Hi Ray, On 12/9/2022 1:13 PM, Huang Rui wrote: > On Wed, Dec 07, 2022 at 11:46:45PM +0800, Karny, Wyes wrote: >> From ACPI spec below 3 modes for CPPC can be defined: >> 1. Non autonomous: OS scaling governor specifies operating frequency/ >> performance level through `Desired Performance` register and PMFW >> follows that. >> 2. Guided autonomous: OS scaling governor specifies min and max >> frequencies/ performance levels through `Minimum Performance` and >> `Maximum Performance` register, and PMFW can autonomously select an >> operating frequency in this range. >> 3. Fully autonomous: OS only hints (via EPP) to PMFW for the required >> energy performance preference for the workload and PMFW autonomously >> scales the frequency. >> >> Currently (1) is supported by amd_pstate as passive mode, and (3) is >> implemented by EPP support. This change is to support (2). >> >> In guided autonomous mode the min_perf is based on the input from the >> scaling governor. For example, in case of schedutil this value depends >> on the current utilization. And max_perf is set to max capacity. >> >> To activate guided auto mode ``amd_pstate=guided`` command line >> parameter has to be passed in the kernel. >> >> Signed-off-by: Wyes Karny <wyes.karny@xxxxxxx> >> --- >> .../admin-guide/kernel-parameters.txt | 4 ++ >> drivers/cpufreq/amd-pstate.c | 60 +++++++++++++++---- >> 2 files changed, 53 insertions(+), 11 deletions(-) >> >> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt >> index 42af9ca0127e..75e57afba77e 100644 >> --- a/Documentation/admin-guide/kernel-parameters.txt >> +++ b/Documentation/admin-guide/kernel-parameters.txt >> @@ -6970,3 +6970,7 @@ >> management firmware translates the requests into actual >> hardware states (core frequency, data fabric and memory >> clocks etc.) >> + guided >> + Activate guided autonomous mode. Driver requests minimum >> + performance and maximum performance and the PMFW autonomously >> + selects frequencies in this range. >> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c >> index 204e39006dda..05e4003a77ee 100644 >> --- a/drivers/cpufreq/amd-pstate.c >> +++ b/drivers/cpufreq/amd-pstate.c >> @@ -50,6 +50,20 @@ >> #define AMD_PSTATE_TRANSITION_LATENCY 20000 >> #define AMD_PSTATE_TRANSITION_DELAY 1000 >> >> +enum amd_pstate_mode { >> + CPPC_DISABLE = 0, >> + CPPC_PASSIVE, >> + CPPC_GUIDED, >> + CPPC_MODE_MAX, >> +}; >> + >> +static const char * const amd_pstate_mode_string[] = { >> + [CPPC_DISABLE] = "disable", >> + [CPPC_PASSIVE] = "passive", >> + [CPPC_GUIDED] = "guided", >> + NULL, >> +}; >> + >> /* >> * TODO: We need more time to fine tune processors with shared memory solution >> * with community together. >> @@ -60,7 +74,18 @@ >> * 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 = CPPC_DISABLE; >> + >> +static inline int get_mode_idx_from_str(const char *str, size_t size) >> +{ >> + int i = 0; >> + >> + for (; i < CPPC_MODE_MAX; ++i) { >> + if (!strncmp(str, amd_pstate_mode_string[i], size)) >> + return i; >> + } >> + return -EINVAL; >> +} >> >> static inline int pstate_enable(bool enable) >> { >> @@ -212,12 +237,18 @@ static inline bool amd_pstate_sample(struct amd_cpudata *cpudata) >> } >> >> static void amd_pstate_update(struct amd_cpudata *cpudata, u32 min_perf, >> - u32 des_perf, u32 max_perf, bool fast_switch) >> + u32 des_perf, u32 max_perf, bool fast_switch, int flags) >> { >> u64 prev = READ_ONCE(cpudata->cppc_req_cached); >> u64 value = prev; >> >> des_perf = clamp_t(unsigned long, des_perf, min_perf, max_perf); >> + >> + if (cppc_state == CPPC_GUIDED && flags & CPUFREQ_GOV_DYNAMIC_SWITCHING) { >> + min_perf = des_perf; >> + des_perf = 0; >> + } > > Since we would like to modify the min_perf on share memory processors as > well. The current cppc_set_perf() in cppc_acpi doesn't provide the MIN/MAX > values. Could you please add the max_perf/min_perf in cppc_acpi.c as well? > Then the APIs will be available on the share memory processors like Rome. Sure. Thanks for pointing this out. > > Thanks, > Ray > >> + >> value &= ~AMD_CPPC_MIN_PERF(~0L); >> value |= AMD_CPPC_MIN_PERF(min_perf); >> >> @@ -272,7 +303,7 @@ static int amd_pstate_target(struct cpufreq_policy *policy, >> >> cpufreq_freq_transition_begin(policy, &freqs); >> amd_pstate_update(cpudata, min_perf, des_perf, >> - max_perf, false); >> + max_perf, false, policy->governor->flags); >> cpufreq_freq_transition_end(policy, &freqs, false); >> >> return 0; >> @@ -306,7 +337,8 @@ static void amd_pstate_adjust_perf(unsigned int cpu, >> if (max_perf < min_perf) >> max_perf = min_perf; >> >> - amd_pstate_update(cpudata, min_perf, des_perf, max_perf, true); >> + amd_pstate_update(cpudata, min_perf, des_perf, max_perf, true, >> + policy->governor->flags); >> } >> >> static int amd_get_min_freq(struct amd_cpudata *cpudata) >> @@ -627,7 +659,7 @@ static int __init amd_pstate_init(void) >> * enable the amd_pstate passive mode driver explicitly >> * with amd_pstate=passive in kernel command line >> */ >> - if (!cppc_load) { >> + if (cppc_state == CPPC_DISABLE) { >> pr_debug("driver load is disabled, boot with amd_pstate=passive to enable this\n"); >> return -ENODEV; >> } >> @@ -670,16 +702,22 @@ device_initcall(amd_pstate_init); >> >> static int __init amd_pstate_param(char *str) >> { >> + int size, 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 >= CPPC_DISABLE && mode_idx < CPPC_MODE_MAX) { >> + cppc_state = mode_idx; >> + if (cppc_state == CPPC_DISABLE) >> + pr_info("driver is explicitly disabled\n"); >> + return 0; >> + } >> + >> + return -EINVAL; >> } >> early_param("amd_pstate", amd_pstate_param); >> >> -- >> 2.34.1 >> -- Thanks & Regards, Wyes