xref: /freebsd/sys/dev/cfi/cfi_dev.c (revision 6c6c03be2ddb04c54e455122799923deaefa4114)
1 /*-
2  * Copyright (c) 2007, Juniper Networks, Inc.
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  * 3. Neither the name of the author nor the names of any co-contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
22  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
23  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
24  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
25  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/bus.h>
36 #include <sys/conf.h>
37 #include <sys/ioccom.h>
38 #include <sys/kernel.h>
39 #include <sys/malloc.h>
40 #include <sys/proc.h>
41 #include <sys/sysctl.h>
42 #include <sys/types.h>
43 #include <sys/uio.h>
44 
45 #include <sys/cfictl.h>
46 
47 #include <machine/atomic.h>
48 #include <machine/bus.h>
49 
50 #include <dev/cfi/cfi_var.h>
51 
52 static d_open_t cfi_devopen;
53 static d_close_t cfi_devclose;
54 static d_read_t cfi_devread;
55 static d_write_t cfi_devwrite;
56 static d_ioctl_t cfi_devioctl;
57 
58 struct cdevsw cfi_cdevsw = {
59 	.d_version	=	D_VERSION,
60 	.d_flags	=	0,
61 	.d_name		=	cfi_driver_name,
62 	.d_open		=	cfi_devopen,
63 	.d_close	=	cfi_devclose,
64 	.d_read		=	cfi_devread,
65 	.d_write	=	cfi_devwrite,
66 	.d_ioctl	=	cfi_devioctl,
67 };
68 
69 /*
70  * Begin writing into a new block/sector.  We read the sector into
71  * memory and keep updating that, until we move into another sector
72  * or the process stops writing. At that time we write the whole
73  * sector to flash (see cfi_block_finish).
74  */
75 static int
76 cfi_block_start(struct cfi_softc *sc, u_int ofs)
77 {
78 	union {
79 		uint8_t		*x8;
80 		uint16_t	*x16;
81 		uint32_t	*x32;
82 	} ptr;
83 	u_int rofs, rsz;
84 	uint32_t val;
85 	int r;
86 
87 	rofs = 0;
88 	for (r = 0; r < sc->sc_regions; r++) {
89 		rsz = sc->sc_region[r].r_blocks * sc->sc_region[r].r_blksz;
90 		if (ofs < rofs + rsz)
91 			break;
92 		rofs += rsz;
93 	}
94 	if (r == sc->sc_regions)
95 		return (EFAULT);
96 
97 	sc->sc_wrbufsz = sc->sc_region[r].r_blksz;
98 	sc->sc_wrbuf = malloc(sc->sc_wrbufsz, M_TEMP, M_WAITOK);
99 	sc->sc_wrofs = ofs - (ofs - rofs) % sc->sc_wrbufsz;
100 
101 	/* Read the block from flash for byte-serving. */
102 	ptr.x8 = sc->sc_wrbuf;
103 	for (r = 0; r < sc->sc_wrbufsz; r += sc->sc_width) {
104 		val = cfi_read(sc, sc->sc_wrofs + r);
105 		switch (sc->sc_width) {
106 		case 1:
107 			*(ptr.x8)++ = val;
108 			break;
109 		case 2:
110 			*(ptr.x16)++ = val;
111 			break;
112 		case 4:
113 			*(ptr.x32)++ = val;
114 			break;
115 		}
116 	}
117 	sc->sc_writing = 1;
118 	return (0);
119 }
120 
121 /*
122  * Finish updating the current block/sector by writing the compound
123  * set of changes to the flash.
124  */
125 static int
126 cfi_block_finish(struct cfi_softc *sc)
127 {
128 	int error;
129 
130 	error = cfi_write_block(sc);
131 	free(sc->sc_wrbuf, M_TEMP);
132 	sc->sc_wrbuf = NULL;
133 	sc->sc_wrbufsz = 0;
134 	sc->sc_wrofs = 0;
135 	sc->sc_writing = 0;
136 	return (error);
137 }
138 
139 static int
140 cfi_devopen(struct cdev *dev, int oflags, int devtype, struct thread *td)
141 {
142 	struct cfi_softc *sc;
143 
144 	sc = dev->si_drv1;
145 	/* We allow only 1 open. */
146 	if (!atomic_cmpset_acq_ptr(&sc->sc_opened, NULL, td->td_proc))
147 		return (EBUSY);
148 	return (0);
149 }
150 
151 static int
152 cfi_devclose(struct cdev *dev, int fflag, int devtype, struct thread *td)
153 {
154 	struct cfi_softc *sc;
155 	int error;
156 
157 	sc = dev->si_drv1;
158 	/* Sanity. Not really necessary. */
159 	if (sc->sc_opened != td->td_proc)
160 		return (ENXIO);
161 
162 	error = (sc->sc_writing) ? cfi_block_finish(sc) : 0;
163 	sc->sc_opened = NULL;
164 	return (error);
165 }
166 
167 static int
168 cfi_devread(struct cdev *dev, struct uio *uio, int ioflag)
169 {
170 	union {
171 		uint8_t		x8[4];
172 		uint16_t	x16[2];
173 		uint32_t	x32[1];
174 	} buf;
175 	struct cfi_softc *sc;
176 	u_int ofs;
177 	uint32_t val;
178 	int error;
179 
180 	sc = dev->si_drv1;
181 
182 	error = (sc->sc_writing) ? cfi_block_finish(sc) : 0;
183 	if (!error)
184 		error = (uio->uio_offset > sc->sc_size) ? EIO : 0;
185 
186 	while (error == 0 && uio->uio_resid > 0 &&
187 	    uio->uio_offset < sc->sc_size) {
188 		ofs = uio->uio_offset;
189 		val = cfi_read(sc, ofs);
190 		switch (sc->sc_width) {
191 		case 1:
192 			buf.x8[0] = val;
193 			break;
194 		case 2:
195 			buf.x16[0] = val;
196 			break;
197 		case 4:
198 			buf.x32[0] = val;
199 			break;
200 		}
201 		ofs &= sc->sc_width - 1;
202 		error = uiomove(buf.x8 + ofs,
203 		    MIN(uio->uio_resid, sc->sc_width - ofs), uio);
204 	}
205 	return (error);
206 }
207 
208 static int
209 cfi_devwrite(struct cdev *dev, struct uio *uio, int ioflag)
210 {
211 	struct cfi_softc *sc;
212 	u_int ofs, top;
213 	int error;
214 
215 	sc = dev->si_drv1;
216 
217 	error = (uio->uio_offset > sc->sc_size) ? EIO : 0;
218 	while (error == 0 && uio->uio_resid > 0 &&
219 	    uio->uio_offset < sc->sc_size) {
220 		ofs = uio->uio_offset;
221 
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 (ofs < sc->sc_wrofs || ofs >= top)
229 				cfi_block_finish(sc);
230 		}
231 
232 		/* Start writing to a (new) block if applicable. */
233 		if (!sc->sc_writing) {
234 			error = cfi_block_start(sc, uio->uio_offset);
235 			if (error)
236 				break;
237 		}
238 
239 		top = sc->sc_wrofs + sc->sc_wrbufsz;
240 		error = uiomove(sc->sc_wrbuf + ofs - sc->sc_wrofs,
241 		    MIN(top - ofs, uio->uio_resid), uio);
242 	}
243 	return (error);
244 }
245 
246 static int
247 cfi_devioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
248     struct thread *td)
249 {
250 	struct cfi_softc *sc;
251 	struct cfiocqry *rq;
252 	int error;
253 	u_char val;
254 
255 	if (cmd != CFIOCQRY)
256 		return (ENOIOCTL);
257 
258 	sc = dev->si_drv1;
259 
260 	error = (sc->sc_writing) ? cfi_block_finish(sc) : 0;
261 	if (error)
262 		return (error);
263 
264 	rq = (struct cfiocqry *)data;
265 
266 	if (rq->offset >= sc->sc_size / sc->sc_width)
267 		return (ESPIPE);
268 	if (rq->offset + rq->count > sc->sc_size / sc->sc_width)
269 		return (ENOSPC);
270 
271 	while (!error && rq->count--) {
272 		val = cfi_read_qry(sc, rq->offset++);
273 		error = copyout(&val, rq->buffer++, 1);
274 	}
275 
276 	return (error);
277 }
278