1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2012 Chelsio Communications, Inc.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28 #include <sys/cdefs.h>
29 #include "opt_inet.h"
30 #include "opt_inet6.h"
31
32 #include <sys/param.h>
33 #include <sys/eventhandler.h>
34 #include <sys/systm.h>
35 #include <sys/kernel.h>
36 #include <sys/module.h>
37 #include <sys/bus.h>
38 #include <sys/lock.h>
39 #include <sys/mutex.h>
40 #include <sys/rwlock.h>
41 #include <sys/socket.h>
42 #include <sys/sbuf.h>
43 #include <netinet/in.h>
44
45 #include "common/common.h"
46 #include "common/t4_msg.h"
47 #include "t4_l2t.h"
48
49 /*
50 * Module locking notes: There is a RW lock protecting the L2 table as a
51 * whole plus a spinlock per L2T entry. Entry lookups and allocations happen
52 * under the protection of the table lock, individual entry changes happen
53 * while holding that entry's spinlock. The table lock nests outside the
54 * entry locks. Allocations of new entries take the table lock as writers so
55 * no other lookups can happen while allocating new entries. Entry updates
56 * take the table lock as readers so multiple entries can be updated in
57 * parallel. An L2T entry can be dropped by decrementing its reference count
58 * and therefore can happen in parallel with entry allocation but no entry
59 * can change state or increment its ref count during allocation as both of
60 * these perform lookups.
61 *
62 * Note: We do not take references to ifnets in this module because both
63 * the TOE and the sockets already hold references to the interfaces and the
64 * lifetime of an L2T entry is fully contained in the lifetime of the TOE.
65 */
66
67 /*
68 * Allocate a free L2T entry. Must be called with l2t_data.lock held.
69 */
70 struct l2t_entry *
t4_alloc_l2e(struct l2t_data * d)71 t4_alloc_l2e(struct l2t_data *d)
72 {
73 struct l2t_entry *end, *e, **p;
74
75 rw_assert(&d->lock, RA_WLOCKED);
76
77 if (!atomic_load_acq_int(&d->nfree))
78 return (NULL);
79
80 /* there's definitely a free entry */
81 for (e = d->rover, end = &d->l2tab[d->l2t_size]; e != end; ++e)
82 if (atomic_load_acq_int(&e->refcnt) == 0)
83 goto found;
84
85 for (e = d->l2tab; atomic_load_acq_int(&e->refcnt); ++e)
86 continue;
87 found:
88 d->rover = e + 1;
89 atomic_subtract_int(&d->nfree, 1);
90
91 /*
92 * The entry we found may be an inactive entry that is
93 * presently in the hash table. We need to remove it.
94 */
95 if (e->state < L2T_STATE_SWITCHING) {
96 for (p = &d->l2tab[e->hash].first; *p; p = &(*p)->next) {
97 if (*p == e) {
98 *p = e->next;
99 e->next = NULL;
100 break;
101 }
102 }
103 }
104
105 e->state = L2T_STATE_UNUSED;
106 return (e);
107 }
108
109 static struct l2t_entry *
find_or_alloc_l2e(struct l2t_data * d,uint16_t vlan,uint8_t port,uint8_t * dmac)110 find_or_alloc_l2e(struct l2t_data *d, uint16_t vlan, uint8_t port, uint8_t *dmac)
111 {
112 struct l2t_entry *end, *e, **p;
113 struct l2t_entry *first_free = NULL;
114
115 for (e = &d->l2tab[0], end = &d->l2tab[d->l2t_size]; e != end; ++e) {
116 if (atomic_load_acq_int(&e->refcnt) == 0) {
117 if (!first_free)
118 first_free = e;
119 } else if (e->state == L2T_STATE_SWITCHING &&
120 memcmp(e->dmac, dmac, ETHER_ADDR_LEN) == 0 &&
121 e->vlan == vlan && e->lport == port)
122 return (e); /* Found existing entry that matches. */
123 }
124
125 if (first_free == NULL)
126 return (NULL); /* No match and no room for a new entry. */
127
128 /*
129 * The entry we found may be an inactive entry that is
130 * presently in the hash table. We need to remove it.
131 */
132 e = first_free;
133 if (e->state < L2T_STATE_SWITCHING) {
134 for (p = &d->l2tab[e->hash].first; *p; p = &(*p)->next) {
135 if (*p == e) {
136 *p = e->next;
137 e->next = NULL;
138 break;
139 }
140 }
141 }
142 e->state = L2T_STATE_UNUSED;
143 return (e);
144 }
145
146 static void
mk_write_l2e(struct adapter * sc,struct l2t_entry * e,int sync,int reply,void * dst)147 mk_write_l2e(struct adapter *sc, struct l2t_entry *e, int sync, int reply,
148 void *dst)
149 {
150 struct cpl_l2t_write_req *req;
151 int idx;
152
153 req = dst;
154 idx = e->idx + sc->vres.l2t.start;
155 INIT_TP_WR(req, 0);
156 OPCODE_TID(req) = htonl(MK_OPCODE_TID(CPL_L2T_WRITE_REQ, idx |
157 V_SYNC_WR(sync) | V_TID_QID(e->iqid)));
158 req->params = htons(V_L2T_W_PORT(e->lport) | V_L2T_W_NOREPLY(!reply));
159 req->l2t_idx = htons(idx);
160 req->vlan = htons(e->vlan);
161 memcpy(req->dst_mac, e->dmac, sizeof(req->dst_mac));
162 }
163
164 /*
165 * Write an L2T entry. Must be called with the entry locked.
166 * The write may be synchronous or asynchronous.
167 */
168 int
t4_write_l2e(struct l2t_entry * e,int sync)169 t4_write_l2e(struct l2t_entry *e, int sync)
170 {
171 struct sge_wrq *wrq;
172 struct adapter *sc;
173 struct wrq_cookie cookie;
174 struct cpl_l2t_write_req *req;
175
176 mtx_assert(&e->lock, MA_OWNED);
177 MPASS(e->wrq != NULL);
178
179 wrq = e->wrq;
180 sc = wrq->adapter;
181
182 req = start_wrq_wr(wrq, howmany(sizeof(*req), 16), &cookie);
183 if (req == NULL)
184 return (ENOMEM);
185
186 mk_write_l2e(sc, e, sync, sync, req);
187
188 commit_wrq_wr(wrq, req, &cookie);
189
190 if (sync && e->state != L2T_STATE_SWITCHING)
191 e->state = L2T_STATE_SYNC_WRITE;
192
193 return (0);
194 }
195
196 /*
197 * Allocate an L2T entry for use by a TLS connection. These entries are
198 * associated with a specific VLAN and destination MAC that never changes.
199 * However, multiple TLS connections might share a single entry.
200 *
201 * If a new L2T entry is allocated, a work request to initialize it is
202 * written to 'txq' and 'ndesc' will be set to 1. Otherwise, 'ndesc'
203 * will be set to 0.
204 *
205 * To avoid races, separate L2T entries are reserved for individual
206 * queues since the L2T entry update is written to a txq just prior to
207 * TLS work requests that will depend on it being written.
208 */
209 struct l2t_entry *
t4_l2t_alloc_tls(struct adapter * sc,struct sge_txq * txq,void * dst,int * ndesc,uint16_t vlan,uint8_t port,uint8_t * eth_addr)210 t4_l2t_alloc_tls(struct adapter *sc, struct sge_txq *txq, void *dst,
211 int *ndesc, uint16_t vlan, uint8_t port, uint8_t *eth_addr)
212 {
213 struct l2t_data *d;
214 struct l2t_entry *e;
215 int i;
216
217 TXQ_LOCK_ASSERT_OWNED(txq);
218
219 d = sc->l2t;
220 *ndesc = 0;
221
222 rw_rlock(&d->lock);
223
224 /* First, try to find an existing entry. */
225 for (i = 0; i < d->l2t_size; i++) {
226 e = &d->l2tab[i];
227 if (e->state != L2T_STATE_TLS)
228 continue;
229 if (e->vlan == vlan && e->lport == port &&
230 e->wrq == (struct sge_wrq *)txq &&
231 memcmp(e->dmac, eth_addr, ETHER_ADDR_LEN) == 0) {
232 if (atomic_fetchadd_int(&e->refcnt, 1) == 0) {
233 /*
234 * This entry wasn't held but is still
235 * valid, so decrement nfree.
236 */
237 atomic_subtract_int(&d->nfree, 1);
238 }
239 KASSERT(e->refcnt > 0,
240 ("%s: refcount overflow", __func__));
241 rw_runlock(&d->lock);
242 return (e);
243 }
244 }
245
246 /*
247 * Don't bother rechecking if the upgrade fails since the txq is
248 * already locked.
249 */
250 if (!rw_try_upgrade(&d->lock)) {
251 rw_runlock(&d->lock);
252 rw_wlock(&d->lock);
253 }
254
255 /* Match not found, allocate a new entry. */
256 e = t4_alloc_l2e(d);
257 if (e == NULL) {
258 rw_wunlock(&d->lock);
259 return (e);
260 }
261
262 /* Initialize the entry. */
263 e->state = L2T_STATE_TLS;
264 e->vlan = vlan;
265 e->lport = port;
266 e->iqid = sc->sge.fwq.abs_id;
267 e->wrq = (struct sge_wrq *)txq;
268 memcpy(e->dmac, eth_addr, ETHER_ADDR_LEN);
269 atomic_store_rel_int(&e->refcnt, 1);
270 rw_wunlock(&d->lock);
271
272 /* Write out the work request. */
273 *ndesc = howmany(sizeof(struct cpl_l2t_write_req), EQ_ESIZE);
274 MPASS(*ndesc == 1);
275 mk_write_l2e(sc, e, 1, 0, dst);
276
277 return (e);
278 }
279
280 /*
281 * Allocate an L2T entry for use by a switching rule. Such need to be
282 * explicitly freed and while busy they are not on any hash chain, so normal
283 * address resolution updates do not see them.
284 */
285 struct l2t_entry *
t4_l2t_alloc_switching(struct adapter * sc,uint16_t vlan,uint8_t port,uint8_t * eth_addr)286 t4_l2t_alloc_switching(struct adapter *sc, uint16_t vlan, uint8_t port,
287 uint8_t *eth_addr)
288 {
289 struct l2t_data *d = sc->l2t;
290 struct l2t_entry *e;
291 int rc;
292
293 rw_wlock(&d->lock);
294 e = find_or_alloc_l2e(d, vlan, port, eth_addr);
295 if (e) {
296 if (atomic_load_acq_int(&e->refcnt) == 0) {
297 mtx_lock(&e->lock); /* avoid race with t4_l2t_free */
298 e->wrq = &sc->sge.ctrlq[0];
299 e->iqid = sc->sge.fwq.abs_id;
300 e->state = L2T_STATE_SWITCHING;
301 e->vlan = vlan;
302 e->lport = port;
303 memcpy(e->dmac, eth_addr, ETHER_ADDR_LEN);
304 atomic_store_rel_int(&e->refcnt, 1);
305 atomic_subtract_int(&d->nfree, 1);
306 rc = t4_write_l2e(e, 0);
307 mtx_unlock(&e->lock);
308 if (rc != 0)
309 e = NULL;
310 } else {
311 MPASS(e->vlan == vlan);
312 MPASS(e->lport == port);
313 atomic_add_int(&e->refcnt, 1);
314 }
315 }
316 rw_wunlock(&d->lock);
317 return (e);
318 }
319
320 int
t4_init_l2t(struct adapter * sc,int flags)321 t4_init_l2t(struct adapter *sc, int flags)
322 {
323 int i, l2t_size;
324 struct l2t_data *d;
325
326 l2t_size = sc->vres.l2t.size;
327 if (l2t_size < 2) /* At least 1 bucket for IP and 1 for IPv6 */
328 return (EINVAL);
329
330 d = malloc(sizeof(*d) + l2t_size * sizeof (struct l2t_entry), M_CXGBE,
331 M_ZERO | flags);
332 if (!d)
333 return (ENOMEM);
334
335 d->l2t_size = l2t_size;
336 d->rover = d->l2tab;
337 atomic_store_rel_int(&d->nfree, l2t_size);
338 rw_init(&d->lock, "L2T");
339
340 for (i = 0; i < l2t_size; i++) {
341 struct l2t_entry *e = &d->l2tab[i];
342
343 e->idx = i;
344 e->state = L2T_STATE_UNUSED;
345 mtx_init(&e->lock, "L2T_E", NULL, MTX_DEF);
346 STAILQ_INIT(&e->wr_list);
347 atomic_store_rel_int(&e->refcnt, 0);
348 }
349
350 sc->l2t = d;
351
352 return (0);
353 }
354
355 int
t4_free_l2t(struct l2t_data * d)356 t4_free_l2t(struct l2t_data *d)
357 {
358 int i;
359
360 for (i = 0; i < d->l2t_size; i++)
361 mtx_destroy(&d->l2tab[i].lock);
362 rw_destroy(&d->lock);
363 free(d, M_CXGBE);
364
365 return (0);
366 }
367
368 int
do_l2t_write_rpl(struct sge_iq * iq,const struct rss_header * rss,struct mbuf * m)369 do_l2t_write_rpl(struct sge_iq *iq, const struct rss_header *rss,
370 struct mbuf *m)
371 {
372 const struct cpl_l2t_write_rpl *rpl = (const void *)(rss + 1);
373 unsigned int tid = GET_TID(rpl);
374 unsigned int idx = tid % L2T_SIZE;
375
376 if (__predict_false(rpl->status != CPL_ERR_NONE)) {
377 log(LOG_ERR,
378 "Unexpected L2T_WRITE_RPL (%u) for entry at hw_idx %u\n",
379 rpl->status, idx);
380 return (EINVAL);
381 }
382
383 return (0);
384 }
385
386 static inline unsigned int
vlan_prio(const struct l2t_entry * e)387 vlan_prio(const struct l2t_entry *e)
388 {
389 return e->vlan >> 13;
390 }
391
392 static char
l2e_state(const struct l2t_entry * e)393 l2e_state(const struct l2t_entry *e)
394 {
395 switch (e->state) {
396 case L2T_STATE_VALID: return 'V'; /* valid, fast-path entry */
397 case L2T_STATE_STALE: return 'S'; /* needs revalidation, but usable */
398 case L2T_STATE_SYNC_WRITE: return 'W';
399 case L2T_STATE_RESOLVING: return STAILQ_EMPTY(&e->wr_list) ? 'R' : 'A';
400 case L2T_STATE_SWITCHING: return 'X';
401 case L2T_STATE_TLS: return 'T';
402 default: return 'U';
403 }
404 }
405
406 int
sysctl_l2t(SYSCTL_HANDLER_ARGS)407 sysctl_l2t(SYSCTL_HANDLER_ARGS)
408 {
409 struct adapter *sc = arg1;
410 struct l2t_data *l2t = sc->l2t;
411 struct l2t_entry *e;
412 struct sbuf *sb;
413 int rc, i, header = 0;
414 char ip[INET6_ADDRSTRLEN];
415
416 if (l2t == NULL)
417 return (ENXIO);
418
419 rc = sysctl_wire_old_buffer(req, 0);
420 if (rc != 0)
421 return (rc);
422
423 sb = sbuf_new_for_sysctl(NULL, NULL, 4096, req);
424 if (sb == NULL)
425 return (ENOMEM);
426
427 e = &l2t->l2tab[0];
428 for (i = 0; i < l2t->l2t_size; i++, e++) {
429 mtx_lock(&e->lock);
430 if (e->state == L2T_STATE_UNUSED)
431 goto skip;
432
433 if (header == 0) {
434 sbuf_printf(sb, " Idx IP address "
435 "Ethernet address VLAN/P LP State Users Port");
436 header = 1;
437 }
438 if (e->state >= L2T_STATE_SWITCHING)
439 ip[0] = 0;
440 else {
441 inet_ntop(e->ipv6 ? AF_INET6 : AF_INET, &e->addr[0],
442 &ip[0], sizeof(ip));
443 }
444
445 /*
446 * XXX: IPv6 addresses may not align properly in the output.
447 */
448 sbuf_printf(sb, "\n%4u %-15s %02x:%02x:%02x:%02x:%02x:%02x %4d"
449 " %u %2u %c %5u %s",
450 e->idx, ip, e->dmac[0], e->dmac[1], e->dmac[2],
451 e->dmac[3], e->dmac[4], e->dmac[5],
452 e->vlan & 0xfff, vlan_prio(e), e->lport,
453 l2e_state(e), atomic_load_acq_int(&e->refcnt),
454 e->ifp ? if_name(e->ifp) : "-");
455 skip:
456 mtx_unlock(&e->lock);
457 }
458
459 rc = sbuf_finish(sb);
460 sbuf_delete(sb);
461
462 return (rc);
463 }
464