perf tool x86: Consolidate is_amd check into single function

There are multiple places where x86 specific code determines AMD vs
Intel arch and acts based on that. Consolidate those checks into a
single function.

Signed-off-by: Ravi Bangoria <ravi.bangoria@amd.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ali Saidi <alisaidi@amazon.com>
Cc: Ananth Narayan <ananth.narayan@amd.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sandipan Das <sandipan.das@amd.com>
Cc: Santosh Shukla <santosh.shukla@amd.com>
Link: https://lore.kernel.org/r/20230613095506.547-3-ravi.bangoria@amd.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Author: Ravi Bangoria

tools/perf/arch/x86/util/Build

@@ -10,6 +10,7 @@ perf-y += evlist.o
 perf-y += mem-events.o
 perf-y += evsel.o
 perf-y += iostat.o
+perf-y += env.o
 
 perf-$(CONFIG_DWARF) += dwarf-regs.o
 perf-$(CONFIG_BPF_PROLOGUE) += dwarf-regs.o

tools/perf/arch/x86/util/env.c

@@ -0,0 +1,19 @@
+// SPDX-License-Identifier: GPL-2.0
+#include "linux/string.h"
+#include "util/env.h"
+#include "env.h"
+
+bool x86__is_amd_cpu(void)
+{
+	struct perf_env env = { .total_mem = 0, };
+	static int is_amd; /* 0: Uninitialized, 1: Yes, -1: No */
+
+	if (is_amd)
+		goto ret;
+
+	perf_env__cpuid(&env);
+	is_amd = env.cpuid && strstarts(env.cpuid, "AuthenticAMD") ? 1 : -1;
+
+ret:
+	return is_amd >= 1 ? true : false;
+}

tools/perf/arch/x86/util/env.h

@@ -0,0 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _X86_ENV_H
+#define _X86_ENV_H
+
+bool x86__is_amd_cpu(void);
+
+#endif /* _X86_ENV_H */

tools/perf/arch/x86/util/evsel.c

@@ -8,6 +8,7 @@
 #include "linux/string.h"
 #include "evsel.h"
 #include "util/debug.h"
+#include "env.h"
 
 #define IBS_FETCH_L3MISSONLY   (1ULL << 59)
 #define IBS_OP_L3MISSONLY      (1ULL << 16)
@@ -78,23 +79,10 @@ void arch__post_evsel_config(struct evsel *evsel, struct perf_event_attr *attr)
 {
 	struct perf_pmu *evsel_pmu, *ibs_fetch_pmu, *ibs_op_pmu;
 	static int warned_once;
-	/* 0: Uninitialized, 1: Yes, -1: No */
-	static int is_amd;
 
-	if (warned_once || is_amd == -1)
+	if (warned_once || !x86__is_amd_cpu())
 		return;
 
-	if (!is_amd) {
-		struct perf_env *env = evsel__env(evsel);
-
-		if (!perf_env__cpuid(env) || !env->cpuid ||
-		    !strstarts(env->cpuid, "AuthenticAMD")) {
-			is_amd = -1;
-			return;
-		}
-		is_amd = 1;
-	}
-
 	evsel_pmu = evsel__find_pmu(evsel);
 	if (!evsel_pmu)
 		return;

tools/perf/arch/x86/util/mem-events.c

@@ -5,6 +5,7 @@
 #include "map_symbol.h"
 #include "mem-events.h"
 #include "linux/string.h"
+#include "env.h"
 
 static char mem_loads_name[100];
 static bool mem_loads_name__init;
@@ -27,28 +28,12 @@ static struct perf_mem_event perf_mem_events_amd[PERF_MEM_EVENTS__MAX] = {
 	E("mem-ldst",	"ibs_op//",	"ibs_op"),
 };
 
-static int perf_mem_is_amd_cpu(void)
-{
-	struct perf_env env = { .total_mem = 0, };
-
-	perf_env__cpuid(&env);
-	if (env.cpuid && strstarts(env.cpuid, "AuthenticAMD"))
-		return 1;
-	return -1;
-}
-
 struct perf_mem_event *perf_mem_events__ptr(int i)
 {
-	/* 0: Uninitialized, 1: Yes, -1: No */
-	static int is_amd;
-
 	if (i >= PERF_MEM_EVENTS__MAX)
 		return NULL;
 
-	if (!is_amd)
-		is_amd = perf_mem_is_amd_cpu();
-
-	if (is_amd == 1)
+	if (x86__is_amd_cpu())
 		return &perf_mem_events_amd[i];
 
 	return &perf_mem_events_intel[i];