[PATCH v7 02/10] cpupower: Add the function to check AMD P-State enabled

From: Huang Rui <ray.huang@amd.com>
To: Shuah Khan <skhan@linuxfoundation.org>,
	"Rafael J . Wysocki" <rafael.j.wysocki@intel.com>,
	<linux-pm@vger.kernel.org>
Cc: Deepak Sharma <deepak.sharma@amd.com>,
	Alex Deucher <alexander.deucher@amd.com>,
	Mario Limonciello <mario.limonciello@amd.com>,
	Steven Noonan <steven@valvesoftware.com>,
	Nathan Fontenot <nathan.fontenot@amd.com>,
	Jinzhou Su <Jinzhou.Su@amd.com>,
	Xiaojian Du <Xiaojian.Du@amd.com>,
	Perry Yuan <Perry.Yuan@amd.com>, Jassmine Meng <li.meng@amd.com>,
	Borislav Petkov <bp@alien8.de>,
	Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@kernel.org>,
	Viresh Kumar <viresh.kumar@linaro.org>,
	Steven Rostedt <rostedt@goodmis.org>,
	"Giovanni Gherdovich" <ggherdovich@suse.cz>,
	<linux-kernel@vger.kernel.org>, Huang Rui <ray.huang@amd.com>
Subject: [PATCH v7 02/10] cpupower: Add the function to check AMD P-State enabled
Date: Tue, 22 Feb 2022 23:34:18 +0800	[thread overview]
Message-ID: <20220222153426.2216974-3-ray.huang@amd.com> (raw)
In-Reply-To: <20220222153426.2216974-1-ray.huang@amd.com>

The processor with AMD P-State function also supports legacy ACPI
hardware P-States feature as well. Once driver sets AMD P-State eanbled,
the processor will respond the finer grain AMD P-State feature instead of
legacy ACPI P-States. So it introduces the cpupower_amd_pstate_enabled()
to check whether the current kernel enables AMD P-State or AMD CPUFreq
module.

Signed-off-by: Huang Rui <ray.huang@amd.com>
---
 tools/power/cpupower/utils/helpers/helpers.h | 10 ++++++++++
 tools/power/cpupower/utils/helpers/misc.c    | 18 ++++++++++++++++++
 2 files changed, 28 insertions(+)

diff --git a/tools/power/cpupower/utils/helpers/helpers.h b/tools/power/cpupower/utils/helpers/helpers.h
index b4813efdfb00..62771a086871 100644
--- a/tools/power/cpupower/utils/helpers/helpers.h
+++ b/tools/power/cpupower/utils/helpers/helpers.h
@@ -11,6 +11,7 @@
 
 #include <libintl.h>
 #include <locale.h>
+#include <stdbool.h>
 
 #include "helpers/bitmask.h"
 #include <cpupower.h>
@@ -136,6 +137,12 @@ extern int decode_pstates(unsigned int cpu, int boost_states,
 
 extern int cpufreq_has_boost_support(unsigned int cpu, int *support,
 				     int *active, int * states);
+
+/* AMD P-State stuff **************************/
+bool cpupower_amd_pstate_enabled(void);
+
+/* AMD P-State stuff **************************/
+
 /*
  * CPUID functions returning a single datum
  */
@@ -168,6 +175,9 @@ static inline int cpufreq_has_boost_support(unsigned int cpu, int *support,
 					    int *active, int * states)
 { return -1; }
 
+static inline bool cpupower_amd_pstate_enabled(void)
+{ return false; }
+
 /* cpuid and cpuinfo helpers  **************************/
 
 static inline unsigned int cpuid_eax(unsigned int op) { return 0; };
diff --git a/tools/power/cpupower/utils/helpers/misc.c b/tools/power/cpupower/utils/helpers/misc.c
index fc6e34511721..0c483cdefcc2 100644
--- a/tools/power/cpupower/utils/helpers/misc.c
+++ b/tools/power/cpupower/utils/helpers/misc.c
@@ -3,9 +3,11 @@
 #include <stdio.h>
 #include <errno.h>
 #include <stdlib.h>
+#include <string.h>
 
 #include "helpers/helpers.h"
 #include "helpers/sysfs.h"
+#include "cpufreq.h"
 
 #if defined(__i386__) || defined(__x86_64__)
 
@@ -83,6 +85,22 @@ int cpupower_intel_set_perf_bias(unsigned int cpu, unsigned int val)
 	return 0;
 }
 
+bool cpupower_amd_pstate_enabled(void)
+{
+	char *driver = cpufreq_get_driver(0);
+	bool ret = false;
+
+	if (!driver)
+		return ret;
+
+	if (!strcmp(driver, "amd-pstate"))
+		ret = true;
+
+	cpufreq_put_driver(driver);
+
+	return ret;
+}
+
 #endif /* #if defined(__i386__) || defined(__x86_64__) */
 
 /* get_cpustate
-- 
2.25.1

