blob: a2d323c473f8bd5789e75b0a6ae504115347e065 [file] [log] [blame]
Dimitris Michailidis625ba2c2010-04-01 15:28:25 +00001/*
2 * This file is part of the Chelsio T4 Ethernet driver for Linux.
3 *
4 * Copyright (c) 2003-2010 Chelsio Communications, Inc. All rights reserved.
5 *
6 * This software is available to you under a choice of one of two
7 * licenses. You may choose to be licensed under the terms of the GNU
8 * General Public License (GPL) Version 2, available from the file
9 * COPYING in the main directory of this source tree, or the
10 * OpenIB.org BSD license below:
11 *
12 * Redistribution and use in source and binary forms, with or
13 * without modification, are permitted provided that the following
14 * conditions are met:
15 *
16 * - Redistributions of source code must retain the above
17 * copyright notice, this list of conditions and the following
18 * disclaimer.
19 *
20 * - Redistributions in binary form must reproduce the above
21 * copyright notice, this list of conditions and the following
22 * disclaimer in the documentation and/or other materials
23 * provided with the distribution.
24 *
25 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
26 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
27 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
28 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
29 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
30 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
31 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
32 * SOFTWARE.
33 */
34
35#include <linux/skbuff.h>
36#include <linux/netdevice.h>
37#include <linux/if.h>
38#include <linux/if_vlan.h>
39#include <linux/jhash.h>
40#include <net/neighbour.h>
41#include "cxgb4.h"
42#include "l2t.h"
43#include "t4_msg.h"
44#include "t4fw_api.h"
45
46#define VLAN_NONE 0xfff
47
48/* identifies sync vs async L2T_WRITE_REQs */
49#define F_SYNC_WR (1 << 12)
50
51enum {
52 L2T_STATE_VALID, /* entry is up to date */
53 L2T_STATE_STALE, /* entry may be used but needs revalidation */
54 L2T_STATE_RESOLVING, /* entry needs address resolution */
55 L2T_STATE_SYNC_WRITE, /* synchronous write of entry underway */
56
57 /* when state is one of the below the entry is not hashed */
58 L2T_STATE_SWITCHING, /* entry is being used by a switching filter */
59 L2T_STATE_UNUSED /* entry not in use */
60};
61
62struct l2t_data {
63 rwlock_t lock;
64 atomic_t nfree; /* number of free entries */
65 struct l2t_entry *rover; /* starting point for next allocation */
66 struct l2t_entry l2tab[L2T_SIZE];
67};
68
69static inline unsigned int vlan_prio(const struct l2t_entry *e)
70{
71 return e->vlan >> 13;
72}
73
74static inline void l2t_hold(struct l2t_data *d, struct l2t_entry *e)
75{
76 if (atomic_add_return(1, &e->refcnt) == 1) /* 0 -> 1 transition */
77 atomic_dec(&d->nfree);
78}
79
80/*
81 * To avoid having to check address families we do not allow v4 and v6
82 * neighbors to be on the same hash chain. We keep v4 entries in the first
83 * half of available hash buckets and v6 in the second.
84 */
85enum {
86 L2T_SZ_HALF = L2T_SIZE / 2,
87 L2T_HASH_MASK = L2T_SZ_HALF - 1
88};
89
90static inline unsigned int arp_hash(const u32 *key, int ifindex)
91{
92 return jhash_2words(*key, ifindex, 0) & L2T_HASH_MASK;
93}
94
95static inline unsigned int ipv6_hash(const u32 *key, int ifindex)
96{
97 u32 xor = key[0] ^ key[1] ^ key[2] ^ key[3];
98
99 return L2T_SZ_HALF + (jhash_2words(xor, ifindex, 0) & L2T_HASH_MASK);
100}
101
102static unsigned int addr_hash(const u32 *addr, int addr_len, int ifindex)
103{
104 return addr_len == 4 ? arp_hash(addr, ifindex) :
105 ipv6_hash(addr, ifindex);
106}
107
108/*
109 * Checks if an L2T entry is for the given IP/IPv6 address. It does not check
110 * whether the L2T entry and the address are of the same address family.
111 * Callers ensure an address is only checked against L2T entries of the same
112 * family, something made trivial by the separation of IP and IPv6 hash chains
113 * mentioned above. Returns 0 if there's a match,
114 */
115static int addreq(const struct l2t_entry *e, const u32 *addr)
116{
117 if (e->v6)
118 return (e->addr[0] ^ addr[0]) | (e->addr[1] ^ addr[1]) |
119 (e->addr[2] ^ addr[2]) | (e->addr[3] ^ addr[3]);
120 return e->addr[0] ^ addr[0];
121}
122
123static void neigh_replace(struct l2t_entry *e, struct neighbour *n)
124{
125 neigh_hold(n);
126 if (e->neigh)
127 neigh_release(e->neigh);
128 e->neigh = n;
129}
130
131/*
132 * Write an L2T entry. Must be called with the entry locked.
133 * The write may be synchronous or asynchronous.
134 */
135static int write_l2e(struct adapter *adap, struct l2t_entry *e, int sync)
136{
137 struct sk_buff *skb;
138 struct cpl_l2t_write_req *req;
139
140 skb = alloc_skb(sizeof(*req), GFP_ATOMIC);
141 if (!skb)
142 return -ENOMEM;
143
144 req = (struct cpl_l2t_write_req *)__skb_put(skb, sizeof(*req));
145 INIT_TP_WR(req, 0);
146
147 OPCODE_TID(req) = htonl(MK_OPCODE_TID(CPL_L2T_WRITE_REQ,
148 e->idx | (sync ? F_SYNC_WR : 0) |
149 TID_QID(adap->sge.fw_evtq.abs_id)));
150 req->params = htons(L2T_W_PORT(e->lport) | L2T_W_NOREPLY(!sync));
151 req->l2t_idx = htons(e->idx);
152 req->vlan = htons(e->vlan);
153 if (e->neigh)
154 memcpy(e->dmac, e->neigh->ha, sizeof(e->dmac));
155 memcpy(req->dst_mac, e->dmac, sizeof(req->dst_mac));
156
157 set_wr_txq(skb, CPL_PRIORITY_CONTROL, 0);
158 t4_ofld_send(adap, skb);
159
160 if (sync && e->state != L2T_STATE_SWITCHING)
161 e->state = L2T_STATE_SYNC_WRITE;
162 return 0;
163}
164
165/*
166 * Send packets waiting in an L2T entry's ARP queue. Must be called with the
167 * entry locked.
168 */
169static void send_pending(struct adapter *adap, struct l2t_entry *e)
170{
171 while (e->arpq_head) {
172 struct sk_buff *skb = e->arpq_head;
173
174 e->arpq_head = skb->next;
175 skb->next = NULL;
176 t4_ofld_send(adap, skb);
177 }
178 e->arpq_tail = NULL;
179}
180
181/*
182 * Process a CPL_L2T_WRITE_RPL. Wake up the ARP queue if it completes a
183 * synchronous L2T_WRITE. Note that the TID in the reply is really the L2T
184 * index it refers to.
185 */
186void do_l2t_write_rpl(struct adapter *adap, const struct cpl_l2t_write_rpl *rpl)
187{
188 unsigned int tid = GET_TID(rpl);
189 unsigned int idx = tid & (L2T_SIZE - 1);
190
191 if (unlikely(rpl->status != CPL_ERR_NONE)) {
192 dev_err(adap->pdev_dev,
193 "Unexpected L2T_WRITE_RPL status %u for entry %u\n",
194 rpl->status, idx);
195 return;
196 }
197
198 if (tid & F_SYNC_WR) {
199 struct l2t_entry *e = &adap->l2t->l2tab[idx];
200
201 spin_lock(&e->lock);
202 if (e->state != L2T_STATE_SWITCHING) {
203 send_pending(adap, e);
204 e->state = (e->neigh->nud_state & NUD_STALE) ?
205 L2T_STATE_STALE : L2T_STATE_VALID;
206 }
207 spin_unlock(&e->lock);
208 }
209}
210
211/*
212 * Add a packet to an L2T entry's queue of packets awaiting resolution.
213 * Must be called with the entry's lock held.
214 */
215static inline void arpq_enqueue(struct l2t_entry *e, struct sk_buff *skb)
216{
217 skb->next = NULL;
218 if (e->arpq_head)
219 e->arpq_tail->next = skb;
220 else
221 e->arpq_head = skb;
222 e->arpq_tail = skb;
223}
224
225int cxgb4_l2t_send(struct net_device *dev, struct sk_buff *skb,
226 struct l2t_entry *e)
227{
228 struct adapter *adap = netdev2adap(dev);
229
230again:
231 switch (e->state) {
232 case L2T_STATE_STALE: /* entry is stale, kick off revalidation */
233 neigh_event_send(e->neigh, NULL);
234 spin_lock_bh(&e->lock);
235 if (e->state == L2T_STATE_STALE)
236 e->state = L2T_STATE_VALID;
237 spin_unlock_bh(&e->lock);
238 case L2T_STATE_VALID: /* fast-path, send the packet on */
239 return t4_ofld_send(adap, skb);
240 case L2T_STATE_RESOLVING:
241 case L2T_STATE_SYNC_WRITE:
242 spin_lock_bh(&e->lock);
243 if (e->state != L2T_STATE_SYNC_WRITE &&
244 e->state != L2T_STATE_RESOLVING) {
245 spin_unlock_bh(&e->lock);
246 goto again;
247 }
248 arpq_enqueue(e, skb);
249 spin_unlock_bh(&e->lock);
250
251 if (e->state == L2T_STATE_RESOLVING &&
252 !neigh_event_send(e->neigh, NULL)) {
253 spin_lock_bh(&e->lock);
254 if (e->state == L2T_STATE_RESOLVING && e->arpq_head)
255 write_l2e(adap, e, 1);
256 spin_unlock_bh(&e->lock);
257 }
258 }
259 return 0;
260}
261EXPORT_SYMBOL(cxgb4_l2t_send);
262
263/*
264 * Allocate a free L2T entry. Must be called with l2t_data.lock held.
265 */
266static struct l2t_entry *alloc_l2e(struct l2t_data *d)
267{
268 struct l2t_entry *end, *e, **p;
269
270 if (!atomic_read(&d->nfree))
271 return NULL;
272
273 /* there's definitely a free entry */
274 for (e = d->rover, end = &d->l2tab[L2T_SIZE]; e != end; ++e)
275 if (atomic_read(&e->refcnt) == 0)
276 goto found;
277
278 for (e = d->l2tab; atomic_read(&e->refcnt); ++e)
279 ;
280found:
281 d->rover = e + 1;
282 atomic_dec(&d->nfree);
283
284 /*
285 * The entry we found may be an inactive entry that is
286 * presently in the hash table. We need to remove it.
287 */
288 if (e->state < L2T_STATE_SWITCHING)
289 for (p = &d->l2tab[e->hash].first; *p; p = &(*p)->next)
290 if (*p == e) {
291 *p = e->next;
292 e->next = NULL;
293 break;
294 }
295
296 e->state = L2T_STATE_UNUSED;
297 return e;
298}
299
300/*
301 * Called when an L2T entry has no more users.
302 */
303static void t4_l2e_free(struct l2t_entry *e)
304{
305 struct l2t_data *d;
306
307 spin_lock_bh(&e->lock);
308 if (atomic_read(&e->refcnt) == 0) { /* hasn't been recycled */
309 if (e->neigh) {
310 neigh_release(e->neigh);
311 e->neigh = NULL;
312 }
Dimitris Michailidis204dc3c2010-06-18 10:05:29 +0000313 while (e->arpq_head) {
314 struct sk_buff *skb = e->arpq_head;
315
316 e->arpq_head = skb->next;
Denis Kirjanov05eda042010-06-30 23:45:52 +0000317 kfree_skb(skb);
Dimitris Michailidis204dc3c2010-06-18 10:05:29 +0000318 }
319 e->arpq_tail = NULL;
Dimitris Michailidis625ba2c2010-04-01 15:28:25 +0000320 }
321 spin_unlock_bh(&e->lock);
322
323 d = container_of(e, struct l2t_data, l2tab[e->idx]);
324 atomic_inc(&d->nfree);
325}
326
327void cxgb4_l2t_release(struct l2t_entry *e)
328{
329 if (atomic_dec_and_test(&e->refcnt))
330 t4_l2e_free(e);
331}
332EXPORT_SYMBOL(cxgb4_l2t_release);
333
334/*
335 * Update an L2T entry that was previously used for the same next hop as neigh.
336 * Must be called with softirqs disabled.
337 */
338static void reuse_entry(struct l2t_entry *e, struct neighbour *neigh)
339{
340 unsigned int nud_state;
341
342 spin_lock(&e->lock); /* avoid race with t4_l2t_free */
343 if (neigh != e->neigh)
344 neigh_replace(e, neigh);
345 nud_state = neigh->nud_state;
346 if (memcmp(e->dmac, neigh->ha, sizeof(e->dmac)) ||
347 !(nud_state & NUD_VALID))
348 e->state = L2T_STATE_RESOLVING;
349 else if (nud_state & NUD_CONNECTED)
350 e->state = L2T_STATE_VALID;
351 else
352 e->state = L2T_STATE_STALE;
353 spin_unlock(&e->lock);
354}
355
356struct l2t_entry *cxgb4_l2t_get(struct l2t_data *d, struct neighbour *neigh,
357 const struct net_device *physdev,
358 unsigned int priority)
359{
360 u8 lport;
361 u16 vlan;
362 struct l2t_entry *e;
363 int addr_len = neigh->tbl->key_len;
364 u32 *addr = (u32 *)neigh->primary_key;
365 int ifidx = neigh->dev->ifindex;
366 int hash = addr_hash(addr, addr_len, ifidx);
367
368 if (neigh->dev->flags & IFF_LOOPBACK)
369 lport = netdev2pinfo(physdev)->tx_chan + 4;
370 else
371 lport = netdev2pinfo(physdev)->lport;
372
373 if (neigh->dev->priv_flags & IFF_802_1Q_VLAN)
374 vlan = vlan_dev_vlan_id(neigh->dev);
375 else
376 vlan = VLAN_NONE;
377
378 write_lock_bh(&d->lock);
379 for (e = d->l2tab[hash].first; e; e = e->next)
380 if (!addreq(e, addr) && e->ifindex == ifidx &&
381 e->vlan == vlan && e->lport == lport) {
382 l2t_hold(d, e);
383 if (atomic_read(&e->refcnt) == 1)
384 reuse_entry(e, neigh);
385 goto done;
386 }
387
388 /* Need to allocate a new entry */
389 e = alloc_l2e(d);
390 if (e) {
391 spin_lock(&e->lock); /* avoid race with t4_l2t_free */
392 e->state = L2T_STATE_RESOLVING;
393 memcpy(e->addr, addr, addr_len);
394 e->ifindex = ifidx;
395 e->hash = hash;
396 e->lport = lport;
397 e->v6 = addr_len == 16;
398 atomic_set(&e->refcnt, 1);
399 neigh_replace(e, neigh);
400 e->vlan = vlan;
401 e->next = d->l2tab[hash].first;
402 d->l2tab[hash].first = e;
403 spin_unlock(&e->lock);
404 }
405done:
406 write_unlock_bh(&d->lock);
407 return e;
408}
409EXPORT_SYMBOL(cxgb4_l2t_get);
410
411/*
412 * Called when address resolution fails for an L2T entry to handle packets
413 * on the arpq head. If a packet specifies a failure handler it is invoked,
414 * otherwise the packet is sent to the device.
415 */
416static void handle_failed_resolution(struct adapter *adap, struct sk_buff *arpq)
417{
418 while (arpq) {
419 struct sk_buff *skb = arpq;
420 const struct l2t_skb_cb *cb = L2T_SKB_CB(skb);
421
422 arpq = skb->next;
423 skb->next = NULL;
424 if (cb->arp_err_handler)
425 cb->arp_err_handler(cb->handle, skb);
426 else
427 t4_ofld_send(adap, skb);
428 }
429}
430
431/*
432 * Called when the host's neighbor layer makes a change to some entry that is
433 * loaded into the HW L2 table.
434 */
435void t4_l2t_update(struct adapter *adap, struct neighbour *neigh)
436{
437 struct l2t_entry *e;
438 struct sk_buff *arpq = NULL;
439 struct l2t_data *d = adap->l2t;
440 int addr_len = neigh->tbl->key_len;
441 u32 *addr = (u32 *) neigh->primary_key;
442 int ifidx = neigh->dev->ifindex;
443 int hash = addr_hash(addr, addr_len, ifidx);
444
445 read_lock_bh(&d->lock);
446 for (e = d->l2tab[hash].first; e; e = e->next)
447 if (!addreq(e, addr) && e->ifindex == ifidx) {
448 spin_lock(&e->lock);
449 if (atomic_read(&e->refcnt))
450 goto found;
451 spin_unlock(&e->lock);
452 break;
453 }
454 read_unlock_bh(&d->lock);
455 return;
456
457 found:
458 read_unlock(&d->lock);
459
460 if (neigh != e->neigh)
461 neigh_replace(e, neigh);
462
463 if (e->state == L2T_STATE_RESOLVING) {
464 if (neigh->nud_state & NUD_FAILED) {
465 arpq = e->arpq_head;
466 e->arpq_head = e->arpq_tail = NULL;
467 } else if ((neigh->nud_state & (NUD_CONNECTED | NUD_STALE)) &&
468 e->arpq_head) {
469 write_l2e(adap, e, 1);
470 }
471 } else {
472 e->state = neigh->nud_state & NUD_CONNECTED ?
473 L2T_STATE_VALID : L2T_STATE_STALE;
474 if (memcmp(e->dmac, neigh->ha, sizeof(e->dmac)))
475 write_l2e(adap, e, 0);
476 }
477
478 spin_unlock_bh(&e->lock);
479
480 if (arpq)
481 handle_failed_resolution(adap, arpq);
482}
483
Dimitris Michailidis625ba2c2010-04-01 15:28:25 +0000484struct l2t_data *t4_init_l2t(void)
485{
486 int i;
487 struct l2t_data *d;
488
489 d = t4_alloc_mem(sizeof(*d));
490 if (!d)
491 return NULL;
492
493 d->rover = d->l2tab;
494 atomic_set(&d->nfree, L2T_SIZE);
495 rwlock_init(&d->lock);
496
497 for (i = 0; i < L2T_SIZE; ++i) {
498 d->l2tab[i].idx = i;
499 d->l2tab[i].state = L2T_STATE_UNUSED;
500 spin_lock_init(&d->l2tab[i].lock);
501 atomic_set(&d->l2tab[i].refcnt, 0);
502 }
503 return d;
504}
505
506#include <linux/module.h>
507#include <linux/debugfs.h>
508#include <linux/seq_file.h>
509
510static inline void *l2t_get_idx(struct seq_file *seq, loff_t pos)
511{
512 struct l2t_entry *l2tab = seq->private;
513
514 return pos >= L2T_SIZE ? NULL : &l2tab[pos];
515}
516
517static void *l2t_seq_start(struct seq_file *seq, loff_t *pos)
518{
519 return *pos ? l2t_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
520}
521
522static void *l2t_seq_next(struct seq_file *seq, void *v, loff_t *pos)
523{
524 v = l2t_get_idx(seq, *pos);
525 if (v)
526 ++*pos;
527 return v;
528}
529
530static void l2t_seq_stop(struct seq_file *seq, void *v)
531{
532}
533
534static char l2e_state(const struct l2t_entry *e)
535{
536 switch (e->state) {
537 case L2T_STATE_VALID: return 'V';
538 case L2T_STATE_STALE: return 'S';
539 case L2T_STATE_SYNC_WRITE: return 'W';
540 case L2T_STATE_RESOLVING: return e->arpq_head ? 'A' : 'R';
541 case L2T_STATE_SWITCHING: return 'X';
542 default:
543 return 'U';
544 }
545}
546
547static int l2t_seq_show(struct seq_file *seq, void *v)
548{
549 if (v == SEQ_START_TOKEN)
550 seq_puts(seq, " Idx IP address "
551 "Ethernet address VLAN/P LP State Users Port\n");
552 else {
553 char ip[60];
554 struct l2t_entry *e = v;
555
556 spin_lock_bh(&e->lock);
557 if (e->state == L2T_STATE_SWITCHING)
558 ip[0] = '\0';
559 else
560 sprintf(ip, e->v6 ? "%pI6c" : "%pI4", e->addr);
561 seq_printf(seq, "%4u %-25s %17pM %4d %u %2u %c %5u %s\n",
562 e->idx, ip, e->dmac,
563 e->vlan & VLAN_VID_MASK, vlan_prio(e), e->lport,
564 l2e_state(e), atomic_read(&e->refcnt),
565 e->neigh ? e->neigh->dev->name : "");
566 spin_unlock_bh(&e->lock);
567 }
568 return 0;
569}
570
571static const struct seq_operations l2t_seq_ops = {
572 .start = l2t_seq_start,
573 .next = l2t_seq_next,
574 .stop = l2t_seq_stop,
575 .show = l2t_seq_show
576};
577
578static int l2t_seq_open(struct inode *inode, struct file *file)
579{
580 int rc = seq_open(file, &l2t_seq_ops);
581
582 if (!rc) {
583 struct adapter *adap = inode->i_private;
584 struct seq_file *seq = file->private_data;
585
586 seq->private = adap->l2t->l2tab;
587 }
588 return rc;
589}
590
591const struct file_operations t4_l2t_fops = {
592 .owner = THIS_MODULE,
593 .open = l2t_seq_open,
594 .read = seq_read,
595 .llseek = seq_lseek,
596 .release = seq_release,
597};