drm/i915: add support for checking if we hold an RPM reference

[linux-drm-fsl-dcu.git] / drivers / gpu / drm / i915 / intel_drv.h

diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 9837a2546a63ae9536ebd4239aea01cba2bd3395..eff7d2e7d71b881c6d5eb65a4e14b6c31b23ab7b 100644 (file)
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1442,8 +1442,58 @@ static inline void
 assert_rpm_wakelock_held(struct drm_i915_private *dev_priv)
 {
        assert_rpm_device_not_suspended(dev_priv);
+       WARN_ONCE(!atomic_read(&dev_priv->pm.wakeref_count),
+                 "RPM wakelock ref not held during HW access");
 }
 
+/**
+ * disable_rpm_wakeref_asserts - disable the RPM assert checks
+ * @dev_priv: i915 device instance
+ *
+ * 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 drm_i915_private *dev_priv)
+{
+       atomic_inc(&dev_priv->pm.wakeref_count);
+}
+
+/**
+ * enable_rpm_wakeref_asserts - re-enable the RPM assert checks
+ * @dev_priv: i915 device instance
+ *
+ * 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 drm_i915_private *dev_priv)
+{
+       atomic_dec(&dev_priv->pm.wakeref_count);
+}
+
+/* TODO: convert users of these to rely instead on proper RPM refcounting */
+#define DISABLE_RPM_WAKEREF_ASSERTS(dev_priv)  \
+       disable_rpm_wakeref_asserts(dev_priv)
+
+#define ENABLE_RPM_WAKEREF_ASSERTS(dev_priv)   \
+       enable_rpm_wakeref_asserts(dev_priv)
+
 void intel_runtime_pm_get(struct drm_i915_private *dev_priv);
 void intel_runtime_pm_get_noresume(struct drm_i915_private *dev_priv);
 void intel_runtime_pm_put(struct drm_i915_private *dev_priv);