intel_runtime_pm.c

  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#include <drm/intel/display_parent_interface.h>
 33
 34#include "i915_drv.h"
 35#include "i915_trace.h"
 36
 37/**
 38 * DOC: runtime pm
 39 *
 40 * The i915 driver supports dynamic enabling and disabling of entire hardware
 41 * blocks at runtime. This is especially important on the display side where
 42 * software is supposed to control many power gates manually on recent hardware,
 43 * since on the GT side a lot of the power management is done by the hardware.
 44 * But even there some manual control at the device level is required.
 45 *
 46 * Since i915 supports a diverse set of platforms with a unified codebase and
 47 * hardware engineers just love to shuffle functionality around between power
 48 * domains there's a sizeable amount of indirection required. This file provides
 49 * generic functions to the driver for grabbing and releasing references for
 50 * abstract power domains. It then maps those to the actual power wells
 51 * present for a given platform.
 52 */
 53
 54static struct drm_i915_private *rpm_to_i915(struct intel_runtime_pm *rpm)
 55{
 56	return container_of(rpm, struct drm_i915_private, runtime_pm);
 57}
 58
 59#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM)
 60
 61static void init_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm)
 62{
 63	if (!rpm->debug.class)
 64		ref_tracker_dir_init(&rpm->debug, INTEL_REFTRACK_DEAD_COUNT,
 65				     "intel_runtime_pm");
 66}
 67
 68static intel_wakeref_t
 69track_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm)
 70{
 71	if (!rpm->available || rpm->no_wakeref_tracking)
 72		return INTEL_WAKEREF_DEF;
 73
 74	return intel_ref_tracker_alloc(&rpm->debug);
 75}
 76
 77static void untrack_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm,
 78					     intel_wakeref_t wakeref)
 79{
 80	if (!rpm->available || rpm->no_wakeref_tracking)
 81		return;
 82
 83	intel_ref_tracker_free(&rpm->debug, wakeref);
 84}
 85
 86static void untrack_all_intel_runtime_pm_wakerefs(struct intel_runtime_pm *rpm)
 87{
 88	ref_tracker_dir_exit(&rpm->debug);
 89}
 90
 91static noinline void
 92__intel_wakeref_dec_and_check_tracking(struct intel_runtime_pm *rpm)
 93{
 94	unsigned long flags;
 95
 96	if (!atomic_dec_and_lock_irqsave(&rpm->wakeref_count,
 97					 &rpm->debug.lock,
 98					 flags))
 99		return;
100
101	ref_tracker_dir_print_locked(&rpm->debug, INTEL_REFTRACK_PRINT_LIMIT);
102	spin_unlock_irqrestore(&rpm->debug.lock, flags);
103}
104
105void print_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm,
106				    struct drm_printer *p)
107{
108	intel_ref_tracker_show(&rpm->debug, p);
109}
110
111#else
112
113static void init_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm)
114{
115}
116
117static intel_wakeref_t
118track_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm)
119{
120	return INTEL_WAKEREF_DEF;
121}
122
123static void untrack_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm,
124					     intel_wakeref_t wakeref)
125{
126}
127
128static void
129__intel_wakeref_dec_and_check_tracking(struct intel_runtime_pm *rpm)
130{
131	atomic_dec(&rpm->wakeref_count);
132}
133
134static void
135untrack_all_intel_runtime_pm_wakerefs(struct intel_runtime_pm *rpm)
136{
137}
138
139#endif
140
141static void
142intel_runtime_pm_acquire(struct intel_runtime_pm *rpm, bool wakelock)
143{
144	if (wakelock) {
145		atomic_add(1 + INTEL_RPM_WAKELOCK_BIAS, &rpm->wakeref_count);
146		assert_rpm_wakelock_held(rpm);
147	} else {
148		atomic_inc(&rpm->wakeref_count);
149		assert_rpm_raw_wakeref_held(rpm);
150	}
151}
152
153static void
154intel_runtime_pm_release(struct intel_runtime_pm *rpm, int wakelock)
155{
156	if (wakelock) {
157		assert_rpm_wakelock_held(rpm);
158		atomic_sub(INTEL_RPM_WAKELOCK_BIAS, &rpm->wakeref_count);
159	} else {
160		assert_rpm_raw_wakeref_held(rpm);
161	}
162
163	__intel_wakeref_dec_and_check_tracking(rpm);
164}
165
166static intel_wakeref_t __intel_runtime_pm_get(struct intel_runtime_pm *rpm,
167					      bool wakelock)
168{
169	struct drm_i915_private *i915 = rpm_to_i915(rpm);
170	int ret;
171
172	ret = pm_runtime_get_sync(rpm->kdev);
173	drm_WARN_ONCE(&i915->drm, ret < 0,
174		      "pm_runtime_get_sync() failed: %d\n", ret);
175
176	intel_runtime_pm_acquire(rpm, wakelock);
177
178	return track_intel_runtime_pm_wakeref(rpm);
179}
180
181static struct intel_runtime_pm *drm_to_rpm(const struct drm_device *drm)
182{
183	struct drm_i915_private *i915 = to_i915(drm);
184
185	return &i915->runtime_pm;
186}
187
188static struct ref_tracker *i915_display_rpm_get(const struct drm_device *drm)
189{
190	return intel_runtime_pm_get(drm_to_rpm(drm));
191}
192
193static struct ref_tracker *i915_display_rpm_get_raw(const struct drm_device *drm)
194{
195	return intel_runtime_pm_get_raw(drm_to_rpm(drm));
196}
197
198static struct ref_tracker *i915_display_rpm_get_if_in_use(const struct drm_device *drm)
199{
200	return intel_runtime_pm_get_if_in_use(drm_to_rpm(drm));
201}
202
203static struct ref_tracker *i915_display_rpm_get_noresume(const struct drm_device *drm)
204{
205	return intel_runtime_pm_get_noresume(drm_to_rpm(drm));
206}
207
208static void i915_display_rpm_put(const struct drm_device *drm, struct ref_tracker *wakeref)
209{
210	intel_runtime_pm_put(drm_to_rpm(drm), wakeref);
211}
212
213static void i915_display_rpm_put_raw(const struct drm_device *drm, struct ref_tracker *wakeref)
214{
215	intel_runtime_pm_put_raw(drm_to_rpm(drm), wakeref);
216}
217
218static void i915_display_rpm_put_unchecked(const struct drm_device *drm)
219{
220	intel_runtime_pm_put_unchecked(drm_to_rpm(drm));
221}
222
223static bool i915_display_rpm_suspended(const struct drm_device *drm)
224{
225	return intel_runtime_pm_suspended(drm_to_rpm(drm));
226}
227
228static void i915_display_rpm_assert_held(const struct drm_device *drm)
229{
230	assert_rpm_wakelock_held(drm_to_rpm(drm));
231}
232
233static void i915_display_rpm_assert_block(const struct drm_device *drm)
234{
235	disable_rpm_wakeref_asserts(drm_to_rpm(drm));
236}
237
238static void i915_display_rpm_assert_unblock(const struct drm_device *drm)
239{
240	enable_rpm_wakeref_asserts(drm_to_rpm(drm));
241}
242
243const struct intel_display_rpm_interface i915_display_rpm_interface = {
244	.get = i915_display_rpm_get,
245	.get_raw = i915_display_rpm_get_raw,
246	.get_if_in_use = i915_display_rpm_get_if_in_use,
247	.get_noresume = i915_display_rpm_get_noresume,
248	.put = i915_display_rpm_put,
249	.put_raw = i915_display_rpm_put_raw,
250	.put_unchecked = i915_display_rpm_put_unchecked,
251	.suspended = i915_display_rpm_suspended,
252	.assert_held = i915_display_rpm_assert_held,
253	.assert_block = i915_display_rpm_assert_block,
254	.assert_unblock = i915_display_rpm_assert_unblock
255};
256
257/**
258 * intel_runtime_pm_get_raw - grab a raw runtime pm reference
259 * @rpm: the intel_runtime_pm structure
260 *
261 * This is the unlocked version of intel_display_power_is_enabled() and should
262 * only be used from error capture and recovery code where deadlocks are
263 * possible.
264 * This function grabs a device-level runtime pm reference (mostly used for
265 * asynchronous PM management from display code) and ensures that it is powered
266 * up. Raw references are not considered during wakelock assert checks.
267 *
268 * Any runtime pm reference obtained by this function must have a symmetric
269 * call to intel_runtime_pm_put_raw() to release the reference again.
270 *
271 * Returns: the wakeref cookie to pass to intel_runtime_pm_put_raw(), evaluates
272 * as True if the wakeref was acquired, or False otherwise.
273 */
274intel_wakeref_t intel_runtime_pm_get_raw(struct intel_runtime_pm *rpm)
275{
276	return __intel_runtime_pm_get(rpm, false);
277}
278
279/**
280 * intel_runtime_pm_get - grab a runtime pm reference
281 * @rpm: the intel_runtime_pm structure
282 *
283 * This function grabs a device-level runtime pm reference (mostly used for GEM
284 * code to ensure the GTT or GT is on) and ensures that it is powered up.
285 *
286 * Any runtime pm reference obtained by this function must have a symmetric
287 * call to intel_runtime_pm_put() to release the reference again.
288 *
289 * Returns: the wakeref cookie to pass to intel_runtime_pm_put()
290 */
291intel_wakeref_t intel_runtime_pm_get(struct intel_runtime_pm *rpm)
292{
293	return __intel_runtime_pm_get(rpm, true);
294}
295
296/**
297 * __intel_runtime_pm_get_if_active - grab a runtime pm reference if device is active
298 * @rpm: the intel_runtime_pm structure
299 * @ignore_usecount: get a ref even if dev->power.usage_count is 0
300 *
301 * This function grabs a device-level runtime pm reference if the device is
302 * already active and ensures that it is powered up. It is illegal to try
303 * and access the HW should intel_runtime_pm_get_if_active() report failure.
304 *
305 * If @ignore_usecount is true, a reference will be acquired even if there is no
306 * user requiring the device to be powered up (dev->power.usage_count == 0).
307 * If the function returns false in this case then it's guaranteed that the
308 * device's runtime suspend hook has been called already or that it will be
309 * called (and hence it's also guaranteed that the device's runtime resume
310 * hook will be called eventually).
311 *
312 * Any runtime pm reference obtained by this function must have a symmetric
313 * call to intel_runtime_pm_put() to release the reference again.
314 *
315 * Returns: the wakeref cookie to pass to intel_runtime_pm_put(), evaluates
316 * as True if the wakeref was acquired, or False otherwise.
317 */
318static intel_wakeref_t __intel_runtime_pm_get_if_active(struct intel_runtime_pm *rpm,
319							bool ignore_usecount)
320{
321	if (IS_ENABLED(CONFIG_PM)) {
322		/*
323		 * In cases runtime PM is disabled by the RPM core and we get
324		 * an -EINVAL return value we are not supposed to call this
325		 * function, since the power state is undefined. This applies
326		 * atm to the late/early system suspend/resume handlers.
327		 */
328		if ((ignore_usecount &&
329		     pm_runtime_get_if_active(rpm->kdev) <= 0) ||
330		    (!ignore_usecount &&
331		     pm_runtime_get_if_in_use(rpm->kdev) <= 0))
332			return NULL;
333	}
334
335	intel_runtime_pm_acquire(rpm, true);
336
337	return track_intel_runtime_pm_wakeref(rpm);
338}
339
340intel_wakeref_t intel_runtime_pm_get_if_in_use(struct intel_runtime_pm *rpm)
341{
342	return __intel_runtime_pm_get_if_active(rpm, false);
343}
344
345intel_wakeref_t intel_runtime_pm_get_if_active(struct intel_runtime_pm *rpm)
346{
347	return __intel_runtime_pm_get_if_active(rpm, true);
348}
349
350/**
351 * intel_runtime_pm_get_noresume - grab a runtime pm reference
352 * @rpm: the intel_runtime_pm structure
353 *
354 * This function grabs a device-level runtime pm reference.
355 *
356 * It will _not_ resume the device but instead only get an extra wakeref.
357 * Therefore it is only valid to call this functions from contexts where
358 * the device is known to be active and with another wakeref previously hold.
359 *
360 * Any runtime pm reference obtained by this function must have a symmetric
361 * call to intel_runtime_pm_put() to release the reference again.
362 *
363 * Returns: the wakeref cookie to pass to intel_runtime_pm_put()
364 */
365intel_wakeref_t intel_runtime_pm_get_noresume(struct intel_runtime_pm *rpm)
366{
367	assert_rpm_raw_wakeref_held(rpm);
368	pm_runtime_get_noresume(rpm->kdev);
369
370	intel_runtime_pm_acquire(rpm, true);
371
372	return track_intel_runtime_pm_wakeref(rpm);
373}
374
375static void __intel_runtime_pm_put(struct intel_runtime_pm *rpm,
376				   intel_wakeref_t wref,
377				   bool wakelock)
378{
379	struct device *kdev = rpm->kdev;
380
381	untrack_intel_runtime_pm_wakeref(rpm, wref);
382
383	intel_runtime_pm_release(rpm, wakelock);
384
385	pm_runtime_mark_last_busy(kdev);
386	pm_runtime_put_autosuspend(kdev);
387}
388
389/**
390 * intel_runtime_pm_put_raw - release a raw runtime pm reference
391 * @rpm: the intel_runtime_pm structure
392 * @wref: wakeref acquired for the reference that is being released
393 *
394 * This function drops the device-level runtime pm reference obtained by
395 * intel_runtime_pm_get_raw() and might power down the corresponding
396 * hardware block right away if this is the last reference.
397 */
398void
399intel_runtime_pm_put_raw(struct intel_runtime_pm *rpm, intel_wakeref_t wref)
400{
401	__intel_runtime_pm_put(rpm, wref, false);
402}
403
404/**
405 * intel_runtime_pm_put_unchecked - release an unchecked runtime pm reference
406 * @rpm: the intel_runtime_pm structure
407 *
408 * This function drops the device-level runtime pm reference obtained by
409 * intel_runtime_pm_get() and might power down the corresponding
410 * hardware block right away if this is the last reference.
411 *
412 * This function exists only for historical reasons and should be avoided in
413 * new code, as the correctness of its use cannot be checked. Always use
414 * intel_runtime_pm_put() instead.
415 */
416void intel_runtime_pm_put_unchecked(struct intel_runtime_pm *rpm)
417{
418	__intel_runtime_pm_put(rpm, INTEL_WAKEREF_DEF, true);
419}
420
421#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM)
422/**
423 * intel_runtime_pm_put - release a runtime pm reference
424 * @rpm: the intel_runtime_pm structure
425 * @wref: wakeref acquired for the reference that is being released
426 *
427 * This function drops the device-level runtime pm reference obtained by
428 * intel_runtime_pm_get() and might power down the corresponding
429 * hardware block right away if this is the last reference.
430 */
431void intel_runtime_pm_put(struct intel_runtime_pm *rpm, intel_wakeref_t wref)
432{
433	__intel_runtime_pm_put(rpm, wref, true);
434}
435#endif
436
437/**
438 * intel_runtime_pm_enable - enable runtime pm
439 * @rpm: the intel_runtime_pm structure
440 *
441 * This function enables runtime pm at the end of the driver load sequence.
442 *
443 * Note that this function does currently not enable runtime pm for the
444 * subordinate display power domains. That is done by
445 * intel_power_domains_enable().
446 */
447void intel_runtime_pm_enable(struct intel_runtime_pm *rpm)
448{
449	struct drm_i915_private *i915 = rpm_to_i915(rpm);
450	struct device *kdev = rpm->kdev;
451
452	/*
453	 * Disable the system suspend direct complete optimization, which can
454	 * leave the device suspended skipping the driver's suspend handlers
455	 * if the device was already runtime suspended. This is needed due to
456	 * the difference in our runtime and system suspend sequence and
457	 * because the HDA driver may require us to enable the audio power
458	 * domain during system suspend.
459	 */
460	dev_pm_set_driver_flags(kdev, DPM_FLAG_NO_DIRECT_COMPLETE);
461
462	pm_runtime_set_autosuspend_delay(kdev, 10000); /* 10s */
463	pm_runtime_mark_last_busy(kdev);
464
465	/*
466	 * Take a permanent reference to disable the RPM functionality and drop
467	 * it only when unloading the driver. Use the low level get/put helpers,
468	 * so the driver's own RPM reference tracking asserts also work on
469	 * platforms without RPM support.
470	 */
471	if (!rpm->available) {
472		int ret;
473
474		pm_runtime_dont_use_autosuspend(kdev);
475		ret = pm_runtime_get_sync(kdev);
476		drm_WARN(&i915->drm, ret < 0,
477			 "pm_runtime_get_sync() failed: %d\n", ret);
478	} else {
479		pm_runtime_use_autosuspend(kdev);
480	}
481
482	/*
483	 *  FIXME: Temp hammer to keep autosupend disable on lmem supported platforms.
484	 *  As per PCIe specs 5.3.1.4.1, all iomem read write request over a PCIe
485	 *  function will be unsupported in case PCIe endpoint function is in D3.
486	 *  Let's keep i915 autosuspend control 'on' till we fix all known issue
487	 *  with lmem access in D3.
488	 */
489	if (!IS_DGFX(i915))
490		pm_runtime_allow(kdev);
491
492	/*
493	 * The core calls the driver load handler with an RPM reference held.
494	 * We drop that here and will reacquire it during unloading in
495	 * intel_power_domains_fini().
496	 */
497	pm_runtime_put_autosuspend(kdev);
498}
499
500void intel_runtime_pm_disable(struct intel_runtime_pm *rpm)
501{
502	struct drm_i915_private *i915 = rpm_to_i915(rpm);
503	struct device *kdev = rpm->kdev;
504
505	/* Transfer rpm ownership back to core */
506	drm_WARN(&i915->drm, pm_runtime_get_sync(kdev) < 0,
507		 "Failed to pass rpm ownership back to core\n");
508
509	pm_runtime_dont_use_autosuspend(kdev);
510
511	if (!rpm->available)
512		pm_runtime_put(kdev);
513}
514
515void intel_runtime_pm_driver_release(struct intel_runtime_pm *rpm)
516{
517	struct drm_i915_private *i915 = rpm_to_i915(rpm);
518	int count = atomic_read(&rpm->wakeref_count);
519
520	intel_wakeref_auto_fini(&rpm->userfault_wakeref);
521
522	drm_WARN(&i915->drm, count,
523		 "i915 raw-wakerefs=%d wakelocks=%d on cleanup\n",
524		 intel_rpm_raw_wakeref_count(count),
525		 intel_rpm_wakelock_count(count));
526}
527
528void intel_runtime_pm_driver_last_release(struct intel_runtime_pm *rpm)
529{
530	intel_runtime_pm_driver_release(rpm);
531	untrack_all_intel_runtime_pm_wakerefs(rpm);
532}
533
534void intel_runtime_pm_init_early(struct intel_runtime_pm *rpm)
535{
536	struct drm_i915_private *i915 = rpm_to_i915(rpm);
537	struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
538	struct device *kdev = &pdev->dev;
539
540	rpm->kdev = kdev;
541	rpm->available = HAS_RUNTIME_PM(i915);
542	atomic_set(&rpm->wakeref_count, 0);
543
544	init_intel_runtime_pm_wakeref(rpm);
545	INIT_LIST_HEAD(&rpm->lmem_userfault_list);
546	spin_lock_init(&rpm->lmem_userfault_lock);
547	intel_wakeref_auto_init(&rpm->userfault_wakeref, i915);
548}