1 /* SPDX-License-Identifier: GPL-2.0 */
15  * struct em_perf_state - Performance state of a performance domain
16  * @performance:	CPU performance (capacity) at a given frequency
25 	unsigned long performance;  member
35  * EM_PERF_STATE_INEFFICIENT: The performance state is inefficient. There is
36  * in this em_perf_domain, another performance state with a higher frequency
43  * struct em_perf_table - Performance states table
46  * @state:	List of performance states, in ascending order
55  * struct em_perf_domain - Performance domain
57  * @nr_perf_states:	Number of performance states
58  * @min_perf_state:	Minimum allowed Performance State index
59  * @max_perf_state:	Maximum allowed Performance State index
61  * @cpus:		Cpumask covering the CPUs of the domain. It's here
62  *			for performance reasons to avoid potential cache
66  * In case of CPU device, a "performance domain" represents a group of CPUs
67  * whose performance is scaled together. All CPUs of a performance domain
68  * must have the same micro-architecture. Performance domains often have
69  * a 1-to-1 mapping with CPUFreq policies. In case of other devices the @cpus
84  *  EM_PERF_DOMAIN_MICROWATTS: The power values are in micro-Watts or some
97 #define em_span_cpus(em) (to_cpumask((em)->cpus))
98 #define em_is_artificial(em) ((em)->flags & EM_PERF_DOMAIN_ARTIFICIAL)
102  * The max power value in micro-Watts. The limit of 64 Watts is set as
104  * 32bit value limit for total Perf Domain power implies a limit of
105  * maximum CPUs in such domain to 64.
111  * limits to number of CPUs in the Perf. Domain.
122 	 * active_power() - Provide power at the next performance state of
125 	 * @power	: Active power at the performance state
127 	 * @freq	: Frequency at the performance state in kHz
130 	 * active_power() must find the lowest performance state of 'dev' above
134 	 * In case of CPUs, the power is the one of a single CPU in the domain,
135 	 * expressed in micro-Watts or an abstract scale. It is expected to
144 	 * get_cost() - Provide the cost at the given performance state of
147 	 * @freq	: Frequency at the performance state in kHz
148 	 * @cost	: The cost value for the performance state
151 	 * In case of CPUs, the cost is the one of a single CPU in the domain.
185  * em_pd_get_efficient_state() - Get an efficient performance state from the EM
186  * @table:		List of performance states, in ascending order
187  * @pd:			performance domain for which this must be done
193  * Return: An efficient performance state id, high enough to meet @max_util
200 	unsigned long pd_flags = pd->flags;  in em_pd_get_efficient_state()
201 	int min_ps = pd->min_perf_state;  in em_pd_get_efficient_state()
202 	int max_ps = pd->max_perf_state;  in em_pd_get_efficient_state()
208 		if (ps->performance >= max_util) {  in em_pd_get_efficient_state()
210 			    ps->flags & EM_PERF_STATE_INEFFICIENT)  in em_pd_get_efficient_state()
220  * em_cpu_energy() - Estimates the energy consumed by the CPUs of a
221  *		performance domain
222  * @pd		: performance domain for which energy has to be estimated
223  * @max_util	: highest utilization among CPUs of the domain
224  * @sum_util	: sum of the utilization of all CPUs in the domain
232  * Return: the sum of the energy consumed by the CPUs of the domain assuming
233  * a capacity state satisfying the max utilization of the domain.
251 	 * In order to predict the performance state, map the utilization of  in em_cpu_energy()
252 	 * the most utilized CPU of the performance domain to a requested  in em_cpu_energy()
253 	 * performance, like schedutil. Take also into account that the real  in em_cpu_energy()
254 	 * performance might be set lower (due to thermal capping). Thus, clamp  in em_cpu_energy()
256 	 * effective performance.  in em_cpu_energy()
261 	 * Find the lowest performance state of the Energy Model above the  in em_cpu_energy()
262 	 * requested performance.  in em_cpu_energy()
264 	em_table = rcu_dereference(pd->em_table);  in em_cpu_energy()
265 	i = em_pd_get_efficient_state(em_table->state, pd, max_util);  in em_cpu_energy()
266 	ps = &em_table->state[i];  in em_cpu_energy()
269 	 * The performance (capacity) of a CPU in the domain at the performance  in em_cpu_energy()
272 	 *                     ps->freq * scale_cpu  in em_cpu_energy()
273 	 *   ps->performance = --------------------                  (1)  in em_cpu_energy()
277 	 * the EM), the energy consumed by this CPU at that performance state  in em_cpu_energy()
280 	 *             ps->power * cpu_util  in em_cpu_energy()
281 	 *   cpu_nrg = --------------------                          (2)  in em_cpu_energy()
282 	 *               ps->performance  in em_cpu_energy()
284 	 * since 'cpu_util / ps->performance' represents its percentage of busy  in em_cpu_energy()
292 	 * By injecting (1) in (2), 'cpu_nrg' can be re-expressed as a product  in em_cpu_energy()
295 	 *             ps->power * cpu_max_freq  in em_cpu_energy()
296 	 *   cpu_nrg = ------------------------ * cpu_util           (3)  in em_cpu_energy()
297 	 *               ps->freq * scale_cpu  in em_cpu_energy()
300 	 * as 'ps->cost'.  in em_cpu_energy()
302 	 * Since all CPUs of the domain have the same micro-architecture, they  in em_cpu_energy()
303 	 * share the same 'ps->cost', and the same CPU capacity. Hence, the  in em_cpu_energy()
304 	 * total energy of the domain (which is the simple sum of the energy of  in em_cpu_energy()
307 	 *   pd_nrg = ps->cost * \Sum cpu_util                       (4)  in em_cpu_energy()
309 	return ps->cost * sum_util;  in em_cpu_energy()
313  * em_pd_nr_perf_states() - Get the number of performance states of a perf.
314  *				domain
315  * @pd		: performance domain for which this must be done
317  * Return: the number of performance states in the performance domain table
321 	return pd->nr_perf_states;  in em_pd_nr_perf_states()
325  * em_perf_state_from_pd() - Get the performance states table of perf.
326  *				domain
327  * @pd		: performance domain for which this must be done
330  * of the performance states table is finished, the rcu_read_unlock() should
333  * Return: the pointer to performance states table of the performance domain
338 	return rcu_dereference(pd->em_table)->state;  in em_perf_state_from_pd()
352 	return -EINVAL;  in em_dev_register_perf_domain()
385 	return -EINVAL;  in em_dev_update_perf_domain()
396 	return -EINVAL;  in em_dev_compute_costs()
400 	return -EINVAL;  in em_dev_update_chip_binning()
406 	return -EINVAL;  in em_update_performance_limits()