xref: /freebsd/sys/powerpc/powernv/opal_nvram.c (revision 6b2c1e49da284f28ec7b52f7c031474087e37104)
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/uio.h>
38 
39 #include <dev/ofw/openfirm.h>
40 #include <dev/ofw/ofw_bus.h>
41 #include <dev/ofw/ofw_bus_subr.h>
42 
43 #include <machine/bus.h>
44 #include <machine/md_var.h>
45 #include <machine/pio.h>
46 #include <machine/resource.h>
47 
48 #include "opal.h"
49 
50 #include <sys/rman.h>
51 
52 #include <vm/vm.h>
53 #include <vm/pmap.h>
54 
55 #define	NVRAM_BUFSIZE	(65536)	/* 64k blocks */
56 
57 struct opal_nvram_softc {
58 	device_t	 sc_dev;
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 /*
68  * Device interface.
69  */
70 static int		opal_nvram_probe(device_t);
71 static int		opal_nvram_attach(device_t);
72 static int		opal_nvram_detach(device_t);
73 
74 /*
75  * Driver methods.
76  */
77 static device_method_t	opal_nvram_methods[] = {
78 	/* Device interface */
79 	DEVMETHOD(device_probe,		opal_nvram_probe),
80 	DEVMETHOD(device_attach,	opal_nvram_attach),
81 	DEVMETHOD(device_detach,	opal_nvram_detach),
82 
83 	{ 0, 0 }
84 };
85 
86 static driver_t	opal_nvram_driver = {
87 	"opal_nvram",
88 	opal_nvram_methods,
89 	sizeof(struct opal_nvram_softc)
90 };
91 
92 static devclass_t opal_nvram_devclass;
93 
94 DRIVER_MODULE(opal_nvram, opal, opal_nvram_driver, opal_nvram_devclass, 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_flags =	D_NEEDGIANT,
109 	.d_open =	opal_nvram_open,
110 	.d_close =	opal_nvram_close,
111 	.d_read =	opal_nvram_read,
112 	.d_write =	opal_nvram_write,
113 	.d_ioctl =	opal_nvram_ioctl,
114 	.d_name =	"nvram",
115 };
116 
117 static int
118 opal_nvram_probe(device_t dev)
119 {
120 
121 	if (!ofw_bus_is_compatible(dev, "ibm,opal-nvram"))
122 		return (ENXIO);
123 
124 	device_set_desc(dev, "OPAL NVRAM");
125 	return (BUS_PROBE_DEFAULT);
126 }
127 
128 static int
129 opal_nvram_attach(device_t dev)
130 {
131 	struct opal_nvram_softc *sc;
132 	phandle_t node;
133 	int err;
134 
135 	node = ofw_bus_get_node(dev);
136 	sc = device_get_softc(dev);
137 
138 	sc->sc_dev = dev;
139 
140 	err = OF_getencprop(node, "#bytes", &sc->sc_size,
141 	    sizeof(sc->sc_size));
142 
143 	if (err < 0)
144 		return (ENXIO);
145 
146 	sc->sc_buf = contigmalloc(NVRAM_BUFSIZE, M_DEVBUF, M_WAITOK,
147 	    0, BUS_SPACE_MAXADDR, PAGE_SIZE, 0);
148 	if (sc->sc_buf == NULL) {
149 		device_printf(dev, "No memory for buffer.\n");
150 		return (ENXIO);
151 	}
152 	sc->sc_buf_phys = pmap_kextract((vm_offset_t)sc->sc_buf);
153 	sc->sc_cdev = make_dev(&opal_nvram_cdevsw, 0, 0, 0, 0600,
154 	    "nvram");
155 	sc->sc_cdev->si_drv1 = sc;
156 
157 	return (0);
158 }
159 
160 static int
161 opal_nvram_detach(device_t dev)
162 {
163 	struct opal_nvram_softc *sc;
164 
165 	sc = device_get_softc(dev);
166 
167 	if (sc->sc_cdev != NULL)
168 		destroy_dev(sc->sc_cdev);
169 	if (sc->sc_buf != NULL)
170 		contigfree(sc->sc_buf, NVRAM_BUFSIZE, M_DEVBUF);
171 
172 	return (0);
173 }
174 
175 static int
176 opal_nvram_open(struct cdev *dev, int flags, int fmt, struct thread *td)
177 {
178 	struct opal_nvram_softc *sc = dev->si_drv1;
179 
180 	if (sc->sc_isopen)
181 		return EBUSY;
182 	sc->sc_isopen = 1;
183 	return (0);
184 }
185 
186 static int
187 opal_nvram_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
188 {
189 	struct opal_nvram_softc *sc = dev->si_drv1;
190 
191 	sc->sc_isopen = 0;
192 	return (0);
193 }
194 
195 static int
196 opal_nvram_read(struct cdev *dev, struct uio *uio, int ioflag)
197 {
198 	struct opal_nvram_softc *sc = dev->si_drv1;
199 	int rv, amnt;
200 
201 	rv = 0;
202 	while (uio->uio_resid > 0) {
203 		amnt = MIN(uio->uio_resid, sc->sc_size - uio->uio_offset);
204 		amnt = MIN(amnt, NVRAM_BUFSIZE);
205 		if (amnt == 0)
206 			break;
207 
208 		rv = opal_call(OPAL_READ_NVRAM, sc->sc_buf_phys,
209 		    amnt, uio->uio_offset);
210 		if (rv != OPAL_SUCCESS) {
211 			switch (rv) {
212 			case OPAL_HARDWARE:
213 				rv = EIO;
214 				break;
215 			case OPAL_PARAMETER:
216 				rv = EINVAL;
217 				break;
218 			}
219 			break;
220 		}
221 		rv = uiomove(sc->sc_buf, amnt, uio);
222 		if (rv != 0)
223 			break;
224 	}
225 	return (rv);
226 }
227 
228 static int
229 opal_nvram_write(struct cdev *dev, struct uio *uio, int ioflag)
230 {
231 	off_t offset;
232 	int rv, amnt;
233 	struct opal_nvram_softc *sc = dev->si_drv1;
234 
235 	rv = 0;
236 	while (uio->uio_resid > 0) {
237 		amnt = MIN(uio->uio_resid, sc->sc_size - uio->uio_offset);
238 		amnt = MIN(amnt, NVRAM_BUFSIZE);
239 		if (amnt == 0) {
240 			rv = ENOSPC;
241 			break;
242 		}
243 		offset = uio->uio_offset;
244 		rv = uiomove(sc->sc_buf, amnt, uio);
245 		if (rv != 0)
246 			break;
247 		rv = opal_call(OPAL_WRITE_NVRAM, sc->sc_buf_phys, amnt,
248 		    offset);
249 		if (rv != OPAL_SUCCESS) {
250 			switch (rv) {
251 			case OPAL_HARDWARE:
252 				rv = EIO;
253 				break;
254 			case OPAL_PARAMETER:
255 				rv = EINVAL;
256 				break;
257 			}
258 			break;
259 		}
260 	}
261 	return (rv);
262 }
263 
264 static int
265 opal_nvram_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
266     struct thread *td)
267 {
268 	struct opal_nvram_softc *sc = dev->si_drv1;
269 
270 	switch (cmd) {
271 	case DIOCGMEDIASIZE:
272 		*(off_t *)data = sc->sc_size;
273 		return (0);
274 	}
275 	return (EINVAL);
276 }
277