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/9.0/sys/net/netisr.c 222531 2011-05-31 15:11:43Z nwhitehorn $");
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/interrupt.h>
74 #include <sys/lock.h>
75 #include <sys/mbuf.h>
76 #include <sys/mutex.h>
77 #include <sys/pcpu.h>
78 #include <sys/proc.h>
79 #include <sys/rmlock.h>
80 #include <sys/sched.h>
81 #include <sys/smp.h>
82 #include <sys/socket.h>
83 #include <sys/sysctl.h>
84 #include <sys/systm.h>
85
86 #ifdef DDB
87 #include <ddb/ddb.h>
88 #endif
89
90 #define _WANT_NETISR_INTERNAL /* Enable definitions from netisr_internal.h */
91 #include <net/if.h>
92 #include <net/if_var.h>
93 #include <net/netisr.h>
94 #include <net/netisr_internal.h>
95 #include <net/vnet.h>
96
97 /*-
98 * Synchronize use and modification of the registered netisr data structures;
99 * acquire a read lock while modifying the set of registered protocols to
100 * prevent partially registered or unregistered protocols from being run.
101 *
102 * The following data structures and fields are protected by this lock:
103 *
104 * - The netisr_proto array, including all fields of struct netisr_proto.
105 * - The nws array, including all fields of struct netisr_worker.
106 * - The nws_array array.
107 *
108 * Note: the NETISR_LOCKING define controls whether read locks are acquired
109 * in packet processing paths requiring netisr registration stability. This
110 * is disabled by default as it can lead to measurable performance
111 * degradation even with rmlocks (3%-6% for loopback ping-pong traffic), and
112 * because netisr registration and unregistration is extremely rare at
113 * runtime. If it becomes more common, this decision should be revisited.
114 *
115 * XXXRW: rmlocks don't support assertions.
116 */
117 static struct rmlock netisr_rmlock;
118 #define NETISR_LOCK_INIT() rm_init_flags(&netisr_rmlock, "netisr", \
119 RM_NOWITNESS)
120 #define NETISR_LOCK_ASSERT()
121 #define NETISR_RLOCK(tracker) rm_rlock(&netisr_rmlock, (tracker))
122 #define NETISR_RUNLOCK(tracker) rm_runlock(&netisr_rmlock, (tracker))
123 #define NETISR_WLOCK() rm_wlock(&netisr_rmlock)
124 #define NETISR_WUNLOCK() rm_wunlock(&netisr_rmlock)
125 /* #define NETISR_LOCKING */
126
127 SYSCTL_NODE(_net, OID_AUTO, isr, CTLFLAG_RW, 0, "netisr");
128
129 /*-
130 * Three global direct dispatch policies are supported:
131 *
132 * NETISR_DISPATCH_QUEUED: All work is deferred for a netisr, regardless of
133 * context (may be overriden by protocols).
134 *
135 * NETISR_DISPATCH_HYBRID: If the executing context allows direct dispatch,
136 * and we're running on the CPU the work would be performed on, then direct
137 * dispatch it if it wouldn't violate ordering constraints on the workstream.
138 *
139 * NETISR_DISPATCH_DIRECT: If the executing context allows direct dispatch,
140 * always direct dispatch. (The default.)
141 *
142 * Notice that changing the global policy could lead to short periods of
143 * misordered processing, but this is considered acceptable as compared to
144 * the complexity of enforcing ordering during policy changes. Protocols can
145 * override the global policy (when they're not doing that, they select
146 * NETISR_DISPATCH_DEFAULT).
147 */
148 #define NETISR_DISPATCH_POLICY_DEFAULT NETISR_DISPATCH_DIRECT
149 #define NETISR_DISPATCH_POLICY_MAXSTR 20 /* Used for temporary buffers. */
150 static u_int netisr_dispatch_policy = NETISR_DISPATCH_POLICY_DEFAULT;
151 static int sysctl_netisr_dispatch_policy(SYSCTL_HANDLER_ARGS);
152 SYSCTL_PROC(_net_isr, OID_AUTO, dispatch, CTLTYPE_STRING | CTLFLAG_RW |
153 CTLFLAG_TUN, 0, 0, sysctl_netisr_dispatch_policy, "A",
154 "netisr dispatch policy");
155
156 /*
157 * These sysctls were used in previous versions to control and export
158 * dispatch policy state. Now, we provide read-only export via them so that
159 * older netstat binaries work. At some point they can be garbage collected.
160 */
161 static int netisr_direct_force;
162 SYSCTL_INT(_net_isr, OID_AUTO, direct_force, CTLFLAG_RD,
163 &netisr_direct_force, 0, "compat: force direct dispatch");
164
165 static int netisr_direct;
166 SYSCTL_INT(_net_isr, OID_AUTO, direct, CTLFLAG_RD, &netisr_direct, 0,
167 "compat: enable direct dispatch");
168
169 /*
170 * Allow the administrator to limit the number of threads (CPUs) to use for
171 * netisr. We don't check netisr_maxthreads before creating the thread for
172 * CPU 0, so in practice we ignore values <= 1. This must be set at boot.
173 * We will create at most one thread per CPU.
174 */
175 static int netisr_maxthreads = -1; /* Max number of threads. */
176 TUNABLE_INT("net.isr.maxthreads", &netisr_maxthreads);
177 SYSCTL_INT(_net_isr, OID_AUTO, maxthreads, CTLFLAG_RDTUN,
178 &netisr_maxthreads, 0,
179 "Use at most this many CPUs for netisr processing");
180
181 static int netisr_bindthreads = 0; /* Bind threads to CPUs. */
182 TUNABLE_INT("net.isr.bindthreads", &netisr_bindthreads);
183 SYSCTL_INT(_net_isr, OID_AUTO, bindthreads, CTLFLAG_RDTUN,
184 &netisr_bindthreads, 0, "Bind netisr threads to CPUs.");
185
186 /*
187 * Limit per-workstream mbuf queue limits s to at most net.isr.maxqlimit,
188 * both for initial configuration and later modification using
189 * netisr_setqlimit().
190 */
191 #define NETISR_DEFAULT_MAXQLIMIT 10240
192 static u_int netisr_maxqlimit = NETISR_DEFAULT_MAXQLIMIT;
193 TUNABLE_INT("net.isr.maxqlimit", &netisr_maxqlimit);
194 SYSCTL_UINT(_net_isr, OID_AUTO, maxqlimit, CTLFLAG_RDTUN,
195 &netisr_maxqlimit, 0,
196 "Maximum netisr per-protocol, per-CPU queue depth.");
197
198 /*
199 * The default per-workstream mbuf queue limit for protocols that don't
200 * initialize the nh_qlimit field of their struct netisr_handler. If this is
201 * set above netisr_maxqlimit, we truncate it to the maximum during boot.
202 */
203 #define NETISR_DEFAULT_DEFAULTQLIMIT 256
204 static u_int netisr_defaultqlimit = NETISR_DEFAULT_DEFAULTQLIMIT;
205 TUNABLE_INT("net.isr.defaultqlimit", &netisr_defaultqlimit);
206 SYSCTL_UINT(_net_isr, OID_AUTO, defaultqlimit, CTLFLAG_RDTUN,
207 &netisr_defaultqlimit, 0,
208 "Default netisr per-protocol, per-CPU queue limit if not set by protocol");
209
210 /*
211 * Store and export the compile-time constant NETISR_MAXPROT limit on the
212 * number of protocols that can register with netisr at a time. This is
213 * required for crashdump analysis, as it sizes netisr_proto[].
214 */
215 static u_int netisr_maxprot = NETISR_MAXPROT;
216 SYSCTL_UINT(_net_isr, OID_AUTO, maxprot, CTLFLAG_RD,
217 &netisr_maxprot, 0,
218 "Compile-time limit on the number of protocols supported by netisr.");
219
220 /*
221 * The netisr_proto array describes all registered protocols, indexed by
222 * protocol number. See netisr_internal.h for more details.
223 */
224 static struct netisr_proto netisr_proto[NETISR_MAXPROT];
225
226 /*
227 * Per-CPU workstream data. See netisr_internal.h for more details.
228 */
229 DPCPU_DEFINE(struct netisr_workstream, nws);
230
231 /*
232 * Map contiguous values between 0 and nws_count into CPU IDs appropriate for
233 * accessing workstreams. This allows constructions of the form
234 * DPCPU_ID_GET(nws_array[arbitraryvalue % nws_count], nws).
235 */
236 static u_int nws_array[MAXCPU];
237
238 /*
239 * Number of registered workstreams. Will be at most the number of running
240 * CPUs once fully started.
241 */
242 static u_int nws_count;
243 SYSCTL_UINT(_net_isr, OID_AUTO, numthreads, CTLFLAG_RD,
244 &nws_count, 0, "Number of extant netisr threads.");
245
246 /*
247 * Synchronization for each workstream: a mutex protects all mutable fields
248 * in each stream, including per-protocol state (mbuf queues). The SWI is
249 * woken up if asynchronous dispatch is required.
250 */
251 #define NWS_LOCK(s) mtx_lock(&(s)->nws_mtx)
252 #define NWS_LOCK_ASSERT(s) mtx_assert(&(s)->nws_mtx, MA_OWNED)
253 #define NWS_UNLOCK(s) mtx_unlock(&(s)->nws_mtx)
254 #define NWS_SIGNAL(s) swi_sched((s)->nws_swi_cookie, 0)
255
256 /*
257 * Utility routines for protocols that implement their own mapping of flows
258 * to CPUs.
259 */
260 u_int
261 netisr_get_cpucount(void)
262 {
263
264 return (nws_count);
265 }
266
267 u_int
268 netisr_get_cpuid(u_int cpunumber)
269 {
270
271 KASSERT(cpunumber < nws_count, ("%s: %u > %u", __func__, cpunumber,
272 nws_count));
273
274 return (nws_array[cpunumber]);
275 }
276
277 /*
278 * The default implementation of flow -> CPU ID mapping.
279 *
280 * Non-static so that protocols can use it to map their own work to specific
281 * CPUs in a manner consistent to netisr for affinity purposes.
282 */
283 u_int
284 netisr_default_flow2cpu(u_int flowid)
285 {
286
287 return (nws_array[flowid % nws_count]);
288 }
289
290 /*
291 * Dispatch tunable and sysctl configuration.
292 */
293 struct netisr_dispatch_table_entry {
294 u_int ndte_policy;
295 const char *ndte_policy_str;
296 };
297 static const struct netisr_dispatch_table_entry netisr_dispatch_table[] = {
298 { NETISR_DISPATCH_DEFAULT, "default" },
299 { NETISR_DISPATCH_DEFERRED, "deferred" },
300 { NETISR_DISPATCH_HYBRID, "hybrid" },
301 { NETISR_DISPATCH_DIRECT, "direct" },
302 };
303 static const u_int netisr_dispatch_table_len =
304 (sizeof(netisr_dispatch_table) / sizeof(netisr_dispatch_table[0]));
305
306 static void
307 netisr_dispatch_policy_to_str(u_int dispatch_policy, char *buffer,
308 u_int buflen)
309 {
310 const struct netisr_dispatch_table_entry *ndtep;
311 const char *str;
312 u_int i;
313
314 str = "unknown";
315 for (i = 0; i < netisr_dispatch_table_len; i++) {
316 ndtep = &netisr_dispatch_table[i];
317 if (ndtep->ndte_policy == dispatch_policy) {
318 str = ndtep->ndte_policy_str;
319 break;
320 }
321 }
322 snprintf(buffer, buflen, "%s", str);
323 }
324
325 static int
326 netisr_dispatch_policy_from_str(const char *str, u_int *dispatch_policyp)
327 {
328 const struct netisr_dispatch_table_entry *ndtep;
329 u_int i;
330
331 for (i = 0; i < netisr_dispatch_table_len; i++) {
332 ndtep = &netisr_dispatch_table[i];
333 if (strcmp(ndtep->ndte_policy_str, str) == 0) {
334 *dispatch_policyp = ndtep->ndte_policy;
335 return (0);
336 }
337 }
338 return (EINVAL);
339 }
340
341 static void
342 netisr_dispatch_policy_compat(void)
343 {
344
345 switch (netisr_dispatch_policy) {
346 case NETISR_DISPATCH_DEFERRED:
347 netisr_direct_force = 0;
348 netisr_direct = 0;
349 break;
350
351 case NETISR_DISPATCH_HYBRID:
352 netisr_direct_force = 0;
353 netisr_direct = 1;
354 break;
355
356 case NETISR_DISPATCH_DIRECT:
357 netisr_direct_force = 1;
358 netisr_direct = 1;
359 break;
360
361 default:
362 panic("%s: unknown policy %u", __func__,
363 netisr_dispatch_policy);
364 }
365 }
366
367 static int
368 sysctl_netisr_dispatch_policy(SYSCTL_HANDLER_ARGS)
369 {
370 char tmp[NETISR_DISPATCH_POLICY_MAXSTR];
371 u_int dispatch_policy;
372 int error;
373
374 netisr_dispatch_policy_to_str(netisr_dispatch_policy, tmp,
375 sizeof(tmp));
376 error = sysctl_handle_string(oidp, tmp, sizeof(tmp), req);
377 if (error == 0 && req->newptr != NULL) {
378 error = netisr_dispatch_policy_from_str(tmp,
379 &dispatch_policy);
380 if (error == 0 && dispatch_policy == NETISR_DISPATCH_DEFAULT)
381 error = EINVAL;
382 if (error == 0) {
383 netisr_dispatch_policy = dispatch_policy;
384 netisr_dispatch_policy_compat();
385 }
386 }
387 return (error);
388 }
389
390 /*
391 * Register a new netisr handler, which requires initializing per-protocol
392 * fields for each workstream. All netisr work is briefly suspended while
393 * the protocol is installed.
394 */
395 void
396 netisr_register(const struct netisr_handler *nhp)
397 {
398 struct netisr_work *npwp;
399 const char *name;
400 u_int i, proto;
401
402 proto = nhp->nh_proto;
403 name = nhp->nh_name;
404
405 /*
406 * Test that the requested registration is valid.
407 */
408 KASSERT(nhp->nh_name != NULL,
409 ("%s: nh_name NULL for %u", __func__, proto));
410 KASSERT(nhp->nh_handler != NULL,
411 ("%s: nh_handler NULL for %s", __func__, name));
412 KASSERT(nhp->nh_policy == NETISR_POLICY_SOURCE ||
413 nhp->nh_policy == NETISR_POLICY_FLOW ||
414 nhp->nh_policy == NETISR_POLICY_CPU,
415 ("%s: unsupported nh_policy %u for %s", __func__,
416 nhp->nh_policy, name));
417 KASSERT(nhp->nh_policy == NETISR_POLICY_FLOW ||
418 nhp->nh_m2flow == NULL,
419 ("%s: nh_policy != FLOW but m2flow defined for %s", __func__,
420 name));
421 KASSERT(nhp->nh_policy == NETISR_POLICY_CPU || nhp->nh_m2cpuid == NULL,
422 ("%s: nh_policy != CPU but m2cpuid defined for %s", __func__,
423 name));
424 KASSERT(nhp->nh_policy != NETISR_POLICY_CPU || nhp->nh_m2cpuid != NULL,
425 ("%s: nh_policy == CPU but m2cpuid not defined for %s", __func__,
426 name));
427 KASSERT(nhp->nh_dispatch == NETISR_DISPATCH_DEFAULT ||
428 nhp->nh_dispatch == NETISR_DISPATCH_DEFERRED ||
429 nhp->nh_dispatch == NETISR_DISPATCH_HYBRID ||
430 nhp->nh_dispatch == NETISR_DISPATCH_DIRECT,
431 ("%s: invalid nh_dispatch (%u)", __func__, nhp->nh_dispatch));
432
433 KASSERT(proto < NETISR_MAXPROT,
434 ("%s(%u, %s): protocol too big", __func__, proto, name));
435
436 /*
437 * Test that no existing registration exists for this protocol.
438 */
439 NETISR_WLOCK();
440 KASSERT(netisr_proto[proto].np_name == NULL,
441 ("%s(%u, %s): name present", __func__, proto, name));
442 KASSERT(netisr_proto[proto].np_handler == NULL,
443 ("%s(%u, %s): handler present", __func__, proto, name));
444
445 netisr_proto[proto].np_name = name;
446 netisr_proto[proto].np_handler = nhp->nh_handler;
447 netisr_proto[proto].np_m2flow = nhp->nh_m2flow;
448 netisr_proto[proto].np_m2cpuid = nhp->nh_m2cpuid;
449 netisr_proto[proto].np_drainedcpu = nhp->nh_drainedcpu;
450 if (nhp->nh_qlimit == 0)
451 netisr_proto[proto].np_qlimit = netisr_defaultqlimit;
452 else if (nhp->nh_qlimit > netisr_maxqlimit) {
453 printf("%s: %s requested queue limit %u capped to "
454 "net.isr.maxqlimit %u\n", __func__, name, nhp->nh_qlimit,
455 netisr_maxqlimit);
456 netisr_proto[proto].np_qlimit = netisr_maxqlimit;
457 } else
458 netisr_proto[proto].np_qlimit = nhp->nh_qlimit;
459 netisr_proto[proto].np_policy = nhp->nh_policy;
460 netisr_proto[proto].np_dispatch = nhp->nh_dispatch;
461 CPU_FOREACH(i) {
462 npwp = &(DPCPU_ID_PTR(i, nws))->nws_work[proto];
463 bzero(npwp, sizeof(*npwp));
464 npwp->nw_qlimit = netisr_proto[proto].np_qlimit;
465 }
466 NETISR_WUNLOCK();
467 }
468
469 /*
470 * Clear drop counters across all workstreams for a protocol.
471 */
472 void
473 netisr_clearqdrops(const struct netisr_handler *nhp)
474 {
475 struct netisr_work *npwp;
476 #ifdef INVARIANTS
477 const char *name;
478 #endif
479 u_int i, proto;
480
481 proto = nhp->nh_proto;
482 #ifdef INVARIANTS
483 name = nhp->nh_name;
484 #endif
485 KASSERT(proto < NETISR_MAXPROT,
486 ("%s(%u): protocol too big for %s", __func__, proto, name));
487
488 NETISR_WLOCK();
489 KASSERT(netisr_proto[proto].np_handler != NULL,
490 ("%s(%u): protocol not registered for %s", __func__, proto,
491 name));
492
493 CPU_FOREACH(i) {
494 npwp = &(DPCPU_ID_PTR(i, nws))->nws_work[proto];
495 npwp->nw_qdrops = 0;
496 }
497 NETISR_WUNLOCK();
498 }
499
500 /*
501 * Query current drop counters across all workstreams for a protocol.
502 */
503 void
504 netisr_getqdrops(const struct netisr_handler *nhp, u_int64_t *qdropp)
505 {
506 struct netisr_work *npwp;
507 struct rm_priotracker tracker;
508 #ifdef INVARIANTS
509 const char *name;
510 #endif
511 u_int i, proto;
512
513 *qdropp = 0;
514 proto = nhp->nh_proto;
515 #ifdef INVARIANTS
516 name = nhp->nh_name;
517 #endif
518 KASSERT(proto < NETISR_MAXPROT,
519 ("%s(%u): protocol too big for %s", __func__, proto, name));
520
521 NETISR_RLOCK(&tracker);
522 KASSERT(netisr_proto[proto].np_handler != NULL,
523 ("%s(%u): protocol not registered for %s", __func__, proto,
524 name));
525
526 CPU_FOREACH(i) {
527 npwp = &(DPCPU_ID_PTR(i, nws))->nws_work[proto];
528 *qdropp += npwp->nw_qdrops;
529 }
530 NETISR_RUNLOCK(&tracker);
531 }
532
533 /*
534 * Query current per-workstream queue limit for a protocol.
535 */
536 void
537 netisr_getqlimit(const struct netisr_handler *nhp, u_int *qlimitp)
538 {
539 struct rm_priotracker tracker;
540 #ifdef INVARIANTS
541 const char *name;
542 #endif
543 u_int proto;
544
545 proto = nhp->nh_proto;
546 #ifdef INVARIANTS
547 name = nhp->nh_name;
548 #endif
549 KASSERT(proto < NETISR_MAXPROT,
550 ("%s(%u): protocol too big for %s", __func__, proto, name));
551
552 NETISR_RLOCK(&tracker);
553 KASSERT(netisr_proto[proto].np_handler != NULL,
554 ("%s(%u): protocol not registered for %s", __func__, proto,
555 name));
556 *qlimitp = netisr_proto[proto].np_qlimit;
557 NETISR_RUNLOCK(&tracker);
558 }
559
560 /*
561 * Update the queue limit across per-workstream queues for a protocol. We
562 * simply change the limits, and don't drain overflowed packets as they will
563 * (hopefully) take care of themselves shortly.
564 */
565 int
566 netisr_setqlimit(const struct netisr_handler *nhp, u_int qlimit)
567 {
568 struct netisr_work *npwp;
569 #ifdef INVARIANTS
570 const char *name;
571 #endif
572 u_int i, proto;
573
574 if (qlimit > netisr_maxqlimit)
575 return (EINVAL);
576
577 proto = nhp->nh_proto;
578 #ifdef INVARIANTS
579 name = nhp->nh_name;
580 #endif
581 KASSERT(proto < NETISR_MAXPROT,
582 ("%s(%u): protocol too big for %s", __func__, proto, name));
583
584 NETISR_WLOCK();
585 KASSERT(netisr_proto[proto].np_handler != NULL,
586 ("%s(%u): protocol not registered for %s", __func__, proto,
587 name));
588
589 netisr_proto[proto].np_qlimit = qlimit;
590 CPU_FOREACH(i) {
591 npwp = &(DPCPU_ID_PTR(i, nws))->nws_work[proto];
592 npwp->nw_qlimit = qlimit;
593 }
594 NETISR_WUNLOCK();
595 return (0);
596 }
597
598 /*
599 * Drain all packets currently held in a particular protocol work queue.
600 */
601 static void
602 netisr_drain_proto(struct netisr_work *npwp)
603 {
604 struct mbuf *m;
605
606 /*
607 * We would assert the lock on the workstream but it's not passed in.
608 */
609 while ((m = npwp->nw_head) != NULL) {
610 npwp->nw_head = m->m_nextpkt;
611 m->m_nextpkt = NULL;
612 if (npwp->nw_head == NULL)
613 npwp->nw_tail = NULL;
614 npwp->nw_len--;
615 m_freem(m);
616 }
617 KASSERT(npwp->nw_tail == NULL, ("%s: tail", __func__));
618 KASSERT(npwp->nw_len == 0, ("%s: len", __func__));
619 }
620
621 /*
622 * Remove the registration of a network protocol, which requires clearing
623 * per-protocol fields across all workstreams, including freeing all mbufs in
624 * the queues at time of unregister. All work in netisr is briefly suspended
625 * while this takes place.
626 */
627 void
628 netisr_unregister(const struct netisr_handler *nhp)
629 {
630 struct netisr_work *npwp;
631 #ifdef INVARIANTS
632 const char *name;
633 #endif
634 u_int i, proto;
635
636 proto = nhp->nh_proto;
637 #ifdef INVARIANTS
638 name = nhp->nh_name;
639 #endif
640 KASSERT(proto < NETISR_MAXPROT,
641 ("%s(%u): protocol too big for %s", __func__, proto, name));
642
643 NETISR_WLOCK();
644 KASSERT(netisr_proto[proto].np_handler != NULL,
645 ("%s(%u): protocol not registered for %s", __func__, proto,
646 name));
647
648 netisr_proto[proto].np_name = NULL;
649 netisr_proto[proto].np_handler = NULL;
650 netisr_proto[proto].np_m2flow = NULL;
651 netisr_proto[proto].np_m2cpuid = NULL;
652 netisr_proto[proto].np_qlimit = 0;
653 netisr_proto[proto].np_policy = 0;
654 CPU_FOREACH(i) {
655 npwp = &(DPCPU_ID_PTR(i, nws))->nws_work[proto];
656 netisr_drain_proto(npwp);
657 bzero(npwp, sizeof(*npwp));
658 }
659 NETISR_WUNLOCK();
660 }
661
662 /*
663 * Compose the global and per-protocol policies on dispatch, and return the
664 * dispatch policy to use.
665 */
666 static u_int
667 netisr_get_dispatch(struct netisr_proto *npp)
668 {
669
670 /*
671 * Protocol-specific configuration overrides the global default.
672 */
673 if (npp->np_dispatch != NETISR_DISPATCH_DEFAULT)
674 return (npp->np_dispatch);
675 return (netisr_dispatch_policy);
676 }
677
678 /*
679 * Look up the workstream given a packet and source identifier. Do this by
680 * checking the protocol's policy, and optionally call out to the protocol
681 * for assistance if required.
682 */
683 static struct mbuf *
684 netisr_select_cpuid(struct netisr_proto *npp, u_int dispatch_policy,
685 uintptr_t source, struct mbuf *m, u_int *cpuidp)
686 {
687 struct ifnet *ifp;
688 u_int policy;
689
690 NETISR_LOCK_ASSERT();
691
692 /*
693 * In the event we have only one worker, shortcut and deliver to it
694 * without further ado.
695 */
696 if (nws_count == 1) {
697 *cpuidp = nws_array[0];
698 return (m);
699 }
700
701 /*
702 * What happens next depends on the policy selected by the protocol.
703 * If we want to support per-interface policies, we should do that
704 * here first.
705 */
706 policy = npp->np_policy;
707 if (policy == NETISR_POLICY_CPU) {
708 m = npp->np_m2cpuid(m, source, cpuidp);
709 if (m == NULL)
710 return (NULL);
711
712 /*
713 * It's possible for a protocol not to have a good idea about
714 * where to process a packet, in which case we fall back on
715 * the netisr code to decide. In the hybrid case, return the
716 * current CPU ID, which will force an immediate direct
717 * dispatch. In the queued case, fall back on the SOURCE
718 * policy.
719 */
720 if (*cpuidp != NETISR_CPUID_NONE)
721 return (m);
722 if (dispatch_policy == NETISR_DISPATCH_HYBRID) {
723 *cpuidp = curcpu;
724 return (m);
725 }
726 policy = NETISR_POLICY_SOURCE;
727 }
728
729 if (policy == NETISR_POLICY_FLOW) {
730 if (!(m->m_flags & M_FLOWID) && npp->np_m2flow != NULL) {
731 m = npp->np_m2flow(m, source);
732 if (m == NULL)
733 return (NULL);
734 }
735 if (m->m_flags & M_FLOWID) {
736 *cpuidp =
737 netisr_default_flow2cpu(m->m_pkthdr.flowid);
738 return (m);
739 }
740 policy = NETISR_POLICY_SOURCE;
741 }
742
743 KASSERT(policy == NETISR_POLICY_SOURCE,
744 ("%s: invalid policy %u for %s", __func__, npp->np_policy,
745 npp->np_name));
746
747 ifp = m->m_pkthdr.rcvif;
748 if (ifp != NULL)
749 *cpuidp = nws_array[(ifp->if_index + source) % nws_count];
750 else
751 *cpuidp = nws_array[source % nws_count];
752 return (m);
753 }
754
755 /*
756 * Process packets associated with a workstream and protocol. For reasons of
757 * fairness, we process up to one complete netisr queue at a time, moving the
758 * queue to a stack-local queue for processing, but do not loop refreshing
759 * from the global queue. The caller is responsible for deciding whether to
760 * loop, and for setting the NWS_RUNNING flag. The passed workstream will be
761 * locked on entry and relocked before return, but will be released while
762 * processing. The number of packets processed is returned.
763 */
764 static u_int
765 netisr_process_workstream_proto(struct netisr_workstream *nwsp, u_int proto)
766 {
767 struct netisr_work local_npw, *npwp;
768 u_int handled;
769 struct mbuf *m;
770
771 NETISR_LOCK_ASSERT();
772 NWS_LOCK_ASSERT(nwsp);
773
774 KASSERT(nwsp->nws_flags & NWS_RUNNING,
775 ("%s(%u): not running", __func__, proto));
776 KASSERT(proto >= 0 && proto < NETISR_MAXPROT,
777 ("%s(%u): invalid proto\n", __func__, proto));
778
779 npwp = &nwsp->nws_work[proto];
780 if (npwp->nw_len == 0)
781 return (0);
782
783 /*
784 * Move the global work queue to a thread-local work queue.
785 *
786 * Notice that this means the effective maximum length of the queue
787 * is actually twice that of the maximum queue length specified in
788 * the protocol registration call.
789 */
790 handled = npwp->nw_len;
791 local_npw = *npwp;
792 npwp->nw_head = NULL;
793 npwp->nw_tail = NULL;
794 npwp->nw_len = 0;
795 nwsp->nws_pendingbits &= ~(1 << proto);
796 NWS_UNLOCK(nwsp);
797 while ((m = local_npw.nw_head) != NULL) {
798 local_npw.nw_head = m->m_nextpkt;
799 m->m_nextpkt = NULL;
800 if (local_npw.nw_head == NULL)
801 local_npw.nw_tail = NULL;
802 local_npw.nw_len--;
803 VNET_ASSERT(m->m_pkthdr.rcvif != NULL,
804 ("%s:%d rcvif == NULL: m=%p", __func__, __LINE__, m));
805 CURVNET_SET(m->m_pkthdr.rcvif->if_vnet);
806 netisr_proto[proto].np_handler(m);
807 CURVNET_RESTORE();
808 }
809 KASSERT(local_npw.nw_len == 0,
810 ("%s(%u): len %u", __func__, proto, local_npw.nw_len));
811 if (netisr_proto[proto].np_drainedcpu)
812 netisr_proto[proto].np_drainedcpu(nwsp->nws_cpu);
813 NWS_LOCK(nwsp);
814 npwp->nw_handled += handled;
815 return (handled);
816 }
817
818 /*
819 * SWI handler for netisr -- processes packets in a set of workstreams that
820 * it owns, woken up by calls to NWS_SIGNAL(). If this workstream is already
821 * being direct dispatched, go back to sleep and wait for the dispatching
822 * thread to wake us up again.
823 */
824 static void
825 swi_net(void *arg)
826 {
827 #ifdef NETISR_LOCKING
828 struct rm_priotracker tracker;
829 #endif
830 struct netisr_workstream *nwsp;
831 u_int bits, prot;
832
833 nwsp = arg;
834
835 #ifdef DEVICE_POLLING
836 KASSERT(nws_count == 1,
837 ("%s: device_polling but nws_count != 1", __func__));
838 netisr_poll();
839 #endif
840 #ifdef NETISR_LOCKING
841 NETISR_RLOCK(&tracker);
842 #endif
843 NWS_LOCK(nwsp);
844 KASSERT(!(nwsp->nws_flags & NWS_RUNNING), ("swi_net: running"));
845 if (nwsp->nws_flags & NWS_DISPATCHING)
846 goto out;
847 nwsp->nws_flags |= NWS_RUNNING;
848 nwsp->nws_flags &= ~NWS_SCHEDULED;
849 while ((bits = nwsp->nws_pendingbits) != 0) {
850 while ((prot = ffs(bits)) != 0) {
851 prot--;
852 bits &= ~(1 << prot);
853 (void)netisr_process_workstream_proto(nwsp, prot);
854 }
855 }
856 nwsp->nws_flags &= ~NWS_RUNNING;
857 out:
858 NWS_UNLOCK(nwsp);
859 #ifdef NETISR_LOCKING
860 NETISR_RUNLOCK(&tracker);
861 #endif
862 #ifdef DEVICE_POLLING
863 netisr_pollmore();
864 #endif
865 }
866
867 static int
868 netisr_queue_workstream(struct netisr_workstream *nwsp, u_int proto,
869 struct netisr_work *npwp, struct mbuf *m, int *dosignalp)
870 {
871
872 NWS_LOCK_ASSERT(nwsp);
873
874 *dosignalp = 0;
875 if (npwp->nw_len < npwp->nw_qlimit) {
876 m->m_nextpkt = NULL;
877 if (npwp->nw_head == NULL) {
878 npwp->nw_head = m;
879 npwp->nw_tail = m;
880 } else {
881 npwp->nw_tail->m_nextpkt = m;
882 npwp->nw_tail = m;
883 }
884 npwp->nw_len++;
885 if (npwp->nw_len > npwp->nw_watermark)
886 npwp->nw_watermark = npwp->nw_len;
887
888 /*
889 * We must set the bit regardless of NWS_RUNNING, so that
890 * swi_net() keeps calling netisr_process_workstream_proto().
891 */
892 nwsp->nws_pendingbits |= (1 << proto);
893 if (!(nwsp->nws_flags &
894 (NWS_RUNNING | NWS_DISPATCHING | NWS_SCHEDULED))) {
895 nwsp->nws_flags |= NWS_SCHEDULED;
896 *dosignalp = 1; /* Defer until unlocked. */
897 }
898 npwp->nw_queued++;
899 return (0);
900 } else {
901 m_freem(m);
902 npwp->nw_qdrops++;
903 return (ENOBUFS);
904 }
905 }
906
907 static int
908 netisr_queue_internal(u_int proto, struct mbuf *m, u_int cpuid)
909 {
910 struct netisr_workstream *nwsp;
911 struct netisr_work *npwp;
912 int dosignal, error;
913
914 #ifdef NETISR_LOCKING
915 NETISR_LOCK_ASSERT();
916 #endif
917 KASSERT(cpuid <= mp_maxid, ("%s: cpuid too big (%u, %u)", __func__,
918 cpuid, mp_maxid));
919 KASSERT(!CPU_ABSENT(cpuid), ("%s: CPU %u absent", __func__, cpuid));
920
921 dosignal = 0;
922 error = 0;
923 nwsp = DPCPU_ID_PTR(cpuid, nws);
924 npwp = &nwsp->nws_work[proto];
925 NWS_LOCK(nwsp);
926 error = netisr_queue_workstream(nwsp, proto, npwp, m, &dosignal);
927 NWS_UNLOCK(nwsp);
928 if (dosignal)
929 NWS_SIGNAL(nwsp);
930 return (error);
931 }
932
933 int
934 netisr_queue_src(u_int proto, uintptr_t source, struct mbuf *m)
935 {
936 #ifdef NETISR_LOCKING
937 struct rm_priotracker tracker;
938 #endif
939 u_int cpuid;
940 int error;
941
942 KASSERT(proto < NETISR_MAXPROT,
943 ("%s: invalid proto %u", __func__, proto));
944
945 #ifdef NETISR_LOCKING
946 NETISR_RLOCK(&tracker);
947 #endif
948 KASSERT(netisr_proto[proto].np_handler != NULL,
949 ("%s: invalid proto %u", __func__, proto));
950
951 m = netisr_select_cpuid(&netisr_proto[proto], NETISR_DISPATCH_DEFERRED,
952 source, m, &cpuid);
953 if (m != NULL) {
954 KASSERT(!CPU_ABSENT(cpuid), ("%s: CPU %u absent", __func__,
955 cpuid));
956 error = netisr_queue_internal(proto, m, cpuid);
957 } else
958 error = ENOBUFS;
959 #ifdef NETISR_LOCKING
960 NETISR_RUNLOCK(&tracker);
961 #endif
962 return (error);
963 }
964
965 int
966 netisr_queue(u_int proto, struct mbuf *m)
967 {
968
969 return (netisr_queue_src(proto, 0, m));
970 }
971
972 /*
973 * Dispatch a packet for netisr processing; direct dispatch is permitted by
974 * calling context.
975 */
976 int
977 netisr_dispatch_src(u_int proto, uintptr_t source, struct mbuf *m)
978 {
979 #ifdef NETISR_LOCKING
980 struct rm_priotracker tracker;
981 #endif
982 struct netisr_workstream *nwsp;
983 struct netisr_proto *npp;
984 struct netisr_work *npwp;
985 int dosignal, error;
986 u_int cpuid, dispatch_policy;
987
988 KASSERT(proto < NETISR_MAXPROT,
989 ("%s: invalid proto %u", __func__, proto));
990 #ifdef NETISR_LOCKING
991 NETISR_RLOCK(&tracker);
992 #endif
993 npp = &netisr_proto[proto];
994 KASSERT(npp->np_handler != NULL, ("%s: invalid proto %u", __func__,
995 proto));
996
997 dispatch_policy = netisr_get_dispatch(npp);
998 if (dispatch_policy == NETISR_DISPATCH_DEFERRED)
999 return (netisr_queue_src(proto, source, m));
1000
1001 /*
1002 * If direct dispatch is forced, then unconditionally dispatch
1003 * without a formal CPU selection. Borrow the current CPU's stats,
1004 * even if there's no worker on it. In this case we don't update
1005 * nws_flags because all netisr processing will be source ordered due
1006 * to always being forced to directly dispatch.
1007 */
1008 if (dispatch_policy == NETISR_DISPATCH_DIRECT) {
1009 nwsp = DPCPU_PTR(nws);
1010 npwp = &nwsp->nws_work[proto];
1011 npwp->nw_dispatched++;
1012 npwp->nw_handled++;
1013 netisr_proto[proto].np_handler(m);
1014 error = 0;
1015 goto out_unlock;
1016 }
1017
1018 KASSERT(dispatch_policy == NETISR_DISPATCH_HYBRID,
1019 ("%s: unknown dispatch policy (%u)", __func__, dispatch_policy));
1020
1021 /*
1022 * Otherwise, we execute in a hybrid mode where we will try to direct
1023 * dispatch if we're on the right CPU and the netisr worker isn't
1024 * already running.
1025 */
1026 sched_pin();
1027 m = netisr_select_cpuid(&netisr_proto[proto], NETISR_DISPATCH_HYBRID,
1028 source, m, &cpuid);
1029 if (m == NULL) {
1030 error = ENOBUFS;
1031 goto out_unpin;
1032 }
1033 KASSERT(!CPU_ABSENT(cpuid), ("%s: CPU %u absent", __func__, cpuid));
1034 if (cpuid != curcpu)
1035 goto queue_fallback;
1036 nwsp = DPCPU_PTR(nws);
1037 npwp = &nwsp->nws_work[proto];
1038
1039 /*-
1040 * We are willing to direct dispatch only if three conditions hold:
1041 *
1042 * (1) The netisr worker isn't already running,
1043 * (2) Another thread isn't already directly dispatching, and
1044 * (3) The netisr hasn't already been woken up.
1045 */
1046 NWS_LOCK(nwsp);
1047 if (nwsp->nws_flags & (NWS_RUNNING | NWS_DISPATCHING | NWS_SCHEDULED)) {
1048 error = netisr_queue_workstream(nwsp, proto, npwp, m,
1049 &dosignal);
1050 NWS_UNLOCK(nwsp);
1051 if (dosignal)
1052 NWS_SIGNAL(nwsp);
1053 goto out_unpin;
1054 }
1055
1056 /*
1057 * The current thread is now effectively the netisr worker, so set
1058 * the dispatching flag to prevent concurrent processing of the
1059 * stream from another thread (even the netisr worker), which could
1060 * otherwise lead to effective misordering of the stream.
1061 */
1062 nwsp->nws_flags |= NWS_DISPATCHING;
1063 NWS_UNLOCK(nwsp);
1064 netisr_proto[proto].np_handler(m);
1065 NWS_LOCK(nwsp);
1066 nwsp->nws_flags &= ~NWS_DISPATCHING;
1067 npwp->nw_handled++;
1068 npwp->nw_hybrid_dispatched++;
1069
1070 /*
1071 * If other work was enqueued by another thread while we were direct
1072 * dispatching, we need to signal the netisr worker to do that work.
1073 * In the future, we might want to do some of that work in the
1074 * current thread, rather than trigger further context switches. If
1075 * so, we'll want to establish a reasonable bound on the work done in
1076 * the "borrowed" context.
1077 */
1078 if (nwsp->nws_pendingbits != 0) {
1079 nwsp->nws_flags |= NWS_SCHEDULED;
1080 dosignal = 1;
1081 } else
1082 dosignal = 0;
1083 NWS_UNLOCK(nwsp);
1084 if (dosignal)
1085 NWS_SIGNAL(nwsp);
1086 error = 0;
1087 goto out_unpin;
1088
1089 queue_fallback:
1090 error = netisr_queue_internal(proto, m, cpuid);
1091 out_unpin:
1092 sched_unpin();
1093 out_unlock:
1094 #ifdef NETISR_LOCKING
1095 NETISR_RUNLOCK(&tracker);
1096 #endif
1097 return (error);
1098 }
1099
1100 int
1101 netisr_dispatch(u_int proto, struct mbuf *m)
1102 {
1103
1104 return (netisr_dispatch_src(proto, 0, m));
1105 }
1106
1107 #ifdef DEVICE_POLLING
1108 /*
1109 * Kernel polling borrows a netisr thread to run interface polling in; this
1110 * function allows kernel polling to request that the netisr thread be
1111 * scheduled even if no packets are pending for protocols.
1112 */
1113 void
1114 netisr_sched_poll(void)
1115 {
1116 struct netisr_workstream *nwsp;
1117
1118 nwsp = DPCPU_ID_PTR(nws_array[0], nws);
1119 NWS_SIGNAL(nwsp);
1120 }
1121 #endif
1122
1123 static void
1124 netisr_start_swi(u_int cpuid, struct pcpu *pc)
1125 {
1126 char swiname[12];
1127 struct netisr_workstream *nwsp;
1128 int error;
1129
1130 KASSERT(!CPU_ABSENT(cpuid), ("%s: CPU %u absent", __func__, cpuid));
1131
1132 nwsp = DPCPU_ID_PTR(cpuid, nws);
1133 mtx_init(&nwsp->nws_mtx, "netisr_mtx", NULL, MTX_DEF);
1134 nwsp->nws_cpu = cpuid;
1135 snprintf(swiname, sizeof(swiname), "netisr %u", cpuid);
1136 error = swi_add(&nwsp->nws_intr_event, swiname, swi_net, nwsp,
1137 SWI_NET, INTR_MPSAFE, &nwsp->nws_swi_cookie);
1138 if (error)
1139 panic("%s: swi_add %d", __func__, error);
1140 pc->pc_netisr = nwsp->nws_intr_event;
1141 if (netisr_bindthreads) {
1142 error = intr_event_bind(nwsp->nws_intr_event, cpuid);
1143 if (error != 0)
1144 printf("%s: cpu %u: intr_event_bind: %d", __func__,
1145 cpuid, error);
1146 }
1147 NETISR_WLOCK();
1148 nws_array[nws_count] = nwsp->nws_cpu;
1149 nws_count++;
1150 NETISR_WUNLOCK();
1151 }
1152
1153 /*
1154 * Initialize the netisr subsystem. We rely on BSS and static initialization
1155 * of most fields in global data structures.
1156 *
1157 * Start a worker thread for the boot CPU so that we can support network
1158 * traffic immediately in case the network stack is used before additional
1159 * CPUs are started (for example, diskless boot).
1160 */
1161 static void
1162 netisr_init(void *arg)
1163 {
1164 char tmp[NETISR_DISPATCH_POLICY_MAXSTR];
1165 u_int dispatch_policy;
1166 int error;
1167
1168 KASSERT(curcpu == 0, ("%s: not on CPU 0", __func__));
1169
1170 NETISR_LOCK_INIT();
1171 if (netisr_maxthreads < 1)
1172 netisr_maxthreads = 1;
1173 if (netisr_maxthreads > mp_ncpus) {
1174 printf("netisr_init: forcing maxthreads from %d to %d\n",
1175 netisr_maxthreads, mp_ncpus);
1176 netisr_maxthreads = mp_ncpus;
1177 }
1178 if (netisr_defaultqlimit > netisr_maxqlimit) {
1179 printf("netisr_init: forcing defaultqlimit from %d to %d\n",
1180 netisr_defaultqlimit, netisr_maxqlimit);
1181 netisr_defaultqlimit = netisr_maxqlimit;
1182 }
1183 #ifdef DEVICE_POLLING
1184 /*
1185 * The device polling code is not yet aware of how to deal with
1186 * multiple netisr threads, so for the time being compiling in device
1187 * polling disables parallel netisr workers.
1188 */
1189 if (netisr_maxthreads != 1 || netisr_bindthreads != 0) {
1190 printf("netisr_init: forcing maxthreads to 1 and "
1191 "bindthreads to 0 for device polling\n");
1192 netisr_maxthreads = 1;
1193 netisr_bindthreads = 0;
1194 }
1195 #endif
1196
1197 if (TUNABLE_STR_FETCH("net.isr.dispatch", tmp, sizeof(tmp))) {
1198 error = netisr_dispatch_policy_from_str(tmp,
1199 &dispatch_policy);
1200 if (error == 0 && dispatch_policy == NETISR_DISPATCH_DEFAULT)
1201 error = EINVAL;
1202 if (error == 0) {
1203 netisr_dispatch_policy = dispatch_policy;
1204 netisr_dispatch_policy_compat();
1205 } else
1206 printf(
1207 "%s: invalid dispatch policy %s, using default\n",
1208 __func__, tmp);
1209 }
1210
1211 netisr_start_swi(curcpu, pcpu_find(curcpu));
1212 }
1213 SYSINIT(netisr_init, SI_SUB_SOFTINTR, SI_ORDER_FIRST, netisr_init, NULL);
1214
1215 /*
1216 * Start worker threads for additional CPUs. No attempt to gracefully handle
1217 * work reassignment, we don't yet support dynamic reconfiguration.
1218 */
1219 static void
1220 netisr_start(void *arg)
1221 {
1222 struct pcpu *pc;
1223
1224 STAILQ_FOREACH(pc, &cpuhead, pc_allcpu) {
1225 if (nws_count >= netisr_maxthreads)
1226 break;
1227 /* XXXRW: Is skipping absent CPUs still required here? */
1228 if (CPU_ABSENT(pc->pc_cpuid))
1229 continue;
1230 /* Worker will already be present for boot CPU. */
1231 if (pc->pc_netisr != NULL)
1232 continue;
1233 netisr_start_swi(pc->pc_cpuid, pc);
1234 }
1235 }
1236 SYSINIT(netisr_start, SI_SUB_SMP, SI_ORDER_MIDDLE, netisr_start, NULL);
1237
1238 /*
1239 * Sysctl monitoring for netisr: query a list of registered protocols.
1240 */
1241 static int
1242 sysctl_netisr_proto(SYSCTL_HANDLER_ARGS)
1243 {
1244 struct rm_priotracker tracker;
1245 struct sysctl_netisr_proto *snpp, *snp_array;
1246 struct netisr_proto *npp;
1247 u_int counter, proto;
1248 int error;
1249
1250 if (req->newptr != NULL)
1251 return (EINVAL);
1252 snp_array = malloc(sizeof(*snp_array) * NETISR_MAXPROT, M_TEMP,
1253 M_ZERO | M_WAITOK);
1254 counter = 0;
1255 NETISR_RLOCK(&tracker);
1256 for (proto = 0; proto < NETISR_MAXPROT; proto++) {
1257 npp = &netisr_proto[proto];
1258 if (npp->np_name == NULL)
1259 continue;
1260 snpp = &snp_array[counter];
1261 snpp->snp_version = sizeof(*snpp);
1262 strlcpy(snpp->snp_name, npp->np_name, NETISR_NAMEMAXLEN);
1263 snpp->snp_proto = proto;
1264 snpp->snp_qlimit = npp->np_qlimit;
1265 snpp->snp_policy = npp->np_policy;
1266 snpp->snp_dispatch = npp->np_dispatch;
1267 if (npp->np_m2flow != NULL)
1268 snpp->snp_flags |= NETISR_SNP_FLAGS_M2FLOW;
1269 if (npp->np_m2cpuid != NULL)
1270 snpp->snp_flags |= NETISR_SNP_FLAGS_M2CPUID;
1271 if (npp->np_drainedcpu != NULL)
1272 snpp->snp_flags |= NETISR_SNP_FLAGS_DRAINEDCPU;
1273 counter++;
1274 }
1275 NETISR_RUNLOCK(&tracker);
1276 KASSERT(counter <= NETISR_MAXPROT,
1277 ("sysctl_netisr_proto: counter too big (%d)", counter));
1278 error = SYSCTL_OUT(req, snp_array, sizeof(*snp_array) * counter);
1279 free(snp_array, M_TEMP);
1280 return (error);
1281 }
1282
1283 SYSCTL_PROC(_net_isr, OID_AUTO, proto,
1284 CTLFLAG_RD|CTLTYPE_STRUCT|CTLFLAG_MPSAFE, 0, 0, sysctl_netisr_proto,
1285 "S,sysctl_netisr_proto",
1286 "Return list of protocols registered with netisr");
1287
1288 /*
1289 * Sysctl monitoring for netisr: query a list of workstreams.
1290 */
1291 static int
1292 sysctl_netisr_workstream(SYSCTL_HANDLER_ARGS)
1293 {
1294 struct rm_priotracker tracker;
1295 struct sysctl_netisr_workstream *snwsp, *snws_array;
1296 struct netisr_workstream *nwsp;
1297 u_int counter, cpuid;
1298 int error;
1299
1300 if (req->newptr != NULL)
1301 return (EINVAL);
1302 snws_array = malloc(sizeof(*snws_array) * MAXCPU, M_TEMP,
1303 M_ZERO | M_WAITOK);
1304 counter = 0;
1305 NETISR_RLOCK(&tracker);
1306 CPU_FOREACH(cpuid) {
1307 nwsp = DPCPU_ID_PTR(cpuid, nws);
1308 if (nwsp->nws_intr_event == NULL)
1309 continue;
1310 NWS_LOCK(nwsp);
1311 snwsp = &snws_array[counter];
1312 snwsp->snws_version = sizeof(*snwsp);
1313
1314 /*
1315 * For now, we equate workstream IDs and CPU IDs in the
1316 * kernel, but expose them independently to userspace in case
1317 * that assumption changes in the future.
1318 */
1319 snwsp->snws_wsid = cpuid;
1320 snwsp->snws_cpu = cpuid;
1321 if (nwsp->nws_intr_event != NULL)
1322 snwsp->snws_flags |= NETISR_SNWS_FLAGS_INTR;
1323 NWS_UNLOCK(nwsp);
1324 counter++;
1325 }
1326 NETISR_RUNLOCK(&tracker);
1327 KASSERT(counter <= MAXCPU,
1328 ("sysctl_netisr_workstream: counter too big (%d)", counter));
1329 error = SYSCTL_OUT(req, snws_array, sizeof(*snws_array) * counter);
1330 free(snws_array, M_TEMP);
1331 return (error);
1332 }
1333
1334 SYSCTL_PROC(_net_isr, OID_AUTO, workstream,
1335 CTLFLAG_RD|CTLTYPE_STRUCT|CTLFLAG_MPSAFE, 0, 0, sysctl_netisr_workstream,
1336 "S,sysctl_netisr_workstream",
1337 "Return list of workstreams implemented by netisr");
1338
1339 /*
1340 * Sysctl monitoring for netisr: query per-protocol data across all
1341 * workstreams.
1342 */
1343 static int
1344 sysctl_netisr_work(SYSCTL_HANDLER_ARGS)
1345 {
1346 struct rm_priotracker tracker;
1347 struct sysctl_netisr_work *snwp, *snw_array;
1348 struct netisr_workstream *nwsp;
1349 struct netisr_proto *npp;
1350 struct netisr_work *nwp;
1351 u_int counter, cpuid, proto;
1352 int error;
1353
1354 if (req->newptr != NULL)
1355 return (EINVAL);
1356 snw_array = malloc(sizeof(*snw_array) * MAXCPU * NETISR_MAXPROT,
1357 M_TEMP, M_ZERO | M_WAITOK);
1358 counter = 0;
1359 NETISR_RLOCK(&tracker);
1360 CPU_FOREACH(cpuid) {
1361 nwsp = DPCPU_ID_PTR(cpuid, nws);
1362 if (nwsp->nws_intr_event == NULL)
1363 continue;
1364 NWS_LOCK(nwsp);
1365 for (proto = 0; proto < NETISR_MAXPROT; proto++) {
1366 npp = &netisr_proto[proto];
1367 if (npp->np_name == NULL)
1368 continue;
1369 nwp = &nwsp->nws_work[proto];
1370 snwp = &snw_array[counter];
1371 snwp->snw_version = sizeof(*snwp);
1372 snwp->snw_wsid = cpuid; /* See comment above. */
1373 snwp->snw_proto = proto;
1374 snwp->snw_len = nwp->nw_len;
1375 snwp->snw_watermark = nwp->nw_watermark;
1376 snwp->snw_dispatched = nwp->nw_dispatched;
1377 snwp->snw_hybrid_dispatched =
1378 nwp->nw_hybrid_dispatched;
1379 snwp->snw_qdrops = nwp->nw_qdrops;
1380 snwp->snw_queued = nwp->nw_queued;
1381 snwp->snw_handled = nwp->nw_handled;
1382 counter++;
1383 }
1384 NWS_UNLOCK(nwsp);
1385 }
1386 KASSERT(counter <= MAXCPU * NETISR_MAXPROT,
1387 ("sysctl_netisr_work: counter too big (%d)", counter));
1388 NETISR_RUNLOCK(&tracker);
1389 error = SYSCTL_OUT(req, snw_array, sizeof(*snw_array) * counter);
1390 free(snw_array, M_TEMP);
1391 return (error);
1392 }
1393
1394 SYSCTL_PROC(_net_isr, OID_AUTO, work,
1395 CTLFLAG_RD|CTLTYPE_STRUCT|CTLFLAG_MPSAFE, 0, 0, sysctl_netisr_work,
1396 "S,sysctl_netisr_work",
1397 "Return list of per-workstream, per-protocol work in netisr");
1398
1399 #ifdef DDB
1400 DB_SHOW_COMMAND(netisr, db_show_netisr)
1401 {
1402 struct netisr_workstream *nwsp;
1403 struct netisr_work *nwp;
1404 int first, proto;
1405 u_int cpuid;
1406
1407 db_printf("%3s %6s %5s %5s %5s %8s %8s %8s %8s\n", "CPU", "Proto",
1408 "Len", "WMark", "Max", "Disp", "HDisp", "Drop", "Queue");
1409 CPU_FOREACH(cpuid) {
1410 nwsp = DPCPU_ID_PTR(cpuid, nws);
1411 if (nwsp->nws_intr_event == NULL)
1412 continue;
1413 first = 1;
1414 for (proto = 0; proto < NETISR_MAXPROT; proto++) {
1415 if (netisr_proto[proto].np_handler == NULL)
1416 continue;
1417 nwp = &nwsp->nws_work[proto];
1418 if (first) {
1419 db_printf("%3d ", cpuid);
1420 first = 0;
1421 } else
1422 db_printf("%3s ", "");
1423 db_printf(
1424 "%6s %5d %5d %5d %8ju %8ju %8ju %8ju\n",
1425 netisr_proto[proto].np_name, nwp->nw_len,
1426 nwp->nw_watermark, nwp->nw_qlimit,
1427 nwp->nw_dispatched, nwp->nw_hybrid_dispatched,
1428 nwp->nw_qdrops, nwp->nw_queued);
1429 }
1430 }
1431 }
1432 #endif
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