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 1.40 2008/05/02 07:40:32 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 static void netmsg_sync_func(struct netmsg *msg); 60 61 struct netmsg_port_registration { 62 TAILQ_ENTRY(netmsg_port_registration) npr_entry; 63 lwkt_port_t npr_port; 64 }; 65 66 static struct netisr netisrs[NETISR_MAX]; 67 static TAILQ_HEAD(,netmsg_port_registration) netreglist; 68 69 /* Per-CPU thread to handle any protocol. */ 70 struct thread netisr_cpu[MAXCPU]; 71 lwkt_port netisr_afree_rport; 72 lwkt_port netisr_adone_rport; 73 lwkt_port netisr_apanic_rport; 74 lwkt_port netisr_sync_port; 75 76 static int (*netmsg_fwd_port_fn)(lwkt_port_t, lwkt_msg_t); 77 78 static int netisr_mpsafe_thread = 0; 79 TUNABLE_INT("netisr.mpsafe_thread", &netisr_mpsafe_thread); 80 81 /* 82 * netisr_afree_rport replymsg function, only used to handle async 83 * messages which the sender has abandoned to their fate. 84 */ 85 static void 86 netisr_autofree_reply(lwkt_port_t port, lwkt_msg_t msg) 87 { 88 kfree(msg, M_LWKTMSG); 89 } 90 91 /* 92 * We need a custom putport function to handle the case where the 93 * message target is the current thread's message port. This case 94 * can occur when the TCP or UDP stack does a direct callback to NFS and NFS 95 * then turns around and executes a network operation synchronously. 96 * 97 * To prevent deadlocking, we must execute these self-referential messages 98 * synchronously, effectively turning the message into a glorified direct 99 * procedure call back into the protocol stack. The operation must be 100 * complete on return or we will deadlock, so panic if it isn't. 101 */ 102 static int 103 netmsg_put_port(lwkt_port_t port, lwkt_msg_t lmsg) 104 { 105 netmsg_t netmsg = (void *)lmsg; 106 107 if ((lmsg->ms_flags & MSGF_SYNC) && port == &curthread->td_msgport) { 108 netmsg->nm_dispatch(netmsg); 109 if ((lmsg->ms_flags & MSGF_DONE) == 0) 110 panic("netmsg_put_port: self-referential deadlock on netport"); 111 return(EASYNC); 112 } else { 113 return(netmsg_fwd_port_fn(port, lmsg)); 114 } 115 } 116 117 /* 118 * UNIX DOMAIN sockets still have to run their uipc functions synchronously, 119 * because they depend on the user proc context for a number of things 120 * (like creds) which we have not yet incorporated into the message structure. 121 * 122 * However, we maintain or message/port abstraction. Having a special 123 * synchronous port which runs the commands synchronously gives us the 124 * ability to serialize operations in one place later on when we start 125 * removing the BGL. 126 */ 127 static int 128 netmsg_sync_putport(lwkt_port_t port, lwkt_msg_t lmsg) 129 { 130 netmsg_t netmsg = (void *)lmsg; 131 132 KKASSERT((lmsg->ms_flags & MSGF_DONE) == 0); 133 134 lmsg->ms_target_port = port; /* required for abort */ 135 netmsg->nm_dispatch(netmsg); 136 return(EASYNC); 137 } 138 139 static void 140 netisr_init(void) 141 { 142 int i; 143 144 TAILQ_INIT(&netreglist); 145 146 /* 147 * Create default per-cpu threads for generic protocol handling. 148 */ 149 for (i = 0; i < ncpus; ++i) { 150 lwkt_create(netisr_mpsafe_thread ? 151 netmsg_service_loop_mpsafe : netmsg_service_loop, 152 NULL, NULL, &netisr_cpu[i], 153 0, i, "netisr_cpu %d", i); 154 netmsg_service_port_init(&netisr_cpu[i].td_msgport); 155 } 156 157 /* 158 * The netisr_afree_rport is a special reply port which automatically 159 * frees the replied message. The netisr_adone_rport simply marks 160 * the message as being done. The netisr_apanic_rport panics if 161 * the message is replied to. 162 */ 163 lwkt_initport_replyonly(&netisr_afree_rport, netisr_autofree_reply); 164 lwkt_initport_replyonly_null(&netisr_adone_rport); 165 lwkt_initport_panic(&netisr_apanic_rport); 166 167 /* 168 * The netisr_syncport is a special port which executes the message 169 * synchronously and waits for it if EASYNC is returned. 170 */ 171 lwkt_initport_putonly(&netisr_sync_port, netmsg_sync_putport); 172 } 173 174 SYSINIT(netisr, SI_SUB_PRE_DRIVERS, SI_ORDER_FIRST, netisr_init, NULL); 175 176 /* 177 * Finish initializing the message port for a netmsg service. This also 178 * registers the port for synchronous cleanup operations such as when an 179 * ifnet is being destroyed. There is no deregistration API yet. 180 */ 181 void 182 netmsg_service_port_init(lwkt_port_t port) 183 { 184 struct netmsg_port_registration *reg; 185 186 /* 187 * Override the putport function. Our custom function checks for 188 * self-references and executes such commands synchronously. 189 */ 190 if (netmsg_fwd_port_fn == NULL) 191 netmsg_fwd_port_fn = port->mp_putport; 192 KKASSERT(netmsg_fwd_port_fn == port->mp_putport); 193 port->mp_putport = netmsg_put_port; 194 195 /* 196 * Keep track of ports using the netmsg API so we can synchronize 197 * certain operations (such as freeing an ifnet structure) across all 198 * consumers. 199 */ 200 reg = kmalloc(sizeof(*reg), M_TEMP, M_WAITOK|M_ZERO); 201 reg->npr_port = port; 202 TAILQ_INSERT_TAIL(&netreglist, reg, npr_entry); 203 } 204 205 /* 206 * This function synchronizes the caller with all netmsg services. For 207 * example, if an interface is being removed we must make sure that all 208 * packets related to that interface complete processing before the structure 209 * can actually be freed. This sort of synchronization is an alternative to 210 * ref-counting the netif, removing the ref counting overhead in favor of 211 * placing additional overhead in the netif freeing sequence (where it is 212 * inconsequential). 213 */ 214 void 215 netmsg_service_sync(void) 216 { 217 struct netmsg_port_registration *reg; 218 struct netmsg smsg; 219 220 netmsg_init(&smsg, &curthread->td_msgport, 0, netmsg_sync_func); 221 222 TAILQ_FOREACH(reg, &netreglist, npr_entry) { 223 lwkt_domsg(reg->npr_port, &smsg.nm_lmsg, 0); 224 } 225 } 226 227 /* 228 * The netmsg function simply replies the message. API semantics require 229 * EASYNC to be returned if the netmsg function disposes of the message. 230 */ 231 static void 232 netmsg_sync_func(struct netmsg *msg) 233 { 234 lwkt_replymsg(&msg->nm_lmsg, 0); 235 } 236 237 /* 238 * Generic netmsg service loop. Some protocols may roll their own but all 239 * must do the basic command dispatch function call done here. 240 */ 241 void 242 netmsg_service_loop(void *arg) 243 { 244 struct netmsg *msg; 245 246 while ((msg = lwkt_waitport(&curthread->td_msgport, 0))) { 247 msg->nm_dispatch(msg); 248 } 249 } 250 251 /* 252 * MPSAFE version of netmsg_service_loop() 253 */ 254 void 255 netmsg_service_loop_mpsafe(void *arg) 256 { 257 rel_mplock(); 258 259 struct netmsg *msg; 260 261 while ((msg = lwkt_waitport(&curthread->td_msgport, 0))) { 262 msg->nm_dispatch(msg); 263 } 264 } 265 266 /* 267 * Call the netisr directly. 268 * Queueing may be done in the msg port layer at its discretion. 269 */ 270 void 271 netisr_dispatch(int num, struct mbuf *m) 272 { 273 /* just queue it for now XXX JH */ 274 netisr_queue(num, m); 275 } 276 277 /* 278 * Same as netisr_dispatch(), but always queue. 279 * This is either used in places where we are not confident that 280 * direct dispatch is possible, or where queueing is required. 281 */ 282 int 283 netisr_queue(int num, struct mbuf *m) 284 { 285 struct netisr *ni; 286 struct netmsg_packet *pmsg; 287 lwkt_port_t port; 288 289 KASSERT((num > 0 && num <= (sizeof(netisrs)/sizeof(netisrs[0]))), 290 ("netisr_queue: bad isr %d", num)); 291 292 ni = &netisrs[num]; 293 if (ni->ni_handler == NULL) { 294 kprintf("netisr_queue: unregistered isr %d\n", num); 295 m_freem(m); 296 return (EIO); 297 } 298 299 if ((port = ni->ni_mport(&m)) == NULL) 300 return (EIO); 301 302 pmsg = &m->m_hdr.mh_netmsg; 303 304 netmsg_init(&pmsg->nm_netmsg, &netisr_apanic_rport, 0, ni->ni_handler); 305 pmsg->nm_packet = m; 306 pmsg->nm_netmsg.nm_lmsg.u.ms_result = num; 307 lwkt_sendmsg(port, &pmsg->nm_netmsg.nm_lmsg); 308 return (0); 309 } 310 311 void 312 netisr_register(int num, lwkt_portfn_t mportfn, netisr_fn_t handler) 313 { 314 KASSERT((num > 0 && num <= (sizeof(netisrs)/sizeof(netisrs[0]))), 315 ("netisr_register: bad isr %d", num)); 316 netmsg_init(&netisrs[num].ni_netmsg, &netisr_adone_rport, 0, NULL); 317 netisrs[num].ni_mport = mportfn; 318 netisrs[num].ni_handler = handler; 319 } 320 321 int 322 netisr_unregister(int num) 323 { 324 KASSERT((num > 0 && num <= (sizeof(netisrs)/sizeof(netisrs[0]))), 325 ("unregister_netisr: bad isr number: %d\n", num)); 326 327 /* XXX JH */ 328 return (0); 329 } 330 331 /* 332 * Return message port for default handler thread on CPU 0. 333 */ 334 lwkt_port_t 335 cpu0_portfn(struct mbuf **mptr) 336 { 337 return (&netisr_cpu[0].td_msgport); 338 } 339 340 lwkt_port_t 341 cpu_portfn(int cpu) 342 { 343 return (&netisr_cpu[cpu].td_msgport); 344 } 345 346 /* ARGSUSED */ 347 lwkt_port_t 348 cpu0_soport(struct socket *so __unused, struct sockaddr *nam __unused, 349 struct mbuf **dummy __unused, int req __unused) 350 { 351 return (&netisr_cpu[0].td_msgport); 352 } 353 354 lwkt_port_t 355 sync_soport(struct socket *so __unused, struct sockaddr *nam __unused, 356 struct mbuf **dummy __unused, int req __unused) 357 { 358 return (&netisr_sync_port); 359 } 360 361 /* 362 * schednetisr() is used to call the netisr handler from the appropriate 363 * netisr thread for polling and other purposes. 364 * 365 * This function may be called from a hard interrupt or IPI and must be 366 * MP SAFE and non-blocking. We use a fixed per-cpu message instead of 367 * trying to allocate one. We must get ourselves onto the target cpu 368 * to safely check the MSGF_DONE bit on the message but since the message 369 * will be sent to that cpu anyway this does not add any extra work beyond 370 * what lwkt_sendmsg() would have already had to do to schedule the target 371 * thread. 372 */ 373 static void 374 schednetisr_remote(void *data) 375 { 376 int num = (int)data; 377 struct netisr *ni = &netisrs[num]; 378 lwkt_port_t port = &netisr_cpu[0].td_msgport; 379 struct netmsg *pmsg; 380 381 pmsg = &netisrs[num].ni_netmsg; 382 crit_enter(); 383 if (pmsg->nm_lmsg.ms_flags & MSGF_DONE) { 384 netmsg_init(pmsg, &netisr_adone_rport, 0, ni->ni_handler); 385 pmsg->nm_lmsg.u.ms_result = num; 386 lwkt_sendmsg(port, &pmsg->nm_lmsg); 387 } 388 crit_exit(); 389 } 390 391 void 392 schednetisr(int num) 393 { 394 KASSERT((num > 0 && num <= (sizeof(netisrs)/sizeof(netisrs[0]))), 395 ("schednetisr: bad isr %d", num)); 396 #ifdef SMP 397 if (mycpu->gd_cpuid != 0) 398 lwkt_send_ipiq(globaldata_find(0), schednetisr_remote, (void *)num); 399 else 400 schednetisr_remote((void *)num); 401 #else 402 schednetisr_remote((void *)num); 403 #endif 404 } 405 406 lwkt_port_t 407 netisr_mport(int num, struct mbuf **m0) 408 { 409 struct netisr *ni; 410 struct netmsg_packet *pmsg; 411 lwkt_port_t port; 412 struct mbuf *m = *m0; 413 414 *m0 = NULL; 415 416 KASSERT((num > 0 && num <= (sizeof(netisrs)/sizeof(netisrs[0]))), 417 ("netisr_queue: bad isr %d", num)); 418 419 ni = &netisrs[num]; 420 if (ni->ni_handler == NULL) { 421 kprintf("netisr_queue: unregistered isr %d\n", num); 422 m_freem(m); 423 return NULL; 424 } 425 426 if ((port = ni->ni_mport(&m)) == NULL) 427 return NULL; 428 429 pmsg = &m->m_hdr.mh_netmsg; 430 431 netmsg_init(&pmsg->nm_netmsg, &netisr_apanic_rport, 0, ni->ni_handler); 432 pmsg->nm_packet = m; 433 pmsg->nm_netmsg.nm_lmsg.u.ms_result = num; 434 435 *m0 = m; 436 return port; 437 } 438