From 6bed3237624e3faad1592543952907cd01a42c83 Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Sun, 1 Apr 2018 20:36:13 +1000 Subject: powerpc: use NMI IPI for smp_send_stop Use the NMI IPI rather than smp_call_function for smp_send_stop. Have stopped CPUs hard disable interrupts rather than just soft disable. This function is used in crash/panic/shutdown paths to bring other CPUs down as quickly and reliably as possible, and minimizing their potential to cause trouble. Avoiding the Linux smp_call_function infrastructure and (if supported) using true NMI IPIs makes this more robust. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman --- arch/powerpc/kernel/smp.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'arch/powerpc') diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c index cfc08b099c49..db88660bf6bd 100644 --- a/arch/powerpc/kernel/smp.c +++ b/arch/powerpc/kernel/smp.c @@ -565,7 +565,11 @@ void crash_send_ipi(void (*crash_ipi_callback)(struct pt_regs *)) } #endif +#ifdef CONFIG_NMI_IPI +static void stop_this_cpu(struct pt_regs *regs) +#else static void stop_this_cpu(void *dummy) +#endif { /* Remove this CPU */ set_cpu_online(smp_processor_id(), false); @@ -577,7 +581,11 @@ static void stop_this_cpu(void *dummy) void smp_send_stop(void) { +#ifdef CONFIG_NMI_IPI + smp_send_nmi_ipi(NMI_IPI_ALL_OTHERS, stop_this_cpu, 1000000); +#else smp_call_function(stop_this_cpu, NULL, 0); +#endif } struct thread_info *current_set[NR_CPUS]; -- cgit v1.2.3