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 1.35 2007/07/10 20:24:57 dillon 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 /* 79 * netisr_afree_rport replymsg function, only used to handle async 80 * messages which the sender has abandoned to their fate. 81 */ 82 static void 83 netisr_autofree_reply(lwkt_port_t port, lwkt_msg_t msg) 84 { 85 kfree(msg, M_LWKTMSG); 86 } 87 88 /* 89 * We need a custom putport function to handle the case where the 90 * message target is the current thread's message port. This case 91 * can occur when the TCP or UDP stack does a direct callback to NFS and NFS 92 * then turns around and executes a network operation synchronously. 93 * 94 * To prevent deadlocking, we must execute these self-referential messages 95 * synchronously, effectively turning the message into a glorified direct 96 * procedure call back into the protocol stack. The operation must be 97 * complete on return or we will deadlock, so panic if it isn't. 98 */ 99 static int 100 netmsg_put_port(lwkt_port_t port, lwkt_msg_t lmsg) 101 { 102 netmsg_t netmsg = (void *)lmsg; 103 104 if ((lmsg->ms_flags & MSGF_SYNC) && port == &curthread->td_msgport) { 105 netmsg->nm_dispatch(netmsg); 106 if ((lmsg->ms_flags & MSGF_DONE) == 0) 107 panic("netmsg_put_port: self-referential deadlock on netport"); 108 return(EASYNC); 109 } else { 110 return(netmsg_fwd_port_fn(port, lmsg)); 111 } 112 } 113 114 /* 115 * UNIX DOMAIN sockets still have to run their uipc functions synchronously, 116 * because they depend on the user proc context for a number of things 117 * (like creds) which we have not yet incorporated into the message structure. 118 * 119 * However, we maintain or message/port abstraction. Having a special 120 * synchronous port which runs the commands synchronously gives us the 121 * ability to serialize operations in one place later on when we start 122 * removing the BGL. 123 */ 124 static int 125 netmsg_sync_putport(lwkt_port_t port, lwkt_msg_t lmsg) 126 { 127 netmsg_t netmsg = (void *)lmsg; 128 129 KKASSERT((lmsg->ms_flags & MSGF_DONE) == 0); 130 131 lmsg->ms_target_port = port; /* required for abort */ 132 netmsg->nm_dispatch(netmsg); 133 return(EASYNC); 134 } 135 136 static void 137 netisr_init(void) 138 { 139 int i; 140 141 TAILQ_INIT(&netreglist); 142 143 /* 144 * Create default per-cpu threads for generic protocol handling. 145 */ 146 for (i = 0; i < ncpus; ++i) { 147 lwkt_create(netmsg_service_loop, NULL, NULL, &netisr_cpu[i], 0, i, 148 "netisr_cpu %d", i); 149 netmsg_service_port_init(&netisr_cpu[i].td_msgport); 150 } 151 152 /* 153 * The netisr_afree_rport is a special reply port which automatically 154 * frees the replied message. The netisr_adone_rport simply marks 155 * the message as being done. The netisr_apanic_rport panics if 156 * the message is replied to. 157 */ 158 lwkt_initport_replyonly(&netisr_afree_rport, netisr_autofree_reply); 159 lwkt_initport_replyonly_null(&netisr_adone_rport); 160 lwkt_initport_panic(&netisr_apanic_rport); 161 162 /* 163 * The netisr_syncport is a special port which executes the message 164 * synchronously and waits for it if EASYNC is returned. 165 */ 166 lwkt_initport_putonly(&netisr_sync_port, netmsg_sync_putport); 167 } 168 169 SYSINIT(netisr, SI_SUB_PROTO_BEGIN, SI_ORDER_FIRST, netisr_init, NULL); 170 171 /* 172 * Finish initializing the message port for a netmsg service. This also 173 * registers the port for synchronous cleanup operations such as when an 174 * ifnet is being destroyed. There is no deregistration API yet. 175 */ 176 void 177 netmsg_service_port_init(lwkt_port_t port) 178 { 179 struct netmsg_port_registration *reg; 180 181 /* 182 * Override the putport function. Our custom function checks for 183 * self-references and executes such commands synchronously. 184 */ 185 if (netmsg_fwd_port_fn == NULL) 186 netmsg_fwd_port_fn = port->mp_putport; 187 KKASSERT(netmsg_fwd_port_fn == port->mp_putport); 188 port->mp_putport = netmsg_put_port; 189 190 /* 191 * Keep track of ports using the netmsg API so we can synchronize 192 * certain operations (such as freeing an ifnet structure) across all 193 * consumers. 194 */ 195 reg = kmalloc(sizeof(*reg), M_TEMP, M_WAITOK|M_ZERO); 196 reg->npr_port = port; 197 TAILQ_INSERT_TAIL(&netreglist, reg, npr_entry); 198 } 199 200 /* 201 * This function synchronizes the caller with all netmsg services. For 202 * example, if an interface is being removed we must make sure that all 203 * packets related to that interface complete processing before the structure 204 * can actually be freed. This sort of synchronization is an alternative to 205 * ref-counting the netif, removing the ref counting overhead in favor of 206 * placing additional overhead in the netif freeing sequence (where it is 207 * inconsequential). 208 */ 209 void 210 netmsg_service_sync(void) 211 { 212 struct netmsg_port_registration *reg; 213 struct netmsg smsg; 214 215 netmsg_init(&smsg, &curthread->td_msgport, 0, netmsg_sync_func); 216 217 TAILQ_FOREACH(reg, &netreglist, npr_entry) { 218 lwkt_domsg(reg->npr_port, &smsg.nm_lmsg, 0); 219 } 220 } 221 222 /* 223 * The netmsg function simply replies the message. API semantics require 224 * EASYNC to be returned if the netmsg function disposes of the message. 225 */ 226 static void 227 netmsg_sync_func(struct netmsg *msg) 228 { 229 lwkt_replymsg(&msg->nm_lmsg, 0); 230 } 231 232 /* 233 * Generic netmsg service loop. Some protocols may roll their own but all 234 * must do the basic command dispatch function call done here. 235 */ 236 void 237 netmsg_service_loop(void *arg) 238 { 239 struct netmsg *msg; 240 241 while ((msg = lwkt_waitport(&curthread->td_msgport, 0))) { 242 msg->nm_dispatch(msg); 243 } 244 } 245 246 /* 247 * Call the netisr directly. 248 * Queueing may be done in the msg port layer at its discretion. 249 */ 250 void 251 netisr_dispatch(int num, struct mbuf *m) 252 { 253 /* just queue it for now XXX JH */ 254 netisr_queue(num, m); 255 } 256 257 /* 258 * Same as netisr_dispatch(), but always queue. 259 * This is either used in places where we are not confident that 260 * direct dispatch is possible, or where queueing is required. 261 */ 262 int 263 netisr_queue(int num, struct mbuf *m) 264 { 265 struct netisr *ni; 266 struct netmsg_packet *pmsg; 267 lwkt_port_t port; 268 269 KASSERT((num > 0 && num <= (sizeof(netisrs)/sizeof(netisrs[0]))), 270 ("netisr_queue: bad isr %d", num)); 271 272 ni = &netisrs[num]; 273 if (ni->ni_handler == NULL) { 274 kprintf("netisr_queue: unregistered isr %d\n", num); 275 return (EIO); 276 } 277 278 if ((port = ni->ni_mport(&m)) == NULL) 279 return (EIO); 280 281 pmsg = &m->m_hdr.mh_netmsg; 282 283 netmsg_init(&pmsg->nm_netmsg, &netisr_apanic_rport, 0, ni->ni_handler); 284 pmsg->nm_packet = m; 285 pmsg->nm_netmsg.nm_lmsg.u.ms_result = num; 286 lwkt_sendmsg(port, &pmsg->nm_netmsg.nm_lmsg); 287 return (0); 288 } 289 290 void 291 netisr_register(int num, lwkt_portfn_t mportfn, netisr_fn_t handler) 292 { 293 KASSERT((num > 0 && num <= (sizeof(netisrs)/sizeof(netisrs[0]))), 294 ("netisr_register: bad isr %d", num)); 295 netmsg_init(&netisrs[num].ni_netmsg, &netisr_adone_rport, 0, NULL); 296 netisrs[num].ni_mport = mportfn; 297 netisrs[num].ni_handler = handler; 298 } 299 300 int 301 netisr_unregister(int num) 302 { 303 KASSERT((num > 0 && num <= (sizeof(netisrs)/sizeof(netisrs[0]))), 304 ("unregister_netisr: bad isr number: %d\n", num)); 305 306 /* XXX JH */ 307 return (0); 308 } 309 310 /* 311 * Return message port for default handler thread on CPU 0. 312 */ 313 lwkt_port_t 314 cpu0_portfn(struct mbuf **mptr) 315 { 316 return (&netisr_cpu[0].td_msgport); 317 } 318 319 lwkt_port_t 320 cpu_portfn(int cpu) 321 { 322 return (&netisr_cpu[cpu].td_msgport); 323 } 324 325 /* ARGSUSED */ 326 lwkt_port_t 327 cpu0_soport(struct socket *so __unused, struct sockaddr *nam __unused, 328 int req __unused) 329 { 330 return (&netisr_cpu[0].td_msgport); 331 } 332 333 lwkt_port_t 334 sync_soport(struct socket *so __unused, struct sockaddr *nam __unused, 335 int req __unused) 336 { 337 return (&netisr_sync_port); 338 } 339 340 /* 341 * schednetisr() is used to call the netisr handler from the appropriate 342 * netisr thread for polling and other purposes. 343 * 344 * This function may be called from a hard interrupt or IPI and must be 345 * MP SAFE and non-blocking. We use a fixed per-cpu message instead of 346 * trying to allocate one. We must get ourselves onto the target cpu 347 * to safely check the MSGF_DONE bit on the message but since the message 348 * will be sent to that cpu anyway this does not add any extra work beyond 349 * what lwkt_sendmsg() would have already had to do to schedule the target 350 * thread. 351 */ 352 static void 353 schednetisr_remote(void *data) 354 { 355 int num = (int)data; 356 struct netisr *ni = &netisrs[num]; 357 lwkt_port_t port = &netisr_cpu[0].td_msgport; 358 struct netmsg *pmsg; 359 360 pmsg = &netisrs[num].ni_netmsg; 361 crit_enter(); 362 if (pmsg->nm_lmsg.ms_flags & MSGF_DONE) { 363 netmsg_init(pmsg, &netisr_adone_rport, 0, ni->ni_handler); 364 pmsg->nm_lmsg.u.ms_result = num; 365 lwkt_sendmsg(port, &pmsg->nm_lmsg); 366 } 367 crit_exit(); 368 } 369 370 void 371 schednetisr(int num) 372 { 373 KASSERT((num > 0 && num <= (sizeof(netisrs)/sizeof(netisrs[0]))), 374 ("schednetisr: bad isr %d", num)); 375 #ifdef SMP 376 if (mycpu->gd_cpuid != 0) 377 lwkt_send_ipiq(globaldata_find(0), schednetisr_remote, (void *)num); 378 else 379 schednetisr_remote((void *)num); 380 #else 381 schednetisr_remote((void *)num); 382 #endif 383 } 384 385