NetBSD/sys/sys/bufq.h

159 lines
6.1 KiB
C

/* $NetBSD: bufq.h,v 1.3 2005/03/31 11:28:53 yamt Exp $ */
/* NetBSD: buf.h,v 1.75 2004/09/18 16:40:11 yamt Exp */
/*-
* Copyright (c) 1999, 2000 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
* NASA Ames Research Center.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the NetBSD
* Foundation, Inc. and its contributors.
* 4. Neither the name of The NetBSD Foundation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
/*
* Copyright (c) 1982, 1986, 1989, 1993
* The Regents of the University of California. All rights reserved.
* (c) UNIX System Laboratories, Inc.
* All or some portions of this file are derived from material licensed
* to the University of California by American Telephone and Telegraph
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)buf.h 8.9 (Berkeley) 3/30/95
*/
#if !defined(_KERNEL)
#error not supposed to be exposed to userland.
#endif
struct buf;
/*
* Device driver buffer queue.
*/
struct bufq_state {
void (*bq_put)(struct bufq_state *, struct buf *);
struct buf *(*bq_get)(struct bufq_state *, int);
void *bq_private;
int bq_flags; /* Flags from bufq_alloc() */
};
/*
* Flags for bufq_alloc.
*/
#define BUFQ_SORT_RAWBLOCK 0x0001 /* Sort by b_rawblkno */
#define BUFQ_SORT_CYLINDER 0x0002 /* Sort by b_cylinder, b_rawblkno */
#define _BUFQ_DEFAULT 0x00f0 /* Let bufq_alloc() choose strategy */
#define BUFQ_FCFS 0x0010 /* First-come first-serve */
#define BUFQ_DISKSORT 0x0020 /* Min seek sort */
#define BUFQ_READ_PRIO 0x0030 /* Min seek and read priority */
#define BUFQ_PRIOCSCAN 0x0040 /* Per-priority CSCAN */
#define BUFQ_SORT_MASK 0x000f
#define BUFQ_METHOD_MASK 0x00f0
extern int bufq_disk_default_strat;
#define BUFQ_DISK_DEFAULT_STRAT() bufq_disk_default_strat
void bufq_alloc(struct bufq_state *, int);
void bufq_drain(struct bufq_state *);
void bufq_free(struct bufq_state *);
#define BUFQ_PUT(bufq, bp) \
(*(bufq)->bq_put)((bufq), (bp)) /* Put buffer in queue */
#define BUFQ_GET(bufq) \
(*(bufq)->bq_get)((bufq), 1) /* Get and remove buffer from queue */
#define BUFQ_PEEK(bufq) \
(*(bufq)->bq_get)((bufq), 0) /* Get buffer from queue */
static __inline int buf_inorder(const struct buf *, const struct buf *, int)
__unused;
#include <sys/null.h> /* for NULL */
/*
* Check if two buf's are in ascending order.
*/
static __inline int
buf_inorder(const struct buf *bp, const struct buf *bq, int sortby)
{
if (bp == NULL || bq == NULL)
return (bq == NULL);
if (sortby == BUFQ_SORT_CYLINDER) {
if (bp->b_cylinder != bq->b_cylinder)
return bp->b_cylinder < bq->b_cylinder;
else
return bp->b_rawblkno < bq->b_rawblkno;
} else
return bp->b_rawblkno < bq->b_rawblkno;
}
struct bufq_strat {
const char *bs_name;
void (*bs_initfn)(struct bufq_state *);
int bs_id;
};
#define BUFQ_DEFINE(name, id, initfn) \
static const struct bufq_strat bufq_strat_##name = { \
.bs_name = #name, \
.bs_id = id, \
.bs_initfn = initfn \
}; \
__link_set_add_rodata(bufq_strats, bufq_strat_##name)