1 /* 2 * Copyright (c) 1996 John S. Dyson 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 immediately at the beginning of the file, without modification, 10 * this list of conditions, and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. Absolutely no warranty of function or purpose is made by the author 15 * John S. Dyson. 16 * 4. This work was done expressly for inclusion into FreeBSD. Other use 17 * is allowed if this notation is included. 18 * 5. Modifications may be freely made to this file if the above conditions 19 * are met. 20 * 21 * $FreeBSD: src/sys/sys/pipe.h,v 1.16 1999/12/29 04:24:45 peter Exp $ 22 * $DragonFly: src/sys/sys/pipe.h,v 1.10 2006/06/10 20:00:17 dillon Exp $ 23 */ 24 25 #ifndef _SYS_PIPE_H_ 26 #define _SYS_PIPE_H_ 27 28 #if defined(_KERNEL) || defined(_KERNEL_STRUCTURES) 29 30 #ifndef _SYS_TYPES_H_ 31 #include <sys/types.h> 32 #endif 33 #ifndef _SYS_TIME_H_ 34 #include <sys/time.h> /* for struct timespec */ 35 #endif 36 #ifndef _SYS_SELINFO_H_ 37 #include <sys/selinfo.h> /* for struct selinfo */ 38 #endif 39 #ifndef _SYS_XIO_H_ 40 #include <sys/xio.h> /* for struct xio */ 41 #endif 42 #ifndef _MACHINE_PARAM_H_ 43 #include <machine/param.h> /* for PAGE_SIZE */ 44 #endif 45 46 /* 47 * Pipe buffer size, keep moderate in value, pipes take kva space. 48 */ 49 #ifndef PIPE_SIZE 50 #define PIPE_SIZE 16384 51 #endif 52 53 #ifndef BIG_PIPE_SIZE 54 #define BIG_PIPE_SIZE (64*1024) 55 #endif 56 57 /* 58 * PIPE_MINDIRECT MUST be smaller than PIPE_SIZE and MUST be bigger 59 * than PIPE_BUF. 60 */ 61 #ifndef PIPE_MINDIRECT 62 #define PIPE_MINDIRECT 8192 63 #endif 64 65 /* 66 * Pipe buffer information. 67 * Separate in, out, cnt are used to simplify calculations. 68 * Buffered write is active when the buffer.cnt field is set. 69 */ 70 struct pipebuf { 71 u_int cnt; /* number of chars currently in buffer */ 72 u_int in; /* in pointer */ 73 u_int out; /* out pointer */ 74 u_int size; /* size of buffer */ 75 caddr_t buffer; /* kva of buffer */ 76 struct vm_object *object; /* VM object containing buffer */ 77 }; 78 79 /* 80 * Bits in pipe_state. 81 */ 82 #define PIPE_ASYNC 0x0004 /* Async? I/O. */ 83 #define PIPE_WANTR 0x0008 /* Reader wants some characters. */ 84 #define PIPE_WANTW 0x0010 /* Writer wants space to put characters. */ 85 #define PIPE_WANT 0x0020 /* Pipe is wanted to be run-down. */ 86 #define PIPE_SEL 0x0040 /* Pipe has a select active. */ 87 #define PIPE_EOF 0x0080 /* Pipe is in EOF condition. */ 88 #define PIPE_LOCK 0x0100 /* Process has exclusive access to pointers/data. */ 89 #define PIPE_LWANT 0x0200 /* Process wants exclusive access to pointers/data. */ 90 #define PIPE_DIRECTW 0x0400 /* Pipe direct write active. */ 91 #define PIPE_DIRECTOK 0x0800 /* Direct mode ok. */ 92 #define PIPE_DIRECTIP 0x1000 /* Direct write buffer build in progress */ 93 94 enum pipe_feature { PIPE_COPY, PIPE_KMEM, PIPE_SFBUF1, PIPE_SFBUF2 }; 95 /* 96 * Per-pipe data structure. 97 * Two of these are linked together to produce bi-directional pipes. 98 * 99 * NOTE: pipe_buffer.out has the dual purpose of tracking the copy offset 100 * for both the direct write case (with the rest of pipe_buffer) and the 101 * buffered write case (with pipe_map). 102 */ 103 struct pipe { 104 struct pipebuf pipe_buffer; /* data storage */ 105 struct xio pipe_map; /* mapping for direct I/O */ 106 vm_offset_t pipe_kva; /* kva mapping (testing only) */ 107 cpumask_t pipe_kvamask; /* kva cpu mask opt */ 108 struct selinfo pipe_sel; /* for compat with select */ 109 struct timespec pipe_atime; /* time of last access */ 110 struct timespec pipe_mtime; /* time of last modify */ 111 struct timespec pipe_ctime; /* time of status change */ 112 struct sigio *pipe_sigio; /* information for async I/O */ 113 struct pipe *pipe_peer; /* link with other direction */ 114 u_int pipe_state; /* pipe status info */ 115 enum pipe_feature pipe_feature; /* pipe transfer features */ 116 int pipe_busy; /* busy flag, mostly to handle rundown sanely */ 117 }; 118 119 #endif /* _KERNEL || _KERNEL_STRUCTURES */ 120 #endif /* !_SYS_PIPE_H_ */ 121