drivers/staging/unisys/uislib/uisthread.c

   1 /* uisthread.c
   2  *
   3  * Copyright (C) 2010 - 2013 UNISYS CORPORATION
   4  * All rights reserved.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or (at
   9  * your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
  14  * NON INFRINGEMENT.  See the GNU General Public License for more
  15  * details.
  16  */
  17
  18 /* @ALL_INSPECTED */
  19 #include <asm/processor.h>
  20 #include <linux/signal.h>
  21 #include <linux/sched.h>
  22 #include <linux/kthread.h>
  23 #include "uisutils.h"
  24 #include "uisthread.h"
  25
  26 /* this is shorter than using __FILE__ (full path name) in
  27  * debug/info/error messages
  28  */
  29 #define CURRENT_FILE_PC UISLIB_PC_uisthread_c
  30 #define __MYFILE__ "uisthread.c"
  31
  32 /*****************************************************/
  33 /* Exported functions                                */
  34 /*****************************************************/
  35
  36 /* returns 0 for failure, 1 for success */
  37 int
  38 uisthread_start(struct uisthread_info *thrinfo,
  39                 int (*threadfn)(void *), void *thrcontext, char *name)
  40 {
  41         /* used to stop the thread */
  42         init_completion(&thrinfo->has_stopped);
  43         thrinfo->task = kthread_run(threadfn, thrcontext, name);
  44         if (IS_ERR(thrinfo->task)) {
  45                 thrinfo->id = 0;
  46                 return 0;       /* failure */
  47         }
  48         thrinfo->id = thrinfo->task->pid;
  49         return 1;
  50 }
  51 EXPORT_SYMBOL_GPL(uisthread_start);
  52
  53 void
  54 uisthread_stop(struct uisthread_info *thrinfo)
  55 {
  56         int stopped = 0;
  57
  58         if (thrinfo->id == 0)
  59                 return;         /* thread not running */
  60
  61         kthread_stop(thrinfo->task);
  62         /* give up if the thread has NOT died in 1 minute */
  63         if (wait_for_completion_timeout(&thrinfo->has_stopped, 60 * HZ))
  64                 stopped = 1;
  65
  66         if (stopped)
  67                 thrinfo->id = 0;
  68 }
  69 EXPORT_SYMBOL_GPL(uisthread_stop);