1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * A power allocator to manage temperature |
4 | * |
5 | * Copyright (C) 2014 ARM Ltd. |
6 | * |
7 | */ |
8 | |
9 | #define pr_fmt(fmt) "Power allocator: " fmt |
10 | |
11 | #include <linux/slab.h> |
12 | #include <linux/thermal.h> |
13 | |
14 | #define CREATE_TRACE_POINTS |
15 | #include "thermal_trace_ipa.h" |
16 | |
17 | #include "thermal_core.h" |
18 | |
19 | #define FRAC_BITS 10 |
20 | #define int_to_frac(x) ((x) << FRAC_BITS) |
21 | #define frac_to_int(x) ((x) >> FRAC_BITS) |
22 | |
23 | /** |
24 | * mul_frac() - multiply two fixed-point numbers |
25 | * @x: first multiplicand |
26 | * @y: second multiplicand |
27 | * |
28 | * Return: the result of multiplying two fixed-point numbers. The |
29 | * result is also a fixed-point number. |
30 | */ |
31 | static inline s64 mul_frac(s64 x, s64 y) |
32 | { |
33 | return (x * y) >> FRAC_BITS; |
34 | } |
35 | |
36 | /** |
37 | * div_frac() - divide two fixed-point numbers |
38 | * @x: the dividend |
39 | * @y: the divisor |
40 | * |
41 | * Return: the result of dividing two fixed-point numbers. The |
42 | * result is also a fixed-point number. |
43 | */ |
44 | static inline s64 div_frac(s64 x, s64 y) |
45 | { |
46 | return div_s64(dividend: x << FRAC_BITS, divisor: y); |
47 | } |
48 | |
49 | /** |
50 | * struct power_actor - internal power information for power actor |
51 | * @req_power: requested power value (not weighted) |
52 | * @max_power: max allocatable power for this actor |
53 | * @granted_power: granted power for this actor |
54 | * @extra_actor_power: extra power that this actor can receive |
55 | * @weighted_req_power: weighted requested power as input to IPA |
56 | */ |
57 | struct power_actor { |
58 | u32 req_power; |
59 | u32 max_power; |
60 | u32 granted_power; |
61 | u32 ; |
62 | u32 weighted_req_power; |
63 | }; |
64 | |
65 | /** |
66 | * struct power_allocator_params - parameters for the power allocator governor |
67 | * @allocated_tzp: whether we have allocated tzp for this thermal zone and |
68 | * it needs to be freed on unbind |
69 | * @err_integral: accumulated error in the PID controller. |
70 | * @prev_err: error in the previous iteration of the PID controller. |
71 | * Used to calculate the derivative term. |
72 | * @sustainable_power: Sustainable power (heat) that this thermal zone can |
73 | * dissipate |
74 | * @trip_switch_on: first passive trip point of the thermal zone. The |
75 | * governor switches on when this trip point is crossed. |
76 | * If the thermal zone only has one passive trip point, |
77 | * @trip_switch_on should be NULL. |
78 | * @trip_max: last passive trip point of the thermal zone. The |
79 | * temperature we are controlling for. |
80 | * @total_weight: Sum of all thermal instances weights |
81 | * @num_actors: number of cooling devices supporting IPA callbacks |
82 | * @buffer_size: internal buffer size, to avoid runtime re-calculation |
83 | * @power: buffer for all power actors internal power information |
84 | */ |
85 | struct power_allocator_params { |
86 | bool allocated_tzp; |
87 | s64 err_integral; |
88 | s32 prev_err; |
89 | u32 sustainable_power; |
90 | const struct thermal_trip *trip_switch_on; |
91 | const struct thermal_trip *trip_max; |
92 | int total_weight; |
93 | unsigned int num_actors; |
94 | unsigned int buffer_size; |
95 | struct power_actor *power; |
96 | }; |
97 | |
98 | static bool power_actor_is_valid(struct power_allocator_params *params, |
99 | struct thermal_instance *instance) |
100 | { |
101 | return (instance->trip == params->trip_max && |
102 | cdev_is_power_actor(cdev: instance->cdev)); |
103 | } |
104 | |
105 | /** |
106 | * estimate_sustainable_power() - Estimate the sustainable power of a thermal zone |
107 | * @tz: thermal zone we are operating in |
108 | * |
109 | * For thermal zones that don't provide a sustainable_power in their |
110 | * thermal_zone_params, estimate one. Calculate it using the minimum |
111 | * power of all the cooling devices as that gives a valid value that |
112 | * can give some degree of functionality. For optimal performance of |
113 | * this governor, provide a sustainable_power in the thermal zone's |
114 | * thermal_zone_params. |
115 | */ |
116 | static u32 estimate_sustainable_power(struct thermal_zone_device *tz) |
117 | { |
118 | struct power_allocator_params *params = tz->governor_data; |
119 | struct thermal_cooling_device *cdev; |
120 | struct thermal_instance *instance; |
121 | u32 sustainable_power = 0; |
122 | u32 min_power; |
123 | |
124 | list_for_each_entry(instance, &tz->thermal_instances, tz_node) { |
125 | if (!power_actor_is_valid(params, instance)) |
126 | continue; |
127 | |
128 | cdev = instance->cdev; |
129 | if (cdev->ops->state2power(cdev, instance->upper, &min_power)) |
130 | continue; |
131 | |
132 | sustainable_power += min_power; |
133 | } |
134 | |
135 | return sustainable_power; |
136 | } |
137 | |
138 | /** |
139 | * estimate_pid_constants() - Estimate the constants for the PID controller |
140 | * @tz: thermal zone for which to estimate the constants |
141 | * @sustainable_power: sustainable power for the thermal zone |
142 | * @trip_switch_on: trip point for the switch on temperature |
143 | * @control_temp: target temperature for the power allocator governor |
144 | * |
145 | * This function is used to update the estimation of the PID |
146 | * controller constants in struct thermal_zone_parameters. |
147 | */ |
148 | static void estimate_pid_constants(struct thermal_zone_device *tz, |
149 | u32 sustainable_power, |
150 | const struct thermal_trip *trip_switch_on, |
151 | int control_temp) |
152 | { |
153 | u32 temperature_threshold = control_temp; |
154 | s32 k_i; |
155 | |
156 | if (trip_switch_on) |
157 | temperature_threshold -= trip_switch_on->temperature; |
158 | |
159 | /* |
160 | * estimate_pid_constants() tries to find appropriate default |
161 | * values for thermal zones that don't provide them. If a |
162 | * system integrator has configured a thermal zone with two |
163 | * passive trip points at the same temperature, that person |
164 | * hasn't put any effort to set up the thermal zone properly |
165 | * so just give up. |
166 | */ |
167 | if (!temperature_threshold) |
168 | return; |
169 | |
170 | tz->tzp->k_po = int_to_frac(sustainable_power) / |
171 | temperature_threshold; |
172 | |
173 | tz->tzp->k_pu = int_to_frac(2 * sustainable_power) / |
174 | temperature_threshold; |
175 | |
176 | k_i = tz->tzp->k_pu / 10; |
177 | tz->tzp->k_i = k_i > 0 ? k_i : 1; |
178 | |
179 | /* |
180 | * The default for k_d and integral_cutoff is 0, so we can |
181 | * leave them as they are. |
182 | */ |
183 | } |
184 | |
185 | /** |
186 | * get_sustainable_power() - Get the right sustainable power |
187 | * @tz: thermal zone for which to estimate the constants |
188 | * @params: parameters for the power allocator governor |
189 | * @control_temp: target temperature for the power allocator governor |
190 | * |
191 | * This function is used for getting the proper sustainable power value based |
192 | * on variables which might be updated by the user sysfs interface. If that |
193 | * happen the new value is going to be estimated and updated. It is also used |
194 | * after thermal zone binding, where the initial values where set to 0. |
195 | */ |
196 | static u32 get_sustainable_power(struct thermal_zone_device *tz, |
197 | struct power_allocator_params *params, |
198 | int control_temp) |
199 | { |
200 | u32 sustainable_power; |
201 | |
202 | if (!tz->tzp->sustainable_power) |
203 | sustainable_power = estimate_sustainable_power(tz); |
204 | else |
205 | sustainable_power = tz->tzp->sustainable_power; |
206 | |
207 | /* Check if it's init value 0 or there was update via sysfs */ |
208 | if (sustainable_power != params->sustainable_power) { |
209 | estimate_pid_constants(tz, sustainable_power, |
210 | trip_switch_on: params->trip_switch_on, control_temp); |
211 | |
212 | /* Do the estimation only once and make available in sysfs */ |
213 | tz->tzp->sustainable_power = sustainable_power; |
214 | params->sustainable_power = sustainable_power; |
215 | } |
216 | |
217 | return sustainable_power; |
218 | } |
219 | |
220 | /** |
221 | * pid_controller() - PID controller |
222 | * @tz: thermal zone we are operating in |
223 | * @control_temp: the target temperature in millicelsius |
224 | * @max_allocatable_power: maximum allocatable power for this thermal zone |
225 | * |
226 | * This PID controller increases the available power budget so that the |
227 | * temperature of the thermal zone gets as close as possible to |
228 | * @control_temp and limits the power if it exceeds it. k_po is the |
229 | * proportional term when we are overshooting, k_pu is the |
230 | * proportional term when we are undershooting. integral_cutoff is a |
231 | * threshold below which we stop accumulating the error. The |
232 | * accumulated error is only valid if the requested power will make |
233 | * the system warmer. If the system is mostly idle, there's no point |
234 | * in accumulating positive error. |
235 | * |
236 | * Return: The power budget for the next period. |
237 | */ |
238 | static u32 pid_controller(struct thermal_zone_device *tz, |
239 | int control_temp, |
240 | u32 max_allocatable_power) |
241 | { |
242 | struct power_allocator_params *params = tz->governor_data; |
243 | s64 p, i, d, power_range; |
244 | s32 err, max_power_frac; |
245 | u32 sustainable_power; |
246 | |
247 | max_power_frac = int_to_frac(max_allocatable_power); |
248 | |
249 | sustainable_power = get_sustainable_power(tz, params, control_temp); |
250 | |
251 | err = control_temp - tz->temperature; |
252 | err = int_to_frac(err); |
253 | |
254 | /* Calculate the proportional term */ |
255 | p = mul_frac(x: err < 0 ? tz->tzp->k_po : tz->tzp->k_pu, y: err); |
256 | |
257 | /* |
258 | * Calculate the integral term |
259 | * |
260 | * if the error is less than cut off allow integration (but |
261 | * the integral is limited to max power) |
262 | */ |
263 | i = mul_frac(x: tz->tzp->k_i, y: params->err_integral); |
264 | |
265 | if (err < int_to_frac(tz->tzp->integral_cutoff)) { |
266 | s64 i_next = i + mul_frac(x: tz->tzp->k_i, y: err); |
267 | |
268 | if (abs(i_next) < max_power_frac) { |
269 | i = i_next; |
270 | params->err_integral += err; |
271 | } |
272 | } |
273 | |
274 | /* |
275 | * Calculate the derivative term |
276 | * |
277 | * We do err - prev_err, so with a positive k_d, a decreasing |
278 | * error (i.e. driving closer to the line) results in less |
279 | * power being applied, slowing down the controller) |
280 | */ |
281 | d = mul_frac(x: tz->tzp->k_d, y: err - params->prev_err); |
282 | d = div_frac(x: d, y: jiffies_to_msecs(j: tz->passive_delay_jiffies)); |
283 | params->prev_err = err; |
284 | |
285 | power_range = p + i + d; |
286 | |
287 | /* feed-forward the known sustainable dissipatable power */ |
288 | power_range = sustainable_power + frac_to_int(power_range); |
289 | |
290 | power_range = clamp(power_range, (s64)0, (s64)max_allocatable_power); |
291 | |
292 | trace_thermal_power_allocator_pid(tz, frac_to_int(err), |
293 | frac_to_int(params->err_integral), |
294 | frac_to_int(p), frac_to_int(i), |
295 | frac_to_int(d), output: power_range); |
296 | |
297 | return power_range; |
298 | } |
299 | |
300 | /** |
301 | * power_actor_set_power() - limit the maximum power a cooling device consumes |
302 | * @cdev: pointer to &thermal_cooling_device |
303 | * @instance: thermal instance to update |
304 | * @power: the power in milliwatts |
305 | * |
306 | * Set the cooling device to consume at most @power milliwatts. The limit is |
307 | * expected to be a cap at the maximum power consumption. |
308 | * |
309 | * Return: 0 on success, -EINVAL if the cooling device does not |
310 | * implement the power actor API or -E* for other failures. |
311 | */ |
312 | static int |
313 | power_actor_set_power(struct thermal_cooling_device *cdev, |
314 | struct thermal_instance *instance, u32 power) |
315 | { |
316 | unsigned long state; |
317 | int ret; |
318 | |
319 | ret = cdev->ops->power2state(cdev, power, &state); |
320 | if (ret) |
321 | return ret; |
322 | |
323 | instance->target = clamp_val(state, instance->lower, instance->upper); |
324 | mutex_lock(&cdev->lock); |
325 | __thermal_cdev_update(cdev); |
326 | mutex_unlock(lock: &cdev->lock); |
327 | |
328 | return 0; |
329 | } |
330 | |
331 | /** |
332 | * divvy_up_power() - divvy the allocated power between the actors |
333 | * @power: buffer for all power actors internal power information |
334 | * @num_actors: number of power actors in this thermal zone |
335 | * @total_req_power: sum of all weighted requested power for all actors |
336 | * @power_range: total allocated power |
337 | * |
338 | * This function divides the total allocated power (@power_range) |
339 | * fairly between the actors. It first tries to give each actor a |
340 | * share of the @power_range according to how much power it requested |
341 | * compared to the rest of the actors. For example, if only one actor |
342 | * requests power, then it receives all the @power_range. If |
343 | * three actors each requests 1mW, each receives a third of the |
344 | * @power_range. |
345 | * |
346 | * If any actor received more than their maximum power, then that |
347 | * surplus is re-divvied among the actors based on how far they are |
348 | * from their respective maximums. |
349 | */ |
350 | static void divvy_up_power(struct power_actor *power, int num_actors, |
351 | u32 total_req_power, u32 power_range) |
352 | { |
353 | u32 = 0; |
354 | u32 = 0; |
355 | int i; |
356 | |
357 | /* |
358 | * Prevent division by 0 if none of the actors request power. |
359 | */ |
360 | if (!total_req_power) |
361 | total_req_power = 1; |
362 | |
363 | for (i = 0; i < num_actors; i++) { |
364 | struct power_actor *pa = &power[i]; |
365 | u64 req_range = (u64)pa->req_power * power_range; |
366 | |
367 | pa->granted_power = DIV_ROUND_CLOSEST_ULL(req_range, |
368 | total_req_power); |
369 | |
370 | if (pa->granted_power > pa->max_power) { |
371 | extra_power += pa->granted_power - pa->max_power; |
372 | pa->granted_power = pa->max_power; |
373 | } |
374 | |
375 | pa->extra_actor_power = pa->max_power - pa->granted_power; |
376 | capped_extra_power += pa->extra_actor_power; |
377 | } |
378 | |
379 | if (!extra_power || !capped_extra_power) |
380 | return; |
381 | |
382 | /* |
383 | * Re-divvy the reclaimed extra among actors based on |
384 | * how far they are from the max |
385 | */ |
386 | extra_power = min(extra_power, capped_extra_power); |
387 | |
388 | for (i = 0; i < num_actors; i++) { |
389 | struct power_actor *pa = &power[i]; |
390 | u64 = pa->extra_actor_power; |
391 | |
392 | extra_range *= extra_power; |
393 | pa->granted_power += DIV_ROUND_CLOSEST_ULL(extra_range, |
394 | capped_extra_power); |
395 | } |
396 | } |
397 | |
398 | static int allocate_power(struct thermal_zone_device *tz, int control_temp) |
399 | { |
400 | struct power_allocator_params *params = tz->governor_data; |
401 | unsigned int num_actors = params->num_actors; |
402 | struct power_actor *power = params->power; |
403 | struct thermal_cooling_device *cdev; |
404 | struct thermal_instance *instance; |
405 | u32 total_weighted_req_power = 0; |
406 | u32 max_allocatable_power = 0; |
407 | u32 total_granted_power = 0; |
408 | u32 total_req_power = 0; |
409 | u32 power_range, weight; |
410 | int i = 0, ret; |
411 | |
412 | if (!num_actors) |
413 | return -ENODEV; |
414 | |
415 | /* Clean all buffers for new power estimations */ |
416 | memset(power, 0, params->buffer_size); |
417 | |
418 | list_for_each_entry(instance, &tz->thermal_instances, tz_node) { |
419 | struct power_actor *pa = &power[i]; |
420 | |
421 | if (!power_actor_is_valid(params, instance)) |
422 | continue; |
423 | |
424 | cdev = instance->cdev; |
425 | |
426 | ret = cdev->ops->get_requested_power(cdev, &pa->req_power); |
427 | if (ret) |
428 | continue; |
429 | |
430 | if (!params->total_weight) |
431 | weight = 1 << FRAC_BITS; |
432 | else |
433 | weight = instance->weight; |
434 | |
435 | pa->weighted_req_power = frac_to_int(weight * pa->req_power); |
436 | |
437 | ret = cdev->ops->state2power(cdev, instance->lower, |
438 | &pa->max_power); |
439 | if (ret) |
440 | continue; |
441 | |
442 | total_req_power += pa->req_power; |
443 | max_allocatable_power += pa->max_power; |
444 | total_weighted_req_power += pa->weighted_req_power; |
445 | |
446 | i++; |
447 | } |
448 | |
449 | power_range = pid_controller(tz, control_temp, max_allocatable_power); |
450 | |
451 | divvy_up_power(power, num_actors, total_req_power: total_weighted_req_power, |
452 | power_range); |
453 | |
454 | i = 0; |
455 | list_for_each_entry(instance, &tz->thermal_instances, tz_node) { |
456 | struct power_actor *pa = &power[i]; |
457 | |
458 | if (!power_actor_is_valid(params, instance)) |
459 | continue; |
460 | |
461 | power_actor_set_power(cdev: instance->cdev, instance, |
462 | power: pa->granted_power); |
463 | total_granted_power += pa->granted_power; |
464 | |
465 | trace_thermal_power_actor(tz, actor_id: i, req_power: pa->req_power, |
466 | granted_power: pa->granted_power); |
467 | i++; |
468 | } |
469 | |
470 | trace_thermal_power_allocator(tz, total_req_power, total_granted_power, |
471 | num_actors, power_range, |
472 | max_allocatable_power, current_temp: tz->temperature, |
473 | delta_temp: control_temp - tz->temperature); |
474 | |
475 | return 0; |
476 | } |
477 | |
478 | /** |
479 | * get_governor_trips() - get the two trip points that are key for this governor |
480 | * @tz: thermal zone to operate on |
481 | * @params: pointer to private data for this governor |
482 | * |
483 | * The power allocator governor works optimally with two trips points: |
484 | * a "switch on" trip point and a "maximum desired temperature". These |
485 | * are defined as the first and last passive trip points. |
486 | * |
487 | * If there is only one trip point, then that's considered to be the |
488 | * "maximum desired temperature" trip point and the governor is always |
489 | * on. If there are no passive or active trip points, then the |
490 | * governor won't do anything. In fact, its throttle function |
491 | * won't be called at all. |
492 | */ |
493 | static void get_governor_trips(struct thermal_zone_device *tz, |
494 | struct power_allocator_params *params) |
495 | { |
496 | const struct thermal_trip *first_passive = NULL; |
497 | const struct thermal_trip *last_passive = NULL; |
498 | const struct thermal_trip *last_active = NULL; |
499 | const struct thermal_trip *trip; |
500 | |
501 | for_each_trip(tz, trip) { |
502 | switch (trip->type) { |
503 | case THERMAL_TRIP_PASSIVE: |
504 | if (!first_passive) { |
505 | first_passive = trip; |
506 | break; |
507 | } |
508 | last_passive = trip; |
509 | break; |
510 | case THERMAL_TRIP_ACTIVE: |
511 | last_active = trip; |
512 | break; |
513 | default: |
514 | break; |
515 | } |
516 | } |
517 | |
518 | if (last_passive) { |
519 | params->trip_switch_on = first_passive; |
520 | params->trip_max = last_passive; |
521 | } else if (first_passive) { |
522 | params->trip_switch_on = NULL; |
523 | params->trip_max = first_passive; |
524 | } else { |
525 | params->trip_switch_on = NULL; |
526 | params->trip_max = last_active; |
527 | } |
528 | } |
529 | |
530 | static void reset_pid_controller(struct power_allocator_params *params) |
531 | { |
532 | params->err_integral = 0; |
533 | params->prev_err = 0; |
534 | } |
535 | |
536 | static void allow_maximum_power(struct thermal_zone_device *tz, bool update) |
537 | { |
538 | struct power_allocator_params *params = tz->governor_data; |
539 | struct thermal_cooling_device *cdev; |
540 | struct thermal_instance *instance; |
541 | u32 req_power; |
542 | |
543 | list_for_each_entry(instance, &tz->thermal_instances, tz_node) { |
544 | if (!power_actor_is_valid(params, instance)) |
545 | continue; |
546 | |
547 | cdev = instance->cdev; |
548 | |
549 | instance->target = 0; |
550 | mutex_lock(&cdev->lock); |
551 | /* |
552 | * Call for updating the cooling devices local stats and avoid |
553 | * periods of dozen of seconds when those have not been |
554 | * maintained. |
555 | */ |
556 | cdev->ops->get_requested_power(cdev, &req_power); |
557 | |
558 | if (update) |
559 | __thermal_cdev_update(cdev); |
560 | |
561 | mutex_unlock(lock: &cdev->lock); |
562 | } |
563 | } |
564 | |
565 | /** |
566 | * check_power_actors() - Check all cooling devices and warn when they are |
567 | * not power actors |
568 | * @tz: thermal zone to operate on |
569 | * @params: power allocator private data |
570 | * |
571 | * Check all cooling devices in the @tz and warn every time they are missing |
572 | * power actor API. The warning should help to investigate the issue, which |
573 | * could be e.g. lack of Energy Model for a given device. |
574 | * |
575 | * If all of the cooling devices currently attached to @tz implement the power |
576 | * actor API, return the number of them (which may be 0, because some cooling |
577 | * devices may be attached later). Otherwise, return -EINVAL. |
578 | */ |
579 | static int check_power_actors(struct thermal_zone_device *tz, |
580 | struct power_allocator_params *params) |
581 | { |
582 | struct thermal_instance *instance; |
583 | int ret = 0; |
584 | |
585 | list_for_each_entry(instance, &tz->thermal_instances, tz_node) { |
586 | if (instance->trip != params->trip_max) |
587 | continue; |
588 | |
589 | if (!cdev_is_power_actor(cdev: instance->cdev)) { |
590 | dev_warn(&tz->device, "power_allocator: %s is not a power actor\n" , |
591 | instance->cdev->type); |
592 | return -EINVAL; |
593 | } |
594 | ret++; |
595 | } |
596 | |
597 | return ret; |
598 | } |
599 | |
600 | static int allocate_actors_buffer(struct power_allocator_params *params, |
601 | int num_actors) |
602 | { |
603 | int ret; |
604 | |
605 | kfree(objp: params->power); |
606 | |
607 | /* There might be no cooling devices yet. */ |
608 | if (!num_actors) { |
609 | ret = 0; |
610 | goto clean_state; |
611 | } |
612 | |
613 | params->power = kcalloc(n: num_actors, size: sizeof(struct power_actor), |
614 | GFP_KERNEL); |
615 | if (!params->power) { |
616 | ret = -ENOMEM; |
617 | goto clean_state; |
618 | } |
619 | |
620 | params->num_actors = num_actors; |
621 | params->buffer_size = num_actors * sizeof(struct power_actor); |
622 | |
623 | return 0; |
624 | |
625 | clean_state: |
626 | params->num_actors = 0; |
627 | params->buffer_size = 0; |
628 | params->power = NULL; |
629 | return ret; |
630 | } |
631 | |
632 | static void power_allocator_update_tz(struct thermal_zone_device *tz, |
633 | enum thermal_notify_event reason) |
634 | { |
635 | struct power_allocator_params *params = tz->governor_data; |
636 | struct thermal_instance *instance; |
637 | int num_actors = 0; |
638 | |
639 | switch (reason) { |
640 | case THERMAL_TZ_BIND_CDEV: |
641 | case THERMAL_TZ_UNBIND_CDEV: |
642 | list_for_each_entry(instance, &tz->thermal_instances, tz_node) |
643 | if (power_actor_is_valid(params, instance)) |
644 | num_actors++; |
645 | |
646 | if (num_actors == params->num_actors) |
647 | return; |
648 | |
649 | allocate_actors_buffer(params, num_actors); |
650 | break; |
651 | case THERMAL_INSTANCE_WEIGHT_CHANGED: |
652 | params->total_weight = 0; |
653 | list_for_each_entry(instance, &tz->thermal_instances, tz_node) |
654 | if (power_actor_is_valid(params, instance)) |
655 | params->total_weight += instance->weight; |
656 | break; |
657 | default: |
658 | break; |
659 | } |
660 | } |
661 | |
662 | /** |
663 | * power_allocator_bind() - bind the power_allocator governor to a thermal zone |
664 | * @tz: thermal zone to bind it to |
665 | * |
666 | * Initialize the PID controller parameters and bind it to the thermal |
667 | * zone. |
668 | * |
669 | * Return: 0 on success, or -ENOMEM if we ran out of memory, or -EINVAL |
670 | * when there are unsupported cooling devices in the @tz. |
671 | */ |
672 | static int power_allocator_bind(struct thermal_zone_device *tz) |
673 | { |
674 | struct power_allocator_params *params; |
675 | int ret; |
676 | |
677 | params = kzalloc(size: sizeof(*params), GFP_KERNEL); |
678 | if (!params) |
679 | return -ENOMEM; |
680 | |
681 | get_governor_trips(tz, params); |
682 | |
683 | ret = check_power_actors(tz, params); |
684 | if (ret < 0) { |
685 | dev_warn(&tz->device, "power_allocator: binding failed\n" ); |
686 | kfree(objp: params); |
687 | return ret; |
688 | } |
689 | |
690 | ret = allocate_actors_buffer(params, num_actors: ret); |
691 | if (ret) { |
692 | dev_warn(&tz->device, "power_allocator: allocation failed\n" ); |
693 | kfree(objp: params); |
694 | return ret; |
695 | } |
696 | |
697 | if (!tz->tzp) { |
698 | tz->tzp = kzalloc(size: sizeof(*tz->tzp), GFP_KERNEL); |
699 | if (!tz->tzp) { |
700 | ret = -ENOMEM; |
701 | goto free_params; |
702 | } |
703 | |
704 | params->allocated_tzp = true; |
705 | } |
706 | |
707 | if (!tz->tzp->sustainable_power) |
708 | dev_warn(&tz->device, "power_allocator: sustainable_power will be estimated\n" ); |
709 | else |
710 | params->sustainable_power = tz->tzp->sustainable_power; |
711 | |
712 | if (params->trip_max) |
713 | estimate_pid_constants(tz, sustainable_power: tz->tzp->sustainable_power, |
714 | trip_switch_on: params->trip_switch_on, |
715 | control_temp: params->trip_max->temperature); |
716 | |
717 | reset_pid_controller(params); |
718 | |
719 | tz->governor_data = params; |
720 | |
721 | return 0; |
722 | |
723 | free_params: |
724 | kfree(objp: params->power); |
725 | kfree(objp: params); |
726 | |
727 | return ret; |
728 | } |
729 | |
730 | static void power_allocator_unbind(struct thermal_zone_device *tz) |
731 | { |
732 | struct power_allocator_params *params = tz->governor_data; |
733 | |
734 | dev_dbg(&tz->device, "Unbinding from thermal zone %d\n" , tz->id); |
735 | |
736 | if (params->allocated_tzp) { |
737 | kfree(objp: tz->tzp); |
738 | tz->tzp = NULL; |
739 | } |
740 | |
741 | kfree(objp: params->power); |
742 | kfree(objp: tz->governor_data); |
743 | tz->governor_data = NULL; |
744 | } |
745 | |
746 | static int power_allocator_throttle(struct thermal_zone_device *tz, |
747 | const struct thermal_trip *trip) |
748 | { |
749 | struct power_allocator_params *params = tz->governor_data; |
750 | bool update; |
751 | |
752 | lockdep_assert_held(&tz->lock); |
753 | |
754 | /* |
755 | * We get called for every trip point but we only need to do |
756 | * our calculations once |
757 | */ |
758 | if (trip != params->trip_max) |
759 | return 0; |
760 | |
761 | trip = params->trip_switch_on; |
762 | if (trip && tz->temperature < trip->temperature) { |
763 | update = tz->passive; |
764 | tz->passive = 0; |
765 | reset_pid_controller(params); |
766 | allow_maximum_power(tz, update); |
767 | return 0; |
768 | } |
769 | |
770 | tz->passive = 1; |
771 | |
772 | return allocate_power(tz, control_temp: params->trip_max->temperature); |
773 | } |
774 | |
775 | static struct thermal_governor thermal_gov_power_allocator = { |
776 | .name = "power_allocator" , |
777 | .bind_to_tz = power_allocator_bind, |
778 | .unbind_from_tz = power_allocator_unbind, |
779 | .throttle = power_allocator_throttle, |
780 | .update_tz = power_allocator_update_tz, |
781 | }; |
782 | THERMAL_GOVERNOR_DECLARE(thermal_gov_power_allocator); |
783 | |