perf tools: Move x86__is_amd_cpu() to util/env.c

It can be called from non-x86 platform so let's move it to the general
util directory.  Also add a new helper perf_env__is_x86_amd_cpu() so
that it can be called with an existing perf_env as well.

Reviewed-by: James Clark <james.clark@linaro.org>
Reviewed-by: Ravi Bangoria <ravi.bangoria@amd.com>
Acked-by: Kan Liang <kan.liang@linux.intel.com>
Cc: James Clark <james.clark@arm.com>
Cc: Atish Patra <atishp@atishpatra.org>
Cc: Mingwei Zhang <mizhang@google.com>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Palmer Dabbelt <palmer@rivosinc.com>
Link: https://lore.kernel.org/r/20241016062359.264929-7-namhyung@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

tools/perf/arch/x86/util/Build

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

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

@@ -16,7 +16,7 @@
 #include "../../../util/fncache.h"
 #include "../../../util/pmus.h"
 #include "mem-events.h"
-#include "env.h"
+#include "util/env.h"
 
 void perf_pmu__arch_init(struct perf_pmu *pmu __maybe_unused)
 {

tools/perf/util/env.c

@@ -5,6 +5,7 @@
 #include "util/header.h"
 #include "linux/compiler.h"
 #include <linux/ctype.h>
+#include <linux/string.h>
 #include <linux/zalloc.h>
 #include "cgroup.h"
 #include <errno.h>
@@ -639,3 +640,25 @@ void perf_env__find_br_cntr_info(struct perf_env *env,
 					     env->pmu_caps->br_cntr_width;
 	}
 }
+
+bool perf_env__is_x86_amd_cpu(struct perf_env *env)
+{
+	static int is_amd; /* 0: Uninitialized, 1: Yes, -1: No */
+
+	if (is_amd == 0)
+		is_amd = env->cpuid && strstarts(env->cpuid, "AuthenticAMD") ? 1 : -1;
+
+	return is_amd >= 1 ? true : false;
+}
+
+bool x86__is_amd_cpu(void)
+{
+	struct perf_env env = { .total_mem = 0, };
+	bool is_amd;
+
+	perf_env__cpuid(&env);
+	is_amd = perf_env__is_x86_amd_cpu(&env);
+	perf_env__exit(&env);
+
+	return is_amd;
+}

tools/perf/util/env.h

@@ -195,4 +195,8 @@ bool perf_env__has_pmu_mapping(struct perf_env *env, const char *pmu_name);
 void perf_env__find_br_cntr_info(struct perf_env *env,
 				 unsigned int *nr,
 				 unsigned int *width);
+
+bool x86__is_amd_cpu(void);
+bool perf_env__is_x86_amd_cpu(struct perf_env *env);
+
 #endif /* __PERF_ENV_H */