sys/net/netisr.c

   1 /*
   2  * Copyright (c) 2003, 2004 Matthew Dillon. All rights reserved.
   3  * Copyright (c) 2003, 2004 Jeffrey M. Hsu.  All rights reserved.
   4  * Copyright (c) 2003 Jonathan Lemon.  All rights reserved.
   5  * Copyright (c) 2003, 2004 The DragonFly Project.  All rights reserved.
   6  *
   7  * This code is derived from software contributed to The DragonFly Project
   8  * by Jonathan Lemon, Jeffrey M. Hsu, and Matthew Dillon.
   9  *
  10  * Jonathan Lemon gave Jeffrey Hsu permission to combine his copyright
  11  * into this one around July 8 2004.
  12  *
  13  * Redistribution and use in source and binary forms, with or without
  14  * modification, are permitted provided that the following conditions
  15  * are met:
  16  * 1. Redistributions of source code must retain the above copyright
  17  *    notice, this list of conditions and the following disclaimer.
  18  * 2. Redistributions in binary form must reproduce the above copyright
  19  *    notice, this list of conditions and the following disclaimer in the
  20  *    documentation and/or other materials provided with the distribution.
  21  * 3. Neither the name of The DragonFly Project nor the names of its
  22  *    contributors may be used to endorse or promote products derived
  23  *    from this software without specific, prior written permission.
  24  *
  25  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  26  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  27  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  28  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  29  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  30  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  31  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  32  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  33  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  34  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  35  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  36  * SUCH DAMAGE.
  37  *
  38  * $DragonFly: src/sys/net/netisr.c,v 1.27 2006/09/05 00:55:46 dillon Exp $
  39  */
  40
  41 /*
  42  * Copyright (c) 2003, 2004 Jeffrey M. Hsu.  All rights reserved.
  43  *
  44  * License terms: all terms for the DragonFly license above plus the following:
  45  *
  46  * 4. All advertising materials mentioning features or use of this software
  47  *    must display the following acknowledgement:
  48  *
  49  *      This product includes software developed by Jeffrey M. Hsu
  50  *      for the DragonFly Project.
  51  *
  52  *    This requirement may be waived with permission from Jeffrey Hsu.
  53  *    This requirement will sunset and may be removed on July 8 2005,
  54  *    after which the standard DragonFly license (as shown above) will
  55  *    apply.
  56  */
  57
  58 #include <sys/param.h>
  59 #include <sys/systm.h>
  60 #include <sys/kernel.h>
  61 #include <sys/malloc.h>
  62 #include <sys/msgport.h>
  63 #include <sys/proc.h>
  64 #include <sys/interrupt.h>
  65 #include <sys/socket.h>
  66 #include <sys/sysctl.h>
  67 #include <net/if.h>
  68 #include <net/if_var.h>
  69 #include <net/netisr.h>
  70 #include <machine/cpufunc.h>
  71 #include <machine/ipl.h>
  72
  73 #include <sys/thread2.h>
  74 #include <sys/msgport2.h>
  75
  76 static int netmsg_sync_func(struct netmsg *msg);
  77
  78 struct netmsg_port_registration {
  79     TAILQ_ENTRY(netmsg_port_registration) npr_entry;
  80     lwkt_port_t npr_port;
  81 };
  82
  83 static struct netisr netisrs[NETISR_MAX];
  84 static TAILQ_HEAD(,netmsg_port_registration) netreglist;
  85
  86 /* Per-CPU thread to handle any protocol.  */
  87 struct thread netisr_cpu[MAXCPU];
  88 lwkt_port netisr_afree_rport;
  89 lwkt_port netisr_adone_rport;
  90 lwkt_port netisr_apanic_rport;
  91 lwkt_port netisr_sync_port;
  92
  93 /*
  94  * netisr_afree_rport replymsg function, only used to handle async
  95  * messages which the sender has abandoned to their fate.
  96  */
  97 static void
  98 netisr_autofree_reply(lwkt_port_t port, lwkt_msg_t msg)
  99 {
 100     kfree(msg, M_LWKTMSG);
 101 }
 102
 103 static void
 104 netisr_autopanic_reply(lwkt_port_t port, lwkt_msg_t msg)
 105 {
 106     panic("unreplyable msg %p was replied!", msg);
 107 }
 108
 109 /*
 110  * We must construct a custom putport function (which runs in the context
 111  * of the message originator)
 112  *
 113  * Our custom putport must check for self-referential messages, which can
 114  * occur when the so_upcall routine is called (e.g. nfs).  Self referential
 115  * messages are executed synchronously.  However, we must panic if the message
 116  * is not marked DONE on completion because the self-referential case cannot
 117  * block without deadlocking.
 118  *
 119  * note: ms_target_port does not need to be set when returning a synchronous
 120  * error code.
 121  */
 122 static int
 123 netmsg_put_port(lwkt_port_t port, lwkt_msg_t lmsg)
 124 {
 125     int error;
 126
 127     if ((lmsg->ms_flags & MSGF_ASYNC) == 0 && port->mp_td == curthread) {
 128         error = lmsg->ms_cmd.cm_func(lmsg);
 129         if (error == EASYNC && (lmsg->ms_flags & MSGF_DONE) == 0)
 130             panic("netmsg_put_port: self-referential deadlock on netport");
 131         return(error);
 132     } else {
 133         return(lwkt_default_putport(port, lmsg));
 134     }
 135 }
 136
 137 /*
 138  * UNIX DOMAIN sockets still have to run their uipc functions synchronously,
 139  * because they depend on the user proc context for a number of things
 140  * (like creds) which we have not yet incorporated into the message structure.
 141  *
 142  * However, we maintain or message/port abstraction.  Having a special
 143  * synchronous port which runs the commands synchronously gives us the
 144  * ability to serialize operations in one place later on when we start
 145  * removing the BGL.
 146  *
 147  * We clear MSGF_DONE prior to executing the message in order to close
 148  * any potential replymsg races with the flags field.  If a synchronous
 149  * result code is returned we set MSGF_DONE again.  MSGF_DONE's flag state
 150  * must be correct or the caller will be confused.
 151  */
 152 static int
 153 netmsg_sync_putport(lwkt_port_t port, lwkt_msg_t lmsg)
 154 {
 155     int error;
 156
 157     lmsg->ms_flags &= ~MSGF_DONE;
 158     lmsg->ms_target_port = port;        /* required for abort */
 159     error = lmsg->ms_cmd.cm_func(lmsg);
 160     if (error == EASYNC)
 161         error = lwkt_waitmsg(lmsg);
 162     else
 163         lmsg->ms_flags |= MSGF_DONE;
 164     return(error);
 165 }
 166
 167 static void
 168 netmsg_sync_abortport(lwkt_port_t port, lwkt_msg_t lmsg)
 169 {
 170     lmsg->ms_abort_port = lmsg->ms_reply_port;
 171     lmsg->ms_flags |= MSGF_ABORTED;
 172     lmsg->ms_abort.cm_func(lmsg);
 173 }
 174
 175 static void
 176 netisr_init(void)
 177 {
 178     int i;
 179
 180     TAILQ_INIT(&netreglist);
 181
 182     /*
 183      * Create default per-cpu threads for generic protocol handling.
 184      */
 185     for (i = 0; i < ncpus; ++i) {
 186         lwkt_create(netmsg_service_loop, NULL, NULL, &netisr_cpu[i], 0, i,
 187                     "netisr_cpu %d", i);
 188         netmsg_service_port_init(&netisr_cpu[i].td_msgport);
 189     }
 190
 191     /*
 192      * The netisr_afree_rport is a special reply port which automatically
 193      * frees the replied message.  The netisr_adone_rport simply marks
 194      * the message as being done.  The netisr_apanic_rport panics if
 195      * the message is replied to.
 196      */
 197     lwkt_initport(&netisr_afree_rport, NULL);
 198     netisr_afree_rport.mp_replyport = netisr_autofree_reply;
 199     lwkt_initport_null_rport(&netisr_adone_rport, NULL);
 200     lwkt_initport(&netisr_apanic_rport, NULL);
 201     netisr_apanic_rport.mp_replyport = netisr_autopanic_reply;
 202
 203     /*
 204      * The netisr_syncport is a special port which executes the message
 205      * synchronously and waits for it if EASYNC is returned.
 206      */
 207     lwkt_initport(&netisr_sync_port, NULL);
 208     netisr_sync_port.mp_putport = netmsg_sync_putport;
 209     netisr_sync_port.mp_abortport = netmsg_sync_abortport;
 210 }
 211
 212 SYSINIT(netisr, SI_SUB_PROTO_BEGIN, SI_ORDER_FIRST, netisr_init, NULL);
 213
 214 /*
 215  * Finish initializing the message port for a netmsg service.  This also
 216  * registers the port for synchronous cleanup operations such as when an
 217  * ifnet is being destroyed.  There is no deregistration API yet.
 218  */
 219 void
 220 netmsg_service_port_init(lwkt_port_t port)
 221 {
 222     struct netmsg_port_registration *reg;
 223
 224     /*
 225      * Override the putport function.  Our custom function checks for
 226      * self-references and executes such commands synchronously.
 227      */
 228     port->mp_putport = netmsg_put_port;
 229
 230     /*
 231      * Keep track of ports using the netmsg API so we can synchronize
 232      * certain operations (such as freeing an ifnet structure) across all
 233      * consumers.
 234      */
 235     reg = kmalloc(sizeof(*reg), M_TEMP, M_WAITOK|M_ZERO);
 236     reg->npr_port = port;
 237     TAILQ_INSERT_TAIL(&netreglist, reg, npr_entry);
 238 }
 239
 240 /*
 241  * This function synchronizes the caller with all netmsg services.  For
 242  * example, if an interface is being removed we must make sure that all
 243  * packets related to that interface complete processing before the structure
 244  * can actually be freed.  This sort of synchronization is an alternative to
 245  * ref-counting the netif, removing the ref counting overhead in favor of
 246  * placing additional overhead in the netif freeing sequence (where it is
 247  * inconsequential).
 248  */
 249 void
 250 netmsg_service_sync(void)
 251 {
 252     struct netmsg_port_registration *reg;
 253     struct netmsg smsg;
 254
 255     lwkt_initmsg(&smsg.nm_lmsg, &curthread->td_msgport, 0,
 256                 lwkt_cmd_func((void *)netmsg_sync_func), lwkt_cmd_op_none);
 257
 258     TAILQ_FOREACH(reg, &netreglist, npr_entry) {
 259         lwkt_domsg(reg->npr_port, &smsg.nm_lmsg);
 260     }
 261 }
 262
 263 /*
 264  * The netmsg function simply replies the message.  API semantics require
 265  * EASYNC to be returned if the netmsg function disposes of the message.
 266  */
 267 static int
 268 netmsg_sync_func(struct netmsg *msg)
 269 {
 270     lwkt_replymsg(&msg->nm_lmsg, 0);
 271     return(EASYNC);
 272 }
 273
 274 /*
 275  * Generic netmsg service loop.  Some protocols may roll their own but all
 276  * must do the basic command dispatch function call done here.
 277  */
 278 void
 279 netmsg_service_loop(void *arg)
 280 {
 281     struct netmsg *msg;
 282
 283     while ((msg = lwkt_waitport(&curthread->td_msgport, NULL))) {
 284         msg->nm_lmsg.ms_cmd.cm_func(&msg->nm_lmsg);
 285     }
 286 }
 287
 288 /*
 289  * Call the netisr directly.
 290  * Queueing may be done in the msg port layer at its discretion.
 291  */
 292 void
 293 netisr_dispatch(int num, struct mbuf *m)
 294 {
 295     /* just queue it for now XXX JH */
 296     netisr_queue(num, m);
 297 }
 298
 299 /*
 300  * Same as netisr_dispatch(), but always queue.
 301  * This is either used in places where we are not confident that
 302  * direct dispatch is possible, or where queueing is required.
 303  */
 304 int
 305 netisr_queue(int num, struct mbuf *m)
 306 {
 307     struct netisr *ni;
 308     struct netmsg_packet *pmsg;
 309     lwkt_port_t port;
 310
 311     KASSERT((num > 0 && num <= (sizeof(netisrs)/sizeof(netisrs[0]))),
 312         ("netisr_queue: bad isr %d", num));
 313
 314     ni = &netisrs[num];
 315     if (ni->ni_handler == NULL) {
 316         printf("netisr_queue: unregistered isr %d\n", num);
 317         return (EIO);
 318     }
 319
 320     if ((port = ni->ni_mport(&m)) == NULL)
 321         return (EIO);
 322
 323     pmsg = &m->m_hdr.mh_netmsg;
 324
 325     lwkt_initmsg(&pmsg->nm_lmsg, &netisr_apanic_rport, 0,
 326                 lwkt_cmd_func((void *)ni->ni_handler), lwkt_cmd_op_none);
 327     pmsg->nm_packet = m;
 328     pmsg->nm_lmsg.u.ms_result = num;
 329     lwkt_sendmsg(port, &pmsg->nm_lmsg);
 330     return (0);
 331 }
 332
 333 void
 334 netisr_register(int num, lwkt_portfn_t mportfn, netisr_fn_t handler)
 335 {
 336     KASSERT((num > 0 && num <= (sizeof(netisrs)/sizeof(netisrs[0]))),
 337         ("netisr_register: bad isr %d", num));
 338     lwkt_initmsg(&netisrs[num].ni_netmsg.nm_lmsg, &netisr_adone_rport, 0,
 339             lwkt_cmd_op_none, lwkt_cmd_op_none);
 340     netisrs[num].ni_mport = mportfn;
 341     netisrs[num].ni_handler = handler;
 342 }
 343
 344 int
 345 netisr_unregister(int num)
 346 {
 347     KASSERT((num > 0 && num <= (sizeof(netisrs)/sizeof(netisrs[0]))),
 348         ("unregister_netisr: bad isr number: %d\n", num));
 349
 350     /* XXX JH */
 351     return (0);
 352 }
 353
 354 /*
 355  * Return message port for default handler thread on CPU 0.
 356  */
 357 lwkt_port_t
 358 cpu0_portfn(struct mbuf **mptr)
 359 {
 360     return (&netisr_cpu[0].td_msgport);
 361 }
 362
 363 lwkt_port_t
 364 cpu_portfn(int cpu)
 365 {
 366     return (&netisr_cpu[cpu].td_msgport);
 367 }
 368
 369 /* ARGSUSED */
 370 lwkt_port_t
 371 cpu0_soport(struct socket *so __unused, struct sockaddr *nam __unused,
 372             int req __unused)
 373 {
 374     return (&netisr_cpu[0].td_msgport);
 375 }
 376
 377 lwkt_port_t
 378 sync_soport(struct socket *so __unused, struct sockaddr *nam __unused,
 379             int req __unused)
 380 {
 381     return (&netisr_sync_port);
 382 }
 383
 384 /*
 385  * schednetisr() is used to call the netisr handler from the appropriate
 386  * netisr thread for polling and other purposes.
 387  *
 388  * This function may be called from a hard interrupt or IPI and must be
 389  * MP SAFE and non-blocking.  We use a fixed per-cpu message instead of
 390  * trying to allocate one.  We must get ourselves onto the target cpu
 391  * to safely check the MSGF_DONE bit on the message but since the message
 392  * will be sent to that cpu anyway this does not add any extra work beyond
 393  * what lwkt_sendmsg() would have already had to do to schedule the target
 394  * thread.
 395  */
 396 static void
 397 schednetisr_remote(void *data)
 398 {
 399     int num = (int)data;
 400     struct netisr *ni = &netisrs[num];
 401     lwkt_port_t port = &netisr_cpu[0].td_msgport;
 402     struct netmsg *pmsg;
 403
 404     pmsg = &netisrs[num].ni_netmsg;
 405     crit_enter();
 406     if (pmsg->nm_lmsg.ms_flags & MSGF_DONE) {
 407         lwkt_initmsg(&pmsg->nm_lmsg, &netisr_adone_rport, 0,
 408                     lwkt_cmd_func((void *)ni->ni_handler), lwkt_cmd_op_none);
 409         pmsg->nm_lmsg.u.ms_result = num;
 410         lwkt_sendmsg(port, &pmsg->nm_lmsg);
 411     }
 412     crit_exit();
 413 }
 414
 415 void
 416 schednetisr(int num)
 417 {
 418     KASSERT((num > 0 && num <= (sizeof(netisrs)/sizeof(netisrs[0]))),
 419         ("schednetisr: bad isr %d", num));
 420 #ifdef SMP
 421     if (mycpu->gd_cpuid != 0)
 422         lwkt_send_ipiq(globaldata_find(0), schednetisr_remote, (void *)num);
 423     else
 424         schednetisr_remote((void *)num);
 425 #else
 426     schednetisr_remote((void *)num);
 427 #endif
 428 }
 429