[PATCH v1 5/6] perf tools: Use pmus to describe type from attribute

[Ian Rogers <irogers@google.com>]

When dumping a perf_event_attr, use pmus to find the PMU and its name
by the type number. This allows dynamically added PMUs to be described.

Before:
```
$ perf stat -vv -e data_read true
...
perf_event_attr:
  type                             24
  size                             136
  config                           0x20ff
  sample_type                      IDENTIFIER
  read_format                      TOTAL_TIME_ENABLED|TOTAL_TIME_RUNNING
  disabled                         1
  inherit                          1
  exclude_guest                    1
...
```

After:
```
$ perf stat -vv -e data_read true
...
perf_event_attr:
  type                             24 (uncore_imc_free_running_0)
  size                             136
  config                           0x20ff
  sample_type                      IDENTIFIER
  read_format                      TOTAL_TIME_ENABLED|TOTAL_TIME_RUNNING
  disabled                         1
  inherit                          1
  exclude_guest                    1
...
```

However, it also means that when we have a PMU name we prefer it to a
hard coded name:

Before:
```
$ perf stat -vv -e cycles true
...
perf_event_attr:
  type                             1 (PERF_TYPE_SOFTWARE)
  size                             136
  config                           0x2 (PERF_COUNT_SW_PAGE_FAULTS)
  sample_type                      IDENTIFIER
  read_format                      TOTAL_TIME_ENABLED|TOTAL_TIME_RUNNING
  disabled                         1
  inherit                          1
  enable_on_exec                   1
  exclude_guest                    1
...
```

After:
```
$ perf stat -vv -e faults true
...
perf_event_attr:
  type                             1 (software)
  size                             136
  config                           0x2 (PERF_COUNT_SW_PAGE_FAULTS)
  sample_type                      IDENTIFIER
  read_format                      TOTAL_TIME_ENABLED|TOTAL_TIME_RUNNING
  disabled                         1
  inherit                          1
  enable_on_exec                   1
  exclude_guest                    1
...
```

It feels more consistent to do this, rather than only prefer a PMU
name when a hard coded name isn't available.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/perf_event_attr_fprintf.c | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/tools/perf/util/perf_event_attr_fprintf.c b/tools/perf/util/perf_event_attr_fprintf.c
index 8f04d3b7f3ec..29e66835da3a 100644
--- a/tools/perf/util/perf_event_attr_fprintf.c
+++ b/tools/perf/util/perf_event_attr_fprintf.c
@@ -7,6 +7,8 @@
 #include <linux/types.h>
 #include <linux/perf_event.h>
 #include "util/evsel_fprintf.h"
+#include "util/pmu.h"
+#include "util/pmus.h"
 #include "trace-event.h"
 
 struct bit_names {
@@ -75,9 +77,12 @@ static void __p_read_format(char *buf, size_t size, u64 value)
 }
 
 #define ENUM_ID_TO_STR_CASE(x) case x: return (#x);
-static const char *stringify_perf_type_id(u64 value)
+static const char *stringify_perf_type_id(struct perf_pmu *pmu, u32 type)
 {
-	switch (value) {
+	if (pmu)
+		return pmu->name;
+
+	switch (type) {
 	ENUM_ID_TO_STR_CASE(PERF_TYPE_HARDWARE)
 	ENUM_ID_TO_STR_CASE(PERF_TYPE_SOFTWARE)
 	ENUM_ID_TO_STR_CASE(PERF_TYPE_TRACEPOINT)
@@ -175,9 +180,9 @@ do {								\
 #define print_id_unsigned(_s)	PRINT_ID(_s, "%"PRIu64)
 #define print_id_hex(_s)	PRINT_ID(_s, "%#"PRIx64)
 
-static void __p_type_id(char *buf, size_t size, u64 value)
+static void __p_type_id(struct perf_pmu *pmu, char *buf, size_t size, u64 value)
 {
-	print_id_unsigned(stringify_perf_type_id(value));
+	print_id_unsigned(stringify_perf_type_id(pmu, value));
 }
 
 static void __p_config_hw_id(char *buf, size_t size, u64 value)
@@ -246,7 +251,7 @@ static void __p_config_id(char *buf, size_t size, u32 type, u64 value)
 #define p_sample_type(val)	__p_sample_type(buf, BUF_SIZE, val)
 #define p_branch_sample_type(val) __p_branch_sample_type(buf, BUF_SIZE, val)
 #define p_read_format(val)	__p_read_format(buf, BUF_SIZE, val)
-#define p_type_id(val)		__p_type_id(buf, BUF_SIZE, val)
+#define p_type_id(val)		__p_type_id(pmu, buf, BUF_SIZE, val)
 #define p_config_id(val)	__p_config_id(buf, BUF_SIZE, attr->type, val)
 
 #define PRINT_ATTRn(_n, _f, _p, _a)			\
@@ -262,6 +267,7 @@ do {							\
 int perf_event_attr__fprintf(FILE *fp, struct perf_event_attr *attr,
 			     attr__fprintf_f attr__fprintf, void *priv)
 {
+	struct perf_pmu *pmu = perf_pmus__find_by_type(attr->type);
 	char buf[BUF_SIZE];
 	int ret = 0;
 
-- 
2.44.0.278.ge034bb2e1d-goog