[PATCH v2 3/5] cpupower: Add EPP value change support

From: Wyes Karny
Date: Fri Jun 16 2023 - 08:11:21 EST


amd_pstate and intel_pstate active mode drivers support energy
performance preference feature. Through this user can convey it's
energy/performance preference to platform. Add this value change
capability to cpupower.

To change the EPP value use below command:
cpupower set --epp performance

Signed-off-by: Wyes Karny <wyes.karny@xxxxxxx>
---
tools/power/cpupower/utils/cpupower-set.c | 23 +++++++++++++++++++-
tools/power/cpupower/utils/helpers/helpers.h | 5 +++++
tools/power/cpupower/utils/helpers/misc.c | 19 ++++++++++++++++
3 files changed, 46 insertions(+), 1 deletion(-)

diff --git a/tools/power/cpupower/utils/cpupower-set.c b/tools/power/cpupower/utils/cpupower-set.c
index 180d5ba877e6..a789b123dbd4 100644
--- a/tools/power/cpupower/utils/cpupower-set.c
+++ b/tools/power/cpupower/utils/cpupower-set.c
@@ -18,6 +18,7 @@

static struct option set_opts[] = {
{"perf-bias", required_argument, NULL, 'b'},
+ {"epp", required_argument, NULL, 'e'},
{ },
};

@@ -37,11 +38,13 @@ int cmd_set(int argc, char **argv)
union {
struct {
int perf_bias:1;
+ int epp:1;
};
int params;
} params;
int perf_bias = 0;
int ret = 0;
+ char epp[30];

ret = uname(&uts);
if (!ret && (!strcmp(uts.machine, "ppc64le") ||
@@ -55,7 +58,7 @@ int cmd_set(int argc, char **argv)

params.params = 0;
/* parameter parsing */
- while ((ret = getopt_long(argc, argv, "b:",
+ while ((ret = getopt_long(argc, argv, "b:e:",
set_opts, NULL)) != -1) {
switch (ret) {
case 'b':
@@ -69,6 +72,15 @@ int cmd_set(int argc, char **argv)
}
params.perf_bias = 1;
break;
+ case 'e':
+ if (params.epp)
+ print_wrong_arg_exit();
+ if (sscanf(optarg, "%29s", epp) != 1) {
+ print_wrong_arg_exit();
+ return -EINVAL;
+ }
+ params.epp = 1;
+ break;
default:
print_wrong_arg_exit();
}
@@ -102,6 +114,15 @@ int cmd_set(int argc, char **argv)
break;
}
}
+
+ if (params.epp) {
+ ret = cpupower_set_epp(cpu, epp);
+ if (ret) {
+ fprintf(stderr,
+ "Error setting epp value on CPU %d\n", cpu);
+ break;
+ }
+ }
}
return ret;
}
diff --git a/tools/power/cpupower/utils/helpers/helpers.h b/tools/power/cpupower/utils/helpers/helpers.h
index 96e4bede078b..5d998de2d291 100644
--- a/tools/power/cpupower/utils/helpers/helpers.h
+++ b/tools/power/cpupower/utils/helpers/helpers.h
@@ -116,6 +116,8 @@ extern int cpupower_intel_set_perf_bias(unsigned int cpu, unsigned int val);
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);
+
/* Read/Write msr ****************************/

/* PCI stuff ****************************/
@@ -173,6 +175,9 @@ static inline int cpupower_intel_get_perf_bias(unsigned int cpu)
static inline unsigned long long msr_intel_get_turbo_ratio(unsigned int cpu)
{ return 0; };

+static inline int cpupower_set_epp(unsigned int cpu, char *epp)
+{ return -1; };
+
/* Read/Write msr ****************************/

static inline int cpufreq_has_boost_support(unsigned int cpu, int *support,
diff --git a/tools/power/cpupower/utils/helpers/misc.c b/tools/power/cpupower/utils/helpers/misc.c
index 21f653cd472c..63c3f26ef874 100644
--- a/tools/power/cpupower/utils/helpers/misc.c
+++ b/tools/power/cpupower/utils/helpers/misc.c
@@ -87,6 +87,25 @@ int cpupower_intel_set_perf_bias(unsigned int cpu, unsigned int val)
return 0;
}

+int cpupower_set_epp(unsigned int cpu, char *epp)
+{
+ char path[SYSFS_PATH_MAX];
+ char linebuf[30] = {};
+
+ snprintf(path, sizeof(path),
+ PATH_TO_CPU "cpu%u/cpufreq/energy_performance_preference", cpu);
+
+ if (!is_valid_path(path))
+ return -1;
+
+ snprintf(linebuf, sizeof(linebuf), "%s", epp);
+
+ if (cpupower_write_sysfs(path, linebuf, 30) <= 0)
+ return -1;
+
+ return 0;
+}
+
bool cpupower_amd_pstate_enabled(void)
{
char *driver = cpufreq_get_driver(0);
--
2.34.1