From c4f3b52ce7b16824befb16ab3d045c891b08b7db Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Tue, 20 Dec 2016 04:30:05 +1000 Subject: 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 Signed-off-by: Michael Ellerman --- arch/powerpc/include/asm/paca.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'arch/powerpc/include/asm/paca.h') diff --git a/arch/powerpc/include/asm/paca.h b/arch/powerpc/include/asm/paca.h index 601e2327dd8c..b1197c1affac 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 */ -- cgit v1.2.3