1 files changed, 265 insertions, 0 deletions
diff --git a/arch/ia64/kernel/crash.c b/arch/ia64/kernel/crash.c
new file mode 100644
index 000000000..fec70d662
--- /dev/null
+++ b/arch/ia64/kernel/crash.c
@@ -0,0 +1,265 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * arch/ia64/kernel/crash.c
+ *
+ * Architecture specific (ia64) functions for kexec based crash dumps.
+ *
+ * Created by: Khalid Aziz <khalid.aziz@hp.com>
+ * Copyright (C) 2005 Hewlett-Packard Development Company, L.P.
+ * Copyright (C) 2005 Intel Corp	Zou Nan hai <nanhai.zou@intel.com>
+ *
+ */
+#include <linux/smp.h>
+#include <linux/delay.h>
+#include <linux/crash_dump.h>
+#include <linux/memblock.h>
+#include <linux/kexec.h>
+#include <linux/elfcore.h>
+#include <linux/sysctl.h>
+#include <linux/init.h>
+#include <linux/kdebug.h>
+
+#include <asm/mca.h>
+
+int kdump_status[NR_CPUS];
+static atomic_t kdump_cpu_frozen;
+atomic_t kdump_in_progress;
+static int kdump_freeze_monarch;
+static int kdump_on_init = 1;
+static int kdump_on_fatal_mca = 1;
+
+extern void ia64_dump_cpu_regs(void *);
+
+static DEFINE_PER_CPU(struct elf_prstatus, elf_prstatus);
+
+void
+crash_save_this_cpu(void)
+{
+	void *buf;
+	unsigned long cfm, sof, sol;
+
+	int cpu = smp_processor_id();
+	struct elf_prstatus *prstatus = &per_cpu(elf_prstatus, cpu);
+
+	elf_greg_t *dst = (elf_greg_t *)&(prstatus->pr_reg);
+	memset(prstatus, 0, sizeof(*prstatus));
+	prstatus->pr_pid = current->pid;
+
+	ia64_dump_cpu_regs(dst);
+	cfm = dst[43];
+	sol = (cfm >> 7) & 0x7f;
+	sof = cfm & 0x7f;
+	dst[46] = (unsigned long)ia64_rse_skip_regs((unsigned long *)dst[46],
+			sof - sol);
+
+	buf = (u64 *) per_cpu_ptr(crash_notes, cpu);
+	if (!buf)
+		return;
+	buf = append_elf_note(buf, KEXEC_CORE_NOTE_NAME, NT_PRSTATUS, prstatus,
+			sizeof(*prstatus));
+	final_note(buf);
+}
+
+#ifdef CONFIG_SMP
+static int
+kdump_wait_cpu_freeze(void)
+{
+	int cpu_num = num_online_cpus() - 1;
+	int timeout = 1000;
+	while(timeout-- > 0) {
+		if (atomic_read(&kdump_cpu_frozen) == cpu_num)
+			return 0;
+		udelay(1000);
+	}
+	return 1;
+}
+#endif
+
+void
+machine_crash_shutdown(struct pt_regs *pt)
+{
+	/* This function is only called after the system
+	 * has paniced or is otherwise in a critical state.
+	 * The minimum amount of code to allow a kexec'd kernel
+	 * to run successfully needs to happen here.
+	 *
+	 * In practice this means shooting down the other cpus in
+	 * an SMP system.
+	 */
+	kexec_disable_iosapic();
+#ifdef CONFIG_SMP
+	/*
+	 * If kdump_on_init is set and an INIT is asserted here, kdump will
+	 * be started again via INIT monarch.
+	 */
+	local_irq_disable();
+	ia64_set_psr_mc();	/* mask MCA/INIT */
+	if (atomic_inc_return(&kdump_in_progress) != 1)
+		unw_init_running(kdump_cpu_freeze, NULL);
+
+	/*
+	 * Now this cpu is ready for kdump.
+	 * Stop all others by IPI or INIT.  They could receive INIT from
+	 * outside and might be INIT monarch, but only thing they have to
+	 * do is falling into kdump_cpu_freeze().
+	 *
+	 * If an INIT is asserted here:
+	 * - All receivers might be slaves, since some of cpus could already
+	 *   be frozen and INIT might be masked on monarch.  In this case,
+	 *   all slaves will be frozen soon since kdump_in_progress will let
+	 *   them into DIE_INIT_SLAVE_LEAVE.
+	 * - One might be a monarch, but INIT rendezvous will fail since
+	 *   at least this cpu already have INIT masked so it never join
+	 *   to the rendezvous.  In this case, all slaves and monarch will
+	 *   be frozen soon with no wait since the INIT rendezvous is skipped
+	 *   by kdump_in_progress.
+	 */
+	kdump_smp_send_stop();
+	/* not all cpu response to IPI, send INIT to freeze them */
+	if (kdump_wait_cpu_freeze()) {
+		kdump_smp_send_init();
+		/* wait again, don't go ahead if possible */
+		kdump_wait_cpu_freeze();
+	}
+#endif
+}
+
+static void
+machine_kdump_on_init(void)
+{
+	crash_save_vmcoreinfo();
+	local_irq_disable();
+	kexec_disable_iosapic();
+	machine_kexec(ia64_kimage);
+}
+
+void
+kdump_cpu_freeze(struct unw_frame_info *info, void *arg)
+{
+	int cpuid;
+
+	local_irq_disable();
+	cpuid = smp_processor_id();
+	crash_save_this_cpu();
+	current->thread.ksp = (__u64)info->sw - 16;
+
+	ia64_set_psr_mc();	/* mask MCA/INIT and stop reentrance */
+
+	atomic_inc(&kdump_cpu_frozen);
+	kdump_status[cpuid] = 1;
+	mb();
+	for (;;)
+		cpu_relax();
+}
+
+static int
+kdump_init_notifier(struct notifier_block *self, unsigned long val, void *data)
+{
+	struct ia64_mca_notify_die *nd;
+	struct die_args *args = data;
+
+	if (atomic_read(&kdump_in_progress)) {
+		switch (val) {
+		case DIE_INIT_MONARCH_LEAVE:
+			if (!kdump_freeze_monarch)
+				break;
+			fallthrough;
+		case DIE_INIT_SLAVE_LEAVE:
+		case DIE_INIT_MONARCH_ENTER:
+		case DIE_MCA_RENDZVOUS_LEAVE:
+			unw_init_running(kdump_cpu_freeze, NULL);
+			break;
+		}
+	}
+
+	if (!kdump_on_init && !kdump_on_fatal_mca)
+		return NOTIFY_DONE;
+
+	if (!ia64_kimage) {
+		if (val == DIE_INIT_MONARCH_LEAVE)
+			ia64_mca_printk(KERN_NOTICE
+					"%s: kdump not configured\n",
+					__func__);
+		return NOTIFY_DONE;
+	}
+
+	if (val != DIE_INIT_MONARCH_LEAVE &&
+	    val != DIE_INIT_MONARCH_PROCESS &&
+	    val != DIE_MCA_MONARCH_LEAVE)
+		return NOTIFY_DONE;
+
+	nd = (struct ia64_mca_notify_die *)args->err;
+
+	switch (val) {
+	case DIE_INIT_MONARCH_PROCESS:
+		/* Reason code 1 means machine check rendezvous*/
+		if (kdump_on_init && (nd->sos->rv_rc != 1)) {
+			if (atomic_inc_return(&kdump_in_progress) != 1)
+				kdump_freeze_monarch = 1;
+		}
+		break;
+	case DIE_INIT_MONARCH_LEAVE:
+		/* Reason code 1 means machine check rendezvous*/
+		if (kdump_on_init && (nd->sos->rv_rc != 1))
+			machine_kdump_on_init();
+		break;
+	case DIE_MCA_MONARCH_LEAVE:
+		/* *(nd->data) indicate if MCA is recoverable */
+		if (kdump_on_fatal_mca && !(*(nd->data))) {
+			if (atomic_inc_return(&kdump_in_progress) == 1)
+				machine_kdump_on_init();
+			/* We got fatal MCA while kdump!? No way!! */
+		}
+		break;
+	}
+	return NOTIFY_DONE;
+}
+
+#ifdef CONFIG_SYSCTL
+static struct ctl_table kdump_ctl_table[] = {
+	{
+		.procname = "kdump_on_init",
+		.data = &kdump_on_init,
+		.maxlen = sizeof(int),
+		.mode = 0644,
+		.proc_handler = proc_dointvec,
+	},
+	{
+		.procname = "kdump_on_fatal_mca",
+		.data = &kdump_on_fatal_mca,
+		.maxlen = sizeof(int),
+		.mode = 0644,
+		.proc_handler = proc_dointvec,
+	},
+	{ }
+};
+
+static struct ctl_table sys_table[] = {
+	{
+	  .procname = "kernel",
+	  .mode = 0555,
+	  .child = kdump_ctl_table,
+	},
+	{ }
+};
+#endif
+
+static int
+machine_crash_setup(void)
+{
+	/* be notified before default_monarch_init_process */
+	static struct notifier_block kdump_init_notifier_nb = {
+		.notifier_call = kdump_init_notifier,
+		.priority = 1,
+	};
+	int ret;
+	if((ret = register_die_notifier(&kdump_init_notifier_nb)) != 0)
+		return ret;
+#ifdef CONFIG_SYSCTL
+	register_sysctl_table(sys_table);
+#endif
+	return 0;
+}
+
+__initcall(machine_crash_setup);
+