1/*-
2 * Copyright (c) 2003, 2005 Alan L. Cox <alc@cs.rice.edu>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * $FreeBSD$
27 */
28
29#ifndef _MACHINE_SF_BUF_H_
30#define	_MACHINE_SF_BUF_H_
31
32/*
33 * On this machine, the only purpose for which sf_buf is used is to implement
34 * an opaque pointer required by the machine-independent parts of the kernel.
35 * That pointer references the vm_page that is "mapped" by the sf_buf.  The
36 * actual mapping is provided by the direct virtual-to-physical mapping.
37 */
38static inline vm_offset_t
39sf_buf_kva(struct sf_buf *sf)
40{
41
42	return (PHYS_TO_DMAP(VM_PAGE_TO_PHYS((vm_page_t)sf)));
43}
44
45static inline vm_page_t
46sf_buf_page(struct sf_buf *sf)
47{
48
49	return ((vm_page_t)sf);
50}
51#endif /* !_MACHINE_SF_BUF_H_ */
52