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authorLinus Torvalds <torvalds@linux-foundation.org>2020-08-15 18:17:01 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2020-08-15 18:17:01 +0300
commit1a5d9dbbaf3af4d029a081bd58dc83b6a25d109e (patch)
tree25988ffefb12daf18931b65bc60b02eb8306d567 /drivers
parent884e0d3dd59dde1c1f0fbb5b9db2bcdc581982c7 (diff)
parentf3db6de55e95eee6457a14912dd382a6cfc98edd (diff)
downloadlinux-1a5d9dbbaf3af4d029a081bd58dc83b6a25d109e.tar.xz
Merge tag 'pm-5.9-rc1-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull one more power management update from Rafael Wysocki: "Modify the intel_pstate driver to allow it to work in the passive mode with hardware-managed P-states (HWP) enabled" * tag 'pm-5.9-rc1-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: cpufreq: intel_pstate: Implement passive mode with HWP enabled
Diffstat (limited to 'drivers')
-rw-r--r--drivers/cpufreq/cpufreq.c6
-rw-r--r--drivers/cpufreq/intel_pstate.c245
2 files changed, 184 insertions, 67 deletions
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index afad06b91c77..02ab56b2a0d8 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -73,8 +73,6 @@ static inline bool has_target(void)
static unsigned int __cpufreq_get(struct cpufreq_policy *policy);
static int cpufreq_init_governor(struct cpufreq_policy *policy);
static void cpufreq_exit_governor(struct cpufreq_policy *policy);
-static int cpufreq_start_governor(struct cpufreq_policy *policy);
-static void cpufreq_stop_governor(struct cpufreq_policy *policy);
static void cpufreq_governor_limits(struct cpufreq_policy *policy);
static int cpufreq_set_policy(struct cpufreq_policy *policy,
struct cpufreq_governor *new_gov,
@@ -2266,7 +2264,7 @@ static void cpufreq_exit_governor(struct cpufreq_policy *policy)
module_put(policy->governor->owner);
}
-static int cpufreq_start_governor(struct cpufreq_policy *policy)
+int cpufreq_start_governor(struct cpufreq_policy *policy)
{
int ret;
@@ -2293,7 +2291,7 @@ static int cpufreq_start_governor(struct cpufreq_policy *policy)
return 0;
}
-static void cpufreq_stop_governor(struct cpufreq_policy *policy)
+void cpufreq_stop_governor(struct cpufreq_policy *policy)
{
if (cpufreq_suspended || !policy->governor)
return;
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index fc459c9c00ff..e0220a6fbc69 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -36,6 +36,7 @@
#define INTEL_PSTATE_SAMPLING_INTERVAL (10 * NSEC_PER_MSEC)
#define INTEL_CPUFREQ_TRANSITION_LATENCY 20000
+#define INTEL_CPUFREQ_TRANSITION_DELAY_HWP 5000
#define INTEL_CPUFREQ_TRANSITION_DELAY 500
#ifdef CONFIG_ACPI
@@ -220,6 +221,7 @@ struct global_params {
* preference/bias
* @epp_saved: Saved EPP/EPB during system suspend or CPU offline
* operation
+ * @epp_cached Cached HWP energy-performance preference value
* @hwp_req_cached: Cached value of the last HWP Request MSR
* @hwp_cap_cached: Cached value of the last HWP Capabilities MSR
* @last_io_update: Last time when IO wake flag was set
@@ -257,6 +259,7 @@ struct cpudata {
s16 epp_policy;
s16 epp_default;
s16 epp_saved;
+ s16 epp_cached;
u64 hwp_req_cached;
u64 hwp_cap_cached;
u64 last_io_update;
@@ -639,6 +642,26 @@ static int intel_pstate_get_energy_pref_index(struct cpudata *cpu_data, int *raw
return index;
}
+static int intel_pstate_set_epp(struct cpudata *cpu, u32 epp)
+{
+ /*
+ * Use the cached HWP Request MSR value, because in the active mode the
+ * register itself may be updated by intel_pstate_hwp_boost_up() or
+ * intel_pstate_hwp_boost_down() at any time.
+ */
+ u64 value = READ_ONCE(cpu->hwp_req_cached);
+
+ value &= ~GENMASK_ULL(31, 24);
+ value |= (u64)epp << 24;
+ /*
+ * The only other updater of hwp_req_cached in the active mode,
+ * intel_pstate_hwp_set(), is called under the same lock as this
+ * function, so it cannot run in parallel with the update below.
+ */
+ WRITE_ONCE(cpu->hwp_req_cached, value);
+ return wrmsrl_on_cpu(cpu->cpu, MSR_HWP_REQUEST, value);
+}
+
static int intel_pstate_set_energy_pref_index(struct cpudata *cpu_data,
int pref_index, bool use_raw,
u32 raw_epp)
@@ -650,28 +673,12 @@ static int intel_pstate_set_energy_pref_index(struct cpudata *cpu_data,
epp = cpu_data->epp_default;
if (boot_cpu_has(X86_FEATURE_HWP_EPP)) {
- /*
- * Use the cached HWP Request MSR value, because the register
- * itself may be updated by intel_pstate_hwp_boost_up() or
- * intel_pstate_hwp_boost_down() at any time.
- */
- u64 value = READ_ONCE(cpu_data->hwp_req_cached);
-
- value &= ~GENMASK_ULL(31, 24);
-
if (use_raw)
epp = raw_epp;
else if (epp == -EINVAL)
epp = epp_values[pref_index - 1];
- value |= (u64)epp << 24;
- /*
- * The only other updater of hwp_req_cached in the active mode,
- * intel_pstate_hwp_set(), is called under the same lock as this
- * function, so it cannot run in parallel with the update below.
- */
- WRITE_ONCE(cpu_data->hwp_req_cached, value);
- ret = wrmsrl_on_cpu(cpu_data->cpu, MSR_HWP_REQUEST, value);
+ ret = intel_pstate_set_epp(cpu_data, epp);
} else {
if (epp == -EINVAL)
epp = (pref_index - 1) << 2;
@@ -697,10 +704,12 @@ static ssize_t show_energy_performance_available_preferences(
cpufreq_freq_attr_ro(energy_performance_available_preferences);
+static struct cpufreq_driver intel_pstate;
+
static ssize_t store_energy_performance_preference(
struct cpufreq_policy *policy, const char *buf, size_t count)
{
- struct cpudata *cpu_data = all_cpu_data[policy->cpu];
+ struct cpudata *cpu = all_cpu_data[policy->cpu];
char str_preference[21];
bool raw = false;
ssize_t ret;
@@ -725,15 +734,44 @@ static ssize_t store_energy_performance_preference(
raw = true;
}
+ /*
+ * This function runs with the policy R/W semaphore held, which
+ * guarantees that the driver pointer will not change while it is
+ * running.
+ */
+ if (!intel_pstate_driver)
+ return -EAGAIN;
+
mutex_lock(&intel_pstate_limits_lock);
- ret = intel_pstate_set_energy_pref_index(cpu_data, ret, raw, epp);
- if (!ret)
- ret = count;
+ if (intel_pstate_driver == &intel_pstate) {
+ ret = intel_pstate_set_energy_pref_index(cpu, ret, raw, epp);
+ } else {
+ /*
+ * In the passive mode the governor needs to be stopped on the
+ * target CPU before the EPP update and restarted after it,
+ * which is super-heavy-weight, so make sure it is worth doing
+ * upfront.
+ */
+ if (!raw)
+ epp = ret ? epp_values[ret - 1] : cpu->epp_default;
+
+ if (cpu->epp_cached != epp) {
+ int err;
+
+ cpufreq_stop_governor(policy);
+ ret = intel_pstate_set_epp(cpu, epp);
+ err = cpufreq_start_governor(policy);
+ if (!ret) {
+ cpu->epp_cached = epp;
+ ret = err;
+ }
+ }
+ }
mutex_unlock(&intel_pstate_limits_lock);
- return ret;
+ return ret ?: count;
}
static ssize_t show_energy_performance_preference(
@@ -1145,8 +1183,6 @@ static ssize_t store_no_turbo(struct kobject *a, struct kobj_attribute *b,
return count;
}
-static struct cpufreq_driver intel_pstate;
-
static void update_qos_request(enum freq_qos_req_type type)
{
int max_state, turbo_max, freq, i, perf_pct;
@@ -1330,9 +1366,10 @@ static const struct attribute_group intel_pstate_attr_group = {
static const struct x86_cpu_id intel_pstate_cpu_ee_disable_ids[];
+static struct kobject *intel_pstate_kobject;
+
static void __init intel_pstate_sysfs_expose_params(void)
{
- struct kobject *intel_pstate_kobject;
int rc;
intel_pstate_kobject = kobject_create_and_add("intel_pstate",
@@ -1357,17 +1394,31 @@ static void __init intel_pstate_sysfs_expose_params(void)
rc = sysfs_create_file(intel_pstate_kobject, &min_perf_pct.attr);
WARN_ON(rc);
- if (hwp_active) {
- rc = sysfs_create_file(intel_pstate_kobject,
- &hwp_dynamic_boost.attr);
- WARN_ON(rc);
- }
-
if (x86_match_cpu(intel_pstate_cpu_ee_disable_ids)) {
rc = sysfs_create_file(intel_pstate_kobject, &energy_efficiency.attr);
WARN_ON(rc);
}
}
+
+static void intel_pstate_sysfs_expose_hwp_dynamic_boost(void)
+{
+ int rc;
+
+ if (!hwp_active)
+ return;
+
+ rc = sysfs_create_file(intel_pstate_kobject, &hwp_dynamic_boost.attr);
+ WARN_ON_ONCE(rc);
+}
+
+static void intel_pstate_sysfs_hide_hwp_dynamic_boost(void)
+{
+ if (!hwp_active)
+ return;
+
+ sysfs_remove_file(intel_pstate_kobject, &hwp_dynamic_boost.attr);
+}
+
/************************** sysfs end ************************/
static void intel_pstate_hwp_enable(struct cpudata *cpudata)
@@ -2247,7 +2298,10 @@ static int intel_pstate_verify_policy(struct cpufreq_policy_data *policy)
static void intel_cpufreq_stop_cpu(struct cpufreq_policy *policy)
{
- intel_pstate_set_min_pstate(all_cpu_data[policy->cpu]);
+ if (hwp_active)
+ intel_pstate_hwp_force_min_perf(policy->cpu);
+ else
+ intel_pstate_set_min_pstate(all_cpu_data[policy->cpu]);
}
static void intel_pstate_stop_cpu(struct cpufreq_policy *policy)
@@ -2255,12 +2309,10 @@ static void intel_pstate_stop_cpu(struct cpufreq_policy *policy)
pr_debug("CPU %d exiting\n", policy->cpu);
intel_pstate_clear_update_util_hook(policy->cpu);
- if (hwp_active) {
+ if (hwp_active)
intel_pstate_hwp_save_state(policy);
- intel_pstate_hwp_force_min_perf(policy->cpu);
- } else {
- intel_cpufreq_stop_cpu(policy);
- }
+
+ intel_cpufreq_stop_cpu(policy);
}
static int intel_pstate_cpu_exit(struct cpufreq_policy *policy)
@@ -2390,13 +2442,71 @@ static void intel_cpufreq_trace(struct cpudata *cpu, unsigned int trace_type, in
fp_toint(cpu->iowait_boost * 100));
}
+static void intel_cpufreq_adjust_hwp(struct cpudata *cpu, u32 target_pstate,
+ bool fast_switch)
+{
+ u64 prev = READ_ONCE(cpu->hwp_req_cached), value = prev;
+
+ value &= ~HWP_MIN_PERF(~0L);
+ value |= HWP_MIN_PERF(target_pstate);
+
+ /*
+ * The entire MSR needs to be updated in order to update the HWP min
+ * field in it, so opportunistically update the max too if needed.
+ */
+ value &= ~HWP_MAX_PERF(~0L);
+ value |= HWP_MAX_PERF(cpu->max_perf_ratio);
+
+ if (value == prev)
+ return;
+
+ WRITE_ONCE(cpu->hwp_req_cached, value);
+ if (fast_switch)
+ wrmsrl(MSR_HWP_REQUEST, value);
+ else
+ wrmsrl_on_cpu(cpu->cpu, MSR_HWP_REQUEST, value);
+}
+
+static void intel_cpufreq_adjust_perf_ctl(struct cpudata *cpu,
+ u32 target_pstate, bool fast_switch)
+{
+ if (fast_switch)
+ wrmsrl(MSR_IA32_PERF_CTL,
+ pstate_funcs.get_val(cpu, target_pstate));
+ else
+ wrmsrl_on_cpu(cpu->cpu, MSR_IA32_PERF_CTL,
+ pstate_funcs.get_val(cpu, target_pstate));
+}
+
+static int intel_cpufreq_update_pstate(struct cpudata *cpu, int target_pstate,
+ bool fast_switch)
+{
+ int old_pstate = cpu->pstate.current_pstate;
+
+ target_pstate = intel_pstate_prepare_request(cpu, target_pstate);
+ if (target_pstate != old_pstate) {
+ cpu->pstate.current_pstate = target_pstate;
+ if (hwp_active)
+ intel_cpufreq_adjust_hwp(cpu, target_pstate,
+ fast_switch);
+ else
+ intel_cpufreq_adjust_perf_ctl(cpu, target_pstate,
+ fast_switch);
+ }
+
+ intel_cpufreq_trace(cpu, fast_switch ? INTEL_PSTATE_TRACE_FAST_SWITCH :
+ INTEL_PSTATE_TRACE_TARGET, old_pstate);
+
+ return target_pstate;
+}
+
static int intel_cpufreq_target(struct cpufreq_policy *policy,
unsigned int target_freq,
unsigned int relation)
{
struct cpudata *cpu = all_cpu_data[policy->cpu];
struct cpufreq_freqs freqs;
- int target_pstate, old_pstate;
+ int target_pstate;
update_turbo_state();
@@ -2404,6 +2514,7 @@ static int intel_cpufreq_target(struct cpufreq_policy *policy,
freqs.new = target_freq;
cpufreq_freq_transition_begin(policy, &freqs);
+
switch (relation) {
case CPUFREQ_RELATION_L:
target_pstate = DIV_ROUND_UP(freqs.new, cpu->pstate.scaling);
@@ -2415,15 +2526,11 @@ static int intel_cpufreq_target(struct cpufreq_policy *policy,
target_pstate = DIV_ROUND_CLOSEST(freqs.new, cpu->pstate.scaling);
break;
}
- target_pstate = intel_pstate_prepare_request(cpu, target_pstate);
- old_pstate = cpu->pstate.current_pstate;
- if (target_pstate != cpu->pstate.current_pstate) {
- cpu->pstate.current_pstate = target_pstate;
- wrmsrl_on_cpu(policy->cpu, MSR_IA32_PERF_CTL,
- pstate_funcs.get_val(cpu, target_pstate));
- }
+
+ target_pstate = intel_cpufreq_update_pstate(cpu, target_pstate, false);
+
freqs.new = target_pstate * cpu->pstate.scaling;
- intel_cpufreq_trace(cpu, INTEL_PSTATE_TRACE_TARGET, old_pstate);
+
cpufreq_freq_transition_end(policy, &freqs, false);
return 0;
@@ -2433,15 +2540,14 @@ static unsigned int intel_cpufreq_fast_switch(struct cpufreq_policy *policy,
unsigned int target_freq)
{
struct cpudata *cpu = all_cpu_data[policy->cpu];
- int target_pstate, old_pstate;
+ int target_pstate;
update_turbo_state();
target_pstate = DIV_ROUND_UP(target_freq, cpu->pstate.scaling);
- target_pstate = intel_pstate_prepare_request(cpu, target_pstate);
- old_pstate = cpu->pstate.current_pstate;
- intel_pstate_update_pstate(cpu, target_pstate);
- intel_cpufreq_trace(cpu, INTEL_PSTATE_TRACE_FAST_SWITCH, old_pstate);
+
+ target_pstate = intel_cpufreq_update_pstate(cpu, target_pstate, true);
+
return target_pstate * cpu->pstate.scaling;
}
@@ -2461,7 +2567,6 @@ static int intel_cpufreq_cpu_init(struct cpufreq_policy *policy)
return ret;
policy->cpuinfo.transition_latency = INTEL_CPUFREQ_TRANSITION_LATENCY;
- policy->transition_delay_us = INTEL_CPUFREQ_TRANSITION_DELAY;
/* This reflects the intel_pstate_get_cpu_pstates() setting. */
policy->cur = policy->cpuinfo.min_freq;
@@ -2473,10 +2578,18 @@ static int intel_cpufreq_cpu_init(struct cpufreq_policy *policy)
cpu = all_cpu_data[policy->cpu];
- if (hwp_active)
+ if (hwp_active) {
+ u64 value;
+
intel_pstate_get_hwp_max(policy->cpu, &turbo_max, &max_state);
- else
+ policy->transition_delay_us = INTEL_CPUFREQ_TRANSITION_DELAY_HWP;
+ rdmsrl_on_cpu(cpu->cpu, MSR_HWP_REQUEST, &value);
+ WRITE_ONCE(cpu->hwp_req_cached, value);
+ cpu->epp_cached = (value & GENMASK_ULL(31, 24)) >> 24;
+ } else {
turbo_max = cpu->pstate.turbo_pstate;
+ policy->transition_delay_us = INTEL_CPUFREQ_TRANSITION_DELAY;
+ }
min_freq = DIV_ROUND_UP(turbo_max * global.min_perf_pct, 100);
min_freq *= cpu->pstate.scaling;
@@ -2553,6 +2666,10 @@ static void intel_pstate_driver_cleanup(void)
}
}
put_online_cpus();
+
+ if (intel_pstate_driver == &intel_pstate)
+ intel_pstate_sysfs_hide_hwp_dynamic_boost();
+
intel_pstate_driver = NULL;
}
@@ -2560,6 +2677,9 @@ static int intel_pstate_register_driver(struct cpufreq_driver *driver)
{
int ret;
+ if (driver == &intel_pstate)
+ intel_pstate_sysfs_expose_hwp_dynamic_boost();
+
memset(&global, 0, sizeof(global));
global.max_perf_pct = 100;
@@ -2577,9 +2697,6 @@ static int intel_pstate_register_driver(struct cpufreq_driver *driver)
static int intel_pstate_unregister_driver(void)
{
- if (hwp_active)
- return -EBUSY;
-
cpufreq_unregister_driver(intel_pstate_driver);
intel_pstate_driver_cleanup();
@@ -2835,7 +2952,10 @@ static int __init intel_pstate_init(void)
hwp_active++;
hwp_mode_bdw = id->driver_data;
intel_pstate.attr = hwp_cpufreq_attrs;
- default_driver = &intel_pstate;
+ intel_cpufreq.attr = hwp_cpufreq_attrs;
+ if (!default_driver)
+ default_driver = &intel_pstate;
+
goto hwp_cpu_matched;
}
} else {
@@ -2906,14 +3026,13 @@ static int __init intel_pstate_setup(char *str)
if (!str)
return -EINVAL;
- if (!strcmp(str, "disable")) {
+ if (!strcmp(str, "disable"))
no_load = 1;
- } else if (!strcmp(str, "active")) {
+ else if (!strcmp(str, "active"))
default_driver = &intel_pstate;
- } else if (!strcmp(str, "passive")) {
+ else if (!strcmp(str, "passive"))
default_driver = &intel_cpufreq;
- no_hwp = 1;
- }
+
if (!strcmp(str, "no_hwp")) {
pr_info("HWP disabled\n");
no_hwp = 1;