FreeBSD/Linux Kernel Cross Reference
sys/net/netisr.c
1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2007-2009 Robert N. M. Watson
5 * Copyright (c) 2010-2011 Juniper Networks, Inc.
6 * All rights reserved.
7 *
8 * This software was developed by Robert N. M. Watson under contract
9 * to Juniper Networks, Inc.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
35
36 /*
37 * netisr is a packet dispatch service, allowing synchronous (directly
38 * dispatched) and asynchronous (deferred dispatch) processing of packets by
39 * registered protocol handlers. Callers pass a protocol identifier and
40 * packet to netisr, along with a direct dispatch hint, and work will either
41 * be immediately processed by the registered handler, or passed to a
42 * software interrupt (SWI) thread for deferred dispatch. Callers will
43 * generally select one or the other based on:
44 *
45 * - Whether directly dispatching a netisr handler lead to code reentrance or
46 * lock recursion, such as entering the socket code from the socket code.
47 * - Whether directly dispatching a netisr handler lead to recursive
48 * processing, such as when decapsulating several wrapped layers of tunnel
49 * information (IPSEC within IPSEC within ...).
50 *
51 * Maintaining ordering for protocol streams is a critical design concern.
52 * Enforcing ordering limits the opportunity for concurrency, but maintains
53 * the strong ordering requirements found in some protocols, such as TCP. Of
54 * related concern is CPU affinity--it is desirable to process all data
55 * associated with a particular stream on the same CPU over time in order to
56 * avoid acquiring locks associated with the connection on different CPUs,
57 * keep connection data in one cache, and to generally encourage associated
58 * user threads to live on the same CPU as the stream. It's also desirable
59 * to avoid lock migration and contention where locks are associated with
60 * more than one flow.
61 *
62 * netisr supports several policy variations, represented by the
63 * NETISR_POLICY_* constants, allowing protocols to play various roles in
64 * identifying flows, assigning work to CPUs, etc. These are described in
65 * netisr.h.
66 */
67
68 #include "opt_ddb.h"
69 #include "opt_device_polling.h"
70
71 #include <sys/param.h>
72 #include <sys/bus.h>
73 #include <sys/kernel.h>
74 #include <sys/kthread.h>
75 #include <sys/malloc.h>
76 #include <sys/interrupt.h>
77 #include <sys/lock.h>
78 #include <sys/mbuf.h>
79 #include <sys/mutex.h>
80 #include <sys/pcpu.h>
81 #include <sys/proc.h>
82 #include <sys/rmlock.h>
83 #include <sys/sched.h>
84 #include <sys/smp.h>
85 #include <sys/socket.h>
86 #include <sys/sysctl.h>
87 #include <sys/systm.h>
88
89 #ifdef DDB
90 #include <ddb/ddb.h>
91 #endif
92
93 #define _WANT_NETISR_INTERNAL /* Enable definitions from netisr_internal.h */
94 #include <net/if.h>
95 #include <net/if_var.h>
96 #include <net/netisr.h>
97 #include <net/netisr_internal.h>
98 #include <net/vnet.h>
99
100 /*-
101 * Synchronize use and modification of the registered netisr data structures;
102 * acquire a read lock while modifying the set of registered protocols to
103 * prevent partially registered or unregistered protocols from being run.
104 *
105 * The following data structures and fields are protected by this lock:
106 *
107 * - The netisr_proto array, including all fields of struct netisr_proto.
108 * - The nws array, including all fields of struct netisr_worker.
109 * - The nws_array array.
110 *
111 * Note: the NETISR_LOCKING define controls whether read locks are acquired
112 * in packet processing paths requiring netisr registration stability. This
113 * is disabled by default as it can lead to measurable performance
114 * degradation even with rmlocks (3%-6% for loopback ping-pong traffic), and
115 * because netisr registration and unregistration is extremely rare at
116 * runtime. If it becomes more common, this decision should be revisited.
117 *
118 * XXXRW: rmlocks don't support assertions.
119 */
120 static struct rmlock netisr_rmlock;
121 #define NETISR_LOCK_INIT() rm_init_flags(&netisr_rmlock, "netisr", \
122 RM_NOWITNESS)
123 #define NETISR_LOCK_ASSERT()
124 #define NETISR_RLOCK(tracker) rm_rlock(&netisr_rmlock, (tracker))
125 #define NETISR_RUNLOCK(tracker) rm_runlock(&netisr_rmlock, (tracker))
126 #define NETISR_WLOCK() rm_wlock(&netisr_rmlock)
127 #define NETISR_WUNLOCK() rm_wunlock(&netisr_rmlock)
128 /* #define NETISR_LOCKING */
129
130 static SYSCTL_NODE(_net, OID_AUTO, isr, CTLFLAG_RW, 0, "netisr");
131
132 /*-
133 * Three global direct dispatch policies are supported:
134 *
135 * NETISR_DISPATCH_DEFERRED: All work is deferred for a netisr, regardless of
136 * context (may be overridden by protocols).
137 *
138 * NETISR_DISPATCH_HYBRID: If the executing context allows direct dispatch,
139 * and we're running on the CPU the work would be performed on, then direct
140 * dispatch it if it wouldn't violate ordering constraints on the workstream.
141 *
142 * NETISR_DISPATCH_DIRECT: If the executing context allows direct dispatch,
143 * always direct dispatch. (The default.)
144 *
145 * Notice that changing the global policy could lead to short periods of
146 * misordered processing, but this is considered acceptable as compared to
147 * the complexity of enforcing ordering during policy changes. Protocols can
148 * override the global policy (when they're not doing that, they select
149 * NETISR_DISPATCH_DEFAULT).
150 */
151 #define NETISR_DISPATCH_POLICY_DEFAULT NETISR_DISPATCH_DIRECT
152 #define NETISR_DISPATCH_POLICY_MAXSTR 20 /* Used for temporary buffers. */
153 static u_int netisr_dispatch_policy = NETISR_DISPATCH_POLICY_DEFAULT;
154 static int sysctl_netisr_dispatch_policy(SYSCTL_HANDLER_ARGS);
155 SYSCTL_PROC(_net_isr, OID_AUTO, dispatch, CTLTYPE_STRING | CTLFLAG_RWTUN,
156 0, 0, sysctl_netisr_dispatch_policy, "A",
157 "netisr dispatch policy");
158
159 /*
160 * Allow the administrator to limit the number of threads (CPUs) to use for
161 * netisr. We don't check netisr_maxthreads before creating the thread for
162 * CPU 0. This must be set at boot. We will create at most one thread per CPU.
163 * By default we initialize this to 1 which would assign just 1 cpu (cpu0) and
164 * therefore only 1 workstream. If set to -1, netisr would use all cpus
165 * (mp_ncpus) and therefore would have those many workstreams. One workstream
166 * per thread (CPU).
167 */
168 static int netisr_maxthreads = 1; /* Max number of threads. */
169 SYSCTL_INT(_net_isr, OID_AUTO, maxthreads, CTLFLAG_RDTUN,
170 &netisr_maxthreads, 0,
171 "Use at most this many CPUs for netisr processing");
172
173 static int netisr_bindthreads = 0; /* Bind threads to CPUs. */
174 SYSCTL_INT(_net_isr, OID_AUTO, bindthreads, CTLFLAG_RDTUN,
175 &netisr_bindthreads, 0, "Bind netisr threads to CPUs.");
176
177 /*
178 * Limit per-workstream mbuf queue limits s to at most net.isr.maxqlimit,
179 * both for initial configuration and later modification using
180 * netisr_setqlimit().
181 */
182 #define NETISR_DEFAULT_MAXQLIMIT 10240
183 static u_int netisr_maxqlimit = NETISR_DEFAULT_MAXQLIMIT;
184 SYSCTL_UINT(_net_isr, OID_AUTO, maxqlimit, CTLFLAG_RDTUN,
185 &netisr_maxqlimit, 0,
186 "Maximum netisr per-protocol, per-CPU queue depth.");
187
188 /*
189 * The default per-workstream mbuf queue limit for protocols that don't
190 * initialize the nh_qlimit field of their struct netisr_handler. If this is
191 * set above netisr_maxqlimit, we truncate it to the maximum during boot.
192 */
193 #define NETISR_DEFAULT_DEFAULTQLIMIT 256
194 static u_int netisr_defaultqlimit = NETISR_DEFAULT_DEFAULTQLIMIT;
195 SYSCTL_UINT(_net_isr, OID_AUTO, defaultqlimit, CTLFLAG_RDTUN,
196 &netisr_defaultqlimit, 0,
197 "Default netisr per-protocol, per-CPU queue limit if not set by protocol");
198
199 /*
200 * Store and export the compile-time constant NETISR_MAXPROT limit on the
201 * number of protocols that can register with netisr at a time. This is
202 * required for crashdump analysis, as it sizes netisr_proto[].
203 */
204 static u_int netisr_maxprot = NETISR_MAXPROT;
205 SYSCTL_UINT(_net_isr, OID_AUTO, maxprot, CTLFLAG_RD,
206 &netisr_maxprot, 0,
207 "Compile-time limit on the number of protocols supported by netisr.");
208
209 /*
210 * The netisr_proto array describes all registered protocols, indexed by
211 * protocol number. See netisr_internal.h for more details.
212 */
213 static struct netisr_proto netisr_proto[NETISR_MAXPROT];
214
215 #ifdef VIMAGE
216 /*
217 * The netisr_enable array describes a per-VNET flag for registered
218 * protocols on whether this netisr is active in this VNET or not.
219 * netisr_register() will automatically enable the netisr for the
220 * default VNET and all currently active instances.
221 * netisr_unregister() will disable all active VNETs, including vnet0.
222 * Individual network stack instances can be enabled/disabled by the
223 * netisr_(un)register _vnet() functions.
224 * With this we keep the one netisr_proto per protocol but add a
225 * mechanism to stop netisr processing for vnet teardown.
226 * Apart from that we expect a VNET to always be enabled.
227 */
228 VNET_DEFINE_STATIC(u_int, netisr_enable[NETISR_MAXPROT]);
229 #define V_netisr_enable VNET(netisr_enable)
230 #endif
231
232 /*
233 * Per-CPU workstream data. See netisr_internal.h for more details.
234 */
235 DPCPU_DEFINE(struct netisr_workstream, nws);
236
237 /*
238 * Map contiguous values between 0 and nws_count into CPU IDs appropriate for
239 * accessing workstreams. This allows constructions of the form
240 * DPCPU_ID_GET(nws_array[arbitraryvalue % nws_count], nws).
241 */
242 static u_int nws_array[MAXCPU];
243
244 /*
245 * Number of registered workstreams. Will be at most the number of running
246 * CPUs once fully started.
247 */
248 static u_int nws_count;
249 SYSCTL_UINT(_net_isr, OID_AUTO, numthreads, CTLFLAG_RD,
250 &nws_count, 0, "Number of extant netisr threads.");
251
252 /*
253 * Synchronization for each workstream: a mutex protects all mutable fields
254 * in each stream, including per-protocol state (mbuf queues). The SWI is
255 * woken up if asynchronous dispatch is required.
256 */
257 #define NWS_LOCK(s) mtx_lock(&(s)->nws_mtx)
258 #define NWS_LOCK_ASSERT(s) mtx_assert(&(s)->nws_mtx, MA_OWNED)
259 #define NWS_UNLOCK(s) mtx_unlock(&(s)->nws_mtx)
260 #define NWS_SIGNAL(s) swi_sched((s)->nws_swi_cookie, 0)
261
262 /*
263 * Utility routines for protocols that implement their own mapping of flows
264 * to CPUs.
265 */
266 u_int
267 netisr_get_cpucount(void)
268 {
269
270 return (nws_count);
271 }
272
273 u_int
274 netisr_get_cpuid(u_int cpunumber)
275 {
276
277 return (nws_array[cpunumber % nws_count]);
278 }
279
280 /*
281 * The default implementation of flow -> CPU ID mapping.
282 *
283 * Non-static so that protocols can use it to map their own work to specific
284 * CPUs in a manner consistent to netisr for affinity purposes.
285 */
286 u_int
287 netisr_default_flow2cpu(u_int flowid)
288 {
289
290 return (nws_array[flowid % nws_count]);
291 }
292
293 /*
294 * Dispatch tunable and sysctl configuration.
295 */
296 struct netisr_dispatch_table_entry {
297 u_int ndte_policy;
298 const char *ndte_policy_str;
299 };
300 static const struct netisr_dispatch_table_entry netisr_dispatch_table[] = {
301 { NETISR_DISPATCH_DEFAULT, "default" },
302 { NETISR_DISPATCH_DEFERRED, "deferred" },
303 { NETISR_DISPATCH_HYBRID, "hybrid" },
304 { NETISR_DISPATCH_DIRECT, "direct" },
305 };
306
307 static void
308 netisr_dispatch_policy_to_str(u_int dispatch_policy, char *buffer,
309 u_int buflen)
310 {
311 const struct netisr_dispatch_table_entry *ndtep;
312 const char *str;
313 u_int i;
314
315 str = "unknown";
316 for (i = 0; i < nitems(netisr_dispatch_table); i++) {
317 ndtep = &netisr_dispatch_table[i];
318 if (ndtep->ndte_policy == dispatch_policy) {
319 str = ndtep->ndte_policy_str;
320 break;
321 }
322 }
323 snprintf(buffer, buflen, "%s", str);
324 }
325
326 static int
327 netisr_dispatch_policy_from_str(const char *str, u_int *dispatch_policyp)
328 {
329 const struct netisr_dispatch_table_entry *ndtep;
330 u_int i;
331
332 for (i = 0; i < nitems(netisr_dispatch_table); i++) {
333 ndtep = &netisr_dispatch_table[i];
334 if (strcmp(ndtep->ndte_policy_str, str) == 0) {
335 *dispatch_policyp = ndtep->ndte_policy;
336 return (0);
337 }
338 }
339 return (EINVAL);
340 }
341
342 static int
343 sysctl_netisr_dispatch_policy(SYSCTL_HANDLER_ARGS)
344 {
345 char tmp[NETISR_DISPATCH_POLICY_MAXSTR];
346 u_int dispatch_policy;
347 int error;
348
349 netisr_dispatch_policy_to_str(netisr_dispatch_policy, tmp,
350 sizeof(tmp));
351 error = sysctl_handle_string(oidp, tmp, sizeof(tmp), req);
352 if (error == 0 && req->newptr != NULL) {
353 error = netisr_dispatch_policy_from_str(tmp,
354 &dispatch_policy);
355 if (error == 0 && dispatch_policy == NETISR_DISPATCH_DEFAULT)
356 error = EINVAL;
357 if (error == 0)
358 netisr_dispatch_policy = dispatch_policy;
359 }
360 return (error);
361 }
362
363 /*
364 * Register a new netisr handler, which requires initializing per-protocol
365 * fields for each workstream. All netisr work is briefly suspended while
366 * the protocol is installed.
367 */
368 void
369 netisr_register(const struct netisr_handler *nhp)
370 {
371 VNET_ITERATOR_DECL(vnet_iter);
372 struct netisr_work *npwp;
373 const char *name;
374 u_int i, proto;
375
376 proto = nhp->nh_proto;
377 name = nhp->nh_name;
378
379 /*
380 * Test that the requested registration is valid.
381 */
382 KASSERT(nhp->nh_name != NULL,
383 ("%s: nh_name NULL for %u", __func__, proto));
384 KASSERT(nhp->nh_handler != NULL,
385 ("%s: nh_handler NULL for %s", __func__, name));
386 KASSERT(nhp->nh_policy == NETISR_POLICY_SOURCE ||
387 nhp->nh_policy == NETISR_POLICY_FLOW ||
388 nhp->nh_policy == NETISR_POLICY_CPU,
389 ("%s: unsupported nh_policy %u for %s", __func__,
390 nhp->nh_policy, name));
391 KASSERT(nhp->nh_policy == NETISR_POLICY_FLOW ||
392 nhp->nh_m2flow == NULL,
393 ("%s: nh_policy != FLOW but m2flow defined for %s", __func__,
394 name));
395 KASSERT(nhp->nh_policy == NETISR_POLICY_CPU || nhp->nh_m2cpuid == NULL,
396 ("%s: nh_policy != CPU but m2cpuid defined for %s", __func__,
397 name));
398 KASSERT(nhp->nh_policy != NETISR_POLICY_CPU || nhp->nh_m2cpuid != NULL,
399 ("%s: nh_policy == CPU but m2cpuid not defined for %s", __func__,
400 name));
401 KASSERT(nhp->nh_dispatch == NETISR_DISPATCH_DEFAULT ||
402 nhp->nh_dispatch == NETISR_DISPATCH_DEFERRED ||
403 nhp->nh_dispatch == NETISR_DISPATCH_HYBRID ||
404 nhp->nh_dispatch == NETISR_DISPATCH_DIRECT,
405 ("%s: invalid nh_dispatch (%u)", __func__, nhp->nh_dispatch));
406
407 KASSERT(proto < NETISR_MAXPROT,
408 ("%s(%u, %s): protocol too big", __func__, proto, name));
409
410 /*
411 * Test that no existing registration exists for this protocol.
412 */
413 NETISR_WLOCK();
414 KASSERT(netisr_proto[proto].np_name == NULL,
415 ("%s(%u, %s): name present", __func__, proto, name));
416 KASSERT(netisr_proto[proto].np_handler == NULL,
417 ("%s(%u, %s): handler present", __func__, proto, name));
418
419 netisr_proto[proto].np_name = name;
420 netisr_proto[proto].np_handler = nhp->nh_handler;
421 netisr_proto[proto].np_m2flow = nhp->nh_m2flow;
422 netisr_proto[proto].np_m2cpuid = nhp->nh_m2cpuid;
423 netisr_proto[proto].np_drainedcpu = nhp->nh_drainedcpu;
424 if (nhp->nh_qlimit == 0)
425 netisr_proto[proto].np_qlimit = netisr_defaultqlimit;
426 else if (nhp->nh_qlimit > netisr_maxqlimit) {
427 printf("%s: %s requested queue limit %u capped to "
428 "net.isr.maxqlimit %u\n", __func__, name, nhp->nh_qlimit,
429 netisr_maxqlimit);
430 netisr_proto[proto].np_qlimit = netisr_maxqlimit;
431 } else
432 netisr_proto[proto].np_qlimit = nhp->nh_qlimit;
433 netisr_proto[proto].np_policy = nhp->nh_policy;
434 netisr_proto[proto].np_dispatch = nhp->nh_dispatch;
435 CPU_FOREACH(i) {
436 npwp = &(DPCPU_ID_PTR(i, nws))->nws_work[proto];
437 bzero(npwp, sizeof(*npwp));
438 npwp->nw_qlimit = netisr_proto[proto].np_qlimit;
439 }
440
441 #ifdef VIMAGE
442 /*
443 * Test that we are in vnet0 and have a curvnet set.
444 */
445 KASSERT(curvnet != NULL, ("%s: curvnet is NULL", __func__));
446 KASSERT(IS_DEFAULT_VNET(curvnet), ("%s: curvnet %p is not vnet0 %p",
447 __func__, curvnet, vnet0));
448 VNET_LIST_RLOCK_NOSLEEP();
449 VNET_FOREACH(vnet_iter) {
450 CURVNET_SET(vnet_iter);
451 V_netisr_enable[proto] = 1;
452 CURVNET_RESTORE();
453 }
454 VNET_LIST_RUNLOCK_NOSLEEP();
455 #endif
456 NETISR_WUNLOCK();
457 }
458
459 /*
460 * Clear drop counters across all workstreams for a protocol.
461 */
462 void
463 netisr_clearqdrops(const struct netisr_handler *nhp)
464 {
465 struct netisr_work *npwp;
466 #ifdef INVARIANTS
467 const char *name;
468 #endif
469 u_int i, proto;
470
471 proto = nhp->nh_proto;
472 #ifdef INVARIANTS
473 name = nhp->nh_name;
474 #endif
475 KASSERT(proto < NETISR_MAXPROT,
476 ("%s(%u): protocol too big for %s", __func__, proto, name));
477
478 NETISR_WLOCK();
479 KASSERT(netisr_proto[proto].np_handler != NULL,
480 ("%s(%u): protocol not registered for %s", __func__, proto,
481 name));
482
483 CPU_FOREACH(i) {
484 npwp = &(DPCPU_ID_PTR(i, nws))->nws_work[proto];
485 npwp->nw_qdrops = 0;
486 }
487 NETISR_WUNLOCK();
488 }
489
490 /*
491 * Query current drop counters across all workstreams for a protocol.
492 */
493 void
494 netisr_getqdrops(const struct netisr_handler *nhp, u_int64_t *qdropp)
495 {
496 struct netisr_work *npwp;
497 struct rm_priotracker tracker;
498 #ifdef INVARIANTS
499 const char *name;
500 #endif
501 u_int i, proto;
502
503 *qdropp = 0;
504 proto = nhp->nh_proto;
505 #ifdef INVARIANTS
506 name = nhp->nh_name;
507 #endif
508 KASSERT(proto < NETISR_MAXPROT,
509 ("%s(%u): protocol too big for %s", __func__, proto, name));
510
511 NETISR_RLOCK(&tracker);
512 KASSERT(netisr_proto[proto].np_handler != NULL,
513 ("%s(%u): protocol not registered for %s", __func__, proto,
514 name));
515
516 CPU_FOREACH(i) {
517 npwp = &(DPCPU_ID_PTR(i, nws))->nws_work[proto];
518 *qdropp += npwp->nw_qdrops;
519 }
520 NETISR_RUNLOCK(&tracker);
521 }
522
523 /*
524 * Query current per-workstream queue limit for a protocol.
525 */
526 void
527 netisr_getqlimit(const struct netisr_handler *nhp, u_int *qlimitp)
528 {
529 struct rm_priotracker tracker;
530 #ifdef INVARIANTS
531 const char *name;
532 #endif
533 u_int proto;
534
535 proto = nhp->nh_proto;
536 #ifdef INVARIANTS
537 name = nhp->nh_name;
538 #endif
539 KASSERT(proto < NETISR_MAXPROT,
540 ("%s(%u): protocol too big for %s", __func__, proto, name));
541
542 NETISR_RLOCK(&tracker);
543 KASSERT(netisr_proto[proto].np_handler != NULL,
544 ("%s(%u): protocol not registered for %s", __func__, proto,
545 name));
546 *qlimitp = netisr_proto[proto].np_qlimit;
547 NETISR_RUNLOCK(&tracker);
548 }
549
550 /*
551 * Update the queue limit across per-workstream queues for a protocol. We
552 * simply change the limits, and don't drain overflowed packets as they will
553 * (hopefully) take care of themselves shortly.
554 */
555 int
556 netisr_setqlimit(const struct netisr_handler *nhp, u_int qlimit)
557 {
558 struct netisr_work *npwp;
559 #ifdef INVARIANTS
560 const char *name;
561 #endif
562 u_int i, proto;
563
564 if (qlimit > netisr_maxqlimit)
565 return (EINVAL);
566
567 proto = nhp->nh_proto;
568 #ifdef INVARIANTS
569 name = nhp->nh_name;
570 #endif
571 KASSERT(proto < NETISR_MAXPROT,
572 ("%s(%u): protocol too big for %s", __func__, proto, name));
573
574 NETISR_WLOCK();
575 KASSERT(netisr_proto[proto].np_handler != NULL,
576 ("%s(%u): protocol not registered for %s", __func__, proto,
577 name));
578
579 netisr_proto[proto].np_qlimit = qlimit;
580 CPU_FOREACH(i) {
581 npwp = &(DPCPU_ID_PTR(i, nws))->nws_work[proto];
582 npwp->nw_qlimit = qlimit;
583 }
584 NETISR_WUNLOCK();
585 return (0);
586 }
587
588 /*
589 * Drain all packets currently held in a particular protocol work queue.
590 */
591 static void
592 netisr_drain_proto(struct netisr_work *npwp)
593 {
594 struct mbuf *m;
595
596 /*
597 * We would assert the lock on the workstream but it's not passed in.
598 */
599 while ((m = npwp->nw_head) != NULL) {
600 npwp->nw_head = m->m_nextpkt;
601 m->m_nextpkt = NULL;
602 if (npwp->nw_head == NULL)
603 npwp->nw_tail = NULL;
604 npwp->nw_len--;
605 m_freem(m);
606 }
607 KASSERT(npwp->nw_tail == NULL, ("%s: tail", __func__));
608 KASSERT(npwp->nw_len == 0, ("%s: len", __func__));
609 }
610
611 /*
612 * Remove the registration of a network protocol, which requires clearing
613 * per-protocol fields across all workstreams, including freeing all mbufs in
614 * the queues at time of unregister. All work in netisr is briefly suspended
615 * while this takes place.
616 */
617 void
618 netisr_unregister(const struct netisr_handler *nhp)
619 {
620 VNET_ITERATOR_DECL(vnet_iter);
621 struct netisr_work *npwp;
622 #ifdef INVARIANTS
623 const char *name;
624 #endif
625 u_int i, proto;
626
627 proto = nhp->nh_proto;
628 #ifdef INVARIANTS
629 name = nhp->nh_name;
630 #endif
631 KASSERT(proto < NETISR_MAXPROT,
632 ("%s(%u): protocol too big for %s", __func__, proto, name));
633
634 NETISR_WLOCK();
635 KASSERT(netisr_proto[proto].np_handler != NULL,
636 ("%s(%u): protocol not registered for %s", __func__, proto,
637 name));
638
639 #ifdef VIMAGE
640 VNET_LIST_RLOCK_NOSLEEP();
641 VNET_FOREACH(vnet_iter) {
642 CURVNET_SET(vnet_iter);
643 V_netisr_enable[proto] = 0;
644 CURVNET_RESTORE();
645 }
646 VNET_LIST_RUNLOCK_NOSLEEP();
647 #endif
648
649 netisr_proto[proto].np_name = NULL;
650 netisr_proto[proto].np_handler = NULL;
651 netisr_proto[proto].np_m2flow = NULL;
652 netisr_proto[proto].np_m2cpuid = NULL;
653 netisr_proto[proto].np_qlimit = 0;
654 netisr_proto[proto].np_policy = 0;
655 CPU_FOREACH(i) {
656 npwp = &(DPCPU_ID_PTR(i, nws))->nws_work[proto];
657 netisr_drain_proto(npwp);
658 bzero(npwp, sizeof(*npwp));
659 }
660 NETISR_WUNLOCK();
661 }
662
663 #ifdef VIMAGE
664 void
665 netisr_register_vnet(const struct netisr_handler *nhp)
666 {
667 u_int proto;
668
669 proto = nhp->nh_proto;
670
671 KASSERT(curvnet != NULL, ("%s: curvnet is NULL", __func__));
672 KASSERT(proto < NETISR_MAXPROT,
673 ("%s(%u): protocol too big for %s", __func__, proto, nhp->nh_name));
674 NETISR_WLOCK();
675 KASSERT(netisr_proto[proto].np_handler != NULL,
676 ("%s(%u): protocol not registered for %s", __func__, proto,
677 nhp->nh_name));
678
679 V_netisr_enable[proto] = 1;
680 NETISR_WUNLOCK();
681 }
682
683 static void
684 netisr_drain_proto_vnet(struct vnet *vnet, u_int proto)
685 {
686 struct netisr_workstream *nwsp;
687 struct netisr_work *npwp;
688 struct mbuf *m, *mp, *n, *ne;
689 u_int i;
690
691 KASSERT(vnet != NULL, ("%s: vnet is NULL", __func__));
692 NETISR_LOCK_ASSERT();
693
694 CPU_FOREACH(i) {
695 nwsp = DPCPU_ID_PTR(i, nws);
696 if (nwsp->nws_intr_event == NULL)
697 continue;
698 npwp = &nwsp->nws_work[proto];
699 NWS_LOCK(nwsp);
700
701 /*
702 * Rather than dissecting and removing mbufs from the middle
703 * of the chain, we build a new chain if the packet stays and
704 * update the head and tail pointers at the end. All packets
705 * matching the given vnet are freed.
706 */
707 m = npwp->nw_head;
708 n = ne = NULL;
709 while (m != NULL) {
710 mp = m;
711 m = m->m_nextpkt;
712 mp->m_nextpkt = NULL;
713 if (mp->m_pkthdr.rcvif->if_vnet != vnet) {
714 if (n == NULL) {
715 n = ne = mp;
716 } else {
717 ne->m_nextpkt = mp;
718 ne = mp;
719 }
720 continue;
721 }
722 /* This is a packet in the selected vnet. Free it. */
723 npwp->nw_len--;
724 m_freem(mp);
725 }
726 npwp->nw_head = n;
727 npwp->nw_tail = ne;
728 NWS_UNLOCK(nwsp);
729 }
730 }
731
732 void
733 netisr_unregister_vnet(const struct netisr_handler *nhp)
734 {
735 u_int proto;
736
737 proto = nhp->nh_proto;
738
739 KASSERT(curvnet != NULL, ("%s: curvnet is NULL", __func__));
740 KASSERT(proto < NETISR_MAXPROT,
741 ("%s(%u): protocol too big for %s", __func__, proto, nhp->nh_name));
742 NETISR_WLOCK();
743 KASSERT(netisr_proto[proto].np_handler != NULL,
744 ("%s(%u): protocol not registered for %s", __func__, proto,
745 nhp->nh_name));
746
747 V_netisr_enable[proto] = 0;
748
749 netisr_drain_proto_vnet(curvnet, proto);
750 NETISR_WUNLOCK();
751 }
752 #endif
753
754 /*
755 * Compose the global and per-protocol policies on dispatch, and return the
756 * dispatch policy to use.
757 */
758 static u_int
759 netisr_get_dispatch(struct netisr_proto *npp)
760 {
761
762 /*
763 * Protocol-specific configuration overrides the global default.
764 */
765 if (npp->np_dispatch != NETISR_DISPATCH_DEFAULT)
766 return (npp->np_dispatch);
767 return (netisr_dispatch_policy);
768 }
769
770 /*
771 * Look up the workstream given a packet and source identifier. Do this by
772 * checking the protocol's policy, and optionally call out to the protocol
773 * for assistance if required.
774 */
775 static struct mbuf *
776 netisr_select_cpuid(struct netisr_proto *npp, u_int dispatch_policy,
777 uintptr_t source, struct mbuf *m, u_int *cpuidp)
778 {
779 struct ifnet *ifp;
780 u_int policy;
781
782 NETISR_LOCK_ASSERT();
783
784 /*
785 * In the event we have only one worker, shortcut and deliver to it
786 * without further ado.
787 */
788 if (nws_count == 1) {
789 *cpuidp = nws_array[0];
790 return (m);
791 }
792
793 /*
794 * What happens next depends on the policy selected by the protocol.
795 * If we want to support per-interface policies, we should do that
796 * here first.
797 */
798 policy = npp->np_policy;
799 if (policy == NETISR_POLICY_CPU) {
800 m = npp->np_m2cpuid(m, source, cpuidp);
801 if (m == NULL)
802 return (NULL);
803
804 /*
805 * It's possible for a protocol not to have a good idea about
806 * where to process a packet, in which case we fall back on
807 * the netisr code to decide. In the hybrid case, return the
808 * current CPU ID, which will force an immediate direct
809 * dispatch. In the queued case, fall back on the SOURCE
810 * policy.
811 */
812 if (*cpuidp != NETISR_CPUID_NONE) {
813 *cpuidp = netisr_get_cpuid(*cpuidp);
814 return (m);
815 }
816 if (dispatch_policy == NETISR_DISPATCH_HYBRID) {
817 *cpuidp = netisr_get_cpuid(curcpu);
818 return (m);
819 }
820 policy = NETISR_POLICY_SOURCE;
821 }
822
823 if (policy == NETISR_POLICY_FLOW) {
824 if (M_HASHTYPE_GET(m) == M_HASHTYPE_NONE &&
825 npp->np_m2flow != NULL) {
826 m = npp->np_m2flow(m, source);
827 if (m == NULL)
828 return (NULL);
829 }
830 if (M_HASHTYPE_GET(m) != M_HASHTYPE_NONE) {
831 *cpuidp =
832 netisr_default_flow2cpu(m->m_pkthdr.flowid);
833 return (m);
834 }
835 policy = NETISR_POLICY_SOURCE;
836 }
837
838 KASSERT(policy == NETISR_POLICY_SOURCE,
839 ("%s: invalid policy %u for %s", __func__, npp->np_policy,
840 npp->np_name));
841
842 ifp = m->m_pkthdr.rcvif;
843 if (ifp != NULL)
844 *cpuidp = nws_array[(ifp->if_index + source) % nws_count];
845 else
846 *cpuidp = nws_array[source % nws_count];
847 return (m);
848 }
849
850 /*
851 * Process packets associated with a workstream and protocol. For reasons of
852 * fairness, we process up to one complete netisr queue at a time, moving the
853 * queue to a stack-local queue for processing, but do not loop refreshing
854 * from the global queue. The caller is responsible for deciding whether to
855 * loop, and for setting the NWS_RUNNING flag. The passed workstream will be
856 * locked on entry and relocked before return, but will be released while
857 * processing. The number of packets processed is returned.
858 */
859 static u_int
860 netisr_process_workstream_proto(struct netisr_workstream *nwsp, u_int proto)
861 {
862 struct netisr_work local_npw, *npwp;
863 u_int handled;
864 struct mbuf *m;
865
866 NETISR_LOCK_ASSERT();
867 NWS_LOCK_ASSERT(nwsp);
868
869 KASSERT(nwsp->nws_flags & NWS_RUNNING,
870 ("%s(%u): not running", __func__, proto));
871 KASSERT(proto >= 0 && proto < NETISR_MAXPROT,
872 ("%s(%u): invalid proto\n", __func__, proto));
873
874 npwp = &nwsp->nws_work[proto];
875 if (npwp->nw_len == 0)
876 return (0);
877
878 /*
879 * Move the global work queue to a thread-local work queue.
880 *
881 * Notice that this means the effective maximum length of the queue
882 * is actually twice that of the maximum queue length specified in
883 * the protocol registration call.
884 */
885 handled = npwp->nw_len;
886 local_npw = *npwp;
887 npwp->nw_head = NULL;
888 npwp->nw_tail = NULL;
889 npwp->nw_len = 0;
890 nwsp->nws_pendingbits &= ~(1 << proto);
891 NWS_UNLOCK(nwsp);
892 while ((m = local_npw.nw_head) != NULL) {
893 local_npw.nw_head = m->m_nextpkt;
894 m->m_nextpkt = NULL;
895 if (local_npw.nw_head == NULL)
896 local_npw.nw_tail = NULL;
897 local_npw.nw_len--;
898 VNET_ASSERT(m->m_pkthdr.rcvif != NULL,
899 ("%s:%d rcvif == NULL: m=%p", __func__, __LINE__, m));
900 CURVNET_SET(m->m_pkthdr.rcvif->if_vnet);
901 netisr_proto[proto].np_handler(m);
902 CURVNET_RESTORE();
903 }
904 KASSERT(local_npw.nw_len == 0,
905 ("%s(%u): len %u", __func__, proto, local_npw.nw_len));
906 if (netisr_proto[proto].np_drainedcpu)
907 netisr_proto[proto].np_drainedcpu(nwsp->nws_cpu);
908 NWS_LOCK(nwsp);
909 npwp->nw_handled += handled;
910 return (handled);
911 }
912
913 /*
914 * SWI handler for netisr -- processes packets in a set of workstreams that
915 * it owns, woken up by calls to NWS_SIGNAL(). If this workstream is already
916 * being direct dispatched, go back to sleep and wait for the dispatching
917 * thread to wake us up again.
918 */
919 static void
920 swi_net(void *arg)
921 {
922 #ifdef NETISR_LOCKING
923 struct rm_priotracker tracker;
924 #endif
925 struct netisr_workstream *nwsp;
926 u_int bits, prot;
927
928 nwsp = arg;
929
930 #ifdef DEVICE_POLLING
931 KASSERT(nws_count == 1,
932 ("%s: device_polling but nws_count != 1", __func__));
933 netisr_poll();
934 #endif
935 #ifdef NETISR_LOCKING
936 NETISR_RLOCK(&tracker);
937 #endif
938 NWS_LOCK(nwsp);
939 KASSERT(!(nwsp->nws_flags & NWS_RUNNING), ("swi_net: running"));
940 if (nwsp->nws_flags & NWS_DISPATCHING)
941 goto out;
942 nwsp->nws_flags |= NWS_RUNNING;
943 nwsp->nws_flags &= ~NWS_SCHEDULED;
944 while ((bits = nwsp->nws_pendingbits) != 0) {
945 while ((prot = ffs(bits)) != 0) {
946 prot--;
947 bits &= ~(1 << prot);
948 (void)netisr_process_workstream_proto(nwsp, prot);
949 }
950 }
951 nwsp->nws_flags &= ~NWS_RUNNING;
952 out:
953 NWS_UNLOCK(nwsp);
954 #ifdef NETISR_LOCKING
955 NETISR_RUNLOCK(&tracker);
956 #endif
957 #ifdef DEVICE_POLLING
958 netisr_pollmore();
959 #endif
960 }
961
962 static int
963 netisr_queue_workstream(struct netisr_workstream *nwsp, u_int proto,
964 struct netisr_work *npwp, struct mbuf *m, int *dosignalp)
965 {
966
967 NWS_LOCK_ASSERT(nwsp);
968
969 *dosignalp = 0;
970 if (npwp->nw_len < npwp->nw_qlimit) {
971 m->m_nextpkt = NULL;
972 if (npwp->nw_head == NULL) {
973 npwp->nw_head = m;
974 npwp->nw_tail = m;
975 } else {
976 npwp->nw_tail->m_nextpkt = m;
977 npwp->nw_tail = m;
978 }
979 npwp->nw_len++;
980 if (npwp->nw_len > npwp->nw_watermark)
981 npwp->nw_watermark = npwp->nw_len;
982
983 /*
984 * We must set the bit regardless of NWS_RUNNING, so that
985 * swi_net() keeps calling netisr_process_workstream_proto().
986 */
987 nwsp->nws_pendingbits |= (1 << proto);
988 if (!(nwsp->nws_flags &
989 (NWS_RUNNING | NWS_DISPATCHING | NWS_SCHEDULED))) {
990 nwsp->nws_flags |= NWS_SCHEDULED;
991 *dosignalp = 1; /* Defer until unlocked. */
992 }
993 npwp->nw_queued++;
994 return (0);
995 } else {
996 m_freem(m);
997 npwp->nw_qdrops++;
998 return (ENOBUFS);
999 }
1000 }
1001
1002 static int
1003 netisr_queue_internal(u_int proto, struct mbuf *m, u_int cpuid)
1004 {
1005 struct netisr_workstream *nwsp;
1006 struct netisr_work *npwp;
1007 int dosignal, error;
1008
1009 #ifdef NETISR_LOCKING
1010 NETISR_LOCK_ASSERT();
1011 #endif
1012 KASSERT(cpuid <= mp_maxid, ("%s: cpuid too big (%u, %u)", __func__,
1013 cpuid, mp_maxid));
1014 KASSERT(!CPU_ABSENT(cpuid), ("%s: CPU %u absent", __func__, cpuid));
1015
1016 dosignal = 0;
1017 error = 0;
1018 nwsp = DPCPU_ID_PTR(cpuid, nws);
1019 npwp = &nwsp->nws_work[proto];
1020 NWS_LOCK(nwsp);
1021 error = netisr_queue_workstream(nwsp, proto, npwp, m, &dosignal);
1022 NWS_UNLOCK(nwsp);
1023 if (dosignal)
1024 NWS_SIGNAL(nwsp);
1025 return (error);
1026 }
1027
1028 int
1029 netisr_queue_src(u_int proto, uintptr_t source, struct mbuf *m)
1030 {
1031 #ifdef NETISR_LOCKING
1032 struct rm_priotracker tracker;
1033 #endif
1034 u_int cpuid;
1035 int error;
1036
1037 KASSERT(proto < NETISR_MAXPROT,
1038 ("%s: invalid proto %u", __func__, proto));
1039
1040 #ifdef NETISR_LOCKING
1041 NETISR_RLOCK(&tracker);
1042 #endif
1043 KASSERT(netisr_proto[proto].np_handler != NULL,
1044 ("%s: invalid proto %u", __func__, proto));
1045
1046 #ifdef VIMAGE
1047 if (V_netisr_enable[proto] == 0) {
1048 m_freem(m);
1049 return (ENOPROTOOPT);
1050 }
1051 #endif
1052
1053 m = netisr_select_cpuid(&netisr_proto[proto], NETISR_DISPATCH_DEFERRED,
1054 source, m, &cpuid);
1055 if (m != NULL) {
1056 KASSERT(!CPU_ABSENT(cpuid), ("%s: CPU %u absent", __func__,
1057 cpuid));
1058 VNET_ASSERT(m->m_pkthdr.rcvif != NULL,
1059 ("%s:%d rcvif == NULL: m=%p", __func__, __LINE__, m));
1060 error = netisr_queue_internal(proto, m, cpuid);
1061 } else
1062 error = ENOBUFS;
1063 #ifdef NETISR_LOCKING
1064 NETISR_RUNLOCK(&tracker);
1065 #endif
1066 return (error);
1067 }
1068
1069 int
1070 netisr_queue(u_int proto, struct mbuf *m)
1071 {
1072
1073 return (netisr_queue_src(proto, 0, m));
1074 }
1075
1076 /*
1077 * Dispatch a packet for netisr processing; direct dispatch is permitted by
1078 * calling context.
1079 */
1080 int
1081 netisr_dispatch_src(u_int proto, uintptr_t source, struct mbuf *m)
1082 {
1083 #ifdef NETISR_LOCKING
1084 struct rm_priotracker tracker;
1085 #endif
1086 struct netisr_workstream *nwsp;
1087 struct netisr_proto *npp;
1088 struct netisr_work *npwp;
1089 int dosignal, error;
1090 u_int cpuid, dispatch_policy;
1091
1092 KASSERT(proto < NETISR_MAXPROT,
1093 ("%s: invalid proto %u", __func__, proto));
1094 #ifdef NETISR_LOCKING
1095 NETISR_RLOCK(&tracker);
1096 #endif
1097 npp = &netisr_proto[proto];
1098 KASSERT(npp->np_handler != NULL, ("%s: invalid proto %u", __func__,
1099 proto));
1100
1101 #ifdef VIMAGE
1102 if (V_netisr_enable[proto] == 0) {
1103 m_freem(m);
1104 return (ENOPROTOOPT);
1105 }
1106 #endif
1107
1108 dispatch_policy = netisr_get_dispatch(npp);
1109 if (dispatch_policy == NETISR_DISPATCH_DEFERRED)
1110 return (netisr_queue_src(proto, source, m));
1111
1112 /*
1113 * If direct dispatch is forced, then unconditionally dispatch
1114 * without a formal CPU selection. Borrow the current CPU's stats,
1115 * even if there's no worker on it. In this case we don't update
1116 * nws_flags because all netisr processing will be source ordered due
1117 * to always being forced to directly dispatch.
1118 */
1119 if (dispatch_policy == NETISR_DISPATCH_DIRECT) {
1120 nwsp = DPCPU_PTR(nws);
1121 npwp = &nwsp->nws_work[proto];
1122 npwp->nw_dispatched++;
1123 npwp->nw_handled++;
1124 netisr_proto[proto].np_handler(m);
1125 error = 0;
1126 goto out_unlock;
1127 }
1128
1129 KASSERT(dispatch_policy == NETISR_DISPATCH_HYBRID,
1130 ("%s: unknown dispatch policy (%u)", __func__, dispatch_policy));
1131
1132 /*
1133 * Otherwise, we execute in a hybrid mode where we will try to direct
1134 * dispatch if we're on the right CPU and the netisr worker isn't
1135 * already running.
1136 */
1137 sched_pin();
1138 m = netisr_select_cpuid(&netisr_proto[proto], NETISR_DISPATCH_HYBRID,
1139 source, m, &cpuid);
1140 if (m == NULL) {
1141 error = ENOBUFS;
1142 goto out_unpin;
1143 }
1144 KASSERT(!CPU_ABSENT(cpuid), ("%s: CPU %u absent", __func__, cpuid));
1145 if (cpuid != curcpu)
1146 goto queue_fallback;
1147 nwsp = DPCPU_PTR(nws);
1148 npwp = &nwsp->nws_work[proto];
1149
1150 /*-
1151 * We are willing to direct dispatch only if three conditions hold:
1152 *
1153 * (1) The netisr worker isn't already running,
1154 * (2) Another thread isn't already directly dispatching, and
1155 * (3) The netisr hasn't already been woken up.
1156 */
1157 NWS_LOCK(nwsp);
1158 if (nwsp->nws_flags & (NWS_RUNNING | NWS_DISPATCHING | NWS_SCHEDULED)) {
1159 error = netisr_queue_workstream(nwsp, proto, npwp, m,
1160 &dosignal);
1161 NWS_UNLOCK(nwsp);
1162 if (dosignal)
1163 NWS_SIGNAL(nwsp);
1164 goto out_unpin;
1165 }
1166
1167 /*
1168 * The current thread is now effectively the netisr worker, so set
1169 * the dispatching flag to prevent concurrent processing of the
1170 * stream from another thread (even the netisr worker), which could
1171 * otherwise lead to effective misordering of the stream.
1172 */
1173 nwsp->nws_flags |= NWS_DISPATCHING;
1174 NWS_UNLOCK(nwsp);
1175 netisr_proto[proto].np_handler(m);
1176 NWS_LOCK(nwsp);
1177 nwsp->nws_flags &= ~NWS_DISPATCHING;
1178 npwp->nw_handled++;
1179 npwp->nw_hybrid_dispatched++;
1180
1181 /*
1182 * If other work was enqueued by another thread while we were direct
1183 * dispatching, we need to signal the netisr worker to do that work.
1184 * In the future, we might want to do some of that work in the
1185 * current thread, rather than trigger further context switches. If
1186 * so, we'll want to establish a reasonable bound on the work done in
1187 * the "borrowed" context.
1188 */
1189 if (nwsp->nws_pendingbits != 0) {
1190 nwsp->nws_flags |= NWS_SCHEDULED;
1191 dosignal = 1;
1192 } else
1193 dosignal = 0;
1194 NWS_UNLOCK(nwsp);
1195 if (dosignal)
1196 NWS_SIGNAL(nwsp);
1197 error = 0;
1198 goto out_unpin;
1199
1200 queue_fallback:
1201 error = netisr_queue_internal(proto, m, cpuid);
1202 out_unpin:
1203 sched_unpin();
1204 out_unlock:
1205 #ifdef NETISR_LOCKING
1206 NETISR_RUNLOCK(&tracker);
1207 #endif
1208 return (error);
1209 }
1210
1211 int
1212 netisr_dispatch(u_int proto, struct mbuf *m)
1213 {
1214
1215 return (netisr_dispatch_src(proto, 0, m));
1216 }
1217
1218 #ifdef DEVICE_POLLING
1219 /*
1220 * Kernel polling borrows a netisr thread to run interface polling in; this
1221 * function allows kernel polling to request that the netisr thread be
1222 * scheduled even if no packets are pending for protocols.
1223 */
1224 void
1225 netisr_sched_poll(void)
1226 {
1227 struct netisr_workstream *nwsp;
1228
1229 nwsp = DPCPU_ID_PTR(nws_array[0], nws);
1230 NWS_SIGNAL(nwsp);
1231 }
1232 #endif
1233
1234 static void
1235 netisr_start_swi(u_int cpuid, struct pcpu *pc)
1236 {
1237 char swiname[12];
1238 struct netisr_workstream *nwsp;
1239 int error;
1240
1241 KASSERT(!CPU_ABSENT(cpuid), ("%s: CPU %u absent", __func__, cpuid));
1242
1243 nwsp = DPCPU_ID_PTR(cpuid, nws);
1244 mtx_init(&nwsp->nws_mtx, "netisr_mtx", NULL, MTX_DEF);
1245 nwsp->nws_cpu = cpuid;
1246 snprintf(swiname, sizeof(swiname), "netisr %u", cpuid);
1247 error = swi_add(&nwsp->nws_intr_event, swiname, swi_net, nwsp,
1248 SWI_NET, INTR_MPSAFE, &nwsp->nws_swi_cookie);
1249 if (error)
1250 panic("%s: swi_add %d", __func__, error);
1251 pc->pc_netisr = nwsp->nws_intr_event;
1252 if (netisr_bindthreads) {
1253 error = intr_event_bind(nwsp->nws_intr_event, cpuid);
1254 if (error != 0)
1255 printf("%s: cpu %u: intr_event_bind: %d", __func__,
1256 cpuid, error);
1257 }
1258 NETISR_WLOCK();
1259 nws_array[nws_count] = nwsp->nws_cpu;
1260 nws_count++;
1261 NETISR_WUNLOCK();
1262 }
1263
1264 /*
1265 * Initialize the netisr subsystem. We rely on BSS and static initialization
1266 * of most fields in global data structures.
1267 *
1268 * Start a worker thread for the boot CPU so that we can support network
1269 * traffic immediately in case the network stack is used before additional
1270 * CPUs are started (for example, diskless boot).
1271 */
1272 static void
1273 netisr_init(void *arg)
1274 {
1275 struct pcpu *pc;
1276
1277 NETISR_LOCK_INIT();
1278 if (netisr_maxthreads == 0 || netisr_maxthreads < -1 )
1279 netisr_maxthreads = 1; /* default behavior */
1280 else if (netisr_maxthreads == -1)
1281 netisr_maxthreads = mp_ncpus; /* use max cpus */
1282 if (netisr_maxthreads > mp_ncpus) {
1283 printf("netisr_init: forcing maxthreads from %d to %d\n",
1284 netisr_maxthreads, mp_ncpus);
1285 netisr_maxthreads = mp_ncpus;
1286 }
1287 if (netisr_defaultqlimit > netisr_maxqlimit) {
1288 printf("netisr_init: forcing defaultqlimit from %d to %d\n",
1289 netisr_defaultqlimit, netisr_maxqlimit);
1290 netisr_defaultqlimit = netisr_maxqlimit;
1291 }
1292 #ifdef DEVICE_POLLING
1293 /*
1294 * The device polling code is not yet aware of how to deal with
1295 * multiple netisr threads, so for the time being compiling in device
1296 * polling disables parallel netisr workers.
1297 */
1298 if (netisr_maxthreads != 1 || netisr_bindthreads != 0) {
1299 printf("netisr_init: forcing maxthreads to 1 and "
1300 "bindthreads to 0 for device polling\n");
1301 netisr_maxthreads = 1;
1302 netisr_bindthreads = 0;
1303 }
1304 #endif
1305
1306 #ifdef EARLY_AP_STARTUP
1307 STAILQ_FOREACH(pc, &cpuhead, pc_allcpu) {
1308 if (nws_count >= netisr_maxthreads)
1309 break;
1310 netisr_start_swi(pc->pc_cpuid, pc);
1311 }
1312 #else
1313 pc = get_pcpu();
1314 netisr_start_swi(pc->pc_cpuid, pc);
1315 #endif
1316 }
1317 SYSINIT(netisr_init, SI_SUB_SOFTINTR, SI_ORDER_FIRST, netisr_init, NULL);
1318
1319 #ifndef EARLY_AP_STARTUP
1320 /*
1321 * Start worker threads for additional CPUs. No attempt to gracefully handle
1322 * work reassignment, we don't yet support dynamic reconfiguration.
1323 */
1324 static void
1325 netisr_start(void *arg)
1326 {
1327 struct pcpu *pc;
1328
1329 STAILQ_FOREACH(pc, &cpuhead, pc_allcpu) {
1330 if (nws_count >= netisr_maxthreads)
1331 break;
1332 /* Worker will already be present for boot CPU. */
1333 if (pc->pc_netisr != NULL)
1334 continue;
1335 netisr_start_swi(pc->pc_cpuid, pc);
1336 }
1337 }
1338 SYSINIT(netisr_start, SI_SUB_SMP, SI_ORDER_MIDDLE, netisr_start, NULL);
1339 #endif
1340
1341 /*
1342 * Sysctl monitoring for netisr: query a list of registered protocols.
1343 */
1344 static int
1345 sysctl_netisr_proto(SYSCTL_HANDLER_ARGS)
1346 {
1347 struct rm_priotracker tracker;
1348 struct sysctl_netisr_proto *snpp, *snp_array;
1349 struct netisr_proto *npp;
1350 u_int counter, proto;
1351 int error;
1352
1353 if (req->newptr != NULL)
1354 return (EINVAL);
1355 snp_array = malloc(sizeof(*snp_array) * NETISR_MAXPROT, M_TEMP,
1356 M_ZERO | M_WAITOK);
1357 counter = 0;
1358 NETISR_RLOCK(&tracker);
1359 for (proto = 0; proto < NETISR_MAXPROT; proto++) {
1360 npp = &netisr_proto[proto];
1361 if (npp->np_name == NULL)
1362 continue;
1363 snpp = &snp_array[counter];
1364 snpp->snp_version = sizeof(*snpp);
1365 strlcpy(snpp->snp_name, npp->np_name, NETISR_NAMEMAXLEN);
1366 snpp->snp_proto = proto;
1367 snpp->snp_qlimit = npp->np_qlimit;
1368 snpp->snp_policy = npp->np_policy;
1369 snpp->snp_dispatch = npp->np_dispatch;
1370 if (npp->np_m2flow != NULL)
1371 snpp->snp_flags |= NETISR_SNP_FLAGS_M2FLOW;
1372 if (npp->np_m2cpuid != NULL)
1373 snpp->snp_flags |= NETISR_SNP_FLAGS_M2CPUID;
1374 if (npp->np_drainedcpu != NULL)
1375 snpp->snp_flags |= NETISR_SNP_FLAGS_DRAINEDCPU;
1376 counter++;
1377 }
1378 NETISR_RUNLOCK(&tracker);
1379 KASSERT(counter <= NETISR_MAXPROT,
1380 ("sysctl_netisr_proto: counter too big (%d)", counter));
1381 error = SYSCTL_OUT(req, snp_array, sizeof(*snp_array) * counter);
1382 free(snp_array, M_TEMP);
1383 return (error);
1384 }
1385
1386 SYSCTL_PROC(_net_isr, OID_AUTO, proto,
1387 CTLFLAG_RD|CTLTYPE_STRUCT|CTLFLAG_MPSAFE, 0, 0, sysctl_netisr_proto,
1388 "S,sysctl_netisr_proto",
1389 "Return list of protocols registered with netisr");
1390
1391 /*
1392 * Sysctl monitoring for netisr: query a list of workstreams.
1393 */
1394 static int
1395 sysctl_netisr_workstream(SYSCTL_HANDLER_ARGS)
1396 {
1397 struct rm_priotracker tracker;
1398 struct sysctl_netisr_workstream *snwsp, *snws_array;
1399 struct netisr_workstream *nwsp;
1400 u_int counter, cpuid;
1401 int error;
1402
1403 if (req->newptr != NULL)
1404 return (EINVAL);
1405 snws_array = malloc(sizeof(*snws_array) * MAXCPU, M_TEMP,
1406 M_ZERO | M_WAITOK);
1407 counter = 0;
1408 NETISR_RLOCK(&tracker);
1409 CPU_FOREACH(cpuid) {
1410 nwsp = DPCPU_ID_PTR(cpuid, nws);
1411 if (nwsp->nws_intr_event == NULL)
1412 continue;
1413 NWS_LOCK(nwsp);
1414 snwsp = &snws_array[counter];
1415 snwsp->snws_version = sizeof(*snwsp);
1416
1417 /*
1418 * For now, we equate workstream IDs and CPU IDs in the
1419 * kernel, but expose them independently to userspace in case
1420 * that assumption changes in the future.
1421 */
1422 snwsp->snws_wsid = cpuid;
1423 snwsp->snws_cpu = cpuid;
1424 if (nwsp->nws_intr_event != NULL)
1425 snwsp->snws_flags |= NETISR_SNWS_FLAGS_INTR;
1426 NWS_UNLOCK(nwsp);
1427 counter++;
1428 }
1429 NETISR_RUNLOCK(&tracker);
1430 KASSERT(counter <= MAXCPU,
1431 ("sysctl_netisr_workstream: counter too big (%d)", counter));
1432 error = SYSCTL_OUT(req, snws_array, sizeof(*snws_array) * counter);
1433 free(snws_array, M_TEMP);
1434 return (error);
1435 }
1436
1437 SYSCTL_PROC(_net_isr, OID_AUTO, workstream,
1438 CTLFLAG_RD|CTLTYPE_STRUCT|CTLFLAG_MPSAFE, 0, 0, sysctl_netisr_workstream,
1439 "S,sysctl_netisr_workstream",
1440 "Return list of workstreams implemented by netisr");
1441
1442 /*
1443 * Sysctl monitoring for netisr: query per-protocol data across all
1444 * workstreams.
1445 */
1446 static int
1447 sysctl_netisr_work(SYSCTL_HANDLER_ARGS)
1448 {
1449 struct rm_priotracker tracker;
1450 struct sysctl_netisr_work *snwp, *snw_array;
1451 struct netisr_workstream *nwsp;
1452 struct netisr_proto *npp;
1453 struct netisr_work *nwp;
1454 u_int counter, cpuid, proto;
1455 int error;
1456
1457 if (req->newptr != NULL)
1458 return (EINVAL);
1459 snw_array = malloc(sizeof(*snw_array) * MAXCPU * NETISR_MAXPROT,
1460 M_TEMP, M_ZERO | M_WAITOK);
1461 counter = 0;
1462 NETISR_RLOCK(&tracker);
1463 CPU_FOREACH(cpuid) {
1464 nwsp = DPCPU_ID_PTR(cpuid, nws);
1465 if (nwsp->nws_intr_event == NULL)
1466 continue;
1467 NWS_LOCK(nwsp);
1468 for (proto = 0; proto < NETISR_MAXPROT; proto++) {
1469 npp = &netisr_proto[proto];
1470 if (npp->np_name == NULL)
1471 continue;
1472 nwp = &nwsp->nws_work[proto];
1473 snwp = &snw_array[counter];
1474 snwp->snw_version = sizeof(*snwp);
1475 snwp->snw_wsid = cpuid; /* See comment above. */
1476 snwp->snw_proto = proto;
1477 snwp->snw_len = nwp->nw_len;
1478 snwp->snw_watermark = nwp->nw_watermark;
1479 snwp->snw_dispatched = nwp->nw_dispatched;
1480 snwp->snw_hybrid_dispatched =
1481 nwp->nw_hybrid_dispatched;
1482 snwp->snw_qdrops = nwp->nw_qdrops;
1483 snwp->snw_queued = nwp->nw_queued;
1484 snwp->snw_handled = nwp->nw_handled;
1485 counter++;
1486 }
1487 NWS_UNLOCK(nwsp);
1488 }
1489 KASSERT(counter <= MAXCPU * NETISR_MAXPROT,
1490 ("sysctl_netisr_work: counter too big (%d)", counter));
1491 NETISR_RUNLOCK(&tracker);
1492 error = SYSCTL_OUT(req, snw_array, sizeof(*snw_array) * counter);
1493 free(snw_array, M_TEMP);
1494 return (error);
1495 }
1496
1497 SYSCTL_PROC(_net_isr, OID_AUTO, work,
1498 CTLFLAG_RD|CTLTYPE_STRUCT|CTLFLAG_MPSAFE, 0, 0, sysctl_netisr_work,
1499 "S,sysctl_netisr_work",
1500 "Return list of per-workstream, per-protocol work in netisr");
1501
1502 #ifdef DDB
1503 DB_SHOW_COMMAND(netisr, db_show_netisr)
1504 {
1505 struct netisr_workstream *nwsp;
1506 struct netisr_work *nwp;
1507 int first, proto;
1508 u_int cpuid;
1509
1510 db_printf("%3s %6s %5s %5s %5s %8s %8s %8s %8s\n", "CPU", "Proto",
1511 "Len", "WMark", "Max", "Disp", "HDisp", "Drop", "Queue");
1512 CPU_FOREACH(cpuid) {
1513 nwsp = DPCPU_ID_PTR(cpuid, nws);
1514 if (nwsp->nws_intr_event == NULL)
1515 continue;
1516 first = 1;
1517 for (proto = 0; proto < NETISR_MAXPROT; proto++) {
1518 if (netisr_proto[proto].np_handler == NULL)
1519 continue;
1520 nwp = &nwsp->nws_work[proto];
1521 if (first) {
1522 db_printf("%3d ", cpuid);
1523 first = 0;
1524 } else
1525 db_printf("%3s ", "");
1526 db_printf(
1527 "%6s %5d %5d %5d %8ju %8ju %8ju %8ju\n",
1528 netisr_proto[proto].np_name, nwp->nw_len,
1529 nwp->nw_watermark, nwp->nw_qlimit,
1530 nwp->nw_dispatched, nwp->nw_hybrid_dispatched,
1531 nwp->nw_qdrops, nwp->nw_queued);
1532 }
1533 }
1534 }
1535 #endif
Cache object: ce545b35f192f77376e8d5694da1ef19
|