/*
   * linux/include/linux/sunrpc/sched.h
   *
   * Scheduling primitives for kernel Sun RPC.
   *
   * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
   */
  
  #ifndef _LINUX_SUNRPC_SCHED_H_
  #define _LINUX_SUNRPC_SCHED_H_
  
  #include <linux/timer.h>
  #include <linux/ktime.h>
  #include <linux/sunrpc/types.h>
  #include <linux/spinlock.h>
  #include <linux/wait.h>
  #include <linux/workqueue.h>
  #include <linux/sunrpc/xdr.h>
  
  /*
   * This is the actual RPC procedure call info.
   */
  struct rpc_procinfo;
  struct rpc_message {
  	struct rpc_procinfo *	rpc_proc;	/* Procedure information */
  	void *			rpc_argp;	/* Arguments */
  	void *			rpc_resp;	/* Result */
  	struct rpc_cred *	rpc_cred;	/* Credentials */
  };
  
  struct rpc_call_ops;
  struct rpc_wait_queue;
  struct rpc_wait {
  	struct list_head	list;		/* wait queue links */
  	struct list_head	links;		/* Links to related tasks */
  	struct list_head	timer_list;	/* Timer list */
  	unsigned long		expires;
  };
  
  /*
   * This is the RPC task struct
   */
  struct rpc_task {
  	atomic_t		tk_count;	/* Reference count */
  	struct list_head	tk_task;	/* global list of tasks */
  	struct rpc_clnt *	tk_client;	/* RPC client */
  	struct rpc_rqst *	tk_rqstp;	/* RPC request */
  
  	/*
  	 * RPC call state
  	 */
  	struct rpc_message	tk_msg;		/* RPC call info */
  
  	/*
  	 * callback	to be executed after waking up
  	 * action	next procedure for async tasks
  	 * tk_ops	caller callbacks
  	 */
  	void			(*tk_callback)(struct rpc_task *);
  	void			(*tk_action)(struct rpc_task *);
  	const struct rpc_call_ops *tk_ops;
  	void *			tk_calldata;
  
  	unsigned long		tk_timeout;	/* timeout for rpc_sleep() */
  	unsigned long		tk_runstate;	/* Task run status */
  	struct workqueue_struct	*tk_workqueue;	/* Normally rpciod, but could
  						 * be any workqueue
  						 */
  	struct rpc_wait_queue 	*tk_waitqueue;	/* RPC wait queue we're on */
  	union {
  		struct work_struct	tk_work;	/* Async task work queue */
  		struct rpc_wait		tk_wait;	/* RPC wait */
  	} u;
  
  	ktime_t			tk_start;	/* RPC task init timestamp */
  
  	pid_t			tk_owner;	/* Process id for batching tasks */
  	int			tk_status;	/* result of last operation */
  	unsigned short		tk_flags;	/* misc flags */
  	unsigned short		tk_timeouts;	/* maj timeouts */
  
  #if defined(RPC_DEBUG) || defined(RPC_TRACEPOINTS)
  	unsigned short		tk_pid;		/* debugging aid */
  #endif
  	unsigned char		tk_priority : 2,/* Task priority */
  				tk_garb_retry : 2,
  				tk_cred_retry : 2,
  				tk_rebind_retry : 2;
  };
  
  typedef void			(*rpc_action)(struct rpc_task *);
  
  struct rpc_call_ops {
  	void (*rpc_call_prepare)(struct rpc_task *, void *);
  	void (*rpc_call_done)(struct rpc_task *, void *);
  	void (*rpc_count_stats)(struct rpc_task *, void *);
  	void (*rpc_release)(void *);
  };
  
  struct rpc_task_setup {
  	struct rpc_task *task;
  	struct rpc_clnt *rpc_client;
  	const struct rpc_message *rpc_message;
  	const struct rpc_call_ops *callback_ops;
  	void *callback_data;
  	struct workqueue_struct *workqueue;
  	unsigned short flags;
  	signed char priority;
  };
  
  /*
   * RPC task flags
   */
  #define RPC_TASK_ASYNC		0x0001		/* is an async task */
  #define RPC_TASK_SWAPPER	0x0002		/* is swapping in/out */
  #define RPC_CALL_MAJORSEEN	0x0020		/* major timeout seen */
  #define RPC_TASK_ROOTCREDS	0x0040		/* force root creds */
  #define RPC_TASK_DYNAMIC	0x0080		/* task was kmalloc'ed */
  #define RPC_TASK_KILLED		0x0100		/* task was killed */
  #define RPC_TASK_SOFT		0x0200		/* Use soft timeouts */
  #define RPC_TASK_SOFTCONN	0x0400		/* Fail if can't connect */
  #define RPC_TASK_SENT		0x0800		/* message was sent */
  #define RPC_TASK_TIMEOUT	0x1000		/* fail with ETIMEDOUT on timeout */
  #define RPC_TASK_NOCONNECT	0x2000		/* return ENOTCONN if not connected */
  #define RPC_TASK_NO_RETRANS_TIMEOUT	0x4000		/* wait forever for a reply */
  
  #define RPC_IS_ASYNC(t)		((t)->tk_flags & RPC_TASK_ASYNC)
  #define RPC_IS_SWAPPER(t)	((t)->tk_flags & RPC_TASK_SWAPPER)
  #define RPC_DO_ROOTOVERRIDE(t)	((t)->tk_flags & RPC_TASK_ROOTCREDS)
  #define RPC_ASSASSINATED(t)	((t)->tk_flags & RPC_TASK_KILLED)
  #define RPC_IS_SOFT(t)		((t)->tk_flags & (RPC_TASK_SOFT|RPC_TASK_TIMEOUT))
  #define RPC_IS_SOFTCONN(t)	((t)->tk_flags & RPC_TASK_SOFTCONN)
  #define RPC_WAS_SENT(t)		((t)->tk_flags & RPC_TASK_SENT)
  
  #define RPC_TASK_RUNNING	0
  #define RPC_TASK_QUEUED		1
  #define RPC_TASK_ACTIVE		2
  
  #define RPC_IS_RUNNING(t)	test_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
  #define rpc_set_running(t)	set_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
  #define rpc_test_and_set_running(t) \
  				test_and_set_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
  #define rpc_clear_running(t)	\
  	do { \
  		smp_mb__before_clear_bit(); \
  		clear_bit(RPC_TASK_RUNNING, &(t)->tk_runstate); \
  		smp_mb__after_clear_bit(); \
  	} while (0)
  
  #define RPC_IS_QUEUED(t)	test_bit(RPC_TASK_QUEUED, &(t)->tk_runstate)
  #define rpc_set_queued(t)	set_bit(RPC_TASK_QUEUED, &(t)->tk_runstate)
  #define rpc_clear_queued(t)	\
  	do { \
  		smp_mb__before_clear_bit(); \
  		clear_bit(RPC_TASK_QUEUED, &(t)->tk_runstate); \
  		smp_mb__after_clear_bit(); \
  	} while (0)
  
  #define RPC_IS_ACTIVATED(t)	test_bit(RPC_TASK_ACTIVE, &(t)->tk_runstate)
  
  /*
   * Task priorities.
   * Note: if you change these, you must also change
   * the task initialization definitions below.
   */
  #define RPC_PRIORITY_LOW	(-1)
  #define RPC_PRIORITY_NORMAL	(0)
  #define RPC_PRIORITY_HIGH	(1)
  #define RPC_PRIORITY_PRIVILEGED	(2)
  #define RPC_NR_PRIORITY		(1 + RPC_PRIORITY_PRIVILEGED - RPC_PRIORITY_LOW)
  
  struct rpc_timer {
  	struct timer_list timer;
  	struct list_head list;
  	unsigned long expires;
  };
  
  /*
   * RPC synchronization objects
   */
  struct rpc_wait_queue {
  	spinlock_t		lock;
  	struct list_head	tasks[RPC_NR_PRIORITY];	/* task queue for each priority level */
  	pid_t			owner;			/* process id of last task serviced */
  	unsigned char		maxpriority;		/* maximum priority (0 if queue is not a priority queue) */
  	unsigned char		priority;		/* current priority */
  	unsigned char		nr;			/* # tasks remaining for cookie */
  	unsigned short		qlen;			/* total # tasks waiting in queue */
  	struct rpc_timer	timer_list;
  #if defined(RPC_DEBUG) || defined(RPC_TRACEPOINTS)
  	const char *		name;
  #endif
  };
  
  /*
   * This is the # requests to send consecutively
   * from a single cookie.  The aim is to improve
   * performance of NFS operations such as read/write.
   */
  #define RPC_BATCH_COUNT			16
  #define RPC_IS_PRIORITY(q)		((q)->maxpriority > 0)
  
  /*
   * Function prototypes
   */
  struct rpc_task *rpc_new_task(const struct rpc_task_setup *);
  struct rpc_task *rpc_run_task(const struct rpc_task_setup *);
  struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
  				const struct rpc_call_ops *ops);
  void		rpc_put_task(struct rpc_task *);
  void		rpc_put_task_async(struct rpc_task *);
  void		rpc_exit_task(struct rpc_task *);
  void		rpc_exit(struct rpc_task *, int);
  void		rpc_release_calldata(const struct rpc_call_ops *, void *);
  void		rpc_killall_tasks(struct rpc_clnt *);
  void		rpc_execute(struct rpc_task *);
  void		rpc_init_priority_wait_queue(struct rpc_wait_queue *, const char *);
  void		rpc_init_wait_queue(struct rpc_wait_queue *, const char *);
  void		rpc_destroy_wait_queue(struct rpc_wait_queue *);
  void		rpc_sleep_on(struct rpc_wait_queue *, struct rpc_task *,
  					rpc_action action);
  void		rpc_sleep_on_priority(struct rpc_wait_queue *,
  					struct rpc_task *,
  					rpc_action action,
  					int priority);
  void		rpc_wake_up_queued_task(struct rpc_wait_queue *,
  					struct rpc_task *);
  void		rpc_wake_up(struct rpc_wait_queue *);
  struct rpc_task *rpc_wake_up_next(struct rpc_wait_queue *);
  struct rpc_task *rpc_wake_up_first(struct rpc_wait_queue *,
  					bool (*)(struct rpc_task *, void *),
  					void *);
  void		rpc_wake_up_status(struct rpc_wait_queue *, int);
  void		rpc_delay(struct rpc_task *, unsigned long);
  void *		rpc_malloc(struct rpc_task *, size_t);
  void		rpc_free(void *);
  int		rpciod_up(void);
  void		rpciod_down(void);
  int		__rpc_wait_for_completion_task(struct rpc_task *task, int (*)(void *));
  #ifdef RPC_DEBUG
  struct net;
  void		rpc_show_tasks(struct net *);
  #endif
  int		rpc_init_mempool(void);
  void		rpc_destroy_mempool(void);
  extern struct workqueue_struct *rpciod_workqueue;
  void		rpc_prepare_task(struct rpc_task *task);
  
  static inline int rpc_wait_for_completion_task(struct rpc_task *task)
  {
  	return __rpc_wait_for_completion_task(task, NULL);
  }
  
  #if defined(RPC_DEBUG) || defined (RPC_TRACEPOINTS)
  static inline const char * rpc_qname(const struct rpc_wait_queue *q)
  {
  	return ((q && q->name) ? q->name : "unknown");
  }
  
  static inline void rpc_assign_waitqueue_name(struct rpc_wait_queue *q,
  		const char *name)
  {
  	q->name = name;
  }
  #else
  static inline void rpc_assign_waitqueue_name(struct rpc_wait_queue *q,
  		const char *name)
  {
  }
  #endif
  
  #endif /* _LINUX_SUNRPC_SCHED_H_ */