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/linker_set.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>
53 #include <dev/usb/usb_debug.h>
54 #include <dev/usb/usb_util.h>
57 #include <sys/kthread.h>
58 #include <sys/sched.h>
60 #if (__FreeBSD_version < 700000)
61 #define thread_lock(td) mtx_lock_spin(&sched_lock)
62 #define thread_unlock(td) mtx_unlock_spin(&sched_lock)
65 #if (__FreeBSD_version >= 800000)
66 #define USB_THREAD_CREATE(f, s, p, ...) \
67 kproc_create((f), (s), (p), RFHIGHPID, 0, __VA_ARGS__)
68 #define USB_THREAD_SUSPEND(p) kproc_suspend(p,0)
69 #define USB_THREAD_EXIT(err) kproc_exit(err)
71 #define USB_THREAD_CREATE(f, s, p, ...) \
72 kthread_create((f), (s), (p), RFHIGHPID, 0, __VA_ARGS__)
73 #define USB_THREAD_SUSPEND(p) kthread_suspend(p,0)
74 #define USB_THREAD_EXIT(err) kthread_exit(err)
78 static int usb_proc_debug;
80 SYSCTL_NODE(_hw_usb, OID_AUTO, proc, CTLFLAG_RW, 0, "USB process");
81 SYSCTL_INT(_hw_usb_proc, OID_AUTO, debug, CTLFLAG_RW, &usb_proc_debug, 0,
85 /*------------------------------------------------------------------------*
88 * This function is the USB process dispatcher.
89 *------------------------------------------------------------------------*/
91 usb_process(void *arg)
93 struct usb_process *up = arg;
94 struct usb_proc_msg *pm;
100 sched_prio(td, up->up_prio);
103 mtx_lock(up->up_mtx);
113 * NOTE to reimplementors: dequeueing a command from the
114 * "used" queue and executing it must be atomic, with regard
115 * to the "up_mtx" mutex. That means any attempt to queue a
116 * command by another thread must be blocked until either:
118 * 1) the command sleeps
120 * 2) the command returns
122 * Here is a practical example that shows how this helps
125 * Assume that you want to set the baud rate on a USB serial
126 * device. During the programming of the device you don't
127 * want to receive nor transmit any data, because it will be
128 * garbage most likely anyway. The programming of our USB
129 * device takes 20 milliseconds and it needs to call
130 * functions that sleep.
132 * Non-working solution: Before we queue the programming
133 * command, we stop transmission and reception of data. Then
134 * we queue a programming command. At the end of the
135 * programming command we enable transmission and reception
138 * Problem: If a second programming command is queued while the
139 * first one is sleeping, we end up enabling transmission
140 * and reception of data too early.
142 * Working solution: Before we queue the programming command,
143 * we stop transmission and reception of data. Then we queue
144 * a programming command. Then we queue a second command
145 * that only enables transmission and reception of data.
147 * Why it works: If a second programming command is queued
148 * while the first one is sleeping, then the queueing of a
149 * second command to enable the data transfers, will cause
150 * the previous one, which is still on the queue, to be
151 * removed from the queue, and re-inserted after the last
152 * baud rate programming command, which then gives the
155 pm = TAILQ_FIRST(&up->up_qhead);
158 DPRINTF("Message pm=%p, cb=%p (enter)\n",
159 pm, pm->pm_callback);
161 (pm->pm_callback) (pm);
163 if (pm == TAILQ_FIRST(&up->up_qhead)) {
164 /* nothing changed */
165 TAILQ_REMOVE(&up->up_qhead, pm, pm_qentry);
166 pm->pm_qentry.tqe_prev = NULL;
168 DPRINTF("Message pm=%p (leave)\n", pm);
172 /* end if messages - check if anyone is waiting for sync */
175 cv_broadcast(&up->up_drain);
178 cv_wait(&up->up_cv, up->up_mtx);
182 cv_signal(&up->up_cv);
183 mtx_unlock(up->up_mtx);
188 /*------------------------------------------------------------------------*
191 * This function will create a process using the given "prio" that can
192 * execute callbacks. The mutex pointed to by "p_mtx" will be applied
193 * before calling the callbacks and released after that the callback
194 * has returned. The structure pointed to by "up" is assumed to be
195 * zeroed before this function is called.
200 *------------------------------------------------------------------------*/
202 usb_proc_create(struct usb_process *up, struct mtx *p_mtx,
203 const char *pmesg, uint8_t prio)
208 TAILQ_INIT(&up->up_qhead);
210 cv_init(&up->up_cv, "wmsg");
211 cv_init(&up->up_drain, "dmsg");
213 if (USB_THREAD_CREATE(&usb_process, up,
214 &up->up_ptr, pmesg)) {
215 DPRINTFN(0, "Unable to create USB process.");
226 /*------------------------------------------------------------------------*
229 * NOTE: If the structure pointed to by "up" is all zero, this
230 * function does nothing.
232 * NOTE: Messages that are pending on the process queue will not be
233 * removed nor called.
234 *------------------------------------------------------------------------*/
236 usb_proc_free(struct usb_process *up)
238 /* check if not initialised */
239 if (up->up_mtx == NULL)
244 cv_destroy(&up->up_cv);
245 cv_destroy(&up->up_drain);
247 /* make sure that we do not enter here again */
251 /*------------------------------------------------------------------------*
254 * This function will queue one of the passed USB process messages on
255 * the USB process queue. The first message that is not already queued
256 * will get queued. If both messages are already queued the one queued
257 * last will be removed from the queue and queued in the end. The USB
258 * process mutex must be locked when calling this function. This
259 * function exploits the fact that a process can only do one callback
260 * at a time. The message that was queued is returned.
261 *------------------------------------------------------------------------*/
263 usb_proc_msignal(struct usb_process *up, void *_pm0, void *_pm1)
265 struct usb_proc_msg *pm0 = _pm0;
266 struct usb_proc_msg *pm1 = _pm1;
267 struct usb_proc_msg *pm2;
271 /* check if gone, return dummy value */
275 mtx_assert(up->up_mtx, MA_OWNED);
279 if (pm0->pm_qentry.tqe_prev) {
282 if (pm1->pm_qentry.tqe_prev) {
287 * No entries are queued. Queue "pm0" and use the existing
292 /* Check if we need to increment the message number. */
293 if (pm0->pm_num == up->up_msg_num) {
298 /* Check if we need to increment the message number. */
299 if (pm1->pm_num == up->up_msg_num) {
305 * Both entries are queued. Re-queue the entry closest to
308 d = (pm1->pm_num - pm0->pm_num);
310 /* Check sign after subtraction */
311 if (d & 0x80000000) {
317 TAILQ_REMOVE(&up->up_qhead, pm2, pm_qentry);
319 pm2 = NULL; /* panic - should not happen */
322 DPRINTF(" t=%u, num=%u\n", t, up->up_msg_num);
324 /* Put message last on queue */
326 pm2->pm_num = up->up_msg_num;
327 TAILQ_INSERT_TAIL(&up->up_qhead, pm2, pm_qentry);
329 /* Check if we need to wakeup the USB process. */
332 up->up_msleep = 0; /* save "cv_signal()" calls */
333 cv_signal(&up->up_cv);
338 /*------------------------------------------------------------------------*
342 * 0: USB process is running
343 * Else: USB process is tearing down
344 *------------------------------------------------------------------------*/
346 usb_proc_is_gone(struct usb_process *up)
351 mtx_assert(up->up_mtx, MA_OWNED);
355 /*------------------------------------------------------------------------*
358 * This function will return when the USB process message pointed to
359 * by "pm" is no longer on a queue. This function must be called
360 * having "up->up_mtx" locked.
361 *------------------------------------------------------------------------*/
363 usb_proc_mwait(struct usb_process *up, void *_pm0, void *_pm1)
365 struct usb_proc_msg *pm0 = _pm0;
366 struct usb_proc_msg *pm1 = _pm1;
372 mtx_assert(up->up_mtx, MA_OWNED);
374 if (up->up_curtd == curthread) {
375 /* Just remove the messages from the queue. */
376 if (pm0->pm_qentry.tqe_prev) {
377 TAILQ_REMOVE(&up->up_qhead, pm0, pm_qentry);
378 pm0->pm_qentry.tqe_prev = NULL;
380 if (pm1->pm_qentry.tqe_prev) {
381 TAILQ_REMOVE(&up->up_qhead, pm1, pm_qentry);
382 pm1->pm_qentry.tqe_prev = NULL;
385 while (pm0->pm_qentry.tqe_prev ||
386 pm1->pm_qentry.tqe_prev) {
387 /* check if config thread is gone */
391 cv_wait(&up->up_drain, up->up_mtx);
395 /*------------------------------------------------------------------------*
398 * This function will tear down an USB process, waiting for the
399 * currently executing command to return.
401 * NOTE: If the structure pointed to by "up" is all zero,
402 * this function does nothing.
403 *------------------------------------------------------------------------*/
405 usb_proc_drain(struct usb_process *up)
407 /* check if not initialised */
408 if (up->up_mtx == NULL)
410 /* handle special case with Giant */
411 if (up->up_mtx != &Giant)
412 mtx_assert(up->up_mtx, MA_NOTOWNED);
414 mtx_lock(up->up_mtx);
416 /* Set the gone flag */
422 /* Check if we need to wakeup the USB process */
424 if (up->up_msleep || up->up_csleep) {
427 cv_signal(&up->up_cv);
429 /* Check if we are still cold booted */
432 USB_THREAD_SUSPEND(up->up_ptr);
433 printf("WARNING: A USB process has "
434 "been left suspended!\n");
437 cv_wait(&up->up_cv, up->up_mtx);
439 /* Check if someone is waiting - should not happen */
443 cv_broadcast(&up->up_drain);
444 DPRINTF("WARNING: Someone is waiting "
445 "for USB process drain!\n");
447 mtx_unlock(up->up_mtx);