xref: /freebsd/sys/powerpc/powernv/opal_nvram.c (revision aa1a8ff2d6dbc51ef058f46f3db5a8bb77967145)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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 
28 #include <sys/param.h>
29 #include <sys/systm.h>
30 #include <sys/module.h>
31 #include <sys/bus.h>
32 #include <sys/conf.h>
33 #include <sys/disk.h>
34 #include <sys/kernel.h>
35 #include <sys/mutex.h>
36 #include <sys/uio.h>
37 
38 #include <dev/ofw/openfirm.h>
39 #include <dev/ofw/ofw_bus.h>
40 #include <dev/ofw/ofw_bus_subr.h>
41 
42 #include <machine/bus.h>
43 #include <machine/md_var.h>
44 #include <machine/pio.h>
45 #include <machine/resource.h>
46 
47 #include "opal.h"
48 
49 #include <sys/rman.h>
50 
51 #include <vm/vm.h>
52 #include <vm/pmap.h>
53 
54 #define	NVRAM_BUFSIZE	(65536)	/* 64k blocks */
55 
56 struct opal_nvram_softc {
57 	device_t	 sc_dev;
58 	struct mtx	 sc_mtx;
59 	uint32_t	 sc_size;
60 	uint8_t		*sc_buf;
61 	vm_paddr_t	 sc_buf_phys;
62 
63 	struct cdev 	*sc_cdev;
64 	int		 sc_isopen;
65 };
66 
67 #define	NVRAM_LOCK(sc)		mtx_lock(&sc->sc_mtx)
68 #define	NVRAM_UNLOCK(sc)	mtx_unlock(&sc->sc_mtx)
69 
70 /*
71  * Device interface.
72  */
73 static int		opal_nvram_probe(device_t);
74 static int		opal_nvram_attach(device_t);
75 static int		opal_nvram_detach(device_t);
76 
77 /*
78  * Driver methods.
79  */
80 static device_method_t	opal_nvram_methods[] = {
81 	/* Device interface */
82 	DEVMETHOD(device_probe,		opal_nvram_probe),
83 	DEVMETHOD(device_attach,	opal_nvram_attach),
84 	DEVMETHOD(device_detach,	opal_nvram_detach),
85 	{ 0, 0 }
86 };
87 
88 static driver_t	opal_nvram_driver = {
89 	"opal_nvram",
90 	opal_nvram_methods,
91 	sizeof(struct opal_nvram_softc)
92 };
93 
94 DRIVER_MODULE(opal_nvram, opal, opal_nvram_driver, 0, 0);
95 
96 /*
97  * Cdev methods.
98  */
99 
100 static	d_open_t	opal_nvram_open;
101 static	d_close_t	opal_nvram_close;
102 static	d_read_t	opal_nvram_read;
103 static	d_write_t	opal_nvram_write;
104 static	d_ioctl_t	opal_nvram_ioctl;
105 
106 static struct cdevsw opal_nvram_cdevsw = {
107 	.d_version =	D_VERSION,
108 	.d_open =	opal_nvram_open,
109 	.d_close =	opal_nvram_close,
110 	.d_read =	opal_nvram_read,
111 	.d_write =	opal_nvram_write,
112 	.d_ioctl =	opal_nvram_ioctl,
113 	.d_name =	"nvram",
114 };
115 
116 static int
117 opal_nvram_probe(device_t dev)
118 {
119 
120 	if (!ofw_bus_is_compatible(dev, "ibm,opal-nvram"))
121 		return (ENXIO);
122 
123 	device_set_desc(dev, "OPAL NVRAM");
124 	return (BUS_PROBE_DEFAULT);
125 }
126 
127 static int
128 opal_nvram_attach(device_t dev)
129 {
130 	struct opal_nvram_softc *sc;
131 	phandle_t node;
132 	int err;
133 
134 	node = ofw_bus_get_node(dev);
135 	sc = device_get_softc(dev);
136 
137 	sc->sc_dev = dev;
138 
139 	err = OF_getencprop(node, "#bytes", &sc->sc_size,
140 	    sizeof(sc->sc_size));
141 
142 	if (err < 0)
143 		return (ENXIO);
144 
145 	sc->sc_buf = contigmalloc(NVRAM_BUFSIZE, M_DEVBUF, M_WAITOK,
146 	    0, BUS_SPACE_MAXADDR, PAGE_SIZE, 0);
147 	if (sc->sc_buf == NULL) {
148 		device_printf(dev, "No memory for buffer.\n");
149 		return (ENXIO);
150 	}
151 	sc->sc_buf_phys = pmap_kextract((vm_offset_t)sc->sc_buf);
152 	sc->sc_cdev = make_dev(&opal_nvram_cdevsw, 0, 0, 0, 0600,
153 	    "nvram");
154 	sc->sc_cdev->si_drv1 = sc;
155 
156 	mtx_init(&sc->sc_mtx, "opal_nvram", 0, MTX_DEF);
157 
158 	return (0);
159 }
160 
161 static int
162 opal_nvram_detach(device_t dev)
163 {
164 	struct opal_nvram_softc *sc;
165 
166 	sc = device_get_softc(dev);
167 
168 	if (sc->sc_cdev != NULL)
169 		destroy_dev(sc->sc_cdev);
170 	if (sc->sc_buf != NULL)
171 		contigfree(sc->sc_buf, NVRAM_BUFSIZE, M_DEVBUF);
172 
173 	mtx_destroy(&sc->sc_mtx);
174 
175 	return (0);
176 }
177 
178 static int
179 opal_nvram_open(struct cdev *dev, int flags, int fmt, struct thread *td)
180 {
181 	struct opal_nvram_softc *sc = dev->si_drv1;
182 	int err;
183 
184 	err = 0;
185 
186 	NVRAM_LOCK(sc);
187 	if (sc->sc_isopen)
188 		err = EBUSY;
189 	else
190 		sc->sc_isopen = 1;
191 	NVRAM_UNLOCK(sc);
192 
193 	return (err);
194 }
195 
196 static int
197 opal_nvram_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
198 {
199 	struct opal_nvram_softc *sc = dev->si_drv1;
200 
201 	NVRAM_LOCK(sc);
202 	sc->sc_isopen = 0;
203 	NVRAM_UNLOCK(sc);
204 
205 	return (0);
206 }
207 
208 static int
209 opal_nvram_read(struct cdev *dev, struct uio *uio, int ioflag)
210 {
211 	struct opal_nvram_softc *sc = dev->si_drv1;
212 	int rv, amnt;
213 
214 	rv = 0;
215 
216 	NVRAM_LOCK(sc);
217 	while (uio->uio_resid > 0) {
218 		amnt = MIN(uio->uio_resid, sc->sc_size - uio->uio_offset);
219 		amnt = MIN(amnt, NVRAM_BUFSIZE);
220 		if (amnt == 0)
221 			break;
222 
223 		rv = opal_call(OPAL_READ_NVRAM, sc->sc_buf_phys,
224 		    amnt, uio->uio_offset);
225 		if (rv != OPAL_SUCCESS) {
226 			switch (rv) {
227 			case OPAL_HARDWARE:
228 				rv = EIO;
229 				break;
230 			case OPAL_PARAMETER:
231 				rv = EINVAL;
232 				break;
233 			}
234 			break;
235 		}
236 		rv = uiomove(sc->sc_buf, amnt, uio);
237 		if (rv != 0)
238 			break;
239 	}
240 	NVRAM_UNLOCK(sc);
241 
242 	return (rv);
243 }
244 
245 static int
246 opal_nvram_write(struct cdev *dev, struct uio *uio, int ioflag)
247 {
248 	off_t offset;
249 	int rv, amnt;
250 	struct opal_nvram_softc *sc = dev->si_drv1;
251 
252 	rv = 0;
253 
254 	NVRAM_LOCK(sc);
255 	while (uio->uio_resid > 0) {
256 		amnt = MIN(uio->uio_resid, sc->sc_size - uio->uio_offset);
257 		amnt = MIN(amnt, NVRAM_BUFSIZE);
258 		if (amnt == 0) {
259 			rv = ENOSPC;
260 			break;
261 		}
262 		offset = uio->uio_offset;
263 		rv = uiomove(sc->sc_buf, amnt, uio);
264 		if (rv != 0)
265 			break;
266 		rv = opal_call(OPAL_WRITE_NVRAM, sc->sc_buf_phys, amnt,
267 		    offset);
268 		if (rv != OPAL_SUCCESS) {
269 			switch (rv) {
270 			case OPAL_HARDWARE:
271 				rv = EIO;
272 				break;
273 			case OPAL_PARAMETER:
274 				rv = EINVAL;
275 				break;
276 			}
277 			break;
278 		}
279 	}
280 
281 	NVRAM_UNLOCK(sc);
282 
283 	return (rv);
284 }
285 
286 static int
287 opal_nvram_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
288     struct thread *td)
289 {
290 	struct opal_nvram_softc *sc = dev->si_drv1;
291 
292 	switch (cmd) {
293 	case DIOCGMEDIASIZE:
294 		*(off_t *)data = sc->sc_size;
295 		return (0);
296 	}
297 	return (EINVAL);
298 }
299