xref: /freebsd/sys/kern/subr_autoconf.c (revision 17ee9d00bc1ae1e598c38f25826f861e4bc6c3ce)
1 /*
2  * Copyright (c) 1992, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * This software was developed by the Computer Systems Engineering group
6  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
7  * contributed to Berkeley.
8  *
9  * All advertising materials mentioning features or use of this software
10  * must display the following acknowledgement:
11  *	This product includes software developed by the University of
12  *	California, Lawrence Berkeley Laboratories.
13  *
14  * Redistribution and use in source and binary forms, with or without
15  * modification, are permitted provided that the following conditions
16  * are met:
17  * 1. Redistributions of source code must retain the above copyright
18  *    notice, this list of conditions and the following disclaimer.
19  * 2. Redistributions in binary form must reproduce the above copyright
20  *    notice, this list of conditions and the following disclaimer in the
21  *    documentation and/or other materials provided with the distribution.
22  * 3. All advertising materials mentioning features or use of this software
23  *    must display the following acknowledgement:
24  *	This product includes software developed by the University of
25  *	California, Berkeley and its contributors.
26  * 4. Neither the name of the University nor the names of its contributors
27  *    may be used to endorse or promote products derived from this software
28  *    without specific prior written permission.
29  *
30  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
31  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
32  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
33  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
34  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
35  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
36  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
37  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
38  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
39  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
40  * SUCH DAMAGE.
41  *
42  *	@(#)subr_autoconf.c	8.1 (Berkeley) 6/10/93
43  *
44  * $Id$
45  */
46 
47 #include <sys/param.h>
48 #include <sys/device.h>
49 #include <sys/malloc.h>
50 
51 /*
52  * Autoconfiguration subroutines.
53  */
54 
55 /*
56  * ioconf.c exports exactly two names: cfdata and cfroots.  All system
57  * devices and drivers are found via these tables.
58  */
59 extern struct cfdata cfdata[];
60 extern short cfroots[];
61 
62 #define	ROOT ((struct device *)NULL)
63 
64 struct matchinfo {
65 	cfmatch_t fn;
66 	struct	device *parent;
67 	void	*aux;
68 	struct	cfdata *match;
69 	int	pri;
70 };
71 
72 /*
73  * Apply the matching function and choose the best.  This is used
74  * a few times and we want to keep the code small.
75  */
76 static void
77 mapply(m, cf)
78 	register struct matchinfo *m;
79 	register struct cfdata *cf;
80 {
81 	register int pri;
82 
83 	if (m->fn != NULL)
84 		pri = (*m->fn)(m->parent, cf, m->aux);
85 	else
86 		pri = (*cf->cf_driver->cd_match)(m->parent, cf, m->aux);
87 	if (pri > m->pri) {
88 		m->match = cf;
89 		m->pri = pri;
90 	}
91 }
92 
93 /*
94  * Iterate over all potential children of some device, calling the given
95  * function (default being the child's match function) for each one.
96  * Nonzero returns are matches; the highest value returned is considered
97  * the best match.  Return the `found child' if we got a match, or NULL
98  * otherwise.  The `aux' pointer is simply passed on through.
99  *
100  * Note that this function is designed so that it can be used to apply
101  * an arbitrary function to all potential children (its return value
102  * can be ignored).
103  */
104 struct cfdata *
105 config_search(fn, parent, aux)
106 	cfmatch_t fn;
107 	register struct device *parent;
108 	void *aux;
109 {
110 	register struct cfdata *cf;
111 	register short *p;
112 	struct matchinfo m;
113 
114 	m.fn = fn;
115 	m.parent = parent;
116 	m.aux = aux;
117 	m.match = NULL;
118 	m.pri = 0;
119 	for (cf = cfdata; cf->cf_driver; cf++) {
120 		/*
121 		 * Skip cf if no longer eligible, otherwise scan through
122 		 * parents for one matching `parent', and try match function.
123 		 */
124 		if (cf->cf_fstate == FSTATE_FOUND)
125 			continue;
126 		for (p = cf->cf_parents; *p >= 0; p++)
127 			if (parent->dv_cfdata == &cfdata[*p])
128 				mapply(&m, cf);
129 	}
130 	return (m.match);
131 }
132 
133 /*
134  * Find the given root device.
135  * This is much like config_search, but there is no parent.
136  */
137 struct cfdata *
138 config_rootsearch(fn, rootname, aux)
139 	register cfmatch_t fn;
140 	register char *rootname;
141 	register void *aux;
142 {
143 	register struct cfdata *cf;
144 	register short *p;
145 	struct matchinfo m;
146 
147 	m.fn = fn;
148 	m.parent = ROOT;
149 	m.aux = aux;
150 	m.match = NULL;
151 	m.pri = 0;
152 	/*
153 	 * Look at root entries for matching name.  We do not bother
154 	 * with found-state here since only one root should ever be
155 	 * searched (and it must be done first).
156 	 */
157 	for (p = cfroots; *p >= 0; p++) {
158 		cf = &cfdata[*p];
159 		if (strcmp(cf->cf_driver->cd_name, rootname) == 0)
160 			mapply(&m, cf);
161 	}
162 	return (m.match);
163 }
164 
165 static char *msgs[3] = { "", " not configured\n", " unsupported\n" };
166 
167 /*
168  * The given `aux' argument describes a device that has been found
169  * on the given parent, but not necessarily configured.  Locate the
170  * configuration data for that device (using the cd_match configuration
171  * driver function) and attach it, and return true.  If the device was
172  * not configured, call the given `print' function and return 0.
173  */
174 int
175 config_found(parent, aux, print)
176 	struct device *parent;
177 	void *aux;
178 	cfprint_t print;
179 {
180 	struct cfdata *cf;
181 
182 	if ((cf = config_search((cfmatch_t)NULL, parent, aux)) != NULL) {
183 		config_attach(parent, cf, aux, print);
184 		return (1);
185 	}
186 	printf(msgs[(*print)(aux, parent->dv_xname)]);
187 	return (0);
188 }
189 
190 /*
191  * As above, but for root devices.
192  */
193 int
194 config_rootfound(rootname, aux)
195 	char *rootname;
196 	void *aux;
197 {
198 	struct cfdata *cf;
199 
200 	if ((cf = config_rootsearch((cfmatch_t)NULL, rootname, aux)) != NULL) {
201 		config_attach(ROOT, cf, aux, (cfprint_t)NULL);
202 		return (1);
203 	}
204 	printf("root device %s not configured\n", rootname);
205 	return (0);
206 }
207 
208 /* just like sprintf(buf, "%d") except that it works from the end */
209 static char *
210 number(ep, n)
211 	register char *ep;
212 	register int n;
213 {
214 
215 	*--ep = 0;
216 	while (n >= 10) {
217 		*--ep = (n % 10) + '0';
218 		n /= 10;
219 	}
220 	*--ep = n + '0';
221 	return (ep);
222 }
223 
224 /*
225  * Attach a found device.  Allocates memory for device variables.
226  */
227 void
228 config_attach(parent, cf, aux, print)
229 	register struct device *parent;
230 	register struct cfdata *cf;
231 	register void *aux;
232 	cfprint_t print;
233 {
234 	register struct device *dev;
235 	register struct cfdriver *cd;
236 	register size_t lname, lunit;
237 	register char *xunit;
238 	int myunit;
239 	char num[10];
240 	static struct device **nextp = &alldevs;
241 
242 	cd = cf->cf_driver;
243 	if (cd->cd_devsize < sizeof(struct device))
244 		panic("config_attach");
245 	myunit = cf->cf_unit;
246 	if (cf->cf_fstate == FSTATE_NOTFOUND)
247 		cf->cf_fstate = FSTATE_FOUND;
248 	else
249 		cf->cf_unit++;
250 
251 	/* compute length of name and decimal expansion of unit number */
252 	lname = strlen(cd->cd_name);
253 	xunit = number(&num[sizeof num], myunit);
254 	lunit = &num[sizeof num] - xunit;
255 	if (lname + lunit >= sizeof(dev->dv_xname))
256 		panic("config_attach: device name too long");
257 
258 	/* get memory for all device vars */
259 	dev = (struct device *)malloc(cd->cd_devsize, M_DEVBUF, M_WAITOK);
260 					/* XXX cannot wait! */
261 	bzero(dev, cd->cd_devsize);
262 	*nextp = dev;			/* link up */
263 	nextp = &dev->dv_next;
264 	dev->dv_class = cd->cd_class;
265 	dev->dv_cfdata = cf;
266 	dev->dv_unit = myunit;
267 	bcopy(cd->cd_name, dev->dv_xname, lname);
268 	bcopy(xunit, dev->dv_xname + lname, lunit);
269 	dev->dv_parent = parent;
270 	if (parent == ROOT)
271 		printf("%s (root)", dev->dv_xname);
272 	else {
273 		printf("%s at %s", dev->dv_xname, parent->dv_xname);
274 		(void) (*print)(aux, (char *)0);
275 	}
276 
277 	/* put this device in the devices array */
278 	if (dev->dv_unit >= cd->cd_ndevs) {
279 		/*
280 		 * Need to expand the array.
281 		 */
282 		int old = cd->cd_ndevs, oldbytes, new, newbytes;
283 		void **nsp;
284 
285 		if (old == 0) {
286 			nsp = malloc(MINALLOCSIZE, M_DEVBUF, M_WAITOK);	/*XXX*/
287 			bzero(nsp, MINALLOCSIZE);
288 			cd->cd_ndevs = MINALLOCSIZE / sizeof(void *);
289 		} else {
290 			new = cd->cd_ndevs;
291 			do {
292 				new *= 2;
293 			} while (new <= dev->dv_unit);
294 			cd->cd_ndevs = new;
295 			oldbytes = old * sizeof(void *);
296 			newbytes = new * sizeof(void *);
297 			nsp = malloc(newbytes, M_DEVBUF, M_WAITOK);	/*XXX*/
298 			bcopy(cd->cd_devs, nsp, oldbytes);
299 			bzero(&nsp[old], newbytes - oldbytes);
300 			free(cd->cd_devs, M_DEVBUF);
301 		}
302 		cd->cd_devs = nsp;
303 	}
304 	if (cd->cd_devs[dev->dv_unit])
305 		panic("config_attach: duplicate %s", dev->dv_xname);
306 	cd->cd_devs[dev->dv_unit] = dev;
307 
308 	/*
309 	 * Before attaching, clobber any unfound devices that are
310 	 * otherwise identical.
311 	 */
312 	for (cf = cfdata; cf->cf_driver; cf++)
313 		if (cf->cf_driver == cd && cf->cf_unit == dev->dv_unit &&
314 		    cf->cf_fstate == FSTATE_NOTFOUND)
315 			cf->cf_fstate = FSTATE_FOUND;
316 	(*cd->cd_attach)(parent, dev, aux);
317 }
318 
319 /*
320  * Attach an event.  These must come from initially-zero space (see
321  * commented-out assignments below), but that occurs naturally for
322  * device instance variables.
323  */
324 void
325 evcnt_attach(dev, name, ev)
326 	struct device *dev;
327 	const char *name;
328 	struct evcnt *ev;
329 {
330 	static struct evcnt **nextp = &allevents;
331 
332 #ifdef DIAGNOSTIC
333 	if (strlen(name) >= sizeof(ev->ev_name))
334 		panic("evcnt_attach");
335 #endif
336 	/* ev->ev_next = NULL; */
337 	ev->ev_dev = dev;
338 	/* ev->ev_count = 0; */
339 	strcpy(ev->ev_name, name);
340 	*nextp = ev;
341 	nextp = &ev->ev_next;
342 }
343