xref: /dragonfly/sys/dev/virtual/vkernel/cdrom/vcd.c (revision 25a2db75)
1 /*
2  * Copyright (c) 2007 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 
35 /*
36  * Virtual CDROM driver
37  */
38 #include <sys/types.h>
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/kernel.h>
42 #include <sys/malloc.h>
43 #include <sys/conf.h>
44 #include <sys/buf.h>
45 #include <sys/devicestat.h>
46 #include <sys/disk.h>
47 #include <machine/md_var.h>
48 
49 #include <sys/buf2.h>
50 
51 #include <sys/stat.h>
52 #include <unistd.h>
53 
54 struct vcd_softc {
55 	struct bio_queue_head bio_queue;
56 	struct devstat stats;
57 	struct disk disk;
58 	cdev_t dev;
59 	int unit;
60 	int fd;
61 };
62 
63 static d_strategy_t	vcdstrategy;
64 static d_open_t		vcdopen;
65 
66 static struct dev_ops vcd_ops = {
67 	{ "vcd", 0, D_DISK },
68         .d_open =	vcdopen,
69         .d_close =	nullclose,
70         .d_read =	physread,
71         .d_write =	physwrite,
72         .d_strategy =	vcdstrategy,
73 };
74 
75 static void
76 vcdinit(void *dummy __unused)
77 {
78 	struct vkdisk_info *dsk;
79 	struct vcd_softc *sc;
80 	struct stat st;
81 	int i;
82 
83 	for (i = 0; i < DiskNum; i++) {
84 		/* check that the 'bus device' has been initialized */
85 		dsk = &DiskInfo[i];
86 		if (dsk == NULL || dsk->type != VKD_CD)
87 			continue;
88 		if (dsk->fd < 0 || fstat(dsk->fd, &st) < 0)
89 			continue;
90 
91 		/* and create a new device */
92 		sc = kmalloc(sizeof(*sc), M_DEVBUF, M_WAITOK | M_ZERO);
93 		sc->unit = dsk->unit;
94 		sc->fd = dsk->fd;
95 		bioq_init(&sc->bio_queue);
96 		devstat_add_entry(&sc->stats, "vcd", sc->unit, 2048,
97 				  DEVSTAT_NO_ORDERED_TAGS,
98 				  DEVSTAT_TYPE_DIRECT | DEVSTAT_TYPE_IF_OTHER,
99 				  DEVSTAT_PRIORITY_DISK);
100 		sc->dev = disk_create(sc->unit, &sc->disk, &vcd_ops);
101 		sc->dev->si_drv1 = sc;
102 		sc->dev->si_iosize_max = 256 * 1024;
103 	}
104 }
105 
106 SYSINIT(vcdisk, SI_SUB_DRIVERS, SI_ORDER_FIRST, vcdinit, NULL);
107 
108 static int
109 vcdopen(struct dev_open_args *ap)
110 {
111 	struct vcd_softc *sc;
112 	struct disk_info info;
113 	struct stat st;
114 	cdev_t dev;
115 
116 	dev = ap->a_head.a_dev;
117 	sc = dev->si_drv1;
118 	if (fstat(sc->fd, &st) < 0 || st.st_size == 0)
119 		return(ENXIO);
120 
121 	bzero(&info, sizeof(info));
122 	info.d_media_blksize = 2048;
123 	info.d_media_blocks = st.st_size / info.d_media_blksize;
124 	info.d_dsflags = DSO_ONESLICE | DSO_COMPATLABEL | DSO_COMPATPARTA |
125 			 DSO_RAWEXTENSIONS;
126 	info.d_nheads = 1;
127 	info.d_ncylinders = 1;
128 	info.d_secpertrack = info.d_media_blocks;
129 	info.d_secpercyl = info.d_secpertrack * info.d_nheads;
130 
131 	disk_setdiskinfo(&sc->disk, &info);
132 	return(0);
133 }
134 
135 static int
136 vcdstrategy(struct dev_strategy_args *ap)
137 {
138 	struct bio *bio = ap->a_bio;
139 	struct buf *bp;
140 	struct vcd_softc *sc;
141 	cdev_t dev;
142 	int n;
143 
144 	dev = ap->a_head.a_dev;
145 	sc = dev->si_drv1;
146 
147 	bioqdisksort(&sc->bio_queue, bio);
148 	while ((bio = bioq_takefirst(&sc->bio_queue)) != NULL) {
149 		bp = bio->bio_buf;
150 
151 		devstat_start_transaction(&sc->stats);
152 
153 		switch(bp->b_cmd) {
154 		case BUF_CMD_READ:
155 			n = pread(sc->fd, bp->b_data,
156 				  bp->b_bcount, bio->bio_offset);
157 			break;
158 		case BUF_CMD_WRITE:
159 			/* XXX HANDLE SHORT WRITE XXX */
160 			n = pwrite(sc->fd, bp->b_data,
161 				   bp->b_bcount, bio->bio_offset);
162 			break;
163 		default:
164 			panic("vcd: bad b_cmd %d", bp->b_cmd);
165 			break; /* not reached */
166 		}
167 		if (n != bp->b_bcount) {
168 			bp->b_error = EIO;
169 			bp->b_flags |= B_ERROR;
170 		}
171 
172 		bp->b_resid = bp->b_bcount - n;
173 		devstat_end_transaction_buf(&sc->stats, bp);
174 		biodone(bio);
175 	}
176 	return(0);
177 }
178