drm/i915/bdw: debugfs updates

All the gen8 debugfs stuff I wasn't too lazy to update. We'll need more
later, I am certain.

v2: Fix up the register name in the debugfs output as suggested by
Paulo.

Signed-off-by: Ben Widawsky <ben@bwidawsk.net> (v1)
Reviewed-by: Paulo Zanoni <przanoni@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_debugfs.c

@@ -1623,7 +1623,7 @@ static int i915_swizzle_info(struct seq_file *m, void *data)
 			   I915_READ16(C0DRB3));
 		seq_printf(m, "C1DRB3 = 0x%04x\n",
 			   I915_READ16(C1DRB3));
-	} else if (IS_GEN6(dev) || IS_GEN7(dev)) {
+	} else if (INTEL_INFO(dev)->gen >= 6) {
 		seq_printf(m, "MAD_DIMM_C0 = 0x%08x\n",
 			   I915_READ(MAD_DIMM_C0));
 		seq_printf(m, "MAD_DIMM_C1 = 0x%08x\n",
@@ -1632,8 +1632,12 @@ static int i915_swizzle_info(struct seq_file *m, void *data)
 			   I915_READ(MAD_DIMM_C2));
 		seq_printf(m, "TILECTL = 0x%08x\n",
 			   I915_READ(TILECTL));
-		seq_printf(m, "ARB_MODE = 0x%08x\n",
-			   I915_READ(ARB_MODE));
+		if (IS_GEN8(dev))
+			seq_printf(m, "GAMTARBMODE = 0x%08x\n",
+				   I915_READ(GAMTARBMODE));
+		else
+			seq_printf(m, "ARB_MODE = 0x%08x\n",
+				   I915_READ(ARB_MODE));
 		seq_printf(m, "DISP_ARB_CTL = 0x%08x\n",
 			   I915_READ(DISP_ARB_CTL));
 	}