perf tools: Use pmus to describe type from attribute

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 faults 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 <[e-mail]>
Tested-by: Arnaldo Carvalho de Melo <[e-mail]>
Tested-by: Kan Liang <[e-mail]>
Cc: Adrian Hunter <[e-mail]>
Cc: Alexander Shishkin <[e-mail]>
Cc: Ingo Molnar <[e-mail]>
Cc: James Clark <[e-mail]>
Cc: Jiri Olsa <[e-mail]>
Cc: Mark Rutland <[e-mail]>
Cc: Namhyung Kim <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Ravi Bangoria <[e-mail]>
Cc: Yang Jihong <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/util/perf_event_attr_fprintf.c

···
 #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 {
···
 }
 
 #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)
···
 #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)
···
 #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)			\
···
 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;