From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Andr=C3=A9=20Fabian=20Silva=20Delgado?=
 <emulatorman@parabola.nu>
Date: Wed, 5 Aug 2015 17:04:01 -0300
Subject: Initial import

---
 arch/mips/kernel/crash.c | 70 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 70 insertions(+)
 create mode 100644 arch/mips/kernel/crash.c

(limited to 'arch/mips/kernel/crash.c')

diff --git a/arch/mips/kernel/crash.c b/arch/mips/kernel/crash.c
new file mode 100644
index 000000000..d434d5d5a
--- /dev/null
+++ b/arch/mips/kernel/crash.c
@@ -0,0 +1,70 @@
+#include <linux/kernel.h>
+#include <linux/smp.h>
+#include <linux/reboot.h>
+#include <linux/kexec.h>
+#include <linux/bootmem.h>
+#include <linux/crash_dump.h>
+#include <linux/delay.h>
+#include <linux/irq.h>
+#include <linux/types.h>
+#include <linux/sched.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 *ignore)
+{
+	struct pt_regs *regs;
+	int cpu = smp_processor_id();
+
+	regs = task_pt_regs(current);
+
+	if (!cpu_online(cpu))
+		return;
+
+	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();
+	relocated_kexec_smp_wait(NULL);
+	/* NOTREACHED */
+}
+
+static void crash_kexec_prepare_cpus(void)
+{
+	unsigned int msecs;
+
+	unsigned int ncpus = num_online_cpus() - 1;/* Excluding the panic cpu */
+
+	dump_send_ipi(crash_shutdown_secondary);
+	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);
+	}
+}
+
+#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);
+}
-- 
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