1 /* 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 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 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 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 32 * SUCH DAMAGE. 33 * 34 * $DragonFly: src/sys/sys/xio.h,v 1.6 2005/03/01 23:35:16 dillon Exp $ 35 */ 36 37 /* 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. 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 83 void xio_init(xio_t xio); 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); 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 } 115 116 #endif /* _KERNEL */ 117 118 #endif /* !_SYS_XIO_H_ */ 119