1 files changed, 103 insertions, 0 deletions
diff --git a/arch/mips/kernel/crash.c b/arch/mips/kernel/crash.c
new file mode 100644
index 000000000..81845ba04
--- /dev/null
+++ b/arch/mips/kernel/crash.c
@@ -0,0 +1,103 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/kernel.h>
+#include <linux/smp.h>
+#include <linux/reboot.h>
+#include <linux/kexec.h>
+#include <linux/memblock.h>
+#include <linux/crash_dump.h>
+#include <linux/delay.h>
+#include <linux/irq.h>
+#include <linux/types.h>
+#include <linux/sched.h>
+#include <linux/sched/task_stack.h>
+
+/* This keeps a track of which one is crashing cpu. */
+static int crashing_cpu = -1;
+static cpumask_t cpus_in_crash = CPU_MASK_NONE;
+
+#ifdef CONFIG_SMP
+static void crash_shutdown_secondary(void *passed_regs)
+{
+	struct pt_regs *regs = passed_regs;
+	int cpu = smp_processor_id();
+
+	/*
+	 * If we are passed registers, use those.  Otherwise get the
+	 * regs from the last interrupt, which should be correct, as
+	 * we are in an interrupt.  But if the regs are not there,
+	 * pull them from the top of the stack.  They are probably
+	 * wrong, but we need something to keep from crashing again.
+	 */
+	if (!regs)
+		regs = get_irq_regs();
+	if (!regs)
+		regs = task_pt_regs(current);
+
+	if (!cpu_online(cpu))
+		return;
+
+	/* We won't be sent IPIs any more. */
+	set_cpu_online(cpu, false);
+
+	local_irq_disable();
+	if (!cpumask_test_cpu(cpu, &cpus_in_crash))
+		crash_save_cpu(regs, cpu);
+	cpumask_set_cpu(cpu, &cpus_in_crash);
+
+	while (!atomic_read(&kexec_ready_to_reboot))
+		cpu_relax();
+
+	kexec_reboot();
+
+	/* NOTREACHED */
+}
+
+static void crash_kexec_prepare_cpus(void)
+{
+	static int cpus_stopped;
+	unsigned int msecs;
+	unsigned int ncpus;
+
+	if (cpus_stopped)
+		return;
+
+	ncpus = num_online_cpus() - 1;/* Excluding the panic cpu */
+
+	smp_call_function(crash_shutdown_secondary, NULL, 0);
+	smp_wmb();
+
+	/*
+	 * The crash CPU sends an IPI and wait for other CPUs to
+	 * respond. Delay of at least 10 seconds.
+	 */
+	pr_emerg("Sending IPI to other cpus...\n");
+	msecs = 10000;
+	while ((cpumask_weight(&cpus_in_crash) < ncpus) && (--msecs > 0)) {
+		cpu_relax();
+		mdelay(1);
+	}
+
+	cpus_stopped = 1;
+}
+
+/* Override the weak function in kernel/panic.c */
+void crash_smp_send_stop(void)
+{
+	if (_crash_smp_send_stop)
+		_crash_smp_send_stop();
+
+	crash_kexec_prepare_cpus();
+}
+
+#else /* !defined(CONFIG_SMP)  */
+static void crash_kexec_prepare_cpus(void) {}
+#endif /* !defined(CONFIG_SMP)	*/
+
+void default_machine_crash_shutdown(struct pt_regs *regs)
+{
+	local_irq_disable();
+	crashing_cpu = smp_processor_id();
+	crash_save_cpu(regs, crashing_cpu);
+	crash_kexec_prepare_cpus();
+	cpumask_set_cpu(crashing_cpu, &cpus_in_crash);
+}