drm/i915: remap l3 on hw init

If any l3 rows have been previously remapped, we must remap them after
GPU reset/resume too.

v2: Just return (no warn) on remapping init if not IVB (Jesse)
Move the check of schizo userspace to i915_gem_l3_remap (Jesse)

Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index d2eaa00..1c08e09 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -3527,6 +3527,38 @@
 	return 0;
 }
 
+void i915_gem_l3_remap(struct drm_device *dev)
+{
+	drm_i915_private_t *dev_priv = dev->dev_private;
+	u32 misccpctl;
+	int i;
+
+	if (!IS_IVYBRIDGE(dev))
+		return;
+
+	if (!dev_priv->mm.l3_remap_info)
+		return;
+
+	misccpctl = I915_READ(GEN7_MISCCPCTL);
+	I915_WRITE(GEN7_MISCCPCTL, misccpctl & ~GEN7_DOP_CLOCK_GATE_ENABLE);
+	POSTING_READ(GEN7_MISCCPCTL);
+
+	for (i = 0; i < GEN7_L3LOG_SIZE; i += 4) {
+		u32 remap = I915_READ(GEN7_L3LOG_BASE + i);
+		if (remap && remap != dev_priv->mm.l3_remap_info[i/4])
+			DRM_DEBUG("0x%x was already programmed to %x\n",
+				  GEN7_L3LOG_BASE + i, remap);
+		if (remap && !dev_priv->mm.l3_remap_info[i/4])
+			DRM_DEBUG_DRIVER("Clearing remapped register\n");
+		I915_WRITE(GEN7_L3LOG_BASE + i, dev_priv->mm.l3_remap_info[i/4]);
+	}
+
+	/* Make sure all the writes land before disabling dop clock gating */
+	POSTING_READ(GEN7_L3LOG_BASE);
+
+	I915_WRITE(GEN7_MISCCPCTL, misccpctl);
+}
+
 void i915_gem_init_swizzling(struct drm_device *dev)
 {
 	drm_i915_private_t *dev_priv = dev->dev_private;
@@ -3616,6 +3648,8 @@
 	drm_i915_private_t *dev_priv = dev->dev_private;
 	int ret;
 
+	i915_gem_l3_remap(dev);
+
 	i915_gem_init_swizzling(dev);
 
 	ret = intel_init_render_ring_buffer(dev);