1 /* $NetBSD: intel_runtime_pm.h,v 1.2 2021/12/18 23:45:29 riastradh Exp $ */ 2 3 /* SPDX-License-Identifier: MIT */ 4 /* 5 * Copyright 2019 Intel Corporation 6 */ 7 8 #ifndef __INTEL_RUNTIME_PM_H__ 9 #define __INTEL_RUNTIME_PM_H__ 10 11 #include <linux/types.h> 12 13 #include "display/intel_display.h" 14 15 #include "intel_wakeref.h" 16 17 #include "i915_utils.h" 18 19 struct device; 20 struct drm_i915_private; 21 struct drm_printer; 22 23 enum i915_drm_suspend_mode { 24 I915_DRM_SUSPEND_IDLE, 25 I915_DRM_SUSPEND_MEM, 26 I915_DRM_SUSPEND_HIBERNATE, 27 }; 28 29 /* 30 * This struct helps tracking the state needed for runtime PM, which puts the 31 * device in PCI D3 state. Notice that when this happens, nothing on the 32 * graphics device works, even register access, so we don't get interrupts nor 33 * anything else. 34 * 35 * Every piece of our code that needs to actually touch the hardware needs to 36 * either call intel_runtime_pm_get or call intel_display_power_get with the 37 * appropriate power domain. 38 * 39 * Our driver uses the autosuspend delay feature, which means we'll only really 40 * suspend if we stay with zero refcount for a certain amount of time. The 41 * default value is currently very conservative (see intel_runtime_pm_enable), but 42 * it can be changed with the standard runtime PM files from sysfs. 43 * 44 * The irqs_disabled variable becomes true exactly after we disable the IRQs and 45 * goes back to false exactly before we reenable the IRQs. We use this variable 46 * to check if someone is trying to enable/disable IRQs while they're supposed 47 * to be disabled. This shouldn't happen and we'll print some error messages in 48 * case it happens. 49 * 50 * For more, read the Documentation/power/runtime_pm.rst. 51 */ 52 struct intel_runtime_pm { 53 atomic_t wakeref_count; 54 struct device *kdev; /* points to i915->drm.pdev->dev */ 55 bool available; 56 bool suspended; 57 bool irqs_enabled; 58 59 #if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM) 60 /* 61 * To aide detection of wakeref leaks and general misuse, we 62 * track all wakeref holders. With manual markup (i.e. returning 63 * a cookie to each rpm_get caller which they then supply to their 64 * paired rpm_put) we can remove corresponding pairs of and keep 65 * the array trimmed to active wakerefs. 66 */ 67 struct intel_runtime_pm_debug { 68 spinlock_t lock; 69 70 depot_stack_handle_t last_acquire; 71 depot_stack_handle_t last_release; 72 73 depot_stack_handle_t *owners; 74 unsigned long count; 75 } debug; 76 #endif 77 }; 78 79 #define BITS_PER_WAKEREF \ 80 BITS_PER_TYPE(struct_member(struct intel_runtime_pm, wakeref_count)) 81 #define INTEL_RPM_WAKELOCK_SHIFT (BITS_PER_WAKEREF / 2) 82 #define INTEL_RPM_WAKELOCK_BIAS (1 << INTEL_RPM_WAKELOCK_SHIFT) 83 #define INTEL_RPM_RAW_WAKEREF_MASK (INTEL_RPM_WAKELOCK_BIAS - 1) 84 85 static inline int 86 intel_rpm_raw_wakeref_count(int wakeref_count) 87 { 88 return wakeref_count & INTEL_RPM_RAW_WAKEREF_MASK; 89 } 90 91 static inline int 92 intel_rpm_wakelock_count(int wakeref_count) 93 { 94 return wakeref_count >> INTEL_RPM_WAKELOCK_SHIFT; 95 } 96 97 static inline void 98 assert_rpm_device_not_suspended(struct intel_runtime_pm *rpm) 99 { 100 WARN_ONCE(rpm->suspended, 101 "Device suspended during HW access\n"); 102 } 103 104 static inline void 105 __assert_rpm_raw_wakeref_held(struct intel_runtime_pm *rpm, int wakeref_count) 106 { 107 assert_rpm_device_not_suspended(rpm); 108 WARN_ONCE(!intel_rpm_raw_wakeref_count(wakeref_count), 109 "RPM raw-wakeref not held\n"); 110 } 111 112 static inline void 113 __assert_rpm_wakelock_held(struct intel_runtime_pm *rpm, int wakeref_count) 114 { 115 __assert_rpm_raw_wakeref_held(rpm, wakeref_count); 116 WARN_ONCE(!intel_rpm_wakelock_count(wakeref_count), 117 "RPM wakelock ref not held during HW access\n"); 118 } 119 120 static inline void 121 assert_rpm_raw_wakeref_held(struct intel_runtime_pm *rpm) 122 { 123 __assert_rpm_raw_wakeref_held(rpm, atomic_read(&rpm->wakeref_count)); 124 } 125 126 static inline void 127 assert_rpm_wakelock_held(struct intel_runtime_pm *rpm) 128 { 129 __assert_rpm_wakelock_held(rpm, atomic_read(&rpm->wakeref_count)); 130 } 131 132 /** 133 * disable_rpm_wakeref_asserts - disable the RPM assert checks 134 * @rpm: the intel_runtime_pm structure 135 * 136 * This function disable asserts that check if we hold an RPM wakelock 137 * reference, while keeping the device-not-suspended checks still enabled. 138 * It's meant to be used only in special circumstances where our rule about 139 * the wakelock refcount wrt. the device power state doesn't hold. According 140 * to this rule at any point where we access the HW or want to keep the HW in 141 * an active state we must hold an RPM wakelock reference acquired via one of 142 * the intel_runtime_pm_get() helpers. Currently there are a few special spots 143 * where this rule doesn't hold: the IRQ and suspend/resume handlers, the 144 * forcewake release timer, and the GPU RPS and hangcheck works. All other 145 * users should avoid using this function. 146 * 147 * Any calls to this function must have a symmetric call to 148 * enable_rpm_wakeref_asserts(). 149 */ 150 static inline void 151 disable_rpm_wakeref_asserts(struct intel_runtime_pm *rpm) 152 { 153 atomic_add(INTEL_RPM_WAKELOCK_BIAS + 1, 154 &rpm->wakeref_count); 155 } 156 157 /** 158 * enable_rpm_wakeref_asserts - re-enable the RPM assert checks 159 * @rpm: the intel_runtime_pm structure 160 * 161 * This function re-enables the RPM assert checks after disabling them with 162 * disable_rpm_wakeref_asserts. It's meant to be used only in special 163 * circumstances otherwise its use should be avoided. 164 * 165 * Any calls to this function must have a symmetric call to 166 * disable_rpm_wakeref_asserts(). 167 */ 168 static inline void 169 enable_rpm_wakeref_asserts(struct intel_runtime_pm *rpm) 170 { 171 atomic_sub(INTEL_RPM_WAKELOCK_BIAS + 1, 172 &rpm->wakeref_count); 173 } 174 175 void intel_runtime_pm_init_early(struct intel_runtime_pm *rpm); 176 void intel_runtime_pm_enable(struct intel_runtime_pm *rpm); 177 void intel_runtime_pm_disable(struct intel_runtime_pm *rpm); 178 void intel_runtime_pm_driver_release(struct intel_runtime_pm *rpm); 179 180 intel_wakeref_t intel_runtime_pm_get(struct intel_runtime_pm *rpm); 181 intel_wakeref_t intel_runtime_pm_get_if_in_use(struct intel_runtime_pm *rpm); 182 intel_wakeref_t intel_runtime_pm_get_noresume(struct intel_runtime_pm *rpm); 183 intel_wakeref_t intel_runtime_pm_get_raw(struct intel_runtime_pm *rpm); 184 185 #define with_intel_runtime_pm(rpm, wf) \ 186 for ((wf) = intel_runtime_pm_get(rpm); (wf); \ 187 intel_runtime_pm_put((rpm), (wf)), (wf) = 0) 188 189 #define with_intel_runtime_pm_if_in_use(rpm, wf) \ 190 for ((wf) = intel_runtime_pm_get_if_in_use(rpm); (wf); \ 191 intel_runtime_pm_put((rpm), (wf)), (wf) = 0) 192 193 void intel_runtime_pm_put_unchecked(struct intel_runtime_pm *rpm); 194 #if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM) 195 void intel_runtime_pm_put(struct intel_runtime_pm *rpm, intel_wakeref_t wref); 196 #else 197 static inline void 198 intel_runtime_pm_put(struct intel_runtime_pm *rpm, intel_wakeref_t wref) 199 { 200 intel_runtime_pm_put_unchecked(rpm); 201 } 202 #endif 203 void intel_runtime_pm_put_raw(struct intel_runtime_pm *rpm, intel_wakeref_t wref); 204 205 #if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM) 206 void print_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm, 207 struct drm_printer *p); 208 #else 209 static inline void print_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm, 210 struct drm_printer *p) 211 { 212 } 213 #endif 214 215 #endif /* __INTEL_RUNTIME_PM_H__ */ 216
Indexes created Sun Sep 21 20:09:37 GMT 2025