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>
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
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:
static void __do_restart(void *ignore)
{
+ __arch_local_irq_stosm(0x04); /* enable DAT */
smp_send_stop();
#ifdef CONFIG_CRASH_DUMP
crash_kexec(NULL);
#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
}
{
struct kimage *image = data;
+ __arch_local_irq_stosm(0x04); /* enable DAT */
pfault_fini();
tracing_off();
debug_locks_off();