2 * Copyright (c) 2004 The DragonFly Project. All rights reserved.
4 * This code is derived from software contributed to The DragonFly Project
5 * by Hiten Pandya <hmp@backplane.com> and Matthew Dillon
6 * <dillon@backplane.com>.
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in
16 * the documentation and/or other materials provided with the
18 * 3. Neither the name of The DragonFly Project nor the names of its
19 * contributors may be used to endorse or promote products derived
20 * from this software without specific, prior written permission.
22 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
23 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
24 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
25 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
26 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
27 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
28 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
29 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
30 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
31 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
32 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * The MSF_BUF API is an augmentation similar to the SFBUF APIs and uses XIO
36 * page array handling. The SFBUF API originally came from:
38 * Copyright (c) 2003 Alan L. Cox <alc@cs.rice.edu>. All rights reserved.
39 * Copyright (c) 1998 David Greenman. All rights reserved.
40 * src/sys/sys/sfbuf.h,v 1.4 2004/04/01 17:58:06 dillon
42 * $DragonFly: src/sys/sys/msfbuf.h,v 1.4 2004/07/12 06:17:03 hmp Exp $
44 #ifndef _SYS_MSFBUF_H_
45 #define _SYS_MSFBUF_H_
48 #include <sys/queue.h>
56 * MSF_BUFs are used for caching ephermal mappings that span more than
59 * The interface returns an msf_buf data structure which has information
60 * about managing the ephermal mapping, its KVA pointer and an embedded
61 * XIO structure which describes the mapping.
63 * The embedded XIO structure be passed around to the DEV system because
64 * it is ref-counted; thus making it perfectly usable by anything that
65 * can accept an XIO as a transfer unit, most notably the buffer-cache
71 LIST_ENTRY(msf_buf) active_list; /* active list of buffers */
72 TAILQ_ENTRY(msf_buf) free_list; /* free list of buffers */
73 vm_offset_t m_kva; /* KVA offset */
74 cpumask_t m_cpumask; /* CPU mask for synchronization */
75 struct xio m_xio; /* xio embedded */
76 int m_refcnt; /* map usage tracking */
77 int m_flags; /* control flags */
83 * Return a KVA offset to the client
87 msf_buf_kva(struct msf_buf *msf)
93 * Return a reference to the underlying pages of an MSF_BUF
97 msf_buf_pages(struct msf_buf *msf)
99 return (msf->m_xio.xio_pages);
102 /* API function prototypes */
103 struct msf_buf *msf_buf_alloc(vm_page_t *pg_ary, int npages, int flags);
104 void msf_buf_free(struct msf_buf *);
105 void msf_buf_ref(struct msf_buf *);