xref: /freebsd/sys/dev/cfi/cfi_disk.c (revision 830940567b49bb0c08dfaed40418999e76616909)
1 /*-
2  * Copyright (c) 2009 Sam Leffler, Errno Consulting
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, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24  */
25 
26 #include <sys/cdefs.h>
27 __FBSDID("$FreeBSD$");
28 
29 #include <sys/param.h>
30 #include <sys/systm.h>
31 #include <sys/bio.h>
32 #include <sys/bus.h>
33 #include <sys/conf.h>
34 #include <sys/kernel.h>
35 #include <sys/malloc.h>
36 #include <sys/lock.h>
37 #include <sys/mutex.h>
38 #include <sys/module.h>
39 #include <sys/rman.h>
40 #include <sys/sysctl.h>
41 #include <sys/taskqueue.h>
42 
43 #include <machine/bus.h>
44 
45 #include <dev/cfi/cfi_var.h>
46 
47 #include <geom/geom_disk.h>
48 
49 struct cfi_disk_softc {
50 	struct cfi_softc *parent;
51 	struct disk	*disk;
52 	int		flags;
53 #define	CFI_DISK_OPEN	0x0001
54 	struct bio_queue_head bioq;	/* bio queue */
55 	struct mtx	qlock;		/* bioq lock */
56 	struct taskqueue *tq;		/* private task queue for i/o request */
57 	struct task	iotask;		/* i/o processing */
58 };
59 
60 #define	CFI_DISK_SECSIZE	512
61 #define	CFI_DISK_MAXIOSIZE	65536
62 
63 static int cfi_disk_detach(device_t);
64 static int cfi_disk_open(struct disk *);
65 static int cfi_disk_close(struct disk *);
66 static void cfi_io_proc(void *, int);
67 static void cfi_disk_strategy(struct bio *);
68 static int cfi_disk_ioctl(struct disk *, u_long, void *, int, struct thread *);
69 
70 static int
71 cfi_disk_probe(device_t dev)
72 {
73 	return 0;
74 }
75 
76 static int
77 cfi_disk_attach(device_t dev)
78 {
79 	struct cfi_disk_softc *sc = device_get_softc(dev);
80 
81 	sc->parent = device_get_softc(device_get_parent(dev));
82 	/* validate interface width; assumed by other code */
83 	if (sc->parent->sc_width != 1 &&
84 	    sc->parent->sc_width != 2 &&
85 	    sc->parent->sc_width != 4)
86 		return EINVAL;
87 
88 	sc->disk = disk_alloc();
89 	if (sc->disk == NULL)
90 		return ENOMEM;
91 	sc->disk->d_name = "cfid";
92 	sc->disk->d_unit = device_get_unit(dev);
93 	sc->disk->d_open = cfi_disk_open;
94 	sc->disk->d_close = cfi_disk_close;
95 	sc->disk->d_strategy = cfi_disk_strategy;
96 	sc->disk->d_ioctl = cfi_disk_ioctl;
97 	sc->disk->d_dump = NULL;		/* NB: no dumps */
98 	sc->disk->d_sectorsize = CFI_DISK_SECSIZE;
99 	sc->disk->d_mediasize = sc->parent->sc_size;
100 	sc->disk->d_maxsize = CFI_DISK_MAXIOSIZE;
101 	/* NB: use stripesize to hold the erase/region size */
102 	if (sc->parent->sc_regions) {
103 		/*
104 		 * Multiple regions, use the last one.  This is a
105 		 * total hack as it's (presently) used only by
106 		 * geom_redboot to locate the FIS directory which
107 		 * lies at the start of the last erase region.
108 		 */
109 		sc->disk->d_stripesize =
110 		    sc->parent->sc_region[sc->parent->sc_regions-1].r_blksz;
111 	} else
112 		sc->disk->d_stripesize = sc->disk->d_mediasize;
113 	sc->disk->d_drv1 = sc;
114 	disk_create(sc->disk, DISK_VERSION);
115 
116 	mtx_init(&sc->qlock, "CFID I/O lock", NULL, MTX_DEF);
117 	bioq_init(&sc->bioq);
118 
119 	sc->tq = taskqueue_create("cfid_taskq", M_NOWAIT,
120 		taskqueue_thread_enqueue, &sc->tq);
121 	taskqueue_start_threads(&sc->tq, 1, PI_DISK, "cfid taskq");
122 
123 	TASK_INIT(&sc->iotask, 0, cfi_io_proc, sc);
124 
125 	return 0;
126 }
127 
128 static int
129 cfi_disk_detach(device_t dev)
130 {
131 	struct cfi_disk_softc *sc = device_get_softc(dev);
132 
133 	if (sc->flags & CFI_DISK_OPEN)
134 		return EBUSY;
135 	taskqueue_free(sc->tq);
136 	/* XXX drain bioq */
137 	disk_destroy(sc->disk);
138 	mtx_destroy(&sc->qlock);
139 	return 0;
140 }
141 
142 static int
143 cfi_disk_open(struct disk *dp)
144 {
145 	struct cfi_disk_softc *sc = dp->d_drv1;
146 
147 	/* XXX no interlock with /dev/cfi */
148 	sc->flags |= CFI_DISK_OPEN;
149 	return 0;
150 }
151 
152 static int
153 cfi_disk_close(struct disk *dp)
154 {
155 	struct cfi_disk_softc *sc = dp->d_drv1;
156 
157 	sc->flags &= ~CFI_DISK_OPEN;
158 	return 0;
159 }
160 
161 static void
162 cfi_disk_read(struct cfi_softc *sc, struct bio *bp)
163 {
164 	long resid;
165 
166 	KASSERT(sc->sc_width == 1 || sc->sc_width == 2 || sc->sc_width == 4,
167 	    ("sc_width %d", sc->sc_width));
168 
169 	if (sc->sc_writing) {
170 		bp->bio_error = cfi_block_finish(sc);
171 		if (bp->bio_error) {
172 			bp->bio_flags |= BIO_ERROR;
173 			goto done;
174 		}
175 	}
176 	if (bp->bio_offset > sc->sc_size) {
177 		bp->bio_flags |= BIO_ERROR;
178 		bp->bio_error = EIO;
179 		goto done;
180 	}
181 	resid = bp->bio_bcount;
182 	if (sc->sc_width == 1) {
183 		uint8_t *dp = (uint8_t *)bp->bio_data;
184 		while (resid > 0 && bp->bio_offset < sc->sc_size) {
185 			*dp++ = cfi_read(sc, bp->bio_offset);
186 			bp->bio_offset += 1, resid -= 1;
187 		}
188 	} else if (sc->sc_width == 2) {
189 		uint16_t *dp = (uint16_t *)bp->bio_data;
190 		while (resid > 0 && bp->bio_offset < sc->sc_size) {
191 			*dp++ = cfi_read(sc, bp->bio_offset);
192 			bp->bio_offset += 2, resid -= 2;
193 		}
194 	} else {
195 		uint32_t *dp = (uint32_t *)bp->bio_data;
196 		while (resid > 0 && bp->bio_offset < sc->sc_size) {
197 			*dp++ = cfi_read(sc, bp->bio_offset);
198 			bp->bio_offset += 4, resid -= 4;
199 		}
200 	}
201 	bp->bio_resid = resid;
202 done:
203 	biodone(bp);
204 }
205 
206 static void
207 cfi_disk_write(struct cfi_softc *sc, struct bio *bp)
208 {
209 	long resid;
210 	u_int top;
211 
212 	KASSERT(sc->sc_width == 1 || sc->sc_width == 2 || sc->sc_width == 4,
213 	    ("sc_width %d", sc->sc_width));
214 
215 	if (bp->bio_offset > sc->sc_size) {
216 		bp->bio_flags |= BIO_ERROR;
217 		bp->bio_error = EIO;
218 		goto done;
219 	}
220 	resid = bp->bio_bcount;
221 	while (resid > 0) {
222 		/*
223 		 * Finish the current block if we're about to write
224 		 * to a different block.
225 		 */
226 		if (sc->sc_writing) {
227 			top = sc->sc_wrofs + sc->sc_wrbufsz;
228 			if (bp->bio_offset < sc->sc_wrofs ||
229 			    bp->bio_offset >= top)
230 				cfi_block_finish(sc);
231 		}
232 
233 		/* Start writing to a (new) block if applicable. */
234 		if (!sc->sc_writing) {
235 			bp->bio_error = cfi_block_start(sc, bp->bio_offset);
236 			if (bp->bio_error) {
237 				bp->bio_flags |= BIO_ERROR;
238 				goto done;
239 			}
240 		}
241 
242 		top = sc->sc_wrofs + sc->sc_wrbufsz;
243 		bcopy(bp->bio_data,
244 		    sc->sc_wrbuf + bp->bio_offset - sc->sc_wrofs,
245 		    MIN(top - bp->bio_offset, resid));
246 		resid -= MIN(top - bp->bio_offset, resid);
247 	}
248 	bp->bio_resid = resid;
249 done:
250 	biodone(bp);
251 }
252 
253 static void
254 cfi_io_proc(void *arg, int pending)
255 {
256 	struct cfi_disk_softc *sc = arg;
257 	struct cfi_softc *cfi = sc->parent;
258 	struct bio *bp;
259 
260 	for (;;) {
261 		mtx_lock(&sc->qlock);
262 		bp = bioq_takefirst(&sc->bioq);
263 		mtx_unlock(&sc->qlock);
264 		if (bp == NULL)
265 			break;
266 
267 		switch (bp->bio_cmd) {
268 		case BIO_READ:
269 			cfi_disk_read(cfi, bp);
270 			break;
271 		case BIO_WRITE:
272 			cfi_disk_write(cfi, bp);
273 			break;
274 		}
275 	}
276 }
277 
278 static void
279 cfi_disk_strategy(struct bio *bp)
280 {
281 	struct cfi_disk_softc *sc = bp->bio_disk->d_drv1;
282 
283 	if (sc == NULL)
284 		goto invalid;
285 	if (bp->bio_bcount == 0) {
286 		bp->bio_resid = bp->bio_bcount;
287 		biodone(bp);
288 		return;
289 	}
290 	switch (bp->bio_cmd) {
291 	case BIO_READ:
292 	case BIO_WRITE:
293 		mtx_lock(&sc->qlock);
294 		/* no value in sorting requests? */
295 		bioq_insert_tail(&sc->bioq, bp);
296 		mtx_unlock(&sc->qlock);
297 		taskqueue_enqueue(sc->tq, &sc->iotask);
298 		return;
299 	}
300 	/* fall thru... */
301 invalid:
302 	bp->bio_flags |= BIO_ERROR;
303 	bp->bio_error = EINVAL;
304 	biodone(bp);
305 }
306 
307 static int
308 cfi_disk_ioctl(struct disk *dp, u_long cmd, void *data, int fflag,
309 	struct thread *td)
310 {
311 	return EINVAL;
312 }
313 
314 static device_method_t cfi_disk_methods[] = {
315 	DEVMETHOD(device_probe,		cfi_disk_probe),
316 	DEVMETHOD(device_attach,	cfi_disk_attach),
317 	DEVMETHOD(device_detach,	cfi_disk_detach),
318 
319 	{ 0, 0 }
320 };
321 static driver_t cfi_disk_driver = {
322 	"cfid",
323 	cfi_disk_methods,
324 	sizeof(struct cfi_disk_softc),
325 };
326 DRIVER_MODULE(cfid, cfi, cfi_disk_driver, cfi_diskclass, 0, NULL);
327