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>

1 files changed, 8 insertions, 4 deletions

diff --git a/arch/s390/kernel/entry64.S b/arch/s390/kernel/entry64.S
index 349b7eeb348a..95e9d93d4f41 100644
--- a/arch/s390/kernel/entry64.S
+++ b/arch/s390/kernel/entry64.S
@@ -412,6 +412,11 @@ ENTRY(pgm_check_handler)
 1:      UPDATE_VTIME %r14,__LC_SYNC_ENTER_TIMER
         LAST_BREAK %r14
         lg      %r15,__LC_KERNEL_STACK
+        lg      %r14,__TI_task(%r12)
+        lghi    %r13,__LC_PGM_TDB
+        tm      __LC_PGM_ILC+2,0x02     # check for transaction abort
+        jz      2f
+        mvc     __THREAD_trap_tdb(256,%r14),0(%r13)
 2:      aghi    %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
         la      %r11,STACK_FRAME_OVERHEAD(%r15)
         stmg    %r0,%r7,__PT_R0(%r11)
@@ -422,13 +427,12 @@ ENTRY(pgm_check_handler)
         stg     %r10,__PT_ARGS(%r11)
         tm      __LC_PGM_ILC+3,0x80     # check for per exception
         jz      0f
-        lg      %r1,__TI_task(%r12)
         tmhh    %r8,0x0001              # kernel per event ?
         jz      pgm_kprobe
         oi      __TI_flags+7(%r12),_TIF_PER_TRAP
-        mvc     __THREAD_per_address(8,%r1),__LC_PER_ADDRESS
-        mvc     __THREAD_per_cause(2,%r1),__LC_PER_CAUSE
-        mvc     __THREAD_per_paid(1,%r1),__LC_PER_PAID
+        mvc     __THREAD_per_address(8,%r14),__LC_PER_ADDRESS
+        mvc     __THREAD_per_cause(2,%r14),__LC_PER_CAUSE
+        mvc     __THREAD_per_paid(1,%r14),__LC_PER_PAID
 0:      REENABLE_IRQS
         xc      __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
         larl    %r1,pgm_check_table