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 (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21 /*
22 * Copyright 2008 Sun Microsystems, Inc. All rights reserved.
23 * Use is subject to license terms.
24 */
25
26 #include <sys/types.h>
27 #include <sys/modctl.h>
28 #include <sys/stat.h>
29 #include <sys/proc.h>
30 #include <sys/ddi.h>
31 #include <sys/sunddi.h>
32 #include <sys/kmem.h>
33 #include <sys/file.h>
34 #include <sys/rsm/rsm_common.h>
35 #include <sys/rsm/rsmpi.h>
36 #include <sys/rsm/rsmpi_driver.h>
37
38 /* lint -w2 */
39 static struct modlmisc modlmisc = {
40 &mod_miscops, "RSMOPS module",
41 };
42
43 static struct modlinkage modlinkage = {
44 MODREV_1, (void *)&modlmisc, NULL
45 };
46
47 static kmutex_t rsmops_lock;
48
49 static rsmops_drv_t *rsmops_drv_head = NULL;
50
51 static int rsmops_threads_started = 0;
52
53 int
54 _init(void)
55 {
56 int err;
57
58 mutex_init(&rsmops_lock, NULL, MUTEX_DEFAULT, NULL);
59
60 if ((err = mod_install(&modlinkage)) != 0)
61 mutex_destroy(&rsmops_lock);
62
63 return (err);
64 }
65
66 int
67 _fini(void)
68 {
69 int err;
70
71 mutex_enter(&rsmops_lock);
72 if (rsmops_drv_head) {
73 /* Somebody is still registered with us - we cannot unload */
74 mutex_exit(&rsmops_lock);
75 return (EBUSY);
76 }
77 if (rsmops_threads_started) {
78 /*
79 * Some threads have been started. We do not have any
80 * well-supported way of checking whether they have all
81 * exited. For now, fail attempt to unload if we have
82 * ever started any threads. This is overkill, but ...
83 */
84 mutex_exit(&rsmops_lock);
85 return (EBUSY);
86 }
87 mutex_exit(&rsmops_lock);
88
89 if ((err = mod_remove(&modlinkage)) == 0)
90 mutex_destroy(&rsmops_lock);
91 return (err);
92 }
93
94 int
95 _info(struct modinfo *modinfop)
96 {
97 return (mod_info(&modlinkage, modinfop));
98 }
99
100 static void
101 rsmops_thread_entry(rsmops_drv_t *p_drv)
102 {
103 /* p_drv->ctrl_cnt has already been increased by the time we get here */
104 ASSERT(p_drv->drv.rsm_thread_entry_pt);
105
106 /* call the driver with the thread */
107 (*(p_drv->drv.rsm_thread_entry_pt))(p_drv->drv.drv_name);
108
109 /* thread has returned */
110 mutex_enter(&rsmops_lock);
111 p_drv->ctrl_cnt--;
112 mutex_exit(&rsmops_lock);
113 }
114
115 /* This is expected to be called from the driver's init function */
116 int
117 rsm_register_driver(rsmops_registry_t *p_registry)
118 {
119 rsmops_drv_t **pp_tail;
120 rsmops_drv_t *p;
121
122 if (p_registry->rsm_version > RSM_VERSION) {
123 /* The driver is up-rev than me. Fail attempt to register */
124 return (RSMERR_BAD_DRIVER_VERSION);
125 }
126
127 /*
128 * RSM_VERSION: Since this is the first version, there cannot be any
129 * down-rev drivers - this will be an issue in the future
130 */
131 if (p_registry->rsm_version != RSM_VERSION)
132 return (RSMERR_BAD_DRIVER_VERSION);
133
134 mutex_enter(&rsmops_lock);
135 /* First, search that this driver is not already registered */
136 pp_tail = &rsmops_drv_head;
137 while (*pp_tail) {
138 if (strcmp((*pp_tail)->drv.drv_name, p_registry->drv_name)
139 == 0) {
140 mutex_exit(&rsmops_lock);
141 return (RSMERR_DRIVER_NAME_IN_USE);
142 }
143 pp_tail = &((*pp_tail)->next);
144 }
145
146 p = kmem_alloc(sizeof (rsmops_drv_t), KM_SLEEP);
147 p->drv = *p_registry; /* copy entire rsmops_registry_t structure */
148 p->next = NULL;
149 p->ctrl_cnt = 0;
150 p->ctrl_head = NULL;
151
152 if (p->drv.rsm_thread_entry_pt) {
153 /* thread entry point is defined - we need to create a thread */
154 extern pri_t minclsyspri;
155
156 p->ctrl_cnt++; /* bump up the count right now */
157 p->thread_id = thread_create(NULL, 0, rsmops_thread_entry,
158 p, 0, &p0, TS_RUN, minclsyspri);
159 rsmops_threads_started++;
160 } else
161 p->thread_id = NULL;
162
163 *pp_tail = p;
164 mutex_exit(&rsmops_lock);
165 return (RSM_SUCCESS);
166 }
167
168 /*
169 * This is expected to be called from the driver's fini function
170 * if this function returns EBUSY, the driver is supposed to fail
171 * its own fini operation
172 */
173 int
174 rsm_unregister_driver(rsmops_registry_t *p_registry)
175 {
176 rsmops_drv_t **pp_tail;
177 rsmops_drv_t *p;
178
179 mutex_enter(&rsmops_lock);
180
181 /* Search for the driver */
182 pp_tail = &rsmops_drv_head;
183 while (*pp_tail) {
184 if (strcmp((*pp_tail)->drv.drv_name, p_registry->drv_name)) {
185 pp_tail = &((*pp_tail)->next);
186 continue;
187 }
188 /* check ref count - if somebody is using it, return EBUSY */
189 if ((*pp_tail)->ctrl_cnt) {
190 mutex_exit(&rsmops_lock);
191 return (RSMERR_CTLRS_REGISTERED);
192 }
193 /* Nobody is using it - we can allow the unregister to happen */
194 p = *pp_tail;
195
196 /* Stomp the guy out of our linked list */
197 *pp_tail = (*pp_tail)->next;
198
199 /* release the memory */
200 kmem_free(p, sizeof (rsmops_drv_t));
201
202 mutex_exit(&rsmops_lock);
203 return (RSM_SUCCESS);
204 }
205
206 /* Could not find the guy */
207 mutex_exit(&rsmops_lock);
208 return (RSMERR_DRIVER_NOT_REGISTERED);
209 }
210
211 /* Should be called holding the rsmops_lock mutex */
212 static rsmops_drv_t *
213 find_rsmpi_driver(const char *name)
214 {
215 rsmops_drv_t *p_rsmops_list;
216
217 ASSERT(MUTEX_HELD(&rsmops_lock));
218 /* the name is of the form "sci", "wci" etc */
219
220 for (p_rsmops_list = rsmops_drv_head; p_rsmops_list != NULL;
221 p_rsmops_list = p_rsmops_list->next) {
222
223 if (strcmp(name, p_rsmops_list->drv.drv_name) == 0) {
224 return (p_rsmops_list);
225 }
226 }
227 return (NULL);
228 }
229
230
231 /* Should be called holding the rsmops_lock mutex */
232 static rsmops_ctrl_t *
233 find_rsmpi_controller(const char *name, uint_t number)
234 {
235 rsmops_drv_t *p_drv;
236 rsmops_ctrl_t *p;
237
238 ASSERT(MUTEX_HELD(&rsmops_lock));
239
240 if ((p_drv = find_rsmpi_driver(name)) == NULL)
241 return (NULL);
242
243 for (p = p_drv->ctrl_head; p != NULL; p = p->next) {
244 ASSERT(p->p_drv == p_drv);
245 if (p->number == number)
246 return (p);
247 }
248 return (NULL);
249 }
250
251 /* Should be called holding the rsmops_lock mutex */
252 static rsmops_ctrl_t *
253 find_rsmpi_controller_handle(rsm_controller_handle_t cntlr_handle)
254 {
255 rsmops_drv_t *p_drv;
256 rsmops_ctrl_t *p;
257
258 ASSERT(MUTEX_HELD(&rsmops_lock));
259
260 for (p_drv = rsmops_drv_head; p_drv != NULL; p_drv = p_drv->next) {
261 for (p = p_drv->ctrl_head; p != NULL; p = p->next) {
262 if (p->handle == cntlr_handle)
263 return (p);
264 }
265 }
266
267 return (NULL);
268 }
269
270 static vnode_t *
271 rsmops_device_open(const char *major_name, const minor_t minor_num);
272
273 int
274 rsm_get_controller(const char *name, uint_t number,
275 rsm_controller_object_t *controller, uint_t version)
276 {
277 rsmops_ctrl_t *p_ctrl;
278 rsmops_drv_t *p_drv;
279 vnode_t *vp;
280 int error;
281 int (*rsm_get_controller_handler)
282 (const char *name, uint_t number,
283 rsm_controller_object_t *pcontroller, uint_t version);
284
285 mutex_enter(&rsmops_lock);
286
287 /* check if the controller is already registered */
288 if ((p_ctrl = find_rsmpi_controller(name, number)) == NULL) {
289 /*
290 * controller is not registered. We should try to load it
291 * First check if the driver is registered
292 */
293 if ((p_drv = find_rsmpi_driver(name)) == NULL) {
294 /* Cannot find the driver. Try to load him */
295 mutex_exit(&rsmops_lock);
296 if ((error = modload("drv", (char *)name)) == -1) {
297 return (RSMERR_CTLR_NOT_PRESENT);
298 }
299 mutex_enter(&rsmops_lock);
300 if ((p_drv = find_rsmpi_driver(name)) == NULL) {
301 mutex_exit(&rsmops_lock);
302 /*
303 * Cannot find yet - maybe the driver we loaded
304 * was not a RSMPI driver at all. We'll just
305 * fail this call.
306 */
307 return (RSMERR_CTLR_NOT_PRESENT);
308 }
309 }
310 ASSERT(p_drv);
311 p_ctrl = find_rsmpi_controller(name, number);
312 if (p_ctrl == NULL) {
313 /*
314 * controller is not registered.
315 * try to do a VOP_OPEN to force it to get registered
316 */
317 mutex_exit(&rsmops_lock);
318 vp = rsmops_device_open(name, number);
319 mutex_enter(&rsmops_lock);
320 if (vp != NULL) {
321 (void) VOP_CLOSE(vp, FREAD|FWRITE, 0, 0,
322 CRED(), NULL);
323 VN_RELE(vp);
324 }
325 p_ctrl = find_rsmpi_controller(name, number);
326 if (p_ctrl == NULL) {
327 mutex_exit(&rsmops_lock);
328 return (RSMERR_CTLR_NOT_PRESENT);
329 }
330 }
331 ASSERT(p_ctrl);
332 } else {
333 p_drv = p_ctrl->p_drv;
334 }
335 ASSERT(p_drv);
336 ASSERT(p_drv == p_ctrl->p_drv);
337
338 rsm_get_controller_handler = p_drv->drv.rsm_get_controller_handler;
339 /*
340 * Increase the refcnt right now, so that attempts to deregister
341 * while we are using this entry will fail
342 */
343 p_ctrl->refcnt++;
344 mutex_exit(&rsmops_lock);
345
346 error = (*rsm_get_controller_handler)(name, number, controller,
347 version);
348 if (error != RSM_SUCCESS) {
349 /* We failed - drop the refcnt back */
350 mutex_enter(&rsmops_lock);
351 /*
352 * Even though we had released the global lock, we can
353 * guarantee that p_ctrl is still meaningful (and has not
354 * been deregistered, freed whatever) because we were holding
355 * refcnt on it. So, it is okay to just use p_ctrl here
356 * after re-acquiring the global lock
357 */
358 p_ctrl->refcnt--;
359 mutex_exit(&rsmops_lock);
360 } else {
361 /*
362 * Initialize the controller handle field
363 */
364 mutex_enter(&rsmops_lock);
365 if ((p_ctrl = find_rsmpi_controller(name, number)) == NULL) {
366 mutex_exit(&rsmops_lock);
367 return (RSMERR_CTLR_NOT_PRESENT);
368 }
369
370 p_ctrl->handle = controller->handle;
371 mutex_exit(&rsmops_lock);
372 }
373 return (error);
374 }
375
376 int
377 rsm_release_controller(const char *name, uint_t number,
378 rsm_controller_object_t *controller)
379 {
380 rsmops_ctrl_t *p_ctrl;
381 rsmops_drv_t *p_drv;
382 int error;
383 int (*releaser)(const char *name, uint_t number,
384 rsm_controller_object_t *controller);
385
386 mutex_enter(&rsmops_lock);
387
388 if ((p_ctrl = find_rsmpi_controller(name, number)) == NULL) {
389 mutex_exit(&rsmops_lock);
390 return (RSMERR_CTLR_NOT_PRESENT);
391 }
392 p_drv = find_rsmpi_driver(name);
393 ASSERT(p_drv); /* If we found controller, there MUST be a driver */
394
395 /* Found the appropriate driver. Forward the call to it */
396 releaser = p_drv->drv.rsm_release_controller_handler;
397 mutex_exit(&rsmops_lock);
398
399 error = (*releaser)(name, number, controller);
400 if (error == RSM_SUCCESS) {
401 mutex_enter(&rsmops_lock);
402 p_ctrl->refcnt--;
403 mutex_exit(&rsmops_lock);
404 }
405 return (error);
406 }
407
408 /* This is expected to be called from the driver's attach function */
409 int
410 rsm_register_controller(const char *name, uint_t number,
411 rsm_controller_attr_t *attrp)
412 {
413 rsmops_drv_t *p_drv;
414 rsmops_ctrl_t *p_ctrl;
415
416 if (strlen(name) > MAX_DRVNAME)
417 return (RSMERR_NAME_TOO_LONG);
418
419 mutex_enter(&rsmops_lock);
420
421 /* Check if the driver is registered with us */
422 p_drv = find_rsmpi_driver(name);
423 if (p_drv == NULL) {
424 /*
425 * Hey! Driver is not registered, but we are getting a
426 * controller ??
427 */
428 mutex_exit(&rsmops_lock);
429 return (RSMERR_DRIVER_NOT_REGISTERED);
430 }
431
432 /* Check if the controller is already registered with us */
433 p_ctrl = find_rsmpi_controller(name, number);
434 if (p_ctrl) {
435 /* already registered */
436 mutex_exit(&rsmops_lock);
437 return (RSMERR_CTLR_ALREADY_REGISTERED);
438 }
439
440 /* WAIT: sanity check - verify that the dip matches up to name,number */
441
442 p_ctrl = kmem_alloc(sizeof (rsmops_ctrl_t), KM_SLEEP);
443
444 /* bump up controller count on the driver */
445 p_drv->ctrl_cnt++;
446
447 p_ctrl->p_drv = p_drv; /* setup the back pointer */
448 p_ctrl->number = number;
449 p_ctrl->refcnt = 0;
450 p_ctrl->attrp = attrp;
451 p_ctrl->handle = NULL;
452
453 /* Now link to head of list */
454 p_ctrl->next = p_drv->ctrl_head;
455 p_drv->ctrl_head = p_ctrl;
456
457 mutex_exit(&rsmops_lock);
458
459 return (RSM_SUCCESS);
460 }
461
462 /*
463 * This is expected to be called from the driver's detach function
464 * if this function returns EBUSY, the driver is supposed to fail
465 * his own detach operation
466 */
467 int
468 rsm_unregister_controller(const char *name, uint_t number)
469 {
470 rsmops_drv_t *p_drv;
471 rsmops_ctrl_t **p_prev;
472 rsmops_ctrl_t *found;
473
474 mutex_enter(&rsmops_lock);
475
476 /* Check if the driver is registered with us */
477 p_drv = find_rsmpi_driver(name);
478 if (p_drv == NULL) {
479 /* Hey! Driver is not registered */
480 mutex_exit(&rsmops_lock);
481 return (RSMERR_DRIVER_NOT_REGISTERED);
482 }
483
484 /* Search for the controller in the list */
485 for (p_prev = &p_drv->ctrl_head; *p_prev; p_prev = &((*p_prev)->next)) {
486 if ((*p_prev)->number == number) {
487 /* Found the controller. Check if it is busy */
488 found = *p_prev;
489
490 if (found->refcnt) {
491 /* Controller is busy - handles outstanding */
492 mutex_exit(&rsmops_lock);
493 return (RSMERR_CTLR_IN_USE);
494 }
495 /* unlink it out */
496 *p_prev = found->next;
497 /* bump down controller count on the driver */
498 p_drv->ctrl_cnt--;
499
500 mutex_exit(&rsmops_lock);
501 kmem_free(found, sizeof (rsmops_ctrl_t));
502 return (RSM_SUCCESS);
503 }
504 }
505 mutex_exit(&rsmops_lock);
506 /* Could not find the right controller */
507 return (RSMERR_CTLR_NOT_REGISTERED);
508 }
509
510
511 /*
512 * This opens and closes the appropriate device with minor number -
513 * hopefully, it will cause the driver to attach and register a controller
514 * with us
515 */
516 static vnode_t *
517 rsmops_device_open(const char *major_name, const minor_t minor_num)
518 {
519 major_t maj;
520 vnode_t *vp;
521 int ret;
522
523 if (minor_num == (minor_t)-1) {
524 return (NULL);
525 }
526
527 maj = ddi_name_to_major((char *)major_name);
528 if (maj == (major_t)-1) {
529 return (NULL);
530 }
531
532 vp = makespecvp(makedevice(maj, minor_num), VCHR);
533
534 ret = VOP_OPEN(&vp, FREAD|FWRITE, CRED(), NULL);
535 if (ret == 0) {
536 return (vp);
537 } else {
538 VN_RELE(vp);
539 return (NULL);
540 }
541 }
542
543 /*
544 * Attributes for controller identified by the handle are returned
545 * via *attrp. Modifications of attributes is prohibited by client!
546 */
547 int
548 rsm_get_controller_attr(rsm_controller_handle_t handle,
549 rsm_controller_attr_t **attrp)
550 {
551
552 rsmops_ctrl_t *p_ctrl;
553
554 if (handle == NULL)
555 return (RSMERR_BAD_CTLR_HNDL);
556
557 mutex_enter(&rsmops_lock);
558
559 /* find controller */
560 if ((p_ctrl = find_rsmpi_controller_handle(handle)) == NULL) {
561 /* can't supply attributes for invalid controller */
562 mutex_exit(&rsmops_lock);
563 return (RSMERR_BAD_CTLR_HNDL);
564 }
565 *attrp = p_ctrl->attrp;
566 mutex_exit(&rsmops_lock);
567
568 return (RSM_SUCCESS);
569 }