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 15 struct device; 16 struct drm_i915_private; 17 struct drm_printer; 18 19 enum 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 */ 48 struct 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 #if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM) 57 /* 58 * To aide detection of wakeref leaks and general misuse, we 59 * track all wakeref holders. With manual markup (i.e. returning 60 * a cookie to each rpm_get caller which they then supply to their 61 * paired rpm_put) we can remove corresponding pairs of and keep 62 * the array trimmed to active wakerefs. 63 */ 64 struct intel_runtime_pm_debug { 65 spinlock_t lock; 66 67 depot_stack_handle_t last_acquire; 68 depot_stack_handle_t last_release; 69 70 depot_stack_handle_t *owners; 71 unsigned long count; 72 } debug; 73 #endif 74 }; 75 76 #define BITS_PER_WAKEREF \ 77 BITS_PER_TYPE(struct_member(struct intel_runtime_pm, wakeref_count)) 78 #define INTEL_RPM_WAKELOCK_SHIFT (BITS_PER_WAKEREF / 2) 79 #define INTEL_RPM_WAKELOCK_BIAS (1 << INTEL_RPM_WAKELOCK_SHIFT) 80 #define INTEL_RPM_RAW_WAKEREF_MASK (INTEL_RPM_WAKELOCK_BIAS - 1) 81 82 static inline int 83 intel_rpm_raw_wakeref_count(int wakeref_count) 84 { 85 return wakeref_count & INTEL_RPM_RAW_WAKEREF_MASK; 86 } 87 88 static inline int 89 intel_rpm_wakelock_count(int wakeref_count) 90 { 91 return wakeref_count >> INTEL_RPM_WAKELOCK_SHIFT; 92 } 93 94 static inline void 95 assert_rpm_device_not_suspended(struct intel_runtime_pm *rpm) 96 { 97 WARN_ONCE(rpm->suspended, 98 "Device suspended during HW access\n"); 99 } 100 101 static inline void 102 __assert_rpm_raw_wakeref_held(struct intel_runtime_pm *rpm, int wakeref_count) 103 { 104 assert_rpm_device_not_suspended(rpm); 105 WARN_ONCE(!intel_rpm_raw_wakeref_count(wakeref_count), 106 "RPM raw-wakeref not held\n"); 107 } 108 109 static inline void 110 __assert_rpm_wakelock_held(struct intel_runtime_pm *rpm, int wakeref_count) 111 { 112 __assert_rpm_raw_wakeref_held(rpm, wakeref_count); 113 WARN_ONCE(!intel_rpm_wakelock_count(wakeref_count), 114 "RPM wakelock ref not held during HW access\n"); 115 } 116 117 static inline void 118 assert_rpm_raw_wakeref_held(struct intel_runtime_pm *rpm) 119 { 120 __assert_rpm_raw_wakeref_held(rpm, atomic_read(&rpm->wakeref_count)); 121 } 122 123 static inline void 124 assert_rpm_wakelock_held(struct intel_runtime_pm *rpm) 125 { 126 __assert_rpm_wakelock_held(rpm, atomic_read(&rpm->wakeref_count)); 127 } 128 129 /** 130 * disable_rpm_wakeref_asserts - disable the RPM assert checks 131 * @rpm: the intel_runtime_pm structure 132 * 133 * This function disable asserts that check if we hold an RPM wakelock 134 * reference, while keeping the device-not-suspended checks still enabled. 135 * It's meant to be used only in special circumstances where our rule about 136 * the wakelock refcount wrt. the device power state doesn't hold. According 137 * to this rule at any point where we access the HW or want to keep the HW in 138 * an active state we must hold an RPM wakelock reference acquired via one of 139 * the intel_runtime_pm_get() helpers. Currently there are a few special spots 140 * where this rule doesn't hold: the IRQ and suspend/resume handlers, the 141 * forcewake release timer, and the GPU RPS and hangcheck works. All other 142 * users should avoid using this function. 143 * 144 * Any calls to this function must have a symmetric call to 145 * enable_rpm_wakeref_asserts(). 146 */ 147 static inline void 148 disable_rpm_wakeref_asserts(struct intel_runtime_pm *rpm) 149 { 150 atomic_add(INTEL_RPM_WAKELOCK_BIAS + 1, 151 &rpm->wakeref_count); 152 } 153 154 /** 155 * enable_rpm_wakeref_asserts - re-enable the RPM assert checks 156 * @rpm: the intel_runtime_pm structure 157 * 158 * This function re-enables the RPM assert checks after disabling them with 159 * disable_rpm_wakeref_asserts. It's meant to be used only in special 160 * circumstances otherwise its use should be avoided. 161 * 162 * Any calls to this function must have a symmetric call to 163 * disable_rpm_wakeref_asserts(). 164 */ 165 static inline void 166 enable_rpm_wakeref_asserts(struct intel_runtime_pm *rpm) 167 { 168 atomic_sub(INTEL_RPM_WAKELOCK_BIAS + 1, 169 &rpm->wakeref_count); 170 } 171 172 void intel_runtime_pm_init_early(struct intel_runtime_pm *rpm); 173 void intel_runtime_pm_enable(struct intel_runtime_pm *rpm); 174 void intel_runtime_pm_disable(struct intel_runtime_pm *rpm); 175 void intel_runtime_pm_driver_release(struct intel_runtime_pm *rpm); 176 177 intel_wakeref_t intel_runtime_pm_get(struct intel_runtime_pm *rpm); 178 intel_wakeref_t intel_runtime_pm_get_if_in_use(struct intel_runtime_pm *rpm); 179 intel_wakeref_t intel_runtime_pm_get_if_active(struct intel_runtime_pm *rpm); 180 intel_wakeref_t intel_runtime_pm_get_noresume(struct intel_runtime_pm *rpm); 181 intel_wakeref_t intel_runtime_pm_get_raw(struct intel_runtime_pm *rpm); 182 183 #define with_intel_runtime_pm(rpm, wf) \ 184 for ((wf) = intel_runtime_pm_get(rpm); (wf); \ 185 intel_runtime_pm_put((rpm), (wf)), (wf) = 0) 186 187 #define with_intel_runtime_pm_if_in_use(rpm, wf) \ 188 for ((wf) = intel_runtime_pm_get_if_in_use(rpm); (wf); \ 189 intel_runtime_pm_put((rpm), (wf)), (wf) = 0) 190 191 #define with_intel_runtime_pm_if_active(rpm, wf) \ 192 for ((wf) = intel_runtime_pm_get_if_active(rpm); (wf); \ 193 intel_runtime_pm_put((rpm), (wf)), (wf) = 0) 194 195 void intel_runtime_pm_put_unchecked(struct intel_runtime_pm *rpm); 196 #if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM) 197 void intel_runtime_pm_put(struct intel_runtime_pm *rpm, intel_wakeref_t wref); 198 #else 199 static inline void 200 intel_runtime_pm_put(struct intel_runtime_pm *rpm, intel_wakeref_t wref) 201 { 202 intel_runtime_pm_put_unchecked(rpm); 203 } 204 #endif 205 void intel_runtime_pm_put_raw(struct intel_runtime_pm *rpm, intel_wakeref_t wref); 206 207 #if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM) 208 void print_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm, 209 struct drm_printer *p); 210 #else 211 static inline void print_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm, 212 struct drm_printer *p) 213 { 214 } 215 #endif 216 217 #endif /* __INTEL_RUNTIME_PM_H__ */ 218