?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
bnx2: Update version to 2.0.16.
[linux-2.6.git] / drivers / net / xen-netfront.c
blobb50fedcef8ac9dd9872a51ed63cb0b6c3135c778
1 /*
2 * Virtual network driver for conversing with remote driver backends.
3 *
4 * Copyright (c) 2002-2005, K A Fraser
5 * Copyright (c) 2005, XenSource Ltd
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License version 2
9 * as published by the Free Software Foundation; or, when distributed
10 * separately from the Linux kernel or incorporated into other
11 * software packages, subject to the following license:
12 *
13 * Permission is hereby granted, free of charge, to any person obtaining a copy
14 * of this source file (the "Software"), to deal in the Software without
15 * restriction, including without limitation the rights to use, copy, modify,
16 * merge, publish, distribute, sublicense, and/or sell copies of the Software,
17 * and to permit persons to whom the Software is furnished to do so, subject to
18 * the following conditions:
19 *
20 * The above copyright notice and this permission notice shall be included in
21 * all copies or substantial portions of the Software.
22 *
23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
24 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
25 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
26 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
27 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
28 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
29 * IN THE SOFTWARE.
30 */
31
32 #include <linux/module.h>
33 #include <linux/kernel.h>
34 #include <linux/netdevice.h>
35 #include <linux/etherdevice.h>
36 #include <linux/skbuff.h>
37 #include <linux/ethtool.h>
38 #include <linux/if_ether.h>
39 #include <linux/tcp.h>
40 #include <linux/udp.h>
41 #include <linux/moduleparam.h>
42 #include <linux/mm.h>
43 #include <linux/slab.h>
44 #include <net/ip.h>
45
46 #include <xen/xen.h>
47 #include <xen/xenbus.h>
48 #include <xen/events.h>
49 #include <xen/page.h>
50 #include <xen/grant_table.h>
51
52 #include <xen/interface/io/netif.h>
53 #include <xen/interface/memory.h>
54 #include <xen/interface/grant_table.h>
55
56 static const struct ethtool_ops xennet_ethtool_ops;
57
58 struct netfront_cb {
59 struct page *page;
60 unsigned offset;
61 };
62
63 #define NETFRONT_SKB_CB(skb) ((struct netfront_cb *)((skb)->cb))
64
65 #define RX_COPY_THRESHOLD 256
66
67 #define GRANT_INVALID_REF 0
68
69 #define NET_TX_RING_SIZE __RING_SIZE((struct xen_netif_tx_sring *)0, PAGE_SIZE)
70 #define NET_RX_RING_SIZE __RING_SIZE((struct xen_netif_rx_sring *)0, PAGE_SIZE)
71 #define TX_MAX_TARGET min_t(int, NET_RX_RING_SIZE, 256)
72
73 struct netfront_info {
74 struct list_head list;
75 struct net_device *netdev;
76
77 struct napi_struct napi;
78
79 unsigned int evtchn;
80 struct xenbus_device *xbdev;
81
82 spinlock_t tx_lock;
83 struct xen_netif_tx_front_ring tx;
84 int tx_ring_ref;
85
86 /*
87 * {tx,rx}_skbs store outstanding skbuffs. Free tx_skb entries
88 * are linked from tx_skb_freelist through skb_entry.link.
89 *
90 * NB. Freelist index entries are always going to be less than
91 * PAGE_OFFSET, whereas pointers to skbs will always be equal or
92 * greater than PAGE_OFFSET: we use this property to distinguish
93 * them.
94 */
95 union skb_entry {
96 struct sk_buff *skb;
97 unsigned long link;
98 } tx_skbs[NET_TX_RING_SIZE];
99 grant_ref_t gref_tx_head;
100 grant_ref_t grant_tx_ref[NET_TX_RING_SIZE];
101 unsigned tx_skb_freelist;
102
103 spinlock_t rx_lock ____cacheline_aligned_in_smp;
104 struct xen_netif_rx_front_ring rx;
105 int rx_ring_ref;
106
107 /* Receive-ring batched refills. */
108 #define RX_MIN_TARGET 8
109 #define RX_DFL_MIN_TARGET 64
110 #define RX_MAX_TARGET min_t(int, NET_RX_RING_SIZE, 256)
111 unsigned rx_min_target, rx_max_target, rx_target;
112 struct sk_buff_head rx_batch;
113
114 struct timer_list rx_refill_timer;
115
116 struct sk_buff *rx_skbs[NET_RX_RING_SIZE];
117 grant_ref_t gref_rx_head;
118 grant_ref_t grant_rx_ref[NET_RX_RING_SIZE];
119
120 unsigned long rx_pfn_array[NET_RX_RING_SIZE];
121 struct multicall_entry rx_mcl[NET_RX_RING_SIZE+1];
122 struct mmu_update rx_mmu[NET_RX_RING_SIZE];
123 };
124
125 struct netfront_rx_info {
126 struct xen_netif_rx_response rx;
127 struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX - 1];
128 };
129
130 static void skb_entry_set_link(union skb_entry *list, unsigned short id)
131 {
132 list->link = id;
133 }
134
135 static int skb_entry_is_link(const union skb_entry *list)
136 {
137 BUILD_BUG_ON(sizeof(list->skb) != sizeof(list->link));
138 return ((unsigned long)list->skb < PAGE_OFFSET);
139 }
140
141 /*
142 * Access macros for acquiring freeing slots in tx_skbs[].
143 */
144
145 static void add_id_to_freelist(unsigned *head, union skb_entry *list,
146 unsigned short id)
147 {
148 skb_entry_set_link(&list[id], *head);
149 *head = id;
150 }
151
152 static unsigned short get_id_from_freelist(unsigned *head,
153 union skb_entry *list)
154 {
155 unsigned int id = *head;
156 *head = list[id].link;
157 return id;
158 }
159
160 static int xennet_rxidx(RING_IDX idx)
161 {
162 return idx & (NET_RX_RING_SIZE - 1);
163 }
164
165 static struct sk_buff *xennet_get_rx_skb(struct netfront_info *np,
166 RING_IDX ri)
167 {
168 int i = xennet_rxidx(ri);
169 struct sk_buff *skb = np->rx_skbs[i];
170 np->rx_skbs[i] = NULL;
171 return skb;
172 }
173
174 static grant_ref_t xennet_get_rx_ref(struct netfront_info *np,
175 RING_IDX ri)
176 {
177 int i = xennet_rxidx(ri);
178 grant_ref_t ref = np->grant_rx_ref[i];
179 np->grant_rx_ref[i] = GRANT_INVALID_REF;
180 return ref;
181 }
182
183 #ifdef CONFIG_SYSFS
184 static int xennet_sysfs_addif(struct net_device *netdev);
185 static void xennet_sysfs_delif(struct net_device *netdev);
186 #else /* !CONFIG_SYSFS */
187 #define xennet_sysfs_addif(dev) (0)
188 #define xennet_sysfs_delif(dev) do { } while (0)
189 #endif
190
191 static int xennet_can_sg(struct net_device *dev)
192 {
193 return dev->features & NETIF_F_SG;
194 }
195
196
197 static void rx_refill_timeout(unsigned long data)
198 {
199 struct net_device *dev = (struct net_device *)data;
200 struct netfront_info *np = netdev_priv(dev);
201 napi_schedule(&np->napi);
202 }
203
204 static int netfront_tx_slot_available(struct netfront_info *np)
205 {
206 return ((np->tx.req_prod_pvt - np->tx.rsp_cons) <
207 (TX_MAX_TARGET - MAX_SKB_FRAGS - 2));
208 }
209
210 static void xennet_maybe_wake_tx(struct net_device *dev)
211 {
212 struct netfront_info *np = netdev_priv(dev);
213
214 if (unlikely(netif_queue_stopped(dev)) &&
215 netfront_tx_slot_available(np) &&
216 likely(netif_running(dev)))
217 netif_wake_queue(dev);
218 }
219
220 static void xennet_alloc_rx_buffers(struct net_device *dev)
221 {
222 unsigned short id;
223 struct netfront_info *np = netdev_priv(dev);
224 struct sk_buff *skb;
225 struct page *page;
226 int i, batch_target, notify;
227 RING_IDX req_prod = np->rx.req_prod_pvt;
228 grant_ref_t ref;
229 unsigned long pfn;
230 void *vaddr;
231 struct xen_netif_rx_request *req;
232
233 if (unlikely(!netif_carrier_ok(dev)))
234 return;
235
236 /*
237 * Allocate skbuffs greedily, even though we batch updates to the
238 * receive ring. This creates a less bursty demand on the memory
239 * allocator, so should reduce the chance of failed allocation requests
240 * both for ourself and for other kernel subsystems.
241 */
242 batch_target = np->rx_target - (req_prod - np->rx.rsp_cons);
243 for (i = skb_queue_len(&np->rx_batch); i < batch_target; i++) {
244 skb = __netdev_alloc_skb(dev, RX_COPY_THRESHOLD + NET_IP_ALIGN,
245 GFP_ATOMIC | __GFP_NOWARN);
246 if (unlikely(!skb))
247 goto no_skb;
248
249 /* Align ip header to a 16 bytes boundary */
250 skb_reserve(skb, NET_IP_ALIGN);
251
252 page = alloc_page(GFP_ATOMIC | __GFP_NOWARN);
253 if (!page) {
254 kfree_skb(skb);
255 no_skb:
256 /* Any skbuffs queued for refill? Force them out. */
257 if (i != 0)
258 goto refill;
259 /* Could not allocate any skbuffs. Try again later. */
260 mod_timer(&np->rx_refill_timer,
261 jiffies + (HZ/10));
262 break;
263 }
264
265 skb_shinfo(skb)->frags[0].page = page;
266 skb_shinfo(skb)->nr_frags = 1;
267 __skb_queue_tail(&np->rx_batch, skb);
268 }
269
270 /* Is the batch large enough to be worthwhile? */
271 if (i < (np->rx_target/2)) {
272 if (req_prod > np->rx.sring->req_prod)
273 goto push;
274 return;
275 }
276
277 /* Adjust our fill target if we risked running out of buffers. */
278 if (((req_prod - np->rx.sring->rsp_prod) < (np->rx_target / 4)) &&
279 ((np->rx_target *= 2) > np->rx_max_target))
280 np->rx_target = np->rx_max_target;
281
282 refill:
283 for (i = 0; ; i++) {
284 skb = __skb_dequeue(&np->rx_batch);
285 if (skb == NULL)
286 break;
287
288 skb->dev = dev;
289
290 id = xennet_rxidx(req_prod + i);
291
292 BUG_ON(np->rx_skbs[id]);
293 np->rx_skbs[id] = skb;
294
295 ref = gnttab_claim_grant_reference(&np->gref_rx_head);
296 BUG_ON((signed short)ref < 0);
297 np->grant_rx_ref[id] = ref;
298
299 pfn = page_to_pfn(skb_shinfo(skb)->frags[0].page);
300 vaddr = page_address(skb_shinfo(skb)->frags[0].page);
301
302 req = RING_GET_REQUEST(&np->rx, req_prod + i);
303 gnttab_grant_foreign_access_ref(ref,
304 np->xbdev->otherend_id,
305 pfn_to_mfn(pfn),
306 0);
307
308 req->id = id;
309 req->gref = ref;
310 }
311
312 wmb(); /* barrier so backend seens requests */
313
314 /* Above is a suitable barrier to ensure backend will see requests. */
315 np->rx.req_prod_pvt = req_prod + i;
316 push:
317 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&np->rx, notify);
318 if (notify)
319 notify_remote_via_irq(np->netdev->irq);
320 }
321
322 static int xennet_open(struct net_device *dev)
323 {
324 struct netfront_info *np = netdev_priv(dev);
325
326 napi_enable(&np->napi);
327
328 spin_lock_bh(&np->rx_lock);
329 if (netif_carrier_ok(dev)) {
330 xennet_alloc_rx_buffers(dev);
331 np->rx.sring->rsp_event = np->rx.rsp_cons + 1;
332 if (RING_HAS_UNCONSUMED_RESPONSES(&np->rx))
333 napi_schedule(&np->napi);
334 }
335 spin_unlock_bh(&np->rx_lock);
336
337 netif_start_queue(dev);
338
339 return 0;
340 }
341
342 static void xennet_tx_buf_gc(struct net_device *dev)
343 {
344 RING_IDX cons, prod;
345 unsigned short id;
346 struct netfront_info *np = netdev_priv(dev);
347 struct sk_buff *skb;
348
349 BUG_ON(!netif_carrier_ok(dev));
350
351 do {
352 prod = np->tx.sring->rsp_prod;
353 rmb(); /* Ensure we see responses up to 'rp'. */
354
355 for (cons = np->tx.rsp_cons; cons != prod; cons++) {
356 struct xen_netif_tx_response *txrsp;
357
358 txrsp = RING_GET_RESPONSE(&np->tx, cons);
359 if (txrsp->status == NETIF_RSP_NULL)
360 continue;
361
362 id = txrsp->id;
363 skb = np->tx_skbs[id].skb;
364 if (unlikely(gnttab_query_foreign_access(
365 np->grant_tx_ref[id]) != 0)) {
366 printk(KERN_ALERT "xennet_tx_buf_gc: warning "
367 "-- grant still in use by backend "
368 "domain.\n");
369 BUG();
370 }
371 gnttab_end_foreign_access_ref(
372 np->grant_tx_ref[id], GNTMAP_readonly);
373 gnttab_release_grant_reference(
374 &np->gref_tx_head, np->grant_tx_ref[id]);
375 np->grant_tx_ref[id] = GRANT_INVALID_REF;
376 add_id_to_freelist(&np->tx_skb_freelist, np->tx_skbs, id);
377 dev_kfree_skb_irq(skb);
378 }
379
380 np->tx.rsp_cons = prod;
381
382 /*
383 * Set a new event, then check for race with update of tx_cons.
384 * Note that it is essential to schedule a callback, no matter
385 * how few buffers are pending. Even if there is space in the
386 * transmit ring, higher layers may be blocked because too much
387 * data is outstanding: in such cases notification from Xen is
388 * likely to be the only kick that we'll get.
389 */
390 np->tx.sring->rsp_event =
391 prod + ((np->tx.sring->req_prod - prod) >> 1) + 1;
392 mb(); /* update shared area */
393 } while ((cons == prod) && (prod != np->tx.sring->rsp_prod));
394
395 xennet_maybe_wake_tx(dev);
396 }
397
398 static void xennet_make_frags(struct sk_buff *skb, struct net_device *dev,
399 struct xen_netif_tx_request *tx)
400 {
401 struct netfront_info *np = netdev_priv(dev);
402 char *data = skb->data;
403 unsigned long mfn;
404 RING_IDX prod = np->tx.req_prod_pvt;
405 int frags = skb_shinfo(skb)->nr_frags;
406 unsigned int offset = offset_in_page(data);
407 unsigned int len = skb_headlen(skb);
408 unsigned int id;
409 grant_ref_t ref;
410 int i;
411
412 /* While the header overlaps a page boundary (including being
413 larger than a page), split it it into page-sized chunks. */
414 while (len > PAGE_SIZE - offset) {
415 tx->size = PAGE_SIZE - offset;
416 tx->flags |= NETTXF_more_data;
417 len -= tx->size;
418 data += tx->size;
419 offset = 0;
420
421 id = get_id_from_freelist(&np->tx_skb_freelist, np->tx_skbs);
422 np->tx_skbs[id].skb = skb_get(skb);
423 tx = RING_GET_REQUEST(&np->tx, prod++);
424 tx->id = id;
425 ref = gnttab_claim_grant_reference(&np->gref_tx_head);
426 BUG_ON((signed short)ref < 0);
427
428 mfn = virt_to_mfn(data);
429 gnttab_grant_foreign_access_ref(ref, np->xbdev->otherend_id,
430 mfn, GNTMAP_readonly);
431
432 tx->gref = np->grant_tx_ref[id] = ref;
433 tx->offset = offset;
434 tx->size = len;
435 tx->flags = 0;
436 }
437
438 /* Grant backend access to each skb fragment page. */
439 for (i = 0; i < frags; i++) {
440 skb_frag_t *frag = skb_shinfo(skb)->frags + i;
441
442 tx->flags |= NETTXF_more_data;
443
444 id = get_id_from_freelist(&np->tx_skb_freelist, np->tx_skbs);
445 np->tx_skbs[id].skb = skb_get(skb);
446 tx = RING_GET_REQUEST(&np->tx, prod++);
447 tx->id = id;
448 ref = gnttab_claim_grant_reference(&np->gref_tx_head);
449 BUG_ON((signed short)ref < 0);
450
451 mfn = pfn_to_mfn(page_to_pfn(frag->page));
452 gnttab_grant_foreign_access_ref(ref, np->xbdev->otherend_id,
453 mfn, GNTMAP_readonly);
454
455 tx->gref = np->grant_tx_ref[id] = ref;
456 tx->offset = frag->page_offset;
457 tx->size = frag->size;
458 tx->flags = 0;
459 }
460
461 np->tx.req_prod_pvt = prod;
462 }
463
464 static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev)
465 {
466 unsigned short id;
467 struct netfront_info *np = netdev_priv(dev);
468 struct xen_netif_tx_request *tx;
469 struct xen_netif_extra_info *extra;
470 char *data = skb->data;
471 RING_IDX i;
472 grant_ref_t ref;
473 unsigned long mfn;
474 int notify;
475 int frags = skb_shinfo(skb)->nr_frags;
476 unsigned int offset = offset_in_page(data);
477 unsigned int len = skb_headlen(skb);
478
479 frags += DIV_ROUND_UP(offset + len, PAGE_SIZE);
480 if (unlikely(frags > MAX_SKB_FRAGS + 1)) {
481 printk(KERN_ALERT "xennet: skb rides the rocket: %d frags\n",
482 frags);
483 dump_stack();
484 goto drop;
485 }
486
487 spin_lock_irq(&np->tx_lock);
488
489 if (unlikely(!netif_carrier_ok(dev) ||
490 (frags > 1 && !xennet_can_sg(dev)) ||
491 netif_needs_gso(dev, skb))) {
492 spin_unlock_irq(&np->tx_lock);
493 goto drop;
494 }
495
496 i = np->tx.req_prod_pvt;
497
498 id = get_id_from_freelist(&np->tx_skb_freelist, np->tx_skbs);
499 np->tx_skbs[id].skb = skb;
500
501 tx = RING_GET_REQUEST(&np->tx, i);
502
503 tx->id = id;
504 ref = gnttab_claim_grant_reference(&np->gref_tx_head);
505 BUG_ON((signed short)ref < 0);
506 mfn = virt_to_mfn(data);
507 gnttab_grant_foreign_access_ref(
508 ref, np->xbdev->otherend_id, mfn, GNTMAP_readonly);
509 tx->gref = np->grant_tx_ref[id] = ref;
510 tx->offset = offset;
511 tx->size = len;
512 extra = NULL;
513
514 tx->flags = 0;
515 if (skb->ip_summed == CHECKSUM_PARTIAL)
516 /* local packet? */
517 tx->flags |= NETTXF_csum_blank | NETTXF_data_validated;
518 else if (skb->ip_summed == CHECKSUM_UNNECESSARY)
519 /* remote but checksummed. */
520 tx->flags |= NETTXF_data_validated;
521
522 if (skb_shinfo(skb)->gso_size) {
523 struct xen_netif_extra_info *gso;
524
525 gso = (struct xen_netif_extra_info *)
526 RING_GET_REQUEST(&np->tx, ++i);
527
528 if (extra)
529 extra->flags |= XEN_NETIF_EXTRA_FLAG_MORE;
530 else
531 tx->flags |= NETTXF_extra_info;
532
533 gso->u.gso.size = skb_shinfo(skb)->gso_size;
534 gso->u.gso.type = XEN_NETIF_GSO_TYPE_TCPV4;
535 gso->u.gso.pad = 0;
536 gso->u.gso.features = 0;
537
538 gso->type = XEN_NETIF_EXTRA_TYPE_GSO;
539 gso->flags = 0;
540 extra = gso;
541 }
542
543 np->tx.req_prod_pvt = i + 1;
544
545 xennet_make_frags(skb, dev, tx);
546 tx->size = skb->len;
547
548 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&np->tx, notify);
549 if (notify)
550 notify_remote_via_irq(np->netdev->irq);
551
552 dev->stats.tx_bytes += skb->len;
553 dev->stats.tx_packets++;
554
555 /* Note: It is not safe to access skb after xennet_tx_buf_gc()! */
556 xennet_tx_buf_gc(dev);
557
558 if (!netfront_tx_slot_available(np))
559 netif_stop_queue(dev);
560
561 spin_unlock_irq(&np->tx_lock);
562
563 return NETDEV_TX_OK;
564
565 drop:
566 dev->stats.tx_dropped++;
567 dev_kfree_skb(skb);
568 return NETDEV_TX_OK;
569 }
570
571 static int xennet_close(struct net_device *dev)
572 {
573 struct netfront_info *np = netdev_priv(dev);
574 netif_stop_queue(np->netdev);
575 napi_disable(&np->napi);
576 return 0;
577 }
578
579 static void xennet_move_rx_slot(struct netfront_info *np, struct sk_buff *skb,
580 grant_ref_t ref)
581 {
582 int new = xennet_rxidx(np->rx.req_prod_pvt);
583
584 BUG_ON(np->rx_skbs[new]);
585 np->rx_skbs[new] = skb;
586 np->grant_rx_ref[new] = ref;
587 RING_GET_REQUEST(&np->rx, np->rx.req_prod_pvt)->id = new;
588 RING_GET_REQUEST(&np->rx, np->rx.req_prod_pvt)->gref = ref;
589 np->rx.req_prod_pvt++;
590 }
591
592 static int xennet_get_extras(struct netfront_info *np,
593 struct xen_netif_extra_info *extras,
594 RING_IDX rp)
595
596 {
597 struct xen_netif_extra_info *extra;
598 struct device *dev = &np->netdev->dev;
599 RING_IDX cons = np->rx.rsp_cons;
600 int err = 0;
601
602 do {
603 struct sk_buff *skb;
604 grant_ref_t ref;
605
606 if (unlikely(cons + 1 == rp)) {
607 if (net_ratelimit())
608 dev_warn(dev, "Missing extra info\n");
609 err = -EBADR;
610 break;
611 }
612
613 extra = (struct xen_netif_extra_info *)
614 RING_GET_RESPONSE(&np->rx, ++cons);
615
616 if (unlikely(!extra->type ||
617 extra->type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
618 if (net_ratelimit())
619 dev_warn(dev, "Invalid extra type: %d\n",
620 extra->type);
621 err = -EINVAL;
622 } else {
623 memcpy(&extras[extra->type - 1], extra,
624 sizeof(*extra));
625 }
626
627 skb = xennet_get_rx_skb(np, cons);
628 ref = xennet_get_rx_ref(np, cons);
629 xennet_move_rx_slot(np, skb, ref);
630 } while (extra->flags & XEN_NETIF_EXTRA_FLAG_MORE);
631
632 np->rx.rsp_cons = cons;
633 return err;
634 }
635
636 static int xennet_get_responses(struct netfront_info *np,
637 struct netfront_rx_info *rinfo, RING_IDX rp,
638 struct sk_buff_head *list)
639 {
640 struct xen_netif_rx_response *rx = &rinfo->rx;
641 struct xen_netif_extra_info *extras = rinfo->extras;
642 struct device *dev = &np->netdev->dev;
643 RING_IDX cons = np->rx.rsp_cons;
644 struct sk_buff *skb = xennet_get_rx_skb(np, cons);
645 grant_ref_t ref = xennet_get_rx_ref(np, cons);
646 int max = MAX_SKB_FRAGS + (rx->status <= RX_COPY_THRESHOLD);
647 int frags = 1;
648 int err = 0;
649 unsigned long ret;
650
651 if (rx->flags & NETRXF_extra_info) {
652 err = xennet_get_extras(np, extras, rp);
653 cons = np->rx.rsp_cons;
654 }
655
656 for (;;) {
657 if (unlikely(rx->status < 0 ||
658 rx->offset + rx->status > PAGE_SIZE)) {
659 if (net_ratelimit())
660 dev_warn(dev, "rx->offset: %x, size: %u\n",
661 rx->offset, rx->status);
662 xennet_move_rx_slot(np, skb, ref);
663 err = -EINVAL;
664 goto next;
665 }
666
667 /*
668 * This definitely indicates a bug, either in this driver or in
669 * the backend driver. In future this should flag the bad
670 * situation to the system controller to reboot the backed.
671 */
672 if (ref == GRANT_INVALID_REF) {
673 if (net_ratelimit())
674 dev_warn(dev, "Bad rx response id %d.\n",
675 rx->id);
676 err = -EINVAL;
677 goto next;
678 }
679
680 ret = gnttab_end_foreign_access_ref(ref, 0);
681 BUG_ON(!ret);
682
683 gnttab_release_grant_reference(&np->gref_rx_head, ref);
684
685 __skb_queue_tail(list, skb);
686
687 next:
688 if (!(rx->flags & NETRXF_more_data))
689 break;
690
691 if (cons + frags == rp) {
692 if (net_ratelimit())
693 dev_warn(dev, "Need more frags\n");
694 err = -ENOENT;
695 break;
696 }
697
698 rx = RING_GET_RESPONSE(&np->rx, cons + frags);
699 skb = xennet_get_rx_skb(np, cons + frags);
700 ref = xennet_get_rx_ref(np, cons + frags);
701 frags++;
702 }
703
704 if (unlikely(frags > max)) {
705 if (net_ratelimit())
706 dev_warn(dev, "Too many frags\n");
707 err = -E2BIG;
708 }
709
710 if (unlikely(err))
711 np->rx.rsp_cons = cons + frags;
712
713 return err;
714 }
715
716 static int xennet_set_skb_gso(struct sk_buff *skb,
717 struct xen_netif_extra_info *gso)
718 {
719 if (!gso->u.gso.size) {
720 if (net_ratelimit())
721 printk(KERN_WARNING "GSO size must not be zero.\n");
722 return -EINVAL;
723 }
724
725 /* Currently only TCPv4 S.O. is supported. */
726 if (gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV4) {
727 if (net_ratelimit())
728 printk(KERN_WARNING "Bad GSO type %d.\n", gso->u.gso.type);
729 return -EINVAL;
730 }
731
732 skb_shinfo(skb)->gso_size = gso->u.gso.size;
733 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
734
735 /* Header must be checked, and gso_segs computed. */
736 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
737 skb_shinfo(skb)->gso_segs = 0;
738
739 return 0;
740 }
741
742 static RING_IDX xennet_fill_frags(struct netfront_info *np,
743 struct sk_buff *skb,
744 struct sk_buff_head *list)
745 {
746 struct skb_shared_info *shinfo = skb_shinfo(skb);
747 int nr_frags = shinfo->nr_frags;
748 RING_IDX cons = np->rx.rsp_cons;
749 skb_frag_t *frag = shinfo->frags + nr_frags;
750 struct sk_buff *nskb;
751
752 while ((nskb = __skb_dequeue(list))) {
753 struct xen_netif_rx_response *rx =
754 RING_GET_RESPONSE(&np->rx, ++cons);
755
756 frag->page = skb_shinfo(nskb)->frags[0].page;
757 frag->page_offset = rx->offset;
758 frag->size = rx->status;
759
760 skb->data_len += rx->status;
761
762 skb_shinfo(nskb)->nr_frags = 0;
763 kfree_skb(nskb);
764
765 frag++;
766 nr_frags++;
767 }
768
769 shinfo->nr_frags = nr_frags;
770 return cons;
771 }
772
773 static int skb_checksum_setup(struct sk_buff *skb)
774 {
775 struct iphdr *iph;
776 unsigned char *th;
777 int err = -EPROTO;
778
779 if (skb->protocol != htons(ETH_P_IP))
780 goto out;
781
782 iph = (void *)skb->data;
783 th = skb->data + 4 * iph->ihl;
784 if (th >= skb_tail_pointer(skb))
785 goto out;
786
787 skb->csum_start = th - skb->head;
788 switch (iph->protocol) {
789 case IPPROTO_TCP:
790 skb->csum_offset = offsetof(struct tcphdr, check);
791 break;
792 case IPPROTO_UDP:
793 skb->csum_offset = offsetof(struct udphdr, check);
794 break;
795 default:
796 if (net_ratelimit())
797 printk(KERN_ERR "Attempting to checksum a non-"
798 "TCP/UDP packet, dropping a protocol"
799 " %d packet", iph->protocol);
800 goto out;
801 }
802
803 if ((th + skb->csum_offset + 2) > skb_tail_pointer(skb))
804 goto out;
805
806 err = 0;
807
808 out:
809 return err;
810 }
811
812 static int handle_incoming_queue(struct net_device *dev,
813 struct sk_buff_head *rxq)
814 {
815 int packets_dropped = 0;
816 struct sk_buff *skb;
817
818 while ((skb = __skb_dequeue(rxq)) != NULL) {
819 struct page *page = NETFRONT_SKB_CB(skb)->page;
820 void *vaddr = page_address(page);
821 unsigned offset = NETFRONT_SKB_CB(skb)->offset;
822
823 memcpy(skb->data, vaddr + offset,
824 skb_headlen(skb));
825
826 if (page != skb_shinfo(skb)->frags[0].page)
827 __free_page(page);
828
829 /* Ethernet work: Delayed to here as it peeks the header. */
830 skb->protocol = eth_type_trans(skb, dev);
831
832 if (skb->ip_summed == CHECKSUM_PARTIAL) {
833 if (skb_checksum_setup(skb)) {
834 kfree_skb(skb);
835 packets_dropped++;
836 dev->stats.rx_errors++;
837 continue;
838 }
839 }
840
841 dev->stats.rx_packets++;
842 dev->stats.rx_bytes += skb->len;
843
844 /* Pass it up. */
845 netif_receive_skb(skb);
846 }
847
848 return packets_dropped;
849 }
850
851 static int xennet_poll(struct napi_struct *napi, int budget)
852 {
853 struct netfront_info *np = container_of(napi, struct netfront_info, napi);
854 struct net_device *dev = np->netdev;
855 struct sk_buff *skb;
856 struct netfront_rx_info rinfo;
857 struct xen_netif_rx_response *rx = &rinfo.rx;
858 struct xen_netif_extra_info *extras = rinfo.extras;
859 RING_IDX i, rp;
860 int work_done;
861 struct sk_buff_head rxq;
862 struct sk_buff_head errq;
863 struct sk_buff_head tmpq;
864 unsigned long flags;
865 unsigned int len;
866 int err;
867
868 spin_lock(&np->rx_lock);
869
870 skb_queue_head_init(&rxq);
871 skb_queue_head_init(&errq);
872 skb_queue_head_init(&tmpq);
873
874 rp = np->rx.sring->rsp_prod;
875 rmb(); /* Ensure we see queued responses up to 'rp'. */
876
877 i = np->rx.rsp_cons;
878 work_done = 0;
879 while ((i != rp) && (work_done < budget)) {
880 memcpy(rx, RING_GET_RESPONSE(&np->rx, i), sizeof(*rx));
881 memset(extras, 0, sizeof(rinfo.extras));
882
883 err = xennet_get_responses(np, &rinfo, rp, &tmpq);
884
885 if (unlikely(err)) {
886 err:
887 while ((skb = __skb_dequeue(&tmpq)))
888 __skb_queue_tail(&errq, skb);
889 dev->stats.rx_errors++;
890 i = np->rx.rsp_cons;
891 continue;
892 }
893
894 skb = __skb_dequeue(&tmpq);
895
896 if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) {
897 struct xen_netif_extra_info *gso;
898 gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1];
899
900 if (unlikely(xennet_set_skb_gso(skb, gso))) {
901 __skb_queue_head(&tmpq, skb);
902 np->rx.rsp_cons += skb_queue_len(&tmpq);
903 goto err;
904 }
905 }
906
907 NETFRONT_SKB_CB(skb)->page = skb_shinfo(skb)->frags[0].page;
908 NETFRONT_SKB_CB(skb)->offset = rx->offset;
909
910 len = rx->status;
911 if (len > RX_COPY_THRESHOLD)
912 len = RX_COPY_THRESHOLD;
913 skb_put(skb, len);
914
915 if (rx->status > len) {
916 skb_shinfo(skb)->frags[0].page_offset =
917 rx->offset + len;
918 skb_shinfo(skb)->frags[0].size = rx->status - len;
919 skb->data_len = rx->status - len;
920 } else {
921 skb_shinfo(skb)->frags[0].page = NULL;
922 skb_shinfo(skb)->nr_frags = 0;
923 }
924
925 i = xennet_fill_frags(np, skb, &tmpq);
926
927 /*
928 * Truesize approximates the size of true data plus
929 * any supervisor overheads. Adding hypervisor
930 * overheads has been shown to significantly reduce
931 * achievable bandwidth with the default receive
932 * buffer size. It is therefore not wise to account
933 * for it here.
934 *
935 * After alloc_skb(RX_COPY_THRESHOLD), truesize is set
936 * to RX_COPY_THRESHOLD + the supervisor
937 * overheads. Here, we add the size of the data pulled
938 * in xennet_fill_frags().
939 *
940 * We also adjust for any unused space in the main
941 * data area by subtracting (RX_COPY_THRESHOLD -
942 * len). This is especially important with drivers
943 * which split incoming packets into header and data,
944 * using only 66 bytes of the main data area (see the
945 * e1000 driver for example.) On such systems,
946 * without this last adjustement, our achievable
947 * receive throughout using the standard receive
948 * buffer size was cut by 25%(!!!).
949 */
950 skb->truesize += skb->data_len - (RX_COPY_THRESHOLD - len);
951 skb->len += skb->data_len;
952
953 if (rx->flags & NETRXF_csum_blank)
954 skb->ip_summed = CHECKSUM_PARTIAL;
955 else if (rx->flags & NETRXF_data_validated)
956 skb->ip_summed = CHECKSUM_UNNECESSARY;
957
958 __skb_queue_tail(&rxq, skb);
959
960 np->rx.rsp_cons = ++i;
961 work_done++;
962 }
963
964 __skb_queue_purge(&errq);
965
966 work_done -= handle_incoming_queue(dev, &rxq);
967
968 /* If we get a callback with very few responses, reduce fill target. */
969 /* NB. Note exponential increase, linear decrease. */
970 if (((np->rx.req_prod_pvt - np->rx.sring->rsp_prod) >
971 ((3*np->rx_target) / 4)) &&
972 (--np->rx_target < np->rx_min_target))
973 np->rx_target = np->rx_min_target;
974
975 xennet_alloc_rx_buffers(dev);
976
977 if (work_done < budget) {
978 int more_to_do = 0;
979
980 local_irq_save(flags);
981
982 RING_FINAL_CHECK_FOR_RESPONSES(&np->rx, more_to_do);
983 if (!more_to_do)
984 __napi_complete(napi);
985
986 local_irq_restore(flags);
987 }
988
989 spin_unlock(&np->rx_lock);
990
991 return work_done;
992 }
993
994 static int xennet_change_mtu(struct net_device *dev, int mtu)
995 {
996 int max = xennet_can_sg(dev) ? 65535 - ETH_HLEN : ETH_DATA_LEN;
997
998 if (mtu > max)
999 return -EINVAL;
1000 dev->mtu = mtu;
1001 return 0;
1002 }
1003
1004 static void xennet_release_tx_bufs(struct netfront_info *np)
1005 {
1006 struct sk_buff *skb;
1007 int i;
1008
1009 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1010 /* Skip over entries which are actually freelist references */
1011 if (skb_entry_is_link(&np->tx_skbs[i]))
1012 continue;
1013
1014 skb = np->tx_skbs[i].skb;
1015 gnttab_end_foreign_access_ref(np->grant_tx_ref[i],
1016 GNTMAP_readonly);
1017 gnttab_release_grant_reference(&np->gref_tx_head,
1018 np->grant_tx_ref[i]);
1019 np->grant_tx_ref[i] = GRANT_INVALID_REF;
1020 add_id_to_freelist(&np->tx_skb_freelist, np->tx_skbs, i);
1021 dev_kfree_skb_irq(skb);
1022 }
1023 }
1024
1025 static void xennet_release_rx_bufs(struct netfront_info *np)
1026 {
1027 struct mmu_update *mmu = np->rx_mmu;
1028 struct multicall_entry *mcl = np->rx_mcl;
1029 struct sk_buff_head free_list;
1030 struct sk_buff *skb;
1031 unsigned long mfn;
1032 int xfer = 0, noxfer = 0, unused = 0;
1033 int id, ref;
1034
1035 dev_warn(&np->netdev->dev, "%s: fix me for copying receiver.\n",
1036 __func__);
1037 return;
1038
1039 skb_queue_head_init(&free_list);
1040
1041 spin_lock_bh(&np->rx_lock);
1042
1043 for (id = 0; id < NET_RX_RING_SIZE; id++) {
1044 ref = np->grant_rx_ref[id];
1045 if (ref == GRANT_INVALID_REF) {
1046 unused++;
1047 continue;
1048 }
1049
1050 skb = np->rx_skbs[id];
1051 mfn = gnttab_end_foreign_transfer_ref(ref);
1052 gnttab_release_grant_reference(&np->gref_rx_head, ref);
1053 np->grant_rx_ref[id] = GRANT_INVALID_REF;
1054
1055 if (0 == mfn) {
1056 skb_shinfo(skb)->nr_frags = 0;
1057 dev_kfree_skb(skb);
1058 noxfer++;
1059 continue;
1060 }
1061
1062 if (!xen_feature(XENFEAT_auto_translated_physmap)) {
1063 /* Remap the page. */
1064 struct page *page = skb_shinfo(skb)->frags[0].page;
1065 unsigned long pfn = page_to_pfn(page);
1066 void *vaddr = page_address(page);
1067
1068 MULTI_update_va_mapping(mcl, (unsigned long)vaddr,
1069 mfn_pte(mfn, PAGE_KERNEL),
1070 0);
1071 mcl++;
1072 mmu->ptr = ((u64)mfn << PAGE_SHIFT)
1073 | MMU_MACHPHYS_UPDATE;
1074 mmu->val = pfn;
1075 mmu++;
1076
1077 set_phys_to_machine(pfn, mfn);
1078 }
1079 __skb_queue_tail(&free_list, skb);
1080 xfer++;
1081 }
1082
1083 dev_info(&np->netdev->dev, "%s: %d xfer, %d noxfer, %d unused\n",
1084 __func__, xfer, noxfer, unused);
1085
1086 if (xfer) {
1087 if (!xen_feature(XENFEAT_auto_translated_physmap)) {
1088 /* Do all the remapping work and M2P updates. */
1089 MULTI_mmu_update(mcl, np->rx_mmu, mmu - np->rx_mmu,
1090 NULL, DOMID_SELF);
1091 mcl++;
1092 HYPERVISOR_multicall(np->rx_mcl, mcl - np->rx_mcl);
1093 }
1094 }
1095
1096 __skb_queue_purge(&free_list);
1097
1098 spin_unlock_bh(&np->rx_lock);
1099 }
1100
1101 static void xennet_uninit(struct net_device *dev)
1102 {
1103 struct netfront_info *np = netdev_priv(dev);
1104 xennet_release_tx_bufs(np);
1105 xennet_release_rx_bufs(np);
1106 gnttab_free_grant_references(np->gref_tx_head);
1107 gnttab_free_grant_references(np->gref_rx_head);
1108 }
1109
1110 static const struct net_device_ops xennet_netdev_ops = {
1111 .ndo_open = xennet_open,
1112 .ndo_uninit = xennet_uninit,
1113 .ndo_stop = xennet_close,
1114 .ndo_start_xmit = xennet_start_xmit,
1115 .ndo_change_mtu = xennet_change_mtu,
1116 .ndo_set_mac_address = eth_mac_addr,
1117 .ndo_validate_addr = eth_validate_addr,
1118 };
1119
1120 static struct net_device * __devinit xennet_create_dev(struct xenbus_device *dev)
1121 {
1122 int i, err;
1123 struct net_device *netdev;
1124 struct netfront_info *np;
1125
1126 netdev = alloc_etherdev(sizeof(struct netfront_info));
1127 if (!netdev) {
1128 printk(KERN_WARNING "%s> alloc_etherdev failed.\n",
1129 __func__);
1130 return ERR_PTR(-ENOMEM);
1131 }
1132
1133 np = netdev_priv(netdev);
1134 np->xbdev = dev;
1135
1136 spin_lock_init(&np->tx_lock);
1137 spin_lock_init(&np->rx_lock);
1138
1139 skb_queue_head_init(&np->rx_batch);
1140 np->rx_target = RX_DFL_MIN_TARGET;
1141 np->rx_min_target = RX_DFL_MIN_TARGET;
1142 np->rx_max_target = RX_MAX_TARGET;
1143
1144 init_timer(&np->rx_refill_timer);
1145 np->rx_refill_timer.data = (unsigned long)netdev;
1146 np->rx_refill_timer.function = rx_refill_timeout;
1147
1148 /* Initialise tx_skbs as a free chain containing every entry. */
1149 np->tx_skb_freelist = 0;
1150 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1151 skb_entry_set_link(&np->tx_skbs[i], i+1);
1152 np->grant_tx_ref[i] = GRANT_INVALID_REF;
1153 }
1154
1155 /* Clear out rx_skbs */
1156 for (i = 0; i < NET_RX_RING_SIZE; i++) {
1157 np->rx_skbs[i] = NULL;
1158 np->grant_rx_ref[i] = GRANT_INVALID_REF;
1159 }
1160
1161 /* A grant for every tx ring slot */
1162 if (gnttab_alloc_grant_references(TX_MAX_TARGET,
1163 &np->gref_tx_head) < 0) {
1164 printk(KERN_ALERT "#### netfront can't alloc tx grant refs\n");
1165 err = -ENOMEM;
1166 goto exit;
1167 }
1168 /* A grant for every rx ring slot */
1169 if (gnttab_alloc_grant_references(RX_MAX_TARGET,
1170 &np->gref_rx_head) < 0) {
1171 printk(KERN_ALERT "#### netfront can't alloc rx grant refs\n");
1172 err = -ENOMEM;
1173 goto exit_free_tx;
1174 }
1175
1176 netdev->netdev_ops = &xennet_netdev_ops;
1177
1178 netif_napi_add(netdev, &np->napi, xennet_poll, 64);
1179 netdev->features = NETIF_F_IP_CSUM;
1180
1181 SET_ETHTOOL_OPS(netdev, &xennet_ethtool_ops);
1182 SET_NETDEV_DEV(netdev, &dev->dev);
1183
1184 np->netdev = netdev;
1185
1186 netif_carrier_off(netdev);
1187
1188 return netdev;
1189
1190 exit_free_tx:
1191 gnttab_free_grant_references(np->gref_tx_head);
1192 exit:
1193 free_netdev(netdev);
1194 return ERR_PTR(err);
1195 }
1196
1197 /**
1198 * Entry point to this code when a new device is created. Allocate the basic
1199 * structures and the ring buffers for communication with the backend, and
1200 * inform the backend of the appropriate details for those.
1201 */
1202 static int __devinit netfront_probe(struct xenbus_device *dev,
1203 const struct xenbus_device_id *id)
1204 {
1205 int err;
1206 struct net_device *netdev;
1207 struct netfront_info *info;
1208
1209 netdev = xennet_create_dev(dev);
1210 if (IS_ERR(netdev)) {
1211 err = PTR_ERR(netdev);
1212 xenbus_dev_fatal(dev, err, "creating netdev");
1213 return err;
1214 }
1215
1216 info = netdev_priv(netdev);
1217 dev_set_drvdata(&dev->dev, info);
1218
1219 err = register_netdev(info->netdev);
1220 if (err) {
1221 printk(KERN_WARNING "%s: register_netdev err=%d\n",
1222 __func__, err);
1223 goto fail;
1224 }
1225
1226 err = xennet_sysfs_addif(info->netdev);
1227 if (err) {
1228 unregister_netdev(info->netdev);
1229 printk(KERN_WARNING "%s: add sysfs failed err=%d\n",
1230 __func__, err);
1231 goto fail;
1232 }
1233
1234 return 0;
1235
1236 fail:
1237 free_netdev(netdev);
1238 dev_set_drvdata(&dev->dev, NULL);
1239 return err;
1240 }
1241
1242 static void xennet_end_access(int ref, void *page)
1243 {
1244 /* This frees the page as a side-effect */
1245 if (ref != GRANT_INVALID_REF)
1246 gnttab_end_foreign_access(ref, 0, (unsigned long)page);
1247 }
1248
1249 static void xennet_disconnect_backend(struct netfront_info *info)
1250 {
1251 /* Stop old i/f to prevent errors whilst we rebuild the state. */
1252 spin_lock_bh(&info->rx_lock);
1253 spin_lock_irq(&info->tx_lock);
1254 netif_carrier_off(info->netdev);
1255 spin_unlock_irq(&info->tx_lock);
1256 spin_unlock_bh(&info->rx_lock);
1257
1258 if (info->netdev->irq)
1259 unbind_from_irqhandler(info->netdev->irq, info->netdev);
1260 info->evtchn = info->netdev->irq = 0;
1261
1262 /* End access and free the pages */
1263 xennet_end_access(info->tx_ring_ref, info->tx.sring);
1264 xennet_end_access(info->rx_ring_ref, info->rx.sring);
1265
1266 info->tx_ring_ref = GRANT_INVALID_REF;
1267 info->rx_ring_ref = GRANT_INVALID_REF;
1268 info->tx.sring = NULL;
1269 info->rx.sring = NULL;
1270 }
1271
1272 /**
1273 * We are reconnecting to the backend, due to a suspend/resume, or a backend
1274 * driver restart. We tear down our netif structure and recreate it, but
1275 * leave the device-layer structures intact so that this is transparent to the
1276 * rest of the kernel.
1277 */
1278 static int netfront_resume(struct xenbus_device *dev)
1279 {
1280 struct netfront_info *info = dev_get_drvdata(&dev->dev);
1281
1282 dev_dbg(&dev->dev, "%s\n", dev->nodename);
1283
1284 xennet_disconnect_backend(info);
1285 return 0;
1286 }
1287
1288 static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[])
1289 {
1290 char *s, *e, *macstr;
1291 int i;
1292
1293 macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL);
1294 if (IS_ERR(macstr))
1295 return PTR_ERR(macstr);
1296
1297 for (i = 0; i < ETH_ALEN; i++) {
1298 mac[i] = simple_strtoul(s, &e, 16);
1299 if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) {
1300 kfree(macstr);
1301 return -ENOENT;
1302 }
1303 s = e+1;
1304 }
1305
1306 kfree(macstr);
1307 return 0;
1308 }
1309
1310 static irqreturn_t xennet_interrupt(int irq, void *dev_id)
1311 {
1312 struct net_device *dev = dev_id;
1313 struct netfront_info *np = netdev_priv(dev);
1314 unsigned long flags;
1315
1316 spin_lock_irqsave(&np->tx_lock, flags);
1317
1318 if (likely(netif_carrier_ok(dev))) {
1319 xennet_tx_buf_gc(dev);
1320 /* Under tx_lock: protects access to rx shared-ring indexes. */
1321 if (RING_HAS_UNCONSUMED_RESPONSES(&np->rx))
1322 napi_schedule(&np->napi);
1323 }
1324
1325 spin_unlock_irqrestore(&np->tx_lock, flags);
1326
1327 return IRQ_HANDLED;
1328 }
1329
1330 static int setup_netfront(struct xenbus_device *dev, struct netfront_info *info)
1331 {
1332 struct xen_netif_tx_sring *txs;
1333 struct xen_netif_rx_sring *rxs;
1334 int err;
1335 struct net_device *netdev = info->netdev;
1336
1337 info->tx_ring_ref = GRANT_INVALID_REF;
1338 info->rx_ring_ref = GRANT_INVALID_REF;
1339 info->rx.sring = NULL;
1340 info->tx.sring = NULL;
1341 netdev->irq = 0;
1342
1343 err = xen_net_read_mac(dev, netdev->dev_addr);
1344 if (err) {
1345 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
1346 goto fail;
1347 }
1348
1349 txs = (struct xen_netif_tx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1350 if (!txs) {
1351 err = -ENOMEM;
1352 xenbus_dev_fatal(dev, err, "allocating tx ring page");
1353 goto fail;
1354 }
1355 SHARED_RING_INIT(txs);
1356 FRONT_RING_INIT(&info->tx, txs, PAGE_SIZE);
1357
1358 err = xenbus_grant_ring(dev, virt_to_mfn(txs));
1359 if (err < 0) {
1360 free_page((unsigned long)txs);
1361 goto fail;
1362 }
1363
1364 info->tx_ring_ref = err;
1365 rxs = (struct xen_netif_rx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1366 if (!rxs) {
1367 err = -ENOMEM;
1368 xenbus_dev_fatal(dev, err, "allocating rx ring page");
1369 goto fail;
1370 }
1371 SHARED_RING_INIT(rxs);
1372 FRONT_RING_INIT(&info->rx, rxs, PAGE_SIZE);
1373
1374 err = xenbus_grant_ring(dev, virt_to_mfn(rxs));
1375 if (err < 0) {
1376 free_page((unsigned long)rxs);
1377 goto fail;
1378 }
1379 info->rx_ring_ref = err;
1380
1381 err = xenbus_alloc_evtchn(dev, &info->evtchn);
1382 if (err)
1383 goto fail;
1384
1385 err = bind_evtchn_to_irqhandler(info->evtchn, xennet_interrupt,
1386 IRQF_SAMPLE_RANDOM, netdev->name,
1387 netdev);
1388 if (err < 0)
1389 goto fail;
1390 netdev->irq = err;
1391 return 0;
1392
1393 fail:
1394 return err;
1395 }
1396
1397 /* Common code used when first setting up, and when resuming. */
1398 static int talk_to_backend(struct xenbus_device *dev,
1399 struct netfront_info *info)
1400 {
1401 const char *message;
1402 struct xenbus_transaction xbt;
1403 int err;
1404
1405 /* Create shared ring, alloc event channel. */
1406 err = setup_netfront(dev, info);
1407 if (err)
1408 goto out;
1409
1410 again:
1411 err = xenbus_transaction_start(&xbt);
1412 if (err) {
1413 xenbus_dev_fatal(dev, err, "starting transaction");
1414 goto destroy_ring;
1415 }
1416
1417 err = xenbus_printf(xbt, dev->nodename, "tx-ring-ref", "%u",
1418 info->tx_ring_ref);
1419 if (err) {
1420 message = "writing tx ring-ref";
1421 goto abort_transaction;
1422 }
1423 err = xenbus_printf(xbt, dev->nodename, "rx-ring-ref", "%u",
1424 info->rx_ring_ref);
1425 if (err) {
1426 message = "writing rx ring-ref";
1427 goto abort_transaction;
1428 }
1429 err = xenbus_printf(xbt, dev->nodename,
1430 "event-channel", "%u", info->evtchn);
1431 if (err) {
1432 message = "writing event-channel";
1433 goto abort_transaction;
1434 }
1435
1436 err = xenbus_printf(xbt, dev->nodename, "request-rx-copy", "%u",
1437 1);
1438 if (err) {
1439 message = "writing request-rx-copy";
1440 goto abort_transaction;
1441 }
1442
1443 err = xenbus_printf(xbt, dev->nodename, "feature-rx-notify", "%d", 1);
1444 if (err) {
1445 message = "writing feature-rx-notify";
1446 goto abort_transaction;
1447 }
1448
1449 err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", 1);
1450 if (err) {
1451 message = "writing feature-sg";
1452 goto abort_transaction;
1453 }
1454
1455 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4", "%d", 1);
1456 if (err) {
1457 message = "writing feature-gso-tcpv4";
1458 goto abort_transaction;
1459 }
1460
1461 err = xenbus_transaction_end(xbt, 0);
1462 if (err) {
1463 if (err == -EAGAIN)
1464 goto again;
1465 xenbus_dev_fatal(dev, err, "completing transaction");
1466 goto destroy_ring;
1467 }
1468
1469 return 0;
1470
1471 abort_transaction:
1472 xenbus_transaction_end(xbt, 1);
1473 xenbus_dev_fatal(dev, err, "%s", message);
1474 destroy_ring:
1475 xennet_disconnect_backend(info);
1476 out:
1477 return err;
1478 }
1479
1480 static int xennet_set_sg(struct net_device *dev, u32 data)
1481 {
1482 if (data) {
1483 struct netfront_info *np = netdev_priv(dev);
1484 int val;
1485
1486 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, "feature-sg",
1487 "%d", &val) < 0)
1488 val = 0;
1489 if (!val)
1490 return -ENOSYS;
1491 } else if (dev->mtu > ETH_DATA_LEN)
1492 dev->mtu = ETH_DATA_LEN;
1493
1494 return ethtool_op_set_sg(dev, data);
1495 }
1496
1497 static int xennet_set_tso(struct net_device *dev, u32 data)
1498 {
1499 if (data) {
1500 struct netfront_info *np = netdev_priv(dev);
1501 int val;
1502
1503 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1504 "feature-gso-tcpv4", "%d", &val) < 0)
1505 val = 0;
1506 if (!val)
1507 return -ENOSYS;
1508 }
1509
1510 return ethtool_op_set_tso(dev, data);
1511 }
1512
1513 static void xennet_set_features(struct net_device *dev)
1514 {
1515 /* Turn off all GSO bits except ROBUST. */
1516 dev->features &= ~NETIF_F_GSO_MASK;
1517 dev->features |= NETIF_F_GSO_ROBUST;
1518 xennet_set_sg(dev, 0);
1519
1520 /* We need checksum offload to enable scatter/gather and TSO. */
1521 if (!(dev->features & NETIF_F_IP_CSUM))
1522 return;
1523
1524 if (!xennet_set_sg(dev, 1))
1525 xennet_set_tso(dev, 1);
1526 }
1527
1528 static int xennet_connect(struct net_device *dev)
1529 {
1530 struct netfront_info *np = netdev_priv(dev);
1531 int i, requeue_idx, err;
1532 struct sk_buff *skb;
1533 grant_ref_t ref;
1534 struct xen_netif_rx_request *req;
1535 unsigned int feature_rx_copy;
1536
1537 err = xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1538 "feature-rx-copy", "%u", &feature_rx_copy);
1539 if (err != 1)
1540 feature_rx_copy = 0;
1541
1542 if (!feature_rx_copy) {
1543 dev_info(&dev->dev,
1544 "backend does not support copying receive path\n");
1545 return -ENODEV;
1546 }
1547
1548 err = talk_to_backend(np->xbdev, np);
1549 if (err)
1550 return err;
1551
1552 xennet_set_features(dev);
1553
1554 spin_lock_bh(&np->rx_lock);
1555 spin_lock_irq(&np->tx_lock);
1556
1557 /* Step 1: Discard all pending TX packet fragments. */
1558 xennet_release_tx_bufs(np);
1559
1560 /* Step 2: Rebuild the RX buffer freelist and the RX ring itself. */
1561 for (requeue_idx = 0, i = 0; i < NET_RX_RING_SIZE; i++) {
1562 if (!np->rx_skbs[i])
1563 continue;
1564
1565 skb = np->rx_skbs[requeue_idx] = xennet_get_rx_skb(np, i);
1566 ref = np->grant_rx_ref[requeue_idx] = xennet_get_rx_ref(np, i);
1567 req = RING_GET_REQUEST(&np->rx, requeue_idx);
1568
1569 gnttab_grant_foreign_access_ref(
1570 ref, np->xbdev->otherend_id,
1571 pfn_to_mfn(page_to_pfn(skb_shinfo(skb)->
1572 frags->page)),
1573 0);
1574 req->gref = ref;
1575 req->id = requeue_idx;
1576
1577 requeue_idx++;
1578 }
1579
1580 np->rx.req_prod_pvt = requeue_idx;
1581
1582 /*
1583 * Step 3: All public and private state should now be sane. Get
1584 * ready to start sending and receiving packets and give the driver
1585 * domain a kick because we've probably just requeued some
1586 * packets.
1587 */
1588 netif_carrier_on(np->netdev);
1589 notify_remote_via_irq(np->netdev->irq);
1590 xennet_tx_buf_gc(dev);
1591 xennet_alloc_rx_buffers(dev);
1592
1593 spin_unlock_irq(&np->tx_lock);
1594 spin_unlock_bh(&np->rx_lock);
1595
1596 return 0;
1597 }
1598
1599 /**
1600 * Callback received when the backend's state changes.
1601 */
1602 static void backend_changed(struct xenbus_device *dev,
1603 enum xenbus_state backend_state)
1604 {
1605 struct netfront_info *np = dev_get_drvdata(&dev->dev);
1606 struct net_device *netdev = np->netdev;
1607
1608 dev_dbg(&dev->dev, "%s\n", xenbus_strstate(backend_state));
1609
1610 switch (backend_state) {
1611 case XenbusStateInitialising:
1612 case XenbusStateInitialised:
1613 case XenbusStateConnected:
1614 case XenbusStateUnknown:
1615 case XenbusStateClosed:
1616 break;
1617
1618 case XenbusStateInitWait:
1619 if (dev->state != XenbusStateInitialising)
1620 break;
1621 if (xennet_connect(netdev) != 0)
1622 break;
1623 xenbus_switch_state(dev, XenbusStateConnected);
1624 netif_notify_peers(netdev);
1625 break;
1626
1627 case XenbusStateClosing:
1628 xenbus_frontend_closed(dev);
1629 break;
1630 }
1631 }
1632
1633 static const struct ethtool_ops xennet_ethtool_ops =
1634 {
1635 .set_tx_csum = ethtool_op_set_tx_csum,
1636 .set_sg = xennet_set_sg,
1637 .set_tso = xennet_set_tso,
1638 .get_link = ethtool_op_get_link,
1639 };
1640
1641 #ifdef CONFIG_SYSFS
1642 static ssize_t show_rxbuf_min(struct device *dev,
1643 struct device_attribute *attr, char *buf)
1644 {
1645 struct net_device *netdev = to_net_dev(dev);
1646 struct netfront_info *info = netdev_priv(netdev);
1647
1648 return sprintf(buf, "%u\n", info->rx_min_target);
1649 }
1650
1651 static ssize_t store_rxbuf_min(struct device *dev,
1652 struct device_attribute *attr,
1653 const char *buf, size_t len)
1654 {
1655 struct net_device *netdev = to_net_dev(dev);
1656 struct netfront_info *np = netdev_priv(netdev);
1657 char *endp;
1658 unsigned long target;
1659
1660 if (!capable(CAP_NET_ADMIN))
1661 return -EPERM;
1662
1663 target = simple_strtoul(buf, &endp, 0);
1664 if (endp == buf)
1665 return -EBADMSG;
1666
1667 if (target < RX_MIN_TARGET)
1668 target = RX_MIN_TARGET;
1669 if (target > RX_MAX_TARGET)
1670 target = RX_MAX_TARGET;
1671
1672 spin_lock_bh(&np->rx_lock);
1673 if (target > np->rx_max_target)
1674 np->rx_max_target = target;
1675 np->rx_min_target = target;
1676 if (target > np->rx_target)
1677 np->rx_target = target;
1678
1679 xennet_alloc_rx_buffers(netdev);
1680
1681 spin_unlock_bh(&np->rx_lock);
1682 return len;
1683 }
1684
1685 static ssize_t show_rxbuf_max(struct device *dev,
1686 struct device_attribute *attr, char *buf)
1687 {
1688 struct net_device *netdev = to_net_dev(dev);
1689 struct netfront_info *info = netdev_priv(netdev);
1690
1691 return sprintf(buf, "%u\n", info->rx_max_target);
1692 }
1693
1694 static ssize_t store_rxbuf_max(struct device *dev,
1695 struct device_attribute *attr,
1696 const char *buf, size_t len)
1697 {
1698 struct net_device *netdev = to_net_dev(dev);
1699 struct netfront_info *np = netdev_priv(netdev);
1700 char *endp;
1701 unsigned long target;
1702
1703 if (!capable(CAP_NET_ADMIN))
1704 return -EPERM;
1705
1706 target = simple_strtoul(buf, &endp, 0);
1707 if (endp == buf)
1708 return -EBADMSG;
1709
1710 if (target < RX_MIN_TARGET)
1711 target = RX_MIN_TARGET;
1712 if (target > RX_MAX_TARGET)
1713 target = RX_MAX_TARGET;
1714
1715 spin_lock_bh(&np->rx_lock);
1716 if (target < np->rx_min_target)
1717 np->rx_min_target = target;
1718 np->rx_max_target = target;
1719 if (target < np->rx_target)
1720 np->rx_target = target;
1721
1722 xennet_alloc_rx_buffers(netdev);
1723
1724 spin_unlock_bh(&np->rx_lock);
1725 return len;
1726 }
1727
1728 static ssize_t show_rxbuf_cur(struct device *dev,
1729 struct device_attribute *attr, char *buf)
1730 {
1731 struct net_device *netdev = to_net_dev(dev);
1732 struct netfront_info *info = netdev_priv(netdev);
1733
1734 return sprintf(buf, "%u\n", info->rx_target);
1735 }
1736
1737 static struct device_attribute xennet_attrs[] = {
1738 __ATTR(rxbuf_min, S_IRUGO|S_IWUSR, show_rxbuf_min, store_rxbuf_min),
1739 __ATTR(rxbuf_max, S_IRUGO|S_IWUSR, show_rxbuf_max, store_rxbuf_max),
1740 __ATTR(rxbuf_cur, S_IRUGO, show_rxbuf_cur, NULL),
1741 };
1742
1743 static int xennet_sysfs_addif(struct net_device *netdev)
1744 {
1745 int i;
1746 int err;
1747
1748 for (i = 0; i < ARRAY_SIZE(xennet_attrs); i++) {
1749 err = device_create_file(&netdev->dev,
1750 &xennet_attrs[i]);
1751 if (err)
1752 goto fail;
1753 }
1754 return 0;
1755
1756 fail:
1757 while (--i >= 0)
1758 device_remove_file(&netdev->dev, &xennet_attrs[i]);
1759 return err;
1760 }
1761
1762 static void xennet_sysfs_delif(struct net_device *netdev)
1763 {
1764 int i;
1765
1766 for (i = 0; i < ARRAY_SIZE(xennet_attrs); i++)
1767 device_remove_file(&netdev->dev, &xennet_attrs[i]);
1768 }
1769
1770 #endif /* CONFIG_SYSFS */
1771
1772 static struct xenbus_device_id netfront_ids[] = {
1773 { "vif" },
1774 { "" }
1775 };
1776
1777
1778 static int __devexit xennet_remove(struct xenbus_device *dev)
1779 {
1780 struct netfront_info *info = dev_get_drvdata(&dev->dev);
1781
1782 dev_dbg(&dev->dev, "%s\n", dev->nodename);
1783
1784 unregister_netdev(info->netdev);
1785
1786 xennet_disconnect_backend(info);
1787
1788 del_timer_sync(&info->rx_refill_timer);
1789
1790 xennet_sysfs_delif(info->netdev);
1791
1792 free_netdev(info->netdev);
1793
1794 return 0;
1795 }
1796
1797 static struct xenbus_driver netfront_driver = {
1798 .name = "vif",
1799 .owner = THIS_MODULE,
1800 .ids = netfront_ids,
1801 .probe = netfront_probe,
1802 .remove = __devexit_p(xennet_remove),
1803 .resume = netfront_resume,
1804 .otherend_changed = backend_changed,
1805 };
1806
1807 static int __init netif_init(void)
1808 {
1809 if (!xen_domain())
1810 return -ENODEV;
1811
1812 if (xen_initial_domain())
1813 return 0;
1814
1815 printk(KERN_INFO "Initialising Xen virtual ethernet driver.\n");
1816
1817 return xenbus_register_frontend(&netfront_driver);
1818 }
1819 module_init(netif_init);
1820
1821
1822 static void __exit netif_exit(void)
1823 {
1824 if (xen_initial_domain())
1825 return;
1826
1827 xenbus_unregister_driver(&netfront_driver);
1828 }
1829 module_exit(netif_exit);
1830
1831 MODULE_DESCRIPTION("Xen virtual network device frontend");
1832 MODULE_LICENSE("GPL");
1833 MODULE_ALIAS("xen:vif");
1834 MODULE_ALIAS("xennet");
Linus' kernel tree