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Linux 4.2.1
[linux/fpc-iii.git] / drivers / net / xen-netfront.c
blobf948c46d51329970c186b2886c267ffba2e807db
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 static unsigned int xennet_max_queues;
61 module_param_named(max_queues, xennet_max_queues, uint, 0644);
62 MODULE_PARM_DESC(max_queues,
63 "Maximum number of queues per virtual interface");
64
65 static const struct ethtool_ops xennet_ethtool_ops;
66
67 struct netfront_cb {
68 int pull_to;
69 };
70
71 #define NETFRONT_SKB_CB(skb) ((struct netfront_cb *)((skb)->cb))
72
73 #define RX_COPY_THRESHOLD 256
74
75 #define GRANT_INVALID_REF 0
76
77 #define NET_TX_RING_SIZE __CONST_RING_SIZE(xen_netif_tx, PAGE_SIZE)
78 #define NET_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, PAGE_SIZE)
79
80 /* Minimum number of Rx slots (includes slot for GSO metadata). */
81 #define NET_RX_SLOTS_MIN (XEN_NETIF_NR_SLOTS_MIN + 1)
82
83 /* Queue name is interface name with "-qNNN" appended */
84 #define QUEUE_NAME_SIZE (IFNAMSIZ + 6)
85
86 /* IRQ name is queue name with "-tx" or "-rx" appended */
87 #define IRQ_NAME_SIZE (QUEUE_NAME_SIZE + 3)
88
89 struct netfront_stats {
90 u64 packets;
91 u64 bytes;
92 struct u64_stats_sync syncp;
93 };
94
95 struct netfront_info;
96
97 struct netfront_queue {
98 unsigned int id; /* Queue ID, 0-based */
99 char name[QUEUE_NAME_SIZE]; /* DEVNAME-qN */
100 struct netfront_info *info;
101
102 struct napi_struct napi;
103
104 /* Split event channels support, tx_* == rx_* when using
105 * single event channel.
106 */
107 unsigned int tx_evtchn, rx_evtchn;
108 unsigned int tx_irq, rx_irq;
109 /* Only used when split event channels support is enabled */
110 char tx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-tx */
111 char rx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-rx */
112
113 spinlock_t tx_lock;
114 struct xen_netif_tx_front_ring tx;
115 int tx_ring_ref;
116
117 /*
118 * {tx,rx}_skbs store outstanding skbuffs. Free tx_skb entries
119 * are linked from tx_skb_freelist through skb_entry.link.
120 *
121 * NB. Freelist index entries are always going to be less than
122 * PAGE_OFFSET, whereas pointers to skbs will always be equal or
123 * greater than PAGE_OFFSET: we use this property to distinguish
124 * them.
125 */
126 union skb_entry {
127 struct sk_buff *skb;
128 unsigned long link;
129 } tx_skbs[NET_TX_RING_SIZE];
130 grant_ref_t gref_tx_head;
131 grant_ref_t grant_tx_ref[NET_TX_RING_SIZE];
132 struct page *grant_tx_page[NET_TX_RING_SIZE];
133 unsigned tx_skb_freelist;
134
135 spinlock_t rx_lock ____cacheline_aligned_in_smp;
136 struct xen_netif_rx_front_ring rx;
137 int rx_ring_ref;
138
139 struct timer_list rx_refill_timer;
140
141 struct sk_buff *rx_skbs[NET_RX_RING_SIZE];
142 grant_ref_t gref_rx_head;
143 grant_ref_t grant_rx_ref[NET_RX_RING_SIZE];
144 };
145
146 struct netfront_info {
147 struct list_head list;
148 struct net_device *netdev;
149
150 struct xenbus_device *xbdev;
151
152 /* Multi-queue support */
153 struct netfront_queue *queues;
154
155 /* Statistics */
156 struct netfront_stats __percpu *rx_stats;
157 struct netfront_stats __percpu *tx_stats;
158
159 atomic_t rx_gso_checksum_fixup;
160 };
161
162 struct netfront_rx_info {
163 struct xen_netif_rx_response rx;
164 struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX - 1];
165 };
166
167 static void skb_entry_set_link(union skb_entry *list, unsigned short id)
168 {
169 list->link = id;
170 }
171
172 static int skb_entry_is_link(const union skb_entry *list)
173 {
174 BUILD_BUG_ON(sizeof(list->skb) != sizeof(list->link));
175 return (unsigned long)list->skb < PAGE_OFFSET;
176 }
177
178 /*
179 * Access macros for acquiring freeing slots in tx_skbs[].
180 */
181
182 static void add_id_to_freelist(unsigned *head, union skb_entry *list,
183 unsigned short id)
184 {
185 skb_entry_set_link(&list[id], *head);
186 *head = id;
187 }
188
189 static unsigned short get_id_from_freelist(unsigned *head,
190 union skb_entry *list)
191 {
192 unsigned int id = *head;
193 *head = list[id].link;
194 return id;
195 }
196
197 static int xennet_rxidx(RING_IDX idx)
198 {
199 return idx & (NET_RX_RING_SIZE - 1);
200 }
201
202 static struct sk_buff *xennet_get_rx_skb(struct netfront_queue *queue,
203 RING_IDX ri)
204 {
205 int i = xennet_rxidx(ri);
206 struct sk_buff *skb = queue->rx_skbs[i];
207 queue->rx_skbs[i] = NULL;
208 return skb;
209 }
210
211 static grant_ref_t xennet_get_rx_ref(struct netfront_queue *queue,
212 RING_IDX ri)
213 {
214 int i = xennet_rxidx(ri);
215 grant_ref_t ref = queue->grant_rx_ref[i];
216 queue->grant_rx_ref[i] = GRANT_INVALID_REF;
217 return ref;
218 }
219
220 #ifdef CONFIG_SYSFS
221 static const struct attribute_group xennet_dev_group;
222 #endif
223
224 static bool xennet_can_sg(struct net_device *dev)
225 {
226 return dev->features & NETIF_F_SG;
227 }
228
229
230 static void rx_refill_timeout(unsigned long data)
231 {
232 struct netfront_queue *queue = (struct netfront_queue *)data;
233 napi_schedule(&queue->napi);
234 }
235
236 static int netfront_tx_slot_available(struct netfront_queue *queue)
237 {
238 return (queue->tx.req_prod_pvt - queue->tx.rsp_cons) <
239 (NET_TX_RING_SIZE - MAX_SKB_FRAGS - 2);
240 }
241
242 static void xennet_maybe_wake_tx(struct netfront_queue *queue)
243 {
244 struct net_device *dev = queue->info->netdev;
245 struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, queue->id);
246
247 if (unlikely(netif_tx_queue_stopped(dev_queue)) &&
248 netfront_tx_slot_available(queue) &&
249 likely(netif_running(dev)))
250 netif_tx_wake_queue(netdev_get_tx_queue(dev, queue->id));
251 }
252
253
254 static struct sk_buff *xennet_alloc_one_rx_buffer(struct netfront_queue *queue)
255 {
256 struct sk_buff *skb;
257 struct page *page;
258
259 skb = __netdev_alloc_skb(queue->info->netdev,
260 RX_COPY_THRESHOLD + NET_IP_ALIGN,
261 GFP_ATOMIC | __GFP_NOWARN);
262 if (unlikely(!skb))
263 return NULL;
264
265 page = alloc_page(GFP_ATOMIC | __GFP_NOWARN);
266 if (!page) {
267 kfree_skb(skb);
268 return NULL;
269 }
270 skb_add_rx_frag(skb, 0, page, 0, 0, PAGE_SIZE);
271
272 /* Align ip header to a 16 bytes boundary */
273 skb_reserve(skb, NET_IP_ALIGN);
274 skb->dev = queue->info->netdev;
275
276 return skb;
277 }
278
279
280 static void xennet_alloc_rx_buffers(struct netfront_queue *queue)
281 {
282 RING_IDX req_prod = queue->rx.req_prod_pvt;
283 int notify;
284
285 if (unlikely(!netif_carrier_ok(queue->info->netdev)))
286 return;
287
288 for (req_prod = queue->rx.req_prod_pvt;
289 req_prod - queue->rx.rsp_cons < NET_RX_RING_SIZE;
290 req_prod++) {
291 struct sk_buff *skb;
292 unsigned short id;
293 grant_ref_t ref;
294 unsigned long pfn;
295 struct xen_netif_rx_request *req;
296
297 skb = xennet_alloc_one_rx_buffer(queue);
298 if (!skb)
299 break;
300
301 id = xennet_rxidx(req_prod);
302
303 BUG_ON(queue->rx_skbs[id]);
304 queue->rx_skbs[id] = skb;
305
306 ref = gnttab_claim_grant_reference(&queue->gref_rx_head);
307 BUG_ON((signed short)ref < 0);
308 queue->grant_rx_ref[id] = ref;
309
310 pfn = page_to_pfn(skb_frag_page(&skb_shinfo(skb)->frags[0]));
311
312 req = RING_GET_REQUEST(&queue->rx, req_prod);
313 gnttab_grant_foreign_access_ref(ref,
314 queue->info->xbdev->otherend_id,
315 pfn_to_mfn(pfn),
316 0);
317
318 req->id = id;
319 req->gref = ref;
320 }
321
322 queue->rx.req_prod_pvt = req_prod;
323
324 /* Not enough requests? Try again later. */
325 if (req_prod - queue->rx.rsp_cons < NET_RX_SLOTS_MIN) {
326 mod_timer(&queue->rx_refill_timer, jiffies + (HZ/10));
327 return;
328 }
329
330 wmb(); /* barrier so backend seens requests */
331
332 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->rx, notify);
333 if (notify)
334 notify_remote_via_irq(queue->rx_irq);
335 }
336
337 static int xennet_open(struct net_device *dev)
338 {
339 struct netfront_info *np = netdev_priv(dev);
340 unsigned int num_queues = dev->real_num_tx_queues;
341 unsigned int i = 0;
342 struct netfront_queue *queue = NULL;
343
344 for (i = 0; i < num_queues; ++i) {
345 queue = &np->queues[i];
346 napi_enable(&queue->napi);
347
348 spin_lock_bh(&queue->rx_lock);
349 if (netif_carrier_ok(dev)) {
350 xennet_alloc_rx_buffers(queue);
351 queue->rx.sring->rsp_event = queue->rx.rsp_cons + 1;
352 if (RING_HAS_UNCONSUMED_RESPONSES(&queue->rx))
353 napi_schedule(&queue->napi);
354 }
355 spin_unlock_bh(&queue->rx_lock);
356 }
357
358 netif_tx_start_all_queues(dev);
359
360 return 0;
361 }
362
363 static void xennet_tx_buf_gc(struct netfront_queue *queue)
364 {
365 RING_IDX cons, prod;
366 unsigned short id;
367 struct sk_buff *skb;
368
369 BUG_ON(!netif_carrier_ok(queue->info->netdev));
370
371 do {
372 prod = queue->tx.sring->rsp_prod;
373 rmb(); /* Ensure we see responses up to 'rp'. */
374
375 for (cons = queue->tx.rsp_cons; cons != prod; cons++) {
376 struct xen_netif_tx_response *txrsp;
377
378 txrsp = RING_GET_RESPONSE(&queue->tx, cons);
379 if (txrsp->status == XEN_NETIF_RSP_NULL)
380 continue;
381
382 id = txrsp->id;
383 skb = queue->tx_skbs[id].skb;
384 if (unlikely(gnttab_query_foreign_access(
385 queue->grant_tx_ref[id]) != 0)) {
386 pr_alert("%s: warning -- grant still in use by backend domain\n",
387 __func__);
388 BUG();
389 }
390 gnttab_end_foreign_access_ref(
391 queue->grant_tx_ref[id], GNTMAP_readonly);
392 gnttab_release_grant_reference(
393 &queue->gref_tx_head, queue->grant_tx_ref[id]);
394 queue->grant_tx_ref[id] = GRANT_INVALID_REF;
395 queue->grant_tx_page[id] = NULL;
396 add_id_to_freelist(&queue->tx_skb_freelist, queue->tx_skbs, id);
397 dev_kfree_skb_irq(skb);
398 }
399
400 queue->tx.rsp_cons = prod;
401
402 /*
403 * Set a new event, then check for race with update of tx_cons.
404 * Note that it is essential to schedule a callback, no matter
405 * how few buffers are pending. Even if there is space in the
406 * transmit ring, higher layers may be blocked because too much
407 * data is outstanding: in such cases notification from Xen is
408 * likely to be the only kick that we'll get.
409 */
410 queue->tx.sring->rsp_event =
411 prod + ((queue->tx.sring->req_prod - prod) >> 1) + 1;
412 mb(); /* update shared area */
413 } while ((cons == prod) && (prod != queue->tx.sring->rsp_prod));
414
415 xennet_maybe_wake_tx(queue);
416 }
417
418 static struct xen_netif_tx_request *xennet_make_one_txreq(
419 struct netfront_queue *queue, struct sk_buff *skb,
420 struct page *page, unsigned int offset, unsigned int len)
421 {
422 unsigned int id;
423 struct xen_netif_tx_request *tx;
424 grant_ref_t ref;
425
426 len = min_t(unsigned int, PAGE_SIZE - offset, len);
427
428 id = get_id_from_freelist(&queue->tx_skb_freelist, queue->tx_skbs);
429 tx = RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++);
430 ref = gnttab_claim_grant_reference(&queue->gref_tx_head);
431 BUG_ON((signed short)ref < 0);
432
433 gnttab_grant_foreign_access_ref(ref, queue->info->xbdev->otherend_id,
434 page_to_mfn(page), GNTMAP_readonly);
435
436 queue->tx_skbs[id].skb = skb;
437 queue->grant_tx_page[id] = page;
438 queue->grant_tx_ref[id] = ref;
439
440 tx->id = id;
441 tx->gref = ref;
442 tx->offset = offset;
443 tx->size = len;
444 tx->flags = 0;
445
446 return tx;
447 }
448
449 static struct xen_netif_tx_request *xennet_make_txreqs(
450 struct netfront_queue *queue, struct xen_netif_tx_request *tx,
451 struct sk_buff *skb, struct page *page,
452 unsigned int offset, unsigned int len)
453 {
454 /* Skip unused frames from start of page */
455 page += offset >> PAGE_SHIFT;
456 offset &= ~PAGE_MASK;
457
458 while (len) {
459 tx->flags |= XEN_NETTXF_more_data;
460 tx = xennet_make_one_txreq(queue, skb_get(skb),
461 page, offset, len);
462 page++;
463 offset = 0;
464 len -= tx->size;
465 }
466
467 return tx;
468 }
469
470 /*
471 * Count how many ring slots are required to send this skb. Each frag
472 * might be a compound page.
473 */
474 static int xennet_count_skb_slots(struct sk_buff *skb)
475 {
476 int i, frags = skb_shinfo(skb)->nr_frags;
477 int pages;
478
479 pages = PFN_UP(offset_in_page(skb->data) + skb_headlen(skb));
480
481 for (i = 0; i < frags; i++) {
482 skb_frag_t *frag = skb_shinfo(skb)->frags + i;
483 unsigned long size = skb_frag_size(frag);
484 unsigned long offset = frag->page_offset;
485
486 /* Skip unused frames from start of page */
487 offset &= ~PAGE_MASK;
488
489 pages += PFN_UP(offset + size);
490 }
491
492 return pages;
493 }
494
495 static u16 xennet_select_queue(struct net_device *dev, struct sk_buff *skb,
496 void *accel_priv, select_queue_fallback_t fallback)
497 {
498 unsigned int num_queues = dev->real_num_tx_queues;
499 u32 hash;
500 u16 queue_idx;
501
502 /* First, check if there is only one queue */
503 if (num_queues == 1) {
504 queue_idx = 0;
505 } else {
506 hash = skb_get_hash(skb);
507 queue_idx = hash % num_queues;
508 }
509
510 return queue_idx;
511 }
512
513 static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev)
514 {
515 struct netfront_info *np = netdev_priv(dev);
516 struct netfront_stats *tx_stats = this_cpu_ptr(np->tx_stats);
517 struct xen_netif_tx_request *tx, *first_tx;
518 unsigned int i;
519 int notify;
520 int slots;
521 struct page *page;
522 unsigned int offset;
523 unsigned int len;
524 unsigned long flags;
525 struct netfront_queue *queue = NULL;
526 unsigned int num_queues = dev->real_num_tx_queues;
527 u16 queue_index;
528
529 /* Drop the packet if no queues are set up */
530 if (num_queues < 1)
531 goto drop;
532 /* Determine which queue to transmit this SKB on */
533 queue_index = skb_get_queue_mapping(skb);
534 queue = &np->queues[queue_index];
535
536 /* If skb->len is too big for wire format, drop skb and alert
537 * user about misconfiguration.
538 */
539 if (unlikely(skb->len > XEN_NETIF_MAX_TX_SIZE)) {
540 net_alert_ratelimited(
541 "xennet: skb->len = %u, too big for wire format\n",
542 skb->len);
543 goto drop;
544 }
545
546 slots = xennet_count_skb_slots(skb);
547 if (unlikely(slots > MAX_SKB_FRAGS + 1)) {
548 net_dbg_ratelimited("xennet: skb rides the rocket: %d slots, %d bytes\n",
549 slots, skb->len);
550 if (skb_linearize(skb))
551 goto drop;
552 }
553
554 page = virt_to_page(skb->data);
555 offset = offset_in_page(skb->data);
556 len = skb_headlen(skb);
557
558 spin_lock_irqsave(&queue->tx_lock, flags);
559
560 if (unlikely(!netif_carrier_ok(dev) ||
561 (slots > 1 && !xennet_can_sg(dev)) ||
562 netif_needs_gso(skb, netif_skb_features(skb)))) {
563 spin_unlock_irqrestore(&queue->tx_lock, flags);
564 goto drop;
565 }
566
567 /* First request for the linear area. */
568 first_tx = tx = xennet_make_one_txreq(queue, skb,
569 page, offset, len);
570 page++;
571 offset = 0;
572 len -= tx->size;
573
574 if (skb->ip_summed == CHECKSUM_PARTIAL)
575 /* local packet? */
576 tx->flags |= XEN_NETTXF_csum_blank | XEN_NETTXF_data_validated;
577 else if (skb->ip_summed == CHECKSUM_UNNECESSARY)
578 /* remote but checksummed. */
579 tx->flags |= XEN_NETTXF_data_validated;
580
581 /* Optional extra info after the first request. */
582 if (skb_shinfo(skb)->gso_size) {
583 struct xen_netif_extra_info *gso;
584
585 gso = (struct xen_netif_extra_info *)
586 RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++);
587
588 tx->flags |= XEN_NETTXF_extra_info;
589
590 gso->u.gso.size = skb_shinfo(skb)->gso_size;
591 gso->u.gso.type = (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) ?
592 XEN_NETIF_GSO_TYPE_TCPV6 :
593 XEN_NETIF_GSO_TYPE_TCPV4;
594 gso->u.gso.pad = 0;
595 gso->u.gso.features = 0;
596
597 gso->type = XEN_NETIF_EXTRA_TYPE_GSO;
598 gso->flags = 0;
599 }
600
601 /* Requests for the rest of the linear area. */
602 tx = xennet_make_txreqs(queue, tx, skb, page, offset, len);
603
604 /* Requests for all the frags. */
605 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
606 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
607 tx = xennet_make_txreqs(queue, tx, skb,
608 skb_frag_page(frag), frag->page_offset,
609 skb_frag_size(frag));
610 }
611
612 /* First request has the packet length. */
613 first_tx->size = skb->len;
614
615 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->tx, notify);
616 if (notify)
617 notify_remote_via_irq(queue->tx_irq);
618
619 u64_stats_update_begin(&tx_stats->syncp);
620 tx_stats->bytes += skb->len;
621 tx_stats->packets++;
622 u64_stats_update_end(&tx_stats->syncp);
623
624 /* Note: It is not safe to access skb after xennet_tx_buf_gc()! */
625 xennet_tx_buf_gc(queue);
626
627 if (!netfront_tx_slot_available(queue))
628 netif_tx_stop_queue(netdev_get_tx_queue(dev, queue->id));
629
630 spin_unlock_irqrestore(&queue->tx_lock, flags);
631
632 return NETDEV_TX_OK;
633
634 drop:
635 dev->stats.tx_dropped++;
636 dev_kfree_skb_any(skb);
637 return NETDEV_TX_OK;
638 }
639
640 static int xennet_close(struct net_device *dev)
641 {
642 struct netfront_info *np = netdev_priv(dev);
643 unsigned int num_queues = dev->real_num_tx_queues;
644 unsigned int i;
645 struct netfront_queue *queue;
646 netif_tx_stop_all_queues(np->netdev);
647 for (i = 0; i < num_queues; ++i) {
648 queue = &np->queues[i];
649 napi_disable(&queue->napi);
650 }
651 return 0;
652 }
653
654 static void xennet_move_rx_slot(struct netfront_queue *queue, struct sk_buff *skb,
655 grant_ref_t ref)
656 {
657 int new = xennet_rxidx(queue->rx.req_prod_pvt);
658
659 BUG_ON(queue->rx_skbs[new]);
660 queue->rx_skbs[new] = skb;
661 queue->grant_rx_ref[new] = ref;
662 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->id = new;
663 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->gref = ref;
664 queue->rx.req_prod_pvt++;
665 }
666
667 static int xennet_get_extras(struct netfront_queue *queue,
668 struct xen_netif_extra_info *extras,
669 RING_IDX rp)
670
671 {
672 struct xen_netif_extra_info *extra;
673 struct device *dev = &queue->info->netdev->dev;
674 RING_IDX cons = queue->rx.rsp_cons;
675 int err = 0;
676
677 do {
678 struct sk_buff *skb;
679 grant_ref_t ref;
680
681 if (unlikely(cons + 1 == rp)) {
682 if (net_ratelimit())
683 dev_warn(dev, "Missing extra info\n");
684 err = -EBADR;
685 break;
686 }
687
688 extra = (struct xen_netif_extra_info *)
689 RING_GET_RESPONSE(&queue->rx, ++cons);
690
691 if (unlikely(!extra->type ||
692 extra->type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
693 if (net_ratelimit())
694 dev_warn(dev, "Invalid extra type: %d\n",
695 extra->type);
696 err = -EINVAL;
697 } else {
698 memcpy(&extras[extra->type - 1], extra,
699 sizeof(*extra));
700 }
701
702 skb = xennet_get_rx_skb(queue, cons);
703 ref = xennet_get_rx_ref(queue, cons);
704 xennet_move_rx_slot(queue, skb, ref);
705 } while (extra->flags & XEN_NETIF_EXTRA_FLAG_MORE);
706
707 queue->rx.rsp_cons = cons;
708 return err;
709 }
710
711 static int xennet_get_responses(struct netfront_queue *queue,
712 struct netfront_rx_info *rinfo, RING_IDX rp,
713 struct sk_buff_head *list)
714 {
715 struct xen_netif_rx_response *rx = &rinfo->rx;
716 struct xen_netif_extra_info *extras = rinfo->extras;
717 struct device *dev = &queue->info->netdev->dev;
718 RING_IDX cons = queue->rx.rsp_cons;
719 struct sk_buff *skb = xennet_get_rx_skb(queue, cons);
720 grant_ref_t ref = xennet_get_rx_ref(queue, cons);
721 int max = MAX_SKB_FRAGS + (rx->status <= RX_COPY_THRESHOLD);
722 int slots = 1;
723 int err = 0;
724 unsigned long ret;
725
726 if (rx->flags & XEN_NETRXF_extra_info) {
727 err = xennet_get_extras(queue, extras, rp);
728 cons = queue->rx.rsp_cons;
729 }
730
731 for (;;) {
732 if (unlikely(rx->status < 0 ||
733 rx->offset + rx->status > PAGE_SIZE)) {
734 if (net_ratelimit())
735 dev_warn(dev, "rx->offset: %u, size: %d\n",
736 rx->offset, rx->status);
737 xennet_move_rx_slot(queue, skb, ref);
738 err = -EINVAL;
739 goto next;
740 }
741
742 /*
743 * This definitely indicates a bug, either in this driver or in
744 * the backend driver. In future this should flag the bad
745 * situation to the system controller to reboot the backend.
746 */
747 if (ref == GRANT_INVALID_REF) {
748 if (net_ratelimit())
749 dev_warn(dev, "Bad rx response id %d.\n",
750 rx->id);
751 err = -EINVAL;
752 goto next;
753 }
754
755 ret = gnttab_end_foreign_access_ref(ref, 0);
756 BUG_ON(!ret);
757
758 gnttab_release_grant_reference(&queue->gref_rx_head, ref);
759
760 __skb_queue_tail(list, skb);
761
762 next:
763 if (!(rx->flags & XEN_NETRXF_more_data))
764 break;
765
766 if (cons + slots == rp) {
767 if (net_ratelimit())
768 dev_warn(dev, "Need more slots\n");
769 err = -ENOENT;
770 break;
771 }
772
773 rx = RING_GET_RESPONSE(&queue->rx, cons + slots);
774 skb = xennet_get_rx_skb(queue, cons + slots);
775 ref = xennet_get_rx_ref(queue, cons + slots);
776 slots++;
777 }
778
779 if (unlikely(slots > max)) {
780 if (net_ratelimit())
781 dev_warn(dev, "Too many slots\n");
782 err = -E2BIG;
783 }
784
785 if (unlikely(err))
786 queue->rx.rsp_cons = cons + slots;
787
788 return err;
789 }
790
791 static int xennet_set_skb_gso(struct sk_buff *skb,
792 struct xen_netif_extra_info *gso)
793 {
794 if (!gso->u.gso.size) {
795 if (net_ratelimit())
796 pr_warn("GSO size must not be zero\n");
797 return -EINVAL;
798 }
799
800 if (gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV4 &&
801 gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV6) {
802 if (net_ratelimit())
803 pr_warn("Bad GSO type %d\n", gso->u.gso.type);
804 return -EINVAL;
805 }
806
807 skb_shinfo(skb)->gso_size = gso->u.gso.size;
808 skb_shinfo(skb)->gso_type =
809 (gso->u.gso.type == XEN_NETIF_GSO_TYPE_TCPV4) ?
810 SKB_GSO_TCPV4 :
811 SKB_GSO_TCPV6;
812
813 /* Header must be checked, and gso_segs computed. */
814 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
815 skb_shinfo(skb)->gso_segs = 0;
816
817 return 0;
818 }
819
820 static RING_IDX xennet_fill_frags(struct netfront_queue *queue,
821 struct sk_buff *skb,
822 struct sk_buff_head *list)
823 {
824 struct skb_shared_info *shinfo = skb_shinfo(skb);
825 RING_IDX cons = queue->rx.rsp_cons;
826 struct sk_buff *nskb;
827
828 while ((nskb = __skb_dequeue(list))) {
829 struct xen_netif_rx_response *rx =
830 RING_GET_RESPONSE(&queue->rx, ++cons);
831 skb_frag_t *nfrag = &skb_shinfo(nskb)->frags[0];
832
833 if (shinfo->nr_frags == MAX_SKB_FRAGS) {
834 unsigned int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
835
836 BUG_ON(pull_to <= skb_headlen(skb));
837 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
838 }
839 BUG_ON(shinfo->nr_frags >= MAX_SKB_FRAGS);
840
841 skb_add_rx_frag(skb, shinfo->nr_frags, skb_frag_page(nfrag),
842 rx->offset, rx->status, PAGE_SIZE);
843
844 skb_shinfo(nskb)->nr_frags = 0;
845 kfree_skb(nskb);
846 }
847
848 return cons;
849 }
850
851 static int checksum_setup(struct net_device *dev, struct sk_buff *skb)
852 {
853 bool recalculate_partial_csum = false;
854
855 /*
856 * A GSO SKB must be CHECKSUM_PARTIAL. However some buggy
857 * peers can fail to set NETRXF_csum_blank when sending a GSO
858 * frame. In this case force the SKB to CHECKSUM_PARTIAL and
859 * recalculate the partial checksum.
860 */
861 if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) {
862 struct netfront_info *np = netdev_priv(dev);
863 atomic_inc(&np->rx_gso_checksum_fixup);
864 skb->ip_summed = CHECKSUM_PARTIAL;
865 recalculate_partial_csum = true;
866 }
867
868 /* A non-CHECKSUM_PARTIAL SKB does not require setup. */
869 if (skb->ip_summed != CHECKSUM_PARTIAL)
870 return 0;
871
872 return skb_checksum_setup(skb, recalculate_partial_csum);
873 }
874
875 static int handle_incoming_queue(struct netfront_queue *queue,
876 struct sk_buff_head *rxq)
877 {
878 struct netfront_stats *rx_stats = this_cpu_ptr(queue->info->rx_stats);
879 int packets_dropped = 0;
880 struct sk_buff *skb;
881
882 while ((skb = __skb_dequeue(rxq)) != NULL) {
883 int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
884
885 if (pull_to > skb_headlen(skb))
886 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
887
888 /* Ethernet work: Delayed to here as it peeks the header. */
889 skb->protocol = eth_type_trans(skb, queue->info->netdev);
890 skb_reset_network_header(skb);
891
892 if (checksum_setup(queue->info->netdev, skb)) {
893 kfree_skb(skb);
894 packets_dropped++;
895 queue->info->netdev->stats.rx_errors++;
896 continue;
897 }
898
899 u64_stats_update_begin(&rx_stats->syncp);
900 rx_stats->packets++;
901 rx_stats->bytes += skb->len;
902 u64_stats_update_end(&rx_stats->syncp);
903
904 /* Pass it up. */
905 napi_gro_receive(&queue->napi, skb);
906 }
907
908 return packets_dropped;
909 }
910
911 static int xennet_poll(struct napi_struct *napi, int budget)
912 {
913 struct netfront_queue *queue = container_of(napi, struct netfront_queue, napi);
914 struct net_device *dev = queue->info->netdev;
915 struct sk_buff *skb;
916 struct netfront_rx_info rinfo;
917 struct xen_netif_rx_response *rx = &rinfo.rx;
918 struct xen_netif_extra_info *extras = rinfo.extras;
919 RING_IDX i, rp;
920 int work_done;
921 struct sk_buff_head rxq;
922 struct sk_buff_head errq;
923 struct sk_buff_head tmpq;
924 int err;
925
926 spin_lock(&queue->rx_lock);
927
928 skb_queue_head_init(&rxq);
929 skb_queue_head_init(&errq);
930 skb_queue_head_init(&tmpq);
931
932 rp = queue->rx.sring->rsp_prod;
933 rmb(); /* Ensure we see queued responses up to 'rp'. */
934
935 i = queue->rx.rsp_cons;
936 work_done = 0;
937 while ((i != rp) && (work_done < budget)) {
938 memcpy(rx, RING_GET_RESPONSE(&queue->rx, i), sizeof(*rx));
939 memset(extras, 0, sizeof(rinfo.extras));
940
941 err = xennet_get_responses(queue, &rinfo, rp, &tmpq);
942
943 if (unlikely(err)) {
944 err:
945 while ((skb = __skb_dequeue(&tmpq)))
946 __skb_queue_tail(&errq, skb);
947 dev->stats.rx_errors++;
948 i = queue->rx.rsp_cons;
949 continue;
950 }
951
952 skb = __skb_dequeue(&tmpq);
953
954 if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) {
955 struct xen_netif_extra_info *gso;
956 gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1];
957
958 if (unlikely(xennet_set_skb_gso(skb, gso))) {
959 __skb_queue_head(&tmpq, skb);
960 queue->rx.rsp_cons += skb_queue_len(&tmpq);
961 goto err;
962 }
963 }
964
965 NETFRONT_SKB_CB(skb)->pull_to = rx->status;
966 if (NETFRONT_SKB_CB(skb)->pull_to > RX_COPY_THRESHOLD)
967 NETFRONT_SKB_CB(skb)->pull_to = RX_COPY_THRESHOLD;
968
969 skb_shinfo(skb)->frags[0].page_offset = rx->offset;
970 skb_frag_size_set(&skb_shinfo(skb)->frags[0], rx->status);
971 skb->data_len = rx->status;
972 skb->len += rx->status;
973
974 i = xennet_fill_frags(queue, skb, &tmpq);
975
976 if (rx->flags & XEN_NETRXF_csum_blank)
977 skb->ip_summed = CHECKSUM_PARTIAL;
978 else if (rx->flags & XEN_NETRXF_data_validated)
979 skb->ip_summed = CHECKSUM_UNNECESSARY;
980
981 __skb_queue_tail(&rxq, skb);
982
983 queue->rx.rsp_cons = ++i;
984 work_done++;
985 }
986
987 __skb_queue_purge(&errq);
988
989 work_done -= handle_incoming_queue(queue, &rxq);
990
991 xennet_alloc_rx_buffers(queue);
992
993 if (work_done < budget) {
994 int more_to_do = 0;
995
996 napi_complete(napi);
997
998 RING_FINAL_CHECK_FOR_RESPONSES(&queue->rx, more_to_do);
999 if (more_to_do)
1000 napi_schedule(napi);
1001 }
1002
1003 spin_unlock(&queue->rx_lock);
1004
1005 return work_done;
1006 }
1007
1008 static int xennet_change_mtu(struct net_device *dev, int mtu)
1009 {
1010 int max = xennet_can_sg(dev) ? XEN_NETIF_MAX_TX_SIZE : ETH_DATA_LEN;
1011
1012 if (mtu > max)
1013 return -EINVAL;
1014 dev->mtu = mtu;
1015 return 0;
1016 }
1017
1018 static struct rtnl_link_stats64 *xennet_get_stats64(struct net_device *dev,
1019 struct rtnl_link_stats64 *tot)
1020 {
1021 struct netfront_info *np = netdev_priv(dev);
1022 int cpu;
1023
1024 for_each_possible_cpu(cpu) {
1025 struct netfront_stats *rx_stats = per_cpu_ptr(np->rx_stats, cpu);
1026 struct netfront_stats *tx_stats = per_cpu_ptr(np->tx_stats, cpu);
1027 u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
1028 unsigned int start;
1029
1030 do {
1031 start = u64_stats_fetch_begin_irq(&tx_stats->syncp);
1032 tx_packets = tx_stats->packets;
1033 tx_bytes = tx_stats->bytes;
1034 } while (u64_stats_fetch_retry_irq(&tx_stats->syncp, start));
1035
1036 do {
1037 start = u64_stats_fetch_begin_irq(&rx_stats->syncp);
1038 rx_packets = rx_stats->packets;
1039 rx_bytes = rx_stats->bytes;
1040 } while (u64_stats_fetch_retry_irq(&rx_stats->syncp, start));
1041
1042 tot->rx_packets += rx_packets;
1043 tot->tx_packets += tx_packets;
1044 tot->rx_bytes += rx_bytes;
1045 tot->tx_bytes += tx_bytes;
1046 }
1047
1048 tot->rx_errors = dev->stats.rx_errors;
1049 tot->tx_dropped = dev->stats.tx_dropped;
1050
1051 return tot;
1052 }
1053
1054 static void xennet_release_tx_bufs(struct netfront_queue *queue)
1055 {
1056 struct sk_buff *skb;
1057 int i;
1058
1059 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1060 /* Skip over entries which are actually freelist references */
1061 if (skb_entry_is_link(&queue->tx_skbs[i]))
1062 continue;
1063
1064 skb = queue->tx_skbs[i].skb;
1065 get_page(queue->grant_tx_page[i]);
1066 gnttab_end_foreign_access(queue->grant_tx_ref[i],
1067 GNTMAP_readonly,
1068 (unsigned long)page_address(queue->grant_tx_page[i]));
1069 queue->grant_tx_page[i] = NULL;
1070 queue->grant_tx_ref[i] = GRANT_INVALID_REF;
1071 add_id_to_freelist(&queue->tx_skb_freelist, queue->tx_skbs, i);
1072 dev_kfree_skb_irq(skb);
1073 }
1074 }
1075
1076 static void xennet_release_rx_bufs(struct netfront_queue *queue)
1077 {
1078 int id, ref;
1079
1080 spin_lock_bh(&queue->rx_lock);
1081
1082 for (id = 0; id < NET_RX_RING_SIZE; id++) {
1083 struct sk_buff *skb;
1084 struct page *page;
1085
1086 skb = queue->rx_skbs[id];
1087 if (!skb)
1088 continue;
1089
1090 ref = queue->grant_rx_ref[id];
1091 if (ref == GRANT_INVALID_REF)
1092 continue;
1093
1094 page = skb_frag_page(&skb_shinfo(skb)->frags[0]);
1095
1096 /* gnttab_end_foreign_access() needs a page ref until
1097 * foreign access is ended (which may be deferred).
1098 */
1099 get_page(page);
1100 gnttab_end_foreign_access(ref, 0,
1101 (unsigned long)page_address(page));
1102 queue->grant_rx_ref[id] = GRANT_INVALID_REF;
1103
1104 kfree_skb(skb);
1105 }
1106
1107 spin_unlock_bh(&queue->rx_lock);
1108 }
1109
1110 static netdev_features_t xennet_fix_features(struct net_device *dev,
1111 netdev_features_t features)
1112 {
1113 struct netfront_info *np = netdev_priv(dev);
1114 int val;
1115
1116 if (features & NETIF_F_SG) {
1117 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, "feature-sg",
1118 "%d", &val) < 0)
1119 val = 0;
1120
1121 if (!val)
1122 features &= ~NETIF_F_SG;
1123 }
1124
1125 if (features & NETIF_F_IPV6_CSUM) {
1126 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1127 "feature-ipv6-csum-offload", "%d", &val) < 0)
1128 val = 0;
1129
1130 if (!val)
1131 features &= ~NETIF_F_IPV6_CSUM;
1132 }
1133
1134 if (features & NETIF_F_TSO) {
1135 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1136 "feature-gso-tcpv4", "%d", &val) < 0)
1137 val = 0;
1138
1139 if (!val)
1140 features &= ~NETIF_F_TSO;
1141 }
1142
1143 if (features & NETIF_F_TSO6) {
1144 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1145 "feature-gso-tcpv6", "%d", &val) < 0)
1146 val = 0;
1147
1148 if (!val)
1149 features &= ~NETIF_F_TSO6;
1150 }
1151
1152 return features;
1153 }
1154
1155 static int xennet_set_features(struct net_device *dev,
1156 netdev_features_t features)
1157 {
1158 if (!(features & NETIF_F_SG) && dev->mtu > ETH_DATA_LEN) {
1159 netdev_info(dev, "Reducing MTU because no SG offload");
1160 dev->mtu = ETH_DATA_LEN;
1161 }
1162
1163 return 0;
1164 }
1165
1166 static irqreturn_t xennet_tx_interrupt(int irq, void *dev_id)
1167 {
1168 struct netfront_queue *queue = dev_id;
1169 unsigned long flags;
1170
1171 spin_lock_irqsave(&queue->tx_lock, flags);
1172 xennet_tx_buf_gc(queue);
1173 spin_unlock_irqrestore(&queue->tx_lock, flags);
1174
1175 return IRQ_HANDLED;
1176 }
1177
1178 static irqreturn_t xennet_rx_interrupt(int irq, void *dev_id)
1179 {
1180 struct netfront_queue *queue = dev_id;
1181 struct net_device *dev = queue->info->netdev;
1182
1183 if (likely(netif_carrier_ok(dev) &&
1184 RING_HAS_UNCONSUMED_RESPONSES(&queue->rx)))
1185 napi_schedule(&queue->napi);
1186
1187 return IRQ_HANDLED;
1188 }
1189
1190 static irqreturn_t xennet_interrupt(int irq, void *dev_id)
1191 {
1192 xennet_tx_interrupt(irq, dev_id);
1193 xennet_rx_interrupt(irq, dev_id);
1194 return IRQ_HANDLED;
1195 }
1196
1197 #ifdef CONFIG_NET_POLL_CONTROLLER
1198 static void xennet_poll_controller(struct net_device *dev)
1199 {
1200 /* Poll each queue */
1201 struct netfront_info *info = netdev_priv(dev);
1202 unsigned int num_queues = dev->real_num_tx_queues;
1203 unsigned int i;
1204 for (i = 0; i < num_queues; ++i)
1205 xennet_interrupt(0, &info->queues[i]);
1206 }
1207 #endif
1208
1209 static const struct net_device_ops xennet_netdev_ops = {
1210 .ndo_open = xennet_open,
1211 .ndo_stop = xennet_close,
1212 .ndo_start_xmit = xennet_start_xmit,
1213 .ndo_change_mtu = xennet_change_mtu,
1214 .ndo_get_stats64 = xennet_get_stats64,
1215 .ndo_set_mac_address = eth_mac_addr,
1216 .ndo_validate_addr = eth_validate_addr,
1217 .ndo_fix_features = xennet_fix_features,
1218 .ndo_set_features = xennet_set_features,
1219 .ndo_select_queue = xennet_select_queue,
1220 #ifdef CONFIG_NET_POLL_CONTROLLER
1221 .ndo_poll_controller = xennet_poll_controller,
1222 #endif
1223 };
1224
1225 static void xennet_free_netdev(struct net_device *netdev)
1226 {
1227 struct netfront_info *np = netdev_priv(netdev);
1228
1229 free_percpu(np->rx_stats);
1230 free_percpu(np->tx_stats);
1231 free_netdev(netdev);
1232 }
1233
1234 static struct net_device *xennet_create_dev(struct xenbus_device *dev)
1235 {
1236 int err;
1237 struct net_device *netdev;
1238 struct netfront_info *np;
1239
1240 netdev = alloc_etherdev_mq(sizeof(struct netfront_info), xennet_max_queues);
1241 if (!netdev)
1242 return ERR_PTR(-ENOMEM);
1243
1244 np = netdev_priv(netdev);
1245 np->xbdev = dev;
1246
1247 np->queues = NULL;
1248
1249 err = -ENOMEM;
1250 np->rx_stats = netdev_alloc_pcpu_stats(struct netfront_stats);
1251 if (np->rx_stats == NULL)
1252 goto exit;
1253 np->tx_stats = netdev_alloc_pcpu_stats(struct netfront_stats);
1254 if (np->tx_stats == NULL)
1255 goto exit;
1256
1257 netdev->netdev_ops = &xennet_netdev_ops;
1258
1259 netdev->features = NETIF_F_IP_CSUM | NETIF_F_RXCSUM |
1260 NETIF_F_GSO_ROBUST;
1261 netdev->hw_features = NETIF_F_SG |
1262 NETIF_F_IPV6_CSUM |
1263 NETIF_F_TSO | NETIF_F_TSO6;
1264
1265 /*
1266 * Assume that all hw features are available for now. This set
1267 * will be adjusted by the call to netdev_update_features() in
1268 * xennet_connect() which is the earliest point where we can
1269 * negotiate with the backend regarding supported features.
1270 */
1271 netdev->features |= netdev->hw_features;
1272
1273 netdev->ethtool_ops = &xennet_ethtool_ops;
1274 SET_NETDEV_DEV(netdev, &dev->dev);
1275
1276 np->netdev = netdev;
1277
1278 netif_carrier_off(netdev);
1279
1280 return netdev;
1281
1282 exit:
1283 xennet_free_netdev(netdev);
1284 return ERR_PTR(err);
1285 }
1286
1287 /**
1288 * Entry point to this code when a new device is created. Allocate the basic
1289 * structures and the ring buffers for communication with the backend, and
1290 * inform the backend of the appropriate details for those.
1291 */
1292 static int netfront_probe(struct xenbus_device *dev,
1293 const struct xenbus_device_id *id)
1294 {
1295 int err;
1296 struct net_device *netdev;
1297 struct netfront_info *info;
1298
1299 netdev = xennet_create_dev(dev);
1300 if (IS_ERR(netdev)) {
1301 err = PTR_ERR(netdev);
1302 xenbus_dev_fatal(dev, err, "creating netdev");
1303 return err;
1304 }
1305
1306 info = netdev_priv(netdev);
1307 dev_set_drvdata(&dev->dev, info);
1308 #ifdef CONFIG_SYSFS
1309 info->netdev->sysfs_groups[0] = &xennet_dev_group;
1310 #endif
1311 err = register_netdev(info->netdev);
1312 if (err) {
1313 pr_warn("%s: register_netdev err=%d\n", __func__, err);
1314 goto fail;
1315 }
1316
1317 return 0;
1318
1319 fail:
1320 xennet_free_netdev(netdev);
1321 dev_set_drvdata(&dev->dev, NULL);
1322 return err;
1323 }
1324
1325 static void xennet_end_access(int ref, void *page)
1326 {
1327 /* This frees the page as a side-effect */
1328 if (ref != GRANT_INVALID_REF)
1329 gnttab_end_foreign_access(ref, 0, (unsigned long)page);
1330 }
1331
1332 static void xennet_disconnect_backend(struct netfront_info *info)
1333 {
1334 unsigned int i = 0;
1335 unsigned int num_queues = info->netdev->real_num_tx_queues;
1336
1337 netif_carrier_off(info->netdev);
1338
1339 for (i = 0; i < num_queues; ++i) {
1340 struct netfront_queue *queue = &info->queues[i];
1341
1342 if (queue->tx_irq && (queue->tx_irq == queue->rx_irq))
1343 unbind_from_irqhandler(queue->tx_irq, queue);
1344 if (queue->tx_irq && (queue->tx_irq != queue->rx_irq)) {
1345 unbind_from_irqhandler(queue->tx_irq, queue);
1346 unbind_from_irqhandler(queue->rx_irq, queue);
1347 }
1348 queue->tx_evtchn = queue->rx_evtchn = 0;
1349 queue->tx_irq = queue->rx_irq = 0;
1350
1351 napi_synchronize(&queue->napi);
1352
1353 xennet_release_tx_bufs(queue);
1354 xennet_release_rx_bufs(queue);
1355 gnttab_free_grant_references(queue->gref_tx_head);
1356 gnttab_free_grant_references(queue->gref_rx_head);
1357
1358 /* End access and free the pages */
1359 xennet_end_access(queue->tx_ring_ref, queue->tx.sring);
1360 xennet_end_access(queue->rx_ring_ref, queue->rx.sring);
1361
1362 queue->tx_ring_ref = GRANT_INVALID_REF;
1363 queue->rx_ring_ref = GRANT_INVALID_REF;
1364 queue->tx.sring = NULL;
1365 queue->rx.sring = NULL;
1366 }
1367 }
1368
1369 /**
1370 * We are reconnecting to the backend, due to a suspend/resume, or a backend
1371 * driver restart. We tear down our netif structure and recreate it, but
1372 * leave the device-layer structures intact so that this is transparent to the
1373 * rest of the kernel.
1374 */
1375 static int netfront_resume(struct xenbus_device *dev)
1376 {
1377 struct netfront_info *info = dev_get_drvdata(&dev->dev);
1378
1379 dev_dbg(&dev->dev, "%s\n", dev->nodename);
1380
1381 xennet_disconnect_backend(info);
1382 return 0;
1383 }
1384
1385 static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[])
1386 {
1387 char *s, *e, *macstr;
1388 int i;
1389
1390 macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL);
1391 if (IS_ERR(macstr))
1392 return PTR_ERR(macstr);
1393
1394 for (i = 0; i < ETH_ALEN; i++) {
1395 mac[i] = simple_strtoul(s, &e, 16);
1396 if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) {
1397 kfree(macstr);
1398 return -ENOENT;
1399 }
1400 s = e+1;
1401 }
1402
1403 kfree(macstr);
1404 return 0;
1405 }
1406
1407 static int setup_netfront_single(struct netfront_queue *queue)
1408 {
1409 int err;
1410
1411 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn);
1412 if (err < 0)
1413 goto fail;
1414
1415 err = bind_evtchn_to_irqhandler(queue->tx_evtchn,
1416 xennet_interrupt,
1417 0, queue->info->netdev->name, queue);
1418 if (err < 0)
1419 goto bind_fail;
1420 queue->rx_evtchn = queue->tx_evtchn;
1421 queue->rx_irq = queue->tx_irq = err;
1422
1423 return 0;
1424
1425 bind_fail:
1426 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn);
1427 queue->tx_evtchn = 0;
1428 fail:
1429 return err;
1430 }
1431
1432 static int setup_netfront_split(struct netfront_queue *queue)
1433 {
1434 int err;
1435
1436 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn);
1437 if (err < 0)
1438 goto fail;
1439 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->rx_evtchn);
1440 if (err < 0)
1441 goto alloc_rx_evtchn_fail;
1442
1443 snprintf(queue->tx_irq_name, sizeof(queue->tx_irq_name),
1444 "%s-tx", queue->name);
1445 err = bind_evtchn_to_irqhandler(queue->tx_evtchn,
1446 xennet_tx_interrupt,
1447 0, queue->tx_irq_name, queue);
1448 if (err < 0)
1449 goto bind_tx_fail;
1450 queue->tx_irq = err;
1451
1452 snprintf(queue->rx_irq_name, sizeof(queue->rx_irq_name),
1453 "%s-rx", queue->name);
1454 err = bind_evtchn_to_irqhandler(queue->rx_evtchn,
1455 xennet_rx_interrupt,
1456 0, queue->rx_irq_name, queue);
1457 if (err < 0)
1458 goto bind_rx_fail;
1459 queue->rx_irq = err;
1460
1461 return 0;
1462
1463 bind_rx_fail:
1464 unbind_from_irqhandler(queue->tx_irq, queue);
1465 queue->tx_irq = 0;
1466 bind_tx_fail:
1467 xenbus_free_evtchn(queue->info->xbdev, queue->rx_evtchn);
1468 queue->rx_evtchn = 0;
1469 alloc_rx_evtchn_fail:
1470 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn);
1471 queue->tx_evtchn = 0;
1472 fail:
1473 return err;
1474 }
1475
1476 static int setup_netfront(struct xenbus_device *dev,
1477 struct netfront_queue *queue, unsigned int feature_split_evtchn)
1478 {
1479 struct xen_netif_tx_sring *txs;
1480 struct xen_netif_rx_sring *rxs;
1481 grant_ref_t gref;
1482 int err;
1483
1484 queue->tx_ring_ref = GRANT_INVALID_REF;
1485 queue->rx_ring_ref = GRANT_INVALID_REF;
1486 queue->rx.sring = NULL;
1487 queue->tx.sring = NULL;
1488
1489 txs = (struct xen_netif_tx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1490 if (!txs) {
1491 err = -ENOMEM;
1492 xenbus_dev_fatal(dev, err, "allocating tx ring page");
1493 goto fail;
1494 }
1495 SHARED_RING_INIT(txs);
1496 FRONT_RING_INIT(&queue->tx, txs, PAGE_SIZE);
1497
1498 err = xenbus_grant_ring(dev, txs, 1, &gref);
1499 if (err < 0)
1500 goto grant_tx_ring_fail;
1501 queue->tx_ring_ref = gref;
1502
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 alloc_rx_ring_fail;
1508 }
1509 SHARED_RING_INIT(rxs);
1510 FRONT_RING_INIT(&queue->rx, rxs, PAGE_SIZE);
1511
1512 err = xenbus_grant_ring(dev, rxs, 1, &gref);
1513 if (err < 0)
1514 goto grant_rx_ring_fail;
1515 queue->rx_ring_ref = gref;
1516
1517 if (feature_split_evtchn)
1518 err = setup_netfront_split(queue);
1519 /* setup single event channel if
1520 * a) feature-split-event-channels == 0
1521 * b) feature-split-event-channels == 1 but failed to setup
1522 */
1523 if (!feature_split_evtchn || (feature_split_evtchn && err))
1524 err = setup_netfront_single(queue);
1525
1526 if (err)
1527 goto alloc_evtchn_fail;
1528
1529 return 0;
1530
1531 /* If we fail to setup netfront, it is safe to just revoke access to
1532 * granted pages because backend is not accessing it at this point.
1533 */
1534 alloc_evtchn_fail:
1535 gnttab_end_foreign_access_ref(queue->rx_ring_ref, 0);
1536 grant_rx_ring_fail:
1537 free_page((unsigned long)rxs);
1538 alloc_rx_ring_fail:
1539 gnttab_end_foreign_access_ref(queue->tx_ring_ref, 0);
1540 grant_tx_ring_fail:
1541 free_page((unsigned long)txs);
1542 fail:
1543 return err;
1544 }
1545
1546 /* Queue-specific initialisation
1547 * This used to be done in xennet_create_dev() but must now
1548 * be run per-queue.
1549 */
1550 static int xennet_init_queue(struct netfront_queue *queue)
1551 {
1552 unsigned short i;
1553 int err = 0;
1554
1555 spin_lock_init(&queue->tx_lock);
1556 spin_lock_init(&queue->rx_lock);
1557
1558 setup_timer(&queue->rx_refill_timer, rx_refill_timeout,
1559 (unsigned long)queue);
1560
1561 snprintf(queue->name, sizeof(queue->name), "%s-q%u",
1562 queue->info->netdev->name, queue->id);
1563
1564 /* Initialise tx_skbs as a free chain containing every entry. */
1565 queue->tx_skb_freelist = 0;
1566 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1567 skb_entry_set_link(&queue->tx_skbs[i], i+1);
1568 queue->grant_tx_ref[i] = GRANT_INVALID_REF;
1569 queue->grant_tx_page[i] = NULL;
1570 }
1571
1572 /* Clear out rx_skbs */
1573 for (i = 0; i < NET_RX_RING_SIZE; i++) {
1574 queue->rx_skbs[i] = NULL;
1575 queue->grant_rx_ref[i] = GRANT_INVALID_REF;
1576 }
1577
1578 /* A grant for every tx ring slot */
1579 if (gnttab_alloc_grant_references(NET_TX_RING_SIZE,
1580 &queue->gref_tx_head) < 0) {
1581 pr_alert("can't alloc tx grant refs\n");
1582 err = -ENOMEM;
1583 goto exit;
1584 }
1585
1586 /* A grant for every rx ring slot */
1587 if (gnttab_alloc_grant_references(NET_RX_RING_SIZE,
1588 &queue->gref_rx_head) < 0) {
1589 pr_alert("can't alloc rx grant refs\n");
1590 err = -ENOMEM;
1591 goto exit_free_tx;
1592 }
1593
1594 return 0;
1595
1596 exit_free_tx:
1597 gnttab_free_grant_references(queue->gref_tx_head);
1598 exit:
1599 return err;
1600 }
1601
1602 static int write_queue_xenstore_keys(struct netfront_queue *queue,
1603 struct xenbus_transaction *xbt, int write_hierarchical)
1604 {
1605 /* Write the queue-specific keys into XenStore in the traditional
1606 * way for a single queue, or in a queue subkeys for multiple
1607 * queues.
1608 */
1609 struct xenbus_device *dev = queue->info->xbdev;
1610 int err;
1611 const char *message;
1612 char *path;
1613 size_t pathsize;
1614
1615 /* Choose the correct place to write the keys */
1616 if (write_hierarchical) {
1617 pathsize = strlen(dev->nodename) + 10;
1618 path = kzalloc(pathsize, GFP_KERNEL);
1619 if (!path) {
1620 err = -ENOMEM;
1621 message = "out of memory while writing ring references";
1622 goto error;
1623 }
1624 snprintf(path, pathsize, "%s/queue-%u",
1625 dev->nodename, queue->id);
1626 } else {
1627 path = (char *)dev->nodename;
1628 }
1629
1630 /* Write ring references */
1631 err = xenbus_printf(*xbt, path, "tx-ring-ref", "%u",
1632 queue->tx_ring_ref);
1633 if (err) {
1634 message = "writing tx-ring-ref";
1635 goto error;
1636 }
1637
1638 err = xenbus_printf(*xbt, path, "rx-ring-ref", "%u",
1639 queue->rx_ring_ref);
1640 if (err) {
1641 message = "writing rx-ring-ref";
1642 goto error;
1643 }
1644
1645 /* Write event channels; taking into account both shared
1646 * and split event channel scenarios.
1647 */
1648 if (queue->tx_evtchn == queue->rx_evtchn) {
1649 /* Shared event channel */
1650 err = xenbus_printf(*xbt, path,
1651 "event-channel", "%u", queue->tx_evtchn);
1652 if (err) {
1653 message = "writing event-channel";
1654 goto error;
1655 }
1656 } else {
1657 /* Split event channels */
1658 err = xenbus_printf(*xbt, path,
1659 "event-channel-tx", "%u", queue->tx_evtchn);
1660 if (err) {
1661 message = "writing event-channel-tx";
1662 goto error;
1663 }
1664
1665 err = xenbus_printf(*xbt, path,
1666 "event-channel-rx", "%u", queue->rx_evtchn);
1667 if (err) {
1668 message = "writing event-channel-rx";
1669 goto error;
1670 }
1671 }
1672
1673 if (write_hierarchical)
1674 kfree(path);
1675 return 0;
1676
1677 error:
1678 if (write_hierarchical)
1679 kfree(path);
1680 xenbus_dev_fatal(dev, err, "%s", message);
1681 return err;
1682 }
1683
1684 static void xennet_destroy_queues(struct netfront_info *info)
1685 {
1686 unsigned int i;
1687
1688 rtnl_lock();
1689
1690 for (i = 0; i < info->netdev->real_num_tx_queues; i++) {
1691 struct netfront_queue *queue = &info->queues[i];
1692
1693 if (netif_running(info->netdev))
1694 napi_disable(&queue->napi);
1695 del_timer_sync(&queue->rx_refill_timer);
1696 netif_napi_del(&queue->napi);
1697 }
1698
1699 rtnl_unlock();
1700
1701 kfree(info->queues);
1702 info->queues = NULL;
1703 }
1704
1705 static int xennet_create_queues(struct netfront_info *info,
1706 unsigned int num_queues)
1707 {
1708 unsigned int i;
1709 int ret;
1710
1711 info->queues = kcalloc(num_queues, sizeof(struct netfront_queue),
1712 GFP_KERNEL);
1713 if (!info->queues)
1714 return -ENOMEM;
1715
1716 rtnl_lock();
1717
1718 for (i = 0; i < num_queues; i++) {
1719 struct netfront_queue *queue = &info->queues[i];
1720
1721 queue->id = i;
1722 queue->info = info;
1723
1724 ret = xennet_init_queue(queue);
1725 if (ret < 0) {
1726 dev_warn(&info->netdev->dev,
1727 "only created %d queues\n", i);
1728 num_queues = i;
1729 break;
1730 }
1731
1732 netif_napi_add(queue->info->netdev, &queue->napi,
1733 xennet_poll, 64);
1734 if (netif_running(info->netdev))
1735 napi_enable(&queue->napi);
1736 }
1737
1738 netif_set_real_num_tx_queues(info->netdev, num_queues);
1739
1740 rtnl_unlock();
1741
1742 if (num_queues == 0) {
1743 dev_err(&info->netdev->dev, "no queues\n");
1744 return -EINVAL;
1745 }
1746 return 0;
1747 }
1748
1749 /* Common code used when first setting up, and when resuming. */
1750 static int talk_to_netback(struct xenbus_device *dev,
1751 struct netfront_info *info)
1752 {
1753 const char *message;
1754 struct xenbus_transaction xbt;
1755 int err;
1756 unsigned int feature_split_evtchn;
1757 unsigned int i = 0;
1758 unsigned int max_queues = 0;
1759 struct netfront_queue *queue = NULL;
1760 unsigned int num_queues = 1;
1761
1762 info->netdev->irq = 0;
1763
1764 /* Check if backend supports multiple queues */
1765 err = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
1766 "multi-queue-max-queues", "%u", &max_queues);
1767 if (err < 0)
1768 max_queues = 1;
1769 num_queues = min(max_queues, xennet_max_queues);
1770
1771 /* Check feature-split-event-channels */
1772 err = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
1773 "feature-split-event-channels", "%u",
1774 &feature_split_evtchn);
1775 if (err < 0)
1776 feature_split_evtchn = 0;
1777
1778 /* Read mac addr. */
1779 err = xen_net_read_mac(dev, info->netdev->dev_addr);
1780 if (err) {
1781 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
1782 goto out;
1783 }
1784
1785 if (info->queues)
1786 xennet_destroy_queues(info);
1787
1788 err = xennet_create_queues(info, num_queues);
1789 if (err < 0)
1790 goto destroy_ring;
1791
1792 /* Create shared ring, alloc event channel -- for each queue */
1793 for (i = 0; i < num_queues; ++i) {
1794 queue = &info->queues[i];
1795 err = setup_netfront(dev, queue, feature_split_evtchn);
1796 if (err) {
1797 /* setup_netfront() will tidy up the current
1798 * queue on error, but we need to clean up
1799 * those already allocated.
1800 */
1801 if (i > 0) {
1802 rtnl_lock();
1803 netif_set_real_num_tx_queues(info->netdev, i);
1804 rtnl_unlock();
1805 goto destroy_ring;
1806 } else {
1807 goto out;
1808 }
1809 }
1810 }
1811
1812 again:
1813 err = xenbus_transaction_start(&xbt);
1814 if (err) {
1815 xenbus_dev_fatal(dev, err, "starting transaction");
1816 goto destroy_ring;
1817 }
1818
1819 if (num_queues == 1) {
1820 err = write_queue_xenstore_keys(&info->queues[0], &xbt, 0); /* flat */
1821 if (err)
1822 goto abort_transaction_no_dev_fatal;
1823 } else {
1824 /* Write the number of queues */
1825 err = xenbus_printf(xbt, dev->nodename, "multi-queue-num-queues",
1826 "%u", num_queues);
1827 if (err) {
1828 message = "writing multi-queue-num-queues";
1829 goto abort_transaction_no_dev_fatal;
1830 }
1831
1832 /* Write the keys for each queue */
1833 for (i = 0; i < num_queues; ++i) {
1834 queue = &info->queues[i];
1835 err = write_queue_xenstore_keys(queue, &xbt, 1); /* hierarchical */
1836 if (err)
1837 goto abort_transaction_no_dev_fatal;
1838 }
1839 }
1840
1841 /* The remaining keys are not queue-specific */
1842 err = xenbus_printf(xbt, dev->nodename, "request-rx-copy", "%u",
1843 1);
1844 if (err) {
1845 message = "writing request-rx-copy";
1846 goto abort_transaction;
1847 }
1848
1849 err = xenbus_printf(xbt, dev->nodename, "feature-rx-notify", "%d", 1);
1850 if (err) {
1851 message = "writing feature-rx-notify";
1852 goto abort_transaction;
1853 }
1854
1855 err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", 1);
1856 if (err) {
1857 message = "writing feature-sg";
1858 goto abort_transaction;
1859 }
1860
1861 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4", "%d", 1);
1862 if (err) {
1863 message = "writing feature-gso-tcpv4";
1864 goto abort_transaction;
1865 }
1866
1867 err = xenbus_write(xbt, dev->nodename, "feature-gso-tcpv6", "1");
1868 if (err) {
1869 message = "writing feature-gso-tcpv6";
1870 goto abort_transaction;
1871 }
1872
1873 err = xenbus_write(xbt, dev->nodename, "feature-ipv6-csum-offload",
1874 "1");
1875 if (err) {
1876 message = "writing feature-ipv6-csum-offload";
1877 goto abort_transaction;
1878 }
1879
1880 err = xenbus_transaction_end(xbt, 0);
1881 if (err) {
1882 if (err == -EAGAIN)
1883 goto again;
1884 xenbus_dev_fatal(dev, err, "completing transaction");
1885 goto destroy_ring;
1886 }
1887
1888 return 0;
1889
1890 abort_transaction:
1891 xenbus_dev_fatal(dev, err, "%s", message);
1892 abort_transaction_no_dev_fatal:
1893 xenbus_transaction_end(xbt, 1);
1894 destroy_ring:
1895 xennet_disconnect_backend(info);
1896 kfree(info->queues);
1897 info->queues = NULL;
1898 out:
1899 return err;
1900 }
1901
1902 static int xennet_connect(struct net_device *dev)
1903 {
1904 struct netfront_info *np = netdev_priv(dev);
1905 unsigned int num_queues = 0;
1906 int err;
1907 unsigned int feature_rx_copy;
1908 unsigned int j = 0;
1909 struct netfront_queue *queue = NULL;
1910
1911 err = xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1912 "feature-rx-copy", "%u", &feature_rx_copy);
1913 if (err != 1)
1914 feature_rx_copy = 0;
1915
1916 if (!feature_rx_copy) {
1917 dev_info(&dev->dev,
1918 "backend does not support copying receive path\n");
1919 return -ENODEV;
1920 }
1921
1922 err = talk_to_netback(np->xbdev, np);
1923 if (err)
1924 return err;
1925
1926 /* talk_to_netback() sets the correct number of queues */
1927 num_queues = dev->real_num_tx_queues;
1928
1929 rtnl_lock();
1930 netdev_update_features(dev);
1931 rtnl_unlock();
1932
1933 /*
1934 * All public and private state should now be sane. Get
1935 * ready to start sending and receiving packets and give the driver
1936 * domain a kick because we've probably just requeued some
1937 * packets.
1938 */
1939 netif_carrier_on(np->netdev);
1940 for (j = 0; j < num_queues; ++j) {
1941 queue = &np->queues[j];
1942
1943 notify_remote_via_irq(queue->tx_irq);
1944 if (queue->tx_irq != queue->rx_irq)
1945 notify_remote_via_irq(queue->rx_irq);
1946
1947 spin_lock_irq(&queue->tx_lock);
1948 xennet_tx_buf_gc(queue);
1949 spin_unlock_irq(&queue->tx_lock);
1950
1951 spin_lock_bh(&queue->rx_lock);
1952 xennet_alloc_rx_buffers(queue);
1953 spin_unlock_bh(&queue->rx_lock);
1954 }
1955
1956 return 0;
1957 }
1958
1959 /**
1960 * Callback received when the backend's state changes.
1961 */
1962 static void netback_changed(struct xenbus_device *dev,
1963 enum xenbus_state backend_state)
1964 {
1965 struct netfront_info *np = dev_get_drvdata(&dev->dev);
1966 struct net_device *netdev = np->netdev;
1967
1968 dev_dbg(&dev->dev, "%s\n", xenbus_strstate(backend_state));
1969
1970 switch (backend_state) {
1971 case XenbusStateInitialising:
1972 case XenbusStateInitialised:
1973 case XenbusStateReconfiguring:
1974 case XenbusStateReconfigured:
1975 case XenbusStateUnknown:
1976 break;
1977
1978 case XenbusStateInitWait:
1979 if (dev->state != XenbusStateInitialising)
1980 break;
1981 if (xennet_connect(netdev) != 0)
1982 break;
1983 xenbus_switch_state(dev, XenbusStateConnected);
1984 break;
1985
1986 case XenbusStateConnected:
1987 netdev_notify_peers(netdev);
1988 break;
1989
1990 case XenbusStateClosed:
1991 if (dev->state == XenbusStateClosed)
1992 break;
1993 /* Missed the backend's CLOSING state -- fallthrough */
1994 case XenbusStateClosing:
1995 xenbus_frontend_closed(dev);
1996 break;
1997 }
1998 }
1999
2000 static const struct xennet_stat {
2001 char name[ETH_GSTRING_LEN];
2002 u16 offset;
2003 } xennet_stats[] = {
2004 {
2005 "rx_gso_checksum_fixup",
2006 offsetof(struct netfront_info, rx_gso_checksum_fixup)
2007 },
2008 };
2009
2010 static int xennet_get_sset_count(struct net_device *dev, int string_set)
2011 {
2012 switch (string_set) {
2013 case ETH_SS_STATS:
2014 return ARRAY_SIZE(xennet_stats);
2015 default:
2016 return -EINVAL;
2017 }
2018 }
2019
2020 static void xennet_get_ethtool_stats(struct net_device *dev,
2021 struct ethtool_stats *stats, u64 * data)
2022 {
2023 void *np = netdev_priv(dev);
2024 int i;
2025
2026 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
2027 data[i] = atomic_read((atomic_t *)(np + xennet_stats[i].offset));
2028 }
2029
2030 static void xennet_get_strings(struct net_device *dev, u32 stringset, u8 * data)
2031 {
2032 int i;
2033
2034 switch (stringset) {
2035 case ETH_SS_STATS:
2036 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
2037 memcpy(data + i * ETH_GSTRING_LEN,
2038 xennet_stats[i].name, ETH_GSTRING_LEN);
2039 break;
2040 }
2041 }
2042
2043 static const struct ethtool_ops xennet_ethtool_ops =
2044 {
2045 .get_link = ethtool_op_get_link,
2046
2047 .get_sset_count = xennet_get_sset_count,
2048 .get_ethtool_stats = xennet_get_ethtool_stats,
2049 .get_strings = xennet_get_strings,
2050 };
2051
2052 #ifdef CONFIG_SYSFS
2053 static ssize_t show_rxbuf(struct device *dev,
2054 struct device_attribute *attr, char *buf)
2055 {
2056 return sprintf(buf, "%lu\n", NET_RX_RING_SIZE);
2057 }
2058
2059 static ssize_t store_rxbuf(struct device *dev,
2060 struct device_attribute *attr,
2061 const char *buf, size_t len)
2062 {
2063 char *endp;
2064 unsigned long target;
2065
2066 if (!capable(CAP_NET_ADMIN))
2067 return -EPERM;
2068
2069 target = simple_strtoul(buf, &endp, 0);
2070 if (endp == buf)
2071 return -EBADMSG;
2072
2073 /* rxbuf_min and rxbuf_max are no longer configurable. */
2074
2075 return len;
2076 }
2077
2078 static DEVICE_ATTR(rxbuf_min, S_IRUGO|S_IWUSR, show_rxbuf, store_rxbuf);
2079 static DEVICE_ATTR(rxbuf_max, S_IRUGO|S_IWUSR, show_rxbuf, store_rxbuf);
2080 static DEVICE_ATTR(rxbuf_cur, S_IRUGO, show_rxbuf, NULL);
2081
2082 static struct attribute *xennet_dev_attrs[] = {
2083 &dev_attr_rxbuf_min.attr,
2084 &dev_attr_rxbuf_max.attr,
2085 &dev_attr_rxbuf_cur.attr,
2086 NULL
2087 };
2088
2089 static const struct attribute_group xennet_dev_group = {
2090 .attrs = xennet_dev_attrs
2091 };
2092 #endif /* CONFIG_SYSFS */
2093
2094 static int xennet_remove(struct xenbus_device *dev)
2095 {
2096 struct netfront_info *info = dev_get_drvdata(&dev->dev);
2097
2098 dev_dbg(&dev->dev, "%s\n", dev->nodename);
2099
2100 xennet_disconnect_backend(info);
2101
2102 unregister_netdev(info->netdev);
2103
2104 xennet_destroy_queues(info);
2105 xennet_free_netdev(info->netdev);
2106
2107 return 0;
2108 }
2109
2110 static const struct xenbus_device_id netfront_ids[] = {
2111 { "vif" },
2112 { "" }
2113 };
2114
2115 static struct xenbus_driver netfront_driver = {
2116 .ids = netfront_ids,
2117 .probe = netfront_probe,
2118 .remove = xennet_remove,
2119 .resume = netfront_resume,
2120 .otherend_changed = netback_changed,
2121 };
2122
2123 static int __init netif_init(void)
2124 {
2125 if (!xen_domain())
2126 return -ENODEV;
2127
2128 if (!xen_has_pv_nic_devices())
2129 return -ENODEV;
2130
2131 pr_info("Initialising Xen virtual ethernet driver\n");
2132
2133 /* Allow as many queues as there are CPUs, by default */
2134 xennet_max_queues = num_online_cpus();
2135
2136 return xenbus_register_frontend(&netfront_driver);
2137 }
2138 module_init(netif_init);
2139
2140
2141 static void __exit netif_exit(void)
2142 {
2143 xenbus_unregister_driver(&netfront_driver);
2144 }
2145 module_exit(netif_exit);
2146
2147 MODULE_DESCRIPTION("Xen virtual network device frontend");
2148 MODULE_LICENSE("GPL");
2149 MODULE_ALIAS("xen:vif");
2150 MODULE_ALIAS("xennet");
Linux with added FPC-III support