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Merge tag 'modules-for-v5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu...
[mirror_ubuntu-hirsute-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 #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 static DECLARE_WAIT_QUEUE_HEAD(module_wq);
91
92 struct netfront_stats {
93 u64 packets;
94 u64 bytes;
95 struct u64_stats_sync syncp;
96 };
97
98 struct netfront_info;
99
100 struct netfront_queue {
101 unsigned int id; /* Queue ID, 0-based */
102 char name[QUEUE_NAME_SIZE]; /* DEVNAME-qN */
103 struct netfront_info *info;
104
105 struct napi_struct napi;
106
107 /* Split event channels support, tx_* == rx_* when using
108 * single event channel.
109 */
110 unsigned int tx_evtchn, rx_evtchn;
111 unsigned int tx_irq, rx_irq;
112 /* Only used when split event channels support is enabled */
113 char tx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-tx */
114 char rx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-rx */
115
116 spinlock_t tx_lock;
117 struct xen_netif_tx_front_ring tx;
118 int tx_ring_ref;
119
120 /*
121 * {tx,rx}_skbs store outstanding skbuffs. Free tx_skb entries
122 * are linked from tx_skb_freelist through skb_entry.link.
123 *
124 * NB. Freelist index entries are always going to be less than
125 * PAGE_OFFSET, whereas pointers to skbs will always be equal or
126 * greater than PAGE_OFFSET: we use this property to distinguish
127 * them.
128 */
129 union skb_entry {
130 struct sk_buff *skb;
131 unsigned long link;
132 } tx_skbs[NET_TX_RING_SIZE];
133 grant_ref_t gref_tx_head;
134 grant_ref_t grant_tx_ref[NET_TX_RING_SIZE];
135 struct page *grant_tx_page[NET_TX_RING_SIZE];
136 unsigned tx_skb_freelist;
137
138 spinlock_t rx_lock ____cacheline_aligned_in_smp;
139 struct xen_netif_rx_front_ring rx;
140 int rx_ring_ref;
141
142 struct timer_list rx_refill_timer;
143
144 struct sk_buff *rx_skbs[NET_RX_RING_SIZE];
145 grant_ref_t gref_rx_head;
146 grant_ref_t grant_rx_ref[NET_RX_RING_SIZE];
147 };
148
149 struct netfront_info {
150 struct list_head list;
151 struct net_device *netdev;
152
153 struct xenbus_device *xbdev;
154
155 /* Multi-queue support */
156 struct netfront_queue *queues;
157
158 /* Statistics */
159 struct netfront_stats __percpu *rx_stats;
160 struct netfront_stats __percpu *tx_stats;
161
162 atomic_t rx_gso_checksum_fixup;
163 };
164
165 struct netfront_rx_info {
166 struct xen_netif_rx_response rx;
167 struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX - 1];
168 };
169
170 static void skb_entry_set_link(union skb_entry *list, unsigned short id)
171 {
172 list->link = id;
173 }
174
175 static int skb_entry_is_link(const union skb_entry *list)
176 {
177 BUILD_BUG_ON(sizeof(list->skb) != sizeof(list->link));
178 return (unsigned long)list->skb < PAGE_OFFSET;
179 }
180
181 /*
182 * Access macros for acquiring freeing slots in tx_skbs[].
183 */
184
185 static void add_id_to_freelist(unsigned *head, union skb_entry *list,
186 unsigned short id)
187 {
188 skb_entry_set_link(&list[id], *head);
189 *head = id;
190 }
191
192 static unsigned short get_id_from_freelist(unsigned *head,
193 union skb_entry *list)
194 {
195 unsigned int id = *head;
196 *head = list[id].link;
197 return id;
198 }
199
200 static int xennet_rxidx(RING_IDX idx)
201 {
202 return idx & (NET_RX_RING_SIZE - 1);
203 }
204
205 static struct sk_buff *xennet_get_rx_skb(struct netfront_queue *queue,
206 RING_IDX ri)
207 {
208 int i = xennet_rxidx(ri);
209 struct sk_buff *skb = queue->rx_skbs[i];
210 queue->rx_skbs[i] = NULL;
211 return skb;
212 }
213
214 static grant_ref_t xennet_get_rx_ref(struct netfront_queue *queue,
215 RING_IDX ri)
216 {
217 int i = xennet_rxidx(ri);
218 grant_ref_t ref = queue->grant_rx_ref[i];
219 queue->grant_rx_ref[i] = GRANT_INVALID_REF;
220 return ref;
221 }
222
223 #ifdef CONFIG_SYSFS
224 static const struct attribute_group xennet_dev_group;
225 #endif
226
227 static bool xennet_can_sg(struct net_device *dev)
228 {
229 return dev->features & NETIF_F_SG;
230 }
231
232
233 static void rx_refill_timeout(struct timer_list *t)
234 {
235 struct netfront_queue *queue = from_timer(queue, t, rx_refill_timer);
236 napi_schedule(&queue->napi);
237 }
238
239 static int netfront_tx_slot_available(struct netfront_queue *queue)
240 {
241 return (queue->tx.req_prod_pvt - queue->tx.rsp_cons) <
242 (NET_TX_RING_SIZE - XEN_NETIF_NR_SLOTS_MIN - 1);
243 }
244
245 static void xennet_maybe_wake_tx(struct netfront_queue *queue)
246 {
247 struct net_device *dev = queue->info->netdev;
248 struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, queue->id);
249
250 if (unlikely(netif_tx_queue_stopped(dev_queue)) &&
251 netfront_tx_slot_available(queue) &&
252 likely(netif_running(dev)))
253 netif_tx_wake_queue(netdev_get_tx_queue(dev, queue->id));
254 }
255
256
257 static struct sk_buff *xennet_alloc_one_rx_buffer(struct netfront_queue *queue)
258 {
259 struct sk_buff *skb;
260 struct page *page;
261
262 skb = __netdev_alloc_skb(queue->info->netdev,
263 RX_COPY_THRESHOLD + NET_IP_ALIGN,
264 GFP_ATOMIC | __GFP_NOWARN);
265 if (unlikely(!skb))
266 return NULL;
267
268 page = alloc_page(GFP_ATOMIC | __GFP_NOWARN);
269 if (!page) {
270 kfree_skb(skb);
271 return NULL;
272 }
273 skb_add_rx_frag(skb, 0, page, 0, 0, PAGE_SIZE);
274
275 /* Align ip header to a 16 bytes boundary */
276 skb_reserve(skb, NET_IP_ALIGN);
277 skb->dev = queue->info->netdev;
278
279 return skb;
280 }
281
282
283 static void xennet_alloc_rx_buffers(struct netfront_queue *queue)
284 {
285 RING_IDX req_prod = queue->rx.req_prod_pvt;
286 int notify;
287 int err = 0;
288
289 if (unlikely(!netif_carrier_ok(queue->info->netdev)))
290 return;
291
292 for (req_prod = queue->rx.req_prod_pvt;
293 req_prod - queue->rx.rsp_cons < NET_RX_RING_SIZE;
294 req_prod++) {
295 struct sk_buff *skb;
296 unsigned short id;
297 grant_ref_t ref;
298 struct page *page;
299 struct xen_netif_rx_request *req;
300
301 skb = xennet_alloc_one_rx_buffer(queue);
302 if (!skb) {
303 err = -ENOMEM;
304 break;
305 }
306
307 id = xennet_rxidx(req_prod);
308
309 BUG_ON(queue->rx_skbs[id]);
310 queue->rx_skbs[id] = skb;
311
312 ref = gnttab_claim_grant_reference(&queue->gref_rx_head);
313 WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)(int)ref));
314 queue->grant_rx_ref[id] = ref;
315
316 page = skb_frag_page(&skb_shinfo(skb)->frags[0]);
317
318 req = RING_GET_REQUEST(&queue->rx, req_prod);
319 gnttab_page_grant_foreign_access_ref_one(ref,
320 queue->info->xbdev->otherend_id,
321 page,
322 0);
323 req->id = id;
324 req->gref = ref;
325 }
326
327 queue->rx.req_prod_pvt = req_prod;
328
329 /* Try again later if there are not enough requests or skb allocation
330 * failed.
331 * Enough requests is quantified as the sum of newly created slots and
332 * the unconsumed slots at the backend.
333 */
334 if (req_prod - queue->rx.rsp_cons < NET_RX_SLOTS_MIN ||
335 unlikely(err)) {
336 mod_timer(&queue->rx_refill_timer, jiffies + (HZ/10));
337 return;
338 }
339
340 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 if (!np->queues)
353 return -ENODEV;
354
355 for (i = 0; i < num_queues; ++i) {
356 queue = &np->queues[i];
357 napi_enable(&queue->napi);
358
359 spin_lock_bh(&queue->rx_lock);
360 if (netif_carrier_ok(dev)) {
361 xennet_alloc_rx_buffers(queue);
362 queue->rx.sring->rsp_event = queue->rx.rsp_cons + 1;
363 if (RING_HAS_UNCONSUMED_RESPONSES(&queue->rx))
364 napi_schedule(&queue->napi);
365 }
366 spin_unlock_bh(&queue->rx_lock);
367 }
368
369 netif_tx_start_all_queues(dev);
370
371 return 0;
372 }
373
374 static void xennet_tx_buf_gc(struct netfront_queue *queue)
375 {
376 RING_IDX cons, prod;
377 unsigned short id;
378 struct sk_buff *skb;
379 bool more_to_do;
380
381 BUG_ON(!netif_carrier_ok(queue->info->netdev));
382
383 do {
384 prod = queue->tx.sring->rsp_prod;
385 rmb(); /* Ensure we see responses up to 'rp'. */
386
387 for (cons = queue->tx.rsp_cons; cons != prod; cons++) {
388 struct xen_netif_tx_response *txrsp;
389
390 txrsp = RING_GET_RESPONSE(&queue->tx, cons);
391 if (txrsp->status == XEN_NETIF_RSP_NULL)
392 continue;
393
394 id = txrsp->id;
395 skb = queue->tx_skbs[id].skb;
396 if (unlikely(gnttab_query_foreign_access(
397 queue->grant_tx_ref[id]) != 0)) {
398 pr_alert("%s: warning -- grant still in use by backend domain\n",
399 __func__);
400 BUG();
401 }
402 gnttab_end_foreign_access_ref(
403 queue->grant_tx_ref[id], GNTMAP_readonly);
404 gnttab_release_grant_reference(
405 &queue->gref_tx_head, queue->grant_tx_ref[id]);
406 queue->grant_tx_ref[id] = GRANT_INVALID_REF;
407 queue->grant_tx_page[id] = NULL;
408 add_id_to_freelist(&queue->tx_skb_freelist, queue->tx_skbs, id);
409 dev_kfree_skb_irq(skb);
410 }
411
412 queue->tx.rsp_cons = prod;
413
414 RING_FINAL_CHECK_FOR_RESPONSES(&queue->tx, more_to_do);
415 } while (more_to_do);
416
417 xennet_maybe_wake_tx(queue);
418 }
419
420 struct xennet_gnttab_make_txreq {
421 struct netfront_queue *queue;
422 struct sk_buff *skb;
423 struct page *page;
424 struct xen_netif_tx_request *tx; /* Last request */
425 unsigned int size;
426 };
427
428 static void xennet_tx_setup_grant(unsigned long gfn, unsigned int offset,
429 unsigned int len, void *data)
430 {
431 struct xennet_gnttab_make_txreq *info = data;
432 unsigned int id;
433 struct xen_netif_tx_request *tx;
434 grant_ref_t ref;
435 /* convenient aliases */
436 struct page *page = info->page;
437 struct netfront_queue *queue = info->queue;
438 struct sk_buff *skb = info->skb;
439
440 id = get_id_from_freelist(&queue->tx_skb_freelist, queue->tx_skbs);
441 tx = RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++);
442 ref = gnttab_claim_grant_reference(&queue->gref_tx_head);
443 WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)(int)ref));
444
445 gnttab_grant_foreign_access_ref(ref, queue->info->xbdev->otherend_id,
446 gfn, GNTMAP_readonly);
447
448 queue->tx_skbs[id].skb = skb;
449 queue->grant_tx_page[id] = page;
450 queue->grant_tx_ref[id] = ref;
451
452 tx->id = id;
453 tx->gref = ref;
454 tx->offset = offset;
455 tx->size = len;
456 tx->flags = 0;
457
458 info->tx = tx;
459 info->size += tx->size;
460 }
461
462 static struct xen_netif_tx_request *xennet_make_first_txreq(
463 struct netfront_queue *queue, struct sk_buff *skb,
464 struct page *page, unsigned int offset, unsigned int len)
465 {
466 struct xennet_gnttab_make_txreq info = {
467 .queue = queue,
468 .skb = skb,
469 .page = page,
470 .size = 0,
471 };
472
473 gnttab_for_one_grant(page, offset, len, xennet_tx_setup_grant, &info);
474
475 return info.tx;
476 }
477
478 static void xennet_make_one_txreq(unsigned long gfn, unsigned int offset,
479 unsigned int len, void *data)
480 {
481 struct xennet_gnttab_make_txreq *info = data;
482
483 info->tx->flags |= XEN_NETTXF_more_data;
484 skb_get(info->skb);
485 xennet_tx_setup_grant(gfn, offset, len, data);
486 }
487
488 static struct xen_netif_tx_request *xennet_make_txreqs(
489 struct netfront_queue *queue, struct xen_netif_tx_request *tx,
490 struct sk_buff *skb, struct page *page,
491 unsigned int offset, unsigned int len)
492 {
493 struct xennet_gnttab_make_txreq info = {
494 .queue = queue,
495 .skb = skb,
496 .tx = tx,
497 };
498
499 /* Skip unused frames from start of page */
500 page += offset >> PAGE_SHIFT;
501 offset &= ~PAGE_MASK;
502
503 while (len) {
504 info.page = page;
505 info.size = 0;
506
507 gnttab_foreach_grant_in_range(page, offset, len,
508 xennet_make_one_txreq,
509 &info);
510
511 page++;
512 offset = 0;
513 len -= info.size;
514 }
515
516 return info.tx;
517 }
518
519 /*
520 * Count how many ring slots are required to send this skb. Each frag
521 * might be a compound page.
522 */
523 static int xennet_count_skb_slots(struct sk_buff *skb)
524 {
525 int i, frags = skb_shinfo(skb)->nr_frags;
526 int slots;
527
528 slots = gnttab_count_grant(offset_in_page(skb->data),
529 skb_headlen(skb));
530
531 for (i = 0; i < frags; i++) {
532 skb_frag_t *frag = skb_shinfo(skb)->frags + i;
533 unsigned long size = skb_frag_size(frag);
534 unsigned long offset = frag->page_offset;
535
536 /* Skip unused frames from start of page */
537 offset &= ~PAGE_MASK;
538
539 slots += gnttab_count_grant(offset, size);
540 }
541
542 return slots;
543 }
544
545 static u16 xennet_select_queue(struct net_device *dev, struct sk_buff *skb,
546 struct net_device *sb_dev)
547 {
548 unsigned int num_queues = dev->real_num_tx_queues;
549 u32 hash;
550 u16 queue_idx;
551
552 /* First, check if there is only one queue */
553 if (num_queues == 1) {
554 queue_idx = 0;
555 } else {
556 hash = skb_get_hash(skb);
557 queue_idx = hash % num_queues;
558 }
559
560 return queue_idx;
561 }
562
563 #define MAX_XEN_SKB_FRAGS (65536 / XEN_PAGE_SIZE + 1)
564
565 static netdev_tx_t xennet_start_xmit(struct sk_buff *skb, struct net_device *dev)
566 {
567 struct netfront_info *np = netdev_priv(dev);
568 struct netfront_stats *tx_stats = this_cpu_ptr(np->tx_stats);
569 struct xen_netif_tx_request *tx, *first_tx;
570 unsigned int i;
571 int notify;
572 int slots;
573 struct page *page;
574 unsigned int offset;
575 unsigned int len;
576 unsigned long flags;
577 struct netfront_queue *queue = NULL;
578 unsigned int num_queues = dev->real_num_tx_queues;
579 u16 queue_index;
580 struct sk_buff *nskb;
581
582 /* Drop the packet if no queues are set up */
583 if (num_queues < 1)
584 goto drop;
585 /* Determine which queue to transmit this SKB on */
586 queue_index = skb_get_queue_mapping(skb);
587 queue = &np->queues[queue_index];
588
589 /* If skb->len is too big for wire format, drop skb and alert
590 * user about misconfiguration.
591 */
592 if (unlikely(skb->len > XEN_NETIF_MAX_TX_SIZE)) {
593 net_alert_ratelimited(
594 "xennet: skb->len = %u, too big for wire format\n",
595 skb->len);
596 goto drop;
597 }
598
599 slots = xennet_count_skb_slots(skb);
600 if (unlikely(slots > MAX_XEN_SKB_FRAGS + 1)) {
601 net_dbg_ratelimited("xennet: skb rides the rocket: %d slots, %d bytes\n",
602 slots, skb->len);
603 if (skb_linearize(skb))
604 goto drop;
605 }
606
607 page = virt_to_page(skb->data);
608 offset = offset_in_page(skb->data);
609
610 /* The first req should be at least ETH_HLEN size or the packet will be
611 * dropped by netback.
612 */
613 if (unlikely(PAGE_SIZE - offset < ETH_HLEN)) {
614 nskb = skb_copy(skb, GFP_ATOMIC);
615 if (!nskb)
616 goto drop;
617 dev_consume_skb_any(skb);
618 skb = nskb;
619 page = virt_to_page(skb->data);
620 offset = offset_in_page(skb->data);
621 }
622
623 len = skb_headlen(skb);
624
625 spin_lock_irqsave(&queue->tx_lock, flags);
626
627 if (unlikely(!netif_carrier_ok(dev) ||
628 (slots > 1 && !xennet_can_sg(dev)) ||
629 netif_needs_gso(skb, netif_skb_features(skb)))) {
630 spin_unlock_irqrestore(&queue->tx_lock, flags);
631 goto drop;
632 }
633
634 /* First request for the linear area. */
635 first_tx = tx = xennet_make_first_txreq(queue, skb,
636 page, offset, len);
637 offset += tx->size;
638 if (offset == PAGE_SIZE) {
639 page++;
640 offset = 0;
641 }
642 len -= tx->size;
643
644 if (skb->ip_summed == CHECKSUM_PARTIAL)
645 /* local packet? */
646 tx->flags |= XEN_NETTXF_csum_blank | XEN_NETTXF_data_validated;
647 else if (skb->ip_summed == CHECKSUM_UNNECESSARY)
648 /* remote but checksummed. */
649 tx->flags |= XEN_NETTXF_data_validated;
650
651 /* Optional extra info after the first request. */
652 if (skb_shinfo(skb)->gso_size) {
653 struct xen_netif_extra_info *gso;
654
655 gso = (struct xen_netif_extra_info *)
656 RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++);
657
658 tx->flags |= XEN_NETTXF_extra_info;
659
660 gso->u.gso.size = skb_shinfo(skb)->gso_size;
661 gso->u.gso.type = (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) ?
662 XEN_NETIF_GSO_TYPE_TCPV6 :
663 XEN_NETIF_GSO_TYPE_TCPV4;
664 gso->u.gso.pad = 0;
665 gso->u.gso.features = 0;
666
667 gso->type = XEN_NETIF_EXTRA_TYPE_GSO;
668 gso->flags = 0;
669 }
670
671 /* Requests for the rest of the linear area. */
672 tx = xennet_make_txreqs(queue, tx, skb, page, offset, len);
673
674 /* Requests for all the frags. */
675 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
676 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
677 tx = xennet_make_txreqs(queue, tx, skb,
678 skb_frag_page(frag), frag->page_offset,
679 skb_frag_size(frag));
680 }
681
682 /* First request has the packet length. */
683 first_tx->size = skb->len;
684
685 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->tx, notify);
686 if (notify)
687 notify_remote_via_irq(queue->tx_irq);
688
689 u64_stats_update_begin(&tx_stats->syncp);
690 tx_stats->bytes += skb->len;
691 tx_stats->packets++;
692 u64_stats_update_end(&tx_stats->syncp);
693
694 /* Note: It is not safe to access skb after xennet_tx_buf_gc()! */
695 xennet_tx_buf_gc(queue);
696
697 if (!netfront_tx_slot_available(queue))
698 netif_tx_stop_queue(netdev_get_tx_queue(dev, queue->id));
699
700 spin_unlock_irqrestore(&queue->tx_lock, flags);
701
702 return NETDEV_TX_OK;
703
704 drop:
705 dev->stats.tx_dropped++;
706 dev_kfree_skb_any(skb);
707 return NETDEV_TX_OK;
708 }
709
710 static int xennet_close(struct net_device *dev)
711 {
712 struct netfront_info *np = netdev_priv(dev);
713 unsigned int num_queues = dev->real_num_tx_queues;
714 unsigned int i;
715 struct netfront_queue *queue;
716 netif_tx_stop_all_queues(np->netdev);
717 for (i = 0; i < num_queues; ++i) {
718 queue = &np->queues[i];
719 napi_disable(&queue->napi);
720 }
721 return 0;
722 }
723
724 static void xennet_move_rx_slot(struct netfront_queue *queue, struct sk_buff *skb,
725 grant_ref_t ref)
726 {
727 int new = xennet_rxidx(queue->rx.req_prod_pvt);
728
729 BUG_ON(queue->rx_skbs[new]);
730 queue->rx_skbs[new] = skb;
731 queue->grant_rx_ref[new] = ref;
732 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->id = new;
733 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->gref = ref;
734 queue->rx.req_prod_pvt++;
735 }
736
737 static int xennet_get_extras(struct netfront_queue *queue,
738 struct xen_netif_extra_info *extras,
739 RING_IDX rp)
740
741 {
742 struct xen_netif_extra_info *extra;
743 struct device *dev = &queue->info->netdev->dev;
744 RING_IDX cons = queue->rx.rsp_cons;
745 int err = 0;
746
747 do {
748 struct sk_buff *skb;
749 grant_ref_t ref;
750
751 if (unlikely(cons + 1 == rp)) {
752 if (net_ratelimit())
753 dev_warn(dev, "Missing extra info\n");
754 err = -EBADR;
755 break;
756 }
757
758 extra = (struct xen_netif_extra_info *)
759 RING_GET_RESPONSE(&queue->rx, ++cons);
760
761 if (unlikely(!extra->type ||
762 extra->type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
763 if (net_ratelimit())
764 dev_warn(dev, "Invalid extra type: %d\n",
765 extra->type);
766 err = -EINVAL;
767 } else {
768 memcpy(&extras[extra->type - 1], extra,
769 sizeof(*extra));
770 }
771
772 skb = xennet_get_rx_skb(queue, cons);
773 ref = xennet_get_rx_ref(queue, cons);
774 xennet_move_rx_slot(queue, skb, ref);
775 } while (extra->flags & XEN_NETIF_EXTRA_FLAG_MORE);
776
777 queue->rx.rsp_cons = cons;
778 return err;
779 }
780
781 static int xennet_get_responses(struct netfront_queue *queue,
782 struct netfront_rx_info *rinfo, RING_IDX rp,
783 struct sk_buff_head *list)
784 {
785 struct xen_netif_rx_response *rx = &rinfo->rx;
786 struct xen_netif_extra_info *extras = rinfo->extras;
787 struct device *dev = &queue->info->netdev->dev;
788 RING_IDX cons = queue->rx.rsp_cons;
789 struct sk_buff *skb = xennet_get_rx_skb(queue, cons);
790 grant_ref_t ref = xennet_get_rx_ref(queue, cons);
791 int max = XEN_NETIF_NR_SLOTS_MIN + (rx->status <= RX_COPY_THRESHOLD);
792 int slots = 1;
793 int err = 0;
794 unsigned long ret;
795
796 if (rx->flags & XEN_NETRXF_extra_info) {
797 err = xennet_get_extras(queue, extras, rp);
798 cons = queue->rx.rsp_cons;
799 }
800
801 for (;;) {
802 if (unlikely(rx->status < 0 ||
803 rx->offset + rx->status > XEN_PAGE_SIZE)) {
804 if (net_ratelimit())
805 dev_warn(dev, "rx->offset: %u, size: %d\n",
806 rx->offset, rx->status);
807 xennet_move_rx_slot(queue, skb, ref);
808 err = -EINVAL;
809 goto next;
810 }
811
812 /*
813 * This definitely indicates a bug, either in this driver or in
814 * the backend driver. In future this should flag the bad
815 * situation to the system controller to reboot the backend.
816 */
817 if (ref == GRANT_INVALID_REF) {
818 if (net_ratelimit())
819 dev_warn(dev, "Bad rx response id %d.\n",
820 rx->id);
821 err = -EINVAL;
822 goto next;
823 }
824
825 ret = gnttab_end_foreign_access_ref(ref, 0);
826 BUG_ON(!ret);
827
828 gnttab_release_grant_reference(&queue->gref_rx_head, ref);
829
830 __skb_queue_tail(list, skb);
831
832 next:
833 if (!(rx->flags & XEN_NETRXF_more_data))
834 break;
835
836 if (cons + slots == rp) {
837 if (net_ratelimit())
838 dev_warn(dev, "Need more slots\n");
839 err = -ENOENT;
840 break;
841 }
842
843 rx = RING_GET_RESPONSE(&queue->rx, cons + slots);
844 skb = xennet_get_rx_skb(queue, cons + slots);
845 ref = xennet_get_rx_ref(queue, cons + slots);
846 slots++;
847 }
848
849 if (unlikely(slots > max)) {
850 if (net_ratelimit())
851 dev_warn(dev, "Too many slots\n");
852 err = -E2BIG;
853 }
854
855 if (unlikely(err))
856 queue->rx.rsp_cons = cons + slots;
857
858 return err;
859 }
860
861 static int xennet_set_skb_gso(struct sk_buff *skb,
862 struct xen_netif_extra_info *gso)
863 {
864 if (!gso->u.gso.size) {
865 if (net_ratelimit())
866 pr_warn("GSO size must not be zero\n");
867 return -EINVAL;
868 }
869
870 if (gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV4 &&
871 gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV6) {
872 if (net_ratelimit())
873 pr_warn("Bad GSO type %d\n", gso->u.gso.type);
874 return -EINVAL;
875 }
876
877 skb_shinfo(skb)->gso_size = gso->u.gso.size;
878 skb_shinfo(skb)->gso_type =
879 (gso->u.gso.type == XEN_NETIF_GSO_TYPE_TCPV4) ?
880 SKB_GSO_TCPV4 :
881 SKB_GSO_TCPV6;
882
883 /* Header must be checked, and gso_segs computed. */
884 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
885 skb_shinfo(skb)->gso_segs = 0;
886
887 return 0;
888 }
889
890 static RING_IDX xennet_fill_frags(struct netfront_queue *queue,
891 struct sk_buff *skb,
892 struct sk_buff_head *list)
893 {
894 RING_IDX cons = queue->rx.rsp_cons;
895 struct sk_buff *nskb;
896
897 while ((nskb = __skb_dequeue(list))) {
898 struct xen_netif_rx_response *rx =
899 RING_GET_RESPONSE(&queue->rx, ++cons);
900 skb_frag_t *nfrag = &skb_shinfo(nskb)->frags[0];
901
902 if (skb_shinfo(skb)->nr_frags == MAX_SKB_FRAGS) {
903 unsigned int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
904
905 BUG_ON(pull_to < skb_headlen(skb));
906 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
907 }
908 if (unlikely(skb_shinfo(skb)->nr_frags >= MAX_SKB_FRAGS)) {
909 queue->rx.rsp_cons = ++cons;
910 kfree_skb(nskb);
911 return ~0U;
912 }
913
914 skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
915 skb_frag_page(nfrag),
916 rx->offset, rx->status, PAGE_SIZE);
917
918 skb_shinfo(nskb)->nr_frags = 0;
919 kfree_skb(nskb);
920 }
921
922 return cons;
923 }
924
925 static int checksum_setup(struct net_device *dev, struct sk_buff *skb)
926 {
927 bool recalculate_partial_csum = false;
928
929 /*
930 * A GSO SKB must be CHECKSUM_PARTIAL. However some buggy
931 * peers can fail to set NETRXF_csum_blank when sending a GSO
932 * frame. In this case force the SKB to CHECKSUM_PARTIAL and
933 * recalculate the partial checksum.
934 */
935 if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) {
936 struct netfront_info *np = netdev_priv(dev);
937 atomic_inc(&np->rx_gso_checksum_fixup);
938 skb->ip_summed = CHECKSUM_PARTIAL;
939 recalculate_partial_csum = true;
940 }
941
942 /* A non-CHECKSUM_PARTIAL SKB does not require setup. */
943 if (skb->ip_summed != CHECKSUM_PARTIAL)
944 return 0;
945
946 return skb_checksum_setup(skb, recalculate_partial_csum);
947 }
948
949 static int handle_incoming_queue(struct netfront_queue *queue,
950 struct sk_buff_head *rxq)
951 {
952 struct netfront_stats *rx_stats = this_cpu_ptr(queue->info->rx_stats);
953 int packets_dropped = 0;
954 struct sk_buff *skb;
955
956 while ((skb = __skb_dequeue(rxq)) != NULL) {
957 int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
958
959 if (pull_to > skb_headlen(skb))
960 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
961
962 /* Ethernet work: Delayed to here as it peeks the header. */
963 skb->protocol = eth_type_trans(skb, queue->info->netdev);
964 skb_reset_network_header(skb);
965
966 if (checksum_setup(queue->info->netdev, skb)) {
967 kfree_skb(skb);
968 packets_dropped++;
969 queue->info->netdev->stats.rx_errors++;
970 continue;
971 }
972
973 u64_stats_update_begin(&rx_stats->syncp);
974 rx_stats->packets++;
975 rx_stats->bytes += skb->len;
976 u64_stats_update_end(&rx_stats->syncp);
977
978 /* Pass it up. */
979 napi_gro_receive(&queue->napi, skb);
980 }
981
982 return packets_dropped;
983 }
984
985 static int xennet_poll(struct napi_struct *napi, int budget)
986 {
987 struct netfront_queue *queue = container_of(napi, struct netfront_queue, napi);
988 struct net_device *dev = queue->info->netdev;
989 struct sk_buff *skb;
990 struct netfront_rx_info rinfo;
991 struct xen_netif_rx_response *rx = &rinfo.rx;
992 struct xen_netif_extra_info *extras = rinfo.extras;
993 RING_IDX i, rp;
994 int work_done;
995 struct sk_buff_head rxq;
996 struct sk_buff_head errq;
997 struct sk_buff_head tmpq;
998 int err;
999
1000 spin_lock(&queue->rx_lock);
1001
1002 skb_queue_head_init(&rxq);
1003 skb_queue_head_init(&errq);
1004 skb_queue_head_init(&tmpq);
1005
1006 rp = queue->rx.sring->rsp_prod;
1007 rmb(); /* Ensure we see queued responses up to 'rp'. */
1008
1009 i = queue->rx.rsp_cons;
1010 work_done = 0;
1011 while ((i != rp) && (work_done < budget)) {
1012 memcpy(rx, RING_GET_RESPONSE(&queue->rx, i), sizeof(*rx));
1013 memset(extras, 0, sizeof(rinfo.extras));
1014
1015 err = xennet_get_responses(queue, &rinfo, rp, &tmpq);
1016
1017 if (unlikely(err)) {
1018 err:
1019 while ((skb = __skb_dequeue(&tmpq)))
1020 __skb_queue_tail(&errq, skb);
1021 dev->stats.rx_errors++;
1022 i = queue->rx.rsp_cons;
1023 continue;
1024 }
1025
1026 skb = __skb_dequeue(&tmpq);
1027
1028 if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) {
1029 struct xen_netif_extra_info *gso;
1030 gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1];
1031
1032 if (unlikely(xennet_set_skb_gso(skb, gso))) {
1033 __skb_queue_head(&tmpq, skb);
1034 queue->rx.rsp_cons += skb_queue_len(&tmpq);
1035 goto err;
1036 }
1037 }
1038
1039 NETFRONT_SKB_CB(skb)->pull_to = rx->status;
1040 if (NETFRONT_SKB_CB(skb)->pull_to > RX_COPY_THRESHOLD)
1041 NETFRONT_SKB_CB(skb)->pull_to = RX_COPY_THRESHOLD;
1042
1043 skb_shinfo(skb)->frags[0].page_offset = rx->offset;
1044 skb_frag_size_set(&skb_shinfo(skb)->frags[0], rx->status);
1045 skb->data_len = rx->status;
1046 skb->len += rx->status;
1047
1048 i = xennet_fill_frags(queue, skb, &tmpq);
1049 if (unlikely(i == ~0U))
1050 goto err;
1051
1052 if (rx->flags & XEN_NETRXF_csum_blank)
1053 skb->ip_summed = CHECKSUM_PARTIAL;
1054 else if (rx->flags & XEN_NETRXF_data_validated)
1055 skb->ip_summed = CHECKSUM_UNNECESSARY;
1056
1057 __skb_queue_tail(&rxq, skb);
1058
1059 queue->rx.rsp_cons = ++i;
1060 work_done++;
1061 }
1062
1063 __skb_queue_purge(&errq);
1064
1065 work_done -= handle_incoming_queue(queue, &rxq);
1066
1067 xennet_alloc_rx_buffers(queue);
1068
1069 if (work_done < budget) {
1070 int more_to_do = 0;
1071
1072 napi_complete_done(napi, work_done);
1073
1074 RING_FINAL_CHECK_FOR_RESPONSES(&queue->rx, more_to_do);
1075 if (more_to_do)
1076 napi_schedule(napi);
1077 }
1078
1079 spin_unlock(&queue->rx_lock);
1080
1081 return work_done;
1082 }
1083
1084 static int xennet_change_mtu(struct net_device *dev, int mtu)
1085 {
1086 int max = xennet_can_sg(dev) ? XEN_NETIF_MAX_TX_SIZE : ETH_DATA_LEN;
1087
1088 if (mtu > max)
1089 return -EINVAL;
1090 dev->mtu = mtu;
1091 return 0;
1092 }
1093
1094 static void xennet_get_stats64(struct net_device *dev,
1095 struct rtnl_link_stats64 *tot)
1096 {
1097 struct netfront_info *np = netdev_priv(dev);
1098 int cpu;
1099
1100 for_each_possible_cpu(cpu) {
1101 struct netfront_stats *rx_stats = per_cpu_ptr(np->rx_stats, cpu);
1102 struct netfront_stats *tx_stats = per_cpu_ptr(np->tx_stats, cpu);
1103 u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
1104 unsigned int start;
1105
1106 do {
1107 start = u64_stats_fetch_begin_irq(&tx_stats->syncp);
1108 tx_packets = tx_stats->packets;
1109 tx_bytes = tx_stats->bytes;
1110 } while (u64_stats_fetch_retry_irq(&tx_stats->syncp, start));
1111
1112 do {
1113 start = u64_stats_fetch_begin_irq(&rx_stats->syncp);
1114 rx_packets = rx_stats->packets;
1115 rx_bytes = rx_stats->bytes;
1116 } while (u64_stats_fetch_retry_irq(&rx_stats->syncp, start));
1117
1118 tot->rx_packets += rx_packets;
1119 tot->tx_packets += tx_packets;
1120 tot->rx_bytes += rx_bytes;
1121 tot->tx_bytes += tx_bytes;
1122 }
1123
1124 tot->rx_errors = dev->stats.rx_errors;
1125 tot->tx_dropped = dev->stats.tx_dropped;
1126 }
1127
1128 static void xennet_release_tx_bufs(struct netfront_queue *queue)
1129 {
1130 struct sk_buff *skb;
1131 int i;
1132
1133 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1134 /* Skip over entries which are actually freelist references */
1135 if (skb_entry_is_link(&queue->tx_skbs[i]))
1136 continue;
1137
1138 skb = queue->tx_skbs[i].skb;
1139 get_page(queue->grant_tx_page[i]);
1140 gnttab_end_foreign_access(queue->grant_tx_ref[i],
1141 GNTMAP_readonly,
1142 (unsigned long)page_address(queue->grant_tx_page[i]));
1143 queue->grant_tx_page[i] = NULL;
1144 queue->grant_tx_ref[i] = GRANT_INVALID_REF;
1145 add_id_to_freelist(&queue->tx_skb_freelist, queue->tx_skbs, i);
1146 dev_kfree_skb_irq(skb);
1147 }
1148 }
1149
1150 static void xennet_release_rx_bufs(struct netfront_queue *queue)
1151 {
1152 int id, ref;
1153
1154 spin_lock_bh(&queue->rx_lock);
1155
1156 for (id = 0; id < NET_RX_RING_SIZE; id++) {
1157 struct sk_buff *skb;
1158 struct page *page;
1159
1160 skb = queue->rx_skbs[id];
1161 if (!skb)
1162 continue;
1163
1164 ref = queue->grant_rx_ref[id];
1165 if (ref == GRANT_INVALID_REF)
1166 continue;
1167
1168 page = skb_frag_page(&skb_shinfo(skb)->frags[0]);
1169
1170 /* gnttab_end_foreign_access() needs a page ref until
1171 * foreign access is ended (which may be deferred).
1172 */
1173 get_page(page);
1174 gnttab_end_foreign_access(ref, 0,
1175 (unsigned long)page_address(page));
1176 queue->grant_rx_ref[id] = GRANT_INVALID_REF;
1177
1178 kfree_skb(skb);
1179 }
1180
1181 spin_unlock_bh(&queue->rx_lock);
1182 }
1183
1184 static netdev_features_t xennet_fix_features(struct net_device *dev,
1185 netdev_features_t features)
1186 {
1187 struct netfront_info *np = netdev_priv(dev);
1188
1189 if (features & NETIF_F_SG &&
1190 !xenbus_read_unsigned(np->xbdev->otherend, "feature-sg", 0))
1191 features &= ~NETIF_F_SG;
1192
1193 if (features & NETIF_F_IPV6_CSUM &&
1194 !xenbus_read_unsigned(np->xbdev->otherend,
1195 "feature-ipv6-csum-offload", 0))
1196 features &= ~NETIF_F_IPV6_CSUM;
1197
1198 if (features & NETIF_F_TSO &&
1199 !xenbus_read_unsigned(np->xbdev->otherend, "feature-gso-tcpv4", 0))
1200 features &= ~NETIF_F_TSO;
1201
1202 if (features & NETIF_F_TSO6 &&
1203 !xenbus_read_unsigned(np->xbdev->otherend, "feature-gso-tcpv6", 0))
1204 features &= ~NETIF_F_TSO6;
1205
1206 return features;
1207 }
1208
1209 static int xennet_set_features(struct net_device *dev,
1210 netdev_features_t features)
1211 {
1212 if (!(features & NETIF_F_SG) && dev->mtu > ETH_DATA_LEN) {
1213 netdev_info(dev, "Reducing MTU because no SG offload");
1214 dev->mtu = ETH_DATA_LEN;
1215 }
1216
1217 return 0;
1218 }
1219
1220 static irqreturn_t xennet_tx_interrupt(int irq, void *dev_id)
1221 {
1222 struct netfront_queue *queue = dev_id;
1223 unsigned long flags;
1224
1225 spin_lock_irqsave(&queue->tx_lock, flags);
1226 xennet_tx_buf_gc(queue);
1227 spin_unlock_irqrestore(&queue->tx_lock, flags);
1228
1229 return IRQ_HANDLED;
1230 }
1231
1232 static irqreturn_t xennet_rx_interrupt(int irq, void *dev_id)
1233 {
1234 struct netfront_queue *queue = dev_id;
1235 struct net_device *dev = queue->info->netdev;
1236
1237 if (likely(netif_carrier_ok(dev) &&
1238 RING_HAS_UNCONSUMED_RESPONSES(&queue->rx)))
1239 napi_schedule(&queue->napi);
1240
1241 return IRQ_HANDLED;
1242 }
1243
1244 static irqreturn_t xennet_interrupt(int irq, void *dev_id)
1245 {
1246 xennet_tx_interrupt(irq, dev_id);
1247 xennet_rx_interrupt(irq, dev_id);
1248 return IRQ_HANDLED;
1249 }
1250
1251 #ifdef CONFIG_NET_POLL_CONTROLLER
1252 static void xennet_poll_controller(struct net_device *dev)
1253 {
1254 /* Poll each queue */
1255 struct netfront_info *info = netdev_priv(dev);
1256 unsigned int num_queues = dev->real_num_tx_queues;
1257 unsigned int i;
1258 for (i = 0; i < num_queues; ++i)
1259 xennet_interrupt(0, &info->queues[i]);
1260 }
1261 #endif
1262
1263 static const struct net_device_ops xennet_netdev_ops = {
1264 .ndo_open = xennet_open,
1265 .ndo_stop = xennet_close,
1266 .ndo_start_xmit = xennet_start_xmit,
1267 .ndo_change_mtu = xennet_change_mtu,
1268 .ndo_get_stats64 = xennet_get_stats64,
1269 .ndo_set_mac_address = eth_mac_addr,
1270 .ndo_validate_addr = eth_validate_addr,
1271 .ndo_fix_features = xennet_fix_features,
1272 .ndo_set_features = xennet_set_features,
1273 .ndo_select_queue = xennet_select_queue,
1274 #ifdef CONFIG_NET_POLL_CONTROLLER
1275 .ndo_poll_controller = xennet_poll_controller,
1276 #endif
1277 };
1278
1279 static void xennet_free_netdev(struct net_device *netdev)
1280 {
1281 struct netfront_info *np = netdev_priv(netdev);
1282
1283 free_percpu(np->rx_stats);
1284 free_percpu(np->tx_stats);
1285 free_netdev(netdev);
1286 }
1287
1288 static struct net_device *xennet_create_dev(struct xenbus_device *dev)
1289 {
1290 int err;
1291 struct net_device *netdev;
1292 struct netfront_info *np;
1293
1294 netdev = alloc_etherdev_mq(sizeof(struct netfront_info), xennet_max_queues);
1295 if (!netdev)
1296 return ERR_PTR(-ENOMEM);
1297
1298 np = netdev_priv(netdev);
1299 np->xbdev = dev;
1300
1301 np->queues = NULL;
1302
1303 err = -ENOMEM;
1304 np->rx_stats = netdev_alloc_pcpu_stats(struct netfront_stats);
1305 if (np->rx_stats == NULL)
1306 goto exit;
1307 np->tx_stats = netdev_alloc_pcpu_stats(struct netfront_stats);
1308 if (np->tx_stats == NULL)
1309 goto exit;
1310
1311 netdev->netdev_ops = &xennet_netdev_ops;
1312
1313 netdev->features = NETIF_F_IP_CSUM | NETIF_F_RXCSUM |
1314 NETIF_F_GSO_ROBUST;
1315 netdev->hw_features = NETIF_F_SG |
1316 NETIF_F_IPV6_CSUM |
1317 NETIF_F_TSO | NETIF_F_TSO6;
1318
1319 /*
1320 * Assume that all hw features are available for now. This set
1321 * will be adjusted by the call to netdev_update_features() in
1322 * xennet_connect() which is the earliest point where we can
1323 * negotiate with the backend regarding supported features.
1324 */
1325 netdev->features |= netdev->hw_features;
1326
1327 netdev->ethtool_ops = &xennet_ethtool_ops;
1328 netdev->min_mtu = ETH_MIN_MTU;
1329 netdev->max_mtu = XEN_NETIF_MAX_TX_SIZE;
1330 SET_NETDEV_DEV(netdev, &dev->dev);
1331
1332 np->netdev = netdev;
1333
1334 netif_carrier_off(netdev);
1335
1336 xenbus_switch_state(dev, XenbusStateInitialising);
1337 wait_event(module_wq,
1338 xenbus_read_driver_state(dev->otherend) !=
1339 XenbusStateClosed &&
1340 xenbus_read_driver_state(dev->otherend) !=
1341 XenbusStateUnknown);
1342 return netdev;
1343
1344 exit:
1345 xennet_free_netdev(netdev);
1346 return ERR_PTR(err);
1347 }
1348
1349 /**
1350 * Entry point to this code when a new device is created. Allocate the basic
1351 * structures and the ring buffers for communication with the backend, and
1352 * inform the backend of the appropriate details for those.
1353 */
1354 static int netfront_probe(struct xenbus_device *dev,
1355 const struct xenbus_device_id *id)
1356 {
1357 int err;
1358 struct net_device *netdev;
1359 struct netfront_info *info;
1360
1361 netdev = xennet_create_dev(dev);
1362 if (IS_ERR(netdev)) {
1363 err = PTR_ERR(netdev);
1364 xenbus_dev_fatal(dev, err, "creating netdev");
1365 return err;
1366 }
1367
1368 info = netdev_priv(netdev);
1369 dev_set_drvdata(&dev->dev, info);
1370 #ifdef CONFIG_SYSFS
1371 info->netdev->sysfs_groups[0] = &xennet_dev_group;
1372 #endif
1373
1374 return 0;
1375 }
1376
1377 static void xennet_end_access(int ref, void *page)
1378 {
1379 /* This frees the page as a side-effect */
1380 if (ref != GRANT_INVALID_REF)
1381 gnttab_end_foreign_access(ref, 0, (unsigned long)page);
1382 }
1383
1384 static void xennet_disconnect_backend(struct netfront_info *info)
1385 {
1386 unsigned int i = 0;
1387 unsigned int num_queues = info->netdev->real_num_tx_queues;
1388
1389 netif_carrier_off(info->netdev);
1390
1391 for (i = 0; i < num_queues && info->queues; ++i) {
1392 struct netfront_queue *queue = &info->queues[i];
1393
1394 del_timer_sync(&queue->rx_refill_timer);
1395
1396 if (queue->tx_irq && (queue->tx_irq == queue->rx_irq))
1397 unbind_from_irqhandler(queue->tx_irq, queue);
1398 if (queue->tx_irq && (queue->tx_irq != queue->rx_irq)) {
1399 unbind_from_irqhandler(queue->tx_irq, queue);
1400 unbind_from_irqhandler(queue->rx_irq, queue);
1401 }
1402 queue->tx_evtchn = queue->rx_evtchn = 0;
1403 queue->tx_irq = queue->rx_irq = 0;
1404
1405 if (netif_running(info->netdev))
1406 napi_synchronize(&queue->napi);
1407
1408 xennet_release_tx_bufs(queue);
1409 xennet_release_rx_bufs(queue);
1410 gnttab_free_grant_references(queue->gref_tx_head);
1411 gnttab_free_grant_references(queue->gref_rx_head);
1412
1413 /* End access and free the pages */
1414 xennet_end_access(queue->tx_ring_ref, queue->tx.sring);
1415 xennet_end_access(queue->rx_ring_ref, queue->rx.sring);
1416
1417 queue->tx_ring_ref = GRANT_INVALID_REF;
1418 queue->rx_ring_ref = GRANT_INVALID_REF;
1419 queue->tx.sring = NULL;
1420 queue->rx.sring = NULL;
1421 }
1422 }
1423
1424 /**
1425 * We are reconnecting to the backend, due to a suspend/resume, or a backend
1426 * driver restart. We tear down our netif structure and recreate it, but
1427 * leave the device-layer structures intact so that this is transparent to the
1428 * rest of the kernel.
1429 */
1430 static int netfront_resume(struct xenbus_device *dev)
1431 {
1432 struct netfront_info *info = dev_get_drvdata(&dev->dev);
1433
1434 dev_dbg(&dev->dev, "%s\n", dev->nodename);
1435
1436 xennet_disconnect_backend(info);
1437 return 0;
1438 }
1439
1440 static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[])
1441 {
1442 char *s, *e, *macstr;
1443 int i;
1444
1445 macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL);
1446 if (IS_ERR(macstr))
1447 return PTR_ERR(macstr);
1448
1449 for (i = 0; i < ETH_ALEN; i++) {
1450 mac[i] = simple_strtoul(s, &e, 16);
1451 if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) {
1452 kfree(macstr);
1453 return -ENOENT;
1454 }
1455 s = e+1;
1456 }
1457
1458 kfree(macstr);
1459 return 0;
1460 }
1461
1462 static int setup_netfront_single(struct netfront_queue *queue)
1463 {
1464 int err;
1465
1466 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn);
1467 if (err < 0)
1468 goto fail;
1469
1470 err = bind_evtchn_to_irqhandler(queue->tx_evtchn,
1471 xennet_interrupt,
1472 0, queue->info->netdev->name, queue);
1473 if (err < 0)
1474 goto bind_fail;
1475 queue->rx_evtchn = queue->tx_evtchn;
1476 queue->rx_irq = queue->tx_irq = err;
1477
1478 return 0;
1479
1480 bind_fail:
1481 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn);
1482 queue->tx_evtchn = 0;
1483 fail:
1484 return err;
1485 }
1486
1487 static int setup_netfront_split(struct netfront_queue *queue)
1488 {
1489 int err;
1490
1491 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn);
1492 if (err < 0)
1493 goto fail;
1494 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->rx_evtchn);
1495 if (err < 0)
1496 goto alloc_rx_evtchn_fail;
1497
1498 snprintf(queue->tx_irq_name, sizeof(queue->tx_irq_name),
1499 "%s-tx", queue->name);
1500 err = bind_evtchn_to_irqhandler(queue->tx_evtchn,
1501 xennet_tx_interrupt,
1502 0, queue->tx_irq_name, queue);
1503 if (err < 0)
1504 goto bind_tx_fail;
1505 queue->tx_irq = err;
1506
1507 snprintf(queue->rx_irq_name, sizeof(queue->rx_irq_name),
1508 "%s-rx", queue->name);
1509 err = bind_evtchn_to_irqhandler(queue->rx_evtchn,
1510 xennet_rx_interrupt,
1511 0, queue->rx_irq_name, queue);
1512 if (err < 0)
1513 goto bind_rx_fail;
1514 queue->rx_irq = err;
1515
1516 return 0;
1517
1518 bind_rx_fail:
1519 unbind_from_irqhandler(queue->tx_irq, queue);
1520 queue->tx_irq = 0;
1521 bind_tx_fail:
1522 xenbus_free_evtchn(queue->info->xbdev, queue->rx_evtchn);
1523 queue->rx_evtchn = 0;
1524 alloc_rx_evtchn_fail:
1525 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn);
1526 queue->tx_evtchn = 0;
1527 fail:
1528 return err;
1529 }
1530
1531 static int setup_netfront(struct xenbus_device *dev,
1532 struct netfront_queue *queue, unsigned int feature_split_evtchn)
1533 {
1534 struct xen_netif_tx_sring *txs;
1535 struct xen_netif_rx_sring *rxs;
1536 grant_ref_t gref;
1537 int err;
1538
1539 queue->tx_ring_ref = GRANT_INVALID_REF;
1540 queue->rx_ring_ref = GRANT_INVALID_REF;
1541 queue->rx.sring = NULL;
1542 queue->tx.sring = NULL;
1543
1544 txs = (struct xen_netif_tx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1545 if (!txs) {
1546 err = -ENOMEM;
1547 xenbus_dev_fatal(dev, err, "allocating tx ring page");
1548 goto fail;
1549 }
1550 SHARED_RING_INIT(txs);
1551 FRONT_RING_INIT(&queue->tx, txs, XEN_PAGE_SIZE);
1552
1553 err = xenbus_grant_ring(dev, txs, 1, &gref);
1554 if (err < 0)
1555 goto grant_tx_ring_fail;
1556 queue->tx_ring_ref = gref;
1557
1558 rxs = (struct xen_netif_rx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1559 if (!rxs) {
1560 err = -ENOMEM;
1561 xenbus_dev_fatal(dev, err, "allocating rx ring page");
1562 goto alloc_rx_ring_fail;
1563 }
1564 SHARED_RING_INIT(rxs);
1565 FRONT_RING_INIT(&queue->rx, rxs, XEN_PAGE_SIZE);
1566
1567 err = xenbus_grant_ring(dev, rxs, 1, &gref);
1568 if (err < 0)
1569 goto grant_rx_ring_fail;
1570 queue->rx_ring_ref = gref;
1571
1572 if (feature_split_evtchn)
1573 err = setup_netfront_split(queue);
1574 /* setup single event channel if
1575 * a) feature-split-event-channels == 0
1576 * b) feature-split-event-channels == 1 but failed to setup
1577 */
1578 if (!feature_split_evtchn || (feature_split_evtchn && err))
1579 err = setup_netfront_single(queue);
1580
1581 if (err)
1582 goto alloc_evtchn_fail;
1583
1584 return 0;
1585
1586 /* If we fail to setup netfront, it is safe to just revoke access to
1587 * granted pages because backend is not accessing it at this point.
1588 */
1589 alloc_evtchn_fail:
1590 gnttab_end_foreign_access_ref(queue->rx_ring_ref, 0);
1591 grant_rx_ring_fail:
1592 free_page((unsigned long)rxs);
1593 alloc_rx_ring_fail:
1594 gnttab_end_foreign_access_ref(queue->tx_ring_ref, 0);
1595 grant_tx_ring_fail:
1596 free_page((unsigned long)txs);
1597 fail:
1598 return err;
1599 }
1600
1601 /* Queue-specific initialisation
1602 * This used to be done in xennet_create_dev() but must now
1603 * be run per-queue.
1604 */
1605 static int xennet_init_queue(struct netfront_queue *queue)
1606 {
1607 unsigned short i;
1608 int err = 0;
1609 char *devid;
1610
1611 spin_lock_init(&queue->tx_lock);
1612 spin_lock_init(&queue->rx_lock);
1613
1614 timer_setup(&queue->rx_refill_timer, rx_refill_timeout, 0);
1615
1616 devid = strrchr(queue->info->xbdev->nodename, '/') + 1;
1617 snprintf(queue->name, sizeof(queue->name), "vif%s-q%u",
1618 devid, queue->id);
1619
1620 /* Initialise tx_skbs as a free chain containing every entry. */
1621 queue->tx_skb_freelist = 0;
1622 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1623 skb_entry_set_link(&queue->tx_skbs[i], i+1);
1624 queue->grant_tx_ref[i] = GRANT_INVALID_REF;
1625 queue->grant_tx_page[i] = NULL;
1626 }
1627
1628 /* Clear out rx_skbs */
1629 for (i = 0; i < NET_RX_RING_SIZE; i++) {
1630 queue->rx_skbs[i] = NULL;
1631 queue->grant_rx_ref[i] = GRANT_INVALID_REF;
1632 }
1633
1634 /* A grant for every tx ring slot */
1635 if (gnttab_alloc_grant_references(NET_TX_RING_SIZE,
1636 &queue->gref_tx_head) < 0) {
1637 pr_alert("can't alloc tx grant refs\n");
1638 err = -ENOMEM;
1639 goto exit;
1640 }
1641
1642 /* A grant for every rx ring slot */
1643 if (gnttab_alloc_grant_references(NET_RX_RING_SIZE,
1644 &queue->gref_rx_head) < 0) {
1645 pr_alert("can't alloc rx grant refs\n");
1646 err = -ENOMEM;
1647 goto exit_free_tx;
1648 }
1649
1650 return 0;
1651
1652 exit_free_tx:
1653 gnttab_free_grant_references(queue->gref_tx_head);
1654 exit:
1655 return err;
1656 }
1657
1658 static int write_queue_xenstore_keys(struct netfront_queue *queue,
1659 struct xenbus_transaction *xbt, int write_hierarchical)
1660 {
1661 /* Write the queue-specific keys into XenStore in the traditional
1662 * way for a single queue, or in a queue subkeys for multiple
1663 * queues.
1664 */
1665 struct xenbus_device *dev = queue->info->xbdev;
1666 int err;
1667 const char *message;
1668 char *path;
1669 size_t pathsize;
1670
1671 /* Choose the correct place to write the keys */
1672 if (write_hierarchical) {
1673 pathsize = strlen(dev->nodename) + 10;
1674 path = kzalloc(pathsize, GFP_KERNEL);
1675 if (!path) {
1676 err = -ENOMEM;
1677 message = "out of memory while writing ring references";
1678 goto error;
1679 }
1680 snprintf(path, pathsize, "%s/queue-%u",
1681 dev->nodename, queue->id);
1682 } else {
1683 path = (char *)dev->nodename;
1684 }
1685
1686 /* Write ring references */
1687 err = xenbus_printf(*xbt, path, "tx-ring-ref", "%u",
1688 queue->tx_ring_ref);
1689 if (err) {
1690 message = "writing tx-ring-ref";
1691 goto error;
1692 }
1693
1694 err = xenbus_printf(*xbt, path, "rx-ring-ref", "%u",
1695 queue->rx_ring_ref);
1696 if (err) {
1697 message = "writing rx-ring-ref";
1698 goto error;
1699 }
1700
1701 /* Write event channels; taking into account both shared
1702 * and split event channel scenarios.
1703 */
1704 if (queue->tx_evtchn == queue->rx_evtchn) {
1705 /* Shared event channel */
1706 err = xenbus_printf(*xbt, path,
1707 "event-channel", "%u", queue->tx_evtchn);
1708 if (err) {
1709 message = "writing event-channel";
1710 goto error;
1711 }
1712 } else {
1713 /* Split event channels */
1714 err = xenbus_printf(*xbt, path,
1715 "event-channel-tx", "%u", queue->tx_evtchn);
1716 if (err) {
1717 message = "writing event-channel-tx";
1718 goto error;
1719 }
1720
1721 err = xenbus_printf(*xbt, path,
1722 "event-channel-rx", "%u", queue->rx_evtchn);
1723 if (err) {
1724 message = "writing event-channel-rx";
1725 goto error;
1726 }
1727 }
1728
1729 if (write_hierarchical)
1730 kfree(path);
1731 return 0;
1732
1733 error:
1734 if (write_hierarchical)
1735 kfree(path);
1736 xenbus_dev_fatal(dev, err, "%s", message);
1737 return err;
1738 }
1739
1740 static void xennet_destroy_queues(struct netfront_info *info)
1741 {
1742 unsigned int i;
1743
1744 for (i = 0; i < info->netdev->real_num_tx_queues; i++) {
1745 struct netfront_queue *queue = &info->queues[i];
1746
1747 if (netif_running(info->netdev))
1748 napi_disable(&queue->napi);
1749 netif_napi_del(&queue->napi);
1750 }
1751
1752 kfree(info->queues);
1753 info->queues = NULL;
1754 }
1755
1756 static int xennet_create_queues(struct netfront_info *info,
1757 unsigned int *num_queues)
1758 {
1759 unsigned int i;
1760 int ret;
1761
1762 info->queues = kcalloc(*num_queues, sizeof(struct netfront_queue),
1763 GFP_KERNEL);
1764 if (!info->queues)
1765 return -ENOMEM;
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->xbdev->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 if (*num_queues == 0) {
1790 dev_err(&info->xbdev->dev, "no queues\n");
1791 return -EINVAL;
1792 }
1793 return 0;
1794 }
1795
1796 /* Common code used when first setting up, and when resuming. */
1797 static int talk_to_netback(struct xenbus_device *dev,
1798 struct netfront_info *info)
1799 {
1800 const char *message;
1801 struct xenbus_transaction xbt;
1802 int err;
1803 unsigned int feature_split_evtchn;
1804 unsigned int i = 0;
1805 unsigned int max_queues = 0;
1806 struct netfront_queue *queue = NULL;
1807 unsigned int num_queues = 1;
1808
1809 info->netdev->irq = 0;
1810
1811 /* Check if backend supports multiple queues */
1812 max_queues = xenbus_read_unsigned(info->xbdev->otherend,
1813 "multi-queue-max-queues", 1);
1814 num_queues = min(max_queues, xennet_max_queues);
1815
1816 /* Check feature-split-event-channels */
1817 feature_split_evtchn = xenbus_read_unsigned(info->xbdev->otherend,
1818 "feature-split-event-channels", 0);
1819
1820 /* Read mac addr. */
1821 err = xen_net_read_mac(dev, info->netdev->dev_addr);
1822 if (err) {
1823 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
1824 goto out_unlocked;
1825 }
1826
1827 rtnl_lock();
1828 if (info->queues)
1829 xennet_destroy_queues(info);
1830
1831 err = xennet_create_queues(info, &num_queues);
1832 if (err < 0) {
1833 xenbus_dev_fatal(dev, err, "creating queues");
1834 kfree(info->queues);
1835 info->queues = NULL;
1836 goto out;
1837 }
1838 rtnl_unlock();
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 rtnl_lock();
1936 xennet_destroy_queues(info);
1937 out:
1938 rtnl_unlock();
1939 out_unlocked:
1940 device_unregister(&dev->dev);
1941 return err;
1942 }
1943
1944 static int xennet_connect(struct net_device *dev)
1945 {
1946 struct netfront_info *np = netdev_priv(dev);
1947 unsigned int num_queues = 0;
1948 int err;
1949 unsigned int j = 0;
1950 struct netfront_queue *queue = NULL;
1951
1952 if (!xenbus_read_unsigned(np->xbdev->otherend, "feature-rx-copy", 0)) {
1953 dev_info(&dev->dev,
1954 "backend does not support copying receive path\n");
1955 return -ENODEV;
1956 }
1957
1958 err = talk_to_netback(np->xbdev, np);
1959 if (err)
1960 return err;
1961
1962 /* talk_to_netback() sets the correct number of queues */
1963 num_queues = dev->real_num_tx_queues;
1964
1965 if (dev->reg_state == NETREG_UNINITIALIZED) {
1966 err = register_netdev(dev);
1967 if (err) {
1968 pr_warn("%s: register_netdev err=%d\n", __func__, err);
1969 device_unregister(&np->xbdev->dev);
1970 return err;
1971 }
1972 }
1973
1974 rtnl_lock();
1975 netdev_update_features(dev);
1976 rtnl_unlock();
1977
1978 /*
1979 * All public and private state should now be sane. Get
1980 * ready to start sending and receiving packets and give the driver
1981 * domain a kick because we've probably just requeued some
1982 * packets.
1983 */
1984 netif_carrier_on(np->netdev);
1985 for (j = 0; j < num_queues; ++j) {
1986 queue = &np->queues[j];
1987
1988 notify_remote_via_irq(queue->tx_irq);
1989 if (queue->tx_irq != queue->rx_irq)
1990 notify_remote_via_irq(queue->rx_irq);
1991
1992 spin_lock_irq(&queue->tx_lock);
1993 xennet_tx_buf_gc(queue);
1994 spin_unlock_irq(&queue->tx_lock);
1995
1996 spin_lock_bh(&queue->rx_lock);
1997 xennet_alloc_rx_buffers(queue);
1998 spin_unlock_bh(&queue->rx_lock);
1999 }
2000
2001 return 0;
2002 }
2003
2004 /**
2005 * Callback received when the backend's state changes.
2006 */
2007 static void netback_changed(struct xenbus_device *dev,
2008 enum xenbus_state backend_state)
2009 {
2010 struct netfront_info *np = dev_get_drvdata(&dev->dev);
2011 struct net_device *netdev = np->netdev;
2012
2013 dev_dbg(&dev->dev, "%s\n", xenbus_strstate(backend_state));
2014
2015 wake_up_all(&module_wq);
2016
2017 switch (backend_state) {
2018 case XenbusStateInitialising:
2019 case XenbusStateInitialised:
2020 case XenbusStateReconfiguring:
2021 case XenbusStateReconfigured:
2022 case XenbusStateUnknown:
2023 break;
2024
2025 case XenbusStateInitWait:
2026 if (dev->state != XenbusStateInitialising)
2027 break;
2028 if (xennet_connect(netdev) != 0)
2029 break;
2030 xenbus_switch_state(dev, XenbusStateConnected);
2031 break;
2032
2033 case XenbusStateConnected:
2034 netdev_notify_peers(netdev);
2035 break;
2036
2037 case XenbusStateClosed:
2038 if (dev->state == XenbusStateClosed)
2039 break;
2040 /* Fall through - Missed the backend's CLOSING state. */
2041 case XenbusStateClosing:
2042 xenbus_frontend_closed(dev);
2043 break;
2044 }
2045 }
2046
2047 static const struct xennet_stat {
2048 char name[ETH_GSTRING_LEN];
2049 u16 offset;
2050 } xennet_stats[] = {
2051 {
2052 "rx_gso_checksum_fixup",
2053 offsetof(struct netfront_info, rx_gso_checksum_fixup)
2054 },
2055 };
2056
2057 static int xennet_get_sset_count(struct net_device *dev, int string_set)
2058 {
2059 switch (string_set) {
2060 case ETH_SS_STATS:
2061 return ARRAY_SIZE(xennet_stats);
2062 default:
2063 return -EINVAL;
2064 }
2065 }
2066
2067 static void xennet_get_ethtool_stats(struct net_device *dev,
2068 struct ethtool_stats *stats, u64 * data)
2069 {
2070 void *np = netdev_priv(dev);
2071 int i;
2072
2073 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
2074 data[i] = atomic_read((atomic_t *)(np + xennet_stats[i].offset));
2075 }
2076
2077 static void xennet_get_strings(struct net_device *dev, u32 stringset, u8 * data)
2078 {
2079 int i;
2080
2081 switch (stringset) {
2082 case ETH_SS_STATS:
2083 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
2084 memcpy(data + i * ETH_GSTRING_LEN,
2085 xennet_stats[i].name, ETH_GSTRING_LEN);
2086 break;
2087 }
2088 }
2089
2090 static const struct ethtool_ops xennet_ethtool_ops =
2091 {
2092 .get_link = ethtool_op_get_link,
2093
2094 .get_sset_count = xennet_get_sset_count,
2095 .get_ethtool_stats = xennet_get_ethtool_stats,
2096 .get_strings = xennet_get_strings,
2097 };
2098
2099 #ifdef CONFIG_SYSFS
2100 static ssize_t show_rxbuf(struct device *dev,
2101 struct device_attribute *attr, char *buf)
2102 {
2103 return sprintf(buf, "%lu\n", NET_RX_RING_SIZE);
2104 }
2105
2106 static ssize_t store_rxbuf(struct device *dev,
2107 struct device_attribute *attr,
2108 const char *buf, size_t len)
2109 {
2110 char *endp;
2111 unsigned long target;
2112
2113 if (!capable(CAP_NET_ADMIN))
2114 return -EPERM;
2115
2116 target = simple_strtoul(buf, &endp, 0);
2117 if (endp == buf)
2118 return -EBADMSG;
2119
2120 /* rxbuf_min and rxbuf_max are no longer configurable. */
2121
2122 return len;
2123 }
2124
2125 static DEVICE_ATTR(rxbuf_min, 0644, show_rxbuf, store_rxbuf);
2126 static DEVICE_ATTR(rxbuf_max, 0644, show_rxbuf, store_rxbuf);
2127 static DEVICE_ATTR(rxbuf_cur, 0444, show_rxbuf, NULL);
2128
2129 static struct attribute *xennet_dev_attrs[] = {
2130 &dev_attr_rxbuf_min.attr,
2131 &dev_attr_rxbuf_max.attr,
2132 &dev_attr_rxbuf_cur.attr,
2133 NULL
2134 };
2135
2136 static const struct attribute_group xennet_dev_group = {
2137 .attrs = xennet_dev_attrs
2138 };
2139 #endif /* CONFIG_SYSFS */
2140
2141 static int xennet_remove(struct xenbus_device *dev)
2142 {
2143 struct netfront_info *info = dev_get_drvdata(&dev->dev);
2144
2145 dev_dbg(&dev->dev, "%s\n", dev->nodename);
2146
2147 if (xenbus_read_driver_state(dev->otherend) != XenbusStateClosed) {
2148 xenbus_switch_state(dev, XenbusStateClosing);
2149 wait_event(module_wq,
2150 xenbus_read_driver_state(dev->otherend) ==
2151 XenbusStateClosing ||
2152 xenbus_read_driver_state(dev->otherend) ==
2153 XenbusStateUnknown);
2154
2155 xenbus_switch_state(dev, XenbusStateClosed);
2156 wait_event(module_wq,
2157 xenbus_read_driver_state(dev->otherend) ==
2158 XenbusStateClosed ||
2159 xenbus_read_driver_state(dev->otherend) ==
2160 XenbusStateUnknown);
2161 }
2162
2163 xennet_disconnect_backend(info);
2164
2165 if (info->netdev->reg_state == NETREG_REGISTERED)
2166 unregister_netdev(info->netdev);
2167
2168 if (info->queues) {
2169 rtnl_lock();
2170 xennet_destroy_queues(info);
2171 rtnl_unlock();
2172 }
2173 xennet_free_netdev(info->netdev);
2174
2175 return 0;
2176 }
2177
2178 static const struct xenbus_device_id netfront_ids[] = {
2179 { "vif" },
2180 { "" }
2181 };
2182
2183 static struct xenbus_driver netfront_driver = {
2184 .ids = netfront_ids,
2185 .probe = netfront_probe,
2186 .remove = xennet_remove,
2187 .resume = netfront_resume,
2188 .otherend_changed = netback_changed,
2189 };
2190
2191 static int __init netif_init(void)
2192 {
2193 if (!xen_domain())
2194 return -ENODEV;
2195
2196 if (!xen_has_pv_nic_devices())
2197 return -ENODEV;
2198
2199 pr_info("Initialising Xen virtual ethernet driver\n");
2200
2201 /* Allow as many queues as there are CPUs inut max. 8 if user has not
2202 * specified a value.
2203 */
2204 if (xennet_max_queues == 0)
2205 xennet_max_queues = min_t(unsigned int, MAX_QUEUES_DEFAULT,
2206 num_online_cpus());
2207
2208 return xenbus_register_frontend(&netfront_driver);
2209 }
2210 module_init(netif_init);
2211
2212
2213 static void __exit netif_exit(void)
2214 {
2215 xenbus_unregister_driver(&netfront_driver);
2216 }
2217 module_exit(netif_exit);
2218
2219 MODULE_DESCRIPTION("Xen virtual network device frontend");
2220 MODULE_LICENSE("GPL");
2221 MODULE_ALIAS("xen:vif");
2222 MODULE_ALIAS("xennet");
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