@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/tools/perf/arch/s390/util/header.c b/tools/perf/arch/s390/util/header.c
index a78064c25ced..231294b80dc4 100644
--- a/tools/perf/arch/s390/util/header.c
+++ b/tools/perf/arch/s390/util/header.c
@@ -146,3 +146,21 @@ char *get_cpuid_str(struct perf_pmu *pmu __maybe_unused)
 		zfree(&buf);
 	return buf;
 }
+
+/*
+ * Compare the cpuid string returned by get_cpuid() function
+ * with the name generated by the jevents file read from
+ * pmu-events/arch/s390/mapfile.csv.
+ *
+ * Parameter mapcpuid is the cpuid as stored in the
+ * pmu-events/arch/s390/mapfile.csv. This is just the type number.
+ * Parameter cpuid is the cpuid returned by function get_cpuid().
+ */
+int strcmp_cpuid_str(const char *mapcpuid, const char *cpuid)
+{
+	char *cp = strchr(cpuid, ',');
+
+	if (cp == NULL)
+		return -1;
+	return strncmp(cp + 1, mapcpuid, strlen(mapcpuid));
+}