sys/sys/sfbuf.h

   1 /*
   2  * Copyright (c) 2003 Alan L. Cox <alc@cs.rice.edu>.  All rights reserved.
   3  * Copyright (c) 1998 David Greenman.  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  * $DragonFly: src/sys/sys/sfbuf.h,v 1.9 2006/05/20 02:42:13 dillon Exp $
  27  */
  28
  29 #ifndef _SFBUF_H_
  30 #define _SFBUF_H_
  31
  32 #ifndef _SYS_TYPES_H_
  33 #include <sys/types.h>
  34 #endif
  35 #ifndef _SYS_QUEUE_H_
  36 #include <sys/queue.h>
  37 #endif
  38
  39
  40 #if !defined(_KERNEL) && !defined(_KERNEL_STRUCTURES)
  41 #error "This file should not be included by userland programs."
  42 #endif
  43
  44 struct sf_buf {
  45         LIST_ENTRY(sf_buf) list_entry;  /* hash chain of active buffers */
  46         TAILQ_ENTRY(sf_buf) free_entry; /* list of free buffers */
  47         struct          vm_page *m;     /* currently mapped page */
  48         vm_offset_t     kva;            /* va of mapping */
  49         int             refcnt;         /* usage of this mapping */
  50         int             flags;          /* global SFBA flags */
  51         cpumask_t       cpumask;        /* cpu mapping synchronization */
  52 };
  53
  54 /*
  55  * sf_buf_alloc() flags (not all are stored in sf->flags)
  56  */
  57 #define SFB_CPUPRIVATE  0x0001          /* sync mapping to current cpu only */
  58 #define SFBA_ONFREEQ    0x0002          /* on the free queue (lazy move) */
  59 #define SFB_CATCH       0x0004          /* allow interruption */
  60
  61 static __inline vm_offset_t
  62 sf_buf_kva(struct sf_buf *sf)
  63 {
  64         return(sf->kva);
  65 }
  66
  67 static __inline struct vm_page *
  68 sf_buf_page(struct sf_buf *sf)
  69 {
  70          return(sf->m);
  71 }
  72
  73
  74 #if defined(_KERNEL)
  75
  76 extern int nsfbufs;
  77
  78 struct sf_buf  *sf_buf_alloc(struct vm_page *, int flags);
  79 void            sf_buf_free(struct sf_buf *);
  80 void            sf_buf_ref(struct sf_buf *);
  81
  82 #endif
  83
  84 #endif