1 /*- 2 * Copyright (c) 2001-2002 Luigi Rizzo 3 * 4 * Supported by: the Xorp Project (www.xorp.org) 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 * 27 * $FreeBSD: src/sys/kern/kern_poll.c,v 1.2.2.4 2002/06/27 23:26:33 luigi Exp $ 28 */ 29 30 #include "opt_ifpoll.h" 31 32 #include <sys/param.h> 33 #include <sys/kernel.h> 34 #include <sys/ktr.h> 35 #include <sys/malloc.h> 36 #include <sys/serialize.h> 37 #include <sys/socket.h> 38 #include <sys/sysctl.h> 39 40 #include <sys/thread2.h> 41 #include <sys/msgport2.h> 42 43 #include <machine/atomic.h> 44 #include <machine/clock.h> 45 #include <machine/smp.h> 46 47 #include <net/if.h> 48 #include <net/if_poll.h> 49 #include <net/netmsg2.h> 50 51 /* 52 * Polling support for network device drivers. 53 * 54 * Drivers which support this feature try to register one status polling 55 * handler and several TX/RX polling handlers with the polling code. 56 * If interface's if_npoll is called with non-NULL second argument, then 57 * a register operation is requested, else a deregister operation is 58 * requested. If the requested operation is "register", driver should 59 * setup the ifpoll_info passed in accoding its own needs: 60 * ifpoll_info.ifpi_status.status_func == NULL 61 * No status polling handler will be installed on CPU(0) 62 * ifpoll_info.ifpi_rx[n].poll_func == NULL 63 * No RX polling handler will be installed on CPU(n) 64 * ifpoll_info.ifpi_tx[n].poll_func == NULL 65 * No TX polling handler will be installed on CPU(n) 66 * 67 * RX is polled at the specified polling frequency (net.ifpoll.X.pollhz). 68 * TX and status polling could be done at lower frequency than RX frequency 69 * (net.ifpoll.0.status_frac and net.ifpoll.X.tx_frac). To avoid systimer 70 * staggering at high frequency, RX systimer gives TX and status polling a 71 * piggyback (XXX). 72 * 73 * All of the registered polling handlers are called only if the interface 74 * is marked as 'IFF_RUNNING and IFF_NPOLLING'. However, the interface's 75 * register and deregister function (ifnet.if_npoll) will be called even 76 * if interface is not marked with 'IFF_RUNNING'. 77 * 78 * If registration is successful, the driver must disable interrupts, 79 * and further I/O is performed through the TX/RX polling handler, which 80 * are invoked (at least once per clock tick) with 3 arguments: the "arg" 81 * passed at register time, a struct ifnet pointer, and a "count" limit. 82 * The registered serializer will be held before calling the related 83 * polling handler. 84 * 85 * The count limit specifies how much work the handler can do during the 86 * call -- typically this is the number of packets to be received, or 87 * transmitted, etc. (drivers are free to interpret this number, as long 88 * as the max time spent in the function grows roughly linearly with the 89 * count). 90 * 91 * A second variable controls the sharing of CPU between polling/kernel 92 * network processing, and other activities (typically userlevel tasks): 93 * net.ifpoll.X.{rx,tx}.user_frac (between 0 and 100, default 50) sets the 94 * share of CPU allocated to user tasks. CPU is allocated proportionally 95 * to the shares, by dynamically adjusting the "count" (poll_burst). 96 * 97 * Other parameters can should be left to their default values. 98 * The following constraints hold 99 * 100 * 1 <= poll_burst <= poll_burst_max 101 * 1 <= poll_each_burst <= poll_burst_max 102 * MIN_POLL_BURST_MAX <= poll_burst_max <= MAX_POLL_BURST_MAX 103 */ 104 105 #define IFPOLL_LIST_LEN 128 106 #define IFPOLL_FREQ_MAX 30000 107 108 #define MIN_IOPOLL_BURST_MAX 10 109 #define MAX_IOPOLL_BURST_MAX 5000 110 #define IOPOLL_BURST_MAX 375 /* good for 1000Mbit net and HZ=4000 */ 111 112 #define IOPOLL_EACH_BURST 15 113 114 #define IFPOLL_FREQ_DEFAULT 4000 115 116 #define IFPOLL_TXFRAC_DEFAULT 1 /* 1/1 of the pollhz */ 117 #define IFPOLL_STFRAC_DEFAULT 40 /* 1/40 of the pollhz */ 118 119 #define IFPOLL_RX 0x1 120 #define IFPOLL_TX 0x2 121 122 union ifpoll_time { 123 struct timeval tv; 124 uint64_t tsc; 125 }; 126 127 struct iopoll_rec { 128 struct lwkt_serialize *serializer; 129 struct ifnet *ifp; 130 void *arg; 131 ifpoll_iofn_t poll_func; 132 }; 133 134 struct iopoll_ctx { 135 union ifpoll_time prev_t; 136 u_long short_ticks; /* statistics */ 137 u_long lost_polls; /* statistics */ 138 u_long suspect; /* statistics */ 139 u_long stalled; /* statistics */ 140 uint32_t pending_polls; /* state */ 141 142 struct netmsg_base poll_netmsg; 143 struct netmsg_base poll_more_netmsg; 144 145 int poll_cpuid; 146 int pollhz; 147 uint32_t phase; /* state */ 148 int residual_burst; /* state */ 149 uint32_t poll_each_burst; /* tunable */ 150 union ifpoll_time poll_start_t; /* state */ 151 152 uint32_t poll_burst; /* state */ 153 uint32_t poll_burst_max; /* tunable */ 154 uint32_t user_frac; /* tunable */ 155 uint32_t kern_frac; /* state */ 156 157 uint32_t poll_handlers; /* next free entry in pr[]. */ 158 struct iopoll_rec pr[IFPOLL_LIST_LEN]; 159 160 struct sysctl_ctx_list poll_sysctl_ctx; 161 struct sysctl_oid *poll_sysctl_tree; 162 } __cachealign; 163 164 struct poll_comm { 165 struct systimer pollclock; 166 int poll_cpuid; 167 168 int stfrac_count; /* state */ 169 int poll_stfrac; /* tunable */ 170 171 int txfrac_count; /* state */ 172 int poll_txfrac; /* tunable */ 173 174 int pollhz; /* tunable */ 175 176 struct sysctl_ctx_list sysctl_ctx; 177 struct sysctl_oid *sysctl_tree; 178 } __cachealign; 179 180 struct stpoll_rec { 181 struct lwkt_serialize *serializer; 182 struct ifnet *ifp; 183 ifpoll_stfn_t status_func; 184 }; 185 186 struct stpoll_ctx { 187 struct netmsg_base poll_netmsg; 188 189 uint32_t poll_handlers; /* next free entry in pr[]. */ 190 struct stpoll_rec pr[IFPOLL_LIST_LEN]; 191 192 struct sysctl_ctx_list poll_sysctl_ctx; 193 struct sysctl_oid *poll_sysctl_tree; 194 } __cachealign; 195 196 struct iopoll_sysctl_netmsg { 197 struct netmsg_base base; 198 struct iopoll_ctx *ctx; 199 }; 200 201 void ifpoll_init_pcpu(int); 202 static void ifpoll_register_handler(netmsg_t); 203 static void ifpoll_deregister_handler(netmsg_t); 204 205 /* 206 * Status polling 207 */ 208 static void stpoll_init(void); 209 static void stpoll_handler(netmsg_t); 210 static void stpoll_clock(struct stpoll_ctx *); 211 static int stpoll_register(struct ifnet *, const struct ifpoll_status *); 212 static int stpoll_deregister(struct ifnet *); 213 214 /* 215 * RX/TX polling 216 */ 217 static struct iopoll_ctx *iopoll_ctx_create(int, int); 218 static void iopoll_init(int); 219 static void rxpoll_handler(netmsg_t); 220 static void txpoll_handler(netmsg_t); 221 static void rxpollmore_handler(netmsg_t); 222 static void txpollmore_handler(netmsg_t); 223 static void iopoll_clock(struct iopoll_ctx *); 224 static int iopoll_register(struct ifnet *, struct iopoll_ctx *, 225 const struct ifpoll_io *); 226 static int iopoll_deregister(struct ifnet *, struct iopoll_ctx *); 227 228 static void iopoll_add_sysctl(struct sysctl_ctx_list *, 229 struct sysctl_oid_list *, struct iopoll_ctx *, int); 230 static void sysctl_burstmax_handler(netmsg_t); 231 static int sysctl_burstmax(SYSCTL_HANDLER_ARGS); 232 static void sysctl_eachburst_handler(netmsg_t); 233 static int sysctl_eachburst(SYSCTL_HANDLER_ARGS); 234 235 /* 236 * Common functions 237 */ 238 static void poll_comm_init(int); 239 static void poll_comm_start(int); 240 static void poll_comm_adjust_pollhz(struct poll_comm *); 241 static void poll_comm_systimer0(systimer_t, int, struct intrframe *); 242 static void poll_comm_systimer(systimer_t, int, struct intrframe *); 243 static void sysctl_pollhz_handler(netmsg_t); 244 static void sysctl_stfrac_handler(netmsg_t); 245 static void sysctl_txfrac_handler(netmsg_t); 246 static int sysctl_pollhz(SYSCTL_HANDLER_ARGS); 247 static int sysctl_stfrac(SYSCTL_HANDLER_ARGS); 248 static int sysctl_txfrac(SYSCTL_HANDLER_ARGS); 249 static int sysctl_compat_npoll_stfrac(SYSCTL_HANDLER_ARGS); 250 static int sysctl_compat_npoll_cpuid(SYSCTL_HANDLER_ARGS); 251 252 static struct stpoll_ctx stpoll_context; 253 static struct poll_comm *poll_common[MAXCPU]; 254 static struct iopoll_ctx *rxpoll_context[MAXCPU]; 255 static struct iopoll_ctx *txpoll_context[MAXCPU]; 256 257 SYSCTL_NODE(_net, OID_AUTO, ifpoll, CTLFLAG_RW, 0, 258 "Network device polling parameters"); 259 260 static int iopoll_burst_max = IOPOLL_BURST_MAX; 261 static int iopoll_each_burst = IOPOLL_EACH_BURST; 262 263 static int ifpoll_pollhz = IFPOLL_FREQ_DEFAULT; 264 static int ifpoll_stfrac = IFPOLL_STFRAC_DEFAULT; 265 static int ifpoll_txfrac = IFPOLL_TXFRAC_DEFAULT; 266 267 TUNABLE_INT("net.ifpoll.burst_max", &iopoll_burst_max); 268 TUNABLE_INT("net.ifpoll.each_burst", &iopoll_each_burst); 269 TUNABLE_INT("net.ifpoll.pollhz", &ifpoll_pollhz); 270 TUNABLE_INT("net.ifpoll.status_frac", &ifpoll_stfrac); 271 TUNABLE_INT("net.ifpoll.tx_frac", &ifpoll_txfrac); 272 273 static __inline void 274 ifpoll_sendmsg_oncpu(netmsg_t msg) 275 { 276 if (msg->lmsg.ms_flags & MSGF_DONE) 277 lwkt_sendmsg(netisr_portfn(mycpuid), &msg->lmsg); 278 } 279 280 static __inline void 281 sched_stpoll(struct stpoll_ctx *st_ctx) 282 { 283 ifpoll_sendmsg_oncpu((netmsg_t)&st_ctx->poll_netmsg); 284 } 285 286 static __inline void 287 sched_iopoll(struct iopoll_ctx *io_ctx) 288 { 289 ifpoll_sendmsg_oncpu((netmsg_t)&io_ctx->poll_netmsg); 290 } 291 292 static __inline void 293 sched_iopollmore(struct iopoll_ctx *io_ctx) 294 { 295 ifpoll_sendmsg_oncpu((netmsg_t)&io_ctx->poll_more_netmsg); 296 } 297 298 static __inline void 299 ifpoll_time_get(union ifpoll_time *t) 300 { 301 if (__predict_true(tsc_present)) 302 t->tsc = rdtsc(); 303 else 304 microuptime(&t->tv); 305 } 306 307 /* Return time diff in us */ 308 static __inline int 309 ifpoll_time_diff(const union ifpoll_time *s, const union ifpoll_time *e) 310 { 311 if (__predict_true(tsc_present)) { 312 return (((e->tsc - s->tsc) * 1000000) / tsc_frequency); 313 } else { 314 return ((e->tv.tv_usec - s->tv.tv_usec) + 315 (e->tv.tv_sec - s->tv.tv_sec) * 1000000); 316 } 317 } 318 319 /* 320 * Initialize per-cpu qpolling(4) context. Called from kern_clock.c: 321 */ 322 void 323 ifpoll_init_pcpu(int cpuid) 324 { 325 if (cpuid >= ncpus2) 326 return; 327 328 poll_comm_init(cpuid); 329 330 if (cpuid == 0) 331 stpoll_init(); 332 iopoll_init(cpuid); 333 334 poll_comm_start(cpuid); 335 } 336 337 int 338 ifpoll_register(struct ifnet *ifp) 339 { 340 struct ifpoll_info *info; 341 struct netmsg_base nmsg; 342 int error; 343 344 if (ifp->if_npoll == NULL) { 345 /* Device does not support polling */ 346 return EOPNOTSUPP; 347 } 348 349 info = kmalloc(sizeof(*info), M_TEMP, M_WAITOK | M_ZERO); 350 351 /* 352 * Attempt to register. Interlock with IFF_NPOLLING. 353 */ 354 355 ifnet_serialize_all(ifp); 356 357 if (ifp->if_flags & IFF_NPOLLING) { 358 /* Already polling */ 359 ifnet_deserialize_all(ifp); 360 kfree(info, M_TEMP); 361 return EBUSY; 362 } 363 364 info->ifpi_ifp = ifp; 365 366 ifp->if_flags |= IFF_NPOLLING; 367 ifp->if_npoll(ifp, info); 368 KASSERT(ifp->if_npoll_cpuid >= 0, ("invalid npoll cpuid")); 369 370 ifnet_deserialize_all(ifp); 371 372 netmsg_init(&nmsg, NULL, &curthread->td_msgport, 373 0, ifpoll_register_handler); 374 nmsg.lmsg.u.ms_resultp = info; 375 376 error = lwkt_domsg(netisr_portfn(0), &nmsg.lmsg, 0); 377 if (error) { 378 if (!ifpoll_deregister(ifp)) { 379 if_printf(ifp, "ifpoll_register: " 380 "ifpoll_deregister failed!\n"); 381 } 382 } 383 384 kfree(info, M_TEMP); 385 return error; 386 } 387 388 int 389 ifpoll_deregister(struct ifnet *ifp) 390 { 391 struct netmsg_base nmsg; 392 int error; 393 394 if (ifp->if_npoll == NULL) 395 return EOPNOTSUPP; 396 397 ifnet_serialize_all(ifp); 398 399 if ((ifp->if_flags & IFF_NPOLLING) == 0) { 400 ifnet_deserialize_all(ifp); 401 return EINVAL; 402 } 403 ifp->if_flags &= ~IFF_NPOLLING; 404 405 ifnet_deserialize_all(ifp); 406 407 netmsg_init(&nmsg, NULL, &curthread->td_msgport, 408 0, ifpoll_deregister_handler); 409 nmsg.lmsg.u.ms_resultp = ifp; 410 411 error = lwkt_domsg(netisr_portfn(0), &nmsg.lmsg, 0); 412 if (!error) { 413 ifnet_serialize_all(ifp); 414 ifp->if_npoll(ifp, NULL); 415 KASSERT(ifp->if_npoll_cpuid < 0, ("invalid npoll cpuid")); 416 ifnet_deserialize_all(ifp); 417 } 418 return error; 419 } 420 421 static void 422 ifpoll_register_handler(netmsg_t nmsg) 423 { 424 const struct ifpoll_info *info = nmsg->lmsg.u.ms_resultp; 425 int cpuid = mycpuid, nextcpu; 426 int error; 427 428 KKASSERT(cpuid < ncpus2); 429 KKASSERT(&curthread->td_msgport == netisr_portfn(cpuid)); 430 431 if (cpuid == 0) { 432 error = stpoll_register(info->ifpi_ifp, &info->ifpi_status); 433 if (error) 434 goto failed; 435 } 436 437 error = iopoll_register(info->ifpi_ifp, rxpoll_context[cpuid], 438 &info->ifpi_rx[cpuid]); 439 if (error) 440 goto failed; 441 442 error = iopoll_register(info->ifpi_ifp, txpoll_context[cpuid], 443 &info->ifpi_tx[cpuid]); 444 if (error) 445 goto failed; 446 447 /* Adjust polling frequency, after all registration is done */ 448 poll_comm_adjust_pollhz(poll_common[cpuid]); 449 450 nextcpu = cpuid + 1; 451 if (nextcpu < ncpus2) 452 lwkt_forwardmsg(netisr_portfn(nextcpu), &nmsg->lmsg); 453 else 454 lwkt_replymsg(&nmsg->lmsg, 0); 455 return; 456 failed: 457 lwkt_replymsg(&nmsg->lmsg, error); 458 } 459 460 static void 461 ifpoll_deregister_handler(netmsg_t nmsg) 462 { 463 struct ifnet *ifp = nmsg->lmsg.u.ms_resultp; 464 int cpuid = mycpuid, nextcpu; 465 466 KKASSERT(cpuid < ncpus2); 467 KKASSERT(&curthread->td_msgport == netisr_portfn(cpuid)); 468 469 /* Ignore errors */ 470 if (cpuid == 0) 471 stpoll_deregister(ifp); 472 iopoll_deregister(ifp, rxpoll_context[cpuid]); 473 iopoll_deregister(ifp, txpoll_context[cpuid]); 474 475 /* Adjust polling frequency, after all deregistration is done */ 476 poll_comm_adjust_pollhz(poll_common[cpuid]); 477 478 nextcpu = cpuid + 1; 479 if (nextcpu < ncpus2) 480 lwkt_forwardmsg(netisr_portfn(nextcpu), &nmsg->lmsg); 481 else 482 lwkt_replymsg(&nmsg->lmsg, 0); 483 } 484 485 static void 486 stpoll_init(void) 487 { 488 struct stpoll_ctx *st_ctx = &stpoll_context; 489 const struct poll_comm *comm = poll_common[0]; 490 491 sysctl_ctx_init(&st_ctx->poll_sysctl_ctx); 492 st_ctx->poll_sysctl_tree = SYSCTL_ADD_NODE(&st_ctx->poll_sysctl_ctx, 493 SYSCTL_CHILDREN(comm->sysctl_tree), 494 OID_AUTO, "status", CTLFLAG_RD, 0, ""); 495 496 SYSCTL_ADD_UINT(&st_ctx->poll_sysctl_ctx, 497 SYSCTL_CHILDREN(st_ctx->poll_sysctl_tree), 498 OID_AUTO, "handlers", CTLFLAG_RD, 499 &st_ctx->poll_handlers, 0, 500 "Number of registered status poll handlers"); 501 502 netmsg_init(&st_ctx->poll_netmsg, NULL, &netisr_adone_rport, 503 0, stpoll_handler); 504 } 505 506 /* 507 * stpoll_handler is scheduled by sched_stpoll when appropriate, typically 508 * once per polling systimer tick. 509 */ 510 static void 511 stpoll_handler(netmsg_t msg) 512 { 513 struct stpoll_ctx *st_ctx = &stpoll_context; 514 struct thread *td = curthread; 515 int i; 516 517 KKASSERT(&td->td_msgport == netisr_portfn(0)); 518 519 crit_enter_quick(td); 520 521 /* Reply ASAP */ 522 lwkt_replymsg(&msg->lmsg, 0); 523 524 if (st_ctx->poll_handlers == 0) { 525 crit_exit_quick(td); 526 return; 527 } 528 529 for (i = 0; i < st_ctx->poll_handlers; ++i) { 530 const struct stpoll_rec *rec = &st_ctx->pr[i]; 531 struct ifnet *ifp = rec->ifp; 532 533 if (!lwkt_serialize_try(rec->serializer)) 534 continue; 535 536 if ((ifp->if_flags & (IFF_RUNNING | IFF_NPOLLING)) == 537 (IFF_RUNNING | IFF_NPOLLING)) 538 rec->status_func(ifp); 539 540 lwkt_serialize_exit(rec->serializer); 541 } 542 543 crit_exit_quick(td); 544 } 545 546 /* 547 * Hook from status poll systimer. Tries to schedule an status poll. 548 * NOTE: Caller should hold critical section. 549 */ 550 static void 551 stpoll_clock(struct stpoll_ctx *st_ctx) 552 { 553 KKASSERT(mycpuid == 0); 554 555 if (st_ctx->poll_handlers == 0) 556 return; 557 sched_stpoll(st_ctx); 558 } 559 560 static int 561 stpoll_register(struct ifnet *ifp, const struct ifpoll_status *st_rec) 562 { 563 struct stpoll_ctx *st_ctx = &stpoll_context; 564 int error; 565 566 KKASSERT(&curthread->td_msgport == netisr_portfn(0)); 567 568 if (st_rec->status_func == NULL) 569 return 0; 570 571 /* 572 * Check if there is room. 573 */ 574 if (st_ctx->poll_handlers >= IFPOLL_LIST_LEN) { 575 /* 576 * List full, cannot register more entries. 577 * This should never happen; if it does, it is probably a 578 * broken driver trying to register multiple times. Checking 579 * this at runtime is expensive, and won't solve the problem 580 * anyways, so just report a few times and then give up. 581 */ 582 static int verbose = 10; /* XXX */ 583 584 if (verbose > 0) { 585 kprintf("status poll handlers list full, " 586 "maybe a broken driver ?\n"); 587 verbose--; 588 } 589 error = ENOENT; 590 } else { 591 struct stpoll_rec *rec = &st_ctx->pr[st_ctx->poll_handlers]; 592 593 rec->ifp = ifp; 594 rec->serializer = st_rec->serializer; 595 rec->status_func = st_rec->status_func; 596 597 st_ctx->poll_handlers++; 598 error = 0; 599 } 600 return error; 601 } 602 603 static int 604 stpoll_deregister(struct ifnet *ifp) 605 { 606 struct stpoll_ctx *st_ctx = &stpoll_context; 607 int i, error; 608 609 KKASSERT(&curthread->td_msgport == netisr_portfn(0)); 610 611 for (i = 0; i < st_ctx->poll_handlers; ++i) { 612 if (st_ctx->pr[i].ifp == ifp) /* Found it */ 613 break; 614 } 615 if (i == st_ctx->poll_handlers) { 616 error = ENOENT; 617 } else { 618 st_ctx->poll_handlers--; 619 if (i < st_ctx->poll_handlers) { 620 /* Last entry replaces this one. */ 621 st_ctx->pr[i] = st_ctx->pr[st_ctx->poll_handlers]; 622 } 623 error = 0; 624 } 625 return error; 626 } 627 628 static __inline void 629 iopoll_reset_state(struct iopoll_ctx *io_ctx) 630 { 631 crit_enter(); 632 io_ctx->poll_burst = io_ctx->poll_each_burst; 633 io_ctx->pending_polls = 0; 634 io_ctx->residual_burst = 0; 635 io_ctx->phase = 0; 636 io_ctx->kern_frac = 0; 637 bzero(&io_ctx->poll_start_t, sizeof(io_ctx->poll_start_t)); 638 bzero(&io_ctx->prev_t, sizeof(io_ctx->prev_t)); 639 crit_exit(); 640 } 641 642 static void 643 iopoll_init(int cpuid) 644 { 645 KKASSERT(cpuid < ncpus2); 646 647 rxpoll_context[cpuid] = iopoll_ctx_create(cpuid, IFPOLL_RX); 648 txpoll_context[cpuid] = iopoll_ctx_create(cpuid, IFPOLL_TX); 649 } 650 651 static struct iopoll_ctx * 652 iopoll_ctx_create(int cpuid, int poll_type) 653 { 654 struct poll_comm *comm; 655 struct iopoll_ctx *io_ctx; 656 const char *poll_type_str; 657 netisr_fn_t handler, more_handler; 658 659 KKASSERT(poll_type == IFPOLL_RX || poll_type == IFPOLL_TX); 660 661 /* 662 * Make sure that tunables are in sane state 663 */ 664 if (iopoll_burst_max < MIN_IOPOLL_BURST_MAX) 665 iopoll_burst_max = MIN_IOPOLL_BURST_MAX; 666 else if (iopoll_burst_max > MAX_IOPOLL_BURST_MAX) 667 iopoll_burst_max = MAX_IOPOLL_BURST_MAX; 668 669 if (iopoll_each_burst > iopoll_burst_max) 670 iopoll_each_burst = iopoll_burst_max; 671 672 comm = poll_common[cpuid]; 673 674 /* 675 * Create the per-cpu polling context 676 */ 677 io_ctx = kmalloc_cachealign(sizeof(*io_ctx), M_DEVBUF, 678 M_WAITOK | M_ZERO); 679 680 io_ctx->poll_each_burst = iopoll_each_burst; 681 io_ctx->poll_burst_max = iopoll_burst_max; 682 io_ctx->user_frac = 50; 683 if (poll_type == IFPOLL_RX) 684 io_ctx->pollhz = comm->pollhz; 685 else 686 io_ctx->pollhz = comm->pollhz / (comm->poll_txfrac + 1); 687 io_ctx->poll_cpuid = cpuid; 688 iopoll_reset_state(io_ctx); 689 690 if (poll_type == IFPOLL_RX) { 691 handler = rxpoll_handler; 692 more_handler = rxpollmore_handler; 693 } else { 694 handler = txpoll_handler; 695 more_handler = txpollmore_handler; 696 } 697 698 netmsg_init(&io_ctx->poll_netmsg, NULL, &netisr_adone_rport, 699 0, handler); 700 io_ctx->poll_netmsg.lmsg.u.ms_resultp = io_ctx; 701 702 netmsg_init(&io_ctx->poll_more_netmsg, NULL, &netisr_adone_rport, 703 0, more_handler); 704 io_ctx->poll_more_netmsg.lmsg.u.ms_resultp = io_ctx; 705 706 /* 707 * Initialize per-cpu sysctl nodes 708 */ 709 if (poll_type == IFPOLL_RX) 710 poll_type_str = "rx"; 711 else 712 poll_type_str = "tx"; 713 714 sysctl_ctx_init(&io_ctx->poll_sysctl_ctx); 715 io_ctx->poll_sysctl_tree = SYSCTL_ADD_NODE(&io_ctx->poll_sysctl_ctx, 716 SYSCTL_CHILDREN(comm->sysctl_tree), 717 OID_AUTO, poll_type_str, CTLFLAG_RD, 0, ""); 718 iopoll_add_sysctl(&io_ctx->poll_sysctl_ctx, 719 SYSCTL_CHILDREN(io_ctx->poll_sysctl_tree), io_ctx, poll_type); 720 721 return io_ctx; 722 } 723 724 /* 725 * Hook from iopoll systimer. Tries to schedule an iopoll, but keeps 726 * track of lost ticks due to the previous handler taking too long. 727 * Normally, this should not happen, because polling handler should 728 * run for a short time. However, in some cases (e.g. when there are 729 * changes in link status etc.) the drivers take a very long time 730 * (even in the order of milliseconds) to reset and reconfigure the 731 * device, causing apparent lost polls. 732 * 733 * The first part of the code is just for debugging purposes, and tries 734 * to count how often hardclock ticks are shorter than they should, 735 * meaning either stray interrupts or delayed events. 736 * 737 * WARNING! called from fastint or IPI, the MP lock might not be held. 738 * NOTE: Caller should hold critical section. 739 */ 740 static void 741 iopoll_clock(struct iopoll_ctx *io_ctx) 742 { 743 union ifpoll_time t; 744 int delta; 745 746 KKASSERT(mycpuid == io_ctx->poll_cpuid); 747 748 if (io_ctx->poll_handlers == 0) 749 return; 750 751 ifpoll_time_get(&t); 752 delta = ifpoll_time_diff(&io_ctx->prev_t, &t); 753 if (delta * io_ctx->pollhz < 500000) 754 io_ctx->short_ticks++; 755 else 756 io_ctx->prev_t = t; 757 758 if (io_ctx->pending_polls > 100) { 759 /* 760 * Too much, assume it has stalled (not always true 761 * see comment above). 762 */ 763 io_ctx->stalled++; 764 io_ctx->pending_polls = 0; 765 io_ctx->phase = 0; 766 } 767 768 if (io_ctx->phase <= 2) { 769 if (io_ctx->phase != 0) 770 io_ctx->suspect++; 771 io_ctx->phase = 1; 772 sched_iopoll(io_ctx); 773 io_ctx->phase = 2; 774 } 775 if (io_ctx->pending_polls++ > 0) 776 io_ctx->lost_polls++; 777 } 778 779 /* 780 * rxpoll_handler and txpoll_handler are scheduled by sched_iopoll when 781 * appropriate, typically once per polling systimer tick. 782 * 783 * Note that the message is replied immediately in order to allow a new 784 * ISR to be scheduled in the handler. 785 */ 786 static void 787 rxpoll_handler(netmsg_t msg) 788 { 789 struct iopoll_ctx *io_ctx; 790 struct thread *td = curthread; 791 int i, cycles; 792 793 io_ctx = msg->lmsg.u.ms_resultp; 794 KKASSERT(&td->td_msgport == netisr_portfn(io_ctx->poll_cpuid)); 795 796 crit_enter_quick(td); 797 798 /* Reply ASAP */ 799 lwkt_replymsg(&msg->lmsg, 0); 800 801 if (io_ctx->poll_handlers == 0) { 802 crit_exit_quick(td); 803 return; 804 } 805 806 io_ctx->phase = 3; 807 if (io_ctx->residual_burst == 0) { 808 /* First call in this tick */ 809 ifpoll_time_get(&io_ctx->poll_start_t); 810 io_ctx->residual_burst = io_ctx->poll_burst; 811 } 812 cycles = (io_ctx->residual_burst < io_ctx->poll_each_burst) ? 813 io_ctx->residual_burst : io_ctx->poll_each_burst; 814 io_ctx->residual_burst -= cycles; 815 816 for (i = 0; i < io_ctx->poll_handlers; i++) { 817 const struct iopoll_rec *rec = &io_ctx->pr[i]; 818 struct ifnet *ifp = rec->ifp; 819 820 if (!lwkt_serialize_try(rec->serializer)) 821 continue; 822 823 if ((ifp->if_flags & (IFF_RUNNING | IFF_NPOLLING)) == 824 (IFF_RUNNING | IFF_NPOLLING)) 825 rec->poll_func(ifp, rec->arg, cycles); 826 827 lwkt_serialize_exit(rec->serializer); 828 } 829 830 /* 831 * Do a quick exit/enter to catch any higher-priority 832 * interrupt sources. 833 */ 834 crit_exit_quick(td); 835 crit_enter_quick(td); 836 837 sched_iopollmore(io_ctx); 838 io_ctx->phase = 4; 839 840 crit_exit_quick(td); 841 } 842 843 static void 844 txpoll_handler(netmsg_t msg) 845 { 846 struct iopoll_ctx *io_ctx; 847 struct thread *td = curthread; 848 int i; 849 850 io_ctx = msg->lmsg.u.ms_resultp; 851 KKASSERT(&td->td_msgport == netisr_portfn(io_ctx->poll_cpuid)); 852 853 crit_enter_quick(td); 854 855 /* Reply ASAP */ 856 lwkt_replymsg(&msg->lmsg, 0); 857 858 if (io_ctx->poll_handlers == 0) { 859 crit_exit_quick(td); 860 return; 861 } 862 863 io_ctx->phase = 3; 864 865 for (i = 0; i < io_ctx->poll_handlers; i++) { 866 const struct iopoll_rec *rec = &io_ctx->pr[i]; 867 struct ifnet *ifp = rec->ifp; 868 869 if (!lwkt_serialize_try(rec->serializer)) 870 continue; 871 872 if ((ifp->if_flags & (IFF_RUNNING | IFF_NPOLLING)) == 873 (IFF_RUNNING | IFF_NPOLLING)) 874 rec->poll_func(ifp, rec->arg, -1); 875 876 lwkt_serialize_exit(rec->serializer); 877 } 878 879 /* 880 * Do a quick exit/enter to catch any higher-priority 881 * interrupt sources. 882 */ 883 crit_exit_quick(td); 884 crit_enter_quick(td); 885 886 sched_iopollmore(io_ctx); 887 io_ctx->phase = 4; 888 889 crit_exit_quick(td); 890 } 891 892 /* 893 * rxpollmore_handler and txpollmore_handler are called after other netisr's, 894 * possibly scheduling another rxpoll_handler or txpoll_handler call, or 895 * adapting the burst size for the next cycle. 896 * 897 * It is very bad to fetch large bursts of packets from a single card at once, 898 * because the burst could take a long time to be completely processed leading 899 * to unfairness. To reduce the problem, and also to account better for time 900 * spent in network-related processing, we split the burst in smaller chunks 901 * of fixed size, giving control to the other netisr's between chunks. This 902 * helps in improving the fairness, reducing livelock and accounting for the 903 * work performed in low level handling. 904 */ 905 static void 906 rxpollmore_handler(netmsg_t msg) 907 { 908 struct thread *td = curthread; 909 struct iopoll_ctx *io_ctx; 910 union ifpoll_time t; 911 int kern_load; 912 uint32_t pending_polls; 913 914 io_ctx = msg->lmsg.u.ms_resultp; 915 KKASSERT(&td->td_msgport == netisr_portfn(io_ctx->poll_cpuid)); 916 917 crit_enter_quick(td); 918 919 /* Replay ASAP */ 920 lwkt_replymsg(&msg->lmsg, 0); 921 922 if (io_ctx->poll_handlers == 0) { 923 crit_exit_quick(td); 924 return; 925 } 926 927 io_ctx->phase = 5; 928 if (io_ctx->residual_burst > 0) { 929 sched_iopoll(io_ctx); 930 crit_exit_quick(td); 931 /* Will run immediately on return, followed by netisrs */ 932 return; 933 } 934 935 /* Here we can account time spent in iopoll's in this tick */ 936 ifpoll_time_get(&t); 937 kern_load = ifpoll_time_diff(&io_ctx->poll_start_t, &t); 938 kern_load = (kern_load * io_ctx->pollhz) / 10000; /* 0..100 */ 939 io_ctx->kern_frac = kern_load; 940 941 if (kern_load > (100 - io_ctx->user_frac)) { 942 /* Try decrease ticks */ 943 if (io_ctx->poll_burst > 1) 944 io_ctx->poll_burst--; 945 } else { 946 if (io_ctx->poll_burst < io_ctx->poll_burst_max) 947 io_ctx->poll_burst++; 948 } 949 950 io_ctx->pending_polls--; 951 pending_polls = io_ctx->pending_polls; 952 953 if (pending_polls == 0) { 954 /* We are done */ 955 io_ctx->phase = 0; 956 } else { 957 /* 958 * Last cycle was long and caused us to miss one or more 959 * hardclock ticks. Restart processing again, but slightly 960 * reduce the burst size to prevent that this happens again. 961 */ 962 io_ctx->poll_burst -= (io_ctx->poll_burst / 8); 963 if (io_ctx->poll_burst < 1) 964 io_ctx->poll_burst = 1; 965 sched_iopoll(io_ctx); 966 io_ctx->phase = 6; 967 } 968 969 crit_exit_quick(td); 970 } 971 972 static void 973 txpollmore_handler(netmsg_t msg) 974 { 975 struct thread *td = curthread; 976 struct iopoll_ctx *io_ctx; 977 uint32_t pending_polls; 978 979 io_ctx = msg->lmsg.u.ms_resultp; 980 KKASSERT(&td->td_msgport == netisr_portfn(io_ctx->poll_cpuid)); 981 982 crit_enter_quick(td); 983 984 /* Replay ASAP */ 985 lwkt_replymsg(&msg->lmsg, 0); 986 987 if (io_ctx->poll_handlers == 0) { 988 crit_exit_quick(td); 989 return; 990 } 991 992 io_ctx->phase = 5; 993 994 io_ctx->pending_polls--; 995 pending_polls = io_ctx->pending_polls; 996 997 if (pending_polls == 0) { 998 /* We are done */ 999 io_ctx->phase = 0; 1000 } else { 1001 /* 1002 * Last cycle was long and caused us to miss one or more 1003 * hardclock ticks. Restart processing again. 1004 */ 1005 sched_iopoll(io_ctx); 1006 io_ctx->phase = 6; 1007 } 1008 1009 crit_exit_quick(td); 1010 } 1011 1012 static void 1013 iopoll_add_sysctl(struct sysctl_ctx_list *ctx, struct sysctl_oid_list *parent, 1014 struct iopoll_ctx *io_ctx, int poll_type) 1015 { 1016 if (poll_type == IFPOLL_RX) { 1017 SYSCTL_ADD_PROC(ctx, parent, OID_AUTO, "burst_max", 1018 CTLTYPE_UINT | CTLFLAG_RW, io_ctx, 0, sysctl_burstmax, 1019 "IU", "Max Polling burst size"); 1020 1021 SYSCTL_ADD_PROC(ctx, parent, OID_AUTO, "each_burst", 1022 CTLTYPE_UINT | CTLFLAG_RW, io_ctx, 0, sysctl_eachburst, 1023 "IU", "Max size of each burst"); 1024 1025 SYSCTL_ADD_UINT(ctx, parent, OID_AUTO, "burst", CTLFLAG_RD, 1026 &io_ctx->poll_burst, 0, "Current polling burst size"); 1027 1028 SYSCTL_ADD_UINT(ctx, parent, OID_AUTO, "user_frac", CTLFLAG_RW, 1029 &io_ctx->user_frac, 0, "Desired user fraction of cpu time"); 1030 1031 SYSCTL_ADD_UINT(ctx, parent, OID_AUTO, "kern_frac", CTLFLAG_RD, 1032 &io_ctx->kern_frac, 0, "Kernel fraction of cpu time"); 1033 1034 SYSCTL_ADD_INT(ctx, parent, OID_AUTO, "residual_burst", CTLFLAG_RD, 1035 &io_ctx->residual_burst, 0, 1036 "# of residual cycles in burst"); 1037 } 1038 1039 SYSCTL_ADD_UINT(ctx, parent, OID_AUTO, "phase", CTLFLAG_RD, 1040 &io_ctx->phase, 0, "Polling phase"); 1041 1042 SYSCTL_ADD_ULONG(ctx, parent, OID_AUTO, "suspect", CTLFLAG_RW, 1043 &io_ctx->suspect, "Suspected events"); 1044 1045 SYSCTL_ADD_ULONG(ctx, parent, OID_AUTO, "stalled", CTLFLAG_RW, 1046 &io_ctx->stalled, "Potential stalls"); 1047 1048 SYSCTL_ADD_ULONG(ctx, parent, OID_AUTO, "short_ticks", CTLFLAG_RW, 1049 &io_ctx->short_ticks, 1050 "Hardclock ticks shorter than they should be"); 1051 1052 SYSCTL_ADD_ULONG(ctx, parent, OID_AUTO, "lost_polls", CTLFLAG_RW, 1053 &io_ctx->lost_polls, 1054 "How many times we would have lost a poll tick"); 1055 1056 SYSCTL_ADD_UINT(ctx, parent, OID_AUTO, "pending_polls", CTLFLAG_RD, 1057 &io_ctx->pending_polls, 0, "Do we need to poll again"); 1058 1059 SYSCTL_ADD_UINT(ctx, parent, OID_AUTO, "handlers", CTLFLAG_RD, 1060 &io_ctx->poll_handlers, 0, "Number of registered poll handlers"); 1061 } 1062 1063 static void 1064 sysctl_burstmax_handler(netmsg_t nmsg) 1065 { 1066 struct iopoll_sysctl_netmsg *msg = (struct iopoll_sysctl_netmsg *)nmsg; 1067 struct iopoll_ctx *io_ctx; 1068 1069 io_ctx = msg->ctx; 1070 KKASSERT(&curthread->td_msgport == netisr_portfn(io_ctx->poll_cpuid)); 1071 1072 io_ctx->poll_burst_max = nmsg->lmsg.u.ms_result; 1073 if (io_ctx->poll_each_burst > io_ctx->poll_burst_max) 1074 io_ctx->poll_each_burst = io_ctx->poll_burst_max; 1075 if (io_ctx->poll_burst > io_ctx->poll_burst_max) 1076 io_ctx->poll_burst = io_ctx->poll_burst_max; 1077 if (io_ctx->residual_burst > io_ctx->poll_burst_max) 1078 io_ctx->residual_burst = io_ctx->poll_burst_max; 1079 1080 lwkt_replymsg(&nmsg->lmsg, 0); 1081 } 1082 1083 static int 1084 sysctl_burstmax(SYSCTL_HANDLER_ARGS) 1085 { 1086 struct iopoll_ctx *io_ctx = arg1; 1087 struct iopoll_sysctl_netmsg msg; 1088 uint32_t burst_max; 1089 int error; 1090 1091 burst_max = io_ctx->poll_burst_max; 1092 error = sysctl_handle_int(oidp, &burst_max, 0, req); 1093 if (error || req->newptr == NULL) 1094 return error; 1095 if (burst_max < MIN_IOPOLL_BURST_MAX) 1096 burst_max = MIN_IOPOLL_BURST_MAX; 1097 else if (burst_max > MAX_IOPOLL_BURST_MAX) 1098 burst_max = MAX_IOPOLL_BURST_MAX; 1099 1100 netmsg_init(&msg.base, NULL, &curthread->td_msgport, 1101 0, sysctl_burstmax_handler); 1102 msg.base.lmsg.u.ms_result = burst_max; 1103 msg.ctx = io_ctx; 1104 1105 return lwkt_domsg(netisr_portfn(io_ctx->poll_cpuid), &msg.base.lmsg, 0); 1106 } 1107 1108 static void 1109 sysctl_eachburst_handler(netmsg_t nmsg) 1110 { 1111 struct iopoll_sysctl_netmsg *msg = (struct iopoll_sysctl_netmsg *)nmsg; 1112 struct iopoll_ctx *io_ctx; 1113 uint32_t each_burst; 1114 1115 io_ctx = msg->ctx; 1116 KKASSERT(&curthread->td_msgport == netisr_portfn(io_ctx->poll_cpuid)); 1117 1118 each_burst = nmsg->lmsg.u.ms_result; 1119 if (each_burst > io_ctx->poll_burst_max) 1120 each_burst = io_ctx->poll_burst_max; 1121 else if (each_burst < 1) 1122 each_burst = 1; 1123 io_ctx->poll_each_burst = each_burst; 1124 1125 lwkt_replymsg(&nmsg->lmsg, 0); 1126 } 1127 1128 static int 1129 sysctl_eachburst(SYSCTL_HANDLER_ARGS) 1130 { 1131 struct iopoll_ctx *io_ctx = arg1; 1132 struct iopoll_sysctl_netmsg msg; 1133 uint32_t each_burst; 1134 int error; 1135 1136 each_burst = io_ctx->poll_each_burst; 1137 error = sysctl_handle_int(oidp, &each_burst, 0, req); 1138 if (error || req->newptr == NULL) 1139 return error; 1140 1141 netmsg_init(&msg.base, NULL, &curthread->td_msgport, 1142 0, sysctl_eachburst_handler); 1143 msg.base.lmsg.u.ms_result = each_burst; 1144 msg.ctx = io_ctx; 1145 1146 return lwkt_domsg(netisr_portfn(io_ctx->poll_cpuid), &msg.base.lmsg, 0); 1147 } 1148 1149 static int 1150 iopoll_register(struct ifnet *ifp, struct iopoll_ctx *io_ctx, 1151 const struct ifpoll_io *io_rec) 1152 { 1153 int error; 1154 1155 KKASSERT(&curthread->td_msgport == netisr_portfn(io_ctx->poll_cpuid)); 1156 1157 if (io_rec->poll_func == NULL) 1158 return 0; 1159 1160 /* 1161 * Check if there is room. 1162 */ 1163 if (io_ctx->poll_handlers >= IFPOLL_LIST_LEN) { 1164 /* 1165 * List full, cannot register more entries. 1166 * This should never happen; if it does, it is probably a 1167 * broken driver trying to register multiple times. Checking 1168 * this at runtime is expensive, and won't solve the problem 1169 * anyways, so just report a few times and then give up. 1170 */ 1171 static int verbose = 10; /* XXX */ 1172 if (verbose > 0) { 1173 kprintf("io poll handlers list full, " 1174 "maybe a broken driver ?\n"); 1175 verbose--; 1176 } 1177 error = ENOENT; 1178 } else { 1179 struct iopoll_rec *rec = &io_ctx->pr[io_ctx->poll_handlers]; 1180 1181 rec->ifp = ifp; 1182 rec->serializer = io_rec->serializer; 1183 rec->arg = io_rec->arg; 1184 rec->poll_func = io_rec->poll_func; 1185 1186 io_ctx->poll_handlers++; 1187 error = 0; 1188 } 1189 return error; 1190 } 1191 1192 static int 1193 iopoll_deregister(struct ifnet *ifp, struct iopoll_ctx *io_ctx) 1194 { 1195 int i, error; 1196 1197 KKASSERT(&curthread->td_msgport == netisr_portfn(io_ctx->poll_cpuid)); 1198 1199 for (i = 0; i < io_ctx->poll_handlers; ++i) { 1200 if (io_ctx->pr[i].ifp == ifp) /* Found it */ 1201 break; 1202 } 1203 if (i == io_ctx->poll_handlers) { 1204 error = ENOENT; 1205 } else { 1206 io_ctx->poll_handlers--; 1207 if (i < io_ctx->poll_handlers) { 1208 /* Last entry replaces this one. */ 1209 io_ctx->pr[i] = io_ctx->pr[io_ctx->poll_handlers]; 1210 } 1211 1212 if (io_ctx->poll_handlers == 0) 1213 iopoll_reset_state(io_ctx); 1214 error = 0; 1215 } 1216 return error; 1217 } 1218 1219 static void 1220 poll_comm_init(int cpuid) 1221 { 1222 struct poll_comm *comm; 1223 char cpuid_str[16]; 1224 1225 comm = kmalloc_cachealign(sizeof(*comm), M_DEVBUF, M_WAITOK | M_ZERO); 1226 1227 if (ifpoll_stfrac < 1) 1228 ifpoll_stfrac = IFPOLL_STFRAC_DEFAULT; 1229 if (ifpoll_txfrac < 1) 1230 ifpoll_txfrac = IFPOLL_TXFRAC_DEFAULT; 1231 1232 comm->pollhz = ifpoll_pollhz; 1233 comm->poll_cpuid = cpuid; 1234 comm->poll_stfrac = ifpoll_stfrac - 1; 1235 comm->poll_txfrac = ifpoll_txfrac - 1; 1236 1237 ksnprintf(cpuid_str, sizeof(cpuid_str), "%d", cpuid); 1238 1239 sysctl_ctx_init(&comm->sysctl_ctx); 1240 comm->sysctl_tree = SYSCTL_ADD_NODE(&comm->sysctl_ctx, 1241 SYSCTL_STATIC_CHILDREN(_net_ifpoll), 1242 OID_AUTO, cpuid_str, CTLFLAG_RD, 0, ""); 1243 1244 SYSCTL_ADD_PROC(&comm->sysctl_ctx, SYSCTL_CHILDREN(comm->sysctl_tree), 1245 OID_AUTO, "pollhz", CTLTYPE_INT | CTLFLAG_RW, 1246 comm, 0, sysctl_pollhz, 1247 "I", "Device polling frequency"); 1248 1249 if (cpuid == 0) { 1250 SYSCTL_ADD_PROC(&comm->sysctl_ctx, 1251 SYSCTL_CHILDREN(comm->sysctl_tree), 1252 OID_AUTO, "status_frac", 1253 CTLTYPE_INT | CTLFLAG_RW, 1254 comm, 0, sysctl_stfrac, 1255 "I", "# of cycles before status is polled"); 1256 } 1257 SYSCTL_ADD_PROC(&comm->sysctl_ctx, SYSCTL_CHILDREN(comm->sysctl_tree), 1258 OID_AUTO, "tx_frac", CTLTYPE_INT | CTLFLAG_RW, 1259 comm, 0, sysctl_txfrac, 1260 "I", "# of cycles before TX is polled"); 1261 1262 poll_common[cpuid] = comm; 1263 } 1264 1265 static void 1266 poll_comm_start(int cpuid) 1267 { 1268 struct poll_comm *comm = poll_common[cpuid]; 1269 systimer_func_t func; 1270 1271 /* 1272 * Initialize systimer 1273 */ 1274 if (cpuid == 0) 1275 func = poll_comm_systimer0; 1276 else 1277 func = poll_comm_systimer; 1278 systimer_init_periodic_nq(&comm->pollclock, func, comm, 1); 1279 } 1280 1281 static void 1282 _poll_comm_systimer(struct poll_comm *comm) 1283 { 1284 if (comm->txfrac_count-- == 0) { 1285 comm->txfrac_count = comm->poll_txfrac; 1286 iopoll_clock(txpoll_context[comm->poll_cpuid]); 1287 } 1288 iopoll_clock(rxpoll_context[comm->poll_cpuid]); 1289 } 1290 1291 static void 1292 poll_comm_systimer0(systimer_t info, int in_ipi __unused, 1293 struct intrframe *frame __unused) 1294 { 1295 struct poll_comm *comm = info->data; 1296 globaldata_t gd = mycpu; 1297 1298 KKASSERT(comm->poll_cpuid == gd->gd_cpuid && gd->gd_cpuid == 0); 1299 1300 crit_enter_gd(gd); 1301 1302 if (comm->stfrac_count-- == 0) { 1303 comm->stfrac_count = comm->poll_stfrac; 1304 stpoll_clock(&stpoll_context); 1305 } 1306 _poll_comm_systimer(comm); 1307 1308 crit_exit_gd(gd); 1309 } 1310 1311 static void 1312 poll_comm_systimer(systimer_t info, int in_ipi __unused, 1313 struct intrframe *frame __unused) 1314 { 1315 struct poll_comm *comm = info->data; 1316 globaldata_t gd = mycpu; 1317 1318 KKASSERT(comm->poll_cpuid == gd->gd_cpuid && gd->gd_cpuid != 0); 1319 1320 crit_enter_gd(gd); 1321 _poll_comm_systimer(comm); 1322 crit_exit_gd(gd); 1323 } 1324 1325 static void 1326 poll_comm_adjust_pollhz(struct poll_comm *comm) 1327 { 1328 uint32_t handlers; 1329 int pollhz = 1; 1330 1331 KKASSERT(&curthread->td_msgport == netisr_portfn(comm->poll_cpuid)); 1332 1333 /* 1334 * If there is no polling handler registered, set systimer 1335 * frequency to the lowest value. Polling systimer frequency 1336 * will be adjusted to the requested value, once there are 1337 * registered handlers. 1338 */ 1339 handlers = rxpoll_context[mycpuid]->poll_handlers + 1340 txpoll_context[mycpuid]->poll_handlers; 1341 if (comm->poll_cpuid == 0) 1342 handlers += stpoll_context.poll_handlers; 1343 if (handlers) 1344 pollhz = comm->pollhz; 1345 systimer_adjust_periodic(&comm->pollclock, pollhz); 1346 } 1347 1348 static int 1349 sysctl_pollhz(SYSCTL_HANDLER_ARGS) 1350 { 1351 struct poll_comm *comm = arg1; 1352 struct netmsg_base nmsg; 1353 int error, phz; 1354 1355 phz = comm->pollhz; 1356 error = sysctl_handle_int(oidp, &phz, 0, req); 1357 if (error || req->newptr == NULL) 1358 return error; 1359 if (phz <= 0) 1360 return EINVAL; 1361 else if (phz > IFPOLL_FREQ_MAX) 1362 phz = IFPOLL_FREQ_MAX; 1363 1364 netmsg_init(&nmsg, NULL, &curthread->td_msgport, 1365 0, sysctl_pollhz_handler); 1366 nmsg.lmsg.u.ms_result = phz; 1367 1368 return lwkt_domsg(netisr_portfn(comm->poll_cpuid), &nmsg.lmsg, 0); 1369 } 1370 1371 static void 1372 sysctl_pollhz_handler(netmsg_t nmsg) 1373 { 1374 struct poll_comm *comm = poll_common[mycpuid]; 1375 1376 KKASSERT(&curthread->td_msgport == netisr_portfn(comm->poll_cpuid)); 1377 1378 /* Save polling frequency */ 1379 comm->pollhz = nmsg->lmsg.u.ms_result; 1380 1381 /* 1382 * Adjust cached pollhz 1383 */ 1384 rxpoll_context[mycpuid]->pollhz = comm->pollhz; 1385 txpoll_context[mycpuid]->pollhz = 1386 comm->pollhz / (comm->poll_txfrac + 1); 1387 1388 /* 1389 * Adjust polling frequency 1390 */ 1391 poll_comm_adjust_pollhz(comm); 1392 1393 lwkt_replymsg(&nmsg->lmsg, 0); 1394 } 1395 1396 static int 1397 sysctl_stfrac(SYSCTL_HANDLER_ARGS) 1398 { 1399 struct poll_comm *comm = arg1; 1400 struct netmsg_base nmsg; 1401 int error, stfrac; 1402 1403 KKASSERT(comm->poll_cpuid == 0); 1404 1405 stfrac = comm->poll_stfrac + 1; 1406 error = sysctl_handle_int(oidp, &stfrac, 0, req); 1407 if (error || req->newptr == NULL) 1408 return error; 1409 if (stfrac < 1) 1410 return EINVAL; 1411 1412 netmsg_init(&nmsg, NULL, &curthread->td_msgport, 1413 0, sysctl_stfrac_handler); 1414 nmsg.lmsg.u.ms_result = stfrac - 1; 1415 1416 return lwkt_domsg(netisr_portfn(comm->poll_cpuid), &nmsg.lmsg, 0); 1417 } 1418 1419 static void 1420 sysctl_stfrac_handler(netmsg_t nmsg) 1421 { 1422 struct poll_comm *comm = poll_common[mycpuid]; 1423 int stfrac = nmsg->lmsg.u.ms_result; 1424 1425 KKASSERT(&curthread->td_msgport == netisr_portfn(comm->poll_cpuid)); 1426 1427 crit_enter(); 1428 comm->poll_stfrac = stfrac; 1429 if (comm->stfrac_count > comm->poll_stfrac) 1430 comm->stfrac_count = comm->poll_stfrac; 1431 crit_exit(); 1432 1433 lwkt_replymsg(&nmsg->lmsg, 0); 1434 } 1435 1436 static int 1437 sysctl_txfrac(SYSCTL_HANDLER_ARGS) 1438 { 1439 struct poll_comm *comm = arg1; 1440 struct netmsg_base nmsg; 1441 int error, txfrac; 1442 1443 txfrac = comm->poll_txfrac + 1; 1444 error = sysctl_handle_int(oidp, &txfrac, 0, req); 1445 if (error || req->newptr == NULL) 1446 return error; 1447 if (txfrac < 1) 1448 return EINVAL; 1449 1450 netmsg_init(&nmsg, NULL, &curthread->td_msgport, 1451 0, sysctl_txfrac_handler); 1452 nmsg.lmsg.u.ms_result = txfrac - 1; 1453 1454 return lwkt_domsg(netisr_portfn(comm->poll_cpuid), &nmsg.lmsg, 0); 1455 } 1456 1457 static void 1458 sysctl_txfrac_handler(netmsg_t nmsg) 1459 { 1460 struct poll_comm *comm = poll_common[mycpuid]; 1461 int txfrac = nmsg->lmsg.u.ms_result; 1462 1463 KKASSERT(&curthread->td_msgport == netisr_portfn(comm->poll_cpuid)); 1464 1465 crit_enter(); 1466 comm->poll_txfrac = txfrac; 1467 if (comm->txfrac_count > comm->poll_txfrac) 1468 comm->txfrac_count = comm->poll_txfrac; 1469 crit_exit(); 1470 1471 lwkt_replymsg(&nmsg->lmsg, 0); 1472 } 1473 1474 void 1475 ifpoll_compat_setup(struct ifpoll_compat *cp, 1476 struct sysctl_ctx_list *sysctl_ctx, 1477 struct sysctl_oid *sysctl_tree, 1478 int unit, struct lwkt_serialize *slz) 1479 { 1480 cp->ifpc_stcount = 0; 1481 cp->ifpc_stfrac = ((poll_common[0]->poll_stfrac + 1) * 1482 howmany(IOPOLL_BURST_MAX, IOPOLL_EACH_BURST)) - 1; 1483 1484 cp->ifpc_cpuid = unit % ncpus2; 1485 cp->ifpc_serializer = slz; 1486 1487 if (sysctl_ctx != NULL && sysctl_tree != NULL) { 1488 SYSCTL_ADD_PROC(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree), 1489 OID_AUTO, "npoll_stfrac", CTLTYPE_INT | CTLFLAG_RW, 1490 cp, 0, sysctl_compat_npoll_stfrac, "I", 1491 "polling status frac"); 1492 SYSCTL_ADD_PROC(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree), 1493 OID_AUTO, "npoll_cpuid", CTLTYPE_INT | CTLFLAG_RW, 1494 cp, 0, sysctl_compat_npoll_cpuid, "I", 1495 "polling cpuid"); 1496 } 1497 } 1498 1499 static int 1500 sysctl_compat_npoll_stfrac(SYSCTL_HANDLER_ARGS) 1501 { 1502 struct ifpoll_compat *cp = arg1; 1503 int error = 0, stfrac; 1504 1505 lwkt_serialize_enter(cp->ifpc_serializer); 1506 1507 stfrac = cp->ifpc_stfrac + 1; 1508 error = sysctl_handle_int(oidp, &stfrac, 0, req); 1509 if (!error && req->newptr != NULL) { 1510 if (stfrac < 1) { 1511 error = EINVAL; 1512 } else { 1513 cp->ifpc_stfrac = stfrac - 1; 1514 if (cp->ifpc_stcount > cp->ifpc_stfrac) 1515 cp->ifpc_stcount = cp->ifpc_stfrac; 1516 } 1517 } 1518 1519 lwkt_serialize_exit(cp->ifpc_serializer); 1520 return error; 1521 } 1522 1523 static int 1524 sysctl_compat_npoll_cpuid(SYSCTL_HANDLER_ARGS) 1525 { 1526 struct ifpoll_compat *cp = arg1; 1527 int error = 0, cpuid; 1528 1529 lwkt_serialize_enter(cp->ifpc_serializer); 1530 1531 cpuid = cp->ifpc_cpuid; 1532 error = sysctl_handle_int(oidp, &cpuid, 0, req); 1533 if (!error && req->newptr != NULL) { 1534 if (cpuid < 0 || cpuid >= ncpus2) 1535 error = EINVAL; 1536 else 1537 cp->ifpc_cpuid = cpuid; 1538 } 1539 1540 lwkt_serialize_exit(cp->ifpc_serializer); 1541 return error; 1542 } 1543