1 /*
2  * Copyright © 2012-2014 Intel Corporation
3  *
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:
10  *
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.
14  *
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.
22  *
23  * Authors:
24  *    Eugeni Dodonov <eugeni.dodonov@intel.com>
25  *    Daniel Vetter <daniel.vetter@ffwll.ch>
26  *
27  */
28 
29 #include <linux/pm_runtime.h>
30 
31 #include <drm/drm_print.h>
32 
33 #include "i915_drv.h"
34 #include "i915_trace.h"
35 
36 /**
37  * DOC: runtime pm
38  *
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.
44  *
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.
51  */
52 
53 #if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM)
54 
55 #include <linux/sort.h>
56 
57 #define STACKDEPTH 8
58 
__save_depot_stack(void)59 static noinline depot_stack_handle_t __save_depot_stack(void)
60 {
61 	unsigned long entries[STACKDEPTH];
62 	unsigned int n;
63 
64 	n = stack_trace_save(entries, ARRAY_SIZE(entries), 1);
65 	return stack_depot_save(entries, n, GFP_NOWAIT | __GFP_NOWARN);
66 }
67 
init_intel_runtime_pm_wakeref(struct intel_runtime_pm * rpm)68 static void init_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm)
69 {
70 	spin_lock_init(&rpm->debug.lock);
71 	stack_depot_init();
72 }
73 
74 static noinline depot_stack_handle_t
track_intel_runtime_pm_wakeref(struct intel_runtime_pm * rpm)75 track_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm)
76 {
77 	depot_stack_handle_t stack, *stacks;
78 	unsigned long flags;
79 
80 	if (rpm->no_wakeref_tracking)
81 		return -1;
82 
83 	stack = __save_depot_stack();
84 	if (!stack)
85 		return -1;
86 
87 	spin_lock_irqsave(&rpm->debug.lock, flags);
88 
89 	if (!rpm->debug.count)
90 		rpm->debug.last_acquire = stack;
91 
92 	stacks = krealloc(rpm->debug.owners,
93 			  (rpm->debug.count + 1) * sizeof(*stacks),
94 			  GFP_NOWAIT | __GFP_NOWARN);
95 	if (stacks) {
96 		stacks[rpm->debug.count++] = stack;
97 		rpm->debug.owners = stacks;
98 	} else {
99 		stack = -1;
100 	}
101 
102 	spin_unlock_irqrestore(&rpm->debug.lock, flags);
103 
104 	return stack;
105 }
106 
untrack_intel_runtime_pm_wakeref(struct intel_runtime_pm * rpm,depot_stack_handle_t stack)107 static void untrack_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm,
108 					     depot_stack_handle_t stack)
109 {
110 	struct drm_i915_private *i915 = container_of(rpm,
111 						     struct drm_i915_private,
112 						     runtime_pm);
113 	unsigned long flags, n;
114 	bool found = false;
115 
116 	if (unlikely(stack == -1))
117 		return;
118 
119 	spin_lock_irqsave(&rpm->debug.lock, flags);
120 	for (n = rpm->debug.count; n--; ) {
121 		if (rpm->debug.owners[n] == stack) {
122 			memmove(rpm->debug.owners + n,
123 				rpm->debug.owners + n + 1,
124 				(--rpm->debug.count - n) * sizeof(stack));
125 			found = true;
126 			break;
127 		}
128 	}
129 	spin_unlock_irqrestore(&rpm->debug.lock, flags);
130 
131 	if (drm_WARN(&i915->drm, !found,
132 		     "Unmatched wakeref (tracking %lu), count %u\n",
133 		     rpm->debug.count, atomic_read(&rpm->wakeref_count))) {
134 		char *buf;
135 
136 		buf = kmalloc(PAGE_SIZE, GFP_NOWAIT | __GFP_NOWARN);
137 		if (!buf)
138 			return;
139 
140 		stack_depot_snprint(stack, buf, PAGE_SIZE, 2);
141 		DRM_DEBUG_DRIVER("wakeref %x from\n%s", stack, buf);
142 
143 		stack = READ_ONCE(rpm->debug.last_release);
144 		if (stack) {
145 			stack_depot_snprint(stack, buf, PAGE_SIZE, 2);
146 			DRM_DEBUG_DRIVER("wakeref last released at\n%s", buf);
147 		}
148 
149 		kfree(buf);
150 	}
151 }
152 
cmphandle(const void * _a,const void * _b)153 static int cmphandle(const void *_a, const void *_b)
154 {
155 	const depot_stack_handle_t * const a = _a, * const b = _b;
156 
157 	if (*a < *b)
158 		return -1;
159 	else if (*a > *b)
160 		return 1;
161 	else
162 		return 0;
163 }
164 
165 static void
__print_intel_runtime_pm_wakeref(struct drm_printer * p,const struct intel_runtime_pm_debug * dbg)166 __print_intel_runtime_pm_wakeref(struct drm_printer *p,
167 				 const struct intel_runtime_pm_debug *dbg)
168 {
169 	unsigned long i;
170 	char *buf;
171 
172 	buf = kmalloc(PAGE_SIZE, GFP_NOWAIT | __GFP_NOWARN);
173 	if (!buf)
174 		return;
175 
176 	if (dbg->last_acquire) {
177 		stack_depot_snprint(dbg->last_acquire, buf, PAGE_SIZE, 2);
178 		drm_printf(p, "Wakeref last acquired:\n%s", buf);
179 	}
180 
181 	if (dbg->last_release) {
182 		stack_depot_snprint(dbg->last_release, buf, PAGE_SIZE, 2);
183 		drm_printf(p, "Wakeref last released:\n%s", buf);
184 	}
185 
186 	drm_printf(p, "Wakeref count: %lu\n", dbg->count);
187 
188 	sort(dbg->owners, dbg->count, sizeof(*dbg->owners), cmphandle, NULL);
189 
190 	for (i = 0; i < dbg->count; i++) {
191 		depot_stack_handle_t stack = dbg->owners[i];
192 		unsigned long rep;
193 
194 		rep = 1;
195 		while (i + 1 < dbg->count && dbg->owners[i + 1] == stack)
196 			rep++, i++;
197 		stack_depot_snprint(stack, buf, PAGE_SIZE, 2);
198 		drm_printf(p, "Wakeref x%lu taken at:\n%s", rep, buf);
199 	}
200 
201 	kfree(buf);
202 }
203 
204 static noinline void
__untrack_all_wakerefs(struct intel_runtime_pm_debug * debug,struct intel_runtime_pm_debug * saved)205 __untrack_all_wakerefs(struct intel_runtime_pm_debug *debug,
206 		       struct intel_runtime_pm_debug *saved)
207 {
208 	*saved = *debug;
209 
210 	debug->owners = NULL;
211 	debug->count = 0;
212 	debug->last_release = __save_depot_stack();
213 }
214 
215 static void
dump_and_free_wakeref_tracking(struct intel_runtime_pm_debug * debug)216 dump_and_free_wakeref_tracking(struct intel_runtime_pm_debug *debug)
217 {
218 	if (debug->count) {
219 		struct drm_printer p = drm_debug_printer("i915");
220 
221 		__print_intel_runtime_pm_wakeref(&p, debug);
222 	}
223 
224 	kfree(debug->owners);
225 }
226 
227 static noinline void
__intel_wakeref_dec_and_check_tracking(struct intel_runtime_pm * rpm)228 __intel_wakeref_dec_and_check_tracking(struct intel_runtime_pm *rpm)
229 {
230 	struct intel_runtime_pm_debug dbg = {};
231 	unsigned long flags;
232 
233 	if (!atomic_dec_and_lock_irqsave(&rpm->wakeref_count,
234 					 &rpm->debug.lock,
235 					 flags))
236 		return;
237 
238 	__untrack_all_wakerefs(&rpm->debug, &dbg);
239 	spin_unlock_irqrestore(&rpm->debug.lock, flags);
240 
241 	dump_and_free_wakeref_tracking(&dbg);
242 }
243 
244 static noinline void
untrack_all_intel_runtime_pm_wakerefs(struct intel_runtime_pm * rpm)245 untrack_all_intel_runtime_pm_wakerefs(struct intel_runtime_pm *rpm)
246 {
247 	struct intel_runtime_pm_debug dbg = {};
248 	unsigned long flags;
249 
250 	spin_lock_irqsave(&rpm->debug.lock, flags);
251 	__untrack_all_wakerefs(&rpm->debug, &dbg);
252 	spin_unlock_irqrestore(&rpm->debug.lock, flags);
253 
254 	dump_and_free_wakeref_tracking(&dbg);
255 }
256 
print_intel_runtime_pm_wakeref(struct intel_runtime_pm * rpm,struct drm_printer * p)257 void print_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm,
258 				    struct drm_printer *p)
259 {
260 	struct intel_runtime_pm_debug dbg = {};
261 
262 	do {
263 		unsigned long alloc = dbg.count;
264 		depot_stack_handle_t *s;
265 
266 		spin_lock_irq(&rpm->debug.lock);
267 		dbg.count = rpm->debug.count;
268 		if (dbg.count <= alloc) {
269 			memcpy(dbg.owners,
270 			       rpm->debug.owners,
271 			       dbg.count * sizeof(*s));
272 		}
273 		dbg.last_acquire = rpm->debug.last_acquire;
274 		dbg.last_release = rpm->debug.last_release;
275 		spin_unlock_irq(&rpm->debug.lock);
276 		if (dbg.count <= alloc)
277 			break;
278 
279 		s = krealloc(dbg.owners,
280 			     dbg.count * sizeof(*s),
281 			     GFP_NOWAIT | __GFP_NOWARN);
282 		if (!s)
283 			goto out;
284 
285 		dbg.owners = s;
286 	} while (1);
287 
288 	__print_intel_runtime_pm_wakeref(p, &dbg);
289 
290 out:
291 	kfree(dbg.owners);
292 }
293 
294 #else
295 
init_intel_runtime_pm_wakeref(struct intel_runtime_pm * rpm)296 static void init_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm)
297 {
298 }
299 
300 static depot_stack_handle_t
track_intel_runtime_pm_wakeref(struct intel_runtime_pm * rpm)301 track_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm)
302 {
303 	return -1;
304 }
305 
untrack_intel_runtime_pm_wakeref(struct intel_runtime_pm * rpm,intel_wakeref_t wref)306 static void untrack_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm,
307 					     intel_wakeref_t wref)
308 {
309 }
310 
311 static void
__intel_wakeref_dec_and_check_tracking(struct intel_runtime_pm * rpm)312 __intel_wakeref_dec_and_check_tracking(struct intel_runtime_pm *rpm)
313 {
314 	atomic_dec(&rpm->wakeref_count);
315 }
316 
317 static void
untrack_all_intel_runtime_pm_wakerefs(struct intel_runtime_pm * rpm)318 untrack_all_intel_runtime_pm_wakerefs(struct intel_runtime_pm *rpm)
319 {
320 }
321 
322 #endif
323 
324 static void
intel_runtime_pm_acquire(struct intel_runtime_pm * rpm,bool wakelock)325 intel_runtime_pm_acquire(struct intel_runtime_pm *rpm, bool wakelock)
326 {
327 	if (wakelock) {
328 		atomic_add(1 + INTEL_RPM_WAKELOCK_BIAS, &rpm->wakeref_count);
329 		assert_rpm_wakelock_held(rpm);
330 	} else {
331 		atomic_inc(&rpm->wakeref_count);
332 		assert_rpm_raw_wakeref_held(rpm);
333 	}
334 }
335 
336 static void
intel_runtime_pm_release(struct intel_runtime_pm * rpm,int wakelock)337 intel_runtime_pm_release(struct intel_runtime_pm *rpm, int wakelock)
338 {
339 	if (wakelock) {
340 		assert_rpm_wakelock_held(rpm);
341 		atomic_sub(INTEL_RPM_WAKELOCK_BIAS, &rpm->wakeref_count);
342 	} else {
343 		assert_rpm_raw_wakeref_held(rpm);
344 	}
345 
346 	__intel_wakeref_dec_and_check_tracking(rpm);
347 }
348 
__intel_runtime_pm_get(struct intel_runtime_pm * rpm,bool wakelock)349 static intel_wakeref_t __intel_runtime_pm_get(struct intel_runtime_pm *rpm,
350 					      bool wakelock)
351 {
352 	struct drm_i915_private *i915 = container_of(rpm,
353 						     struct drm_i915_private,
354 						     runtime_pm);
355 	int ret;
356 
357 	ret = pm_runtime_get_sync(rpm->kdev);
358 	drm_WARN_ONCE(&i915->drm, ret < 0,
359 		      "pm_runtime_get_sync() failed: %d\n", ret);
360 
361 	intel_runtime_pm_acquire(rpm, wakelock);
362 
363 	return track_intel_runtime_pm_wakeref(rpm);
364 }
365 
366 /**
367  * intel_runtime_pm_get_raw - grab a raw runtime pm reference
368  * @rpm: the intel_runtime_pm structure
369  *
370  * This is the unlocked version of intel_display_power_is_enabled() and should
371  * only be used from error capture and recovery code where deadlocks are
372  * possible.
373  * This function grabs a device-level runtime pm reference (mostly used for
374  * asynchronous PM management from display code) and ensures that it is powered
375  * up. Raw references are not considered during wakelock assert checks.
376  *
377  * Any runtime pm reference obtained by this function must have a symmetric
378  * call to intel_runtime_pm_put_raw() to release the reference again.
379  *
380  * Returns: the wakeref cookie to pass to intel_runtime_pm_put_raw(), evaluates
381  * as True if the wakeref was acquired, or False otherwise.
382  */
intel_runtime_pm_get_raw(struct intel_runtime_pm * rpm)383 intel_wakeref_t intel_runtime_pm_get_raw(struct intel_runtime_pm *rpm)
384 {
385 	return __intel_runtime_pm_get(rpm, false);
386 }
387 
388 /**
389  * intel_runtime_pm_get - grab a runtime pm reference
390  * @rpm: the intel_runtime_pm structure
391  *
392  * This function grabs a device-level runtime pm reference (mostly used for GEM
393  * code to ensure the GTT or GT is on) and ensures that it is powered up.
394  *
395  * Any runtime pm reference obtained by this function must have a symmetric
396  * call to intel_runtime_pm_put() to release the reference again.
397  *
398  * Returns: the wakeref cookie to pass to intel_runtime_pm_put()
399  */
intel_runtime_pm_get(struct intel_runtime_pm * rpm)400 intel_wakeref_t intel_runtime_pm_get(struct intel_runtime_pm *rpm)
401 {
402 	return __intel_runtime_pm_get(rpm, true);
403 }
404 
405 /**
406  * __intel_runtime_pm_get_if_active - grab a runtime pm reference if device is active
407  * @rpm: the intel_runtime_pm structure
408  * @ignore_usecount: get a ref even if dev->power.usage_count is 0
409  *
410  * This function grabs a device-level runtime pm reference if the device is
411  * already active and ensures that it is powered up. It is illegal to try
412  * and access the HW should intel_runtime_pm_get_if_active() report failure.
413  *
414  * If @ignore_usecount is true, a reference will be acquired even if there is no
415  * user requiring the device to be powered up (dev->power.usage_count == 0).
416  * If the function returns false in this case then it's guaranteed that the
417  * device's runtime suspend hook has been called already or that it will be
418  * called (and hence it's also guaranteed that the device's runtime resume
419  * hook will be called eventually).
420  *
421  * Any runtime pm reference obtained by this function must have a symmetric
422  * call to intel_runtime_pm_put() to release the reference again.
423  *
424  * Returns: the wakeref cookie to pass to intel_runtime_pm_put(), evaluates
425  * as True if the wakeref was acquired, or False otherwise.
426  */
__intel_runtime_pm_get_if_active(struct intel_runtime_pm * rpm,bool ignore_usecount)427 static intel_wakeref_t __intel_runtime_pm_get_if_active(struct intel_runtime_pm *rpm,
428 							bool ignore_usecount)
429 {
430 	if (IS_ENABLED(CONFIG_PM)) {
431 		/*
432 		 * In cases runtime PM is disabled by the RPM core and we get
433 		 * an -EINVAL return value we are not supposed to call this
434 		 * function, since the power state is undefined. This applies
435 		 * atm to the late/early system suspend/resume handlers.
436 		 */
437 		if (pm_runtime_get_if_active(rpm->kdev, ignore_usecount) <= 0)
438 			return 0;
439 	}
440 
441 	intel_runtime_pm_acquire(rpm, true);
442 
443 	return track_intel_runtime_pm_wakeref(rpm);
444 }
445 
intel_runtime_pm_get_if_in_use(struct intel_runtime_pm * rpm)446 intel_wakeref_t intel_runtime_pm_get_if_in_use(struct intel_runtime_pm *rpm)
447 {
448 	return __intel_runtime_pm_get_if_active(rpm, false);
449 }
450 
intel_runtime_pm_get_if_active(struct intel_runtime_pm * rpm)451 intel_wakeref_t intel_runtime_pm_get_if_active(struct intel_runtime_pm *rpm)
452 {
453 	return __intel_runtime_pm_get_if_active(rpm, true);
454 }
455 
456 /**
457  * intel_runtime_pm_get_noresume - grab a runtime pm reference
458  * @rpm: the intel_runtime_pm structure
459  *
460  * This function grabs a device-level runtime pm reference (mostly used for GEM
461  * code to ensure the GTT or GT is on).
462  *
463  * It will _not_ power up the device but instead only check that it's powered
464  * on.  Therefore it is only valid to call this functions from contexts where
465  * the device is known to be powered up and where trying to power it up would
466  * result in hilarity and deadlocks. That pretty much means only the system
467  * suspend/resume code where this is used to grab runtime pm references for
468  * delayed setup down in work items.
469  *
470  * Any runtime pm reference obtained by this function must have a symmetric
471  * call to intel_runtime_pm_put() to release the reference again.
472  *
473  * Returns: the wakeref cookie to pass to intel_runtime_pm_put()
474  */
intel_runtime_pm_get_noresume(struct intel_runtime_pm * rpm)475 intel_wakeref_t intel_runtime_pm_get_noresume(struct intel_runtime_pm *rpm)
476 {
477 	assert_rpm_wakelock_held(rpm);
478 	pm_runtime_get_noresume(rpm->kdev);
479 
480 	intel_runtime_pm_acquire(rpm, true);
481 
482 	return track_intel_runtime_pm_wakeref(rpm);
483 }
484 
__intel_runtime_pm_put(struct intel_runtime_pm * rpm,intel_wakeref_t wref,bool wakelock)485 static void __intel_runtime_pm_put(struct intel_runtime_pm *rpm,
486 				   intel_wakeref_t wref,
487 				   bool wakelock)
488 {
489 	struct device *kdev = rpm->kdev;
490 
491 	untrack_intel_runtime_pm_wakeref(rpm, wref);
492 
493 	intel_runtime_pm_release(rpm, wakelock);
494 
495 	pm_runtime_mark_last_busy(kdev);
496 	pm_runtime_put_autosuspend(kdev);
497 }
498 
499 /**
500  * intel_runtime_pm_put_raw - release a raw runtime pm reference
501  * @rpm: the intel_runtime_pm structure
502  * @wref: wakeref acquired for the reference that is being released
503  *
504  * This function drops the device-level runtime pm reference obtained by
505  * intel_runtime_pm_get_raw() and might power down the corresponding
506  * hardware block right away if this is the last reference.
507  */
508 void
intel_runtime_pm_put_raw(struct intel_runtime_pm * rpm,intel_wakeref_t wref)509 intel_runtime_pm_put_raw(struct intel_runtime_pm *rpm, intel_wakeref_t wref)
510 {
511 	__intel_runtime_pm_put(rpm, wref, false);
512 }
513 
514 /**
515  * intel_runtime_pm_put_unchecked - release an unchecked runtime pm reference
516  * @rpm: the intel_runtime_pm structure
517  *
518  * This function drops the device-level runtime pm reference obtained by
519  * intel_runtime_pm_get() and might power down the corresponding
520  * hardware block right away if this is the last reference.
521  *
522  * This function exists only for historical reasons and should be avoided in
523  * new code, as the correctness of its use cannot be checked. Always use
524  * intel_runtime_pm_put() instead.
525  */
intel_runtime_pm_put_unchecked(struct intel_runtime_pm * rpm)526 void intel_runtime_pm_put_unchecked(struct intel_runtime_pm *rpm)
527 {
528 	__intel_runtime_pm_put(rpm, -1, true);
529 }
530 
531 #if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM)
532 /**
533  * intel_runtime_pm_put - release a runtime pm reference
534  * @rpm: the intel_runtime_pm structure
535  * @wref: wakeref acquired for the reference that is being released
536  *
537  * This function drops the device-level runtime pm reference obtained by
538  * intel_runtime_pm_get() and might power down the corresponding
539  * hardware block right away if this is the last reference.
540  */
intel_runtime_pm_put(struct intel_runtime_pm * rpm,intel_wakeref_t wref)541 void intel_runtime_pm_put(struct intel_runtime_pm *rpm, intel_wakeref_t wref)
542 {
543 	__intel_runtime_pm_put(rpm, wref, true);
544 }
545 #endif
546 
547 /**
548  * intel_runtime_pm_enable - enable runtime pm
549  * @rpm: the intel_runtime_pm structure
550  *
551  * This function enables runtime pm at the end of the driver load sequence.
552  *
553  * Note that this function does currently not enable runtime pm for the
554  * subordinate display power domains. That is done by
555  * intel_power_domains_enable().
556  */
intel_runtime_pm_enable(struct intel_runtime_pm * rpm)557 void intel_runtime_pm_enable(struct intel_runtime_pm *rpm)
558 {
559 	struct drm_i915_private *i915 = container_of(rpm,
560 						     struct drm_i915_private,
561 						     runtime_pm);
562 	struct device *kdev = rpm->kdev;
563 
564 	/*
565 	 * Disable the system suspend direct complete optimization, which can
566 	 * leave the device suspended skipping the driver's suspend handlers
567 	 * if the device was already runtime suspended. This is needed due to
568 	 * the difference in our runtime and system suspend sequence and
569 	 * becaue the HDA driver may require us to enable the audio power
570 	 * domain during system suspend.
571 	 */
572 	dev_pm_set_driver_flags(kdev, DPM_FLAG_NO_DIRECT_COMPLETE);
573 
574 	pm_runtime_set_autosuspend_delay(kdev, 10000); /* 10s */
575 	pm_runtime_mark_last_busy(kdev);
576 
577 	/*
578 	 * Take a permanent reference to disable the RPM functionality and drop
579 	 * it only when unloading the driver. Use the low level get/put helpers,
580 	 * so the driver's own RPM reference tracking asserts also work on
581 	 * platforms without RPM support.
582 	 */
583 	if (!rpm->available) {
584 		int ret;
585 
586 		pm_runtime_dont_use_autosuspend(kdev);
587 		ret = pm_runtime_get_sync(kdev);
588 		drm_WARN(&i915->drm, ret < 0,
589 			 "pm_runtime_get_sync() failed: %d\n", ret);
590 	} else {
591 		pm_runtime_use_autosuspend(kdev);
592 	}
593 
594 	/*
595 	 *  FIXME: Temp hammer to keep autosupend disable on lmem supported platforms.
596 	 *  As per PCIe specs 5.3.1.4.1, all iomem read write request over a PCIe
597 	 *  function will be unsupported in case PCIe endpoint function is in D3.
598 	 *  Let's keep i915 autosuspend control 'on' till we fix all known issue
599 	 *  with lmem access in D3.
600 	 */
601 	if (!IS_DGFX(i915))
602 		pm_runtime_allow(kdev);
603 
604 	/*
605 	 * The core calls the driver load handler with an RPM reference held.
606 	 * We drop that here and will reacquire it during unloading in
607 	 * intel_power_domains_fini().
608 	 */
609 	pm_runtime_put_autosuspend(kdev);
610 }
611 
intel_runtime_pm_disable(struct intel_runtime_pm * rpm)612 void intel_runtime_pm_disable(struct intel_runtime_pm *rpm)
613 {
614 	struct drm_i915_private *i915 = container_of(rpm,
615 						     struct drm_i915_private,
616 						     runtime_pm);
617 	struct device *kdev = rpm->kdev;
618 
619 	/* Transfer rpm ownership back to core */
620 	drm_WARN(&i915->drm, pm_runtime_get_sync(kdev) < 0,
621 		 "Failed to pass rpm ownership back to core\n");
622 
623 	pm_runtime_dont_use_autosuspend(kdev);
624 
625 	if (!rpm->available)
626 		pm_runtime_put(kdev);
627 }
628 
intel_runtime_pm_driver_release(struct intel_runtime_pm * rpm)629 void intel_runtime_pm_driver_release(struct intel_runtime_pm *rpm)
630 {
631 	struct drm_i915_private *i915 = container_of(rpm,
632 						     struct drm_i915_private,
633 						     runtime_pm);
634 	int count = atomic_read(&rpm->wakeref_count);
635 
636 	intel_wakeref_auto_fini(&rpm->userfault_wakeref);
637 
638 	drm_WARN(&i915->drm, count,
639 		 "i915 raw-wakerefs=%d wakelocks=%d on cleanup\n",
640 		 intel_rpm_raw_wakeref_count(count),
641 		 intel_rpm_wakelock_count(count));
642 
643 	untrack_all_intel_runtime_pm_wakerefs(rpm);
644 }
645 
intel_runtime_pm_init_early(struct intel_runtime_pm * rpm)646 void intel_runtime_pm_init_early(struct intel_runtime_pm *rpm)
647 {
648 	struct drm_i915_private *i915 =
649 			container_of(rpm, struct drm_i915_private, runtime_pm);
650 	struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
651 	struct device *kdev = &pdev->dev;
652 
653 	rpm->kdev = kdev;
654 	rpm->available = HAS_RUNTIME_PM(i915);
655 	rpm->suspended = false;
656 	atomic_set(&rpm->wakeref_count, 0);
657 
658 	init_intel_runtime_pm_wakeref(rpm);
659 	INIT_LIST_HEAD(&rpm->lmem_userfault_list);
660 	spin_lock_init(&rpm->lmem_userfault_lock);
661 	intel_wakeref_auto_init(&rpm->userfault_wakeref, i915);
662 }
663