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 1.2 2003/07/22 17:03:33 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);
71 * Send a message asynchronously. This function requests asynchronous
72 * completion and calls lwkt_beginmsg(). If the target port decides to
73 * run the message synchronously this function will automatically queue
74 * the message to the current thread's message queue to present a
75 * consistent interface to the caller.
77 * The message's ms_cmd must be initialized and its ms_flags must be
78 * at least zero'd out. lwkt_sendmsg() will initialize the message's
79 * reply port to the current thread's built-in reply port.
82 lwkt_sendmsg(lwkt_port_t port, lwkt_msg_t msg)
86 msg->ms_flags |= MSGF_ASYNC;
87 msg->ms_flags &= ~(MSGF_REPLY | MSGF_QUEUED);
88 msg->ms_reply_port = &curthread->td_msgport;
90 if ((error = lwkt_beginmsg(port, msg)) != EINPROGRESS) {
91 lwkt_replymsg(msg, error);
98 * Send a message synchronously. This function requests synchronous
99 * completion and calls lwkt_beginmsg(). If the target port decides to
100 * run the message asynchronously this function will block waiting for
101 * the message to complete. Since MSGF_ASYNC is not set the target
102 * will not attempt to queue the reply to a reply port but will simply
103 * wake up anyone waiting on the message.
105 * A synchronous error code is always returned.
107 * The message's ms_cmd must be initialized and its ms_flags must be
108 * at least zero'd out. lwkt_domsg() will initialize the message's
109 * reply port to the current thread's built-in reply port.
112 lwkt_domsg(lwkt_port_t port, lwkt_msg_t msg)
116 msg->ms_flags &= ~(MSGF_ASYNC | MSGF_REPLY | MSGF_QUEUED);
117 msg->ms_reply_port = &curthread->td_msgport;
118 msg->ms_abortreq = 0;
119 if ((error = lwkt_beginmsg(port, msg)) == EINPROGRESS) {
120 error = lwkt_waitmsg(msg);
128 * Wait for a message that we originated to complete, remove it from
129 * the reply queue if necessary, and return its error code.
131 * This call may be used in virtually any situation, including for the
132 * case where you used lwkt_sendmsg() to initiate the message.
134 * Note that we don't own the message any more so we cannot safely
135 * modify ms_flags, meaning we can't clear MSGF_ASYNC as an optimization.
136 * However, since any remote cpu replying to the message will IPI the
137 * message over to us for action, a critical section is sufficient to
141 lwkt_waitmsg(lwkt_msg_t msg)
146 * Done but not queued case (message was originally a synchronous request)
148 if ((msg->ms_flags & (MSGF_DONE|MSGF_REPLY)) == MSGF_DONE)
149 return(msg->ms_error);
151 port = msg->ms_reply_port;
152 KKASSERT(port->mp_td == curthread); /* for now */
154 if ((msg->ms_flags & MSGF_DONE) == 0) {
155 port->mp_flags |= MSGPORTF_WAITING;
157 lwkt_deschedule_self();
159 } while ((msg->ms_flags & MSGF_DONE) == 0);
160 port->mp_flags &= ~MSGPORTF_WAITING;
163 * We own the message now.
165 if (msg->ms_flags & MSGF_QUEUED) {
166 msg->ms_flags &= ~MSGF_QUEUED;
167 TAILQ_REMOVE(&port->mp_msgq, msg, ms_node);
170 return(msg->ms_error);
174 /************************************************************************
176 ************************************************************************/
181 * Initialize a port for use and assign it to the specified thread.
184 lwkt_init_port(lwkt_port_t port, thread_t td)
186 bzero(port, sizeof(*port));
187 TAILQ_INIT(&port->mp_msgq);
189 port->mp_beginmsg = lwkt_putport;
190 port->mp_abortmsg = lwkt_abortport;
191 port->mp_returnmsg = lwkt_replyport;
197 * This function is typically assigned to the mp_replymsg port vector.
199 * The message is being returned to the specified port. The port is
200 * owned by the mp_td thread. If we are on the same cpu as the mp_td
201 * thread we can trivially queue the message to the messageq, otherwise
202 * we have to send an ipi message to the correct cpu. We then schedule
205 * If MSGF_ASYNC is not set we do not bother queueing the message, we
206 * just set the DONE bit.
208 * Note that the IPIQ callback function (*_remote) is entered with a
209 * critical section already held.
214 _lwkt_replyport(lwkt_port_t port, lwkt_msg_t msg)
216 thread_t td = port->mp_td;
218 if (td->td_cpu == mycpu->gd_cpuid) {
219 TAILQ_INSERT_TAIL(&port->mp_msgq, msg, ms_node);
220 msg->ms_flags |= MSGF_DONE | MSGF_REPLY | MSGF_QUEUED;
221 if (port->mp_flags & MSGPORTF_WAITING)
224 lwkt_send_ipiq(td->td_cpu, (ipifunc_t)lwkt_replyport_remote, msg);
230 lwkt_replyport_remote(lwkt_msg_t msg)
232 _lwkt_replyport(msg->ms_reply_port, msg);
237 lwkt_replyport(lwkt_port_t port, lwkt_msg_t msg)
240 if (msg->ms_flags & MSGF_ASYNC) {
241 _lwkt_replyport(port, msg);
243 msg->ms_flags |= MSGF_DONE;
244 if (port->mp_flags & MSGPORTF_WAITING)
245 lwkt_schedule(port->mp_td);
253 * This function is typically assigned to the mp_beginmsg port vector.
255 * Queue a message to the target port and wakeup the thread owning it.
256 * This function always returns EINPROGRESS and may be assigned to a
257 * message port's mp_beginmsg function vector.
262 _lwkt_putport(lwkt_port_t port, lwkt_msg_t msg)
264 thread_t td = port->mp_td;
266 if (td->td_cpu == mycpu->gd_cpuid) {
267 TAILQ_INSERT_TAIL(&port->mp_msgq, msg, ms_node);
268 msg->ms_flags |= MSGF_QUEUED;
269 if (port->mp_flags & MSGPORTF_WAITING)
272 msg->ms_target_port = port;
273 lwkt_send_ipiq(td->td_cpu, (ipifunc_t)lwkt_putport_remote, msg);
279 lwkt_putport_remote(lwkt_msg_t msg)
281 _lwkt_putport(msg->ms_target_port, msg);
285 lwkt_putport(lwkt_port_t port, lwkt_msg_t msg)
288 _lwkt_putport(port, msg);
296 * This function is typically assigned to the mp_abortmsg port vector.
298 * This function attempts to abort a message. Aborts are always
299 * optional, so we could just do nothing if we wanted. We get onto the
300 * cpu owning the port, check to see if the message is queued on the
301 * port's message queue, and remove and abort it if it is. Otherwise
304 * Note that we cannot safely use ms_target_port because the port might
305 * have forwarded the message on to some other port and we could race
306 * against that use of ms_target_port.
311 _lwkt_abortport(lwkt_port_t port)
313 thread_t td = port->mp_td;
316 if (td->td_cpu == mycpu->gd_cpuid) {
318 msg = TAILQ_FIRST(&port->mp_msgq);
320 if (msg->ms_abortreq) {
321 TAILQ_REMOVE(&port->mp_msgq, msg, ms_node);
322 msg->ms_flags &= ~MSGF_QUEUED;
323 lwkt_replymsg(msg, ECONNABORTED); /* YYY dangerous from IPI? */
326 msg = TAILQ_NEXT(msg, ms_node);
329 lwkt_send_ipiq(td->td_cpu, (ipifunc_t)lwkt_abortport_remote, port);
335 lwkt_abortport_remote(lwkt_port_t port)
337 _lwkt_abortport(port);
341 lwkt_abortport(lwkt_port_t port, lwkt_msg_t msg)
343 msg->ms_abortreq = 1;
345 _lwkt_abortport(port);
352 * Retrieve the next message from the port's message queue, return NULL
353 * if no messages are pending.
355 * The calling thread MUST own the port.
358 lwkt_getport(lwkt_port_t port)
362 KKASSERT(port->mp_td == curthread);
365 if ((msg = TAILQ_FIRST(&port->mp_msgq)) != NULL) {
366 TAILQ_REMOVE(&port->mp_msgq, msg, ms_node);
367 msg->ms_flags &= ~MSGF_QUEUED;
376 * Retrieve the next message from the port's message queue, block until
377 * a message is ready. This function never returns NULL.
380 lwkt_waitport(lwkt_port_t port)
384 KKASSERT(port->mp_td == curthread);
387 if ((msg = TAILQ_FIRST(&port->mp_msgq)) == NULL) {
388 port->mp_flags |= MSGPORTF_WAITING;
390 lwkt_deschedule_self();
392 } while ((msg = TAILQ_FIRST(&port->mp_msgq)) == NULL);
393 port->mp_flags &= ~MSGPORTF_WAITING;
395 TAILQ_REMOVE(&port->mp_msgq, msg, ms_node);
396 msg->ms_flags &= ~MSGF_QUEUED;