diff options
| author | Michael Holzheu <holzheu@linux.vnet.ibm.com> | 2012-05-21 11:30:30 +0200 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2012-05-23 17:06:51 +0200 |
| commit | fa7c0043425624ed65b94a6fabe750c7b0af8719 (patch) | |
| tree | 8e21c28d65b56a0bd22af1b9a196083233341b3c /arch/s390/kernel | |
| parent | a9fbf1a53836d4105f95df947ac00e22311dff33 (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')
| -rw-r--r-- | arch/s390/kernel/base.S | 12 | ||||
| -rw-r--r-- | arch/s390/kernel/ipl.c | 1 | ||||
| -rw-r--r-- | arch/s390/kernel/machine_kexec.c | 3 |
3 files changed, 15 insertions, 1 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) +.Lcontinue: br %r14 .align 16 .Lrestart_psw: .long 0x00080000,0x80000000 + .Lrestart_part2 + .section .data..nosave,"aw",@progbits +.align 8 +.Lcontinue_psw: + .quad 0,.Lcontinue + .previous + .section .bss .align 8 .Lctlregs: diff --git a/arch/s390/kernel/ipl.c b/arch/s390/kernel/ipl.c index 8342e65a140d..dcfdcb3ea163 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); diff --git a/arch/s390/kernel/machine_kexec.c b/arch/s390/kernel/machine_kexec.c index 03d2027d656a..cdacf8f91b2d 100644 --- a/arch/s390/kernel/machine_kexec.c +++ b/arch/s390/kernel/machine_kexec.c @@ -80,8 +80,8 @@ static void __do_machine_kdump(void *image) #ifdef CONFIG_CRASH_DUMP int (*start_kdump)(int) = (void *)((struct kimage *) image)->start; - __load_psw_mask(PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA); setup_regs(); + __load_psw_mask(PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA); start_kdump(1); #endif } @@ -214,6 +214,7 @@ static void __machine_kexec(void *data) { struct kimage *image = data; + __arch_local_irq_stosm(0x04); /* enable DAT */ pfault_fini(); tracing_off(); debug_locks_off(); |