Annotation of src/sys/sys/xio.h, revision 1.6

1.1       dillon      1: /*
1.5       dillon      2:  * Copyright (c) 2003,2004 The DragonFly Project.  All rights reserved.
                      3:  * 
                      4:  * This code is derived from software contributed to The DragonFly Project
                      5:  * by Matthew Dillon <dillon@backplane.com>
                      6:  * 
1.1       dillon      7:  * Redistribution and use in source and binary forms, with or without
                      8:  * modification, are permitted provided that the following conditions
                      9:  * are met:
1.5       dillon     10:  * 
1.1       dillon     11:  * 1. Redistributions of source code must retain the above copyright
                     12:  *    notice, this list of conditions and the following disclaimer.
                     13:  * 2. Redistributions in binary form must reproduce the above copyright
1.5       dillon     14:  *    notice, this list of conditions and the following disclaimer in
                     15:  *    the documentation and/or other materials provided with the
                     16:  *    distribution.
                     17:  * 3. Neither the name of The DragonFly Project nor the names of its
                     18:  *    contributors may be used to endorse or promote products derived
                     19:  *    from this software without specific, prior written permission.
                     20:  * 
                     21:  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
                     22:  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
                     23:  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
                     24:  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
                     25:  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
                     26:  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
                     27:  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
                     28:  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
                     29:  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
                     30:  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
                     31:  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
1.1       dillon     32:  * SUCH DAMAGE.
1.5       dillon     33:  * 
1.1       dillon     34:  * $DragonFly$
                     35:  */
                     36: 
                     37: /*
1.6     ! dillon     38:  * An XIO holds a platform-agnostic page list representing a data set for
        !            39:  * the purposes of I/O, mapping (SFBUF/MSFBUF), or other operations.  The
        !            40:  * representation of the data set is byte aligned.  xio_offset and xio_bytes
        !            41:  * specifies the precise byte-ranged block within the page list being
        !            42:  * represented.
        !            43:  *
        !            44:  * XIOs do not track an ongoing I/O, they simply represent a block of data.
        !            45:  * For this reason most XIO API functions have a 'uoffset' argument which
        !            46:  * the caller may use to index within the represented dataset.  This index
        !            47:  * is relative to the represented dataset, NOT to the beginning of the
        !            48:  * first page.
1.1       dillon     49:  */
                     50: #ifndef _SYS_XIO_H_
                     51: #define        _SYS_XIO_H_
                     52: 
                     53: #if defined(_KERNEL) || defined(_KERNEL_STRUCTURES)
                     54: 
                     55: #ifndef _SYS_MSGPORT_H_
                     56: #include <sys/msgport.h>
                     57: #endif
                     58: 
                     59: #define XIO_INTERNAL_PAGES     btoc(MAXPHYS)
                     60: #define XIO_INTERNAL_SIZE      (XIO_INTERNAL_PAGES * PAGE_SIZE)
                     61: 
                     62: struct vm_page;
                     63: 
                     64: struct xio {
                     65:        struct vm_page **xio_pages;
                     66:        int     xio_npages;     /* number of pages in xio_pages[] array */
                     67:        int     xio_offset;     /* byte offset (may exceed a page) */
                     68:        int     xio_bytes;      /* number of bytes to transfer */
                     69:        int     xio_flags;
                     70:        int     xio_error;
                     71:        struct vm_page *xio_internal_pages[XIO_INTERNAL_PAGES];
                     72: };
                     73: 
                     74: typedef struct xio *xio_t;
                     75: 
                     76: #define XIOF_READ      0x0001
                     77: #define XIOF_WRITE     0x0002
                     78: 
                     79: #endif
                     80: 
                     81: #if defined(_KERNEL)
                     82: 
1.4       dillon     83: void xio_init(xio_t xio);
1.1       dillon     84: int xio_init_ubuf(xio_t xio, void *ubase, size_t ubytes, int vmprot);
                     85: int xio_init_kbuf(xio_t xio, void *kbase, size_t kbytes);
                     86: void xio_release(xio_t xio);
1.6     ! dillon     87: int xio_uio_copy(xio_t xio, int uoffset, struct uio *uio, int *sizep);
        !            88: int xio_copy_xtou(xio_t xio, int uoffset, void *uptr, int bytes);
        !            89: int xio_copy_xtok(xio_t xio, int uoffset, void *kptr, int bytes);
        !            90: 
        !            91: /*
        !            92:  * XIOs are not modified by copy operations, the caller must track the 
        !            93:  * offset itself.  This routine will return the number of bytes remaining
        !            94:  * in an XIO's buffer given an offset relative to the buffer used to
        !            95:  * originally construct the XIO.
        !            96:  */
        !            97: static __inline
        !            98: int
        !            99: xio_remaining(xio_t xio, int uoffset)
        !           100: {
        !           101:        return(xio->xio_bytes - uoffset);
        !           102: }
        !           103: 
        !           104: /*
        !           105:  * XIOs do not map data but if the page list WERE mapped, this routine will
        !           106:  * return the actual KVA offset given a user offset relative to the original
        !           107:  * buffer used to construct the XIO.
        !           108:  */
        !           109: static __inline
        !           110: int
        !           111: xio_kvaoffset(xio_t xio, int uoffset)
        !           112: {
        !           113:        return(xio->xio_offset + uoffset);
        !           114: }
1.1       dillon    115: 
                    116: #endif /* _KERNEL */
                    117: 
1.2       joerg     118: #endif /* !_SYS_XIO_H_ */