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      1 /*	$NetBSD: callout.h,v 1.32 2015/02/07 19:36:42 christos Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2000, 2003, 2006, 2007, 2008 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
      9  * NASA Ames Research Center, and by Andrew Doran.
     10  *
     11  * Redistribution and use in source and binary forms, with or without
     12  * modification, are permitted provided that the following conditions
     13  * are met:
     14  * 1. Redistributions of source code must retain the above copyright
     15  *    notice, this list of conditions and the following disclaimer.
     16  * 2. Redistributions in binary form must reproduce the above copyright
     17  *    notice, this list of conditions and the following disclaimer in the
     18  *    documentation and/or other materials provided with the distribution.
     19  *
     20  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     22  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     23  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     24  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     30  * POSSIBILITY OF SUCH DAMAGE.
     31  */
     32 
     33 #ifndef _SYS_CALLOUT_H_
     34 #define _SYS_CALLOUT_H_
     35 
     36 #include <sys/types.h>
     37 
     38 /*
     39  * The callout implementation is private to kern_timeout.c yet uses
     40  * caller-supplied storage, as lightweight callout operations are
     41  * critical to system performance.
     42  *
     43  * The size of callout_t must remain constant in order to ensure ABI
     44  * compatibility for kernel modules: it may become smaller, but must
     45  * not grow.  If more space is required, rearrange the members of
     46  * callout_impl_t.
     47  */
     48 typedef struct callout {
     49 	void	*_c_store[10];
     50 } callout_t;
     51 
     52 /* Internal flags. */
     53 #define	CALLOUT_BOUND		0x0001	/* bound to a specific CPU */
     54 #define	CALLOUT_PENDING		0x0002	/* callout is on the queue */
     55 #define	CALLOUT_FIRED		0x0004	/* callout has fired */
     56 #define	CALLOUT_INVOKING	0x0008	/* callout function is being invoked */
     57 
     58 /* End-user flags. */
     59 #define	CALLOUT_MPSAFE		0x0100	/* does not need kernel_lock */
     60 #define	CALLOUT_FLAGMASK	0xff00
     61 
     62 #define CALLOUT_FMT	"\177\020\
     63 b\00BOUND\0\
     64 b\01PENDING\0\
     65 b\02FIRED\0\
     66 b\03INVOKING\0\
     67 b\10MPSAFE\0"
     68 
     69 #ifdef _CALLOUT_PRIVATE
     70 
     71 /* The following funkyness is to appease gcc3's strict aliasing. */
     72 struct callout_circq {
     73 	/* next element */
     74 	union {
     75 		struct callout_impl	*elem;
     76 		struct callout_circq	*list;
     77 	} cq_next;
     78 	/* previous element */
     79 	union {
     80 		struct callout_impl	*elem;
     81 		struct callout_circq	*list;
     82 	} cq_prev;
     83 };
     84 #define	cq_next_e	cq_next.elem
     85 #define	cq_prev_e	cq_prev.elem
     86 #define	cq_next_l	cq_next.list
     87 #define	cq_prev_l	cq_prev.list
     88 
     89 struct callout_cpu;
     90 
     91 typedef struct callout_impl {
     92 	struct callout_circq c_list;		/* linkage on queue */
     93 	void	(*c_func)(void *);		/* function to call */
     94 	void	*c_arg;				/* function argument */
     95 	struct callout_cpu * volatile c_cpu;	/* associated CPU */
     96 	int	c_time;				/* when callout fires */
     97 	u_int	c_flags;			/* state of this entry */
     98 	u_int	c_magic;			/* magic number */
     99 } callout_impl_t;
    100 #define	CALLOUT_MAGIC		0x11deeba1
    101 
    102 #endif	/* _CALLOUT_PRIVATE */
    103 
    104 #ifdef _KERNEL
    105 struct cpu_info;
    106 
    107 void	callout_startup(void);
    108 void	callout_init_cpu(struct cpu_info *);
    109 void	callout_hardclock(void);
    110 
    111 void	callout_init(callout_t *, u_int);
    112 void	callout_destroy(callout_t *);
    113 void	callout_setfunc(callout_t *, void (*)(void *), void *);
    114 void	callout_reset(callout_t *, int, void (*)(void *), void *);
    115 void	callout_schedule(callout_t *, int);
    116 bool	callout_stop(callout_t *);
    117 bool	callout_halt(callout_t *, void *);
    118 bool	callout_pending(callout_t *);
    119 bool	callout_expired(callout_t *);
    120 bool	callout_active(callout_t *);
    121 bool	callout_invoking(callout_t *);
    122 void	callout_ack(callout_t *);
    123 void	callout_bind(callout_t *, struct cpu_info *);
    124 #endif	/* _KERNEL */
    125 
    126 #endif /* !_SYS_CALLOUT_H_ */
    127