xref: /illumos-gate/usr/src/lib/fm/topo/libtopo/common/topo_module.c (revision a07094369b21309434206d9b3601d162693466fc)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in comodliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 #include <signal.h>
30 #include <dirent.h>
31 #include <limits.h>
32 #include <alloca.h>
33 #include <unistd.h>
34 #include <stdio.h>
35 #include <pthread.h>
36 #include <errno.h>
37 #include <strings.h>
38 #include <assert.h>
39 #include <sys/nvpair.h>
40 
41 #include <topo_string.h>
42 #include <topo_alloc.h>
43 #include <topo_module.h>
44 #include <topo_error.h>
45 #include <topo_subr.h>
46 
47 extern nv_alloc_ops_t topo_nv_alloc_ops;
48 
49 void
50 topo_mod_release(topo_mod_t *mod, tnode_t *node)
51 {
52 	topo_mod_enter(mod);
53 
54 	if (mod->tm_info->tmi_release != NULL)
55 		mod->tm_info->tmi_release(mod, node);
56 
57 	topo_mod_exit(mod);
58 }
59 
60 void
61 topo_mod_hold(topo_mod_t *mod)
62 {
63 	(void) pthread_mutex_lock(&mod->tm_lock);
64 	mod->tm_refs++;
65 	assert(mod->tm_refs != 0);
66 	(void) pthread_mutex_unlock(&mod->tm_lock);
67 }
68 
69 void
70 topo_mod_rele(topo_mod_t *mod)
71 {
72 	assert(mod->tm_refs != 0);
73 
74 	(void) pthread_mutex_lock(&mod->tm_lock);
75 
76 	/*
77 	 * Lazy unload module
78 	 */
79 	if (--mod->tm_refs == 0)
80 		topo_modhash_unload(mod);
81 	else
82 		(void) pthread_mutex_unlock(&mod->tm_lock);
83 }
84 
85 void
86 topo_mod_enter(topo_mod_t *mod)
87 {
88 	(void) pthread_mutex_lock(&mod->tm_lock);
89 
90 	while (mod->tm_busy != 0)
91 		(void) pthread_cond_wait(&mod->tm_cv, &mod->tm_lock);
92 
93 	++mod->tm_busy;
94 
95 	(void) pthread_mutex_unlock(&mod->tm_lock);
96 }
97 
98 void
99 topo_mod_exit(topo_mod_t *mod)
100 {
101 	(void) pthread_mutex_lock(&mod->tm_lock);
102 	--mod->tm_busy;
103 
104 	assert(mod->tm_busy == 0);
105 
106 	(void) pthread_cond_broadcast(&mod->tm_cv);
107 	(void) pthread_mutex_unlock(&mod->tm_lock);
108 }
109 
110 static void
111 topo_modhash_lock(topo_modhash_t *mhp)
112 {
113 	(void) pthread_mutex_lock(&mhp->mh_lock);
114 }
115 
116 static void
117 topo_modhash_unlock(topo_modhash_t *mhp)
118 {
119 	(void) pthread_mutex_unlock(&mhp->mh_lock);
120 }
121 
122 static void
123 topo_mod_stop(topo_mod_t *mod)
124 {
125 	if (mod->tm_flags & TOPO_MOD_INIT) {
126 		mod->tm_mops->mop_fini(mod);
127 		if (mod->tm_flags & TOPO_MOD_REG)
128 			topo_mod_unregister(mod);
129 	}
130 
131 	mod->tm_flags = TOPO_MOD_FINI;
132 
133 	topo_dprintf(TOPO_DBG_MOD, "module %s stopped\n", mod->tm_name);
134 }
135 
136 static int
137 topo_mod_start(topo_mod_t *mod)
138 {
139 	topo_dprintf(TOPO_DBG_MOD, "starting module %s\n", mod->tm_name);
140 
141 	if (mod->tm_mops->mop_init(mod) != 0) {
142 		mod->tm_errno = errno ? errno : ETOPO_MOD_INIT;
143 		topo_dprintf(TOPO_DBG_ERR,
144 		    "module %s failed to initialize: %s\n", mod->tm_name,
145 		    topo_strerror(mod->tm_errno));
146 		return (-1);
147 	}
148 
149 	mod->tm_flags |= TOPO_MOD_INIT;
150 
151 	if (!(mod->tm_flags & TOPO_MOD_REG)) {
152 		topo_dprintf(TOPO_DBG_ERR,
153 		    "module %s failed to register\n", mod->tm_name);
154 		mod->tm_errno = ETOPO_MOD_NOREG;
155 		topo_mod_stop(mod);
156 		return (-1);
157 	}
158 
159 	topo_dprintf(TOPO_DBG_MOD, "module %s started\n", mod->tm_name);
160 
161 	return (0);
162 }
163 
164 topo_mod_t *
165 topo_mod_lookup(topo_hdl_t *thp, const char *path)
166 {
167 	char *p;
168 	char name[PATH_MAX];
169 	topo_mod_t *mod;
170 	topo_modhash_t *mhp = thp->th_modhash;
171 
172 	(void) strlcpy(name, topo_strbasename(path), sizeof (name));
173 	if ((p = strrchr(name, '.')) != NULL && strcmp(p, ".so") == 0)
174 	*p = '\0'; /* strip trailing .so from any module name */
175 
176 	topo_modhash_lock(mhp);
177 	mod = topo_modhash_lookup(mhp, name);
178 	topo_modhash_unlock(mhp);
179 
180 	return (mod);
181 }
182 
183 static void
184 topo_mod_destroy(topo_mod_t *mod)
185 {
186 	topo_hdl_t *thp = mod->tm_hdl;
187 
188 	if (mod == NULL)
189 		return;
190 
191 	assert(mod->tm_refs == 0);
192 	assert(!topo_mutex_held(&mod->tm_lock));
193 
194 	if (mod->tm_name != NULL)
195 		topo_hdl_strfree(thp, mod->tm_name);
196 	if (mod->tm_path != NULL)
197 		topo_hdl_strfree(thp, mod->tm_path);
198 	if (mod->tm_rootdir != NULL)
199 		topo_hdl_strfree(thp, mod->tm_rootdir);
200 
201 	topo_hdl_free(thp, mod, sizeof (topo_mod_t));
202 }
203 
204 static topo_mod_t *
205 set_create_error(topo_hdl_t *thp, topo_mod_t *mod, const char *path, int err)
206 {
207 	topo_dprintf(TOPO_DBG_ERR, "unable to load module %s: %s\n",
208 	    path, topo_strerror(err));
209 
210 	if (mod != NULL)
211 		topo_mod_destroy(mod);
212 
213 	(void) topo_hdl_seterrno(thp, err);
214 
215 	return (NULL);
216 }
217 
218 static topo_mod_t *
219 topo_mod_create(topo_hdl_t *thp, const char *name, const char *path,
220     const topo_modops_t *ops)
221 {
222 	topo_mod_t *mod;
223 
224 	if (topo_modhash_lookup(thp->th_modhash, name) != NULL)
225 		return (set_create_error(thp, NULL, path, ETOPO_MOD_LOADED));
226 
227 	if ((mod = topo_hdl_zalloc(thp, sizeof (topo_mod_t))) == NULL)
228 		return (set_create_error(thp, mod, path, ETOPO_NOMEM));
229 
230 	(void) pthread_mutex_init(&mod->tm_lock, NULL);
231 
232 	mod->tm_name = topo_hdl_strdup(thp, name);
233 	mod->tm_path = topo_hdl_strdup(thp, path);
234 	mod->tm_rootdir = topo_hdl_strdup(thp, thp->th_rootdir);
235 	if (mod->tm_name == NULL || mod->tm_path == NULL ||
236 	    mod->tm_rootdir == NULL)
237 		return (set_create_error(thp, mod, path, ETOPO_NOMEM));
238 
239 	mod->tm_mops = (topo_modops_t *)ops;
240 	mod->tm_hdl = thp;
241 	mod->tm_alloc = thp->th_alloc;
242 	mod->tm_version = TOPO_VERSION;
243 
244 	/*
245 	 * Module will be held upon a successful return from topo_mod_start()
246 	 */
247 	if ((topo_mod_start(mod)) < 0)
248 		return (set_create_error(thp, mod, path, mod->tm_errno));
249 
250 	topo_dprintf(TOPO_DBG_MOD, "loaded module %s\n", mod->tm_name);
251 
252 	return (mod);
253 }
254 
255 topo_modhash_t *
256 topo_modhash_create(topo_hdl_t *thp)
257 {
258 	topo_modhash_t *mhp;
259 
260 	if ((mhp = topo_hdl_zalloc(thp, sizeof (topo_modhash_t))) == NULL)
261 		return (NULL);
262 
263 	mhp->mh_hashlen = TOPO_HASH_BUCKETS;
264 	if ((mhp->mh_hash = topo_hdl_zalloc(thp,
265 	    sizeof (void *) * mhp->mh_hashlen)) == NULL) {
266 		topo_hdl_free(thp, mhp, sizeof (topo_modhash_t));
267 		return (NULL);
268 	}
269 	mhp->mh_nelems = 0;
270 	(void) pthread_mutex_init(&mhp->mh_lock, NULL);
271 
272 	thp->th_modhash = mhp;
273 
274 	return (mhp);
275 }
276 
277 void
278 topo_modhash_destroy(topo_hdl_t *thp)
279 {
280 	topo_modhash_t *mhp = thp->th_modhash;
281 
282 	if (mhp == NULL)
283 		return;
284 
285 	assert(mhp->mh_nelems == 0);
286 
287 	topo_hdl_free(thp, mhp->mh_hash, sizeof (void *) * mhp->mh_hashlen);
288 	topo_hdl_free(thp, mhp, sizeof (topo_modhash_t));
289 	thp->th_modhash = NULL;
290 }
291 
292 topo_mod_t *
293 topo_modhash_lookup(topo_modhash_t *mhp, const char *name)
294 {
295 	topo_mod_t *mod = NULL;
296 	uint_t h;
297 
298 	h = topo_strhash(name) % mhp->mh_hashlen;
299 
300 	for (mod = mhp->mh_hash[h]; mod != NULL; mod = mod->tm_next) {
301 		if (strcmp(name, mod->tm_name) == 0)
302 			break;
303 	}
304 
305 	return (mod);
306 }
307 
308 topo_mod_t *
309 topo_modhash_load(topo_hdl_t *thp, const char *path, const topo_modops_t *ops)
310 {
311 	char name[PATH_MAX], *p;
312 	topo_modhash_t *mhp = thp->th_modhash;
313 	topo_mod_t *mod;
314 	uint_t h;
315 
316 	topo_modhash_lock(mhp);
317 
318 	(void) strlcpy(name, topo_strbasename(path), sizeof (name));
319 	if ((p = strrchr(name, '.')) != NULL && strcmp(p, ".so") == 0)
320 		*p = '\0'; /* strip trailing .so from any module name */
321 
322 	if ((mod = topo_mod_create(thp, name, path, ops)) == NULL) {
323 		topo_hdl_unlock(thp);
324 		return (NULL); /* th_errno set */
325 	}
326 
327 	topo_mod_hold(mod);
328 
329 	h = topo_strhash(name) % mhp->mh_hashlen;
330 	mod->tm_next = mhp->mh_hash[h];
331 	mhp->mh_hash[h] = mod;
332 	mhp->mh_nelems++;
333 	topo_modhash_unlock(mhp);
334 
335 	return (mod);
336 }
337 
338 void
339 topo_modhash_unload(topo_mod_t *mod)
340 {
341 	uint_t h;
342 	topo_mod_t **pp, *mp;
343 	topo_hdl_t *thp = mod->tm_hdl;
344 	topo_modhash_t *mhp;
345 
346 	assert(topo_mutex_held(&mod->tm_lock));
347 	assert(mod->tm_busy == 0);
348 
349 	mhp = thp->th_modhash;
350 	topo_modhash_lock(mhp);
351 
352 	assert(mhp != NULL);
353 
354 	h = topo_strhash(mod->tm_name) % mhp->mh_hashlen;
355 	pp = &mhp->mh_hash[h];
356 
357 	for (mp = *pp; mp != NULL; mp = mp->tm_next) {
358 		if (mp == mod)
359 			break;
360 		else
361 			pp = &mp->tm_next;
362 	}
363 
364 	if (mp != NULL) {
365 		*pp = mod->tm_next;
366 
367 		assert(mhp->mh_nelems != 0);
368 
369 		mhp->mh_nelems--;
370 
371 	}
372 	topo_modhash_unlock(mhp);
373 
374 	(void) pthread_mutex_unlock(&mod->tm_lock);
375 
376 	topo_mod_stop(mod);
377 	topo_mod_destroy(mod);
378 
379 }
380 
381 void
382 topo_modhash_unload_all(topo_hdl_t *thp)
383 {
384 	int i;
385 	topo_modhash_t *mhp = thp->th_modhash;
386 	topo_mod_t *mp, **pp;
387 
388 	topo_modhash_lock(mhp);
389 	for (i = 0; i < TOPO_HASH_BUCKETS; ++i) {
390 		pp = &mhp->mh_hash[i];
391 		mp = *pp;
392 		while (mp != NULL) {
393 			topo_mod_stop(mp);
394 
395 			assert(mp->tm_refs == 1);
396 
397 			--mp->tm_refs;
398 			*pp = mp->tm_next;
399 			topo_mod_destroy(mp);
400 			mp = *pp;
401 
402 			--mhp->mh_nelems;
403 		}
404 	}
405 	topo_modhash_unlock(mhp);
406 }
407