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1 | /* |
2 | * SPDX-License-Identifier: MIT | |
3 | * | |
4 | * Copyright © 2019 Intel Corporation | |
5 | */ | |
6 | ||
7 | #ifndef INTEL_WAKEREF_H | |
8 | #define INTEL_WAKEREF_H | |
9 | ||
10 | #include <linux/atomic.h> | |
11 | #include <linux/mutex.h> | |
b27e35ae | 12 | #include <linux/refcount.h> |
d91e6578 | 13 | #include <linux/stackdepot.h> |
b27e35ae | 14 | #include <linux/timer.h> |
d91e6578 | 15 | |
58a111f0 | 16 | struct intel_runtime_pm; |
d91e6578 CW |
17 | |
18 | typedef depot_stack_handle_t intel_wakeref_t; | |
19 | ||
20 | struct intel_wakeref { | |
21 | atomic_t count; | |
22 | struct mutex mutex; | |
23 | intel_wakeref_t wakeref; | |
24 | }; | |
25 | ||
26 | void __intel_wakeref_init(struct intel_wakeref *wf, | |
27 | struct lock_class_key *key); | |
28 | #define intel_wakeref_init(wf) do { \ | |
29 | static struct lock_class_key __key; \ | |
30 | \ | |
31 | __intel_wakeref_init((wf), &__key); \ | |
32 | } while (0) | |
33 | ||
58a111f0 | 34 | int __intel_wakeref_get_first(struct intel_runtime_pm *rpm, |
d91e6578 CW |
35 | struct intel_wakeref *wf, |
36 | int (*fn)(struct intel_wakeref *wf)); | |
58a111f0 | 37 | int __intel_wakeref_put_last(struct intel_runtime_pm *rpm, |
d91e6578 CW |
38 | struct intel_wakeref *wf, |
39 | int (*fn)(struct intel_wakeref *wf)); | |
40 | ||
41 | /** | |
42 | * intel_wakeref_get: Acquire the wakeref | |
43 | * @i915: the drm_i915_private device | |
44 | * @wf: the wakeref | |
45 | * @fn: callback for acquired the wakeref, called only on first acquire. | |
46 | * | |
47 | * Acquire a hold on the wakeref. The first user to do so, will acquire | |
48 | * the runtime pm wakeref and then call the @fn underneath the wakeref | |
49 | * mutex. | |
50 | * | |
51 | * Note that @fn is allowed to fail, in which case the runtime-pm wakeref | |
52 | * will be released and the acquisition unwound, and an error reported. | |
53 | * | |
54 | * Returns: 0 if the wakeref was acquired successfully, or a negative error | |
55 | * code otherwise. | |
56 | */ | |
57 | static inline int | |
58a111f0 | 58 | intel_wakeref_get(struct intel_runtime_pm *rpm, |
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59 | struct intel_wakeref *wf, |
60 | int (*fn)(struct intel_wakeref *wf)) | |
61 | { | |
62 | if (unlikely(!atomic_inc_not_zero(&wf->count))) | |
58a111f0 | 63 | return __intel_wakeref_get_first(rpm, wf, fn); |
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64 | |
65 | return 0; | |
66 | } | |
67 | ||
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68 | /** |
69 | * intel_wakeref_get_if_in_use: Acquire the wakeref | |
70 | * @wf: the wakeref | |
71 | * | |
72 | * Acquire a hold on the wakeref, but only if the wakeref is already | |
73 | * active. | |
74 | * | |
75 | * Returns: true if the wakeref was acquired, false otherwise. | |
76 | */ | |
77 | static inline bool | |
78 | intel_wakeref_get_if_active(struct intel_wakeref *wf) | |
79 | { | |
80 | return atomic_inc_not_zero(&wf->count); | |
81 | } | |
82 | ||
d91e6578 CW |
83 | /** |
84 | * intel_wakeref_put: Release the wakeref | |
85 | * @i915: the drm_i915_private device | |
86 | * @wf: the wakeref | |
87 | * @fn: callback for releasing the wakeref, called only on final release. | |
88 | * | |
89 | * Release our hold on the wakeref. When there are no more users, | |
90 | * the runtime pm wakeref will be released after the @fn callback is called | |
91 | * underneath the wakeref mutex. | |
92 | * | |
93 | * Note that @fn is allowed to fail, in which case the runtime-pm wakeref | |
94 | * is retained and an error reported. | |
95 | * | |
96 | * Returns: 0 if the wakeref was released successfully, or a negative error | |
97 | * code otherwise. | |
98 | */ | |
99 | static inline int | |
58a111f0 | 100 | intel_wakeref_put(struct intel_runtime_pm *rpm, |
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101 | struct intel_wakeref *wf, |
102 | int (*fn)(struct intel_wakeref *wf)) | |
103 | { | |
104 | if (atomic_dec_and_mutex_lock(&wf->count, &wf->mutex)) | |
58a111f0 | 105 | return __intel_wakeref_put_last(rpm, wf, fn); |
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106 | |
107 | return 0; | |
108 | } | |
109 | ||
110 | /** | |
111 | * intel_wakeref_lock: Lock the wakeref (mutex) | |
112 | * @wf: the wakeref | |
113 | * | |
114 | * Locks the wakeref to prevent it being acquired or released. New users | |
115 | * can still adjust the counter, but the wakeref itself (and callback) | |
116 | * cannot be acquired or released. | |
117 | */ | |
118 | static inline void | |
119 | intel_wakeref_lock(struct intel_wakeref *wf) | |
120 | __acquires(wf->mutex) | |
121 | { | |
122 | mutex_lock(&wf->mutex); | |
123 | } | |
124 | ||
125 | /** | |
126 | * intel_wakeref_unlock: Unlock the wakeref | |
127 | * @wf: the wakeref | |
128 | * | |
129 | * Releases a previously acquired intel_wakeref_lock(). | |
130 | */ | |
131 | static inline void | |
132 | intel_wakeref_unlock(struct intel_wakeref *wf) | |
133 | __releases(wf->mutex) | |
134 | { | |
135 | mutex_unlock(&wf->mutex); | |
136 | } | |
137 | ||
138 | /** | |
139 | * intel_wakeref_active: Query whether the wakeref is currently held | |
140 | * @wf: the wakeref | |
141 | * | |
142 | * Returns: true if the wakeref is currently held. | |
143 | */ | |
144 | static inline bool | |
145 | intel_wakeref_active(struct intel_wakeref *wf) | |
146 | { | |
7ee280a7 | 147 | return READ_ONCE(wf->wakeref); |
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148 | } |
149 | ||
b27e35ae | 150 | struct intel_wakeref_auto { |
58a111f0 | 151 | struct intel_runtime_pm *rpm; |
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152 | struct timer_list timer; |
153 | intel_wakeref_t wakeref; | |
154 | spinlock_t lock; | |
155 | refcount_t count; | |
156 | }; | |
157 | ||
158 | /** | |
159 | * intel_wakeref_auto: Delay the runtime-pm autosuspend | |
160 | * @wf: the wakeref | |
161 | * @timeout: relative timeout in jiffies | |
162 | * | |
163 | * The runtime-pm core uses a suspend delay after the last wakeref | |
164 | * is released before triggering runtime suspend of the device. That | |
165 | * delay is configurable via sysfs with little regard to the device | |
166 | * characteristics. Instead, we want to tune the autosuspend based on our | |
167 | * HW knowledge. intel_wakeref_auto() delays the sleep by the supplied | |
168 | * timeout. | |
169 | * | |
170 | * Pass @timeout = 0 to cancel a previous autosuspend by executing the | |
171 | * suspend immediately. | |
172 | */ | |
173 | void intel_wakeref_auto(struct intel_wakeref_auto *wf, unsigned long timeout); | |
174 | ||
175 | void intel_wakeref_auto_init(struct intel_wakeref_auto *wf, | |
58a111f0 | 176 | struct intel_runtime_pm *rpm); |
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177 | void intel_wakeref_auto_fini(struct intel_wakeref_auto *wf); |
178 | ||
d91e6578 | 179 | #endif /* INTEL_WAKEREF_H */ |