3 * Copyright (c) 2008 Hans Petter Selasky. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 #ifdef USB_GLOBAL_INCLUDE_FILE
28 #include USB_GLOBAL_INCLUDE_FILE
30 #include <sys/stdint.h>
31 #include <sys/stddef.h>
32 #include <sys/param.h>
33 #include <sys/queue.h>
34 #include <sys/types.h>
35 #include <sys/systm.h>
36 #include <sys/kernel.h>
38 #include <sys/module.h>
40 #include <sys/mutex.h>
41 #include <sys/condvar.h>
42 #include <sys/sysctl.h>
44 #include <sys/unistd.h>
45 #include <sys/callout.h>
46 #include <sys/malloc.h>
49 #include <dev/usb/usb.h>
50 #include <dev/usb/usbdi.h>
51 #include <dev/usb/usbdi_util.h>
52 #include <dev/usb/usb_process.h>
54 #define USB_DEBUG_VAR usb_proc_debug
55 #include <dev/usb/usb_debug.h>
56 #include <dev/usb/usb_util.h>
59 #include <sys/kthread.h>
60 #include <sys/sched.h>
61 #endif /* USB_GLOBAL_INCLUDE_FILE */
63 #if (__FreeBSD_version < 700000)
64 #define thread_lock(td) mtx_lock_spin(&sched_lock)
65 #define thread_unlock(td) mtx_unlock_spin(&sched_lock)
68 #if (__FreeBSD_version >= 800000)
69 static struct proc *usbproc;
70 static int usb_pcount;
71 #define USB_THREAD_CREATE(f, s, p, ...) \
72 kproc_kthread_add((f), (s), &usbproc, (p), RFHIGHPID, \
73 0, "usb", __VA_ARGS__)
74 #if (__FreeBSD_version >= 900000)
75 #define USB_THREAD_SUSPEND_CHECK() kthread_suspend_check()
77 #define USB_THREAD_SUSPEND_CHECK() kthread_suspend_check(curthread)
79 #define USB_THREAD_SUSPEND(p) kthread_suspend(p,0)
80 #define USB_THREAD_EXIT(err) kthread_exit()
82 #define USB_THREAD_CREATE(f, s, p, ...) \
83 kthread_create((f), (s), (p), RFHIGHPID, 0, __VA_ARGS__)
84 #define USB_THREAD_SUSPEND_CHECK() kthread_suspend_check(curproc)
85 #define USB_THREAD_SUSPEND(p) kthread_suspend(p,0)
86 #define USB_THREAD_EXIT(err) kthread_exit(err)
90 static int usb_proc_debug;
92 static SYSCTL_NODE(_hw_usb, OID_AUTO, proc, CTLFLAG_RW, 0, "USB process");
93 SYSCTL_INT(_hw_usb_proc, OID_AUTO, debug, CTLFLAG_RWTUN, &usb_proc_debug, 0,
97 /*------------------------------------------------------------------------*
100 * This function is the USB process dispatcher.
101 *------------------------------------------------------------------------*/
103 usb_process(void *arg)
105 struct usb_process *up = arg;
106 struct usb_proc_msg *pm;
109 /* in case of attach error, check for suspended */
110 USB_THREAD_SUSPEND_CHECK();
112 /* adjust priority */
115 sched_prio(td, up->up_prio);
118 mtx_lock(up->up_mtx);
128 * NOTE to reimplementors: dequeueing a command from the
129 * "used" queue and executing it must be atomic, with regard
130 * to the "up_mtx" mutex. That means any attempt to queue a
131 * command by another thread must be blocked until either:
133 * 1) the command sleeps
135 * 2) the command returns
137 * Here is a practical example that shows how this helps
140 * Assume that you want to set the baud rate on a USB serial
141 * device. During the programming of the device you don't
142 * want to receive nor transmit any data, because it will be
143 * garbage most likely anyway. The programming of our USB
144 * device takes 20 milliseconds and it needs to call
145 * functions that sleep.
147 * Non-working solution: Before we queue the programming
148 * command, we stop transmission and reception of data. Then
149 * we queue a programming command. At the end of the
150 * programming command we enable transmission and reception
153 * Problem: If a second programming command is queued while the
154 * first one is sleeping, we end up enabling transmission
155 * and reception of data too early.
157 * Working solution: Before we queue the programming command,
158 * we stop transmission and reception of data. Then we queue
159 * a programming command. Then we queue a second command
160 * that only enables transmission and reception of data.
162 * Why it works: If a second programming command is queued
163 * while the first one is sleeping, then the queueing of a
164 * second command to enable the data transfers, will cause
165 * the previous one, which is still on the queue, to be
166 * removed from the queue, and re-inserted after the last
167 * baud rate programming command, which then gives the
170 pm = TAILQ_FIRST(&up->up_qhead);
173 DPRINTF("Message pm=%p, cb=%p (enter)\n",
174 pm, pm->pm_callback);
176 (pm->pm_callback) (pm);
178 if (pm == TAILQ_FIRST(&up->up_qhead)) {
179 /* nothing changed */
180 TAILQ_REMOVE(&up->up_qhead, pm, pm_qentry);
181 pm->pm_qentry.tqe_prev = NULL;
183 DPRINTF("Message pm=%p (leave)\n", pm);
187 /* end if messages - check if anyone is waiting for sync */
190 cv_broadcast(&up->up_drain);
193 cv_wait(&up->up_cv, up->up_mtx);
197 cv_signal(&up->up_cv);
198 mtx_unlock(up->up_mtx);
199 #if (__FreeBSD_version >= 800000)
200 /* Clear the proc pointer if this is the last thread. */
201 if (--usb_pcount == 0)
208 /*------------------------------------------------------------------------*
211 * This function will create a process using the given "prio" that can
212 * execute callbacks. The mutex pointed to by "p_mtx" will be applied
213 * before calling the callbacks and released after that the callback
214 * has returned. The structure pointed to by "up" is assumed to be
215 * zeroed before this function is called.
220 *------------------------------------------------------------------------*/
222 usb_proc_create(struct usb_process *up, struct mtx *p_mtx,
223 const char *pmesg, uint8_t prio)
228 TAILQ_INIT(&up->up_qhead);
230 cv_init(&up->up_cv, "-");
231 cv_init(&up->up_drain, "usbdrain");
233 if (USB_THREAD_CREATE(&usb_process, up,
234 &up->up_ptr, "%s", pmesg)) {
235 DPRINTFN(0, "Unable to create USB process.");
239 #if (__FreeBSD_version >= 800000)
249 /*------------------------------------------------------------------------*
252 * NOTE: If the structure pointed to by "up" is all zero, this
253 * function does nothing.
255 * NOTE: Messages that are pending on the process queue will not be
256 * removed nor called.
257 *------------------------------------------------------------------------*/
259 usb_proc_free(struct usb_process *up)
261 /* check if not initialised */
262 if (up->up_mtx == NULL)
267 cv_destroy(&up->up_cv);
268 cv_destroy(&up->up_drain);
270 /* make sure that we do not enter here again */
274 /*------------------------------------------------------------------------*
277 * This function will queue one of the passed USB process messages on
278 * the USB process queue. The first message that is not already queued
279 * will get queued. If both messages are already queued the one queued
280 * last will be removed from the queue and queued in the end. The USB
281 * process mutex must be locked when calling this function. This
282 * function exploits the fact that a process can only do one callback
283 * at a time. The message that was queued is returned.
284 *------------------------------------------------------------------------*/
286 usb_proc_msignal(struct usb_process *up, void *_pm0, void *_pm1)
288 struct usb_proc_msg *pm0 = _pm0;
289 struct usb_proc_msg *pm1 = _pm1;
290 struct usb_proc_msg *pm2;
294 /* check if gone, return dummy value */
298 mtx_assert(up->up_mtx, MA_OWNED);
302 if (pm0->pm_qentry.tqe_prev) {
305 if (pm1->pm_qentry.tqe_prev) {
310 * No entries are queued. Queue "pm0" and use the existing
315 /* Check if we need to increment the message number. */
316 if (pm0->pm_num == up->up_msg_num) {
321 /* Check if we need to increment the message number. */
322 if (pm1->pm_num == up->up_msg_num) {
328 * Both entries are queued. Re-queue the entry closest to
331 d = (pm1->pm_num - pm0->pm_num);
333 /* Check sign after subtraction */
334 if (d & 0x80000000) {
340 TAILQ_REMOVE(&up->up_qhead, pm2, pm_qentry);
342 pm2 = NULL; /* panic - should not happen */
345 DPRINTF(" t=%u, num=%u\n", t, up->up_msg_num);
347 /* Put message last on queue */
349 pm2->pm_num = up->up_msg_num;
350 TAILQ_INSERT_TAIL(&up->up_qhead, pm2, pm_qentry);
352 /* Check if we need to wakeup the USB process. */
355 up->up_msleep = 0; /* save "cv_signal()" calls */
356 cv_signal(&up->up_cv);
361 /*------------------------------------------------------------------------*
365 * 0: USB process is running
366 * Else: USB process is tearing down
367 *------------------------------------------------------------------------*/
369 usb_proc_is_gone(struct usb_process *up)
375 * Allow calls when up_mtx is NULL, before the USB process
376 * structure is initialised.
378 if (up->up_mtx != NULL)
379 mtx_assert(up->up_mtx, MA_OWNED);
383 /*------------------------------------------------------------------------*
386 * This function will return when the USB process message pointed to
387 * by "pm" is no longer on a queue. This function must be called
388 * having "up->up_mtx" locked.
389 *------------------------------------------------------------------------*/
391 usb_proc_mwait(struct usb_process *up, void *_pm0, void *_pm1)
393 struct usb_proc_msg *pm0 = _pm0;
394 struct usb_proc_msg *pm1 = _pm1;
400 mtx_assert(up->up_mtx, MA_OWNED);
402 if (up->up_curtd == curthread) {
403 /* Just remove the messages from the queue. */
404 if (pm0->pm_qentry.tqe_prev) {
405 TAILQ_REMOVE(&up->up_qhead, pm0, pm_qentry);
406 pm0->pm_qentry.tqe_prev = NULL;
408 if (pm1->pm_qentry.tqe_prev) {
409 TAILQ_REMOVE(&up->up_qhead, pm1, pm_qentry);
410 pm1->pm_qentry.tqe_prev = NULL;
413 while (pm0->pm_qentry.tqe_prev ||
414 pm1->pm_qentry.tqe_prev) {
415 /* check if config thread is gone */
419 cv_wait(&up->up_drain, up->up_mtx);
423 /*------------------------------------------------------------------------*
426 * This function will tear down an USB process, waiting for the
427 * currently executing command to return.
429 * NOTE: If the structure pointed to by "up" is all zero,
430 * this function does nothing.
431 *------------------------------------------------------------------------*/
433 usb_proc_drain(struct usb_process *up)
435 /* check if not initialised */
436 if (up->up_mtx == NULL)
438 /* handle special case with Giant */
439 if (up->up_mtx != &Giant)
440 mtx_assert(up->up_mtx, MA_NOTOWNED);
442 mtx_lock(up->up_mtx);
444 /* Set the gone flag */
450 /* Check if we need to wakeup the USB process */
452 if (up->up_msleep || up->up_csleep) {
455 cv_signal(&up->up_cv);
457 /* Check if we are still cold booted */
460 USB_THREAD_SUSPEND(up->up_ptr);
461 printf("WARNING: A USB process has "
462 "been left suspended\n");
465 cv_wait(&up->up_cv, up->up_mtx);
467 /* Check if someone is waiting - should not happen */
471 cv_broadcast(&up->up_drain);
472 DPRINTF("WARNING: Someone is waiting "
473 "for USB process drain!\n");
475 mtx_unlock(up->up_mtx);
478 /*------------------------------------------------------------------------*
481 * This function is called to re-wakeup the given USB
482 * process. This usually happens after that the USB system has been in
483 * polling mode, like during a panic. This function must be called
484 * having "up->up_mtx" locked.
485 *------------------------------------------------------------------------*/
487 usb_proc_rewakeup(struct usb_process *up)
489 /* check if not initialised */
490 if (up->up_mtx == NULL)
496 mtx_assert(up->up_mtx, MA_OWNED);
498 if (up->up_msleep == 0) {
500 cv_signal(&up->up_cv);
504 /*------------------------------------------------------------------------*
505 * usb_proc_is_called_from
507 * This function will return non-zero if called from inside the USB
508 * process passed as first argument. Else this function returns zero.
509 *------------------------------------------------------------------------*/
511 usb_proc_is_called_from(struct usb_process *up)
513 return (up->up_curtd == curthread);