perf pmu-events: Hide the pmu_events

Hide that the pmu_event structs are an array with a new wrapper struct.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.garry@huawei.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Will Deacon <will@kernel.org>
Cc: Xing Zhengjun <zhengjun.xing@linux.intel.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20220812230949.683239-12-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

3 files changed, 57 insertions, 46 deletions

diff --git a/tools/perf/pmu-events/empty-pmu-events.c b/tools/perf/pmu-events/empty-pmu-events.c
index bee1967baa2b..5ed8c0aa4817 100644
--- a/tools/perf/pmu-events/empty-pmu-events.c
+++ b/tools/perf/pmu-events/empty-pmu-events.c
@@ -176,6 +176,10 @@ static const struct pmu_event pme_test_soc_cpu[] = {
 	},
 };
 
+/* Struct used to make the PMU event table implementation opaque to callers. */
+struct pmu_events_table {
+	const struct pmu_event *entries;
+};
 
 /*
  * Map a CPU to its table of PMU events. The CPU is identified by the
@@ -188,7 +192,7 @@ static const struct pmu_event pme_test_soc_cpu[] = {
 struct pmu_events_map {
 	const char *arch;
 	const char *cpuid;
-	const struct pmu_event *table;
+	const struct pmu_events_table table;
 };
 
 /*
@@ -199,12 +203,12 @@ static const struct pmu_events_map pmu_events_map[] = {
 	{
 		.arch = "testarch",
 		.cpuid = "testcpu",
-		.table = pme_test_soc_cpu,
+		.table = { pme_test_soc_cpu },
 	},
 	{
 		.arch = 0,
 		.cpuid = 0,
-		.table = 0,
+		.table = { 0 },
 	},
 };
 
@@ -234,23 +238,23 @@ static const struct pmu_event pme_test_soc_sys[] = {
 
 struct pmu_sys_events {
 	const char *name;
-	const struct pmu_event *table;
+	const struct pmu_events_table table;
 };
 
 static const struct pmu_sys_events pmu_sys_event_tables[] = {
 	{
-		.table = pme_test_soc_sys,
+		.table = { pme_test_soc_sys },
 		.name = "pme_test_soc_sys",
 	},
 	{
-		.table = 0
+		.table = { 0 }
 	},
 };
 
-int pmu_events_table_for_each_event(const struct pmu_event *table, pmu_event_iter_fn fn,
+int pmu_events_table_for_each_event(const struct pmu_events_table *table, pmu_event_iter_fn fn,
 				    void *data)
 {
-	for (const struct pmu_event *pe = &table[0];
+	for (const struct pmu_event *pe = &table->entries[0];
 	     pe->name || pe->metric_group || pe->metric_name;
 	     pe++) {
 		int ret = fn(pe, table, data);
@@ -261,9 +265,9 @@ int pmu_events_table_for_each_event(const struct pmu_event *table, pmu_event_ite
 	return 0;
 }
 
-const struct pmu_event *perf_pmu__find_table(struct perf_pmu *pmu)
+const struct pmu_events_table *perf_pmu__find_table(struct perf_pmu *pmu)
 {
-	const struct pmu_event *table = NULL;
+	const struct pmu_events_table *table = NULL;
 	char *cpuid = perf_pmu__getcpuid(pmu);
 	int i;
 
@@ -277,11 +281,11 @@ const struct pmu_event *perf_pmu__find_table(struct perf_pmu *pmu)
 	for (;;) {
 		const struct pmu_events_map *map = &pmu_events_map[i++];
 
-		if (!map->table)
+		if (!map->cpuid)
 			break;
 
 		if (!strcmp_cpuid_str(map->cpuid, cpuid)) {
-			table = map->table;
+			table = &map->table;
 			break;
 		}
 	}
@@ -289,13 +293,13 @@ const struct pmu_event *perf_pmu__find_table(struct perf_pmu *pmu)
 	return table;
 }
 
-const struct pmu_event *find_core_events_table(const char *arch, const char *cpuid)
+const struct pmu_events_table *find_core_events_table(const char *arch, const char *cpuid)
 {
 	for (const struct pmu_events_map *tables = &pmu_events_map[0];
-	     tables->table;
+	     tables->arch;
 	     tables++) {
 		if (!strcmp(tables->arch, arch) && !strcmp_cpuid_str(tables->cpuid, cpuid))
-			return tables->table;
+			return &tables->table;
 	}
 	return NULL;
 }
@@ -303,9 +307,9 @@ const struct pmu_event *find_core_events_table(const char *arch, const char *cpu
 int pmu_for_each_core_event(pmu_event_iter_fn fn, void *data)
 {
 	for (const struct pmu_events_map *tables = &pmu_events_map[0];
-	     tables->table;
+	     tables->arch;
 	     tables++) {
-		int ret = pmu_events_table_for_each_event(tables->table, fn, data);
+		int ret = pmu_events_table_for_each_event(&tables->table, fn, data);
 
 		if (ret)
 			return ret;
@@ -313,13 +317,13 @@ int pmu_for_each_core_event(pmu_event_iter_fn fn, void *data)
 	return 0;
 }
 
-const struct pmu_event *find_sys_events_table(const char *name)
+const struct pmu_events_table *find_sys_events_table(const char *name)
 {
 	for (const struct pmu_sys_events *tables = &pmu_sys_event_tables[0];
 	     tables->name;
 	     tables++) {
 		if (!strcmp(tables->name, name))
-			return tables->table;
+			return &tables->table;
 	}
 	return NULL;
 }
@@ -329,7 +333,7 @@ int pmu_for_each_sys_event(pmu_event_iter_fn fn, void *data)
 	for (const struct pmu_sys_events *tables = &pmu_sys_event_tables[0];
 	     tables->name;
 	     tables++) {
-		int ret = pmu_events_table_for_each_event(tables->table, fn, data);
+		int ret = pmu_events_table_for_each_event(&tables->table, fn, data);
 
 		if (ret)
 			return ret;
diff --git a/tools/perf/pmu-events/jevents.py b/tools/perf/pmu-events/jevents.py
index 977f2061a990..4b7948ba57d6 100755
--- a/tools/perf/pmu-events/jevents.py
+++ b/tools/perf/pmu-events/jevents.py
@@ -335,6 +335,11 @@ def process_one_file(parents: Sequence[str], item: os.DirEntry) -> None:
 def print_mapping_table(archs: Sequence[str]) -> None:
   """Read the mapfile and generate the struct from cpuid string to event table."""
   _args.output_file.write("""
+/* Struct used to make the PMU event table implementation opaque to callers. */
+struct pmu_events_table {
+        const struct pmu_event *entries;
+};
+
 /*
  * Map a CPU to its table of PMU events. The CPU is identified by the
  * cpuid field, which is an arch-specific identifier for the CPU.
@@ -346,7 +351,7 @@ def print_mapping_table(archs: Sequence[str]) -> None:
 struct pmu_events_map {
         const char *arch;
         const char *cpuid;
-        const struct pmu_event *table;
+        struct pmu_events_table table;
 };
 
 /*
@@ -360,7 +365,7 @@ const struct pmu_events_map pmu_events_map[] = {
       _args.output_file.write("""{
 \t.arch = "testarch",
 \t.cpuid = "testcpu",
-\t.table = pme_test_soc_cpu,
+\t.table = { pme_test_soc_cpu },
 },
 """)
     else:
@@ -375,7 +380,7 @@ const struct pmu_events_map pmu_events_map[] = {
             _args.output_file.write(f"""{{
 \t.arch = "{arch}",
 \t.cpuid = "{cpuid}",
-\t.table = {tblname}
+\t.table = {{ {tblname} }}
 }},
 """)
           first = False
@@ -383,7 +388,7 @@ const struct pmu_events_map pmu_events_map[] = {
   _args.output_file.write("""{
 \t.arch = 0,
 \t.cpuid = 0,
-\t.table = 0,
+\t.table = { 0 },
 }
 };
 """)
@@ -394,26 +399,26 @@ def print_system_mapping_table() -> None:
   _args.output_file.write("""
 struct pmu_sys_events {
 \tconst char *name;
-\tconst struct pmu_event *table;
+\tstruct pmu_events_table table;
 };
 
 static const struct pmu_sys_events pmu_sys_event_tables[] = {
 """)
   for tblname in _sys_event_tables:
     _args.output_file.write(f"""\t{{
-\t\t.table = {tblname},
+\t\t.table = {{ {tblname} }},
 \t\t.name = \"{tblname}\",
 \t}},
 """)
   _args.output_file.write("""\t{
-\t\t.table = 0
+\t\t.table = { 0 }
 \t},
 };
 
-int pmu_events_table_for_each_event(const struct pmu_event *table, pmu_event_iter_fn fn,
+int pmu_events_table_for_each_event(const struct pmu_events_table *table, pmu_event_iter_fn fn,
                                     void *data)
 {
-        for (const struct pmu_event *pe = &table[0];
+        for (const struct pmu_event *pe = &table->entries[0];
              pe->name || pe->metric_group || pe->metric_name;
              pe++) {
                 int ret = fn(pe, table, data);
@@ -424,9 +429,9 @@ int pmu_events_table_for_each_event(const struct pmu_event *table, pmu_event_ite
         return 0;
 }
 
-const struct pmu_event *perf_pmu__find_table(struct perf_pmu *pmu)
+const struct pmu_events_table *perf_pmu__find_table(struct perf_pmu *pmu)
 {
-        const struct pmu_event *table = NULL;
+        const struct pmu_events_table *table = NULL;
         char *cpuid = perf_pmu__getcpuid(pmu);
         int i;
 
@@ -439,11 +444,11 @@ const struct pmu_event *perf_pmu__find_table(struct perf_pmu *pmu)
         i = 0;
         for (;;) {
                 const struct pmu_events_map *map = &pmu_events_map[i++];
-                if (!map->table)
+                if (!map->arch)
                         break;
 
                 if (!strcmp_cpuid_str(map->cpuid, cpuid)) {
-                        table = map->table;
+                        table = &map->table;
                         break;
                 }
         }
@@ -451,13 +456,13 @@ const struct pmu_event *perf_pmu__find_table(struct perf_pmu *pmu)
         return table;
 }
 
-const struct pmu_event *find_core_events_table(const char *arch, const char *cpuid)
+const struct pmu_events_table *find_core_events_table(const char *arch, const char *cpuid)
 {
         for (const struct pmu_events_map *tables = &pmu_events_map[0];
-             tables->table;
+             tables->arch;
              tables++) {
                 if (!strcmp(tables->arch, arch) && !strcmp_cpuid_str(tables->cpuid, cpuid))
-                        return tables->table;
+                        return &tables->table;
         }
         return NULL;
 }
@@ -465,9 +470,9 @@ const struct pmu_event *find_core_events_table(const char *arch, const char *cpu
 int pmu_for_each_core_event(pmu_event_iter_fn fn, void *data)
 {
         for (const struct pmu_events_map *tables = &pmu_events_map[0];
-             tables->table;
+             tables->arch;
              tables++) {
-                int ret = pmu_events_table_for_each_event(tables->table, fn, data);
+                int ret = pmu_events_table_for_each_event(&tables->table, fn, data);
 
                 if (ret)
                         return ret;
@@ -475,13 +480,13 @@ int pmu_for_each_core_event(pmu_event_iter_fn fn, void *data)
         return 0;
 }
 
-const struct pmu_event *find_sys_events_table(const char *name)
+const struct pmu_events_table *find_sys_events_table(const char *name)
 {
         for (const struct pmu_sys_events *tables = &pmu_sys_event_tables[0];
              tables->name;
              tables++) {
                 if (!strcmp(tables->name, name))
-                        return tables->table;
+                        return &tables->table;
         }
         return NULL;
 }
@@ -491,7 +496,7 @@ int pmu_for_each_sys_event(pmu_event_iter_fn fn, void *data)
         for (const struct pmu_sys_events *tables = &pmu_sys_event_tables[0];
              tables->name;
              tables++) {
-                int ret = pmu_events_table_for_each_event(tables->table, fn, data);
+                int ret = pmu_events_table_for_each_event(&tables->table, fn, data);
 
                 if (ret)
                         return ret;
diff --git a/tools/perf/pmu-events/pmu-events.h b/tools/perf/pmu-events/pmu-events.h
index 70672842f77f..fe343c4d8016 100644
--- a/tools/perf/pmu-events/pmu-events.h
+++ b/tools/perf/pmu-events/pmu-events.h
@@ -30,18 +30,20 @@ struct pmu_event {
 	const char *metric_constraint;
 };
 
+struct pmu_events_table;
+
 typedef int (*pmu_event_iter_fn)(const struct pmu_event *pe,
-				 const struct pmu_event *table,
+				 const struct pmu_events_table *table,
 				 void *data);
 
-int pmu_events_table_for_each_event(const struct pmu_event *table, pmu_event_iter_fn fn,
+int pmu_events_table_for_each_event(const struct pmu_events_table *table, pmu_event_iter_fn fn,
 				    void *data);
 
-const struct pmu_event *perf_pmu__find_table(struct perf_pmu *pmu);
-const struct pmu_event *find_core_events_table(const char *arch, const char *cpuid);
+const struct pmu_events_table *perf_pmu__find_table(struct perf_pmu *pmu);
+const struct pmu_events_table *find_core_events_table(const char *arch, const char *cpuid);
 int pmu_for_each_core_event(pmu_event_iter_fn fn, void *data);
 
-const struct pmu_event *find_sys_events_table(const char *name);
+const struct pmu_events_table *find_sys_events_table(const char *name);
 int pmu_for_each_sys_event(pmu_event_iter_fn fn, void *data);
 
 #endif