treewide: remove redundant IS_ERR() before error code check
[linux/fpc-iii.git] / drivers / gpu / drm / i915 / intel_runtime_pm.c
blobad719c9602af9abfa1363acfb774098c22aee8c0
1 /*
2 * Copyright © 2012-2014 Intel Corporation
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21 * IN THE SOFTWARE.
23 * Authors:
24 * Eugeni Dodonov <eugeni.dodonov@intel.com>
25 * Daniel Vetter <daniel.vetter@ffwll.ch>
29 #include <linux/pm_runtime.h>
31 #include <drm/drm_print.h>
33 #include "i915_drv.h"
34 #include "i915_trace.h"
36 /**
37 * DOC: runtime pm
39 * The i915 driver supports dynamic enabling and disabling of entire hardware
40 * blocks at runtime. This is especially important on the display side where
41 * software is supposed to control many power gates manually on recent hardware,
42 * since on the GT side a lot of the power management is done by the hardware.
43 * But even there some manual control at the device level is required.
45 * Since i915 supports a diverse set of platforms with a unified codebase and
46 * hardware engineers just love to shuffle functionality around between power
47 * domains there's a sizeable amount of indirection required. This file provides
48 * generic functions to the driver for grabbing and releasing references for
49 * abstract power domains. It then maps those to the actual power wells
50 * present for a given platform.
53 #if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM)
55 #include <linux/sort.h>
57 #define STACKDEPTH 8
59 static noinline depot_stack_handle_t __save_depot_stack(void)
61 unsigned long entries[STACKDEPTH];
62 unsigned int n;
64 n = stack_trace_save(entries, ARRAY_SIZE(entries), 1);
65 return stack_depot_save(entries, n, GFP_NOWAIT | __GFP_NOWARN);
68 static void __print_depot_stack(depot_stack_handle_t stack,
69 char *buf, int sz, int indent)
71 unsigned long *entries;
72 unsigned int nr_entries;
74 nr_entries = stack_depot_fetch(stack, &entries);
75 stack_trace_snprint(buf, sz, entries, nr_entries, indent);
78 static void init_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm)
80 spin_lock_init(&rpm->debug.lock);
83 static noinline depot_stack_handle_t
84 track_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm)
86 depot_stack_handle_t stack, *stacks;
87 unsigned long flags;
89 if (!rpm->available)
90 return -1;
92 stack = __save_depot_stack();
93 if (!stack)
94 return -1;
96 spin_lock_irqsave(&rpm->debug.lock, flags);
98 if (!rpm->debug.count)
99 rpm->debug.last_acquire = stack;
101 stacks = krealloc(rpm->debug.owners,
102 (rpm->debug.count + 1) * sizeof(*stacks),
103 GFP_NOWAIT | __GFP_NOWARN);
104 if (stacks) {
105 stacks[rpm->debug.count++] = stack;
106 rpm->debug.owners = stacks;
107 } else {
108 stack = -1;
111 spin_unlock_irqrestore(&rpm->debug.lock, flags);
113 return stack;
116 static void untrack_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm,
117 depot_stack_handle_t stack)
119 unsigned long flags, n;
120 bool found = false;
122 if (unlikely(stack == -1))
123 return;
125 spin_lock_irqsave(&rpm->debug.lock, flags);
126 for (n = rpm->debug.count; n--; ) {
127 if (rpm->debug.owners[n] == stack) {
128 memmove(rpm->debug.owners + n,
129 rpm->debug.owners + n + 1,
130 (--rpm->debug.count - n) * sizeof(stack));
131 found = true;
132 break;
135 spin_unlock_irqrestore(&rpm->debug.lock, flags);
137 if (WARN(!found,
138 "Unmatched wakeref (tracking %lu), count %u\n",
139 rpm->debug.count, atomic_read(&rpm->wakeref_count))) {
140 char *buf;
142 buf = kmalloc(PAGE_SIZE, GFP_NOWAIT | __GFP_NOWARN);
143 if (!buf)
144 return;
146 __print_depot_stack(stack, buf, PAGE_SIZE, 2);
147 DRM_DEBUG_DRIVER("wakeref %x from\n%s", stack, buf);
149 stack = READ_ONCE(rpm->debug.last_release);
150 if (stack) {
151 __print_depot_stack(stack, buf, PAGE_SIZE, 2);
152 DRM_DEBUG_DRIVER("wakeref last released at\n%s", buf);
155 kfree(buf);
159 static int cmphandle(const void *_a, const void *_b)
161 const depot_stack_handle_t * const a = _a, * const b = _b;
163 if (*a < *b)
164 return -1;
165 else if (*a > *b)
166 return 1;
167 else
168 return 0;
171 static void
172 __print_intel_runtime_pm_wakeref(struct drm_printer *p,
173 const struct intel_runtime_pm_debug *dbg)
175 unsigned long i;
176 char *buf;
178 buf = kmalloc(PAGE_SIZE, GFP_NOWAIT | __GFP_NOWARN);
179 if (!buf)
180 return;
182 if (dbg->last_acquire) {
183 __print_depot_stack(dbg->last_acquire, buf, PAGE_SIZE, 2);
184 drm_printf(p, "Wakeref last acquired:\n%s", buf);
187 if (dbg->last_release) {
188 __print_depot_stack(dbg->last_release, buf, PAGE_SIZE, 2);
189 drm_printf(p, "Wakeref last released:\n%s", buf);
192 drm_printf(p, "Wakeref count: %lu\n", dbg->count);
194 sort(dbg->owners, dbg->count, sizeof(*dbg->owners), cmphandle, NULL);
196 for (i = 0; i < dbg->count; i++) {
197 depot_stack_handle_t stack = dbg->owners[i];
198 unsigned long rep;
200 rep = 1;
201 while (i + 1 < dbg->count && dbg->owners[i + 1] == stack)
202 rep++, i++;
203 __print_depot_stack(stack, buf, PAGE_SIZE, 2);
204 drm_printf(p, "Wakeref x%lu taken at:\n%s", rep, buf);
207 kfree(buf);
210 static noinline void
211 __untrack_all_wakerefs(struct intel_runtime_pm_debug *debug,
212 struct intel_runtime_pm_debug *saved)
214 *saved = *debug;
216 debug->owners = NULL;
217 debug->count = 0;
218 debug->last_release = __save_depot_stack();
221 static void
222 dump_and_free_wakeref_tracking(struct intel_runtime_pm_debug *debug)
224 if (debug->count) {
225 struct drm_printer p = drm_debug_printer("i915");
227 __print_intel_runtime_pm_wakeref(&p, debug);
230 kfree(debug->owners);
233 static noinline void
234 __intel_wakeref_dec_and_check_tracking(struct intel_runtime_pm *rpm)
236 struct intel_runtime_pm_debug dbg = {};
237 unsigned long flags;
239 if (!atomic_dec_and_lock_irqsave(&rpm->wakeref_count,
240 &rpm->debug.lock,
241 flags))
242 return;
244 __untrack_all_wakerefs(&rpm->debug, &dbg);
245 spin_unlock_irqrestore(&rpm->debug.lock, flags);
247 dump_and_free_wakeref_tracking(&dbg);
250 static noinline void
251 untrack_all_intel_runtime_pm_wakerefs(struct intel_runtime_pm *rpm)
253 struct intel_runtime_pm_debug dbg = {};
254 unsigned long flags;
256 spin_lock_irqsave(&rpm->debug.lock, flags);
257 __untrack_all_wakerefs(&rpm->debug, &dbg);
258 spin_unlock_irqrestore(&rpm->debug.lock, flags);
260 dump_and_free_wakeref_tracking(&dbg);
263 void print_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm,
264 struct drm_printer *p)
266 struct intel_runtime_pm_debug dbg = {};
268 do {
269 unsigned long alloc = dbg.count;
270 depot_stack_handle_t *s;
272 spin_lock_irq(&rpm->debug.lock);
273 dbg.count = rpm->debug.count;
274 if (dbg.count <= alloc) {
275 memcpy(dbg.owners,
276 rpm->debug.owners,
277 dbg.count * sizeof(*s));
279 dbg.last_acquire = rpm->debug.last_acquire;
280 dbg.last_release = rpm->debug.last_release;
281 spin_unlock_irq(&rpm->debug.lock);
282 if (dbg.count <= alloc)
283 break;
285 s = krealloc(dbg.owners,
286 dbg.count * sizeof(*s),
287 GFP_NOWAIT | __GFP_NOWARN);
288 if (!s)
289 goto out;
291 dbg.owners = s;
292 } while (1);
294 __print_intel_runtime_pm_wakeref(p, &dbg);
296 out:
297 kfree(dbg.owners);
300 #else
302 static void init_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm)
306 static depot_stack_handle_t
307 track_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm)
309 return -1;
312 static void untrack_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm,
313 intel_wakeref_t wref)
317 static void
318 __intel_wakeref_dec_and_check_tracking(struct intel_runtime_pm *rpm)
320 atomic_dec(&rpm->wakeref_count);
323 static void
324 untrack_all_intel_runtime_pm_wakerefs(struct intel_runtime_pm *rpm)
328 #endif
330 static void
331 intel_runtime_pm_acquire(struct intel_runtime_pm *rpm, bool wakelock)
333 if (wakelock) {
334 atomic_add(1 + INTEL_RPM_WAKELOCK_BIAS, &rpm->wakeref_count);
335 assert_rpm_wakelock_held(rpm);
336 } else {
337 atomic_inc(&rpm->wakeref_count);
338 assert_rpm_raw_wakeref_held(rpm);
342 static void
343 intel_runtime_pm_release(struct intel_runtime_pm *rpm, int wakelock)
345 if (wakelock) {
346 assert_rpm_wakelock_held(rpm);
347 atomic_sub(INTEL_RPM_WAKELOCK_BIAS, &rpm->wakeref_count);
348 } else {
349 assert_rpm_raw_wakeref_held(rpm);
352 __intel_wakeref_dec_and_check_tracking(rpm);
355 static intel_wakeref_t __intel_runtime_pm_get(struct intel_runtime_pm *rpm,
356 bool wakelock)
358 int ret;
360 ret = pm_runtime_get_sync(rpm->kdev);
361 WARN_ONCE(ret < 0, "pm_runtime_get_sync() failed: %d\n", ret);
363 intel_runtime_pm_acquire(rpm, wakelock);
365 return track_intel_runtime_pm_wakeref(rpm);
369 * intel_runtime_pm_get_raw - grab a raw runtime pm reference
370 * @rpm: the intel_runtime_pm structure
372 * This is the unlocked version of intel_display_power_is_enabled() and should
373 * only be used from error capture and recovery code where deadlocks are
374 * possible.
375 * This function grabs a device-level runtime pm reference (mostly used for
376 * asynchronous PM management from display code) and ensures that it is powered
377 * up. Raw references are not considered during wakelock assert checks.
379 * Any runtime pm reference obtained by this function must have a symmetric
380 * call to intel_runtime_pm_put_raw() to release the reference again.
382 * Returns: the wakeref cookie to pass to intel_runtime_pm_put_raw(), evaluates
383 * as True if the wakeref was acquired, or False otherwise.
385 intel_wakeref_t intel_runtime_pm_get_raw(struct intel_runtime_pm *rpm)
387 return __intel_runtime_pm_get(rpm, false);
391 * intel_runtime_pm_get - grab a runtime pm reference
392 * @rpm: the intel_runtime_pm structure
394 * This function grabs a device-level runtime pm reference (mostly used for GEM
395 * code to ensure the GTT or GT is on) and ensures that it is powered up.
397 * Any runtime pm reference obtained by this function must have a symmetric
398 * call to intel_runtime_pm_put() to release the reference again.
400 * Returns: the wakeref cookie to pass to intel_runtime_pm_put()
402 intel_wakeref_t intel_runtime_pm_get(struct intel_runtime_pm *rpm)
404 return __intel_runtime_pm_get(rpm, true);
408 * intel_runtime_pm_get_if_in_use - grab a runtime pm reference if device in use
409 * @rpm: the intel_runtime_pm structure
411 * This function grabs a device-level runtime pm reference if the device is
412 * already in use and ensures that it is powered up. It is illegal to try
413 * and access the HW should intel_runtime_pm_get_if_in_use() report failure.
415 * Any runtime pm reference obtained by this function must have a symmetric
416 * call to intel_runtime_pm_put() to release the reference again.
418 * Returns: the wakeref cookie to pass to intel_runtime_pm_put(), evaluates
419 * as True if the wakeref was acquired, or False otherwise.
421 intel_wakeref_t intel_runtime_pm_get_if_in_use(struct intel_runtime_pm *rpm)
423 if (IS_ENABLED(CONFIG_PM)) {
425 * In cases runtime PM is disabled by the RPM core and we get
426 * an -EINVAL return value we are not supposed to call this
427 * function, since the power state is undefined. This applies
428 * atm to the late/early system suspend/resume handlers.
430 if (pm_runtime_get_if_in_use(rpm->kdev) <= 0)
431 return 0;
434 intel_runtime_pm_acquire(rpm, true);
436 return track_intel_runtime_pm_wakeref(rpm);
440 * intel_runtime_pm_get_noresume - grab a runtime pm reference
441 * @rpm: the intel_runtime_pm structure
443 * This function grabs a device-level runtime pm reference (mostly used for GEM
444 * code to ensure the GTT or GT is on).
446 * It will _not_ power up the device but instead only check that it's powered
447 * on. Therefore it is only valid to call this functions from contexts where
448 * the device is known to be powered up and where trying to power it up would
449 * result in hilarity and deadlocks. That pretty much means only the system
450 * suspend/resume code where this is used to grab runtime pm references for
451 * delayed setup down in work items.
453 * Any runtime pm reference obtained by this function must have a symmetric
454 * call to intel_runtime_pm_put() to release the reference again.
456 * Returns: the wakeref cookie to pass to intel_runtime_pm_put()
458 intel_wakeref_t intel_runtime_pm_get_noresume(struct intel_runtime_pm *rpm)
460 assert_rpm_wakelock_held(rpm);
461 pm_runtime_get_noresume(rpm->kdev);
463 intel_runtime_pm_acquire(rpm, true);
465 return track_intel_runtime_pm_wakeref(rpm);
468 static void __intel_runtime_pm_put(struct intel_runtime_pm *rpm,
469 intel_wakeref_t wref,
470 bool wakelock)
472 struct device *kdev = rpm->kdev;
474 untrack_intel_runtime_pm_wakeref(rpm, wref);
476 intel_runtime_pm_release(rpm, wakelock);
478 pm_runtime_mark_last_busy(kdev);
479 pm_runtime_put_autosuspend(kdev);
483 * intel_runtime_pm_put_raw - release a raw runtime pm reference
484 * @rpm: the intel_runtime_pm structure
485 * @wref: wakeref acquired for the reference that is being released
487 * This function drops the device-level runtime pm reference obtained by
488 * intel_runtime_pm_get_raw() and might power down the corresponding
489 * hardware block right away if this is the last reference.
491 void
492 intel_runtime_pm_put_raw(struct intel_runtime_pm *rpm, intel_wakeref_t wref)
494 __intel_runtime_pm_put(rpm, wref, false);
498 * intel_runtime_pm_put_unchecked - release an unchecked runtime pm reference
499 * @rpm: the intel_runtime_pm structure
501 * This function drops the device-level runtime pm reference obtained by
502 * intel_runtime_pm_get() and might power down the corresponding
503 * hardware block right away if this is the last reference.
505 * This function exists only for historical reasons and should be avoided in
506 * new code, as the correctness of its use cannot be checked. Always use
507 * intel_runtime_pm_put() instead.
509 void intel_runtime_pm_put_unchecked(struct intel_runtime_pm *rpm)
511 __intel_runtime_pm_put(rpm, -1, true);
514 #if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM)
516 * intel_runtime_pm_put - release a runtime pm reference
517 * @rpm: the intel_runtime_pm structure
518 * @wref: wakeref acquired for the reference that is being released
520 * This function drops the device-level runtime pm reference obtained by
521 * intel_runtime_pm_get() and might power down the corresponding
522 * hardware block right away if this is the last reference.
524 void intel_runtime_pm_put(struct intel_runtime_pm *rpm, intel_wakeref_t wref)
526 __intel_runtime_pm_put(rpm, wref, true);
528 #endif
531 * intel_runtime_pm_enable - enable runtime pm
532 * @rpm: the intel_runtime_pm structure
534 * This function enables runtime pm at the end of the driver load sequence.
536 * Note that this function does currently not enable runtime pm for the
537 * subordinate display power domains. That is done by
538 * intel_power_domains_enable().
540 void intel_runtime_pm_enable(struct intel_runtime_pm *rpm)
542 struct device *kdev = rpm->kdev;
545 * Disable the system suspend direct complete optimization, which can
546 * leave the device suspended skipping the driver's suspend handlers
547 * if the device was already runtime suspended. This is needed due to
548 * the difference in our runtime and system suspend sequence and
549 * becaue the HDA driver may require us to enable the audio power
550 * domain during system suspend.
552 dev_pm_set_driver_flags(kdev, DPM_FLAG_NEVER_SKIP);
554 pm_runtime_set_autosuspend_delay(kdev, 10000); /* 10s */
555 pm_runtime_mark_last_busy(kdev);
558 * Take a permanent reference to disable the RPM functionality and drop
559 * it only when unloading the driver. Use the low level get/put helpers,
560 * so the driver's own RPM reference tracking asserts also work on
561 * platforms without RPM support.
563 if (!rpm->available) {
564 int ret;
566 pm_runtime_dont_use_autosuspend(kdev);
567 ret = pm_runtime_get_sync(kdev);
568 WARN(ret < 0, "pm_runtime_get_sync() failed: %d\n", ret);
569 } else {
570 pm_runtime_use_autosuspend(kdev);
574 * The core calls the driver load handler with an RPM reference held.
575 * We drop that here and will reacquire it during unloading in
576 * intel_power_domains_fini().
578 pm_runtime_put_autosuspend(kdev);
581 void intel_runtime_pm_disable(struct intel_runtime_pm *rpm)
583 struct device *kdev = rpm->kdev;
585 /* Transfer rpm ownership back to core */
586 WARN(pm_runtime_get_sync(kdev) < 0,
587 "Failed to pass rpm ownership back to core\n");
589 pm_runtime_dont_use_autosuspend(kdev);
591 if (!rpm->available)
592 pm_runtime_put(kdev);
595 void intel_runtime_pm_driver_release(struct intel_runtime_pm *rpm)
597 int count = atomic_read(&rpm->wakeref_count);
599 WARN(count,
600 "i915 raw-wakerefs=%d wakelocks=%d on cleanup\n",
601 intel_rpm_raw_wakeref_count(count),
602 intel_rpm_wakelock_count(count));
604 untrack_all_intel_runtime_pm_wakerefs(rpm);
607 void intel_runtime_pm_init_early(struct intel_runtime_pm *rpm)
609 struct drm_i915_private *i915 =
610 container_of(rpm, struct drm_i915_private, runtime_pm);
611 struct pci_dev *pdev = i915->drm.pdev;
612 struct device *kdev = &pdev->dev;
614 rpm->kdev = kdev;
615 rpm->available = HAS_RUNTIME_PM(i915);
617 init_intel_runtime_pm_wakeref(rpm);