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drivers/net/ethernet/sun: remove depends on CONFIG_EXPERIMENTAL
[linux/fpc-iii.git] / drivers / net / xen-netfront.c
blob7ffa43bd7cf9e9f3b1fc43f83d0ec4c53b355765
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 <asm/xen/page.h>
47 #include <xen/xen.h>
48 #include <xen/xenbus.h>
49 #include <xen/events.h>
50 #include <xen/page.h>
51 #include <xen/platform_pci.h>
52 #include <xen/grant_table.h>
53
54 #include <xen/interface/io/netif.h>
55 #include <xen/interface/memory.h>
56 #include <xen/interface/grant_table.h>
57
58 static const struct ethtool_ops xennet_ethtool_ops;
59
60 struct netfront_cb {
61 int pull_to;
62 };
63
64 #define NETFRONT_SKB_CB(skb) ((struct netfront_cb *)((skb)->cb))
65
66 #define RX_COPY_THRESHOLD 256
67
68 #define GRANT_INVALID_REF 0
69
70 #define NET_TX_RING_SIZE __CONST_RING_SIZE(xen_netif_tx, PAGE_SIZE)
71 #define NET_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, PAGE_SIZE)
72 #define TX_MAX_TARGET min_t(int, NET_TX_RING_SIZE, 256)
73
74 struct netfront_stats {
75 u64 rx_packets;
76 u64 tx_packets;
77 u64 rx_bytes;
78 u64 tx_bytes;
79 struct u64_stats_sync syncp;
80 };
81
82 struct netfront_info {
83 struct list_head list;
84 struct net_device *netdev;
85
86 struct napi_struct napi;
87
88 unsigned int evtchn;
89 struct xenbus_device *xbdev;
90
91 spinlock_t tx_lock;
92 struct xen_netif_tx_front_ring tx;
93 int tx_ring_ref;
94
95 /*
96 * {tx,rx}_skbs store outstanding skbuffs. Free tx_skb entries
97 * are linked from tx_skb_freelist through skb_entry.link.
98 *
99 * NB. Freelist index entries are always going to be less than
100 * PAGE_OFFSET, whereas pointers to skbs will always be equal or
101 * greater than PAGE_OFFSET: we use this property to distinguish
102 * them.
103 */
104 union skb_entry {
105 struct sk_buff *skb;
106 unsigned long link;
107 } tx_skbs[NET_TX_RING_SIZE];
108 grant_ref_t gref_tx_head;
109 grant_ref_t grant_tx_ref[NET_TX_RING_SIZE];
110 unsigned tx_skb_freelist;
111
112 spinlock_t rx_lock ____cacheline_aligned_in_smp;
113 struct xen_netif_rx_front_ring rx;
114 int rx_ring_ref;
115
116 /* Receive-ring batched refills. */
117 #define RX_MIN_TARGET 8
118 #define RX_DFL_MIN_TARGET 64
119 #define RX_MAX_TARGET min_t(int, NET_RX_RING_SIZE, 256)
120 unsigned rx_min_target, rx_max_target, rx_target;
121 struct sk_buff_head rx_batch;
122
123 struct timer_list rx_refill_timer;
124
125 struct sk_buff *rx_skbs[NET_RX_RING_SIZE];
126 grant_ref_t gref_rx_head;
127 grant_ref_t grant_rx_ref[NET_RX_RING_SIZE];
128
129 unsigned long rx_pfn_array[NET_RX_RING_SIZE];
130 struct multicall_entry rx_mcl[NET_RX_RING_SIZE+1];
131 struct mmu_update rx_mmu[NET_RX_RING_SIZE];
132
133 /* Statistics */
134 struct netfront_stats __percpu *stats;
135
136 unsigned long rx_gso_checksum_fixup;
137 };
138
139 struct netfront_rx_info {
140 struct xen_netif_rx_response rx;
141 struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX - 1];
142 };
143
144 static void skb_entry_set_link(union skb_entry *list, unsigned short id)
145 {
146 list->link = id;
147 }
148
149 static int skb_entry_is_link(const union skb_entry *list)
150 {
151 BUILD_BUG_ON(sizeof(list->skb) != sizeof(list->link));
152 return (unsigned long)list->skb < PAGE_OFFSET;
153 }
154
155 /*
156 * Access macros for acquiring freeing slots in tx_skbs[].
157 */
158
159 static void add_id_to_freelist(unsigned *head, union skb_entry *list,
160 unsigned short id)
161 {
162 skb_entry_set_link(&list[id], *head);
163 *head = id;
164 }
165
166 static unsigned short get_id_from_freelist(unsigned *head,
167 union skb_entry *list)
168 {
169 unsigned int id = *head;
170 *head = list[id].link;
171 return id;
172 }
173
174 static int xennet_rxidx(RING_IDX idx)
175 {
176 return idx & (NET_RX_RING_SIZE - 1);
177 }
178
179 static struct sk_buff *xennet_get_rx_skb(struct netfront_info *np,
180 RING_IDX ri)
181 {
182 int i = xennet_rxidx(ri);
183 struct sk_buff *skb = np->rx_skbs[i];
184 np->rx_skbs[i] = NULL;
185 return skb;
186 }
187
188 static grant_ref_t xennet_get_rx_ref(struct netfront_info *np,
189 RING_IDX ri)
190 {
191 int i = xennet_rxidx(ri);
192 grant_ref_t ref = np->grant_rx_ref[i];
193 np->grant_rx_ref[i] = GRANT_INVALID_REF;
194 return ref;
195 }
196
197 #ifdef CONFIG_SYSFS
198 static int xennet_sysfs_addif(struct net_device *netdev);
199 static void xennet_sysfs_delif(struct net_device *netdev);
200 #else /* !CONFIG_SYSFS */
201 #define xennet_sysfs_addif(dev) (0)
202 #define xennet_sysfs_delif(dev) do { } while (0)
203 #endif
204
205 static bool xennet_can_sg(struct net_device *dev)
206 {
207 return dev->features & NETIF_F_SG;
208 }
209
210
211 static void rx_refill_timeout(unsigned long data)
212 {
213 struct net_device *dev = (struct net_device *)data;
214 struct netfront_info *np = netdev_priv(dev);
215 napi_schedule(&np->napi);
216 }
217
218 static int netfront_tx_slot_available(struct netfront_info *np)
219 {
220 return (np->tx.req_prod_pvt - np->tx.rsp_cons) <
221 (TX_MAX_TARGET - MAX_SKB_FRAGS - 2);
222 }
223
224 static void xennet_maybe_wake_tx(struct net_device *dev)
225 {
226 struct netfront_info *np = netdev_priv(dev);
227
228 if (unlikely(netif_queue_stopped(dev)) &&
229 netfront_tx_slot_available(np) &&
230 likely(netif_running(dev)))
231 netif_wake_queue(dev);
232 }
233
234 static void xennet_alloc_rx_buffers(struct net_device *dev)
235 {
236 unsigned short id;
237 struct netfront_info *np = netdev_priv(dev);
238 struct sk_buff *skb;
239 struct page *page;
240 int i, batch_target, notify;
241 RING_IDX req_prod = np->rx.req_prod_pvt;
242 grant_ref_t ref;
243 unsigned long pfn;
244 void *vaddr;
245 struct xen_netif_rx_request *req;
246
247 if (unlikely(!netif_carrier_ok(dev)))
248 return;
249
250 /*
251 * Allocate skbuffs greedily, even though we batch updates to the
252 * receive ring. This creates a less bursty demand on the memory
253 * allocator, so should reduce the chance of failed allocation requests
254 * both for ourself and for other kernel subsystems.
255 */
256 batch_target = np->rx_target - (req_prod - np->rx.rsp_cons);
257 for (i = skb_queue_len(&np->rx_batch); i < batch_target; i++) {
258 skb = __netdev_alloc_skb(dev, RX_COPY_THRESHOLD + NET_IP_ALIGN,
259 GFP_ATOMIC | __GFP_NOWARN);
260 if (unlikely(!skb))
261 goto no_skb;
262
263 /* Align ip header to a 16 bytes boundary */
264 skb_reserve(skb, NET_IP_ALIGN);
265
266 page = alloc_page(GFP_ATOMIC | __GFP_NOWARN);
267 if (!page) {
268 kfree_skb(skb);
269 no_skb:
270 /* Any skbuffs queued for refill? Force them out. */
271 if (i != 0)
272 goto refill;
273 /* Could not allocate any skbuffs. Try again later. */
274 mod_timer(&np->rx_refill_timer,
275 jiffies + (HZ/10));
276 break;
277 }
278
279 __skb_fill_page_desc(skb, 0, page, 0, 0);
280 skb_shinfo(skb)->nr_frags = 1;
281 __skb_queue_tail(&np->rx_batch, skb);
282 }
283
284 /* Is the batch large enough to be worthwhile? */
285 if (i < (np->rx_target/2)) {
286 if (req_prod > np->rx.sring->req_prod)
287 goto push;
288 return;
289 }
290
291 /* Adjust our fill target if we risked running out of buffers. */
292 if (((req_prod - np->rx.sring->rsp_prod) < (np->rx_target / 4)) &&
293 ((np->rx_target *= 2) > np->rx_max_target))
294 np->rx_target = np->rx_max_target;
295
296 refill:
297 for (i = 0; ; i++) {
298 skb = __skb_dequeue(&np->rx_batch);
299 if (skb == NULL)
300 break;
301
302 skb->dev = dev;
303
304 id = xennet_rxidx(req_prod + i);
305
306 BUG_ON(np->rx_skbs[id]);
307 np->rx_skbs[id] = skb;
308
309 ref = gnttab_claim_grant_reference(&np->gref_rx_head);
310 BUG_ON((signed short)ref < 0);
311 np->grant_rx_ref[id] = ref;
312
313 pfn = page_to_pfn(skb_frag_page(&skb_shinfo(skb)->frags[0]));
314 vaddr = page_address(skb_frag_page(&skb_shinfo(skb)->frags[0]));
315
316 req = RING_GET_REQUEST(&np->rx, req_prod + i);
317 gnttab_grant_foreign_access_ref(ref,
318 np->xbdev->otherend_id,
319 pfn_to_mfn(pfn),
320 0);
321
322 req->id = id;
323 req->gref = ref;
324 }
325
326 wmb(); /* barrier so backend seens requests */
327
328 /* Above is a suitable barrier to ensure backend will see requests. */
329 np->rx.req_prod_pvt = req_prod + i;
330 push:
331 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&np->rx, notify);
332 if (notify)
333 notify_remote_via_irq(np->netdev->irq);
334 }
335
336 static int xennet_open(struct net_device *dev)
337 {
338 struct netfront_info *np = netdev_priv(dev);
339
340 napi_enable(&np->napi);
341
342 spin_lock_bh(&np->rx_lock);
343 if (netif_carrier_ok(dev)) {
344 xennet_alloc_rx_buffers(dev);
345 np->rx.sring->rsp_event = np->rx.rsp_cons + 1;
346 if (RING_HAS_UNCONSUMED_RESPONSES(&np->rx))
347 napi_schedule(&np->napi);
348 }
349 spin_unlock_bh(&np->rx_lock);
350
351 netif_start_queue(dev);
352
353 return 0;
354 }
355
356 static void xennet_tx_buf_gc(struct net_device *dev)
357 {
358 RING_IDX cons, prod;
359 unsigned short id;
360 struct netfront_info *np = netdev_priv(dev);
361 struct sk_buff *skb;
362
363 BUG_ON(!netif_carrier_ok(dev));
364
365 do {
366 prod = np->tx.sring->rsp_prod;
367 rmb(); /* Ensure we see responses up to 'rp'. */
368
369 for (cons = np->tx.rsp_cons; cons != prod; cons++) {
370 struct xen_netif_tx_response *txrsp;
371
372 txrsp = RING_GET_RESPONSE(&np->tx, cons);
373 if (txrsp->status == XEN_NETIF_RSP_NULL)
374 continue;
375
376 id = txrsp->id;
377 skb = np->tx_skbs[id].skb;
378 if (unlikely(gnttab_query_foreign_access(
379 np->grant_tx_ref[id]) != 0)) {
380 printk(KERN_ALERT "xennet_tx_buf_gc: warning "
381 "-- grant still in use by backend "
382 "domain.\n");
383 BUG();
384 }
385 gnttab_end_foreign_access_ref(
386 np->grant_tx_ref[id], GNTMAP_readonly);
387 gnttab_release_grant_reference(
388 &np->gref_tx_head, np->grant_tx_ref[id]);
389 np->grant_tx_ref[id] = GRANT_INVALID_REF;
390 add_id_to_freelist(&np->tx_skb_freelist, np->tx_skbs, id);
391 dev_kfree_skb_irq(skb);
392 }
393
394 np->tx.rsp_cons = prod;
395
396 /*
397 * Set a new event, then check for race with update of tx_cons.
398 * Note that it is essential to schedule a callback, no matter
399 * how few buffers are pending. Even if there is space in the
400 * transmit ring, higher layers may be blocked because too much
401 * data is outstanding: in such cases notification from Xen is
402 * likely to be the only kick that we'll get.
403 */
404 np->tx.sring->rsp_event =
405 prod + ((np->tx.sring->req_prod - prod) >> 1) + 1;
406 mb(); /* update shared area */
407 } while ((cons == prod) && (prod != np->tx.sring->rsp_prod));
408
409 xennet_maybe_wake_tx(dev);
410 }
411
412 static void xennet_make_frags(struct sk_buff *skb, struct net_device *dev,
413 struct xen_netif_tx_request *tx)
414 {
415 struct netfront_info *np = netdev_priv(dev);
416 char *data = skb->data;
417 unsigned long mfn;
418 RING_IDX prod = np->tx.req_prod_pvt;
419 int frags = skb_shinfo(skb)->nr_frags;
420 unsigned int offset = offset_in_page(data);
421 unsigned int len = skb_headlen(skb);
422 unsigned int id;
423 grant_ref_t ref;
424 int i;
425
426 /* While the header overlaps a page boundary (including being
427 larger than a page), split it it into page-sized chunks. */
428 while (len > PAGE_SIZE - offset) {
429 tx->size = PAGE_SIZE - offset;
430 tx->flags |= XEN_NETTXF_more_data;
431 len -= tx->size;
432 data += tx->size;
433 offset = 0;
434
435 id = get_id_from_freelist(&np->tx_skb_freelist, np->tx_skbs);
436 np->tx_skbs[id].skb = skb_get(skb);
437 tx = RING_GET_REQUEST(&np->tx, prod++);
438 tx->id = id;
439 ref = gnttab_claim_grant_reference(&np->gref_tx_head);
440 BUG_ON((signed short)ref < 0);
441
442 mfn = virt_to_mfn(data);
443 gnttab_grant_foreign_access_ref(ref, np->xbdev->otherend_id,
444 mfn, GNTMAP_readonly);
445
446 tx->gref = np->grant_tx_ref[id] = ref;
447 tx->offset = offset;
448 tx->size = len;
449 tx->flags = 0;
450 }
451
452 /* Grant backend access to each skb fragment page. */
453 for (i = 0; i < frags; i++) {
454 skb_frag_t *frag = skb_shinfo(skb)->frags + i;
455 struct page *page = skb_frag_page(frag);
456
457 len = skb_frag_size(frag);
458 offset = frag->page_offset;
459
460 /* Data must not cross a page boundary. */
461 BUG_ON(len + offset > PAGE_SIZE<<compound_order(page));
462
463 /* Skip unused frames from start of page */
464 page += offset >> PAGE_SHIFT;
465 offset &= ~PAGE_MASK;
466
467 while (len > 0) {
468 unsigned long bytes;
469
470 BUG_ON(offset >= PAGE_SIZE);
471
472 bytes = PAGE_SIZE - offset;
473 if (bytes > len)
474 bytes = len;
475
476 tx->flags |= XEN_NETTXF_more_data;
477
478 id = get_id_from_freelist(&np->tx_skb_freelist,
479 np->tx_skbs);
480 np->tx_skbs[id].skb = skb_get(skb);
481 tx = RING_GET_REQUEST(&np->tx, prod++);
482 tx->id = id;
483 ref = gnttab_claim_grant_reference(&np->gref_tx_head);
484 BUG_ON((signed short)ref < 0);
485
486 mfn = pfn_to_mfn(page_to_pfn(page));
487 gnttab_grant_foreign_access_ref(ref,
488 np->xbdev->otherend_id,
489 mfn, GNTMAP_readonly);
490
491 tx->gref = np->grant_tx_ref[id] = ref;
492 tx->offset = offset;
493 tx->size = bytes;
494 tx->flags = 0;
495
496 offset += bytes;
497 len -= bytes;
498
499 /* Next frame */
500 if (offset == PAGE_SIZE && len) {
501 BUG_ON(!PageCompound(page));
502 page++;
503 offset = 0;
504 }
505 }
506 }
507
508 np->tx.req_prod_pvt = prod;
509 }
510
511 /*
512 * Count how many ring slots are required to send the frags of this
513 * skb. Each frag might be a compound page.
514 */
515 static int xennet_count_skb_frag_slots(struct sk_buff *skb)
516 {
517 int i, frags = skb_shinfo(skb)->nr_frags;
518 int pages = 0;
519
520 for (i = 0; i < frags; i++) {
521 skb_frag_t *frag = skb_shinfo(skb)->frags + i;
522 unsigned long size = skb_frag_size(frag);
523 unsigned long offset = frag->page_offset;
524
525 /* Skip unused frames from start of page */
526 offset &= ~PAGE_MASK;
527
528 pages += PFN_UP(offset + size);
529 }
530
531 return pages;
532 }
533
534 static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev)
535 {
536 unsigned short id;
537 struct netfront_info *np = netdev_priv(dev);
538 struct netfront_stats *stats = this_cpu_ptr(np->stats);
539 struct xen_netif_tx_request *tx;
540 struct xen_netif_extra_info *extra;
541 char *data = skb->data;
542 RING_IDX i;
543 grant_ref_t ref;
544 unsigned long mfn;
545 int notify;
546 int slots;
547 unsigned int offset = offset_in_page(data);
548 unsigned int len = skb_headlen(skb);
549 unsigned long flags;
550
551 slots = DIV_ROUND_UP(offset + len, PAGE_SIZE) +
552 xennet_count_skb_frag_slots(skb);
553 if (unlikely(slots > MAX_SKB_FRAGS + 1)) {
554 net_alert_ratelimited(
555 "xennet: skb rides the rocket: %d slots\n", slots);
556 goto drop;
557 }
558
559 spin_lock_irqsave(&np->tx_lock, flags);
560
561 if (unlikely(!netif_carrier_ok(dev) ||
562 (slots > 1 && !xennet_can_sg(dev)) ||
563 netif_needs_gso(skb, netif_skb_features(skb)))) {
564 spin_unlock_irqrestore(&np->tx_lock, flags);
565 goto drop;
566 }
567
568 i = np->tx.req_prod_pvt;
569
570 id = get_id_from_freelist(&np->tx_skb_freelist, np->tx_skbs);
571 np->tx_skbs[id].skb = skb;
572
573 tx = RING_GET_REQUEST(&np->tx, i);
574
575 tx->id = id;
576 ref = gnttab_claim_grant_reference(&np->gref_tx_head);
577 BUG_ON((signed short)ref < 0);
578 mfn = virt_to_mfn(data);
579 gnttab_grant_foreign_access_ref(
580 ref, np->xbdev->otherend_id, mfn, GNTMAP_readonly);
581 tx->gref = np->grant_tx_ref[id] = ref;
582 tx->offset = offset;
583 tx->size = len;
584 extra = NULL;
585
586 tx->flags = 0;
587 if (skb->ip_summed == CHECKSUM_PARTIAL)
588 /* local packet? */
589 tx->flags |= XEN_NETTXF_csum_blank | XEN_NETTXF_data_validated;
590 else if (skb->ip_summed == CHECKSUM_UNNECESSARY)
591 /* remote but checksummed. */
592 tx->flags |= XEN_NETTXF_data_validated;
593
594 if (skb_shinfo(skb)->gso_size) {
595 struct xen_netif_extra_info *gso;
596
597 gso = (struct xen_netif_extra_info *)
598 RING_GET_REQUEST(&np->tx, ++i);
599
600 if (extra)
601 extra->flags |= XEN_NETIF_EXTRA_FLAG_MORE;
602 else
603 tx->flags |= XEN_NETTXF_extra_info;
604
605 gso->u.gso.size = skb_shinfo(skb)->gso_size;
606 gso->u.gso.type = XEN_NETIF_GSO_TYPE_TCPV4;
607 gso->u.gso.pad = 0;
608 gso->u.gso.features = 0;
609
610 gso->type = XEN_NETIF_EXTRA_TYPE_GSO;
611 gso->flags = 0;
612 extra = gso;
613 }
614
615 np->tx.req_prod_pvt = i + 1;
616
617 xennet_make_frags(skb, dev, tx);
618 tx->size = skb->len;
619
620 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&np->tx, notify);
621 if (notify)
622 notify_remote_via_irq(np->netdev->irq);
623
624 u64_stats_update_begin(&stats->syncp);
625 stats->tx_bytes += skb->len;
626 stats->tx_packets++;
627 u64_stats_update_end(&stats->syncp);
628
629 /* Note: It is not safe to access skb after xennet_tx_buf_gc()! */
630 xennet_tx_buf_gc(dev);
631
632 if (!netfront_tx_slot_available(np))
633 netif_stop_queue(dev);
634
635 spin_unlock_irqrestore(&np->tx_lock, flags);
636
637 return NETDEV_TX_OK;
638
639 drop:
640 dev->stats.tx_dropped++;
641 dev_kfree_skb(skb);
642 return NETDEV_TX_OK;
643 }
644
645 static int xennet_close(struct net_device *dev)
646 {
647 struct netfront_info *np = netdev_priv(dev);
648 netif_stop_queue(np->netdev);
649 napi_disable(&np->napi);
650 return 0;
651 }
652
653 static void xennet_move_rx_slot(struct netfront_info *np, struct sk_buff *skb,
654 grant_ref_t ref)
655 {
656 int new = xennet_rxidx(np->rx.req_prod_pvt);
657
658 BUG_ON(np->rx_skbs[new]);
659 np->rx_skbs[new] = skb;
660 np->grant_rx_ref[new] = ref;
661 RING_GET_REQUEST(&np->rx, np->rx.req_prod_pvt)->id = new;
662 RING_GET_REQUEST(&np->rx, np->rx.req_prod_pvt)->gref = ref;
663 np->rx.req_prod_pvt++;
664 }
665
666 static int xennet_get_extras(struct netfront_info *np,
667 struct xen_netif_extra_info *extras,
668 RING_IDX rp)
669
670 {
671 struct xen_netif_extra_info *extra;
672 struct device *dev = &np->netdev->dev;
673 RING_IDX cons = np->rx.rsp_cons;
674 int err = 0;
675
676 do {
677 struct sk_buff *skb;
678 grant_ref_t ref;
679
680 if (unlikely(cons + 1 == rp)) {
681 if (net_ratelimit())
682 dev_warn(dev, "Missing extra info\n");
683 err = -EBADR;
684 break;
685 }
686
687 extra = (struct xen_netif_extra_info *)
688 RING_GET_RESPONSE(&np->rx, ++cons);
689
690 if (unlikely(!extra->type ||
691 extra->type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
692 if (net_ratelimit())
693 dev_warn(dev, "Invalid extra type: %d\n",
694 extra->type);
695 err = -EINVAL;
696 } else {
697 memcpy(&extras[extra->type - 1], extra,
698 sizeof(*extra));
699 }
700
701 skb = xennet_get_rx_skb(np, cons);
702 ref = xennet_get_rx_ref(np, cons);
703 xennet_move_rx_slot(np, skb, ref);
704 } while (extra->flags & XEN_NETIF_EXTRA_FLAG_MORE);
705
706 np->rx.rsp_cons = cons;
707 return err;
708 }
709
710 static int xennet_get_responses(struct netfront_info *np,
711 struct netfront_rx_info *rinfo, RING_IDX rp,
712 struct sk_buff_head *list)
713 {
714 struct xen_netif_rx_response *rx = &rinfo->rx;
715 struct xen_netif_extra_info *extras = rinfo->extras;
716 struct device *dev = &np->netdev->dev;
717 RING_IDX cons = np->rx.rsp_cons;
718 struct sk_buff *skb = xennet_get_rx_skb(np, cons);
719 grant_ref_t ref = xennet_get_rx_ref(np, cons);
720 int max = MAX_SKB_FRAGS + (rx->status <= RX_COPY_THRESHOLD);
721 int frags = 1;
722 int err = 0;
723 unsigned long ret;
724
725 if (rx->flags & XEN_NETRXF_extra_info) {
726 err = xennet_get_extras(np, extras, rp);
727 cons = np->rx.rsp_cons;
728 }
729
730 for (;;) {
731 if (unlikely(rx->status < 0 ||
732 rx->offset + rx->status > PAGE_SIZE)) {
733 if (net_ratelimit())
734 dev_warn(dev, "rx->offset: %x, size: %u\n",
735 rx->offset, rx->status);
736 xennet_move_rx_slot(np, skb, ref);
737 err = -EINVAL;
738 goto next;
739 }
740
741 /*
742 * This definitely indicates a bug, either in this driver or in
743 * the backend driver. In future this should flag the bad
744 * situation to the system controller to reboot the backed.
745 */
746 if (ref == GRANT_INVALID_REF) {
747 if (net_ratelimit())
748 dev_warn(dev, "Bad rx response id %d.\n",
749 rx->id);
750 err = -EINVAL;
751 goto next;
752 }
753
754 ret = gnttab_end_foreign_access_ref(ref, 0);
755 BUG_ON(!ret);
756
757 gnttab_release_grant_reference(&np->gref_rx_head, ref);
758
759 __skb_queue_tail(list, skb);
760
761 next:
762 if (!(rx->flags & XEN_NETRXF_more_data))
763 break;
764
765 if (cons + frags == rp) {
766 if (net_ratelimit())
767 dev_warn(dev, "Need more frags\n");
768 err = -ENOENT;
769 break;
770 }
771
772 rx = RING_GET_RESPONSE(&np->rx, cons + frags);
773 skb = xennet_get_rx_skb(np, cons + frags);
774 ref = xennet_get_rx_ref(np, cons + frags);
775 frags++;
776 }
777
778 if (unlikely(frags > max)) {
779 if (net_ratelimit())
780 dev_warn(dev, "Too many frags\n");
781 err = -E2BIG;
782 }
783
784 if (unlikely(err))
785 np->rx.rsp_cons = cons + frags;
786
787 return err;
788 }
789
790 static int xennet_set_skb_gso(struct sk_buff *skb,
791 struct xen_netif_extra_info *gso)
792 {
793 if (!gso->u.gso.size) {
794 if (net_ratelimit())
795 printk(KERN_WARNING "GSO size must not be zero.\n");
796 return -EINVAL;
797 }
798
799 /* Currently only TCPv4 S.O. is supported. */
800 if (gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV4) {
801 if (net_ratelimit())
802 printk(KERN_WARNING "Bad GSO type %d.\n", gso->u.gso.type);
803 return -EINVAL;
804 }
805
806 skb_shinfo(skb)->gso_size = gso->u.gso.size;
807 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
808
809 /* Header must be checked, and gso_segs computed. */
810 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
811 skb_shinfo(skb)->gso_segs = 0;
812
813 return 0;
814 }
815
816 static RING_IDX xennet_fill_frags(struct netfront_info *np,
817 struct sk_buff *skb,
818 struct sk_buff_head *list)
819 {
820 struct skb_shared_info *shinfo = skb_shinfo(skb);
821 int nr_frags = shinfo->nr_frags;
822 RING_IDX cons = np->rx.rsp_cons;
823 struct sk_buff *nskb;
824
825 while ((nskb = __skb_dequeue(list))) {
826 struct xen_netif_rx_response *rx =
827 RING_GET_RESPONSE(&np->rx, ++cons);
828 skb_frag_t *nfrag = &skb_shinfo(nskb)->frags[0];
829
830 __skb_fill_page_desc(skb, nr_frags,
831 skb_frag_page(nfrag),
832 rx->offset, rx->status);
833
834 skb->data_len += rx->status;
835
836 skb_shinfo(nskb)->nr_frags = 0;
837 kfree_skb(nskb);
838
839 nr_frags++;
840 }
841
842 shinfo->nr_frags = nr_frags;
843 return cons;
844 }
845
846 static int checksum_setup(struct net_device *dev, struct sk_buff *skb)
847 {
848 struct iphdr *iph;
849 unsigned char *th;
850 int err = -EPROTO;
851 int recalculate_partial_csum = 0;
852
853 /*
854 * A GSO SKB must be CHECKSUM_PARTIAL. However some buggy
855 * peers can fail to set NETRXF_csum_blank when sending a GSO
856 * frame. In this case force the SKB to CHECKSUM_PARTIAL and
857 * recalculate the partial checksum.
858 */
859 if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) {
860 struct netfront_info *np = netdev_priv(dev);
861 np->rx_gso_checksum_fixup++;
862 skb->ip_summed = CHECKSUM_PARTIAL;
863 recalculate_partial_csum = 1;
864 }
865
866 /* A non-CHECKSUM_PARTIAL SKB does not require setup. */
867 if (skb->ip_summed != CHECKSUM_PARTIAL)
868 return 0;
869
870 if (skb->protocol != htons(ETH_P_IP))
871 goto out;
872
873 iph = (void *)skb->data;
874 th = skb->data + 4 * iph->ihl;
875 if (th >= skb_tail_pointer(skb))
876 goto out;
877
878 skb->csum_start = th - skb->head;
879 switch (iph->protocol) {
880 case IPPROTO_TCP:
881 skb->csum_offset = offsetof(struct tcphdr, check);
882
883 if (recalculate_partial_csum) {
884 struct tcphdr *tcph = (struct tcphdr *)th;
885 tcph->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr,
886 skb->len - iph->ihl*4,
887 IPPROTO_TCP, 0);
888 }
889 break;
890 case IPPROTO_UDP:
891 skb->csum_offset = offsetof(struct udphdr, check);
892
893 if (recalculate_partial_csum) {
894 struct udphdr *udph = (struct udphdr *)th;
895 udph->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr,
896 skb->len - iph->ihl*4,
897 IPPROTO_UDP, 0);
898 }
899 break;
900 default:
901 if (net_ratelimit())
902 printk(KERN_ERR "Attempting to checksum a non-"
903 "TCP/UDP packet, dropping a protocol"
904 " %d packet", iph->protocol);
905 goto out;
906 }
907
908 if ((th + skb->csum_offset + 2) > skb_tail_pointer(skb))
909 goto out;
910
911 err = 0;
912
913 out:
914 return err;
915 }
916
917 static int handle_incoming_queue(struct net_device *dev,
918 struct sk_buff_head *rxq)
919 {
920 struct netfront_info *np = netdev_priv(dev);
921 struct netfront_stats *stats = this_cpu_ptr(np->stats);
922 int packets_dropped = 0;
923 struct sk_buff *skb;
924
925 while ((skb = __skb_dequeue(rxq)) != NULL) {
926 int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
927
928 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
929
930 /* Ethernet work: Delayed to here as it peeks the header. */
931 skb->protocol = eth_type_trans(skb, dev);
932
933 if (checksum_setup(dev, skb)) {
934 kfree_skb(skb);
935 packets_dropped++;
936 dev->stats.rx_errors++;
937 continue;
938 }
939
940 u64_stats_update_begin(&stats->syncp);
941 stats->rx_packets++;
942 stats->rx_bytes += skb->len;
943 u64_stats_update_end(&stats->syncp);
944
945 /* Pass it up. */
946 netif_receive_skb(skb);
947 }
948
949 return packets_dropped;
950 }
951
952 static int xennet_poll(struct napi_struct *napi, int budget)
953 {
954 struct netfront_info *np = container_of(napi, struct netfront_info, napi);
955 struct net_device *dev = np->netdev;
956 struct sk_buff *skb;
957 struct netfront_rx_info rinfo;
958 struct xen_netif_rx_response *rx = &rinfo.rx;
959 struct xen_netif_extra_info *extras = rinfo.extras;
960 RING_IDX i, rp;
961 int work_done;
962 struct sk_buff_head rxq;
963 struct sk_buff_head errq;
964 struct sk_buff_head tmpq;
965 unsigned long flags;
966 int err;
967
968 spin_lock(&np->rx_lock);
969
970 skb_queue_head_init(&rxq);
971 skb_queue_head_init(&errq);
972 skb_queue_head_init(&tmpq);
973
974 rp = np->rx.sring->rsp_prod;
975 rmb(); /* Ensure we see queued responses up to 'rp'. */
976
977 i = np->rx.rsp_cons;
978 work_done = 0;
979 while ((i != rp) && (work_done < budget)) {
980 memcpy(rx, RING_GET_RESPONSE(&np->rx, i), sizeof(*rx));
981 memset(extras, 0, sizeof(rinfo.extras));
982
983 err = xennet_get_responses(np, &rinfo, rp, &tmpq);
984
985 if (unlikely(err)) {
986 err:
987 while ((skb = __skb_dequeue(&tmpq)))
988 __skb_queue_tail(&errq, skb);
989 dev->stats.rx_errors++;
990 i = np->rx.rsp_cons;
991 continue;
992 }
993
994 skb = __skb_dequeue(&tmpq);
995
996 if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) {
997 struct xen_netif_extra_info *gso;
998 gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1];
999
1000 if (unlikely(xennet_set_skb_gso(skb, gso))) {
1001 __skb_queue_head(&tmpq, skb);
1002 np->rx.rsp_cons += skb_queue_len(&tmpq);
1003 goto err;
1004 }
1005 }
1006
1007 NETFRONT_SKB_CB(skb)->pull_to = rx->status;
1008 if (NETFRONT_SKB_CB(skb)->pull_to > RX_COPY_THRESHOLD)
1009 NETFRONT_SKB_CB(skb)->pull_to = RX_COPY_THRESHOLD;
1010
1011 skb_shinfo(skb)->frags[0].page_offset = rx->offset;
1012 skb_frag_size_set(&skb_shinfo(skb)->frags[0], rx->status);
1013 skb->data_len = rx->status;
1014
1015 i = xennet_fill_frags(np, skb, &tmpq);
1016
1017 /*
1018 * Truesize is the actual allocation size, even if the
1019 * allocation is only partially used.
1020 */
1021 skb->truesize += PAGE_SIZE * skb_shinfo(skb)->nr_frags;
1022 skb->len += skb->data_len;
1023
1024 if (rx->flags & XEN_NETRXF_csum_blank)
1025 skb->ip_summed = CHECKSUM_PARTIAL;
1026 else if (rx->flags & XEN_NETRXF_data_validated)
1027 skb->ip_summed = CHECKSUM_UNNECESSARY;
1028
1029 __skb_queue_tail(&rxq, skb);
1030
1031 np->rx.rsp_cons = ++i;
1032 work_done++;
1033 }
1034
1035 __skb_queue_purge(&errq);
1036
1037 work_done -= handle_incoming_queue(dev, &rxq);
1038
1039 /* If we get a callback with very few responses, reduce fill target. */
1040 /* NB. Note exponential increase, linear decrease. */
1041 if (((np->rx.req_prod_pvt - np->rx.sring->rsp_prod) >
1042 ((3*np->rx_target) / 4)) &&
1043 (--np->rx_target < np->rx_min_target))
1044 np->rx_target = np->rx_min_target;
1045
1046 xennet_alloc_rx_buffers(dev);
1047
1048 if (work_done < budget) {
1049 int more_to_do = 0;
1050
1051 local_irq_save(flags);
1052
1053 RING_FINAL_CHECK_FOR_RESPONSES(&np->rx, more_to_do);
1054 if (!more_to_do)
1055 __napi_complete(napi);
1056
1057 local_irq_restore(flags);
1058 }
1059
1060 spin_unlock(&np->rx_lock);
1061
1062 return work_done;
1063 }
1064
1065 static int xennet_change_mtu(struct net_device *dev, int mtu)
1066 {
1067 int max = xennet_can_sg(dev) ? 65535 - ETH_HLEN : ETH_DATA_LEN;
1068
1069 if (mtu > max)
1070 return -EINVAL;
1071 dev->mtu = mtu;
1072 return 0;
1073 }
1074
1075 static struct rtnl_link_stats64 *xennet_get_stats64(struct net_device *dev,
1076 struct rtnl_link_stats64 *tot)
1077 {
1078 struct netfront_info *np = netdev_priv(dev);
1079 int cpu;
1080
1081 for_each_possible_cpu(cpu) {
1082 struct netfront_stats *stats = per_cpu_ptr(np->stats, cpu);
1083 u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
1084 unsigned int start;
1085
1086 do {
1087 start = u64_stats_fetch_begin_bh(&stats->syncp);
1088
1089 rx_packets = stats->rx_packets;
1090 tx_packets = stats->tx_packets;
1091 rx_bytes = stats->rx_bytes;
1092 tx_bytes = stats->tx_bytes;
1093 } while (u64_stats_fetch_retry_bh(&stats->syncp, start));
1094
1095 tot->rx_packets += rx_packets;
1096 tot->tx_packets += tx_packets;
1097 tot->rx_bytes += rx_bytes;
1098 tot->tx_bytes += tx_bytes;
1099 }
1100
1101 tot->rx_errors = dev->stats.rx_errors;
1102 tot->tx_dropped = dev->stats.tx_dropped;
1103
1104 return tot;
1105 }
1106
1107 static void xennet_release_tx_bufs(struct netfront_info *np)
1108 {
1109 struct sk_buff *skb;
1110 int i;
1111
1112 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1113 /* Skip over entries which are actually freelist references */
1114 if (skb_entry_is_link(&np->tx_skbs[i]))
1115 continue;
1116
1117 skb = np->tx_skbs[i].skb;
1118 gnttab_end_foreign_access_ref(np->grant_tx_ref[i],
1119 GNTMAP_readonly);
1120 gnttab_release_grant_reference(&np->gref_tx_head,
1121 np->grant_tx_ref[i]);
1122 np->grant_tx_ref[i] = GRANT_INVALID_REF;
1123 add_id_to_freelist(&np->tx_skb_freelist, np->tx_skbs, i);
1124 dev_kfree_skb_irq(skb);
1125 }
1126 }
1127
1128 static void xennet_release_rx_bufs(struct netfront_info *np)
1129 {
1130 struct mmu_update *mmu = np->rx_mmu;
1131 struct multicall_entry *mcl = np->rx_mcl;
1132 struct sk_buff_head free_list;
1133 struct sk_buff *skb;
1134 unsigned long mfn;
1135 int xfer = 0, noxfer = 0, unused = 0;
1136 int id, ref;
1137
1138 dev_warn(&np->netdev->dev, "%s: fix me for copying receiver.\n",
1139 __func__);
1140 return;
1141
1142 skb_queue_head_init(&free_list);
1143
1144 spin_lock_bh(&np->rx_lock);
1145
1146 for (id = 0; id < NET_RX_RING_SIZE; id++) {
1147 ref = np->grant_rx_ref[id];
1148 if (ref == GRANT_INVALID_REF) {
1149 unused++;
1150 continue;
1151 }
1152
1153 skb = np->rx_skbs[id];
1154 mfn = gnttab_end_foreign_transfer_ref(ref);
1155 gnttab_release_grant_reference(&np->gref_rx_head, ref);
1156 np->grant_rx_ref[id] = GRANT_INVALID_REF;
1157
1158 if (0 == mfn) {
1159 skb_shinfo(skb)->nr_frags = 0;
1160 dev_kfree_skb(skb);
1161 noxfer++;
1162 continue;
1163 }
1164
1165 if (!xen_feature(XENFEAT_auto_translated_physmap)) {
1166 /* Remap the page. */
1167 const struct page *page =
1168 skb_frag_page(&skb_shinfo(skb)->frags[0]);
1169 unsigned long pfn = page_to_pfn(page);
1170 void *vaddr = page_address(page);
1171
1172 MULTI_update_va_mapping(mcl, (unsigned long)vaddr,
1173 mfn_pte(mfn, PAGE_KERNEL),
1174 0);
1175 mcl++;
1176 mmu->ptr = ((u64)mfn << PAGE_SHIFT)
1177 | MMU_MACHPHYS_UPDATE;
1178 mmu->val = pfn;
1179 mmu++;
1180
1181 set_phys_to_machine(pfn, mfn);
1182 }
1183 __skb_queue_tail(&free_list, skb);
1184 xfer++;
1185 }
1186
1187 dev_info(&np->netdev->dev, "%s: %d xfer, %d noxfer, %d unused\n",
1188 __func__, xfer, noxfer, unused);
1189
1190 if (xfer) {
1191 if (!xen_feature(XENFEAT_auto_translated_physmap)) {
1192 /* Do all the remapping work and M2P updates. */
1193 MULTI_mmu_update(mcl, np->rx_mmu, mmu - np->rx_mmu,
1194 NULL, DOMID_SELF);
1195 mcl++;
1196 HYPERVISOR_multicall(np->rx_mcl, mcl - np->rx_mcl);
1197 }
1198 }
1199
1200 __skb_queue_purge(&free_list);
1201
1202 spin_unlock_bh(&np->rx_lock);
1203 }
1204
1205 static void xennet_uninit(struct net_device *dev)
1206 {
1207 struct netfront_info *np = netdev_priv(dev);
1208 xennet_release_tx_bufs(np);
1209 xennet_release_rx_bufs(np);
1210 gnttab_free_grant_references(np->gref_tx_head);
1211 gnttab_free_grant_references(np->gref_rx_head);
1212 }
1213
1214 static netdev_features_t xennet_fix_features(struct net_device *dev,
1215 netdev_features_t features)
1216 {
1217 struct netfront_info *np = netdev_priv(dev);
1218 int val;
1219
1220 if (features & NETIF_F_SG) {
1221 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, "feature-sg",
1222 "%d", &val) < 0)
1223 val = 0;
1224
1225 if (!val)
1226 features &= ~NETIF_F_SG;
1227 }
1228
1229 if (features & NETIF_F_TSO) {
1230 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1231 "feature-gso-tcpv4", "%d", &val) < 0)
1232 val = 0;
1233
1234 if (!val)
1235 features &= ~NETIF_F_TSO;
1236 }
1237
1238 return features;
1239 }
1240
1241 static int xennet_set_features(struct net_device *dev,
1242 netdev_features_t features)
1243 {
1244 if (!(features & NETIF_F_SG) && dev->mtu > ETH_DATA_LEN) {
1245 netdev_info(dev, "Reducing MTU because no SG offload");
1246 dev->mtu = ETH_DATA_LEN;
1247 }
1248
1249 return 0;
1250 }
1251
1252 static irqreturn_t xennet_interrupt(int irq, void *dev_id)
1253 {
1254 struct net_device *dev = dev_id;
1255 struct netfront_info *np = netdev_priv(dev);
1256 unsigned long flags;
1257
1258 spin_lock_irqsave(&np->tx_lock, flags);
1259
1260 if (likely(netif_carrier_ok(dev))) {
1261 xennet_tx_buf_gc(dev);
1262 /* Under tx_lock: protects access to rx shared-ring indexes. */
1263 if (RING_HAS_UNCONSUMED_RESPONSES(&np->rx))
1264 napi_schedule(&np->napi);
1265 }
1266
1267 spin_unlock_irqrestore(&np->tx_lock, flags);
1268
1269 return IRQ_HANDLED;
1270 }
1271
1272 #ifdef CONFIG_NET_POLL_CONTROLLER
1273 static void xennet_poll_controller(struct net_device *dev)
1274 {
1275 xennet_interrupt(0, dev);
1276 }
1277 #endif
1278
1279 static const struct net_device_ops xennet_netdev_ops = {
1280 .ndo_open = xennet_open,
1281 .ndo_uninit = xennet_uninit,
1282 .ndo_stop = xennet_close,
1283 .ndo_start_xmit = xennet_start_xmit,
1284 .ndo_change_mtu = xennet_change_mtu,
1285 .ndo_get_stats64 = xennet_get_stats64,
1286 .ndo_set_mac_address = eth_mac_addr,
1287 .ndo_validate_addr = eth_validate_addr,
1288 .ndo_fix_features = xennet_fix_features,
1289 .ndo_set_features = xennet_set_features,
1290 #ifdef CONFIG_NET_POLL_CONTROLLER
1291 .ndo_poll_controller = xennet_poll_controller,
1292 #endif
1293 };
1294
1295 static struct net_device *xennet_create_dev(struct xenbus_device *dev)
1296 {
1297 int i, err;
1298 struct net_device *netdev;
1299 struct netfront_info *np;
1300
1301 netdev = alloc_etherdev(sizeof(struct netfront_info));
1302 if (!netdev)
1303 return ERR_PTR(-ENOMEM);
1304
1305 np = netdev_priv(netdev);
1306 np->xbdev = dev;
1307
1308 spin_lock_init(&np->tx_lock);
1309 spin_lock_init(&np->rx_lock);
1310
1311 skb_queue_head_init(&np->rx_batch);
1312 np->rx_target = RX_DFL_MIN_TARGET;
1313 np->rx_min_target = RX_DFL_MIN_TARGET;
1314 np->rx_max_target = RX_MAX_TARGET;
1315
1316 init_timer(&np->rx_refill_timer);
1317 np->rx_refill_timer.data = (unsigned long)netdev;
1318 np->rx_refill_timer.function = rx_refill_timeout;
1319
1320 err = -ENOMEM;
1321 np->stats = alloc_percpu(struct netfront_stats);
1322 if (np->stats == NULL)
1323 goto exit;
1324
1325 /* Initialise tx_skbs as a free chain containing every entry. */
1326 np->tx_skb_freelist = 0;
1327 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1328 skb_entry_set_link(&np->tx_skbs[i], i+1);
1329 np->grant_tx_ref[i] = GRANT_INVALID_REF;
1330 }
1331
1332 /* Clear out rx_skbs */
1333 for (i = 0; i < NET_RX_RING_SIZE; i++) {
1334 np->rx_skbs[i] = NULL;
1335 np->grant_rx_ref[i] = GRANT_INVALID_REF;
1336 }
1337
1338 /* A grant for every tx ring slot */
1339 if (gnttab_alloc_grant_references(TX_MAX_TARGET,
1340 &np->gref_tx_head) < 0) {
1341 printk(KERN_ALERT "#### netfront can't alloc tx grant refs\n");
1342 err = -ENOMEM;
1343 goto exit_free_stats;
1344 }
1345 /* A grant for every rx ring slot */
1346 if (gnttab_alloc_grant_references(RX_MAX_TARGET,
1347 &np->gref_rx_head) < 0) {
1348 printk(KERN_ALERT "#### netfront can't alloc rx grant refs\n");
1349 err = -ENOMEM;
1350 goto exit_free_tx;
1351 }
1352
1353 netdev->netdev_ops = &xennet_netdev_ops;
1354
1355 netif_napi_add(netdev, &np->napi, xennet_poll, 64);
1356 netdev->features = NETIF_F_IP_CSUM | NETIF_F_RXCSUM |
1357 NETIF_F_GSO_ROBUST;
1358 netdev->hw_features = NETIF_F_IP_CSUM | NETIF_F_SG | NETIF_F_TSO;
1359
1360 /*
1361 * Assume that all hw features are available for now. This set
1362 * will be adjusted by the call to netdev_update_features() in
1363 * xennet_connect() which is the earliest point where we can
1364 * negotiate with the backend regarding supported features.
1365 */
1366 netdev->features |= netdev->hw_features;
1367
1368 SET_ETHTOOL_OPS(netdev, &xennet_ethtool_ops);
1369 SET_NETDEV_DEV(netdev, &dev->dev);
1370
1371 np->netdev = netdev;
1372
1373 netif_carrier_off(netdev);
1374
1375 return netdev;
1376
1377 exit_free_tx:
1378 gnttab_free_grant_references(np->gref_tx_head);
1379 exit_free_stats:
1380 free_percpu(np->stats);
1381 exit:
1382 free_netdev(netdev);
1383 return ERR_PTR(err);
1384 }
1385
1386 /**
1387 * Entry point to this code when a new device is created. Allocate the basic
1388 * structures and the ring buffers for communication with the backend, and
1389 * inform the backend of the appropriate details for those.
1390 */
1391 static int netfront_probe(struct xenbus_device *dev,
1392 const struct xenbus_device_id *id)
1393 {
1394 int err;
1395 struct net_device *netdev;
1396 struct netfront_info *info;
1397
1398 netdev = xennet_create_dev(dev);
1399 if (IS_ERR(netdev)) {
1400 err = PTR_ERR(netdev);
1401 xenbus_dev_fatal(dev, err, "creating netdev");
1402 return err;
1403 }
1404
1405 info = netdev_priv(netdev);
1406 dev_set_drvdata(&dev->dev, info);
1407
1408 err = register_netdev(info->netdev);
1409 if (err) {
1410 printk(KERN_WARNING "%s: register_netdev err=%d\n",
1411 __func__, err);
1412 goto fail;
1413 }
1414
1415 err = xennet_sysfs_addif(info->netdev);
1416 if (err) {
1417 unregister_netdev(info->netdev);
1418 printk(KERN_WARNING "%s: add sysfs failed err=%d\n",
1419 __func__, err);
1420 goto fail;
1421 }
1422
1423 return 0;
1424
1425 fail:
1426 free_netdev(netdev);
1427 dev_set_drvdata(&dev->dev, NULL);
1428 return err;
1429 }
1430
1431 static void xennet_end_access(int ref, void *page)
1432 {
1433 /* This frees the page as a side-effect */
1434 if (ref != GRANT_INVALID_REF)
1435 gnttab_end_foreign_access(ref, 0, (unsigned long)page);
1436 }
1437
1438 static void xennet_disconnect_backend(struct netfront_info *info)
1439 {
1440 /* Stop old i/f to prevent errors whilst we rebuild the state. */
1441 spin_lock_bh(&info->rx_lock);
1442 spin_lock_irq(&info->tx_lock);
1443 netif_carrier_off(info->netdev);
1444 spin_unlock_irq(&info->tx_lock);
1445 spin_unlock_bh(&info->rx_lock);
1446
1447 if (info->netdev->irq)
1448 unbind_from_irqhandler(info->netdev->irq, info->netdev);
1449 info->evtchn = info->netdev->irq = 0;
1450
1451 /* End access and free the pages */
1452 xennet_end_access(info->tx_ring_ref, info->tx.sring);
1453 xennet_end_access(info->rx_ring_ref, info->rx.sring);
1454
1455 info->tx_ring_ref = GRANT_INVALID_REF;
1456 info->rx_ring_ref = GRANT_INVALID_REF;
1457 info->tx.sring = NULL;
1458 info->rx.sring = NULL;
1459 }
1460
1461 /**
1462 * We are reconnecting to the backend, due to a suspend/resume, or a backend
1463 * driver restart. We tear down our netif structure and recreate it, but
1464 * leave the device-layer structures intact so that this is transparent to the
1465 * rest of the kernel.
1466 */
1467 static int netfront_resume(struct xenbus_device *dev)
1468 {
1469 struct netfront_info *info = dev_get_drvdata(&dev->dev);
1470
1471 dev_dbg(&dev->dev, "%s\n", dev->nodename);
1472
1473 xennet_disconnect_backend(info);
1474 return 0;
1475 }
1476
1477 static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[])
1478 {
1479 char *s, *e, *macstr;
1480 int i;
1481
1482 macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL);
1483 if (IS_ERR(macstr))
1484 return PTR_ERR(macstr);
1485
1486 for (i = 0; i < ETH_ALEN; i++) {
1487 mac[i] = simple_strtoul(s, &e, 16);
1488 if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) {
1489 kfree(macstr);
1490 return -ENOENT;
1491 }
1492 s = e+1;
1493 }
1494
1495 kfree(macstr);
1496 return 0;
1497 }
1498
1499 static int setup_netfront(struct xenbus_device *dev, struct netfront_info *info)
1500 {
1501 struct xen_netif_tx_sring *txs;
1502 struct xen_netif_rx_sring *rxs;
1503 int err;
1504 struct net_device *netdev = info->netdev;
1505
1506 info->tx_ring_ref = GRANT_INVALID_REF;
1507 info->rx_ring_ref = GRANT_INVALID_REF;
1508 info->rx.sring = NULL;
1509 info->tx.sring = NULL;
1510 netdev->irq = 0;
1511
1512 err = xen_net_read_mac(dev, netdev->dev_addr);
1513 if (err) {
1514 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
1515 goto fail;
1516 }
1517
1518 txs = (struct xen_netif_tx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1519 if (!txs) {
1520 err = -ENOMEM;
1521 xenbus_dev_fatal(dev, err, "allocating tx ring page");
1522 goto fail;
1523 }
1524 SHARED_RING_INIT(txs);
1525 FRONT_RING_INIT(&info->tx, txs, PAGE_SIZE);
1526
1527 err = xenbus_grant_ring(dev, virt_to_mfn(txs));
1528 if (err < 0) {
1529 free_page((unsigned long)txs);
1530 goto fail;
1531 }
1532
1533 info->tx_ring_ref = err;
1534 rxs = (struct xen_netif_rx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1535 if (!rxs) {
1536 err = -ENOMEM;
1537 xenbus_dev_fatal(dev, err, "allocating rx ring page");
1538 goto fail;
1539 }
1540 SHARED_RING_INIT(rxs);
1541 FRONT_RING_INIT(&info->rx, rxs, PAGE_SIZE);
1542
1543 err = xenbus_grant_ring(dev, virt_to_mfn(rxs));
1544 if (err < 0) {
1545 free_page((unsigned long)rxs);
1546 goto fail;
1547 }
1548 info->rx_ring_ref = err;
1549
1550 err = xenbus_alloc_evtchn(dev, &info->evtchn);
1551 if (err)
1552 goto fail;
1553
1554 err = bind_evtchn_to_irqhandler(info->evtchn, xennet_interrupt,
1555 0, netdev->name, netdev);
1556 if (err < 0)
1557 goto fail;
1558 netdev->irq = err;
1559 return 0;
1560
1561 fail:
1562 return err;
1563 }
1564
1565 /* Common code used when first setting up, and when resuming. */
1566 static int talk_to_netback(struct xenbus_device *dev,
1567 struct netfront_info *info)
1568 {
1569 const char *message;
1570 struct xenbus_transaction xbt;
1571 int err;
1572
1573 /* Create shared ring, alloc event channel. */
1574 err = setup_netfront(dev, info);
1575 if (err)
1576 goto out;
1577
1578 again:
1579 err = xenbus_transaction_start(&xbt);
1580 if (err) {
1581 xenbus_dev_fatal(dev, err, "starting transaction");
1582 goto destroy_ring;
1583 }
1584
1585 err = xenbus_printf(xbt, dev->nodename, "tx-ring-ref", "%u",
1586 info->tx_ring_ref);
1587 if (err) {
1588 message = "writing tx ring-ref";
1589 goto abort_transaction;
1590 }
1591 err = xenbus_printf(xbt, dev->nodename, "rx-ring-ref", "%u",
1592 info->rx_ring_ref);
1593 if (err) {
1594 message = "writing rx ring-ref";
1595 goto abort_transaction;
1596 }
1597 err = xenbus_printf(xbt, dev->nodename,
1598 "event-channel", "%u", info->evtchn);
1599 if (err) {
1600 message = "writing event-channel";
1601 goto abort_transaction;
1602 }
1603
1604 err = xenbus_printf(xbt, dev->nodename, "request-rx-copy", "%u",
1605 1);
1606 if (err) {
1607 message = "writing request-rx-copy";
1608 goto abort_transaction;
1609 }
1610
1611 err = xenbus_printf(xbt, dev->nodename, "feature-rx-notify", "%d", 1);
1612 if (err) {
1613 message = "writing feature-rx-notify";
1614 goto abort_transaction;
1615 }
1616
1617 err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", 1);
1618 if (err) {
1619 message = "writing feature-sg";
1620 goto abort_transaction;
1621 }
1622
1623 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4", "%d", 1);
1624 if (err) {
1625 message = "writing feature-gso-tcpv4";
1626 goto abort_transaction;
1627 }
1628
1629 err = xenbus_transaction_end(xbt, 0);
1630 if (err) {
1631 if (err == -EAGAIN)
1632 goto again;
1633 xenbus_dev_fatal(dev, err, "completing transaction");
1634 goto destroy_ring;
1635 }
1636
1637 return 0;
1638
1639 abort_transaction:
1640 xenbus_transaction_end(xbt, 1);
1641 xenbus_dev_fatal(dev, err, "%s", message);
1642 destroy_ring:
1643 xennet_disconnect_backend(info);
1644 out:
1645 return err;
1646 }
1647
1648 static int xennet_connect(struct net_device *dev)
1649 {
1650 struct netfront_info *np = netdev_priv(dev);
1651 int i, requeue_idx, err;
1652 struct sk_buff *skb;
1653 grant_ref_t ref;
1654 struct xen_netif_rx_request *req;
1655 unsigned int feature_rx_copy;
1656
1657 err = xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1658 "feature-rx-copy", "%u", &feature_rx_copy);
1659 if (err != 1)
1660 feature_rx_copy = 0;
1661
1662 if (!feature_rx_copy) {
1663 dev_info(&dev->dev,
1664 "backend does not support copying receive path\n");
1665 return -ENODEV;
1666 }
1667
1668 err = talk_to_netback(np->xbdev, np);
1669 if (err)
1670 return err;
1671
1672 rtnl_lock();
1673 netdev_update_features(dev);
1674 rtnl_unlock();
1675
1676 spin_lock_bh(&np->rx_lock);
1677 spin_lock_irq(&np->tx_lock);
1678
1679 /* Step 1: Discard all pending TX packet fragments. */
1680 xennet_release_tx_bufs(np);
1681
1682 /* Step 2: Rebuild the RX buffer freelist and the RX ring itself. */
1683 for (requeue_idx = 0, i = 0; i < NET_RX_RING_SIZE; i++) {
1684 skb_frag_t *frag;
1685 const struct page *page;
1686 if (!np->rx_skbs[i])
1687 continue;
1688
1689 skb = np->rx_skbs[requeue_idx] = xennet_get_rx_skb(np, i);
1690 ref = np->grant_rx_ref[requeue_idx] = xennet_get_rx_ref(np, i);
1691 req = RING_GET_REQUEST(&np->rx, requeue_idx);
1692
1693 frag = &skb_shinfo(skb)->frags[0];
1694 page = skb_frag_page(frag);
1695 gnttab_grant_foreign_access_ref(
1696 ref, np->xbdev->otherend_id,
1697 pfn_to_mfn(page_to_pfn(page)),
1698 0);
1699 req->gref = ref;
1700 req->id = requeue_idx;
1701
1702 requeue_idx++;
1703 }
1704
1705 np->rx.req_prod_pvt = requeue_idx;
1706
1707 /*
1708 * Step 3: All public and private state should now be sane. Get
1709 * ready to start sending and receiving packets and give the driver
1710 * domain a kick because we've probably just requeued some
1711 * packets.
1712 */
1713 netif_carrier_on(np->netdev);
1714 notify_remote_via_irq(np->netdev->irq);
1715 xennet_tx_buf_gc(dev);
1716 xennet_alloc_rx_buffers(dev);
1717
1718 spin_unlock_irq(&np->tx_lock);
1719 spin_unlock_bh(&np->rx_lock);
1720
1721 return 0;
1722 }
1723
1724 /**
1725 * Callback received when the backend's state changes.
1726 */
1727 static void netback_changed(struct xenbus_device *dev,
1728 enum xenbus_state backend_state)
1729 {
1730 struct netfront_info *np = dev_get_drvdata(&dev->dev);
1731 struct net_device *netdev = np->netdev;
1732
1733 dev_dbg(&dev->dev, "%s\n", xenbus_strstate(backend_state));
1734
1735 switch (backend_state) {
1736 case XenbusStateInitialising:
1737 case XenbusStateInitialised:
1738 case XenbusStateReconfiguring:
1739 case XenbusStateReconfigured:
1740 case XenbusStateUnknown:
1741 case XenbusStateClosed:
1742 break;
1743
1744 case XenbusStateInitWait:
1745 if (dev->state != XenbusStateInitialising)
1746 break;
1747 if (xennet_connect(netdev) != 0)
1748 break;
1749 xenbus_switch_state(dev, XenbusStateConnected);
1750 break;
1751
1752 case XenbusStateConnected:
1753 netdev_notify_peers(netdev);
1754 break;
1755
1756 case XenbusStateClosing:
1757 xenbus_frontend_closed(dev);
1758 break;
1759 }
1760 }
1761
1762 static const struct xennet_stat {
1763 char name[ETH_GSTRING_LEN];
1764 u16 offset;
1765 } xennet_stats[] = {
1766 {
1767 "rx_gso_checksum_fixup",
1768 offsetof(struct netfront_info, rx_gso_checksum_fixup)
1769 },
1770 };
1771
1772 static int xennet_get_sset_count(struct net_device *dev, int string_set)
1773 {
1774 switch (string_set) {
1775 case ETH_SS_STATS:
1776 return ARRAY_SIZE(xennet_stats);
1777 default:
1778 return -EINVAL;
1779 }
1780 }
1781
1782 static void xennet_get_ethtool_stats(struct net_device *dev,
1783 struct ethtool_stats *stats, u64 * data)
1784 {
1785 void *np = netdev_priv(dev);
1786 int i;
1787
1788 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
1789 data[i] = *(unsigned long *)(np + xennet_stats[i].offset);
1790 }
1791
1792 static void xennet_get_strings(struct net_device *dev, u32 stringset, u8 * data)
1793 {
1794 int i;
1795
1796 switch (stringset) {
1797 case ETH_SS_STATS:
1798 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
1799 memcpy(data + i * ETH_GSTRING_LEN,
1800 xennet_stats[i].name, ETH_GSTRING_LEN);
1801 break;
1802 }
1803 }
1804
1805 static const struct ethtool_ops xennet_ethtool_ops =
1806 {
1807 .get_link = ethtool_op_get_link,
1808
1809 .get_sset_count = xennet_get_sset_count,
1810 .get_ethtool_stats = xennet_get_ethtool_stats,
1811 .get_strings = xennet_get_strings,
1812 };
1813
1814 #ifdef CONFIG_SYSFS
1815 static ssize_t show_rxbuf_min(struct device *dev,
1816 struct device_attribute *attr, char *buf)
1817 {
1818 struct net_device *netdev = to_net_dev(dev);
1819 struct netfront_info *info = netdev_priv(netdev);
1820
1821 return sprintf(buf, "%u\n", info->rx_min_target);
1822 }
1823
1824 static ssize_t store_rxbuf_min(struct device *dev,
1825 struct device_attribute *attr,
1826 const char *buf, size_t len)
1827 {
1828 struct net_device *netdev = to_net_dev(dev);
1829 struct netfront_info *np = netdev_priv(netdev);
1830 char *endp;
1831 unsigned long target;
1832
1833 if (!capable(CAP_NET_ADMIN))
1834 return -EPERM;
1835
1836 target = simple_strtoul(buf, &endp, 0);
1837 if (endp == buf)
1838 return -EBADMSG;
1839
1840 if (target < RX_MIN_TARGET)
1841 target = RX_MIN_TARGET;
1842 if (target > RX_MAX_TARGET)
1843 target = RX_MAX_TARGET;
1844
1845 spin_lock_bh(&np->rx_lock);
1846 if (target > np->rx_max_target)
1847 np->rx_max_target = target;
1848 np->rx_min_target = target;
1849 if (target > np->rx_target)
1850 np->rx_target = target;
1851
1852 xennet_alloc_rx_buffers(netdev);
1853
1854 spin_unlock_bh(&np->rx_lock);
1855 return len;
1856 }
1857
1858 static ssize_t show_rxbuf_max(struct device *dev,
1859 struct device_attribute *attr, char *buf)
1860 {
1861 struct net_device *netdev = to_net_dev(dev);
1862 struct netfront_info *info = netdev_priv(netdev);
1863
1864 return sprintf(buf, "%u\n", info->rx_max_target);
1865 }
1866
1867 static ssize_t store_rxbuf_max(struct device *dev,
1868 struct device_attribute *attr,
1869 const char *buf, size_t len)
1870 {
1871 struct net_device *netdev = to_net_dev(dev);
1872 struct netfront_info *np = netdev_priv(netdev);
1873 char *endp;
1874 unsigned long target;
1875
1876 if (!capable(CAP_NET_ADMIN))
1877 return -EPERM;
1878
1879 target = simple_strtoul(buf, &endp, 0);
1880 if (endp == buf)
1881 return -EBADMSG;
1882
1883 if (target < RX_MIN_TARGET)
1884 target = RX_MIN_TARGET;
1885 if (target > RX_MAX_TARGET)
1886 target = RX_MAX_TARGET;
1887
1888 spin_lock_bh(&np->rx_lock);
1889 if (target < np->rx_min_target)
1890 np->rx_min_target = target;
1891 np->rx_max_target = target;
1892 if (target < np->rx_target)
1893 np->rx_target = target;
1894
1895 xennet_alloc_rx_buffers(netdev);
1896
1897 spin_unlock_bh(&np->rx_lock);
1898 return len;
1899 }
1900
1901 static ssize_t show_rxbuf_cur(struct device *dev,
1902 struct device_attribute *attr, char *buf)
1903 {
1904 struct net_device *netdev = to_net_dev(dev);
1905 struct netfront_info *info = netdev_priv(netdev);
1906
1907 return sprintf(buf, "%u\n", info->rx_target);
1908 }
1909
1910 static struct device_attribute xennet_attrs[] = {
1911 __ATTR(rxbuf_min, S_IRUGO|S_IWUSR, show_rxbuf_min, store_rxbuf_min),
1912 __ATTR(rxbuf_max, S_IRUGO|S_IWUSR, show_rxbuf_max, store_rxbuf_max),
1913 __ATTR(rxbuf_cur, S_IRUGO, show_rxbuf_cur, NULL),
1914 };
1915
1916 static int xennet_sysfs_addif(struct net_device *netdev)
1917 {
1918 int i;
1919 int err;
1920
1921 for (i = 0; i < ARRAY_SIZE(xennet_attrs); i++) {
1922 err = device_create_file(&netdev->dev,
1923 &xennet_attrs[i]);
1924 if (err)
1925 goto fail;
1926 }
1927 return 0;
1928
1929 fail:
1930 while (--i >= 0)
1931 device_remove_file(&netdev->dev, &xennet_attrs[i]);
1932 return err;
1933 }
1934
1935 static void xennet_sysfs_delif(struct net_device *netdev)
1936 {
1937 int i;
1938
1939 for (i = 0; i < ARRAY_SIZE(xennet_attrs); i++)
1940 device_remove_file(&netdev->dev, &xennet_attrs[i]);
1941 }
1942
1943 #endif /* CONFIG_SYSFS */
1944
1945 static const struct xenbus_device_id netfront_ids[] = {
1946 { "vif" },
1947 { "" }
1948 };
1949
1950
1951 static int xennet_remove(struct xenbus_device *dev)
1952 {
1953 struct netfront_info *info = dev_get_drvdata(&dev->dev);
1954
1955 dev_dbg(&dev->dev, "%s\n", dev->nodename);
1956
1957 xennet_disconnect_backend(info);
1958
1959 xennet_sysfs_delif(info->netdev);
1960
1961 unregister_netdev(info->netdev);
1962
1963 del_timer_sync(&info->rx_refill_timer);
1964
1965 free_percpu(info->stats);
1966
1967 free_netdev(info->netdev);
1968
1969 return 0;
1970 }
1971
1972 static DEFINE_XENBUS_DRIVER(netfront, ,
1973 .probe = netfront_probe,
1974 .remove = xennet_remove,
1975 .resume = netfront_resume,
1976 .otherend_changed = netback_changed,
1977 );
1978
1979 static int __init netif_init(void)
1980 {
1981 if (!xen_domain())
1982 return -ENODEV;
1983
1984 if (xen_hvm_domain() && !xen_platform_pci_unplug)
1985 return -ENODEV;
1986
1987 printk(KERN_INFO "Initialising Xen virtual ethernet driver.\n");
1988
1989 return xenbus_register_frontend(&netfront_driver);
1990 }
1991 module_init(netif_init);
1992
1993
1994 static void __exit netif_exit(void)
1995 {
1996 xenbus_unregister_driver(&netfront_driver);
1997 }
1998 module_exit(netif_exit);
1999
2000 MODULE_DESCRIPTION("Xen virtual network device frontend");
2001 MODULE_LICENSE("GPL");
2002 MODULE_ALIAS("xen:vif");
2003 MODULE_ALIAS("xennet");
Linux with added FPC-III support