s390: add support for transactional memory

Allow user-space processes to use transactional execution (TX).
If the TX facility is available user space programs can use
transactions for fine-grained serialization based on the data
objects that are referenced during a transaction. This is
useful for lockless data structures and speculative compiler
optimizations.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/include/asm/processor.h

@@ -76,14 +76,20 @@ struct thread_struct {
 	unsigned long gmap_addr;	/* address of last gmap fault. */
 	struct per_regs per_user;	/* User specified PER registers */
 	struct per_event per_event;	/* Cause of the last PER trap */
+	unsigned long per_flags;	/* Flags to control debug behavior */
         /* pfault_wait is used to block the process on a pfault event */
 	unsigned long pfault_wait;
 	struct list_head list;
 	/* cpu runtime instrumentation */
 	struct runtime_instr_cb *ri_cb;
 	int ri_signum;
+#ifdef CONFIG_64BIT
+	unsigned char trap_tdb[256];	/* Transaction abort diagnose block */
+#endif
 };
 
+#define PER_FLAG_NO_TE		1UL	/* Flag to disable transactions. */
+
 typedef struct thread_struct thread_struct;
 
 /*