xref: /freebsd/sys/powerpc/powernv/opal_nvram.c (revision d7d962ead0b6e5e8a39202d0590022082bf5bfb6)
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 static devclass_t opal_nvram_devclass;
97 
98 DRIVER_MODULE(opal_nvram, opal, opal_nvram_driver, opal_nvram_devclass, 0, 0);
99 
100 /*
101  * Cdev methods.
102  */
103 
104 static	d_open_t	opal_nvram_open;
105 static	d_close_t	opal_nvram_close;
106 static	d_read_t	opal_nvram_read;
107 static	d_write_t	opal_nvram_write;
108 static	d_ioctl_t	opal_nvram_ioctl;
109 
110 static struct cdevsw opal_nvram_cdevsw = {
111 	.d_version =	D_VERSION,
112 	.d_open =	opal_nvram_open,
113 	.d_close =	opal_nvram_close,
114 	.d_read =	opal_nvram_read,
115 	.d_write =	opal_nvram_write,
116 	.d_ioctl =	opal_nvram_ioctl,
117 	.d_name =	"nvram",
118 };
119 
120 static int
121 opal_nvram_probe(device_t dev)
122 {
123 
124 	if (!ofw_bus_is_compatible(dev, "ibm,opal-nvram"))
125 		return (ENXIO);
126 
127 	device_set_desc(dev, "OPAL NVRAM");
128 	return (BUS_PROBE_DEFAULT);
129 }
130 
131 static int
132 opal_nvram_attach(device_t dev)
133 {
134 	struct opal_nvram_softc *sc;
135 	phandle_t node;
136 	int err;
137 
138 	node = ofw_bus_get_node(dev);
139 	sc = device_get_softc(dev);
140 
141 	sc->sc_dev = dev;
142 
143 	err = OF_getencprop(node, "#bytes", &sc->sc_size,
144 	    sizeof(sc->sc_size));
145 
146 	if (err < 0)
147 		return (ENXIO);
148 
149 	sc->sc_buf = contigmalloc(NVRAM_BUFSIZE, M_DEVBUF, M_WAITOK,
150 	    0, BUS_SPACE_MAXADDR, PAGE_SIZE, 0);
151 	if (sc->sc_buf == NULL) {
152 		device_printf(dev, "No memory for buffer.\n");
153 		return (ENXIO);
154 	}
155 	sc->sc_buf_phys = pmap_kextract((vm_offset_t)sc->sc_buf);
156 	sc->sc_cdev = make_dev(&opal_nvram_cdevsw, 0, 0, 0, 0600,
157 	    "nvram");
158 	sc->sc_cdev->si_drv1 = sc;
159 
160 	mtx_init(&sc->sc_mtx, "opal_nvram", 0, MTX_DEF);
161 
162 	return (0);
163 }
164 
165 static int
166 opal_nvram_detach(device_t dev)
167 {
168 	struct opal_nvram_softc *sc;
169 
170 	sc = device_get_softc(dev);
171 
172 	if (sc->sc_cdev != NULL)
173 		destroy_dev(sc->sc_cdev);
174 	if (sc->sc_buf != NULL)
175 		contigfree(sc->sc_buf, NVRAM_BUFSIZE, M_DEVBUF);
176 
177 	mtx_destroy(&sc->sc_mtx);
178 
179 	return (0);
180 }
181 
182 static int
183 opal_nvram_open(struct cdev *dev, int flags, int fmt, struct thread *td)
184 {
185 	struct opal_nvram_softc *sc = dev->si_drv1;
186 	int err;
187 
188 	err = 0;
189 
190 	NVRAM_LOCK(sc);
191 	if (sc->sc_isopen)
192 		err = EBUSY;
193 	else
194 		sc->sc_isopen = 1;
195 	NVRAM_UNLOCK(sc);
196 
197 	return (err);
198 }
199 
200 static int
201 opal_nvram_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
202 {
203 	struct opal_nvram_softc *sc = dev->si_drv1;
204 
205 	NVRAM_LOCK(sc);
206 	sc->sc_isopen = 0;
207 	NVRAM_UNLOCK(sc);
208 
209 	return (0);
210 }
211 
212 static int
213 opal_nvram_read(struct cdev *dev, struct uio *uio, int ioflag)
214 {
215 	struct opal_nvram_softc *sc = dev->si_drv1;
216 	int rv, amnt;
217 
218 	rv = 0;
219 
220 	NVRAM_LOCK(sc);
221 	while (uio->uio_resid > 0) {
222 		amnt = MIN(uio->uio_resid, sc->sc_size - uio->uio_offset);
223 		amnt = MIN(amnt, NVRAM_BUFSIZE);
224 		if (amnt == 0)
225 			break;
226 
227 		rv = opal_call(OPAL_READ_NVRAM, sc->sc_buf_phys,
228 		    amnt, uio->uio_offset);
229 		if (rv != OPAL_SUCCESS) {
230 			switch (rv) {
231 			case OPAL_HARDWARE:
232 				rv = EIO;
233 				break;
234 			case OPAL_PARAMETER:
235 				rv = EINVAL;
236 				break;
237 			}
238 			break;
239 		}
240 		rv = uiomove(sc->sc_buf, amnt, uio);
241 		if (rv != 0)
242 			break;
243 	}
244 	NVRAM_UNLOCK(sc);
245 
246 	return (rv);
247 }
248 
249 static int
250 opal_nvram_write(struct cdev *dev, struct uio *uio, int ioflag)
251 {
252 	off_t offset;
253 	int rv, amnt;
254 	struct opal_nvram_softc *sc = dev->si_drv1;
255 
256 	rv = 0;
257 
258 	NVRAM_LOCK(sc);
259 	while (uio->uio_resid > 0) {
260 		amnt = MIN(uio->uio_resid, sc->sc_size - uio->uio_offset);
261 		amnt = MIN(amnt, NVRAM_BUFSIZE);
262 		if (amnt == 0) {
263 			rv = ENOSPC;
264 			break;
265 		}
266 		offset = uio->uio_offset;
267 		rv = uiomove(sc->sc_buf, amnt, uio);
268 		if (rv != 0)
269 			break;
270 		rv = opal_call(OPAL_WRITE_NVRAM, sc->sc_buf_phys, amnt,
271 		    offset);
272 		if (rv != OPAL_SUCCESS) {
273 			switch (rv) {
274 			case OPAL_HARDWARE:
275 				rv = EIO;
276 				break;
277 			case OPAL_PARAMETER:
278 				rv = EINVAL;
279 				break;
280 			}
281 			break;
282 		}
283 	}
284 
285 	NVRAM_UNLOCK(sc);
286 
287 	return (rv);
288 }
289 
290 static int
291 opal_nvram_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
292     struct thread *td)
293 {
294 	struct opal_nvram_softc *sc = dev->si_drv1;
295 
296 	switch (cmd) {
297 	case DIOCGMEDIASIZE:
298 		*(off_t *)data = sc->sc_size;
299 		return (0);
300 	}
301 	return (EINVAL);
302 }
303