110 lines
2.5 KiB
C
110 lines
2.5 KiB
C
|
/*
|
||
|
|
* SVC Greybus "watchdog" driver.
|
||
|
|
*
|
||
|
|
* Copyright 2016 Google Inc.
|
||
|
|
*
|
||
|
|
* Released under the GPLv2 only.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <linux/delay.h>
|
||
|
|
#include <linux/workqueue.h>
|
||
|
|
#include "greybus.h"
|
||
|
|
|
||
|
|
#define SVC_WATCHDOG_PERIOD (2*HZ)
|
||
|
|
|
||
|
|
struct gb_svc_watchdog {
|
||
|
|
struct delayed_work work;
|
||
|
|
struct gb_svc *svc;
|
||
|
|
bool finished;
|
||
|
|
};
|
||
|
|
|
||
|
|
static struct delayed_work reset_work;
|
||
|
|
|
||
|
|
static void greybus_reset(struct work_struct *work)
|
||
|
|
{
|
||
|
|
static char start_path[256] = "/system/bin/start";
|
||
|
|
static char *envp[] = {
|
||
|
|
"HOME=/",
|
||
|
|
"PATH=/sbin:/vendor/bin:/system/sbin:/system/bin:/system/xbin",
|
||
|
|
NULL,
|
||
|
|
};
|
||
|
|
static char *argv[] = {
|
||
|
|
start_path,
|
||
|
|
"unipro_reset",
|
||
|
|
NULL,
|
||
|
|
};
|
||
|
|
|
||
|
|
printk(KERN_ERR "svc_watchdog: calling \"%s %s\" to reset greybus network!\n",
|
||
|
|
argv[0], argv[1]);
|
||
|
|
call_usermodehelper(start_path, argv, envp, UMH_WAIT_EXEC);
|
||
|
|
}
|
||
|
|
|
||
|
|
static void do_work(struct work_struct *work)
|
||
|
|
{
|
||
|
|
struct gb_svc_watchdog *watchdog;
|
||
|
|
struct gb_svc *svc;
|
||
|
|
int retval;
|
||
|
|
|
||
|
|
watchdog = container_of(work, struct gb_svc_watchdog, work.work);
|
||
|
|
svc = watchdog->svc;
|
||
|
|
|
||
|
|
dev_dbg(&svc->dev, "%s: ping.\n", __func__);
|
||
|
|
retval = gb_svc_ping(svc);
|
||
|
|
if (retval) {
|
||
|
|
/*
|
||
|
|
* Something went really wrong, let's warn userspace and then
|
||
|
|
* pull the plug and reset the whole greybus network.
|
||
|
|
* We need to do this outside of this workqueue as we will be
|
||
|
|
* tearing down the svc device itself. So queue up
|
||
|
|
* yet-another-callback to do that.
|
||
|
|
*/
|
||
|
|
dev_err(&svc->dev,
|
||
|
|
"SVC ping has returned %d, something is wrong!!!\n",
|
||
|
|
retval);
|
||
|
|
dev_err(&svc->dev, "Resetting the greybus network, watch out!!!\n");
|
||
|
|
|
||
|
|
INIT_DELAYED_WORK(&reset_work, greybus_reset);
|
||
|
|
queue_delayed_work(system_wq, &reset_work, HZ/2);
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* resubmit our work to happen again, if we are still "alive" */
|
||
|
|
if (!watchdog->finished)
|
||
|
|
queue_delayed_work(system_wq, &watchdog->work,
|
||
|
|
SVC_WATCHDOG_PERIOD);
|
||
|
|
}
|
||
|
|
|
||
|
|
int gb_svc_watchdog_create(struct gb_svc *svc)
|
||
|
|
{
|
||
|
|
struct gb_svc_watchdog *watchdog;
|
||
|
|
|
||
|
|
if (svc->watchdog)
|
||
|
|
return 0;
|
||
|
|
|
||
|
|
watchdog = kmalloc(sizeof(*watchdog), GFP_KERNEL);
|
||
|
|
if (!watchdog)
|
||
|
|
return -ENOMEM;
|
||
|
|
|
||
|
|
watchdog->finished = false;
|
||
|
|
watchdog->svc = svc;
|
||
|
|
INIT_DELAYED_WORK(&watchdog->work, do_work);
|
||
|
|
svc->watchdog = watchdog;
|
||
|
|
|
||
|
|
queue_delayed_work(system_wq, &watchdog->work,
|
||
|
|
SVC_WATCHDOG_PERIOD);
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
void gb_svc_watchdog_destroy(struct gb_svc *svc)
|
||
|
|
{
|
||
|
|
struct gb_svc_watchdog *watchdog = svc->watchdog;
|
||
|
|
|
||
|
|
if (!watchdog)
|
||
|
|
return;
|
||
|
|
|
||
|
|
watchdog->finished = true;
|
||
|
|
cancel_delayed_work_sync(&watchdog->work);
|
||
|
|
svc->watchdog = NULL;
|
||
|
|
kfree(watchdog);
|
||
|
|
}
|