powerpc/64s: Disallow system reset vs system reset reentrancy
In preparation for using a dedicated stack for system reset interrupts,
prevent a nested system reset from recovering, in order to simplify
code that is called in crash/debug path. This allows a system reset
interrupt to just use the base stack pointer.
Keep an in_nmi nesting counter similarly to the in_mce counter. Consider
the interrrupt non-recoverable if it is taken inside another system
reset.
Interrupt nesting could be allowed similarly to MCE, but system reset
is a special case that's not for normal operation, so simplicity wins
until there is requirement for nested system reset interrupts.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/arch/powerpc/include/asm/paca.h b/arch/powerpc/include/asm/paca.h
index 601e232..b1197c1 100644
--- a/arch/powerpc/include/asm/paca.h
+++ b/arch/powerpc/include/asm/paca.h
@@ -187,12 +187,15 @@ struct paca_struct {
#ifdef CONFIG_PPC_BOOK3S_64
/* Exclusive emergency stack pointer for machine check exception. */
void *mc_emergency_sp;
+
+ u16 in_nmi; /* In nmi handler */
+
/*
* Flag to check whether we are in machine check early handler
* and already using emergency stack.
*/
u16 in_mce;
- u8 hmi_event_available; /* HMI event is available */
+ u8 hmi_event_available; /* HMI event is available */
#endif
/* Stuff for accurate time accounting */