s390/sclp: fix addressing mode clobber

The early mini sclp driver may be called in zArch mode either in
31 or 64 bit addressing mode.
If called in 31 bit addressing mode the new external interrupt psw
however would switch to 64 bit addressing mode. This would cause an
addressing exception within the interrupt handler, since the code
didn't expect the zArch/31 bit addressing mode combination.

Fix this by setting the new psw addressing mode bits so they fit
the current addressing mode.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/arch/s390/kernel/sclp.S b/arch/s390/kernel/sclp.S
index bf053898630de935aa4bcbd875c62a405169384c..b6506ee32a363749c5effc99d81d551b90b9fc3d 100644 (file)
--- a/arch/s390/kernel/sclp.S
+++ b/arch/s390/kernel/sclp.S
@@ -44,6 +44,12 @@ _sclp_wait_int:
 #endif
        mvc     .LoldpswS1-.LbaseS1(16,%r13),0(%r8)
        mvc     0(16,%r8),0(%r9)
+#ifdef CONFIG_64BIT
+       epsw    %r6,%r7                         # set current addressing mode
+       nill    %r6,0x1                         # in new psw (31 or 64 bit mode)
+       nilh    %r7,0x8000
+       stm     %r6,%r7,0(%r8)
+#endif
        lhi     %r6,0x0200                      # cr mask for ext int (cr0.54)
        ltr     %r2,%r2
        jz      .LsetctS1
@@ -87,7 +93,7 @@ _sclp_wait_int:
        .long   0x00080000, 0x80000000+.LwaitS1 # PSW to handle ext int
 #ifdef CONFIG_64BIT
 .LextpswS1_64:
-       .quad   0x0000000180000000, .LwaitS1    # PSW to handle ext int, 64 bit
+       .quad   0, .LwaitS1                     # PSW to handle ext int, 64 bit
 #endif
 .LwaitpswS1:
        .long   0x010a0000, 0x00000000+.LloopS1 # PSW to wait for ext int