+ * - Disabling OA counters on Gen6+ (3 DWords = 12 bytes)
+ * - Ending MI_REPORT_PERF_COUNT on Gen5+, plus associated PIPE_CONTROLs:
+ * - Two sets of PIPE_CONTROLs, which become 4 PIPE_CONTROLs each on SNB,
+ * which are 5 DWords each ==> 2 * 4 * 5 * 4 = 160 bytes
+ * - 3 DWords for MI_REPORT_PERF_COUNT itself on Gen6+. ==> 12 bytes.
+ * On Ironlake, it's 6 DWords, but we have some slack due to the lack of
+ * Sandybridge PIPE_CONTROL madness.
+ * - CC_STATE workaround on HSW (17 * 4 = 68 bytes)
+ * - 10 dwords for initial mi_flush
+ * - 2 dwords for CC state setup
+ * - 5 dwords for the required pipe control at the end
+ * - Restoring L3 configuration: (24 dwords = 96 bytes)
+ * - 2*6 dwords for two PIPE_CONTROL flushes.
+ * - 7 dwords for L3 configuration set-up.
+ * - 5 dwords for L3 atomic set-up (on HSW).