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1/* SPDX-License-Identifier: MIT */
2/*
3 * Copyright © 2019 Intel Corporation
4 */
5
6#ifndef __INTEL_RUNTIME_PM_H__
7#define __INTEL_RUNTIME_PM_H__
8
9#include <linux/pm_runtime.h>
10#include <linux/types.h>
11
12#include "intel_wakeref.h"
13
14struct device;
15struct drm_i915_private;
16struct drm_printer;
17
18/*
19 * This struct helps tracking the state needed for runtime PM, which puts the
20 * device in PCI D3 state. Notice that when this happens, nothing on the
21 * graphics device works, even register access, so we don't get interrupts nor
22 * anything else.
23 *
24 * Every piece of our code that needs to actually touch the hardware needs to
25 * either call intel_runtime_pm_get or call intel_display_power_get with the
26 * appropriate power domain.
27 *
28 * Our driver uses the autosuspend delay feature, which means we'll only really
29 * suspend if we stay with zero refcount for a certain amount of time. The
30 * default value is currently very conservative (see intel_runtime_pm_enable), but
31 * it can be changed with the standard runtime PM files from sysfs.
32 *
33 * The irqs_disabled variable becomes true exactly after we disable the IRQs and
34 * goes back to false exactly before we reenable the IRQs. We use this variable
35 * to check if someone is trying to enable/disable IRQs while they're supposed
36 * to be disabled. This shouldn't happen and we'll print some error messages in
37 * case it happens.
38 *
39 * For more, read the Documentation/power/runtime_pm.rst.
40 */
41struct intel_runtime_pm {
42 atomic_t wakeref_count;
43 struct device *kdev; /* points to i915->drm.dev */
44 bool available;
45 bool irqs_enabled;
46 bool no_wakeref_tracking;
47
48 /*
49 * Protects access to lmem usefault list.
50 * It is required, if we are outside of the runtime suspend path,
51 * access to @lmem_userfault_list requires always first grabbing the
52 * runtime pm, to ensure we can't race against runtime suspend.
53 * Once we have that we also need to grab @lmem_userfault_lock,
54 * at which point we have exclusive access.
55 * The runtime suspend path is special since it doesn't really hold any locks,
56 * but instead has exclusive access by virtue of all other accesses requiring
57 * holding the runtime pm wakeref.
58 */
59 spinlock_t lmem_userfault_lock;
60
61 /*
62 * Keep list of userfaulted gem obj, which require to release their
63 * mmap mappings at runtime suspend path.
64 */
65 struct list_head lmem_userfault_list;
66
67 /* Manual runtime pm autosuspend delay for user GGTT/lmem mmaps */
68 struct intel_wakeref_auto userfault_wakeref;
69
70#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM)
71 /*
72 * To aide detection of wakeref leaks and general misuse, we
73 * track all wakeref holders. With manual markup (i.e. returning
74 * a cookie to each rpm_get caller which they then supply to their
75 * paired rpm_put) we can remove corresponding pairs of and keep
76 * the array trimmed to active wakerefs.
77 */
78 struct ref_tracker_dir debug;
79#endif
80};
81
82#define BITS_PER_WAKEREF \
83 BITS_PER_TYPE(typeof_member(struct intel_runtime_pm, wakeref_count))
84#define INTEL_RPM_WAKELOCK_SHIFT (BITS_PER_WAKEREF / 2)
85#define INTEL_RPM_WAKELOCK_BIAS (1 << INTEL_RPM_WAKELOCK_SHIFT)
86#define INTEL_RPM_RAW_WAKEREF_MASK (INTEL_RPM_WAKELOCK_BIAS - 1)
87
88static inline int
89intel_rpm_raw_wakeref_count(int wakeref_count)
90{
91 return wakeref_count & INTEL_RPM_RAW_WAKEREF_MASK;
92}
93
94static inline int
95intel_rpm_wakelock_count(int wakeref_count)
96{
97 return wakeref_count >> INTEL_RPM_WAKELOCK_SHIFT;
98}
99
100static inline void
101assert_rpm_device_not_suspended(struct intel_runtime_pm *rpm)
102{
103 WARN_ONCE(pm_runtime_suspended(rpm->kdev),
104 "Device suspended during HW access\n");
105}
106
107static inline void
108__assert_rpm_raw_wakeref_held(struct intel_runtime_pm *rpm, int wakeref_count)
109{
110 assert_rpm_device_not_suspended(rpm);
111 WARN_ONCE(!intel_rpm_raw_wakeref_count(wakeref_count),
112 "RPM raw-wakeref not held\n");
113}
114
115static inline void
116__assert_rpm_wakelock_held(struct intel_runtime_pm *rpm, int wakeref_count)
117{
118 __assert_rpm_raw_wakeref_held(rpm, wakeref_count);
119 WARN_ONCE(!intel_rpm_wakelock_count(wakeref_count),
120 "RPM wakelock ref not held during HW access\n");
121}
122
123static inline void
124assert_rpm_raw_wakeref_held(struct intel_runtime_pm *rpm)
125{
126 __assert_rpm_raw_wakeref_held(rpm, atomic_read(&rpm->wakeref_count));
127}
128
129static inline void
130assert_rpm_wakelock_held(struct intel_runtime_pm *rpm)
131{
132 __assert_rpm_wakelock_held(rpm, atomic_read(&rpm->wakeref_count));
133}
134
135/**
136 * disable_rpm_wakeref_asserts - disable the RPM assert checks
137 * @rpm: the intel_runtime_pm structure
138 *
139 * This function disable asserts that check if we hold an RPM wakelock
140 * reference, while keeping the device-not-suspended checks still enabled.
141 * It's meant to be used only in special circumstances where our rule about
142 * the wakelock refcount wrt. the device power state doesn't hold. According
143 * to this rule at any point where we access the HW or want to keep the HW in
144 * an active state we must hold an RPM wakelock reference acquired via one of
145 * the intel_runtime_pm_get() helpers. Currently there are a few special spots
146 * where this rule doesn't hold: the IRQ and suspend/resume handlers, the
147 * forcewake release timer, and the GPU RPS and hangcheck works. All other
148 * users should avoid using this function.
149 *
150 * Any calls to this function must have a symmetric call to
151 * enable_rpm_wakeref_asserts().
152 */
153static inline void
154disable_rpm_wakeref_asserts(struct intel_runtime_pm *rpm)
155{
156 atomic_add(INTEL_RPM_WAKELOCK_BIAS + 1,
157 &rpm->wakeref_count);
158}
159
160/**
161 * enable_rpm_wakeref_asserts - re-enable the RPM assert checks
162 * @rpm: the intel_runtime_pm structure
163 *
164 * This function re-enables the RPM assert checks after disabling them with
165 * disable_rpm_wakeref_asserts. It's meant to be used only in special
166 * circumstances otherwise its use should be avoided.
167 *
168 * Any calls to this function must have a symmetric call to
169 * disable_rpm_wakeref_asserts().
170 */
171static inline void
172enable_rpm_wakeref_asserts(struct intel_runtime_pm *rpm)
173{
174 atomic_sub(INTEL_RPM_WAKELOCK_BIAS + 1,
175 &rpm->wakeref_count);
176}
177
178void intel_runtime_pm_init_early(struct intel_runtime_pm *rpm);
179void intel_runtime_pm_enable(struct intel_runtime_pm *rpm);
180void intel_runtime_pm_disable(struct intel_runtime_pm *rpm);
181void intel_runtime_pm_driver_release(struct intel_runtime_pm *rpm);
182void intel_runtime_pm_driver_last_release(struct intel_runtime_pm *rpm);
183
184intel_wakeref_t intel_runtime_pm_get(struct intel_runtime_pm *rpm);
185intel_wakeref_t intel_runtime_pm_get_if_in_use(struct intel_runtime_pm *rpm);
186intel_wakeref_t intel_runtime_pm_get_if_active(struct intel_runtime_pm *rpm);
187intel_wakeref_t intel_runtime_pm_get_noresume(struct intel_runtime_pm *rpm);
188intel_wakeref_t intel_runtime_pm_get_raw(struct intel_runtime_pm *rpm);
189
190#define with_intel_runtime_pm(rpm, wf) \
191 for ((wf) = intel_runtime_pm_get(rpm); (wf); \
192 intel_runtime_pm_put((rpm), (wf)), (wf) = 0)
193
194#define with_intel_runtime_pm_if_in_use(rpm, wf) \
195 for ((wf) = intel_runtime_pm_get_if_in_use(rpm); (wf); \
196 intel_runtime_pm_put((rpm), (wf)), (wf) = 0)
197
198#define with_intel_runtime_pm_if_active(rpm, wf) \
199 for ((wf) = intel_runtime_pm_get_if_active(rpm); (wf); \
200 intel_runtime_pm_put((rpm), (wf)), (wf) = 0)
201
202void intel_runtime_pm_put_unchecked(struct intel_runtime_pm *rpm);
203#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM)
204void intel_runtime_pm_put(struct intel_runtime_pm *rpm, intel_wakeref_t wref);
205#else
206static inline void
207intel_runtime_pm_put(struct intel_runtime_pm *rpm, intel_wakeref_t wref)
208{
209 intel_runtime_pm_put_unchecked(rpm);
210}
211#endif
212void intel_runtime_pm_put_raw(struct intel_runtime_pm *rpm, intel_wakeref_t wref);
213
214#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM)
215void print_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm,
216 struct drm_printer *p);
217#else
218static inline void print_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm,
219 struct drm_printer *p)
220{
221}
222#endif
223
224#endif /* __INTEL_RUNTIME_PM_H__ */
1/* SPDX-License-Identifier: MIT */
2/*
3 * Copyright © 2019 Intel Corporation
4 */
5
6#ifndef __INTEL_RUNTIME_PM_H__
7#define __INTEL_RUNTIME_PM_H__
8
9#include <linux/types.h>
10
11#include "intel_wakeref.h"
12
13#include "i915_utils.h"
14
15struct device;
16struct drm_i915_private;
17struct drm_printer;
18
19enum i915_drm_suspend_mode {
20 I915_DRM_SUSPEND_IDLE,
21 I915_DRM_SUSPEND_MEM,
22 I915_DRM_SUSPEND_HIBERNATE,
23};
24
25/*
26 * This struct helps tracking the state needed for runtime PM, which puts the
27 * device in PCI D3 state. Notice that when this happens, nothing on the
28 * graphics device works, even register access, so we don't get interrupts nor
29 * anything else.
30 *
31 * Every piece of our code that needs to actually touch the hardware needs to
32 * either call intel_runtime_pm_get or call intel_display_power_get with the
33 * appropriate power domain.
34 *
35 * Our driver uses the autosuspend delay feature, which means we'll only really
36 * suspend if we stay with zero refcount for a certain amount of time. The
37 * default value is currently very conservative (see intel_runtime_pm_enable), but
38 * it can be changed with the standard runtime PM files from sysfs.
39 *
40 * The irqs_disabled variable becomes true exactly after we disable the IRQs and
41 * goes back to false exactly before we reenable the IRQs. We use this variable
42 * to check if someone is trying to enable/disable IRQs while they're supposed
43 * to be disabled. This shouldn't happen and we'll print some error messages in
44 * case it happens.
45 *
46 * For more, read the Documentation/power/runtime_pm.rst.
47 */
48struct intel_runtime_pm {
49 atomic_t wakeref_count;
50 struct device *kdev; /* points to i915->drm.dev */
51 bool available;
52 bool suspended;
53 bool irqs_enabled;
54 bool no_wakeref_tracking;
55
56 /*
57 * Protects access to lmem usefault list.
58 * It is required, if we are outside of the runtime suspend path,
59 * access to @lmem_userfault_list requires always first grabbing the
60 * runtime pm, to ensure we can't race against runtime suspend.
61 * Once we have that we also need to grab @lmem_userfault_lock,
62 * at which point we have exclusive access.
63 * The runtime suspend path is special since it doesn't really hold any locks,
64 * but instead has exclusive access by virtue of all other accesses requiring
65 * holding the runtime pm wakeref.
66 */
67 spinlock_t lmem_userfault_lock;
68
69 /*
70 * Keep list of userfaulted gem obj, which require to release their
71 * mmap mappings at runtime suspend path.
72 */
73 struct list_head lmem_userfault_list;
74
75 /* Manual runtime pm autosuspend delay for user GGTT/lmem mmaps */
76 struct intel_wakeref_auto userfault_wakeref;
77
78#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM)
79 /*
80 * To aide detection of wakeref leaks and general misuse, we
81 * track all wakeref holders. With manual markup (i.e. returning
82 * a cookie to each rpm_get caller which they then supply to their
83 * paired rpm_put) we can remove corresponding pairs of and keep
84 * the array trimmed to active wakerefs.
85 */
86 struct intel_runtime_pm_debug {
87 spinlock_t lock;
88
89 depot_stack_handle_t last_acquire;
90 depot_stack_handle_t last_release;
91
92 depot_stack_handle_t *owners;
93 unsigned long count;
94 } debug;
95#endif
96};
97
98#define BITS_PER_WAKEREF \
99 BITS_PER_TYPE(struct_member(struct intel_runtime_pm, wakeref_count))
100#define INTEL_RPM_WAKELOCK_SHIFT (BITS_PER_WAKEREF / 2)
101#define INTEL_RPM_WAKELOCK_BIAS (1 << INTEL_RPM_WAKELOCK_SHIFT)
102#define INTEL_RPM_RAW_WAKEREF_MASK (INTEL_RPM_WAKELOCK_BIAS - 1)
103
104static inline int
105intel_rpm_raw_wakeref_count(int wakeref_count)
106{
107 return wakeref_count & INTEL_RPM_RAW_WAKEREF_MASK;
108}
109
110static inline int
111intel_rpm_wakelock_count(int wakeref_count)
112{
113 return wakeref_count >> INTEL_RPM_WAKELOCK_SHIFT;
114}
115
116static inline void
117assert_rpm_device_not_suspended(struct intel_runtime_pm *rpm)
118{
119 WARN_ONCE(rpm->suspended,
120 "Device suspended during HW access\n");
121}
122
123static inline void
124__assert_rpm_raw_wakeref_held(struct intel_runtime_pm *rpm, int wakeref_count)
125{
126 assert_rpm_device_not_suspended(rpm);
127 WARN_ONCE(!intel_rpm_raw_wakeref_count(wakeref_count),
128 "RPM raw-wakeref not held\n");
129}
130
131static inline void
132__assert_rpm_wakelock_held(struct intel_runtime_pm *rpm, int wakeref_count)
133{
134 __assert_rpm_raw_wakeref_held(rpm, wakeref_count);
135 WARN_ONCE(!intel_rpm_wakelock_count(wakeref_count),
136 "RPM wakelock ref not held during HW access\n");
137}
138
139static inline void
140assert_rpm_raw_wakeref_held(struct intel_runtime_pm *rpm)
141{
142 __assert_rpm_raw_wakeref_held(rpm, atomic_read(&rpm->wakeref_count));
143}
144
145static inline void
146assert_rpm_wakelock_held(struct intel_runtime_pm *rpm)
147{
148 __assert_rpm_wakelock_held(rpm, atomic_read(&rpm->wakeref_count));
149}
150
151/**
152 * disable_rpm_wakeref_asserts - disable the RPM assert checks
153 * @rpm: the intel_runtime_pm structure
154 *
155 * This function disable asserts that check if we hold an RPM wakelock
156 * reference, while keeping the device-not-suspended checks still enabled.
157 * It's meant to be used only in special circumstances where our rule about
158 * the wakelock refcount wrt. the device power state doesn't hold. According
159 * to this rule at any point where we access the HW or want to keep the HW in
160 * an active state we must hold an RPM wakelock reference acquired via one of
161 * the intel_runtime_pm_get() helpers. Currently there are a few special spots
162 * where this rule doesn't hold: the IRQ and suspend/resume handlers, the
163 * forcewake release timer, and the GPU RPS and hangcheck works. All other
164 * users should avoid using this function.
165 *
166 * Any calls to this function must have a symmetric call to
167 * enable_rpm_wakeref_asserts().
168 */
169static inline void
170disable_rpm_wakeref_asserts(struct intel_runtime_pm *rpm)
171{
172 atomic_add(INTEL_RPM_WAKELOCK_BIAS + 1,
173 &rpm->wakeref_count);
174}
175
176/**
177 * enable_rpm_wakeref_asserts - re-enable the RPM assert checks
178 * @rpm: the intel_runtime_pm structure
179 *
180 * This function re-enables the RPM assert checks after disabling them with
181 * disable_rpm_wakeref_asserts. It's meant to be used only in special
182 * circumstances otherwise its use should be avoided.
183 *
184 * Any calls to this function must have a symmetric call to
185 * disable_rpm_wakeref_asserts().
186 */
187static inline void
188enable_rpm_wakeref_asserts(struct intel_runtime_pm *rpm)
189{
190 atomic_sub(INTEL_RPM_WAKELOCK_BIAS + 1,
191 &rpm->wakeref_count);
192}
193
194void intel_runtime_pm_init_early(struct intel_runtime_pm *rpm);
195void intel_runtime_pm_enable(struct intel_runtime_pm *rpm);
196void intel_runtime_pm_disable(struct intel_runtime_pm *rpm);
197void intel_runtime_pm_driver_release(struct intel_runtime_pm *rpm);
198
199intel_wakeref_t intel_runtime_pm_get(struct intel_runtime_pm *rpm);
200intel_wakeref_t intel_runtime_pm_get_if_in_use(struct intel_runtime_pm *rpm);
201intel_wakeref_t intel_runtime_pm_get_if_active(struct intel_runtime_pm *rpm);
202intel_wakeref_t intel_runtime_pm_get_noresume(struct intel_runtime_pm *rpm);
203intel_wakeref_t intel_runtime_pm_get_raw(struct intel_runtime_pm *rpm);
204
205#define with_intel_runtime_pm(rpm, wf) \
206 for ((wf) = intel_runtime_pm_get(rpm); (wf); \
207 intel_runtime_pm_put((rpm), (wf)), (wf) = 0)
208
209#define with_intel_runtime_pm_if_in_use(rpm, wf) \
210 for ((wf) = intel_runtime_pm_get_if_in_use(rpm); (wf); \
211 intel_runtime_pm_put((rpm), (wf)), (wf) = 0)
212
213#define with_intel_runtime_pm_if_active(rpm, wf) \
214 for ((wf) = intel_runtime_pm_get_if_active(rpm); (wf); \
215 intel_runtime_pm_put((rpm), (wf)), (wf) = 0)
216
217void intel_runtime_pm_put_unchecked(struct intel_runtime_pm *rpm);
218#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM)
219void intel_runtime_pm_put(struct intel_runtime_pm *rpm, intel_wakeref_t wref);
220#else
221static inline void
222intel_runtime_pm_put(struct intel_runtime_pm *rpm, intel_wakeref_t wref)
223{
224 intel_runtime_pm_put_unchecked(rpm);
225}
226#endif
227void intel_runtime_pm_put_raw(struct intel_runtime_pm *rpm, intel_wakeref_t wref);
228
229#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM)
230void print_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm,
231 struct drm_printer *p);
232#else
233static inline void print_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm,
234 struct drm_printer *p)
235{
236}
237#endif
238
239#endif /* __INTEL_RUNTIME_PM_H__ */