[PATCH v3 14/21] cpupower: add the function to check amd-pstate enabled

From: Huang Rui
Date: Fri Oct 29 2021 - 09:05:05 EST


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

Signed-off-by: Huang Rui <ray.huang@xxxxxxx>
---
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..e03cc97297aa 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-States stuff **************************/
+extern bool cpupower_amd_pstate_enabled(void);
+
+/* AMD P-States 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