[S390] Use alternative user-copy operations for new hardware.

This introduces new user-copy operations which are optimized for
copying more than 256 Bytes on new hardware.

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

1 files changed, 13 insertions, 0 deletions

diff --git a/arch/s390/kernel/head64.S b/arch/s390/kernel/head64.S
index 1ebaa338aa7e..a8bdd96494c7 100644
--- a/arch/s390/kernel/head64.S
+++ b/arch/s390/kernel/head64.S
@@ -250,6 +250,19 @@ startup_continue:
         oi      7(%r12),0x80            # set IDTE flag
 0:
 
+#
+# find out if we have the MVCOS instruction
+#
+        la      %r1,0f-.LPG1(%r13)      # set program check address
+        stg     %r1,__LC_PGM_NEW_PSW+8
+        .short  0xc800                  # mvcos 0(%r0),0(%r0),%r0
+        .short  0x0000
+        .short  0x0000
+0:      tm      0x8f,0x13               # special-operation exception?
+        bno     1f-.LPG1(%r13)          # if yes, MVCOS is present
+        oi      6(%r12),2               # set MVCOS flag
+1:
+
         lpswe .Lentry-.LPG1(13)         # jump to _stext in primary-space,
                                         # virtual and never return ...
         .align 16