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/10.0/sys/net/netisr.c 255329 2013-09-06 21:02:43Z davide $");
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 static 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 * Allow the administrator to limit the number of threads (CPUs) to use for
158 * netisr. We don't check netisr_maxthreads before creating the thread for
159 * CPU 0, so in practice we ignore values <= 1. This must be set at boot.
160 * We will create at most one thread per CPU.
161 */
162 static int netisr_maxthreads = -1; /* Max number of threads. */
163 TUNABLE_INT("net.isr.maxthreads", &netisr_maxthreads);
164 SYSCTL_INT(_net_isr, OID_AUTO, maxthreads, CTLFLAG_RDTUN,
165 &netisr_maxthreads, 0,
166 "Use at most this many CPUs for netisr processing");
167
168 static int netisr_bindthreads = 0; /* Bind threads to CPUs. */
169 TUNABLE_INT("net.isr.bindthreads", &netisr_bindthreads);
170 SYSCTL_INT(_net_isr, OID_AUTO, bindthreads, CTLFLAG_RDTUN,
171 &netisr_bindthreads, 0, "Bind netisr threads to CPUs.");
172
173 /*
174 * Limit per-workstream mbuf queue limits s to at most net.isr.maxqlimit,
175 * both for initial configuration and later modification using
176 * netisr_setqlimit().
177 */
178 #define NETISR_DEFAULT_MAXQLIMIT 10240
179 static u_int netisr_maxqlimit = NETISR_DEFAULT_MAXQLIMIT;
180 TUNABLE_INT("net.isr.maxqlimit", &netisr_maxqlimit);
181 SYSCTL_UINT(_net_isr, OID_AUTO, maxqlimit, CTLFLAG_RDTUN,
182 &netisr_maxqlimit, 0,
183 "Maximum netisr per-protocol, per-CPU queue depth.");
184
185 /*
186 * The default per-workstream mbuf queue limit for protocols that don't
187 * initialize the nh_qlimit field of their struct netisr_handler. If this is
188 * set above netisr_maxqlimit, we truncate it to the maximum during boot.
189 */
190 #define NETISR_DEFAULT_DEFAULTQLIMIT 256
191 static u_int netisr_defaultqlimit = NETISR_DEFAULT_DEFAULTQLIMIT;
192 TUNABLE_INT("net.isr.defaultqlimit", &netisr_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 /*
214 * Per-CPU workstream data. See netisr_internal.h for more details.
215 */
216 DPCPU_DEFINE(struct netisr_workstream, nws);
217
218 /*
219 * Map contiguous values between 0 and nws_count into CPU IDs appropriate for
220 * accessing workstreams. This allows constructions of the form
221 * DPCPU_ID_GET(nws_array[arbitraryvalue % nws_count], nws).
222 */
223 static u_int nws_array[MAXCPU];
224
225 /*
226 * Number of registered workstreams. Will be at most the number of running
227 * CPUs once fully started.
228 */
229 static u_int nws_count;
230 SYSCTL_UINT(_net_isr, OID_AUTO, numthreads, CTLFLAG_RD,
231 &nws_count, 0, "Number of extant netisr threads.");
232
233 /*
234 * Synchronization for each workstream: a mutex protects all mutable fields
235 * in each stream, including per-protocol state (mbuf queues). The SWI is
236 * woken up if asynchronous dispatch is required.
237 */
238 #define NWS_LOCK(s) mtx_lock(&(s)->nws_mtx)
239 #define NWS_LOCK_ASSERT(s) mtx_assert(&(s)->nws_mtx, MA_OWNED)
240 #define NWS_UNLOCK(s) mtx_unlock(&(s)->nws_mtx)
241 #define NWS_SIGNAL(s) swi_sched((s)->nws_swi_cookie, 0)
242
243 /*
244 * Utility routines for protocols that implement their own mapping of flows
245 * to CPUs.
246 */
247 u_int
248 netisr_get_cpucount(void)
249 {
250
251 return (nws_count);
252 }
253
254 u_int
255 netisr_get_cpuid(u_int cpunumber)
256 {
257
258 KASSERT(cpunumber < nws_count, ("%s: %u > %u", __func__, cpunumber,
259 nws_count));
260
261 return (nws_array[cpunumber]);
262 }
263
264 /*
265 * The default implementation of flow -> CPU ID mapping.
266 *
267 * Non-static so that protocols can use it to map their own work to specific
268 * CPUs in a manner consistent to netisr for affinity purposes.
269 */
270 u_int
271 netisr_default_flow2cpu(u_int flowid)
272 {
273
274 return (nws_array[flowid % nws_count]);
275 }
276
277 /*
278 * Dispatch tunable and sysctl configuration.
279 */
280 struct netisr_dispatch_table_entry {
281 u_int ndte_policy;
282 const char *ndte_policy_str;
283 };
284 static const struct netisr_dispatch_table_entry netisr_dispatch_table[] = {
285 { NETISR_DISPATCH_DEFAULT, "default" },
286 { NETISR_DISPATCH_DEFERRED, "deferred" },
287 { NETISR_DISPATCH_HYBRID, "hybrid" },
288 { NETISR_DISPATCH_DIRECT, "direct" },
289 };
290 static const u_int netisr_dispatch_table_len =
291 (sizeof(netisr_dispatch_table) / sizeof(netisr_dispatch_table[0]));
292
293 static void
294 netisr_dispatch_policy_to_str(u_int dispatch_policy, char *buffer,
295 u_int buflen)
296 {
297 const struct netisr_dispatch_table_entry *ndtep;
298 const char *str;
299 u_int i;
300
301 str = "unknown";
302 for (i = 0; i < netisr_dispatch_table_len; i++) {
303 ndtep = &netisr_dispatch_table[i];
304 if (ndtep->ndte_policy == dispatch_policy) {
305 str = ndtep->ndte_policy_str;
306 break;
307 }
308 }
309 snprintf(buffer, buflen, "%s", str);
310 }
311
312 static int
313 netisr_dispatch_policy_from_str(const char *str, u_int *dispatch_policyp)
314 {
315 const struct netisr_dispatch_table_entry *ndtep;
316 u_int i;
317
318 for (i = 0; i < netisr_dispatch_table_len; i++) {
319 ndtep = &netisr_dispatch_table[i];
320 if (strcmp(ndtep->ndte_policy_str, str) == 0) {
321 *dispatch_policyp = ndtep->ndte_policy;
322 return (0);
323 }
324 }
325 return (EINVAL);
326 }
327
328 static int
329 sysctl_netisr_dispatch_policy(SYSCTL_HANDLER_ARGS)
330 {
331 char tmp[NETISR_DISPATCH_POLICY_MAXSTR];
332 u_int dispatch_policy;
333 int error;
334
335 netisr_dispatch_policy_to_str(netisr_dispatch_policy, tmp,
336 sizeof(tmp));
337 error = sysctl_handle_string(oidp, tmp, sizeof(tmp), req);
338 if (error == 0 && req->newptr != NULL) {
339 error = netisr_dispatch_policy_from_str(tmp,
340 &dispatch_policy);
341 if (error == 0 && dispatch_policy == NETISR_DISPATCH_DEFAULT)
342 error = EINVAL;
343 if (error == 0)
344 netisr_dispatch_policy = dispatch_policy;
345 }
346 return (error);
347 }
348
349 /*
350 * Register a new netisr handler, which requires initializing per-protocol
351 * fields for each workstream. All netisr work is briefly suspended while
352 * the protocol is installed.
353 */
354 void
355 netisr_register(const struct netisr_handler *nhp)
356 {
357 struct netisr_work *npwp;
358 const char *name;
359 u_int i, proto;
360
361 proto = nhp->nh_proto;
362 name = nhp->nh_name;
363
364 /*
365 * Test that the requested registration is valid.
366 */
367 KASSERT(nhp->nh_name != NULL,
368 ("%s: nh_name NULL for %u", __func__, proto));
369 KASSERT(nhp->nh_handler != NULL,
370 ("%s: nh_handler NULL for %s", __func__, name));
371 KASSERT(nhp->nh_policy == NETISR_POLICY_SOURCE ||
372 nhp->nh_policy == NETISR_POLICY_FLOW ||
373 nhp->nh_policy == NETISR_POLICY_CPU,
374 ("%s: unsupported nh_policy %u for %s", __func__,
375 nhp->nh_policy, name));
376 KASSERT(nhp->nh_policy == NETISR_POLICY_FLOW ||
377 nhp->nh_m2flow == NULL,
378 ("%s: nh_policy != FLOW but m2flow defined for %s", __func__,
379 name));
380 KASSERT(nhp->nh_policy == NETISR_POLICY_CPU || nhp->nh_m2cpuid == NULL,
381 ("%s: nh_policy != CPU but m2cpuid defined for %s", __func__,
382 name));
383 KASSERT(nhp->nh_policy != NETISR_POLICY_CPU || nhp->nh_m2cpuid != NULL,
384 ("%s: nh_policy == CPU but m2cpuid not defined for %s", __func__,
385 name));
386 KASSERT(nhp->nh_dispatch == NETISR_DISPATCH_DEFAULT ||
387 nhp->nh_dispatch == NETISR_DISPATCH_DEFERRED ||
388 nhp->nh_dispatch == NETISR_DISPATCH_HYBRID ||
389 nhp->nh_dispatch == NETISR_DISPATCH_DIRECT,
390 ("%s: invalid nh_dispatch (%u)", __func__, nhp->nh_dispatch));
391
392 KASSERT(proto < NETISR_MAXPROT,
393 ("%s(%u, %s): protocol too big", __func__, proto, name));
394
395 /*
396 * Test that no existing registration exists for this protocol.
397 */
398 NETISR_WLOCK();
399 KASSERT(netisr_proto[proto].np_name == NULL,
400 ("%s(%u, %s): name present", __func__, proto, name));
401 KASSERT(netisr_proto[proto].np_handler == NULL,
402 ("%s(%u, %s): handler present", __func__, proto, name));
403
404 netisr_proto[proto].np_name = name;
405 netisr_proto[proto].np_handler = nhp->nh_handler;
406 netisr_proto[proto].np_m2flow = nhp->nh_m2flow;
407 netisr_proto[proto].np_m2cpuid = nhp->nh_m2cpuid;
408 netisr_proto[proto].np_drainedcpu = nhp->nh_drainedcpu;
409 if (nhp->nh_qlimit == 0)
410 netisr_proto[proto].np_qlimit = netisr_defaultqlimit;
411 else if (nhp->nh_qlimit > netisr_maxqlimit) {
412 printf("%s: %s requested queue limit %u capped to "
413 "net.isr.maxqlimit %u\n", __func__, name, nhp->nh_qlimit,
414 netisr_maxqlimit);
415 netisr_proto[proto].np_qlimit = netisr_maxqlimit;
416 } else
417 netisr_proto[proto].np_qlimit = nhp->nh_qlimit;
418 netisr_proto[proto].np_policy = nhp->nh_policy;
419 netisr_proto[proto].np_dispatch = nhp->nh_dispatch;
420 CPU_FOREACH(i) {
421 npwp = &(DPCPU_ID_PTR(i, nws))->nws_work[proto];
422 bzero(npwp, sizeof(*npwp));
423 npwp->nw_qlimit = netisr_proto[proto].np_qlimit;
424 }
425 NETISR_WUNLOCK();
426 }
427
428 /*
429 * Clear drop counters across all workstreams for a protocol.
430 */
431 void
432 netisr_clearqdrops(const struct netisr_handler *nhp)
433 {
434 struct netisr_work *npwp;
435 #ifdef INVARIANTS
436 const char *name;
437 #endif
438 u_int i, proto;
439
440 proto = nhp->nh_proto;
441 #ifdef INVARIANTS
442 name = nhp->nh_name;
443 #endif
444 KASSERT(proto < NETISR_MAXPROT,
445 ("%s(%u): protocol too big for %s", __func__, proto, name));
446
447 NETISR_WLOCK();
448 KASSERT(netisr_proto[proto].np_handler != NULL,
449 ("%s(%u): protocol not registered for %s", __func__, proto,
450 name));
451
452 CPU_FOREACH(i) {
453 npwp = &(DPCPU_ID_PTR(i, nws))->nws_work[proto];
454 npwp->nw_qdrops = 0;
455 }
456 NETISR_WUNLOCK();
457 }
458
459 /*
460 * Query current drop counters across all workstreams for a protocol.
461 */
462 void
463 netisr_getqdrops(const struct netisr_handler *nhp, u_int64_t *qdropp)
464 {
465 struct netisr_work *npwp;
466 struct rm_priotracker tracker;
467 #ifdef INVARIANTS
468 const char *name;
469 #endif
470 u_int i, proto;
471
472 *qdropp = 0;
473 proto = nhp->nh_proto;
474 #ifdef INVARIANTS
475 name = nhp->nh_name;
476 #endif
477 KASSERT(proto < NETISR_MAXPROT,
478 ("%s(%u): protocol too big for %s", __func__, proto, name));
479
480 NETISR_RLOCK(&tracker);
481 KASSERT(netisr_proto[proto].np_handler != NULL,
482 ("%s(%u): protocol not registered for %s", __func__, proto,
483 name));
484
485 CPU_FOREACH(i) {
486 npwp = &(DPCPU_ID_PTR(i, nws))->nws_work[proto];
487 *qdropp += npwp->nw_qdrops;
488 }
489 NETISR_RUNLOCK(&tracker);
490 }
491
492 /*
493 * Query current per-workstream queue limit for a protocol.
494 */
495 void
496 netisr_getqlimit(const struct netisr_handler *nhp, u_int *qlimitp)
497 {
498 struct rm_priotracker tracker;
499 #ifdef INVARIANTS
500 const char *name;
501 #endif
502 u_int proto;
503
504 proto = nhp->nh_proto;
505 #ifdef INVARIANTS
506 name = nhp->nh_name;
507 #endif
508 KASSERT(proto < NETISR_MAXPROT,
509 ("%s(%u): protocol too big for %s", __func__, proto, name));
510
511 NETISR_RLOCK(&tracker);
512 KASSERT(netisr_proto[proto].np_handler != NULL,
513 ("%s(%u): protocol not registered for %s", __func__, proto,
514 name));
515 *qlimitp = netisr_proto[proto].np_qlimit;
516 NETISR_RUNLOCK(&tracker);
517 }
518
519 /*
520 * Update the queue limit across per-workstream queues for a protocol. We
521 * simply change the limits, and don't drain overflowed packets as they will
522 * (hopefully) take care of themselves shortly.
523 */
524 int
525 netisr_setqlimit(const struct netisr_handler *nhp, u_int qlimit)
526 {
527 struct netisr_work *npwp;
528 #ifdef INVARIANTS
529 const char *name;
530 #endif
531 u_int i, proto;
532
533 if (qlimit > netisr_maxqlimit)
534 return (EINVAL);
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_WLOCK();
544 KASSERT(netisr_proto[proto].np_handler != NULL,
545 ("%s(%u): protocol not registered for %s", __func__, proto,
546 name));
547
548 netisr_proto[proto].np_qlimit = qlimit;
549 CPU_FOREACH(i) {
550 npwp = &(DPCPU_ID_PTR(i, nws))->nws_work[proto];
551 npwp->nw_qlimit = qlimit;
552 }
553 NETISR_WUNLOCK();
554 return (0);
555 }
556
557 /*
558 * Drain all packets currently held in a particular protocol work queue.
559 */
560 static void
561 netisr_drain_proto(struct netisr_work *npwp)
562 {
563 struct mbuf *m;
564
565 /*
566 * We would assert the lock on the workstream but it's not passed in.
567 */
568 while ((m = npwp->nw_head) != NULL) {
569 npwp->nw_head = m->m_nextpkt;
570 m->m_nextpkt = NULL;
571 if (npwp->nw_head == NULL)
572 npwp->nw_tail = NULL;
573 npwp->nw_len--;
574 m_freem(m);
575 }
576 KASSERT(npwp->nw_tail == NULL, ("%s: tail", __func__));
577 KASSERT(npwp->nw_len == 0, ("%s: len", __func__));
578 }
579
580 /*
581 * Remove the registration of a network protocol, which requires clearing
582 * per-protocol fields across all workstreams, including freeing all mbufs in
583 * the queues at time of unregister. All work in netisr is briefly suspended
584 * while this takes place.
585 */
586 void
587 netisr_unregister(const struct netisr_handler *nhp)
588 {
589 struct netisr_work *npwp;
590 #ifdef INVARIANTS
591 const char *name;
592 #endif
593 u_int i, proto;
594
595 proto = nhp->nh_proto;
596 #ifdef INVARIANTS
597 name = nhp->nh_name;
598 #endif
599 KASSERT(proto < NETISR_MAXPROT,
600 ("%s(%u): protocol too big for %s", __func__, proto, name));
601
602 NETISR_WLOCK();
603 KASSERT(netisr_proto[proto].np_handler != NULL,
604 ("%s(%u): protocol not registered for %s", __func__, proto,
605 name));
606
607 netisr_proto[proto].np_name = NULL;
608 netisr_proto[proto].np_handler = NULL;
609 netisr_proto[proto].np_m2flow = NULL;
610 netisr_proto[proto].np_m2cpuid = NULL;
611 netisr_proto[proto].np_qlimit = 0;
612 netisr_proto[proto].np_policy = 0;
613 CPU_FOREACH(i) {
614 npwp = &(DPCPU_ID_PTR(i, nws))->nws_work[proto];
615 netisr_drain_proto(npwp);
616 bzero(npwp, sizeof(*npwp));
617 }
618 NETISR_WUNLOCK();
619 }
620
621 /*
622 * Compose the global and per-protocol policies on dispatch, and return the
623 * dispatch policy to use.
624 */
625 static u_int
626 netisr_get_dispatch(struct netisr_proto *npp)
627 {
628
629 /*
630 * Protocol-specific configuration overrides the global default.
631 */
632 if (npp->np_dispatch != NETISR_DISPATCH_DEFAULT)
633 return (npp->np_dispatch);
634 return (netisr_dispatch_policy);
635 }
636
637 /*
638 * Look up the workstream given a packet and source identifier. Do this by
639 * checking the protocol's policy, and optionally call out to the protocol
640 * for assistance if required.
641 */
642 static struct mbuf *
643 netisr_select_cpuid(struct netisr_proto *npp, u_int dispatch_policy,
644 uintptr_t source, struct mbuf *m, u_int *cpuidp)
645 {
646 struct ifnet *ifp;
647 u_int policy;
648
649 NETISR_LOCK_ASSERT();
650
651 /*
652 * In the event we have only one worker, shortcut and deliver to it
653 * without further ado.
654 */
655 if (nws_count == 1) {
656 *cpuidp = nws_array[0];
657 return (m);
658 }
659
660 /*
661 * What happens next depends on the policy selected by the protocol.
662 * If we want to support per-interface policies, we should do that
663 * here first.
664 */
665 policy = npp->np_policy;
666 if (policy == NETISR_POLICY_CPU) {
667 m = npp->np_m2cpuid(m, source, cpuidp);
668 if (m == NULL)
669 return (NULL);
670
671 /*
672 * It's possible for a protocol not to have a good idea about
673 * where to process a packet, in which case we fall back on
674 * the netisr code to decide. In the hybrid case, return the
675 * current CPU ID, which will force an immediate direct
676 * dispatch. In the queued case, fall back on the SOURCE
677 * policy.
678 */
679 if (*cpuidp != NETISR_CPUID_NONE)
680 return (m);
681 if (dispatch_policy == NETISR_DISPATCH_HYBRID) {
682 *cpuidp = curcpu;
683 return (m);
684 }
685 policy = NETISR_POLICY_SOURCE;
686 }
687
688 if (policy == NETISR_POLICY_FLOW) {
689 if (!(m->m_flags & M_FLOWID) && npp->np_m2flow != NULL) {
690 m = npp->np_m2flow(m, source);
691 if (m == NULL)
692 return (NULL);
693 }
694 if (m->m_flags & M_FLOWID) {
695 *cpuidp =
696 netisr_default_flow2cpu(m->m_pkthdr.flowid);
697 return (m);
698 }
699 policy = NETISR_POLICY_SOURCE;
700 }
701
702 KASSERT(policy == NETISR_POLICY_SOURCE,
703 ("%s: invalid policy %u for %s", __func__, npp->np_policy,
704 npp->np_name));
705
706 ifp = m->m_pkthdr.rcvif;
707 if (ifp != NULL)
708 *cpuidp = nws_array[(ifp->if_index + source) % nws_count];
709 else
710 *cpuidp = nws_array[source % nws_count];
711 return (m);
712 }
713
714 /*
715 * Process packets associated with a workstream and protocol. For reasons of
716 * fairness, we process up to one complete netisr queue at a time, moving the
717 * queue to a stack-local queue for processing, but do not loop refreshing
718 * from the global queue. The caller is responsible for deciding whether to
719 * loop, and for setting the NWS_RUNNING flag. The passed workstream will be
720 * locked on entry and relocked before return, but will be released while
721 * processing. The number of packets processed is returned.
722 */
723 static u_int
724 netisr_process_workstream_proto(struct netisr_workstream *nwsp, u_int proto)
725 {
726 struct netisr_work local_npw, *npwp;
727 u_int handled;
728 struct mbuf *m;
729
730 NETISR_LOCK_ASSERT();
731 NWS_LOCK_ASSERT(nwsp);
732
733 KASSERT(nwsp->nws_flags & NWS_RUNNING,
734 ("%s(%u): not running", __func__, proto));
735 KASSERT(proto >= 0 && proto < NETISR_MAXPROT,
736 ("%s(%u): invalid proto\n", __func__, proto));
737
738 npwp = &nwsp->nws_work[proto];
739 if (npwp->nw_len == 0)
740 return (0);
741
742 /*
743 * Move the global work queue to a thread-local work queue.
744 *
745 * Notice that this means the effective maximum length of the queue
746 * is actually twice that of the maximum queue length specified in
747 * the protocol registration call.
748 */
749 handled = npwp->nw_len;
750 local_npw = *npwp;
751 npwp->nw_head = NULL;
752 npwp->nw_tail = NULL;
753 npwp->nw_len = 0;
754 nwsp->nws_pendingbits &= ~(1 << proto);
755 NWS_UNLOCK(nwsp);
756 while ((m = local_npw.nw_head) != NULL) {
757 local_npw.nw_head = m->m_nextpkt;
758 m->m_nextpkt = NULL;
759 if (local_npw.nw_head == NULL)
760 local_npw.nw_tail = NULL;
761 local_npw.nw_len--;
762 VNET_ASSERT(m->m_pkthdr.rcvif != NULL,
763 ("%s:%d rcvif == NULL: m=%p", __func__, __LINE__, m));
764 CURVNET_SET(m->m_pkthdr.rcvif->if_vnet);
765 netisr_proto[proto].np_handler(m);
766 CURVNET_RESTORE();
767 }
768 KASSERT(local_npw.nw_len == 0,
769 ("%s(%u): len %u", __func__, proto, local_npw.nw_len));
770 if (netisr_proto[proto].np_drainedcpu)
771 netisr_proto[proto].np_drainedcpu(nwsp->nws_cpu);
772 NWS_LOCK(nwsp);
773 npwp->nw_handled += handled;
774 return (handled);
775 }
776
777 /*
778 * SWI handler for netisr -- processes packets in a set of workstreams that
779 * it owns, woken up by calls to NWS_SIGNAL(). If this workstream is already
780 * being direct dispatched, go back to sleep and wait for the dispatching
781 * thread to wake us up again.
782 */
783 static void
784 swi_net(void *arg)
785 {
786 #ifdef NETISR_LOCKING
787 struct rm_priotracker tracker;
788 #endif
789 struct netisr_workstream *nwsp;
790 u_int bits, prot;
791
792 nwsp = arg;
793
794 #ifdef DEVICE_POLLING
795 KASSERT(nws_count == 1,
796 ("%s: device_polling but nws_count != 1", __func__));
797 netisr_poll();
798 #endif
799 #ifdef NETISR_LOCKING
800 NETISR_RLOCK(&tracker);
801 #endif
802 NWS_LOCK(nwsp);
803 KASSERT(!(nwsp->nws_flags & NWS_RUNNING), ("swi_net: running"));
804 if (nwsp->nws_flags & NWS_DISPATCHING)
805 goto out;
806 nwsp->nws_flags |= NWS_RUNNING;
807 nwsp->nws_flags &= ~NWS_SCHEDULED;
808 while ((bits = nwsp->nws_pendingbits) != 0) {
809 while ((prot = ffs(bits)) != 0) {
810 prot--;
811 bits &= ~(1 << prot);
812 (void)netisr_process_workstream_proto(nwsp, prot);
813 }
814 }
815 nwsp->nws_flags &= ~NWS_RUNNING;
816 out:
817 NWS_UNLOCK(nwsp);
818 #ifdef NETISR_LOCKING
819 NETISR_RUNLOCK(&tracker);
820 #endif
821 #ifdef DEVICE_POLLING
822 netisr_pollmore();
823 #endif
824 }
825
826 static int
827 netisr_queue_workstream(struct netisr_workstream *nwsp, u_int proto,
828 struct netisr_work *npwp, struct mbuf *m, int *dosignalp)
829 {
830
831 NWS_LOCK_ASSERT(nwsp);
832
833 *dosignalp = 0;
834 if (npwp->nw_len < npwp->nw_qlimit) {
835 m->m_nextpkt = NULL;
836 if (npwp->nw_head == NULL) {
837 npwp->nw_head = m;
838 npwp->nw_tail = m;
839 } else {
840 npwp->nw_tail->m_nextpkt = m;
841 npwp->nw_tail = m;
842 }
843 npwp->nw_len++;
844 if (npwp->nw_len > npwp->nw_watermark)
845 npwp->nw_watermark = npwp->nw_len;
846
847 /*
848 * We must set the bit regardless of NWS_RUNNING, so that
849 * swi_net() keeps calling netisr_process_workstream_proto().
850 */
851 nwsp->nws_pendingbits |= (1 << proto);
852 if (!(nwsp->nws_flags &
853 (NWS_RUNNING | NWS_DISPATCHING | NWS_SCHEDULED))) {
854 nwsp->nws_flags |= NWS_SCHEDULED;
855 *dosignalp = 1; /* Defer until unlocked. */
856 }
857 npwp->nw_queued++;
858 return (0);
859 } else {
860 m_freem(m);
861 npwp->nw_qdrops++;
862 return (ENOBUFS);
863 }
864 }
865
866 static int
867 netisr_queue_internal(u_int proto, struct mbuf *m, u_int cpuid)
868 {
869 struct netisr_workstream *nwsp;
870 struct netisr_work *npwp;
871 int dosignal, error;
872
873 #ifdef NETISR_LOCKING
874 NETISR_LOCK_ASSERT();
875 #endif
876 KASSERT(cpuid <= mp_maxid, ("%s: cpuid too big (%u, %u)", __func__,
877 cpuid, mp_maxid));
878 KASSERT(!CPU_ABSENT(cpuid), ("%s: CPU %u absent", __func__, cpuid));
879
880 dosignal = 0;
881 error = 0;
882 nwsp = DPCPU_ID_PTR(cpuid, nws);
883 npwp = &nwsp->nws_work[proto];
884 NWS_LOCK(nwsp);
885 error = netisr_queue_workstream(nwsp, proto, npwp, m, &dosignal);
886 NWS_UNLOCK(nwsp);
887 if (dosignal)
888 NWS_SIGNAL(nwsp);
889 return (error);
890 }
891
892 int
893 netisr_queue_src(u_int proto, uintptr_t source, struct mbuf *m)
894 {
895 #ifdef NETISR_LOCKING
896 struct rm_priotracker tracker;
897 #endif
898 u_int cpuid;
899 int error;
900
901 KASSERT(proto < NETISR_MAXPROT,
902 ("%s: invalid proto %u", __func__, proto));
903
904 #ifdef NETISR_LOCKING
905 NETISR_RLOCK(&tracker);
906 #endif
907 KASSERT(netisr_proto[proto].np_handler != NULL,
908 ("%s: invalid proto %u", __func__, proto));
909
910 m = netisr_select_cpuid(&netisr_proto[proto], NETISR_DISPATCH_DEFERRED,
911 source, m, &cpuid);
912 if (m != NULL) {
913 KASSERT(!CPU_ABSENT(cpuid), ("%s: CPU %u absent", __func__,
914 cpuid));
915 error = netisr_queue_internal(proto, m, cpuid);
916 } else
917 error = ENOBUFS;
918 #ifdef NETISR_LOCKING
919 NETISR_RUNLOCK(&tracker);
920 #endif
921 return (error);
922 }
923
924 int
925 netisr_queue(u_int proto, struct mbuf *m)
926 {
927
928 return (netisr_queue_src(proto, 0, m));
929 }
930
931 /*
932 * Dispatch a packet for netisr processing; direct dispatch is permitted by
933 * calling context.
934 */
935 int
936 netisr_dispatch_src(u_int proto, uintptr_t source, struct mbuf *m)
937 {
938 #ifdef NETISR_LOCKING
939 struct rm_priotracker tracker;
940 #endif
941 struct netisr_workstream *nwsp;
942 struct netisr_proto *npp;
943 struct netisr_work *npwp;
944 int dosignal, error;
945 u_int cpuid, dispatch_policy;
946
947 KASSERT(proto < NETISR_MAXPROT,
948 ("%s: invalid proto %u", __func__, proto));
949 #ifdef NETISR_LOCKING
950 NETISR_RLOCK(&tracker);
951 #endif
952 npp = &netisr_proto[proto];
953 KASSERT(npp->np_handler != NULL, ("%s: invalid proto %u", __func__,
954 proto));
955
956 dispatch_policy = netisr_get_dispatch(npp);
957 if (dispatch_policy == NETISR_DISPATCH_DEFERRED)
958 return (netisr_queue_src(proto, source, m));
959
960 /*
961 * If direct dispatch is forced, then unconditionally dispatch
962 * without a formal CPU selection. Borrow the current CPU's stats,
963 * even if there's no worker on it. In this case we don't update
964 * nws_flags because all netisr processing will be source ordered due
965 * to always being forced to directly dispatch.
966 */
967 if (dispatch_policy == NETISR_DISPATCH_DIRECT) {
968 nwsp = DPCPU_PTR(nws);
969 npwp = &nwsp->nws_work[proto];
970 npwp->nw_dispatched++;
971 npwp->nw_handled++;
972 netisr_proto[proto].np_handler(m);
973 error = 0;
974 goto out_unlock;
975 }
976
977 KASSERT(dispatch_policy == NETISR_DISPATCH_HYBRID,
978 ("%s: unknown dispatch policy (%u)", __func__, dispatch_policy));
979
980 /*
981 * Otherwise, we execute in a hybrid mode where we will try to direct
982 * dispatch if we're on the right CPU and the netisr worker isn't
983 * already running.
984 */
985 sched_pin();
986 m = netisr_select_cpuid(&netisr_proto[proto], NETISR_DISPATCH_HYBRID,
987 source, m, &cpuid);
988 if (m == NULL) {
989 error = ENOBUFS;
990 goto out_unpin;
991 }
992 KASSERT(!CPU_ABSENT(cpuid), ("%s: CPU %u absent", __func__, cpuid));
993 if (cpuid != curcpu)
994 goto queue_fallback;
995 nwsp = DPCPU_PTR(nws);
996 npwp = &nwsp->nws_work[proto];
997
998 /*-
999 * We are willing to direct dispatch only if three conditions hold:
1000 *
1001 * (1) The netisr worker isn't already running,
1002 * (2) Another thread isn't already directly dispatching, and
1003 * (3) The netisr hasn't already been woken up.
1004 */
1005 NWS_LOCK(nwsp);
1006 if (nwsp->nws_flags & (NWS_RUNNING | NWS_DISPATCHING | NWS_SCHEDULED)) {
1007 error = netisr_queue_workstream(nwsp, proto, npwp, m,
1008 &dosignal);
1009 NWS_UNLOCK(nwsp);
1010 if (dosignal)
1011 NWS_SIGNAL(nwsp);
1012 goto out_unpin;
1013 }
1014
1015 /*
1016 * The current thread is now effectively the netisr worker, so set
1017 * the dispatching flag to prevent concurrent processing of the
1018 * stream from another thread (even the netisr worker), which could
1019 * otherwise lead to effective misordering of the stream.
1020 */
1021 nwsp->nws_flags |= NWS_DISPATCHING;
1022 NWS_UNLOCK(nwsp);
1023 netisr_proto[proto].np_handler(m);
1024 NWS_LOCK(nwsp);
1025 nwsp->nws_flags &= ~NWS_DISPATCHING;
1026 npwp->nw_handled++;
1027 npwp->nw_hybrid_dispatched++;
1028
1029 /*
1030 * If other work was enqueued by another thread while we were direct
1031 * dispatching, we need to signal the netisr worker to do that work.
1032 * In the future, we might want to do some of that work in the
1033 * current thread, rather than trigger further context switches. If
1034 * so, we'll want to establish a reasonable bound on the work done in
1035 * the "borrowed" context.
1036 */
1037 if (nwsp->nws_pendingbits != 0) {
1038 nwsp->nws_flags |= NWS_SCHEDULED;
1039 dosignal = 1;
1040 } else
1041 dosignal = 0;
1042 NWS_UNLOCK(nwsp);
1043 if (dosignal)
1044 NWS_SIGNAL(nwsp);
1045 error = 0;
1046 goto out_unpin;
1047
1048 queue_fallback:
1049 error = netisr_queue_internal(proto, m, cpuid);
1050 out_unpin:
1051 sched_unpin();
1052 out_unlock:
1053 #ifdef NETISR_LOCKING
1054 NETISR_RUNLOCK(&tracker);
1055 #endif
1056 return (error);
1057 }
1058
1059 int
1060 netisr_dispatch(u_int proto, struct mbuf *m)
1061 {
1062
1063 return (netisr_dispatch_src(proto, 0, m));
1064 }
1065
1066 #ifdef DEVICE_POLLING
1067 /*
1068 * Kernel polling borrows a netisr thread to run interface polling in; this
1069 * function allows kernel polling to request that the netisr thread be
1070 * scheduled even if no packets are pending for protocols.
1071 */
1072 void
1073 netisr_sched_poll(void)
1074 {
1075 struct netisr_workstream *nwsp;
1076
1077 nwsp = DPCPU_ID_PTR(nws_array[0], nws);
1078 NWS_SIGNAL(nwsp);
1079 }
1080 #endif
1081
1082 static void
1083 netisr_start_swi(u_int cpuid, struct pcpu *pc)
1084 {
1085 char swiname[12];
1086 struct netisr_workstream *nwsp;
1087 int error;
1088
1089 KASSERT(!CPU_ABSENT(cpuid), ("%s: CPU %u absent", __func__, cpuid));
1090
1091 nwsp = DPCPU_ID_PTR(cpuid, nws);
1092 mtx_init(&nwsp->nws_mtx, "netisr_mtx", NULL, MTX_DEF);
1093 nwsp->nws_cpu = cpuid;
1094 snprintf(swiname, sizeof(swiname), "netisr %u", cpuid);
1095 error = swi_add(&nwsp->nws_intr_event, swiname, swi_net, nwsp,
1096 SWI_NET, INTR_MPSAFE, &nwsp->nws_swi_cookie);
1097 if (error)
1098 panic("%s: swi_add %d", __func__, error);
1099 pc->pc_netisr = nwsp->nws_intr_event;
1100 if (netisr_bindthreads) {
1101 error = intr_event_bind(nwsp->nws_intr_event, cpuid);
1102 if (error != 0)
1103 printf("%s: cpu %u: intr_event_bind: %d", __func__,
1104 cpuid, error);
1105 }
1106 NETISR_WLOCK();
1107 nws_array[nws_count] = nwsp->nws_cpu;
1108 nws_count++;
1109 NETISR_WUNLOCK();
1110 }
1111
1112 /*
1113 * Initialize the netisr subsystem. We rely on BSS and static initialization
1114 * of most fields in global data structures.
1115 *
1116 * Start a worker thread for the boot CPU so that we can support network
1117 * traffic immediately in case the network stack is used before additional
1118 * CPUs are started (for example, diskless boot).
1119 */
1120 static void
1121 netisr_init(void *arg)
1122 {
1123 char tmp[NETISR_DISPATCH_POLICY_MAXSTR];
1124 u_int dispatch_policy;
1125 int error;
1126
1127 KASSERT(curcpu == 0, ("%s: not on CPU 0", __func__));
1128
1129 NETISR_LOCK_INIT();
1130 if (netisr_maxthreads < 1)
1131 netisr_maxthreads = 1;
1132 if (netisr_maxthreads > mp_ncpus) {
1133 printf("netisr_init: forcing maxthreads from %d to %d\n",
1134 netisr_maxthreads, mp_ncpus);
1135 netisr_maxthreads = mp_ncpus;
1136 }
1137 if (netisr_defaultqlimit > netisr_maxqlimit) {
1138 printf("netisr_init: forcing defaultqlimit from %d to %d\n",
1139 netisr_defaultqlimit, netisr_maxqlimit);
1140 netisr_defaultqlimit = netisr_maxqlimit;
1141 }
1142 #ifdef DEVICE_POLLING
1143 /*
1144 * The device polling code is not yet aware of how to deal with
1145 * multiple netisr threads, so for the time being compiling in device
1146 * polling disables parallel netisr workers.
1147 */
1148 if (netisr_maxthreads != 1 || netisr_bindthreads != 0) {
1149 printf("netisr_init: forcing maxthreads to 1 and "
1150 "bindthreads to 0 for device polling\n");
1151 netisr_maxthreads = 1;
1152 netisr_bindthreads = 0;
1153 }
1154 #endif
1155
1156 if (TUNABLE_STR_FETCH("net.isr.dispatch", tmp, sizeof(tmp))) {
1157 error = netisr_dispatch_policy_from_str(tmp,
1158 &dispatch_policy);
1159 if (error == 0 && dispatch_policy == NETISR_DISPATCH_DEFAULT)
1160 error = EINVAL;
1161 if (error == 0)
1162 netisr_dispatch_policy = dispatch_policy;
1163 else
1164 printf(
1165 "%s: invalid dispatch policy %s, using default\n",
1166 __func__, tmp);
1167 }
1168
1169 netisr_start_swi(curcpu, pcpu_find(curcpu));
1170 }
1171 SYSINIT(netisr_init, SI_SUB_SOFTINTR, SI_ORDER_FIRST, netisr_init, NULL);
1172
1173 /*
1174 * Start worker threads for additional CPUs. No attempt to gracefully handle
1175 * work reassignment, we don't yet support dynamic reconfiguration.
1176 */
1177 static void
1178 netisr_start(void *arg)
1179 {
1180 struct pcpu *pc;
1181
1182 STAILQ_FOREACH(pc, &cpuhead, pc_allcpu) {
1183 if (nws_count >= netisr_maxthreads)
1184 break;
1185 /* XXXRW: Is skipping absent CPUs still required here? */
1186 if (CPU_ABSENT(pc->pc_cpuid))
1187 continue;
1188 /* Worker will already be present for boot CPU. */
1189 if (pc->pc_netisr != NULL)
1190 continue;
1191 netisr_start_swi(pc->pc_cpuid, pc);
1192 }
1193 }
1194 SYSINIT(netisr_start, SI_SUB_SMP, SI_ORDER_MIDDLE, netisr_start, NULL);
1195
1196 /*
1197 * Sysctl monitoring for netisr: query a list of registered protocols.
1198 */
1199 static int
1200 sysctl_netisr_proto(SYSCTL_HANDLER_ARGS)
1201 {
1202 struct rm_priotracker tracker;
1203 struct sysctl_netisr_proto *snpp, *snp_array;
1204 struct netisr_proto *npp;
1205 u_int counter, proto;
1206 int error;
1207
1208 if (req->newptr != NULL)
1209 return (EINVAL);
1210 snp_array = malloc(sizeof(*snp_array) * NETISR_MAXPROT, M_TEMP,
1211 M_ZERO | M_WAITOK);
1212 counter = 0;
1213 NETISR_RLOCK(&tracker);
1214 for (proto = 0; proto < NETISR_MAXPROT; proto++) {
1215 npp = &netisr_proto[proto];
1216 if (npp->np_name == NULL)
1217 continue;
1218 snpp = &snp_array[counter];
1219 snpp->snp_version = sizeof(*snpp);
1220 strlcpy(snpp->snp_name, npp->np_name, NETISR_NAMEMAXLEN);
1221 snpp->snp_proto = proto;
1222 snpp->snp_qlimit = npp->np_qlimit;
1223 snpp->snp_policy = npp->np_policy;
1224 snpp->snp_dispatch = npp->np_dispatch;
1225 if (npp->np_m2flow != NULL)
1226 snpp->snp_flags |= NETISR_SNP_FLAGS_M2FLOW;
1227 if (npp->np_m2cpuid != NULL)
1228 snpp->snp_flags |= NETISR_SNP_FLAGS_M2CPUID;
1229 if (npp->np_drainedcpu != NULL)
1230 snpp->snp_flags |= NETISR_SNP_FLAGS_DRAINEDCPU;
1231 counter++;
1232 }
1233 NETISR_RUNLOCK(&tracker);
1234 KASSERT(counter <= NETISR_MAXPROT,
1235 ("sysctl_netisr_proto: counter too big (%d)", counter));
1236 error = SYSCTL_OUT(req, snp_array, sizeof(*snp_array) * counter);
1237 free(snp_array, M_TEMP);
1238 return (error);
1239 }
1240
1241 SYSCTL_PROC(_net_isr, OID_AUTO, proto,
1242 CTLFLAG_RD|CTLTYPE_STRUCT|CTLFLAG_MPSAFE, 0, 0, sysctl_netisr_proto,
1243 "S,sysctl_netisr_proto",
1244 "Return list of protocols registered with netisr");
1245
1246 /*
1247 * Sysctl monitoring for netisr: query a list of workstreams.
1248 */
1249 static int
1250 sysctl_netisr_workstream(SYSCTL_HANDLER_ARGS)
1251 {
1252 struct rm_priotracker tracker;
1253 struct sysctl_netisr_workstream *snwsp, *snws_array;
1254 struct netisr_workstream *nwsp;
1255 u_int counter, cpuid;
1256 int error;
1257
1258 if (req->newptr != NULL)
1259 return (EINVAL);
1260 snws_array = malloc(sizeof(*snws_array) * MAXCPU, M_TEMP,
1261 M_ZERO | M_WAITOK);
1262 counter = 0;
1263 NETISR_RLOCK(&tracker);
1264 CPU_FOREACH(cpuid) {
1265 nwsp = DPCPU_ID_PTR(cpuid, nws);
1266 if (nwsp->nws_intr_event == NULL)
1267 continue;
1268 NWS_LOCK(nwsp);
1269 snwsp = &snws_array[counter];
1270 snwsp->snws_version = sizeof(*snwsp);
1271
1272 /*
1273 * For now, we equate workstream IDs and CPU IDs in the
1274 * kernel, but expose them independently to userspace in case
1275 * that assumption changes in the future.
1276 */
1277 snwsp->snws_wsid = cpuid;
1278 snwsp->snws_cpu = cpuid;
1279 if (nwsp->nws_intr_event != NULL)
1280 snwsp->snws_flags |= NETISR_SNWS_FLAGS_INTR;
1281 NWS_UNLOCK(nwsp);
1282 counter++;
1283 }
1284 NETISR_RUNLOCK(&tracker);
1285 KASSERT(counter <= MAXCPU,
1286 ("sysctl_netisr_workstream: counter too big (%d)", counter));
1287 error = SYSCTL_OUT(req, snws_array, sizeof(*snws_array) * counter);
1288 free(snws_array, M_TEMP);
1289 return (error);
1290 }
1291
1292 SYSCTL_PROC(_net_isr, OID_AUTO, workstream,
1293 CTLFLAG_RD|CTLTYPE_STRUCT|CTLFLAG_MPSAFE, 0, 0, sysctl_netisr_workstream,
1294 "S,sysctl_netisr_workstream",
1295 "Return list of workstreams implemented by netisr");
1296
1297 /*
1298 * Sysctl monitoring for netisr: query per-protocol data across all
1299 * workstreams.
1300 */
1301 static int
1302 sysctl_netisr_work(SYSCTL_HANDLER_ARGS)
1303 {
1304 struct rm_priotracker tracker;
1305 struct sysctl_netisr_work *snwp, *snw_array;
1306 struct netisr_workstream *nwsp;
1307 struct netisr_proto *npp;
1308 struct netisr_work *nwp;
1309 u_int counter, cpuid, proto;
1310 int error;
1311
1312 if (req->newptr != NULL)
1313 return (EINVAL);
1314 snw_array = malloc(sizeof(*snw_array) * MAXCPU * NETISR_MAXPROT,
1315 M_TEMP, M_ZERO | M_WAITOK);
1316 counter = 0;
1317 NETISR_RLOCK(&tracker);
1318 CPU_FOREACH(cpuid) {
1319 nwsp = DPCPU_ID_PTR(cpuid, nws);
1320 if (nwsp->nws_intr_event == NULL)
1321 continue;
1322 NWS_LOCK(nwsp);
1323 for (proto = 0; proto < NETISR_MAXPROT; proto++) {
1324 npp = &netisr_proto[proto];
1325 if (npp->np_name == NULL)
1326 continue;
1327 nwp = &nwsp->nws_work[proto];
1328 snwp = &snw_array[counter];
1329 snwp->snw_version = sizeof(*snwp);
1330 snwp->snw_wsid = cpuid; /* See comment above. */
1331 snwp->snw_proto = proto;
1332 snwp->snw_len = nwp->nw_len;
1333 snwp->snw_watermark = nwp->nw_watermark;
1334 snwp->snw_dispatched = nwp->nw_dispatched;
1335 snwp->snw_hybrid_dispatched =
1336 nwp->nw_hybrid_dispatched;
1337 snwp->snw_qdrops = nwp->nw_qdrops;
1338 snwp->snw_queued = nwp->nw_queued;
1339 snwp->snw_handled = nwp->nw_handled;
1340 counter++;
1341 }
1342 NWS_UNLOCK(nwsp);
1343 }
1344 KASSERT(counter <= MAXCPU * NETISR_MAXPROT,
1345 ("sysctl_netisr_work: counter too big (%d)", counter));
1346 NETISR_RUNLOCK(&tracker);
1347 error = SYSCTL_OUT(req, snw_array, sizeof(*snw_array) * counter);
1348 free(snw_array, M_TEMP);
1349 return (error);
1350 }
1351
1352 SYSCTL_PROC(_net_isr, OID_AUTO, work,
1353 CTLFLAG_RD|CTLTYPE_STRUCT|CTLFLAG_MPSAFE, 0, 0, sysctl_netisr_work,
1354 "S,sysctl_netisr_work",
1355 "Return list of per-workstream, per-protocol work in netisr");
1356
1357 #ifdef DDB
1358 DB_SHOW_COMMAND(netisr, db_show_netisr)
1359 {
1360 struct netisr_workstream *nwsp;
1361 struct netisr_work *nwp;
1362 int first, proto;
1363 u_int cpuid;
1364
1365 db_printf("%3s %6s %5s %5s %5s %8s %8s %8s %8s\n", "CPU", "Proto",
1366 "Len", "WMark", "Max", "Disp", "HDisp", "Drop", "Queue");
1367 CPU_FOREACH(cpuid) {
1368 nwsp = DPCPU_ID_PTR(cpuid, nws);
1369 if (nwsp->nws_intr_event == NULL)
1370 continue;
1371 first = 1;
1372 for (proto = 0; proto < NETISR_MAXPROT; proto++) {
1373 if (netisr_proto[proto].np_handler == NULL)
1374 continue;
1375 nwp = &nwsp->nws_work[proto];
1376 if (first) {
1377 db_printf("%3d ", cpuid);
1378 first = 0;
1379 } else
1380 db_printf("%3s ", "");
1381 db_printf(
1382 "%6s %5d %5d %5d %8ju %8ju %8ju %8ju\n",
1383 netisr_proto[proto].np_name, nwp->nw_len,
1384 nwp->nw_watermark, nwp->nw_qlimit,
1385 nwp->nw_dispatched, nwp->nw_hybrid_dispatched,
1386 nwp->nw_qdrops, nwp->nw_queued);
1387 }
1388 }
1389 }
1390 #endif
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