FreeBSD/Linux Kernel Cross Reference
sys/net/netisr.c
1 /*-
2 * Copyright (c) 2007-2009 Robert N. M. Watson
3 * Copyright (c) 2010-2011 Juniper Networks, Inc.
4 * All rights reserved.
5 *
6 * This software was developed by Robert N. M. Watson under contract
7 * to Juniper Networks, Inc.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 */
30
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD: releng/11.0/sys/net/netisr.c 301270 2016-06-03 13:57:10Z bz $");
33
34 /*
35 * netisr is a packet dispatch service, allowing synchronous (directly
36 * dispatched) and asynchronous (deferred dispatch) processing of packets by
37 * registered protocol handlers. Callers pass a protocol identifier and
38 * packet to netisr, along with a direct dispatch hint, and work will either
39 * be immediately processed by the registered handler, or passed to a
40 * software interrupt (SWI) thread for deferred dispatch. Callers will
41 * generally select one or the other based on:
42 *
43 * - Whether directly dispatching a netisr handler lead to code reentrance or
44 * lock recursion, such as entering the socket code from the socket code.
45 * - Whether directly dispatching a netisr handler lead to recursive
46 * processing, such as when decapsulating several wrapped layers of tunnel
47 * information (IPSEC within IPSEC within ...).
48 *
49 * Maintaining ordering for protocol streams is a critical design concern.
50 * Enforcing ordering limits the opportunity for concurrency, but maintains
51 * the strong ordering requirements found in some protocols, such as TCP. Of
52 * related concern is CPU affinity--it is desirable to process all data
53 * associated with a particular stream on the same CPU over time in order to
54 * avoid acquiring locks associated with the connection on different CPUs,
55 * keep connection data in one cache, and to generally encourage associated
56 * user threads to live on the same CPU as the stream. It's also desirable
57 * to avoid lock migration and contention where locks are associated with
58 * more than one flow.
59 *
60 * netisr supports several policy variations, represented by the
61 * NETISR_POLICY_* constants, allowing protocols to play various roles in
62 * identifying flows, assigning work to CPUs, etc. These are described in
63 * netisr.h.
64 */
65
66 #include "opt_ddb.h"
67 #include "opt_device_polling.h"
68
69 #include <sys/param.h>
70 #include <sys/bus.h>
71 #include <sys/kernel.h>
72 #include <sys/kthread.h>
73 #include <sys/malloc.h>
74 #include <sys/interrupt.h>
75 #include <sys/lock.h>
76 #include <sys/mbuf.h>
77 #include <sys/mutex.h>
78 #include <sys/pcpu.h>
79 #include <sys/proc.h>
80 #include <sys/rmlock.h>
81 #include <sys/sched.h>
82 #include <sys/smp.h>
83 #include <sys/socket.h>
84 #include <sys/sysctl.h>
85 #include <sys/systm.h>
86
87 #ifdef DDB
88 #include <ddb/ddb.h>
89 #endif
90
91 #define _WANT_NETISR_INTERNAL /* Enable definitions from netisr_internal.h */
92 #include <net/if.h>
93 #include <net/if_var.h>
94 #include <net/netisr.h>
95 #include <net/netisr_internal.h>
96 #include <net/vnet.h>
97
98 /*-
99 * Synchronize use and modification of the registered netisr data structures;
100 * acquire a read lock while modifying the set of registered protocols to
101 * prevent partially registered or unregistered protocols from being run.
102 *
103 * The following data structures and fields are protected by this lock:
104 *
105 * - The netisr_proto array, including all fields of struct netisr_proto.
106 * - The nws array, including all fields of struct netisr_worker.
107 * - The nws_array array.
108 *
109 * Note: the NETISR_LOCKING define controls whether read locks are acquired
110 * in packet processing paths requiring netisr registration stability. This
111 * is disabled by default as it can lead to measurable performance
112 * degradation even with rmlocks (3%-6% for loopback ping-pong traffic), and
113 * because netisr registration and unregistration is extremely rare at
114 * runtime. If it becomes more common, this decision should be revisited.
115 *
116 * XXXRW: rmlocks don't support assertions.
117 */
118 static struct rmlock netisr_rmlock;
119 #define NETISR_LOCK_INIT() rm_init_flags(&netisr_rmlock, "netisr", \
120 RM_NOWITNESS)
121 #define NETISR_LOCK_ASSERT()
122 #define NETISR_RLOCK(tracker) rm_rlock(&netisr_rmlock, (tracker))
123 #define NETISR_RUNLOCK(tracker) rm_runlock(&netisr_rmlock, (tracker))
124 #define NETISR_WLOCK() rm_wlock(&netisr_rmlock)
125 #define NETISR_WUNLOCK() rm_wunlock(&netisr_rmlock)
126 /* #define NETISR_LOCKING */
127
128 static SYSCTL_NODE(_net, OID_AUTO, isr, CTLFLAG_RW, 0, "netisr");
129
130 /*-
131 * Three global direct dispatch policies are supported:
132 *
133 * NETISR_DISPATCH_DEFERRED: All work is deferred for a netisr, regardless of
134 * context (may be overriden by protocols).
135 *
136 * NETISR_DISPATCH_HYBRID: If the executing context allows direct dispatch,
137 * and we're running on the CPU the work would be performed on, then direct
138 * dispatch it if it wouldn't violate ordering constraints on the workstream.
139 *
140 * NETISR_DISPATCH_DIRECT: If the executing context allows direct dispatch,
141 * always direct dispatch. (The default.)
142 *
143 * Notice that changing the global policy could lead to short periods of
144 * misordered processing, but this is considered acceptable as compared to
145 * the complexity of enforcing ordering during policy changes. Protocols can
146 * override the global policy (when they're not doing that, they select
147 * NETISR_DISPATCH_DEFAULT).
148 */
149 #define NETISR_DISPATCH_POLICY_DEFAULT NETISR_DISPATCH_DIRECT
150 #define NETISR_DISPATCH_POLICY_MAXSTR 20 /* Used for temporary buffers. */
151 static u_int netisr_dispatch_policy = NETISR_DISPATCH_POLICY_DEFAULT;
152 static int sysctl_netisr_dispatch_policy(SYSCTL_HANDLER_ARGS);
153 SYSCTL_PROC(_net_isr, OID_AUTO, dispatch, CTLTYPE_STRING | CTLFLAG_RWTUN,
154 0, 0, sysctl_netisr_dispatch_policy, "A",
155 "netisr dispatch policy");
156
157 /*
158 * Allow the administrator to limit the number of threads (CPUs) to use for
159 * netisr. We don't check netisr_maxthreads before creating the thread for
160 * CPU 0. This must be set at boot. We will create at most one thread per CPU.
161 * By default we initialize this to 1 which would assign just 1 cpu (cpu0) and
162 * therefore only 1 workstream. If set to -1, netisr would use all cpus
163 * (mp_ncpus) and therefore would have those many workstreams. One workstream
164 * per thread (CPU).
165 */
166 static int netisr_maxthreads = 1; /* Max number of threads. */
167 SYSCTL_INT(_net_isr, OID_AUTO, maxthreads, CTLFLAG_RDTUN,
168 &netisr_maxthreads, 0,
169 "Use at most this many CPUs for netisr processing");
170
171 static int netisr_bindthreads = 0; /* Bind threads to CPUs. */
172 SYSCTL_INT(_net_isr, OID_AUTO, bindthreads, CTLFLAG_RDTUN,
173 &netisr_bindthreads, 0, "Bind netisr threads to CPUs.");
174
175 /*
176 * Limit per-workstream mbuf queue limits s to at most net.isr.maxqlimit,
177 * both for initial configuration and later modification using
178 * netisr_setqlimit().
179 */
180 #define NETISR_DEFAULT_MAXQLIMIT 10240
181 static u_int netisr_maxqlimit = NETISR_DEFAULT_MAXQLIMIT;
182 SYSCTL_UINT(_net_isr, OID_AUTO, maxqlimit, CTLFLAG_RDTUN,
183 &netisr_maxqlimit, 0,
184 "Maximum netisr per-protocol, per-CPU queue depth.");
185
186 /*
187 * The default per-workstream mbuf queue limit for protocols that don't
188 * initialize the nh_qlimit field of their struct netisr_handler. If this is
189 * set above netisr_maxqlimit, we truncate it to the maximum during boot.
190 */
191 #define NETISR_DEFAULT_DEFAULTQLIMIT 256
192 static u_int netisr_defaultqlimit = NETISR_DEFAULT_DEFAULTQLIMIT;
193 SYSCTL_UINT(_net_isr, OID_AUTO, defaultqlimit, CTLFLAG_RDTUN,
194 &netisr_defaultqlimit, 0,
195 "Default netisr per-protocol, per-CPU queue limit if not set by protocol");
196
197 /*
198 * Store and export the compile-time constant NETISR_MAXPROT limit on the
199 * number of protocols that can register with netisr at a time. This is
200 * required for crashdump analysis, as it sizes netisr_proto[].
201 */
202 static u_int netisr_maxprot = NETISR_MAXPROT;
203 SYSCTL_UINT(_net_isr, OID_AUTO, maxprot, CTLFLAG_RD,
204 &netisr_maxprot, 0,
205 "Compile-time limit on the number of protocols supported by netisr.");
206
207 /*
208 * The netisr_proto array describes all registered protocols, indexed by
209 * protocol number. See netisr_internal.h for more details.
210 */
211 static struct netisr_proto netisr_proto[NETISR_MAXPROT];
212
213 #ifdef VIMAGE
214 /*
215 * The netisr_enable array describes a per-VNET flag for registered
216 * protocols on whether this netisr is active in this VNET or not.
217 * netisr_register() will automatically enable the netisr for the
218 * default VNET and all currently active instances.
219 * netisr_unregister() will disable all active VNETs, including vnet0.
220 * Individual network stack instances can be enabled/disabled by the
221 * netisr_(un)register _vnet() functions.
222 * With this we keep the one netisr_proto per protocol but add a
223 * mechanism to stop netisr processing for vnet teardown.
224 * Apart from that we expect a VNET to always be enabled.
225 */
226 static VNET_DEFINE(u_int, netisr_enable[NETISR_MAXPROT]);
227 #define V_netisr_enable VNET(netisr_enable)
228 #endif
229
230 /*
231 * Per-CPU workstream data. See netisr_internal.h for more details.
232 */
233 DPCPU_DEFINE(struct netisr_workstream, nws);
234
235 /*
236 * Map contiguous values between 0 and nws_count into CPU IDs appropriate for
237 * accessing workstreams. This allows constructions of the form
238 * DPCPU_ID_GET(nws_array[arbitraryvalue % nws_count], nws).
239 */
240 static u_int nws_array[MAXCPU];
241
242 /*
243 * Number of registered workstreams. Will be at most the number of running
244 * CPUs once fully started.
245 */
246 static u_int nws_count;
247 SYSCTL_UINT(_net_isr, OID_AUTO, numthreads, CTLFLAG_RD,
248 &nws_count, 0, "Number of extant netisr threads.");
249
250 /*
251 * Synchronization for each workstream: a mutex protects all mutable fields
252 * in each stream, including per-protocol state (mbuf queues). The SWI is
253 * woken up if asynchronous dispatch is required.
254 */
255 #define NWS_LOCK(s) mtx_lock(&(s)->nws_mtx)
256 #define NWS_LOCK_ASSERT(s) mtx_assert(&(s)->nws_mtx, MA_OWNED)
257 #define NWS_UNLOCK(s) mtx_unlock(&(s)->nws_mtx)
258 #define NWS_SIGNAL(s) swi_sched((s)->nws_swi_cookie, 0)
259
260 /*
261 * Utility routines for protocols that implement their own mapping of flows
262 * to CPUs.
263 */
264 u_int
265 netisr_get_cpucount(void)
266 {
267
268 return (nws_count);
269 }
270
271 u_int
272 netisr_get_cpuid(u_int cpunumber)
273 {
274
275 KASSERT(cpunumber < nws_count, ("%s: %u > %u", __func__, cpunumber,
276 nws_count));
277
278 return (nws_array[cpunumber]);
279 }
280
281 /*
282 * The default implementation of flow -> CPU ID mapping.
283 *
284 * Non-static so that protocols can use it to map their own work to specific
285 * CPUs in a manner consistent to netisr for affinity purposes.
286 */
287 u_int
288 netisr_default_flow2cpu(u_int flowid)
289 {
290
291 return (nws_array[flowid % nws_count]);
292 }
293
294 /*
295 * Dispatch tunable and sysctl configuration.
296 */
297 struct netisr_dispatch_table_entry {
298 u_int ndte_policy;
299 const char *ndte_policy_str;
300 };
301 static const struct netisr_dispatch_table_entry netisr_dispatch_table[] = {
302 { NETISR_DISPATCH_DEFAULT, "default" },
303 { NETISR_DISPATCH_DEFERRED, "deferred" },
304 { NETISR_DISPATCH_HYBRID, "hybrid" },
305 { NETISR_DISPATCH_DIRECT, "direct" },
306 };
307
308 static void
309 netisr_dispatch_policy_to_str(u_int dispatch_policy, char *buffer,
310 u_int buflen)
311 {
312 const struct netisr_dispatch_table_entry *ndtep;
313 const char *str;
314 u_int i;
315
316 str = "unknown";
317 for (i = 0; i < nitems(netisr_dispatch_table); i++) {
318 ndtep = &netisr_dispatch_table[i];
319 if (ndtep->ndte_policy == dispatch_policy) {
320 str = ndtep->ndte_policy_str;
321 break;
322 }
323 }
324 snprintf(buffer, buflen, "%s", str);
325 }
326
327 static int
328 netisr_dispatch_policy_from_str(const char *str, u_int *dispatch_policyp)
329 {
330 const struct netisr_dispatch_table_entry *ndtep;
331 u_int i;
332
333 for (i = 0; i < nitems(netisr_dispatch_table); i++) {
334 ndtep = &netisr_dispatch_table[i];
335 if (strcmp(ndtep->ndte_policy_str, str) == 0) {
336 *dispatch_policyp = ndtep->ndte_policy;
337 return (0);
338 }
339 }
340 return (EINVAL);
341 }
342
343 static int
344 sysctl_netisr_dispatch_policy(SYSCTL_HANDLER_ARGS)
345 {
346 char tmp[NETISR_DISPATCH_POLICY_MAXSTR];
347 u_int dispatch_policy;
348 int error;
349
350 netisr_dispatch_policy_to_str(netisr_dispatch_policy, tmp,
351 sizeof(tmp));
352 error = sysctl_handle_string(oidp, tmp, sizeof(tmp), req);
353 if (error == 0 && req->newptr != NULL) {
354 error = netisr_dispatch_policy_from_str(tmp,
355 &dispatch_policy);
356 if (error == 0 && dispatch_policy == NETISR_DISPATCH_DEFAULT)
357 error = EINVAL;
358 if (error == 0)
359 netisr_dispatch_policy = dispatch_policy;
360 }
361 return (error);
362 }
363
364 /*
365 * Register a new netisr handler, which requires initializing per-protocol
366 * fields for each workstream. All netisr work is briefly suspended while
367 * the protocol is installed.
368 */
369 void
370 netisr_register(const struct netisr_handler *nhp)
371 {
372 VNET_ITERATOR_DECL(vnet_iter);
373 struct netisr_work *npwp;
374 const char *name;
375 u_int i, proto;
376
377 proto = nhp->nh_proto;
378 name = nhp->nh_name;
379
380 /*
381 * Test that the requested registration is valid.
382 */
383 KASSERT(nhp->nh_name != NULL,
384 ("%s: nh_name NULL for %u", __func__, proto));
385 KASSERT(nhp->nh_handler != NULL,
386 ("%s: nh_handler NULL for %s", __func__, name));
387 KASSERT(nhp->nh_policy == NETISR_POLICY_SOURCE ||
388 nhp->nh_policy == NETISR_POLICY_FLOW ||
389 nhp->nh_policy == NETISR_POLICY_CPU,
390 ("%s: unsupported nh_policy %u for %s", __func__,
391 nhp->nh_policy, name));
392 KASSERT(nhp->nh_policy == NETISR_POLICY_FLOW ||
393 nhp->nh_m2flow == NULL,
394 ("%s: nh_policy != FLOW but m2flow defined for %s", __func__,
395 name));
396 KASSERT(nhp->nh_policy == NETISR_POLICY_CPU || nhp->nh_m2cpuid == NULL,
397 ("%s: nh_policy != CPU but m2cpuid defined for %s", __func__,
398 name));
399 KASSERT(nhp->nh_policy != NETISR_POLICY_CPU || nhp->nh_m2cpuid != NULL,
400 ("%s: nh_policy == CPU but m2cpuid not defined for %s", __func__,
401 name));
402 KASSERT(nhp->nh_dispatch == NETISR_DISPATCH_DEFAULT ||
403 nhp->nh_dispatch == NETISR_DISPATCH_DEFERRED ||
404 nhp->nh_dispatch == NETISR_DISPATCH_HYBRID ||
405 nhp->nh_dispatch == NETISR_DISPATCH_DIRECT,
406 ("%s: invalid nh_dispatch (%u)", __func__, nhp->nh_dispatch));
407
408 KASSERT(proto < NETISR_MAXPROT,
409 ("%s(%u, %s): protocol too big", __func__, proto, name));
410
411 /*
412 * Test that no existing registration exists for this protocol.
413 */
414 NETISR_WLOCK();
415 KASSERT(netisr_proto[proto].np_name == NULL,
416 ("%s(%u, %s): name present", __func__, proto, name));
417 KASSERT(netisr_proto[proto].np_handler == NULL,
418 ("%s(%u, %s): handler present", __func__, proto, name));
419
420 netisr_proto[proto].np_name = name;
421 netisr_proto[proto].np_handler = nhp->nh_handler;
422 netisr_proto[proto].np_m2flow = nhp->nh_m2flow;
423 netisr_proto[proto].np_m2cpuid = nhp->nh_m2cpuid;
424 netisr_proto[proto].np_drainedcpu = nhp->nh_drainedcpu;
425 if (nhp->nh_qlimit == 0)
426 netisr_proto[proto].np_qlimit = netisr_defaultqlimit;
427 else if (nhp->nh_qlimit > netisr_maxqlimit) {
428 printf("%s: %s requested queue limit %u capped to "
429 "net.isr.maxqlimit %u\n", __func__, name, nhp->nh_qlimit,
430 netisr_maxqlimit);
431 netisr_proto[proto].np_qlimit = netisr_maxqlimit;
432 } else
433 netisr_proto[proto].np_qlimit = nhp->nh_qlimit;
434 netisr_proto[proto].np_policy = nhp->nh_policy;
435 netisr_proto[proto].np_dispatch = nhp->nh_dispatch;
436 CPU_FOREACH(i) {
437 npwp = &(DPCPU_ID_PTR(i, nws))->nws_work[proto];
438 bzero(npwp, sizeof(*npwp));
439 npwp->nw_qlimit = netisr_proto[proto].np_qlimit;
440 }
441
442 #ifdef VIMAGE
443 /*
444 * Test that we are in vnet0 and have a curvnet set.
445 */
446 KASSERT(curvnet != NULL, ("%s: curvnet is NULL", __func__));
447 KASSERT(IS_DEFAULT_VNET(curvnet), ("%s: curvnet %p is not vnet0 %p",
448 __func__, curvnet, vnet0));
449 VNET_LIST_RLOCK_NOSLEEP();
450 VNET_FOREACH(vnet_iter) {
451 CURVNET_SET(vnet_iter);
452 V_netisr_enable[proto] = 1;
453 CURVNET_RESTORE();
454 }
455 VNET_LIST_RUNLOCK_NOSLEEP();
456 #endif
457 NETISR_WUNLOCK();
458 }
459
460 /*
461 * Clear drop counters across all workstreams for a protocol.
462 */
463 void
464 netisr_clearqdrops(const struct netisr_handler *nhp)
465 {
466 struct netisr_work *npwp;
467 #ifdef INVARIANTS
468 const char *name;
469 #endif
470 u_int i, proto;
471
472 proto = nhp->nh_proto;
473 #ifdef INVARIANTS
474 name = nhp->nh_name;
475 #endif
476 KASSERT(proto < NETISR_MAXPROT,
477 ("%s(%u): protocol too big for %s", __func__, proto, name));
478
479 NETISR_WLOCK();
480 KASSERT(netisr_proto[proto].np_handler != NULL,
481 ("%s(%u): protocol not registered for %s", __func__, proto,
482 name));
483
484 CPU_FOREACH(i) {
485 npwp = &(DPCPU_ID_PTR(i, nws))->nws_work[proto];
486 npwp->nw_qdrops = 0;
487 }
488 NETISR_WUNLOCK();
489 }
490
491 /*
492 * Query current drop counters across all workstreams for a protocol.
493 */
494 void
495 netisr_getqdrops(const struct netisr_handler *nhp, u_int64_t *qdropp)
496 {
497 struct netisr_work *npwp;
498 struct rm_priotracker tracker;
499 #ifdef INVARIANTS
500 const char *name;
501 #endif
502 u_int i, proto;
503
504 *qdropp = 0;
505 proto = nhp->nh_proto;
506 #ifdef INVARIANTS
507 name = nhp->nh_name;
508 #endif
509 KASSERT(proto < NETISR_MAXPROT,
510 ("%s(%u): protocol too big for %s", __func__, proto, name));
511
512 NETISR_RLOCK(&tracker);
513 KASSERT(netisr_proto[proto].np_handler != NULL,
514 ("%s(%u): protocol not registered for %s", __func__, proto,
515 name));
516
517 CPU_FOREACH(i) {
518 npwp = &(DPCPU_ID_PTR(i, nws))->nws_work[proto];
519 *qdropp += npwp->nw_qdrops;
520 }
521 NETISR_RUNLOCK(&tracker);
522 }
523
524 /*
525 * Query current per-workstream queue limit for a protocol.
526 */
527 void
528 netisr_getqlimit(const struct netisr_handler *nhp, u_int *qlimitp)
529 {
530 struct rm_priotracker tracker;
531 #ifdef INVARIANTS
532 const char *name;
533 #endif
534 u_int proto;
535
536 proto = nhp->nh_proto;
537 #ifdef INVARIANTS
538 name = nhp->nh_name;
539 #endif
540 KASSERT(proto < NETISR_MAXPROT,
541 ("%s(%u): protocol too big for %s", __func__, proto, name));
542
543 NETISR_RLOCK(&tracker);
544 KASSERT(netisr_proto[proto].np_handler != NULL,
545 ("%s(%u): protocol not registered for %s", __func__, proto,
546 name));
547 *qlimitp = netisr_proto[proto].np_qlimit;
548 NETISR_RUNLOCK(&tracker);
549 }
550
551 /*
552 * Update the queue limit across per-workstream queues for a protocol. We
553 * simply change the limits, and don't drain overflowed packets as they will
554 * (hopefully) take care of themselves shortly.
555 */
556 int
557 netisr_setqlimit(const struct netisr_handler *nhp, u_int qlimit)
558 {
559 struct netisr_work *npwp;
560 #ifdef INVARIANTS
561 const char *name;
562 #endif
563 u_int i, proto;
564
565 if (qlimit > netisr_maxqlimit)
566 return (EINVAL);
567
568 proto = nhp->nh_proto;
569 #ifdef INVARIANTS
570 name = nhp->nh_name;
571 #endif
572 KASSERT(proto < NETISR_MAXPROT,
573 ("%s(%u): protocol too big for %s", __func__, proto, name));
574
575 NETISR_WLOCK();
576 KASSERT(netisr_proto[proto].np_handler != NULL,
577 ("%s(%u): protocol not registered for %s", __func__, proto,
578 name));
579
580 netisr_proto[proto].np_qlimit = qlimit;
581 CPU_FOREACH(i) {
582 npwp = &(DPCPU_ID_PTR(i, nws))->nws_work[proto];
583 npwp->nw_qlimit = qlimit;
584 }
585 NETISR_WUNLOCK();
586 return (0);
587 }
588
589 /*
590 * Drain all packets currently held in a particular protocol work queue.
591 */
592 static void
593 netisr_drain_proto(struct netisr_work *npwp)
594 {
595 struct mbuf *m;
596
597 /*
598 * We would assert the lock on the workstream but it's not passed in.
599 */
600 while ((m = npwp->nw_head) != NULL) {
601 npwp->nw_head = m->m_nextpkt;
602 m->m_nextpkt = NULL;
603 if (npwp->nw_head == NULL)
604 npwp->nw_tail = NULL;
605 npwp->nw_len--;
606 m_freem(m);
607 }
608 KASSERT(npwp->nw_tail == NULL, ("%s: tail", __func__));
609 KASSERT(npwp->nw_len == 0, ("%s: len", __func__));
610 }
611
612 /*
613 * Remove the registration of a network protocol, which requires clearing
614 * per-protocol fields across all workstreams, including freeing all mbufs in
615 * the queues at time of unregister. All work in netisr is briefly suspended
616 * while this takes place.
617 */
618 void
619 netisr_unregister(const struct netisr_handler *nhp)
620 {
621 VNET_ITERATOR_DECL(vnet_iter);
622 struct netisr_work *npwp;
623 #ifdef INVARIANTS
624 const char *name;
625 #endif
626 u_int i, proto;
627
628 proto = nhp->nh_proto;
629 #ifdef INVARIANTS
630 name = nhp->nh_name;
631 #endif
632 KASSERT(proto < NETISR_MAXPROT,
633 ("%s(%u): protocol too big for %s", __func__, proto, name));
634
635 NETISR_WLOCK();
636 KASSERT(netisr_proto[proto].np_handler != NULL,
637 ("%s(%u): protocol not registered for %s", __func__, proto,
638 name));
639
640 #ifdef VIMAGE
641 VNET_LIST_RLOCK_NOSLEEP();
642 VNET_FOREACH(vnet_iter) {
643 CURVNET_SET(vnet_iter);
644 V_netisr_enable[proto] = 0;
645 CURVNET_RESTORE();
646 }
647 VNET_LIST_RUNLOCK_NOSLEEP();
648 #endif
649
650 netisr_proto[proto].np_name = NULL;
651 netisr_proto[proto].np_handler = NULL;
652 netisr_proto[proto].np_m2flow = NULL;
653 netisr_proto[proto].np_m2cpuid = NULL;
654 netisr_proto[proto].np_qlimit = 0;
655 netisr_proto[proto].np_policy = 0;
656 CPU_FOREACH(i) {
657 npwp = &(DPCPU_ID_PTR(i, nws))->nws_work[proto];
658 netisr_drain_proto(npwp);
659 bzero(npwp, sizeof(*npwp));
660 }
661 NETISR_WUNLOCK();
662 }
663
664 #ifdef VIMAGE
665 void
666 netisr_register_vnet(const struct netisr_handler *nhp)
667 {
668 u_int proto;
669
670 proto = nhp->nh_proto;
671
672 KASSERT(curvnet != NULL, ("%s: curvnet is NULL", __func__));
673 KASSERT(proto < NETISR_MAXPROT,
674 ("%s(%u): protocol too big for %s", __func__, proto, nhp->nh_name));
675 NETISR_WLOCK();
676 KASSERT(netisr_proto[proto].np_handler != NULL,
677 ("%s(%u): protocol not registered for %s", __func__, proto,
678 nhp->nh_name));
679
680 V_netisr_enable[proto] = 1;
681 NETISR_WUNLOCK();
682 }
683
684 static void
685 netisr_drain_proto_vnet(struct vnet *vnet, u_int proto)
686 {
687 struct netisr_workstream *nwsp;
688 struct netisr_work *npwp;
689 struct mbuf *m, *mp, *n, *ne;
690 u_int i;
691
692 KASSERT(vnet != NULL, ("%s: vnet is NULL", __func__));
693 NETISR_LOCK_ASSERT();
694
695 CPU_FOREACH(i) {
696 nwsp = DPCPU_ID_PTR(i, nws);
697 if (nwsp->nws_intr_event == NULL)
698 continue;
699 npwp = &nwsp->nws_work[proto];
700 NWS_LOCK(nwsp);
701
702 /*
703 * Rather than dissecting and removing mbufs from the middle
704 * of the chain, we build a new chain if the packet stays and
705 * update the head and tail pointers at the end. All packets
706 * matching the given vnet are freed.
707 */
708 m = npwp->nw_head;
709 n = ne = NULL;
710 while (m != NULL) {
711 mp = m;
712 m = m->m_nextpkt;
713 mp->m_nextpkt = NULL;
714 if (mp->m_pkthdr.rcvif->if_vnet != vnet) {
715 if (n == NULL) {
716 n = ne = mp;
717 } else {
718 ne->m_nextpkt = mp;
719 ne = mp;
720 }
721 continue;
722 }
723 /* This is a packet in the selected vnet. Free it. */
724 npwp->nw_len--;
725 m_freem(mp);
726 }
727 npwp->nw_head = n;
728 npwp->nw_tail = ne;
729 NWS_UNLOCK(nwsp);
730 }
731 }
732
733 void
734 netisr_unregister_vnet(const struct netisr_handler *nhp)
735 {
736 u_int proto;
737
738 proto = nhp->nh_proto;
739
740 KASSERT(curvnet != NULL, ("%s: curvnet is NULL", __func__));
741 KASSERT(proto < NETISR_MAXPROT,
742 ("%s(%u): protocol too big for %s", __func__, proto, nhp->nh_name));
743 NETISR_WLOCK();
744 KASSERT(netisr_proto[proto].np_handler != NULL,
745 ("%s(%u): protocol not registered for %s", __func__, proto,
746 nhp->nh_name));
747
748 V_netisr_enable[proto] = 0;
749
750 netisr_drain_proto_vnet(curvnet, proto);
751 NETISR_WUNLOCK();
752 }
753 #endif
754
755 /*
756 * Compose the global and per-protocol policies on dispatch, and return the
757 * dispatch policy to use.
758 */
759 static u_int
760 netisr_get_dispatch(struct netisr_proto *npp)
761 {
762
763 /*
764 * Protocol-specific configuration overrides the global default.
765 */
766 if (npp->np_dispatch != NETISR_DISPATCH_DEFAULT)
767 return (npp->np_dispatch);
768 return (netisr_dispatch_policy);
769 }
770
771 /*
772 * Look up the workstream given a packet and source identifier. Do this by
773 * checking the protocol's policy, and optionally call out to the protocol
774 * for assistance if required.
775 */
776 static struct mbuf *
777 netisr_select_cpuid(struct netisr_proto *npp, u_int dispatch_policy,
778 uintptr_t source, struct mbuf *m, u_int *cpuidp)
779 {
780 struct ifnet *ifp;
781 u_int policy;
782
783 NETISR_LOCK_ASSERT();
784
785 /*
786 * In the event we have only one worker, shortcut and deliver to it
787 * without further ado.
788 */
789 if (nws_count == 1) {
790 *cpuidp = nws_array[0];
791 return (m);
792 }
793
794 /*
795 * What happens next depends on the policy selected by the protocol.
796 * If we want to support per-interface policies, we should do that
797 * here first.
798 */
799 policy = npp->np_policy;
800 if (policy == NETISR_POLICY_CPU) {
801 m = npp->np_m2cpuid(m, source, cpuidp);
802 if (m == NULL)
803 return (NULL);
804
805 /*
806 * It's possible for a protocol not to have a good idea about
807 * where to process a packet, in which case we fall back on
808 * the netisr code to decide. In the hybrid case, return the
809 * current CPU ID, which will force an immediate direct
810 * dispatch. In the queued case, fall back on the SOURCE
811 * policy.
812 */
813 if (*cpuidp != NETISR_CPUID_NONE)
814 return (m);
815 if (dispatch_policy == NETISR_DISPATCH_HYBRID) {
816 *cpuidp = curcpu;
817 return (m);
818 }
819 policy = NETISR_POLICY_SOURCE;
820 }
821
822 if (policy == NETISR_POLICY_FLOW) {
823 if (M_HASHTYPE_GET(m) == M_HASHTYPE_NONE &&
824 npp->np_m2flow != NULL) {
825 m = npp->np_m2flow(m, source);
826 if (m == NULL)
827 return (NULL);
828 }
829 if (M_HASHTYPE_GET(m) != M_HASHTYPE_NONE) {
830 *cpuidp =
831 netisr_default_flow2cpu(m->m_pkthdr.flowid);
832 return (m);
833 }
834 policy = NETISR_POLICY_SOURCE;
835 }
836
837 KASSERT(policy == NETISR_POLICY_SOURCE,
838 ("%s: invalid policy %u for %s", __func__, npp->np_policy,
839 npp->np_name));
840
841 ifp = m->m_pkthdr.rcvif;
842 if (ifp != NULL)
843 *cpuidp = nws_array[(ifp->if_index + source) % nws_count];
844 else
845 *cpuidp = nws_array[source % nws_count];
846 return (m);
847 }
848
849 /*
850 * Process packets associated with a workstream and protocol. For reasons of
851 * fairness, we process up to one complete netisr queue at a time, moving the
852 * queue to a stack-local queue for processing, but do not loop refreshing
853 * from the global queue. The caller is responsible for deciding whether to
854 * loop, and for setting the NWS_RUNNING flag. The passed workstream will be
855 * locked on entry and relocked before return, but will be released while
856 * processing. The number of packets processed is returned.
857 */
858 static u_int
859 netisr_process_workstream_proto(struct netisr_workstream *nwsp, u_int proto)
860 {
861 struct netisr_work local_npw, *npwp;
862 u_int handled;
863 struct mbuf *m;
864
865 NETISR_LOCK_ASSERT();
866 NWS_LOCK_ASSERT(nwsp);
867
868 KASSERT(nwsp->nws_flags & NWS_RUNNING,
869 ("%s(%u): not running", __func__, proto));
870 KASSERT(proto >= 0 && proto < NETISR_MAXPROT,
871 ("%s(%u): invalid proto\n", __func__, proto));
872
873 npwp = &nwsp->nws_work[proto];
874 if (npwp->nw_len == 0)
875 return (0);
876
877 /*
878 * Move the global work queue to a thread-local work queue.
879 *
880 * Notice that this means the effective maximum length of the queue
881 * is actually twice that of the maximum queue length specified in
882 * the protocol registration call.
883 */
884 handled = npwp->nw_len;
885 local_npw = *npwp;
886 npwp->nw_head = NULL;
887 npwp->nw_tail = NULL;
888 npwp->nw_len = 0;
889 nwsp->nws_pendingbits &= ~(1 << proto);
890 NWS_UNLOCK(nwsp);
891 while ((m = local_npw.nw_head) != NULL) {
892 local_npw.nw_head = m->m_nextpkt;
893 m->m_nextpkt = NULL;
894 if (local_npw.nw_head == NULL)
895 local_npw.nw_tail = NULL;
896 local_npw.nw_len--;
897 VNET_ASSERT(m->m_pkthdr.rcvif != NULL,
898 ("%s:%d rcvif == NULL: m=%p", __func__, __LINE__, m));
899 CURVNET_SET(m->m_pkthdr.rcvif->if_vnet);
900 netisr_proto[proto].np_handler(m);
901 CURVNET_RESTORE();
902 }
903 KASSERT(local_npw.nw_len == 0,
904 ("%s(%u): len %u", __func__, proto, local_npw.nw_len));
905 if (netisr_proto[proto].np_drainedcpu)
906 netisr_proto[proto].np_drainedcpu(nwsp->nws_cpu);
907 NWS_LOCK(nwsp);
908 npwp->nw_handled += handled;
909 return (handled);
910 }
911
912 /*
913 * SWI handler for netisr -- processes packets in a set of workstreams that
914 * it owns, woken up by calls to NWS_SIGNAL(). If this workstream is already
915 * being direct dispatched, go back to sleep and wait for the dispatching
916 * thread to wake us up again.
917 */
918 static void
919 swi_net(void *arg)
920 {
921 #ifdef NETISR_LOCKING
922 struct rm_priotracker tracker;
923 #endif
924 struct netisr_workstream *nwsp;
925 u_int bits, prot;
926
927 nwsp = arg;
928
929 #ifdef DEVICE_POLLING
930 KASSERT(nws_count == 1,
931 ("%s: device_polling but nws_count != 1", __func__));
932 netisr_poll();
933 #endif
934 #ifdef NETISR_LOCKING
935 NETISR_RLOCK(&tracker);
936 #endif
937 NWS_LOCK(nwsp);
938 KASSERT(!(nwsp->nws_flags & NWS_RUNNING), ("swi_net: running"));
939 if (nwsp->nws_flags & NWS_DISPATCHING)
940 goto out;
941 nwsp->nws_flags |= NWS_RUNNING;
942 nwsp->nws_flags &= ~NWS_SCHEDULED;
943 while ((bits = nwsp->nws_pendingbits) != 0) {
944 while ((prot = ffs(bits)) != 0) {
945 prot--;
946 bits &= ~(1 << prot);
947 (void)netisr_process_workstream_proto(nwsp, prot);
948 }
949 }
950 nwsp->nws_flags &= ~NWS_RUNNING;
951 out:
952 NWS_UNLOCK(nwsp);
953 #ifdef NETISR_LOCKING
954 NETISR_RUNLOCK(&tracker);
955 #endif
956 #ifdef DEVICE_POLLING
957 netisr_pollmore();
958 #endif
959 }
960
961 static int
962 netisr_queue_workstream(struct netisr_workstream *nwsp, u_int proto,
963 struct netisr_work *npwp, struct mbuf *m, int *dosignalp)
964 {
965
966 NWS_LOCK_ASSERT(nwsp);
967
968 *dosignalp = 0;
969 if (npwp->nw_len < npwp->nw_qlimit) {
970 m->m_nextpkt = NULL;
971 if (npwp->nw_head == NULL) {
972 npwp->nw_head = m;
973 npwp->nw_tail = m;
974 } else {
975 npwp->nw_tail->m_nextpkt = m;
976 npwp->nw_tail = m;
977 }
978 npwp->nw_len++;
979 if (npwp->nw_len > npwp->nw_watermark)
980 npwp->nw_watermark = npwp->nw_len;
981
982 /*
983 * We must set the bit regardless of NWS_RUNNING, so that
984 * swi_net() keeps calling netisr_process_workstream_proto().
985 */
986 nwsp->nws_pendingbits |= (1 << proto);
987 if (!(nwsp->nws_flags &
988 (NWS_RUNNING | NWS_DISPATCHING | NWS_SCHEDULED))) {
989 nwsp->nws_flags |= NWS_SCHEDULED;
990 *dosignalp = 1; /* Defer until unlocked. */
991 }
992 npwp->nw_queued++;
993 return (0);
994 } else {
995 m_freem(m);
996 npwp->nw_qdrops++;
997 return (ENOBUFS);
998 }
999 }
1000
1001 static int
1002 netisr_queue_internal(u_int proto, struct mbuf *m, u_int cpuid)
1003 {
1004 struct netisr_workstream *nwsp;
1005 struct netisr_work *npwp;
1006 int dosignal, error;
1007
1008 #ifdef NETISR_LOCKING
1009 NETISR_LOCK_ASSERT();
1010 #endif
1011 KASSERT(cpuid <= mp_maxid, ("%s: cpuid too big (%u, %u)", __func__,
1012 cpuid, mp_maxid));
1013 KASSERT(!CPU_ABSENT(cpuid), ("%s: CPU %u absent", __func__, cpuid));
1014
1015 dosignal = 0;
1016 error = 0;
1017 nwsp = DPCPU_ID_PTR(cpuid, nws);
1018 npwp = &nwsp->nws_work[proto];
1019 NWS_LOCK(nwsp);
1020 error = netisr_queue_workstream(nwsp, proto, npwp, m, &dosignal);
1021 NWS_UNLOCK(nwsp);
1022 if (dosignal)
1023 NWS_SIGNAL(nwsp);
1024 return (error);
1025 }
1026
1027 int
1028 netisr_queue_src(u_int proto, uintptr_t source, struct mbuf *m)
1029 {
1030 #ifdef NETISR_LOCKING
1031 struct rm_priotracker tracker;
1032 #endif
1033 u_int cpuid;
1034 int error;
1035
1036 KASSERT(proto < NETISR_MAXPROT,
1037 ("%s: invalid proto %u", __func__, proto));
1038
1039 #ifdef NETISR_LOCKING
1040 NETISR_RLOCK(&tracker);
1041 #endif
1042 KASSERT(netisr_proto[proto].np_handler != NULL,
1043 ("%s: invalid proto %u", __func__, proto));
1044
1045 #ifdef VIMAGE
1046 if (V_netisr_enable[proto] == 0) {
1047 m_freem(m);
1048 return (ENOPROTOOPT);
1049 }
1050 #endif
1051
1052 m = netisr_select_cpuid(&netisr_proto[proto], NETISR_DISPATCH_DEFERRED,
1053 source, m, &cpuid);
1054 if (m != NULL) {
1055 KASSERT(!CPU_ABSENT(cpuid), ("%s: CPU %u absent", __func__,
1056 cpuid));
1057 error = netisr_queue_internal(proto, m, cpuid);
1058 } else
1059 error = ENOBUFS;
1060 #ifdef NETISR_LOCKING
1061 NETISR_RUNLOCK(&tracker);
1062 #endif
1063 return (error);
1064 }
1065
1066 int
1067 netisr_queue(u_int proto, struct mbuf *m)
1068 {
1069
1070 return (netisr_queue_src(proto, 0, m));
1071 }
1072
1073 /*
1074 * Dispatch a packet for netisr processing; direct dispatch is permitted by
1075 * calling context.
1076 */
1077 int
1078 netisr_dispatch_src(u_int proto, uintptr_t source, struct mbuf *m)
1079 {
1080 #ifdef NETISR_LOCKING
1081 struct rm_priotracker tracker;
1082 #endif
1083 struct netisr_workstream *nwsp;
1084 struct netisr_proto *npp;
1085 struct netisr_work *npwp;
1086 int dosignal, error;
1087 u_int cpuid, dispatch_policy;
1088
1089 KASSERT(proto < NETISR_MAXPROT,
1090 ("%s: invalid proto %u", __func__, proto));
1091 #ifdef NETISR_LOCKING
1092 NETISR_RLOCK(&tracker);
1093 #endif
1094 npp = &netisr_proto[proto];
1095 KASSERT(npp->np_handler != NULL, ("%s: invalid proto %u", __func__,
1096 proto));
1097
1098 #ifdef VIMAGE
1099 if (V_netisr_enable[proto] == 0) {
1100 m_freem(m);
1101 return (ENOPROTOOPT);
1102 }
1103 #endif
1104
1105 dispatch_policy = netisr_get_dispatch(npp);
1106 if (dispatch_policy == NETISR_DISPATCH_DEFERRED)
1107 return (netisr_queue_src(proto, source, m));
1108
1109 /*
1110 * If direct dispatch is forced, then unconditionally dispatch
1111 * without a formal CPU selection. Borrow the current CPU's stats,
1112 * even if there's no worker on it. In this case we don't update
1113 * nws_flags because all netisr processing will be source ordered due
1114 * to always being forced to directly dispatch.
1115 */
1116 if (dispatch_policy == NETISR_DISPATCH_DIRECT) {
1117 nwsp = DPCPU_PTR(nws);
1118 npwp = &nwsp->nws_work[proto];
1119 npwp->nw_dispatched++;
1120 npwp->nw_handled++;
1121 netisr_proto[proto].np_handler(m);
1122 error = 0;
1123 goto out_unlock;
1124 }
1125
1126 KASSERT(dispatch_policy == NETISR_DISPATCH_HYBRID,
1127 ("%s: unknown dispatch policy (%u)", __func__, dispatch_policy));
1128
1129 /*
1130 * Otherwise, we execute in a hybrid mode where we will try to direct
1131 * dispatch if we're on the right CPU and the netisr worker isn't
1132 * already running.
1133 */
1134 sched_pin();
1135 m = netisr_select_cpuid(&netisr_proto[proto], NETISR_DISPATCH_HYBRID,
1136 source, m, &cpuid);
1137 if (m == NULL) {
1138 error = ENOBUFS;
1139 goto out_unpin;
1140 }
1141 KASSERT(!CPU_ABSENT(cpuid), ("%s: CPU %u absent", __func__, cpuid));
1142 if (cpuid != curcpu)
1143 goto queue_fallback;
1144 nwsp = DPCPU_PTR(nws);
1145 npwp = &nwsp->nws_work[proto];
1146
1147 /*-
1148 * We are willing to direct dispatch only if three conditions hold:
1149 *
1150 * (1) The netisr worker isn't already running,
1151 * (2) Another thread isn't already directly dispatching, and
1152 * (3) The netisr hasn't already been woken up.
1153 */
1154 NWS_LOCK(nwsp);
1155 if (nwsp->nws_flags & (NWS_RUNNING | NWS_DISPATCHING | NWS_SCHEDULED)) {
1156 error = netisr_queue_workstream(nwsp, proto, npwp, m,
1157 &dosignal);
1158 NWS_UNLOCK(nwsp);
1159 if (dosignal)
1160 NWS_SIGNAL(nwsp);
1161 goto out_unpin;
1162 }
1163
1164 /*
1165 * The current thread is now effectively the netisr worker, so set
1166 * the dispatching flag to prevent concurrent processing of the
1167 * stream from another thread (even the netisr worker), which could
1168 * otherwise lead to effective misordering of the stream.
1169 */
1170 nwsp->nws_flags |= NWS_DISPATCHING;
1171 NWS_UNLOCK(nwsp);
1172 netisr_proto[proto].np_handler(m);
1173 NWS_LOCK(nwsp);
1174 nwsp->nws_flags &= ~NWS_DISPATCHING;
1175 npwp->nw_handled++;
1176 npwp->nw_hybrid_dispatched++;
1177
1178 /*
1179 * If other work was enqueued by another thread while we were direct
1180 * dispatching, we need to signal the netisr worker to do that work.
1181 * In the future, we might want to do some of that work in the
1182 * current thread, rather than trigger further context switches. If
1183 * so, we'll want to establish a reasonable bound on the work done in
1184 * the "borrowed" context.
1185 */
1186 if (nwsp->nws_pendingbits != 0) {
1187 nwsp->nws_flags |= NWS_SCHEDULED;
1188 dosignal = 1;
1189 } else
1190 dosignal = 0;
1191 NWS_UNLOCK(nwsp);
1192 if (dosignal)
1193 NWS_SIGNAL(nwsp);
1194 error = 0;
1195 goto out_unpin;
1196
1197 queue_fallback:
1198 error = netisr_queue_internal(proto, m, cpuid);
1199 out_unpin:
1200 sched_unpin();
1201 out_unlock:
1202 #ifdef NETISR_LOCKING
1203 NETISR_RUNLOCK(&tracker);
1204 #endif
1205 return (error);
1206 }
1207
1208 int
1209 netisr_dispatch(u_int proto, struct mbuf *m)
1210 {
1211
1212 return (netisr_dispatch_src(proto, 0, m));
1213 }
1214
1215 #ifdef DEVICE_POLLING
1216 /*
1217 * Kernel polling borrows a netisr thread to run interface polling in; this
1218 * function allows kernel polling to request that the netisr thread be
1219 * scheduled even if no packets are pending for protocols.
1220 */
1221 void
1222 netisr_sched_poll(void)
1223 {
1224 struct netisr_workstream *nwsp;
1225
1226 nwsp = DPCPU_ID_PTR(nws_array[0], nws);
1227 NWS_SIGNAL(nwsp);
1228 }
1229 #endif
1230
1231 static void
1232 netisr_start_swi(u_int cpuid, struct pcpu *pc)
1233 {
1234 char swiname[12];
1235 struct netisr_workstream *nwsp;
1236 int error;
1237
1238 KASSERT(!CPU_ABSENT(cpuid), ("%s: CPU %u absent", __func__, cpuid));
1239
1240 nwsp = DPCPU_ID_PTR(cpuid, nws);
1241 mtx_init(&nwsp->nws_mtx, "netisr_mtx", NULL, MTX_DEF);
1242 nwsp->nws_cpu = cpuid;
1243 snprintf(swiname, sizeof(swiname), "netisr %u", cpuid);
1244 error = swi_add(&nwsp->nws_intr_event, swiname, swi_net, nwsp,
1245 SWI_NET, INTR_MPSAFE, &nwsp->nws_swi_cookie);
1246 if (error)
1247 panic("%s: swi_add %d", __func__, error);
1248 pc->pc_netisr = nwsp->nws_intr_event;
1249 if (netisr_bindthreads) {
1250 error = intr_event_bind(nwsp->nws_intr_event, cpuid);
1251 if (error != 0)
1252 printf("%s: cpu %u: intr_event_bind: %d", __func__,
1253 cpuid, error);
1254 }
1255 NETISR_WLOCK();
1256 nws_array[nws_count] = nwsp->nws_cpu;
1257 nws_count++;
1258 NETISR_WUNLOCK();
1259 }
1260
1261 /*
1262 * Initialize the netisr subsystem. We rely on BSS and static initialization
1263 * of most fields in global data structures.
1264 *
1265 * Start a worker thread for the boot CPU so that we can support network
1266 * traffic immediately in case the network stack is used before additional
1267 * CPUs are started (for example, diskless boot).
1268 */
1269 static void
1270 netisr_init(void *arg)
1271 {
1272 #ifdef EARLY_AP_STARTUP
1273 struct pcpu *pc;
1274 #endif
1275
1276 KASSERT(curcpu == 0, ("%s: not on CPU 0", __func__));
1277
1278 NETISR_LOCK_INIT();
1279 if (netisr_maxthreads == 0 || netisr_maxthreads < -1 )
1280 netisr_maxthreads = 1; /* default behavior */
1281 else if (netisr_maxthreads == -1)
1282 netisr_maxthreads = mp_ncpus; /* use max cpus */
1283 if (netisr_maxthreads > mp_ncpus) {
1284 printf("netisr_init: forcing maxthreads from %d to %d\n",
1285 netisr_maxthreads, mp_ncpus);
1286 netisr_maxthreads = mp_ncpus;
1287 }
1288 if (netisr_defaultqlimit > netisr_maxqlimit) {
1289 printf("netisr_init: forcing defaultqlimit from %d to %d\n",
1290 netisr_defaultqlimit, netisr_maxqlimit);
1291 netisr_defaultqlimit = netisr_maxqlimit;
1292 }
1293 #ifdef DEVICE_POLLING
1294 /*
1295 * The device polling code is not yet aware of how to deal with
1296 * multiple netisr threads, so for the time being compiling in device
1297 * polling disables parallel netisr workers.
1298 */
1299 if (netisr_maxthreads != 1 || netisr_bindthreads != 0) {
1300 printf("netisr_init: forcing maxthreads to 1 and "
1301 "bindthreads to 0 for device polling\n");
1302 netisr_maxthreads = 1;
1303 netisr_bindthreads = 0;
1304 }
1305 #endif
1306
1307 #ifdef EARLY_AP_STARTUP
1308 STAILQ_FOREACH(pc, &cpuhead, pc_allcpu) {
1309 if (nws_count >= netisr_maxthreads)
1310 break;
1311 netisr_start_swi(pc->pc_cpuid, pc);
1312 }
1313 #else
1314 netisr_start_swi(curcpu, pcpu_find(curcpu));
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
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