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(dir: &rpm->debug, INTEL_REFTRACK_DEAD_COUNT, name: dev_name(dev: 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(dir: &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(dir: &rpm->debug, handle: wakeref);
81}
82
83static void untrack_all_intel_runtime_pm_wakerefs(struct intel_runtime_pm *rpm)
84{
85 ref_tracker_dir_exit(dir: &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(dir: &rpm->debug, INTEL_REFTRACK_PRINT_LIMIT);
99 spin_unlock_irqrestore(lock: &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(dir: &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(i: 1 + INTEL_RPM_WAKELOCK_BIAS, v: &rpm->wakeref_count);
143 assert_rpm_wakelock_held(rpm);
144 } else {
145 atomic_inc(v: &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, v: &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(dev: 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, wakelock: 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, wakelock: 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 ((ignore_usecount &&
250 pm_runtime_get_if_active(dev: rpm->kdev) <= 0) ||
251 (!ignore_usecount &&
252 pm_runtime_get_if_in_use(dev: rpm->kdev) <= 0))
253 return 0;
254 }
255
256 intel_runtime_pm_acquire(rpm, wakelock: true);
257
258 return track_intel_runtime_pm_wakeref(rpm);
259}
260
261intel_wakeref_t intel_runtime_pm_get_if_in_use(struct intel_runtime_pm *rpm)
262{
263 return __intel_runtime_pm_get_if_active(rpm, ignore_usecount: false);
264}
265
266intel_wakeref_t intel_runtime_pm_get_if_active(struct intel_runtime_pm *rpm)
267{
268 return __intel_runtime_pm_get_if_active(rpm, ignore_usecount: true);
269}
270
271/**
272 * intel_runtime_pm_get_noresume - grab a runtime pm reference
273 * @rpm: the intel_runtime_pm structure
274 *
275 * This function grabs a device-level runtime pm reference (mostly used for GEM
276 * code to ensure the GTT or GT is on).
277 *
278 * It will _not_ power up the device but instead only check that it's powered
279 * on. Therefore it is only valid to call this functions from contexts where
280 * the device is known to be powered up and where trying to power it up would
281 * result in hilarity and deadlocks. That pretty much means only the system
282 * suspend/resume code where this is used to grab runtime pm references for
283 * delayed setup down in work items.
284 *
285 * Any runtime pm reference obtained by this function must have a symmetric
286 * call to intel_runtime_pm_put() to release the reference again.
287 *
288 * Returns: the wakeref cookie to pass to intel_runtime_pm_put()
289 */
290intel_wakeref_t intel_runtime_pm_get_noresume(struct intel_runtime_pm *rpm)
291{
292 assert_rpm_wakelock_held(rpm);
293 pm_runtime_get_noresume(dev: rpm->kdev);
294
295 intel_runtime_pm_acquire(rpm, wakelock: true);
296
297 return track_intel_runtime_pm_wakeref(rpm);
298}
299
300static void __intel_runtime_pm_put(struct intel_runtime_pm *rpm,
301 intel_wakeref_t wref,
302 bool wakelock)
303{
304 struct device *kdev = rpm->kdev;
305
306 untrack_intel_runtime_pm_wakeref(rpm, wakeref: wref);
307
308 intel_runtime_pm_release(rpm, wakelock);
309
310 pm_runtime_mark_last_busy(dev: kdev);
311 pm_runtime_put_autosuspend(dev: kdev);
312}
313
314/**
315 * intel_runtime_pm_put_raw - release a raw runtime pm reference
316 * @rpm: the intel_runtime_pm structure
317 * @wref: wakeref acquired for the reference that is being released
318 *
319 * This function drops the device-level runtime pm reference obtained by
320 * intel_runtime_pm_get_raw() and might power down the corresponding
321 * hardware block right away if this is the last reference.
322 */
323void
324intel_runtime_pm_put_raw(struct intel_runtime_pm *rpm, intel_wakeref_t wref)
325{
326 __intel_runtime_pm_put(rpm, wref, wakelock: false);
327}
328
329/**
330 * intel_runtime_pm_put_unchecked - release an unchecked runtime pm reference
331 * @rpm: the intel_runtime_pm structure
332 *
333 * This function drops the device-level runtime pm reference obtained by
334 * intel_runtime_pm_get() and might power down the corresponding
335 * hardware block right away if this is the last reference.
336 *
337 * This function exists only for historical reasons and should be avoided in
338 * new code, as the correctness of its use cannot be checked. Always use
339 * intel_runtime_pm_put() instead.
340 */
341void intel_runtime_pm_put_unchecked(struct intel_runtime_pm *rpm)
342{
343 __intel_runtime_pm_put(rpm, wref: -1, wakelock: true);
344}
345
346#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM)
347/**
348 * intel_runtime_pm_put - release a runtime pm reference
349 * @rpm: the intel_runtime_pm structure
350 * @wref: wakeref acquired for the reference that is being released
351 *
352 * This function drops the device-level runtime pm reference obtained by
353 * intel_runtime_pm_get() and might power down the corresponding
354 * hardware block right away if this is the last reference.
355 */
356void intel_runtime_pm_put(struct intel_runtime_pm *rpm, intel_wakeref_t wref)
357{
358 __intel_runtime_pm_put(rpm, wref, wakelock: true);
359}
360#endif
361
362/**
363 * intel_runtime_pm_enable - enable runtime pm
364 * @rpm: the intel_runtime_pm structure
365 *
366 * This function enables runtime pm at the end of the driver load sequence.
367 *
368 * Note that this function does currently not enable runtime pm for the
369 * subordinate display power domains. That is done by
370 * intel_power_domains_enable().
371 */
372void intel_runtime_pm_enable(struct intel_runtime_pm *rpm)
373{
374 struct drm_i915_private *i915 = rpm_to_i915(rpm);
375 struct device *kdev = rpm->kdev;
376
377 /*
378 * Disable the system suspend direct complete optimization, which can
379 * leave the device suspended skipping the driver's suspend handlers
380 * if the device was already runtime suspended. This is needed due to
381 * the difference in our runtime and system suspend sequence and
382 * becaue the HDA driver may require us to enable the audio power
383 * domain during system suspend.
384 */
385 dev_pm_set_driver_flags(dev: kdev, DPM_FLAG_NO_DIRECT_COMPLETE);
386
387 pm_runtime_set_autosuspend_delay(dev: kdev, delay: 10000); /* 10s */
388 pm_runtime_mark_last_busy(dev: kdev);
389
390 /*
391 * Take a permanent reference to disable the RPM functionality and drop
392 * it only when unloading the driver. Use the low level get/put helpers,
393 * so the driver's own RPM reference tracking asserts also work on
394 * platforms without RPM support.
395 */
396 if (!rpm->available) {
397 int ret;
398
399 pm_runtime_dont_use_autosuspend(dev: kdev);
400 ret = pm_runtime_get_sync(dev: kdev);
401 drm_WARN(&i915->drm, ret < 0,
402 "pm_runtime_get_sync() failed: %d\n", ret);
403 } else {
404 pm_runtime_use_autosuspend(dev: kdev);
405 }
406
407 /*
408 * FIXME: Temp hammer to keep autosupend disable on lmem supported platforms.
409 * As per PCIe specs 5.3.1.4.1, all iomem read write request over a PCIe
410 * function will be unsupported in case PCIe endpoint function is in D3.
411 * Let's keep i915 autosuspend control 'on' till we fix all known issue
412 * with lmem access in D3.
413 */
414 if (!IS_DGFX(i915))
415 pm_runtime_allow(dev: kdev);
416
417 /*
418 * The core calls the driver load handler with an RPM reference held.
419 * We drop that here and will reacquire it during unloading in
420 * intel_power_domains_fini().
421 */
422 pm_runtime_put_autosuspend(dev: kdev);
423}
424
425void intel_runtime_pm_disable(struct intel_runtime_pm *rpm)
426{
427 struct drm_i915_private *i915 = rpm_to_i915(rpm);
428 struct device *kdev = rpm->kdev;
429
430 /* Transfer rpm ownership back to core */
431 drm_WARN(&i915->drm, pm_runtime_get_sync(kdev) < 0,
432 "Failed to pass rpm ownership back to core\n");
433
434 pm_runtime_dont_use_autosuspend(dev: kdev);
435
436 if (!rpm->available)
437 pm_runtime_put(dev: kdev);
438}
439
440void intel_runtime_pm_driver_release(struct intel_runtime_pm *rpm)
441{
442 struct drm_i915_private *i915 = rpm_to_i915(rpm);
443 int count = atomic_read(v: &rpm->wakeref_count);
444
445 intel_wakeref_auto_fini(wf: &rpm->userfault_wakeref);
446
447 drm_WARN(&i915->drm, count,
448 "i915 raw-wakerefs=%d wakelocks=%d on cleanup\n",
449 intel_rpm_raw_wakeref_count(count),
450 intel_rpm_wakelock_count(count));
451}
452
453void intel_runtime_pm_driver_last_release(struct intel_runtime_pm *rpm)
454{
455 intel_runtime_pm_driver_release(rpm);
456 untrack_all_intel_runtime_pm_wakerefs(rpm);
457}
458
459void intel_runtime_pm_init_early(struct intel_runtime_pm *rpm)
460{
461 struct drm_i915_private *i915 = rpm_to_i915(rpm);
462 struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
463 struct device *kdev = &pdev->dev;
464
465 rpm->kdev = kdev;
466 rpm->available = HAS_RUNTIME_PM(i915);
467 atomic_set(v: &rpm->wakeref_count, i: 0);
468
469 init_intel_runtime_pm_wakeref(rpm);
470 INIT_LIST_HEAD(list: &rpm->lmem_userfault_list);
471 spin_lock_init(&rpm->lmem_userfault_lock);
472 intel_wakeref_auto_init(wf: &rpm->userfault_wakeref, i915);
473}
474

source code of linux/drivers/gpu/drm/i915/intel_runtime_pm.c