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1/* SPDX-License-Identifier: MIT */2/*3 * Copyright © 2019 Intel Corporation4 */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 14struct device;15struct drm_i915_private;16struct drm_printer;17 18/*19 * This struct helps tracking the state needed for runtime PM, which puts the20 * device in PCI D3 state. Notice that when this happens, nothing on the21 * graphics device works, even register access, so we don't get interrupts nor22 * anything else.23 *24 * Every piece of our code that needs to actually touch the hardware needs to25 * either call intel_runtime_pm_get or call intel_display_power_get with the26 * appropriate power domain.27 *28 * Our driver uses the autosuspend delay feature, which means we'll only really29 * suspend if we stay with zero refcount for a certain amount of time. The30 * default value is currently very conservative (see intel_runtime_pm_enable), but31 * 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 and34 * goes back to false exactly before we reenable the IRQs. We use this variable35 * to check if someone is trying to enable/disable IRQs while they're supposed36 * to be disabled. This shouldn't happen and we'll print some error messages in37 * case it happens.38 *39 * For more, read the Documentation/power/runtime_pm.rst.40 */41struct intel_runtime_pm {42 atomic_t wakeref_count;43 struct device *kdev; /* points to i915->drm.dev */44 bool available;45 bool irqs_enabled;46 bool no_wakeref_tracking;47 48 /*49 * Protects access to lmem usefault list.50 * It is required, if we are outside of the runtime suspend path,51 * access to @lmem_userfault_list requires always first grabbing the52 * runtime pm, to ensure we can't race against runtime suspend.53 * Once we have that we also need to grab @lmem_userfault_lock,54 * at which point we have exclusive access.55 * The runtime suspend path is special since it doesn't really hold any locks,56 * but instead has exclusive access by virtue of all other accesses requiring57 * holding the runtime pm wakeref.58 */59 spinlock_t lmem_userfault_lock;60 61 /*62 * Keep list of userfaulted gem obj, which require to release their63 * mmap mappings at runtime suspend path.64 */65 struct list_head lmem_userfault_list;66 67 /* Manual runtime pm autosuspend delay for user GGTT/lmem mmaps */68 struct intel_wakeref_auto userfault_wakeref;69 70#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM)71 /*72 * To aide detection of wakeref leaks and general misuse, we73 * track all wakeref holders. With manual markup (i.e. returning74 * a cookie to each rpm_get caller which they then supply to their75 * paired rpm_put) we can remove corresponding pairs of and keep76 * the array trimmed to active wakerefs.77 */78 struct ref_tracker_dir debug;79#endif80};81 82#define BITS_PER_WAKEREF \83 BITS_PER_TYPE(typeof_member(struct intel_runtime_pm, wakeref_count))84#define INTEL_RPM_WAKELOCK_SHIFT (BITS_PER_WAKEREF / 2)85#define INTEL_RPM_WAKELOCK_BIAS (1 << INTEL_RPM_WAKELOCK_SHIFT)86#define INTEL_RPM_RAW_WAKEREF_MASK (INTEL_RPM_WAKELOCK_BIAS - 1)87 88static inline int89intel_rpm_raw_wakeref_count(int wakeref_count)90{91 return wakeref_count & INTEL_RPM_RAW_WAKEREF_MASK;92}93 94static inline int95intel_rpm_wakelock_count(int wakeref_count)96{97 return wakeref_count >> INTEL_RPM_WAKELOCK_SHIFT;98}99 100static inline void101assert_rpm_device_not_suspended(struct intel_runtime_pm *rpm)102{103 WARN_ONCE(pm_runtime_suspended(rpm->kdev),104 "Device suspended during HW access\n");105}106 107static inline void108__assert_rpm_raw_wakeref_held(struct intel_runtime_pm *rpm, int wakeref_count)109{110 assert_rpm_device_not_suspended(rpm);111 WARN_ONCE(!intel_rpm_raw_wakeref_count(wakeref_count),112 "RPM raw-wakeref not held\n");113}114 115static inline void116__assert_rpm_wakelock_held(struct intel_runtime_pm *rpm, int wakeref_count)117{118 __assert_rpm_raw_wakeref_held(rpm, wakeref_count);119 WARN_ONCE(!intel_rpm_wakelock_count(wakeref_count),120 "RPM wakelock ref not held during HW access\n");121}122 123static inline void124assert_rpm_raw_wakeref_held(struct intel_runtime_pm *rpm)125{126 __assert_rpm_raw_wakeref_held(rpm, atomic_read(&rpm->wakeref_count));127}128 129static inline void130assert_rpm_wakelock_held(struct intel_runtime_pm *rpm)131{132 __assert_rpm_wakelock_held(rpm, atomic_read(&rpm->wakeref_count));133}134 135/**136 * disable_rpm_wakeref_asserts - disable the RPM assert checks137 * @rpm: the intel_runtime_pm structure138 *139 * This function disable asserts that check if we hold an RPM wakelock140 * reference, while keeping the device-not-suspended checks still enabled.141 * It's meant to be used only in special circumstances where our rule about142 * the wakelock refcount wrt. the device power state doesn't hold. According143 * to this rule at any point where we access the HW or want to keep the HW in144 * an active state we must hold an RPM wakelock reference acquired via one of145 * the intel_runtime_pm_get() helpers. Currently there are a few special spots146 * where this rule doesn't hold: the IRQ and suspend/resume handlers, the147 * forcewake release timer, and the GPU RPS and hangcheck works. All other148 * users should avoid using this function.149 *150 * Any calls to this function must have a symmetric call to151 * enable_rpm_wakeref_asserts().152 */153static inline void154disable_rpm_wakeref_asserts(struct intel_runtime_pm *rpm)155{156 atomic_add(INTEL_RPM_WAKELOCK_BIAS + 1,157 &rpm->wakeref_count);158}159 160/**161 * enable_rpm_wakeref_asserts - re-enable the RPM assert checks162 * @rpm: the intel_runtime_pm structure163 *164 * This function re-enables the RPM assert checks after disabling them with165 * disable_rpm_wakeref_asserts. It's meant to be used only in special166 * circumstances otherwise its use should be avoided.167 *168 * Any calls to this function must have a symmetric call to169 * disable_rpm_wakeref_asserts().170 */171static inline void172enable_rpm_wakeref_asserts(struct intel_runtime_pm *rpm)173{174 atomic_sub(INTEL_RPM_WAKELOCK_BIAS + 1,175 &rpm->wakeref_count);176}177 178void intel_runtime_pm_init_early(struct intel_runtime_pm *rpm);179void intel_runtime_pm_enable(struct intel_runtime_pm *rpm);180void intel_runtime_pm_disable(struct intel_runtime_pm *rpm);181void intel_runtime_pm_driver_release(struct intel_runtime_pm *rpm);182void intel_runtime_pm_driver_last_release(struct intel_runtime_pm *rpm);183 184intel_wakeref_t intel_runtime_pm_get(struct intel_runtime_pm *rpm);185intel_wakeref_t intel_runtime_pm_get_if_in_use(struct intel_runtime_pm *rpm);186intel_wakeref_t intel_runtime_pm_get_if_active(struct intel_runtime_pm *rpm);187intel_wakeref_t intel_runtime_pm_get_noresume(struct intel_runtime_pm *rpm);188intel_wakeref_t intel_runtime_pm_get_raw(struct intel_runtime_pm *rpm);189 190#define with_intel_runtime_pm(rpm, wf) \191 for ((wf) = intel_runtime_pm_get(rpm); (wf); \192 intel_runtime_pm_put((rpm), (wf)), (wf) = 0)193 194#define with_intel_runtime_pm_if_in_use(rpm, wf) \195 for ((wf) = intel_runtime_pm_get_if_in_use(rpm); (wf); \196 intel_runtime_pm_put((rpm), (wf)), (wf) = 0)197 198#define with_intel_runtime_pm_if_active(rpm, wf) \199 for ((wf) = intel_runtime_pm_get_if_active(rpm); (wf); \200 intel_runtime_pm_put((rpm), (wf)), (wf) = 0)201 202void intel_runtime_pm_put_unchecked(struct intel_runtime_pm *rpm);203#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM)204void intel_runtime_pm_put(struct intel_runtime_pm *rpm, intel_wakeref_t wref);205#else206static inline void207intel_runtime_pm_put(struct intel_runtime_pm *rpm, intel_wakeref_t wref)208{209 intel_runtime_pm_put_unchecked(rpm);210}211#endif212void intel_runtime_pm_put_raw(struct intel_runtime_pm *rpm, intel_wakeref_t wref);213 214#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM)215void print_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm,216 struct drm_printer *p);217#else218static inline void print_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm,219 struct drm_printer *p)220{221}222#endif223 224#endif /* __INTEL_RUNTIME_PM_H__ */225