#define SPRN_MCSRR0 0x23a /* Machine Check Save and Restore Register 0 */
#define SPRN_MCSRR1 0x23b /* Machine Check Save and Restore Register 1 */
#define SPRN_BUCSR 0x3f5 /* Branch Control and Status Register */
+#define BUCSR_STAC_EN 0x01000000 /* Segment target addr cache enable */
+#define BUCSR_LS_EN 0x00400000 /* Link stack enable */
#define BUCSR_BBFI 0x00000200 /* Branch buffer flash invalidate */
#define BUCSR_BPEN 0x00000001 /* Branch prediction enable */
-#define BUCSR_ENABLE (BUCSR_BBFI|BUCSR_BPEN)
+#define BUCSR_ENABLE (BUCSR_STAC_EN|BUCSR_LS_EN|BUCSR_BBFI|BUCSR_BPEN)
#define SPRN_BBEAR 0x201 /* Branch Buffer Entry Address Register */
#define SPRN_BBTAR 0x202 /* Branch Buffer Target Address Register */
#define SPRN_PID1 0x279 /* Process ID Register 1 */