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 55 #if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM) 56 /* 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. 62 */ 63 struct intel_runtime_pm_debug { 64 spinlock_t lock; 65 66 depot_stack_handle_t last_acquire; 67 depot_stack_handle_t last_release; 68 69 depot_stack_handle_t *owners; 70 unsigned long count; 71 } debug; 72 #endif 73 }; 74 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) 80 81 static inline int 82 intel_rpm_raw_wakeref_count(int wakeref_count) 83 { 84 return wakeref_count & INTEL_RPM_RAW_WAKEREF_MASK; 85 } 86 87 static inline int 88 intel_rpm_wakelock_count(int wakeref_count) 89 { 90 return wakeref_count >> INTEL_RPM_WAKELOCK_SHIFT; 91 } 92 93 static inline void 94 assert_rpm_device_not_suspended(struct intel_runtime_pm *rpm) 95 { 96 WARN_ONCE(rpm->suspended, 97 "Device suspended during HW access\n"); 98 } 99 100 static inline void 101 __assert_rpm_raw_wakeref_held(struct intel_runtime_pm *rpm, int wakeref_count) 102 { 103 assert_rpm_device_not_suspended(rpm); 104 WARN_ONCE(!intel_rpm_raw_wakeref_count(wakeref_count), 105 "RPM raw-wakeref not held\n"); 106 } 107 108 static inline void 109 __assert_rpm_wakelock_held(struct intel_runtime_pm *rpm, int wakeref_count) 110 { 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"); 114 } 115 116 static inline void 117 assert_rpm_raw_wakeref_held(struct intel_runtime_pm *rpm) 118 { 119 __assert_rpm_raw_wakeref_held(rpm, atomic_read(&rpm->wakeref_count)); 120 } 121 122 static inline void 123 assert_rpm_wakelock_held(struct intel_runtime_pm *rpm) 124 { 125 __assert_rpm_wakelock_held(rpm, atomic_read(&rpm->wakeref_count)); 126 } 127 128 /** 129 * disable_rpm_wakeref_asserts - disable the RPM assert checks 130 * @rpm: the intel_runtime_pm structure 131 * 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. 142 * 143 * Any calls to this function must have a symmetric call to 144 * enable_rpm_wakeref_asserts(). 145 */ 146 static inline void 147 disable_rpm_wakeref_asserts(struct intel_runtime_pm *rpm) 148 { 149 atomic_add(INTEL_RPM_WAKELOCK_BIAS + 1, 150 &rpm->wakeref_count); 151 } 152 153 /** 154 * enable_rpm_wakeref_asserts - re-enable the RPM assert checks 155 * @rpm: the intel_runtime_pm structure 156 * 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. 160 * 161 * Any calls to this function must have a symmetric call to 162 * disable_rpm_wakeref_asserts(). 163 */ 164 static inline void 165 enable_rpm_wakeref_asserts(struct intel_runtime_pm *rpm) 166 { 167 atomic_sub(INTEL_RPM_WAKELOCK_BIAS + 1, 168 &rpm->wakeref_count); 169 } 170 171 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); 175 176 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); 181 182 #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) 185 186 #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) 189 190 #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) 193 194 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); 197 #else 198 static inline void 199 intel_runtime_pm_put(struct intel_runtime_pm *rpm, intel_wakeref_t wref) 200 { 201 intel_runtime_pm_put_unchecked(rpm); 202 } 203 #endif 204 void intel_runtime_pm_put_raw(struct intel_runtime_pm *rpm, intel_wakeref_t wref); 205 206 #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); 209 #else 210 static inline void print_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm, 211 struct drm_printer *p) 212 { 213 } 214 #endif 215 216 #endif /* __INTEL_RUNTIME_PM_H__ */ 217