diff options
Diffstat (limited to 'drivers/gpu/drm/i915/intel_runtime_pm.h')
| -rw-r--r-- | drivers/gpu/drm/i915/intel_runtime_pm.h | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.h b/drivers/gpu/drm/i915/intel_runtime_pm.h index a7acceb13473..40c6530af5bb 100644 --- a/drivers/gpu/drm/i915/intel_runtime_pm.h +++ b/drivers/gpu/drm/i915/intel_runtime_pm.h @@ -11,6 +11,9 @@ #include "intel_display.h" #include "intel_wakeref.h" +#include "i915_utils.h" + +struct device; struct drm_i915_private; struct drm_printer; @@ -20,6 +23,152 @@ enum i915_drm_suspend_mode { I915_DRM_SUSPEND_HIBERNATE, }; +/* + * This struct helps tracking the state needed for runtime PM, which puts the + * device in PCI D3 state. Notice that when this happens, nothing on the + * graphics device works, even register access, so we don't get interrupts nor + * anything else. + * + * Every piece of our code that needs to actually touch the hardware needs to + * either call intel_runtime_pm_get or call intel_display_power_get with the + * appropriate power domain. + * + * Our driver uses the autosuspend delay feature, which means we'll only really + * suspend if we stay with zero refcount for a certain amount of time. The + * default value is currently very conservative (see intel_runtime_pm_enable), but + * it can be changed with the standard runtime PM files from sysfs. + * + * The irqs_disabled variable becomes true exactly after we disable the IRQs and + * goes back to false exactly before we reenable the IRQs. We use this variable + * to check if someone is trying to enable/disable IRQs while they're supposed + * to be disabled. This shouldn't happen and we'll print some error messages in + * case it happens. + * + * For more, read the Documentation/power/runtime_pm.txt. + */ +struct intel_runtime_pm { + atomic_t wakeref_count; + struct device *kdev; /* points to i915->drm.pdev->dev */ + bool available; + bool suspended; + bool irqs_enabled; + +#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM) + /* + * To aide detection of wakeref leaks and general misuse, we + * track all wakeref holders. With manual markup (i.e. returning + * a cookie to each rpm_get caller which they then supply to their + * paired rpm_put) we can remove corresponding pairs of and keep + * the array trimmed to active wakerefs. + */ + struct intel_runtime_pm_debug { + spinlock_t lock; + + depot_stack_handle_t last_acquire; + depot_stack_handle_t last_release; + + depot_stack_handle_t *owners; + unsigned long count; + } debug; +#endif +}; + +#define BITS_PER_WAKEREF \ + BITS_PER_TYPE(struct_member(struct intel_runtime_pm, wakeref_count)) +#define INTEL_RPM_WAKELOCK_SHIFT (BITS_PER_WAKEREF / 2) +#define INTEL_RPM_WAKELOCK_BIAS (1 << INTEL_RPM_WAKELOCK_SHIFT) +#define INTEL_RPM_RAW_WAKEREF_MASK (INTEL_RPM_WAKELOCK_BIAS - 1) + +static inline int +intel_rpm_raw_wakeref_count(int wakeref_count) +{ + return wakeref_count & INTEL_RPM_RAW_WAKEREF_MASK; +} + +static inline int +intel_rpm_wakelock_count(int wakeref_count) +{ + return wakeref_count >> INTEL_RPM_WAKELOCK_SHIFT; +} + +static inline void +assert_rpm_device_not_suspended(struct intel_runtime_pm *rpm) +{ + WARN_ONCE(rpm->suspended, + "Device suspended during HW access\n"); +} + +static inline void +__assert_rpm_raw_wakeref_held(struct intel_runtime_pm *rpm, int wakeref_count) +{ + assert_rpm_device_not_suspended(rpm); + WARN_ONCE(!intel_rpm_raw_wakeref_count(wakeref_count), + "RPM raw-wakeref not held\n"); +} + +static inline void +__assert_rpm_wakelock_held(struct intel_runtime_pm *rpm, int wakeref_count) +{ + __assert_rpm_raw_wakeref_held(rpm, wakeref_count); + WARN_ONCE(!intel_rpm_wakelock_count(wakeref_count), + "RPM wakelock ref not held during HW access\n"); +} + +static inline void +assert_rpm_raw_wakeref_held(struct intel_runtime_pm *rpm) +{ + __assert_rpm_raw_wakeref_held(rpm, atomic_read(&rpm->wakeref_count)); +} + +static inline void +assert_rpm_wakelock_held(struct intel_runtime_pm *rpm) +{ + __assert_rpm_wakelock_held(rpm, atomic_read(&rpm->wakeref_count)); +} + +/** + * disable_rpm_wakeref_asserts - disable the RPM assert checks + * @rpm: the intel_runtime_pm structure + * + * This function disable asserts that check if we hold an RPM wakelock + * reference, while keeping the device-not-suspended checks still enabled. + * It's meant to be used only in special circumstances where our rule about + * the wakelock refcount wrt. the device power state doesn't hold. According + * to this rule at any point where we access the HW or want to keep the HW in + * an active state we must hold an RPM wakelock reference acquired via one of + * the intel_runtime_pm_get() helpers. Currently there are a few special spots + * where this rule doesn't hold: the IRQ and suspend/resume handlers, the + * forcewake release timer, and the GPU RPS and hangcheck works. All other + * users should avoid using this function. + * + * Any calls to this function must have a symmetric call to + * enable_rpm_wakeref_asserts(). + */ +static inline void +disable_rpm_wakeref_asserts(struct intel_runtime_pm *rpm) +{ + atomic_add(INTEL_RPM_WAKELOCK_BIAS + 1, + &rpm->wakeref_count); +} + +/** + * enable_rpm_wakeref_asserts - re-enable the RPM assert checks + * @rpm: the intel_runtime_pm structure + * + * This function re-enables the RPM assert checks after disabling them with + * disable_rpm_wakeref_asserts. It's meant to be used only in special + * circumstances otherwise its use should be avoided. + * + * Any calls to this function must have a symmetric call to + * disable_rpm_wakeref_asserts(). + */ +static inline void +enable_rpm_wakeref_asserts(struct intel_runtime_pm *rpm) +{ + atomic_sub(INTEL_RPM_WAKELOCK_BIAS + 1, + &rpm->wakeref_count); +} + void intel_runtime_pm_init_early(struct drm_i915_private *dev_priv); void intel_runtime_pm_enable(struct drm_i915_private *dev_priv); void intel_runtime_pm_disable(struct drm_i915_private *dev_priv); |