1 // SPDX-License-Identifier: GPL-2.0+
3 * Pvpanic Device Support
5 * Copyright (C) 2013 Fujitsu.
6 * Copyright (C) 2018 ZTE.
7 * Copyright (C) 2021 Oracle.
11 #include <linux/kernel.h>
12 #include <linux/kexec.h>
13 #include <linux/mod_devicetable.h>
14 #include <linux/module.h>
15 #include <linux/platform_device.h>
16 #include <linux/panic_notifier.h>
17 #include <linux/types.h>
18 #include <linux/cdev.h>
19 #include <linux/list.h>
21 #include <uapi/misc/pvpanic.h>
25 MODULE_AUTHOR("Mihai Carabas <mihai.carabas@oracle.com>");
26 MODULE_DESCRIPTION("pvpanic device driver ");
27 MODULE_LICENSE("GPL");
29 static struct list_head pvpanic_list;
30 static spinlock_t pvpanic_lock;
33 pvpanic_send_event(unsigned int event)
35 struct pvpanic_instance *pi_cur;
37 spin_lock(&pvpanic_lock);
38 list_for_each_entry(pi_cur, &pvpanic_list, list) {
39 if (event & pi_cur->capability & pi_cur->events)
40 iowrite8(event, pi_cur->base);
42 spin_unlock(&pvpanic_lock);
46 pvpanic_panic_notify(struct notifier_block *nb, unsigned long code,
49 unsigned int event = PVPANIC_PANICKED;
51 if (kexec_crash_loaded())
52 event = PVPANIC_CRASH_LOADED;
54 pvpanic_send_event(event);
59 static struct notifier_block pvpanic_panic_nb = {
60 .notifier_call = pvpanic_panic_notify,
61 .priority = 1, /* let this called before broken drm_fb_helper */
64 static void pvpanic_remove(void *param)
66 struct pvpanic_instance *pi_cur, *pi_next;
67 struct pvpanic_instance *pi = param;
69 spin_lock(&pvpanic_lock);
70 list_for_each_entry_safe(pi_cur, pi_next, &pvpanic_list, list) {
72 list_del(&pi_cur->list);
76 spin_unlock(&pvpanic_lock);
79 int devm_pvpanic_probe(struct device *dev, struct pvpanic_instance *pi)
84 spin_lock(&pvpanic_lock);
85 list_add(&pi->list, &pvpanic_list);
86 spin_unlock(&pvpanic_lock);
88 return devm_add_action_or_reset(dev, pvpanic_remove, pi);
90 EXPORT_SYMBOL_GPL(devm_pvpanic_probe);
92 static int pvpanic_init(void)
94 INIT_LIST_HEAD(&pvpanic_list);
95 spin_lock_init(&pvpanic_lock);
97 atomic_notifier_chain_register(&panic_notifier_list,
103 static void pvpanic_exit(void)
105 atomic_notifier_chain_unregister(&panic_notifier_list,
110 module_init(pvpanic_init);
111 module_exit(pvpanic_exit);