diff options
author | Perry Yuan <Perry.Yuan@amd.com> | 2023-01-31 17:00:09 +0800 |
---|---|---|
committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2023-02-03 21:59:41 +0100 |
commit | ffa5096a7c338641f70fb06d4778e8cf400181a8 (patch) | |
tree | b603f0be0b63508644c3abfa0604d290fc3aa01b | |
parent | 36c5014e5460963ad7766487c0e22a7ff28681fc (diff) | |
download | linux-stable-ffa5096a7c338641f70fb06d4778e8cf400181a8.tar.gz linux-stable-ffa5096a7c338641f70fb06d4778e8cf400181a8.tar.bz2 linux-stable-ffa5096a7c338641f70fb06d4778e8cf400181a8.zip |
cpufreq: amd-pstate: implement Pstate EPP support for the AMD processors
Add EPP driver support for AMD SoCs which support a dedicated MSR for
CPPC. EPP is used by the DPM controller to configure the frequency that
a core operates at during short periods of activity.
The SoC EPP targets are configured on a scale from 0 to 255 where 0
represents maximum performance and 255 represents maximum efficiency.
The amd-pstate driver exports profile string names to userspace that are
tied to specific EPP values.
The balance_performance string (0x80) provides the best balance for
efficiency versus power on most systems, but users can choose other
strings to meet their needs as well.
$ cat /sys/devices/system/cpu/cpufreq/policy0/energy_performance_available_preferences
default performance balance_performance balance_power power
$ cat /sys/devices/system/cpu/cpufreq/policy0/energy_performance_preference
balance_performance
To enable the driver,it needs to add `amd_pstate=active` to kernel
command line and kernel will load the active mode epp driver
Acked-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Mario Limonciello <Mario.Limonciello@amd.com>
Reviewed-by: Wyes Karny <wyes.karny@amd.com>
Tested-by: Wyes Karny <wyes.karny@amd.com>
Signed-off-by: Perry Yuan <Perry.Yuan@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
-rw-r--r-- | drivers/cpufreq/amd-pstate.c | 420 | ||||
-rw-r--r-- | include/linux/amd-pstate.h | 16 |
2 files changed, 429 insertions, 7 deletions
diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c index 65c16edbbb20..bca86b5b8b12 100644 --- a/drivers/cpufreq/amd-pstate.c +++ b/drivers/cpufreq/amd-pstate.c @@ -59,9 +59,52 @@ * we disable it by default to go acpi-cpufreq on these processors and add a * module parameter to be able to enable it manually for debugging. */ +static struct cpufreq_driver *current_pstate_driver; static struct cpufreq_driver amd_pstate_driver; +static struct cpufreq_driver amd_pstate_epp_driver; static int cppc_state = AMD_PSTATE_DISABLE; +/* + * AMD Energy Preference Performance (EPP) + * The EPP is used in the CCLK DPM controller to drive + * the frequency that a core is going to operate during + * short periods of activity. EPP values will be utilized for + * different OS profiles (balanced, performance, power savings) + * display strings corresponding to EPP index in the + * energy_perf_strings[] + * index String + *------------------------------------- + * 0 default + * 1 performance + * 2 balance_performance + * 3 balance_power + * 4 power + */ +enum energy_perf_value_index { + EPP_INDEX_DEFAULT = 0, + EPP_INDEX_PERFORMANCE, + EPP_INDEX_BALANCE_PERFORMANCE, + EPP_INDEX_BALANCE_POWERSAVE, + EPP_INDEX_POWERSAVE, +}; + +static const char * const energy_perf_strings[] = { + [EPP_INDEX_DEFAULT] = "default", + [EPP_INDEX_PERFORMANCE] = "performance", + [EPP_INDEX_BALANCE_PERFORMANCE] = "balance_performance", + [EPP_INDEX_BALANCE_POWERSAVE] = "balance_power", + [EPP_INDEX_POWERSAVE] = "power", + NULL +}; + +static unsigned int epp_values[] = { + [EPP_INDEX_DEFAULT] = 0, + [EPP_INDEX_PERFORMANCE] = AMD_CPPC_EPP_PERFORMANCE, + [EPP_INDEX_BALANCE_PERFORMANCE] = AMD_CPPC_EPP_BALANCE_PERFORMANCE, + [EPP_INDEX_BALANCE_POWERSAVE] = AMD_CPPC_EPP_BALANCE_POWERSAVE, + [EPP_INDEX_POWERSAVE] = AMD_CPPC_EPP_POWERSAVE, + }; + static inline int get_mode_idx_from_str(const char *str, size_t size) { int i; @@ -73,6 +116,114 @@ static inline int get_mode_idx_from_str(const char *str, size_t size) return -EINVAL; } +static DEFINE_MUTEX(amd_pstate_limits_lock); +static DEFINE_MUTEX(amd_pstate_driver_lock); + +static s16 amd_pstate_get_epp(struct amd_cpudata *cpudata, u64 cppc_req_cached) +{ + u64 epp; + int ret; + + if (boot_cpu_has(X86_FEATURE_CPPC)) { + if (!cppc_req_cached) { + epp = rdmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ, + &cppc_req_cached); + if (epp) + return epp; + } + epp = (cppc_req_cached >> 24) & 0xFF; + } else { + ret = cppc_get_epp_perf(cpudata->cpu, &epp); + if (ret < 0) { + pr_debug("Could not retrieve energy perf value (%d)\n", ret); + return -EIO; + } + } + + return (s16)(epp & 0xff); +} + +static int amd_pstate_get_energy_pref_index(struct amd_cpudata *cpudata) +{ + s16 epp; + int index = -EINVAL; + + epp = amd_pstate_get_epp(cpudata, 0); + if (epp < 0) + return epp; + + switch (epp) { + case AMD_CPPC_EPP_PERFORMANCE: + index = EPP_INDEX_PERFORMANCE; + break; + case AMD_CPPC_EPP_BALANCE_PERFORMANCE: + index = EPP_INDEX_BALANCE_PERFORMANCE; + break; + case AMD_CPPC_EPP_BALANCE_POWERSAVE: + index = EPP_INDEX_BALANCE_POWERSAVE; + break; + case AMD_CPPC_EPP_POWERSAVE: + index = EPP_INDEX_POWERSAVE; + break; + default: + break; + } + + return index; +} + +static int amd_pstate_set_epp(struct amd_cpudata *cpudata, u32 epp) +{ + int ret; + struct cppc_perf_ctrls perf_ctrls; + + if (boot_cpu_has(X86_FEATURE_CPPC)) { + u64 value = READ_ONCE(cpudata->cppc_req_cached); + + value &= ~GENMASK_ULL(31, 24); + value |= (u64)epp << 24; + WRITE_ONCE(cpudata->cppc_req_cached, value); + + ret = wrmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ, value); + if (!ret) + cpudata->epp_cached = epp; + } else { + perf_ctrls.energy_perf = epp; + ret = cppc_set_epp_perf(cpudata->cpu, &perf_ctrls, 1); + if (ret) { + pr_debug("failed to set energy perf value (%d)\n", ret); + return ret; + } + cpudata->epp_cached = epp; + } + + return ret; +} + +static int amd_pstate_set_energy_pref_index(struct amd_cpudata *cpudata, + int pref_index) +{ + int epp = -EINVAL; + int ret; + + if (!pref_index) { + pr_debug("EPP pref_index is invalid\n"); + return -EINVAL; + } + + if (epp == -EINVAL) + epp = epp_values[pref_index]; + + if (epp > 0 && cpudata->policy == CPUFREQ_POLICY_PERFORMANCE) { + pr_debug("EPP cannot be set under performance policy\n"); + return -EBUSY; + } + + ret = amd_pstate_set_epp(cpudata, epp); + + return ret; +} + static inline int pstate_enable(bool enable) { return wrmsrl_safe(MSR_AMD_CPPC_ENABLE, enable); @@ -81,11 +232,21 @@ static inline int pstate_enable(bool enable) static int cppc_enable(bool enable) { int cpu, ret = 0; + struct cppc_perf_ctrls perf_ctrls; for_each_present_cpu(cpu) { ret = cppc_set_enable(cpu, enable); if (ret) return ret; + + /* Enable autonomous mode for EPP */ + if (cppc_state == AMD_PSTATE_ACTIVE) { + /* Set desired perf as zero to allow EPP firmware control */ + perf_ctrls.desired_perf = 0; + ret = cppc_set_perf(cpu, &perf_ctrls); + if (ret) + return ret; + } } return ret; @@ -429,7 +590,7 @@ static void amd_pstate_boost_init(struct amd_cpudata *cpudata) return; cpudata->boost_supported = true; - amd_pstate_driver.boost_enabled = true; + current_pstate_driver->boost_enabled = true; } static void amd_perf_ctl_reset(unsigned int cpu) @@ -603,10 +764,61 @@ static ssize_t show_amd_pstate_highest_perf(struct cpufreq_policy *policy, return sprintf(&buf[0], "%u\n", perf); } +static ssize_t show_energy_performance_available_preferences( + struct cpufreq_policy *policy, char *buf) +{ + int i = 0; + int offset = 0; + + while (energy_perf_strings[i] != NULL) + offset += sysfs_emit_at(buf, offset, "%s ", energy_perf_strings[i++]); + + sysfs_emit_at(buf, offset, "\n"); + + return offset; +} + +static ssize_t store_energy_performance_preference( + struct cpufreq_policy *policy, const char *buf, size_t count) +{ + struct amd_cpudata *cpudata = policy->driver_data; + char str_preference[21]; + ssize_t ret; + + ret = sscanf(buf, "%20s", str_preference); + if (ret != 1) + return -EINVAL; + + ret = match_string(energy_perf_strings, -1, str_preference); + if (ret < 0) + return -EINVAL; + + mutex_lock(&amd_pstate_limits_lock); + ret = amd_pstate_set_energy_pref_index(cpudata, ret); + mutex_unlock(&amd_pstate_limits_lock); + + return ret ?: count; +} + +static ssize_t show_energy_performance_preference( + struct cpufreq_policy *policy, char *buf) +{ + struct amd_cpudata *cpudata = policy->driver_data; + int preference; + + preference = amd_pstate_get_energy_pref_index(cpudata); + if (preference < 0) + return preference; + + return sysfs_emit(buf, "%s\n", energy_perf_strings[preference]); +} + cpufreq_freq_attr_ro(amd_pstate_max_freq); cpufreq_freq_attr_ro(amd_pstate_lowest_nonlinear_freq); cpufreq_freq_attr_ro(amd_pstate_highest_perf); +cpufreq_freq_attr_rw(energy_performance_preference); +cpufreq_freq_attr_ro(energy_performance_available_preferences); static struct freq_attr *amd_pstate_attr[] = { &amd_pstate_max_freq, @@ -615,6 +827,186 @@ static struct freq_attr *amd_pstate_attr[] = { NULL, }; +static struct freq_attr *amd_pstate_epp_attr[] = { + &amd_pstate_max_freq, + &amd_pstate_lowest_nonlinear_freq, + &amd_pstate_highest_perf, + &energy_performance_preference, + &energy_performance_available_preferences, + NULL, +}; + +static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy) +{ + int min_freq, max_freq, nominal_freq, lowest_nonlinear_freq, ret; + struct amd_cpudata *cpudata; + struct device *dev; + int rc; + u64 value; + + /* + * Resetting PERF_CTL_MSR will put the CPU in P0 frequency, + * which is ideal for initialization process. + */ + amd_perf_ctl_reset(policy->cpu); + dev = get_cpu_device(policy->cpu); + if (!dev) + goto free_cpudata1; + + cpudata = kzalloc(sizeof(*cpudata), GFP_KERNEL); + if (!cpudata) + return -ENOMEM; + + cpudata->cpu = policy->cpu; + cpudata->epp_policy = 0; + + rc = amd_pstate_init_perf(cpudata); + if (rc) + goto free_cpudata1; + + min_freq = amd_get_min_freq(cpudata); + max_freq = amd_get_max_freq(cpudata); + nominal_freq = amd_get_nominal_freq(cpudata); + lowest_nonlinear_freq = amd_get_lowest_nonlinear_freq(cpudata); + if (min_freq < 0 || max_freq < 0 || min_freq > max_freq) { + dev_err(dev, "min_freq(%d) or max_freq(%d) value is incorrect\n", + min_freq, max_freq); + ret = -EINVAL; + goto free_cpudata1; + } + + policy->cpuinfo.min_freq = min_freq; + policy->cpuinfo.max_freq = max_freq; + /* It will be updated by governor */ + policy->cur = policy->cpuinfo.min_freq; + + /* Initial processor data capability frequencies */ + cpudata->max_freq = max_freq; + cpudata->min_freq = min_freq; + cpudata->nominal_freq = nominal_freq; + cpudata->lowest_nonlinear_freq = lowest_nonlinear_freq; + + policy->driver_data = cpudata; + + cpudata->epp_cached = amd_pstate_get_epp(cpudata, 0); + + policy->min = policy->cpuinfo.min_freq; + policy->max = policy->cpuinfo.max_freq; + + /* + * Set the policy to powersave to provide a valid fallback value in case + * the default cpufreq governor is neither powersave nor performance. + */ + policy->policy = CPUFREQ_POLICY_POWERSAVE; + + if (boot_cpu_has(X86_FEATURE_CPPC)) { + policy->fast_switch_possible = true; + ret = rdmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ, &value); + if (ret) + return ret; + WRITE_ONCE(cpudata->cppc_req_cached, value); + + ret = rdmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_CAP1, &value); + if (ret) + return ret; + WRITE_ONCE(cpudata->cppc_cap1_cached, value); + } + amd_pstate_boost_init(cpudata); + + return 0; + +free_cpudata1: + kfree(cpudata); + return ret; +} + +static int amd_pstate_epp_cpu_exit(struct cpufreq_policy *policy) +{ + pr_debug("CPU %d exiting\n", policy->cpu); + policy->fast_switch_possible = false; + return 0; +} + +static void amd_pstate_epp_init(unsigned int cpu) +{ + struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); + struct amd_cpudata *cpudata = policy->driver_data; + u32 max_perf, min_perf; + u64 value; + s16 epp; + + max_perf = READ_ONCE(cpudata->highest_perf); + min_perf = READ_ONCE(cpudata->lowest_perf); + + value = READ_ONCE(cpudata->cppc_req_cached); + + if (cpudata->policy == CPUFREQ_POLICY_PERFORMANCE) + min_perf = max_perf; + + /* Initial min/max values for CPPC Performance Controls Register */ + value &= ~AMD_CPPC_MIN_PERF(~0L); + value |= AMD_CPPC_MIN_PERF(min_perf); + + value &= ~AMD_CPPC_MAX_PERF(~0L); + value |= AMD_CPPC_MAX_PERF(max_perf); + + /* CPPC EPP feature require to set zero to the desire perf bit */ + value &= ~AMD_CPPC_DES_PERF(~0L); + value |= AMD_CPPC_DES_PERF(0); + + if (cpudata->epp_policy == cpudata->policy) + goto skip_epp; + + cpudata->epp_policy = cpudata->policy; + + if (cpudata->policy == CPUFREQ_POLICY_PERFORMANCE) { + epp = amd_pstate_get_epp(cpudata, value); + if (epp < 0) + goto skip_epp; + /* force the epp value to be zero for performance policy */ + epp = 0; + } else { + /* Get BIOS pre-defined epp value */ + epp = amd_pstate_get_epp(cpudata, value); + if (epp) + goto skip_epp; + } + /* Set initial EPP value */ + if (boot_cpu_has(X86_FEATURE_CPPC)) { + value &= ~GENMASK_ULL(31, 24); + value |= (u64)epp << 24; + } + +skip_epp: + WRITE_ONCE(cpudata->cppc_req_cached, value); + amd_pstate_set_epp(cpudata, epp); + cpufreq_cpu_put(policy); +} + +static int amd_pstate_epp_set_policy(struct cpufreq_policy *policy) +{ + struct amd_cpudata *cpudata = policy->driver_data; + + if (!policy->cpuinfo.max_freq) + return -ENODEV; + + pr_debug("set_policy: cpuinfo.max %u policy->max %u\n", + policy->cpuinfo.max_freq, policy->max); + + cpudata->policy = policy->policy; + + amd_pstate_epp_init(policy->cpu); + + return 0; +} + +static int amd_pstate_epp_verify_policy(struct cpufreq_policy_data *policy) +{ + cpufreq_verify_within_cpu_limits(policy); + pr_debug("policy_max =%d, policy_min=%d\n", policy->max, policy->min); + return 0; +} + static struct cpufreq_driver amd_pstate_driver = { .flags = CPUFREQ_CONST_LOOPS | CPUFREQ_NEED_UPDATE_LIMITS, .verify = amd_pstate_verify, @@ -628,6 +1020,16 @@ static struct cpufreq_driver amd_pstate_driver = { .attr = amd_pstate_attr, }; +static struct cpufreq_driver amd_pstate_epp_driver = { + .flags = CPUFREQ_CONST_LOOPS, + .verify = amd_pstate_epp_verify_policy, + .setpolicy = amd_pstate_epp_set_policy, + .init = amd_pstate_epp_cpu_init, + .exit = amd_pstate_epp_cpu_exit, + .name = "amd_pstate_epp", + .attr = amd_pstate_epp_attr, +}; + static int __init amd_pstate_init(void) { int ret; @@ -656,7 +1058,8 @@ static int __init amd_pstate_init(void) /* capability check */ if (boot_cpu_has(X86_FEATURE_CPPC)) { pr_debug("AMD CPPC MSR based functionality is supported\n"); - amd_pstate_driver.adjust_perf = amd_pstate_adjust_perf; + if (cppc_state == AMD_PSTATE_PASSIVE) + current_pstate_driver->adjust_perf = amd_pstate_adjust_perf; } else { pr_debug("AMD CPPC shared memory based functionality is supported\n"); static_call_update(amd_pstate_enable, cppc_enable); @@ -667,14 +1070,13 @@ static int __init amd_pstate_init(void) /* enable amd pstate feature */ ret = amd_pstate_enable(true); if (ret) { - pr_err("failed to enable amd-pstate with return %d\n", ret); + pr_err("failed to enable with return %d\n", ret); return ret; } - ret = cpufreq_register_driver(&amd_pstate_driver); + ret = cpufreq_register_driver(current_pstate_driver); if (ret) - pr_err("failed to register amd_pstate_driver with return %d\n", - ret); + pr_err("failed to register with return %d\n", ret); return ret; } @@ -696,6 +1098,12 @@ static int __init amd_pstate_param(char *str) if (cppc_state == AMD_PSTATE_DISABLE) pr_info("driver is explicitly disabled\n"); + if (cppc_state == AMD_PSTATE_ACTIVE) + current_pstate_driver = &amd_pstate_epp_driver; + + if (cppc_state == AMD_PSTATE_PASSIVE) + current_pstate_driver = &amd_pstate_driver; + return 0; } diff --git a/include/linux/amd-pstate.h b/include/linux/amd-pstate.h index dae2ce0f6735..72ea7cf85ca3 100644 --- a/include/linux/amd-pstate.h +++ b/include/linux/amd-pstate.h @@ -12,6 +12,11 @@ #include <linux/pm_qos.h> +#define AMD_CPPC_EPP_PERFORMANCE 0x00 +#define AMD_CPPC_EPP_BALANCE_PERFORMANCE 0x80 +#define AMD_CPPC_EPP_BALANCE_POWERSAVE 0xBF +#define AMD_CPPC_EPP_POWERSAVE 0xFF + /********************************************************************* * AMD P-state INTERFACE * *********************************************************************/ @@ -47,6 +52,10 @@ struct amd_aperf_mperf { * @prev: Last Aperf/Mperf/tsc count value read from register * @freq: current cpu frequency value * @boost_supported: check whether the Processor or SBIOS supports boost mode + * @epp_policy: Last saved policy used to set energy-performance preference + * @epp_cached: Cached CPPC energy-performance preference value + * @policy: Cpufreq policy value + * @cppc_cap1_cached Cached MSR_AMD_CPPC_CAP1 register value * * The amd_cpudata is key private data for each CPU thread in AMD P-State, and * represents all the attributes and goals that AMD P-State requests at runtime. @@ -72,6 +81,12 @@ struct amd_cpudata { u64 freq; bool boost_supported; + + /* EPP feature related attributes*/ + s16 epp_policy; + s16 epp_cached; + u32 policy; + u64 cppc_cap1_cached; }; /* @@ -90,5 +105,4 @@ static const char * const amd_pstate_mode_string[] = { [AMD_PSTATE_ACTIVE] = "active", NULL, }; - #endif /* _LINUX_AMD_PSTATE_H */ |