2 * Copyright (c) 2003 Matthew Dillon <dillon@backplane.com>
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
26 * $DragonFly: src/sys/kern/lwkt_msgport.c,v 1.4 2003/07/25 05:26:50 dillon Exp $
29 #include <sys/param.h>
30 #include <sys/systm.h>
31 #include <sys/kernel.h>
33 #include <sys/rtprio.h>
34 #include <sys/queue.h>
35 #include <sys/sysctl.h>
36 #include <sys/kthread.h>
37 #include <machine/cpu.h>
41 #include <vm/vm_param.h>
42 #include <vm/vm_kern.h>
43 #include <vm/vm_object.h>
44 #include <vm/vm_page.h>
45 #include <vm/vm_map.h>
46 #include <vm/vm_pager.h>
47 #include <vm/vm_extern.h>
48 #include <vm/vm_zone.h>
50 #include <sys/thread2.h>
51 #include <sys/msgport2.h>
53 #include <machine/stdarg.h>
54 #include <machine/ipl.h>
56 #include <machine/smp.h>
60 /************************************************************************
62 ************************************************************************/
64 static void lwkt_replyport_remote(lwkt_msg_t msg);
65 static void lwkt_putport_remote(lwkt_msg_t msg);
66 static void lwkt_abortport_remote(lwkt_port_t port);
69 lwkt_initmsg_td(lwkt_msg_t msg, thread_t td)
72 msg->ms_reply_port = &td->td_msgport;
78 * Send a message asynchronously. This function requests asynchronous
79 * completion and calls lwkt_beginmsg(). If the target port decides to
80 * run the message synchronously this function will automatically queue
81 * the message to the current thread's message queue to present a
82 * consistent interface to the caller.
84 * The message's ms_cmd must be initialized and its ms_flags must be
85 * at least zero'd out. lwkt_sendmsg() will initialize the message's
86 * reply port to the current thread's built-in reply port.
89 lwkt_sendmsg(lwkt_port_t port, lwkt_msg_t msg)
93 msg->ms_flags |= MSGF_ASYNC;
94 msg->ms_flags &= ~(MSGF_REPLY | MSGF_QUEUED);
95 msg->ms_reply_port = &curthread->td_msgport;
97 if ((error = lwkt_beginmsg(port, msg)) != EASYNC) {
98 lwkt_replymsg(msg, error);
105 * Send a message synchronously. This function requests synchronous
106 * completion and calls lwkt_beginmsg(). If the target port decides to
107 * run the message asynchronously this function will block waiting for
108 * the message to complete. Since MSGF_ASYNC is not set the target
109 * will not attempt to queue the reply to a reply port but will simply
110 * wake up anyone waiting on the message.
112 * A synchronous error code is always returned.
114 * The message's ms_cmd must be initialized and its ms_flags must be
115 * at least zero'd out. lwkt_domsg() will initialize the message's
116 * reply port to the current thread's built-in reply port.
119 lwkt_domsg(lwkt_port_t port, lwkt_msg_t msg)
123 msg->ms_flags &= ~(MSGF_ASYNC | MSGF_REPLY | MSGF_QUEUED);
124 msg->ms_reply_port = &curthread->td_msgport;
125 msg->ms_abortreq = 0;
126 if ((error = lwkt_beginmsg(port, msg)) == EASYNC) {
127 error = lwkt_waitmsg(msg);
135 * Wait for a message that we originated to complete, remove it from
136 * the reply queue if necessary, and return its error code.
138 * This call may be used in virtually any situation, including for the
139 * case where you used lwkt_sendmsg() to initiate the message.
141 * Note that we don't own the message any more so we cannot safely
142 * modify ms_flags, meaning we can't clear MSGF_ASYNC as an optimization.
143 * However, since any remote cpu replying to the message will IPI the
144 * message over to us for action, a critical section is sufficient to
148 lwkt_waitmsg(lwkt_msg_t msg)
153 * Done but not queued case (message was originally a synchronous request)
155 if ((msg->ms_flags & (MSGF_DONE|MSGF_REPLY)) == MSGF_DONE)
156 return(msg->ms_error);
158 port = msg->ms_reply_port;
159 KKASSERT(port->mp_td == curthread); /* for now */
161 if ((msg->ms_flags & MSGF_DONE) == 0) {
162 port->mp_flags |= MSGPORTF_WAITING;
164 lwkt_deschedule_self();
166 } while ((msg->ms_flags & MSGF_DONE) == 0);
167 port->mp_flags &= ~MSGPORTF_WAITING;
170 * We own the message now.
172 if (msg->ms_flags & MSGF_QUEUED) {
173 msg->ms_flags &= ~MSGF_QUEUED;
174 TAILQ_REMOVE(&port->mp_msgq, msg, ms_node);
177 return(msg->ms_error);
181 /************************************************************************
183 ************************************************************************/
188 * Initialize a port for use and assign it to the specified thread.
191 lwkt_init_port(lwkt_port_t port, thread_t td)
193 bzero(port, sizeof(*port));
194 TAILQ_INIT(&port->mp_msgq);
196 port->mp_beginmsg = lwkt_putport;
197 port->mp_abortmsg = lwkt_abortport;
198 port->mp_returnmsg = lwkt_replyport;
204 * This function is typically assigned to the mp_replymsg port vector.
206 * The message is being returned to the specified port. The port is
207 * owned by the mp_td thread. If we are on the same cpu as the mp_td
208 * thread we can trivially queue the message to the messageq, otherwise
209 * we have to send an ipi message to the correct cpu. We then schedule
212 * If MSGF_ASYNC is not set we do not bother queueing the message, we
213 * just set the DONE bit.
215 * Note that the IPIQ callback function (*_remote) is entered with a
216 * critical section already held.
221 _lwkt_replyport(lwkt_port_t port, lwkt_msg_t msg)
223 thread_t td = port->mp_td;
225 if (td->td_gd == mycpu) {
226 TAILQ_INSERT_TAIL(&port->mp_msgq, msg, ms_node);
227 msg->ms_flags |= MSGF_DONE | MSGF_REPLY | MSGF_QUEUED;
228 if (port->mp_flags & MSGPORTF_WAITING)
231 lwkt_send_ipiq(td->td_gd->gd_cpuid, (ipifunc_t)lwkt_replyport_remote, msg);
237 lwkt_replyport_remote(lwkt_msg_t msg)
239 _lwkt_replyport(msg->ms_reply_port, msg);
244 lwkt_replyport(lwkt_port_t port, lwkt_msg_t msg)
247 if (msg->ms_flags & MSGF_ASYNC) {
248 _lwkt_replyport(port, msg);
250 msg->ms_flags |= MSGF_DONE;
251 if (port->mp_flags & MSGPORTF_WAITING)
252 lwkt_schedule(port->mp_td);
260 * This function is typically assigned to the mp_beginmsg port vector.
262 * Queue a message to the target port and wakeup the thread owning it.
263 * This function always returns EASYNC and may be assigned to a
264 * message port's mp_beginmsg function vector.
269 _lwkt_putport(lwkt_port_t port, lwkt_msg_t msg)
271 thread_t td = port->mp_td;
273 if (td->td_gd == mycpu) {
274 TAILQ_INSERT_TAIL(&port->mp_msgq, msg, ms_node);
275 msg->ms_flags |= MSGF_QUEUED;
276 if (port->mp_flags & MSGPORTF_WAITING)
279 msg->ms_target_port = port;
280 lwkt_send_ipiq(td->td_gd->gd_cpuid, (ipifunc_t)lwkt_putport_remote, msg);
286 lwkt_putport_remote(lwkt_msg_t msg)
288 _lwkt_putport(msg->ms_target_port, msg);
292 lwkt_putport(lwkt_port_t port, lwkt_msg_t msg)
295 _lwkt_putport(port, msg);
303 * This function is typically assigned to the mp_abortmsg port vector.
305 * This function attempts to abort a message. Aborts are always
306 * optional, so we could just do nothing if we wanted. We get onto the
307 * cpu owning the port, check to see if the message is queued on the
308 * port's message queue, and remove and abort it if it is. Otherwise
311 * Note that we cannot safely use ms_target_port because the port might
312 * have forwarded the message on to some other port and we could race
313 * against that use of ms_target_port.
318 _lwkt_abortport(lwkt_port_t port)
320 thread_t td = port->mp_td;
323 if (td->td_gd == mycpu) {
325 msg = TAILQ_FIRST(&port->mp_msgq);
327 if (msg->ms_abortreq) {
328 TAILQ_REMOVE(&port->mp_msgq, msg, ms_node);
329 msg->ms_flags &= ~MSGF_QUEUED;
330 lwkt_replymsg(msg, ECONNABORTED); /* YYY dangerous from IPI? */
333 msg = TAILQ_NEXT(msg, ms_node);
336 lwkt_send_ipiq(td->td_gd->gd_cpuid, (ipifunc_t)lwkt_abortport_remote, port);
342 lwkt_abortport_remote(lwkt_port_t port)
344 _lwkt_abortport(port);
348 lwkt_abortport(lwkt_port_t port, lwkt_msg_t msg)
350 msg->ms_abortreq = 1;
352 _lwkt_abortport(port);
359 * Retrieve the next message from the port's message queue, return NULL
360 * if no messages are pending.
362 * The calling thread MUST own the port.
365 lwkt_getport(lwkt_port_t port)
369 KKASSERT(port->mp_td == curthread);
372 if ((msg = TAILQ_FIRST(&port->mp_msgq)) != NULL) {
373 TAILQ_REMOVE(&port->mp_msgq, msg, ms_node);
374 msg->ms_flags &= ~MSGF_QUEUED;
383 * Retrieve the next message from the port's message queue, block until
384 * a message is ready. This function never returns NULL.
387 lwkt_waitport(lwkt_port_t port)
391 KKASSERT(port->mp_td == curthread);
394 if ((msg = TAILQ_FIRST(&port->mp_msgq)) == NULL) {
395 port->mp_flags |= MSGPORTF_WAITING;
397 lwkt_deschedule_self();
399 } while ((msg = TAILQ_FIRST(&port->mp_msgq)) == NULL);
400 port->mp_flags &= ~MSGPORTF_WAITING;
402 TAILQ_REMOVE(&port->mp_msgq, msg, ms_node);
403 msg->ms_flags &= ~MSGF_QUEUED;