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