Fix more wrong sizeof() usages, part 1/x
[dragonfly.git] / sys / kern / subr_firmware.c
CommitLineData
32e913d7
JT
1/*-
2 * Copyright (c) 2005-2008, Sam Leffler <sam@errno.com>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice unmodified, this list of conditions, and the following
10 * 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 WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
89e93e6f
RP
25 *
26 * $FreeBSD: src/sys/kern/subr_firmware.c,v 1.13.2.2 2010/02/11 18:34:06 mjacob Exp $
32e913d7
JT
27 */
28
32e913d7
JT
29#include <sys/param.h>
30#include <sys/kernel.h>
31#include <sys/malloc.h>
32#include <sys/queue.h>
33#include <sys/taskqueue.h>
34#include <sys/systm.h>
35#include <sys/lock.h>
36#include <sys/spinlock.h>
37#include <sys/spinlock2.h>
38#include <sys/errno.h>
39#include <sys/linker.h>
d83c779a 40#include <sys/firmware.h>
32e913d7
JT
41#include <sys/priv.h>
42#include <sys/proc.h>
43#include <sys/module.h>
44#include <sys/eventhandler.h>
45
46#include <sys/filedesc.h>
47#include <sys/vnode.h>
48
49/*
50 * Loadable firmware support. See sys/sys/firmware.h and firmware(9)
51 * form more details on the subsystem.
52 *
53 * 'struct firmware' is the user-visible part of the firmware table.
54 * Additional internal information is stored in a 'struct priv_fw'
55 * (currently a static array). A slot is in use if FW_INUSE is true:
56 */
57
58#define FW_INUSE(p) ((p)->file != NULL || (p)->fw.name != NULL)
59
60/*
61 * fw.name != NULL when an image is registered; file != NULL for
62 * autoloaded images whose handling has not been completed.
63 *
64 * The state of a slot evolves as follows:
65 * firmware_register --> fw.name = image_name
66 * (autoloaded image) --> file = module reference
67 * firmware_unregister --> fw.name = NULL
68 * (unloadentry complete) --> file = NULL
69 *
70 * In order for the above to work, the 'file' field must remain
71 * unchanged in firmware_unregister().
72 *
73 * Images residing in the same module are linked to each other
74 * through the 'parent' argument of firmware_register().
75 * One image (typically, one with the same name as the module to let
76 * the autoloading mechanism work) is considered the parent image for
77 * all other images in the same module. Children affect the refcount
78 * on the parent image preventing improper unloading of the image itself.
79 */
80
81struct priv_fw {
82 int refcnt; /* reference count */
83
84 /*
85 * parent entry, see above. Set on firmware_register(),
86 * cleared on firmware_unregister().
87 */
88 struct priv_fw *parent;
89
90 int flags; /* record FIRMWARE_UNLOAD requests */
91#define FW_UNLOAD 0x100
92
93 /*
94 * 'file' is private info managed by the autoload/unload code.
95 * Set at the end of firmware_get(), cleared only in the
96 * firmware_unload_task, so the latter can depend on its value even
97 * while the lock is not held.
98 */
99 linker_file_t file; /* module file, if autoloaded */
100
101 /*
102 * 'fw' is the externally visible image information.
103 * We do not make it the first field in priv_fw, to avoid the
104 * temptation of casting pointers to each other.
105 * Use PRIV_FW(fw) to get a pointer to the cointainer of fw.
106 * Beware, PRIV_FW does not work for a NULL pointer.
107 */
108 struct firmware fw; /* externally visible information */
109};
110
111/*
112 * PRIV_FW returns the pointer to the container of struct firmware *x.
113 * Cast to intptr_t to override the 'const' attribute of x
114 */
115#define PRIV_FW(x) ((struct priv_fw *) \
116 ((intptr_t)(x) - offsetof(struct priv_fw, fw)) )
117
118/*
119 * At the moment we use a static array as backing store for the registry.
120 * Should we move to a dynamic structure, keep in mind that we cannot
121 * reallocate the array because pointers are held externally.
122 * A list may work, though.
123 */
124#define FIRMWARE_MAX 30
125static struct priv_fw firmware_table[FIRMWARE_MAX];
126
127/*
128 * Firmware module operations are handled in a separate task as they
129 * might sleep and they require directory context to do i/o.
130 */
131static struct taskqueue *firmware_tq;
132static struct task firmware_unload_task;
133
134/*
135 * This mutex protects accesses to the firmware table.
136 */
137static struct lock firmware_lock;
138#if 0
139MTX_SYSINIT(firmware, &firmware_lock, "firmware table", MTX_DEF);
140#endif
141
142/*
143 * Helper function to lookup a name.
144 * As a side effect, it sets the pointer to a free slot, if any.
145 * This way we can concentrate most of the registry scanning in
146 * this function, which makes it easier to replace the registry
147 * with some other data structure.
148 */
149static struct priv_fw *
150lookup(const char *name, struct priv_fw **empty_slot)
151{
152 struct priv_fw *fp = NULL;
153 struct priv_fw *dummy;
154 int i;
155
156 if (empty_slot == NULL)
157 empty_slot = &dummy;
158 *empty_slot = NULL;
159 for (i = 0; i < FIRMWARE_MAX; i++) {
160 fp = &firmware_table[i];
161 if (fp->fw.name != NULL && strcasecmp(name, fp->fw.name) == 0)
162 break;
163 else if (!FW_INUSE(fp))
164 *empty_slot = fp;
165 }
166 return (i < FIRMWARE_MAX ) ? fp : NULL;
167}
168
169/*
170 * Register a firmware image with the specified name. The
171 * image name must not already be registered. If this is a
172 * subimage then parent refers to a previously registered
173 * image that this should be associated with.
174 */
175const struct firmware *
176firmware_register(const char *imagename, const void *data, size_t datasize,
177 unsigned int version, const struct firmware *parent)
178{
179 struct priv_fw *match, *frp;
180
181 lockmgr(&firmware_lock, LK_EXCLUSIVE);
182 /*
183 * Do a lookup to make sure the name is unique or find a free slot.
184 */
185 match = lookup(imagename, &frp);
186 if (match != NULL) {
187 lockmgr(&firmware_lock, LK_RELEASE);
188 kprintf("%s: image %s already registered!\n",
189 __func__, imagename);
190 return NULL;
191 }
192 if (frp == NULL) {
193 lockmgr(&firmware_lock, LK_RELEASE);
194 kprintf("%s: cannot register image %s, firmware table full!\n",
195 __func__, imagename);
196 return NULL;
197 }
8075c3b8 198 bzero(frp, sizeof(*frp)); /* start from a clean record */
32e913d7
JT
199 frp->fw.name = imagename;
200 frp->fw.data = data;
201 frp->fw.datasize = datasize;
202 frp->fw.version = version;
203 if (parent != NULL) {
204 frp->parent = PRIV_FW(parent);
205 frp->parent->refcnt++;
206 }
207 lockmgr(&firmware_lock, LK_RELEASE);
208 if (bootverbose)
209 kprintf("firmware: '%s' version %u: %zu bytes loaded at %p\n",
210 imagename, version, datasize, data);
211 return &frp->fw;
212}
213
214/*
215 * Unregister/remove a firmware image. If there are outstanding
216 * references an error is returned and the image is not removed
217 * from the registry.
218 */
219int
220firmware_unregister(const char *imagename)
221{
222 struct priv_fw *fp;
223 int err;
224
225 lockmgr(&firmware_lock, LK_EXCLUSIVE);
226 fp = lookup(imagename, NULL);
227 if (fp == NULL) {
228 /*
229 * It is ok for the lookup to fail; this can happen
230 * when a module is unloaded on last reference and the
231 * module unload handler unregister's each of it's
232 * firmware images.
233 */
234 err = 0;
235 } else if (fp->refcnt != 0) { /* cannot unregister */
236 err = EBUSY;
237 } else {
238 linker_file_t x = fp->file; /* save value */
239
240 if (fp->parent != NULL) /* release parent reference */
241 fp->parent->refcnt--;
242 /*
243 * Clear the whole entry with bzero to make sure we
244 * do not forget anything. Then restore 'file' which is
245 * non-null for autoloaded images.
246 */
247 bzero(fp, sizeof(struct priv_fw));
248 fp->file = x;
249 err = 0;
250 }
251 lockmgr(&firmware_lock, LK_RELEASE);
252 return err;
253}
254
255static void
256loadimage(void *arg, int npending)
257{
89e93e6f 258#ifdef notyet
32e913d7 259 struct thread *td = curthread;
89e93e6f 260#endif
32e913d7
JT
261 char *imagename = arg;
262 struct priv_fw *fp;
263 linker_file_t result;
264 int error;
265
266 /* synchronize with the thread that dispatched us */
267 lockmgr(&firmware_lock, LK_EXCLUSIVE);
268 lockmgr(&firmware_lock, LK_RELEASE);
269
270/* JAT
271 if (td->td_proc->p_fd->fd_rdir == NULL) {
272 kprintf("%s: root not mounted yet, no way to load image\n",
273 imagename);
274 goto done;
275 }
276*/
277 error = linker_reference_module(imagename, NULL, &result);
278 if (error != 0) {
279 kprintf("%s: could not load firmware image, error %d\n",
280 imagename, error);
281 goto done;
282 }
283
284 lockmgr(&firmware_lock, LK_EXCLUSIVE);
285 fp = lookup(imagename, NULL);
286 if (fp == NULL || fp->file != NULL) {
287 lockmgr(&firmware_lock, LK_RELEASE);
288 if (fp == NULL)
289 kprintf("%s: firmware image loaded, "
290 "but did not register\n", imagename);
291 (void) linker_release_module(imagename, NULL, NULL);
292 goto done;
293 }
294 fp->file = result; /* record the module identity */
295 lockmgr(&firmware_lock, LK_RELEASE);
296done:
297 wakeup_one(imagename); /* we're done */
298}
299
300/*
301 * Lookup and potentially load the specified firmware image.
302 * If the firmware is not found in the registry, try to load a kernel
303 * module named as the image name.
304 * If the firmware is located, a reference is returned. The caller must
305 * release this reference for the image to be eligible for removal/unload.
306 */
307const struct firmware *
308firmware_get(const char *imagename)
309{
310 struct task fwload_task;
311 struct thread *td;
312 struct priv_fw *fp;
313
314 lockmgr(&firmware_lock, LK_EXCLUSIVE);
315 fp = lookup(imagename, NULL);
316 if (fp != NULL)
317 goto found;
318 /*
319 * Image not present, try to load the module holding it.
320 */
321 td = curthread;
5c4157c8 322 if (priv_check(td, PRIV_FIRMWARE_LOAD) != 0 || securelevel > 0) {
32e913d7
JT
323 lockmgr(&firmware_lock, LK_RELEASE);
324 kprintf("%s: insufficient privileges to "
325 "load firmware image %s\n", __func__, imagename);
326 return NULL;
327 }
328 /*
329 * Defer load to a thread with known context. linker_reference_module
330 * may do filesystem i/o which requires root & current dirs, etc.
331 * Also we must not hold any lock's over this call which is problematic.
332 */
333 if (!cold) {
334 TASK_INIT(&fwload_task, 0, loadimage, __DECONST(void *,
335 imagename));
336 taskqueue_enqueue(firmware_tq, &fwload_task);
337 lksleep(__DECONST(void *, imagename), &firmware_lock, 0,
338 "fwload", 0);
339 }
340 /*
341 * After attempting to load the module, see if the image is registered.
342 */
343 fp = lookup(imagename, NULL);
344 if (fp == NULL) {
345 lockmgr(&firmware_lock, LK_RELEASE);
346 return NULL;
347 }
348found: /* common exit point on success */
349 fp->refcnt++;
350 lockmgr(&firmware_lock, LK_RELEASE);
351 return &fp->fw;
352}
353
354/*
355 * Release a reference to a firmware image returned by firmware_get.
356 * The caller may specify, with the FIRMWARE_UNLOAD flag, its desire
357 * to release the resource, but the flag is only advisory.
358 *
359 * If this is the last reference to the firmware image, and this is an
360 * autoloaded module, wake up the firmware_unload_task to figure out
361 * what to do with the associated module.
362 */
363void
364firmware_put(const struct firmware *p, int flags)
365{
366 struct priv_fw *fp = PRIV_FW(p);
367
368 lockmgr(&firmware_lock, LK_EXCLUSIVE);
369 fp->refcnt--;
370 if (fp->refcnt == 0) {
371 if (flags & FIRMWARE_UNLOAD)
372 fp->flags |= FW_UNLOAD;
373 if (fp->file)
374 taskqueue_enqueue(firmware_tq, &firmware_unload_task);
375 }
376 lockmgr(&firmware_lock, LK_RELEASE);
377}
378
89e93e6f 379#ifdef notyet
32e913d7
JT
380/*
381 * Setup directory state for the firmware_tq thread so we can do i/o.
382 */
383static void
384set_rootvnode(void *arg, int npending)
385{
386 struct thread *td = curthread;
387 struct proc *p = td->td_proc;
388
389
32e913d7
JT
390#if 0
391 spin_lock_wr(&p->p_fd->fd_spin);
32e913d7
JT
392 if (p->p_fd->fd_cdir == NULL) {
393 p->p_fd->fd_cdir = rootvnode;
394 vref(rootvnode);
395 }
396 if (p->p_fd->fd_rdir == NULL) {
397 p->p_fd->fd_rdir = rootvnode;
398 vref(rootvnode);
399 }
400 spin_unlock_wr(&p->p_fd->fd_spin);
32e913d7
JT
401
402 kfree(arg, M_TEMP);
403#endif
404}
405
406/*
407 * Event handler called on mounting of /; bounce a task
408 * into the task queue thread to setup it's directories.
409 */
410static void
411firmware_mountroot(void *arg)
412{
413 struct task *setroot_task;
414
415 setroot_task = kmalloc(sizeof(struct task), M_TEMP, M_NOWAIT);
416 if (setroot_task != NULL) {
417 TASK_INIT(setroot_task, 0, set_rootvnode, setroot_task);
418 taskqueue_enqueue(firmware_tq, setroot_task);
419 } else
420 kprintf("%s: no memory for task!\n", __func__);
421}
32e913d7
JT
422EVENTHANDLER_DECLARE(mountroot, firmware_mountroot);
423#endif
424
425/*
426 * The body of the task in charge of unloading autoloaded modules
427 * that are not needed anymore.
428 * Images can be cross-linked so we may need to make multiple passes,
429 * but the time we spend in the loop is bounded because we clear entries
430 * as we touch them.
431 */
432static void
433unloadentry(void *unused1, int unused2)
434{
435 int limit = FIRMWARE_MAX;
436 int i; /* current cycle */
437
438 lockmgr(&firmware_lock, LK_EXCLUSIVE);
439 /*
440 * Scan the table. limit is set to make sure we make another
441 * full sweep after matching an entry that requires unloading.
442 */
443 for (i = 0; i < limit; i++) {
444 struct priv_fw *fp;
445 int err;
446
447 fp = &firmware_table[i % FIRMWARE_MAX];
448 if (fp->fw.name == NULL || fp->file == NULL ||
449 fp->refcnt != 0 || (fp->flags & FW_UNLOAD) == 0)
450 continue;
451
452 /*
453 * Found an entry. Now:
454 * 1. bump up limit to make sure we make another full round;
455 * 2. clear FW_UNLOAD so we don't try this entry again.
456 * 3. release the lock while trying to unload the module.
457 * 'file' remains set so that the entry cannot be reused
458 * in the meantime (it also means that fp->file will
459 * not change while we release the lock).
460 */
461 limit = i + FIRMWARE_MAX; /* make another full round */
462 fp->flags &= ~FW_UNLOAD; /* do not try again */
463
464 lockmgr(&firmware_lock, LK_RELEASE);
465 err = linker_release_module(NULL, NULL, fp->file);
466 lockmgr(&firmware_lock, LK_EXCLUSIVE);
467
468 /*
469 * We rely on the module to call firmware_unregister()
470 * on unload to actually release the entry.
471 * If err = 0 we can drop our reference as the system
472 * accepted it. Otherwise unloading failed (e.g. the
473 * module itself gave an error) so our reference is
474 * still valid.
475 */
476 if (err == 0)
477 fp->file = NULL;
478 }
479 lockmgr(&firmware_lock, LK_RELEASE);
480}
481
482/*
483 * Module glue.
484 */
485static int
486firmware_modevent(module_t mod, int type, void *unused)
487{
488 struct priv_fw *fp;
489 int i, err;
490
491 switch (type) {
492 case MOD_LOAD:
493 TASK_INIT(&firmware_unload_task, 0, unloadentry, NULL);
494 lockinit(&firmware_lock, "firmware table", 0, LK_CANRECURSE);
495 firmware_tq = taskqueue_create("taskqueue_firmware", M_WAITOK,
496 taskqueue_thread_enqueue, &firmware_tq);
497 /* NB: use our own loop routine that sets up context */
498 (void) taskqueue_start_threads(&firmware_tq, 1, TDPRI_KERN_DAEMON,
499 -1, "firmware taskq");
500 if (rootvnode != NULL) {
501 /*
502 * Root is already mounted so we won't get an event;
503 * simulate one here.
504 */
89e93e6f 505#ifdef notyet
32e913d7
JT
506 firmware_mountroot(NULL);
507#endif
508 }
509 return 0;
510
511 case MOD_UNLOAD:
512 /* request all autoloaded modules to be released */
513 lockmgr(&firmware_lock, LK_EXCLUSIVE);
514 for (i = 0; i < FIRMWARE_MAX; i++) {
515 fp = &firmware_table[i];
516 fp->flags |= FW_UNLOAD;
517 }
518 lockmgr(&firmware_lock, LK_RELEASE);
519 taskqueue_enqueue(firmware_tq, &firmware_unload_task);
520 taskqueue_drain(firmware_tq, &firmware_unload_task);
521 err = 0;
522 for (i = 0; i < FIRMWARE_MAX; i++) {
523 fp = &firmware_table[i];
524 if (fp->fw.name != NULL) {
525 kprintf("%s: image %p ref %d still active slot %d\n",
526 __func__, fp->fw.name,
527 fp->refcnt, i);
528 err = EINVAL;
529 }
530 }
531 if (err == 0)
532 taskqueue_free(firmware_tq);
533 return err;
534 }
535 return EINVAL;
536}
537
d83c779a
SW
538static moduledata_t firmware_mod = {
539 "firmware",
32e913d7
JT
540 firmware_modevent,
541 NULL
542};
d83c779a
SW
543DECLARE_MODULE(firmware, firmware_mod, SI_SUB_DRIVERS, SI_ORDER_FIRST);
544MODULE_VERSION(firmware, 1);