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 static struct proc *usbproc;
67 static int usb_pcount;
68 #define USB_THREAD_CREATE(f, s, p, ...) \
69 kproc_kthread_add((f), (s), &usbproc, (p), RFHIGHPID, \
70 0, "usb", __VA_ARGS__)
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(p) kthread_suspend(p,0)
77 #define USB_THREAD_EXIT(err) kthread_exit(err)
81 static int usb_proc_debug;
83 SYSCTL_NODE(_hw_usb, OID_AUTO, proc, CTLFLAG_RW, 0, "USB process");
84 SYSCTL_INT(_hw_usb_proc, OID_AUTO, debug, CTLFLAG_RW, &usb_proc_debug, 0,
88 /*------------------------------------------------------------------------*
91 * This function is the USB process dispatcher.
92 *------------------------------------------------------------------------*/
94 usb_process(void *arg)
96 struct usb_process *up = arg;
97 struct usb_proc_msg *pm;
100 /* adjust priority */
103 sched_prio(td, up->up_prio);
106 mtx_lock(up->up_mtx);
116 * NOTE to reimplementors: dequeueing a command from the
117 * "used" queue and executing it must be atomic, with regard
118 * to the "up_mtx" mutex. That means any attempt to queue a
119 * command by another thread must be blocked until either:
121 * 1) the command sleeps
123 * 2) the command returns
125 * Here is a practical example that shows how this helps
128 * Assume that you want to set the baud rate on a USB serial
129 * device. During the programming of the device you don't
130 * want to receive nor transmit any data, because it will be
131 * garbage most likely anyway. The programming of our USB
132 * device takes 20 milliseconds and it needs to call
133 * functions that sleep.
135 * Non-working solution: Before we queue the programming
136 * command, we stop transmission and reception of data. Then
137 * we queue a programming command. At the end of the
138 * programming command we enable transmission and reception
141 * Problem: If a second programming command is queued while the
142 * first one is sleeping, we end up enabling transmission
143 * and reception of data too early.
145 * Working solution: Before we queue the programming command,
146 * we stop transmission and reception of data. Then we queue
147 * a programming command. Then we queue a second command
148 * that only enables transmission and reception of data.
150 * Why it works: If a second programming command is queued
151 * while the first one is sleeping, then the queueing of a
152 * second command to enable the data transfers, will cause
153 * the previous one, which is still on the queue, to be
154 * removed from the queue, and re-inserted after the last
155 * baud rate programming command, which then gives the
158 pm = TAILQ_FIRST(&up->up_qhead);
161 DPRINTF("Message pm=%p, cb=%p (enter)\n",
162 pm, pm->pm_callback);
164 (pm->pm_callback) (pm);
166 if (pm == TAILQ_FIRST(&up->up_qhead)) {
167 /* nothing changed */
168 TAILQ_REMOVE(&up->up_qhead, pm, pm_qentry);
169 pm->pm_qentry.tqe_prev = NULL;
171 DPRINTF("Message pm=%p (leave)\n", pm);
175 /* end if messages - check if anyone is waiting for sync */
178 cv_broadcast(&up->up_drain);
181 cv_wait(&up->up_cv, up->up_mtx);
185 cv_signal(&up->up_cv);
186 mtx_unlock(up->up_mtx);
187 #if (__FreeBSD_version >= 800000)
188 /* Clear the proc pointer if this is the last thread. */
189 if (--usb_pcount == 0)
196 /*------------------------------------------------------------------------*
199 * This function will create a process using the given "prio" that can
200 * execute callbacks. The mutex pointed to by "p_mtx" will be applied
201 * before calling the callbacks and released after that the callback
202 * has returned. The structure pointed to by "up" is assumed to be
203 * zeroed before this function is called.
208 *------------------------------------------------------------------------*/
210 usb_proc_create(struct usb_process *up, struct mtx *p_mtx,
211 const char *pmesg, uint8_t prio)
216 TAILQ_INIT(&up->up_qhead);
218 cv_init(&up->up_cv, "-");
219 cv_init(&up->up_drain, "usbdrain");
221 if (USB_THREAD_CREATE(&usb_process, up,
222 &up->up_ptr, pmesg)) {
223 DPRINTFN(0, "Unable to create USB process.");
227 #if (__FreeBSD_version >= 800000)
237 /*------------------------------------------------------------------------*
240 * NOTE: If the structure pointed to by "up" is all zero, this
241 * function does nothing.
243 * NOTE: Messages that are pending on the process queue will not be
244 * removed nor called.
245 *------------------------------------------------------------------------*/
247 usb_proc_free(struct usb_process *up)
249 /* check if not initialised */
250 if (up->up_mtx == NULL)
255 cv_destroy(&up->up_cv);
256 cv_destroy(&up->up_drain);
258 /* make sure that we do not enter here again */
262 /*------------------------------------------------------------------------*
265 * This function will queue one of the passed USB process messages on
266 * the USB process queue. The first message that is not already queued
267 * will get queued. If both messages are already queued the one queued
268 * last will be removed from the queue and queued in the end. The USB
269 * process mutex must be locked when calling this function. This
270 * function exploits the fact that a process can only do one callback
271 * at a time. The message that was queued is returned.
272 *------------------------------------------------------------------------*/
274 usb_proc_msignal(struct usb_process *up, void *_pm0, void *_pm1)
276 struct usb_proc_msg *pm0 = _pm0;
277 struct usb_proc_msg *pm1 = _pm1;
278 struct usb_proc_msg *pm2;
282 /* check if gone, return dummy value */
286 mtx_assert(up->up_mtx, MA_OWNED);
290 if (pm0->pm_qentry.tqe_prev) {
293 if (pm1->pm_qentry.tqe_prev) {
298 * No entries are queued. Queue "pm0" and use the existing
303 /* Check if we need to increment the message number. */
304 if (pm0->pm_num == up->up_msg_num) {
309 /* Check if we need to increment the message number. */
310 if (pm1->pm_num == up->up_msg_num) {
316 * Both entries are queued. Re-queue the entry closest to
319 d = (pm1->pm_num - pm0->pm_num);
321 /* Check sign after subtraction */
322 if (d & 0x80000000) {
328 TAILQ_REMOVE(&up->up_qhead, pm2, pm_qentry);
330 pm2 = NULL; /* panic - should not happen */
333 DPRINTF(" t=%u, num=%u\n", t, up->up_msg_num);
335 /* Put message last on queue */
337 pm2->pm_num = up->up_msg_num;
338 TAILQ_INSERT_TAIL(&up->up_qhead, pm2, pm_qentry);
340 /* Check if we need to wakeup the USB process. */
343 up->up_msleep = 0; /* save "cv_signal()" calls */
344 cv_signal(&up->up_cv);
349 /*------------------------------------------------------------------------*
353 * 0: USB process is running
354 * Else: USB process is tearing down
355 *------------------------------------------------------------------------*/
357 usb_proc_is_gone(struct usb_process *up)
362 mtx_assert(up->up_mtx, MA_OWNED);
366 /*------------------------------------------------------------------------*
369 * This function will return when the USB process message pointed to
370 * by "pm" is no longer on a queue. This function must be called
371 * having "up->up_mtx" locked.
372 *------------------------------------------------------------------------*/
374 usb_proc_mwait(struct usb_process *up, void *_pm0, void *_pm1)
376 struct usb_proc_msg *pm0 = _pm0;
377 struct usb_proc_msg *pm1 = _pm1;
383 mtx_assert(up->up_mtx, MA_OWNED);
385 if (up->up_curtd == curthread) {
386 /* Just remove the messages from the queue. */
387 if (pm0->pm_qentry.tqe_prev) {
388 TAILQ_REMOVE(&up->up_qhead, pm0, pm_qentry);
389 pm0->pm_qentry.tqe_prev = NULL;
391 if (pm1->pm_qentry.tqe_prev) {
392 TAILQ_REMOVE(&up->up_qhead, pm1, pm_qentry);
393 pm1->pm_qentry.tqe_prev = NULL;
396 while (pm0->pm_qentry.tqe_prev ||
397 pm1->pm_qentry.tqe_prev) {
398 /* check if config thread is gone */
402 cv_wait(&up->up_drain, up->up_mtx);
406 /*------------------------------------------------------------------------*
409 * This function will tear down an USB process, waiting for the
410 * currently executing command to return.
412 * NOTE: If the structure pointed to by "up" is all zero,
413 * this function does nothing.
414 *------------------------------------------------------------------------*/
416 usb_proc_drain(struct usb_process *up)
418 /* check if not initialised */
419 if (up->up_mtx == NULL)
421 /* handle special case with Giant */
422 if (up->up_mtx != &Giant)
423 mtx_assert(up->up_mtx, MA_NOTOWNED);
425 mtx_lock(up->up_mtx);
427 /* Set the gone flag */
433 /* Check if we need to wakeup the USB process */
435 if (up->up_msleep || up->up_csleep) {
438 cv_signal(&up->up_cv);
440 /* Check if we are still cold booted */
443 USB_THREAD_SUSPEND(up->up_ptr);
444 printf("WARNING: A USB process has "
445 "been left suspended!\n");
448 cv_wait(&up->up_cv, up->up_mtx);
450 /* Check if someone is waiting - should not happen */
454 cv_broadcast(&up->up_drain);
455 DPRINTF("WARNING: Someone is waiting "
456 "for USB process drain!\n");
458 mtx_unlock(up->up_mtx);
461 /*------------------------------------------------------------------------*
464 * This function is called to re-wakeup the the given USB
465 * process. This usually happens after that the USB system has been in
466 * polling mode, like during a panic. This function must be called
467 * having "up->up_mtx" locked.
468 *------------------------------------------------------------------------*/
470 usb_proc_rewakeup(struct usb_process *up)
472 /* check if not initialised */
473 if (up->up_mtx == NULL)
479 mtx_assert(up->up_mtx, MA_OWNED);
481 if (up->up_msleep == 0) {
483 cv_signal(&up->up_cv);