xref: /freebsd/sys/powerpc/powernv/opal_nvram.c (revision 8ddb146abcdf061be9f2c0db7e391697dafad85c)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2019 Justin Hibbits
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, 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  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
17  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
18  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
19  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
20  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
21  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
23  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
24  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
25  * POSSIBILITY OF SUCH DAMAGE.
26  *
27  * $FreeBSD$
28  */
29 
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/module.h>
33 #include <sys/bus.h>
34 #include <sys/conf.h>
35 #include <sys/disk.h>
36 #include <sys/kernel.h>
37 #include <sys/mutex.h>
38 #include <sys/uio.h>
39 
40 #include <dev/ofw/openfirm.h>
41 #include <dev/ofw/ofw_bus.h>
42 #include <dev/ofw/ofw_bus_subr.h>
43 
44 #include <machine/bus.h>
45 #include <machine/md_var.h>
46 #include <machine/pio.h>
47 #include <machine/resource.h>
48 
49 #include "opal.h"
50 
51 #include <sys/rman.h>
52 
53 #include <vm/vm.h>
54 #include <vm/pmap.h>
55 
56 #define	NVRAM_BUFSIZE	(65536)	/* 64k blocks */
57 
58 struct opal_nvram_softc {
59 	device_t	 sc_dev;
60 	struct mtx	 sc_mtx;
61 	uint32_t	 sc_size;
62 	uint8_t		*sc_buf;
63 	vm_paddr_t	 sc_buf_phys;
64 
65 	struct cdev 	*sc_cdev;
66 	int		 sc_isopen;
67 };
68 
69 #define	NVRAM_LOCK(sc)		mtx_lock(&sc->sc_mtx)
70 #define	NVRAM_UNLOCK(sc)	mtx_unlock(&sc->sc_mtx)
71 
72 /*
73  * Device interface.
74  */
75 static int		opal_nvram_probe(device_t);
76 static int		opal_nvram_attach(device_t);
77 static int		opal_nvram_detach(device_t);
78 
79 /*
80  * Driver methods.
81  */
82 static device_method_t	opal_nvram_methods[] = {
83 	/* Device interface */
84 	DEVMETHOD(device_probe,		opal_nvram_probe),
85 	DEVMETHOD(device_attach,	opal_nvram_attach),
86 	DEVMETHOD(device_detach,	opal_nvram_detach),
87 	{ 0, 0 }
88 };
89 
90 static driver_t	opal_nvram_driver = {
91 	"opal_nvram",
92 	opal_nvram_methods,
93 	sizeof(struct opal_nvram_softc)
94 };
95 
96 DRIVER_MODULE(opal_nvram, opal, opal_nvram_driver, 0, 0);
97 
98 /*
99  * Cdev methods.
100  */
101 
102 static	d_open_t	opal_nvram_open;
103 static	d_close_t	opal_nvram_close;
104 static	d_read_t	opal_nvram_read;
105 static	d_write_t	opal_nvram_write;
106 static	d_ioctl_t	opal_nvram_ioctl;
107 
108 static struct cdevsw opal_nvram_cdevsw = {
109 	.d_version =	D_VERSION,
110 	.d_open =	opal_nvram_open,
111 	.d_close =	opal_nvram_close,
112 	.d_read =	opal_nvram_read,
113 	.d_write =	opal_nvram_write,
114 	.d_ioctl =	opal_nvram_ioctl,
115 	.d_name =	"nvram",
116 };
117 
118 static int
119 opal_nvram_probe(device_t dev)
120 {
121 
122 	if (!ofw_bus_is_compatible(dev, "ibm,opal-nvram"))
123 		return (ENXIO);
124 
125 	device_set_desc(dev, "OPAL NVRAM");
126 	return (BUS_PROBE_DEFAULT);
127 }
128 
129 static int
130 opal_nvram_attach(device_t dev)
131 {
132 	struct opal_nvram_softc *sc;
133 	phandle_t node;
134 	int err;
135 
136 	node = ofw_bus_get_node(dev);
137 	sc = device_get_softc(dev);
138 
139 	sc->sc_dev = dev;
140 
141 	err = OF_getencprop(node, "#bytes", &sc->sc_size,
142 	    sizeof(sc->sc_size));
143 
144 	if (err < 0)
145 		return (ENXIO);
146 
147 	sc->sc_buf = contigmalloc(NVRAM_BUFSIZE, M_DEVBUF, M_WAITOK,
148 	    0, BUS_SPACE_MAXADDR, PAGE_SIZE, 0);
149 	if (sc->sc_buf == NULL) {
150 		device_printf(dev, "No memory for buffer.\n");
151 		return (ENXIO);
152 	}
153 	sc->sc_buf_phys = pmap_kextract((vm_offset_t)sc->sc_buf);
154 	sc->sc_cdev = make_dev(&opal_nvram_cdevsw, 0, 0, 0, 0600,
155 	    "nvram");
156 	sc->sc_cdev->si_drv1 = sc;
157 
158 	mtx_init(&sc->sc_mtx, "opal_nvram", 0, MTX_DEF);
159 
160 	return (0);
161 }
162 
163 static int
164 opal_nvram_detach(device_t dev)
165 {
166 	struct opal_nvram_softc *sc;
167 
168 	sc = device_get_softc(dev);
169 
170 	if (sc->sc_cdev != NULL)
171 		destroy_dev(sc->sc_cdev);
172 	if (sc->sc_buf != NULL)
173 		contigfree(sc->sc_buf, NVRAM_BUFSIZE, M_DEVBUF);
174 
175 	mtx_destroy(&sc->sc_mtx);
176 
177 	return (0);
178 }
179 
180 static int
181 opal_nvram_open(struct cdev *dev, int flags, int fmt, struct thread *td)
182 {
183 	struct opal_nvram_softc *sc = dev->si_drv1;
184 	int err;
185 
186 	err = 0;
187 
188 	NVRAM_LOCK(sc);
189 	if (sc->sc_isopen)
190 		err = EBUSY;
191 	else
192 		sc->sc_isopen = 1;
193 	NVRAM_UNLOCK(sc);
194 
195 	return (err);
196 }
197 
198 static int
199 opal_nvram_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
200 {
201 	struct opal_nvram_softc *sc = dev->si_drv1;
202 
203 	NVRAM_LOCK(sc);
204 	sc->sc_isopen = 0;
205 	NVRAM_UNLOCK(sc);
206 
207 	return (0);
208 }
209 
210 static int
211 opal_nvram_read(struct cdev *dev, struct uio *uio, int ioflag)
212 {
213 	struct opal_nvram_softc *sc = dev->si_drv1;
214 	int rv, amnt;
215 
216 	rv = 0;
217 
218 	NVRAM_LOCK(sc);
219 	while (uio->uio_resid > 0) {
220 		amnt = MIN(uio->uio_resid, sc->sc_size - uio->uio_offset);
221 		amnt = MIN(amnt, NVRAM_BUFSIZE);
222 		if (amnt == 0)
223 			break;
224 
225 		rv = opal_call(OPAL_READ_NVRAM, sc->sc_buf_phys,
226 		    amnt, uio->uio_offset);
227 		if (rv != OPAL_SUCCESS) {
228 			switch (rv) {
229 			case OPAL_HARDWARE:
230 				rv = EIO;
231 				break;
232 			case OPAL_PARAMETER:
233 				rv = EINVAL;
234 				break;
235 			}
236 			break;
237 		}
238 		rv = uiomove(sc->sc_buf, amnt, uio);
239 		if (rv != 0)
240 			break;
241 	}
242 	NVRAM_UNLOCK(sc);
243 
244 	return (rv);
245 }
246 
247 static int
248 opal_nvram_write(struct cdev *dev, struct uio *uio, int ioflag)
249 {
250 	off_t offset;
251 	int rv, amnt;
252 	struct opal_nvram_softc *sc = dev->si_drv1;
253 
254 	rv = 0;
255 
256 	NVRAM_LOCK(sc);
257 	while (uio->uio_resid > 0) {
258 		amnt = MIN(uio->uio_resid, sc->sc_size - uio->uio_offset);
259 		amnt = MIN(amnt, NVRAM_BUFSIZE);
260 		if (amnt == 0) {
261 			rv = ENOSPC;
262 			break;
263 		}
264 		offset = uio->uio_offset;
265 		rv = uiomove(sc->sc_buf, amnt, uio);
266 		if (rv != 0)
267 			break;
268 		rv = opal_call(OPAL_WRITE_NVRAM, sc->sc_buf_phys, amnt,
269 		    offset);
270 		if (rv != OPAL_SUCCESS) {
271 			switch (rv) {
272 			case OPAL_HARDWARE:
273 				rv = EIO;
274 				break;
275 			case OPAL_PARAMETER:
276 				rv = EINVAL;
277 				break;
278 			}
279 			break;
280 		}
281 	}
282 
283 	NVRAM_UNLOCK(sc);
284 
285 	return (rv);
286 }
287 
288 static int
289 opal_nvram_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
290     struct thread *td)
291 {
292 	struct opal_nvram_softc *sc = dev->si_drv1;
293 
294 	switch (cmd) {
295 	case DIOCGMEDIASIZE:
296 		*(off_t *)data = sc->sc_size;
297 		return (0);
298 	}
299 	return (EINVAL);
300 }
301