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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 */
60#define MAX_QUEUES_DEFAULT 8
61static unsigned int xennet_max_queues;
62module_param_named(max_queues, xennet_max_queues, uint, 0644);
63MODULE_PARM_DESC(max_queues,
64 "Maximum number of queues per virtual interface");
65
66static const struct ethtool_ops xennet_ethtool_ops;
67
68struct netfront_cb {
69 int pull_to;
70};
71
72#define NETFRONT_SKB_CB(skb) ((struct netfront_cb *)((skb)->cb))
73
74#define RX_COPY_THRESHOLD 256
75
76#define GRANT_INVALID_REF 0
77
78#define NET_TX_RING_SIZE __CONST_RING_SIZE(xen_netif_tx, XEN_PAGE_SIZE)
79#define NET_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, XEN_PAGE_SIZE)
80
81/* Minimum number of Rx slots (includes slot for GSO metadata). */
82#define NET_RX_SLOTS_MIN (XEN_NETIF_NR_SLOTS_MIN + 1)
83
84/* Queue name is interface name with "-qNNN" appended */
85#define QUEUE_NAME_SIZE (IFNAMSIZ + 6)
86
87/* IRQ name is queue name with "-tx" or "-rx" appended */
88#define IRQ_NAME_SIZE (QUEUE_NAME_SIZE + 3)
89
90static DECLARE_WAIT_QUEUE_HEAD(module_unload_q);
91
92struct netfront_stats {
93 u64 packets;
94 u64 bytes;
95 struct u64_stats_sync syncp;
96};
97
98struct netfront_info;
99
100struct netfront_queue {
101 unsigned int id; /* Queue ID, 0-based */
102 char name[QUEUE_NAME_SIZE]; /* DEVNAME-qN */
103 struct netfront_info *info;
104
105 struct napi_struct napi;
106
107 /* Split event channels support, tx_* == rx_* when using
108 * single event channel.
109 */
110 unsigned int tx_evtchn, rx_evtchn;
111 unsigned int tx_irq, rx_irq;
112 /* Only used when split event channels support is enabled */
113 char tx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-tx */
114 char rx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-rx */
115
116 spinlock_t tx_lock;
117 struct xen_netif_tx_front_ring tx;
118 int tx_ring_ref;
119
120 /*
121 * {tx,rx}_skbs store outstanding skbuffs. Free tx_skb entries
122 * are linked from tx_skb_freelist through skb_entry.link.
123 *
124 * NB. Freelist index entries are always going to be less than
125 * PAGE_OFFSET, whereas pointers to skbs will always be equal or
126 * greater than PAGE_OFFSET: we use this property to distinguish
127 * them.
128 */
129 union skb_entry {
130 struct sk_buff *skb;
131 unsigned long link;
132 } tx_skbs[NET_TX_RING_SIZE];
133 grant_ref_t gref_tx_head;
134 grant_ref_t grant_tx_ref[NET_TX_RING_SIZE];
135 struct page *grant_tx_page[NET_TX_RING_SIZE];
136 unsigned tx_skb_freelist;
137
138 spinlock_t rx_lock ____cacheline_aligned_in_smp;
139 struct xen_netif_rx_front_ring rx;
140 int rx_ring_ref;
141
142 struct timer_list rx_refill_timer;
143
144 struct sk_buff *rx_skbs[NET_RX_RING_SIZE];
145 grant_ref_t gref_rx_head;
146 grant_ref_t grant_rx_ref[NET_RX_RING_SIZE];
147};
148
149struct netfront_info {
150 struct list_head list;
151 struct net_device *netdev;
152
153 struct xenbus_device *xbdev;
154
155 /* Multi-queue support */
156 struct netfront_queue *queues;
157
158 /* Statistics */
159 struct netfront_stats __percpu *rx_stats;
160 struct netfront_stats __percpu *tx_stats;
161
162 atomic_t rx_gso_checksum_fixup;
163};
164
165struct netfront_rx_info {
166 struct xen_netif_rx_response rx;
167 struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX - 1];
168};
169
170static void skb_entry_set_link(union skb_entry *list, unsigned short id)
171{
172 list->link = id;
173}
174
175static int skb_entry_is_link(const union skb_entry *list)
176{
177 BUILD_BUG_ON(sizeof(list->skb) != sizeof(list->link));
178 return (unsigned long)list->skb < PAGE_OFFSET;
179}
180
181/*
182 * Access macros for acquiring freeing slots in tx_skbs[].
183 */
184
185static void add_id_to_freelist(unsigned *head, union skb_entry *list,
186 unsigned short id)
187{
188 skb_entry_set_link(&list[id], *head);
189 *head = id;
190}
191
192static unsigned short get_id_from_freelist(unsigned *head,
193 union skb_entry *list)
194{
195 unsigned int id = *head;
196 *head = list[id].link;
197 return id;
198}
199
200static int xennet_rxidx(RING_IDX idx)
201{
202 return idx & (NET_RX_RING_SIZE - 1);
203}
204
205static struct sk_buff *xennet_get_rx_skb(struct netfront_queue *queue,
206 RING_IDX ri)
207{
208 int i = xennet_rxidx(ri);
209 struct sk_buff *skb = queue->rx_skbs[i];
210 queue->rx_skbs[i] = NULL;
211 return skb;
212}
213
214static grant_ref_t xennet_get_rx_ref(struct netfront_queue *queue,
215 RING_IDX ri)
216{
217 int i = xennet_rxidx(ri);
218 grant_ref_t ref = queue->grant_rx_ref[i];
219 queue->grant_rx_ref[i] = GRANT_INVALID_REF;
220 return ref;
221}
222
223#ifdef CONFIG_SYSFS
224static const struct attribute_group xennet_dev_group;
225#endif
226
227static bool xennet_can_sg(struct net_device *dev)
228{
229 return dev->features & NETIF_F_SG;
230}
231
232
233static void rx_refill_timeout(struct timer_list *t)
234{
235 struct netfront_queue *queue = from_timer(queue, t, rx_refill_timer);
236 napi_schedule(&queue->napi);
237}
238
239static int netfront_tx_slot_available(struct netfront_queue *queue)
240{
241 return (queue->tx.req_prod_pvt - queue->tx.rsp_cons) <
242 (NET_TX_RING_SIZE - MAX_SKB_FRAGS - 2);
243}
244
245static void xennet_maybe_wake_tx(struct netfront_queue *queue)
246{
247 struct net_device *dev = queue->info->netdev;
248 struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, queue->id);
249
250 if (unlikely(netif_tx_queue_stopped(dev_queue)) &&
251 netfront_tx_slot_available(queue) &&
252 likely(netif_running(dev)))
253 netif_tx_wake_queue(netdev_get_tx_queue(dev, queue->id));
254}
255
256
257static struct sk_buff *xennet_alloc_one_rx_buffer(struct netfront_queue *queue)
258{
259 struct sk_buff *skb;
260 struct page *page;
261
262 skb = __netdev_alloc_skb(queue->info->netdev,
263 RX_COPY_THRESHOLD + NET_IP_ALIGN,
264 GFP_ATOMIC | __GFP_NOWARN);
265 if (unlikely(!skb))
266 return NULL;
267
268 page = alloc_page(GFP_ATOMIC | __GFP_NOWARN);
269 if (!page) {
270 kfree_skb(skb);
271 return NULL;
272 }
273 skb_add_rx_frag(skb, 0, page, 0, 0, PAGE_SIZE);
274
275 /* Align ip header to a 16 bytes boundary */
276 skb_reserve(skb, NET_IP_ALIGN);
277 skb->dev = queue->info->netdev;
278
279 return skb;
280}
281
282
283static void xennet_alloc_rx_buffers(struct netfront_queue *queue)
284{
285 RING_IDX req_prod = queue->rx.req_prod_pvt;
286 int notify;
287 int err = 0;
288
289 if (unlikely(!netif_carrier_ok(queue->info->netdev)))
290 return;
291
292 for (req_prod = queue->rx.req_prod_pvt;
293 req_prod - queue->rx.rsp_cons < NET_RX_RING_SIZE;
294 req_prod++) {
295 struct sk_buff *skb;
296 unsigned short id;
297 grant_ref_t ref;
298 struct page *page;
299 struct xen_netif_rx_request *req;
300
301 skb = xennet_alloc_one_rx_buffer(queue);
302 if (!skb) {
303 err = -ENOMEM;
304 break;
305 }
306
307 id = xennet_rxidx(req_prod);
308
309 BUG_ON(queue->rx_skbs[id]);
310 queue->rx_skbs[id] = skb;
311
312 ref = gnttab_claim_grant_reference(&queue->gref_rx_head);
313 WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)(int)ref));
314 queue->grant_rx_ref[id] = ref;
315
316 page = skb_frag_page(&skb_shinfo(skb)->frags[0]);
317
318 req = RING_GET_REQUEST(&queue->rx, req_prod);
319 gnttab_page_grant_foreign_access_ref_one(ref,
320 queue->info->xbdev->otherend_id,
321 page,
322 0);
323 req->id = id;
324 req->gref = ref;
325 }
326
327 queue->rx.req_prod_pvt = req_prod;
328
329 /* Try again later if there are not enough requests or skb allocation
330 * failed.
331 * Enough requests is quantified as the sum of newly created slots and
332 * the unconsumed slots at the backend.
333 */
334 if (req_prod - queue->rx.rsp_cons < NET_RX_SLOTS_MIN ||
335 unlikely(err)) {
336 mod_timer(&queue->rx_refill_timer, jiffies + (HZ/10));
337 return;
338 }
339
340 wmb(); /* barrier so backend seens requests */
341
342 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->rx, notify);
343 if (notify)
344 notify_remote_via_irq(queue->rx_irq);
345}
346
347static int xennet_open(struct net_device *dev)
348{
349 struct netfront_info *np = netdev_priv(dev);
350 unsigned int num_queues = dev->real_num_tx_queues;
351 unsigned int i = 0;
352 struct netfront_queue *queue = NULL;
353
354 if (!np->queues)
355 return -ENODEV;
356
357 for (i = 0; i < num_queues; ++i) {
358 queue = &np->queues[i];
359 napi_enable(&queue->napi);
360
361 spin_lock_bh(&queue->rx_lock);
362 if (netif_carrier_ok(dev)) {
363 xennet_alloc_rx_buffers(queue);
364 queue->rx.sring->rsp_event = queue->rx.rsp_cons + 1;
365 if (RING_HAS_UNCONSUMED_RESPONSES(&queue->rx))
366 napi_schedule(&queue->napi);
367 }
368 spin_unlock_bh(&queue->rx_lock);
369 }
370
371 netif_tx_start_all_queues(dev);
372
373 return 0;
374}
375
376static void xennet_tx_buf_gc(struct netfront_queue *queue)
377{
378 RING_IDX cons, prod;
379 unsigned short id;
380 struct sk_buff *skb;
381 bool more_to_do;
382
383 BUG_ON(!netif_carrier_ok(queue->info->netdev));
384
385 do {
386 prod = queue->tx.sring->rsp_prod;
387 rmb(); /* Ensure we see responses up to 'rp'. */
388
389 for (cons = queue->tx.rsp_cons; cons != prod; cons++) {
390 struct xen_netif_tx_response *txrsp;
391
392 txrsp = RING_GET_RESPONSE(&queue->tx, cons);
393 if (txrsp->status == XEN_NETIF_RSP_NULL)
394 continue;
395
396 id = txrsp->id;
397 skb = queue->tx_skbs[id].skb;
398 if (unlikely(gnttab_query_foreign_access(
399 queue->grant_tx_ref[id]) != 0)) {
400 pr_alert("%s: warning -- grant still in use by backend domain\n",
401 __func__);
402 BUG();
403 }
404 gnttab_end_foreign_access_ref(
405 queue->grant_tx_ref[id], GNTMAP_readonly);
406 gnttab_release_grant_reference(
407 &queue->gref_tx_head, queue->grant_tx_ref[id]);
408 queue->grant_tx_ref[id] = GRANT_INVALID_REF;
409 queue->grant_tx_page[id] = NULL;
410 add_id_to_freelist(&queue->tx_skb_freelist, queue->tx_skbs, id);
411 dev_kfree_skb_irq(skb);
412 }
413
414 queue->tx.rsp_cons = prod;
415
416 RING_FINAL_CHECK_FOR_RESPONSES(&queue->tx, more_to_do);
417 } while (more_to_do);
418
419 xennet_maybe_wake_tx(queue);
420}
421
422struct xennet_gnttab_make_txreq {
423 struct netfront_queue *queue;
424 struct sk_buff *skb;
425 struct page *page;
426 struct xen_netif_tx_request *tx; /* Last request */
427 unsigned int size;
428};
429
430static void xennet_tx_setup_grant(unsigned long gfn, unsigned int offset,
431 unsigned int len, void *data)
432{
433 struct xennet_gnttab_make_txreq *info = data;
434 unsigned int id;
435 struct xen_netif_tx_request *tx;
436 grant_ref_t ref;
437 /* convenient aliases */
438 struct page *page = info->page;
439 struct netfront_queue *queue = info->queue;
440 struct sk_buff *skb = info->skb;
441
442 id = get_id_from_freelist(&queue->tx_skb_freelist, queue->tx_skbs);
443 tx = RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++);
444 ref = gnttab_claim_grant_reference(&queue->gref_tx_head);
445 WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)(int)ref));
446
447 gnttab_grant_foreign_access_ref(ref, queue->info->xbdev->otherend_id,
448 gfn, GNTMAP_readonly);
449
450 queue->tx_skbs[id].skb = skb;
451 queue->grant_tx_page[id] = page;
452 queue->grant_tx_ref[id] = ref;
453
454 tx->id = id;
455 tx->gref = ref;
456 tx->offset = offset;
457 tx->size = len;
458 tx->flags = 0;
459
460 info->tx = tx;
461 info->size += tx->size;
462}
463
464static struct xen_netif_tx_request *xennet_make_first_txreq(
465 struct netfront_queue *queue, struct sk_buff *skb,
466 struct page *page, unsigned int offset, unsigned int len)
467{
468 struct xennet_gnttab_make_txreq info = {
469 .queue = queue,
470 .skb = skb,
471 .page = page,
472 .size = 0,
473 };
474
475 gnttab_for_one_grant(page, offset, len, xennet_tx_setup_grant, &info);
476
477 return info.tx;
478}
479
480static void xennet_make_one_txreq(unsigned long gfn, unsigned int offset,
481 unsigned int len, void *data)
482{
483 struct xennet_gnttab_make_txreq *info = data;
484
485 info->tx->flags |= XEN_NETTXF_more_data;
486 skb_get(info->skb);
487 xennet_tx_setup_grant(gfn, offset, len, data);
488}
489
490static struct xen_netif_tx_request *xennet_make_txreqs(
491 struct netfront_queue *queue, struct xen_netif_tx_request *tx,
492 struct sk_buff *skb, struct page *page,
493 unsigned int offset, unsigned int len)
494{
495 struct xennet_gnttab_make_txreq info = {
496 .queue = queue,
497 .skb = skb,
498 .tx = tx,
499 };
500
501 /* Skip unused frames from start of page */
502 page += offset >> PAGE_SHIFT;
503 offset &= ~PAGE_MASK;
504
505 while (len) {
506 info.page = page;
507 info.size = 0;
508
509 gnttab_foreach_grant_in_range(page, offset, len,
510 xennet_make_one_txreq,
511 &info);
512
513 page++;
514 offset = 0;
515 len -= info.size;
516 }
517
518 return info.tx;
519}
520
521/*
522 * Count how many ring slots are required to send this skb. Each frag
523 * might be a compound page.
524 */
525static int xennet_count_skb_slots(struct sk_buff *skb)
526{
527 int i, frags = skb_shinfo(skb)->nr_frags;
528 int slots;
529
530 slots = gnttab_count_grant(offset_in_page(skb->data),
531 skb_headlen(skb));
532
533 for (i = 0; i < frags; i++) {
534 skb_frag_t *frag = skb_shinfo(skb)->frags + i;
535 unsigned long size = skb_frag_size(frag);
536 unsigned long offset = frag->page_offset;
537
538 /* Skip unused frames from start of page */
539 offset &= ~PAGE_MASK;
540
541 slots += gnttab_count_grant(offset, size);
542 }
543
544 return slots;
545}
546
547static u16 xennet_select_queue(struct net_device *dev, struct sk_buff *skb,
548 void *accel_priv, select_queue_fallback_t fallback)
549{
550 unsigned int num_queues = dev->real_num_tx_queues;
551 u32 hash;
552 u16 queue_idx;
553
554 /* First, check if there is only one queue */
555 if (num_queues == 1) {
556 queue_idx = 0;
557 } else {
558 hash = skb_get_hash(skb);
559 queue_idx = hash % num_queues;
560 }
561
562 return queue_idx;
563}
564
565#define MAX_XEN_SKB_FRAGS (65536 / XEN_PAGE_SIZE + 1)
566
567static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev)
568{
569 struct netfront_info *np = netdev_priv(dev);
570 struct netfront_stats *tx_stats = this_cpu_ptr(np->tx_stats);
571 struct xen_netif_tx_request *tx, *first_tx;
572 unsigned int i;
573 int notify;
574 int slots;
575 struct page *page;
576 unsigned int offset;
577 unsigned int len;
578 unsigned long flags;
579 struct netfront_queue *queue = NULL;
580 unsigned int num_queues = dev->real_num_tx_queues;
581 u16 queue_index;
582 struct sk_buff *nskb;
583
584 /* Drop the packet if no queues are set up */
585 if (num_queues < 1)
586 goto drop;
587 /* Determine which queue to transmit this SKB on */
588 queue_index = skb_get_queue_mapping(skb);
589 queue = &np->queues[queue_index];
590
591 /* If skb->len is too big for wire format, drop skb and alert
592 * user about misconfiguration.
593 */
594 if (unlikely(skb->len > XEN_NETIF_MAX_TX_SIZE)) {
595 net_alert_ratelimited(
596 "xennet: skb->len = %u, too big for wire format\n",
597 skb->len);
598 goto drop;
599 }
600
601 slots = xennet_count_skb_slots(skb);
602 if (unlikely(slots > MAX_XEN_SKB_FRAGS + 1)) {
603 net_dbg_ratelimited("xennet: skb rides the rocket: %d slots, %d bytes\n",
604 slots, skb->len);
605 if (skb_linearize(skb))
606 goto drop;
607 }
608
609 page = virt_to_page(skb->data);
610 offset = offset_in_page(skb->data);
611
612 /* The first req should be at least ETH_HLEN size or the packet will be
613 * dropped by netback.
614 */
615 if (unlikely(PAGE_SIZE - offset < ETH_HLEN)) {
616 nskb = skb_copy(skb, GFP_ATOMIC);
617 if (!nskb)
618 goto drop;
619 dev_consume_skb_any(skb);
620 skb = nskb;
621 page = virt_to_page(skb->data);
622 offset = offset_in_page(skb->data);
623 }
624
625 len = skb_headlen(skb);
626
627 spin_lock_irqsave(&queue->tx_lock, flags);
628
629 if (unlikely(!netif_carrier_ok(dev) ||
630 (slots > 1 && !xennet_can_sg(dev)) ||
631 netif_needs_gso(skb, netif_skb_features(skb)))) {
632 spin_unlock_irqrestore(&queue->tx_lock, flags);
633 goto drop;
634 }
635
636 /* First request for the linear area. */
637 first_tx = tx = xennet_make_first_txreq(queue, skb,
638 page, offset, len);
639 offset += tx->size;
640 if (offset == PAGE_SIZE) {
641 page++;
642 offset = 0;
643 }
644 len -= tx->size;
645
646 if (skb->ip_summed == CHECKSUM_PARTIAL)
647 /* local packet? */
648 tx->flags |= XEN_NETTXF_csum_blank | XEN_NETTXF_data_validated;
649 else if (skb->ip_summed == CHECKSUM_UNNECESSARY)
650 /* remote but checksummed. */
651 tx->flags |= XEN_NETTXF_data_validated;
652
653 /* Optional extra info after the first request. */
654 if (skb_shinfo(skb)->gso_size) {
655 struct xen_netif_extra_info *gso;
656
657 gso = (struct xen_netif_extra_info *)
658 RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++);
659
660 tx->flags |= XEN_NETTXF_extra_info;
661
662 gso->u.gso.size = skb_shinfo(skb)->gso_size;
663 gso->u.gso.type = (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) ?
664 XEN_NETIF_GSO_TYPE_TCPV6 :
665 XEN_NETIF_GSO_TYPE_TCPV4;
666 gso->u.gso.pad = 0;
667 gso->u.gso.features = 0;
668
669 gso->type = XEN_NETIF_EXTRA_TYPE_GSO;
670 gso->flags = 0;
671 }
672
673 /* Requests for the rest of the linear area. */
674 tx = xennet_make_txreqs(queue, tx, skb, page, offset, len);
675
676 /* Requests for all the frags. */
677 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
678 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
679 tx = xennet_make_txreqs(queue, tx, skb,
680 skb_frag_page(frag), frag->page_offset,
681 skb_frag_size(frag));
682 }
683
684 /* First request has the packet length. */
685 first_tx->size = skb->len;
686
687 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->tx, notify);
688 if (notify)
689 notify_remote_via_irq(queue->tx_irq);
690
691 u64_stats_update_begin(&tx_stats->syncp);
692 tx_stats->bytes += skb->len;
693 tx_stats->packets++;
694 u64_stats_update_end(&tx_stats->syncp);
695
696 /* Note: It is not safe to access skb after xennet_tx_buf_gc()! */
697 xennet_tx_buf_gc(queue);
698
699 if (!netfront_tx_slot_available(queue))
700 netif_tx_stop_queue(netdev_get_tx_queue(dev, queue->id));
701
702 spin_unlock_irqrestore(&queue->tx_lock, flags);
703
704 return NETDEV_TX_OK;
705
706 drop:
707 dev->stats.tx_dropped++;
708 dev_kfree_skb_any(skb);
709 return NETDEV_TX_OK;
710}
711
712static int xennet_close(struct net_device *dev)
713{
714 struct netfront_info *np = netdev_priv(dev);
715 unsigned int num_queues = dev->real_num_tx_queues;
716 unsigned int i;
717 struct netfront_queue *queue;
718 netif_tx_stop_all_queues(np->netdev);
719 for (i = 0; i < num_queues; ++i) {
720 queue = &np->queues[i];
721 napi_disable(&queue->napi);
722 }
723 return 0;
724}
725
726static void xennet_move_rx_slot(struct netfront_queue *queue, struct sk_buff *skb,
727 grant_ref_t ref)
728{
729 int new = xennet_rxidx(queue->rx.req_prod_pvt);
730
731 BUG_ON(queue->rx_skbs[new]);
732 queue->rx_skbs[new] = skb;
733 queue->grant_rx_ref[new] = ref;
734 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->id = new;
735 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->gref = ref;
736 queue->rx.req_prod_pvt++;
737}
738
739static int xennet_get_extras(struct netfront_queue *queue,
740 struct xen_netif_extra_info *extras,
741 RING_IDX rp)
742
743{
744 struct xen_netif_extra_info *extra;
745 struct device *dev = &queue->info->netdev->dev;
746 RING_IDX cons = queue->rx.rsp_cons;
747 int err = 0;
748
749 do {
750 struct sk_buff *skb;
751 grant_ref_t ref;
752
753 if (unlikely(cons + 1 == rp)) {
754 if (net_ratelimit())
755 dev_warn(dev, "Missing extra info\n");
756 err = -EBADR;
757 break;
758 }
759
760 extra = (struct xen_netif_extra_info *)
761 RING_GET_RESPONSE(&queue->rx, ++cons);
762
763 if (unlikely(!extra->type ||
764 extra->type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
765 if (net_ratelimit())
766 dev_warn(dev, "Invalid extra type: %d\n",
767 extra->type);
768 err = -EINVAL;
769 } else {
770 memcpy(&extras[extra->type - 1], extra,
771 sizeof(*extra));
772 }
773
774 skb = xennet_get_rx_skb(queue, cons);
775 ref = xennet_get_rx_ref(queue, cons);
776 xennet_move_rx_slot(queue, skb, ref);
777 } while (extra->flags & XEN_NETIF_EXTRA_FLAG_MORE);
778
779 queue->rx.rsp_cons = cons;
780 return err;
781}
782
783static int xennet_get_responses(struct netfront_queue *queue,
784 struct netfront_rx_info *rinfo, RING_IDX rp,
785 struct sk_buff_head *list)
786{
787 struct xen_netif_rx_response *rx = &rinfo->rx;
788 struct xen_netif_extra_info *extras = rinfo->extras;
789 struct device *dev = &queue->info->netdev->dev;
790 RING_IDX cons = queue->rx.rsp_cons;
791 struct sk_buff *skb = xennet_get_rx_skb(queue, cons);
792 grant_ref_t ref = xennet_get_rx_ref(queue, cons);
793 int max = MAX_SKB_FRAGS + (rx->status <= RX_COPY_THRESHOLD);
794 int slots = 1;
795 int err = 0;
796 unsigned long ret;
797
798 if (rx->flags & XEN_NETRXF_extra_info) {
799 err = xennet_get_extras(queue, extras, rp);
800 cons = queue->rx.rsp_cons;
801 }
802
803 for (;;) {
804 if (unlikely(rx->status < 0 ||
805 rx->offset + rx->status > XEN_PAGE_SIZE)) {
806 if (net_ratelimit())
807 dev_warn(dev, "rx->offset: %u, size: %d\n",
808 rx->offset, rx->status);
809 xennet_move_rx_slot(queue, skb, ref);
810 err = -EINVAL;
811 goto next;
812 }
813
814 /*
815 * This definitely indicates a bug, either in this driver or in
816 * the backend driver. In future this should flag the bad
817 * situation to the system controller to reboot the backend.
818 */
819 if (ref == GRANT_INVALID_REF) {
820 if (net_ratelimit())
821 dev_warn(dev, "Bad rx response id %d.\n",
822 rx->id);
823 err = -EINVAL;
824 goto next;
825 }
826
827 ret = gnttab_end_foreign_access_ref(ref, 0);
828 BUG_ON(!ret);
829
830 gnttab_release_grant_reference(&queue->gref_rx_head, ref);
831
832 __skb_queue_tail(list, skb);
833
834next:
835 if (!(rx->flags & XEN_NETRXF_more_data))
836 break;
837
838 if (cons + slots == rp) {
839 if (net_ratelimit())
840 dev_warn(dev, "Need more slots\n");
841 err = -ENOENT;
842 break;
843 }
844
845 rx = RING_GET_RESPONSE(&queue->rx, cons + slots);
846 skb = xennet_get_rx_skb(queue, cons + slots);
847 ref = xennet_get_rx_ref(queue, cons + slots);
848 slots++;
849 }
850
851 if (unlikely(slots > max)) {
852 if (net_ratelimit())
853 dev_warn(dev, "Too many slots\n");
854 err = -E2BIG;
855 }
856
857 if (unlikely(err))
858 queue->rx.rsp_cons = cons + slots;
859
860 return err;
861}
862
863static int xennet_set_skb_gso(struct sk_buff *skb,
864 struct xen_netif_extra_info *gso)
865{
866 if (!gso->u.gso.size) {
867 if (net_ratelimit())
868 pr_warn("GSO size must not be zero\n");
869 return -EINVAL;
870 }
871
872 if (gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV4 &&
873 gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV6) {
874 if (net_ratelimit())
875 pr_warn("Bad GSO type %d\n", gso->u.gso.type);
876 return -EINVAL;
877 }
878
879 skb_shinfo(skb)->gso_size = gso->u.gso.size;
880 skb_shinfo(skb)->gso_type =
881 (gso->u.gso.type == XEN_NETIF_GSO_TYPE_TCPV4) ?
882 SKB_GSO_TCPV4 :
883 SKB_GSO_TCPV6;
884
885 /* Header must be checked, and gso_segs computed. */
886 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
887 skb_shinfo(skb)->gso_segs = 0;
888
889 return 0;
890}
891
892static RING_IDX xennet_fill_frags(struct netfront_queue *queue,
893 struct sk_buff *skb,
894 struct sk_buff_head *list)
895{
896 struct skb_shared_info *shinfo = skb_shinfo(skb);
897 RING_IDX cons = queue->rx.rsp_cons;
898 struct sk_buff *nskb;
899
900 while ((nskb = __skb_dequeue(list))) {
901 struct xen_netif_rx_response *rx =
902 RING_GET_RESPONSE(&queue->rx, ++cons);
903 skb_frag_t *nfrag = &skb_shinfo(nskb)->frags[0];
904
905 if (shinfo->nr_frags == MAX_SKB_FRAGS) {
906 unsigned int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
907
908 BUG_ON(pull_to <= skb_headlen(skb));
909 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
910 }
911 BUG_ON(shinfo->nr_frags >= MAX_SKB_FRAGS);
912
913 skb_add_rx_frag(skb, shinfo->nr_frags, skb_frag_page(nfrag),
914 rx->offset, rx->status, PAGE_SIZE);
915
916 skb_shinfo(nskb)->nr_frags = 0;
917 kfree_skb(nskb);
918 }
919
920 return cons;
921}
922
923static int checksum_setup(struct net_device *dev, struct sk_buff *skb)
924{
925 bool recalculate_partial_csum = false;
926
927 /*
928 * A GSO SKB must be CHECKSUM_PARTIAL. However some buggy
929 * peers can fail to set NETRXF_csum_blank when sending a GSO
930 * frame. In this case force the SKB to CHECKSUM_PARTIAL and
931 * recalculate the partial checksum.
932 */
933 if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) {
934 struct netfront_info *np = netdev_priv(dev);
935 atomic_inc(&np->rx_gso_checksum_fixup);
936 skb->ip_summed = CHECKSUM_PARTIAL;
937 recalculate_partial_csum = true;
938 }
939
940 /* A non-CHECKSUM_PARTIAL SKB does not require setup. */
941 if (skb->ip_summed != CHECKSUM_PARTIAL)
942 return 0;
943
944 return skb_checksum_setup(skb, recalculate_partial_csum);
945}
946
947static int handle_incoming_queue(struct netfront_queue *queue,
948 struct sk_buff_head *rxq)
949{
950 struct netfront_stats *rx_stats = this_cpu_ptr(queue->info->rx_stats);
951 int packets_dropped = 0;
952 struct sk_buff *skb;
953
954 while ((skb = __skb_dequeue(rxq)) != NULL) {
955 int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
956
957 if (pull_to > skb_headlen(skb))
958 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
959
960 /* Ethernet work: Delayed to here as it peeks the header. */
961 skb->protocol = eth_type_trans(skb, queue->info->netdev);
962 skb_reset_network_header(skb);
963
964 if (checksum_setup(queue->info->netdev, skb)) {
965 kfree_skb(skb);
966 packets_dropped++;
967 queue->info->netdev->stats.rx_errors++;
968 continue;
969 }
970
971 u64_stats_update_begin(&rx_stats->syncp);
972 rx_stats->packets++;
973 rx_stats->bytes += skb->len;
974 u64_stats_update_end(&rx_stats->syncp);
975
976 /* Pass it up. */
977 napi_gro_receive(&queue->napi, skb);
978 }
979
980 return packets_dropped;
981}
982
983static int xennet_poll(struct napi_struct *napi, int budget)
984{
985 struct netfront_queue *queue = container_of(napi, struct netfront_queue, napi);
986 struct net_device *dev = queue->info->netdev;
987 struct sk_buff *skb;
988 struct netfront_rx_info rinfo;
989 struct xen_netif_rx_response *rx = &rinfo.rx;
990 struct xen_netif_extra_info *extras = rinfo.extras;
991 RING_IDX i, rp;
992 int work_done;
993 struct sk_buff_head rxq;
994 struct sk_buff_head errq;
995 struct sk_buff_head tmpq;
996 int err;
997
998 spin_lock(&queue->rx_lock);
999
1000 skb_queue_head_init(&rxq);
1001 skb_queue_head_init(&errq);
1002 skb_queue_head_init(&tmpq);
1003
1004 rp = queue->rx.sring->rsp_prod;
1005 rmb(); /* Ensure we see queued responses up to 'rp'. */
1006
1007 i = queue->rx.rsp_cons;
1008 work_done = 0;
1009 while ((i != rp) && (work_done < budget)) {
1010 memcpy(rx, RING_GET_RESPONSE(&queue->rx, i), sizeof(*rx));
1011 memset(extras, 0, sizeof(rinfo.extras));
1012
1013 err = xennet_get_responses(queue, &rinfo, rp, &tmpq);
1014
1015 if (unlikely(err)) {
1016err:
1017 while ((skb = __skb_dequeue(&tmpq)))
1018 __skb_queue_tail(&errq, skb);
1019 dev->stats.rx_errors++;
1020 i = queue->rx.rsp_cons;
1021 continue;
1022 }
1023
1024 skb = __skb_dequeue(&tmpq);
1025
1026 if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) {
1027 struct xen_netif_extra_info *gso;
1028 gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1];
1029
1030 if (unlikely(xennet_set_skb_gso(skb, gso))) {
1031 __skb_queue_head(&tmpq, skb);
1032 queue->rx.rsp_cons += skb_queue_len(&tmpq);
1033 goto err;
1034 }
1035 }
1036
1037 NETFRONT_SKB_CB(skb)->pull_to = rx->status;
1038 if (NETFRONT_SKB_CB(skb)->pull_to > RX_COPY_THRESHOLD)
1039 NETFRONT_SKB_CB(skb)->pull_to = RX_COPY_THRESHOLD;
1040
1041 skb_shinfo(skb)->frags[0].page_offset = rx->offset;
1042 skb_frag_size_set(&skb_shinfo(skb)->frags[0], rx->status);
1043 skb->data_len = rx->status;
1044 skb->len += rx->status;
1045
1046 i = xennet_fill_frags(queue, skb, &tmpq);
1047
1048 if (rx->flags & XEN_NETRXF_csum_blank)
1049 skb->ip_summed = CHECKSUM_PARTIAL;
1050 else if (rx->flags & XEN_NETRXF_data_validated)
1051 skb->ip_summed = CHECKSUM_UNNECESSARY;
1052
1053 __skb_queue_tail(&rxq, skb);
1054
1055 queue->rx.rsp_cons = ++i;
1056 work_done++;
1057 }
1058
1059 __skb_queue_purge(&errq);
1060
1061 work_done -= handle_incoming_queue(queue, &rxq);
1062
1063 xennet_alloc_rx_buffers(queue);
1064
1065 if (work_done < budget) {
1066 int more_to_do = 0;
1067
1068 napi_complete_done(napi, work_done);
1069
1070 RING_FINAL_CHECK_FOR_RESPONSES(&queue->rx, more_to_do);
1071 if (more_to_do)
1072 napi_schedule(napi);
1073 }
1074
1075 spin_unlock(&queue->rx_lock);
1076
1077 return work_done;
1078}
1079
1080static int xennet_change_mtu(struct net_device *dev, int mtu)
1081{
1082 int max = xennet_can_sg(dev) ? XEN_NETIF_MAX_TX_SIZE : ETH_DATA_LEN;
1083
1084 if (mtu > max)
1085 return -EINVAL;
1086 dev->mtu = mtu;
1087 return 0;
1088}
1089
1090static void xennet_get_stats64(struct net_device *dev,
1091 struct rtnl_link_stats64 *tot)
1092{
1093 struct netfront_info *np = netdev_priv(dev);
1094 int cpu;
1095
1096 for_each_possible_cpu(cpu) {
1097 struct netfront_stats *rx_stats = per_cpu_ptr(np->rx_stats, cpu);
1098 struct netfront_stats *tx_stats = per_cpu_ptr(np->tx_stats, cpu);
1099 u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
1100 unsigned int start;
1101
1102 do {
1103 start = u64_stats_fetch_begin_irq(&tx_stats->syncp);
1104 tx_packets = tx_stats->packets;
1105 tx_bytes = tx_stats->bytes;
1106 } while (u64_stats_fetch_retry_irq(&tx_stats->syncp, start));
1107
1108 do {
1109 start = u64_stats_fetch_begin_irq(&rx_stats->syncp);
1110 rx_packets = rx_stats->packets;
1111 rx_bytes = rx_stats->bytes;
1112 } while (u64_stats_fetch_retry_irq(&rx_stats->syncp, start));
1113
1114 tot->rx_packets += rx_packets;
1115 tot->tx_packets += tx_packets;
1116 tot->rx_bytes += rx_bytes;
1117 tot->tx_bytes += tx_bytes;
1118 }
1119
1120 tot->rx_errors = dev->stats.rx_errors;
1121 tot->tx_dropped = dev->stats.tx_dropped;
1122}
1123
1124static void xennet_release_tx_bufs(struct netfront_queue *queue)
1125{
1126 struct sk_buff *skb;
1127 int i;
1128
1129 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1130 /* Skip over entries which are actually freelist references */
1131 if (skb_entry_is_link(&queue->tx_skbs[i]))
1132 continue;
1133
1134 skb = queue->tx_skbs[i].skb;
1135 get_page(queue->grant_tx_page[i]);
1136 gnttab_end_foreign_access(queue->grant_tx_ref[i],
1137 GNTMAP_readonly,
1138 (unsigned long)page_address(queue->grant_tx_page[i]));
1139 queue->grant_tx_page[i] = NULL;
1140 queue->grant_tx_ref[i] = GRANT_INVALID_REF;
1141 add_id_to_freelist(&queue->tx_skb_freelist, queue->tx_skbs, i);
1142 dev_kfree_skb_irq(skb);
1143 }
1144}
1145
1146static void xennet_release_rx_bufs(struct netfront_queue *queue)
1147{
1148 int id, ref;
1149
1150 spin_lock_bh(&queue->rx_lock);
1151
1152 for (id = 0; id < NET_RX_RING_SIZE; id++) {
1153 struct sk_buff *skb;
1154 struct page *page;
1155
1156 skb = queue->rx_skbs[id];
1157 if (!skb)
1158 continue;
1159
1160 ref = queue->grant_rx_ref[id];
1161 if (ref == GRANT_INVALID_REF)
1162 continue;
1163
1164 page = skb_frag_page(&skb_shinfo(skb)->frags[0]);
1165
1166 /* gnttab_end_foreign_access() needs a page ref until
1167 * foreign access is ended (which may be deferred).
1168 */
1169 get_page(page);
1170 gnttab_end_foreign_access(ref, 0,
1171 (unsigned long)page_address(page));
1172 queue->grant_rx_ref[id] = GRANT_INVALID_REF;
1173
1174 kfree_skb(skb);
1175 }
1176
1177 spin_unlock_bh(&queue->rx_lock);
1178}
1179
1180static netdev_features_t xennet_fix_features(struct net_device *dev,
1181 netdev_features_t features)
1182{
1183 struct netfront_info *np = netdev_priv(dev);
1184
1185 if (features & NETIF_F_SG &&
1186 !xenbus_read_unsigned(np->xbdev->otherend, "feature-sg", 0))
1187 features &= ~NETIF_F_SG;
1188
1189 if (features & NETIF_F_IPV6_CSUM &&
1190 !xenbus_read_unsigned(np->xbdev->otherend,
1191 "feature-ipv6-csum-offload", 0))
1192 features &= ~NETIF_F_IPV6_CSUM;
1193
1194 if (features & NETIF_F_TSO &&
1195 !xenbus_read_unsigned(np->xbdev->otherend, "feature-gso-tcpv4", 0))
1196 features &= ~NETIF_F_TSO;
1197
1198 if (features & NETIF_F_TSO6 &&
1199 !xenbus_read_unsigned(np->xbdev->otherend, "feature-gso-tcpv6", 0))
1200 features &= ~NETIF_F_TSO6;
1201
1202 return features;
1203}
1204
1205static int xennet_set_features(struct net_device *dev,
1206 netdev_features_t features)
1207{
1208 if (!(features & NETIF_F_SG) && dev->mtu > ETH_DATA_LEN) {
1209 netdev_info(dev, "Reducing MTU because no SG offload");
1210 dev->mtu = ETH_DATA_LEN;
1211 }
1212
1213 return 0;
1214}
1215
1216static irqreturn_t xennet_tx_interrupt(int irq, void *dev_id)
1217{
1218 struct netfront_queue *queue = dev_id;
1219 unsigned long flags;
1220
1221 spin_lock_irqsave(&queue->tx_lock, flags);
1222 xennet_tx_buf_gc(queue);
1223 spin_unlock_irqrestore(&queue->tx_lock, flags);
1224
1225 return IRQ_HANDLED;
1226}
1227
1228static irqreturn_t xennet_rx_interrupt(int irq, void *dev_id)
1229{
1230 struct netfront_queue *queue = dev_id;
1231 struct net_device *dev = queue->info->netdev;
1232
1233 if (likely(netif_carrier_ok(dev) &&
1234 RING_HAS_UNCONSUMED_RESPONSES(&queue->rx)))
1235 napi_schedule(&queue->napi);
1236
1237 return IRQ_HANDLED;
1238}
1239
1240static irqreturn_t xennet_interrupt(int irq, void *dev_id)
1241{
1242 xennet_tx_interrupt(irq, dev_id);
1243 xennet_rx_interrupt(irq, dev_id);
1244 return IRQ_HANDLED;
1245}
1246
1247#ifdef CONFIG_NET_POLL_CONTROLLER
1248static void xennet_poll_controller(struct net_device *dev)
1249{
1250 /* Poll each queue */
1251 struct netfront_info *info = netdev_priv(dev);
1252 unsigned int num_queues = dev->real_num_tx_queues;
1253 unsigned int i;
1254 for (i = 0; i < num_queues; ++i)
1255 xennet_interrupt(0, &info->queues[i]);
1256}
1257#endif
1258
1259static const struct net_device_ops xennet_netdev_ops = {
1260 .ndo_open = xennet_open,
1261 .ndo_stop = xennet_close,
1262 .ndo_start_xmit = xennet_start_xmit,
1263 .ndo_change_mtu = xennet_change_mtu,
1264 .ndo_get_stats64 = xennet_get_stats64,
1265 .ndo_set_mac_address = eth_mac_addr,
1266 .ndo_validate_addr = eth_validate_addr,
1267 .ndo_fix_features = xennet_fix_features,
1268 .ndo_set_features = xennet_set_features,
1269 .ndo_select_queue = xennet_select_queue,
1270#ifdef CONFIG_NET_POLL_CONTROLLER
1271 .ndo_poll_controller = xennet_poll_controller,
1272#endif
1273};
1274
1275static void xennet_free_netdev(struct net_device *netdev)
1276{
1277 struct netfront_info *np = netdev_priv(netdev);
1278
1279 free_percpu(np->rx_stats);
1280 free_percpu(np->tx_stats);
1281 free_netdev(netdev);
1282}
1283
1284static struct net_device *xennet_create_dev(struct xenbus_device *dev)
1285{
1286 int err;
1287 struct net_device *netdev;
1288 struct netfront_info *np;
1289
1290 netdev = alloc_etherdev_mq(sizeof(struct netfront_info), xennet_max_queues);
1291 if (!netdev)
1292 return ERR_PTR(-ENOMEM);
1293
1294 np = netdev_priv(netdev);
1295 np->xbdev = dev;
1296
1297 np->queues = NULL;
1298
1299 err = -ENOMEM;
1300 np->rx_stats = netdev_alloc_pcpu_stats(struct netfront_stats);
1301 if (np->rx_stats == NULL)
1302 goto exit;
1303 np->tx_stats = netdev_alloc_pcpu_stats(struct netfront_stats);
1304 if (np->tx_stats == NULL)
1305 goto exit;
1306
1307 netdev->netdev_ops = &xennet_netdev_ops;
1308
1309 netdev->features = NETIF_F_IP_CSUM | NETIF_F_RXCSUM |
1310 NETIF_F_GSO_ROBUST;
1311 netdev->hw_features = NETIF_F_SG |
1312 NETIF_F_IPV6_CSUM |
1313 NETIF_F_TSO | NETIF_F_TSO6;
1314
1315 /*
1316 * Assume that all hw features are available for now. This set
1317 * will be adjusted by the call to netdev_update_features() in
1318 * xennet_connect() which is the earliest point where we can
1319 * negotiate with the backend regarding supported features.
1320 */
1321 netdev->features |= netdev->hw_features;
1322
1323 netdev->ethtool_ops = &xennet_ethtool_ops;
1324 netdev->min_mtu = ETH_MIN_MTU;
1325 netdev->max_mtu = XEN_NETIF_MAX_TX_SIZE;
1326 SET_NETDEV_DEV(netdev, &dev->dev);
1327
1328 np->netdev = netdev;
1329
1330 netif_carrier_off(netdev);
1331
1332 xenbus_switch_state(dev, XenbusStateInitialising);
1333 return netdev;
1334
1335 exit:
1336 xennet_free_netdev(netdev);
1337 return ERR_PTR(err);
1338}
1339
1340/**
1341 * Entry point to this code when a new device is created. Allocate the basic
1342 * structures and the ring buffers for communication with the backend, and
1343 * inform the backend of the appropriate details for those.
1344 */
1345static int netfront_probe(struct xenbus_device *dev,
1346 const struct xenbus_device_id *id)
1347{
1348 int err;
1349 struct net_device *netdev;
1350 struct netfront_info *info;
1351
1352 netdev = xennet_create_dev(dev);
1353 if (IS_ERR(netdev)) {
1354 err = PTR_ERR(netdev);
1355 xenbus_dev_fatal(dev, err, "creating netdev");
1356 return err;
1357 }
1358
1359 info = netdev_priv(netdev);
1360 dev_set_drvdata(&dev->dev, info);
1361#ifdef CONFIG_SYSFS
1362 info->netdev->sysfs_groups[0] = &xennet_dev_group;
1363#endif
1364
1365 return 0;
1366}
1367
1368static void xennet_end_access(int ref, void *page)
1369{
1370 /* This frees the page as a side-effect */
1371 if (ref != GRANT_INVALID_REF)
1372 gnttab_end_foreign_access(ref, 0, (unsigned long)page);
1373}
1374
1375static void xennet_disconnect_backend(struct netfront_info *info)
1376{
1377 unsigned int i = 0;
1378 unsigned int num_queues = info->netdev->real_num_tx_queues;
1379
1380 netif_carrier_off(info->netdev);
1381
1382 for (i = 0; i < num_queues && info->queues; ++i) {
1383 struct netfront_queue *queue = &info->queues[i];
1384
1385 del_timer_sync(&queue->rx_refill_timer);
1386
1387 if (queue->tx_irq && (queue->tx_irq == queue->rx_irq))
1388 unbind_from_irqhandler(queue->tx_irq, queue);
1389 if (queue->tx_irq && (queue->tx_irq != queue->rx_irq)) {
1390 unbind_from_irqhandler(queue->tx_irq, queue);
1391 unbind_from_irqhandler(queue->rx_irq, queue);
1392 }
1393 queue->tx_evtchn = queue->rx_evtchn = 0;
1394 queue->tx_irq = queue->rx_irq = 0;
1395
1396 if (netif_running(info->netdev))
1397 napi_synchronize(&queue->napi);
1398
1399 xennet_release_tx_bufs(queue);
1400 xennet_release_rx_bufs(queue);
1401 gnttab_free_grant_references(queue->gref_tx_head);
1402 gnttab_free_grant_references(queue->gref_rx_head);
1403
1404 /* End access and free the pages */
1405 xennet_end_access(queue->tx_ring_ref, queue->tx.sring);
1406 xennet_end_access(queue->rx_ring_ref, queue->rx.sring);
1407
1408 queue->tx_ring_ref = GRANT_INVALID_REF;
1409 queue->rx_ring_ref = GRANT_INVALID_REF;
1410 queue->tx.sring = NULL;
1411 queue->rx.sring = NULL;
1412 }
1413}
1414
1415/**
1416 * We are reconnecting to the backend, due to a suspend/resume, or a backend
1417 * driver restart. We tear down our netif structure and recreate it, but
1418 * leave the device-layer structures intact so that this is transparent to the
1419 * rest of the kernel.
1420 */
1421static int netfront_resume(struct xenbus_device *dev)
1422{
1423 struct netfront_info *info = dev_get_drvdata(&dev->dev);
1424
1425 dev_dbg(&dev->dev, "%s\n", dev->nodename);
1426
1427 xennet_disconnect_backend(info);
1428 return 0;
1429}
1430
1431static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[])
1432{
1433 char *s, *e, *macstr;
1434 int i;
1435
1436 macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL);
1437 if (IS_ERR(macstr))
1438 return PTR_ERR(macstr);
1439
1440 for (i = 0; i < ETH_ALEN; i++) {
1441 mac[i] = simple_strtoul(s, &e, 16);
1442 if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) {
1443 kfree(macstr);
1444 return -ENOENT;
1445 }
1446 s = e+1;
1447 }
1448
1449 kfree(macstr);
1450 return 0;
1451}
1452
1453static int setup_netfront_single(struct netfront_queue *queue)
1454{
1455 int err;
1456
1457 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn);
1458 if (err < 0)
1459 goto fail;
1460
1461 err = bind_evtchn_to_irqhandler(queue->tx_evtchn,
1462 xennet_interrupt,
1463 0, queue->info->netdev->name, queue);
1464 if (err < 0)
1465 goto bind_fail;
1466 queue->rx_evtchn = queue->tx_evtchn;
1467 queue->rx_irq = queue->tx_irq = err;
1468
1469 return 0;
1470
1471bind_fail:
1472 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn);
1473 queue->tx_evtchn = 0;
1474fail:
1475 return err;
1476}
1477
1478static int setup_netfront_split(struct netfront_queue *queue)
1479{
1480 int err;
1481
1482 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn);
1483 if (err < 0)
1484 goto fail;
1485 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->rx_evtchn);
1486 if (err < 0)
1487 goto alloc_rx_evtchn_fail;
1488
1489 snprintf(queue->tx_irq_name, sizeof(queue->tx_irq_name),
1490 "%s-tx", queue->name);
1491 err = bind_evtchn_to_irqhandler(queue->tx_evtchn,
1492 xennet_tx_interrupt,
1493 0, queue->tx_irq_name, queue);
1494 if (err < 0)
1495 goto bind_tx_fail;
1496 queue->tx_irq = err;
1497
1498 snprintf(queue->rx_irq_name, sizeof(queue->rx_irq_name),
1499 "%s-rx", queue->name);
1500 err = bind_evtchn_to_irqhandler(queue->rx_evtchn,
1501 xennet_rx_interrupt,
1502 0, queue->rx_irq_name, queue);
1503 if (err < 0)
1504 goto bind_rx_fail;
1505 queue->rx_irq = err;
1506
1507 return 0;
1508
1509bind_rx_fail:
1510 unbind_from_irqhandler(queue->tx_irq, queue);
1511 queue->tx_irq = 0;
1512bind_tx_fail:
1513 xenbus_free_evtchn(queue->info->xbdev, queue->rx_evtchn);
1514 queue->rx_evtchn = 0;
1515alloc_rx_evtchn_fail:
1516 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn);
1517 queue->tx_evtchn = 0;
1518fail:
1519 return err;
1520}
1521
1522static int setup_netfront(struct xenbus_device *dev,
1523 struct netfront_queue *queue, unsigned int feature_split_evtchn)
1524{
1525 struct xen_netif_tx_sring *txs;
1526 struct xen_netif_rx_sring *rxs;
1527 grant_ref_t gref;
1528 int err;
1529
1530 queue->tx_ring_ref = GRANT_INVALID_REF;
1531 queue->rx_ring_ref = GRANT_INVALID_REF;
1532 queue->rx.sring = NULL;
1533 queue->tx.sring = NULL;
1534
1535 txs = (struct xen_netif_tx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1536 if (!txs) {
1537 err = -ENOMEM;
1538 xenbus_dev_fatal(dev, err, "allocating tx ring page");
1539 goto fail;
1540 }
1541 SHARED_RING_INIT(txs);
1542 FRONT_RING_INIT(&queue->tx, txs, XEN_PAGE_SIZE);
1543
1544 err = xenbus_grant_ring(dev, txs, 1, &gref);
1545 if (err < 0)
1546 goto grant_tx_ring_fail;
1547 queue->tx_ring_ref = gref;
1548
1549 rxs = (struct xen_netif_rx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1550 if (!rxs) {
1551 err = -ENOMEM;
1552 xenbus_dev_fatal(dev, err, "allocating rx ring page");
1553 goto alloc_rx_ring_fail;
1554 }
1555 SHARED_RING_INIT(rxs);
1556 FRONT_RING_INIT(&queue->rx, rxs, XEN_PAGE_SIZE);
1557
1558 err = xenbus_grant_ring(dev, rxs, 1, &gref);
1559 if (err < 0)
1560 goto grant_rx_ring_fail;
1561 queue->rx_ring_ref = gref;
1562
1563 if (feature_split_evtchn)
1564 err = setup_netfront_split(queue);
1565 /* setup single event channel if
1566 * a) feature-split-event-channels == 0
1567 * b) feature-split-event-channels == 1 but failed to setup
1568 */
1569 if (!feature_split_evtchn || (feature_split_evtchn && err))
1570 err = setup_netfront_single(queue);
1571
1572 if (err)
1573 goto alloc_evtchn_fail;
1574
1575 return 0;
1576
1577 /* If we fail to setup netfront, it is safe to just revoke access to
1578 * granted pages because backend is not accessing it at this point.
1579 */
1580alloc_evtchn_fail:
1581 gnttab_end_foreign_access_ref(queue->rx_ring_ref, 0);
1582grant_rx_ring_fail:
1583 free_page((unsigned long)rxs);
1584alloc_rx_ring_fail:
1585 gnttab_end_foreign_access_ref(queue->tx_ring_ref, 0);
1586grant_tx_ring_fail:
1587 free_page((unsigned long)txs);
1588fail:
1589 return err;
1590}
1591
1592/* Queue-specific initialisation
1593 * This used to be done in xennet_create_dev() but must now
1594 * be run per-queue.
1595 */
1596static int xennet_init_queue(struct netfront_queue *queue)
1597{
1598 unsigned short i;
1599 int err = 0;
1600
1601 spin_lock_init(&queue->tx_lock);
1602 spin_lock_init(&queue->rx_lock);
1603
1604 timer_setup(&queue->rx_refill_timer, rx_refill_timeout, 0);
1605
1606 snprintf(queue->name, sizeof(queue->name), "%s-q%u",
1607 queue->info->netdev->name, queue->id);
1608
1609 /* Initialise tx_skbs as a free chain containing every entry. */
1610 queue->tx_skb_freelist = 0;
1611 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1612 skb_entry_set_link(&queue->tx_skbs[i], i+1);
1613 queue->grant_tx_ref[i] = GRANT_INVALID_REF;
1614 queue->grant_tx_page[i] = NULL;
1615 }
1616
1617 /* Clear out rx_skbs */
1618 for (i = 0; i < NET_RX_RING_SIZE; i++) {
1619 queue->rx_skbs[i] = NULL;
1620 queue->grant_rx_ref[i] = GRANT_INVALID_REF;
1621 }
1622
1623 /* A grant for every tx ring slot */
1624 if (gnttab_alloc_grant_references(NET_TX_RING_SIZE,
1625 &queue->gref_tx_head) < 0) {
1626 pr_alert("can't alloc tx grant refs\n");
1627 err = -ENOMEM;
1628 goto exit;
1629 }
1630
1631 /* A grant for every rx ring slot */
1632 if (gnttab_alloc_grant_references(NET_RX_RING_SIZE,
1633 &queue->gref_rx_head) < 0) {
1634 pr_alert("can't alloc rx grant refs\n");
1635 err = -ENOMEM;
1636 goto exit_free_tx;
1637 }
1638
1639 return 0;
1640
1641 exit_free_tx:
1642 gnttab_free_grant_references(queue->gref_tx_head);
1643 exit:
1644 return err;
1645}
1646
1647static int write_queue_xenstore_keys(struct netfront_queue *queue,
1648 struct xenbus_transaction *xbt, int write_hierarchical)
1649{
1650 /* Write the queue-specific keys into XenStore in the traditional
1651 * way for a single queue, or in a queue subkeys for multiple
1652 * queues.
1653 */
1654 struct xenbus_device *dev = queue->info->xbdev;
1655 int err;
1656 const char *message;
1657 char *path;
1658 size_t pathsize;
1659
1660 /* Choose the correct place to write the keys */
1661 if (write_hierarchical) {
1662 pathsize = strlen(dev->nodename) + 10;
1663 path = kzalloc(pathsize, GFP_KERNEL);
1664 if (!path) {
1665 err = -ENOMEM;
1666 message = "out of memory while writing ring references";
1667 goto error;
1668 }
1669 snprintf(path, pathsize, "%s/queue-%u",
1670 dev->nodename, queue->id);
1671 } else {
1672 path = (char *)dev->nodename;
1673 }
1674
1675 /* Write ring references */
1676 err = xenbus_printf(*xbt, path, "tx-ring-ref", "%u",
1677 queue->tx_ring_ref);
1678 if (err) {
1679 message = "writing tx-ring-ref";
1680 goto error;
1681 }
1682
1683 err = xenbus_printf(*xbt, path, "rx-ring-ref", "%u",
1684 queue->rx_ring_ref);
1685 if (err) {
1686 message = "writing rx-ring-ref";
1687 goto error;
1688 }
1689
1690 /* Write event channels; taking into account both shared
1691 * and split event channel scenarios.
1692 */
1693 if (queue->tx_evtchn == queue->rx_evtchn) {
1694 /* Shared event channel */
1695 err = xenbus_printf(*xbt, path,
1696 "event-channel", "%u", queue->tx_evtchn);
1697 if (err) {
1698 message = "writing event-channel";
1699 goto error;
1700 }
1701 } else {
1702 /* Split event channels */
1703 err = xenbus_printf(*xbt, path,
1704 "event-channel-tx", "%u", queue->tx_evtchn);
1705 if (err) {
1706 message = "writing event-channel-tx";
1707 goto error;
1708 }
1709
1710 err = xenbus_printf(*xbt, path,
1711 "event-channel-rx", "%u", queue->rx_evtchn);
1712 if (err) {
1713 message = "writing event-channel-rx";
1714 goto error;
1715 }
1716 }
1717
1718 if (write_hierarchical)
1719 kfree(path);
1720 return 0;
1721
1722error:
1723 if (write_hierarchical)
1724 kfree(path);
1725 xenbus_dev_fatal(dev, err, "%s", message);
1726 return err;
1727}
1728
1729static void xennet_destroy_queues(struct netfront_info *info)
1730{
1731 unsigned int i;
1732
1733 for (i = 0; i < info->netdev->real_num_tx_queues; i++) {
1734 struct netfront_queue *queue = &info->queues[i];
1735
1736 if (netif_running(info->netdev))
1737 napi_disable(&queue->napi);
1738 netif_napi_del(&queue->napi);
1739 }
1740
1741 kfree(info->queues);
1742 info->queues = NULL;
1743}
1744
1745static int xennet_create_queues(struct netfront_info *info,
1746 unsigned int *num_queues)
1747{
1748 unsigned int i;
1749 int ret;
1750
1751 info->queues = kcalloc(*num_queues, sizeof(struct netfront_queue),
1752 GFP_KERNEL);
1753 if (!info->queues)
1754 return -ENOMEM;
1755
1756 for (i = 0; i < *num_queues; i++) {
1757 struct netfront_queue *queue = &info->queues[i];
1758
1759 queue->id = i;
1760 queue->info = info;
1761
1762 ret = xennet_init_queue(queue);
1763 if (ret < 0) {
1764 dev_warn(&info->xbdev->dev,
1765 "only created %d queues\n", i);
1766 *num_queues = i;
1767 break;
1768 }
1769
1770 netif_napi_add(queue->info->netdev, &queue->napi,
1771 xennet_poll, 64);
1772 if (netif_running(info->netdev))
1773 napi_enable(&queue->napi);
1774 }
1775
1776 netif_set_real_num_tx_queues(info->netdev, *num_queues);
1777
1778 if (*num_queues == 0) {
1779 dev_err(&info->xbdev->dev, "no queues\n");
1780 return -EINVAL;
1781 }
1782 return 0;
1783}
1784
1785/* Common code used when first setting up, and when resuming. */
1786static int talk_to_netback(struct xenbus_device *dev,
1787 struct netfront_info *info)
1788{
1789 const char *message;
1790 struct xenbus_transaction xbt;
1791 int err;
1792 unsigned int feature_split_evtchn;
1793 unsigned int i = 0;
1794 unsigned int max_queues = 0;
1795 struct netfront_queue *queue = NULL;
1796 unsigned int num_queues = 1;
1797
1798 info->netdev->irq = 0;
1799
1800 /* Check if backend supports multiple queues */
1801 max_queues = xenbus_read_unsigned(info->xbdev->otherend,
1802 "multi-queue-max-queues", 1);
1803 num_queues = min(max_queues, xennet_max_queues);
1804
1805 /* Check feature-split-event-channels */
1806 feature_split_evtchn = xenbus_read_unsigned(info->xbdev->otherend,
1807 "feature-split-event-channels", 0);
1808
1809 /* Read mac addr. */
1810 err = xen_net_read_mac(dev, info->netdev->dev_addr);
1811 if (err) {
1812 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
1813 goto out;
1814 }
1815
1816 rtnl_lock();
1817 if (info->queues)
1818 xennet_destroy_queues(info);
1819
1820 err = xennet_create_queues(info, &num_queues);
1821 if (err < 0) {
1822 xenbus_dev_fatal(dev, err, "creating queues");
1823 kfree(info->queues);
1824 info->queues = NULL;
1825 goto out;
1826 }
1827 rtnl_unlock();
1828
1829 /* Create shared ring, alloc event channel -- for each queue */
1830 for (i = 0; i < num_queues; ++i) {
1831 queue = &info->queues[i];
1832 err = setup_netfront(dev, queue, feature_split_evtchn);
1833 if (err)
1834 goto destroy_ring;
1835 }
1836
1837again:
1838 err = xenbus_transaction_start(&xbt);
1839 if (err) {
1840 xenbus_dev_fatal(dev, err, "starting transaction");
1841 goto destroy_ring;
1842 }
1843
1844 if (xenbus_exists(XBT_NIL,
1845 info->xbdev->otherend, "multi-queue-max-queues")) {
1846 /* Write the number of queues */
1847 err = xenbus_printf(xbt, dev->nodename,
1848 "multi-queue-num-queues", "%u", num_queues);
1849 if (err) {
1850 message = "writing multi-queue-num-queues";
1851 goto abort_transaction_no_dev_fatal;
1852 }
1853 }
1854
1855 if (num_queues == 1) {
1856 err = write_queue_xenstore_keys(&info->queues[0], &xbt, 0); /* flat */
1857 if (err)
1858 goto abort_transaction_no_dev_fatal;
1859 } else {
1860 /* Write the keys for each queue */
1861 for (i = 0; i < num_queues; ++i) {
1862 queue = &info->queues[i];
1863 err = write_queue_xenstore_keys(queue, &xbt, 1); /* hierarchical */
1864 if (err)
1865 goto abort_transaction_no_dev_fatal;
1866 }
1867 }
1868
1869 /* The remaining keys are not queue-specific */
1870 err = xenbus_printf(xbt, dev->nodename, "request-rx-copy", "%u",
1871 1);
1872 if (err) {
1873 message = "writing request-rx-copy";
1874 goto abort_transaction;
1875 }
1876
1877 err = xenbus_printf(xbt, dev->nodename, "feature-rx-notify", "%d", 1);
1878 if (err) {
1879 message = "writing feature-rx-notify";
1880 goto abort_transaction;
1881 }
1882
1883 err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", 1);
1884 if (err) {
1885 message = "writing feature-sg";
1886 goto abort_transaction;
1887 }
1888
1889 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4", "%d", 1);
1890 if (err) {
1891 message = "writing feature-gso-tcpv4";
1892 goto abort_transaction;
1893 }
1894
1895 err = xenbus_write(xbt, dev->nodename, "feature-gso-tcpv6", "1");
1896 if (err) {
1897 message = "writing feature-gso-tcpv6";
1898 goto abort_transaction;
1899 }
1900
1901 err = xenbus_write(xbt, dev->nodename, "feature-ipv6-csum-offload",
1902 "1");
1903 if (err) {
1904 message = "writing feature-ipv6-csum-offload";
1905 goto abort_transaction;
1906 }
1907
1908 err = xenbus_transaction_end(xbt, 0);
1909 if (err) {
1910 if (err == -EAGAIN)
1911 goto again;
1912 xenbus_dev_fatal(dev, err, "completing transaction");
1913 goto destroy_ring;
1914 }
1915
1916 return 0;
1917
1918 abort_transaction:
1919 xenbus_dev_fatal(dev, err, "%s", message);
1920abort_transaction_no_dev_fatal:
1921 xenbus_transaction_end(xbt, 1);
1922 destroy_ring:
1923 xennet_disconnect_backend(info);
1924 rtnl_lock();
1925 xennet_destroy_queues(info);
1926 out:
1927 rtnl_unlock();
1928 device_unregister(&dev->dev);
1929 return err;
1930}
1931
1932static int xennet_connect(struct net_device *dev)
1933{
1934 struct netfront_info *np = netdev_priv(dev);
1935 unsigned int num_queues = 0;
1936 int err;
1937 unsigned int j = 0;
1938 struct netfront_queue *queue = NULL;
1939
1940 if (!xenbus_read_unsigned(np->xbdev->otherend, "feature-rx-copy", 0)) {
1941 dev_info(&dev->dev,
1942 "backend does not support copying receive path\n");
1943 return -ENODEV;
1944 }
1945
1946 err = talk_to_netback(np->xbdev, np);
1947 if (err)
1948 return err;
1949
1950 /* talk_to_netback() sets the correct number of queues */
1951 num_queues = dev->real_num_tx_queues;
1952
1953 rtnl_lock();
1954 netdev_update_features(dev);
1955 rtnl_unlock();
1956
1957 if (dev->reg_state == NETREG_UNINITIALIZED) {
1958 err = register_netdev(dev);
1959 if (err) {
1960 pr_warn("%s: register_netdev err=%d\n", __func__, err);
1961 device_unregister(&np->xbdev->dev);
1962 return err;
1963 }
1964 }
1965
1966 /*
1967 * All public and private state should now be sane. Get
1968 * ready to start sending and receiving packets and give the driver
1969 * domain a kick because we've probably just requeued some
1970 * packets.
1971 */
1972 netif_carrier_on(np->netdev);
1973 for (j = 0; j < num_queues; ++j) {
1974 queue = &np->queues[j];
1975
1976 notify_remote_via_irq(queue->tx_irq);
1977 if (queue->tx_irq != queue->rx_irq)
1978 notify_remote_via_irq(queue->rx_irq);
1979
1980 spin_lock_irq(&queue->tx_lock);
1981 xennet_tx_buf_gc(queue);
1982 spin_unlock_irq(&queue->tx_lock);
1983
1984 spin_lock_bh(&queue->rx_lock);
1985 xennet_alloc_rx_buffers(queue);
1986 spin_unlock_bh(&queue->rx_lock);
1987 }
1988
1989 return 0;
1990}
1991
1992/**
1993 * Callback received when the backend's state changes.
1994 */
1995static void netback_changed(struct xenbus_device *dev,
1996 enum xenbus_state backend_state)
1997{
1998 struct netfront_info *np = dev_get_drvdata(&dev->dev);
1999 struct net_device *netdev = np->netdev;
2000
2001 dev_dbg(&dev->dev, "%s\n", xenbus_strstate(backend_state));
2002
2003 switch (backend_state) {
2004 case XenbusStateInitialising:
2005 case XenbusStateInitialised:
2006 case XenbusStateReconfiguring:
2007 case XenbusStateReconfigured:
2008 break;
2009
2010 case XenbusStateUnknown:
2011 wake_up_all(&module_unload_q);
2012 break;
2013
2014 case XenbusStateInitWait:
2015 if (dev->state != XenbusStateInitialising)
2016 break;
2017 if (xennet_connect(netdev) != 0)
2018 break;
2019 xenbus_switch_state(dev, XenbusStateConnected);
2020 break;
2021
2022 case XenbusStateConnected:
2023 netdev_notify_peers(netdev);
2024 break;
2025
2026 case XenbusStateClosed:
2027 wake_up_all(&module_unload_q);
2028 if (dev->state == XenbusStateClosed)
2029 break;
2030 /* Missed the backend's CLOSING state -- fallthrough */
2031 case XenbusStateClosing:
2032 wake_up_all(&module_unload_q);
2033 xenbus_frontend_closed(dev);
2034 break;
2035 }
2036}
2037
2038static const struct xennet_stat {
2039 char name[ETH_GSTRING_LEN];
2040 u16 offset;
2041} xennet_stats[] = {
2042 {
2043 "rx_gso_checksum_fixup",
2044 offsetof(struct netfront_info, rx_gso_checksum_fixup)
2045 },
2046};
2047
2048static int xennet_get_sset_count(struct net_device *dev, int string_set)
2049{
2050 switch (string_set) {
2051 case ETH_SS_STATS:
2052 return ARRAY_SIZE(xennet_stats);
2053 default:
2054 return -EINVAL;
2055 }
2056}
2057
2058static void xennet_get_ethtool_stats(struct net_device *dev,
2059 struct ethtool_stats *stats, u64 * data)
2060{
2061 void *np = netdev_priv(dev);
2062 int i;
2063
2064 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
2065 data[i] = atomic_read((atomic_t *)(np + xennet_stats[i].offset));
2066}
2067
2068static void xennet_get_strings(struct net_device *dev, u32 stringset, u8 * data)
2069{
2070 int i;
2071
2072 switch (stringset) {
2073 case ETH_SS_STATS:
2074 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
2075 memcpy(data + i * ETH_GSTRING_LEN,
2076 xennet_stats[i].name, ETH_GSTRING_LEN);
2077 break;
2078 }
2079}
2080
2081static const struct ethtool_ops xennet_ethtool_ops =
2082{
2083 .get_link = ethtool_op_get_link,
2084
2085 .get_sset_count = xennet_get_sset_count,
2086 .get_ethtool_stats = xennet_get_ethtool_stats,
2087 .get_strings = xennet_get_strings,
2088};
2089
2090#ifdef CONFIG_SYSFS
2091static ssize_t show_rxbuf(struct device *dev,
2092 struct device_attribute *attr, char *buf)
2093{
2094 return sprintf(buf, "%lu\n", NET_RX_RING_SIZE);
2095}
2096
2097static ssize_t store_rxbuf(struct device *dev,
2098 struct device_attribute *attr,
2099 const char *buf, size_t len)
2100{
2101 char *endp;
2102 unsigned long target;
2103
2104 if (!capable(CAP_NET_ADMIN))
2105 return -EPERM;
2106
2107 target = simple_strtoul(buf, &endp, 0);
2108 if (endp == buf)
2109 return -EBADMSG;
2110
2111 /* rxbuf_min and rxbuf_max are no longer configurable. */
2112
2113 return len;
2114}
2115
2116static DEVICE_ATTR(rxbuf_min, 0644, show_rxbuf, store_rxbuf);
2117static DEVICE_ATTR(rxbuf_max, 0644, show_rxbuf, store_rxbuf);
2118static DEVICE_ATTR(rxbuf_cur, 0444, show_rxbuf, NULL);
2119
2120static struct attribute *xennet_dev_attrs[] = {
2121 &dev_attr_rxbuf_min.attr,
2122 &dev_attr_rxbuf_max.attr,
2123 &dev_attr_rxbuf_cur.attr,
2124 NULL
2125};
2126
2127static const struct attribute_group xennet_dev_group = {
2128 .attrs = xennet_dev_attrs
2129};
2130#endif /* CONFIG_SYSFS */
2131
2132static int xennet_remove(struct xenbus_device *dev)
2133{
2134 struct netfront_info *info = dev_get_drvdata(&dev->dev);
2135
2136 dev_dbg(&dev->dev, "%s\n", dev->nodename);
2137
2138 if (xenbus_read_driver_state(dev->otherend) != XenbusStateClosed) {
2139 xenbus_switch_state(dev, XenbusStateClosing);
2140 wait_event(module_unload_q,
2141 xenbus_read_driver_state(dev->otherend) ==
2142 XenbusStateClosing ||
2143 xenbus_read_driver_state(dev->otherend) ==
2144 XenbusStateUnknown);
2145
2146 xenbus_switch_state(dev, XenbusStateClosed);
2147 wait_event(module_unload_q,
2148 xenbus_read_driver_state(dev->otherend) ==
2149 XenbusStateClosed ||
2150 xenbus_read_driver_state(dev->otherend) ==
2151 XenbusStateUnknown);
2152 }
2153
2154 xennet_disconnect_backend(info);
2155
2156 if (info->netdev->reg_state == NETREG_REGISTERED)
2157 unregister_netdev(info->netdev);
2158
2159 if (info->queues) {
2160 rtnl_lock();
2161 xennet_destroy_queues(info);
2162 rtnl_unlock();
2163 }
2164 xennet_free_netdev(info->netdev);
2165
2166 return 0;
2167}
2168
2169static const struct xenbus_device_id netfront_ids[] = {
2170 { "vif" },
2171 { "" }
2172};
2173
2174static struct xenbus_driver netfront_driver = {
2175 .ids = netfront_ids,
2176 .probe = netfront_probe,
2177 .remove = xennet_remove,
2178 .resume = netfront_resume,
2179 .otherend_changed = netback_changed,
2180};
2181
2182static int __init netif_init(void)
2183{
2184 if (!xen_domain())
2185 return -ENODEV;
2186
2187 if (!xen_has_pv_nic_devices())
2188 return -ENODEV;
2189
2190 pr_info("Initialising Xen virtual ethernet driver\n");
2191
2192 /* Allow as many queues as there are CPUs inut max. 8 if user has not
2193 * specified a value.
2194 */
2195 if (xennet_max_queues == 0)
2196 xennet_max_queues = min_t(unsigned int, MAX_QUEUES_DEFAULT,
2197 num_online_cpus());
2198
2199 return xenbus_register_frontend(&netfront_driver);
2200}
2201module_init(netif_init);
2202
2203
2204static void __exit netif_exit(void)
2205{
2206 xenbus_unregister_driver(&netfront_driver);
2207}
2208module_exit(netif_exit);
2209
2210MODULE_DESCRIPTION("Xen virtual network device frontend");
2211MODULE_LICENSE("GPL");
2212MODULE_ALIAS("xen:vif");
2213MODULE_ALIAS("xennet");