[S390] hibernation: fix lowcore handling

Our swsusp_arch_suspend() backend implementation disables prefixing
by setting the contents of the prefix register to 0.
However afterwards common code functions are called which might
access percpu data structures.
Since the lowcore contains e.g. the percpu base pointer this isn't
a good idea. So fix this by copying the hibernating cpu's lowcore to
absolute address zero.

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

1 files changed, 8 insertions, 5 deletions

diff --git a/arch/s390/power/swsusp_asm64.S b/arch/s390/power/swsusp_asm64.S
index 76d688da32fa..e27bd3164897 100644
--- a/arch/s390/power/swsusp_asm64.S
+++ b/arch/s390/power/swsusp_asm64.S
@@ -40,11 +40,11 @@ swsusp_arch_suspend:
         /* Store prefix register on stack */
         stpx    __SF_EMPTY(%r15)
 
-        /* Setup base register for lowcore (absolute 0) */
-        llgf    %r1,__SF_EMPTY(%r15)
+        /* Save prefix register contents for lowcore */
+        llgf    %r4,__SF_EMPTY(%r15)
 
         /* Get pointer to save area */
-        aghi    %r1,0x1000
+        lghi    %r1,0x1000
 
         /* Store registers */
         mvc     0x318(4,%r1),__SF_EMPTY(%r15)   /* move prefix to lowcore */
@@ -79,8 +79,11 @@ swsusp_arch_suspend:
         xc      __SF_EMPTY(4,%r15),__SF_EMPTY(%r15)
         spx     __SF_EMPTY(%r15)
 
-        /* Setup lowcore */
-        brasl   %r14,setup_lowcore_early
+        lghi    %r2,0
+        lghi    %r3,2*PAGE_SIZE
+        lghi    %r5,2*PAGE_SIZE
+1:      mvcle   %r2,%r4,0
+        jo      1b
 
         /* Save image */
         brasl   %r14,swsusp_save