1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
|
// SPDX-License-Identifier: GPL-2.0+
/*
* Pvpanic Device Support
*
* Copyright (C) 2013 Fujitsu.
* Copyright (C) 2018 ZTE.
* Copyright (C) 2021 Oracle.
*/
#include <linux/device.h>
#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");
struct pvpanic_instance {
void __iomem *base;
unsigned int capability;
unsigned int events;
struct list_head list;
};
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);
}
static ssize_t capability_show(struct device *dev, struct device_attribute *attr, char *buf)
{
struct pvpanic_instance *pi = dev_get_drvdata(dev);
return sysfs_emit(buf, "%x\n", pi->capability);
}
static DEVICE_ATTR_RO(capability);
static ssize_t events_show(struct device *dev, struct device_attribute *attr, char *buf)
{
struct pvpanic_instance *pi = dev_get_drvdata(dev);
return sysfs_emit(buf, "%x\n", pi->events);
}
static ssize_t events_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct pvpanic_instance *pi = dev_get_drvdata(dev);
unsigned int tmp;
int err;
err = kstrtouint(buf, 16, &tmp);
if (err)
return err;
if ((tmp & pi->capability) != tmp)
return -EINVAL;
pi->events = tmp;
return count;
}
static DEVICE_ATTR_RW(events);
static struct attribute *pvpanic_dev_attrs[] = {
&dev_attr_capability.attr,
&dev_attr_events.attr,
NULL
};
static const struct attribute_group pvpanic_dev_group = {
.attrs = pvpanic_dev_attrs,
};
const struct attribute_group *pvpanic_dev_groups[] = {
&pvpanic_dev_group,
NULL
};
EXPORT_SYMBOL_GPL(pvpanic_dev_groups);
int devm_pvpanic_probe(struct device *dev, void __iomem *base)
{
struct pvpanic_instance *pi;
if (!base)
return -EINVAL;
pi = devm_kmalloc(dev, sizeof(*pi), GFP_KERNEL);
if (!pi)
return -ENOMEM;
pi->base = base;
pi->capability = PVPANIC_PANICKED | PVPANIC_CRASH_LOADED;
/* initlize capability by RDPT */
pi->capability &= ioread8(base);
pi->events = pi->capability;
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);
|
