+static void ironlake_disable_rc6(struct drm_device *dev)
+{
+ struct drm_i915_private *dev_priv = dev->dev_private;
+
+ /* Wake the GPU, prevent RC6, then restore RSTDBYCTL */
+ I915_WRITE(RSTDBYCTL, I915_READ(RSTDBYCTL) | RCX_SW_EXIT);
+ wait_for(((I915_READ(RSTDBYCTL) & RSX_STATUS_MASK) == RSX_STATUS_ON),
+ 10);
+ POSTING_READ(CCID);
+ I915_WRITE(PWRCTXA, 0);
+ POSTING_READ(PWRCTXA);
+ I915_WRITE(RSTDBYCTL, I915_READ(RSTDBYCTL) & ~RCX_SW_EXIT);
+ POSTING_READ(RSTDBYCTL);
+ i915_gem_object_unpin(dev_priv->renderctx);
+ drm_gem_object_unreference(&dev_priv->renderctx->base);
+ dev_priv->renderctx = NULL;
+ i915_gem_object_unpin(dev_priv->pwrctx);
+ drm_gem_object_unreference(&dev_priv->pwrctx->base);
+ dev_priv->pwrctx = NULL;
+}
+
+void ironlake_enable_rc6(struct drm_device *dev)
+{
+ struct drm_i915_private *dev_priv = dev->dev_private;
+ int ret;
+
+ /*
+ * GPU can automatically power down the render unit if given a page
+ * to save state.
+ */
+ ret = BEGIN_LP_RING(6);
+ if (ret) {
+ ironlake_disable_rc6(dev);
+ return;
+ }
+ OUT_RING(MI_SUSPEND_FLUSH | MI_SUSPEND_FLUSH_EN);
+ OUT_RING(MI_SET_CONTEXT);
+ OUT_RING(dev_priv->renderctx->gtt_offset |
+ MI_MM_SPACE_GTT |
+ MI_SAVE_EXT_STATE_EN |
+ MI_RESTORE_EXT_STATE_EN |
+ MI_RESTORE_INHIBIT);
+ OUT_RING(MI_SUSPEND_FLUSH);
+ OUT_RING(MI_NOOP);
+ OUT_RING(MI_FLUSH);
+ ADVANCE_LP_RING();
+
+ I915_WRITE(PWRCTXA, dev_priv->pwrctx->gtt_offset | PWRCTX_EN);
+ I915_WRITE(RSTDBYCTL, I915_READ(RSTDBYCTL) & ~RCX_SW_EXIT);
+}
+