1 /* SPDX-License-Identifier: MIT */
3 * Copyright © 2019 Intel Corporation
6 #ifndef __INTEL_RUNTIME_PM_H__
7 #define __INTEL_RUNTIME_PM_H__
9 #include <linux/types.h>
11 #include "intel_wakeref.h"
13 #include "i915_utils.h"
16 struct drm_i915_private;
19 enum i915_drm_suspend_mode {
20 I915_DRM_SUSPEND_IDLE,
22 I915_DRM_SUSPEND_HIBERNATE,
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
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.
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.
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
46 * For more, read the Documentation/power/runtime_pm.rst.
48 struct intel_runtime_pm {
49 atomic_t wakeref_count;
50 struct device *kdev; /* points to i915->drm.dev */
55 #if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM)
57 * To aide detection of wakeref leaks and general misuse, we
58 * track all wakeref holders. With manual markup (i.e. returning
59 * a cookie to each rpm_get caller which they then supply to their
60 * paired rpm_put) we can remove corresponding pairs of and keep
61 * the array trimmed to active wakerefs.
63 struct intel_runtime_pm_debug {
66 depot_stack_handle_t last_acquire;
67 depot_stack_handle_t last_release;
69 depot_stack_handle_t *owners;
75 #define BITS_PER_WAKEREF \
76 BITS_PER_TYPE(struct_member(struct intel_runtime_pm, wakeref_count))
77 #define INTEL_RPM_WAKELOCK_SHIFT (BITS_PER_WAKEREF / 2)
78 #define INTEL_RPM_WAKELOCK_BIAS (1 << INTEL_RPM_WAKELOCK_SHIFT)
79 #define INTEL_RPM_RAW_WAKEREF_MASK (INTEL_RPM_WAKELOCK_BIAS - 1)
82 intel_rpm_raw_wakeref_count(int wakeref_count)
84 return wakeref_count & INTEL_RPM_RAW_WAKEREF_MASK;
88 intel_rpm_wakelock_count(int wakeref_count)
90 return wakeref_count >> INTEL_RPM_WAKELOCK_SHIFT;
94 assert_rpm_device_not_suspended(struct intel_runtime_pm *rpm)
96 WARN_ONCE(rpm->suspended,
97 "Device suspended during HW access\n");
101 __assert_rpm_raw_wakeref_held(struct intel_runtime_pm *rpm, int wakeref_count)
103 assert_rpm_device_not_suspended(rpm);
104 WARN_ONCE(!intel_rpm_raw_wakeref_count(wakeref_count),
105 "RPM raw-wakeref not held\n");
109 __assert_rpm_wakelock_held(struct intel_runtime_pm *rpm, int wakeref_count)
111 __assert_rpm_raw_wakeref_held(rpm, wakeref_count);
112 WARN_ONCE(!intel_rpm_wakelock_count(wakeref_count),
113 "RPM wakelock ref not held during HW access\n");
117 assert_rpm_raw_wakeref_held(struct intel_runtime_pm *rpm)
119 __assert_rpm_raw_wakeref_held(rpm, atomic_read(&rpm->wakeref_count));
123 assert_rpm_wakelock_held(struct intel_runtime_pm *rpm)
125 __assert_rpm_wakelock_held(rpm, atomic_read(&rpm->wakeref_count));
129 * disable_rpm_wakeref_asserts - disable the RPM assert checks
130 * @rpm: the intel_runtime_pm structure
132 * This function disable asserts that check if we hold an RPM wakelock
133 * reference, while keeping the device-not-suspended checks still enabled.
134 * It's meant to be used only in special circumstances where our rule about
135 * the wakelock refcount wrt. the device power state doesn't hold. According
136 * to this rule at any point where we access the HW or want to keep the HW in
137 * an active state we must hold an RPM wakelock reference acquired via one of
138 * the intel_runtime_pm_get() helpers. Currently there are a few special spots
139 * where this rule doesn't hold: the IRQ and suspend/resume handlers, the
140 * forcewake release timer, and the GPU RPS and hangcheck works. All other
141 * users should avoid using this function.
143 * Any calls to this function must have a symmetric call to
144 * enable_rpm_wakeref_asserts().
147 disable_rpm_wakeref_asserts(struct intel_runtime_pm *rpm)
149 atomic_add(INTEL_RPM_WAKELOCK_BIAS + 1,
150 &rpm->wakeref_count);
154 * enable_rpm_wakeref_asserts - re-enable the RPM assert checks
155 * @rpm: the intel_runtime_pm structure
157 * This function re-enables the RPM assert checks after disabling them with
158 * disable_rpm_wakeref_asserts. It's meant to be used only in special
159 * circumstances otherwise its use should be avoided.
161 * Any calls to this function must have a symmetric call to
162 * disable_rpm_wakeref_asserts().
165 enable_rpm_wakeref_asserts(struct intel_runtime_pm *rpm)
167 atomic_sub(INTEL_RPM_WAKELOCK_BIAS + 1,
168 &rpm->wakeref_count);
171 void intel_runtime_pm_init_early(struct intel_runtime_pm *rpm);
172 void intel_runtime_pm_enable(struct intel_runtime_pm *rpm);
173 void intel_runtime_pm_disable(struct intel_runtime_pm *rpm);
174 void intel_runtime_pm_driver_release(struct intel_runtime_pm *rpm);
176 intel_wakeref_t intel_runtime_pm_get(struct intel_runtime_pm *rpm);
177 intel_wakeref_t intel_runtime_pm_get_if_in_use(struct intel_runtime_pm *rpm);
178 intel_wakeref_t intel_runtime_pm_get_if_active(struct intel_runtime_pm *rpm);
179 intel_wakeref_t intel_runtime_pm_get_noresume(struct intel_runtime_pm *rpm);
180 intel_wakeref_t intel_runtime_pm_get_raw(struct intel_runtime_pm *rpm);
182 #define with_intel_runtime_pm(rpm, wf) \
183 for ((wf) = intel_runtime_pm_get(rpm); (wf); \
184 intel_runtime_pm_put((rpm), (wf)), (wf) = 0)
186 #define with_intel_runtime_pm_if_in_use(rpm, wf) \
187 for ((wf) = intel_runtime_pm_get_if_in_use(rpm); (wf); \
188 intel_runtime_pm_put((rpm), (wf)), (wf) = 0)
190 #define with_intel_runtime_pm_if_active(rpm, wf) \
191 for ((wf) = intel_runtime_pm_get_if_active(rpm); (wf); \
192 intel_runtime_pm_put((rpm), (wf)), (wf) = 0)
194 void intel_runtime_pm_put_unchecked(struct intel_runtime_pm *rpm);
195 #if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM)
196 void intel_runtime_pm_put(struct intel_runtime_pm *rpm, intel_wakeref_t wref);
199 intel_runtime_pm_put(struct intel_runtime_pm *rpm, intel_wakeref_t wref)
201 intel_runtime_pm_put_unchecked(rpm);
204 void intel_runtime_pm_put_raw(struct intel_runtime_pm *rpm, intel_wakeref_t wref);
206 #if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM)
207 void print_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm,
208 struct drm_printer *p);
210 static inline void print_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm,
211 struct drm_printer *p)
216 #endif /* __INTEL_RUNTIME_PM_H__ */