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/pm_runtime.h> 10 #include <linux/types.h> 11 12 #include "intel_wakeref.h" 13 14 struct device; 15 struct drm_i915_private; 16 struct drm_printer; 17 18 /* 19 * This struct helps tracking the state needed for runtime PM, which puts the 20 * device in PCI D3 state. Notice that when this happens, nothing on the 21 * graphics device works, even register access, so we don't get interrupts nor 22 * anything else. 23 * 24 * Every piece of our code that needs to actually touch the hardware needs to 25 * either call intel_runtime_pm_get or call intel_display_power_get with the 26 * appropriate power domain. 27 * 28 * Our driver uses the autosuspend delay feature, which means we'll only really 29 * suspend if we stay with zero refcount for a certain amount of time. The 30 * default value is currently very conservative (see intel_runtime_pm_enable), but 31 * it can be changed with the standard runtime PM files from sysfs. 32 * 33 * The irqs_disabled variable becomes true exactly after we disable the IRQs and 34 * goes back to false exactly before we reenable the IRQs. We use this variable 35 * to check if someone is trying to enable/disable IRQs while they're supposed 36 * to be disabled. This shouldn't happen and we'll print some error messages in 37 * case it happens. 38 * 39 * For more, read the Documentation/power/runtime_pm.rst. 40 */ 41 struct intel_runtime_pm { 42 atomic_t wakeref_count; 43 struct device *kdev; /* points to i915->drm.dev */ 44 bool available; 45 bool no_wakeref_tracking; 46 47 /* 48 * Protects access to lmem usefault list. 49 * It is required, if we are outside of the runtime suspend path, 50 * access to @lmem_userfault_list requires always first grabbing the 51 * runtime pm, to ensure we can't race against runtime suspend. 52 * Once we have that we also need to grab @lmem_userfault_lock, 53 * at which point we have exclusive access. 54 * The runtime suspend path is special since it doesn't really hold any locks, 55 * but instead has exclusive access by virtue of all other accesses requiring 56 * holding the runtime pm wakeref. 57 */ 58 spinlock_t lmem_userfault_lock; 59 60 /* 61 * Keep list of userfaulted gem obj, which require to release their 62 * mmap mappings at runtime suspend path. 63 */ 64 struct list_head lmem_userfault_list; 65 66 /* Manual runtime pm autosuspend delay for user GGTT/lmem mmaps */ 67 struct intel_wakeref_auto userfault_wakeref; 68 69 #if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM) 70 /* 71 * To aide detection of wakeref leaks and general misuse, we 72 * track all wakeref holders. With manual markup (i.e. returning 73 * a cookie to each rpm_get caller which they then supply to their 74 * paired rpm_put) we can remove corresponding pairs of and keep 75 * the array trimmed to active wakerefs. 76 */ 77 struct ref_tracker_dir debug; 78 #endif 79 }; 80 81 #define BITS_PER_WAKEREF \ 82 BITS_PER_TYPE(typeof_member(struct intel_runtime_pm, wakeref_count)) 83 #define INTEL_RPM_WAKELOCK_SHIFT (BITS_PER_WAKEREF / 2) 84 #define INTEL_RPM_WAKELOCK_BIAS (1 << INTEL_RPM_WAKELOCK_SHIFT) 85 #define INTEL_RPM_RAW_WAKEREF_MASK (INTEL_RPM_WAKELOCK_BIAS - 1) 86 87 static inline int 88 intel_rpm_raw_wakeref_count(int wakeref_count) 89 { 90 return wakeref_count & INTEL_RPM_RAW_WAKEREF_MASK; 91 } 92 93 static inline int 94 intel_rpm_wakelock_count(int wakeref_count) 95 { 96 return wakeref_count >> INTEL_RPM_WAKELOCK_SHIFT; 97 } 98 99 static inline void 100 assert_rpm_device_not_suspended(struct intel_runtime_pm *rpm) 101 { 102 WARN_ONCE(pm_runtime_suspended(rpm->kdev), 103 "Device suspended during HW access\n"); 104 } 105 106 static inline void 107 __assert_rpm_raw_wakeref_held(struct intel_runtime_pm *rpm, int wakeref_count) 108 { 109 assert_rpm_device_not_suspended(rpm); 110 WARN_ONCE(!intel_rpm_raw_wakeref_count(wakeref_count), 111 "RPM raw-wakeref not held\n"); 112 } 113 114 static inline void 115 __assert_rpm_wakelock_held(struct intel_runtime_pm *rpm, int wakeref_count) 116 { 117 __assert_rpm_raw_wakeref_held(rpm, wakeref_count); 118 WARN_ONCE(!intel_rpm_wakelock_count(wakeref_count), 119 "RPM wakelock ref not held during HW access\n"); 120 } 121 122 static inline void 123 assert_rpm_raw_wakeref_held(struct intel_runtime_pm *rpm) 124 { 125 __assert_rpm_raw_wakeref_held(rpm, atomic_read(&rpm->wakeref_count)); 126 } 127 128 static inline void 129 assert_rpm_wakelock_held(struct intel_runtime_pm *rpm) 130 { 131 __assert_rpm_wakelock_held(rpm, atomic_read(&rpm->wakeref_count)); 132 } 133 134 /** 135 * disable_rpm_wakeref_asserts - disable the RPM assert checks 136 * @rpm: the intel_runtime_pm structure 137 * 138 * This function disable asserts that check if we hold an RPM wakelock 139 * reference, while keeping the device-not-suspended checks still enabled. 140 * It's meant to be used only in special circumstances where our rule about 141 * the wakelock refcount wrt. the device power state doesn't hold. According 142 * to this rule at any point where we access the HW or want to keep the HW in 143 * an active state we must hold an RPM wakelock reference acquired via one of 144 * the intel_runtime_pm_get() helpers. Currently there are a few special spots 145 * where this rule doesn't hold: the IRQ and suspend/resume handlers, the 146 * forcewake release timer, and the GPU RPS and hangcheck works. All other 147 * users should avoid using this function. 148 * 149 * Any calls to this function must have a symmetric call to 150 * enable_rpm_wakeref_asserts(). 151 */ 152 static inline void 153 disable_rpm_wakeref_asserts(struct intel_runtime_pm *rpm) 154 { 155 atomic_add(INTEL_RPM_WAKELOCK_BIAS + 1, 156 &rpm->wakeref_count); 157 } 158 159 /** 160 * enable_rpm_wakeref_asserts - re-enable the RPM assert checks 161 * @rpm: the intel_runtime_pm structure 162 * 163 * This function re-enables the RPM assert checks after disabling them with 164 * disable_rpm_wakeref_asserts. It's meant to be used only in special 165 * circumstances otherwise its use should be avoided. 166 * 167 * Any calls to this function must have a symmetric call to 168 * disable_rpm_wakeref_asserts(). 169 */ 170 static inline void 171 enable_rpm_wakeref_asserts(struct intel_runtime_pm *rpm) 172 { 173 atomic_sub(INTEL_RPM_WAKELOCK_BIAS + 1, 174 &rpm->wakeref_count); 175 } 176 177 void intel_runtime_pm_init_early(struct intel_runtime_pm *rpm); 178 void intel_runtime_pm_enable(struct intel_runtime_pm *rpm); 179 void intel_runtime_pm_disable(struct intel_runtime_pm *rpm); 180 void intel_runtime_pm_driver_release(struct intel_runtime_pm *rpm); 181 void intel_runtime_pm_driver_last_release(struct intel_runtime_pm *rpm); 182 183 intel_wakeref_t intel_runtime_pm_get(struct intel_runtime_pm *rpm); 184 intel_wakeref_t intel_runtime_pm_get_if_in_use(struct intel_runtime_pm *rpm); 185 intel_wakeref_t intel_runtime_pm_get_if_active(struct intel_runtime_pm *rpm); 186 intel_wakeref_t intel_runtime_pm_get_noresume(struct intel_runtime_pm *rpm); 187 intel_wakeref_t intel_runtime_pm_get_raw(struct intel_runtime_pm *rpm); 188 189 #define with_intel_runtime_pm(rpm, wf) \ 190 for ((wf) = intel_runtime_pm_get(rpm); (wf); \ 191 intel_runtime_pm_put((rpm), (wf)), (wf) = NULL) 192 193 #define with_intel_runtime_pm_if_in_use(rpm, wf) \ 194 for ((wf) = intel_runtime_pm_get_if_in_use(rpm); (wf); \ 195 intel_runtime_pm_put((rpm), (wf)), (wf) = NULL) 196 197 #define with_intel_runtime_pm_if_active(rpm, wf) \ 198 for ((wf) = intel_runtime_pm_get_if_active(rpm); (wf); \ 199 intel_runtime_pm_put((rpm), (wf)), (wf) = NULL) 200 201 void intel_runtime_pm_put_unchecked(struct intel_runtime_pm *rpm); 202 #if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM) 203 void intel_runtime_pm_put(struct intel_runtime_pm *rpm, intel_wakeref_t wref); 204 #else 205 static inline void 206 intel_runtime_pm_put(struct intel_runtime_pm *rpm, intel_wakeref_t wref) 207 { 208 intel_runtime_pm_put_unchecked(rpm); 209 } 210 #endif 211 void intel_runtime_pm_put_raw(struct intel_runtime_pm *rpm, intel_wakeref_t wref); 212 213 #if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM) 214 void print_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm, 215 struct drm_printer *p); 216 #else 217 static inline void print_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm, 218 struct drm_printer *p) 219 { 220 } 221 #endif 222 223 #endif /* __INTEL_RUNTIME_PM_H__ */ 224