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