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 #if (__FreeBSD_version >= 900000)
71 #define USB_THREAD_SUSPEND_CHECK() kthread_suspend_check()
73 #define USB_THREAD_SUSPEND_CHECK() kthread_suspend_check(curthread)
75 #define USB_THREAD_SUSPEND(p) kthread_suspend(p,0)
76 #define USB_THREAD_EXIT(err) kthread_exit()
78 #define USB_THREAD_CREATE(f, s, p, ...) \
79 kthread_create((f), (s), (p), RFHIGHPID, 0, __VA_ARGS__)
80 #define USB_THREAD_SUSPEND_CHECK() kthread_suspend_check(curproc)
81 #define USB_THREAD_SUSPEND(p) kthread_suspend(p,0)
82 #define USB_THREAD_EXIT(err) kthread_exit(err)
86 static int usb_proc_debug;
88 static SYSCTL_NODE(_hw_usb, OID_AUTO, proc, CTLFLAG_RW, 0, "USB process");
89 SYSCTL_INT(_hw_usb_proc, OID_AUTO, debug, CTLFLAG_RW, &usb_proc_debug, 0,
92 TUNABLE_INT("hw.usb.proc.debug", &usb_proc_debug);
95 /*------------------------------------------------------------------------*
98 * This function is the USB process dispatcher.
99 *------------------------------------------------------------------------*/
101 usb_process(void *arg)
103 struct usb_process *up = arg;
104 struct usb_proc_msg *pm;
107 /* in case of attach error, check for suspended */
108 USB_THREAD_SUSPEND_CHECK();
110 /* adjust priority */
113 sched_prio(td, up->up_prio);
116 mtx_lock(up->up_mtx);
126 * NOTE to reimplementors: dequeueing a command from the
127 * "used" queue and executing it must be atomic, with regard
128 * to the "up_mtx" mutex. That means any attempt to queue a
129 * command by another thread must be blocked until either:
131 * 1) the command sleeps
133 * 2) the command returns
135 * Here is a practical example that shows how this helps
138 * Assume that you want to set the baud rate on a USB serial
139 * device. During the programming of the device you don't
140 * want to receive nor transmit any data, because it will be
141 * garbage most likely anyway. The programming of our USB
142 * device takes 20 milliseconds and it needs to call
143 * functions that sleep.
145 * Non-working solution: Before we queue the programming
146 * command, we stop transmission and reception of data. Then
147 * we queue a programming command. At the end of the
148 * programming command we enable transmission and reception
151 * Problem: If a second programming command is queued while the
152 * first one is sleeping, we end up enabling transmission
153 * and reception of data too early.
155 * Working solution: Before we queue the programming command,
156 * we stop transmission and reception of data. Then we queue
157 * a programming command. Then we queue a second command
158 * that only enables transmission and reception of data.
160 * Why it works: If a second programming command is queued
161 * while the first one is sleeping, then the queueing of a
162 * second command to enable the data transfers, will cause
163 * the previous one, which is still on the queue, to be
164 * removed from the queue, and re-inserted after the last
165 * baud rate programming command, which then gives the
168 pm = TAILQ_FIRST(&up->up_qhead);
171 DPRINTF("Message pm=%p, cb=%p (enter)\n",
172 pm, pm->pm_callback);
174 (pm->pm_callback) (pm);
176 if (pm == TAILQ_FIRST(&up->up_qhead)) {
177 /* nothing changed */
178 TAILQ_REMOVE(&up->up_qhead, pm, pm_qentry);
179 pm->pm_qentry.tqe_prev = NULL;
181 DPRINTF("Message pm=%p (leave)\n", pm);
185 /* end if messages - check if anyone is waiting for sync */
188 cv_broadcast(&up->up_drain);
191 cv_wait(&up->up_cv, up->up_mtx);
195 cv_signal(&up->up_cv);
196 mtx_unlock(up->up_mtx);
197 #if (__FreeBSD_version >= 800000)
198 /* Clear the proc pointer if this is the last thread. */
199 if (--usb_pcount == 0)
206 /*------------------------------------------------------------------------*
209 * This function will create a process using the given "prio" that can
210 * execute callbacks. The mutex pointed to by "p_mtx" will be applied
211 * before calling the callbacks and released after that the callback
212 * has returned. The structure pointed to by "up" is assumed to be
213 * zeroed before this function is called.
218 *------------------------------------------------------------------------*/
220 usb_proc_create(struct usb_process *up, struct mtx *p_mtx,
221 const char *pmesg, uint8_t prio)
226 TAILQ_INIT(&up->up_qhead);
228 cv_init(&up->up_cv, "-");
229 cv_init(&up->up_drain, "usbdrain");
231 if (USB_THREAD_CREATE(&usb_process, up,
232 &up->up_ptr, "%s", pmesg)) {
233 DPRINTFN(0, "Unable to create USB process.");
237 #if (__FreeBSD_version >= 800000)
247 /*------------------------------------------------------------------------*
250 * NOTE: If the structure pointed to by "up" is all zero, this
251 * function does nothing.
253 * NOTE: Messages that are pending on the process queue will not be
254 * removed nor called.
255 *------------------------------------------------------------------------*/
257 usb_proc_free(struct usb_process *up)
259 /* check if not initialised */
260 if (up->up_mtx == NULL)
265 cv_destroy(&up->up_cv);
266 cv_destroy(&up->up_drain);
268 /* make sure that we do not enter here again */
272 /*------------------------------------------------------------------------*
275 * This function will queue one of the passed USB process messages on
276 * the USB process queue. The first message that is not already queued
277 * will get queued. If both messages are already queued the one queued
278 * last will be removed from the queue and queued in the end. The USB
279 * process mutex must be locked when calling this function. This
280 * function exploits the fact that a process can only do one callback
281 * at a time. The message that was queued is returned.
282 *------------------------------------------------------------------------*/
284 usb_proc_msignal(struct usb_process *up, void *_pm0, void *_pm1)
286 struct usb_proc_msg *pm0 = _pm0;
287 struct usb_proc_msg *pm1 = _pm1;
288 struct usb_proc_msg *pm2;
292 /* check if gone, return dummy value */
296 mtx_assert(up->up_mtx, MA_OWNED);
300 if (pm0->pm_qentry.tqe_prev) {
303 if (pm1->pm_qentry.tqe_prev) {
308 * No entries are queued. Queue "pm0" and use the existing
313 /* Check if we need to increment the message number. */
314 if (pm0->pm_num == up->up_msg_num) {
319 /* Check if we need to increment the message number. */
320 if (pm1->pm_num == up->up_msg_num) {
326 * Both entries are queued. Re-queue the entry closest to
329 d = (pm1->pm_num - pm0->pm_num);
331 /* Check sign after subtraction */
332 if (d & 0x80000000) {
338 TAILQ_REMOVE(&up->up_qhead, pm2, pm_qentry);
340 pm2 = NULL; /* panic - should not happen */
343 DPRINTF(" t=%u, num=%u\n", t, up->up_msg_num);
345 /* Put message last on queue */
347 pm2->pm_num = up->up_msg_num;
348 TAILQ_INSERT_TAIL(&up->up_qhead, pm2, pm_qentry);
350 /* Check if we need to wakeup the USB process. */
353 up->up_msleep = 0; /* save "cv_signal()" calls */
354 cv_signal(&up->up_cv);
359 /*------------------------------------------------------------------------*
363 * 0: USB process is running
364 * Else: USB process is tearing down
365 *------------------------------------------------------------------------*/
367 usb_proc_is_gone(struct usb_process *up)
373 * Allow calls when up_mtx is NULL, before the USB process
374 * structure is initialised.
376 if (up->up_mtx != NULL)
377 mtx_assert(up->up_mtx, MA_OWNED);
381 /*------------------------------------------------------------------------*
384 * This function will return when the USB process message pointed to
385 * by "pm" is no longer on a queue. This function must be called
386 * having "up->up_mtx" locked.
387 *------------------------------------------------------------------------*/
389 usb_proc_mwait(struct usb_process *up, void *_pm0, void *_pm1)
391 struct usb_proc_msg *pm0 = _pm0;
392 struct usb_proc_msg *pm1 = _pm1;
398 mtx_assert(up->up_mtx, MA_OWNED);
400 if (up->up_curtd == curthread) {
401 /* Just remove the messages from the queue. */
402 if (pm0->pm_qentry.tqe_prev) {
403 TAILQ_REMOVE(&up->up_qhead, pm0, pm_qentry);
404 pm0->pm_qentry.tqe_prev = NULL;
406 if (pm1->pm_qentry.tqe_prev) {
407 TAILQ_REMOVE(&up->up_qhead, pm1, pm_qentry);
408 pm1->pm_qentry.tqe_prev = NULL;
411 while (pm0->pm_qentry.tqe_prev ||
412 pm1->pm_qentry.tqe_prev) {
413 /* check if config thread is gone */
417 cv_wait(&up->up_drain, up->up_mtx);
421 /*------------------------------------------------------------------------*
424 * This function will tear down an USB process, waiting for the
425 * currently executing command to return.
427 * NOTE: If the structure pointed to by "up" is all zero,
428 * this function does nothing.
429 *------------------------------------------------------------------------*/
431 usb_proc_drain(struct usb_process *up)
433 /* check if not initialised */
434 if (up->up_mtx == NULL)
436 /* handle special case with Giant */
437 if (up->up_mtx != &Giant)
438 mtx_assert(up->up_mtx, MA_NOTOWNED);
440 mtx_lock(up->up_mtx);
442 /* Set the gone flag */
448 /* Check if we need to wakeup the USB process */
450 if (up->up_msleep || up->up_csleep) {
453 cv_signal(&up->up_cv);
455 /* Check if we are still cold booted */
458 USB_THREAD_SUSPEND(up->up_ptr);
459 printf("WARNING: A USB process has "
460 "been left suspended\n");
463 cv_wait(&up->up_cv, up->up_mtx);
465 /* Check if someone is waiting - should not happen */
469 cv_broadcast(&up->up_drain);
470 DPRINTF("WARNING: Someone is waiting "
471 "for USB process drain!\n");
473 mtx_unlock(up->up_mtx);
476 /*------------------------------------------------------------------------*
479 * This function is called to re-wakeup the given USB
480 * process. This usually happens after that the USB system has been in
481 * polling mode, like during a panic. This function must be called
482 * having "up->up_mtx" locked.
483 *------------------------------------------------------------------------*/
485 usb_proc_rewakeup(struct usb_process *up)
487 /* check if not initialised */
488 if (up->up_mtx == NULL)
494 mtx_assert(up->up_mtx, MA_OWNED);
496 if (up->up_msleep == 0) {
498 cv_signal(&up->up_cv);