2 * SPDX-License-Identifier: BSD-2-Clause
4 * Copyright (c) 2005-2008, Sam Leffler <sam@errno.com>
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice unmodified, this list of conditions, and the following
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 #include <sys/cdefs.h>
30 #include <sys/param.h>
31 #include <sys/kernel.h>
32 #include <sys/malloc.h>
33 #include <sys/queue.h>
34 #include <sys/taskqueue.h>
35 #include <sys/systm.h>
37 #include <sys/mutex.h>
38 #include <sys/errno.h>
39 #include <sys/linker.h>
40 #include <sys/firmware.h>
43 #include <sys/module.h>
44 #include <sys/eventhandler.h>
46 #include <sys/filedesc.h>
47 #include <sys/vnode.h>
50 * Loadable firmware support. See sys/sys/firmware.h and firmware(9)
51 * form more details on the subsystem.
53 * 'struct firmware' is the user-visible part of the firmware table.
54 * Additional internal information is stored in a 'struct priv_fw',
55 * which embeds the public firmware structure.
59 * fw.name != NULL when an image is registered; file != NULL for
60 * autoloaded images whose handling has not been completed.
62 * The state of a slot evolves as follows:
63 * firmware_register --> fw.name = image_name
64 * (autoloaded image) --> file = module reference
65 * firmware_unregister --> fw.name = NULL
66 * (unloadentry complete) --> file = NULL
68 * In order for the above to work, the 'file' field must remain
69 * unchanged in firmware_unregister().
71 * Images residing in the same module are linked to each other
72 * through the 'parent' argument of firmware_register().
73 * One image (typically, one with the same name as the module to let
74 * the autoloading mechanism work) is considered the parent image for
75 * all other images in the same module. Children affect the refcount
76 * on the parent image preventing improper unloading of the image itself.
80 int refcnt; /* reference count */
81 LIST_ENTRY(priv_fw) link; /* table linkage */
84 * parent entry, see above. Set on firmware_register(),
85 * cleared on firmware_unregister().
87 struct priv_fw *parent;
89 int flags; /* record FIRMWARE_UNLOAD requests */
90 #define FW_UNLOAD 0x100
93 * 'file' is private info managed by the autoload/unload code.
94 * Set at the end of firmware_get(), cleared only in the
95 * firmware_unload_task, so the latter can depend on its value even
96 * while the lock is not held.
98 linker_file_t file; /* module file, if autoloaded */
101 * 'fw' is the externally visible image information.
102 * We do not make it the first field in priv_fw, to avoid the
103 * temptation of casting pointers to each other.
104 * Use PRIV_FW(fw) to get a pointer to the cointainer of fw.
105 * Beware, PRIV_FW does not work for a NULL pointer.
107 struct firmware fw; /* externally visible information */
111 * PRIV_FW returns the pointer to the container of struct firmware *x.
112 * Cast to intptr_t to override the 'const' attribute of x
114 #define PRIV_FW(x) ((struct priv_fw *) \
115 ((intptr_t)(x) - offsetof(struct priv_fw, fw)) )
118 * Global firmware image registry.
120 static LIST_HEAD(, priv_fw) firmware_table;
123 * Firmware module operations are handled in a separate task as they
124 * might sleep and they require directory context to do i/o.
126 static struct taskqueue *firmware_tq;
127 static struct task firmware_unload_task;
130 * This mutex protects accesses to the firmware table.
132 static struct mtx firmware_mtx;
133 MTX_SYSINIT(firmware, &firmware_mtx, "firmware table", MTX_DEF);
135 static MALLOC_DEFINE(M_FIRMWARE, "firmware", "device firmware images");
138 * Helper function to lookup a name.
139 * As a side effect, it sets the pointer to a free slot, if any.
140 * This way we can concentrate most of the registry scanning in
141 * this function, which makes it easier to replace the registry
142 * with some other data structure.
144 static struct priv_fw *
145 lookup(const char *name)
149 mtx_assert(&firmware_mtx, MA_OWNED);
151 LIST_FOREACH(fp, &firmware_table, link) {
152 if (fp->fw.name != NULL && strcasecmp(name, fp->fw.name) == 0)
159 * Register a firmware image with the specified name. The
160 * image name must not already be registered. If this is a
161 * subimage then parent refers to a previously registered
162 * image that this should be associated with.
164 const struct firmware *
165 firmware_register(const char *imagename, const void *data, size_t datasize,
166 unsigned int version, const struct firmware *parent)
171 mtx_lock(&firmware_mtx);
172 frp = lookup(imagename);
174 mtx_unlock(&firmware_mtx);
175 printf("%s: image %s already registered!\n",
176 __func__, imagename);
179 mtx_unlock(&firmware_mtx);
181 frp = malloc(sizeof(*frp), M_FIRMWARE, M_WAITOK | M_ZERO);
182 name = strdup(imagename, M_FIRMWARE);
184 mtx_lock(&firmware_mtx);
185 if (lookup(imagename) != NULL) {
186 /* We lost a race. */
187 mtx_unlock(&firmware_mtx);
188 free(name, M_FIRMWARE);
189 free(frp, M_FIRMWARE);
194 frp->fw.datasize = datasize;
195 frp->fw.version = version;
197 frp->parent = PRIV_FW(parent);
198 LIST_INSERT_HEAD(&firmware_table, frp, link);
199 mtx_unlock(&firmware_mtx);
201 printf("firmware: '%s' version %u: %zu bytes loaded at %p\n",
202 imagename, version, datasize, data);
207 * Unregister/remove a firmware image. If there are outstanding
208 * references an error is returned and the image is not removed
212 firmware_unregister(const char *imagename)
217 mtx_lock(&firmware_mtx);
218 fp = lookup(imagename);
221 * It is ok for the lookup to fail; this can happen
222 * when a module is unloaded on last reference and the
223 * module unload handler unregister's each of its
227 } else if (fp->refcnt != 0) { /* cannot unregister */
230 LIST_REMOVE(fp, link);
231 free(__DECONST(char *, fp->fw.name), M_FIRMWARE);
232 free(fp, M_FIRMWARE);
235 mtx_unlock(&firmware_mtx);
239 struct fw_loadimage {
240 const char *imagename;
245 loadimage(void *arg, int npending __unused)
247 struct fw_loadimage *fwli = arg;
249 linker_file_t result;
252 error = linker_reference_module(fwli->imagename, NULL, &result);
254 if (bootverbose || (fwli->flags & FIRMWARE_GET_NOWARN) == 0)
255 printf("%s: could not load firmware image, error %d\n",
256 fwli->imagename, error);
257 mtx_lock(&firmware_mtx);
261 mtx_lock(&firmware_mtx);
262 fp = lookup(fwli->imagename);
263 if (fp == NULL || fp->file != NULL) {
264 mtx_unlock(&firmware_mtx);
266 printf("%s: firmware image loaded, "
267 "but did not register\n", fwli->imagename);
268 (void) linker_release_module(fwli->imagename, NULL, NULL);
269 mtx_lock(&firmware_mtx);
272 fp->file = result; /* record the module identity */
275 mtx_unlock(&firmware_mtx);
279 * Lookup and potentially load the specified firmware image.
280 * If the firmware is not found in the registry, try to load a kernel
281 * module named as the image name.
282 * If the firmware is located, a reference is returned. The caller must
283 * release this reference for the image to be eligible for removal/unload.
285 const struct firmware *
286 firmware_get_flags(const char *imagename, uint32_t flags)
288 struct task fwload_task;
292 mtx_lock(&firmware_mtx);
293 fp = lookup(imagename);
297 * Image not present, try to load the module holding it.
300 if (priv_check(td, PRIV_FIRMWARE_LOAD) != 0 ||
301 securelevel_gt(td->td_ucred, 0) != 0) {
302 mtx_unlock(&firmware_mtx);
303 printf("%s: insufficient privileges to "
304 "load firmware image %s\n", __func__, imagename);
308 * Defer load to a thread with known context. linker_reference_module
309 * may do filesystem i/o which requires root & current dirs, etc.
310 * Also we must not hold any mtx's over this call which is problematic.
313 struct fw_loadimage fwli;
315 fwli.imagename = imagename;
317 TASK_INIT(&fwload_task, 0, loadimage, (void *)&fwli);
318 taskqueue_enqueue(firmware_tq, &fwload_task);
320 msleep((void *)&fwli, &firmware_mtx, 0, "fwload", 0);
324 * After attempting to load the module, see if the image is registered.
326 fp = lookup(imagename);
328 mtx_unlock(&firmware_mtx);
331 found: /* common exit point on success */
332 if (fp->refcnt == 0 && fp->parent != NULL)
333 fp->parent->refcnt++;
335 mtx_unlock(&firmware_mtx);
339 const struct firmware *
340 firmware_get(const char *imagename)
343 return (firmware_get_flags(imagename, 0));
347 * Release a reference to a firmware image returned by firmware_get.
348 * The caller may specify, with the FIRMWARE_UNLOAD flag, its desire
349 * to release the resource, but the flag is only advisory.
351 * If this is the last reference to the firmware image, and this is an
352 * autoloaded module, wake up the firmware_unload_task to figure out
353 * what to do with the associated module.
356 firmware_put(const struct firmware *p, int flags)
358 struct priv_fw *fp = PRIV_FW(p);
360 mtx_lock(&firmware_mtx);
362 if (fp->refcnt == 0) {
363 if (fp->parent != NULL)
364 fp->parent->refcnt--;
365 if (flags & FIRMWARE_UNLOAD)
366 fp->flags |= FW_UNLOAD;
368 taskqueue_enqueue(firmware_tq, &firmware_unload_task);
370 mtx_unlock(&firmware_mtx);
374 * Setup directory state for the firmware_tq thread so we can do i/o.
377 set_rootvnode(void *arg, int npending)
385 * Event handler called on mounting of /; bounce a task
386 * into the task queue thread to setup it's directories.
389 firmware_mountroot(void *arg)
391 struct task *setroot_task;
393 setroot_task = malloc(sizeof(struct task), M_TEMP, M_NOWAIT);
394 if (setroot_task != NULL) {
395 TASK_INIT(setroot_task, 0, set_rootvnode, setroot_task);
396 taskqueue_enqueue(firmware_tq, setroot_task);
398 printf("%s: no memory for task!\n", __func__);
400 EVENTHANDLER_DEFINE(mountroot, firmware_mountroot, NULL, 0);
403 * The body of the task in charge of unloading autoloaded modules
404 * that are not needed anymore.
405 * Images can be cross-linked so we may need to make multiple passes,
406 * but the time we spend in the loop is bounded because we clear entries
410 unloadentry(void *unused1, int unused2)
414 mtx_lock(&firmware_mtx);
416 LIST_FOREACH(fp, &firmware_table, link) {
417 if (fp->file == NULL || fp->refcnt != 0 ||
418 (fp->flags & FW_UNLOAD) == 0)
422 * Found an entry. Now:
423 * 1. make sure we scan the table again
424 * 2. clear FW_UNLOAD so we don't try this entry again.
425 * 3. release the lock while trying to unload the module.
427 fp->flags &= ~FW_UNLOAD; /* do not try again */
430 * We rely on the module to call firmware_unregister()
431 * on unload to actually free the entry.
433 mtx_unlock(&firmware_mtx);
434 (void)linker_release_module(NULL, NULL, fp->file);
435 mtx_lock(&firmware_mtx);
438 * When we dropped the lock, another thread could have
439 * removed an element, so we must restart the scan.
443 mtx_unlock(&firmware_mtx);
450 firmware_modevent(module_t mod, int type, void *unused)
458 TASK_INIT(&firmware_unload_task, 0, unloadentry, NULL);
459 firmware_tq = taskqueue_create("taskqueue_firmware", M_WAITOK,
460 taskqueue_thread_enqueue, &firmware_tq);
461 /* NB: use our own loop routine that sets up context */
462 (void) taskqueue_start_threads(&firmware_tq, 1, PWAIT,
464 if (rootvnode != NULL) {
466 * Root is already mounted so we won't get an event;
469 firmware_mountroot(NULL);
474 /* request all autoloaded modules to be released */
475 mtx_lock(&firmware_mtx);
476 LIST_FOREACH(fp, &firmware_table, link)
477 fp->flags |= FW_UNLOAD;
478 mtx_unlock(&firmware_mtx);
479 taskqueue_enqueue(firmware_tq, &firmware_unload_task);
480 taskqueue_drain(firmware_tq, &firmware_unload_task);
482 LIST_FOREACH(fp, &firmware_table, link) {
483 if (fp->fw.name != NULL) {
484 printf("%s: image %s still active, %d refs\n",
485 __func__, fp->fw.name, fp->refcnt);
490 taskqueue_free(firmware_tq);
500 static moduledata_t firmware_mod = {
505 DECLARE_MODULE(firmware, firmware_mod, SI_SUB_DRIVERS, SI_ORDER_FIRST);
506 MODULE_VERSION(firmware, 1);