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 17 struct device; 18 struct drm_i915_private; 19 struct drm_printer; 20 21 enum 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 */ 50 struct intel_runtime_pm { 51 atomic_t wakeref_count; 52 struct device *kdev; /* points to i915->drm.pdev->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 83 static inline int 84 intel_rpm_raw_wakeref_count(int wakeref_count) 85 { 86 return wakeref_count & INTEL_RPM_RAW_WAKEREF_MASK; 87 } 88 89 static inline int 90 intel_rpm_wakelock_count(int wakeref_count) 91 { 92 return wakeref_count >> INTEL_RPM_WAKELOCK_SHIFT; 93 } 94 95 static inline void 96 assert_rpm_device_not_suspended(struct intel_runtime_pm *rpm) 97 { 98 WARN_ONCE(rpm->suspended, 99 "Device suspended during HW access\n"); 100 } 101 102 static 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 } 109 110 static 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 } 117 118 static inline void 119 assert_rpm_raw_wakeref_held(struct intel_runtime_pm *rpm) 120 { 121 __assert_rpm_raw_wakeref_held(rpm, atomic_read(&rpm->wakeref_count)); 122 } 123 124 static inline void 125 assert_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 */ 148 static inline void 149 disable_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 */ 166 static inline void 167 enable_rpm_wakeref_asserts(struct intel_runtime_pm *rpm) 168 { 169 atomic_sub(INTEL_RPM_WAKELOCK_BIAS + 1, 170 &rpm->wakeref_count); 171 } 172 173 void intel_runtime_pm_init_early(struct intel_runtime_pm *rpm); 174 void intel_runtime_pm_enable(struct intel_runtime_pm *rpm); 175 void intel_runtime_pm_disable(struct intel_runtime_pm *rpm); 176 void intel_runtime_pm_driver_release(struct intel_runtime_pm *rpm); 177 178 intel_wakeref_t intel_runtime_pm_get(struct intel_runtime_pm *rpm); 179 intel_wakeref_t intel_runtime_pm_get_if_in_use(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 void intel_runtime_pm_put_unchecked(struct intel_runtime_pm *rpm); 192 #if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM) 193 void intel_runtime_pm_put(struct intel_runtime_pm *rpm, intel_wakeref_t wref); 194 #else 195 static inline void 196 intel_runtime_pm_put(struct intel_runtime_pm *rpm, intel_wakeref_t wref) 197 { 198 intel_runtime_pm_put_unchecked(rpm); 199 } 200 #endif 201 void intel_runtime_pm_put_raw(struct intel_runtime_pm *rpm, intel_wakeref_t wref); 202 203 #if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM) 204 void print_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm, 205 struct drm_printer *p); 206 #else 207 static inline void print_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm, 208 struct drm_printer *p) 209 { 210 } 211 #endif 212 213 #endif /* __INTEL_RUNTIME_PM_H__ */ 214