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

[Mario Limonciello <mario.limonciello@amd.com>]

On 6/16/23 07:10, Wyes Karny wrote:
> 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@amd.com>
> Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
> Signed-off-by: Wyes Karny <wyes.karny@amd.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>

> ---
>   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);