xref: /freebsd/sys/dev/cxgbe/tom/t4_tom_l2t.c (revision 193d9e768ba63fcfb187cfd17f461f7d41345048)
1 /*-
2  * Copyright (c) 2012 Chelsio Communications, Inc.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 #include <sys/cdefs.h>
27 __FBSDID("$FreeBSD$");
28 
29 #include "opt_inet.h"
30 #include "opt_inet6.h"
31 
32 #ifdef TCP_OFFLOAD
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/kernel.h>
36 #include <sys/module.h>
37 #include <sys/bus.h>
38 #include <sys/fnv_hash.h>
39 #include <sys/lock.h>
40 #include <sys/mutex.h>
41 #include <sys/rwlock.h>
42 #include <sys/socket.h>
43 #include <sys/sbuf.h>
44 #include <sys/taskqueue.h>
45 #include <net/if.h>
46 #include <net/if_types.h>
47 #include <net/ethernet.h>
48 #include <net/if_vlan_var.h>
49 #include <net/route.h>
50 #include <netinet/in.h>
51 #include <netinet/toecore.h>
52 
53 #include "common/common.h"
54 #include "common/t4_msg.h"
55 #include "tom/t4_tom_l2t.h"
56 #include "tom/t4_tom.h"
57 
58 #define VLAN_NONE	0xfff
59 
60 static inline void
61 l2t_hold(struct l2t_data *d, struct l2t_entry *e)
62 {
63 
64 	if (atomic_fetchadd_int(&e->refcnt, 1) == 0)  /* 0 -> 1 transition */
65 		atomic_subtract_int(&d->nfree, 1);
66 }
67 
68 static inline u_int
69 l2_hash(struct l2t_data *d, const struct sockaddr *sa, int ifindex)
70 {
71 	u_int hash, half = d->l2t_size / 2, start = 0;
72 	const void *key;
73 	size_t len;
74 
75 	KASSERT(sa->sa_family == AF_INET || sa->sa_family == AF_INET6,
76 	    ("%s: sa %p has unexpected sa_family %d", __func__, sa,
77 	    sa->sa_family));
78 
79 	if (sa->sa_family == AF_INET) {
80 		const struct sockaddr_in *sin = (const void *)sa;
81 
82 		key = &sin->sin_addr;
83 		len = sizeof(sin->sin_addr);
84 	} else {
85 		const struct sockaddr_in6 *sin6 = (const void *)sa;
86 
87 		key = &sin6->sin6_addr;
88 		len = sizeof(sin6->sin6_addr);
89 		start = half;
90 	}
91 
92 	hash = fnv_32_buf(key, len, FNV1_32_INIT);
93 	hash = fnv_32_buf(&ifindex, sizeof(ifindex), hash);
94 	hash %= half;
95 
96 	return (hash + start);
97 }
98 
99 static inline int
100 l2_cmp(const struct sockaddr *sa, struct l2t_entry *e)
101 {
102 
103 	KASSERT(sa->sa_family == AF_INET || sa->sa_family == AF_INET6,
104 	    ("%s: sa %p has unexpected sa_family %d", __func__, sa,
105 	    sa->sa_family));
106 
107 	if (sa->sa_family == AF_INET) {
108 		const struct sockaddr_in *sin = (const void *)sa;
109 
110 		return (e->addr[0] != sin->sin_addr.s_addr);
111 	} else {
112 		const struct sockaddr_in6 *sin6 = (const void *)sa;
113 
114 		return (memcmp(&e->addr[0], &sin6->sin6_addr, sizeof(e->addr)));
115 	}
116 }
117 
118 static inline void
119 l2_store(const struct sockaddr *sa, struct l2t_entry *e)
120 {
121 
122 	KASSERT(sa->sa_family == AF_INET || sa->sa_family == AF_INET6,
123 	    ("%s: sa %p has unexpected sa_family %d", __func__, sa,
124 	    sa->sa_family));
125 
126 	if (sa->sa_family == AF_INET) {
127 		const struct sockaddr_in *sin = (const void *)sa;
128 
129 		e->addr[0] = sin->sin_addr.s_addr;
130 		e->ipv6 = 0;
131 	} else {
132 		const struct sockaddr_in6 *sin6 = (const void *)sa;
133 
134 		memcpy(&e->addr[0], &sin6->sin6_addr, sizeof(e->addr));
135 		e->ipv6 = 1;
136 	}
137 }
138 
139 /*
140  * Add a WR to an L2T entry's queue of work requests awaiting resolution.
141  * Must be called with the entry's lock held.
142  */
143 static inline void
144 arpq_enqueue(struct l2t_entry *e, struct wrqe *wr)
145 {
146 	mtx_assert(&e->lock, MA_OWNED);
147 
148 	STAILQ_INSERT_TAIL(&e->wr_list, wr, link);
149 }
150 
151 static inline void
152 send_pending(struct adapter *sc, struct l2t_entry *e)
153 {
154 	struct wrqe *wr;
155 
156 	mtx_assert(&e->lock, MA_OWNED);
157 
158 	while ((wr = STAILQ_FIRST(&e->wr_list)) != NULL) {
159 		STAILQ_REMOVE_HEAD(&e->wr_list, link);
160 		t4_wrq_tx(sc, wr);
161 	}
162 }
163 
164 static void
165 resolution_failed(struct adapter *sc, struct l2t_entry *e)
166 {
167 	struct tom_data *td = sc->tom_softc;
168 
169 	mtx_assert(&e->lock, MA_OWNED);
170 
171 	mtx_lock(&td->unsent_wr_lock);
172 	STAILQ_CONCAT(&td->unsent_wr_list, &e->wr_list);
173 	mtx_unlock(&td->unsent_wr_lock);
174 
175 	taskqueue_enqueue(taskqueue_thread, &td->reclaim_wr_resources);
176 }
177 
178 static void
179 update_entry(struct adapter *sc, struct l2t_entry *e, uint8_t *lladdr,
180     uint16_t vtag)
181 {
182 
183 	mtx_assert(&e->lock, MA_OWNED);
184 
185 	/*
186 	 * The entry may be in active use (e->refcount > 0) or not.  We update
187 	 * it even when it's not as this simplifies the case where we decide to
188 	 * reuse the entry later.
189 	 */
190 
191 	if (lladdr == NULL &&
192 	    (e->state == L2T_STATE_RESOLVING || e->state == L2T_STATE_FAILED)) {
193 		/*
194 		 * Never got a valid L2 address for this one.  Just mark it as
195 		 * failed instead of removing it from the hash (for which we'd
196 		 * need to wlock the table).
197 		 */
198 		e->state = L2T_STATE_FAILED;
199 		resolution_failed(sc, e);
200 		return;
201 
202 	} else if (lladdr == NULL) {
203 
204 		/* Valid or already-stale entry was deleted (or expired) */
205 
206 		KASSERT(e->state == L2T_STATE_VALID ||
207 		    e->state == L2T_STATE_STALE,
208 		    ("%s: lladdr NULL, state %d", __func__, e->state));
209 
210 		e->state = L2T_STATE_STALE;
211 
212 	} else {
213 
214 		if (e->state == L2T_STATE_RESOLVING ||
215 		    e->state == L2T_STATE_FAILED ||
216 		    memcmp(e->dmac, lladdr, ETHER_ADDR_LEN)) {
217 
218 			/* unresolved -> resolved; or dmac changed */
219 
220 			memcpy(e->dmac, lladdr, ETHER_ADDR_LEN);
221 			e->vlan = vtag;
222 			t4_write_l2e(e, 1);
223 		}
224 		e->state = L2T_STATE_VALID;
225 	}
226 }
227 
228 static int
229 resolve_entry(struct adapter *sc, struct l2t_entry *e)
230 {
231 	struct tom_data *td = sc->tom_softc;
232 	struct toedev *tod = &td->tod;
233 	struct sockaddr_in sin = {0};
234 	struct sockaddr_in6 sin6 = {0};
235 	struct sockaddr *sa;
236 	uint8_t dmac[ETHER_HDR_LEN];
237 	uint16_t vtag = VLAN_NONE;
238 	int rc;
239 
240 	if (e->ipv6 == 0) {
241 		sin.sin_family = AF_INET;
242 		sin.sin_len = sizeof(struct sockaddr_in);
243 		sin.sin_addr.s_addr = e->addr[0];
244 		sa = (void *)&sin;
245 	} else {
246 		sin6.sin6_family = AF_INET6;
247 		sin6.sin6_len = sizeof(struct sockaddr_in6);
248 		memcpy(&sin6.sin6_addr, &e->addr[0], sizeof(e->addr));
249 		sa = (void *)&sin6;
250 	}
251 
252 	rc = toe_l2_resolve(tod, e->ifp, sa, dmac, &vtag);
253 	if (rc == EWOULDBLOCK)
254 		return (rc);
255 
256 	mtx_lock(&e->lock);
257 	update_entry(sc, e, rc == 0 ? dmac : NULL, vtag);
258 	mtx_unlock(&e->lock);
259 
260 	return (rc);
261 }
262 
263 int
264 t4_l2t_send_slow(struct adapter *sc, struct wrqe *wr, struct l2t_entry *e)
265 {
266 
267 again:
268 	switch (e->state) {
269 	case L2T_STATE_STALE:     /* entry is stale, kick off revalidation */
270 
271 		if (resolve_entry(sc, e) != EWOULDBLOCK)
272 			goto again;	/* entry updated, re-examine state */
273 
274 		/* Fall through */
275 
276 	case L2T_STATE_VALID:     /* fast-path, send the packet on */
277 
278 		t4_wrq_tx(sc, wr);
279 		return (0);
280 
281 	case L2T_STATE_RESOLVING:
282 	case L2T_STATE_SYNC_WRITE:
283 
284 		mtx_lock(&e->lock);
285 		if (e->state != L2T_STATE_SYNC_WRITE &&
286 		    e->state != L2T_STATE_RESOLVING) {
287 			/* state changed by the time we got here */
288 			mtx_unlock(&e->lock);
289 			goto again;
290 		}
291 		arpq_enqueue(e, wr);
292 		mtx_unlock(&e->lock);
293 
294 		if (resolve_entry(sc, e) == EWOULDBLOCK)
295 			break;
296 
297 		mtx_lock(&e->lock);
298 		if (e->state == L2T_STATE_VALID && !STAILQ_EMPTY(&e->wr_list))
299 			send_pending(sc, e);
300 		if (e->state == L2T_STATE_FAILED)
301 			resolution_failed(sc, e);
302 		mtx_unlock(&e->lock);
303 		break;
304 
305 	case L2T_STATE_FAILED:
306 		return (EHOSTUNREACH);
307 	}
308 
309 	return (0);
310 }
311 
312 int
313 do_l2t_write_rpl2(struct sge_iq *iq, const struct rss_header *rss,
314     struct mbuf *m)
315 {
316 	struct adapter *sc = iq->adapter;
317 	const struct cpl_l2t_write_rpl *rpl = (const void *)(rss + 1);
318 	unsigned int tid = GET_TID(rpl);
319 	unsigned int idx = tid % L2T_SIZE;
320 
321 	if (__predict_false(rpl->status != CPL_ERR_NONE)) {
322 		log(LOG_ERR,
323 		    "Unexpected L2T_WRITE_RPL (%u) for entry at hw_idx %u\n",
324 		    rpl->status, idx);
325 		return (EINVAL);
326 	}
327 
328 	if (tid & F_SYNC_WR) {
329 		struct l2t_entry *e = &sc->l2t->l2tab[idx - sc->vres.l2t.start];
330 
331 		mtx_lock(&e->lock);
332 		if (e->state != L2T_STATE_SWITCHING) {
333 			send_pending(sc, e);
334 			e->state = L2T_STATE_VALID;
335 		}
336 		mtx_unlock(&e->lock);
337 	}
338 
339 	return (0);
340 }
341 
342 /*
343  * The TOE wants an L2 table entry that it can use to reach the next hop over
344  * the specified port.  Produce such an entry - create one if needed.
345  *
346  * Note that the ifnet could be a pseudo-device like if_vlan, if_lagg, etc. on
347  * top of the real cxgbe interface.
348  */
349 struct l2t_entry *
350 t4_l2t_get(struct port_info *pi, struct ifnet *ifp, struct sockaddr *sa)
351 {
352 	struct l2t_entry *e;
353 	struct adapter *sc = pi->adapter;
354 	struct l2t_data *d = sc->l2t;
355 	u_int hash, smt_idx = pi->port_id;
356 
357 	KASSERT(sa->sa_family == AF_INET || sa->sa_family == AF_INET6,
358 	    ("%s: sa %p has unexpected sa_family %d", __func__, sa,
359 	    sa->sa_family));
360 
361 #ifndef VLAN_TAG
362 	if (ifp->if_type == IFT_L2VLAN)
363 		return (NULL);
364 #endif
365 
366 	hash = l2_hash(d, sa, ifp->if_index);
367 	rw_wlock(&d->lock);
368 	for (e = d->l2tab[hash].first; e; e = e->next) {
369 		if (l2_cmp(sa, e) == 0 && e->ifp == ifp &&
370 		    e->smt_idx == smt_idx) {
371 			l2t_hold(d, e);
372 			goto done;
373 		}
374 	}
375 
376 	/* Need to allocate a new entry */
377 	e = t4_alloc_l2e(d);
378 	if (e) {
379 		mtx_lock(&e->lock);          /* avoid race with t4_l2t_free */
380 		e->next = d->l2tab[hash].first;
381 		d->l2tab[hash].first = e;
382 
383 		e->state = L2T_STATE_RESOLVING;
384 		l2_store(sa, e);
385 		e->ifp = ifp;
386 		e->smt_idx = smt_idx;
387 		e->hash = hash;
388 		e->lport = pi->lport;
389 		e->wrq = &sc->sge.ctrlq[pi->port_id];
390 		e->iqid = sc->sge.ofld_rxq[pi->vi[0].first_ofld_rxq].iq.abs_id;
391 		atomic_store_rel_int(&e->refcnt, 1);
392 #ifdef VLAN_TAG
393 		if (ifp->if_type == IFT_L2VLAN)
394 			VLAN_TAG(ifp, &e->vlan);
395 		else
396 			e->vlan = VLAN_NONE;
397 #endif
398 		mtx_unlock(&e->lock);
399 	}
400 done:
401 	rw_wunlock(&d->lock);
402 	return e;
403 }
404 
405 /*
406  * Called when the host's ARP layer makes a change to some entry that is loaded
407  * into the HW L2 table.
408  */
409 void
410 t4_l2_update(struct toedev *tod, struct ifnet *ifp, struct sockaddr *sa,
411     uint8_t *lladdr, uint16_t vtag)
412 {
413 	struct adapter *sc = tod->tod_softc;
414 	struct l2t_entry *e;
415 	struct l2t_data *d = sc->l2t;
416 	u_int hash;
417 
418 	KASSERT(d != NULL, ("%s: no L2 table", __func__));
419 
420 	hash = l2_hash(d, sa, ifp->if_index);
421 	rw_rlock(&d->lock);
422 	for (e = d->l2tab[hash].first; e; e = e->next) {
423 		if (l2_cmp(sa, e) == 0 && e->ifp == ifp) {
424 			mtx_lock(&e->lock);
425 			if (atomic_load_acq_int(&e->refcnt))
426 				goto found;
427 			e->state = L2T_STATE_STALE;
428 			mtx_unlock(&e->lock);
429 			break;
430 		}
431 	}
432 	rw_runlock(&d->lock);
433 
434 	/*
435 	 * This is of no interest to us.  We've never had an offloaded
436 	 * connection to this destination, and we aren't attempting one right
437 	 * now.
438 	 */
439 	return;
440 
441 found:
442 	rw_runlock(&d->lock);
443 
444 	KASSERT(e->state != L2T_STATE_UNUSED,
445 	    ("%s: unused entry in the hash.", __func__));
446 
447 	update_entry(sc, e, lladdr, vtag);
448 	mtx_unlock(&e->lock);
449 }
450 #endif
451