xref: /freebsd/sys/powerpc/powernv/opal_nvram.c (revision eda14cbc264d6969b02f2b1994cef11148e914f1)
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 
88 	{ 0, 0 }
89 };
90 
91 static driver_t	opal_nvram_driver = {
92 	"opal_nvram",
93 	opal_nvram_methods,
94 	sizeof(struct opal_nvram_softc)
95 };
96 
97 static devclass_t opal_nvram_devclass;
98 
99 DRIVER_MODULE(opal_nvram, opal, opal_nvram_driver, opal_nvram_devclass, 0, 0);
100 
101 /*
102  * Cdev methods.
103  */
104 
105 static	d_open_t	opal_nvram_open;
106 static	d_close_t	opal_nvram_close;
107 static	d_read_t	opal_nvram_read;
108 static	d_write_t	opal_nvram_write;
109 static	d_ioctl_t	opal_nvram_ioctl;
110 
111 static struct cdevsw opal_nvram_cdevsw = {
112 	.d_version =	D_VERSION,
113 	.d_open =	opal_nvram_open,
114 	.d_close =	opal_nvram_close,
115 	.d_read =	opal_nvram_read,
116 	.d_write =	opal_nvram_write,
117 	.d_ioctl =	opal_nvram_ioctl,
118 	.d_name =	"nvram",
119 };
120 
121 static int
122 opal_nvram_probe(device_t dev)
123 {
124 
125 	if (!ofw_bus_is_compatible(dev, "ibm,opal-nvram"))
126 		return (ENXIO);
127 
128 	device_set_desc(dev, "OPAL NVRAM");
129 	return (BUS_PROBE_DEFAULT);
130 }
131 
132 static int
133 opal_nvram_attach(device_t dev)
134 {
135 	struct opal_nvram_softc *sc;
136 	phandle_t node;
137 	int err;
138 
139 	node = ofw_bus_get_node(dev);
140 	sc = device_get_softc(dev);
141 
142 	sc->sc_dev = dev;
143 
144 	err = OF_getencprop(node, "#bytes", &sc->sc_size,
145 	    sizeof(sc->sc_size));
146 
147 	if (err < 0)
148 		return (ENXIO);
149 
150 	sc->sc_buf = contigmalloc(NVRAM_BUFSIZE, M_DEVBUF, M_WAITOK,
151 	    0, BUS_SPACE_MAXADDR, PAGE_SIZE, 0);
152 	if (sc->sc_buf == NULL) {
153 		device_printf(dev, "No memory for buffer.\n");
154 		return (ENXIO);
155 	}
156 	sc->sc_buf_phys = pmap_kextract((vm_offset_t)sc->sc_buf);
157 	sc->sc_cdev = make_dev(&opal_nvram_cdevsw, 0, 0, 0, 0600,
158 	    "nvram");
159 	sc->sc_cdev->si_drv1 = sc;
160 
161 	mtx_init(&sc->sc_mtx, "opal_nvram", 0, MTX_DEF);
162 
163 	return (0);
164 }
165 
166 static int
167 opal_nvram_detach(device_t dev)
168 {
169 	struct opal_nvram_softc *sc;
170 
171 	sc = device_get_softc(dev);
172 
173 	if (sc->sc_cdev != NULL)
174 		destroy_dev(sc->sc_cdev);
175 	if (sc->sc_buf != NULL)
176 		contigfree(sc->sc_buf, NVRAM_BUFSIZE, M_DEVBUF);
177 
178 	mtx_destroy(&sc->sc_mtx);
179 
180 	return (0);
181 }
182 
183 static int
184 opal_nvram_open(struct cdev *dev, int flags, int fmt, struct thread *td)
185 {
186 	struct opal_nvram_softc *sc = dev->si_drv1;
187 	int err;
188 
189 	err = 0;
190 
191 	NVRAM_LOCK(sc);
192 	if (sc->sc_isopen)
193 		err = EBUSY;
194 	else
195 		sc->sc_isopen = 1;
196 	NVRAM_UNLOCK(sc);
197 
198 	return (err);
199 }
200 
201 static int
202 opal_nvram_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
203 {
204 	struct opal_nvram_softc *sc = dev->si_drv1;
205 
206 	NVRAM_LOCK(sc);
207 	sc->sc_isopen = 0;
208 	NVRAM_UNLOCK(sc);
209 
210 	return (0);
211 }
212 
213 static int
214 opal_nvram_read(struct cdev *dev, struct uio *uio, int ioflag)
215 {
216 	struct opal_nvram_softc *sc = dev->si_drv1;
217 	int rv, amnt;
218 
219 	rv = 0;
220 
221 	NVRAM_LOCK(sc);
222 	while (uio->uio_resid > 0) {
223 		amnt = MIN(uio->uio_resid, sc->sc_size - uio->uio_offset);
224 		amnt = MIN(amnt, NVRAM_BUFSIZE);
225 		if (amnt == 0)
226 			break;
227 
228 		rv = opal_call(OPAL_READ_NVRAM, sc->sc_buf_phys,
229 		    amnt, uio->uio_offset);
230 		if (rv != OPAL_SUCCESS) {
231 			switch (rv) {
232 			case OPAL_HARDWARE:
233 				rv = EIO;
234 				break;
235 			case OPAL_PARAMETER:
236 				rv = EINVAL;
237 				break;
238 			}
239 			break;
240 		}
241 		rv = uiomove(sc->sc_buf, amnt, uio);
242 		if (rv != 0)
243 			break;
244 	}
245 	NVRAM_UNLOCK(sc);
246 
247 	return (rv);
248 }
249 
250 static int
251 opal_nvram_write(struct cdev *dev, struct uio *uio, int ioflag)
252 {
253 	off_t offset;
254 	int rv, amnt;
255 	struct opal_nvram_softc *sc = dev->si_drv1;
256 
257 	rv = 0;
258 
259 	NVRAM_LOCK(sc);
260 	while (uio->uio_resid > 0) {
261 		amnt = MIN(uio->uio_resid, sc->sc_size - uio->uio_offset);
262 		amnt = MIN(amnt, NVRAM_BUFSIZE);
263 		if (amnt == 0) {
264 			rv = ENOSPC;
265 			break;
266 		}
267 		offset = uio->uio_offset;
268 		rv = uiomove(sc->sc_buf, amnt, uio);
269 		if (rv != 0)
270 			break;
271 		rv = opal_call(OPAL_WRITE_NVRAM, sc->sc_buf_phys, amnt,
272 		    offset);
273 		if (rv != OPAL_SUCCESS) {
274 			switch (rv) {
275 			case OPAL_HARDWARE:
276 				rv = EIO;
277 				break;
278 			case OPAL_PARAMETER:
279 				rv = EINVAL;
280 				break;
281 			}
282 			break;
283 		}
284 	}
285 
286 	NVRAM_UNLOCK(sc);
287 
288 	return (rv);
289 }
290 
291 static int
292 opal_nvram_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
293     struct thread *td)
294 {
295 	struct opal_nvram_softc *sc = dev->si_drv1;
296 
297 	switch (cmd) {
298 	case DIOCGMEDIASIZE:
299 		*(off_t *)data = sc->sc_size;
300 		return (0);
301 	}
302 	return (EINVAL);
303 }
304