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 1.49 2008/11/01 10:29:31 sephe Exp $ 39 */ 40 41 #include <sys/param.h> 42 #include <sys/systm.h> 43 #include <sys/kernel.h> 44 #include <sys/malloc.h> 45 #include <sys/msgport.h> 46 #include <sys/proc.h> 47 #include <sys/interrupt.h> 48 #include <sys/socket.h> 49 #include <sys/sysctl.h> 50 #include <net/if.h> 51 #include <net/if_var.h> 52 #include <net/netisr.h> 53 #include <machine/cpufunc.h> 54 55 #include <sys/thread2.h> 56 #include <sys/msgport2.h> 57 #include <net/netmsg2.h> 58 59 #define NETISR_GET_MPLOCK(ni) \ 60 do { \ 61 if (((ni)->ni_flags & NETISR_FLAG_MPSAFE) == 0) \ 62 get_mplock(); \ 63 } while (0) 64 65 #define NETISR_REL_MPLOCK(ni) \ 66 do { \ 67 if (((ni)->ni_flags & NETISR_FLAG_MPSAFE) == 0) \ 68 rel_mplock(); \ 69 } while (0) 70 71 static void netmsg_sync_func(struct netmsg *msg); 72 73 struct netmsg_port_registration { 74 TAILQ_ENTRY(netmsg_port_registration) npr_entry; 75 lwkt_port_t npr_port; 76 }; 77 78 static struct netisr netisrs[NETISR_MAX]; 79 static TAILQ_HEAD(,netmsg_port_registration) netreglist; 80 81 /* Per-CPU thread to handle any protocol. */ 82 struct thread netisr_cpu[MAXCPU]; 83 lwkt_port netisr_afree_rport; 84 lwkt_port netisr_adone_rport; 85 lwkt_port netisr_apanic_rport; 86 lwkt_port netisr_sync_port; 87 88 static int (*netmsg_fwd_port_fn)(lwkt_port_t, lwkt_msg_t); 89 90 static int netisr_mpsafe_thread = 0; 91 TUNABLE_INT("net.netisr.mpsafe_thread", &netisr_mpsafe_thread); 92 93 SYSCTL_NODE(_net, OID_AUTO, netisr, CTLFLAG_RW, 0, "netisr"); 94 SYSCTL_INT(_net_netisr, OID_AUTO, mpsafe_thread, CTLFLAG_RW, 95 &netisr_mpsafe_thread, 0, 96 "0:BGL, 1:Adaptive BGL, 2:No BGL(experimental)"); 97 98 static __inline int 99 NETISR_TO_MSGF(const struct netisr *ni) 100 { 101 int msg_flags = 0; 102 103 if (ni->ni_flags & NETISR_FLAG_MPSAFE) 104 msg_flags |= MSGF_MPSAFE; 105 return msg_flags; 106 } 107 108 /* 109 * netisr_afree_rport replymsg function, only used to handle async 110 * messages which the sender has abandoned to their fate. 111 */ 112 static void 113 netisr_autofree_reply(lwkt_port_t port, lwkt_msg_t msg) 114 { 115 kfree(msg, M_LWKTMSG); 116 } 117 118 /* 119 * We need a custom putport function to handle the case where the 120 * message target is the current thread's message port. This case 121 * can occur when the TCP or UDP stack does a direct callback to NFS and NFS 122 * then turns around and executes a network operation synchronously. 123 * 124 * To prevent deadlocking, we must execute these self-referential messages 125 * synchronously, effectively turning the message into a glorified direct 126 * procedure call back into the protocol stack. The operation must be 127 * complete on return or we will deadlock, so panic if it isn't. 128 */ 129 static int 130 netmsg_put_port(lwkt_port_t port, lwkt_msg_t lmsg) 131 { 132 netmsg_t netmsg = (void *)lmsg; 133 134 if ((lmsg->ms_flags & MSGF_SYNC) && port == &curthread->td_msgport) { 135 netmsg->nm_dispatch(netmsg); 136 if ((lmsg->ms_flags & MSGF_DONE) == 0) 137 panic("netmsg_put_port: self-referential deadlock on netport"); 138 return(EASYNC); 139 } else { 140 return(netmsg_fwd_port_fn(port, lmsg)); 141 } 142 } 143 144 /* 145 * UNIX DOMAIN sockets still have to run their uipc functions synchronously, 146 * because they depend on the user proc context for a number of things 147 * (like creds) which we have not yet incorporated into the message structure. 148 * 149 * However, we maintain or message/port abstraction. Having a special 150 * synchronous port which runs the commands synchronously gives us the 151 * ability to serialize operations in one place later on when we start 152 * removing the BGL. 153 */ 154 static int 155 netmsg_sync_putport(lwkt_port_t port, lwkt_msg_t lmsg) 156 { 157 netmsg_t netmsg = (void *)lmsg; 158 159 KKASSERT((lmsg->ms_flags & MSGF_DONE) == 0); 160 161 lmsg->ms_target_port = port; /* required for abort */ 162 netmsg->nm_dispatch(netmsg); 163 return(EASYNC); 164 } 165 166 static void 167 netisr_init(void) 168 { 169 int i; 170 171 TAILQ_INIT(&netreglist); 172 173 /* 174 * Create default per-cpu threads for generic protocol handling. 175 */ 176 for (i = 0; i < ncpus; ++i) { 177 lwkt_create(netmsg_service_loop, &netisr_mpsafe_thread, NULL, 178 &netisr_cpu[i], TDF_NETWORK | TDF_MPSAFE, i, 179 "netisr_cpu %d", i); 180 netmsg_service_port_init(&netisr_cpu[i].td_msgport); 181 } 182 183 /* 184 * The netisr_afree_rport is a special reply port which automatically 185 * frees the replied message. The netisr_adone_rport simply marks 186 * the message as being done. The netisr_apanic_rport panics if 187 * the message is replied to. 188 */ 189 lwkt_initport_replyonly(&netisr_afree_rport, netisr_autofree_reply); 190 lwkt_initport_replyonly_null(&netisr_adone_rport); 191 lwkt_initport_panic(&netisr_apanic_rport); 192 193 /* 194 * The netisr_syncport is a special port which executes the message 195 * synchronously and waits for it if EASYNC is returned. 196 */ 197 lwkt_initport_putonly(&netisr_sync_port, netmsg_sync_putport); 198 } 199 200 SYSINIT(netisr, SI_SUB_PRE_DRIVERS, SI_ORDER_FIRST, netisr_init, NULL); 201 202 /* 203 * Finish initializing the message port for a netmsg service. This also 204 * registers the port for synchronous cleanup operations such as when an 205 * ifnet is being destroyed. There is no deregistration API yet. 206 */ 207 void 208 netmsg_service_port_init(lwkt_port_t port) 209 { 210 struct netmsg_port_registration *reg; 211 212 /* 213 * Override the putport function. Our custom function checks for 214 * self-references and executes such commands synchronously. 215 */ 216 if (netmsg_fwd_port_fn == NULL) 217 netmsg_fwd_port_fn = port->mp_putport; 218 KKASSERT(netmsg_fwd_port_fn == port->mp_putport); 219 port->mp_putport = netmsg_put_port; 220 221 /* 222 * Keep track of ports using the netmsg API so we can synchronize 223 * certain operations (such as freeing an ifnet structure) across all 224 * consumers. 225 */ 226 reg = kmalloc(sizeof(*reg), M_TEMP, M_WAITOK|M_ZERO); 227 reg->npr_port = port; 228 TAILQ_INSERT_TAIL(&netreglist, reg, npr_entry); 229 } 230 231 /* 232 * This function synchronizes the caller with all netmsg services. For 233 * example, if an interface is being removed we must make sure that all 234 * packets related to that interface complete processing before the structure 235 * can actually be freed. This sort of synchronization is an alternative to 236 * ref-counting the netif, removing the ref counting overhead in favor of 237 * placing additional overhead in the netif freeing sequence (where it is 238 * inconsequential). 239 */ 240 void 241 netmsg_service_sync(void) 242 { 243 struct netmsg_port_registration *reg; 244 struct netmsg smsg; 245 246 netmsg_init(&smsg, &curthread->td_msgport, MSGF_MPSAFE, netmsg_sync_func); 247 248 TAILQ_FOREACH(reg, &netreglist, npr_entry) { 249 lwkt_domsg(reg->npr_port, &smsg.nm_lmsg, 0); 250 } 251 } 252 253 /* 254 * The netmsg function simply replies the message. API semantics require 255 * EASYNC to be returned if the netmsg function disposes of the message. 256 */ 257 static void 258 netmsg_sync_func(struct netmsg *msg) 259 { 260 lwkt_replymsg(&msg->nm_lmsg, 0); 261 } 262 263 /* 264 * Return current BGL lock state (1:locked, 0: unlocked) 265 */ 266 int 267 netmsg_service(struct netmsg *msg, int mpsafe_mode, int mplocked) 268 { 269 /* 270 * Adjust the mplock dynamically. 271 */ 272 switch (mpsafe_mode) { 273 case NETMSG_SERVICE_ADAPTIVE: /* Adaptive BGL */ 274 if (msg->nm_lmsg.ms_flags & MSGF_MPSAFE) { 275 if (mplocked) { 276 rel_mplock(); 277 mplocked = 0; 278 } 279 msg->nm_dispatch(msg); 280 /* Leave mpunlocked */ 281 } else { 282 if (!mplocked) { 283 get_mplock(); 284 /* mplocked = 1; not needed */ 285 } 286 msg->nm_dispatch(msg); 287 rel_mplock(); 288 mplocked = 0; 289 /* Leave mpunlocked, next msg might be mpsafe */ 290 } 291 break; 292 293 case NETMSG_SERVICE_MPSAFE: /* No BGL */ 294 if (mplocked) { 295 rel_mplock(); 296 mplocked = 0; 297 } 298 msg->nm_dispatch(msg); 299 /* Leave mpunlocked */ 300 break; 301 302 default: /* BGL */ 303 if (!mplocked) { 304 get_mplock(); 305 mplocked = 1; 306 } 307 msg->nm_dispatch(msg); 308 /* Leave mplocked */ 309 break; 310 } 311 return mplocked; 312 } 313 314 /* 315 * Generic netmsg service loop. Some protocols may roll their own but all 316 * must do the basic command dispatch function call done here. 317 */ 318 void 319 netmsg_service_loop(void *arg) 320 { 321 struct netmsg *msg; 322 int mplocked, *mpsafe_mode = arg; 323 324 /* 325 * Thread was started with TDF_MPSAFE 326 */ 327 mplocked = 0; 328 329 /* 330 * Loop on netmsgs 331 */ 332 while ((msg = lwkt_waitport(&curthread->td_msgport, 0))) { 333 mplocked = netmsg_service(msg, *mpsafe_mode, mplocked); 334 } 335 } 336 337 /* 338 * Call the netisr directly. 339 * Queueing may be done in the msg port layer at its discretion. 340 */ 341 void 342 netisr_dispatch(int num, struct mbuf *m) 343 { 344 /* just queue it for now XXX JH */ 345 netisr_queue(num, m); 346 } 347 348 /* 349 * Same as netisr_dispatch(), but always queue. 350 * This is either used in places where we are not confident that 351 * direct dispatch is possible, or where queueing is required. 352 */ 353 int 354 netisr_queue(int num, struct mbuf *m) 355 { 356 struct netisr *ni; 357 struct netmsg_packet *pmsg; 358 lwkt_port_t port; 359 360 KASSERT((num > 0 && num <= (sizeof(netisrs)/sizeof(netisrs[0]))), 361 ("%s: bad isr %d", __func__, num)); 362 363 ni = &netisrs[num]; 364 if (ni->ni_handler == NULL) { 365 kprintf("%s: unregistered isr %d\n", __func__, num); 366 m_freem(m); 367 return (EIO); 368 } 369 370 if ((port = ni->ni_mport(&m)) == NULL) 371 return (EIO); 372 373 pmsg = &m->m_hdr.mh_netmsg; 374 375 netmsg_init(&pmsg->nm_netmsg, &netisr_apanic_rport, NETISR_TO_MSGF(ni), 376 ni->ni_handler); 377 pmsg->nm_packet = m; 378 pmsg->nm_netmsg.nm_lmsg.u.ms_result = num; 379 lwkt_sendmsg(port, &pmsg->nm_netmsg.nm_lmsg); 380 return (0); 381 } 382 383 void 384 netisr_register(int num, lwkt_portfn_t mportfn, netisr_fn_t handler, 385 uint32_t flags) 386 { 387 struct netisr *ni; 388 389 KASSERT((num > 0 && num <= (sizeof(netisrs)/sizeof(netisrs[0]))), 390 ("netisr_register: bad isr %d", num)); 391 ni = &netisrs[num]; 392 393 ni->ni_mport = mportfn; 394 ni->ni_handler = handler; 395 ni->ni_flags = flags; 396 netmsg_init(&ni->ni_netmsg, &netisr_adone_rport, NETISR_TO_MSGF(ni), NULL); 397 } 398 399 int 400 netisr_unregister(int num) 401 { 402 KASSERT((num > 0 && num <= (sizeof(netisrs)/sizeof(netisrs[0]))), 403 ("unregister_netisr: bad isr number: %d\n", num)); 404 405 /* XXX JH */ 406 return (0); 407 } 408 409 /* 410 * Return message port for default handler thread on CPU 0. 411 */ 412 lwkt_port_t 413 cpu0_portfn(struct mbuf **mptr) 414 { 415 return (&netisr_cpu[0].td_msgport); 416 } 417 418 lwkt_port_t 419 cpu_portfn(int cpu) 420 { 421 return (&netisr_cpu[cpu].td_msgport); 422 } 423 424 /* ARGSUSED */ 425 lwkt_port_t 426 cpu0_soport(struct socket *so __unused, struct sockaddr *nam __unused, 427 struct mbuf **dummy __unused, int req __unused) 428 { 429 return (&netisr_cpu[0].td_msgport); 430 } 431 432 lwkt_port_t 433 cpu0_ctlport(int cmd __unused, struct sockaddr *sa __unused, 434 void *extra __unused) 435 { 436 return (&netisr_cpu[0].td_msgport); 437 } 438 439 lwkt_port_t 440 sync_soport(struct socket *so __unused, struct sockaddr *nam __unused, 441 struct mbuf **dummy __unused, int req __unused) 442 { 443 return (&netisr_sync_port); 444 } 445 446 /* 447 * schednetisr() is used to call the netisr handler from the appropriate 448 * netisr thread for polling and other purposes. 449 * 450 * This function may be called from a hard interrupt or IPI and must be 451 * MP SAFE and non-blocking. We use a fixed per-cpu message instead of 452 * trying to allocate one. We must get ourselves onto the target cpu 453 * to safely check the MSGF_DONE bit on the message but since the message 454 * will be sent to that cpu anyway this does not add any extra work beyond 455 * what lwkt_sendmsg() would have already had to do to schedule the target 456 * thread. 457 */ 458 static void 459 schednetisr_remote(void *data) 460 { 461 int num = (int)data; 462 struct netisr *ni = &netisrs[num]; 463 lwkt_port_t port = &netisr_cpu[0].td_msgport; 464 struct netmsg *pmsg; 465 466 pmsg = &netisrs[num].ni_netmsg; 467 crit_enter(); 468 if (pmsg->nm_lmsg.ms_flags & MSGF_DONE) { 469 netmsg_init(pmsg, &netisr_adone_rport, NETISR_TO_MSGF(ni), 470 ni->ni_handler); 471 pmsg->nm_lmsg.u.ms_result = num; 472 lwkt_sendmsg(port, &pmsg->nm_lmsg); 473 } 474 crit_exit(); 475 } 476 477 void 478 schednetisr(int num) 479 { 480 KASSERT((num > 0 && num <= (sizeof(netisrs)/sizeof(netisrs[0]))), 481 ("schednetisr: bad isr %d", num)); 482 #ifdef SMP 483 if (mycpu->gd_cpuid != 0) 484 lwkt_send_ipiq(globaldata_find(0), schednetisr_remote, (void *)num); 485 else 486 schednetisr_remote((void *)num); 487 #else 488 schednetisr_remote((void *)num); 489 #endif 490 } 491 492 lwkt_port_t 493 netisr_find_port(int num, struct mbuf **m0) 494 { 495 struct netisr *ni; 496 lwkt_port_t port; 497 struct mbuf *m = *m0; 498 499 *m0 = NULL; 500 501 KASSERT((num > 0 && num <= (sizeof(netisrs)/sizeof(netisrs[0]))), 502 ("%s: bad isr %d", __func__, num)); 503 504 ni = &netisrs[num]; 505 if (ni->ni_mport == NULL) { 506 kprintf("%s: unregistered isr %d\n", __func__, num); 507 m_freem(m); 508 return NULL; 509 } 510 511 if ((port = ni->ni_mport(&m)) == NULL) 512 return NULL; 513 514 *m0 = m; 515 return port; 516 } 517 518 void 519 netisr_run(int num, struct mbuf *m) 520 { 521 struct netisr *ni; 522 struct netmsg_packet *pmsg; 523 524 KASSERT((num > 0 && num <= (sizeof(netisrs)/sizeof(netisrs[0]))), 525 ("%s: bad isr %d", __func__, num)); 526 527 ni = &netisrs[num]; 528 if (ni->ni_handler == NULL) { 529 kprintf("%s: unregistered isr %d\n", __func__, num); 530 m_freem(m); 531 return; 532 } 533 534 pmsg = &m->m_hdr.mh_netmsg; 535 536 netmsg_init(&pmsg->nm_netmsg, &netisr_apanic_rport, 0, ni->ni_handler); 537 pmsg->nm_packet = m; 538 pmsg->nm_netmsg.nm_lmsg.u.ms_result = num; 539 540 NETISR_GET_MPLOCK(ni); 541 ni->ni_handler(&pmsg->nm_netmsg); 542 NETISR_REL_MPLOCK(ni); 543 } 544