xref: /freebsd/sys/dev/cxgbe/t4_l2t.c (revision f4b37ed0f8b307b1f3f0f630ca725d68f1dff30d)
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 #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 refereces 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 *
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 /*
110  * Write an L2T entry.  Must be called with the entry locked.
111  * The write may be synchronous or asynchronous.
112  */
113 int
114 t4_write_l2e(struct adapter *sc, struct l2t_entry *e, int sync)
115 {
116 	struct wrq_cookie cookie;
117 	struct cpl_l2t_write_req *req;
118 	int idx = e->idx + sc->vres.l2t.start;
119 
120 	mtx_assert(&e->lock, MA_OWNED);
121 
122 	req = start_wrq_wr(&sc->sge.mgmtq, howmany(sizeof(*req), 16), &cookie);
123 	if (req == NULL)
124 		return (ENOMEM);
125 
126 	INIT_TP_WR(req, 0);
127 	OPCODE_TID(req) = htonl(MK_OPCODE_TID(CPL_L2T_WRITE_REQ, idx |
128 	    V_SYNC_WR(sync) | V_TID_QID(sc->sge.fwq.abs_id)));
129 	req->params = htons(V_L2T_W_PORT(e->lport) | V_L2T_W_NOREPLY(!sync));
130 	req->l2t_idx = htons(idx);
131 	req->vlan = htons(e->vlan);
132 	memcpy(req->dst_mac, e->dmac, sizeof(req->dst_mac));
133 
134 	commit_wrq_wr(&sc->sge.mgmtq, req, &cookie);
135 
136 	if (sync && e->state != L2T_STATE_SWITCHING)
137 		e->state = L2T_STATE_SYNC_WRITE;
138 
139 	return (0);
140 }
141 
142 /*
143  * Allocate an L2T entry for use by a switching rule.  Such need to be
144  * explicitly freed and while busy they are not on any hash chain, so normal
145  * address resolution updates do not see them.
146  */
147 struct l2t_entry *
148 t4_l2t_alloc_switching(struct l2t_data *d)
149 {
150 	struct l2t_entry *e;
151 
152 	rw_wlock(&d->lock);
153 	e = t4_alloc_l2e(d);
154 	if (e) {
155 		mtx_lock(&e->lock);          /* avoid race with t4_l2t_free */
156 		e->state = L2T_STATE_SWITCHING;
157 		atomic_store_rel_int(&e->refcnt, 1);
158 		mtx_unlock(&e->lock);
159 	}
160 	rw_wunlock(&d->lock);
161 	return e;
162 }
163 
164 /*
165  * Sets/updates the contents of a switching L2T entry that has been allocated
166  * with an earlier call to @t4_l2t_alloc_switching.
167  */
168 int
169 t4_l2t_set_switching(struct adapter *sc, struct l2t_entry *e, uint16_t vlan,
170     uint8_t port, uint8_t *eth_addr)
171 {
172 	int rc;
173 
174 	e->vlan = vlan;
175 	e->lport = port;
176 	memcpy(e->dmac, eth_addr, ETHER_ADDR_LEN);
177 	mtx_lock(&e->lock);
178 	rc = t4_write_l2e(sc, e, 0);
179 	mtx_unlock(&e->lock);
180 	return (rc);
181 }
182 
183 int
184 t4_init_l2t(struct adapter *sc, int flags)
185 {
186 	int i, l2t_size;
187 	struct l2t_data *d;
188 
189 	l2t_size = sc->vres.l2t.size;
190 	if (l2t_size < 2)	/* At least 1 bucket for IP and 1 for IPv6 */
191 		return (EINVAL);
192 
193 	d = malloc(sizeof(*d) + l2t_size * sizeof (struct l2t_entry), M_CXGBE,
194 	    M_ZERO | flags);
195 	if (!d)
196 		return (ENOMEM);
197 
198 	d->l2t_size = l2t_size;
199 	d->rover = d->l2tab;
200 	atomic_store_rel_int(&d->nfree, l2t_size);
201 	rw_init(&d->lock, "L2T");
202 
203 	for (i = 0; i < l2t_size; i++) {
204 		struct l2t_entry *e = &d->l2tab[i];
205 
206 		e->idx = i;
207 		e->state = L2T_STATE_UNUSED;
208 		mtx_init(&e->lock, "L2T_E", NULL, MTX_DEF);
209 		STAILQ_INIT(&e->wr_list);
210 		atomic_store_rel_int(&e->refcnt, 0);
211 	}
212 
213 	sc->l2t = d;
214 	t4_register_cpl_handler(sc, CPL_L2T_WRITE_RPL, do_l2t_write_rpl);
215 
216 	return (0);
217 }
218 
219 int
220 t4_free_l2t(struct l2t_data *d)
221 {
222 	int i;
223 
224 	for (i = 0; i < d->l2t_size; i++)
225 		mtx_destroy(&d->l2tab[i].lock);
226 	rw_destroy(&d->lock);
227 	free(d, M_CXGBE);
228 
229 	return (0);
230 }
231 
232 int
233 do_l2t_write_rpl(struct sge_iq *iq, const struct rss_header *rss,
234     struct mbuf *m)
235 {
236 	const struct cpl_l2t_write_rpl *rpl = (const void *)(rss + 1);
237 	unsigned int tid = GET_TID(rpl);
238 	unsigned int idx = tid % L2T_SIZE;
239 
240 	if (__predict_false(rpl->status != CPL_ERR_NONE)) {
241 		log(LOG_ERR,
242 		    "Unexpected L2T_WRITE_RPL (%u) for entry at hw_idx %u\n",
243 		    rpl->status, idx);
244 		return (EINVAL);
245 	}
246 
247 	return (0);
248 }
249 
250 #ifdef SBUF_DRAIN
251 static inline unsigned int
252 vlan_prio(const struct l2t_entry *e)
253 {
254 	return e->vlan >> 13;
255 }
256 
257 static char
258 l2e_state(const struct l2t_entry *e)
259 {
260 	switch (e->state) {
261 	case L2T_STATE_VALID: return 'V';  /* valid, fast-path entry */
262 	case L2T_STATE_STALE: return 'S';  /* needs revalidation, but usable */
263 	case L2T_STATE_SYNC_WRITE: return 'W';
264 	case L2T_STATE_RESOLVING: return STAILQ_EMPTY(&e->wr_list) ? 'R' : 'A';
265 	case L2T_STATE_SWITCHING: return 'X';
266 	default: return 'U';
267 	}
268 }
269 
270 int
271 sysctl_l2t(SYSCTL_HANDLER_ARGS)
272 {
273 	struct adapter *sc = arg1;
274 	struct l2t_data *l2t = sc->l2t;
275 	struct l2t_entry *e;
276 	struct sbuf *sb;
277 	int rc, i, header = 0;
278 	char ip[INET6_ADDRSTRLEN];
279 
280 	if (l2t == NULL)
281 		return (ENXIO);
282 
283 	rc = sysctl_wire_old_buffer(req, 0);
284 	if (rc != 0)
285 		return (rc);
286 
287 	sb = sbuf_new_for_sysctl(NULL, NULL, 4096, req);
288 	if (sb == NULL)
289 		return (ENOMEM);
290 
291 	e = &l2t->l2tab[0];
292 	for (i = 0; i < l2t->l2t_size; i++, e++) {
293 		mtx_lock(&e->lock);
294 		if (e->state == L2T_STATE_UNUSED)
295 			goto skip;
296 
297 		if (header == 0) {
298 			sbuf_printf(sb, " Idx IP address      "
299 			    "Ethernet address  VLAN/P LP State Users Port");
300 			header = 1;
301 		}
302 		if (e->state == L2T_STATE_SWITCHING)
303 			ip[0] = 0;
304 		else {
305 			inet_ntop(e->ipv6 ? AF_INET6 : AF_INET, &e->addr[0],
306 			    &ip[0], sizeof(ip));
307 		}
308 
309 		/*
310 		 * XXX: e->ifp may not be around.
311 		 * XXX: IPv6 addresses may not align properly in the output.
312 		 */
313 		sbuf_printf(sb, "\n%4u %-15s %02x:%02x:%02x:%02x:%02x:%02x %4d"
314 			   " %u %2u   %c   %5u %s",
315 			   e->idx, ip, e->dmac[0], e->dmac[1], e->dmac[2],
316 			   e->dmac[3], e->dmac[4], e->dmac[5],
317 			   e->vlan & 0xfff, vlan_prio(e), e->lport,
318 			   l2e_state(e), atomic_load_acq_int(&e->refcnt),
319 			   e->ifp->if_xname);
320 skip:
321 		mtx_unlock(&e->lock);
322 	}
323 
324 	rc = sbuf_finish(sb);
325 	sbuf_delete(sb);
326 
327 	return (rc);
328 }
329 #endif
330