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Merge tag 'pwm/for-4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry...
[linux/fpc-iii.git] / drivers / net / xen-netfront.c
blob523387e71a8021b81beb46407132def2638fdb48
1 /*
2 * Virtual network driver for conversing with remote driver backends.
3 *
4 * Copyright (c) 2002-2005, K A Fraser
5 * Copyright (c) 2005, XenSource Ltd
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License version 2
9 * as published by the Free Software Foundation; or, when distributed
10 * separately from the Linux kernel or incorporated into other
11 * software packages, subject to the following license:
12 *
13 * Permission is hereby granted, free of charge, to any person obtaining a copy
14 * of this source file (the "Software"), to deal in the Software without
15 * restriction, including without limitation the rights to use, copy, modify,
16 * merge, publish, distribute, sublicense, and/or sell copies of the Software,
17 * and to permit persons to whom the Software is furnished to do so, subject to
18 * the following conditions:
19 *
20 * The above copyright notice and this permission notice shall be included in
21 * all copies or substantial portions of the Software.
22 *
23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
24 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
25 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
26 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
27 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
28 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
29 * IN THE SOFTWARE.
30 */
31
32 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
33
34 #include <linux/module.h>
35 #include <linux/kernel.h>
36 #include <linux/netdevice.h>
37 #include <linux/etherdevice.h>
38 #include <linux/skbuff.h>
39 #include <linux/ethtool.h>
40 #include <linux/if_ether.h>
41 #include <net/tcp.h>
42 #include <linux/udp.h>
43 #include <linux/moduleparam.h>
44 #include <linux/mm.h>
45 #include <linux/slab.h>
46 #include <net/ip.h>
47
48 #include <xen/xen.h>
49 #include <xen/xenbus.h>
50 #include <xen/events.h>
51 #include <xen/page.h>
52 #include <xen/platform_pci.h>
53 #include <xen/grant_table.h>
54
55 #include <xen/interface/io/netif.h>
56 #include <xen/interface/memory.h>
57 #include <xen/interface/grant_table.h>
58
59 /* Module parameters */
60 #define MAX_QUEUES_DEFAULT 8
61 static unsigned int xennet_max_queues;
62 module_param_named(max_queues, xennet_max_queues, uint, 0644);
63 MODULE_PARM_DESC(max_queues,
64 "Maximum number of queues per virtual interface");
65
66 static const struct ethtool_ops xennet_ethtool_ops;
67
68 struct netfront_cb {
69 int pull_to;
70 };
71
72 #define NETFRONT_SKB_CB(skb) ((struct netfront_cb *)((skb)->cb))
73
74 #define RX_COPY_THRESHOLD 256
75
76 #define GRANT_INVALID_REF 0
77
78 #define NET_TX_RING_SIZE __CONST_RING_SIZE(xen_netif_tx, XEN_PAGE_SIZE)
79 #define NET_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, XEN_PAGE_SIZE)
80
81 /* Minimum number of Rx slots (includes slot for GSO metadata). */
82 #define NET_RX_SLOTS_MIN (XEN_NETIF_NR_SLOTS_MIN + 1)
83
84 /* Queue name is interface name with "-qNNN" appended */
85 #define QUEUE_NAME_SIZE (IFNAMSIZ + 6)
86
87 /* IRQ name is queue name with "-tx" or "-rx" appended */
88 #define IRQ_NAME_SIZE (QUEUE_NAME_SIZE + 3)
89
90 struct netfront_stats {
91 u64 packets;
92 u64 bytes;
93 struct u64_stats_sync syncp;
94 };
95
96 struct netfront_info;
97
98 struct netfront_queue {
99 unsigned int id; /* Queue ID, 0-based */
100 char name[QUEUE_NAME_SIZE]; /* DEVNAME-qN */
101 struct netfront_info *info;
102
103 struct napi_struct napi;
104
105 /* Split event channels support, tx_* == rx_* when using
106 * single event channel.
107 */
108 unsigned int tx_evtchn, rx_evtchn;
109 unsigned int tx_irq, rx_irq;
110 /* Only used when split event channels support is enabled */
111 char tx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-tx */
112 char rx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-rx */
113
114 spinlock_t tx_lock;
115 struct xen_netif_tx_front_ring tx;
116 int tx_ring_ref;
117
118 /*
119 * {tx,rx}_skbs store outstanding skbuffs. Free tx_skb entries
120 * are linked from tx_skb_freelist through skb_entry.link.
121 *
122 * NB. Freelist index entries are always going to be less than
123 * PAGE_OFFSET, whereas pointers to skbs will always be equal or
124 * greater than PAGE_OFFSET: we use this property to distinguish
125 * them.
126 */
127 union skb_entry {
128 struct sk_buff *skb;
129 unsigned long link;
130 } tx_skbs[NET_TX_RING_SIZE];
131 grant_ref_t gref_tx_head;
132 grant_ref_t grant_tx_ref[NET_TX_RING_SIZE];
133 struct page *grant_tx_page[NET_TX_RING_SIZE];
134 unsigned tx_skb_freelist;
135
136 spinlock_t rx_lock ____cacheline_aligned_in_smp;
137 struct xen_netif_rx_front_ring rx;
138 int rx_ring_ref;
139
140 struct timer_list rx_refill_timer;
141
142 struct sk_buff *rx_skbs[NET_RX_RING_SIZE];
143 grant_ref_t gref_rx_head;
144 grant_ref_t grant_rx_ref[NET_RX_RING_SIZE];
145 };
146
147 struct netfront_info {
148 struct list_head list;
149 struct net_device *netdev;
150
151 struct xenbus_device *xbdev;
152
153 /* Multi-queue support */
154 struct netfront_queue *queues;
155
156 /* Statistics */
157 struct netfront_stats __percpu *rx_stats;
158 struct netfront_stats __percpu *tx_stats;
159
160 atomic_t rx_gso_checksum_fixup;
161 };
162
163 struct netfront_rx_info {
164 struct xen_netif_rx_response rx;
165 struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX - 1];
166 };
167
168 static void skb_entry_set_link(union skb_entry *list, unsigned short id)
169 {
170 list->link = id;
171 }
172
173 static int skb_entry_is_link(const union skb_entry *list)
174 {
175 BUILD_BUG_ON(sizeof(list->skb) != sizeof(list->link));
176 return (unsigned long)list->skb < PAGE_OFFSET;
177 }
178
179 /*
180 * Access macros for acquiring freeing slots in tx_skbs[].
181 */
182
183 static void add_id_to_freelist(unsigned *head, union skb_entry *list,
184 unsigned short id)
185 {
186 skb_entry_set_link(&list[id], *head);
187 *head = id;
188 }
189
190 static unsigned short get_id_from_freelist(unsigned *head,
191 union skb_entry *list)
192 {
193 unsigned int id = *head;
194 *head = list[id].link;
195 return id;
196 }
197
198 static int xennet_rxidx(RING_IDX idx)
199 {
200 return idx & (NET_RX_RING_SIZE - 1);
201 }
202
203 static struct sk_buff *xennet_get_rx_skb(struct netfront_queue *queue,
204 RING_IDX ri)
205 {
206 int i = xennet_rxidx(ri);
207 struct sk_buff *skb = queue->rx_skbs[i];
208 queue->rx_skbs[i] = NULL;
209 return skb;
210 }
211
212 static grant_ref_t xennet_get_rx_ref(struct netfront_queue *queue,
213 RING_IDX ri)
214 {
215 int i = xennet_rxidx(ri);
216 grant_ref_t ref = queue->grant_rx_ref[i];
217 queue->grant_rx_ref[i] = GRANT_INVALID_REF;
218 return ref;
219 }
220
221 #ifdef CONFIG_SYSFS
222 static const struct attribute_group xennet_dev_group;
223 #endif
224
225 static bool xennet_can_sg(struct net_device *dev)
226 {
227 return dev->features & NETIF_F_SG;
228 }
229
230
231 static void rx_refill_timeout(unsigned long data)
232 {
233 struct netfront_queue *queue = (struct netfront_queue *)data;
234 napi_schedule(&queue->napi);
235 }
236
237 static int netfront_tx_slot_available(struct netfront_queue *queue)
238 {
239 return (queue->tx.req_prod_pvt - queue->tx.rsp_cons) <
240 (NET_TX_RING_SIZE - MAX_SKB_FRAGS - 2);
241 }
242
243 static void xennet_maybe_wake_tx(struct netfront_queue *queue)
244 {
245 struct net_device *dev = queue->info->netdev;
246 struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, queue->id);
247
248 if (unlikely(netif_tx_queue_stopped(dev_queue)) &&
249 netfront_tx_slot_available(queue) &&
250 likely(netif_running(dev)))
251 netif_tx_wake_queue(netdev_get_tx_queue(dev, queue->id));
252 }
253
254
255 static struct sk_buff *xennet_alloc_one_rx_buffer(struct netfront_queue *queue)
256 {
257 struct sk_buff *skb;
258 struct page *page;
259
260 skb = __netdev_alloc_skb(queue->info->netdev,
261 RX_COPY_THRESHOLD + NET_IP_ALIGN,
262 GFP_ATOMIC | __GFP_NOWARN);
263 if (unlikely(!skb))
264 return NULL;
265
266 page = alloc_page(GFP_ATOMIC | __GFP_NOWARN);
267 if (!page) {
268 kfree_skb(skb);
269 return NULL;
270 }
271 skb_add_rx_frag(skb, 0, page, 0, 0, PAGE_SIZE);
272
273 /* Align ip header to a 16 bytes boundary */
274 skb_reserve(skb, NET_IP_ALIGN);
275 skb->dev = queue->info->netdev;
276
277 return skb;
278 }
279
280
281 static void xennet_alloc_rx_buffers(struct netfront_queue *queue)
282 {
283 RING_IDX req_prod = queue->rx.req_prod_pvt;
284 int notify;
285 int err = 0;
286
287 if (unlikely(!netif_carrier_ok(queue->info->netdev)))
288 return;
289
290 for (req_prod = queue->rx.req_prod_pvt;
291 req_prod - queue->rx.rsp_cons < NET_RX_RING_SIZE;
292 req_prod++) {
293 struct sk_buff *skb;
294 unsigned short id;
295 grant_ref_t ref;
296 struct page *page;
297 struct xen_netif_rx_request *req;
298
299 skb = xennet_alloc_one_rx_buffer(queue);
300 if (!skb) {
301 err = -ENOMEM;
302 break;
303 }
304
305 id = xennet_rxidx(req_prod);
306
307 BUG_ON(queue->rx_skbs[id]);
308 queue->rx_skbs[id] = skb;
309
310 ref = gnttab_claim_grant_reference(&queue->gref_rx_head);
311 WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)(int)ref));
312 queue->grant_rx_ref[id] = ref;
313
314 page = skb_frag_page(&skb_shinfo(skb)->frags[0]);
315
316 req = RING_GET_REQUEST(&queue->rx, req_prod);
317 gnttab_page_grant_foreign_access_ref_one(ref,
318 queue->info->xbdev->otherend_id,
319 page,
320 0);
321 req->id = id;
322 req->gref = ref;
323 }
324
325 queue->rx.req_prod_pvt = req_prod;
326
327 /* Try again later if there are not enough requests or skb allocation
328 * failed.
329 * Enough requests is quantified as the sum of newly created slots and
330 * the unconsumed slots at the backend.
331 */
332 if (req_prod - queue->rx.rsp_cons < NET_RX_SLOTS_MIN ||
333 unlikely(err)) {
334 mod_timer(&queue->rx_refill_timer, jiffies + (HZ/10));
335 return;
336 }
337
338 wmb(); /* barrier so backend seens requests */
339
340 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->rx, notify);
341 if (notify)
342 notify_remote_via_irq(queue->rx_irq);
343 }
344
345 static int xennet_open(struct net_device *dev)
346 {
347 struct netfront_info *np = netdev_priv(dev);
348 unsigned int num_queues = dev->real_num_tx_queues;
349 unsigned int i = 0;
350 struct netfront_queue *queue = NULL;
351
352 for (i = 0; i < num_queues; ++i) {
353 queue = &np->queues[i];
354 napi_enable(&queue->napi);
355
356 spin_lock_bh(&queue->rx_lock);
357 if (netif_carrier_ok(dev)) {
358 xennet_alloc_rx_buffers(queue);
359 queue->rx.sring->rsp_event = queue->rx.rsp_cons + 1;
360 if (RING_HAS_UNCONSUMED_RESPONSES(&queue->rx))
361 napi_schedule(&queue->napi);
362 }
363 spin_unlock_bh(&queue->rx_lock);
364 }
365
366 netif_tx_start_all_queues(dev);
367
368 return 0;
369 }
370
371 static void xennet_tx_buf_gc(struct netfront_queue *queue)
372 {
373 RING_IDX cons, prod;
374 unsigned short id;
375 struct sk_buff *skb;
376 bool more_to_do;
377
378 BUG_ON(!netif_carrier_ok(queue->info->netdev));
379
380 do {
381 prod = queue->tx.sring->rsp_prod;
382 rmb(); /* Ensure we see responses up to 'rp'. */
383
384 for (cons = queue->tx.rsp_cons; cons != prod; cons++) {
385 struct xen_netif_tx_response *txrsp;
386
387 txrsp = RING_GET_RESPONSE(&queue->tx, cons);
388 if (txrsp->status == XEN_NETIF_RSP_NULL)
389 continue;
390
391 id = txrsp->id;
392 skb = queue->tx_skbs[id].skb;
393 if (unlikely(gnttab_query_foreign_access(
394 queue->grant_tx_ref[id]) != 0)) {
395 pr_alert("%s: warning -- grant still in use by backend domain\n",
396 __func__);
397 BUG();
398 }
399 gnttab_end_foreign_access_ref(
400 queue->grant_tx_ref[id], GNTMAP_readonly);
401 gnttab_release_grant_reference(
402 &queue->gref_tx_head, queue->grant_tx_ref[id]);
403 queue->grant_tx_ref[id] = GRANT_INVALID_REF;
404 queue->grant_tx_page[id] = NULL;
405 add_id_to_freelist(&queue->tx_skb_freelist, queue->tx_skbs, id);
406 dev_kfree_skb_irq(skb);
407 }
408
409 queue->tx.rsp_cons = prod;
410
411 RING_FINAL_CHECK_FOR_RESPONSES(&queue->tx, more_to_do);
412 } while (more_to_do);
413
414 xennet_maybe_wake_tx(queue);
415 }
416
417 struct xennet_gnttab_make_txreq {
418 struct netfront_queue *queue;
419 struct sk_buff *skb;
420 struct page *page;
421 struct xen_netif_tx_request *tx; /* Last request */
422 unsigned int size;
423 };
424
425 static void xennet_tx_setup_grant(unsigned long gfn, unsigned int offset,
426 unsigned int len, void *data)
427 {
428 struct xennet_gnttab_make_txreq *info = data;
429 unsigned int id;
430 struct xen_netif_tx_request *tx;
431 grant_ref_t ref;
432 /* convenient aliases */
433 struct page *page = info->page;
434 struct netfront_queue *queue = info->queue;
435 struct sk_buff *skb = info->skb;
436
437 id = get_id_from_freelist(&queue->tx_skb_freelist, queue->tx_skbs);
438 tx = RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++);
439 ref = gnttab_claim_grant_reference(&queue->gref_tx_head);
440 WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)(int)ref));
441
442 gnttab_grant_foreign_access_ref(ref, queue->info->xbdev->otherend_id,
443 gfn, GNTMAP_readonly);
444
445 queue->tx_skbs[id].skb = skb;
446 queue->grant_tx_page[id] = page;
447 queue->grant_tx_ref[id] = ref;
448
449 tx->id = id;
450 tx->gref = ref;
451 tx->offset = offset;
452 tx->size = len;
453 tx->flags = 0;
454
455 info->tx = tx;
456 info->size += tx->size;
457 }
458
459 static struct xen_netif_tx_request *xennet_make_first_txreq(
460 struct netfront_queue *queue, struct sk_buff *skb,
461 struct page *page, unsigned int offset, unsigned int len)
462 {
463 struct xennet_gnttab_make_txreq info = {
464 .queue = queue,
465 .skb = skb,
466 .page = page,
467 .size = 0,
468 };
469
470 gnttab_for_one_grant(page, offset, len, xennet_tx_setup_grant, &info);
471
472 return info.tx;
473 }
474
475 static void xennet_make_one_txreq(unsigned long gfn, unsigned int offset,
476 unsigned int len, void *data)
477 {
478 struct xennet_gnttab_make_txreq *info = data;
479
480 info->tx->flags |= XEN_NETTXF_more_data;
481 skb_get(info->skb);
482 xennet_tx_setup_grant(gfn, offset, len, data);
483 }
484
485 static struct xen_netif_tx_request *xennet_make_txreqs(
486 struct netfront_queue *queue, struct xen_netif_tx_request *tx,
487 struct sk_buff *skb, struct page *page,
488 unsigned int offset, unsigned int len)
489 {
490 struct xennet_gnttab_make_txreq info = {
491 .queue = queue,
492 .skb = skb,
493 .tx = tx,
494 };
495
496 /* Skip unused frames from start of page */
497 page += offset >> PAGE_SHIFT;
498 offset &= ~PAGE_MASK;
499
500 while (len) {
501 info.page = page;
502 info.size = 0;
503
504 gnttab_foreach_grant_in_range(page, offset, len,
505 xennet_make_one_txreq,
506 &info);
507
508 page++;
509 offset = 0;
510 len -= info.size;
511 }
512
513 return info.tx;
514 }
515
516 /*
517 * Count how many ring slots are required to send this skb. Each frag
518 * might be a compound page.
519 */
520 static int xennet_count_skb_slots(struct sk_buff *skb)
521 {
522 int i, frags = skb_shinfo(skb)->nr_frags;
523 int slots;
524
525 slots = gnttab_count_grant(offset_in_page(skb->data),
526 skb_headlen(skb));
527
528 for (i = 0; i < frags; i++) {
529 skb_frag_t *frag = skb_shinfo(skb)->frags + i;
530 unsigned long size = skb_frag_size(frag);
531 unsigned long offset = frag->page_offset;
532
533 /* Skip unused frames from start of page */
534 offset &= ~PAGE_MASK;
535
536 slots += gnttab_count_grant(offset, size);
537 }
538
539 return slots;
540 }
541
542 static u16 xennet_select_queue(struct net_device *dev, struct sk_buff *skb,
543 void *accel_priv, select_queue_fallback_t fallback)
544 {
545 unsigned int num_queues = dev->real_num_tx_queues;
546 u32 hash;
547 u16 queue_idx;
548
549 /* First, check if there is only one queue */
550 if (num_queues == 1) {
551 queue_idx = 0;
552 } else {
553 hash = skb_get_hash(skb);
554 queue_idx = hash % num_queues;
555 }
556
557 return queue_idx;
558 }
559
560 #define MAX_XEN_SKB_FRAGS (65536 / XEN_PAGE_SIZE + 1)
561
562 static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev)
563 {
564 struct netfront_info *np = netdev_priv(dev);
565 struct netfront_stats *tx_stats = this_cpu_ptr(np->tx_stats);
566 struct xen_netif_tx_request *tx, *first_tx;
567 unsigned int i;
568 int notify;
569 int slots;
570 struct page *page;
571 unsigned int offset;
572 unsigned int len;
573 unsigned long flags;
574 struct netfront_queue *queue = NULL;
575 unsigned int num_queues = dev->real_num_tx_queues;
576 u16 queue_index;
577 struct sk_buff *nskb;
578
579 /* Drop the packet if no queues are set up */
580 if (num_queues < 1)
581 goto drop;
582 /* Determine which queue to transmit this SKB on */
583 queue_index = skb_get_queue_mapping(skb);
584 queue = &np->queues[queue_index];
585
586 /* If skb->len is too big for wire format, drop skb and alert
587 * user about misconfiguration.
588 */
589 if (unlikely(skb->len > XEN_NETIF_MAX_TX_SIZE)) {
590 net_alert_ratelimited(
591 "xennet: skb->len = %u, too big for wire format\n",
592 skb->len);
593 goto drop;
594 }
595
596 slots = xennet_count_skb_slots(skb);
597 if (unlikely(slots > MAX_XEN_SKB_FRAGS + 1)) {
598 net_dbg_ratelimited("xennet: skb rides the rocket: %d slots, %d bytes\n",
599 slots, skb->len);
600 if (skb_linearize(skb))
601 goto drop;
602 }
603
604 page = virt_to_page(skb->data);
605 offset = offset_in_page(skb->data);
606
607 /* The first req should be at least ETH_HLEN size or the packet will be
608 * dropped by netback.
609 */
610 if (unlikely(PAGE_SIZE - offset < ETH_HLEN)) {
611 nskb = skb_copy(skb, GFP_ATOMIC);
612 if (!nskb)
613 goto drop;
614 dev_consume_skb_any(skb);
615 skb = nskb;
616 page = virt_to_page(skb->data);
617 offset = offset_in_page(skb->data);
618 }
619
620 len = skb_headlen(skb);
621
622 spin_lock_irqsave(&queue->tx_lock, flags);
623
624 if (unlikely(!netif_carrier_ok(dev) ||
625 (slots > 1 && !xennet_can_sg(dev)) ||
626 netif_needs_gso(skb, netif_skb_features(skb)))) {
627 spin_unlock_irqrestore(&queue->tx_lock, flags);
628 goto drop;
629 }
630
631 /* First request for the linear area. */
632 first_tx = tx = xennet_make_first_txreq(queue, skb,
633 page, offset, len);
634 offset += tx->size;
635 if (offset == PAGE_SIZE) {
636 page++;
637 offset = 0;
638 }
639 len -= tx->size;
640
641 if (skb->ip_summed == CHECKSUM_PARTIAL)
642 /* local packet? */
643 tx->flags |= XEN_NETTXF_csum_blank | XEN_NETTXF_data_validated;
644 else if (skb->ip_summed == CHECKSUM_UNNECESSARY)
645 /* remote but checksummed. */
646 tx->flags |= XEN_NETTXF_data_validated;
647
648 /* Optional extra info after the first request. */
649 if (skb_shinfo(skb)->gso_size) {
650 struct xen_netif_extra_info *gso;
651
652 gso = (struct xen_netif_extra_info *)
653 RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++);
654
655 tx->flags |= XEN_NETTXF_extra_info;
656
657 gso->u.gso.size = skb_shinfo(skb)->gso_size;
658 gso->u.gso.type = (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) ?
659 XEN_NETIF_GSO_TYPE_TCPV6 :
660 XEN_NETIF_GSO_TYPE_TCPV4;
661 gso->u.gso.pad = 0;
662 gso->u.gso.features = 0;
663
664 gso->type = XEN_NETIF_EXTRA_TYPE_GSO;
665 gso->flags = 0;
666 }
667
668 /* Requests for the rest of the linear area. */
669 tx = xennet_make_txreqs(queue, tx, skb, page, offset, len);
670
671 /* Requests for all the frags. */
672 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
673 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
674 tx = xennet_make_txreqs(queue, tx, skb,
675 skb_frag_page(frag), frag->page_offset,
676 skb_frag_size(frag));
677 }
678
679 /* First request has the packet length. */
680 first_tx->size = skb->len;
681
682 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->tx, notify);
683 if (notify)
684 notify_remote_via_irq(queue->tx_irq);
685
686 u64_stats_update_begin(&tx_stats->syncp);
687 tx_stats->bytes += skb->len;
688 tx_stats->packets++;
689 u64_stats_update_end(&tx_stats->syncp);
690
691 /* Note: It is not safe to access skb after xennet_tx_buf_gc()! */
692 xennet_tx_buf_gc(queue);
693
694 if (!netfront_tx_slot_available(queue))
695 netif_tx_stop_queue(netdev_get_tx_queue(dev, queue->id));
696
697 spin_unlock_irqrestore(&queue->tx_lock, flags);
698
699 return NETDEV_TX_OK;
700
701 drop:
702 dev->stats.tx_dropped++;
703 dev_kfree_skb_any(skb);
704 return NETDEV_TX_OK;
705 }
706
707 static int xennet_close(struct net_device *dev)
708 {
709 struct netfront_info *np = netdev_priv(dev);
710 unsigned int num_queues = dev->real_num_tx_queues;
711 unsigned int i;
712 struct netfront_queue *queue;
713 netif_tx_stop_all_queues(np->netdev);
714 for (i = 0; i < num_queues; ++i) {
715 queue = &np->queues[i];
716 napi_disable(&queue->napi);
717 }
718 return 0;
719 }
720
721 static void xennet_move_rx_slot(struct netfront_queue *queue, struct sk_buff *skb,
722 grant_ref_t ref)
723 {
724 int new = xennet_rxidx(queue->rx.req_prod_pvt);
725
726 BUG_ON(queue->rx_skbs[new]);
727 queue->rx_skbs[new] = skb;
728 queue->grant_rx_ref[new] = ref;
729 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->id = new;
730 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->gref = ref;
731 queue->rx.req_prod_pvt++;
732 }
733
734 static int xennet_get_extras(struct netfront_queue *queue,
735 struct xen_netif_extra_info *extras,
736 RING_IDX rp)
737
738 {
739 struct xen_netif_extra_info *extra;
740 struct device *dev = &queue->info->netdev->dev;
741 RING_IDX cons = queue->rx.rsp_cons;
742 int err = 0;
743
744 do {
745 struct sk_buff *skb;
746 grant_ref_t ref;
747
748 if (unlikely(cons + 1 == rp)) {
749 if (net_ratelimit())
750 dev_warn(dev, "Missing extra info\n");
751 err = -EBADR;
752 break;
753 }
754
755 extra = (struct xen_netif_extra_info *)
756 RING_GET_RESPONSE(&queue->rx, ++cons);
757
758 if (unlikely(!extra->type ||
759 extra->type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
760 if (net_ratelimit())
761 dev_warn(dev, "Invalid extra type: %d\n",
762 extra->type);
763 err = -EINVAL;
764 } else {
765 memcpy(&extras[extra->type - 1], extra,
766 sizeof(*extra));
767 }
768
769 skb = xennet_get_rx_skb(queue, cons);
770 ref = xennet_get_rx_ref(queue, cons);
771 xennet_move_rx_slot(queue, skb, ref);
772 } while (extra->flags & XEN_NETIF_EXTRA_FLAG_MORE);
773
774 queue->rx.rsp_cons = cons;
775 return err;
776 }
777
778 static int xennet_get_responses(struct netfront_queue *queue,
779 struct netfront_rx_info *rinfo, RING_IDX rp,
780 struct sk_buff_head *list)
781 {
782 struct xen_netif_rx_response *rx = &rinfo->rx;
783 struct xen_netif_extra_info *extras = rinfo->extras;
784 struct device *dev = &queue->info->netdev->dev;
785 RING_IDX cons = queue->rx.rsp_cons;
786 struct sk_buff *skb = xennet_get_rx_skb(queue, cons);
787 grant_ref_t ref = xennet_get_rx_ref(queue, cons);
788 int max = MAX_SKB_FRAGS + (rx->status <= RX_COPY_THRESHOLD);
789 int slots = 1;
790 int err = 0;
791 unsigned long ret;
792
793 if (rx->flags & XEN_NETRXF_extra_info) {
794 err = xennet_get_extras(queue, extras, rp);
795 cons = queue->rx.rsp_cons;
796 }
797
798 for (;;) {
799 if (unlikely(rx->status < 0 ||
800 rx->offset + rx->status > XEN_PAGE_SIZE)) {
801 if (net_ratelimit())
802 dev_warn(dev, "rx->offset: %u, size: %d\n",
803 rx->offset, rx->status);
804 xennet_move_rx_slot(queue, skb, ref);
805 err = -EINVAL;
806 goto next;
807 }
808
809 /*
810 * This definitely indicates a bug, either in this driver or in
811 * the backend driver. In future this should flag the bad
812 * situation to the system controller to reboot the backend.
813 */
814 if (ref == GRANT_INVALID_REF) {
815 if (net_ratelimit())
816 dev_warn(dev, "Bad rx response id %d.\n",
817 rx->id);
818 err = -EINVAL;
819 goto next;
820 }
821
822 ret = gnttab_end_foreign_access_ref(ref, 0);
823 BUG_ON(!ret);
824
825 gnttab_release_grant_reference(&queue->gref_rx_head, ref);
826
827 __skb_queue_tail(list, skb);
828
829 next:
830 if (!(rx->flags & XEN_NETRXF_more_data))
831 break;
832
833 if (cons + slots == rp) {
834 if (net_ratelimit())
835 dev_warn(dev, "Need more slots\n");
836 err = -ENOENT;
837 break;
838 }
839
840 rx = RING_GET_RESPONSE(&queue->rx, cons + slots);
841 skb = xennet_get_rx_skb(queue, cons + slots);
842 ref = xennet_get_rx_ref(queue, cons + slots);
843 slots++;
844 }
845
846 if (unlikely(slots > max)) {
847 if (net_ratelimit())
848 dev_warn(dev, "Too many slots\n");
849 err = -E2BIG;
850 }
851
852 if (unlikely(err))
853 queue->rx.rsp_cons = cons + slots;
854
855 return err;
856 }
857
858 static int xennet_set_skb_gso(struct sk_buff *skb,
859 struct xen_netif_extra_info *gso)
860 {
861 if (!gso->u.gso.size) {
862 if (net_ratelimit())
863 pr_warn("GSO size must not be zero\n");
864 return -EINVAL;
865 }
866
867 if (gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV4 &&
868 gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV6) {
869 if (net_ratelimit())
870 pr_warn("Bad GSO type %d\n", gso->u.gso.type);
871 return -EINVAL;
872 }
873
874 skb_shinfo(skb)->gso_size = gso->u.gso.size;
875 skb_shinfo(skb)->gso_type =
876 (gso->u.gso.type == XEN_NETIF_GSO_TYPE_TCPV4) ?
877 SKB_GSO_TCPV4 :
878 SKB_GSO_TCPV6;
879
880 /* Header must be checked, and gso_segs computed. */
881 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
882 skb_shinfo(skb)->gso_segs = 0;
883
884 return 0;
885 }
886
887 static RING_IDX xennet_fill_frags(struct netfront_queue *queue,
888 struct sk_buff *skb,
889 struct sk_buff_head *list)
890 {
891 struct skb_shared_info *shinfo = skb_shinfo(skb);
892 RING_IDX cons = queue->rx.rsp_cons;
893 struct sk_buff *nskb;
894
895 while ((nskb = __skb_dequeue(list))) {
896 struct xen_netif_rx_response *rx =
897 RING_GET_RESPONSE(&queue->rx, ++cons);
898 skb_frag_t *nfrag = &skb_shinfo(nskb)->frags[0];
899
900 if (shinfo->nr_frags == MAX_SKB_FRAGS) {
901 unsigned int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
902
903 BUG_ON(pull_to <= skb_headlen(skb));
904 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
905 }
906 BUG_ON(shinfo->nr_frags >= MAX_SKB_FRAGS);
907
908 skb_add_rx_frag(skb, shinfo->nr_frags, skb_frag_page(nfrag),
909 rx->offset, rx->status, PAGE_SIZE);
910
911 skb_shinfo(nskb)->nr_frags = 0;
912 kfree_skb(nskb);
913 }
914
915 return cons;
916 }
917
918 static int checksum_setup(struct net_device *dev, struct sk_buff *skb)
919 {
920 bool recalculate_partial_csum = false;
921
922 /*
923 * A GSO SKB must be CHECKSUM_PARTIAL. However some buggy
924 * peers can fail to set NETRXF_csum_blank when sending a GSO
925 * frame. In this case force the SKB to CHECKSUM_PARTIAL and
926 * recalculate the partial checksum.
927 */
928 if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) {
929 struct netfront_info *np = netdev_priv(dev);
930 atomic_inc(&np->rx_gso_checksum_fixup);
931 skb->ip_summed = CHECKSUM_PARTIAL;
932 recalculate_partial_csum = true;
933 }
934
935 /* A non-CHECKSUM_PARTIAL SKB does not require setup. */
936 if (skb->ip_summed != CHECKSUM_PARTIAL)
937 return 0;
938
939 return skb_checksum_setup(skb, recalculate_partial_csum);
940 }
941
942 static int handle_incoming_queue(struct netfront_queue *queue,
943 struct sk_buff_head *rxq)
944 {
945 struct netfront_stats *rx_stats = this_cpu_ptr(queue->info->rx_stats);
946 int packets_dropped = 0;
947 struct sk_buff *skb;
948
949 while ((skb = __skb_dequeue(rxq)) != NULL) {
950 int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
951
952 if (pull_to > skb_headlen(skb))
953 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
954
955 /* Ethernet work: Delayed to here as it peeks the header. */
956 skb->protocol = eth_type_trans(skb, queue->info->netdev);
957 skb_reset_network_header(skb);
958
959 if (checksum_setup(queue->info->netdev, skb)) {
960 kfree_skb(skb);
961 packets_dropped++;
962 queue->info->netdev->stats.rx_errors++;
963 continue;
964 }
965
966 u64_stats_update_begin(&rx_stats->syncp);
967 rx_stats->packets++;
968 rx_stats->bytes += skb->len;
969 u64_stats_update_end(&rx_stats->syncp);
970
971 /* Pass it up. */
972 napi_gro_receive(&queue->napi, skb);
973 }
974
975 return packets_dropped;
976 }
977
978 static int xennet_poll(struct napi_struct *napi, int budget)
979 {
980 struct netfront_queue *queue = container_of(napi, struct netfront_queue, napi);
981 struct net_device *dev = queue->info->netdev;
982 struct sk_buff *skb;
983 struct netfront_rx_info rinfo;
984 struct xen_netif_rx_response *rx = &rinfo.rx;
985 struct xen_netif_extra_info *extras = rinfo.extras;
986 RING_IDX i, rp;
987 int work_done;
988 struct sk_buff_head rxq;
989 struct sk_buff_head errq;
990 struct sk_buff_head tmpq;
991 int err;
992
993 spin_lock(&queue->rx_lock);
994
995 skb_queue_head_init(&rxq);
996 skb_queue_head_init(&errq);
997 skb_queue_head_init(&tmpq);
998
999 rp = queue->rx.sring->rsp_prod;
1000 rmb(); /* Ensure we see queued responses up to 'rp'. */
1001
1002 i = queue->rx.rsp_cons;
1003 work_done = 0;
1004 while ((i != rp) && (work_done < budget)) {
1005 memcpy(rx, RING_GET_RESPONSE(&queue->rx, i), sizeof(*rx));
1006 memset(extras, 0, sizeof(rinfo.extras));
1007
1008 err = xennet_get_responses(queue, &rinfo, rp, &tmpq);
1009
1010 if (unlikely(err)) {
1011 err:
1012 while ((skb = __skb_dequeue(&tmpq)))
1013 __skb_queue_tail(&errq, skb);
1014 dev->stats.rx_errors++;
1015 i = queue->rx.rsp_cons;
1016 continue;
1017 }
1018
1019 skb = __skb_dequeue(&tmpq);
1020
1021 if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) {
1022 struct xen_netif_extra_info *gso;
1023 gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1];
1024
1025 if (unlikely(xennet_set_skb_gso(skb, gso))) {
1026 __skb_queue_head(&tmpq, skb);
1027 queue->rx.rsp_cons += skb_queue_len(&tmpq);
1028 goto err;
1029 }
1030 }
1031
1032 NETFRONT_SKB_CB(skb)->pull_to = rx->status;
1033 if (NETFRONT_SKB_CB(skb)->pull_to > RX_COPY_THRESHOLD)
1034 NETFRONT_SKB_CB(skb)->pull_to = RX_COPY_THRESHOLD;
1035
1036 skb_shinfo(skb)->frags[0].page_offset = rx->offset;
1037 skb_frag_size_set(&skb_shinfo(skb)->frags[0], rx->status);
1038 skb->data_len = rx->status;
1039 skb->len += rx->status;
1040
1041 i = xennet_fill_frags(queue, skb, &tmpq);
1042
1043 if (rx->flags & XEN_NETRXF_csum_blank)
1044 skb->ip_summed = CHECKSUM_PARTIAL;
1045 else if (rx->flags & XEN_NETRXF_data_validated)
1046 skb->ip_summed = CHECKSUM_UNNECESSARY;
1047
1048 __skb_queue_tail(&rxq, skb);
1049
1050 queue->rx.rsp_cons = ++i;
1051 work_done++;
1052 }
1053
1054 __skb_queue_purge(&errq);
1055
1056 work_done -= handle_incoming_queue(queue, &rxq);
1057
1058 xennet_alloc_rx_buffers(queue);
1059
1060 if (work_done < budget) {
1061 int more_to_do = 0;
1062
1063 napi_complete_done(napi, work_done);
1064
1065 RING_FINAL_CHECK_FOR_RESPONSES(&queue->rx, more_to_do);
1066 if (more_to_do)
1067 napi_schedule(napi);
1068 }
1069
1070 spin_unlock(&queue->rx_lock);
1071
1072 return work_done;
1073 }
1074
1075 static int xennet_change_mtu(struct net_device *dev, int mtu)
1076 {
1077 int max = xennet_can_sg(dev) ? XEN_NETIF_MAX_TX_SIZE : ETH_DATA_LEN;
1078
1079 if (mtu > max)
1080 return -EINVAL;
1081 dev->mtu = mtu;
1082 return 0;
1083 }
1084
1085 static void xennet_get_stats64(struct net_device *dev,
1086 struct rtnl_link_stats64 *tot)
1087 {
1088 struct netfront_info *np = netdev_priv(dev);
1089 int cpu;
1090
1091 for_each_possible_cpu(cpu) {
1092 struct netfront_stats *rx_stats = per_cpu_ptr(np->rx_stats, cpu);
1093 struct netfront_stats *tx_stats = per_cpu_ptr(np->tx_stats, cpu);
1094 u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
1095 unsigned int start;
1096
1097 do {
1098 start = u64_stats_fetch_begin_irq(&tx_stats->syncp);
1099 tx_packets = tx_stats->packets;
1100 tx_bytes = tx_stats->bytes;
1101 } while (u64_stats_fetch_retry_irq(&tx_stats->syncp, start));
1102
1103 do {
1104 start = u64_stats_fetch_begin_irq(&rx_stats->syncp);
1105 rx_packets = rx_stats->packets;
1106 rx_bytes = rx_stats->bytes;
1107 } while (u64_stats_fetch_retry_irq(&rx_stats->syncp, start));
1108
1109 tot->rx_packets += rx_packets;
1110 tot->tx_packets += tx_packets;
1111 tot->rx_bytes += rx_bytes;
1112 tot->tx_bytes += tx_bytes;
1113 }
1114
1115 tot->rx_errors = dev->stats.rx_errors;
1116 tot->tx_dropped = dev->stats.tx_dropped;
1117 }
1118
1119 static void xennet_release_tx_bufs(struct netfront_queue *queue)
1120 {
1121 struct sk_buff *skb;
1122 int i;
1123
1124 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1125 /* Skip over entries which are actually freelist references */
1126 if (skb_entry_is_link(&queue->tx_skbs[i]))
1127 continue;
1128
1129 skb = queue->tx_skbs[i].skb;
1130 get_page(queue->grant_tx_page[i]);
1131 gnttab_end_foreign_access(queue->grant_tx_ref[i],
1132 GNTMAP_readonly,
1133 (unsigned long)page_address(queue->grant_tx_page[i]));
1134 queue->grant_tx_page[i] = NULL;
1135 queue->grant_tx_ref[i] = GRANT_INVALID_REF;
1136 add_id_to_freelist(&queue->tx_skb_freelist, queue->tx_skbs, i);
1137 dev_kfree_skb_irq(skb);
1138 }
1139 }
1140
1141 static void xennet_release_rx_bufs(struct netfront_queue *queue)
1142 {
1143 int id, ref;
1144
1145 spin_lock_bh(&queue->rx_lock);
1146
1147 for (id = 0; id < NET_RX_RING_SIZE; id++) {
1148 struct sk_buff *skb;
1149 struct page *page;
1150
1151 skb = queue->rx_skbs[id];
1152 if (!skb)
1153 continue;
1154
1155 ref = queue->grant_rx_ref[id];
1156 if (ref == GRANT_INVALID_REF)
1157 continue;
1158
1159 page = skb_frag_page(&skb_shinfo(skb)->frags[0]);
1160
1161 /* gnttab_end_foreign_access() needs a page ref until
1162 * foreign access is ended (which may be deferred).
1163 */
1164 get_page(page);
1165 gnttab_end_foreign_access(ref, 0,
1166 (unsigned long)page_address(page));
1167 queue->grant_rx_ref[id] = GRANT_INVALID_REF;
1168
1169 kfree_skb(skb);
1170 }
1171
1172 spin_unlock_bh(&queue->rx_lock);
1173 }
1174
1175 static netdev_features_t xennet_fix_features(struct net_device *dev,
1176 netdev_features_t features)
1177 {
1178 struct netfront_info *np = netdev_priv(dev);
1179
1180 if (features & NETIF_F_SG &&
1181 !xenbus_read_unsigned(np->xbdev->otherend, "feature-sg", 0))
1182 features &= ~NETIF_F_SG;
1183
1184 if (features & NETIF_F_IPV6_CSUM &&
1185 !xenbus_read_unsigned(np->xbdev->otherend,
1186 "feature-ipv6-csum-offload", 0))
1187 features &= ~NETIF_F_IPV6_CSUM;
1188
1189 if (features & NETIF_F_TSO &&
1190 !xenbus_read_unsigned(np->xbdev->otherend, "feature-gso-tcpv4", 0))
1191 features &= ~NETIF_F_TSO;
1192
1193 if (features & NETIF_F_TSO6 &&
1194 !xenbus_read_unsigned(np->xbdev->otherend, "feature-gso-tcpv6", 0))
1195 features &= ~NETIF_F_TSO6;
1196
1197 return features;
1198 }
1199
1200 static int xennet_set_features(struct net_device *dev,
1201 netdev_features_t features)
1202 {
1203 if (!(features & NETIF_F_SG) && dev->mtu > ETH_DATA_LEN) {
1204 netdev_info(dev, "Reducing MTU because no SG offload");
1205 dev->mtu = ETH_DATA_LEN;
1206 }
1207
1208 return 0;
1209 }
1210
1211 static irqreturn_t xennet_tx_interrupt(int irq, void *dev_id)
1212 {
1213 struct netfront_queue *queue = dev_id;
1214 unsigned long flags;
1215
1216 spin_lock_irqsave(&queue->tx_lock, flags);
1217 xennet_tx_buf_gc(queue);
1218 spin_unlock_irqrestore(&queue->tx_lock, flags);
1219
1220 return IRQ_HANDLED;
1221 }
1222
1223 static irqreturn_t xennet_rx_interrupt(int irq, void *dev_id)
1224 {
1225 struct netfront_queue *queue = dev_id;
1226 struct net_device *dev = queue->info->netdev;
1227
1228 if (likely(netif_carrier_ok(dev) &&
1229 RING_HAS_UNCONSUMED_RESPONSES(&queue->rx)))
1230 napi_schedule(&queue->napi);
1231
1232 return IRQ_HANDLED;
1233 }
1234
1235 static irqreturn_t xennet_interrupt(int irq, void *dev_id)
1236 {
1237 xennet_tx_interrupt(irq, dev_id);
1238 xennet_rx_interrupt(irq, dev_id);
1239 return IRQ_HANDLED;
1240 }
1241
1242 #ifdef CONFIG_NET_POLL_CONTROLLER
1243 static void xennet_poll_controller(struct net_device *dev)
1244 {
1245 /* Poll each queue */
1246 struct netfront_info *info = netdev_priv(dev);
1247 unsigned int num_queues = dev->real_num_tx_queues;
1248 unsigned int i;
1249 for (i = 0; i < num_queues; ++i)
1250 xennet_interrupt(0, &info->queues[i]);
1251 }
1252 #endif
1253
1254 static const struct net_device_ops xennet_netdev_ops = {
1255 .ndo_open = xennet_open,
1256 .ndo_stop = xennet_close,
1257 .ndo_start_xmit = xennet_start_xmit,
1258 .ndo_change_mtu = xennet_change_mtu,
1259 .ndo_get_stats64 = xennet_get_stats64,
1260 .ndo_set_mac_address = eth_mac_addr,
1261 .ndo_validate_addr = eth_validate_addr,
1262 .ndo_fix_features = xennet_fix_features,
1263 .ndo_set_features = xennet_set_features,
1264 .ndo_select_queue = xennet_select_queue,
1265 #ifdef CONFIG_NET_POLL_CONTROLLER
1266 .ndo_poll_controller = xennet_poll_controller,
1267 #endif
1268 };
1269
1270 static void xennet_free_netdev(struct net_device *netdev)
1271 {
1272 struct netfront_info *np = netdev_priv(netdev);
1273
1274 free_percpu(np->rx_stats);
1275 free_percpu(np->tx_stats);
1276 free_netdev(netdev);
1277 }
1278
1279 static struct net_device *xennet_create_dev(struct xenbus_device *dev)
1280 {
1281 int err;
1282 struct net_device *netdev;
1283 struct netfront_info *np;
1284
1285 netdev = alloc_etherdev_mq(sizeof(struct netfront_info), xennet_max_queues);
1286 if (!netdev)
1287 return ERR_PTR(-ENOMEM);
1288
1289 np = netdev_priv(netdev);
1290 np->xbdev = dev;
1291
1292 np->queues = NULL;
1293
1294 err = -ENOMEM;
1295 np->rx_stats = netdev_alloc_pcpu_stats(struct netfront_stats);
1296 if (np->rx_stats == NULL)
1297 goto exit;
1298 np->tx_stats = netdev_alloc_pcpu_stats(struct netfront_stats);
1299 if (np->tx_stats == NULL)
1300 goto exit;
1301
1302 netdev->netdev_ops = &xennet_netdev_ops;
1303
1304 netdev->features = NETIF_F_IP_CSUM | NETIF_F_RXCSUM |
1305 NETIF_F_GSO_ROBUST;
1306 netdev->hw_features = NETIF_F_SG |
1307 NETIF_F_IPV6_CSUM |
1308 NETIF_F_TSO | NETIF_F_TSO6;
1309
1310 /*
1311 * Assume that all hw features are available for now. This set
1312 * will be adjusted by the call to netdev_update_features() in
1313 * xennet_connect() which is the earliest point where we can
1314 * negotiate with the backend regarding supported features.
1315 */
1316 netdev->features |= netdev->hw_features;
1317
1318 netdev->ethtool_ops = &xennet_ethtool_ops;
1319 netdev->min_mtu = 0;
1320 netdev->max_mtu = XEN_NETIF_MAX_TX_SIZE;
1321 SET_NETDEV_DEV(netdev, &dev->dev);
1322
1323 np->netdev = netdev;
1324
1325 netif_carrier_off(netdev);
1326
1327 return netdev;
1328
1329 exit:
1330 xennet_free_netdev(netdev);
1331 return ERR_PTR(err);
1332 }
1333
1334 /**
1335 * Entry point to this code when a new device is created. Allocate the basic
1336 * structures and the ring buffers for communication with the backend, and
1337 * inform the backend of the appropriate details for those.
1338 */
1339 static int netfront_probe(struct xenbus_device *dev,
1340 const struct xenbus_device_id *id)
1341 {
1342 int err;
1343 struct net_device *netdev;
1344 struct netfront_info *info;
1345
1346 netdev = xennet_create_dev(dev);
1347 if (IS_ERR(netdev)) {
1348 err = PTR_ERR(netdev);
1349 xenbus_dev_fatal(dev, err, "creating netdev");
1350 return err;
1351 }
1352
1353 info = netdev_priv(netdev);
1354 dev_set_drvdata(&dev->dev, info);
1355 #ifdef CONFIG_SYSFS
1356 info->netdev->sysfs_groups[0] = &xennet_dev_group;
1357 #endif
1358 err = register_netdev(info->netdev);
1359 if (err) {
1360 pr_warn("%s: register_netdev err=%d\n", __func__, err);
1361 goto fail;
1362 }
1363
1364 return 0;
1365
1366 fail:
1367 xennet_free_netdev(netdev);
1368 dev_set_drvdata(&dev->dev, NULL);
1369 return err;
1370 }
1371
1372 static void xennet_end_access(int ref, void *page)
1373 {
1374 /* This frees the page as a side-effect */
1375 if (ref != GRANT_INVALID_REF)
1376 gnttab_end_foreign_access(ref, 0, (unsigned long)page);
1377 }
1378
1379 static void xennet_disconnect_backend(struct netfront_info *info)
1380 {
1381 unsigned int i = 0;
1382 unsigned int num_queues = info->netdev->real_num_tx_queues;
1383
1384 netif_carrier_off(info->netdev);
1385
1386 for (i = 0; i < num_queues && info->queues; ++i) {
1387 struct netfront_queue *queue = &info->queues[i];
1388
1389 del_timer_sync(&queue->rx_refill_timer);
1390
1391 if (queue->tx_irq && (queue->tx_irq == queue->rx_irq))
1392 unbind_from_irqhandler(queue->tx_irq, queue);
1393 if (queue->tx_irq && (queue->tx_irq != queue->rx_irq)) {
1394 unbind_from_irqhandler(queue->tx_irq, queue);
1395 unbind_from_irqhandler(queue->rx_irq, queue);
1396 }
1397 queue->tx_evtchn = queue->rx_evtchn = 0;
1398 queue->tx_irq = queue->rx_irq = 0;
1399
1400 if (netif_running(info->netdev))
1401 napi_synchronize(&queue->napi);
1402
1403 xennet_release_tx_bufs(queue);
1404 xennet_release_rx_bufs(queue);
1405 gnttab_free_grant_references(queue->gref_tx_head);
1406 gnttab_free_grant_references(queue->gref_rx_head);
1407
1408 /* End access and free the pages */
1409 xennet_end_access(queue->tx_ring_ref, queue->tx.sring);
1410 xennet_end_access(queue->rx_ring_ref, queue->rx.sring);
1411
1412 queue->tx_ring_ref = GRANT_INVALID_REF;
1413 queue->rx_ring_ref = GRANT_INVALID_REF;
1414 queue->tx.sring = NULL;
1415 queue->rx.sring = NULL;
1416 }
1417 }
1418
1419 /**
1420 * We are reconnecting to the backend, due to a suspend/resume, or a backend
1421 * driver restart. We tear down our netif structure and recreate it, but
1422 * leave the device-layer structures intact so that this is transparent to the
1423 * rest of the kernel.
1424 */
1425 static int netfront_resume(struct xenbus_device *dev)
1426 {
1427 struct netfront_info *info = dev_get_drvdata(&dev->dev);
1428
1429 dev_dbg(&dev->dev, "%s\n", dev->nodename);
1430
1431 xennet_disconnect_backend(info);
1432 return 0;
1433 }
1434
1435 static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[])
1436 {
1437 char *s, *e, *macstr;
1438 int i;
1439
1440 macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL);
1441 if (IS_ERR(macstr))
1442 return PTR_ERR(macstr);
1443
1444 for (i = 0; i < ETH_ALEN; i++) {
1445 mac[i] = simple_strtoul(s, &e, 16);
1446 if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) {
1447 kfree(macstr);
1448 return -ENOENT;
1449 }
1450 s = e+1;
1451 }
1452
1453 kfree(macstr);
1454 return 0;
1455 }
1456
1457 static int setup_netfront_single(struct netfront_queue *queue)
1458 {
1459 int err;
1460
1461 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn);
1462 if (err < 0)
1463 goto fail;
1464
1465 err = bind_evtchn_to_irqhandler(queue->tx_evtchn,
1466 xennet_interrupt,
1467 0, queue->info->netdev->name, queue);
1468 if (err < 0)
1469 goto bind_fail;
1470 queue->rx_evtchn = queue->tx_evtchn;
1471 queue->rx_irq = queue->tx_irq = err;
1472
1473 return 0;
1474
1475 bind_fail:
1476 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn);
1477 queue->tx_evtchn = 0;
1478 fail:
1479 return err;
1480 }
1481
1482 static int setup_netfront_split(struct netfront_queue *queue)
1483 {
1484 int err;
1485
1486 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn);
1487 if (err < 0)
1488 goto fail;
1489 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->rx_evtchn);
1490 if (err < 0)
1491 goto alloc_rx_evtchn_fail;
1492
1493 snprintf(queue->tx_irq_name, sizeof(queue->tx_irq_name),
1494 "%s-tx", queue->name);
1495 err = bind_evtchn_to_irqhandler(queue->tx_evtchn,
1496 xennet_tx_interrupt,
1497 0, queue->tx_irq_name, queue);
1498 if (err < 0)
1499 goto bind_tx_fail;
1500 queue->tx_irq = err;
1501
1502 snprintf(queue->rx_irq_name, sizeof(queue->rx_irq_name),
1503 "%s-rx", queue->name);
1504 err = bind_evtchn_to_irqhandler(queue->rx_evtchn,
1505 xennet_rx_interrupt,
1506 0, queue->rx_irq_name, queue);
1507 if (err < 0)
1508 goto bind_rx_fail;
1509 queue->rx_irq = err;
1510
1511 return 0;
1512
1513 bind_rx_fail:
1514 unbind_from_irqhandler(queue->tx_irq, queue);
1515 queue->tx_irq = 0;
1516 bind_tx_fail:
1517 xenbus_free_evtchn(queue->info->xbdev, queue->rx_evtchn);
1518 queue->rx_evtchn = 0;
1519 alloc_rx_evtchn_fail:
1520 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn);
1521 queue->tx_evtchn = 0;
1522 fail:
1523 return err;
1524 }
1525
1526 static int setup_netfront(struct xenbus_device *dev,
1527 struct netfront_queue *queue, unsigned int feature_split_evtchn)
1528 {
1529 struct xen_netif_tx_sring *txs;
1530 struct xen_netif_rx_sring *rxs;
1531 grant_ref_t gref;
1532 int err;
1533
1534 queue->tx_ring_ref = GRANT_INVALID_REF;
1535 queue->rx_ring_ref = GRANT_INVALID_REF;
1536 queue->rx.sring = NULL;
1537 queue->tx.sring = NULL;
1538
1539 txs = (struct xen_netif_tx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1540 if (!txs) {
1541 err = -ENOMEM;
1542 xenbus_dev_fatal(dev, err, "allocating tx ring page");
1543 goto fail;
1544 }
1545 SHARED_RING_INIT(txs);
1546 FRONT_RING_INIT(&queue->tx, txs, XEN_PAGE_SIZE);
1547
1548 err = xenbus_grant_ring(dev, txs, 1, &gref);
1549 if (err < 0)
1550 goto grant_tx_ring_fail;
1551 queue->tx_ring_ref = gref;
1552
1553 rxs = (struct xen_netif_rx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1554 if (!rxs) {
1555 err = -ENOMEM;
1556 xenbus_dev_fatal(dev, err, "allocating rx ring page");
1557 goto alloc_rx_ring_fail;
1558 }
1559 SHARED_RING_INIT(rxs);
1560 FRONT_RING_INIT(&queue->rx, rxs, XEN_PAGE_SIZE);
1561
1562 err = xenbus_grant_ring(dev, rxs, 1, &gref);
1563 if (err < 0)
1564 goto grant_rx_ring_fail;
1565 queue->rx_ring_ref = gref;
1566
1567 if (feature_split_evtchn)
1568 err = setup_netfront_split(queue);
1569 /* setup single event channel if
1570 * a) feature-split-event-channels == 0
1571 * b) feature-split-event-channels == 1 but failed to setup
1572 */
1573 if (!feature_split_evtchn || (feature_split_evtchn && err))
1574 err = setup_netfront_single(queue);
1575
1576 if (err)
1577 goto alloc_evtchn_fail;
1578
1579 return 0;
1580
1581 /* If we fail to setup netfront, it is safe to just revoke access to
1582 * granted pages because backend is not accessing it at this point.
1583 */
1584 alloc_evtchn_fail:
1585 gnttab_end_foreign_access_ref(queue->rx_ring_ref, 0);
1586 grant_rx_ring_fail:
1587 free_page((unsigned long)rxs);
1588 alloc_rx_ring_fail:
1589 gnttab_end_foreign_access_ref(queue->tx_ring_ref, 0);
1590 grant_tx_ring_fail:
1591 free_page((unsigned long)txs);
1592 fail:
1593 return err;
1594 }
1595
1596 /* Queue-specific initialisation
1597 * This used to be done in xennet_create_dev() but must now
1598 * be run per-queue.
1599 */
1600 static int xennet_init_queue(struct netfront_queue *queue)
1601 {
1602 unsigned short i;
1603 int err = 0;
1604
1605 spin_lock_init(&queue->tx_lock);
1606 spin_lock_init(&queue->rx_lock);
1607
1608 setup_timer(&queue->rx_refill_timer, rx_refill_timeout,
1609 (unsigned long)queue);
1610
1611 snprintf(queue->name, sizeof(queue->name), "%s-q%u",
1612 queue->info->netdev->name, queue->id);
1613
1614 /* Initialise tx_skbs as a free chain containing every entry. */
1615 queue->tx_skb_freelist = 0;
1616 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1617 skb_entry_set_link(&queue->tx_skbs[i], i+1);
1618 queue->grant_tx_ref[i] = GRANT_INVALID_REF;
1619 queue->grant_tx_page[i] = NULL;
1620 }
1621
1622 /* Clear out rx_skbs */
1623 for (i = 0; i < NET_RX_RING_SIZE; i++) {
1624 queue->rx_skbs[i] = NULL;
1625 queue->grant_rx_ref[i] = GRANT_INVALID_REF;
1626 }
1627
1628 /* A grant for every tx ring slot */
1629 if (gnttab_alloc_grant_references(NET_TX_RING_SIZE,
1630 &queue->gref_tx_head) < 0) {
1631 pr_alert("can't alloc tx grant refs\n");
1632 err = -ENOMEM;
1633 goto exit;
1634 }
1635
1636 /* A grant for every rx ring slot */
1637 if (gnttab_alloc_grant_references(NET_RX_RING_SIZE,
1638 &queue->gref_rx_head) < 0) {
1639 pr_alert("can't alloc rx grant refs\n");
1640 err = -ENOMEM;
1641 goto exit_free_tx;
1642 }
1643
1644 return 0;
1645
1646 exit_free_tx:
1647 gnttab_free_grant_references(queue->gref_tx_head);
1648 exit:
1649 return err;
1650 }
1651
1652 static int write_queue_xenstore_keys(struct netfront_queue *queue,
1653 struct xenbus_transaction *xbt, int write_hierarchical)
1654 {
1655 /* Write the queue-specific keys into XenStore in the traditional
1656 * way for a single queue, or in a queue subkeys for multiple
1657 * queues.
1658 */
1659 struct xenbus_device *dev = queue->info->xbdev;
1660 int err;
1661 const char *message;
1662 char *path;
1663 size_t pathsize;
1664
1665 /* Choose the correct place to write the keys */
1666 if (write_hierarchical) {
1667 pathsize = strlen(dev->nodename) + 10;
1668 path = kzalloc(pathsize, GFP_KERNEL);
1669 if (!path) {
1670 err = -ENOMEM;
1671 message = "out of memory while writing ring references";
1672 goto error;
1673 }
1674 snprintf(path, pathsize, "%s/queue-%u",
1675 dev->nodename, queue->id);
1676 } else {
1677 path = (char *)dev->nodename;
1678 }
1679
1680 /* Write ring references */
1681 err = xenbus_printf(*xbt, path, "tx-ring-ref", "%u",
1682 queue->tx_ring_ref);
1683 if (err) {
1684 message = "writing tx-ring-ref";
1685 goto error;
1686 }
1687
1688 err = xenbus_printf(*xbt, path, "rx-ring-ref", "%u",
1689 queue->rx_ring_ref);
1690 if (err) {
1691 message = "writing rx-ring-ref";
1692 goto error;
1693 }
1694
1695 /* Write event channels; taking into account both shared
1696 * and split event channel scenarios.
1697 */
1698 if (queue->tx_evtchn == queue->rx_evtchn) {
1699 /* Shared event channel */
1700 err = xenbus_printf(*xbt, path,
1701 "event-channel", "%u", queue->tx_evtchn);
1702 if (err) {
1703 message = "writing event-channel";
1704 goto error;
1705 }
1706 } else {
1707 /* Split event channels */
1708 err = xenbus_printf(*xbt, path,
1709 "event-channel-tx", "%u", queue->tx_evtchn);
1710 if (err) {
1711 message = "writing event-channel-tx";
1712 goto error;
1713 }
1714
1715 err = xenbus_printf(*xbt, path,
1716 "event-channel-rx", "%u", queue->rx_evtchn);
1717 if (err) {
1718 message = "writing event-channel-rx";
1719 goto error;
1720 }
1721 }
1722
1723 if (write_hierarchical)
1724 kfree(path);
1725 return 0;
1726
1727 error:
1728 if (write_hierarchical)
1729 kfree(path);
1730 xenbus_dev_fatal(dev, err, "%s", message);
1731 return err;
1732 }
1733
1734 static void xennet_destroy_queues(struct netfront_info *info)
1735 {
1736 unsigned int i;
1737
1738 rtnl_lock();
1739
1740 for (i = 0; i < info->netdev->real_num_tx_queues; i++) {
1741 struct netfront_queue *queue = &info->queues[i];
1742
1743 if (netif_running(info->netdev))
1744 napi_disable(&queue->napi);
1745 netif_napi_del(&queue->napi);
1746 }
1747
1748 rtnl_unlock();
1749
1750 kfree(info->queues);
1751 info->queues = NULL;
1752 }
1753
1754 static int xennet_create_queues(struct netfront_info *info,
1755 unsigned int *num_queues)
1756 {
1757 unsigned int i;
1758 int ret;
1759
1760 info->queues = kcalloc(*num_queues, sizeof(struct netfront_queue),
1761 GFP_KERNEL);
1762 if (!info->queues)
1763 return -ENOMEM;
1764
1765 rtnl_lock();
1766
1767 for (i = 0; i < *num_queues; i++) {
1768 struct netfront_queue *queue = &info->queues[i];
1769
1770 queue->id = i;
1771 queue->info = info;
1772
1773 ret = xennet_init_queue(queue);
1774 if (ret < 0) {
1775 dev_warn(&info->netdev->dev,
1776 "only created %d queues\n", i);
1777 *num_queues = i;
1778 break;
1779 }
1780
1781 netif_napi_add(queue->info->netdev, &queue->napi,
1782 xennet_poll, 64);
1783 if (netif_running(info->netdev))
1784 napi_enable(&queue->napi);
1785 }
1786
1787 netif_set_real_num_tx_queues(info->netdev, *num_queues);
1788
1789 rtnl_unlock();
1790
1791 if (*num_queues == 0) {
1792 dev_err(&info->netdev->dev, "no queues\n");
1793 return -EINVAL;
1794 }
1795 return 0;
1796 }
1797
1798 /* Common code used when first setting up, and when resuming. */
1799 static int talk_to_netback(struct xenbus_device *dev,
1800 struct netfront_info *info)
1801 {
1802 const char *message;
1803 struct xenbus_transaction xbt;
1804 int err;
1805 unsigned int feature_split_evtchn;
1806 unsigned int i = 0;
1807 unsigned int max_queues = 0;
1808 struct netfront_queue *queue = NULL;
1809 unsigned int num_queues = 1;
1810
1811 info->netdev->irq = 0;
1812
1813 /* Check if backend supports multiple queues */
1814 max_queues = xenbus_read_unsigned(info->xbdev->otherend,
1815 "multi-queue-max-queues", 1);
1816 num_queues = min(max_queues, xennet_max_queues);
1817
1818 /* Check feature-split-event-channels */
1819 feature_split_evtchn = xenbus_read_unsigned(info->xbdev->otherend,
1820 "feature-split-event-channels", 0);
1821
1822 /* Read mac addr. */
1823 err = xen_net_read_mac(dev, info->netdev->dev_addr);
1824 if (err) {
1825 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
1826 goto out;
1827 }
1828
1829 if (info->queues)
1830 xennet_destroy_queues(info);
1831
1832 err = xennet_create_queues(info, &num_queues);
1833 if (err < 0) {
1834 xenbus_dev_fatal(dev, err, "creating queues");
1835 kfree(info->queues);
1836 info->queues = NULL;
1837 goto out;
1838 }
1839
1840 /* Create shared ring, alloc event channel -- for each queue */
1841 for (i = 0; i < num_queues; ++i) {
1842 queue = &info->queues[i];
1843 err = setup_netfront(dev, queue, feature_split_evtchn);
1844 if (err)
1845 goto destroy_ring;
1846 }
1847
1848 again:
1849 err = xenbus_transaction_start(&xbt);
1850 if (err) {
1851 xenbus_dev_fatal(dev, err, "starting transaction");
1852 goto destroy_ring;
1853 }
1854
1855 if (xenbus_exists(XBT_NIL,
1856 info->xbdev->otherend, "multi-queue-max-queues")) {
1857 /* Write the number of queues */
1858 err = xenbus_printf(xbt, dev->nodename,
1859 "multi-queue-num-queues", "%u", num_queues);
1860 if (err) {
1861 message = "writing multi-queue-num-queues";
1862 goto abort_transaction_no_dev_fatal;
1863 }
1864 }
1865
1866 if (num_queues == 1) {
1867 err = write_queue_xenstore_keys(&info->queues[0], &xbt, 0); /* flat */
1868 if (err)
1869 goto abort_transaction_no_dev_fatal;
1870 } else {
1871 /* Write the keys for each queue */
1872 for (i = 0; i < num_queues; ++i) {
1873 queue = &info->queues[i];
1874 err = write_queue_xenstore_keys(queue, &xbt, 1); /* hierarchical */
1875 if (err)
1876 goto abort_transaction_no_dev_fatal;
1877 }
1878 }
1879
1880 /* The remaining keys are not queue-specific */
1881 err = xenbus_printf(xbt, dev->nodename, "request-rx-copy", "%u",
1882 1);
1883 if (err) {
1884 message = "writing request-rx-copy";
1885 goto abort_transaction;
1886 }
1887
1888 err = xenbus_printf(xbt, dev->nodename, "feature-rx-notify", "%d", 1);
1889 if (err) {
1890 message = "writing feature-rx-notify";
1891 goto abort_transaction;
1892 }
1893
1894 err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", 1);
1895 if (err) {
1896 message = "writing feature-sg";
1897 goto abort_transaction;
1898 }
1899
1900 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4", "%d", 1);
1901 if (err) {
1902 message = "writing feature-gso-tcpv4";
1903 goto abort_transaction;
1904 }
1905
1906 err = xenbus_write(xbt, dev->nodename, "feature-gso-tcpv6", "1");
1907 if (err) {
1908 message = "writing feature-gso-tcpv6";
1909 goto abort_transaction;
1910 }
1911
1912 err = xenbus_write(xbt, dev->nodename, "feature-ipv6-csum-offload",
1913 "1");
1914 if (err) {
1915 message = "writing feature-ipv6-csum-offload";
1916 goto abort_transaction;
1917 }
1918
1919 err = xenbus_transaction_end(xbt, 0);
1920 if (err) {
1921 if (err == -EAGAIN)
1922 goto again;
1923 xenbus_dev_fatal(dev, err, "completing transaction");
1924 goto destroy_ring;
1925 }
1926
1927 return 0;
1928
1929 abort_transaction:
1930 xenbus_dev_fatal(dev, err, "%s", message);
1931 abort_transaction_no_dev_fatal:
1932 xenbus_transaction_end(xbt, 1);
1933 destroy_ring:
1934 xennet_disconnect_backend(info);
1935 xennet_destroy_queues(info);
1936 out:
1937 device_unregister(&dev->dev);
1938 return err;
1939 }
1940
1941 static int xennet_connect(struct net_device *dev)
1942 {
1943 struct netfront_info *np = netdev_priv(dev);
1944 unsigned int num_queues = 0;
1945 int err;
1946 unsigned int j = 0;
1947 struct netfront_queue *queue = NULL;
1948
1949 if (!xenbus_read_unsigned(np->xbdev->otherend, "feature-rx-copy", 0)) {
1950 dev_info(&dev->dev,
1951 "backend does not support copying receive path\n");
1952 return -ENODEV;
1953 }
1954
1955 err = talk_to_netback(np->xbdev, np);
1956 if (err)
1957 return err;
1958
1959 /* talk_to_netback() sets the correct number of queues */
1960 num_queues = dev->real_num_tx_queues;
1961
1962 rtnl_lock();
1963 netdev_update_features(dev);
1964 rtnl_unlock();
1965
1966 /*
1967 * All public and private state should now be sane. Get
1968 * ready to start sending and receiving packets and give the driver
1969 * domain a kick because we've probably just requeued some
1970 * packets.
1971 */
1972 netif_carrier_on(np->netdev);
1973 for (j = 0; j < num_queues; ++j) {
1974 queue = &np->queues[j];
1975
1976 notify_remote_via_irq(queue->tx_irq);
1977 if (queue->tx_irq != queue->rx_irq)
1978 notify_remote_via_irq(queue->rx_irq);
1979
1980 spin_lock_irq(&queue->tx_lock);
1981 xennet_tx_buf_gc(queue);
1982 spin_unlock_irq(&queue->tx_lock);
1983
1984 spin_lock_bh(&queue->rx_lock);
1985 xennet_alloc_rx_buffers(queue);
1986 spin_unlock_bh(&queue->rx_lock);
1987 }
1988
1989 return 0;
1990 }
1991
1992 /**
1993 * Callback received when the backend's state changes.
1994 */
1995 static void netback_changed(struct xenbus_device *dev,
1996 enum xenbus_state backend_state)
1997 {
1998 struct netfront_info *np = dev_get_drvdata(&dev->dev);
1999 struct net_device *netdev = np->netdev;
2000
2001 dev_dbg(&dev->dev, "%s\n", xenbus_strstate(backend_state));
2002
2003 switch (backend_state) {
2004 case XenbusStateInitialising:
2005 case XenbusStateInitialised:
2006 case XenbusStateReconfiguring:
2007 case XenbusStateReconfigured:
2008 case XenbusStateUnknown:
2009 break;
2010
2011 case XenbusStateInitWait:
2012 if (dev->state != XenbusStateInitialising)
2013 break;
2014 if (xennet_connect(netdev) != 0)
2015 break;
2016 xenbus_switch_state(dev, XenbusStateConnected);
2017 break;
2018
2019 case XenbusStateConnected:
2020 netdev_notify_peers(netdev);
2021 break;
2022
2023 case XenbusStateClosed:
2024 if (dev->state == XenbusStateClosed)
2025 break;
2026 /* Missed the backend's CLOSING state -- fallthrough */
2027 case XenbusStateClosing:
2028 xenbus_frontend_closed(dev);
2029 break;
2030 }
2031 }
2032
2033 static const struct xennet_stat {
2034 char name[ETH_GSTRING_LEN];
2035 u16 offset;
2036 } xennet_stats[] = {
2037 {
2038 "rx_gso_checksum_fixup",
2039 offsetof(struct netfront_info, rx_gso_checksum_fixup)
2040 },
2041 };
2042
2043 static int xennet_get_sset_count(struct net_device *dev, int string_set)
2044 {
2045 switch (string_set) {
2046 case ETH_SS_STATS:
2047 return ARRAY_SIZE(xennet_stats);
2048 default:
2049 return -EINVAL;
2050 }
2051 }
2052
2053 static void xennet_get_ethtool_stats(struct net_device *dev,
2054 struct ethtool_stats *stats, u64 * data)
2055 {
2056 void *np = netdev_priv(dev);
2057 int i;
2058
2059 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
2060 data[i] = atomic_read((atomic_t *)(np + xennet_stats[i].offset));
2061 }
2062
2063 static void xennet_get_strings(struct net_device *dev, u32 stringset, u8 * data)
2064 {
2065 int i;
2066
2067 switch (stringset) {
2068 case ETH_SS_STATS:
2069 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
2070 memcpy(data + i * ETH_GSTRING_LEN,
2071 xennet_stats[i].name, ETH_GSTRING_LEN);
2072 break;
2073 }
2074 }
2075
2076 static const struct ethtool_ops xennet_ethtool_ops =
2077 {
2078 .get_link = ethtool_op_get_link,
2079
2080 .get_sset_count = xennet_get_sset_count,
2081 .get_ethtool_stats = xennet_get_ethtool_stats,
2082 .get_strings = xennet_get_strings,
2083 };
2084
2085 #ifdef CONFIG_SYSFS
2086 static ssize_t show_rxbuf(struct device *dev,
2087 struct device_attribute *attr, char *buf)
2088 {
2089 return sprintf(buf, "%lu\n", NET_RX_RING_SIZE);
2090 }
2091
2092 static ssize_t store_rxbuf(struct device *dev,
2093 struct device_attribute *attr,
2094 const char *buf, size_t len)
2095 {
2096 char *endp;
2097 unsigned long target;
2098
2099 if (!capable(CAP_NET_ADMIN))
2100 return -EPERM;
2101
2102 target = simple_strtoul(buf, &endp, 0);
2103 if (endp == buf)
2104 return -EBADMSG;
2105
2106 /* rxbuf_min and rxbuf_max are no longer configurable. */
2107
2108 return len;
2109 }
2110
2111 static DEVICE_ATTR(rxbuf_min, S_IRUGO|S_IWUSR, show_rxbuf, store_rxbuf);
2112 static DEVICE_ATTR(rxbuf_max, S_IRUGO|S_IWUSR, show_rxbuf, store_rxbuf);
2113 static DEVICE_ATTR(rxbuf_cur, S_IRUGO, show_rxbuf, NULL);
2114
2115 static struct attribute *xennet_dev_attrs[] = {
2116 &dev_attr_rxbuf_min.attr,
2117 &dev_attr_rxbuf_max.attr,
2118 &dev_attr_rxbuf_cur.attr,
2119 NULL
2120 };
2121
2122 static const struct attribute_group xennet_dev_group = {
2123 .attrs = xennet_dev_attrs
2124 };
2125 #endif /* CONFIG_SYSFS */
2126
2127 static int xennet_remove(struct xenbus_device *dev)
2128 {
2129 struct netfront_info *info = dev_get_drvdata(&dev->dev);
2130
2131 dev_dbg(&dev->dev, "%s\n", dev->nodename);
2132
2133 xennet_disconnect_backend(info);
2134
2135 unregister_netdev(info->netdev);
2136
2137 if (info->queues)
2138 xennet_destroy_queues(info);
2139 xennet_free_netdev(info->netdev);
2140
2141 return 0;
2142 }
2143
2144 static const struct xenbus_device_id netfront_ids[] = {
2145 { "vif" },
2146 { "" }
2147 };
2148
2149 static struct xenbus_driver netfront_driver = {
2150 .ids = netfront_ids,
2151 .probe = netfront_probe,
2152 .remove = xennet_remove,
2153 .resume = netfront_resume,
2154 .otherend_changed = netback_changed,
2155 };
2156
2157 static int __init netif_init(void)
2158 {
2159 if (!xen_domain())
2160 return -ENODEV;
2161
2162 if (!xen_has_pv_nic_devices())
2163 return -ENODEV;
2164
2165 pr_info("Initialising Xen virtual ethernet driver\n");
2166
2167 /* Allow as many queues as there are CPUs inut max. 8 if user has not
2168 * specified a value.
2169 */
2170 if (xennet_max_queues == 0)
2171 xennet_max_queues = min_t(unsigned int, MAX_QUEUES_DEFAULT,
2172 num_online_cpus());
2173
2174 return xenbus_register_frontend(&netfront_driver);
2175 }
2176 module_init(netif_init);
2177
2178
2179 static void __exit netif_exit(void)
2180 {
2181 xenbus_unregister_driver(&netfront_driver);
2182 }
2183 module_exit(netif_exit);
2184
2185 MODULE_DESCRIPTION("Xen virtual network device frontend");
2186 MODULE_LICENSE("GPL");
2187 MODULE_ALIAS("xen:vif");
2188 MODULE_ALIAS("xennet");
Linux with added FPC-III support