arm64: kdump: implement machine_crash_shutdown()

[karo-tx-linux.git] / arch / arm64 / kernel / smp.c

diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index d4739552da286fcda320327fbd0fe80222adf088..ffee4e454ac5d716b33e107815071eb41cd1a41a 100644 (file)
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -39,6 +39,7 @@
 #include <linux/completion.h>
 #include <linux/of.h>
 #include <linux/irq_work.h>
+#include <linux/kexec.h>
 
 #include <asm/alternative.h>
 #include <asm/atomic.h>
@@ -76,6 +77,7 @@ enum ipi_msg_type {
        IPI_RESCHEDULE,
        IPI_CALL_FUNC,
        IPI_CPU_STOP,
+       IPI_CPU_CRASH_STOP,
        IPI_TIMER,
        IPI_IRQ_WORK,
        IPI_WAKEUP
@@ -756,6 +758,7 @@ static const char *ipi_types[NR_IPI] __tracepoint_string = {
        S(IPI_RESCHEDULE, "Rescheduling interrupts"),
        S(IPI_CALL_FUNC, "Function call interrupts"),
        S(IPI_CPU_STOP, "CPU stop interrupts"),
+       S(IPI_CPU_CRASH_STOP, "CPU stop (for crash dump) interrupts"),
        S(IPI_TIMER, "Timer broadcast interrupts"),
        S(IPI_IRQ_WORK, "IRQ work interrupts"),
        S(IPI_WAKEUP, "CPU wake-up interrupts"),
@@ -830,6 +833,29 @@ static void ipi_cpu_stop(unsigned int cpu)
                cpu_relax();
 }
 
+#ifdef CONFIG_KEXEC_CORE
+static atomic_t waiting_for_crash_ipi = ATOMIC_INIT(0);
+#endif
+
+static void ipi_cpu_crash_stop(unsigned int cpu, struct pt_regs *regs)
+{
+#ifdef CONFIG_KEXEC_CORE
+       crash_save_cpu(regs, cpu);
+
+       atomic_dec(&waiting_for_crash_ipi);
+
+       local_irq_disable();
+
+#ifdef CONFIG_HOTPLUG_CPU
+       if (cpu_ops[cpu]->cpu_die)
+               cpu_ops[cpu]->cpu_die(cpu);
+#endif
+
+       /* just in case */
+       cpu_park_loop();
+#endif
+}
+
 /*
  * Main handler for inter-processor interrupts
  */
@@ -860,6 +886,15 @@ void handle_IPI(int ipinr, struct pt_regs *regs)
                irq_exit();
                break;
 
+       case IPI_CPU_CRASH_STOP:
+               if (IS_ENABLED(CONFIG_KEXEC_CORE)) {
+                       irq_enter();
+                       ipi_cpu_crash_stop(cpu, regs);
+
+                       unreachable();
+               }
+               break;
+
 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
        case IPI_TIMER:
                irq_enter();
@@ -932,6 +967,39 @@ void smp_send_stop(void)
                           cpumask_pr_args(cpu_online_mask));
 }
 
+#ifdef CONFIG_KEXEC_CORE
+void smp_send_crash_stop(void)
+{
+       cpumask_t mask;
+       unsigned long timeout;
+
+       if (num_online_cpus() == 1)
+               return;
+
+       cpumask_copy(&mask, cpu_online_mask);
+       cpumask_clear_cpu(smp_processor_id(), &mask);
+
+       atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
+
+       pr_crit("SMP: stopping secondary CPUs\n");
+       smp_cross_call(&mask, IPI_CPU_CRASH_STOP);
+
+       /* Wait up to one second for other CPUs to stop */
+       timeout = USEC_PER_SEC;
+       while ((atomic_read(&waiting_for_crash_ipi) > 0) && timeout--)
+               udelay(1);
+
+       if (atomic_read(&waiting_for_crash_ipi) > 0)
+               pr_warning("SMP: failed to stop secondary CPUs %*pbl\n",
+                          cpumask_pr_args(&mask));
+}
+
+bool smp_crash_stop_failed(void)
+{
+       return (atomic_read(&waiting_for_crash_ipi) > 0);
+}
+#endif
+
 /*
  * not supported here
  */