1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */ 22 /* All Rights Reserved */ 23 24 25 /* 26 * Copyright 2009 Sun Microsystems, Inc. All rights reserved. 27 * Use is subject to license terms. 28 * 29 * Copyright 2017 Nexenta Systems, Inc. All rights reserved. 30 */ 31 32 /* 33 * UNIX Device Driver Interface functions 34 * (excerpts) 35 */ 36 37 #include <sys/types.h> 38 #include <sys/sysmacros.h> 39 #include <sys/param.h> 40 #include <sys/ddi.h> 41 #include <sys/mkdev.h> 42 #include <sys/debug.h> 43 44 #ifndef NODEV32 45 #define NODEV32 (dev32_t)(-1) 46 #endif /* NODEV32 */ 47 48 /* 49 * return internal major number corresponding to device 50 * number (new format) argument 51 */ 52 major_t 53 getmajor(dev_t dev) 54 { 55 #ifdef _LP64 56 return ((major_t)((dev >> NBITSMINOR64) & MAXMAJ64)); 57 #else 58 return ((major_t)((dev >> NBITSMINOR) & MAXMAJ)); 59 #endif 60 } 61 62 /* 63 * return internal minor number corresponding to device 64 * number (new format) argument 65 */ 66 minor_t 67 getminor(dev_t dev) 68 { 69 #ifdef _LP64 70 return ((minor_t)(dev & MAXMIN64)); 71 #else 72 return ((minor_t)(dev & MAXMIN)); 73 #endif 74 } 75 76 /* 77 * encode external major and minor number arguments into a 78 * new format device number 79 */ 80 dev_t 81 makedevice(major_t maj, minor_t minor) 82 { 83 #ifdef _LP64 84 return (((dev_t)maj << NBITSMINOR64) | (minor & MAXMIN64)); 85 #else 86 return (((dev_t)maj << NBITSMINOR) | (minor & MAXMIN)); 87 #endif 88 } 89 90 /* 91 * Compress 'long' device number encoding to 32-bit device number 92 * encoding. If it won't fit, we return failure, but set the 93 * device number to 32-bit NODEV for the sake of our callers. 94 */ 95 int 96 cmpldev(dev32_t *dst, dev_t dev) 97 { 98 #if defined(_LP64) 99 if (dev == NODEV) { 100 *dst = NODEV32; 101 } else { 102 major_t major = dev >> L_BITSMINOR; 103 minor_t minor = dev & L_MAXMIN; 104 105 if (major > L_MAXMAJ32 || minor > L_MAXMIN32) { 106 *dst = NODEV32; 107 return (0); 108 } 109 110 *dst = (dev32_t)((major << L_BITSMINOR32) | minor); 111 } 112 #else 113 *dst = (dev32_t)dev; 114 #endif 115 return (1); 116 } 117 118 /* 119 * Expand 32-bit dev_t's to long dev_t's. Expansion always "fits" 120 * into the return type, but we're careful to expand NODEV explicitly. 121 */ 122 dev_t 123 expldev(dev32_t dev32) 124 { 125 #ifdef _LP64 126 if (dev32 == NODEV32) 127 return (NODEV); 128 return (makedevice((dev32 >> L_BITSMINOR32) & L_MAXMAJ32, 129 dev32 & L_MAXMIN32)); 130 #else 131 return ((dev_t)dev32); 132 #endif 133 } 134