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
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
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>
34 #include "i915_trace.h"
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>
59 static noinline depot_stack_handle_t
__save_depot_stack(void)
61 unsigned long entries
[STACKDEPTH
];
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
;
92 stack
= __save_depot_stack();
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
);
105 stacks
[rpm
->debug
.count
++] = stack
;
106 rpm
->debug
.owners
= stacks
;
111 spin_unlock_irqrestore(&rpm
->debug
.lock
, flags
);
116 static void untrack_intel_runtime_pm_wakeref(struct intel_runtime_pm
*rpm
,
117 depot_stack_handle_t stack
)
119 unsigned long flags
, n
;
122 if (unlikely(stack
== -1))
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
));
135 spin_unlock_irqrestore(&rpm
->debug
.lock
, flags
);
138 "Unmatched wakeref (tracking %lu), count %u\n",
139 rpm
->debug
.count
, atomic_read(&rpm
->wakeref_count
))) {
142 buf
= kmalloc(PAGE_SIZE
, GFP_NOWAIT
| __GFP_NOWARN
);
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
);
151 __print_depot_stack(stack
, buf
, PAGE_SIZE
, 2);
152 DRM_DEBUG_DRIVER("wakeref last released at\n%s", buf
);
159 static int cmphandle(const void *_a
, const void *_b
)
161 const depot_stack_handle_t
* const a
= _a
, * const b
= _b
;
172 __print_intel_runtime_pm_wakeref(struct drm_printer
*p
,
173 const struct intel_runtime_pm_debug
*dbg
)
178 buf
= kmalloc(PAGE_SIZE
, GFP_NOWAIT
| __GFP_NOWARN
);
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
];
201 while (i
+ 1 < dbg
->count
&& dbg
->owners
[i
+ 1] == stack
)
203 __print_depot_stack(stack
, buf
, PAGE_SIZE
, 2);
204 drm_printf(p
, "Wakeref x%lu taken at:\n%s", rep
, buf
);
211 __untrack_all_wakerefs(struct intel_runtime_pm_debug
*debug
,
212 struct intel_runtime_pm_debug
*saved
)
216 debug
->owners
= NULL
;
218 debug
->last_release
= __save_depot_stack();
222 dump_and_free_wakeref_tracking(struct intel_runtime_pm_debug
*debug
)
225 struct drm_printer p
= drm_debug_printer("i915");
227 __print_intel_runtime_pm_wakeref(&p
, debug
);
230 kfree(debug
->owners
);
234 __intel_wakeref_dec_and_check_tracking(struct intel_runtime_pm
*rpm
)
236 struct intel_runtime_pm_debug dbg
= {};
239 if (!atomic_dec_and_lock_irqsave(&rpm
->wakeref_count
,
244 __untrack_all_wakerefs(&rpm
->debug
, &dbg
);
245 spin_unlock_irqrestore(&rpm
->debug
.lock
, flags
);
247 dump_and_free_wakeref_tracking(&dbg
);
251 untrack_all_intel_runtime_pm_wakerefs(struct intel_runtime_pm
*rpm
)
253 struct intel_runtime_pm_debug dbg
= {};
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
= {};
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
) {
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
)
285 s
= krealloc(dbg
.owners
,
286 dbg
.count
* sizeof(*s
),
287 GFP_NOWAIT
| __GFP_NOWARN
);
294 __print_intel_runtime_pm_wakeref(p
, &dbg
);
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
)
312 static void untrack_intel_runtime_pm_wakeref(struct intel_runtime_pm
*rpm
,
313 intel_wakeref_t wref
)
318 __intel_wakeref_dec_and_check_tracking(struct intel_runtime_pm
*rpm
)
320 atomic_dec(&rpm
->wakeref_count
);
324 untrack_all_intel_runtime_pm_wakerefs(struct intel_runtime_pm
*rpm
)
331 intel_runtime_pm_acquire(struct intel_runtime_pm
*rpm
, bool wakelock
)
334 atomic_add(1 + INTEL_RPM_WAKELOCK_BIAS
, &rpm
->wakeref_count
);
335 assert_rpm_wakelock_held(rpm
);
337 atomic_inc(&rpm
->wakeref_count
);
338 assert_rpm_raw_wakeref_held(rpm
);
343 intel_runtime_pm_release(struct intel_runtime_pm
*rpm
, int wakelock
)
346 assert_rpm_wakelock_held(rpm
);
347 atomic_sub(INTEL_RPM_WAKELOCK_BIAS
, &rpm
->wakeref_count
);
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
,
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
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)
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
,
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.
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);
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
) {
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
);
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
);
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
);
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
;
615 rpm
->available
= HAS_RUNTIME_PM(i915
);
617 init_intel_runtime_pm_wakeref(rpm
);