Messages in this thread | | | Date | Tue, 3 Jan 2023 18:32:45 -0600 | Subject | Re: [PATCH v9 05/13] cpufreq: amd-pstate: optimize driver working mode selection in amd_pstate_param() | From | "Limonciello, Mario" <> |
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On 12/25/2022 10:34, Perry Yuan wrote: > From: Wyes Karny <wyes.karny@amd.com> > > The amd-pstate driver may support multiple working modes. > Introduce a variable to keep track of which mode is currently enabled. > Here we use cppc_state var to indicate which mode is enabled. > This change will help to simplify the the amd_pstate_param() to choose > which mode used for the following driver registration. > > Signed-off-by: Perry Yuan <perry.yuan@amd.com> > Signed-off-by: Wyes Karny <wyes.karny@amd.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
> --- > drivers/cpufreq/amd-pstate.c | 39 +++++++++++++++++++++++++++--------- > include/linux/amd-pstate.h | 17 ++++++++++++++++ > 2 files changed, 46 insertions(+), 10 deletions(-) > > diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c > index c17bd845f5fc..65c16edbbb20 100644 > --- a/drivers/cpufreq/amd-pstate.c > +++ b/drivers/cpufreq/amd-pstate.c > @@ -60,7 +60,18 @@ > * module parameter to be able to enable it manually for debugging. > */ > static struct cpufreq_driver amd_pstate_driver; > -static int cppc_load __initdata; > +static int cppc_state = AMD_PSTATE_DISABLE; > + > +static inline int get_mode_idx_from_str(const char *str, size_t size) > +{ > + int i; > + > + for (i=0; i < AMD_PSTATE_MAX; i++) { > + if (!strncmp(str, amd_pstate_mode_string[i], size)) > + return i; > + } > + return -EINVAL; > +} > > static inline int pstate_enable(bool enable) > { > @@ -626,10 +637,10 @@ static int __init amd_pstate_init(void) > /* > * by default the pstate driver is disabled to load > * enable the amd_pstate passive mode driver explicitly > - * with amd_pstate=passive in kernel command line > + * with amd_pstate=passive or other modes in kernel command line > */ > - if (!cppc_load) { > - pr_debug("driver load is disabled, boot with amd_pstate=passive to enable this\n"); > + if (cppc_state == AMD_PSTATE_DISABLE) { > + pr_debug("driver load is disabled, boot with specific mode to enable this\n"); > return -ENODEV; > } > > @@ -671,16 +682,24 @@ device_initcall(amd_pstate_init); > > static int __init amd_pstate_param(char *str) > { > + size_t size; > + int mode_idx; > + > if (!str) > return -EINVAL; > > - if (!strcmp(str, "disable")) { > - cppc_load = 0; > - pr_info("driver is explicitly disabled\n"); > - } else if (!strcmp(str, "passive")) > - cppc_load = 1; > + size = strlen(str); > + mode_idx = get_mode_idx_from_str(str, size); > > - return 0; > + if (mode_idx >= AMD_PSTATE_DISABLE && mode_idx < AMD_PSTATE_MAX) { > + cppc_state = mode_idx; > + if (cppc_state == AMD_PSTATE_DISABLE) > + pr_info("driver is explicitly disabled\n"); > + > + return 0; > + } > + > + return -EINVAL; > } > early_param("amd_pstate", amd_pstate_param); > > diff --git a/include/linux/amd-pstate.h b/include/linux/amd-pstate.h > index 1c4b8659f171..dae2ce0f6735 100644 > --- a/include/linux/amd-pstate.h > +++ b/include/linux/amd-pstate.h > @@ -74,4 +74,21 @@ struct amd_cpudata { > bool boost_supported; > }; > > +/* > + * enum amd_pstate_mode - driver working mode of amd pstate > + */ > +enum amd_pstate_mode { > + AMD_PSTATE_DISABLE = 0, > + AMD_PSTATE_PASSIVE, > + AMD_PSTATE_ACTIVE, > + AMD_PSTATE_MAX, > +}; > + > +static const char * const amd_pstate_mode_string[] = { > + [AMD_PSTATE_DISABLE] = "disable", > + [AMD_PSTATE_PASSIVE] = "passive", > + [AMD_PSTATE_ACTIVE] = "active", > + NULL, > +}; > + > #endif /* _LINUX_AMD_PSTATE_H */
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