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path: root/drivers/misc/pvpanic/pvpanic.c
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Diffstat (limited to 'drivers/misc/pvpanic/pvpanic.c')
-rw-r--r--drivers/misc/pvpanic/pvpanic.c115
1 files changed, 115 insertions, 0 deletions
diff --git a/drivers/misc/pvpanic/pvpanic.c b/drivers/misc/pvpanic/pvpanic.c
new file mode 100644
index 000000000..049a12006
--- /dev/null
+++ b/drivers/misc/pvpanic/pvpanic.c
@@ -0,0 +1,115 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Pvpanic Device Support
+ *
+ * Copyright (C) 2013 Fujitsu.
+ * Copyright (C) 2018 ZTE.
+ * Copyright (C) 2021 Oracle.
+ */
+
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/kexec.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/panic_notifier.h>
+#include <linux/types.h>
+#include <linux/cdev.h>
+#include <linux/list.h>
+
+#include <uapi/misc/pvpanic.h>
+
+#include "pvpanic.h"
+
+MODULE_AUTHOR("Mihai Carabas <mihai.carabas@oracle.com>");
+MODULE_DESCRIPTION("pvpanic device driver");
+MODULE_LICENSE("GPL");
+
+static struct list_head pvpanic_list;
+static spinlock_t pvpanic_lock;
+
+static void
+pvpanic_send_event(unsigned int event)
+{
+ struct pvpanic_instance *pi_cur;
+
+ if (!spin_trylock(&pvpanic_lock))
+ return;
+
+ list_for_each_entry(pi_cur, &pvpanic_list, list) {
+ if (event & pi_cur->capability & pi_cur->events)
+ iowrite8(event, pi_cur->base);
+ }
+ spin_unlock(&pvpanic_lock);
+}
+
+static int
+pvpanic_panic_notify(struct notifier_block *nb, unsigned long code, void *unused)
+{
+ unsigned int event = PVPANIC_PANICKED;
+
+ if (kexec_crash_loaded())
+ event = PVPANIC_CRASH_LOADED;
+
+ pvpanic_send_event(event);
+
+ return NOTIFY_DONE;
+}
+
+/*
+ * Call our notifier very early on panic, deferring the
+ * action taken to the hypervisor.
+ */
+static struct notifier_block pvpanic_panic_nb = {
+ .notifier_call = pvpanic_panic_notify,
+ .priority = INT_MAX,
+};
+
+static void pvpanic_remove(void *param)
+{
+ struct pvpanic_instance *pi_cur, *pi_next;
+ struct pvpanic_instance *pi = param;
+
+ spin_lock(&pvpanic_lock);
+ list_for_each_entry_safe(pi_cur, pi_next, &pvpanic_list, list) {
+ if (pi_cur == pi) {
+ list_del(&pi_cur->list);
+ break;
+ }
+ }
+ spin_unlock(&pvpanic_lock);
+}
+
+int devm_pvpanic_probe(struct device *dev, struct pvpanic_instance *pi)
+{
+ if (!pi || !pi->base)
+ return -EINVAL;
+
+ spin_lock(&pvpanic_lock);
+ list_add(&pi->list, &pvpanic_list);
+ spin_unlock(&pvpanic_lock);
+
+ dev_set_drvdata(dev, pi);
+
+ return devm_add_action_or_reset(dev, pvpanic_remove, pi);
+}
+EXPORT_SYMBOL_GPL(devm_pvpanic_probe);
+
+static int pvpanic_init(void)
+{
+ INIT_LIST_HEAD(&pvpanic_list);
+ spin_lock_init(&pvpanic_lock);
+
+ atomic_notifier_chain_register(&panic_notifier_list, &pvpanic_panic_nb);
+
+ return 0;
+}
+module_init(pvpanic_init);
+
+static void pvpanic_exit(void)
+{
+ atomic_notifier_chain_unregister(&panic_notifier_list, &pvpanic_panic_nb);
+
+}
+module_exit(pvpanic_exit);