ofrom.c revision 1.29 
1/*	$NetBSD: ofrom.c,v 1.29 2021/01/27 03:10:21 thorpej Exp $	*/
2
3/*
4 * Copyright 1998
5 * Digital Equipment Corporation. All rights reserved.
6 *
7 * This software is furnished under license and may be used and
8 * copied only in accordance with the following terms and conditions.
9 * Subject to these conditions, you may download, copy, install,
10 * use, modify and distribute this software in source and/or binary
11 * form. No title or ownership is transferred hereby.
12 *
13 * 1) Any source code used, modified or distributed must reproduce
14 *    and retain this copyright notice and list of conditions as
15 *    they appear in the source file.
16 *
17 * 2) No right is granted to use any trade name, trademark, or logo of
18 *    Digital Equipment Corporation. Neither the "Digital Equipment
19 *    Corporation" name nor any trademark or logo of Digital Equipment
20 *    Corporation may be used to endorse or promote products derived
21 *    from this software without the prior written permission of
22 *    Digital Equipment Corporation.
23 *
24 * 3) This software is provided "AS-IS" and any express or implied
25 *    warranties, including but not limited to, any implied warranties
26 *    of merchantability, fitness for a particular purpose, or
27 *    non-infringement are disclaimed. In no event shall DIGITAL be
28 *    liable for any damages whatsoever, and in particular, DIGITAL
29 *    shall not be liable for special, indirect, consequential, or
30 *    incidental damages or damages for lost profits, loss of
31 *    revenue or loss of use, whether such damages arise in contract,
32 *    negligence, tort, under statute, in equity, at law or otherwise,
33 *    even if advised of the possibility of such damage.
34 */
35
36/*
37 * XXX open for writing (for user programs to mmap, and write contents)
38 */
39
40#include <sys/cdefs.h>
41__KERNEL_RCSID(0, "$NetBSD: ofrom.c,v 1.29 2021/01/27 03:10:21 thorpej Exp $");
42
43#include <sys/param.h>
44#include <sys/device.h>
45#include <sys/systm.h>
46#include <sys/conf.h>
47#include <sys/fcntl.h>
48#include <sys/bus.h>
49
50#include <uvm/uvm_extern.h>
51
52#include <dev/ofw/openfirm.h>
53
54struct ofrom_softc {
55	int		enabled;
56	paddr_t		base;
57	paddr_t		size;
58};
59
60int ofromprobe(device_t, cfdata_t, void *);
61void ofromattach(device_t, device_t, void *);
62
63CFATTACH_DECL_NEW(ofrom, sizeof(struct ofrom_softc),
64    ofromprobe, ofromattach, NULL, NULL);
65
66extern struct cfdriver ofrom_cd;
67
68dev_type_open(ofromopen);
69dev_type_read(ofromrw);
70dev_type_mmap(ofrommmap);
71
72const struct cdevsw ofrom_cdevsw = {
73	.d_open = ofromopen,
74	.d_close = nullclose,
75	.d_read = ofromrw,
76	.d_write = ofromrw,
77	.d_ioctl = noioctl,
78	.d_stop = nostop,
79	.d_tty = notty,
80	.d_poll = nopoll,
81	.d_mmap = ofrommmap,
82	.d_kqfilter = nokqfilter,
83	.d_discard = nodiscard,
84	.d_flag = 0
85};
86
87static const struct device_compatible_entry compat_data[] = {
88	{ .compat = "rom" },
89	DEVICE_COMPAT_EOL
90};
91
92int
93ofromprobe(device_t parent, cfdata_t cf, void *aux)
94{
95	struct ofbus_attach_args *oba = aux;
96
97	return of_compatible_match(oba->oba_phandle, compat_data) * 5;
98}
99
100
101void
102ofromattach(device_t parent, device_t self, void *aux)
103{
104	struct ofrom_softc *sc = device_private(self);
105	struct ofbus_attach_args *oba = aux;
106	char regbuf[8];
107
108	if (OF_getproplen(oba->oba_phandle, "reg") != 8) {
109		printf(": invalid reg property\n");
110		return;
111	}
112	if (OF_getprop(oba->oba_phandle, "reg", regbuf, sizeof regbuf) != 8) {
113		printf(": couldn't read reg property\n");
114		return;
115	}
116	sc->base = of_decode_int(&regbuf[0]);
117	sc->size = of_decode_int(&regbuf[4]);
118	sc->enabled = 1;
119
120	printf(": %#lx-%#lx\n", sc->base, sc->base + sc->size - 1);
121}
122
123int
124ofromopen(dev_t dev, int oflags, int devtype, struct lwp *l)
125{
126	struct ofrom_softc *sc;
127
128	sc = device_lookup_private(&ofrom_cd, minor(dev));
129	if (!sc || !sc->enabled)
130		return (ENXIO);
131
132	if (oflags & FWRITE)
133		return (EINVAL);
134
135	return (0);
136}
137
138int
139ofromrw(dev_t dev, struct uio *uio, int flags)
140{
141	pmap_t kpm = pmap_kernel();
142	struct ofrom_softc *sc;
143	int c, error = 0;
144	struct iovec *iov;
145	paddr_t v;
146	psize_t o;
147	extern kmutex_t memlock;
148	extern char *memhook;
149
150	sc = device_lookup_private(&ofrom_cd, minor(dev));
151	if (!sc || !sc->enabled)
152		return (ENXIO);			/* XXX PANIC */
153
154	mutex_enter(&memlock);
155	while (uio->uio_resid > 0 && error == 0) {
156		iov = uio->uio_iov;
157		if (iov->iov_len == 0) {
158			uio->uio_iov++;
159			uio->uio_iovcnt--;
160			if (uio->uio_iovcnt < 0)
161				panic("ofromrw");
162			continue;
163		}
164
165		/*
166		 * Since everything is page aligned and no more
167		 * than the rest of a page is done at once, we
168		 * can just check that the offset isn't too big.
169		 */
170		if (uio->uio_offset >= sc->size)
171			break;
172
173		v = sc->base + uio->uio_offset;
174		pmap_kenter_pa((vaddr_t)memhook, trunc_page(v),
175		    uio->uio_rw == UIO_READ ?  VM_PROT_READ : VM_PROT_WRITE,
176		    0);
177		pmap_update(kpm);
178		o = uio->uio_offset & PGOFSET;
179		c = uimin(uio->uio_resid, (int)(PAGE_SIZE - o));
180		error = uiomove((char *)memhook + o, c, uio);
181		pmap_kremove((vaddr_t)memhook, (vaddr_t)memhook + PAGE_SIZE);
182		pmap_update(kpm);
183	}
184	mutex_exit(&memlock);
185
186	return (error);
187}
188
189paddr_t
190ofrommmap(dev_t dev, off_t off, int prot)
191{
192	struct ofrom_softc *sc;
193
194	sc = device_lookup_private(&ofrom_cd, minor(dev));
195	if (!sc || !sc->enabled)
196		return (-1);			/* XXX PANIC */
197
198	if ((u_int)off >= sc->size)
199		return (-1);
200
201	return arm_btop(sc->base + off);
202}
203