diff options
Diffstat (limited to 'arch/powerpc/kernel/smp.c')
| -rw-r--r-- | arch/powerpc/kernel/smp.c | 49 |
1 files changed, 42 insertions, 7 deletions
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c index e16ec7b3b427..9ca7148b5881 100644 --- a/arch/powerpc/kernel/smp.c +++ b/arch/powerpc/kernel/smp.c @@ -566,10 +566,35 @@ 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 nmi_stop_this_cpu(struct pt_regs *regs) +{ + /* + * This is a special case because it never returns, so the NMI IPI + * handling would never mark it as done, which makes any later + * smp_send_nmi_ipi() call spin forever. Mark it done now. + * + * IRQs are already hard disabled by the smp_handle_nmi_ipi. + */ + nmi_ipi_lock(); + nmi_ipi_busy_count--; + nmi_ipi_unlock(); + + /* Remove this CPU */ + set_cpu_online(smp_processor_id(), false); + + spin_begin(); + while (1) + spin_cpu_relax(); +} + +void smp_send_stop(void) +{ + smp_send_nmi_ipi(NMI_IPI_ALL_OTHERS, nmi_stop_this_cpu, 1000000); +} + +#else /* CONFIG_NMI_IPI */ + static void stop_this_cpu(void *dummy) -#endif { /* Remove this CPU */ set_cpu_online(smp_processor_id(), false); @@ -582,12 +607,22 @@ 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 + static bool stopped = false; + + /* + * Prevent waiting on csd lock from a previous smp_send_stop. + * This is racy, but in general callers try to do the right + * thing and only fire off one smp_send_stop (e.g., see + * kernel/panic.c) + */ + if (stopped) + return; + + stopped = true; + smp_call_function(stop_this_cpu, NULL, 0); -#endif } +#endif /* CONFIG_NMI_IPI */ struct thread_info *current_set[NR_CPUS]; |