cregit-Linux how code gets into the kernel

Release 4.11 drivers/staging/greybus/svc_watchdog.c

/*
 * SVC Greybus "watchdog" driver.
 *
 * Copyright 2016 Google Inc.
 *
 * Released under the GPLv2 only.
 */

#include <linux/delay.h>
#include <linux/suspend.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			enabled;
	
struct notifier_block pm_notifier;
};


static struct delayed_work reset_work;


static int svc_watchdog_pm_notifier(struct notifier_block *notifier, unsigned long pm_event, void *unused) { struct gb_svc_watchdog *watchdog = container_of(notifier, struct gb_svc_watchdog, pm_notifier); switch (pm_event) { case PM_SUSPEND_PREPARE: gb_svc_watchdog_disable(watchdog->svc); break; case PM_POST_SUSPEND: gb_svc_watchdog_enable(watchdog->svc); break; default: break; } return NOTIFY_DONE; }

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David Lin67100.00%1100.00%
Total67100.00%1100.00%


static void greybus_reset(struct work_struct *work) { static char const start_path[] = "/system/bin/start"; static char *envp[] = { "HOME=/", "PATH=/sbin:/vendor/bin:/system/sbin:/system/bin:/system/xbin", NULL, }; static char *argv[] = { (char *)start_path, "unipro_reset", NULL, }; pr_err("svc_watchdog: calling \"%s %s\" to reset greybus network!\n", argv[0], argv[1]); call_usermodehelper(start_path, argv, envp, UMH_WAIT_EXEC); }

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Greg Kroah-Hartman7698.70%266.67%
Emmanuil Chatzipetru11.30%133.33%
Total77100.00%3100.00%


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); if (svc->action == GB_SVC_WATCHDOG_BITE_PANIC_KERNEL) { panic("SVC is not responding\n"); } else if (svc->action == GB_SVC_WATCHDOG_BITE_RESET_UNIPRO) { dev_err(&svc->dev, "Resetting the greybus network, watch out!!!\n"); INIT_DELAYED_WORK(&reset_work, greybus_reset); schedule_delayed_work(&reset_work, HZ / 2); /* * Disable ourselves, we don't want to trip again unless * userspace wants us to. */ watchdog->enabled = false; } } /* resubmit our work to happen again, if we are still "alive" */ if (watchdog->enabled) schedule_delayed_work(&watchdog->work, SVC_WATCHDOG_PERIOD); }

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Greg Kroah-Hartman13181.88%250.00%
David Lin2918.12%250.00%
Total160100.00%4100.00%


int gb_svc_watchdog_create(struct gb_svc *svc) { struct gb_svc_watchdog *watchdog; int retval; if (svc->watchdog) return 0; watchdog = kmalloc(sizeof(*watchdog), GFP_KERNEL); if (!watchdog) return -ENOMEM; watchdog->enabled = false; watchdog->svc = svc; INIT_DELAYED_WORK(&watchdog->work, do_work); svc->watchdog = watchdog; watchdog->pm_notifier.notifier_call = svc_watchdog_pm_notifier; retval = register_pm_notifier(&watchdog->pm_notifier); if (retval) { dev_err(&svc->dev, "error registering pm notifier(%d)\n", retval); goto svc_watchdog_create_err; } retval = gb_svc_watchdog_enable(svc); if (retval) { dev_err(&svc->dev, "error enabling watchdog (%d)\n", retval); unregister_pm_notifier(&watchdog->pm_notifier); goto svc_watchdog_create_err; } return retval; svc_watchdog_create_err: svc->watchdog = NULL; kfree(watchdog); return retval; }

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David Lin9253.80%133.33%
Greg Kroah-Hartman7946.20%266.67%
Total171100.00%3100.00%


void gb_svc_watchdog_destroy(struct gb_svc *svc) { struct gb_svc_watchdog *watchdog = svc->watchdog; if (!watchdog) return; unregister_pm_notifier(&watchdog->pm_notifier); gb_svc_watchdog_disable(svc); svc->watchdog = NULL; kfree(watchdog); }

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Greg Kroah-Hartman4183.67%266.67%
David Lin816.33%133.33%
Total49100.00%3100.00%


bool gb_svc_watchdog_enabled(struct gb_svc *svc) { if (!svc || !svc->watchdog) return false; return svc->watchdog->enabled; }

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Greg Kroah-Hartman30100.00%1100.00%
Total30100.00%1100.00%


int gb_svc_watchdog_enable(struct gb_svc *svc) { struct gb_svc_watchdog *watchdog; if (!svc->watchdog) return -ENODEV; watchdog = svc->watchdog; if (watchdog->enabled) return 0; watchdog->enabled = true; schedule_delayed_work(&watchdog->work, SVC_WATCHDOG_PERIOD); return 0; }

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Greg Kroah-Hartman5998.33%266.67%
David Lin11.67%133.33%
Total60100.00%3100.00%


int gb_svc_watchdog_disable(struct gb_svc *svc) { struct gb_svc_watchdog *watchdog; if (!svc->watchdog) return -ENODEV; watchdog = svc->watchdog; if (!watchdog->enabled) return 0; watchdog->enabled = false; cancel_delayed_work_sync(&watchdog->work); return 0; }

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PersonTokensPropCommitsCommitProp
Greg Kroah-Hartman59100.00%2100.00%
Total59100.00%2100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Greg Kroah-Hartman51071.23%337.50%
David Lin20428.49%337.50%
Emmanuil Chatzipetru20.28%225.00%
Total716100.00%8100.00%
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