[PATCH v2 4/5] cpupower: Add support for amd_pstate mode change

From: Wyes Karny
Date: Fri Jun 16 2023 - 08:11:23 EST


amd_pstate supports changing of its mode dynamically via `status` sysfs
file. Add the same capability in cpupower. To change the mode to active
mode use below command:

cpupower set --amd-pstate-mode active

Acked-by: Huang Rui <ray.huang@xxxxxxx>
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@xxxxxxx>
Signed-off-by: Wyes Karny <wyes.karny@xxxxxxx>
---
tools/power/cpupower/utils/cpupower-set.c | 24 ++++++++++++++++++--
tools/power/cpupower/utils/helpers/helpers.h | 3 +++
tools/power/cpupower/utils/helpers/misc.c | 18 +++++++++++++++
3 files changed, 43 insertions(+), 2 deletions(-)

diff --git a/tools/power/cpupower/utils/cpupower-set.c b/tools/power/cpupower/utils/cpupower-set.c
index a789b123dbd4..c2ba69b7ea54 100644
--- a/tools/power/cpupower/utils/cpupower-set.c
+++ b/tools/power/cpupower/utils/cpupower-set.c
@@ -19,6 +19,7 @@
static struct option set_opts[] = {
{"perf-bias", required_argument, NULL, 'b'},
{"epp", required_argument, NULL, 'e'},
+ {"amd-pstate-mode", required_argument, NULL, 'm'},
{ },
};

@@ -39,12 +40,13 @@ int cmd_set(int argc, char **argv)
struct {
int perf_bias:1;
int epp:1;
+ int mode:1;
};
int params;
} params;
int perf_bias = 0;
int ret = 0;
- char epp[30];
+ char epp[30], mode[20];

ret = uname(&uts);
if (!ret && (!strcmp(uts.machine, "ppc64le") ||
@@ -58,7 +60,7 @@ int cmd_set(int argc, char **argv)

params.params = 0;
/* parameter parsing */
- while ((ret = getopt_long(argc, argv, "b:e:",
+ while ((ret = getopt_long(argc, argv, "b:e:m:",
set_opts, NULL)) != -1) {
switch (ret) {
case 'b':
@@ -81,6 +83,17 @@ int cmd_set(int argc, char **argv)
}
params.epp = 1;
break;
+ case 'm':
+ if (cpupower_cpu_info.vendor != X86_VENDOR_AMD)
+ print_wrong_arg_exit();
+ if (params.mode)
+ print_wrong_arg_exit();
+ if (sscanf(optarg, "%19s", mode) != 1) {
+ print_wrong_arg_exit();
+ return -EINVAL;
+ }
+ params.mode = 1;
+ break;
default:
print_wrong_arg_exit();
}
@@ -89,6 +102,12 @@ int cmd_set(int argc, char **argv)
if (!params.params)
print_wrong_arg_exit();

+ if (params.mode) {
+ ret = cpupower_set_amd_pstate_mode(mode);
+ if (ret)
+ fprintf(stderr, "Error setting mode\n");
+ }
+
/* Default is: set all CPUs */
if (bitmask_isallclear(cpus_chosen))
bitmask_setall(cpus_chosen);
@@ -123,6 +142,7 @@ int cmd_set(int argc, char **argv)
break;
}
}
+
}
return ret;
}
diff --git a/tools/power/cpupower/utils/helpers/helpers.h b/tools/power/cpupower/utils/helpers/helpers.h
index 5d998de2d291..d35596631eef 100644
--- a/tools/power/cpupower/utils/helpers/helpers.h
+++ b/tools/power/cpupower/utils/helpers/helpers.h
@@ -117,6 +117,7 @@ extern int cpupower_intel_get_perf_bias(unsigned int cpu);
extern unsigned long long msr_intel_get_turbo_ratio(unsigned int cpu);

extern int cpupower_set_epp(unsigned int cpu, char *epp);
+extern int cpupower_set_amd_pstate_mode(char *mode);

/* Read/Write msr ****************************/

@@ -177,6 +178,8 @@ static inline unsigned long long msr_intel_get_turbo_ratio(unsigned int cpu)

static inline int cpupower_set_epp(unsigned int cpu, char *epp)
{ return -1; };
+static inline int cpupower_set_amd_pstate_mode(char *mode)
+{ return -1; };

/* Read/Write msr ****************************/

diff --git a/tools/power/cpupower/utils/helpers/misc.c b/tools/power/cpupower/utils/helpers/misc.c
index 63c3f26ef874..9df9af8a969e 100644
--- a/tools/power/cpupower/utils/helpers/misc.c
+++ b/tools/power/cpupower/utils/helpers/misc.c
@@ -106,6 +106,24 @@ int cpupower_set_epp(unsigned int cpu, char *epp)
return 0;
}

+int cpupower_set_amd_pstate_mode(char *mode)
+{
+ char path[SYSFS_PATH_MAX];
+ char linebuf[20] = {};
+
+ snprintf(path, sizeof(path), PATH_TO_CPU "amd_pstate/status");
+
+ if (!is_valid_path(path))
+ return -1;
+
+ snprintf(linebuf, sizeof(linebuf), "%s\n", mode);
+
+ if (cpupower_write_sysfs(path, linebuf, 20) <= 0)
+ return -1;
+
+ return 0;
+}
+
bool cpupower_amd_pstate_enabled(void)
{
char *driver = cpufreq_get_driver(0);
--
2.34.1