From 6ba55716a24f5f399ad4d37685e4bb721f8e6dd5 Mon Sep 17 00:00:00 2001 From: Michael Ellerman Date: Wed, 2 May 2018 23:07:27 +1000 Subject: powerpc/nmi: Add an API for sending "safe" NMIs Currently the options we have for sending NMIs are not necessarily safe, that is they can potentially interrupt a CPU in a non-recoverable region of code, meaning the kernel must then panic(). But we'd like to use smp_send_nmi_ipi() to do cross-CPU calls in situations where we don't want to risk a panic(), because it doesn't have the requirement that interrupts must be enabled like smp_call_function(). So add an API for the caller to indicate that it wants to use the NMI infrastructure, but doesn't want to do anything "unsafe". Currently that is implemented by not actually calling cause_nmi_ipi(), instead falling back to an IPI. In future we can pass the safe parameter down to cause_nmi_ipi() and the individual backends can potentially take it into account before deciding what to do. Signed-off-by: Michael Ellerman Reviewed-by: Nicholas Piggin --- arch/powerpc/include/asm/smp.h | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/powerpc/include') diff --git a/arch/powerpc/include/asm/smp.h b/arch/powerpc/include/asm/smp.h index cfecfee1194b..29ffaabdf75b 100644 --- a/arch/powerpc/include/asm/smp.h +++ b/arch/powerpc/include/asm/smp.h @@ -58,6 +58,7 @@ struct smp_ops_t { extern void smp_flush_nmi_ipi(u64 delay_us); extern int smp_send_nmi_ipi(int cpu, void (*fn)(struct pt_regs *), u64 delay_us); +extern int smp_send_safe_nmi_ipi(int cpu, void (*fn)(struct pt_regs *), u64 delay_us); extern void smp_send_debugger_break(void); extern void start_secondary_resume(void); extern void smp_generic_give_timebase(void); -- cgit v1.2.3