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 /* 57 * Protects access to lmem usefault list. 58 * It is required, if we are outside of the runtime suspend path, 59 * access to @lmem_userfault_list requires always first grabbing the 60 * runtime pm, to ensure we can't race against runtime suspend. 61 * Once we have that we also need to grab @lmem_userfault_lock, 62 * at which point we have exclusive access. 63 * The runtime suspend path is special since it doesn't really hold any locks, 64 * but instead has exclusive access by virtue of all other accesses requiring 65 * holding the runtime pm wakeref. 66 */ 67 spinlock_t lmem_userfault_lock; 68 69 /* 70 * Keep list of userfaulted gem obj, which require to release their 71 * mmap mappings at runtime suspend path. 72 */ 73 struct list_head lmem_userfault_list; 74 75 /* Manual runtime pm autosuspend delay for user GGTT/lmem mmaps */ 76 struct intel_wakeref_auto userfault_wakeref; 77 78 #if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM) 79 /* 80 * To aide detection of wakeref leaks and general misuse, we 81 * track all wakeref holders. With manual markup (i.e. returning 82 * a cookie to each rpm_get caller which they then supply to their 83 * paired rpm_put) we can remove corresponding pairs of and keep 84 * the array trimmed to active wakerefs. 85 */ 86 struct intel_runtime_pm_debug { 87 spinlock_t lock; 88 89 depot_stack_handle_t last_acquire; 90 depot_stack_handle_t last_release; 91 92 depot_stack_handle_t *owners; 93 unsigned long count; 94 } debug; 95 #endif 96 }; 97 98 #define BITS_PER_WAKEREF \ 99 BITS_PER_TYPE(typeof_member(struct intel_runtime_pm, wakeref_count)) 100 #define INTEL_RPM_WAKELOCK_SHIFT (BITS_PER_WAKEREF / 2) 101 #define INTEL_RPM_WAKELOCK_BIAS (1 << INTEL_RPM_WAKELOCK_SHIFT) 102 #define INTEL_RPM_RAW_WAKEREF_MASK (INTEL_RPM_WAKELOCK_BIAS - 1) 103 104 static inline int 105 intel_rpm_raw_wakeref_count(int wakeref_count) 106 { 107 return wakeref_count & INTEL_RPM_RAW_WAKEREF_MASK; 108 } 109 110 static inline int 111 intel_rpm_wakelock_count(int wakeref_count) 112 { 113 return wakeref_count >> INTEL_RPM_WAKELOCK_SHIFT; 114 } 115 116 static inline void 117 assert_rpm_device_not_suspended(struct intel_runtime_pm *rpm) 118 { 119 WARN_ONCE(rpm->suspended, 120 "Device suspended during HW access\n"); 121 } 122 123 static inline void 124 __assert_rpm_raw_wakeref_held(struct intel_runtime_pm *rpm, int wakeref_count) 125 { 126 assert_rpm_device_not_suspended(rpm); 127 WARN_ONCE(!intel_rpm_raw_wakeref_count(wakeref_count), 128 "RPM raw-wakeref not held\n"); 129 } 130 131 static inline void 132 __assert_rpm_wakelock_held(struct intel_runtime_pm *rpm, int wakeref_count) 133 { 134 __assert_rpm_raw_wakeref_held(rpm, wakeref_count); 135 WARN_ONCE(!intel_rpm_wakelock_count(wakeref_count), 136 "RPM wakelock ref not held during HW access\n"); 137 } 138 139 static inline void 140 assert_rpm_raw_wakeref_held(struct intel_runtime_pm *rpm) 141 { 142 __assert_rpm_raw_wakeref_held(rpm, atomic_read(&rpm->wakeref_count)); 143 } 144 145 static inline void 146 assert_rpm_wakelock_held(struct intel_runtime_pm *rpm) 147 { 148 __assert_rpm_wakelock_held(rpm, atomic_read(&rpm->wakeref_count)); 149 } 150 151 /** 152 * disable_rpm_wakeref_asserts - disable the RPM assert checks 153 * @rpm: the intel_runtime_pm structure 154 * 155 * This function disable asserts that check if we hold an RPM wakelock 156 * reference, while keeping the device-not-suspended checks still enabled. 157 * It's meant to be used only in special circumstances where our rule about 158 * the wakelock refcount wrt. the device power state doesn't hold. According 159 * to this rule at any point where we access the HW or want to keep the HW in 160 * an active state we must hold an RPM wakelock reference acquired via one of 161 * the intel_runtime_pm_get() helpers. Currently there are a few special spots 162 * where this rule doesn't hold: the IRQ and suspend/resume handlers, the 163 * forcewake release timer, and the GPU RPS and hangcheck works. All other 164 * users should avoid using this function. 165 * 166 * Any calls to this function must have a symmetric call to 167 * enable_rpm_wakeref_asserts(). 168 */ 169 static inline void 170 disable_rpm_wakeref_asserts(struct intel_runtime_pm *rpm) 171 { 172 atomic_add(INTEL_RPM_WAKELOCK_BIAS + 1, 173 &rpm->wakeref_count); 174 } 175 176 /** 177 * enable_rpm_wakeref_asserts - re-enable the RPM assert checks 178 * @rpm: the intel_runtime_pm structure 179 * 180 * This function re-enables the RPM assert checks after disabling them with 181 * disable_rpm_wakeref_asserts. It's meant to be used only in special 182 * circumstances otherwise its use should be avoided. 183 * 184 * Any calls to this function must have a symmetric call to 185 * disable_rpm_wakeref_asserts(). 186 */ 187 static inline void 188 enable_rpm_wakeref_asserts(struct intel_runtime_pm *rpm) 189 { 190 atomic_sub(INTEL_RPM_WAKELOCK_BIAS + 1, 191 &rpm->wakeref_count); 192 } 193 194 void intel_runtime_pm_init_early(struct intel_runtime_pm *rpm); 195 void intel_runtime_pm_enable(struct intel_runtime_pm *rpm); 196 void intel_runtime_pm_disable(struct intel_runtime_pm *rpm); 197 void intel_runtime_pm_driver_release(struct intel_runtime_pm *rpm); 198 199 intel_wakeref_t intel_runtime_pm_get(struct intel_runtime_pm *rpm); 200 intel_wakeref_t intel_runtime_pm_get_if_in_use(struct intel_runtime_pm *rpm); 201 intel_wakeref_t intel_runtime_pm_get_if_active(struct intel_runtime_pm *rpm); 202 intel_wakeref_t intel_runtime_pm_get_noresume(struct intel_runtime_pm *rpm); 203 intel_wakeref_t intel_runtime_pm_get_raw(struct intel_runtime_pm *rpm); 204 205 #define with_intel_runtime_pm(rpm, wf) \ 206 for ((wf) = intel_runtime_pm_get(rpm); (wf); \ 207 intel_runtime_pm_put((rpm), (wf)), (wf) = 0) 208 209 #define with_intel_runtime_pm_if_in_use(rpm, wf) \ 210 for ((wf) = intel_runtime_pm_get_if_in_use(rpm); (wf); \ 211 intel_runtime_pm_put((rpm), (wf)), (wf) = 0) 212 213 #define with_intel_runtime_pm_if_active(rpm, wf) \ 214 for ((wf) = intel_runtime_pm_get_if_active(rpm); (wf); \ 215 intel_runtime_pm_put((rpm), (wf)), (wf) = 0) 216 217 void intel_runtime_pm_put_unchecked(struct intel_runtime_pm *rpm); 218 #if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM) 219 void intel_runtime_pm_put(struct intel_runtime_pm *rpm, intel_wakeref_t wref); 220 #else 221 static inline void 222 intel_runtime_pm_put(struct intel_runtime_pm *rpm, intel_wakeref_t wref) 223 { 224 intel_runtime_pm_put_unchecked(rpm); 225 } 226 #endif 227 void intel_runtime_pm_put_raw(struct intel_runtime_pm *rpm, intel_wakeref_t wref); 228 229 #if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM) 230 void print_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm, 231 struct drm_printer *p); 232 #else 233 static inline void print_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm, 234 struct drm_printer *p) 235 { 236 } 237 #endif 238 239 #endif /* __INTEL_RUNTIME_PM_H__ */ 240