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-or-later
/*
* sun4v watchdog timer
* (c) Copyright 2016 Oracle Corporation
*
* Implement a simple watchdog driver using the built-in sun4v hypervisor
* watchdog support. If time expires, the hypervisor stops or bounces
* the guest domain.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/watchdog.h>
#include <asm/hypervisor.h>
#include <asm/mdesc.h>
#define WDT_TIMEOUT 60
#define WDT_MAX_TIMEOUT 31536000
#define WDT_MIN_TIMEOUT 1
#define WDT_DEFAULT_RESOLUTION_MS 1000 /* 1 second */
static unsigned int timeout;
module_param(timeout, uint, 0);
MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds (default="
__MODULE_STRING(WDT_TIMEOUT) ")");
static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, S_IRUGO);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
static int sun4v_wdt_stop(struct watchdog_device *wdd)
{
sun4v_mach_set_watchdog(0, NULL);
return 0;
}
static int sun4v_wdt_ping(struct watchdog_device *wdd)
{
int hverr;
/*
* HV watchdog timer will round up the timeout
* passed in to the nearest multiple of the
* watchdog resolution in milliseconds.
*/
hverr = sun4v_mach_set_watchdog(wdd->timeout * 1000, NULL);
if (hverr == HV_EINVAL)
return -EINVAL;
return 0;
}
static int sun4v_wdt_set_timeout(struct watchdog_device *wdd,
unsigned int timeout)
{
wdd->timeout = timeout;
return 0;
}
static const struct watchdog_info sun4v_wdt_ident = {
.options = WDIOF_SETTIMEOUT |
WDIOF_MAGICCLOSE |
WDIOF_KEEPALIVEPING,
.identity = "sun4v hypervisor watchdog",
.firmware_version = 0,
};
static const struct watchdog_ops sun4v_wdt_ops = {
.owner = THIS_MODULE,
.start = sun4v_wdt_ping,
.stop = sun4v_wdt_stop,
.ping = sun4v_wdt_ping,
.set_timeout = sun4v_wdt_set_timeout,
};
static struct watchdog_device wdd = {
.info = &sun4v_wdt_ident,
.ops = &sun4v_wdt_ops,
.min_timeout = WDT_MIN_TIMEOUT,
.max_timeout = WDT_MAX_TIMEOUT,
.timeout = WDT_TIMEOUT,
};
static int __init sun4v_wdt_init(void)
{
struct mdesc_handle *handle;
u64 node;
const u64 *value;
int err = 0;
unsigned long major = 1, minor = 1;
/*
* There are 2 properties that can be set from the control
* domain for the watchdog.
* watchdog-resolution
* watchdog-max-timeout
*
* We can expect a handle to be returned otherwise something
* serious is wrong. Correct to return -ENODEV here.
*/
handle = mdesc_grab();
if (!handle)
return -ENODEV;
node = mdesc_node_by_name(handle, MDESC_NODE_NULL, "platform");
err = -ENODEV;
if (node == MDESC_NODE_NULL)
goto out_release;
/*
* This is a safe way to validate if we are on the right
* platform.
*/
if (sun4v_hvapi_register(HV_GRP_CORE, major, &minor))
goto out_hv_unreg;
/* Allow value of watchdog-resolution up to 1s (default) */
value = mdesc_get_property(handle, node, "watchdog-resolution", NULL);
err = -EINVAL;
if (value) {
if (*value == 0 ||
*value > WDT_DEFAULT_RESOLUTION_MS)
goto out_hv_unreg;
}
value = mdesc_get_property(handle, node, "watchdog-max-timeout", NULL);
if (value) {
/*
* If the property value (in ms) is smaller than
* min_timeout, return -EINVAL.
*/
if (*value < wdd.min_timeout * 1000)
goto out_hv_unreg;
/*
* If the property value is smaller than
* default max_timeout then set watchdog max_timeout to
* the value of the property in seconds.
*/
if (*value < wdd.max_timeout * 1000)
wdd.max_timeout = *value / 1000;
}
watchdog_init_timeout(&wdd, timeout, NULL);
watchdog_set_nowayout(&wdd, nowayout);
err = watchdog_register_device(&wdd);
if (err)
goto out_hv_unreg;
pr_info("initialized (timeout=%ds, nowayout=%d)\n",
wdd.timeout, nowayout);
mdesc_release(handle);
return 0;
out_hv_unreg:
sun4v_hvapi_unregister(HV_GRP_CORE);
out_release:
mdesc_release(handle);
return err;
}
static void __exit sun4v_wdt_exit(void)
{
sun4v_hvapi_unregister(HV_GRP_CORE);
watchdog_unregister_device(&wdd);
}
module_init(sun4v_wdt_init);
module_exit(sun4v_wdt_exit);
MODULE_AUTHOR("Wim Coekaerts <wim.coekaerts@oracle.com>");
MODULE_DESCRIPTION("sun4v watchdog driver");
MODULE_LICENSE("GPL");
|
