path: root/arch/s390/kernel/base.S
diff options
authorMichael Holzheu <holzheu@linux.vnet.ibm.com>2012-05-21 11:30:30 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2012-05-23 17:06:51 +0200
commitfa7c0043425624ed65b94a6fabe750c7b0af8719 (patch)
tree8e21c28d65b56a0bd22af1b9a196083233341b3c /arch/s390/kernel/base.S
parenta9fbf1a53836d4105f95df947ac00e22311dff33 (diff)
s390/kdump: Use real mode for PSW restart and kexec
Currently the PSW restart handler and kexec are executed in real mode with DAT=off. For kexec/kdump the function setup_regs() is called that uses the per-cpu variable "crash_notes". Because there are situations when the per-cpu implementation uses vmalloc memory, calling setup_regs() in real mode can cause a program check interrupt. To fix that problem this patch changes the following: * Ensure that diag308_reset() does not change PSW bits to real mode * Enable DAT in __do_restart() after we switched to an online CPU * Enable DAT in __machine_kexec() after we switched to the IPL CPU * Call setup_regs() before we switch to real mode and call purgatory Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/kernel/base.S')
1 files changed, 12 insertions, 0 deletions
diff --git a/arch/s390/kernel/base.S b/arch/s390/kernel/base.S
index 3aa4d00aaf50..c880ff72db44 100644
--- a/arch/s390/kernel/base.S
+++ b/arch/s390/kernel/base.S
@@ -88,6 +88,9 @@ ENTRY(diag308_reset)
stctg %c0,%c15,0(%r4)
larl %r4,.Lfpctl # Floating point control register
stfpc 0(%r4)
+ larl %r4,.Lcontinue_psw # Save PSW flags
+ epsw %r2,%r3
+ stm %r2,%r3,0(%r4)
larl %r4,.Lrestart_psw # Setup restart PSW at absolute 0
lghi %r3,0
lg %r4,0(%r4) # Save PSW
@@ -103,11 +106,20 @@ ENTRY(diag308_reset)
lctlg %c0,%c15,0(%r4)
larl %r4,.Lfpctl # Restore floating point ctl register
lfpc 0(%r4)
+ larl %r4,.Lcontinue_psw # Restore PSW flags
+ lpswe 0(%r4)
br %r14
.align 16
.long 0x00080000,0x80000000 + .Lrestart_part2
+ .section .data..nosave,"aw",@progbits
+.align 8
+ .quad 0,.Lcontinue
+ .previous
.section .bss
.align 8