[S390] Save prefix register for dump on panic

The dump tools expect that the saved prefix register points to the
lowcore of the dump cpu. Since we set the prefix register to 0 during
reipl/dump, we have to save the original prefix register. Before we
start the dump program, we copy the original prefix register to the
designated location in the lowcore.

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

1 files changed, 4 insertions, 1 deletions

diff --git a/arch/s390/kernel/reipl64.S b/arch/s390/kernel/reipl64.S
index f18ef260ca23..dbb3eed38865 100644
--- a/arch/s390/kernel/reipl64.S
+++ b/arch/s390/kernel/reipl64.S
@@ -20,7 +20,7 @@ do_reipl_asm:	basr	%r13,0
                 stg     %r0,__LC_GPREGS_SAVE_AREA-0x1000+8(%r1)
                 stctg   %c0,%c15,__LC_CREGS_SAVE_AREA-0x1000(%r1)
                 stam    %a0,%a15,__LC_AREGS_SAVE_AREA-0x1000(%r1)
-                stpx    __LC_PREFIX_SAVE_AREA-0x1000(%r1)
+                mvc     __LC_PREFIX_SAVE_AREA-0x1000(4,%r1),dump_prefix_page-.Lpg0(%r13)
                 stfpc   __LC_FP_CREG_SAVE_AREA-0x1000(%r1)
                 stckc   .Lclkcmp-.Lpg0(%r13)
                 mvc     __LC_CLOCK_COMP_SAVE_AREA-0x1000(8,%r1),.Lclkcmp-.Lpg0(%r13)
@@ -103,3 +103,6 @@ do_reipl_asm:	basr	%r13,0
                 .long   0x00000000,0x00000000
                 .long   0x00000000,0x00000000
                 .long   0x00000000,0x00000000
+        .globl dump_prefix_page
+dump_prefix_page:
+        .long 0x00000000