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 #define USB_THREAD_SUSPEND_CHECK() kthread_suspend_check()
71 #define USB_THREAD_SUSPEND(p) kthread_suspend(p,0)
72 #define USB_THREAD_EXIT(err) kthread_exit()
74 #define USB_THREAD_CREATE(f, s, p, ...) \
75 kthread_create((f), (s), (p), RFHIGHPID, 0, __VA_ARGS__)
76 #define USB_THREAD_SUSPEND_CHECK() kthread_suspend_check()
77 #define USB_THREAD_SUSPEND(p) kthread_suspend(p,0)
78 #define USB_THREAD_EXIT(err) kthread_exit(err)
82 static int usb_proc_debug;
84 static SYSCTL_NODE(_hw_usb, OID_AUTO, proc, CTLFLAG_RW, 0, "USB process");
85 SYSCTL_INT(_hw_usb_proc, OID_AUTO, debug, CTLFLAG_RW | CTLFLAG_TUN, &usb_proc_debug, 0,
87 TUNABLE_INT("hw.usb.proc.debug", &usb_proc_debug);
90 /*------------------------------------------------------------------------*
93 * This function is the USB process dispatcher.
94 *------------------------------------------------------------------------*/
96 usb_process(void *arg)
98 struct usb_process *up = arg;
99 struct usb_proc_msg *pm;
102 /* in case of attach error, check for suspended */
103 USB_THREAD_SUSPEND_CHECK();
105 /* adjust priority */
108 sched_prio(td, up->up_prio);
111 mtx_lock(up->up_mtx);
121 * NOTE to reimplementors: dequeueing a command from the
122 * "used" queue and executing it must be atomic, with regard
123 * to the "up_mtx" mutex. That means any attempt to queue a
124 * command by another thread must be blocked until either:
126 * 1) the command sleeps
128 * 2) the command returns
130 * Here is a practical example that shows how this helps
133 * Assume that you want to set the baud rate on a USB serial
134 * device. During the programming of the device you don't
135 * want to receive nor transmit any data, because it will be
136 * garbage most likely anyway. The programming of our USB
137 * device takes 20 milliseconds and it needs to call
138 * functions that sleep.
140 * Non-working solution: Before we queue the programming
141 * command, we stop transmission and reception of data. Then
142 * we queue a programming command. At the end of the
143 * programming command we enable transmission and reception
146 * Problem: If a second programming command is queued while the
147 * first one is sleeping, we end up enabling transmission
148 * and reception of data too early.
150 * Working solution: Before we queue the programming command,
151 * we stop transmission and reception of data. Then we queue
152 * a programming command. Then we queue a second command
153 * that only enables transmission and reception of data.
155 * Why it works: If a second programming command is queued
156 * while the first one is sleeping, then the queueing of a
157 * second command to enable the data transfers, will cause
158 * the previous one, which is still on the queue, to be
159 * removed from the queue, and re-inserted after the last
160 * baud rate programming command, which then gives the
163 pm = TAILQ_FIRST(&up->up_qhead);
166 DPRINTF("Message pm=%p, cb=%p (enter)\n",
167 pm, pm->pm_callback);
169 (pm->pm_callback) (pm);
171 if (pm == TAILQ_FIRST(&up->up_qhead)) {
172 /* nothing changed */
173 TAILQ_REMOVE(&up->up_qhead, pm, pm_qentry);
174 pm->pm_qentry.tqe_prev = NULL;
176 DPRINTF("Message pm=%p (leave)\n", pm);
180 /* end if messages - check if anyone is waiting for sync */
183 cv_broadcast(&up->up_drain);
186 cv_wait(&up->up_cv, up->up_mtx);
190 cv_signal(&up->up_cv);
191 mtx_unlock(up->up_mtx);
192 #if (__FreeBSD_version >= 800000)
193 /* Clear the proc pointer if this is the last thread. */
194 if (--usb_pcount == 0)
201 /*------------------------------------------------------------------------*
204 * This function will create a process using the given "prio" that can
205 * execute callbacks. The mutex pointed to by "p_mtx" will be applied
206 * before calling the callbacks and released after that the callback
207 * has returned. The structure pointed to by "up" is assumed to be
208 * zeroed before this function is called.
213 *------------------------------------------------------------------------*/
215 usb_proc_create(struct usb_process *up, struct mtx *p_mtx,
216 const char *pmesg, uint8_t prio)
221 TAILQ_INIT(&up->up_qhead);
223 cv_init(&up->up_cv, "-");
224 cv_init(&up->up_drain, "usbdrain");
226 if (USB_THREAD_CREATE(&usb_process, up,
227 &up->up_ptr, "%s", pmesg)) {
228 DPRINTFN(0, "Unable to create USB process.");
232 #if (__FreeBSD_version >= 800000)
242 /*------------------------------------------------------------------------*
245 * NOTE: If the structure pointed to by "up" is all zero, this
246 * function does nothing.
248 * NOTE: Messages that are pending on the process queue will not be
249 * removed nor called.
250 *------------------------------------------------------------------------*/
252 usb_proc_free(struct usb_process *up)
254 /* check if not initialised */
255 if (up->up_mtx == NULL)
260 cv_destroy(&up->up_cv);
261 cv_destroy(&up->up_drain);
263 /* make sure that we do not enter here again */
267 /*------------------------------------------------------------------------*
270 * This function will queue one of the passed USB process messages on
271 * the USB process queue. The first message that is not already queued
272 * will get queued. If both messages are already queued the one queued
273 * last will be removed from the queue and queued in the end. The USB
274 * process mutex must be locked when calling this function. This
275 * function exploits the fact that a process can only do one callback
276 * at a time. The message that was queued is returned.
277 *------------------------------------------------------------------------*/
279 usb_proc_msignal(struct usb_process *up, void *_pm0, void *_pm1)
281 struct usb_proc_msg *pm0 = _pm0;
282 struct usb_proc_msg *pm1 = _pm1;
283 struct usb_proc_msg *pm2;
287 /* check if gone, return dummy value */
291 mtx_assert(up->up_mtx, MA_OWNED);
295 if (pm0->pm_qentry.tqe_prev) {
298 if (pm1->pm_qentry.tqe_prev) {
303 * No entries are queued. Queue "pm0" and use the existing
308 /* Check if we need to increment the message number. */
309 if (pm0->pm_num == up->up_msg_num) {
314 /* Check if we need to increment the message number. */
315 if (pm1->pm_num == up->up_msg_num) {
321 * Both entries are queued. Re-queue the entry closest to
324 d = (pm1->pm_num - pm0->pm_num);
326 /* Check sign after subtraction */
327 if (d & 0x80000000) {
333 TAILQ_REMOVE(&up->up_qhead, pm2, pm_qentry);
335 pm2 = NULL; /* panic - should not happen */
338 DPRINTF(" t=%u, num=%u\n", t, up->up_msg_num);
340 /* Put message last on queue */
342 pm2->pm_num = up->up_msg_num;
343 TAILQ_INSERT_TAIL(&up->up_qhead, pm2, pm_qentry);
345 /* Check if we need to wakeup the USB process. */
348 up->up_msleep = 0; /* save "cv_signal()" calls */
349 cv_signal(&up->up_cv);
354 /*------------------------------------------------------------------------*
358 * 0: USB process is running
359 * Else: USB process is tearing down
360 *------------------------------------------------------------------------*/
362 usb_proc_is_gone(struct usb_process *up)
368 * Allow calls when up_mtx is NULL, before the USB process
369 * structure is initialised.
371 if (up->up_mtx != NULL)
372 mtx_assert(up->up_mtx, MA_OWNED);
376 /*------------------------------------------------------------------------*
379 * This function will return when the USB process message pointed to
380 * by "pm" is no longer on a queue. This function must be called
381 * having "up->up_mtx" locked.
382 *------------------------------------------------------------------------*/
384 usb_proc_mwait(struct usb_process *up, void *_pm0, void *_pm1)
386 struct usb_proc_msg *pm0 = _pm0;
387 struct usb_proc_msg *pm1 = _pm1;
393 mtx_assert(up->up_mtx, MA_OWNED);
395 if (up->up_curtd == curthread) {
396 /* Just remove the messages from the queue. */
397 if (pm0->pm_qentry.tqe_prev) {
398 TAILQ_REMOVE(&up->up_qhead, pm0, pm_qentry);
399 pm0->pm_qentry.tqe_prev = NULL;
401 if (pm1->pm_qentry.tqe_prev) {
402 TAILQ_REMOVE(&up->up_qhead, pm1, pm_qentry);
403 pm1->pm_qentry.tqe_prev = NULL;
406 while (pm0->pm_qentry.tqe_prev ||
407 pm1->pm_qentry.tqe_prev) {
408 /* check if config thread is gone */
412 cv_wait(&up->up_drain, up->up_mtx);
416 /*------------------------------------------------------------------------*
419 * This function will tear down an USB process, waiting for the
420 * currently executing command to return.
422 * NOTE: If the structure pointed to by "up" is all zero,
423 * this function does nothing.
424 *------------------------------------------------------------------------*/
426 usb_proc_drain(struct usb_process *up)
428 /* check if not initialised */
429 if (up->up_mtx == NULL)
431 /* handle special case with Giant */
432 if (up->up_mtx != &Giant)
433 mtx_assert(up->up_mtx, MA_NOTOWNED);
435 mtx_lock(up->up_mtx);
437 /* Set the gone flag */
443 /* Check if we need to wakeup the USB process */
445 if (up->up_msleep || up->up_csleep) {
448 cv_signal(&up->up_cv);
450 /* Check if we are still cold booted */
453 USB_THREAD_SUSPEND(up->up_ptr);
454 printf("WARNING: A USB process has "
455 "been left suspended\n");
458 cv_wait(&up->up_cv, up->up_mtx);
460 /* Check if someone is waiting - should not happen */
464 cv_broadcast(&up->up_drain);
465 DPRINTF("WARNING: Someone is waiting "
466 "for USB process drain!\n");
468 mtx_unlock(up->up_mtx);
471 /*------------------------------------------------------------------------*
474 * This function is called to re-wakeup the given USB
475 * process. This usually happens after that the USB system has been in
476 * polling mode, like during a panic. This function must be called
477 * having "up->up_mtx" locked.
478 *------------------------------------------------------------------------*/
480 usb_proc_rewakeup(struct usb_process *up)
482 /* check if not initialised */
483 if (up->up_mtx == NULL)
489 mtx_assert(up->up_mtx, MA_OWNED);
491 if (up->up_msleep == 0) {
493 cv_signal(&up->up_cv);