From 36c5014e5460963ad7766487c0e22a7ff28681fc Mon Sep 17 00:00:00 2001 From: Wyes Karny Date: Tue, 31 Jan 2023 17:00:08 +0800 Subject: [PATCH] cpufreq: amd-pstate: optimize driver working mode selection in amd_pstate_param() 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. Acked-by: Huang Rui Reviewed-by: Mario Limonciello Tested-by: Wyes Karny Signed-off-by: Perry Yuan Signed-off-by: Wyes Karny Signed-off-by: Rafael J. Wysocki --- 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 c17bd84..65c16ed 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 1c4b865..dae2ce0 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 */ -- 2.7.4