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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
56static const struct ethtool_ops xennet_ethtool_ops;
57
58struct 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 __CONST_RING_SIZE(xen_netif_tx, PAGE_SIZE)
70#define NET_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, PAGE_SIZE)
71#define TX_MAX_TARGET min_t(int, NET_RX_RING_SIZE, 256)
72
73struct netfront_stats {
74 u64 rx_packets;
75 u64 tx_packets;
76 u64 rx_bytes;
77 u64 tx_bytes;
78 struct u64_stats_sync syncp;
79};
80
81struct netfront_info {
82 struct list_head list;
83 struct net_device *netdev;
84
85 struct napi_struct napi;
86
87 unsigned int evtchn;
88 struct xenbus_device *xbdev;
89
90 spinlock_t tx_lock;
91 struct xen_netif_tx_front_ring tx;
92 int tx_ring_ref;
93
94 /*
95 * {tx,rx}_skbs store outstanding skbuffs. Free tx_skb entries
96 * are linked from tx_skb_freelist through skb_entry.link.
97 *
98 * NB. Freelist index entries are always going to be less than
99 * PAGE_OFFSET, whereas pointers to skbs will always be equal or
100 * greater than PAGE_OFFSET: we use this property to distinguish
101 * them.
102 */
103 union skb_entry {
104 struct sk_buff *skb;
105 unsigned long link;
106 } tx_skbs[NET_TX_RING_SIZE];
107 grant_ref_t gref_tx_head;
108 grant_ref_t grant_tx_ref[NET_TX_RING_SIZE];
109 unsigned tx_skb_freelist;
110
111 spinlock_t rx_lock ____cacheline_aligned_in_smp;
112 struct xen_netif_rx_front_ring rx;
113 int rx_ring_ref;
114
115 /* Receive-ring batched refills. */
116#define RX_MIN_TARGET 8
117#define RX_DFL_MIN_TARGET 64
118#define RX_MAX_TARGET min_t(int, NET_RX_RING_SIZE, 256)
119 unsigned rx_min_target, rx_max_target, rx_target;
120 struct sk_buff_head rx_batch;
121
122 struct timer_list rx_refill_timer;
123
124 struct sk_buff *rx_skbs[NET_RX_RING_SIZE];
125 grant_ref_t gref_rx_head;
126 grant_ref_t grant_rx_ref[NET_RX_RING_SIZE];
127
128 unsigned long rx_pfn_array[NET_RX_RING_SIZE];
129 struct multicall_entry rx_mcl[NET_RX_RING_SIZE+1];
130 struct mmu_update rx_mmu[NET_RX_RING_SIZE];
131
132 /* Statistics */
133 struct netfront_stats __percpu *stats;
134
135 unsigned long rx_gso_checksum_fixup;
136};
137
138struct netfront_rx_info {
139 struct xen_netif_rx_response rx;
140 struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX - 1];
141};
142
143static void skb_entry_set_link(union skb_entry *list, unsigned short id)
144{
145 list->link = id;
146}
147
148static int skb_entry_is_link(const union skb_entry *list)
149{
150 BUILD_BUG_ON(sizeof(list->skb) != sizeof(list->link));
151 return (unsigned long)list->skb < PAGE_OFFSET;
152}
153
154/*
155 * Access macros for acquiring freeing slots in tx_skbs[].
156 */
157
158static void add_id_to_freelist(unsigned *head, union skb_entry *list,
159 unsigned short id)
160{
161 skb_entry_set_link(&list[id], *head);
162 *head = id;
163}
164
165static unsigned short get_id_from_freelist(unsigned *head,
166 union skb_entry *list)
167{
168 unsigned int id = *head;
169 *head = list[id].link;
170 return id;
171}
172
173static int xennet_rxidx(RING_IDX idx)
174{
175 return idx & (NET_RX_RING_SIZE - 1);
176}
177
178static struct sk_buff *xennet_get_rx_skb(struct netfront_info *np,
179 RING_IDX ri)
180{
181 int i = xennet_rxidx(ri);
182 struct sk_buff *skb = np->rx_skbs[i];
183 np->rx_skbs[i] = NULL;
184 return skb;
185}
186
187static grant_ref_t xennet_get_rx_ref(struct netfront_info *np,
188 RING_IDX ri)
189{
190 int i = xennet_rxidx(ri);
191 grant_ref_t ref = np->grant_rx_ref[i];
192 np->grant_rx_ref[i] = GRANT_INVALID_REF;
193 return ref;
194}
195
196#ifdef CONFIG_SYSFS
197static int xennet_sysfs_addif(struct net_device *netdev);
198static void xennet_sysfs_delif(struct net_device *netdev);
199#else /* !CONFIG_SYSFS */
200#define xennet_sysfs_addif(dev) (0)
201#define xennet_sysfs_delif(dev) do { } while (0)
202#endif
203
204static int xennet_can_sg(struct net_device *dev)
205{
206 return dev->features & NETIF_F_SG;
207}
208
209
210static void rx_refill_timeout(unsigned long data)
211{
212 struct net_device *dev = (struct net_device *)data;
213 struct netfront_info *np = netdev_priv(dev);
214 napi_schedule(&np->napi);
215}
216
217static int netfront_tx_slot_available(struct netfront_info *np)
218{
219 return (np->tx.req_prod_pvt - np->tx.rsp_cons) <
220 (TX_MAX_TARGET - MAX_SKB_FRAGS - 2);
221}
222
223static void xennet_maybe_wake_tx(struct net_device *dev)
224{
225 struct netfront_info *np = netdev_priv(dev);
226
227 if (unlikely(netif_queue_stopped(dev)) &&
228 netfront_tx_slot_available(np) &&
229 likely(netif_running(dev)))
230 netif_wake_queue(dev);
231}
232
233static void xennet_alloc_rx_buffers(struct net_device *dev)
234{
235 unsigned short id;
236 struct netfront_info *np = netdev_priv(dev);
237 struct sk_buff *skb;
238 struct page *page;
239 int i, batch_target, notify;
240 RING_IDX req_prod = np->rx.req_prod_pvt;
241 grant_ref_t ref;
242 unsigned long pfn;
243 void *vaddr;
244 struct xen_netif_rx_request *req;
245
246 if (unlikely(!netif_carrier_ok(dev)))
247 return;
248
249 /*
250 * Allocate skbuffs greedily, even though we batch updates to the
251 * receive ring. This creates a less bursty demand on the memory
252 * allocator, so should reduce the chance of failed allocation requests
253 * both for ourself and for other kernel subsystems.
254 */
255 batch_target = np->rx_target - (req_prod - np->rx.rsp_cons);
256 for (i = skb_queue_len(&np->rx_batch); i < batch_target; i++) {
257 skb = __netdev_alloc_skb(dev, RX_COPY_THRESHOLD + NET_IP_ALIGN,
258 GFP_ATOMIC | __GFP_NOWARN);
259 if (unlikely(!skb))
260 goto no_skb;
261
262 /* Align ip header to a 16 bytes boundary */
263 skb_reserve(skb, NET_IP_ALIGN);
264
265 page = alloc_page(GFP_ATOMIC | __GFP_NOWARN);
266 if (!page) {
267 kfree_skb(skb);
268no_skb:
269 /* Any skbuffs queued for refill? Force them out. */
270 if (i != 0)
271 goto refill;
272 /* Could not allocate any skbuffs. Try again later. */
273 mod_timer(&np->rx_refill_timer,
274 jiffies + (HZ/10));
275 break;
276 }
277
278 skb_shinfo(skb)->frags[0].page = page;
279 skb_shinfo(skb)->nr_frags = 1;
280 __skb_queue_tail(&np->rx_batch, skb);
281 }
282
283 /* Is the batch large enough to be worthwhile? */
284 if (i < (np->rx_target/2)) {
285 if (req_prod > np->rx.sring->req_prod)
286 goto push;
287 return;
288 }
289
290 /* Adjust our fill target if we risked running out of buffers. */
291 if (((req_prod - np->rx.sring->rsp_prod) < (np->rx_target / 4)) &&
292 ((np->rx_target *= 2) > np->rx_max_target))
293 np->rx_target = np->rx_max_target;
294
295 refill:
296 for (i = 0; ; i++) {
297 skb = __skb_dequeue(&np->rx_batch);
298 if (skb == NULL)
299 break;
300
301 skb->dev = dev;
302
303 id = xennet_rxidx(req_prod + i);
304
305 BUG_ON(np->rx_skbs[id]);
306 np->rx_skbs[id] = skb;
307
308 ref = gnttab_claim_grant_reference(&np->gref_rx_head);
309 BUG_ON((signed short)ref < 0);
310 np->grant_rx_ref[id] = ref;
311
312 pfn = page_to_pfn(skb_shinfo(skb)->frags[0].page);
313 vaddr = page_address(skb_shinfo(skb)->frags[0].page);
314
315 req = RING_GET_REQUEST(&np->rx, req_prod + i);
316 gnttab_grant_foreign_access_ref(ref,
317 np->xbdev->otherend_id,
318 pfn_to_mfn(pfn),
319 0);
320
321 req->id = id;
322 req->gref = ref;
323 }
324
325 wmb(); /* barrier so backend seens requests */
326
327 /* Above is a suitable barrier to ensure backend will see requests. */
328 np->rx.req_prod_pvt = req_prod + i;
329 push:
330 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&np->rx, notify);
331 if (notify)
332 notify_remote_via_irq(np->netdev->irq);
333}
334
335static int xennet_open(struct net_device *dev)
336{
337 struct netfront_info *np = netdev_priv(dev);
338
339 napi_enable(&np->napi);
340
341 spin_lock_bh(&np->rx_lock);
342 if (netif_carrier_ok(dev)) {
343 xennet_alloc_rx_buffers(dev);
344 np->rx.sring->rsp_event = np->rx.rsp_cons + 1;
345 if (RING_HAS_UNCONSUMED_RESPONSES(&np->rx))
346 napi_schedule(&np->napi);
347 }
348 spin_unlock_bh(&np->rx_lock);
349
350 netif_start_queue(dev);
351
352 return 0;
353}
354
355static void xennet_tx_buf_gc(struct net_device *dev)
356{
357 RING_IDX cons, prod;
358 unsigned short id;
359 struct netfront_info *np = netdev_priv(dev);
360 struct sk_buff *skb;
361
362 BUG_ON(!netif_carrier_ok(dev));
363
364 do {
365 prod = np->tx.sring->rsp_prod;
366 rmb(); /* Ensure we see responses up to 'rp'. */
367
368 for (cons = np->tx.rsp_cons; cons != prod; cons++) {
369 struct xen_netif_tx_response *txrsp;
370
371 txrsp = RING_GET_RESPONSE(&np->tx, cons);
372 if (txrsp->status == XEN_NETIF_RSP_NULL)
373 continue;
374
375 id = txrsp->id;
376 skb = np->tx_skbs[id].skb;
377 if (unlikely(gnttab_query_foreign_access(
378 np->grant_tx_ref[id]) != 0)) {
379 printk(KERN_ALERT "xennet_tx_buf_gc: warning "
380 "-- grant still in use by backend "
381 "domain.\n");
382 BUG();
383 }
384 gnttab_end_foreign_access_ref(
385 np->grant_tx_ref[id], GNTMAP_readonly);
386 gnttab_release_grant_reference(
387 &np->gref_tx_head, np->grant_tx_ref[id]);
388 np->grant_tx_ref[id] = GRANT_INVALID_REF;
389 add_id_to_freelist(&np->tx_skb_freelist, np->tx_skbs, id);
390 dev_kfree_skb_irq(skb);
391 }
392
393 np->tx.rsp_cons = prod;
394
395 /*
396 * Set a new event, then check for race with update of tx_cons.
397 * Note that it is essential to schedule a callback, no matter
398 * how few buffers are pending. Even if there is space in the
399 * transmit ring, higher layers may be blocked because too much
400 * data is outstanding: in such cases notification from Xen is
401 * likely to be the only kick that we'll get.
402 */
403 np->tx.sring->rsp_event =
404 prod + ((np->tx.sring->req_prod - prod) >> 1) + 1;
405 mb(); /* update shared area */
406 } while ((cons == prod) && (prod != np->tx.sring->rsp_prod));
407
408 xennet_maybe_wake_tx(dev);
409}
410
411static void xennet_make_frags(struct sk_buff *skb, struct net_device *dev,
412 struct xen_netif_tx_request *tx)
413{
414 struct netfront_info *np = netdev_priv(dev);
415 char *data = skb->data;
416 unsigned long mfn;
417 RING_IDX prod = np->tx.req_prod_pvt;
418 int frags = skb_shinfo(skb)->nr_frags;
419 unsigned int offset = offset_in_page(data);
420 unsigned int len = skb_headlen(skb);
421 unsigned int id;
422 grant_ref_t ref;
423 int i;
424
425 /* While the header overlaps a page boundary (including being
426 larger than a page), split it it into page-sized chunks. */
427 while (len > PAGE_SIZE - offset) {
428 tx->size = PAGE_SIZE - offset;
429 tx->flags |= XEN_NETTXF_more_data;
430 len -= tx->size;
431 data += tx->size;
432 offset = 0;
433
434 id = get_id_from_freelist(&np->tx_skb_freelist, np->tx_skbs);
435 np->tx_skbs[id].skb = skb_get(skb);
436 tx = RING_GET_REQUEST(&np->tx, prod++);
437 tx->id = id;
438 ref = gnttab_claim_grant_reference(&np->gref_tx_head);
439 BUG_ON((signed short)ref < 0);
440
441 mfn = virt_to_mfn(data);
442 gnttab_grant_foreign_access_ref(ref, np->xbdev->otherend_id,
443 mfn, GNTMAP_readonly);
444
445 tx->gref = np->grant_tx_ref[id] = ref;
446 tx->offset = offset;
447 tx->size = len;
448 tx->flags = 0;
449 }
450
451 /* Grant backend access to each skb fragment page. */
452 for (i = 0; i < frags; i++) {
453 skb_frag_t *frag = skb_shinfo(skb)->frags + i;
454
455 tx->flags |= XEN_NETTXF_more_data;
456
457 id = get_id_from_freelist(&np->tx_skb_freelist, np->tx_skbs);
458 np->tx_skbs[id].skb = skb_get(skb);
459 tx = RING_GET_REQUEST(&np->tx, prod++);
460 tx->id = id;
461 ref = gnttab_claim_grant_reference(&np->gref_tx_head);
462 BUG_ON((signed short)ref < 0);
463
464 mfn = pfn_to_mfn(page_to_pfn(frag->page));
465 gnttab_grant_foreign_access_ref(ref, np->xbdev->otherend_id,
466 mfn, GNTMAP_readonly);
467
468 tx->gref = np->grant_tx_ref[id] = ref;
469 tx->offset = frag->page_offset;
470 tx->size = frag->size;
471 tx->flags = 0;
472 }
473
474 np->tx.req_prod_pvt = prod;
475}
476
477static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev)
478{
479 unsigned short id;
480 struct netfront_info *np = netdev_priv(dev);
481 struct netfront_stats *stats = this_cpu_ptr(np->stats);
482 struct xen_netif_tx_request *tx;
483 struct xen_netif_extra_info *extra;
484 char *data = skb->data;
485 RING_IDX i;
486 grant_ref_t ref;
487 unsigned long mfn;
488 int notify;
489 int frags = skb_shinfo(skb)->nr_frags;
490 unsigned int offset = offset_in_page(data);
491 unsigned int len = skb_headlen(skb);
492
493 frags += DIV_ROUND_UP(offset + len, PAGE_SIZE);
494 if (unlikely(frags > MAX_SKB_FRAGS + 1)) {
495 printk(KERN_ALERT "xennet: skb rides the rocket: %d frags\n",
496 frags);
497 dump_stack();
498 goto drop;
499 }
500
501 spin_lock_irq(&np->tx_lock);
502
503 if (unlikely(!netif_carrier_ok(dev) ||
504 (frags > 1 && !xennet_can_sg(dev)) ||
505 netif_needs_gso(skb, netif_skb_features(skb)))) {
506 spin_unlock_irq(&np->tx_lock);
507 goto drop;
508 }
509
510 i = np->tx.req_prod_pvt;
511
512 id = get_id_from_freelist(&np->tx_skb_freelist, np->tx_skbs);
513 np->tx_skbs[id].skb = skb;
514
515 tx = RING_GET_REQUEST(&np->tx, i);
516
517 tx->id = id;
518 ref = gnttab_claim_grant_reference(&np->gref_tx_head);
519 BUG_ON((signed short)ref < 0);
520 mfn = virt_to_mfn(data);
521 gnttab_grant_foreign_access_ref(
522 ref, np->xbdev->otherend_id, mfn, GNTMAP_readonly);
523 tx->gref = np->grant_tx_ref[id] = ref;
524 tx->offset = offset;
525 tx->size = len;
526 extra = NULL;
527
528 tx->flags = 0;
529 if (skb->ip_summed == CHECKSUM_PARTIAL)
530 /* local packet? */
531 tx->flags |= XEN_NETTXF_csum_blank | XEN_NETTXF_data_validated;
532 else if (skb->ip_summed == CHECKSUM_UNNECESSARY)
533 /* remote but checksummed. */
534 tx->flags |= XEN_NETTXF_data_validated;
535
536 if (skb_shinfo(skb)->gso_size) {
537 struct xen_netif_extra_info *gso;
538
539 gso = (struct xen_netif_extra_info *)
540 RING_GET_REQUEST(&np->tx, ++i);
541
542 if (extra)
543 extra->flags |= XEN_NETIF_EXTRA_FLAG_MORE;
544 else
545 tx->flags |= XEN_NETTXF_extra_info;
546
547 gso->u.gso.size = skb_shinfo(skb)->gso_size;
548 gso->u.gso.type = XEN_NETIF_GSO_TYPE_TCPV4;
549 gso->u.gso.pad = 0;
550 gso->u.gso.features = 0;
551
552 gso->type = XEN_NETIF_EXTRA_TYPE_GSO;
553 gso->flags = 0;
554 extra = gso;
555 }
556
557 np->tx.req_prod_pvt = i + 1;
558
559 xennet_make_frags(skb, dev, tx);
560 tx->size = skb->len;
561
562 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&np->tx, notify);
563 if (notify)
564 notify_remote_via_irq(np->netdev->irq);
565
566 u64_stats_update_begin(&stats->syncp);
567 stats->tx_bytes += skb->len;
568 stats->tx_packets++;
569 u64_stats_update_end(&stats->syncp);
570
571 /* Note: It is not safe to access skb after xennet_tx_buf_gc()! */
572 xennet_tx_buf_gc(dev);
573
574 if (!netfront_tx_slot_available(np))
575 netif_stop_queue(dev);
576
577 spin_unlock_irq(&np->tx_lock);
578
579 return NETDEV_TX_OK;
580
581 drop:
582 dev->stats.tx_dropped++;
583 dev_kfree_skb(skb);
584 return NETDEV_TX_OK;
585}
586
587static int xennet_close(struct net_device *dev)
588{
589 struct netfront_info *np = netdev_priv(dev);
590 netif_stop_queue(np->netdev);
591 napi_disable(&np->napi);
592 return 0;
593}
594
595static void xennet_move_rx_slot(struct netfront_info *np, struct sk_buff *skb,
596 grant_ref_t ref)
597{
598 int new = xennet_rxidx(np->rx.req_prod_pvt);
599
600 BUG_ON(np->rx_skbs[new]);
601 np->rx_skbs[new] = skb;
602 np->grant_rx_ref[new] = ref;
603 RING_GET_REQUEST(&np->rx, np->rx.req_prod_pvt)->id = new;
604 RING_GET_REQUEST(&np->rx, np->rx.req_prod_pvt)->gref = ref;
605 np->rx.req_prod_pvt++;
606}
607
608static int xennet_get_extras(struct netfront_info *np,
609 struct xen_netif_extra_info *extras,
610 RING_IDX rp)
611
612{
613 struct xen_netif_extra_info *extra;
614 struct device *dev = &np->netdev->dev;
615 RING_IDX cons = np->rx.rsp_cons;
616 int err = 0;
617
618 do {
619 struct sk_buff *skb;
620 grant_ref_t ref;
621
622 if (unlikely(cons + 1 == rp)) {
623 if (net_ratelimit())
624 dev_warn(dev, "Missing extra info\n");
625 err = -EBADR;
626 break;
627 }
628
629 extra = (struct xen_netif_extra_info *)
630 RING_GET_RESPONSE(&np->rx, ++cons);
631
632 if (unlikely(!extra->type ||
633 extra->type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
634 if (net_ratelimit())
635 dev_warn(dev, "Invalid extra type: %d\n",
636 extra->type);
637 err = -EINVAL;
638 } else {
639 memcpy(&extras[extra->type - 1], extra,
640 sizeof(*extra));
641 }
642
643 skb = xennet_get_rx_skb(np, cons);
644 ref = xennet_get_rx_ref(np, cons);
645 xennet_move_rx_slot(np, skb, ref);
646 } while (extra->flags & XEN_NETIF_EXTRA_FLAG_MORE);
647
648 np->rx.rsp_cons = cons;
649 return err;
650}
651
652static int xennet_get_responses(struct netfront_info *np,
653 struct netfront_rx_info *rinfo, RING_IDX rp,
654 struct sk_buff_head *list)
655{
656 struct xen_netif_rx_response *rx = &rinfo->rx;
657 struct xen_netif_extra_info *extras = rinfo->extras;
658 struct device *dev = &np->netdev->dev;
659 RING_IDX cons = np->rx.rsp_cons;
660 struct sk_buff *skb = xennet_get_rx_skb(np, cons);
661 grant_ref_t ref = xennet_get_rx_ref(np, cons);
662 int max = MAX_SKB_FRAGS + (rx->status <= RX_COPY_THRESHOLD);
663 int frags = 1;
664 int err = 0;
665 unsigned long ret;
666
667 if (rx->flags & XEN_NETRXF_extra_info) {
668 err = xennet_get_extras(np, extras, rp);
669 cons = np->rx.rsp_cons;
670 }
671
672 for (;;) {
673 if (unlikely(rx->status < 0 ||
674 rx->offset + rx->status > PAGE_SIZE)) {
675 if (net_ratelimit())
676 dev_warn(dev, "rx->offset: %x, size: %u\n",
677 rx->offset, rx->status);
678 xennet_move_rx_slot(np, skb, ref);
679 err = -EINVAL;
680 goto next;
681 }
682
683 /*
684 * This definitely indicates a bug, either in this driver or in
685 * the backend driver. In future this should flag the bad
686 * situation to the system controller to reboot the backed.
687 */
688 if (ref == GRANT_INVALID_REF) {
689 if (net_ratelimit())
690 dev_warn(dev, "Bad rx response id %d.\n",
691 rx->id);
692 err = -EINVAL;
693 goto next;
694 }
695
696 ret = gnttab_end_foreign_access_ref(ref, 0);
697 BUG_ON(!ret);
698
699 gnttab_release_grant_reference(&np->gref_rx_head, ref);
700
701 __skb_queue_tail(list, skb);
702
703next:
704 if (!(rx->flags & XEN_NETRXF_more_data))
705 break;
706
707 if (cons + frags == rp) {
708 if (net_ratelimit())
709 dev_warn(dev, "Need more frags\n");
710 err = -ENOENT;
711 break;
712 }
713
714 rx = RING_GET_RESPONSE(&np->rx, cons + frags);
715 skb = xennet_get_rx_skb(np, cons + frags);
716 ref = xennet_get_rx_ref(np, cons + frags);
717 frags++;
718 }
719
720 if (unlikely(frags > max)) {
721 if (net_ratelimit())
722 dev_warn(dev, "Too many frags\n");
723 err = -E2BIG;
724 }
725
726 if (unlikely(err))
727 np->rx.rsp_cons = cons + frags;
728
729 return err;
730}
731
732static int xennet_set_skb_gso(struct sk_buff *skb,
733 struct xen_netif_extra_info *gso)
734{
735 if (!gso->u.gso.size) {
736 if (net_ratelimit())
737 printk(KERN_WARNING "GSO size must not be zero.\n");
738 return -EINVAL;
739 }
740
741 /* Currently only TCPv4 S.O. is supported. */
742 if (gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV4) {
743 if (net_ratelimit())
744 printk(KERN_WARNING "Bad GSO type %d.\n", gso->u.gso.type);
745 return -EINVAL;
746 }
747
748 skb_shinfo(skb)->gso_size = gso->u.gso.size;
749 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
750
751 /* Header must be checked, and gso_segs computed. */
752 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
753 skb_shinfo(skb)->gso_segs = 0;
754
755 return 0;
756}
757
758static RING_IDX xennet_fill_frags(struct netfront_info *np,
759 struct sk_buff *skb,
760 struct sk_buff_head *list)
761{
762 struct skb_shared_info *shinfo = skb_shinfo(skb);
763 int nr_frags = shinfo->nr_frags;
764 RING_IDX cons = np->rx.rsp_cons;
765 skb_frag_t *frag = shinfo->frags + nr_frags;
766 struct sk_buff *nskb;
767
768 while ((nskb = __skb_dequeue(list))) {
769 struct xen_netif_rx_response *rx =
770 RING_GET_RESPONSE(&np->rx, ++cons);
771
772 frag->page = skb_shinfo(nskb)->frags[0].page;
773 frag->page_offset = rx->offset;
774 frag->size = rx->status;
775
776 skb->data_len += rx->status;
777
778 skb_shinfo(nskb)->nr_frags = 0;
779 kfree_skb(nskb);
780
781 frag++;
782 nr_frags++;
783 }
784
785 shinfo->nr_frags = nr_frags;
786 return cons;
787}
788
789static int checksum_setup(struct net_device *dev, struct sk_buff *skb)
790{
791 struct iphdr *iph;
792 unsigned char *th;
793 int err = -EPROTO;
794 int recalculate_partial_csum = 0;
795
796 /*
797 * A GSO SKB must be CHECKSUM_PARTIAL. However some buggy
798 * peers can fail to set NETRXF_csum_blank when sending a GSO
799 * frame. In this case force the SKB to CHECKSUM_PARTIAL and
800 * recalculate the partial checksum.
801 */
802 if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) {
803 struct netfront_info *np = netdev_priv(dev);
804 np->rx_gso_checksum_fixup++;
805 skb->ip_summed = CHECKSUM_PARTIAL;
806 recalculate_partial_csum = 1;
807 }
808
809 /* A non-CHECKSUM_PARTIAL SKB does not require setup. */
810 if (skb->ip_summed != CHECKSUM_PARTIAL)
811 return 0;
812
813 if (skb->protocol != htons(ETH_P_IP))
814 goto out;
815
816 iph = (void *)skb->data;
817 th = skb->data + 4 * iph->ihl;
818 if (th >= skb_tail_pointer(skb))
819 goto out;
820
821 skb->csum_start = th - skb->head;
822 switch (iph->protocol) {
823 case IPPROTO_TCP:
824 skb->csum_offset = offsetof(struct tcphdr, check);
825
826 if (recalculate_partial_csum) {
827 struct tcphdr *tcph = (struct tcphdr *)th;
828 tcph->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr,
829 skb->len - iph->ihl*4,
830 IPPROTO_TCP, 0);
831 }
832 break;
833 case IPPROTO_UDP:
834 skb->csum_offset = offsetof(struct udphdr, check);
835
836 if (recalculate_partial_csum) {
837 struct udphdr *udph = (struct udphdr *)th;
838 udph->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr,
839 skb->len - iph->ihl*4,
840 IPPROTO_UDP, 0);
841 }
842 break;
843 default:
844 if (net_ratelimit())
845 printk(KERN_ERR "Attempting to checksum a non-"
846 "TCP/UDP packet, dropping a protocol"
847 " %d packet", iph->protocol);
848 goto out;
849 }
850
851 if ((th + skb->csum_offset + 2) > skb_tail_pointer(skb))
852 goto out;
853
854 err = 0;
855
856out:
857 return err;
858}
859
860static int handle_incoming_queue(struct net_device *dev,
861 struct sk_buff_head *rxq)
862{
863 struct netfront_info *np = netdev_priv(dev);
864 struct netfront_stats *stats = this_cpu_ptr(np->stats);
865 int packets_dropped = 0;
866 struct sk_buff *skb;
867
868 while ((skb = __skb_dequeue(rxq)) != NULL) {
869 struct page *page = NETFRONT_SKB_CB(skb)->page;
870 void *vaddr = page_address(page);
871 unsigned offset = NETFRONT_SKB_CB(skb)->offset;
872
873 memcpy(skb->data, vaddr + offset,
874 skb_headlen(skb));
875
876 if (page != skb_shinfo(skb)->frags[0].page)
877 __free_page(page);
878
879 /* Ethernet work: Delayed to here as it peeks the header. */
880 skb->protocol = eth_type_trans(skb, dev);
881
882 if (checksum_setup(dev, skb)) {
883 kfree_skb(skb);
884 packets_dropped++;
885 dev->stats.rx_errors++;
886 continue;
887 }
888
889 u64_stats_update_begin(&stats->syncp);
890 stats->rx_packets++;
891 stats->rx_bytes += skb->len;
892 u64_stats_update_end(&stats->syncp);
893
894 /* Pass it up. */
895 netif_receive_skb(skb);
896 }
897
898 return packets_dropped;
899}
900
901static int xennet_poll(struct napi_struct *napi, int budget)
902{
903 struct netfront_info *np = container_of(napi, struct netfront_info, napi);
904 struct net_device *dev = np->netdev;
905 struct sk_buff *skb;
906 struct netfront_rx_info rinfo;
907 struct xen_netif_rx_response *rx = &rinfo.rx;
908 struct xen_netif_extra_info *extras = rinfo.extras;
909 RING_IDX i, rp;
910 int work_done;
911 struct sk_buff_head rxq;
912 struct sk_buff_head errq;
913 struct sk_buff_head tmpq;
914 unsigned long flags;
915 unsigned int len;
916 int err;
917
918 spin_lock(&np->rx_lock);
919
920 skb_queue_head_init(&rxq);
921 skb_queue_head_init(&errq);
922 skb_queue_head_init(&tmpq);
923
924 rp = np->rx.sring->rsp_prod;
925 rmb(); /* Ensure we see queued responses up to 'rp'. */
926
927 i = np->rx.rsp_cons;
928 work_done = 0;
929 while ((i != rp) && (work_done < budget)) {
930 memcpy(rx, RING_GET_RESPONSE(&np->rx, i), sizeof(*rx));
931 memset(extras, 0, sizeof(rinfo.extras));
932
933 err = xennet_get_responses(np, &rinfo, rp, &tmpq);
934
935 if (unlikely(err)) {
936err:
937 while ((skb = __skb_dequeue(&tmpq)))
938 __skb_queue_tail(&errq, skb);
939 dev->stats.rx_errors++;
940 i = np->rx.rsp_cons;
941 continue;
942 }
943
944 skb = __skb_dequeue(&tmpq);
945
946 if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) {
947 struct xen_netif_extra_info *gso;
948 gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1];
949
950 if (unlikely(xennet_set_skb_gso(skb, gso))) {
951 __skb_queue_head(&tmpq, skb);
952 np->rx.rsp_cons += skb_queue_len(&tmpq);
953 goto err;
954 }
955 }
956
957 NETFRONT_SKB_CB(skb)->page = skb_shinfo(skb)->frags[0].page;
958 NETFRONT_SKB_CB(skb)->offset = rx->offset;
959
960 len = rx->status;
961 if (len > RX_COPY_THRESHOLD)
962 len = RX_COPY_THRESHOLD;
963 skb_put(skb, len);
964
965 if (rx->status > len) {
966 skb_shinfo(skb)->frags[0].page_offset =
967 rx->offset + len;
968 skb_shinfo(skb)->frags[0].size = rx->status - len;
969 skb->data_len = rx->status - len;
970 } else {
971 skb_shinfo(skb)->frags[0].page = NULL;
972 skb_shinfo(skb)->nr_frags = 0;
973 }
974
975 i = xennet_fill_frags(np, skb, &tmpq);
976
977 /*
978 * Truesize approximates the size of true data plus
979 * any supervisor overheads. Adding hypervisor
980 * overheads has been shown to significantly reduce
981 * achievable bandwidth with the default receive
982 * buffer size. It is therefore not wise to account
983 * for it here.
984 *
985 * After alloc_skb(RX_COPY_THRESHOLD), truesize is set
986 * to RX_COPY_THRESHOLD + the supervisor
987 * overheads. Here, we add the size of the data pulled
988 * in xennet_fill_frags().
989 *
990 * We also adjust for any unused space in the main
991 * data area by subtracting (RX_COPY_THRESHOLD -
992 * len). This is especially important with drivers
993 * which split incoming packets into header and data,
994 * using only 66 bytes of the main data area (see the
995 * e1000 driver for example.) On such systems,
996 * without this last adjustement, our achievable
997 * receive throughout using the standard receive
998 * buffer size was cut by 25%(!!!).
999 */
1000 skb->truesize += skb->data_len - (RX_COPY_THRESHOLD - len);
1001 skb->len += skb->data_len;
1002
1003 if (rx->flags & XEN_NETRXF_csum_blank)
1004 skb->ip_summed = CHECKSUM_PARTIAL;
1005 else if (rx->flags & XEN_NETRXF_data_validated)
1006 skb->ip_summed = CHECKSUM_UNNECESSARY;
1007
1008 __skb_queue_tail(&rxq, skb);
1009
1010 np->rx.rsp_cons = ++i;
1011 work_done++;
1012 }
1013
1014 __skb_queue_purge(&errq);
1015
1016 work_done -= handle_incoming_queue(dev, &rxq);
1017
1018 /* If we get a callback with very few responses, reduce fill target. */
1019 /* NB. Note exponential increase, linear decrease. */
1020 if (((np->rx.req_prod_pvt - np->rx.sring->rsp_prod) >
1021 ((3*np->rx_target) / 4)) &&
1022 (--np->rx_target < np->rx_min_target))
1023 np->rx_target = np->rx_min_target;
1024
1025 xennet_alloc_rx_buffers(dev);
1026
1027 if (work_done < budget) {
1028 int more_to_do = 0;
1029
1030 local_irq_save(flags);
1031
1032 RING_FINAL_CHECK_FOR_RESPONSES(&np->rx, more_to_do);
1033 if (!more_to_do)
1034 __napi_complete(napi);
1035
1036 local_irq_restore(flags);
1037 }
1038
1039 spin_unlock(&np->rx_lock);
1040
1041 return work_done;
1042}
1043
1044static int xennet_change_mtu(struct net_device *dev, int mtu)
1045{
1046 int max = xennet_can_sg(dev) ? 65535 - ETH_HLEN : ETH_DATA_LEN;
1047
1048 if (mtu > max)
1049 return -EINVAL;
1050 dev->mtu = mtu;
1051 return 0;
1052}
1053
1054static struct rtnl_link_stats64 *xennet_get_stats64(struct net_device *dev,
1055 struct rtnl_link_stats64 *tot)
1056{
1057 struct netfront_info *np = netdev_priv(dev);
1058 int cpu;
1059
1060 for_each_possible_cpu(cpu) {
1061 struct netfront_stats *stats = per_cpu_ptr(np->stats, cpu);
1062 u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
1063 unsigned int start;
1064
1065 do {
1066 start = u64_stats_fetch_begin_bh(&stats->syncp);
1067
1068 rx_packets = stats->rx_packets;
1069 tx_packets = stats->tx_packets;
1070 rx_bytes = stats->rx_bytes;
1071 tx_bytes = stats->tx_bytes;
1072 } while (u64_stats_fetch_retry_bh(&stats->syncp, start));
1073
1074 tot->rx_packets += rx_packets;
1075 tot->tx_packets += tx_packets;
1076 tot->rx_bytes += rx_bytes;
1077 tot->tx_bytes += tx_bytes;
1078 }
1079
1080 tot->rx_errors = dev->stats.rx_errors;
1081 tot->tx_dropped = dev->stats.tx_dropped;
1082
1083 return tot;
1084}
1085
1086static void xennet_release_tx_bufs(struct netfront_info *np)
1087{
1088 struct sk_buff *skb;
1089 int i;
1090
1091 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1092 /* Skip over entries which are actually freelist references */
1093 if (skb_entry_is_link(&np->tx_skbs[i]))
1094 continue;
1095
1096 skb = np->tx_skbs[i].skb;
1097 gnttab_end_foreign_access_ref(np->grant_tx_ref[i],
1098 GNTMAP_readonly);
1099 gnttab_release_grant_reference(&np->gref_tx_head,
1100 np->grant_tx_ref[i]);
1101 np->grant_tx_ref[i] = GRANT_INVALID_REF;
1102 add_id_to_freelist(&np->tx_skb_freelist, np->tx_skbs, i);
1103 dev_kfree_skb_irq(skb);
1104 }
1105}
1106
1107static void xennet_release_rx_bufs(struct netfront_info *np)
1108{
1109 struct mmu_update *mmu = np->rx_mmu;
1110 struct multicall_entry *mcl = np->rx_mcl;
1111 struct sk_buff_head free_list;
1112 struct sk_buff *skb;
1113 unsigned long mfn;
1114 int xfer = 0, noxfer = 0, unused = 0;
1115 int id, ref;
1116
1117 dev_warn(&np->netdev->dev, "%s: fix me for copying receiver.\n",
1118 __func__);
1119 return;
1120
1121 skb_queue_head_init(&free_list);
1122
1123 spin_lock_bh(&np->rx_lock);
1124
1125 for (id = 0; id < NET_RX_RING_SIZE; id++) {
1126 ref = np->grant_rx_ref[id];
1127 if (ref == GRANT_INVALID_REF) {
1128 unused++;
1129 continue;
1130 }
1131
1132 skb = np->rx_skbs[id];
1133 mfn = gnttab_end_foreign_transfer_ref(ref);
1134 gnttab_release_grant_reference(&np->gref_rx_head, ref);
1135 np->grant_rx_ref[id] = GRANT_INVALID_REF;
1136
1137 if (0 == mfn) {
1138 skb_shinfo(skb)->nr_frags = 0;
1139 dev_kfree_skb(skb);
1140 noxfer++;
1141 continue;
1142 }
1143
1144 if (!xen_feature(XENFEAT_auto_translated_physmap)) {
1145 /* Remap the page. */
1146 struct page *page = skb_shinfo(skb)->frags[0].page;
1147 unsigned long pfn = page_to_pfn(page);
1148 void *vaddr = page_address(page);
1149
1150 MULTI_update_va_mapping(mcl, (unsigned long)vaddr,
1151 mfn_pte(mfn, PAGE_KERNEL),
1152 0);
1153 mcl++;
1154 mmu->ptr = ((u64)mfn << PAGE_SHIFT)
1155 | MMU_MACHPHYS_UPDATE;
1156 mmu->val = pfn;
1157 mmu++;
1158
1159 set_phys_to_machine(pfn, mfn);
1160 }
1161 __skb_queue_tail(&free_list, skb);
1162 xfer++;
1163 }
1164
1165 dev_info(&np->netdev->dev, "%s: %d xfer, %d noxfer, %d unused\n",
1166 __func__, xfer, noxfer, unused);
1167
1168 if (xfer) {
1169 if (!xen_feature(XENFEAT_auto_translated_physmap)) {
1170 /* Do all the remapping work and M2P updates. */
1171 MULTI_mmu_update(mcl, np->rx_mmu, mmu - np->rx_mmu,
1172 NULL, DOMID_SELF);
1173 mcl++;
1174 HYPERVISOR_multicall(np->rx_mcl, mcl - np->rx_mcl);
1175 }
1176 }
1177
1178 __skb_queue_purge(&free_list);
1179
1180 spin_unlock_bh(&np->rx_lock);
1181}
1182
1183static void xennet_uninit(struct net_device *dev)
1184{
1185 struct netfront_info *np = netdev_priv(dev);
1186 xennet_release_tx_bufs(np);
1187 xennet_release_rx_bufs(np);
1188 gnttab_free_grant_references(np->gref_tx_head);
1189 gnttab_free_grant_references(np->gref_rx_head);
1190}
1191
1192static u32 xennet_fix_features(struct net_device *dev, u32 features)
1193{
1194 struct netfront_info *np = netdev_priv(dev);
1195 int val;
1196
1197 if (features & NETIF_F_SG) {
1198 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, "feature-sg",
1199 "%d", &val) < 0)
1200 val = 0;
1201
1202 if (!val)
1203 features &= ~NETIF_F_SG;
1204 }
1205
1206 if (features & NETIF_F_TSO) {
1207 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1208 "feature-gso-tcpv4", "%d", &val) < 0)
1209 val = 0;
1210
1211 if (!val)
1212 features &= ~NETIF_F_TSO;
1213 }
1214
1215 return features;
1216}
1217
1218static int xennet_set_features(struct net_device *dev, u32 features)
1219{
1220 if (!(features & NETIF_F_SG) && dev->mtu > ETH_DATA_LEN) {
1221 netdev_info(dev, "Reducing MTU because no SG offload");
1222 dev->mtu = ETH_DATA_LEN;
1223 }
1224
1225 return 0;
1226}
1227
1228static const struct net_device_ops xennet_netdev_ops = {
1229 .ndo_open = xennet_open,
1230 .ndo_uninit = xennet_uninit,
1231 .ndo_stop = xennet_close,
1232 .ndo_start_xmit = xennet_start_xmit,
1233 .ndo_change_mtu = xennet_change_mtu,
1234 .ndo_get_stats64 = xennet_get_stats64,
1235 .ndo_set_mac_address = eth_mac_addr,
1236 .ndo_validate_addr = eth_validate_addr,
1237 .ndo_fix_features = xennet_fix_features,
1238 .ndo_set_features = xennet_set_features,
1239};
1240
1241static struct net_device * __devinit xennet_create_dev(struct xenbus_device *dev)
1242{
1243 int i, err;
1244 struct net_device *netdev;
1245 struct netfront_info *np;
1246
1247 netdev = alloc_etherdev(sizeof(struct netfront_info));
1248 if (!netdev) {
1249 printk(KERN_WARNING "%s> alloc_etherdev failed.\n",
1250 __func__);
1251 return ERR_PTR(-ENOMEM);
1252 }
1253
1254 np = netdev_priv(netdev);
1255 np->xbdev = dev;
1256
1257 spin_lock_init(&np->tx_lock);
1258 spin_lock_init(&np->rx_lock);
1259
1260 skb_queue_head_init(&np->rx_batch);
1261 np->rx_target = RX_DFL_MIN_TARGET;
1262 np->rx_min_target = RX_DFL_MIN_TARGET;
1263 np->rx_max_target = RX_MAX_TARGET;
1264
1265 init_timer(&np->rx_refill_timer);
1266 np->rx_refill_timer.data = (unsigned long)netdev;
1267 np->rx_refill_timer.function = rx_refill_timeout;
1268
1269 err = -ENOMEM;
1270 np->stats = alloc_percpu(struct netfront_stats);
1271 if (np->stats == NULL)
1272 goto exit;
1273
1274 /* Initialise tx_skbs as a free chain containing every entry. */
1275 np->tx_skb_freelist = 0;
1276 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1277 skb_entry_set_link(&np->tx_skbs[i], i+1);
1278 np->grant_tx_ref[i] = GRANT_INVALID_REF;
1279 }
1280
1281 /* Clear out rx_skbs */
1282 for (i = 0; i < NET_RX_RING_SIZE; i++) {
1283 np->rx_skbs[i] = NULL;
1284 np->grant_rx_ref[i] = GRANT_INVALID_REF;
1285 }
1286
1287 /* A grant for every tx ring slot */
1288 if (gnttab_alloc_grant_references(TX_MAX_TARGET,
1289 &np->gref_tx_head) < 0) {
1290 printk(KERN_ALERT "#### netfront can't alloc tx grant refs\n");
1291 err = -ENOMEM;
1292 goto exit_free_stats;
1293 }
1294 /* A grant for every rx ring slot */
1295 if (gnttab_alloc_grant_references(RX_MAX_TARGET,
1296 &np->gref_rx_head) < 0) {
1297 printk(KERN_ALERT "#### netfront can't alloc rx grant refs\n");
1298 err = -ENOMEM;
1299 goto exit_free_tx;
1300 }
1301
1302 netdev->netdev_ops = &xennet_netdev_ops;
1303
1304 netif_napi_add(netdev, &np->napi, xennet_poll, 64);
1305 netdev->features = NETIF_F_IP_CSUM | NETIF_F_RXCSUM |
1306 NETIF_F_GSO_ROBUST;
1307 netdev->hw_features = NETIF_F_IP_CSUM | NETIF_F_SG | NETIF_F_TSO;
1308
1309 /*
1310 * Assume that all hw features are available for now. This set
1311 * will be adjusted by the call to netdev_update_features() in
1312 * xennet_connect() which is the earliest point where we can
1313 * negotiate with the backend regarding supported features.
1314 */
1315 netdev->features |= netdev->hw_features;
1316
1317 SET_ETHTOOL_OPS(netdev, &xennet_ethtool_ops);
1318 SET_NETDEV_DEV(netdev, &dev->dev);
1319
1320 np->netdev = netdev;
1321
1322 netif_carrier_off(netdev);
1323
1324 return netdev;
1325
1326 exit_free_tx:
1327 gnttab_free_grant_references(np->gref_tx_head);
1328 exit_free_stats:
1329 free_percpu(np->stats);
1330 exit:
1331 free_netdev(netdev);
1332 return ERR_PTR(err);
1333}
1334
1335/**
1336 * Entry point to this code when a new device is created. Allocate the basic
1337 * structures and the ring buffers for communication with the backend, and
1338 * inform the backend of the appropriate details for those.
1339 */
1340static int __devinit netfront_probe(struct xenbus_device *dev,
1341 const struct xenbus_device_id *id)
1342{
1343 int err;
1344 struct net_device *netdev;
1345 struct netfront_info *info;
1346
1347 netdev = xennet_create_dev(dev);
1348 if (IS_ERR(netdev)) {
1349 err = PTR_ERR(netdev);
1350 xenbus_dev_fatal(dev, err, "creating netdev");
1351 return err;
1352 }
1353
1354 info = netdev_priv(netdev);
1355 dev_set_drvdata(&dev->dev, info);
1356
1357 err = register_netdev(info->netdev);
1358 if (err) {
1359 printk(KERN_WARNING "%s: register_netdev err=%d\n",
1360 __func__, err);
1361 goto fail;
1362 }
1363
1364 err = xennet_sysfs_addif(info->netdev);
1365 if (err) {
1366 unregister_netdev(info->netdev);
1367 printk(KERN_WARNING "%s: add sysfs failed err=%d\n",
1368 __func__, err);
1369 goto fail;
1370 }
1371
1372 return 0;
1373
1374 fail:
1375 free_netdev(netdev);
1376 dev_set_drvdata(&dev->dev, NULL);
1377 return err;
1378}
1379
1380static void xennet_end_access(int ref, void *page)
1381{
1382 /* This frees the page as a side-effect */
1383 if (ref != GRANT_INVALID_REF)
1384 gnttab_end_foreign_access(ref, 0, (unsigned long)page);
1385}
1386
1387static void xennet_disconnect_backend(struct netfront_info *info)
1388{
1389 /* Stop old i/f to prevent errors whilst we rebuild the state. */
1390 spin_lock_bh(&info->rx_lock);
1391 spin_lock_irq(&info->tx_lock);
1392 netif_carrier_off(info->netdev);
1393 spin_unlock_irq(&info->tx_lock);
1394 spin_unlock_bh(&info->rx_lock);
1395
1396 if (info->netdev->irq)
1397 unbind_from_irqhandler(info->netdev->irq, info->netdev);
1398 info->evtchn = info->netdev->irq = 0;
1399
1400 /* End access and free the pages */
1401 xennet_end_access(info->tx_ring_ref, info->tx.sring);
1402 xennet_end_access(info->rx_ring_ref, info->rx.sring);
1403
1404 info->tx_ring_ref = GRANT_INVALID_REF;
1405 info->rx_ring_ref = GRANT_INVALID_REF;
1406 info->tx.sring = NULL;
1407 info->rx.sring = NULL;
1408}
1409
1410/**
1411 * We are reconnecting to the backend, due to a suspend/resume, or a backend
1412 * driver restart. We tear down our netif structure and recreate it, but
1413 * leave the device-layer structures intact so that this is transparent to the
1414 * rest of the kernel.
1415 */
1416static int netfront_resume(struct xenbus_device *dev)
1417{
1418 struct netfront_info *info = dev_get_drvdata(&dev->dev);
1419
1420 dev_dbg(&dev->dev, "%s\n", dev->nodename);
1421
1422 xennet_disconnect_backend(info);
1423 return 0;
1424}
1425
1426static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[])
1427{
1428 char *s, *e, *macstr;
1429 int i;
1430
1431 macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL);
1432 if (IS_ERR(macstr))
1433 return PTR_ERR(macstr);
1434
1435 for (i = 0; i < ETH_ALEN; i++) {
1436 mac[i] = simple_strtoul(s, &e, 16);
1437 if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) {
1438 kfree(macstr);
1439 return -ENOENT;
1440 }
1441 s = e+1;
1442 }
1443
1444 kfree(macstr);
1445 return 0;
1446}
1447
1448static irqreturn_t xennet_interrupt(int irq, void *dev_id)
1449{
1450 struct net_device *dev = dev_id;
1451 struct netfront_info *np = netdev_priv(dev);
1452 unsigned long flags;
1453
1454 spin_lock_irqsave(&np->tx_lock, flags);
1455
1456 if (likely(netif_carrier_ok(dev))) {
1457 xennet_tx_buf_gc(dev);
1458 /* Under tx_lock: protects access to rx shared-ring indexes. */
1459 if (RING_HAS_UNCONSUMED_RESPONSES(&np->rx))
1460 napi_schedule(&np->napi);
1461 }
1462
1463 spin_unlock_irqrestore(&np->tx_lock, flags);
1464
1465 return IRQ_HANDLED;
1466}
1467
1468static int setup_netfront(struct xenbus_device *dev, struct netfront_info *info)
1469{
1470 struct xen_netif_tx_sring *txs;
1471 struct xen_netif_rx_sring *rxs;
1472 int err;
1473 struct net_device *netdev = info->netdev;
1474
1475 info->tx_ring_ref = GRANT_INVALID_REF;
1476 info->rx_ring_ref = GRANT_INVALID_REF;
1477 info->rx.sring = NULL;
1478 info->tx.sring = NULL;
1479 netdev->irq = 0;
1480
1481 err = xen_net_read_mac(dev, netdev->dev_addr);
1482 if (err) {
1483 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
1484 goto fail;
1485 }
1486
1487 txs = (struct xen_netif_tx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1488 if (!txs) {
1489 err = -ENOMEM;
1490 xenbus_dev_fatal(dev, err, "allocating tx ring page");
1491 goto fail;
1492 }
1493 SHARED_RING_INIT(txs);
1494 FRONT_RING_INIT(&info->tx, txs, PAGE_SIZE);
1495
1496 err = xenbus_grant_ring(dev, virt_to_mfn(txs));
1497 if (err < 0) {
1498 free_page((unsigned long)txs);
1499 goto fail;
1500 }
1501
1502 info->tx_ring_ref = err;
1503 rxs = (struct xen_netif_rx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1504 if (!rxs) {
1505 err = -ENOMEM;
1506 xenbus_dev_fatal(dev, err, "allocating rx ring page");
1507 goto fail;
1508 }
1509 SHARED_RING_INIT(rxs);
1510 FRONT_RING_INIT(&info->rx, rxs, PAGE_SIZE);
1511
1512 err = xenbus_grant_ring(dev, virt_to_mfn(rxs));
1513 if (err < 0) {
1514 free_page((unsigned long)rxs);
1515 goto fail;
1516 }
1517 info->rx_ring_ref = err;
1518
1519 err = xenbus_alloc_evtchn(dev, &info->evtchn);
1520 if (err)
1521 goto fail;
1522
1523 err = bind_evtchn_to_irqhandler(info->evtchn, xennet_interrupt,
1524 0, netdev->name, netdev);
1525 if (err < 0)
1526 goto fail;
1527 netdev->irq = err;
1528 return 0;
1529
1530 fail:
1531 return err;
1532}
1533
1534/* Common code used when first setting up, and when resuming. */
1535static int talk_to_netback(struct xenbus_device *dev,
1536 struct netfront_info *info)
1537{
1538 const char *message;
1539 struct xenbus_transaction xbt;
1540 int err;
1541
1542 /* Create shared ring, alloc event channel. */
1543 err = setup_netfront(dev, info);
1544 if (err)
1545 goto out;
1546
1547again:
1548 err = xenbus_transaction_start(&xbt);
1549 if (err) {
1550 xenbus_dev_fatal(dev, err, "starting transaction");
1551 goto destroy_ring;
1552 }
1553
1554 err = xenbus_printf(xbt, dev->nodename, "tx-ring-ref", "%u",
1555 info->tx_ring_ref);
1556 if (err) {
1557 message = "writing tx ring-ref";
1558 goto abort_transaction;
1559 }
1560 err = xenbus_printf(xbt, dev->nodename, "rx-ring-ref", "%u",
1561 info->rx_ring_ref);
1562 if (err) {
1563 message = "writing rx ring-ref";
1564 goto abort_transaction;
1565 }
1566 err = xenbus_printf(xbt, dev->nodename,
1567 "event-channel", "%u", info->evtchn);
1568 if (err) {
1569 message = "writing event-channel";
1570 goto abort_transaction;
1571 }
1572
1573 err = xenbus_printf(xbt, dev->nodename, "request-rx-copy", "%u",
1574 1);
1575 if (err) {
1576 message = "writing request-rx-copy";
1577 goto abort_transaction;
1578 }
1579
1580 err = xenbus_printf(xbt, dev->nodename, "feature-rx-notify", "%d", 1);
1581 if (err) {
1582 message = "writing feature-rx-notify";
1583 goto abort_transaction;
1584 }
1585
1586 err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", 1);
1587 if (err) {
1588 message = "writing feature-sg";
1589 goto abort_transaction;
1590 }
1591
1592 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4", "%d", 1);
1593 if (err) {
1594 message = "writing feature-gso-tcpv4";
1595 goto abort_transaction;
1596 }
1597
1598 err = xenbus_transaction_end(xbt, 0);
1599 if (err) {
1600 if (err == -EAGAIN)
1601 goto again;
1602 xenbus_dev_fatal(dev, err, "completing transaction");
1603 goto destroy_ring;
1604 }
1605
1606 return 0;
1607
1608 abort_transaction:
1609 xenbus_transaction_end(xbt, 1);
1610 xenbus_dev_fatal(dev, err, "%s", message);
1611 destroy_ring:
1612 xennet_disconnect_backend(info);
1613 out:
1614 return err;
1615}
1616
1617static int xennet_connect(struct net_device *dev)
1618{
1619 struct netfront_info *np = netdev_priv(dev);
1620 int i, requeue_idx, err;
1621 struct sk_buff *skb;
1622 grant_ref_t ref;
1623 struct xen_netif_rx_request *req;
1624 unsigned int feature_rx_copy;
1625
1626 err = xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1627 "feature-rx-copy", "%u", &feature_rx_copy);
1628 if (err != 1)
1629 feature_rx_copy = 0;
1630
1631 if (!feature_rx_copy) {
1632 dev_info(&dev->dev,
1633 "backend does not support copying receive path\n");
1634 return -ENODEV;
1635 }
1636
1637 err = talk_to_netback(np->xbdev, np);
1638 if (err)
1639 return err;
1640
1641 rtnl_lock();
1642 netdev_update_features(dev);
1643 rtnl_unlock();
1644
1645 spin_lock_bh(&np->rx_lock);
1646 spin_lock_irq(&np->tx_lock);
1647
1648 /* Step 1: Discard all pending TX packet fragments. */
1649 xennet_release_tx_bufs(np);
1650
1651 /* Step 2: Rebuild the RX buffer freelist and the RX ring itself. */
1652 for (requeue_idx = 0, i = 0; i < NET_RX_RING_SIZE; i++) {
1653 if (!np->rx_skbs[i])
1654 continue;
1655
1656 skb = np->rx_skbs[requeue_idx] = xennet_get_rx_skb(np, i);
1657 ref = np->grant_rx_ref[requeue_idx] = xennet_get_rx_ref(np, i);
1658 req = RING_GET_REQUEST(&np->rx, requeue_idx);
1659
1660 gnttab_grant_foreign_access_ref(
1661 ref, np->xbdev->otherend_id,
1662 pfn_to_mfn(page_to_pfn(skb_shinfo(skb)->
1663 frags->page)),
1664 0);
1665 req->gref = ref;
1666 req->id = requeue_idx;
1667
1668 requeue_idx++;
1669 }
1670
1671 np->rx.req_prod_pvt = requeue_idx;
1672
1673 /*
1674 * Step 3: All public and private state should now be sane. Get
1675 * ready to start sending and receiving packets and give the driver
1676 * domain a kick because we've probably just requeued some
1677 * packets.
1678 */
1679 netif_carrier_on(np->netdev);
1680 notify_remote_via_irq(np->netdev->irq);
1681 xennet_tx_buf_gc(dev);
1682 xennet_alloc_rx_buffers(dev);
1683
1684 spin_unlock_irq(&np->tx_lock);
1685 spin_unlock_bh(&np->rx_lock);
1686
1687 return 0;
1688}
1689
1690/**
1691 * Callback received when the backend's state changes.
1692 */
1693static void netback_changed(struct xenbus_device *dev,
1694 enum xenbus_state backend_state)
1695{
1696 struct netfront_info *np = dev_get_drvdata(&dev->dev);
1697 struct net_device *netdev = np->netdev;
1698
1699 dev_dbg(&dev->dev, "%s\n", xenbus_strstate(backend_state));
1700
1701 switch (backend_state) {
1702 case XenbusStateInitialising:
1703 case XenbusStateInitialised:
1704 case XenbusStateReconfiguring:
1705 case XenbusStateReconfigured:
1706 case XenbusStateConnected:
1707 case XenbusStateUnknown:
1708 case XenbusStateClosed:
1709 break;
1710
1711 case XenbusStateInitWait:
1712 if (dev->state != XenbusStateInitialising)
1713 break;
1714 if (xennet_connect(netdev) != 0)
1715 break;
1716 xenbus_switch_state(dev, XenbusStateConnected);
1717 netif_notify_peers(netdev);
1718 break;
1719
1720 case XenbusStateClosing:
1721 xenbus_frontend_closed(dev);
1722 break;
1723 }
1724}
1725
1726static const struct xennet_stat {
1727 char name[ETH_GSTRING_LEN];
1728 u16 offset;
1729} xennet_stats[] = {
1730 {
1731 "rx_gso_checksum_fixup",
1732 offsetof(struct netfront_info, rx_gso_checksum_fixup)
1733 },
1734};
1735
1736static int xennet_get_sset_count(struct net_device *dev, int string_set)
1737{
1738 switch (string_set) {
1739 case ETH_SS_STATS:
1740 return ARRAY_SIZE(xennet_stats);
1741 default:
1742 return -EINVAL;
1743 }
1744}
1745
1746static void xennet_get_ethtool_stats(struct net_device *dev,
1747 struct ethtool_stats *stats, u64 * data)
1748{
1749 void *np = netdev_priv(dev);
1750 int i;
1751
1752 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
1753 data[i] = *(unsigned long *)(np + xennet_stats[i].offset);
1754}
1755
1756static void xennet_get_strings(struct net_device *dev, u32 stringset, u8 * data)
1757{
1758 int i;
1759
1760 switch (stringset) {
1761 case ETH_SS_STATS:
1762 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
1763 memcpy(data + i * ETH_GSTRING_LEN,
1764 xennet_stats[i].name, ETH_GSTRING_LEN);
1765 break;
1766 }
1767}
1768
1769static const struct ethtool_ops xennet_ethtool_ops =
1770{
1771 .get_link = ethtool_op_get_link,
1772
1773 .get_sset_count = xennet_get_sset_count,
1774 .get_ethtool_stats = xennet_get_ethtool_stats,
1775 .get_strings = xennet_get_strings,
1776};
1777
1778#ifdef CONFIG_SYSFS
1779static ssize_t show_rxbuf_min(struct device *dev,
1780 struct device_attribute *attr, char *buf)
1781{
1782 struct net_device *netdev = to_net_dev(dev);
1783 struct netfront_info *info = netdev_priv(netdev);
1784
1785 return sprintf(buf, "%u\n", info->rx_min_target);
1786}
1787
1788static ssize_t store_rxbuf_min(struct device *dev,
1789 struct device_attribute *attr,
1790 const char *buf, size_t len)
1791{
1792 struct net_device *netdev = to_net_dev(dev);
1793 struct netfront_info *np = netdev_priv(netdev);
1794 char *endp;
1795 unsigned long target;
1796
1797 if (!capable(CAP_NET_ADMIN))
1798 return -EPERM;
1799
1800 target = simple_strtoul(buf, &endp, 0);
1801 if (endp == buf)
1802 return -EBADMSG;
1803
1804 if (target < RX_MIN_TARGET)
1805 target = RX_MIN_TARGET;
1806 if (target > RX_MAX_TARGET)
1807 target = RX_MAX_TARGET;
1808
1809 spin_lock_bh(&np->rx_lock);
1810 if (target > np->rx_max_target)
1811 np->rx_max_target = target;
1812 np->rx_min_target = target;
1813 if (target > np->rx_target)
1814 np->rx_target = target;
1815
1816 xennet_alloc_rx_buffers(netdev);
1817
1818 spin_unlock_bh(&np->rx_lock);
1819 return len;
1820}
1821
1822static ssize_t show_rxbuf_max(struct device *dev,
1823 struct device_attribute *attr, char *buf)
1824{
1825 struct net_device *netdev = to_net_dev(dev);
1826 struct netfront_info *info = netdev_priv(netdev);
1827
1828 return sprintf(buf, "%u\n", info->rx_max_target);
1829}
1830
1831static ssize_t store_rxbuf_max(struct device *dev,
1832 struct device_attribute *attr,
1833 const char *buf, size_t len)
1834{
1835 struct net_device *netdev = to_net_dev(dev);
1836 struct netfront_info *np = netdev_priv(netdev);
1837 char *endp;
1838 unsigned long target;
1839
1840 if (!capable(CAP_NET_ADMIN))
1841 return -EPERM;
1842
1843 target = simple_strtoul(buf, &endp, 0);
1844 if (endp == buf)
1845 return -EBADMSG;
1846
1847 if (target < RX_MIN_TARGET)
1848 target = RX_MIN_TARGET;
1849 if (target > RX_MAX_TARGET)
1850 target = RX_MAX_TARGET;
1851
1852 spin_lock_bh(&np->rx_lock);
1853 if (target < np->rx_min_target)
1854 np->rx_min_target = target;
1855 np->rx_max_target = target;
1856 if (target < np->rx_target)
1857 np->rx_target = target;
1858
1859 xennet_alloc_rx_buffers(netdev);
1860
1861 spin_unlock_bh(&np->rx_lock);
1862 return len;
1863}
1864
1865static ssize_t show_rxbuf_cur(struct device *dev,
1866 struct device_attribute *attr, char *buf)
1867{
1868 struct net_device *netdev = to_net_dev(dev);
1869 struct netfront_info *info = netdev_priv(netdev);
1870
1871 return sprintf(buf, "%u\n", info->rx_target);
1872}
1873
1874static struct device_attribute xennet_attrs[] = {
1875 __ATTR(rxbuf_min, S_IRUGO|S_IWUSR, show_rxbuf_min, store_rxbuf_min),
1876 __ATTR(rxbuf_max, S_IRUGO|S_IWUSR, show_rxbuf_max, store_rxbuf_max),
1877 __ATTR(rxbuf_cur, S_IRUGO, show_rxbuf_cur, NULL),
1878};
1879
1880static int xennet_sysfs_addif(struct net_device *netdev)
1881{
1882 int i;
1883 int err;
1884
1885 for (i = 0; i < ARRAY_SIZE(xennet_attrs); i++) {
1886 err = device_create_file(&netdev->dev,
1887 &xennet_attrs[i]);
1888 if (err)
1889 goto fail;
1890 }
1891 return 0;
1892
1893 fail:
1894 while (--i >= 0)
1895 device_remove_file(&netdev->dev, &xennet_attrs[i]);
1896 return err;
1897}
1898
1899static void xennet_sysfs_delif(struct net_device *netdev)
1900{
1901 int i;
1902
1903 for (i = 0; i < ARRAY_SIZE(xennet_attrs); i++)
1904 device_remove_file(&netdev->dev, &xennet_attrs[i]);
1905}
1906
1907#endif /* CONFIG_SYSFS */
1908
1909static struct xenbus_device_id netfront_ids[] = {
1910 { "vif" },
1911 { "" }
1912};
1913
1914
1915static int __devexit xennet_remove(struct xenbus_device *dev)
1916{
1917 struct netfront_info *info = dev_get_drvdata(&dev->dev);
1918
1919 dev_dbg(&dev->dev, "%s\n", dev->nodename);
1920
1921 unregister_netdev(info->netdev);
1922
1923 xennet_disconnect_backend(info);
1924
1925 del_timer_sync(&info->rx_refill_timer);
1926
1927 xennet_sysfs_delif(info->netdev);
1928
1929 free_percpu(info->stats);
1930
1931 free_netdev(info->netdev);
1932
1933 return 0;
1934}
1935
1936static struct xenbus_driver netfront_driver = {
1937 .name = "vif",
1938 .owner = THIS_MODULE,
1939 .ids = netfront_ids,
1940 .probe = netfront_probe,
1941 .remove = __devexit_p(xennet_remove),
1942 .resume = netfront_resume,
1943 .otherend_changed = netback_changed,
1944};
1945
1946static int __init netif_init(void)
1947{
1948 if (!xen_domain())
1949 return -ENODEV;
1950
1951 if (xen_initial_domain())
1952 return 0;
1953
1954 printk(KERN_INFO "Initialising Xen virtual ethernet driver.\n");
1955
1956 return xenbus_register_frontend(&netfront_driver);
1957}
1958module_init(netif_init);
1959
1960
1961static void __exit netif_exit(void)
1962{
1963 if (xen_initial_domain())
1964 return;
1965
1966 xenbus_unregister_driver(&netfront_driver);
1967}
1968module_exit(netif_exit);
1969
1970MODULE_DESCRIPTION("Xen virtual network device frontend");
1971MODULE_LICENSE("GPL");
1972MODULE_ALIAS("xen:vif");
1973MODULE_ALIAS("xennet");
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
33
34#include <linux/module.h>
35#include <linux/kernel.h>
36#include <linux/netdevice.h>
37#include <linux/etherdevice.h>
38#include <linux/skbuff.h>
39#include <linux/ethtool.h>
40#include <linux/if_ether.h>
41#include <net/tcp.h>
42#include <linux/udp.h>
43#include <linux/moduleparam.h>
44#include <linux/mm.h>
45#include <linux/slab.h>
46#include <net/ip.h>
47
48#include <xen/xen.h>
49#include <xen/xenbus.h>
50#include <xen/events.h>
51#include <xen/page.h>
52#include <xen/platform_pci.h>
53#include <xen/grant_table.h>
54
55#include <xen/interface/io/netif.h>
56#include <xen/interface/memory.h>
57#include <xen/interface/grant_table.h>
58
59/* Module parameters */
60static unsigned int xennet_max_queues;
61module_param_named(max_queues, xennet_max_queues, uint, 0644);
62MODULE_PARM_DESC(max_queues,
63 "Maximum number of queues per virtual interface");
64
65static const struct ethtool_ops xennet_ethtool_ops;
66
67struct netfront_cb {
68 int pull_to;
69};
70
71#define NETFRONT_SKB_CB(skb) ((struct netfront_cb *)((skb)->cb))
72
73#define RX_COPY_THRESHOLD 256
74
75#define GRANT_INVALID_REF 0
76
77#define NET_TX_RING_SIZE __CONST_RING_SIZE(xen_netif_tx, XEN_PAGE_SIZE)
78#define NET_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, XEN_PAGE_SIZE)
79
80/* Minimum number of Rx slots (includes slot for GSO metadata). */
81#define NET_RX_SLOTS_MIN (XEN_NETIF_NR_SLOTS_MIN + 1)
82
83/* Queue name is interface name with "-qNNN" appended */
84#define QUEUE_NAME_SIZE (IFNAMSIZ + 6)
85
86/* IRQ name is queue name with "-tx" or "-rx" appended */
87#define IRQ_NAME_SIZE (QUEUE_NAME_SIZE + 3)
88
89struct netfront_stats {
90 u64 packets;
91 u64 bytes;
92 struct u64_stats_sync syncp;
93};
94
95struct netfront_info;
96
97struct netfront_queue {
98 unsigned int id; /* Queue ID, 0-based */
99 char name[QUEUE_NAME_SIZE]; /* DEVNAME-qN */
100 struct netfront_info *info;
101
102 struct napi_struct napi;
103
104 /* Split event channels support, tx_* == rx_* when using
105 * single event channel.
106 */
107 unsigned int tx_evtchn, rx_evtchn;
108 unsigned int tx_irq, rx_irq;
109 /* Only used when split event channels support is enabled */
110 char tx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-tx */
111 char rx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-rx */
112
113 spinlock_t tx_lock;
114 struct xen_netif_tx_front_ring tx;
115 int tx_ring_ref;
116
117 /*
118 * {tx,rx}_skbs store outstanding skbuffs. Free tx_skb entries
119 * are linked from tx_skb_freelist through skb_entry.link.
120 *
121 * NB. Freelist index entries are always going to be less than
122 * PAGE_OFFSET, whereas pointers to skbs will always be equal or
123 * greater than PAGE_OFFSET: we use this property to distinguish
124 * them.
125 */
126 union skb_entry {
127 struct sk_buff *skb;
128 unsigned long link;
129 } tx_skbs[NET_TX_RING_SIZE];
130 grant_ref_t gref_tx_head;
131 grant_ref_t grant_tx_ref[NET_TX_RING_SIZE];
132 struct page *grant_tx_page[NET_TX_RING_SIZE];
133 unsigned tx_skb_freelist;
134
135 spinlock_t rx_lock ____cacheline_aligned_in_smp;
136 struct xen_netif_rx_front_ring rx;
137 int rx_ring_ref;
138
139 struct timer_list rx_refill_timer;
140
141 struct sk_buff *rx_skbs[NET_RX_RING_SIZE];
142 grant_ref_t gref_rx_head;
143 grant_ref_t grant_rx_ref[NET_RX_RING_SIZE];
144};
145
146struct netfront_info {
147 struct list_head list;
148 struct net_device *netdev;
149
150 struct xenbus_device *xbdev;
151
152 /* Multi-queue support */
153 struct netfront_queue *queues;
154
155 /* Statistics */
156 struct netfront_stats __percpu *rx_stats;
157 struct netfront_stats __percpu *tx_stats;
158
159 atomic_t rx_gso_checksum_fixup;
160};
161
162struct netfront_rx_info {
163 struct xen_netif_rx_response rx;
164 struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX - 1];
165};
166
167static void skb_entry_set_link(union skb_entry *list, unsigned short id)
168{
169 list->link = id;
170}
171
172static int skb_entry_is_link(const union skb_entry *list)
173{
174 BUILD_BUG_ON(sizeof(list->skb) != sizeof(list->link));
175 return (unsigned long)list->skb < PAGE_OFFSET;
176}
177
178/*
179 * Access macros for acquiring freeing slots in tx_skbs[].
180 */
181
182static void add_id_to_freelist(unsigned *head, union skb_entry *list,
183 unsigned short id)
184{
185 skb_entry_set_link(&list[id], *head);
186 *head = id;
187}
188
189static unsigned short get_id_from_freelist(unsigned *head,
190 union skb_entry *list)
191{
192 unsigned int id = *head;
193 *head = list[id].link;
194 return id;
195}
196
197static int xennet_rxidx(RING_IDX idx)
198{
199 return idx & (NET_RX_RING_SIZE - 1);
200}
201
202static struct sk_buff *xennet_get_rx_skb(struct netfront_queue *queue,
203 RING_IDX ri)
204{
205 int i = xennet_rxidx(ri);
206 struct sk_buff *skb = queue->rx_skbs[i];
207 queue->rx_skbs[i] = NULL;
208 return skb;
209}
210
211static grant_ref_t xennet_get_rx_ref(struct netfront_queue *queue,
212 RING_IDX ri)
213{
214 int i = xennet_rxidx(ri);
215 grant_ref_t ref = queue->grant_rx_ref[i];
216 queue->grant_rx_ref[i] = GRANT_INVALID_REF;
217 return ref;
218}
219
220#ifdef CONFIG_SYSFS
221static const struct attribute_group xennet_dev_group;
222#endif
223
224static bool xennet_can_sg(struct net_device *dev)
225{
226 return dev->features & NETIF_F_SG;
227}
228
229
230static void rx_refill_timeout(unsigned long data)
231{
232 struct netfront_queue *queue = (struct netfront_queue *)data;
233 napi_schedule(&queue->napi);
234}
235
236static int netfront_tx_slot_available(struct netfront_queue *queue)
237{
238 return (queue->tx.req_prod_pvt - queue->tx.rsp_cons) <
239 (NET_TX_RING_SIZE - MAX_SKB_FRAGS - 2);
240}
241
242static void xennet_maybe_wake_tx(struct netfront_queue *queue)
243{
244 struct net_device *dev = queue->info->netdev;
245 struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, queue->id);
246
247 if (unlikely(netif_tx_queue_stopped(dev_queue)) &&
248 netfront_tx_slot_available(queue) &&
249 likely(netif_running(dev)))
250 netif_tx_wake_queue(netdev_get_tx_queue(dev, queue->id));
251}
252
253
254static struct sk_buff *xennet_alloc_one_rx_buffer(struct netfront_queue *queue)
255{
256 struct sk_buff *skb;
257 struct page *page;
258
259 skb = __netdev_alloc_skb(queue->info->netdev,
260 RX_COPY_THRESHOLD + NET_IP_ALIGN,
261 GFP_ATOMIC | __GFP_NOWARN);
262 if (unlikely(!skb))
263 return NULL;
264
265 page = alloc_page(GFP_ATOMIC | __GFP_NOWARN);
266 if (!page) {
267 kfree_skb(skb);
268 return NULL;
269 }
270 skb_add_rx_frag(skb, 0, page, 0, 0, PAGE_SIZE);
271
272 /* Align ip header to a 16 bytes boundary */
273 skb_reserve(skb, NET_IP_ALIGN);
274 skb->dev = queue->info->netdev;
275
276 return skb;
277}
278
279
280static void xennet_alloc_rx_buffers(struct netfront_queue *queue)
281{
282 RING_IDX req_prod = queue->rx.req_prod_pvt;
283 int notify;
284 int err = 0;
285
286 if (unlikely(!netif_carrier_ok(queue->info->netdev)))
287 return;
288
289 for (req_prod = queue->rx.req_prod_pvt;
290 req_prod - queue->rx.rsp_cons < NET_RX_RING_SIZE;
291 req_prod++) {
292 struct sk_buff *skb;
293 unsigned short id;
294 grant_ref_t ref;
295 struct page *page;
296 struct xen_netif_rx_request *req;
297
298 skb = xennet_alloc_one_rx_buffer(queue);
299 if (!skb) {
300 err = -ENOMEM;
301 break;
302 }
303
304 id = xennet_rxidx(req_prod);
305
306 BUG_ON(queue->rx_skbs[id]);
307 queue->rx_skbs[id] = skb;
308
309 ref = gnttab_claim_grant_reference(&queue->gref_rx_head);
310 WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)(int)ref));
311 queue->grant_rx_ref[id] = ref;
312
313 page = skb_frag_page(&skb_shinfo(skb)->frags[0]);
314
315 req = RING_GET_REQUEST(&queue->rx, req_prod);
316 gnttab_page_grant_foreign_access_ref_one(ref,
317 queue->info->xbdev->otherend_id,
318 page,
319 0);
320 req->id = id;
321 req->gref = ref;
322 }
323
324 queue->rx.req_prod_pvt = req_prod;
325
326 /* Try again later if there are not enough requests or skb allocation
327 * failed.
328 * Enough requests is quantified as the sum of newly created slots and
329 * the unconsumed slots at the backend.
330 */
331 if (req_prod - queue->rx.rsp_cons < NET_RX_SLOTS_MIN ||
332 unlikely(err)) {
333 mod_timer(&queue->rx_refill_timer, jiffies + (HZ/10));
334 return;
335 }
336
337 wmb(); /* barrier so backend seens requests */
338
339 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->rx, notify);
340 if (notify)
341 notify_remote_via_irq(queue->rx_irq);
342}
343
344static int xennet_open(struct net_device *dev)
345{
346 struct netfront_info *np = netdev_priv(dev);
347 unsigned int num_queues = dev->real_num_tx_queues;
348 unsigned int i = 0;
349 struct netfront_queue *queue = NULL;
350
351 for (i = 0; i < num_queues; ++i) {
352 queue = &np->queues[i];
353 napi_enable(&queue->napi);
354
355 spin_lock_bh(&queue->rx_lock);
356 if (netif_carrier_ok(dev)) {
357 xennet_alloc_rx_buffers(queue);
358 queue->rx.sring->rsp_event = queue->rx.rsp_cons + 1;
359 if (RING_HAS_UNCONSUMED_RESPONSES(&queue->rx))
360 napi_schedule(&queue->napi);
361 }
362 spin_unlock_bh(&queue->rx_lock);
363 }
364
365 netif_tx_start_all_queues(dev);
366
367 return 0;
368}
369
370static void xennet_tx_buf_gc(struct netfront_queue *queue)
371{
372 RING_IDX cons, prod;
373 unsigned short id;
374 struct sk_buff *skb;
375 bool more_to_do;
376
377 BUG_ON(!netif_carrier_ok(queue->info->netdev));
378
379 do {
380 prod = queue->tx.sring->rsp_prod;
381 rmb(); /* Ensure we see responses up to 'rp'. */
382
383 for (cons = queue->tx.rsp_cons; cons != prod; cons++) {
384 struct xen_netif_tx_response *txrsp;
385
386 txrsp = RING_GET_RESPONSE(&queue->tx, cons);
387 if (txrsp->status == XEN_NETIF_RSP_NULL)
388 continue;
389
390 id = txrsp->id;
391 skb = queue->tx_skbs[id].skb;
392 if (unlikely(gnttab_query_foreign_access(
393 queue->grant_tx_ref[id]) != 0)) {
394 pr_alert("%s: warning -- grant still in use by backend domain\n",
395 __func__);
396 BUG();
397 }
398 gnttab_end_foreign_access_ref(
399 queue->grant_tx_ref[id], GNTMAP_readonly);
400 gnttab_release_grant_reference(
401 &queue->gref_tx_head, queue->grant_tx_ref[id]);
402 queue->grant_tx_ref[id] = GRANT_INVALID_REF;
403 queue->grant_tx_page[id] = NULL;
404 add_id_to_freelist(&queue->tx_skb_freelist, queue->tx_skbs, id);
405 dev_kfree_skb_irq(skb);
406 }
407
408 queue->tx.rsp_cons = prod;
409
410 RING_FINAL_CHECK_FOR_RESPONSES(&queue->tx, more_to_do);
411 } while (more_to_do);
412
413 xennet_maybe_wake_tx(queue);
414}
415
416struct xennet_gnttab_make_txreq {
417 struct netfront_queue *queue;
418 struct sk_buff *skb;
419 struct page *page;
420 struct xen_netif_tx_request *tx; /* Last request */
421 unsigned int size;
422};
423
424static void xennet_tx_setup_grant(unsigned long gfn, unsigned int offset,
425 unsigned int len, void *data)
426{
427 struct xennet_gnttab_make_txreq *info = data;
428 unsigned int id;
429 struct xen_netif_tx_request *tx;
430 grant_ref_t ref;
431 /* convenient aliases */
432 struct page *page = info->page;
433 struct netfront_queue *queue = info->queue;
434 struct sk_buff *skb = info->skb;
435
436 id = get_id_from_freelist(&queue->tx_skb_freelist, queue->tx_skbs);
437 tx = RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++);
438 ref = gnttab_claim_grant_reference(&queue->gref_tx_head);
439 WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)(int)ref));
440
441 gnttab_grant_foreign_access_ref(ref, queue->info->xbdev->otherend_id,
442 gfn, GNTMAP_readonly);
443
444 queue->tx_skbs[id].skb = skb;
445 queue->grant_tx_page[id] = page;
446 queue->grant_tx_ref[id] = ref;
447
448 tx->id = id;
449 tx->gref = ref;
450 tx->offset = offset;
451 tx->size = len;
452 tx->flags = 0;
453
454 info->tx = tx;
455 info->size += tx->size;
456}
457
458static struct xen_netif_tx_request *xennet_make_first_txreq(
459 struct netfront_queue *queue, struct sk_buff *skb,
460 struct page *page, unsigned int offset, unsigned int len)
461{
462 struct xennet_gnttab_make_txreq info = {
463 .queue = queue,
464 .skb = skb,
465 .page = page,
466 .size = 0,
467 };
468
469 gnttab_for_one_grant(page, offset, len, xennet_tx_setup_grant, &info);
470
471 return info.tx;
472}
473
474static void xennet_make_one_txreq(unsigned long gfn, unsigned int offset,
475 unsigned int len, void *data)
476{
477 struct xennet_gnttab_make_txreq *info = data;
478
479 info->tx->flags |= XEN_NETTXF_more_data;
480 skb_get(info->skb);
481 xennet_tx_setup_grant(gfn, offset, len, data);
482}
483
484static struct xen_netif_tx_request *xennet_make_txreqs(
485 struct netfront_queue *queue, struct xen_netif_tx_request *tx,
486 struct sk_buff *skb, struct page *page,
487 unsigned int offset, unsigned int len)
488{
489 struct xennet_gnttab_make_txreq info = {
490 .queue = queue,
491 .skb = skb,
492 .tx = tx,
493 };
494
495 /* Skip unused frames from start of page */
496 page += offset >> PAGE_SHIFT;
497 offset &= ~PAGE_MASK;
498
499 while (len) {
500 info.page = page;
501 info.size = 0;
502
503 gnttab_foreach_grant_in_range(page, offset, len,
504 xennet_make_one_txreq,
505 &info);
506
507 page++;
508 offset = 0;
509 len -= info.size;
510 }
511
512 return info.tx;
513}
514
515/*
516 * Count how many ring slots are required to send this skb. Each frag
517 * might be a compound page.
518 */
519static int xennet_count_skb_slots(struct sk_buff *skb)
520{
521 int i, frags = skb_shinfo(skb)->nr_frags;
522 int slots;
523
524 slots = gnttab_count_grant(offset_in_page(skb->data),
525 skb_headlen(skb));
526
527 for (i = 0; i < frags; i++) {
528 skb_frag_t *frag = skb_shinfo(skb)->frags + i;
529 unsigned long size = skb_frag_size(frag);
530 unsigned long offset = frag->page_offset;
531
532 /* Skip unused frames from start of page */
533 offset &= ~PAGE_MASK;
534
535 slots += gnttab_count_grant(offset, size);
536 }
537
538 return slots;
539}
540
541static u16 xennet_select_queue(struct net_device *dev, struct sk_buff *skb,
542 void *accel_priv, select_queue_fallback_t fallback)
543{
544 unsigned int num_queues = dev->real_num_tx_queues;
545 u32 hash;
546 u16 queue_idx;
547
548 /* First, check if there is only one queue */
549 if (num_queues == 1) {
550 queue_idx = 0;
551 } else {
552 hash = skb_get_hash(skb);
553 queue_idx = hash % num_queues;
554 }
555
556 return queue_idx;
557}
558
559#define MAX_XEN_SKB_FRAGS (65536 / XEN_PAGE_SIZE + 1)
560
561static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev)
562{
563 struct netfront_info *np = netdev_priv(dev);
564 struct netfront_stats *tx_stats = this_cpu_ptr(np->tx_stats);
565 struct xen_netif_tx_request *tx, *first_tx;
566 unsigned int i;
567 int notify;
568 int slots;
569 struct page *page;
570 unsigned int offset;
571 unsigned int len;
572 unsigned long flags;
573 struct netfront_queue *queue = NULL;
574 unsigned int num_queues = dev->real_num_tx_queues;
575 u16 queue_index;
576 struct sk_buff *nskb;
577
578 /* Drop the packet if no queues are set up */
579 if (num_queues < 1)
580 goto drop;
581 /* Determine which queue to transmit this SKB on */
582 queue_index = skb_get_queue_mapping(skb);
583 queue = &np->queues[queue_index];
584
585 /* If skb->len is too big for wire format, drop skb and alert
586 * user about misconfiguration.
587 */
588 if (unlikely(skb->len > XEN_NETIF_MAX_TX_SIZE)) {
589 net_alert_ratelimited(
590 "xennet: skb->len = %u, too big for wire format\n",
591 skb->len);
592 goto drop;
593 }
594
595 slots = xennet_count_skb_slots(skb);
596 if (unlikely(slots > MAX_XEN_SKB_FRAGS + 1)) {
597 net_dbg_ratelimited("xennet: skb rides the rocket: %d slots, %d bytes\n",
598 slots, skb->len);
599 if (skb_linearize(skb))
600 goto drop;
601 }
602
603 page = virt_to_page(skb->data);
604 offset = offset_in_page(skb->data);
605
606 /* The first req should be at least ETH_HLEN size or the packet will be
607 * dropped by netback.
608 */
609 if (unlikely(PAGE_SIZE - offset < ETH_HLEN)) {
610 nskb = skb_copy(skb, GFP_ATOMIC);
611 if (!nskb)
612 goto drop;
613 dev_kfree_skb_any(skb);
614 skb = nskb;
615 page = virt_to_page(skb->data);
616 offset = offset_in_page(skb->data);
617 }
618
619 len = skb_headlen(skb);
620
621 spin_lock_irqsave(&queue->tx_lock, flags);
622
623 if (unlikely(!netif_carrier_ok(dev) ||
624 (slots > 1 && !xennet_can_sg(dev)) ||
625 netif_needs_gso(skb, netif_skb_features(skb)))) {
626 spin_unlock_irqrestore(&queue->tx_lock, flags);
627 goto drop;
628 }
629
630 /* First request for the linear area. */
631 first_tx = tx = xennet_make_first_txreq(queue, skb,
632 page, offset, len);
633 offset += tx->size;
634 if (offset == PAGE_SIZE) {
635 page++;
636 offset = 0;
637 }
638 len -= tx->size;
639
640 if (skb->ip_summed == CHECKSUM_PARTIAL)
641 /* local packet? */
642 tx->flags |= XEN_NETTXF_csum_blank | XEN_NETTXF_data_validated;
643 else if (skb->ip_summed == CHECKSUM_UNNECESSARY)
644 /* remote but checksummed. */
645 tx->flags |= XEN_NETTXF_data_validated;
646
647 /* Optional extra info after the first request. */
648 if (skb_shinfo(skb)->gso_size) {
649 struct xen_netif_extra_info *gso;
650
651 gso = (struct xen_netif_extra_info *)
652 RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++);
653
654 tx->flags |= XEN_NETTXF_extra_info;
655
656 gso->u.gso.size = skb_shinfo(skb)->gso_size;
657 gso->u.gso.type = (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) ?
658 XEN_NETIF_GSO_TYPE_TCPV6 :
659 XEN_NETIF_GSO_TYPE_TCPV4;
660 gso->u.gso.pad = 0;
661 gso->u.gso.features = 0;
662
663 gso->type = XEN_NETIF_EXTRA_TYPE_GSO;
664 gso->flags = 0;
665 }
666
667 /* Requests for the rest of the linear area. */
668 tx = xennet_make_txreqs(queue, tx, skb, page, offset, len);
669
670 /* Requests for all the frags. */
671 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
672 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
673 tx = xennet_make_txreqs(queue, tx, skb,
674 skb_frag_page(frag), frag->page_offset,
675 skb_frag_size(frag));
676 }
677
678 /* First request has the packet length. */
679 first_tx->size = skb->len;
680
681 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->tx, notify);
682 if (notify)
683 notify_remote_via_irq(queue->tx_irq);
684
685 u64_stats_update_begin(&tx_stats->syncp);
686 tx_stats->bytes += skb->len;
687 tx_stats->packets++;
688 u64_stats_update_end(&tx_stats->syncp);
689
690 /* Note: It is not safe to access skb after xennet_tx_buf_gc()! */
691 xennet_tx_buf_gc(queue);
692
693 if (!netfront_tx_slot_available(queue))
694 netif_tx_stop_queue(netdev_get_tx_queue(dev, queue->id));
695
696 spin_unlock_irqrestore(&queue->tx_lock, flags);
697
698 return NETDEV_TX_OK;
699
700 drop:
701 dev->stats.tx_dropped++;
702 dev_kfree_skb_any(skb);
703 return NETDEV_TX_OK;
704}
705
706static int xennet_close(struct net_device *dev)
707{
708 struct netfront_info *np = netdev_priv(dev);
709 unsigned int num_queues = dev->real_num_tx_queues;
710 unsigned int i;
711 struct netfront_queue *queue;
712 netif_tx_stop_all_queues(np->netdev);
713 for (i = 0; i < num_queues; ++i) {
714 queue = &np->queues[i];
715 napi_disable(&queue->napi);
716 }
717 return 0;
718}
719
720static void xennet_move_rx_slot(struct netfront_queue *queue, struct sk_buff *skb,
721 grant_ref_t ref)
722{
723 int new = xennet_rxidx(queue->rx.req_prod_pvt);
724
725 BUG_ON(queue->rx_skbs[new]);
726 queue->rx_skbs[new] = skb;
727 queue->grant_rx_ref[new] = ref;
728 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->id = new;
729 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->gref = ref;
730 queue->rx.req_prod_pvt++;
731}
732
733static int xennet_get_extras(struct netfront_queue *queue,
734 struct xen_netif_extra_info *extras,
735 RING_IDX rp)
736
737{
738 struct xen_netif_extra_info *extra;
739 struct device *dev = &queue->info->netdev->dev;
740 RING_IDX cons = queue->rx.rsp_cons;
741 int err = 0;
742
743 do {
744 struct sk_buff *skb;
745 grant_ref_t ref;
746
747 if (unlikely(cons + 1 == rp)) {
748 if (net_ratelimit())
749 dev_warn(dev, "Missing extra info\n");
750 err = -EBADR;
751 break;
752 }
753
754 extra = (struct xen_netif_extra_info *)
755 RING_GET_RESPONSE(&queue->rx, ++cons);
756
757 if (unlikely(!extra->type ||
758 extra->type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
759 if (net_ratelimit())
760 dev_warn(dev, "Invalid extra type: %d\n",
761 extra->type);
762 err = -EINVAL;
763 } else {
764 memcpy(&extras[extra->type - 1], extra,
765 sizeof(*extra));
766 }
767
768 skb = xennet_get_rx_skb(queue, cons);
769 ref = xennet_get_rx_ref(queue, cons);
770 xennet_move_rx_slot(queue, skb, ref);
771 } while (extra->flags & XEN_NETIF_EXTRA_FLAG_MORE);
772
773 queue->rx.rsp_cons = cons;
774 return err;
775}
776
777static int xennet_get_responses(struct netfront_queue *queue,
778 struct netfront_rx_info *rinfo, RING_IDX rp,
779 struct sk_buff_head *list)
780{
781 struct xen_netif_rx_response *rx = &rinfo->rx;
782 struct xen_netif_extra_info *extras = rinfo->extras;
783 struct device *dev = &queue->info->netdev->dev;
784 RING_IDX cons = queue->rx.rsp_cons;
785 struct sk_buff *skb = xennet_get_rx_skb(queue, cons);
786 grant_ref_t ref = xennet_get_rx_ref(queue, cons);
787 int max = MAX_SKB_FRAGS + (rx->status <= RX_COPY_THRESHOLD);
788 int slots = 1;
789 int err = 0;
790 unsigned long ret;
791
792 if (rx->flags & XEN_NETRXF_extra_info) {
793 err = xennet_get_extras(queue, extras, rp);
794 cons = queue->rx.rsp_cons;
795 }
796
797 for (;;) {
798 if (unlikely(rx->status < 0 ||
799 rx->offset + rx->status > XEN_PAGE_SIZE)) {
800 if (net_ratelimit())
801 dev_warn(dev, "rx->offset: %u, size: %d\n",
802 rx->offset, rx->status);
803 xennet_move_rx_slot(queue, skb, ref);
804 err = -EINVAL;
805 goto next;
806 }
807
808 /*
809 * This definitely indicates a bug, either in this driver or in
810 * the backend driver. In future this should flag the bad
811 * situation to the system controller to reboot the backend.
812 */
813 if (ref == GRANT_INVALID_REF) {
814 if (net_ratelimit())
815 dev_warn(dev, "Bad rx response id %d.\n",
816 rx->id);
817 err = -EINVAL;
818 goto next;
819 }
820
821 ret = gnttab_end_foreign_access_ref(ref, 0);
822 BUG_ON(!ret);
823
824 gnttab_release_grant_reference(&queue->gref_rx_head, ref);
825
826 __skb_queue_tail(list, skb);
827
828next:
829 if (!(rx->flags & XEN_NETRXF_more_data))
830 break;
831
832 if (cons + slots == rp) {
833 if (net_ratelimit())
834 dev_warn(dev, "Need more slots\n");
835 err = -ENOENT;
836 break;
837 }
838
839 rx = RING_GET_RESPONSE(&queue->rx, cons + slots);
840 skb = xennet_get_rx_skb(queue, cons + slots);
841 ref = xennet_get_rx_ref(queue, cons + slots);
842 slots++;
843 }
844
845 if (unlikely(slots > max)) {
846 if (net_ratelimit())
847 dev_warn(dev, "Too many slots\n");
848 err = -E2BIG;
849 }
850
851 if (unlikely(err))
852 queue->rx.rsp_cons = cons + slots;
853
854 return err;
855}
856
857static int xennet_set_skb_gso(struct sk_buff *skb,
858 struct xen_netif_extra_info *gso)
859{
860 if (!gso->u.gso.size) {
861 if (net_ratelimit())
862 pr_warn("GSO size must not be zero\n");
863 return -EINVAL;
864 }
865
866 if (gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV4 &&
867 gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV6) {
868 if (net_ratelimit())
869 pr_warn("Bad GSO type %d\n", gso->u.gso.type);
870 return -EINVAL;
871 }
872
873 skb_shinfo(skb)->gso_size = gso->u.gso.size;
874 skb_shinfo(skb)->gso_type =
875 (gso->u.gso.type == XEN_NETIF_GSO_TYPE_TCPV4) ?
876 SKB_GSO_TCPV4 :
877 SKB_GSO_TCPV6;
878
879 /* Header must be checked, and gso_segs computed. */
880 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
881 skb_shinfo(skb)->gso_segs = 0;
882
883 return 0;
884}
885
886static RING_IDX xennet_fill_frags(struct netfront_queue *queue,
887 struct sk_buff *skb,
888 struct sk_buff_head *list)
889{
890 struct skb_shared_info *shinfo = skb_shinfo(skb);
891 RING_IDX cons = queue->rx.rsp_cons;
892 struct sk_buff *nskb;
893
894 while ((nskb = __skb_dequeue(list))) {
895 struct xen_netif_rx_response *rx =
896 RING_GET_RESPONSE(&queue->rx, ++cons);
897 skb_frag_t *nfrag = &skb_shinfo(nskb)->frags[0];
898
899 if (shinfo->nr_frags == MAX_SKB_FRAGS) {
900 unsigned int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
901
902 BUG_ON(pull_to <= skb_headlen(skb));
903 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
904 }
905 BUG_ON(shinfo->nr_frags >= MAX_SKB_FRAGS);
906
907 skb_add_rx_frag(skb, shinfo->nr_frags, skb_frag_page(nfrag),
908 rx->offset, rx->status, PAGE_SIZE);
909
910 skb_shinfo(nskb)->nr_frags = 0;
911 kfree_skb(nskb);
912 }
913
914 return cons;
915}
916
917static int checksum_setup(struct net_device *dev, struct sk_buff *skb)
918{
919 bool recalculate_partial_csum = false;
920
921 /*
922 * A GSO SKB must be CHECKSUM_PARTIAL. However some buggy
923 * peers can fail to set NETRXF_csum_blank when sending a GSO
924 * frame. In this case force the SKB to CHECKSUM_PARTIAL and
925 * recalculate the partial checksum.
926 */
927 if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) {
928 struct netfront_info *np = netdev_priv(dev);
929 atomic_inc(&np->rx_gso_checksum_fixup);
930 skb->ip_summed = CHECKSUM_PARTIAL;
931 recalculate_partial_csum = true;
932 }
933
934 /* A non-CHECKSUM_PARTIAL SKB does not require setup. */
935 if (skb->ip_summed != CHECKSUM_PARTIAL)
936 return 0;
937
938 return skb_checksum_setup(skb, recalculate_partial_csum);
939}
940
941static int handle_incoming_queue(struct netfront_queue *queue,
942 struct sk_buff_head *rxq)
943{
944 struct netfront_stats *rx_stats = this_cpu_ptr(queue->info->rx_stats);
945 int packets_dropped = 0;
946 struct sk_buff *skb;
947
948 while ((skb = __skb_dequeue(rxq)) != NULL) {
949 int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
950
951 if (pull_to > skb_headlen(skb))
952 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
953
954 /* Ethernet work: Delayed to here as it peeks the header. */
955 skb->protocol = eth_type_trans(skb, queue->info->netdev);
956 skb_reset_network_header(skb);
957
958 if (checksum_setup(queue->info->netdev, skb)) {
959 kfree_skb(skb);
960 packets_dropped++;
961 queue->info->netdev->stats.rx_errors++;
962 continue;
963 }
964
965 u64_stats_update_begin(&rx_stats->syncp);
966 rx_stats->packets++;
967 rx_stats->bytes += skb->len;
968 u64_stats_update_end(&rx_stats->syncp);
969
970 /* Pass it up. */
971 napi_gro_receive(&queue->napi, skb);
972 }
973
974 return packets_dropped;
975}
976
977static int xennet_poll(struct napi_struct *napi, int budget)
978{
979 struct netfront_queue *queue = container_of(napi, struct netfront_queue, napi);
980 struct net_device *dev = queue->info->netdev;
981 struct sk_buff *skb;
982 struct netfront_rx_info rinfo;
983 struct xen_netif_rx_response *rx = &rinfo.rx;
984 struct xen_netif_extra_info *extras = rinfo.extras;
985 RING_IDX i, rp;
986 int work_done;
987 struct sk_buff_head rxq;
988 struct sk_buff_head errq;
989 struct sk_buff_head tmpq;
990 int err;
991
992 spin_lock(&queue->rx_lock);
993
994 skb_queue_head_init(&rxq);
995 skb_queue_head_init(&errq);
996 skb_queue_head_init(&tmpq);
997
998 rp = queue->rx.sring->rsp_prod;
999 rmb(); /* Ensure we see queued responses up to 'rp'. */
1000
1001 i = queue->rx.rsp_cons;
1002 work_done = 0;
1003 while ((i != rp) && (work_done < budget)) {
1004 memcpy(rx, RING_GET_RESPONSE(&queue->rx, i), sizeof(*rx));
1005 memset(extras, 0, sizeof(rinfo.extras));
1006
1007 err = xennet_get_responses(queue, &rinfo, rp, &tmpq);
1008
1009 if (unlikely(err)) {
1010err:
1011 while ((skb = __skb_dequeue(&tmpq)))
1012 __skb_queue_tail(&errq, skb);
1013 dev->stats.rx_errors++;
1014 i = queue->rx.rsp_cons;
1015 continue;
1016 }
1017
1018 skb = __skb_dequeue(&tmpq);
1019
1020 if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) {
1021 struct xen_netif_extra_info *gso;
1022 gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1];
1023
1024 if (unlikely(xennet_set_skb_gso(skb, gso))) {
1025 __skb_queue_head(&tmpq, skb);
1026 queue->rx.rsp_cons += skb_queue_len(&tmpq);
1027 goto err;
1028 }
1029 }
1030
1031 NETFRONT_SKB_CB(skb)->pull_to = rx->status;
1032 if (NETFRONT_SKB_CB(skb)->pull_to > RX_COPY_THRESHOLD)
1033 NETFRONT_SKB_CB(skb)->pull_to = RX_COPY_THRESHOLD;
1034
1035 skb_shinfo(skb)->frags[0].page_offset = rx->offset;
1036 skb_frag_size_set(&skb_shinfo(skb)->frags[0], rx->status);
1037 skb->data_len = rx->status;
1038 skb->len += rx->status;
1039
1040 i = xennet_fill_frags(queue, skb, &tmpq);
1041
1042 if (rx->flags & XEN_NETRXF_csum_blank)
1043 skb->ip_summed = CHECKSUM_PARTIAL;
1044 else if (rx->flags & XEN_NETRXF_data_validated)
1045 skb->ip_summed = CHECKSUM_UNNECESSARY;
1046
1047 __skb_queue_tail(&rxq, skb);
1048
1049 queue->rx.rsp_cons = ++i;
1050 work_done++;
1051 }
1052
1053 __skb_queue_purge(&errq);
1054
1055 work_done -= handle_incoming_queue(queue, &rxq);
1056
1057 xennet_alloc_rx_buffers(queue);
1058
1059 if (work_done < budget) {
1060 int more_to_do = 0;
1061
1062 napi_complete(napi);
1063
1064 RING_FINAL_CHECK_FOR_RESPONSES(&queue->rx, more_to_do);
1065 if (more_to_do)
1066 napi_schedule(napi);
1067 }
1068
1069 spin_unlock(&queue->rx_lock);
1070
1071 return work_done;
1072}
1073
1074static int xennet_change_mtu(struct net_device *dev, int mtu)
1075{
1076 int max = xennet_can_sg(dev) ? XEN_NETIF_MAX_TX_SIZE : ETH_DATA_LEN;
1077
1078 if (mtu > max)
1079 return -EINVAL;
1080 dev->mtu = mtu;
1081 return 0;
1082}
1083
1084static struct rtnl_link_stats64 *xennet_get_stats64(struct net_device *dev,
1085 struct rtnl_link_stats64 *tot)
1086{
1087 struct netfront_info *np = netdev_priv(dev);
1088 int cpu;
1089
1090 for_each_possible_cpu(cpu) {
1091 struct netfront_stats *rx_stats = per_cpu_ptr(np->rx_stats, cpu);
1092 struct netfront_stats *tx_stats = per_cpu_ptr(np->tx_stats, cpu);
1093 u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
1094 unsigned int start;
1095
1096 do {
1097 start = u64_stats_fetch_begin_irq(&tx_stats->syncp);
1098 tx_packets = tx_stats->packets;
1099 tx_bytes = tx_stats->bytes;
1100 } while (u64_stats_fetch_retry_irq(&tx_stats->syncp, start));
1101
1102 do {
1103 start = u64_stats_fetch_begin_irq(&rx_stats->syncp);
1104 rx_packets = rx_stats->packets;
1105 rx_bytes = rx_stats->bytes;
1106 } while (u64_stats_fetch_retry_irq(&rx_stats->syncp, start));
1107
1108 tot->rx_packets += rx_packets;
1109 tot->tx_packets += tx_packets;
1110 tot->rx_bytes += rx_bytes;
1111 tot->tx_bytes += tx_bytes;
1112 }
1113
1114 tot->rx_errors = dev->stats.rx_errors;
1115 tot->tx_dropped = dev->stats.tx_dropped;
1116
1117 return tot;
1118}
1119
1120static void xennet_release_tx_bufs(struct netfront_queue *queue)
1121{
1122 struct sk_buff *skb;
1123 int i;
1124
1125 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1126 /* Skip over entries which are actually freelist references */
1127 if (skb_entry_is_link(&queue->tx_skbs[i]))
1128 continue;
1129
1130 skb = queue->tx_skbs[i].skb;
1131 get_page(queue->grant_tx_page[i]);
1132 gnttab_end_foreign_access(queue->grant_tx_ref[i],
1133 GNTMAP_readonly,
1134 (unsigned long)page_address(queue->grant_tx_page[i]));
1135 queue->grant_tx_page[i] = NULL;
1136 queue->grant_tx_ref[i] = GRANT_INVALID_REF;
1137 add_id_to_freelist(&queue->tx_skb_freelist, queue->tx_skbs, i);
1138 dev_kfree_skb_irq(skb);
1139 }
1140}
1141
1142static void xennet_release_rx_bufs(struct netfront_queue *queue)
1143{
1144 int id, ref;
1145
1146 spin_lock_bh(&queue->rx_lock);
1147
1148 for (id = 0; id < NET_RX_RING_SIZE; id++) {
1149 struct sk_buff *skb;
1150 struct page *page;
1151
1152 skb = queue->rx_skbs[id];
1153 if (!skb)
1154 continue;
1155
1156 ref = queue->grant_rx_ref[id];
1157 if (ref == GRANT_INVALID_REF)
1158 continue;
1159
1160 page = skb_frag_page(&skb_shinfo(skb)->frags[0]);
1161
1162 /* gnttab_end_foreign_access() needs a page ref until
1163 * foreign access is ended (which may be deferred).
1164 */
1165 get_page(page);
1166 gnttab_end_foreign_access(ref, 0,
1167 (unsigned long)page_address(page));
1168 queue->grant_rx_ref[id] = GRANT_INVALID_REF;
1169
1170 kfree_skb(skb);
1171 }
1172
1173 spin_unlock_bh(&queue->rx_lock);
1174}
1175
1176static netdev_features_t xennet_fix_features(struct net_device *dev,
1177 netdev_features_t features)
1178{
1179 struct netfront_info *np = netdev_priv(dev);
1180
1181 if (features & NETIF_F_SG &&
1182 !xenbus_read_unsigned(np->xbdev->otherend, "feature-sg", 0))
1183 features &= ~NETIF_F_SG;
1184
1185 if (features & NETIF_F_IPV6_CSUM &&
1186 !xenbus_read_unsigned(np->xbdev->otherend,
1187 "feature-ipv6-csum-offload", 0))
1188 features &= ~NETIF_F_IPV6_CSUM;
1189
1190 if (features & NETIF_F_TSO &&
1191 !xenbus_read_unsigned(np->xbdev->otherend, "feature-gso-tcpv4", 0))
1192 features &= ~NETIF_F_TSO;
1193
1194 if (features & NETIF_F_TSO6 &&
1195 !xenbus_read_unsigned(np->xbdev->otherend, "feature-gso-tcpv6", 0))
1196 features &= ~NETIF_F_TSO6;
1197
1198 return features;
1199}
1200
1201static int xennet_set_features(struct net_device *dev,
1202 netdev_features_t features)
1203{
1204 if (!(features & NETIF_F_SG) && dev->mtu > ETH_DATA_LEN) {
1205 netdev_info(dev, "Reducing MTU because no SG offload");
1206 dev->mtu = ETH_DATA_LEN;
1207 }
1208
1209 return 0;
1210}
1211
1212static irqreturn_t xennet_tx_interrupt(int irq, void *dev_id)
1213{
1214 struct netfront_queue *queue = dev_id;
1215 unsigned long flags;
1216
1217 spin_lock_irqsave(&queue->tx_lock, flags);
1218 xennet_tx_buf_gc(queue);
1219 spin_unlock_irqrestore(&queue->tx_lock, flags);
1220
1221 return IRQ_HANDLED;
1222}
1223
1224static irqreturn_t xennet_rx_interrupt(int irq, void *dev_id)
1225{
1226 struct netfront_queue *queue = dev_id;
1227 struct net_device *dev = queue->info->netdev;
1228
1229 if (likely(netif_carrier_ok(dev) &&
1230 RING_HAS_UNCONSUMED_RESPONSES(&queue->rx)))
1231 napi_schedule(&queue->napi);
1232
1233 return IRQ_HANDLED;
1234}
1235
1236static irqreturn_t xennet_interrupt(int irq, void *dev_id)
1237{
1238 xennet_tx_interrupt(irq, dev_id);
1239 xennet_rx_interrupt(irq, dev_id);
1240 return IRQ_HANDLED;
1241}
1242
1243#ifdef CONFIG_NET_POLL_CONTROLLER
1244static void xennet_poll_controller(struct net_device *dev)
1245{
1246 /* Poll each queue */
1247 struct netfront_info *info = netdev_priv(dev);
1248 unsigned int num_queues = dev->real_num_tx_queues;
1249 unsigned int i;
1250 for (i = 0; i < num_queues; ++i)
1251 xennet_interrupt(0, &info->queues[i]);
1252}
1253#endif
1254
1255static const struct net_device_ops xennet_netdev_ops = {
1256 .ndo_open = xennet_open,
1257 .ndo_stop = xennet_close,
1258 .ndo_start_xmit = xennet_start_xmit,
1259 .ndo_change_mtu = xennet_change_mtu,
1260 .ndo_get_stats64 = xennet_get_stats64,
1261 .ndo_set_mac_address = eth_mac_addr,
1262 .ndo_validate_addr = eth_validate_addr,
1263 .ndo_fix_features = xennet_fix_features,
1264 .ndo_set_features = xennet_set_features,
1265 .ndo_select_queue = xennet_select_queue,
1266#ifdef CONFIG_NET_POLL_CONTROLLER
1267 .ndo_poll_controller = xennet_poll_controller,
1268#endif
1269};
1270
1271static void xennet_free_netdev(struct net_device *netdev)
1272{
1273 struct netfront_info *np = netdev_priv(netdev);
1274
1275 free_percpu(np->rx_stats);
1276 free_percpu(np->tx_stats);
1277 free_netdev(netdev);
1278}
1279
1280static struct net_device *xennet_create_dev(struct xenbus_device *dev)
1281{
1282 int err;
1283 struct net_device *netdev;
1284 struct netfront_info *np;
1285
1286 netdev = alloc_etherdev_mq(sizeof(struct netfront_info), xennet_max_queues);
1287 if (!netdev)
1288 return ERR_PTR(-ENOMEM);
1289
1290 np = netdev_priv(netdev);
1291 np->xbdev = dev;
1292
1293 np->queues = NULL;
1294
1295 err = -ENOMEM;
1296 np->rx_stats = netdev_alloc_pcpu_stats(struct netfront_stats);
1297 if (np->rx_stats == NULL)
1298 goto exit;
1299 np->tx_stats = netdev_alloc_pcpu_stats(struct netfront_stats);
1300 if (np->tx_stats == NULL)
1301 goto exit;
1302
1303 netdev->netdev_ops = &xennet_netdev_ops;
1304
1305 netdev->features = NETIF_F_IP_CSUM | NETIF_F_RXCSUM |
1306 NETIF_F_GSO_ROBUST;
1307 netdev->hw_features = NETIF_F_SG |
1308 NETIF_F_IPV6_CSUM |
1309 NETIF_F_TSO | NETIF_F_TSO6;
1310
1311 /*
1312 * Assume that all hw features are available for now. This set
1313 * will be adjusted by the call to netdev_update_features() in
1314 * xennet_connect() which is the earliest point where we can
1315 * negotiate with the backend regarding supported features.
1316 */
1317 netdev->features |= netdev->hw_features;
1318
1319 netdev->ethtool_ops = &xennet_ethtool_ops;
1320 netdev->min_mtu = 0;
1321 netdev->max_mtu = XEN_NETIF_MAX_TX_SIZE;
1322 SET_NETDEV_DEV(netdev, &dev->dev);
1323
1324 np->netdev = netdev;
1325
1326 netif_carrier_off(netdev);
1327
1328 return netdev;
1329
1330 exit:
1331 xennet_free_netdev(netdev);
1332 return ERR_PTR(err);
1333}
1334
1335/**
1336 * Entry point to this code when a new device is created. Allocate the basic
1337 * structures and the ring buffers for communication with the backend, and
1338 * inform the backend of the appropriate details for those.
1339 */
1340static int netfront_probe(struct xenbus_device *dev,
1341 const struct xenbus_device_id *id)
1342{
1343 int err;
1344 struct net_device *netdev;
1345 struct netfront_info *info;
1346
1347 netdev = xennet_create_dev(dev);
1348 if (IS_ERR(netdev)) {
1349 err = PTR_ERR(netdev);
1350 xenbus_dev_fatal(dev, err, "creating netdev");
1351 return err;
1352 }
1353
1354 info = netdev_priv(netdev);
1355 dev_set_drvdata(&dev->dev, info);
1356#ifdef CONFIG_SYSFS
1357 info->netdev->sysfs_groups[0] = &xennet_dev_group;
1358#endif
1359 err = register_netdev(info->netdev);
1360 if (err) {
1361 pr_warn("%s: register_netdev err=%d\n", __func__, err);
1362 goto fail;
1363 }
1364
1365 return 0;
1366
1367 fail:
1368 xennet_free_netdev(netdev);
1369 dev_set_drvdata(&dev->dev, NULL);
1370 return err;
1371}
1372
1373static void xennet_end_access(int ref, void *page)
1374{
1375 /* This frees the page as a side-effect */
1376 if (ref != GRANT_INVALID_REF)
1377 gnttab_end_foreign_access(ref, 0, (unsigned long)page);
1378}
1379
1380static void xennet_disconnect_backend(struct netfront_info *info)
1381{
1382 unsigned int i = 0;
1383 unsigned int num_queues = info->netdev->real_num_tx_queues;
1384
1385 netif_carrier_off(info->netdev);
1386
1387 for (i = 0; i < num_queues && info->queues; ++i) {
1388 struct netfront_queue *queue = &info->queues[i];
1389
1390 del_timer_sync(&queue->rx_refill_timer);
1391
1392 if (queue->tx_irq && (queue->tx_irq == queue->rx_irq))
1393 unbind_from_irqhandler(queue->tx_irq, queue);
1394 if (queue->tx_irq && (queue->tx_irq != queue->rx_irq)) {
1395 unbind_from_irqhandler(queue->tx_irq, queue);
1396 unbind_from_irqhandler(queue->rx_irq, queue);
1397 }
1398 queue->tx_evtchn = queue->rx_evtchn = 0;
1399 queue->tx_irq = queue->rx_irq = 0;
1400
1401 if (netif_running(info->netdev))
1402 napi_synchronize(&queue->napi);
1403
1404 xennet_release_tx_bufs(queue);
1405 xennet_release_rx_bufs(queue);
1406 gnttab_free_grant_references(queue->gref_tx_head);
1407 gnttab_free_grant_references(queue->gref_rx_head);
1408
1409 /* End access and free the pages */
1410 xennet_end_access(queue->tx_ring_ref, queue->tx.sring);
1411 xennet_end_access(queue->rx_ring_ref, queue->rx.sring);
1412
1413 queue->tx_ring_ref = GRANT_INVALID_REF;
1414 queue->rx_ring_ref = GRANT_INVALID_REF;
1415 queue->tx.sring = NULL;
1416 queue->rx.sring = NULL;
1417 }
1418}
1419
1420/**
1421 * We are reconnecting to the backend, due to a suspend/resume, or a backend
1422 * driver restart. We tear down our netif structure and recreate it, but
1423 * leave the device-layer structures intact so that this is transparent to the
1424 * rest of the kernel.
1425 */
1426static int netfront_resume(struct xenbus_device *dev)
1427{
1428 struct netfront_info *info = dev_get_drvdata(&dev->dev);
1429
1430 dev_dbg(&dev->dev, "%s\n", dev->nodename);
1431
1432 xennet_disconnect_backend(info);
1433 return 0;
1434}
1435
1436static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[])
1437{
1438 char *s, *e, *macstr;
1439 int i;
1440
1441 macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL);
1442 if (IS_ERR(macstr))
1443 return PTR_ERR(macstr);
1444
1445 for (i = 0; i < ETH_ALEN; i++) {
1446 mac[i] = simple_strtoul(s, &e, 16);
1447 if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) {
1448 kfree(macstr);
1449 return -ENOENT;
1450 }
1451 s = e+1;
1452 }
1453
1454 kfree(macstr);
1455 return 0;
1456}
1457
1458static int setup_netfront_single(struct netfront_queue *queue)
1459{
1460 int err;
1461
1462 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn);
1463 if (err < 0)
1464 goto fail;
1465
1466 err = bind_evtchn_to_irqhandler(queue->tx_evtchn,
1467 xennet_interrupt,
1468 0, queue->info->netdev->name, queue);
1469 if (err < 0)
1470 goto bind_fail;
1471 queue->rx_evtchn = queue->tx_evtchn;
1472 queue->rx_irq = queue->tx_irq = err;
1473
1474 return 0;
1475
1476bind_fail:
1477 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn);
1478 queue->tx_evtchn = 0;
1479fail:
1480 return err;
1481}
1482
1483static int setup_netfront_split(struct netfront_queue *queue)
1484{
1485 int err;
1486
1487 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn);
1488 if (err < 0)
1489 goto fail;
1490 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->rx_evtchn);
1491 if (err < 0)
1492 goto alloc_rx_evtchn_fail;
1493
1494 snprintf(queue->tx_irq_name, sizeof(queue->tx_irq_name),
1495 "%s-tx", queue->name);
1496 err = bind_evtchn_to_irqhandler(queue->tx_evtchn,
1497 xennet_tx_interrupt,
1498 0, queue->tx_irq_name, queue);
1499 if (err < 0)
1500 goto bind_tx_fail;
1501 queue->tx_irq = err;
1502
1503 snprintf(queue->rx_irq_name, sizeof(queue->rx_irq_name),
1504 "%s-rx", queue->name);
1505 err = bind_evtchn_to_irqhandler(queue->rx_evtchn,
1506 xennet_rx_interrupt,
1507 0, queue->rx_irq_name, queue);
1508 if (err < 0)
1509 goto bind_rx_fail;
1510 queue->rx_irq = err;
1511
1512 return 0;
1513
1514bind_rx_fail:
1515 unbind_from_irqhandler(queue->tx_irq, queue);
1516 queue->tx_irq = 0;
1517bind_tx_fail:
1518 xenbus_free_evtchn(queue->info->xbdev, queue->rx_evtchn);
1519 queue->rx_evtchn = 0;
1520alloc_rx_evtchn_fail:
1521 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn);
1522 queue->tx_evtchn = 0;
1523fail:
1524 return err;
1525}
1526
1527static int setup_netfront(struct xenbus_device *dev,
1528 struct netfront_queue *queue, unsigned int feature_split_evtchn)
1529{
1530 struct xen_netif_tx_sring *txs;
1531 struct xen_netif_rx_sring *rxs;
1532 grant_ref_t gref;
1533 int err;
1534
1535 queue->tx_ring_ref = GRANT_INVALID_REF;
1536 queue->rx_ring_ref = GRANT_INVALID_REF;
1537 queue->rx.sring = NULL;
1538 queue->tx.sring = NULL;
1539
1540 txs = (struct xen_netif_tx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1541 if (!txs) {
1542 err = -ENOMEM;
1543 xenbus_dev_fatal(dev, err, "allocating tx ring page");
1544 goto fail;
1545 }
1546 SHARED_RING_INIT(txs);
1547 FRONT_RING_INIT(&queue->tx, txs, XEN_PAGE_SIZE);
1548
1549 err = xenbus_grant_ring(dev, txs, 1, &gref);
1550 if (err < 0)
1551 goto grant_tx_ring_fail;
1552 queue->tx_ring_ref = gref;
1553
1554 rxs = (struct xen_netif_rx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1555 if (!rxs) {
1556 err = -ENOMEM;
1557 xenbus_dev_fatal(dev, err, "allocating rx ring page");
1558 goto alloc_rx_ring_fail;
1559 }
1560 SHARED_RING_INIT(rxs);
1561 FRONT_RING_INIT(&queue->rx, rxs, XEN_PAGE_SIZE);
1562
1563 err = xenbus_grant_ring(dev, rxs, 1, &gref);
1564 if (err < 0)
1565 goto grant_rx_ring_fail;
1566 queue->rx_ring_ref = gref;
1567
1568 if (feature_split_evtchn)
1569 err = setup_netfront_split(queue);
1570 /* setup single event channel if
1571 * a) feature-split-event-channels == 0
1572 * b) feature-split-event-channels == 1 but failed to setup
1573 */
1574 if (!feature_split_evtchn || (feature_split_evtchn && err))
1575 err = setup_netfront_single(queue);
1576
1577 if (err)
1578 goto alloc_evtchn_fail;
1579
1580 return 0;
1581
1582 /* If we fail to setup netfront, it is safe to just revoke access to
1583 * granted pages because backend is not accessing it at this point.
1584 */
1585alloc_evtchn_fail:
1586 gnttab_end_foreign_access_ref(queue->rx_ring_ref, 0);
1587grant_rx_ring_fail:
1588 free_page((unsigned long)rxs);
1589alloc_rx_ring_fail:
1590 gnttab_end_foreign_access_ref(queue->tx_ring_ref, 0);
1591grant_tx_ring_fail:
1592 free_page((unsigned long)txs);
1593fail:
1594 return err;
1595}
1596
1597/* Queue-specific initialisation
1598 * This used to be done in xennet_create_dev() but must now
1599 * be run per-queue.
1600 */
1601static int xennet_init_queue(struct netfront_queue *queue)
1602{
1603 unsigned short i;
1604 int err = 0;
1605
1606 spin_lock_init(&queue->tx_lock);
1607 spin_lock_init(&queue->rx_lock);
1608
1609 setup_timer(&queue->rx_refill_timer, rx_refill_timeout,
1610 (unsigned long)queue);
1611
1612 snprintf(queue->name, sizeof(queue->name), "%s-q%u",
1613 queue->info->netdev->name, queue->id);
1614
1615 /* Initialise tx_skbs as a free chain containing every entry. */
1616 queue->tx_skb_freelist = 0;
1617 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1618 skb_entry_set_link(&queue->tx_skbs[i], i+1);
1619 queue->grant_tx_ref[i] = GRANT_INVALID_REF;
1620 queue->grant_tx_page[i] = NULL;
1621 }
1622
1623 /* Clear out rx_skbs */
1624 for (i = 0; i < NET_RX_RING_SIZE; i++) {
1625 queue->rx_skbs[i] = NULL;
1626 queue->grant_rx_ref[i] = GRANT_INVALID_REF;
1627 }
1628
1629 /* A grant for every tx ring slot */
1630 if (gnttab_alloc_grant_references(NET_TX_RING_SIZE,
1631 &queue->gref_tx_head) < 0) {
1632 pr_alert("can't alloc tx grant refs\n");
1633 err = -ENOMEM;
1634 goto exit;
1635 }
1636
1637 /* A grant for every rx ring slot */
1638 if (gnttab_alloc_grant_references(NET_RX_RING_SIZE,
1639 &queue->gref_rx_head) < 0) {
1640 pr_alert("can't alloc rx grant refs\n");
1641 err = -ENOMEM;
1642 goto exit_free_tx;
1643 }
1644
1645 return 0;
1646
1647 exit_free_tx:
1648 gnttab_free_grant_references(queue->gref_tx_head);
1649 exit:
1650 return err;
1651}
1652
1653static int write_queue_xenstore_keys(struct netfront_queue *queue,
1654 struct xenbus_transaction *xbt, int write_hierarchical)
1655{
1656 /* Write the queue-specific keys into XenStore in the traditional
1657 * way for a single queue, or in a queue subkeys for multiple
1658 * queues.
1659 */
1660 struct xenbus_device *dev = queue->info->xbdev;
1661 int err;
1662 const char *message;
1663 char *path;
1664 size_t pathsize;
1665
1666 /* Choose the correct place to write the keys */
1667 if (write_hierarchical) {
1668 pathsize = strlen(dev->nodename) + 10;
1669 path = kzalloc(pathsize, GFP_KERNEL);
1670 if (!path) {
1671 err = -ENOMEM;
1672 message = "out of memory while writing ring references";
1673 goto error;
1674 }
1675 snprintf(path, pathsize, "%s/queue-%u",
1676 dev->nodename, queue->id);
1677 } else {
1678 path = (char *)dev->nodename;
1679 }
1680
1681 /* Write ring references */
1682 err = xenbus_printf(*xbt, path, "tx-ring-ref", "%u",
1683 queue->tx_ring_ref);
1684 if (err) {
1685 message = "writing tx-ring-ref";
1686 goto error;
1687 }
1688
1689 err = xenbus_printf(*xbt, path, "rx-ring-ref", "%u",
1690 queue->rx_ring_ref);
1691 if (err) {
1692 message = "writing rx-ring-ref";
1693 goto error;
1694 }
1695
1696 /* Write event channels; taking into account both shared
1697 * and split event channel scenarios.
1698 */
1699 if (queue->tx_evtchn == queue->rx_evtchn) {
1700 /* Shared event channel */
1701 err = xenbus_printf(*xbt, path,
1702 "event-channel", "%u", queue->tx_evtchn);
1703 if (err) {
1704 message = "writing event-channel";
1705 goto error;
1706 }
1707 } else {
1708 /* Split event channels */
1709 err = xenbus_printf(*xbt, path,
1710 "event-channel-tx", "%u", queue->tx_evtchn);
1711 if (err) {
1712 message = "writing event-channel-tx";
1713 goto error;
1714 }
1715
1716 err = xenbus_printf(*xbt, path,
1717 "event-channel-rx", "%u", queue->rx_evtchn);
1718 if (err) {
1719 message = "writing event-channel-rx";
1720 goto error;
1721 }
1722 }
1723
1724 if (write_hierarchical)
1725 kfree(path);
1726 return 0;
1727
1728error:
1729 if (write_hierarchical)
1730 kfree(path);
1731 xenbus_dev_fatal(dev, err, "%s", message);
1732 return err;
1733}
1734
1735static void xennet_destroy_queues(struct netfront_info *info)
1736{
1737 unsigned int i;
1738
1739 rtnl_lock();
1740
1741 for (i = 0; i < info->netdev->real_num_tx_queues; i++) {
1742 struct netfront_queue *queue = &info->queues[i];
1743
1744 if (netif_running(info->netdev))
1745 napi_disable(&queue->napi);
1746 netif_napi_del(&queue->napi);
1747 }
1748
1749 rtnl_unlock();
1750
1751 kfree(info->queues);
1752 info->queues = NULL;
1753}
1754
1755static int xennet_create_queues(struct netfront_info *info,
1756 unsigned int *num_queues)
1757{
1758 unsigned int i;
1759 int ret;
1760
1761 info->queues = kcalloc(*num_queues, sizeof(struct netfront_queue),
1762 GFP_KERNEL);
1763 if (!info->queues)
1764 return -ENOMEM;
1765
1766 rtnl_lock();
1767
1768 for (i = 0; i < *num_queues; i++) {
1769 struct netfront_queue *queue = &info->queues[i];
1770
1771 queue->id = i;
1772 queue->info = info;
1773
1774 ret = xennet_init_queue(queue);
1775 if (ret < 0) {
1776 dev_warn(&info->netdev->dev,
1777 "only created %d queues\n", i);
1778 *num_queues = i;
1779 break;
1780 }
1781
1782 netif_napi_add(queue->info->netdev, &queue->napi,
1783 xennet_poll, 64);
1784 if (netif_running(info->netdev))
1785 napi_enable(&queue->napi);
1786 }
1787
1788 netif_set_real_num_tx_queues(info->netdev, *num_queues);
1789
1790 rtnl_unlock();
1791
1792 if (*num_queues == 0) {
1793 dev_err(&info->netdev->dev, "no queues\n");
1794 return -EINVAL;
1795 }
1796 return 0;
1797}
1798
1799/* Common code used when first setting up, and when resuming. */
1800static int talk_to_netback(struct xenbus_device *dev,
1801 struct netfront_info *info)
1802{
1803 const char *message;
1804 struct xenbus_transaction xbt;
1805 int err;
1806 unsigned int feature_split_evtchn;
1807 unsigned int i = 0;
1808 unsigned int max_queues = 0;
1809 struct netfront_queue *queue = NULL;
1810 unsigned int num_queues = 1;
1811
1812 info->netdev->irq = 0;
1813
1814 /* Check if backend supports multiple queues */
1815 max_queues = xenbus_read_unsigned(info->xbdev->otherend,
1816 "multi-queue-max-queues", 1);
1817 num_queues = min(max_queues, xennet_max_queues);
1818
1819 /* Check feature-split-event-channels */
1820 feature_split_evtchn = xenbus_read_unsigned(info->xbdev->otherend,
1821 "feature-split-event-channels", 0);
1822
1823 /* Read mac addr. */
1824 err = xen_net_read_mac(dev, info->netdev->dev_addr);
1825 if (err) {
1826 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
1827 goto out;
1828 }
1829
1830 if (info->queues)
1831 xennet_destroy_queues(info);
1832
1833 err = xennet_create_queues(info, &num_queues);
1834 if (err < 0) {
1835 xenbus_dev_fatal(dev, err, "creating queues");
1836 kfree(info->queues);
1837 info->queues = NULL;
1838 goto out;
1839 }
1840
1841 /* Create shared ring, alloc event channel -- for each queue */
1842 for (i = 0; i < num_queues; ++i) {
1843 queue = &info->queues[i];
1844 err = setup_netfront(dev, queue, feature_split_evtchn);
1845 if (err)
1846 goto destroy_ring;
1847 }
1848
1849again:
1850 err = xenbus_transaction_start(&xbt);
1851 if (err) {
1852 xenbus_dev_fatal(dev, err, "starting transaction");
1853 goto destroy_ring;
1854 }
1855
1856 if (xenbus_exists(XBT_NIL,
1857 info->xbdev->otherend, "multi-queue-max-queues")) {
1858 /* Write the number of queues */
1859 err = xenbus_printf(xbt, dev->nodename,
1860 "multi-queue-num-queues", "%u", num_queues);
1861 if (err) {
1862 message = "writing multi-queue-num-queues";
1863 goto abort_transaction_no_dev_fatal;
1864 }
1865 }
1866
1867 if (num_queues == 1) {
1868 err = write_queue_xenstore_keys(&info->queues[0], &xbt, 0); /* flat */
1869 if (err)
1870 goto abort_transaction_no_dev_fatal;
1871 } else {
1872 /* Write the keys for each queue */
1873 for (i = 0; i < num_queues; ++i) {
1874 queue = &info->queues[i];
1875 err = write_queue_xenstore_keys(queue, &xbt, 1); /* hierarchical */
1876 if (err)
1877 goto abort_transaction_no_dev_fatal;
1878 }
1879 }
1880
1881 /* The remaining keys are not queue-specific */
1882 err = xenbus_printf(xbt, dev->nodename, "request-rx-copy", "%u",
1883 1);
1884 if (err) {
1885 message = "writing request-rx-copy";
1886 goto abort_transaction;
1887 }
1888
1889 err = xenbus_printf(xbt, dev->nodename, "feature-rx-notify", "%d", 1);
1890 if (err) {
1891 message = "writing feature-rx-notify";
1892 goto abort_transaction;
1893 }
1894
1895 err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", 1);
1896 if (err) {
1897 message = "writing feature-sg";
1898 goto abort_transaction;
1899 }
1900
1901 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4", "%d", 1);
1902 if (err) {
1903 message = "writing feature-gso-tcpv4";
1904 goto abort_transaction;
1905 }
1906
1907 err = xenbus_write(xbt, dev->nodename, "feature-gso-tcpv6", "1");
1908 if (err) {
1909 message = "writing feature-gso-tcpv6";
1910 goto abort_transaction;
1911 }
1912
1913 err = xenbus_write(xbt, dev->nodename, "feature-ipv6-csum-offload",
1914 "1");
1915 if (err) {
1916 message = "writing feature-ipv6-csum-offload";
1917 goto abort_transaction;
1918 }
1919
1920 err = xenbus_transaction_end(xbt, 0);
1921 if (err) {
1922 if (err == -EAGAIN)
1923 goto again;
1924 xenbus_dev_fatal(dev, err, "completing transaction");
1925 goto destroy_ring;
1926 }
1927
1928 return 0;
1929
1930 abort_transaction:
1931 xenbus_dev_fatal(dev, err, "%s", message);
1932abort_transaction_no_dev_fatal:
1933 xenbus_transaction_end(xbt, 1);
1934 destroy_ring:
1935 xennet_disconnect_backend(info);
1936 xennet_destroy_queues(info);
1937 out:
1938 unregister_netdev(info->netdev);
1939 xennet_free_netdev(info->netdev);
1940 return err;
1941}
1942
1943static int xennet_connect(struct net_device *dev)
1944{
1945 struct netfront_info *np = netdev_priv(dev);
1946 unsigned int num_queues = 0;
1947 int err;
1948 unsigned int j = 0;
1949 struct netfront_queue *queue = NULL;
1950
1951 if (!xenbus_read_unsigned(np->xbdev->otherend, "feature-rx-copy", 0)) {
1952 dev_info(&dev->dev,
1953 "backend does not support copying receive path\n");
1954 return -ENODEV;
1955 }
1956
1957 err = talk_to_netback(np->xbdev, np);
1958 if (err)
1959 return err;
1960
1961 /* talk_to_netback() sets the correct number of queues */
1962 num_queues = dev->real_num_tx_queues;
1963
1964 rtnl_lock();
1965 netdev_update_features(dev);
1966 rtnl_unlock();
1967
1968 /*
1969 * All public and private state should now be sane. Get
1970 * ready to start sending and receiving packets and give the driver
1971 * domain a kick because we've probably just requeued some
1972 * packets.
1973 */
1974 netif_carrier_on(np->netdev);
1975 for (j = 0; j < num_queues; ++j) {
1976 queue = &np->queues[j];
1977
1978 notify_remote_via_irq(queue->tx_irq);
1979 if (queue->tx_irq != queue->rx_irq)
1980 notify_remote_via_irq(queue->rx_irq);
1981
1982 spin_lock_irq(&queue->tx_lock);
1983 xennet_tx_buf_gc(queue);
1984 spin_unlock_irq(&queue->tx_lock);
1985
1986 spin_lock_bh(&queue->rx_lock);
1987 xennet_alloc_rx_buffers(queue);
1988 spin_unlock_bh(&queue->rx_lock);
1989 }
1990
1991 return 0;
1992}
1993
1994/**
1995 * Callback received when the backend's state changes.
1996 */
1997static void netback_changed(struct xenbus_device *dev,
1998 enum xenbus_state backend_state)
1999{
2000 struct netfront_info *np = dev_get_drvdata(&dev->dev);
2001 struct net_device *netdev = np->netdev;
2002
2003 dev_dbg(&dev->dev, "%s\n", xenbus_strstate(backend_state));
2004
2005 switch (backend_state) {
2006 case XenbusStateInitialising:
2007 case XenbusStateInitialised:
2008 case XenbusStateReconfiguring:
2009 case XenbusStateReconfigured:
2010 case XenbusStateUnknown:
2011 break;
2012
2013 case XenbusStateInitWait:
2014 if (dev->state != XenbusStateInitialising)
2015 break;
2016 if (xennet_connect(netdev) != 0)
2017 break;
2018 xenbus_switch_state(dev, XenbusStateConnected);
2019 break;
2020
2021 case XenbusStateConnected:
2022 netdev_notify_peers(netdev);
2023 break;
2024
2025 case XenbusStateClosed:
2026 if (dev->state == XenbusStateClosed)
2027 break;
2028 /* Missed the backend's CLOSING state -- fallthrough */
2029 case XenbusStateClosing:
2030 xenbus_frontend_closed(dev);
2031 break;
2032 }
2033}
2034
2035static const struct xennet_stat {
2036 char name[ETH_GSTRING_LEN];
2037 u16 offset;
2038} xennet_stats[] = {
2039 {
2040 "rx_gso_checksum_fixup",
2041 offsetof(struct netfront_info, rx_gso_checksum_fixup)
2042 },
2043};
2044
2045static int xennet_get_sset_count(struct net_device *dev, int string_set)
2046{
2047 switch (string_set) {
2048 case ETH_SS_STATS:
2049 return ARRAY_SIZE(xennet_stats);
2050 default:
2051 return -EINVAL;
2052 }
2053}
2054
2055static void xennet_get_ethtool_stats(struct net_device *dev,
2056 struct ethtool_stats *stats, u64 * data)
2057{
2058 void *np = netdev_priv(dev);
2059 int i;
2060
2061 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
2062 data[i] = atomic_read((atomic_t *)(np + xennet_stats[i].offset));
2063}
2064
2065static void xennet_get_strings(struct net_device *dev, u32 stringset, u8 * data)
2066{
2067 int i;
2068
2069 switch (stringset) {
2070 case ETH_SS_STATS:
2071 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
2072 memcpy(data + i * ETH_GSTRING_LEN,
2073 xennet_stats[i].name, ETH_GSTRING_LEN);
2074 break;
2075 }
2076}
2077
2078static const struct ethtool_ops xennet_ethtool_ops =
2079{
2080 .get_link = ethtool_op_get_link,
2081
2082 .get_sset_count = xennet_get_sset_count,
2083 .get_ethtool_stats = xennet_get_ethtool_stats,
2084 .get_strings = xennet_get_strings,
2085};
2086
2087#ifdef CONFIG_SYSFS
2088static ssize_t show_rxbuf(struct device *dev,
2089 struct device_attribute *attr, char *buf)
2090{
2091 return sprintf(buf, "%lu\n", NET_RX_RING_SIZE);
2092}
2093
2094static ssize_t store_rxbuf(struct device *dev,
2095 struct device_attribute *attr,
2096 const char *buf, size_t len)
2097{
2098 char *endp;
2099 unsigned long target;
2100
2101 if (!capable(CAP_NET_ADMIN))
2102 return -EPERM;
2103
2104 target = simple_strtoul(buf, &endp, 0);
2105 if (endp == buf)
2106 return -EBADMSG;
2107
2108 /* rxbuf_min and rxbuf_max are no longer configurable. */
2109
2110 return len;
2111}
2112
2113static DEVICE_ATTR(rxbuf_min, S_IRUGO|S_IWUSR, show_rxbuf, store_rxbuf);
2114static DEVICE_ATTR(rxbuf_max, S_IRUGO|S_IWUSR, show_rxbuf, store_rxbuf);
2115static DEVICE_ATTR(rxbuf_cur, S_IRUGO, show_rxbuf, NULL);
2116
2117static struct attribute *xennet_dev_attrs[] = {
2118 &dev_attr_rxbuf_min.attr,
2119 &dev_attr_rxbuf_max.attr,
2120 &dev_attr_rxbuf_cur.attr,
2121 NULL
2122};
2123
2124static const struct attribute_group xennet_dev_group = {
2125 .attrs = xennet_dev_attrs
2126};
2127#endif /* CONFIG_SYSFS */
2128
2129static int xennet_remove(struct xenbus_device *dev)
2130{
2131 struct netfront_info *info = dev_get_drvdata(&dev->dev);
2132
2133 dev_dbg(&dev->dev, "%s\n", dev->nodename);
2134
2135 xennet_disconnect_backend(info);
2136
2137 unregister_netdev(info->netdev);
2138
2139 if (info->queues)
2140 xennet_destroy_queues(info);
2141 xennet_free_netdev(info->netdev);
2142
2143 return 0;
2144}
2145
2146static const struct xenbus_device_id netfront_ids[] = {
2147 { "vif" },
2148 { "" }
2149};
2150
2151static struct xenbus_driver netfront_driver = {
2152 .ids = netfront_ids,
2153 .probe = netfront_probe,
2154 .remove = xennet_remove,
2155 .resume = netfront_resume,
2156 .otherend_changed = netback_changed,
2157};
2158
2159static int __init netif_init(void)
2160{
2161 if (!xen_domain())
2162 return -ENODEV;
2163
2164 if (!xen_has_pv_nic_devices())
2165 return -ENODEV;
2166
2167 pr_info("Initialising Xen virtual ethernet driver\n");
2168
2169 /* Allow as many queues as there are CPUs if user has not
2170 * specified a value.
2171 */
2172 if (xennet_max_queues == 0)
2173 xennet_max_queues = num_online_cpus();
2174
2175 return xenbus_register_frontend(&netfront_driver);
2176}
2177module_init(netif_init);
2178
2179
2180static void __exit netif_exit(void)
2181{
2182 xenbus_unregister_driver(&netfront_driver);
2183}
2184module_exit(netif_exit);
2185
2186MODULE_DESCRIPTION("Xen virtual network device frontend");
2187MODULE_LICENSE("GPL");
2188MODULE_ALIAS("xen:vif");
2189MODULE_ALIAS("xennet");