Merge Energy Model material for 5.19 to satisfy dependencies.

Author: rafaeljw

Documentation/power/energy-model.rst

@@ -123,6 +123,26 @@ allows a platform to register EM power values which are reflecting total power
 (static + dynamic). These power values might be coming directly from
 experiments and measurements.
 
+Registration of 'artificial' EM
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+There is an option to provide a custom callback for drivers missing detailed
+knowledge about power value for each performance state. The callback
+.get_cost() is optional and provides the 'cost' values used by the EAS.
+This is useful for platforms that only provide information on relative
+efficiency between CPU types, where one could use the information to
+create an abstract power model. But even an abstract power model can
+sometimes be hard to fit in, given the input power value size restrictions.
+The .get_cost() allows to provide the 'cost' values which reflect the
+efficiency of the CPUs. This would allow to provide EAS information which
+has different relation than what would be forced by the EM internal
+formulas calculating 'cost' values. To register an EM for such platform, the
+driver must set the flag 'milliwatts' to 0, provide .get_power() callback
+and provide .get_cost() callback. The EM framework would handle such platform
+properly during registration. A flag EM_PERF_DOMAIN_ARTIFICIAL is set for such
+platform. Special care should be taken by other frameworks which are using EM
+to test and treat this flag properly.
+
 Registration of 'simple' EM
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
@@ -181,8 +201,8 @@ EM framework::
 
   -> drivers/cpufreq/foo_cpufreq.c
 
-  01	static int est_power(unsigned long *mW, unsigned long *KHz,
-  02			struct device *dev)
+  01	static int est_power(struct device *dev, unsigned long *mW,
+  02			unsigned long *KHz)
   03	{
   04		long freq, power;
   05

drivers/cpufreq/mediatek-cpufreq-hw.c

@@ -51,8 +51,8 @@ static const u16 cpufreq_mtk_offsets[REG_ARRAY_SIZE] = {
 };
 
 static int __maybe_unused
-mtk_cpufreq_get_cpu_power(unsigned long *mW,
-			  unsigned long *KHz, struct device *cpu_dev)
+mtk_cpufreq_get_cpu_power(struct device *cpu_dev, unsigned long *mW,
+			  unsigned long *KHz)
 {
 	struct mtk_cpufreq_data *data;
 	struct cpufreq_policy *policy;

drivers/cpufreq/scmi-cpufreq.c

@@ -96,8 +96,8 @@ scmi_get_sharing_cpus(struct device *cpu_dev, struct cpumask *cpumask)
 }
 
 static int __maybe_unused
-scmi_get_cpu_power(unsigned long *power, unsigned long *KHz,
-		   struct device *cpu_dev)
+scmi_get_cpu_power(struct device *cpu_dev, unsigned long *power,
+		   unsigned long *KHz)
 {
 	unsigned long Hz;
 	int ret, domain;

drivers/opp/of.c

@@ -1448,7 +1448,7 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_get_of_node);
  * Returns 0 on success or a proper -EINVAL value in case of error.
  */
 static int __maybe_unused
-_get_dt_power(unsigned long *mW, unsigned long *kHz, struct device *dev)
+_get_dt_power(struct device *dev, unsigned long *mW, unsigned long *kHz)
 {
 	struct dev_pm_opp *opp;
 	unsigned long opp_freq, opp_power;
@@ -1482,8 +1482,8 @@ _get_dt_power(unsigned long *mW, unsigned long *kHz, struct device *dev)
  * Returns -EINVAL if the power calculation failed because of missing
  * parameters, 0 otherwise.
  */
-static int __maybe_unused _get_power(unsigned long *mW, unsigned long *kHz,
-				     struct device *dev)
+static int __maybe_unused _get_power(struct device *dev, unsigned long *mW,
+				     unsigned long *kHz)
 {
 	struct dev_pm_opp *opp;
 	struct device_node *np;

drivers/powercap/dtpm_cpu.c

@@ -211,7 +211,7 @@ static int __dtpm_cpu_setup(int cpu, struct dtpm *parent)
 		return 0;
 
 	pd = em_cpu_get(cpu);
-	if (!pd)
+	if (!pd || em_is_artificial(pd))
 		return -EINVAL;
 
 	dtpm_cpu = kzalloc(sizeof(*dtpm_cpu), GFP_KERNEL);

drivers/thermal/cpufreq_cooling.c

@@ -328,7 +328,7 @@ static inline bool em_is_sane(struct cpufreq_cooling_device *cpufreq_cdev,
 	struct cpufreq_policy *policy;
 	unsigned int nr_levels;
 
-	if (!em)
+	if (!em || em_is_artificial(em))
 		return false;
 
 	policy = cpufreq_cdev->policy;

drivers/thermal/devfreq_cooling.c

@@ -358,6 +358,7 @@ of_devfreq_cooling_register_power(struct device_node *np, struct devfreq *df,
 	struct thermal_cooling_device *cdev;
 	struct device *dev = df->dev.parent;
 	struct devfreq_cooling_device *dfc;
+	struct em_perf_domain *em;
 	char *name;
 	int err, num_opps;
 
@@ -367,8 +368,9 @@ of_devfreq_cooling_register_power(struct device_node *np, struct devfreq *df,
 
 	dfc->devfreq = df;
 
-	dfc->em_pd = em_pd_get(dev);
-	if (dfc->em_pd) {
+	em = em_pd_get(dev);
+	if (em && !em_is_artificial(em)) {
+		dfc->em_pd = em;
 		devfreq_cooling_ops.get_requested_power =
 			devfreq_cooling_get_requested_power;
 		devfreq_cooling_ops.state2power = devfreq_cooling_state2power;
@@ -379,7 +381,7 @@ of_devfreq_cooling_register_power(struct device_node *np, struct devfreq *df,
 		num_opps = em_pd_nr_perf_states(dfc->em_pd);
 	} else {
 		/* Backward compatibility for drivers which do not use IPA */
-		dev_dbg(dev, "missing EM for cooling device\n");
+		dev_dbg(dev, "missing proper EM for cooling device\n");
 
 		num_opps = dev_pm_opp_get_opp_count(dev);
 

include/linux/energy_model.h

@@ -67,11 +67,16 @@ struct em_perf_domain {
  *
  *  EM_PERF_DOMAIN_SKIP_INEFFICIENCIES: Skip inefficient states when estimating
  *  energy consumption.
+ *
+ *  EM_PERF_DOMAIN_ARTIFICIAL: The power values are artificial and might be
+ *  created by platform missing real power information
  */
 #define EM_PERF_DOMAIN_MILLIWATTS BIT(0)
 #define EM_PERF_DOMAIN_SKIP_INEFFICIENCIES BIT(1)
+#define EM_PERF_DOMAIN_ARTIFICIAL BIT(2)
 
 #define em_span_cpus(em) (to_cpumask((em)->cpus))
+#define em_is_artificial(em) ((em)->flags & EM_PERF_DOMAIN_ARTIFICIAL)
 
 #ifdef CONFIG_ENERGY_MODEL
 #define EM_MAX_POWER 0xFFFF
@@ -96,11 +101,11 @@ struct em_data_callback {
 	/**
 	 * active_power() - Provide power at the next performance state of
 	 *		a device
+	 * @dev		: Device for which we do this operation (can be a CPU)
 	 * @power	: Active power at the performance state
 	 *		(modified)
 	 * @freq	: Frequency at the performance state in kHz
 	 *		(modified)
-	 * @dev		: Device for which we do this operation (can be a CPU)
 	 *
 	 * active_power() must find the lowest performance state of 'dev' above
 	 * 'freq' and update 'power' and 'freq' to the matching active power
@@ -112,11 +117,32 @@ struct em_data_callback {
 	 *
 	 * Return 0 on success.
 	 */
-	int (*active_power)(unsigned long *power, unsigned long *freq,
-			    struct device *dev);
+	int (*active_power)(struct device *dev, unsigned long *power,
+			    unsigned long *freq);
+
+	/**
+	 * get_cost() - Provide the cost at the given performance state of
+	 *		a device
+	 * @dev		: Device for which we do this operation (can be a CPU)
+	 * @freq	: Frequency at the performance state in kHz
+	 * @cost	: The cost value for the performance state
+	 *		(modified)
+	 *
+	 * In case of CPUs, the cost is the one of a single CPU in the domain.
+	 * It is expected to fit in the [0, EM_MAX_POWER] range due to internal
+	 * usage in EAS calculation.
+	 *
+	 * Return 0 on success, or appropriate error value in case of failure.
+	 */
+	int (*get_cost)(struct device *dev, unsigned long freq,
+			unsigned long *cost);
 };
-#define EM_DATA_CB(_active_power_cb) { .active_power = &_active_power_cb }
 #define EM_SET_ACTIVE_POWER_CB(em_cb, cb) ((em_cb).active_power = cb)
+#define EM_ADV_DATA_CB(_active_power_cb, _cost_cb)	\
+	{ .active_power = _active_power_cb,		\
+	  .get_cost = _cost_cb }
+#define EM_DATA_CB(_active_power_cb)			\
+		EM_ADV_DATA_CB(_active_power_cb, NULL)
 
 struct em_perf_domain *em_cpu_get(int cpu);
 struct em_perf_domain *em_pd_get(struct device *dev);
@@ -264,6 +290,7 @@ static inline int em_pd_nr_perf_states(struct em_perf_domain *pd)
 
 #else
 struct em_data_callback {};
+#define EM_ADV_DATA_CB(_active_power_cb, _cost_cb) { }
 #define EM_DATA_CB(_active_power_cb) { }
 #define EM_SET_ACTIVE_POWER_CB(em_cb, cb) do { } while (0)
 

kernel/power/energy_model.c

@@ -54,28 +54,15 @@ static int em_debug_cpus_show(struct seq_file *s, void *unused)
 }
 DEFINE_SHOW_ATTRIBUTE(em_debug_cpus);
 
-static int em_debug_units_show(struct seq_file *s, void *unused)
+static int em_debug_flags_show(struct seq_file *s, void *unused)
 {
 	struct em_perf_domain *pd = s->private;
-	char *units = (pd->flags & EM_PERF_DOMAIN_MILLIWATTS) ?
-		"milliWatts" : "bogoWatts";
 
-	seq_printf(s, "%s\n", units);
+	seq_printf(s, "%#lx\n", pd->flags);
 
 	return 0;
 }
-DEFINE_SHOW_ATTRIBUTE(em_debug_units);
-
-static int em_debug_skip_inefficiencies_show(struct seq_file *s, void *unused)
-{
-	struct em_perf_domain *pd = s->private;
-	int enabled = (pd->flags & EM_PERF_DOMAIN_SKIP_INEFFICIENCIES) ? 1 : 0;
-
-	seq_printf(s, "%d\n", enabled);
-
-	return 0;
-}
-DEFINE_SHOW_ATTRIBUTE(em_debug_skip_inefficiencies);
+DEFINE_SHOW_ATTRIBUTE(em_debug_flags);
 
 static void em_debug_create_pd(struct device *dev)
 {
@@ -89,9 +76,8 @@ static void em_debug_create_pd(struct device *dev)
 		debugfs_create_file("cpus", 0444, d, dev->em_pd->cpus,
 				    &em_debug_cpus_fops);
 
-	debugfs_create_file("units", 0444, d, dev->em_pd, &em_debug_units_fops);
-	debugfs_create_file("skip-inefficiencies", 0444, d, dev->em_pd,
-			    &em_debug_skip_inefficiencies_fops);
+	debugfs_create_file("flags", 0444, d, dev->em_pd,
+			    &em_debug_flags_fops);
 
 	/* Create a sub-directory for each performance state */
 	for (i = 0; i < dev->em_pd->nr_perf_states; i++)
@@ -121,7 +107,8 @@ static void em_debug_remove_pd(struct device *dev) {}
 #endif
 
 static int em_create_perf_table(struct device *dev, struct em_perf_domain *pd,
-				int nr_states, struct em_data_callback *cb)
+				int nr_states, struct em_data_callback *cb,
+				unsigned long flags)
 {
 	unsigned long power, freq, prev_freq = 0, prev_cost = ULONG_MAX;
 	struct em_perf_state *table;
@@ -139,7 +126,7 @@ static int em_create_perf_table(struct device *dev, struct em_perf_domain *pd,
 		 * lowest performance state of 'dev' above 'freq' and updates
 		 * 'power' and 'freq' accordingly.
 		 */
-		ret = cb->active_power(&power, &freq, dev);
+		ret = cb->active_power(dev, &power, &freq);
 		if (ret) {
 			dev_err(dev, "EM: invalid perf. state: %d\n",
 				ret);
@@ -173,10 +160,22 @@ static int em_create_perf_table(struct device *dev, struct em_perf_domain *pd,
 	/* Compute the cost of each performance state. */
 	fmax = (u64) table[nr_states - 1].frequency;
 	for (i = nr_states - 1; i >= 0; i--) {
-		unsigned long power_res = em_scale_power(table[i].power);
+		unsigned long power_res, cost;
+
+		if (flags & EM_PERF_DOMAIN_ARTIFICIAL) {
+			ret = cb->get_cost(dev, table[i].frequency, &cost);
+			if (ret || !cost || cost > EM_MAX_POWER) {
+				dev_err(dev, "EM: invalid cost %lu %d\n",
+					cost, ret);
+				goto free_ps_table;
+			}
+		} else {
+			power_res = em_scale_power(table[i].power);
+			cost = div64_u64(fmax * power_res, table[i].frequency);
+		}
+
+		table[i].cost = cost;
 
-		table[i].cost = div64_u64(fmax * power_res,
-					  table[i].frequency);
 		if (table[i].cost >= prev_cost) {
 			table[i].flags = EM_PERF_STATE_INEFFICIENT;
 			dev_dbg(dev, "EM: OPP:%lu is inefficient\n",
@@ -197,7 +196,8 @@ static int em_create_perf_table(struct device *dev, struct em_perf_domain *pd,
 }
 
 static int em_create_pd(struct device *dev, int nr_states,
-			struct em_data_callback *cb, cpumask_t *cpus)
+			struct em_data_callback *cb, cpumask_t *cpus,
+			unsigned long flags)
 {
 	struct em_perf_domain *pd;
 	struct device *cpu_dev;
@@ -215,7 +215,7 @@ static int em_create_pd(struct device *dev, int nr_states,
 			return -ENOMEM;
 	}
 
-	ret = em_create_perf_table(dev, pd, nr_states, cb);
+	ret = em_create_perf_table(dev, pd, nr_states, cb, flags);
 	if (ret) {
 		kfree(pd);
 		return ret;
@@ -332,6 +332,7 @@ int em_dev_register_perf_domain(struct device *dev, unsigned int nr_states,
 				bool milliwatts)
 {
 	unsigned long cap, prev_cap = 0;
+	unsigned long flags = 0;
 	int cpu, ret;
 
 	if (!dev || !nr_states || !cb)
@@ -378,12 +379,16 @@ int em_dev_register_perf_domain(struct device *dev, unsigned int nr_states,
 		}
 	}
 
-	ret = em_create_pd(dev, nr_states, cb, cpus);
+	if (milliwatts)
+		flags |= EM_PERF_DOMAIN_MILLIWATTS;
+	else if (cb->get_cost)
+		flags |= EM_PERF_DOMAIN_ARTIFICIAL;
+
+	ret = em_create_pd(dev, nr_states, cb, cpus, flags);
 	if (ret)
 		goto unlock;
 
-	if (milliwatts)
-		dev->em_pd->flags |= EM_PERF_DOMAIN_MILLIWATTS;
+	dev->em_pd->flags |= flags;
 
 	em_cpufreq_update_efficiencies(dev);