2 * Copyright (c) 2003,2004 The DragonFly Project. All rights reserved.
4 * This code is derived from software contributed to The DragonFly Project
5 * by Matthew Dillon <dillon@backplane.com>
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in
15 * the documentation and/or other materials provided with the
17 * 3. Neither the name of The DragonFly Project nor the names of its
18 * contributors may be used to endorse or promote products derived
19 * from this software without specific, prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * NOTE! This file may be compiled for userland libraries as well as for
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/kernel.h>
42 #include <sys/rtprio.h>
43 #include <sys/queue.h>
44 #include <sys/sysctl.h>
45 #include <sys/kthread.h>
46 #include <sys/signalvar.h>
47 #include <sys/signal2.h>
48 #include <machine/cpu.h>
52 #include <vm/vm_param.h>
53 #include <vm/vm_kern.h>
54 #include <vm/vm_object.h>
55 #include <vm/vm_page.h>
56 #include <vm/vm_map.h>
57 #include <vm/vm_pager.h>
58 #include <vm/vm_extern.h>
59 #include <vm/vm_zone.h>
61 #include <sys/thread2.h>
62 #include <sys/msgport2.h>
63 #include <sys/spinlock2.h>
64 #include <sys/serialize.h>
66 #include <machine/stdarg.h>
67 #include <machine/cpufunc.h>
68 #include <machine/smp.h>
70 #include <sys/malloc.h>
71 MALLOC_DEFINE(M_LWKTMSG, "lwkt message", "lwkt message");
73 /************************************************************************
75 ************************************************************************/
80 * Request asynchronous completion and call lwkt_beginmsg(). The
81 * target port can opt to execute the message synchronously or
82 * asynchronously and this function will automatically queue the
83 * response if the target executes the message synchronously.
85 * NOTE: The message is in an indeterminant state until this call
86 * returns. The caller should not mess with it (e.g. try to abort it)
90 lwkt_sendmsg(lwkt_port_t port, lwkt_msg_t msg)
94 KKASSERT(msg->ms_reply_port != NULL &&
95 (msg->ms_flags & (MSGF_DONE|MSGF_QUEUED)) == MSGF_DONE);
96 msg->ms_flags &= ~(MSGF_REPLY | MSGF_SYNC | MSGF_DONE);
97 if ((error = lwkt_beginmsg(port, msg)) != EASYNC) {
99 * Target port opted to execute the message synchronously so
100 * queue the response.
102 lwkt_replymsg(msg, error);
109 * Request synchronous completion and call lwkt_beginmsg(). The
110 * target port can opt to execute the message synchronously or
111 * asynchronously and this function will automatically block and
112 * wait for a response if the target executes the message
116 lwkt_domsg(lwkt_port_t port, lwkt_msg_t msg, int flags)
120 KKASSERT(msg->ms_reply_port != NULL &&
121 (msg->ms_flags & (MSGF_DONE|MSGF_QUEUED)) == MSGF_DONE);
122 msg->ms_flags &= ~(MSGF_REPLY | MSGF_DONE);
123 msg->ms_flags |= MSGF_SYNC;
124 if ((error = lwkt_beginmsg(port, msg)) == EASYNC) {
126 * Target port opted to execute the message asynchronously so
127 * block and wait for a reply.
129 error = lwkt_waitmsg(msg, flags);
131 msg->ms_flags |= MSGF_DONE | MSGF_REPLY;
139 * Forward a message received on one port to another port.
142 lwkt_forwardmsg(lwkt_port_t port, lwkt_msg_t msg)
147 KKASSERT((msg->ms_flags & (MSGF_QUEUED|MSGF_DONE|MSGF_REPLY)) == 0);
148 if ((error = port->mp_putport(port, msg)) != EASYNC)
149 lwkt_replymsg(msg, error);
157 * Attempt to abort a message. This only works if MSGF_ABORTABLE is set.
158 * The caller must ensure that the message will not be both replied AND
159 * destroyed while the abort is in progress.
161 * This function issues a callback which might block!
164 lwkt_abortmsg(lwkt_msg_t msg)
167 * A critical section protects us from reply IPIs on this cpu.
172 * Shortcut the operation if the message has already been returned.
173 * The callback typically constructs a lwkt_msg with the abort request,
174 * issues it synchronously, and waits for completion. The callback
175 * is not required to actually abort the message and the target port,
176 * upon receiving an abort request message generated by the callback
177 * should check whether the original message has already completed or
180 if (msg->ms_flags & MSGF_ABORTABLE) {
181 if ((msg->ms_flags & (MSGF_DONE|MSGF_REPLY)) == 0)
182 msg->ms_abortfn(msg);
187 /************************************************************************
188 * PORT INITIALIZATION API *
189 ************************************************************************/
191 static void *lwkt_thread_getport(lwkt_port_t port);
192 static int lwkt_thread_putport(lwkt_port_t port, lwkt_msg_t msg);
193 static int lwkt_thread_waitmsg(lwkt_msg_t msg, int flags);
194 static void *lwkt_thread_waitport(lwkt_port_t port, int flags);
195 static void lwkt_thread_replyport(lwkt_port_t port, lwkt_msg_t msg);
196 static void lwkt_thread_dropmsg(lwkt_port_t port, lwkt_msg_t msg);
198 static void *lwkt_spin_getport(lwkt_port_t port);
199 static int lwkt_spin_putport(lwkt_port_t port, lwkt_msg_t msg);
200 static int lwkt_spin_waitmsg(lwkt_msg_t msg, int flags);
201 static void *lwkt_spin_waitport(lwkt_port_t port, int flags);
202 static void lwkt_spin_replyport(lwkt_port_t port, lwkt_msg_t msg);
203 static void lwkt_spin_dropmsg(lwkt_port_t port, lwkt_msg_t msg);
205 static void *lwkt_serialize_getport(lwkt_port_t port);
206 static int lwkt_serialize_putport(lwkt_port_t port, lwkt_msg_t msg);
207 static int lwkt_serialize_waitmsg(lwkt_msg_t msg, int flags);
208 static void *lwkt_serialize_waitport(lwkt_port_t port, int flags);
209 static void lwkt_serialize_replyport(lwkt_port_t port, lwkt_msg_t msg);
211 static void lwkt_null_replyport(lwkt_port_t port, lwkt_msg_t msg);
212 static void *lwkt_panic_getport(lwkt_port_t port);
213 static int lwkt_panic_putport(lwkt_port_t port, lwkt_msg_t msg);
214 static int lwkt_panic_waitmsg(lwkt_msg_t msg, int flags);
215 static void *lwkt_panic_waitport(lwkt_port_t port, int flags);
216 static void lwkt_panic_replyport(lwkt_port_t port, lwkt_msg_t msg);
217 static void lwkt_panic_dropmsg(lwkt_port_t port, lwkt_msg_t msg);
220 * Core port initialization (internal)
224 _lwkt_initport(lwkt_port_t port,
225 void *(*gportfn)(lwkt_port_t),
226 int (*pportfn)(lwkt_port_t, lwkt_msg_t),
227 int (*wmsgfn)(lwkt_msg_t, int),
228 void *(*wportfn)(lwkt_port_t, int),
229 void (*rportfn)(lwkt_port_t, lwkt_msg_t),
230 void (*dmsgfn)(lwkt_port_t, lwkt_msg_t))
232 bzero(port, sizeof(*port));
233 TAILQ_INIT(&port->mp_msgq);
234 TAILQ_INIT(&port->mp_msgq_prio);
235 port->mp_getport = gportfn;
236 port->mp_putport = pportfn;
237 port->mp_waitmsg = wmsgfn;
238 port->mp_waitport = wportfn;
239 port->mp_replyport = rportfn;
240 port->mp_dropmsg = dmsgfn;
244 * Schedule the target thread. If the message flags contains MSGF_NORESCHED
245 * we tell the scheduler not to reschedule if td is at a higher priority.
247 * This routine is called even if the thread is already scheduled.
251 _lwkt_schedule_msg(thread_t td, int flags)
257 * lwkt_initport_thread()
259 * Initialize a port for use by a particular thread. The port may
260 * only be used by <td>.
263 lwkt_initport_thread(lwkt_port_t port, thread_t td)
269 lwkt_thread_waitport,
270 lwkt_thread_replyport,
271 lwkt_thread_dropmsg);
276 * lwkt_initport_spin()
278 * Initialize a port for use with descriptors that might be accessed
279 * via multiple LWPs, processes, or threads. Has somewhat more
280 * overhead then thread ports.
283 lwkt_initport_spin(lwkt_port_t port, thread_t td)
285 void (*dmsgfn)(lwkt_port_t, lwkt_msg_t);
288 dmsgfn = lwkt_panic_dropmsg;
290 dmsgfn = lwkt_spin_dropmsg;
299 spin_init(&port->mpu_spin);
304 * lwkt_initport_serialize()
306 * Initialize a port for use with descriptors that might be accessed
307 * via multiple LWPs, processes, or threads. Callers are assumed to
308 * have held the serializer (slz).
311 lwkt_initport_serialize(lwkt_port_t port, struct lwkt_serialize *slz)
314 lwkt_serialize_getport,
315 lwkt_serialize_putport,
316 lwkt_serialize_waitmsg,
317 lwkt_serialize_waitport,
318 lwkt_serialize_replyport,
320 port->mpu_serialize = slz;
324 * Similar to the standard initport, this function simply marks the message
325 * as being done and does not attempt to return it to an originating port.
328 lwkt_initport_replyonly_null(lwkt_port_t port)
340 * Initialize a reply-only port, typically used as a message sink. Such
341 * ports can only be used as a reply port.
344 lwkt_initport_replyonly(lwkt_port_t port,
345 void (*rportfn)(lwkt_port_t, lwkt_msg_t))
347 _lwkt_initport(port, lwkt_panic_getport, lwkt_panic_putport,
348 lwkt_panic_waitmsg, lwkt_panic_waitport,
349 rportfn, lwkt_panic_dropmsg);
353 lwkt_initport_putonly(lwkt_port_t port,
354 int (*pportfn)(lwkt_port_t, lwkt_msg_t))
356 _lwkt_initport(port, lwkt_panic_getport, pportfn,
357 lwkt_panic_waitmsg, lwkt_panic_waitport,
358 lwkt_panic_replyport, lwkt_panic_dropmsg);
362 lwkt_initport_panic(lwkt_port_t port)
365 lwkt_panic_getport, lwkt_panic_putport,
366 lwkt_panic_waitmsg, lwkt_panic_waitport,
367 lwkt_panic_replyport, lwkt_panic_dropmsg);
372 _lwkt_pullmsg(lwkt_port_t port, lwkt_msg_t msg)
374 lwkt_msg_queue *queue;
377 * normal case, remove and return the message.
379 if (__predict_false(msg->ms_flags & MSGF_PRIORITY))
380 queue = &port->mp_msgq_prio;
382 queue = &port->mp_msgq;
383 TAILQ_REMOVE(queue, msg, ms_node);
386 * atomic op needed for spin ports
388 atomic_clear_int(&msg->ms_flags, MSGF_QUEUED);
393 _lwkt_pushmsg(lwkt_port_t port, lwkt_msg_t msg)
395 lwkt_msg_queue *queue;
398 * atomic op needed for spin ports
400 atomic_set_int(&msg->ms_flags, MSGF_QUEUED);
401 if (__predict_false(msg->ms_flags & MSGF_PRIORITY))
402 queue = &port->mp_msgq_prio;
404 queue = &port->mp_msgq;
405 TAILQ_INSERT_TAIL(queue, msg, ms_node);
410 _lwkt_pollmsg(lwkt_port_t port)
414 msg = TAILQ_FIRST(&port->mp_msgq_prio);
415 if (__predict_false(msg != NULL))
419 * Priority queue has no message, fallback to non-priority queue.
421 return TAILQ_FIRST(&port->mp_msgq);
426 _lwkt_enqueue_reply(lwkt_port_t port, lwkt_msg_t msg)
429 * atomic op needed for spin ports
431 _lwkt_pushmsg(port, msg);
432 atomic_set_int(&msg->ms_flags, MSGF_REPLY | MSGF_DONE);
435 /************************************************************************
436 * THREAD PORT BACKEND *
437 ************************************************************************
439 * This backend is used when the port a message is retrieved from is owned
440 * by a single thread (the calling thread). Messages are IPId to the
441 * correct cpu before being enqueued to a port. Note that this is fairly
442 * optimal since scheduling would have had to do an IPI anyway if the
443 * message were headed to a different cpu.
447 * This function completes reply processing for the default case in the
448 * context of the originating cpu.
452 lwkt_thread_replyport_remote(lwkt_msg_t msg)
454 lwkt_port_t port = msg->ms_reply_port;
458 * Chase any thread migration that occurs
460 if (port->mpu_td->td_gd != mycpu) {
461 lwkt_send_ipiq(port->mpu_td->td_gd,
462 (ipifunc1_t)lwkt_thread_replyport_remote, msg);
470 KKASSERT(msg->ms_flags & MSGF_INTRANSIT);
471 msg->ms_flags &= ~MSGF_INTRANSIT;
473 flags = msg->ms_flags;
474 if (msg->ms_flags & MSGF_SYNC) {
476 msg->ms_flags |= MSGF_REPLY | MSGF_DONE;
478 _lwkt_enqueue_reply(port, msg);
480 if (port->mp_flags & MSGPORTF_WAITING)
481 _lwkt_schedule_msg(port->mpu_td, flags);
485 * lwkt_thread_replyport() - Backend to lwkt_replymsg()
487 * Called with the reply port as an argument but in the context of the
488 * original target port. Completion must occur on the target port's
491 * The critical section protects us from IPIs on the this CPU.
495 lwkt_thread_replyport(lwkt_port_t port, lwkt_msg_t msg)
499 KKASSERT((msg->ms_flags & (MSGF_DONE|MSGF_QUEUED|MSGF_INTRANSIT)) == 0);
501 if (msg->ms_flags & MSGF_SYNC) {
503 * If a synchronous completion has been requested, just wakeup
504 * the message without bothering to queue it to the target port.
506 * Assume the target thread is non-preemptive, so no critical
507 * section is required.
509 if (port->mpu_td->td_gd == mycpu) {
510 flags = msg->ms_flags;
512 msg->ms_flags |= MSGF_DONE | MSGF_REPLY;
513 if (port->mp_flags & MSGPORTF_WAITING)
514 _lwkt_schedule_msg(port->mpu_td, flags);
517 msg->ms_flags |= MSGF_INTRANSIT;
519 msg->ms_flags |= MSGF_REPLY;
520 lwkt_send_ipiq(port->mpu_td->td_gd,
521 (ipifunc1_t)lwkt_thread_replyport_remote, msg);
525 * If an asynchronous completion has been requested the message
526 * must be queued to the reply port.
528 * A critical section is required to interlock the port queue.
530 if (port->mpu_td->td_gd == mycpu) {
532 _lwkt_enqueue_reply(port, msg);
533 if (port->mp_flags & MSGPORTF_WAITING)
534 _lwkt_schedule_msg(port->mpu_td, msg->ms_flags);
538 msg->ms_flags |= MSGF_INTRANSIT;
540 msg->ms_flags |= MSGF_REPLY;
541 lwkt_send_ipiq(port->mpu_td->td_gd,
542 (ipifunc1_t)lwkt_thread_replyport_remote, msg);
548 * lwkt_thread_dropmsg() - Backend to lwkt_dropmsg()
550 * This function could _only_ be used when caller is in the same thread
551 * as the message's target port owner thread.
554 lwkt_thread_dropmsg(lwkt_port_t port, lwkt_msg_t msg)
556 KASSERT(port->mpu_td == curthread,
557 ("message could only be dropped in the same thread "
558 "as the message target port thread"));
559 crit_enter_quick(port->mpu_td);
560 _lwkt_pullmsg(port, msg);
561 msg->ms_flags |= MSGF_DONE;
562 crit_exit_quick(port->mpu_td);
566 * lwkt_thread_putport() - Backend to lwkt_beginmsg()
568 * Called with the target port as an argument but in the context of the
569 * reply port. This function always implements an asynchronous put to
570 * the target message port, and thus returns EASYNC.
572 * The message must already have cleared MSGF_DONE and MSGF_REPLY
576 lwkt_thread_putport_remote(lwkt_msg_t msg)
578 lwkt_port_t port = msg->ms_target_port;
581 * Chase any thread migration that occurs
583 if (port->mpu_td->td_gd != mycpu) {
584 lwkt_send_ipiq(port->mpu_td->td_gd,
585 (ipifunc1_t)lwkt_thread_putport_remote, msg);
593 KKASSERT(msg->ms_flags & MSGF_INTRANSIT);
594 msg->ms_flags &= ~MSGF_INTRANSIT;
596 _lwkt_pushmsg(port, msg);
597 if (port->mp_flags & MSGPORTF_WAITING)
598 _lwkt_schedule_msg(port->mpu_td, msg->ms_flags);
603 lwkt_thread_putport(lwkt_port_t port, lwkt_msg_t msg)
605 KKASSERT((msg->ms_flags & (MSGF_DONE | MSGF_REPLY)) == 0);
607 msg->ms_target_port = port;
608 if (port->mpu_td->td_gd == mycpu) {
610 _lwkt_pushmsg(port, msg);
611 if (port->mp_flags & MSGPORTF_WAITING)
612 _lwkt_schedule_msg(port->mpu_td, msg->ms_flags);
616 msg->ms_flags |= MSGF_INTRANSIT;
618 lwkt_send_ipiq(port->mpu_td->td_gd,
619 (ipifunc1_t)lwkt_thread_putport_remote, msg);
625 * lwkt_thread_getport()
627 * Retrieve the next message from the port or NULL if no messages
632 lwkt_thread_getport(lwkt_port_t port)
636 KKASSERT(port->mpu_td == curthread);
638 crit_enter_quick(port->mpu_td);
639 if ((msg = _lwkt_pollmsg(port)) != NULL)
640 _lwkt_pullmsg(port, msg);
641 crit_exit_quick(port->mpu_td);
646 * lwkt_thread_waitmsg()
648 * Wait for a particular message to be replied. We must be the only
649 * thread waiting on the message. The port must be owned by the
654 lwkt_thread_waitmsg(lwkt_msg_t msg, int flags)
656 KASSERT((msg->ms_flags & MSGF_DROPABLE) == 0,
657 ("can't wait dropable message"));
659 if ((msg->ms_flags & MSGF_DONE) == 0) {
661 * If the done bit was not set we have to block until it is.
663 lwkt_port_t port = msg->ms_reply_port;
664 thread_t td = curthread;
667 KKASSERT(port->mpu_td == td);
668 crit_enter_quick(td);
671 while ((msg->ms_flags & MSGF_DONE) == 0) {
672 port->mp_flags |= MSGPORTF_WAITING;
673 if (sentabort == 0) {
674 if ((sentabort = lwkt_sleep("waitmsg", flags)) != 0) {
678 lwkt_sleep("waitabt", 0);
680 port->mp_flags &= ~MSGPORTF_WAITING;
682 if (msg->ms_flags & MSGF_QUEUED)
683 _lwkt_pullmsg(port, msg);
687 * If the done bit was set we only have to mess around with the
688 * message if it is queued on the reply port.
690 if (msg->ms_flags & MSGF_QUEUED) {
691 lwkt_port_t port = msg->ms_reply_port;
692 thread_t td = curthread;
694 KKASSERT(port->mpu_td == td);
695 crit_enter_quick(td);
696 _lwkt_pullmsg(port, msg);
700 return(msg->ms_error);
704 * lwkt_thread_waitport()
706 * Wait for a new message to be available on the port. We must be the
707 * the only thread waiting on the port. The port must be owned by caller.
711 lwkt_thread_waitport(lwkt_port_t port, int flags)
713 thread_t td = curthread;
717 KKASSERT(port->mpu_td == td);
718 crit_enter_quick(td);
719 while ((msg = _lwkt_pollmsg(port)) == NULL) {
720 port->mp_flags |= MSGPORTF_WAITING;
721 error = lwkt_sleep("waitport", flags);
722 port->mp_flags &= ~MSGPORTF_WAITING;
726 _lwkt_pullmsg(port, msg);
732 /************************************************************************
733 * SPIN PORT BACKEND *
734 ************************************************************************
736 * This backend uses spinlocks instead of making assumptions about which
737 * thread is accessing the port. It must be used when a port is not owned
738 * by a particular thread. This is less optimal then thread ports but
739 * you don't have a choice if there are multiple threads accessing the port.
741 * Note on MSGPORTF_WAITING - because there may be multiple threads blocked
742 * on the message port, it is the responsibility of the code doing the
743 * wakeup to clear this flag rather then the blocked threads. Some
744 * superfluous wakeups may occur, which is ok.
746 * XXX synchronous message wakeups are not current optimized.
751 lwkt_spin_getport(lwkt_port_t port)
755 spin_lock(&port->mpu_spin);
756 if ((msg = _lwkt_pollmsg(port)) != NULL)
757 _lwkt_pullmsg(port, msg);
758 spin_unlock(&port->mpu_spin);
764 lwkt_spin_putport(lwkt_port_t port, lwkt_msg_t msg)
768 KKASSERT((msg->ms_flags & (MSGF_DONE | MSGF_REPLY)) == 0);
770 msg->ms_target_port = port;
771 spin_lock(&port->mpu_spin);
772 _lwkt_pushmsg(port, msg);
774 if (port->mp_flags & MSGPORTF_WAITING) {
775 port->mp_flags &= ~MSGPORTF_WAITING;
778 spin_unlock(&port->mpu_spin);
786 lwkt_spin_waitmsg(lwkt_msg_t msg, int flags)
792 KASSERT((msg->ms_flags & MSGF_DROPABLE) == 0,
793 ("can't wait dropable message"));
795 if ((msg->ms_flags & MSGF_DONE) == 0) {
796 port = msg->ms_reply_port;
798 spin_lock(&port->mpu_spin);
799 while ((msg->ms_flags & MSGF_DONE) == 0) {
803 * If message was sent synchronously from the beginning
804 * the wakeup will be on the message structure, else it
805 * will be on the port structure.
807 if (msg->ms_flags & MSGF_SYNC) {
809 atomic_set_int(&msg->ms_flags, MSGF_WAITING);
812 port->mp_flags |= MSGPORTF_WAITING;
816 * Only messages which support abort can be interrupted.
817 * We must still wait for message completion regardless.
819 if ((flags & PCATCH) && sentabort == 0) {
820 error = ssleep(won, &port->mpu_spin, PCATCH, "waitmsg", 0);
823 spin_unlock(&port->mpu_spin);
825 spin_lock(&port->mpu_spin);
828 error = ssleep(won, &port->mpu_spin, 0, "waitmsg", 0);
830 /* see note at the top on the MSGPORTF_WAITING flag */
833 * Turn EINTR into ERESTART if the signal indicates.
835 if (sentabort && msg->ms_error == EINTR)
836 msg->ms_error = sentabort;
837 if (msg->ms_flags & MSGF_QUEUED)
838 _lwkt_pullmsg(port, msg);
839 spin_unlock(&port->mpu_spin);
841 if (msg->ms_flags & MSGF_QUEUED) {
842 port = msg->ms_reply_port;
843 spin_lock(&port->mpu_spin);
844 _lwkt_pullmsg(port, msg);
845 spin_unlock(&port->mpu_spin);
848 return(msg->ms_error);
853 lwkt_spin_waitport(lwkt_port_t port, int flags)
858 spin_lock(&port->mpu_spin);
859 while ((msg = _lwkt_pollmsg(port)) == NULL) {
860 port->mp_flags |= MSGPORTF_WAITING;
861 error = ssleep(port, &port->mpu_spin, flags, "waitport", 0);
862 /* see note at the top on the MSGPORTF_WAITING flag */
864 spin_unlock(&port->mpu_spin);
868 _lwkt_pullmsg(port, msg);
869 spin_unlock(&port->mpu_spin);
875 lwkt_spin_replyport(lwkt_port_t port, lwkt_msg_t msg)
879 KKASSERT((msg->ms_flags & (MSGF_DONE|MSGF_QUEUED)) == 0);
881 if (msg->ms_flags & MSGF_SYNC) {
883 * If a synchronous completion has been requested, just wakeup
884 * the message without bothering to queue it to the target port.
886 spin_lock(&port->mpu_spin);
887 msg->ms_flags |= MSGF_DONE | MSGF_REPLY;
889 if (msg->ms_flags & MSGF_WAITING) {
890 atomic_clear_int(&msg->ms_flags, MSGF_WAITING);
893 spin_unlock(&port->mpu_spin);
898 * If an asynchronous completion has been requested the message
899 * must be queued to the reply port.
901 spin_lock(&port->mpu_spin);
902 _lwkt_enqueue_reply(port, msg);
904 if (port->mp_flags & MSGPORTF_WAITING) {
905 port->mp_flags &= ~MSGPORTF_WAITING;
908 spin_unlock(&port->mpu_spin);
915 * lwkt_spin_dropmsg() - Backend to lwkt_dropmsg()
917 * This function could _only_ be used when caller is in the same thread
918 * as the message's target port owner thread.
921 lwkt_spin_dropmsg(lwkt_port_t port, lwkt_msg_t msg)
923 KASSERT(port->mpu_td == curthread,
924 ("message could only be dropped in the same thread "
925 "as the message target port thread\n"));
926 spin_lock(&port->mpu_spin);
927 _lwkt_pullmsg(port, msg);
928 msg->ms_flags |= MSGF_DONE;
929 spin_unlock(&port->mpu_spin);
932 /************************************************************************
933 * SERIALIZER PORT BACKEND *
934 ************************************************************************
936 * This backend uses serializer to protect port accessing. Callers are
937 * assumed to have serializer held. This kind of port is usually created
938 * by network device driver along with _one_ lwkt thread to pipeline
939 * operations which may temporarily release serializer.
941 * Implementation is based on SPIN PORT BACKEND.
946 lwkt_serialize_getport(lwkt_port_t port)
950 ASSERT_SERIALIZED(port->mpu_serialize);
952 if ((msg = _lwkt_pollmsg(port)) != NULL)
953 _lwkt_pullmsg(port, msg);
959 lwkt_serialize_putport(lwkt_port_t port, lwkt_msg_t msg)
961 KKASSERT((msg->ms_flags & (MSGF_DONE | MSGF_REPLY)) == 0);
962 ASSERT_SERIALIZED(port->mpu_serialize);
964 msg->ms_target_port = port;
965 _lwkt_pushmsg(port, msg);
966 if (port->mp_flags & MSGPORTF_WAITING) {
967 port->mp_flags &= ~MSGPORTF_WAITING;
975 lwkt_serialize_waitmsg(lwkt_msg_t msg, int flags)
981 KASSERT((msg->ms_flags & MSGF_DROPABLE) == 0,
982 ("can't wait dropable message"));
984 if ((msg->ms_flags & MSGF_DONE) == 0) {
985 port = msg->ms_reply_port;
987 ASSERT_SERIALIZED(port->mpu_serialize);
990 while ((msg->ms_flags & MSGF_DONE) == 0) {
994 * If message was sent synchronously from the beginning
995 * the wakeup will be on the message structure, else it
996 * will be on the port structure.
998 if (msg->ms_flags & MSGF_SYNC) {
1002 port->mp_flags |= MSGPORTF_WAITING;
1006 * Only messages which support abort can be interrupted.
1007 * We must still wait for message completion regardless.
1009 if ((flags & PCATCH) && sentabort == 0) {
1010 error = zsleep(won, port->mpu_serialize, PCATCH, "waitmsg", 0);
1013 lwkt_serialize_exit(port->mpu_serialize);
1015 lwkt_serialize_enter(port->mpu_serialize);
1018 error = zsleep(won, port->mpu_serialize, 0, "waitmsg", 0);
1020 /* see note at the top on the MSGPORTF_WAITING flag */
1023 * Turn EINTR into ERESTART if the signal indicates.
1025 if (sentabort && msg->ms_error == EINTR)
1026 msg->ms_error = sentabort;
1027 if (msg->ms_flags & MSGF_QUEUED)
1028 _lwkt_pullmsg(port, msg);
1030 if (msg->ms_flags & MSGF_QUEUED) {
1031 port = msg->ms_reply_port;
1033 ASSERT_SERIALIZED(port->mpu_serialize);
1034 _lwkt_pullmsg(port, msg);
1037 return(msg->ms_error);
1042 lwkt_serialize_waitport(lwkt_port_t port, int flags)
1047 ASSERT_SERIALIZED(port->mpu_serialize);
1049 while ((msg = _lwkt_pollmsg(port)) == NULL) {
1050 port->mp_flags |= MSGPORTF_WAITING;
1051 error = zsleep(port, port->mpu_serialize, flags, "waitport", 0);
1052 /* see note at the top on the MSGPORTF_WAITING flag */
1056 _lwkt_pullmsg(port, msg);
1062 lwkt_serialize_replyport(lwkt_port_t port, lwkt_msg_t msg)
1064 KKASSERT((msg->ms_flags & (MSGF_DONE|MSGF_QUEUED)) == 0);
1065 ASSERT_SERIALIZED(port->mpu_serialize);
1067 if (msg->ms_flags & MSGF_SYNC) {
1069 * If a synchronous completion has been requested, just wakeup
1070 * the message without bothering to queue it to the target port.
1072 msg->ms_flags |= MSGF_DONE | MSGF_REPLY;
1076 * If an asynchronous completion has been requested the message
1077 * must be queued to the reply port.
1079 _lwkt_enqueue_reply(port, msg);
1080 if (port->mp_flags & MSGPORTF_WAITING) {
1081 port->mp_flags &= ~MSGPORTF_WAITING;
1087 /************************************************************************
1088 * PANIC AND SPECIAL PORT FUNCTIONS *
1089 ************************************************************************/
1092 * You can point a port's reply vector at this function if you just want
1093 * the message marked done, without any queueing or signaling. This is
1094 * often used for structure-embedded messages.
1098 lwkt_null_replyport(lwkt_port_t port, lwkt_msg_t msg)
1100 msg->ms_flags |= MSGF_DONE | MSGF_REPLY;
1105 lwkt_panic_getport(lwkt_port_t port)
1107 panic("lwkt_getport() illegal on port %p", port);
1112 lwkt_panic_putport(lwkt_port_t port, lwkt_msg_t msg)
1114 panic("lwkt_begin/do/sendmsg() illegal on port %p msg %p", port, msg);
1119 lwkt_panic_waitmsg(lwkt_msg_t msg, int flags)
1121 panic("port %p msg %p cannot be waited on", msg->ms_reply_port, msg);
1126 lwkt_panic_waitport(lwkt_port_t port, int flags)
1128 panic("port %p cannot be waited on", port);
1133 lwkt_panic_replyport(lwkt_port_t port, lwkt_msg_t msg)
1135 panic("lwkt_replymsg() is illegal on port %p msg %p", port, msg);
1140 lwkt_panic_dropmsg(lwkt_port_t port, lwkt_msg_t msg)
1142 panic("lwkt_dropmsg() is illegal on port %p msg %p", port, msg);