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 #define USB_DEBUG_VAR usb_proc_debug
29 #include <sys/stdint.h>
30 #include <sys/stddef.h>
31 #include <sys/param.h>
32 #include <sys/queue.h>
33 #include <sys/types.h>
34 #include <sys/systm.h>
35 #include <sys/kernel.h>
37 #include <sys/module.h>
39 #include <sys/mutex.h>
40 #include <sys/condvar.h>
41 #include <sys/sysctl.h>
43 #include <sys/unistd.h>
44 #include <sys/callout.h>
45 #include <sys/malloc.h>
48 #include <dev/usb/usb.h>
49 #include <dev/usb/usbdi.h>
50 #include <dev/usb/usbdi_util.h>
51 #include <dev/usb/usb_process.h>
52 #include <dev/usb/usb_debug.h>
53 #include <dev/usb/usb_util.h>
56 #include <sys/kthread.h>
57 #include <sys/sched.h>
59 #if (__FreeBSD_version < 700000)
60 #define thread_lock(td) mtx_lock_spin(&sched_lock)
61 #define thread_unlock(td) mtx_unlock_spin(&sched_lock)
64 #if (__FreeBSD_version >= 800000)
65 static struct proc *usbproc;
66 static int usb_pcount;
67 #define USB_THREAD_CREATE(f, s, p, ...) \
68 kproc_kthread_add((f), (s), &usbproc, (p), RFHIGHPID, \
69 0, "usb", __VA_ARGS__)
70 #if (__FreeBSD_version >= 900000)
71 #define USB_THREAD_SUSPEND_CHECK() kthread_suspend_check()
73 #define USB_THREAD_SUSPEND_CHECK() kthread_suspend_check(curthread)
75 #define USB_THREAD_SUSPEND(p) kthread_suspend(p,0)
76 #define USB_THREAD_EXIT(err) kthread_exit()
78 #define USB_THREAD_CREATE(f, s, p, ...) \
79 kthread_create((f), (s), (p), RFHIGHPID, 0, __VA_ARGS__)
80 #define USB_THREAD_SUSPEND_CHECK() kthread_suspend_check(curproc)
81 #define USB_THREAD_SUSPEND(p) kthread_suspend(p,0)
82 #define USB_THREAD_EXIT(err) kthread_exit(err)
86 static int usb_proc_debug;
88 SYSCTL_NODE(_hw_usb, OID_AUTO, proc, CTLFLAG_RW, 0, "USB process");
89 SYSCTL_INT(_hw_usb_proc, OID_AUTO, debug, CTLFLAG_RW | CTLFLAG_TUN, &usb_proc_debug, 0,
91 TUNABLE_INT("hw.usb.proc.debug", &usb_proc_debug);
94 /*------------------------------------------------------------------------*
97 * This function is the USB process dispatcher.
98 *------------------------------------------------------------------------*/
100 usb_process(void *arg)
102 struct usb_process *up = arg;
103 struct usb_proc_msg *pm;
106 /* in case of attach error, check for suspended */
107 USB_THREAD_SUSPEND_CHECK();
109 /* adjust priority */
112 sched_prio(td, up->up_prio);
115 mtx_lock(up->up_mtx);
125 * NOTE to reimplementors: dequeueing a command from the
126 * "used" queue and executing it must be atomic, with regard
127 * to the "up_mtx" mutex. That means any attempt to queue a
128 * command by another thread must be blocked until either:
130 * 1) the command sleeps
132 * 2) the command returns
134 * Here is a practical example that shows how this helps
137 * Assume that you want to set the baud rate on a USB serial
138 * device. During the programming of the device you don't
139 * want to receive nor transmit any data, because it will be
140 * garbage most likely anyway. The programming of our USB
141 * device takes 20 milliseconds and it needs to call
142 * functions that sleep.
144 * Non-working solution: Before we queue the programming
145 * command, we stop transmission and reception of data. Then
146 * we queue a programming command. At the end of the
147 * programming command we enable transmission and reception
150 * Problem: If a second programming command is queued while the
151 * first one is sleeping, we end up enabling transmission
152 * and reception of data too early.
154 * Working solution: Before we queue the programming command,
155 * we stop transmission and reception of data. Then we queue
156 * a programming command. Then we queue a second command
157 * that only enables transmission and reception of data.
159 * Why it works: If a second programming command is queued
160 * while the first one is sleeping, then the queueing of a
161 * second command to enable the data transfers, will cause
162 * the previous one, which is still on the queue, to be
163 * removed from the queue, and re-inserted after the last
164 * baud rate programming command, which then gives the
167 pm = TAILQ_FIRST(&up->up_qhead);
170 DPRINTF("Message pm=%p, cb=%p (enter)\n",
171 pm, pm->pm_callback);
173 (pm->pm_callback) (pm);
175 if (pm == TAILQ_FIRST(&up->up_qhead)) {
176 /* nothing changed */
177 TAILQ_REMOVE(&up->up_qhead, pm, pm_qentry);
178 pm->pm_qentry.tqe_prev = NULL;
180 DPRINTF("Message pm=%p (leave)\n", pm);
184 /* end if messages - check if anyone is waiting for sync */
187 cv_broadcast(&up->up_drain);
190 cv_wait(&up->up_cv, up->up_mtx);
194 cv_signal(&up->up_cv);
195 mtx_unlock(up->up_mtx);
196 #if (__FreeBSD_version >= 800000)
197 /* Clear the proc pointer if this is the last thread. */
198 if (--usb_pcount == 0)
205 /*------------------------------------------------------------------------*
208 * This function will create a process using the given "prio" that can
209 * execute callbacks. The mutex pointed to by "p_mtx" will be applied
210 * before calling the callbacks and released after that the callback
211 * has returned. The structure pointed to by "up" is assumed to be
212 * zeroed before this function is called.
217 *------------------------------------------------------------------------*/
219 usb_proc_create(struct usb_process *up, struct mtx *p_mtx,
220 const char *pmesg, uint8_t prio)
225 TAILQ_INIT(&up->up_qhead);
227 cv_init(&up->up_cv, "-");
228 cv_init(&up->up_drain, "usbdrain");
230 if (USB_THREAD_CREATE(&usb_process, up,
231 &up->up_ptr, "%s", pmesg)) {
232 DPRINTFN(0, "Unable to create USB process.");
236 #if (__FreeBSD_version >= 800000)
246 /*------------------------------------------------------------------------*
249 * NOTE: If the structure pointed to by "up" is all zero, this
250 * function does nothing.
252 * NOTE: Messages that are pending on the process queue will not be
253 * removed nor called.
254 *------------------------------------------------------------------------*/
256 usb_proc_free(struct usb_process *up)
258 /* check if not initialised */
259 if (up->up_mtx == NULL)
264 cv_destroy(&up->up_cv);
265 cv_destroy(&up->up_drain);
267 /* make sure that we do not enter here again */
271 /*------------------------------------------------------------------------*
274 * This function will queue one of the passed USB process messages on
275 * the USB process queue. The first message that is not already queued
276 * will get queued. If both messages are already queued the one queued
277 * last will be removed from the queue and queued in the end. The USB
278 * process mutex must be locked when calling this function. This
279 * function exploits the fact that a process can only do one callback
280 * at a time. The message that was queued is returned.
281 *------------------------------------------------------------------------*/
283 usb_proc_msignal(struct usb_process *up, void *_pm0, void *_pm1)
285 struct usb_proc_msg *pm0 = _pm0;
286 struct usb_proc_msg *pm1 = _pm1;
287 struct usb_proc_msg *pm2;
291 /* check if gone, return dummy value */
295 mtx_assert(up->up_mtx, MA_OWNED);
299 if (pm0->pm_qentry.tqe_prev) {
302 if (pm1->pm_qentry.tqe_prev) {
307 * No entries are queued. Queue "pm0" and use the existing
312 /* Check if we need to increment the message number. */
313 if (pm0->pm_num == up->up_msg_num) {
318 /* Check if we need to increment the message number. */
319 if (pm1->pm_num == up->up_msg_num) {
325 * Both entries are queued. Re-queue the entry closest to
328 d = (pm1->pm_num - pm0->pm_num);
330 /* Check sign after subtraction */
331 if (d & 0x80000000) {
337 TAILQ_REMOVE(&up->up_qhead, pm2, pm_qentry);
339 pm2 = NULL; /* panic - should not happen */
342 DPRINTF(" t=%u, num=%u\n", t, up->up_msg_num);
344 /* Put message last on queue */
346 pm2->pm_num = up->up_msg_num;
347 TAILQ_INSERT_TAIL(&up->up_qhead, pm2, pm_qentry);
349 /* Check if we need to wakeup the USB process. */
352 up->up_msleep = 0; /* save "cv_signal()" calls */
353 cv_signal(&up->up_cv);
358 /*------------------------------------------------------------------------*
362 * 0: USB process is running
363 * Else: USB process is tearing down
364 *------------------------------------------------------------------------*/
366 usb_proc_is_gone(struct usb_process *up)
372 * Allow calls when up_mtx is NULL, before the USB process
373 * structure is initialised.
375 if (up->up_mtx != NULL)
376 mtx_assert(up->up_mtx, MA_OWNED);
380 /*------------------------------------------------------------------------*
383 * This function will return when the USB process message pointed to
384 * by "pm" is no longer on a queue. This function must be called
385 * having "up->up_mtx" locked.
386 *------------------------------------------------------------------------*/
388 usb_proc_mwait(struct usb_process *up, void *_pm0, void *_pm1)
390 struct usb_proc_msg *pm0 = _pm0;
391 struct usb_proc_msg *pm1 = _pm1;
397 mtx_assert(up->up_mtx, MA_OWNED);
399 if (up->up_curtd == curthread) {
400 /* Just remove the messages from the queue. */
401 if (pm0->pm_qentry.tqe_prev) {
402 TAILQ_REMOVE(&up->up_qhead, pm0, pm_qentry);
403 pm0->pm_qentry.tqe_prev = NULL;
405 if (pm1->pm_qentry.tqe_prev) {
406 TAILQ_REMOVE(&up->up_qhead, pm1, pm_qentry);
407 pm1->pm_qentry.tqe_prev = NULL;
410 while (pm0->pm_qentry.tqe_prev ||
411 pm1->pm_qentry.tqe_prev) {
412 /* check if config thread is gone */
416 cv_wait(&up->up_drain, up->up_mtx);
420 /*------------------------------------------------------------------------*
423 * This function will tear down an USB process, waiting for the
424 * currently executing command to return.
426 * NOTE: If the structure pointed to by "up" is all zero,
427 * this function does nothing.
428 *------------------------------------------------------------------------*/
430 usb_proc_drain(struct usb_process *up)
432 /* check if not initialised */
433 if (up->up_mtx == NULL)
435 /* handle special case with Giant */
436 if (up->up_mtx != &Giant)
437 mtx_assert(up->up_mtx, MA_NOTOWNED);
439 mtx_lock(up->up_mtx);
441 /* Set the gone flag */
447 /* Check if we need to wakeup the USB process */
449 if (up->up_msleep || up->up_csleep) {
452 cv_signal(&up->up_cv);
454 /* Check if we are still cold booted */
457 USB_THREAD_SUSPEND(up->up_ptr);
458 printf("WARNING: A USB process has "
459 "been left suspended\n");
462 cv_wait(&up->up_cv, up->up_mtx);
464 /* Check if someone is waiting - should not happen */
468 cv_broadcast(&up->up_drain);
469 DPRINTF("WARNING: Someone is waiting "
470 "for USB process drain!\n");
472 mtx_unlock(up->up_mtx);
475 /*------------------------------------------------------------------------*
478 * This function is called to re-wakeup the given USB
479 * process. This usually happens after that the USB system has been in
480 * polling mode, like during a panic. This function must be called
481 * having "up->up_mtx" locked.
482 *------------------------------------------------------------------------*/
484 usb_proc_rewakeup(struct usb_process *up)
486 /* check if not initialised */
487 if (up->up_mtx == NULL)
493 mtx_assert(up->up_mtx, MA_OWNED);
495 if (up->up_msleep == 0) {
497 cv_signal(&up->up_cv);
501 /*------------------------------------------------------------------------*
502 * usb_proc_is_called_from
504 * This function will return non-zero if called from inside the USB
505 * process passed as first argument. Else this function returns zero.
506 *------------------------------------------------------------------------*/
508 usb_proc_is_called_from(struct usb_process *up)
510 return (up->up_curtd == curthread);