mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-24 17:59:32 +00:00
![wim.coekaerts@oracle.com](/assets/img/avatar_default.png)
This driver adds sparc hypervisor watchdog support. The default timeout is 60 seconds and the range is between 1 and 31536000 seconds. Both watchdog-resolution and watchdog-max-timeout MD properties settings are supported. Signed-off-by: Wim Coekaerts <wim.coekaerts@oracle.com> Reviewed-by: Julian Calaby <julian.calaby@gmail.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: David S. Miller <davem@davemloft.net>
191 lines
4.5 KiB
C
191 lines
4.5 KiB
C
/*
|
|
* 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.
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation; either version
|
|
* 2 of the License, or (at your option) any later version.
|
|
*/
|
|
|
|
#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 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");
|