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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/ipl.c
parenta9fbf1a53836d4105f95df947ac00e22311dff33 (diff)
downloadop-kernel-dev-fa7c0043425624ed65b94a6fabe750c7b0af8719.zip
op-kernel-dev-fa7c0043425624ed65b94a6fabe750c7b0af8719.tar.gz
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/ipl.c')
-rw-r--r--arch/s390/kernel/ipl.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/s390/kernel/ipl.c b/arch/s390/kernel/ipl.c
index 8342e65..dcfdcb3 100644
--- a/arch/s390/kernel/ipl.c
+++ b/arch/s390/kernel/ipl.c
@@ -1750,6 +1750,7 @@ static struct kobj_attribute on_restart_attr =
static void __do_restart(void *ignore)
{
+ __arch_local_irq_stosm(0x04); /* enable DAT */
smp_send_stop();
#ifdef CONFIG_CRASH_DUMP
crash_kexec(NULL);
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