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 SYSCTL_NODE(_hw_usb, OID_AUTO, proc, CTLFLAG_RW, 0, "USB process");
85 SYSCTL_INT(_hw_usb_proc, OID_AUTO, debug, CTLFLAG_RW, &usb_proc_debug, 0,
88 TUNABLE_INT("hw.usb.proc.debug", &usb_proc_debug);
91 /*------------------------------------------------------------------------*
94 * This function is the USB process dispatcher.
95 *------------------------------------------------------------------------*/
97 usb_process(void *arg)
99 struct usb_process *up = arg;
100 struct usb_proc_msg *pm;
103 /* in case of attach error, check for suspended */
104 USB_THREAD_SUSPEND_CHECK();
106 /* adjust priority */
109 sched_prio(td, up->up_prio);
112 mtx_lock(up->up_mtx);
122 * NOTE to reimplementors: dequeueing a command from the
123 * "used" queue and executing it must be atomic, with regard
124 * to the "up_mtx" mutex. That means any attempt to queue a
125 * command by another thread must be blocked until either:
127 * 1) the command sleeps
129 * 2) the command returns
131 * Here is a practical example that shows how this helps
134 * Assume that you want to set the baud rate on a USB serial
135 * device. During the programming of the device you don't
136 * want to receive nor transmit any data, because it will be
137 * garbage most likely anyway. The programming of our USB
138 * device takes 20 milliseconds and it needs to call
139 * functions that sleep.
141 * Non-working solution: Before we queue the programming
142 * command, we stop transmission and reception of data. Then
143 * we queue a programming command. At the end of the
144 * programming command we enable transmission and reception
147 * Problem: If a second programming command is queued while the
148 * first one is sleeping, we end up enabling transmission
149 * and reception of data too early.
151 * Working solution: Before we queue the programming command,
152 * we stop transmission and reception of data. Then we queue
153 * a programming command. Then we queue a second command
154 * that only enables transmission and reception of data.
156 * Why it works: If a second programming command is queued
157 * while the first one is sleeping, then the queueing of a
158 * second command to enable the data transfers, will cause
159 * the previous one, which is still on the queue, to be
160 * removed from the queue, and re-inserted after the last
161 * baud rate programming command, which then gives the
164 pm = TAILQ_FIRST(&up->up_qhead);
167 DPRINTF("Message pm=%p, cb=%p (enter)\n",
168 pm, pm->pm_callback);
170 (pm->pm_callback) (pm);
172 if (pm == TAILQ_FIRST(&up->up_qhead)) {
173 /* nothing changed */
174 TAILQ_REMOVE(&up->up_qhead, pm, pm_qentry);
175 pm->pm_qentry.tqe_prev = NULL;
177 DPRINTF("Message pm=%p (leave)\n", pm);
181 /* end if messages - check if anyone is waiting for sync */
184 cv_broadcast(&up->up_drain);
187 cv_wait(&up->up_cv, up->up_mtx);
191 cv_signal(&up->up_cv);
192 mtx_unlock(up->up_mtx);
193 #if (__FreeBSD_version >= 800000)
194 /* Clear the proc pointer if this is the last thread. */
195 if (--usb_pcount == 0)
202 /*------------------------------------------------------------------------*
205 * This function will create a process using the given "prio" that can
206 * execute callbacks. The mutex pointed to by "p_mtx" will be applied
207 * before calling the callbacks and released after that the callback
208 * has returned. The structure pointed to by "up" is assumed to be
209 * zeroed before this function is called.
214 *------------------------------------------------------------------------*/
216 usb_proc_create(struct usb_process *up, struct mtx *p_mtx,
217 const char *pmesg, uint8_t prio)
222 TAILQ_INIT(&up->up_qhead);
224 cv_init(&up->up_cv, "-");
225 cv_init(&up->up_drain, "usbdrain");
227 if (USB_THREAD_CREATE(&usb_process, up,
228 &up->up_ptr, "%s", pmesg)) {
229 DPRINTFN(0, "Unable to create USB process.");
233 #if (__FreeBSD_version >= 800000)
243 /*------------------------------------------------------------------------*
246 * NOTE: If the structure pointed to by "up" is all zero, this
247 * function does nothing.
249 * NOTE: Messages that are pending on the process queue will not be
250 * removed nor called.
251 *------------------------------------------------------------------------*/
253 usb_proc_free(struct usb_process *up)
255 /* check if not initialised */
256 if (up->up_mtx == NULL)
261 cv_destroy(&up->up_cv);
262 cv_destroy(&up->up_drain);
264 /* make sure that we do not enter here again */
268 /*------------------------------------------------------------------------*
271 * This function will queue one of the passed USB process messages on
272 * the USB process queue. The first message that is not already queued
273 * will get queued. If both messages are already queued the one queued
274 * last will be removed from the queue and queued in the end. The USB
275 * process mutex must be locked when calling this function. This
276 * function exploits the fact that a process can only do one callback
277 * at a time. The message that was queued is returned.
278 *------------------------------------------------------------------------*/
280 usb_proc_msignal(struct usb_process *up, void *_pm0, void *_pm1)
282 struct usb_proc_msg *pm0 = _pm0;
283 struct usb_proc_msg *pm1 = _pm1;
284 struct usb_proc_msg *pm2;
288 /* check if gone, return dummy value */
292 mtx_assert(up->up_mtx, MA_OWNED);
296 if (pm0->pm_qentry.tqe_prev) {
299 if (pm1->pm_qentry.tqe_prev) {
304 * No entries are queued. Queue "pm0" and use the existing
309 /* Check if we need to increment the message number. */
310 if (pm0->pm_num == up->up_msg_num) {
315 /* Check if we need to increment the message number. */
316 if (pm1->pm_num == up->up_msg_num) {
322 * Both entries are queued. Re-queue the entry closest to
325 d = (pm1->pm_num - pm0->pm_num);
327 /* Check sign after subtraction */
328 if (d & 0x80000000) {
334 TAILQ_REMOVE(&up->up_qhead, pm2, pm_qentry);
336 pm2 = NULL; /* panic - should not happen */
339 DPRINTF(" t=%u, num=%u\n", t, up->up_msg_num);
341 /* Put message last on queue */
343 pm2->pm_num = up->up_msg_num;
344 TAILQ_INSERT_TAIL(&up->up_qhead, pm2, pm_qentry);
346 /* Check if we need to wakeup the USB process. */
349 up->up_msleep = 0; /* save "cv_signal()" calls */
350 cv_signal(&up->up_cv);
355 /*------------------------------------------------------------------------*
359 * 0: USB process is running
360 * Else: USB process is tearing down
361 *------------------------------------------------------------------------*/
363 usb_proc_is_gone(struct usb_process *up)
369 * Allow calls when up_mtx is NULL, before the USB process
370 * structure is initialised.
372 if (up->up_mtx != NULL)
373 mtx_assert(up->up_mtx, MA_OWNED);
377 /*------------------------------------------------------------------------*
380 * This function will return when the USB process message pointed to
381 * by "pm" is no longer on a queue. This function must be called
382 * having "up->up_mtx" locked.
383 *------------------------------------------------------------------------*/
385 usb_proc_mwait(struct usb_process *up, void *_pm0, void *_pm1)
387 struct usb_proc_msg *pm0 = _pm0;
388 struct usb_proc_msg *pm1 = _pm1;
394 mtx_assert(up->up_mtx, MA_OWNED);
396 if (up->up_curtd == curthread) {
397 /* Just remove the messages from the queue. */
398 if (pm0->pm_qentry.tqe_prev) {
399 TAILQ_REMOVE(&up->up_qhead, pm0, pm_qentry);
400 pm0->pm_qentry.tqe_prev = NULL;
402 if (pm1->pm_qentry.tqe_prev) {
403 TAILQ_REMOVE(&up->up_qhead, pm1, pm_qentry);
404 pm1->pm_qentry.tqe_prev = NULL;
407 while (pm0->pm_qentry.tqe_prev ||
408 pm1->pm_qentry.tqe_prev) {
409 /* check if config thread is gone */
413 cv_wait(&up->up_drain, up->up_mtx);
417 /*------------------------------------------------------------------------*
420 * This function will tear down an USB process, waiting for the
421 * currently executing command to return.
423 * NOTE: If the structure pointed to by "up" is all zero,
424 * this function does nothing.
425 *------------------------------------------------------------------------*/
427 usb_proc_drain(struct usb_process *up)
429 /* check if not initialised */
430 if (up->up_mtx == NULL)
432 /* handle special case with Giant */
433 if (up->up_mtx != &Giant)
434 mtx_assert(up->up_mtx, MA_NOTOWNED);
436 mtx_lock(up->up_mtx);
438 /* Set the gone flag */
444 /* Check if we need to wakeup the USB process */
446 if (up->up_msleep || up->up_csleep) {
449 cv_signal(&up->up_cv);
451 /* Check if we are still cold booted */
454 USB_THREAD_SUSPEND(up->up_ptr);
455 printf("WARNING: A USB process has "
456 "been left suspended\n");
459 cv_wait(&up->up_cv, up->up_mtx);
461 /* Check if someone is waiting - should not happen */
465 cv_broadcast(&up->up_drain);
466 DPRINTF("WARNING: Someone is waiting "
467 "for USB process drain!\n");
469 mtx_unlock(up->up_mtx);
472 /*------------------------------------------------------------------------*
475 * This function is called to re-wakeup the given USB
476 * process. This usually happens after that the USB system has been in
477 * polling mode, like during a panic. This function must be called
478 * having "up->up_mtx" locked.
479 *------------------------------------------------------------------------*/
481 usb_proc_rewakeup(struct usb_process *up)
483 /* check if not initialised */
484 if (up->up_mtx == NULL)
490 mtx_assert(up->up_mtx, MA_OWNED);
492 if (up->up_msleep == 0) {
494 cv_signal(&up->up_cv);