drm/i915: Use existing function instead of open-coding fence reg clear.

This is once less place to miss a new INTEL_INFO(dev)->gen update now.
Signed-off-by: NEric Anholt <eric@anholt.net>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NKeith Packard <keithp@keithp.com>

drivers/gpu/drm/i915/i915_gem.c

@@ -3856,25 +3856,10 @@ i915_gem_load(struct drm_device *dev)
 		dev_priv->num_fence_regs = 8;
 
 	/* Initialize fence registers to zero */
-	switch (INTEL_INFO(dev)->gen) {
-	case 6:
-		for (i = 0; i < 16; i++)
-			I915_WRITE64(FENCE_REG_SANDYBRIDGE_0 + (i * 8), 0);
-		break;
-	case 5:
-	case 4:
-		for (i = 0; i < 16; i++)
-			I915_WRITE64(FENCE_REG_965_0 + (i * 8), 0);
-		break;
-	case 3:
-		if (IS_I945G(dev) || IS_I945GM(dev) || IS_G33(dev))
-			for (i = 0; i < 8; i++)
-				I915_WRITE(FENCE_REG_945_8 + (i * 4), 0);
-	case 2:
-		for (i = 0; i < 8; i++)
-			I915_WRITE(FENCE_REG_830_0 + (i * 4), 0);
-		break;
+	for (i = 0; i < dev_priv->num_fence_regs; i++) {
+		i915_gem_clear_fence_reg(dev, &dev_priv->fence_regs[i]);
 	}
+
 	i915_gem_detect_bit_6_swizzle(dev);
 	init_waitqueue_head(&dev_priv->pending_flip_queue);