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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 INTEL_WAKEREF_DEF;
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 INTEL_WAKEREF_DEF;
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 ((ignore_usecount &&
250 pm_runtime_get_if_active(rpm->kdev) <= 0) ||
251 (!ignore_usecount &&
252 pm_runtime_get_if_in_use(rpm->kdev) <= 0))
253 return NULL;
254 }
255
256 intel_runtime_pm_acquire(rpm, 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, 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, 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.
276 *
277 * It will _not_ resume the device but instead only get an extra wakeref.
278 * Therefore it is only valid to call this functions from contexts where
279 * the device is known to be active and with another wakeref previously hold.
280 *
281 * Any runtime pm reference obtained by this function must have a symmetric
282 * call to intel_runtime_pm_put() to release the reference again.
283 *
284 * Returns: the wakeref cookie to pass to intel_runtime_pm_put()
285 */
286intel_wakeref_t intel_runtime_pm_get_noresume(struct intel_runtime_pm *rpm)
287{
288 assert_rpm_raw_wakeref_held(rpm);
289 pm_runtime_get_noresume(rpm->kdev);
290
291 intel_runtime_pm_acquire(rpm, true);
292
293 return track_intel_runtime_pm_wakeref(rpm);
294}
295
296static void __intel_runtime_pm_put(struct intel_runtime_pm *rpm,
297 intel_wakeref_t wref,
298 bool wakelock)
299{
300 struct device *kdev = rpm->kdev;
301
302 untrack_intel_runtime_pm_wakeref(rpm, wref);
303
304 intel_runtime_pm_release(rpm, wakelock);
305
306 pm_runtime_mark_last_busy(kdev);
307 pm_runtime_put_autosuspend(kdev);
308}
309
310/**
311 * intel_runtime_pm_put_raw - release a raw runtime pm reference
312 * @rpm: the intel_runtime_pm structure
313 * @wref: wakeref acquired for the reference that is being released
314 *
315 * This function drops the device-level runtime pm reference obtained by
316 * intel_runtime_pm_get_raw() and might power down the corresponding
317 * hardware block right away if this is the last reference.
318 */
319void
320intel_runtime_pm_put_raw(struct intel_runtime_pm *rpm, intel_wakeref_t wref)
321{
322 __intel_runtime_pm_put(rpm, wref, false);
323}
324
325/**
326 * intel_runtime_pm_put_unchecked - release an unchecked runtime pm reference
327 * @rpm: the intel_runtime_pm structure
328 *
329 * This function drops the device-level runtime pm reference obtained by
330 * intel_runtime_pm_get() and might power down the corresponding
331 * hardware block right away if this is the last reference.
332 *
333 * This function exists only for historical reasons and should be avoided in
334 * new code, as the correctness of its use cannot be checked. Always use
335 * intel_runtime_pm_put() instead.
336 */
337void intel_runtime_pm_put_unchecked(struct intel_runtime_pm *rpm)
338{
339 __intel_runtime_pm_put(rpm, INTEL_WAKEREF_DEF, true);
340}
341
342#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM)
343/**
344 * intel_runtime_pm_put - release a runtime pm reference
345 * @rpm: the intel_runtime_pm structure
346 * @wref: wakeref acquired for the reference that is being released
347 *
348 * This function drops the device-level runtime pm reference obtained by
349 * intel_runtime_pm_get() and might power down the corresponding
350 * hardware block right away if this is the last reference.
351 */
352void intel_runtime_pm_put(struct intel_runtime_pm *rpm, intel_wakeref_t wref)
353{
354 __intel_runtime_pm_put(rpm, wref, true);
355}
356#endif
357
358/**
359 * intel_runtime_pm_enable - enable runtime pm
360 * @rpm: the intel_runtime_pm structure
361 *
362 * This function enables runtime pm at the end of the driver load sequence.
363 *
364 * Note that this function does currently not enable runtime pm for the
365 * subordinate display power domains. That is done by
366 * intel_power_domains_enable().
367 */
368void intel_runtime_pm_enable(struct intel_runtime_pm *rpm)
369{
370 struct drm_i915_private *i915 = rpm_to_i915(rpm);
371 struct device *kdev = rpm->kdev;
372
373 /*
374 * Disable the system suspend direct complete optimization, which can
375 * leave the device suspended skipping the driver's suspend handlers
376 * if the device was already runtime suspended. This is needed due to
377 * the difference in our runtime and system suspend sequence and
378 * becaue the HDA driver may require us to enable the audio power
379 * domain during system suspend.
380 */
381 dev_pm_set_driver_flags(kdev, DPM_FLAG_NO_DIRECT_COMPLETE);
382
383 pm_runtime_set_autosuspend_delay(kdev, 10000); /* 10s */
384 pm_runtime_mark_last_busy(kdev);
385
386 /*
387 * Take a permanent reference to disable the RPM functionality and drop
388 * it only when unloading the driver. Use the low level get/put helpers,
389 * so the driver's own RPM reference tracking asserts also work on
390 * platforms without RPM support.
391 */
392 if (!rpm->available) {
393 int ret;
394
395 pm_runtime_dont_use_autosuspend(kdev);
396 ret = pm_runtime_get_sync(kdev);
397 drm_WARN(&i915->drm, ret < 0,
398 "pm_runtime_get_sync() failed: %d\n", ret);
399 } else {
400 pm_runtime_use_autosuspend(kdev);
401 }
402
403 /*
404 * FIXME: Temp hammer to keep autosupend disable on lmem supported platforms.
405 * As per PCIe specs 5.3.1.4.1, all iomem read write request over a PCIe
406 * function will be unsupported in case PCIe endpoint function is in D3.
407 * Let's keep i915 autosuspend control 'on' till we fix all known issue
408 * with lmem access in D3.
409 */
410 if (!IS_DGFX(i915))
411 pm_runtime_allow(kdev);
412
413 /*
414 * The core calls the driver load handler with an RPM reference held.
415 * We drop that here and will reacquire it during unloading in
416 * intel_power_domains_fini().
417 */
418 pm_runtime_put_autosuspend(kdev);
419}
420
421void intel_runtime_pm_disable(struct intel_runtime_pm *rpm)
422{
423 struct drm_i915_private *i915 = rpm_to_i915(rpm);
424 struct device *kdev = rpm->kdev;
425
426 /* Transfer rpm ownership back to core */
427 drm_WARN(&i915->drm, pm_runtime_get_sync(kdev) < 0,
428 "Failed to pass rpm ownership back to core\n");
429
430 pm_runtime_dont_use_autosuspend(kdev);
431
432 if (!rpm->available)
433 pm_runtime_put(kdev);
434}
435
436void intel_runtime_pm_driver_release(struct intel_runtime_pm *rpm)
437{
438 struct drm_i915_private *i915 = rpm_to_i915(rpm);
439 int count = atomic_read(&rpm->wakeref_count);
440
441 intel_wakeref_auto_fini(&rpm->userfault_wakeref);
442
443 drm_WARN(&i915->drm, count,
444 "i915 raw-wakerefs=%d wakelocks=%d on cleanup\n",
445 intel_rpm_raw_wakeref_count(count),
446 intel_rpm_wakelock_count(count));
447}
448
449void intel_runtime_pm_driver_last_release(struct intel_runtime_pm *rpm)
450{
451 intel_runtime_pm_driver_release(rpm);
452 untrack_all_intel_runtime_pm_wakerefs(rpm);
453}
454
455void intel_runtime_pm_init_early(struct intel_runtime_pm *rpm)
456{
457 struct drm_i915_private *i915 = rpm_to_i915(rpm);
458 struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
459 struct device *kdev = &pdev->dev;
460
461 rpm->kdev = kdev;
462 rpm->available = HAS_RUNTIME_PM(i915);
463 atomic_set(&rpm->wakeref_count, 0);
464
465 init_intel_runtime_pm_wakeref(rpm);
466 INIT_LIST_HEAD(&rpm->lmem_userfault_list);
467 spin_lock_init(&rpm->lmem_userfault_lock);
468 intel_wakeref_auto_init(&rpm->userfault_wakeref, i915);
469}
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
59static 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
68static void __print_depot_stack(depot_stack_handle_t stack,
69 char *buf, int sz, int indent)
70{
71 unsigned long *entries;
72 unsigned int nr_entries;
73
74 nr_entries = stack_depot_fetch(stack, &entries);
75 stack_trace_snprint(buf, sz, entries, nr_entries, indent);
76}
77
78static void init_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm)
79{
80 spin_lock_init(&rpm->debug.lock);
81}
82
83static noinline depot_stack_handle_t
84track_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm)
85{
86 depot_stack_handle_t stack, *stacks;
87 unsigned long flags;
88
89 if (!rpm->available)
90 return -1;
91
92 stack = __save_depot_stack();
93 if (!stack)
94 return -1;
95
96 spin_lock_irqsave(&rpm->debug.lock, flags);
97
98 if (!rpm->debug.count)
99 rpm->debug.last_acquire = stack;
100
101 stacks = krealloc(rpm->debug.owners,
102 (rpm->debug.count + 1) * sizeof(*stacks),
103 GFP_NOWAIT | __GFP_NOWARN);
104 if (stacks) {
105 stacks[rpm->debug.count++] = stack;
106 rpm->debug.owners = stacks;
107 } else {
108 stack = -1;
109 }
110
111 spin_unlock_irqrestore(&rpm->debug.lock, flags);
112
113 return stack;
114}
115
116static void untrack_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm,
117 depot_stack_handle_t stack)
118{
119 struct drm_i915_private *i915 = container_of(rpm,
120 struct drm_i915_private,
121 runtime_pm);
122 unsigned long flags, n;
123 bool found = false;
124
125 if (unlikely(stack == -1))
126 return;
127
128 spin_lock_irqsave(&rpm->debug.lock, flags);
129 for (n = rpm->debug.count; n--; ) {
130 if (rpm->debug.owners[n] == stack) {
131 memmove(rpm->debug.owners + n,
132 rpm->debug.owners + n + 1,
133 (--rpm->debug.count - n) * sizeof(stack));
134 found = true;
135 break;
136 }
137 }
138 spin_unlock_irqrestore(&rpm->debug.lock, flags);
139
140 if (drm_WARN(&i915->drm, !found,
141 "Unmatched wakeref (tracking %lu), count %u\n",
142 rpm->debug.count, atomic_read(&rpm->wakeref_count))) {
143 char *buf;
144
145 buf = kmalloc(PAGE_SIZE, GFP_NOWAIT | __GFP_NOWARN);
146 if (!buf)
147 return;
148
149 __print_depot_stack(stack, buf, PAGE_SIZE, 2);
150 DRM_DEBUG_DRIVER("wakeref %x from\n%s", stack, buf);
151
152 stack = READ_ONCE(rpm->debug.last_release);
153 if (stack) {
154 __print_depot_stack(stack, buf, PAGE_SIZE, 2);
155 DRM_DEBUG_DRIVER("wakeref last released at\n%s", buf);
156 }
157
158 kfree(buf);
159 }
160}
161
162static int cmphandle(const void *_a, const void *_b)
163{
164 const depot_stack_handle_t * const a = _a, * const b = _b;
165
166 if (*a < *b)
167 return -1;
168 else if (*a > *b)
169 return 1;
170 else
171 return 0;
172}
173
174static void
175__print_intel_runtime_pm_wakeref(struct drm_printer *p,
176 const struct intel_runtime_pm_debug *dbg)
177{
178 unsigned long i;
179 char *buf;
180
181 buf = kmalloc(PAGE_SIZE, GFP_NOWAIT | __GFP_NOWARN);
182 if (!buf)
183 return;
184
185 if (dbg->last_acquire) {
186 __print_depot_stack(dbg->last_acquire, buf, PAGE_SIZE, 2);
187 drm_printf(p, "Wakeref last acquired:\n%s", buf);
188 }
189
190 if (dbg->last_release) {
191 __print_depot_stack(dbg->last_release, buf, PAGE_SIZE, 2);
192 drm_printf(p, "Wakeref last released:\n%s", buf);
193 }
194
195 drm_printf(p, "Wakeref count: %lu\n", dbg->count);
196
197 sort(dbg->owners, dbg->count, sizeof(*dbg->owners), cmphandle, NULL);
198
199 for (i = 0; i < dbg->count; i++) {
200 depot_stack_handle_t stack = dbg->owners[i];
201 unsigned long rep;
202
203 rep = 1;
204 while (i + 1 < dbg->count && dbg->owners[i + 1] == stack)
205 rep++, i++;
206 __print_depot_stack(stack, buf, PAGE_SIZE, 2);
207 drm_printf(p, "Wakeref x%lu taken at:\n%s", rep, buf);
208 }
209
210 kfree(buf);
211}
212
213static noinline void
214__untrack_all_wakerefs(struct intel_runtime_pm_debug *debug,
215 struct intel_runtime_pm_debug *saved)
216{
217 *saved = *debug;
218
219 debug->owners = NULL;
220 debug->count = 0;
221 debug->last_release = __save_depot_stack();
222}
223
224static void
225dump_and_free_wakeref_tracking(struct intel_runtime_pm_debug *debug)
226{
227 if (debug->count) {
228 struct drm_printer p = drm_debug_printer("i915");
229
230 __print_intel_runtime_pm_wakeref(&p, debug);
231 }
232
233 kfree(debug->owners);
234}
235
236static noinline void
237__intel_wakeref_dec_and_check_tracking(struct intel_runtime_pm *rpm)
238{
239 struct intel_runtime_pm_debug dbg = {};
240 unsigned long flags;
241
242 if (!atomic_dec_and_lock_irqsave(&rpm->wakeref_count,
243 &rpm->debug.lock,
244 flags))
245 return;
246
247 __untrack_all_wakerefs(&rpm->debug, &dbg);
248 spin_unlock_irqrestore(&rpm->debug.lock, flags);
249
250 dump_and_free_wakeref_tracking(&dbg);
251}
252
253static noinline void
254untrack_all_intel_runtime_pm_wakerefs(struct intel_runtime_pm *rpm)
255{
256 struct intel_runtime_pm_debug dbg = {};
257 unsigned long flags;
258
259 spin_lock_irqsave(&rpm->debug.lock, flags);
260 __untrack_all_wakerefs(&rpm->debug, &dbg);
261 spin_unlock_irqrestore(&rpm->debug.lock, flags);
262
263 dump_and_free_wakeref_tracking(&dbg);
264}
265
266void print_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm,
267 struct drm_printer *p)
268{
269 struct intel_runtime_pm_debug dbg = {};
270
271 do {
272 unsigned long alloc = dbg.count;
273 depot_stack_handle_t *s;
274
275 spin_lock_irq(&rpm->debug.lock);
276 dbg.count = rpm->debug.count;
277 if (dbg.count <= alloc) {
278 memcpy(dbg.owners,
279 rpm->debug.owners,
280 dbg.count * sizeof(*s));
281 }
282 dbg.last_acquire = rpm->debug.last_acquire;
283 dbg.last_release = rpm->debug.last_release;
284 spin_unlock_irq(&rpm->debug.lock);
285 if (dbg.count <= alloc)
286 break;
287
288 s = krealloc(dbg.owners,
289 dbg.count * sizeof(*s),
290 GFP_NOWAIT | __GFP_NOWARN);
291 if (!s)
292 goto out;
293
294 dbg.owners = s;
295 } while (1);
296
297 __print_intel_runtime_pm_wakeref(p, &dbg);
298
299out:
300 kfree(dbg.owners);
301}
302
303#else
304
305static void init_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm)
306{
307}
308
309static depot_stack_handle_t
310track_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm)
311{
312 return -1;
313}
314
315static void untrack_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm,
316 intel_wakeref_t wref)
317{
318}
319
320static void
321__intel_wakeref_dec_and_check_tracking(struct intel_runtime_pm *rpm)
322{
323 atomic_dec(&rpm->wakeref_count);
324}
325
326static void
327untrack_all_intel_runtime_pm_wakerefs(struct intel_runtime_pm *rpm)
328{
329}
330
331#endif
332
333static void
334intel_runtime_pm_acquire(struct intel_runtime_pm *rpm, bool wakelock)
335{
336 if (wakelock) {
337 atomic_add(1 + INTEL_RPM_WAKELOCK_BIAS, &rpm->wakeref_count);
338 assert_rpm_wakelock_held(rpm);
339 } else {
340 atomic_inc(&rpm->wakeref_count);
341 assert_rpm_raw_wakeref_held(rpm);
342 }
343}
344
345static void
346intel_runtime_pm_release(struct intel_runtime_pm *rpm, int wakelock)
347{
348 if (wakelock) {
349 assert_rpm_wakelock_held(rpm);
350 atomic_sub(INTEL_RPM_WAKELOCK_BIAS, &rpm->wakeref_count);
351 } else {
352 assert_rpm_raw_wakeref_held(rpm);
353 }
354
355 __intel_wakeref_dec_and_check_tracking(rpm);
356}
357
358static intel_wakeref_t __intel_runtime_pm_get(struct intel_runtime_pm *rpm,
359 bool wakelock)
360{
361 struct drm_i915_private *i915 = container_of(rpm,
362 struct drm_i915_private,
363 runtime_pm);
364 int ret;
365
366 ret = pm_runtime_get_sync(rpm->kdev);
367 drm_WARN_ONCE(&i915->drm, ret < 0,
368 "pm_runtime_get_sync() failed: %d\n", ret);
369
370 intel_runtime_pm_acquire(rpm, wakelock);
371
372 return track_intel_runtime_pm_wakeref(rpm);
373}
374
375/**
376 * intel_runtime_pm_get_raw - grab a raw runtime pm reference
377 * @rpm: the intel_runtime_pm structure
378 *
379 * This is the unlocked version of intel_display_power_is_enabled() and should
380 * only be used from error capture and recovery code where deadlocks are
381 * possible.
382 * This function grabs a device-level runtime pm reference (mostly used for
383 * asynchronous PM management from display code) and ensures that it is powered
384 * up. Raw references are not considered during wakelock assert checks.
385 *
386 * Any runtime pm reference obtained by this function must have a symmetric
387 * call to intel_runtime_pm_put_raw() to release the reference again.
388 *
389 * Returns: the wakeref cookie to pass to intel_runtime_pm_put_raw(), evaluates
390 * as True if the wakeref was acquired, or False otherwise.
391 */
392intel_wakeref_t intel_runtime_pm_get_raw(struct intel_runtime_pm *rpm)
393{
394 return __intel_runtime_pm_get(rpm, false);
395}
396
397/**
398 * intel_runtime_pm_get - grab a runtime pm reference
399 * @rpm: the intel_runtime_pm structure
400 *
401 * This function grabs a device-level runtime pm reference (mostly used for GEM
402 * code to ensure the GTT or GT is on) and ensures that it is powered up.
403 *
404 * Any runtime pm reference obtained by this function must have a symmetric
405 * call to intel_runtime_pm_put() to release the reference again.
406 *
407 * Returns: the wakeref cookie to pass to intel_runtime_pm_put()
408 */
409intel_wakeref_t intel_runtime_pm_get(struct intel_runtime_pm *rpm)
410{
411 return __intel_runtime_pm_get(rpm, true);
412}
413
414/**
415 * intel_runtime_pm_get_if_in_use - grab a runtime pm reference if device in use
416 * @rpm: the intel_runtime_pm structure
417 *
418 * This function grabs a device-level runtime pm reference if the device is
419 * already in use and ensures that it is powered up. It is illegal to try
420 * and access the HW should intel_runtime_pm_get_if_in_use() report failure.
421 *
422 * Any runtime pm reference obtained by this function must have a symmetric
423 * call to intel_runtime_pm_put() to release the reference again.
424 *
425 * Returns: the wakeref cookie to pass to intel_runtime_pm_put(), evaluates
426 * as True if the wakeref was acquired, or False otherwise.
427 */
428intel_wakeref_t intel_runtime_pm_get_if_in_use(struct intel_runtime_pm *rpm)
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_in_use(rpm->kdev) <= 0)
438 return 0;
439 }
440
441 intel_runtime_pm_acquire(rpm, true);
442
443 return track_intel_runtime_pm_wakeref(rpm);
444}
445
446/**
447 * intel_runtime_pm_get_noresume - grab a runtime pm reference
448 * @rpm: the intel_runtime_pm structure
449 *
450 * This function grabs a device-level runtime pm reference (mostly used for GEM
451 * code to ensure the GTT or GT is on).
452 *
453 * It will _not_ power up the device but instead only check that it's powered
454 * on. Therefore it is only valid to call this functions from contexts where
455 * the device is known to be powered up and where trying to power it up would
456 * result in hilarity and deadlocks. That pretty much means only the system
457 * suspend/resume code where this is used to grab runtime pm references for
458 * delayed setup down in work items.
459 *
460 * Any runtime pm reference obtained by this function must have a symmetric
461 * call to intel_runtime_pm_put() to release the reference again.
462 *
463 * Returns: the wakeref cookie to pass to intel_runtime_pm_put()
464 */
465intel_wakeref_t intel_runtime_pm_get_noresume(struct intel_runtime_pm *rpm)
466{
467 assert_rpm_wakelock_held(rpm);
468 pm_runtime_get_noresume(rpm->kdev);
469
470 intel_runtime_pm_acquire(rpm, true);
471
472 return track_intel_runtime_pm_wakeref(rpm);
473}
474
475static void __intel_runtime_pm_put(struct intel_runtime_pm *rpm,
476 intel_wakeref_t wref,
477 bool wakelock)
478{
479 struct device *kdev = rpm->kdev;
480
481 untrack_intel_runtime_pm_wakeref(rpm, wref);
482
483 intel_runtime_pm_release(rpm, wakelock);
484
485 pm_runtime_mark_last_busy(kdev);
486 pm_runtime_put_autosuspend(kdev);
487}
488
489/**
490 * intel_runtime_pm_put_raw - release a raw runtime pm reference
491 * @rpm: the intel_runtime_pm structure
492 * @wref: wakeref acquired for the reference that is being released
493 *
494 * This function drops the device-level runtime pm reference obtained by
495 * intel_runtime_pm_get_raw() and might power down the corresponding
496 * hardware block right away if this is the last reference.
497 */
498void
499intel_runtime_pm_put_raw(struct intel_runtime_pm *rpm, intel_wakeref_t wref)
500{
501 __intel_runtime_pm_put(rpm, wref, false);
502}
503
504/**
505 * intel_runtime_pm_put_unchecked - release an unchecked runtime pm reference
506 * @rpm: the intel_runtime_pm structure
507 *
508 * This function drops the device-level runtime pm reference obtained by
509 * intel_runtime_pm_get() and might power down the corresponding
510 * hardware block right away if this is the last reference.
511 *
512 * This function exists only for historical reasons and should be avoided in
513 * new code, as the correctness of its use cannot be checked. Always use
514 * intel_runtime_pm_put() instead.
515 */
516void intel_runtime_pm_put_unchecked(struct intel_runtime_pm *rpm)
517{
518 __intel_runtime_pm_put(rpm, -1, true);
519}
520
521#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM)
522/**
523 * intel_runtime_pm_put - release a runtime pm reference
524 * @rpm: the intel_runtime_pm structure
525 * @wref: wakeref acquired for the reference that is being released
526 *
527 * This function drops the device-level runtime pm reference obtained by
528 * intel_runtime_pm_get() and might power down the corresponding
529 * hardware block right away if this is the last reference.
530 */
531void intel_runtime_pm_put(struct intel_runtime_pm *rpm, intel_wakeref_t wref)
532{
533 __intel_runtime_pm_put(rpm, wref, true);
534}
535#endif
536
537/**
538 * intel_runtime_pm_enable - enable runtime pm
539 * @rpm: the intel_runtime_pm structure
540 *
541 * This function enables runtime pm at the end of the driver load sequence.
542 *
543 * Note that this function does currently not enable runtime pm for the
544 * subordinate display power domains. That is done by
545 * intel_power_domains_enable().
546 */
547void intel_runtime_pm_enable(struct intel_runtime_pm *rpm)
548{
549 struct drm_i915_private *i915 = container_of(rpm,
550 struct drm_i915_private,
551 runtime_pm);
552 struct device *kdev = rpm->kdev;
553
554 /*
555 * Disable the system suspend direct complete optimization, which can
556 * leave the device suspended skipping the driver's suspend handlers
557 * if the device was already runtime suspended. This is needed due to
558 * the difference in our runtime and system suspend sequence and
559 * becaue the HDA driver may require us to enable the audio power
560 * domain during system suspend.
561 */
562 dev_pm_set_driver_flags(kdev, DPM_FLAG_NO_DIRECT_COMPLETE);
563
564 pm_runtime_set_autosuspend_delay(kdev, 10000); /* 10s */
565 pm_runtime_mark_last_busy(kdev);
566
567 /*
568 * Take a permanent reference to disable the RPM functionality and drop
569 * it only when unloading the driver. Use the low level get/put helpers,
570 * so the driver's own RPM reference tracking asserts also work on
571 * platforms without RPM support.
572 */
573 if (!rpm->available) {
574 int ret;
575
576 pm_runtime_dont_use_autosuspend(kdev);
577 ret = pm_runtime_get_sync(kdev);
578 drm_WARN(&i915->drm, ret < 0,
579 "pm_runtime_get_sync() failed: %d\n", ret);
580 } else {
581 pm_runtime_use_autosuspend(kdev);
582 }
583
584 /*
585 * The core calls the driver load handler with an RPM reference held.
586 * We drop that here and will reacquire it during unloading in
587 * intel_power_domains_fini().
588 */
589 pm_runtime_put_autosuspend(kdev);
590}
591
592void intel_runtime_pm_disable(struct intel_runtime_pm *rpm)
593{
594 struct drm_i915_private *i915 = container_of(rpm,
595 struct drm_i915_private,
596 runtime_pm);
597 struct device *kdev = rpm->kdev;
598
599 /* Transfer rpm ownership back to core */
600 drm_WARN(&i915->drm, pm_runtime_get_sync(kdev) < 0,
601 "Failed to pass rpm ownership back to core\n");
602
603 pm_runtime_dont_use_autosuspend(kdev);
604
605 if (!rpm->available)
606 pm_runtime_put(kdev);
607}
608
609void intel_runtime_pm_driver_release(struct intel_runtime_pm *rpm)
610{
611 struct drm_i915_private *i915 = container_of(rpm,
612 struct drm_i915_private,
613 runtime_pm);
614 int count = atomic_read(&rpm->wakeref_count);
615
616 drm_WARN(&i915->drm, count,
617 "i915 raw-wakerefs=%d wakelocks=%d on cleanup\n",
618 intel_rpm_raw_wakeref_count(count),
619 intel_rpm_wakelock_count(count));
620
621 untrack_all_intel_runtime_pm_wakerefs(rpm);
622}
623
624void intel_runtime_pm_init_early(struct intel_runtime_pm *rpm)
625{
626 struct drm_i915_private *i915 =
627 container_of(rpm, struct drm_i915_private, runtime_pm);
628 struct pci_dev *pdev = i915->drm.pdev;
629 struct device *kdev = &pdev->dev;
630
631 rpm->kdev = kdev;
632 rpm->available = HAS_RUNTIME_PM(i915);
633
634 init_intel_runtime_pm_wakeref(rpm);
635}