xref: /freebsd/sys/dev/cxgbe/tom/t4_tom_l2t.c (revision 8ddb146abcdf061be9f2c0db7e391697dafad85c)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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 __FBSDID("$FreeBSD$");
30 
31 #include "opt_inet.h"
32 #include "opt_inet6.h"
33 
34 #ifdef TCP_OFFLOAD
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/kernel.h>
38 #include <sys/module.h>
39 #include <sys/bus.h>
40 #include <sys/fnv_hash.h>
41 #include <sys/lock.h>
42 #include <sys/mutex.h>
43 #include <sys/rwlock.h>
44 #include <sys/socket.h>
45 #include <sys/sbuf.h>
46 #include <sys/taskqueue.h>
47 #include <net/if.h>
48 #include <net/if_types.h>
49 #include <net/ethernet.h>
50 #include <net/if_vlan_var.h>
51 #include <net/route.h>
52 #include <netinet/in.h>
53 #include <netinet/toecore.h>
54 
55 #include "common/common.h"
56 #include "common/t4_msg.h"
57 #include "tom/t4_tom_l2t.h"
58 #include "tom/t4_tom.h"
59 
60 #define VLAN_NONE	0xfff
61 
62 static inline void
63 l2t_hold(struct l2t_data *d, struct l2t_entry *e)
64 {
65 
66 	if (atomic_fetchadd_int(&e->refcnt, 1) == 0)  /* 0 -> 1 transition */
67 		atomic_subtract_int(&d->nfree, 1);
68 }
69 
70 static inline u_int
71 l2_hash(struct l2t_data *d, const struct sockaddr *sa, int ifindex)
72 {
73 	u_int hash, half = d->l2t_size / 2, start = 0;
74 	const void *key;
75 	size_t len;
76 
77 	KASSERT(sa->sa_family == AF_INET || sa->sa_family == AF_INET6,
78 	    ("%s: sa %p has unexpected sa_family %d", __func__, sa,
79 	    sa->sa_family));
80 
81 	if (sa->sa_family == AF_INET) {
82 		const struct sockaddr_in *sin = (const void *)sa;
83 
84 		key = &sin->sin_addr;
85 		len = sizeof(sin->sin_addr);
86 	} else {
87 		const struct sockaddr_in6 *sin6 = (const void *)sa;
88 
89 		key = &sin6->sin6_addr;
90 		len = sizeof(sin6->sin6_addr);
91 		start = half;
92 	}
93 
94 	hash = fnv_32_buf(key, len, FNV1_32_INIT);
95 	hash = fnv_32_buf(&ifindex, sizeof(ifindex), hash);
96 	hash %= half;
97 
98 	return (hash + start);
99 }
100 
101 static inline int
102 l2_cmp(const struct sockaddr *sa, struct l2t_entry *e)
103 {
104 
105 	KASSERT(sa->sa_family == AF_INET || sa->sa_family == AF_INET6,
106 	    ("%s: sa %p has unexpected sa_family %d", __func__, sa,
107 	    sa->sa_family));
108 
109 	if (sa->sa_family == AF_INET) {
110 		const struct sockaddr_in *sin = (const void *)sa;
111 
112 		return (e->addr[0] != sin->sin_addr.s_addr);
113 	} else {
114 		const struct sockaddr_in6 *sin6 = (const void *)sa;
115 
116 		return (memcmp(&e->addr[0], &sin6->sin6_addr, sizeof(e->addr)));
117 	}
118 }
119 
120 static inline void
121 l2_store(const struct sockaddr *sa, struct l2t_entry *e)
122 {
123 
124 	KASSERT(sa->sa_family == AF_INET || sa->sa_family == AF_INET6,
125 	    ("%s: sa %p has unexpected sa_family %d", __func__, sa,
126 	    sa->sa_family));
127 
128 	if (sa->sa_family == AF_INET) {
129 		const struct sockaddr_in *sin = (const void *)sa;
130 
131 		e->addr[0] = sin->sin_addr.s_addr;
132 		e->ipv6 = 0;
133 	} else {
134 		const struct sockaddr_in6 *sin6 = (const void *)sa;
135 
136 		memcpy(&e->addr[0], &sin6->sin6_addr, sizeof(e->addr));
137 		e->ipv6 = 1;
138 	}
139 }
140 
141 /*
142  * Add a WR to an L2T entry's queue of work requests awaiting resolution.
143  * Must be called with the entry's lock held.
144  */
145 static inline void
146 arpq_enqueue(struct l2t_entry *e, struct wrqe *wr)
147 {
148 	mtx_assert(&e->lock, MA_OWNED);
149 
150 	STAILQ_INSERT_TAIL(&e->wr_list, wr, link);
151 }
152 
153 static inline void
154 send_pending(struct adapter *sc, struct l2t_entry *e)
155 {
156 	struct wrqe *wr;
157 
158 	mtx_assert(&e->lock, MA_OWNED);
159 
160 	while ((wr = STAILQ_FIRST(&e->wr_list)) != NULL) {
161 		STAILQ_REMOVE_HEAD(&e->wr_list, link);
162 		t4_wrq_tx(sc, wr);
163 	}
164 }
165 
166 static void
167 resolution_failed(struct adapter *sc, struct l2t_entry *e)
168 {
169 	struct tom_data *td = sc->tom_softc;
170 
171 	mtx_assert(&e->lock, MA_OWNED);
172 
173 	mtx_lock(&td->unsent_wr_lock);
174 	STAILQ_CONCAT(&td->unsent_wr_list, &e->wr_list);
175 	mtx_unlock(&td->unsent_wr_lock);
176 
177 	taskqueue_enqueue(taskqueue_thread, &td->reclaim_wr_resources);
178 }
179 
180 static void
181 update_entry(struct adapter *sc, struct l2t_entry *e, uint8_t *lladdr,
182     uint16_t vtag)
183 {
184 
185 	mtx_assert(&e->lock, MA_OWNED);
186 
187 	/*
188 	 * The entry may be in active use (e->refcount > 0) or not.  We update
189 	 * it even when it's not as this simplifies the case where we decide to
190 	 * reuse the entry later.
191 	 */
192 
193 	if (lladdr == NULL &&
194 	    (e->state == L2T_STATE_RESOLVING || e->state == L2T_STATE_FAILED)) {
195 		/*
196 		 * Never got a valid L2 address for this one.  Just mark it as
197 		 * failed instead of removing it from the hash (for which we'd
198 		 * need to wlock the table).
199 		 */
200 		e->state = L2T_STATE_FAILED;
201 		resolution_failed(sc, e);
202 		return;
203 
204 	} else if (lladdr == NULL) {
205 
206 		/* Valid or already-stale entry was deleted (or expired) */
207 
208 		KASSERT(e->state == L2T_STATE_VALID ||
209 		    e->state == L2T_STATE_STALE,
210 		    ("%s: lladdr NULL, state %d", __func__, e->state));
211 
212 		e->state = L2T_STATE_STALE;
213 
214 	} else {
215 
216 		if (e->state == L2T_STATE_RESOLVING ||
217 		    e->state == L2T_STATE_FAILED ||
218 		    memcmp(e->dmac, lladdr, ETHER_ADDR_LEN)) {
219 
220 			/* unresolved -> resolved; or dmac changed */
221 
222 			memcpy(e->dmac, lladdr, ETHER_ADDR_LEN);
223 			e->vlan = vtag;
224 			t4_write_l2e(e, 1);
225 		}
226 		e->state = L2T_STATE_VALID;
227 	}
228 }
229 
230 static int
231 resolve_entry(struct adapter *sc, struct l2t_entry *e)
232 {
233 	struct tom_data *td = sc->tom_softc;
234 	struct toedev *tod = &td->tod;
235 	struct sockaddr_in sin = {0};
236 	struct sockaddr_in6 sin6 = {0};
237 	struct sockaddr *sa;
238 	uint8_t dmac[ETHER_HDR_LEN];
239 	uint16_t vtag;
240 	int rc;
241 
242 	if (e->ipv6 == 0) {
243 		sin.sin_family = AF_INET;
244 		sin.sin_len = sizeof(struct sockaddr_in);
245 		sin.sin_addr.s_addr = e->addr[0];
246 		sa = (void *)&sin;
247 	} else {
248 		sin6.sin6_family = AF_INET6;
249 		sin6.sin6_len = sizeof(struct sockaddr_in6);
250 		memcpy(&sin6.sin6_addr, &e->addr[0], sizeof(e->addr));
251 		sa = (void *)&sin6;
252 	}
253 
254 	vtag = EVL_MAKETAG(VLAN_NONE, 0, 0);
255 	rc = toe_l2_resolve(tod, e->ifp, sa, dmac, &vtag);
256 	if (rc == EWOULDBLOCK)
257 		return (rc);
258 
259 	mtx_lock(&e->lock);
260 	update_entry(sc, e, rc == 0 ? dmac : NULL, vtag);
261 	mtx_unlock(&e->lock);
262 
263 	return (rc);
264 }
265 
266 int
267 t4_l2t_send_slow(struct adapter *sc, struct wrqe *wr, struct l2t_entry *e)
268 {
269 
270 again:
271 	switch (e->state) {
272 	case L2T_STATE_STALE:     /* entry is stale, kick off revalidation */
273 
274 		resolve_entry(sc, e);
275 
276 		/* Fall through */
277 
278 	case L2T_STATE_VALID:     /* fast-path, send the packet on */
279 
280 		t4_wrq_tx(sc, wr);
281 		return (0);
282 
283 	case L2T_STATE_RESOLVING:
284 	case L2T_STATE_SYNC_WRITE:
285 
286 		mtx_lock(&e->lock);
287 		if (e->state != L2T_STATE_SYNC_WRITE &&
288 		    e->state != L2T_STATE_RESOLVING) {
289 			/* state changed by the time we got here */
290 			mtx_unlock(&e->lock);
291 			goto again;
292 		}
293 		arpq_enqueue(e, wr);
294 		mtx_unlock(&e->lock);
295 
296 		if (resolve_entry(sc, e) == EWOULDBLOCK)
297 			break;
298 
299 		mtx_lock(&e->lock);
300 		if (e->state == L2T_STATE_VALID && !STAILQ_EMPTY(&e->wr_list))
301 			send_pending(sc, e);
302 		if (e->state == L2T_STATE_FAILED)
303 			resolution_failed(sc, e);
304 		mtx_unlock(&e->lock);
305 		break;
306 
307 	case L2T_STATE_FAILED:
308 		return (EHOSTUNREACH);
309 	}
310 
311 	return (0);
312 }
313 
314 int
315 do_l2t_write_rpl2(struct sge_iq *iq, const struct rss_header *rss,
316     struct mbuf *m)
317 {
318 	struct adapter *sc = iq->adapter;
319 	const struct cpl_l2t_write_rpl *rpl = (const void *)(rss + 1);
320 	unsigned int tid = GET_TID(rpl);
321 	unsigned int idx = tid % L2T_SIZE;
322 
323 	if (__predict_false(rpl->status != CPL_ERR_NONE)) {
324 		log(LOG_ERR,
325 		    "Unexpected L2T_WRITE_RPL (%u) for entry at hw_idx %u\n",
326 		    rpl->status, idx);
327 		return (EINVAL);
328 	}
329 
330 	if (tid & F_SYNC_WR) {
331 		struct l2t_entry *e = &sc->l2t->l2tab[idx - sc->vres.l2t.start];
332 
333 		mtx_lock(&e->lock);
334 		if (e->state != L2T_STATE_SWITCHING) {
335 			send_pending(sc, e);
336 			e->state = L2T_STATE_VALID;
337 		}
338 		mtx_unlock(&e->lock);
339 	}
340 
341 	return (0);
342 }
343 
344 /*
345  * The TOE wants an L2 table entry that it can use to reach the next hop over
346  * the specified port.  Produce such an entry - create one if needed.
347  *
348  * Note that the ifnet could be a pseudo-device like if_vlan, if_lagg, etc. on
349  * top of the real cxgbe interface.
350  */
351 struct l2t_entry *
352 t4_l2t_get(struct port_info *pi, struct ifnet *ifp, struct sockaddr *sa)
353 {
354 	struct l2t_entry *e;
355 	struct adapter *sc = pi->adapter;
356 	struct l2t_data *d = sc->l2t;
357 	u_int hash, smt_idx = pi->port_id;
358 	uint16_t vid, pcp, vtag;
359 
360 	KASSERT(sa->sa_family == AF_INET || sa->sa_family == AF_INET6,
361 	    ("%s: sa %p has unexpected sa_family %d", __func__, sa,
362 	    sa->sa_family));
363 
364 	vid = VLAN_NONE;
365 	pcp = 0;
366 	if (ifp->if_type == IFT_L2VLAN) {
367 		VLAN_TAG(ifp, &vid);
368 		VLAN_PCP(ifp, &pcp);
369 	} else if (ifp->if_pcp != IFNET_PCP_NONE) {
370 		vid = 0;
371 		pcp = ifp->if_pcp;
372 	}
373 	vtag = EVL_MAKETAG(vid, pcp, 0);
374 
375 	hash = l2_hash(d, sa, ifp->if_index);
376 	rw_wlock(&d->lock);
377 	for (e = d->l2tab[hash].first; e; e = e->next) {
378 		if (l2_cmp(sa, e) == 0 && e->ifp == ifp && e->vlan == vtag &&
379 		    e->smt_idx == smt_idx) {
380 			l2t_hold(d, e);
381 			goto done;
382 		}
383 	}
384 
385 	/* Need to allocate a new entry */
386 	e = t4_alloc_l2e(d);
387 	if (e) {
388 		mtx_lock(&e->lock);          /* avoid race with t4_l2t_free */
389 		e->next = d->l2tab[hash].first;
390 		d->l2tab[hash].first = e;
391 
392 		e->state = L2T_STATE_RESOLVING;
393 		l2_store(sa, e);
394 		e->ifp = ifp;
395 		e->smt_idx = smt_idx;
396 		e->hash = hash;
397 		e->lport = pi->lport;
398 		e->wrq = &sc->sge.ctrlq[pi->port_id];
399 		e->iqid = sc->sge.ofld_rxq[pi->vi[0].first_ofld_rxq].iq.abs_id;
400 		atomic_store_rel_int(&e->refcnt, 1);
401 		e->vlan = vtag;
402 		mtx_unlock(&e->lock);
403 	}
404 done:
405 	rw_wunlock(&d->lock);
406 	return e;
407 }
408 
409 /*
410  * Called when the host's ARP layer makes a change to some entry that is loaded
411  * into the HW L2 table.
412  */
413 void
414 t4_l2_update(struct toedev *tod, struct ifnet *ifp, struct sockaddr *sa,
415     uint8_t *lladdr, uint16_t vtag)
416 {
417 	struct adapter *sc = tod->tod_softc;
418 	struct l2t_entry *e;
419 	struct l2t_data *d = sc->l2t;
420 	u_int hash;
421 
422 	KASSERT(d != NULL, ("%s: no L2 table", __func__));
423 
424 	hash = l2_hash(d, sa, ifp->if_index);
425 	rw_rlock(&d->lock);
426 	for (e = d->l2tab[hash].first; e; e = e->next) {
427 		if (l2_cmp(sa, e) == 0 && e->ifp == ifp) {
428 			mtx_lock(&e->lock);
429 			if (atomic_load_acq_int(&e->refcnt))
430 				goto found;
431 			e->state = L2T_STATE_STALE;
432 			mtx_unlock(&e->lock);
433 			break;
434 		}
435 	}
436 	rw_runlock(&d->lock);
437 
438 	/*
439 	 * This is of no interest to us.  We've never had an offloaded
440 	 * connection to this destination, and we aren't attempting one right
441 	 * now.
442 	 */
443 	return;
444 
445 found:
446 	rw_runlock(&d->lock);
447 
448 	KASSERT(e->state != L2T_STATE_UNUSED,
449 	    ("%s: unused entry in the hash.", __func__));
450 
451 	update_entry(sc, e, lladdr, vtag);
452 	mtx_unlock(&e->lock);
453 }
454 #endif
455