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