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-rw-r--r--drivers/net/cxgb3/l2t.c445
1 files changed, 0 insertions, 445 deletions
diff --git a/drivers/net/cxgb3/l2t.c b/drivers/net/cxgb3/l2t.c
deleted file mode 100644
index f452c4003253..000000000000
--- a/drivers/net/cxgb3/l2t.c
+++ /dev/null
@@ -1,445 +0,0 @@
1/*
2 * Copyright (c) 2003-2008 Chelsio, Inc. All rights reserved.
3 *
4 * This software is available to you under a choice of one of two
5 * licenses. You may choose to be licensed under the terms of the GNU
6 * General Public License (GPL) Version 2, available from the file
7 * COPYING in the main directory of this source tree, or the
8 * OpenIB.org BSD license below:
9 *
10 * Redistribution and use in source and binary forms, with or
11 * without modification, are permitted provided that the following
12 * conditions are met:
13 *
14 * - Redistributions of source code must retain the above
15 * copyright notice, this list of conditions and the following
16 * disclaimer.
17 *
18 * - Redistributions in binary form must reproduce the above
19 * copyright notice, this list of conditions and the following
20 * disclaimer in the documentation and/or other materials
21 * provided with the distribution.
22 *
23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30 * SOFTWARE.
31 */
32#include <linux/skbuff.h>
33#include <linux/netdevice.h>
34#include <linux/if.h>
35#include <linux/if_vlan.h>
36#include <linux/jhash.h>
37#include <linux/slab.h>
38#include <net/neighbour.h>
39#include "common.h"
40#include "t3cdev.h"
41#include "cxgb3_defs.h"
42#include "l2t.h"
43#include "t3_cpl.h"
44#include "firmware_exports.h"
45
46#define VLAN_NONE 0xfff
47
48/*
49 * Module locking notes: There is a RW lock protecting the L2 table as a
50 * whole plus a spinlock per L2T entry. Entry lookups and allocations happen
51 * under the protection of the table lock, individual entry changes happen
52 * while holding that entry's spinlock. The table lock nests outside the
53 * entry locks. Allocations of new entries take the table lock as writers so
54 * no other lookups can happen while allocating new entries. Entry updates
55 * take the table lock as readers so multiple entries can be updated in
56 * parallel. An L2T entry can be dropped by decrementing its reference count
57 * and therefore can happen in parallel with entry allocation but no entry
58 * can change state or increment its ref count during allocation as both of
59 * these perform lookups.
60 */
61
62static inline unsigned int vlan_prio(const struct l2t_entry *e)
63{
64 return e->vlan >> 13;
65}
66
67static inline unsigned int arp_hash(u32 key, int ifindex,
68 const struct l2t_data *d)
69{
70 return jhash_2words(key, ifindex, 0) & (d->nentries - 1);
71}
72
73static inline void neigh_replace(struct l2t_entry *e, struct neighbour *n)
74{
75 neigh_hold(n);
76 if (e->neigh)
77 neigh_release(e->neigh);
78 e->neigh = n;
79}
80
81/*
82 * Set up an L2T entry and send any packets waiting in the arp queue. The
83 * supplied skb is used for the CPL_L2T_WRITE_REQ. Must be called with the
84 * entry locked.
85 */
86static int setup_l2e_send_pending(struct t3cdev *dev, struct sk_buff *skb,
87 struct l2t_entry *e)
88{
89 struct cpl_l2t_write_req *req;
90 struct sk_buff *tmp;
91
92 if (!skb) {
93 skb = alloc_skb(sizeof(*req), GFP_ATOMIC);
94 if (!skb)
95 return -ENOMEM;
96 }
97
98 req = (struct cpl_l2t_write_req *)__skb_put(skb, sizeof(*req));
99 req->wr.wr_hi = htonl(V_WR_OP(FW_WROPCODE_FORWARD));
100 OPCODE_TID(req) = htonl(MK_OPCODE_TID(CPL_L2T_WRITE_REQ, e->idx));
101 req->params = htonl(V_L2T_W_IDX(e->idx) | V_L2T_W_IFF(e->smt_idx) |
102 V_L2T_W_VLAN(e->vlan & VLAN_VID_MASK) |
103 V_L2T_W_PRIO(vlan_prio(e)));
104 memcpy(e->dmac, e->neigh->ha, sizeof(e->dmac));
105 memcpy(req->dst_mac, e->dmac, sizeof(req->dst_mac));
106 skb->priority = CPL_PRIORITY_CONTROL;
107 cxgb3_ofld_send(dev, skb);
108
109 skb_queue_walk_safe(&e->arpq, skb, tmp) {
110 __skb_unlink(skb, &e->arpq);
111 cxgb3_ofld_send(dev, skb);
112 }
113 e->state = L2T_STATE_VALID;
114
115 return 0;
116}
117
118/*
119 * Add a packet to the an L2T entry's queue of packets awaiting resolution.
120 * Must be called with the entry's lock held.
121 */
122static inline void arpq_enqueue(struct l2t_entry *e, struct sk_buff *skb)
123{
124 __skb_queue_tail(&e->arpq, skb);
125}
126
127int t3_l2t_send_slow(struct t3cdev *dev, struct sk_buff *skb,
128 struct l2t_entry *e)
129{
130again:
131 switch (e->state) {
132 case L2T_STATE_STALE: /* entry is stale, kick off revalidation */
133 neigh_event_send(e->neigh, NULL);
134 spin_lock_bh(&e->lock);
135 if (e->state == L2T_STATE_STALE)
136 e->state = L2T_STATE_VALID;
137 spin_unlock_bh(&e->lock);
138 case L2T_STATE_VALID: /* fast-path, send the packet on */
139 return cxgb3_ofld_send(dev, skb);
140 case L2T_STATE_RESOLVING:
141 spin_lock_bh(&e->lock);
142 if (e->state != L2T_STATE_RESOLVING) {
143 /* ARP already completed */
144 spin_unlock_bh(&e->lock);
145 goto again;
146 }
147 arpq_enqueue(e, skb);
148 spin_unlock_bh(&e->lock);
149
150 /*
151 * Only the first packet added to the arpq should kick off
152 * resolution. However, because the alloc_skb below can fail,
153 * we allow each packet added to the arpq to retry resolution
154 * as a way of recovering from transient memory exhaustion.
155 * A better way would be to use a work request to retry L2T
156 * entries when there's no memory.
157 */
158 if (!neigh_event_send(e->neigh, NULL)) {
159 skb = alloc_skb(sizeof(struct cpl_l2t_write_req),
160 GFP_ATOMIC);
161 if (!skb)
162 break;
163
164 spin_lock_bh(&e->lock);
165 if (!skb_queue_empty(&e->arpq))
166 setup_l2e_send_pending(dev, skb, e);
167 else /* we lost the race */
168 __kfree_skb(skb);
169 spin_unlock_bh(&e->lock);
170 }
171 }
172 return 0;
173}
174
175EXPORT_SYMBOL(t3_l2t_send_slow);
176
177void t3_l2t_send_event(struct t3cdev *dev, struct l2t_entry *e)
178{
179again:
180 switch (e->state) {
181 case L2T_STATE_STALE: /* entry is stale, kick off revalidation */
182 neigh_event_send(e->neigh, NULL);
183 spin_lock_bh(&e->lock);
184 if (e->state == L2T_STATE_STALE) {
185 e->state = L2T_STATE_VALID;
186 }
187 spin_unlock_bh(&e->lock);
188 return;
189 case L2T_STATE_VALID: /* fast-path, send the packet on */
190 return;
191 case L2T_STATE_RESOLVING:
192 spin_lock_bh(&e->lock);
193 if (e->state != L2T_STATE_RESOLVING) {
194 /* ARP already completed */
195 spin_unlock_bh(&e->lock);
196 goto again;
197 }
198 spin_unlock_bh(&e->lock);
199
200 /*
201 * Only the first packet added to the arpq should kick off
202 * resolution. However, because the alloc_skb below can fail,
203 * we allow each packet added to the arpq to retry resolution
204 * as a way of recovering from transient memory exhaustion.
205 * A better way would be to use a work request to retry L2T
206 * entries when there's no memory.
207 */
208 neigh_event_send(e->neigh, NULL);
209 }
210}
211
212EXPORT_SYMBOL(t3_l2t_send_event);
213
214/*
215 * Allocate a free L2T entry. Must be called with l2t_data.lock held.
216 */
217static struct l2t_entry *alloc_l2e(struct l2t_data *d)
218{
219 struct l2t_entry *end, *e, **p;
220
221 if (!atomic_read(&d->nfree))
222 return NULL;
223
224 /* there's definitely a free entry */
225 for (e = d->rover, end = &d->l2tab[d->nentries]; e != end; ++e)
226 if (atomic_read(&e->refcnt) == 0)
227 goto found;
228
229 for (e = &d->l2tab[1]; atomic_read(&e->refcnt); ++e) ;
230found:
231 d->rover = e + 1;
232 atomic_dec(&d->nfree);
233
234 /*
235 * The entry we found may be an inactive entry that is
236 * presently in the hash table. We need to remove it.
237 */
238 if (e->state != L2T_STATE_UNUSED) {
239 int hash = arp_hash(e->addr, e->ifindex, d);
240
241 for (p = &d->l2tab[hash].first; *p; p = &(*p)->next)
242 if (*p == e) {
243 *p = e->next;
244 break;
245 }
246 e->state = L2T_STATE_UNUSED;
247 }
248 return e;
249}
250
251/*
252 * Called when an L2T entry has no more users. The entry is left in the hash
253 * table since it is likely to be reused but we also bump nfree to indicate
254 * that the entry can be reallocated for a different neighbor. We also drop
255 * the existing neighbor reference in case the neighbor is going away and is
256 * waiting on our reference.
257 *
258 * Because entries can be reallocated to other neighbors once their ref count
259 * drops to 0 we need to take the entry's lock to avoid races with a new
260 * incarnation.
261 */
262void t3_l2e_free(struct l2t_data *d, struct l2t_entry *e)
263{
264 spin_lock_bh(&e->lock);
265 if (atomic_read(&e->refcnt) == 0) { /* hasn't been recycled */
266 if (e->neigh) {
267 neigh_release(e->neigh);
268 e->neigh = NULL;
269 }
270 }
271 spin_unlock_bh(&e->lock);
272 atomic_inc(&d->nfree);
273}
274
275EXPORT_SYMBOL(t3_l2e_free);
276
277/*
278 * Update an L2T entry that was previously used for the same next hop as neigh.
279 * Must be called with softirqs disabled.
280 */
281static inline void reuse_entry(struct l2t_entry *e, struct neighbour *neigh)
282{
283 unsigned int nud_state;
284
285 spin_lock(&e->lock); /* avoid race with t3_l2t_free */
286
287 if (neigh != e->neigh)
288 neigh_replace(e, neigh);
289 nud_state = neigh->nud_state;
290 if (memcmp(e->dmac, neigh->ha, sizeof(e->dmac)) ||
291 !(nud_state & NUD_VALID))
292 e->state = L2T_STATE_RESOLVING;
293 else if (nud_state & NUD_CONNECTED)
294 e->state = L2T_STATE_VALID;
295 else
296 e->state = L2T_STATE_STALE;
297 spin_unlock(&e->lock);
298}
299
300struct l2t_entry *t3_l2t_get(struct t3cdev *cdev, struct neighbour *neigh,
301 struct net_device *dev)
302{
303 struct l2t_entry *e;
304 struct l2t_data *d = L2DATA(cdev);
305 u32 addr = *(u32 *) neigh->primary_key;
306 int ifidx = neigh->dev->ifindex;
307 int hash = arp_hash(addr, ifidx, d);
308 struct port_info *p = netdev_priv(dev);
309 int smt_idx = p->port_id;
310
311 write_lock_bh(&d->lock);
312 for (e = d->l2tab[hash].first; e; e = e->next)
313 if (e->addr == addr && e->ifindex == ifidx &&
314 e->smt_idx == smt_idx) {
315 l2t_hold(d, e);
316 if (atomic_read(&e->refcnt) == 1)
317 reuse_entry(e, neigh);
318 goto done;
319 }
320
321 /* Need to allocate a new entry */
322 e = alloc_l2e(d);
323 if (e) {
324 spin_lock(&e->lock); /* avoid race with t3_l2t_free */
325 e->next = d->l2tab[hash].first;
326 d->l2tab[hash].first = e;
327 e->state = L2T_STATE_RESOLVING;
328 e->addr = addr;
329 e->ifindex = ifidx;
330 e->smt_idx = smt_idx;
331 atomic_set(&e->refcnt, 1);
332 neigh_replace(e, neigh);
333 if (neigh->dev->priv_flags & IFF_802_1Q_VLAN)
334 e->vlan = vlan_dev_vlan_id(neigh->dev);
335 else
336 e->vlan = VLAN_NONE;
337 spin_unlock(&e->lock);
338 }
339done:
340 write_unlock_bh(&d->lock);
341 return e;
342}
343
344EXPORT_SYMBOL(t3_l2t_get);
345
346/*
347 * Called when address resolution fails for an L2T entry to handle packets
348 * on the arpq head. If a packet specifies a failure handler it is invoked,
349 * otherwise the packets is sent to the offload device.
350 *
351 * XXX: maybe we should abandon the latter behavior and just require a failure
352 * handler.
353 */
354static void handle_failed_resolution(struct t3cdev *dev, struct sk_buff_head *arpq)
355{
356 struct sk_buff *skb, *tmp;
357
358 skb_queue_walk_safe(arpq, skb, tmp) {
359 struct l2t_skb_cb *cb = L2T_SKB_CB(skb);
360
361 __skb_unlink(skb, arpq);
362 if (cb->arp_failure_handler)
363 cb->arp_failure_handler(dev, skb);
364 else
365 cxgb3_ofld_send(dev, skb);
366 }
367}
368
369/*
370 * Called when the host's ARP layer makes a change to some entry that is
371 * loaded into the HW L2 table.
372 */
373void t3_l2t_update(struct t3cdev *dev, struct neighbour *neigh)
374{
375 struct sk_buff_head arpq;
376 struct l2t_entry *e;
377 struct l2t_data *d = L2DATA(dev);
378 u32 addr = *(u32 *) neigh->primary_key;
379 int ifidx = neigh->dev->ifindex;
380 int hash = arp_hash(addr, ifidx, d);
381
382 read_lock_bh(&d->lock);
383 for (e = d->l2tab[hash].first; e; e = e->next)
384 if (e->addr == addr && e->ifindex == ifidx) {
385 spin_lock(&e->lock);
386 goto found;
387 }
388 read_unlock_bh(&d->lock);
389 return;
390
391found:
392 __skb_queue_head_init(&arpq);
393
394 read_unlock(&d->lock);
395 if (atomic_read(&e->refcnt)) {
396 if (neigh != e->neigh)
397 neigh_replace(e, neigh);
398
399 if (e->state == L2T_STATE_RESOLVING) {
400 if (neigh->nud_state & NUD_FAILED) {
401 skb_queue_splice_init(&e->arpq, &arpq);
402 } else if (neigh->nud_state & (NUD_CONNECTED|NUD_STALE))
403 setup_l2e_send_pending(dev, NULL, e);
404 } else {
405 e->state = neigh->nud_state & NUD_CONNECTED ?
406 L2T_STATE_VALID : L2T_STATE_STALE;
407 if (memcmp(e->dmac, neigh->ha, 6))
408 setup_l2e_send_pending(dev, NULL, e);
409 }
410 }
411 spin_unlock_bh(&e->lock);
412
413 if (!skb_queue_empty(&arpq))
414 handle_failed_resolution(dev, &arpq);
415}
416
417struct l2t_data *t3_init_l2t(unsigned int l2t_capacity)
418{
419 struct l2t_data *d;
420 int i, size = sizeof(*d) + l2t_capacity * sizeof(struct l2t_entry);
421
422 d = cxgb_alloc_mem(size);
423 if (!d)
424 return NULL;
425
426 d->nentries = l2t_capacity;
427 d->rover = &d->l2tab[1]; /* entry 0 is not used */
428 atomic_set(&d->nfree, l2t_capacity - 1);
429 rwlock_init(&d->lock);
430
431 for (i = 0; i < l2t_capacity; ++i) {
432 d->l2tab[i].idx = i;
433 d->l2tab[i].state = L2T_STATE_UNUSED;
434 __skb_queue_head_init(&d->l2tab[i].arpq);
435 spin_lock_init(&d->l2tab[i].lock);
436 atomic_set(&d->l2tab[i].refcnt, 0);
437 }
438 return d;
439}
440
441void t3_free_l2t(struct l2t_data *d)
442{
443 cxgb_free_mem(d);
444}
445
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