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(p) kthread_suspend(p,0)
71 #define USB_THREAD_EXIT(err) kthread_exit()
73 #define USB_THREAD_CREATE(f, s, p, ...) \
74 kthread_create((f), (s), (p), RFHIGHPID, 0, __VA_ARGS__)
75 #define USB_THREAD_SUSPEND(p) kthread_suspend(p,0)
76 #define USB_THREAD_EXIT(err) kthread_exit(err)
80 static int usb_proc_debug;
82 SYSCTL_NODE(_hw_usb, OID_AUTO, proc, CTLFLAG_RW, 0, "USB process");
83 SYSCTL_INT(_hw_usb_proc, OID_AUTO, debug, CTLFLAG_RW, &usb_proc_debug, 0,
86 TUNABLE_INT("hw.usb.proc.debug", &usb_proc_debug);
89 /*------------------------------------------------------------------------*
92 * This function is the USB process dispatcher.
93 *------------------------------------------------------------------------*/
95 usb_process(void *arg)
97 struct usb_process *up = arg;
98 struct usb_proc_msg *pm;
101 /* adjust priority */
104 sched_prio(td, up->up_prio);
107 mtx_lock(up->up_mtx);
117 * NOTE to reimplementors: dequeueing a command from the
118 * "used" queue and executing it must be atomic, with regard
119 * to the "up_mtx" mutex. That means any attempt to queue a
120 * command by another thread must be blocked until either:
122 * 1) the command sleeps
124 * 2) the command returns
126 * Here is a practical example that shows how this helps
129 * Assume that you want to set the baud rate on a USB serial
130 * device. During the programming of the device you don't
131 * want to receive nor transmit any data, because it will be
132 * garbage most likely anyway. The programming of our USB
133 * device takes 20 milliseconds and it needs to call
134 * functions that sleep.
136 * Non-working solution: Before we queue the programming
137 * command, we stop transmission and reception of data. Then
138 * we queue a programming command. At the end of the
139 * programming command we enable transmission and reception
142 * Problem: If a second programming command is queued while the
143 * first one is sleeping, we end up enabling transmission
144 * and reception of data too early.
146 * Working solution: Before we queue the programming command,
147 * we stop transmission and reception of data. Then we queue
148 * a programming command. Then we queue a second command
149 * that only enables transmission and reception of data.
151 * Why it works: If a second programming command is queued
152 * while the first one is sleeping, then the queueing of a
153 * second command to enable the data transfers, will cause
154 * the previous one, which is still on the queue, to be
155 * removed from the queue, and re-inserted after the last
156 * baud rate programming command, which then gives the
159 pm = TAILQ_FIRST(&up->up_qhead);
162 DPRINTF("Message pm=%p, cb=%p (enter)\n",
163 pm, pm->pm_callback);
165 (pm->pm_callback) (pm);
167 if (pm == TAILQ_FIRST(&up->up_qhead)) {
168 /* nothing changed */
169 TAILQ_REMOVE(&up->up_qhead, pm, pm_qentry);
170 pm->pm_qentry.tqe_prev = NULL;
172 DPRINTF("Message pm=%p (leave)\n", pm);
176 /* end if messages - check if anyone is waiting for sync */
179 cv_broadcast(&up->up_drain);
182 cv_wait(&up->up_cv, up->up_mtx);
186 cv_signal(&up->up_cv);
187 mtx_unlock(up->up_mtx);
188 #if (__FreeBSD_version >= 800000)
189 /* Clear the proc pointer if this is the last thread. */
190 if (--usb_pcount == 0)
197 /*------------------------------------------------------------------------*
200 * This function will create a process using the given "prio" that can
201 * execute callbacks. The mutex pointed to by "p_mtx" will be applied
202 * before calling the callbacks and released after that the callback
203 * has returned. The structure pointed to by "up" is assumed to be
204 * zeroed before this function is called.
209 *------------------------------------------------------------------------*/
211 usb_proc_create(struct usb_process *up, struct mtx *p_mtx,
212 const char *pmesg, uint8_t prio)
217 TAILQ_INIT(&up->up_qhead);
219 cv_init(&up->up_cv, "-");
220 cv_init(&up->up_drain, "usbdrain");
222 if (USB_THREAD_CREATE(&usb_process, up,
223 &up->up_ptr, "%s", pmesg)) {
224 DPRINTFN(0, "Unable to create USB process.");
228 #if (__FreeBSD_version >= 800000)
238 /*------------------------------------------------------------------------*
241 * NOTE: If the structure pointed to by "up" is all zero, this
242 * function does nothing.
244 * NOTE: Messages that are pending on the process queue will not be
245 * removed nor called.
246 *------------------------------------------------------------------------*/
248 usb_proc_free(struct usb_process *up)
250 /* check if not initialised */
251 if (up->up_mtx == NULL)
256 cv_destroy(&up->up_cv);
257 cv_destroy(&up->up_drain);
259 /* make sure that we do not enter here again */
263 /*------------------------------------------------------------------------*
266 * This function will queue one of the passed USB process messages on
267 * the USB process queue. The first message that is not already queued
268 * will get queued. If both messages are already queued the one queued
269 * last will be removed from the queue and queued in the end. The USB
270 * process mutex must be locked when calling this function. This
271 * function exploits the fact that a process can only do one callback
272 * at a time. The message that was queued is returned.
273 *------------------------------------------------------------------------*/
275 usb_proc_msignal(struct usb_process *up, void *_pm0, void *_pm1)
277 struct usb_proc_msg *pm0 = _pm0;
278 struct usb_proc_msg *pm1 = _pm1;
279 struct usb_proc_msg *pm2;
283 /* check if gone, return dummy value */
287 mtx_assert(up->up_mtx, MA_OWNED);
291 if (pm0->pm_qentry.tqe_prev) {
294 if (pm1->pm_qentry.tqe_prev) {
299 * No entries are queued. Queue "pm0" and use the existing
304 /* Check if we need to increment the message number. */
305 if (pm0->pm_num == up->up_msg_num) {
310 /* Check if we need to increment the message number. */
311 if (pm1->pm_num == up->up_msg_num) {
317 * Both entries are queued. Re-queue the entry closest to
320 d = (pm1->pm_num - pm0->pm_num);
322 /* Check sign after subtraction */
323 if (d & 0x80000000) {
329 TAILQ_REMOVE(&up->up_qhead, pm2, pm_qentry);
331 pm2 = NULL; /* panic - should not happen */
334 DPRINTF(" t=%u, num=%u\n", t, up->up_msg_num);
336 /* Put message last on queue */
338 pm2->pm_num = up->up_msg_num;
339 TAILQ_INSERT_TAIL(&up->up_qhead, pm2, pm_qentry);
341 /* Check if we need to wakeup the USB process. */
344 up->up_msleep = 0; /* save "cv_signal()" calls */
345 cv_signal(&up->up_cv);
350 /*------------------------------------------------------------------------*
354 * 0: USB process is running
355 * Else: USB process is tearing down
356 *------------------------------------------------------------------------*/
358 usb_proc_is_gone(struct usb_process *up)
364 * Allow calls when up_mtx is NULL, before the USB process
365 * structure is initialised.
367 if (up->up_mtx != NULL)
368 mtx_assert(up->up_mtx, MA_OWNED);
372 /*------------------------------------------------------------------------*
375 * This function will return when the USB process message pointed to
376 * by "pm" is no longer on a queue. This function must be called
377 * having "up->up_mtx" locked.
378 *------------------------------------------------------------------------*/
380 usb_proc_mwait(struct usb_process *up, void *_pm0, void *_pm1)
382 struct usb_proc_msg *pm0 = _pm0;
383 struct usb_proc_msg *pm1 = _pm1;
389 mtx_assert(up->up_mtx, MA_OWNED);
391 if (up->up_curtd == curthread) {
392 /* Just remove the messages from the queue. */
393 if (pm0->pm_qentry.tqe_prev) {
394 TAILQ_REMOVE(&up->up_qhead, pm0, pm_qentry);
395 pm0->pm_qentry.tqe_prev = NULL;
397 if (pm1->pm_qentry.tqe_prev) {
398 TAILQ_REMOVE(&up->up_qhead, pm1, pm_qentry);
399 pm1->pm_qentry.tqe_prev = NULL;
402 while (pm0->pm_qentry.tqe_prev ||
403 pm1->pm_qentry.tqe_prev) {
404 /* check if config thread is gone */
408 cv_wait(&up->up_drain, up->up_mtx);
412 /*------------------------------------------------------------------------*
415 * This function will tear down an USB process, waiting for the
416 * currently executing command to return.
418 * NOTE: If the structure pointed to by "up" is all zero,
419 * this function does nothing.
420 *------------------------------------------------------------------------*/
422 usb_proc_drain(struct usb_process *up)
424 /* check if not initialised */
425 if (up->up_mtx == NULL)
427 /* handle special case with Giant */
428 if (up->up_mtx != &Giant)
429 mtx_assert(up->up_mtx, MA_NOTOWNED);
431 mtx_lock(up->up_mtx);
433 /* Set the gone flag */
439 /* Check if we need to wakeup the USB process */
441 if (up->up_msleep || up->up_csleep) {
444 cv_signal(&up->up_cv);
446 /* Check if we are still cold booted */
449 USB_THREAD_SUSPEND(up->up_ptr);
450 printf("WARNING: A USB process has "
451 "been left suspended\n");
454 cv_wait(&up->up_cv, up->up_mtx);
456 /* Check if someone is waiting - should not happen */
460 cv_broadcast(&up->up_drain);
461 DPRINTF("WARNING: Someone is waiting "
462 "for USB process drain!\n");
464 mtx_unlock(up->up_mtx);
467 /*------------------------------------------------------------------------*
470 * This function is called to re-wakeup the given USB
471 * process. This usually happens after that the USB system has been in
472 * polling mode, like during a panic. This function must be called
473 * having "up->up_mtx" locked.
474 *------------------------------------------------------------------------*/
476 usb_proc_rewakeup(struct usb_process *up)
478 /* check if not initialised */
479 if (up->up_mtx == NULL)
485 mtx_assert(up->up_mtx, MA_OWNED);
487 if (up->up_msleep == 0) {
489 cv_signal(&up->up_cv);