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[mirror_ubuntu-bionic-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_load_q);
91 static DECLARE_WAIT_QUEUE_HEAD(module_unload_q);
92
93 struct netfront_stats {
94 u64 packets;
95 u64 bytes;
96 struct u64_stats_sync syncp;
97 };
98
99 struct netfront_info;
100
101 struct netfront_queue {
102 unsigned int id; /* Queue ID, 0-based */
103 char name[QUEUE_NAME_SIZE]; /* DEVNAME-qN */
104 struct netfront_info *info;
105
106 struct napi_struct napi;
107
108 /* Split event channels support, tx_* == rx_* when using
109 * single event channel.
110 */
111 unsigned int tx_evtchn, rx_evtchn;
112 unsigned int tx_irq, rx_irq;
113 /* Only used when split event channels support is enabled */
114 char tx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-tx */
115 char rx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-rx */
116
117 spinlock_t tx_lock;
118 struct xen_netif_tx_front_ring tx;
119 int tx_ring_ref;
120
121 /*
122 * {tx,rx}_skbs store outstanding skbuffs. Free tx_skb entries
123 * are linked from tx_skb_freelist through skb_entry.link.
124 *
125 * NB. Freelist index entries are always going to be less than
126 * PAGE_OFFSET, whereas pointers to skbs will always be equal or
127 * greater than PAGE_OFFSET: we use this property to distinguish
128 * them.
129 */
130 union skb_entry {
131 struct sk_buff *skb;
132 unsigned long link;
133 } tx_skbs[NET_TX_RING_SIZE];
134 grant_ref_t gref_tx_head;
135 grant_ref_t grant_tx_ref[NET_TX_RING_SIZE];
136 struct page *grant_tx_page[NET_TX_RING_SIZE];
137 unsigned tx_skb_freelist;
138
139 spinlock_t rx_lock ____cacheline_aligned_in_smp;
140 struct xen_netif_rx_front_ring rx;
141 int rx_ring_ref;
142
143 struct timer_list rx_refill_timer;
144
145 struct sk_buff *rx_skbs[NET_RX_RING_SIZE];
146 grant_ref_t gref_rx_head;
147 grant_ref_t grant_rx_ref[NET_RX_RING_SIZE];
148 };
149
150 struct netfront_info {
151 struct list_head list;
152 struct net_device *netdev;
153
154 struct xenbus_device *xbdev;
155
156 /* Multi-queue support */
157 struct netfront_queue *queues;
158
159 /* Statistics */
160 struct netfront_stats __percpu *rx_stats;
161 struct netfront_stats __percpu *tx_stats;
162
163 atomic_t rx_gso_checksum_fixup;
164 };
165
166 struct netfront_rx_info {
167 struct xen_netif_rx_response rx;
168 struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX - 1];
169 };
170
171 static void skb_entry_set_link(union skb_entry *list, unsigned short id)
172 {
173 list->link = id;
174 }
175
176 static int skb_entry_is_link(const union skb_entry *list)
177 {
178 BUILD_BUG_ON(sizeof(list->skb) != sizeof(list->link));
179 return (unsigned long)list->skb < PAGE_OFFSET;
180 }
181
182 /*
183 * Access macros for acquiring freeing slots in tx_skbs[].
184 */
185
186 static void add_id_to_freelist(unsigned *head, union skb_entry *list,
187 unsigned short id)
188 {
189 skb_entry_set_link(&list[id], *head);
190 *head = id;
191 }
192
193 static unsigned short get_id_from_freelist(unsigned *head,
194 union skb_entry *list)
195 {
196 unsigned int id = *head;
197 *head = list[id].link;
198 return id;
199 }
200
201 static int xennet_rxidx(RING_IDX idx)
202 {
203 return idx & (NET_RX_RING_SIZE - 1);
204 }
205
206 static struct sk_buff *xennet_get_rx_skb(struct netfront_queue *queue,
207 RING_IDX ri)
208 {
209 int i = xennet_rxidx(ri);
210 struct sk_buff *skb = queue->rx_skbs[i];
211 queue->rx_skbs[i] = NULL;
212 return skb;
213 }
214
215 static grant_ref_t xennet_get_rx_ref(struct netfront_queue *queue,
216 RING_IDX ri)
217 {
218 int i = xennet_rxidx(ri);
219 grant_ref_t ref = queue->grant_rx_ref[i];
220 queue->grant_rx_ref[i] = GRANT_INVALID_REF;
221 return ref;
222 }
223
224 #ifdef CONFIG_SYSFS
225 static const struct attribute_group xennet_dev_group;
226 #endif
227
228 static bool xennet_can_sg(struct net_device *dev)
229 {
230 return dev->features & NETIF_F_SG;
231 }
232
233
234 static void rx_refill_timeout(struct timer_list *t)
235 {
236 struct netfront_queue *queue = from_timer(queue, t, rx_refill_timer);
237 napi_schedule(&queue->napi);
238 }
239
240 static int netfront_tx_slot_available(struct netfront_queue *queue)
241 {
242 return (queue->tx.req_prod_pvt - queue->tx.rsp_cons) <
243 (NET_TX_RING_SIZE - XEN_NETIF_NR_SLOTS_MIN - 1);
244 }
245
246 static void xennet_maybe_wake_tx(struct netfront_queue *queue)
247 {
248 struct net_device *dev = queue->info->netdev;
249 struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, queue->id);
250
251 if (unlikely(netif_tx_queue_stopped(dev_queue)) &&
252 netfront_tx_slot_available(queue) &&
253 likely(netif_running(dev)))
254 netif_tx_wake_queue(netdev_get_tx_queue(dev, queue->id));
255 }
256
257
258 static struct sk_buff *xennet_alloc_one_rx_buffer(struct netfront_queue *queue)
259 {
260 struct sk_buff *skb;
261 struct page *page;
262
263 skb = __netdev_alloc_skb(queue->info->netdev,
264 RX_COPY_THRESHOLD + NET_IP_ALIGN,
265 GFP_ATOMIC | __GFP_NOWARN);
266 if (unlikely(!skb))
267 return NULL;
268
269 page = alloc_page(GFP_ATOMIC | __GFP_NOWARN);
270 if (!page) {
271 kfree_skb(skb);
272 return NULL;
273 }
274 skb_add_rx_frag(skb, 0, page, 0, 0, PAGE_SIZE);
275
276 /* Align ip header to a 16 bytes boundary */
277 skb_reserve(skb, NET_IP_ALIGN);
278 skb->dev = queue->info->netdev;
279
280 return skb;
281 }
282
283
284 static void xennet_alloc_rx_buffers(struct netfront_queue *queue)
285 {
286 RING_IDX req_prod = queue->rx.req_prod_pvt;
287 int notify;
288 int err = 0;
289
290 if (unlikely(!netif_carrier_ok(queue->info->netdev)))
291 return;
292
293 for (req_prod = queue->rx.req_prod_pvt;
294 req_prod - queue->rx.rsp_cons < NET_RX_RING_SIZE;
295 req_prod++) {
296 struct sk_buff *skb;
297 unsigned short id;
298 grant_ref_t ref;
299 struct page *page;
300 struct xen_netif_rx_request *req;
301
302 skb = xennet_alloc_one_rx_buffer(queue);
303 if (!skb) {
304 err = -ENOMEM;
305 break;
306 }
307
308 id = xennet_rxidx(req_prod);
309
310 BUG_ON(queue->rx_skbs[id]);
311 queue->rx_skbs[id] = skb;
312
313 ref = gnttab_claim_grant_reference(&queue->gref_rx_head);
314 WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)(int)ref));
315 queue->grant_rx_ref[id] = ref;
316
317 page = skb_frag_page(&skb_shinfo(skb)->frags[0]);
318
319 req = RING_GET_REQUEST(&queue->rx, req_prod);
320 gnttab_page_grant_foreign_access_ref_one(ref,
321 queue->info->xbdev->otherend_id,
322 page,
323 0);
324 req->id = id;
325 req->gref = ref;
326 }
327
328 queue->rx.req_prod_pvt = req_prod;
329
330 /* Try again later if there are not enough requests or skb allocation
331 * failed.
332 * Enough requests is quantified as the sum of newly created slots and
333 * the unconsumed slots at the backend.
334 */
335 if (req_prod - queue->rx.rsp_cons < NET_RX_SLOTS_MIN ||
336 unlikely(err)) {
337 mod_timer(&queue->rx_refill_timer, jiffies + (HZ/10));
338 return;
339 }
340
341 wmb(); /* barrier so backend seens requests */
342
343 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->rx, notify);
344 if (notify)
345 notify_remote_via_irq(queue->rx_irq);
346 }
347
348 static int xennet_open(struct net_device *dev)
349 {
350 struct netfront_info *np = netdev_priv(dev);
351 unsigned int num_queues = dev->real_num_tx_queues;
352 unsigned int i = 0;
353 struct netfront_queue *queue = NULL;
354
355 if (!np->queues)
356 return -ENODEV;
357
358 for (i = 0; i < num_queues; ++i) {
359 queue = &np->queues[i];
360 napi_enable(&queue->napi);
361
362 spin_lock_bh(&queue->rx_lock);
363 if (netif_carrier_ok(dev)) {
364 xennet_alloc_rx_buffers(queue);
365 queue->rx.sring->rsp_event = queue->rx.rsp_cons + 1;
366 if (RING_HAS_UNCONSUMED_RESPONSES(&queue->rx))
367 napi_schedule(&queue->napi);
368 }
369 spin_unlock_bh(&queue->rx_lock);
370 }
371
372 netif_tx_start_all_queues(dev);
373
374 return 0;
375 }
376
377 static void xennet_tx_buf_gc(struct netfront_queue *queue)
378 {
379 RING_IDX cons, prod;
380 unsigned short id;
381 struct sk_buff *skb;
382 bool more_to_do;
383
384 BUG_ON(!netif_carrier_ok(queue->info->netdev));
385
386 do {
387 prod = queue->tx.sring->rsp_prod;
388 rmb(); /* Ensure we see responses up to 'rp'. */
389
390 for (cons = queue->tx.rsp_cons; cons != prod; cons++) {
391 struct xen_netif_tx_response *txrsp;
392
393 txrsp = RING_GET_RESPONSE(&queue->tx, cons);
394 if (txrsp->status == XEN_NETIF_RSP_NULL)
395 continue;
396
397 id = txrsp->id;
398 skb = queue->tx_skbs[id].skb;
399 if (unlikely(gnttab_query_foreign_access(
400 queue->grant_tx_ref[id]) != 0)) {
401 pr_alert("%s: warning -- grant still in use by backend domain\n",
402 __func__);
403 BUG();
404 }
405 gnttab_end_foreign_access_ref(
406 queue->grant_tx_ref[id], GNTMAP_readonly);
407 gnttab_release_grant_reference(
408 &queue->gref_tx_head, queue->grant_tx_ref[id]);
409 queue->grant_tx_ref[id] = GRANT_INVALID_REF;
410 queue->grant_tx_page[id] = NULL;
411 add_id_to_freelist(&queue->tx_skb_freelist, queue->tx_skbs, id);
412 dev_kfree_skb_irq(skb);
413 }
414
415 queue->tx.rsp_cons = prod;
416
417 RING_FINAL_CHECK_FOR_RESPONSES(&queue->tx, more_to_do);
418 } while (more_to_do);
419
420 xennet_maybe_wake_tx(queue);
421 }
422
423 struct xennet_gnttab_make_txreq {
424 struct netfront_queue *queue;
425 struct sk_buff *skb;
426 struct page *page;
427 struct xen_netif_tx_request *tx; /* Last request */
428 unsigned int size;
429 };
430
431 static void xennet_tx_setup_grant(unsigned long gfn, unsigned int offset,
432 unsigned int len, void *data)
433 {
434 struct xennet_gnttab_make_txreq *info = data;
435 unsigned int id;
436 struct xen_netif_tx_request *tx;
437 grant_ref_t ref;
438 /* convenient aliases */
439 struct page *page = info->page;
440 struct netfront_queue *queue = info->queue;
441 struct sk_buff *skb = info->skb;
442
443 id = get_id_from_freelist(&queue->tx_skb_freelist, queue->tx_skbs);
444 tx = RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++);
445 ref = gnttab_claim_grant_reference(&queue->gref_tx_head);
446 WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)(int)ref));
447
448 gnttab_grant_foreign_access_ref(ref, queue->info->xbdev->otherend_id,
449 gfn, GNTMAP_readonly);
450
451 queue->tx_skbs[id].skb = skb;
452 queue->grant_tx_page[id] = page;
453 queue->grant_tx_ref[id] = ref;
454
455 tx->id = id;
456 tx->gref = ref;
457 tx->offset = offset;
458 tx->size = len;
459 tx->flags = 0;
460
461 info->tx = tx;
462 info->size += tx->size;
463 }
464
465 static struct xen_netif_tx_request *xennet_make_first_txreq(
466 struct netfront_queue *queue, struct sk_buff *skb,
467 struct page *page, unsigned int offset, unsigned int len)
468 {
469 struct xennet_gnttab_make_txreq info = {
470 .queue = queue,
471 .skb = skb,
472 .page = page,
473 .size = 0,
474 };
475
476 gnttab_for_one_grant(page, offset, len, xennet_tx_setup_grant, &info);
477
478 return info.tx;
479 }
480
481 static void xennet_make_one_txreq(unsigned long gfn, unsigned int offset,
482 unsigned int len, void *data)
483 {
484 struct xennet_gnttab_make_txreq *info = data;
485
486 info->tx->flags |= XEN_NETTXF_more_data;
487 skb_get(info->skb);
488 xennet_tx_setup_grant(gfn, offset, len, data);
489 }
490
491 static struct xen_netif_tx_request *xennet_make_txreqs(
492 struct netfront_queue *queue, struct xen_netif_tx_request *tx,
493 struct sk_buff *skb, struct page *page,
494 unsigned int offset, unsigned int len)
495 {
496 struct xennet_gnttab_make_txreq info = {
497 .queue = queue,
498 .skb = skb,
499 .tx = tx,
500 };
501
502 /* Skip unused frames from start of page */
503 page += offset >> PAGE_SHIFT;
504 offset &= ~PAGE_MASK;
505
506 while (len) {
507 info.page = page;
508 info.size = 0;
509
510 gnttab_foreach_grant_in_range(page, offset, len,
511 xennet_make_one_txreq,
512 &info);
513
514 page++;
515 offset = 0;
516 len -= info.size;
517 }
518
519 return info.tx;
520 }
521
522 /*
523 * Count how many ring slots are required to send this skb. Each frag
524 * might be a compound page.
525 */
526 static int xennet_count_skb_slots(struct sk_buff *skb)
527 {
528 int i, frags = skb_shinfo(skb)->nr_frags;
529 int slots;
530
531 slots = gnttab_count_grant(offset_in_page(skb->data),
532 skb_headlen(skb));
533
534 for (i = 0; i < frags; i++) {
535 skb_frag_t *frag = skb_shinfo(skb)->frags + i;
536 unsigned long size = skb_frag_size(frag);
537 unsigned long offset = frag->page_offset;
538
539 /* Skip unused frames from start of page */
540 offset &= ~PAGE_MASK;
541
542 slots += gnttab_count_grant(offset, size);
543 }
544
545 return slots;
546 }
547
548 static u16 xennet_select_queue(struct net_device *dev, struct sk_buff *skb,
549 void *accel_priv, select_queue_fallback_t fallback)
550 {
551 unsigned int num_queues = dev->real_num_tx_queues;
552 u32 hash;
553 u16 queue_idx;
554
555 /* First, check if there is only one queue */
556 if (num_queues == 1) {
557 queue_idx = 0;
558 } else {
559 hash = skb_get_hash(skb);
560 queue_idx = hash % num_queues;
561 }
562
563 return queue_idx;
564 }
565
566 #define MAX_XEN_SKB_FRAGS (65536 / XEN_PAGE_SIZE + 1)
567
568 static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev)
569 {
570 struct netfront_info *np = netdev_priv(dev);
571 struct netfront_stats *tx_stats = this_cpu_ptr(np->tx_stats);
572 struct xen_netif_tx_request *tx, *first_tx;
573 unsigned int i;
574 int notify;
575 int slots;
576 struct page *page;
577 unsigned int offset;
578 unsigned int len;
579 unsigned long flags;
580 struct netfront_queue *queue = NULL;
581 unsigned int num_queues = dev->real_num_tx_queues;
582 u16 queue_index;
583 struct sk_buff *nskb;
584
585 /* Drop the packet if no queues are set up */
586 if (num_queues < 1)
587 goto drop;
588 /* Determine which queue to transmit this SKB on */
589 queue_index = skb_get_queue_mapping(skb);
590 queue = &np->queues[queue_index];
591
592 /* If skb->len is too big for wire format, drop skb and alert
593 * user about misconfiguration.
594 */
595 if (unlikely(skb->len > XEN_NETIF_MAX_TX_SIZE)) {
596 net_alert_ratelimited(
597 "xennet: skb->len = %u, too big for wire format\n",
598 skb->len);
599 goto drop;
600 }
601
602 slots = xennet_count_skb_slots(skb);
603 if (unlikely(slots > MAX_XEN_SKB_FRAGS + 1)) {
604 net_dbg_ratelimited("xennet: skb rides the rocket: %d slots, %d bytes\n",
605 slots, skb->len);
606 if (skb_linearize(skb))
607 goto drop;
608 }
609
610 page = virt_to_page(skb->data);
611 offset = offset_in_page(skb->data);
612
613 /* The first req should be at least ETH_HLEN size or the packet will be
614 * dropped by netback.
615 */
616 if (unlikely(PAGE_SIZE - offset < ETH_HLEN)) {
617 nskb = skb_copy(skb, GFP_ATOMIC);
618 if (!nskb)
619 goto drop;
620 dev_consume_skb_any(skb);
621 skb = nskb;
622 page = virt_to_page(skb->data);
623 offset = offset_in_page(skb->data);
624 }
625
626 len = skb_headlen(skb);
627
628 spin_lock_irqsave(&queue->tx_lock, flags);
629
630 if (unlikely(!netif_carrier_ok(dev) ||
631 (slots > 1 && !xennet_can_sg(dev)) ||
632 netif_needs_gso(skb, netif_skb_features(skb)))) {
633 spin_unlock_irqrestore(&queue->tx_lock, flags);
634 goto drop;
635 }
636
637 /* First request for the linear area. */
638 first_tx = tx = xennet_make_first_txreq(queue, skb,
639 page, offset, len);
640 offset += tx->size;
641 if (offset == PAGE_SIZE) {
642 page++;
643 offset = 0;
644 }
645 len -= tx->size;
646
647 if (skb->ip_summed == CHECKSUM_PARTIAL)
648 /* local packet? */
649 tx->flags |= XEN_NETTXF_csum_blank | XEN_NETTXF_data_validated;
650 else if (skb->ip_summed == CHECKSUM_UNNECESSARY)
651 /* remote but checksummed. */
652 tx->flags |= XEN_NETTXF_data_validated;
653
654 /* Optional extra info after the first request. */
655 if (skb_shinfo(skb)->gso_size) {
656 struct xen_netif_extra_info *gso;
657
658 gso = (struct xen_netif_extra_info *)
659 RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++);
660
661 tx->flags |= XEN_NETTXF_extra_info;
662
663 gso->u.gso.size = skb_shinfo(skb)->gso_size;
664 gso->u.gso.type = (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) ?
665 XEN_NETIF_GSO_TYPE_TCPV6 :
666 XEN_NETIF_GSO_TYPE_TCPV4;
667 gso->u.gso.pad = 0;
668 gso->u.gso.features = 0;
669
670 gso->type = XEN_NETIF_EXTRA_TYPE_GSO;
671 gso->flags = 0;
672 }
673
674 /* Requests for the rest of the linear area. */
675 tx = xennet_make_txreqs(queue, tx, skb, page, offset, len);
676
677 /* Requests for all the frags. */
678 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
679 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
680 tx = xennet_make_txreqs(queue, tx, skb,
681 skb_frag_page(frag), frag->page_offset,
682 skb_frag_size(frag));
683 }
684
685 /* First request has the packet length. */
686 first_tx->size = skb->len;
687
688 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->tx, notify);
689 if (notify)
690 notify_remote_via_irq(queue->tx_irq);
691
692 u64_stats_update_begin(&tx_stats->syncp);
693 tx_stats->bytes += skb->len;
694 tx_stats->packets++;
695 u64_stats_update_end(&tx_stats->syncp);
696
697 /* Note: It is not safe to access skb after xennet_tx_buf_gc()! */
698 xennet_tx_buf_gc(queue);
699
700 if (!netfront_tx_slot_available(queue))
701 netif_tx_stop_queue(netdev_get_tx_queue(dev, queue->id));
702
703 spin_unlock_irqrestore(&queue->tx_lock, flags);
704
705 return NETDEV_TX_OK;
706
707 drop:
708 dev->stats.tx_dropped++;
709 dev_kfree_skb_any(skb);
710 return NETDEV_TX_OK;
711 }
712
713 static int xennet_close(struct net_device *dev)
714 {
715 struct netfront_info *np = netdev_priv(dev);
716 unsigned int num_queues = dev->real_num_tx_queues;
717 unsigned int i;
718 struct netfront_queue *queue;
719 netif_tx_stop_all_queues(np->netdev);
720 for (i = 0; i < num_queues; ++i) {
721 queue = &np->queues[i];
722 napi_disable(&queue->napi);
723 }
724 return 0;
725 }
726
727 static void xennet_move_rx_slot(struct netfront_queue *queue, struct sk_buff *skb,
728 grant_ref_t ref)
729 {
730 int new = xennet_rxidx(queue->rx.req_prod_pvt);
731
732 BUG_ON(queue->rx_skbs[new]);
733 queue->rx_skbs[new] = skb;
734 queue->grant_rx_ref[new] = ref;
735 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->id = new;
736 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->gref = ref;
737 queue->rx.req_prod_pvt++;
738 }
739
740 static int xennet_get_extras(struct netfront_queue *queue,
741 struct xen_netif_extra_info *extras,
742 RING_IDX rp)
743
744 {
745 struct xen_netif_extra_info *extra;
746 struct device *dev = &queue->info->netdev->dev;
747 RING_IDX cons = queue->rx.rsp_cons;
748 int err = 0;
749
750 do {
751 struct sk_buff *skb;
752 grant_ref_t ref;
753
754 if (unlikely(cons + 1 == rp)) {
755 if (net_ratelimit())
756 dev_warn(dev, "Missing extra info\n");
757 err = -EBADR;
758 break;
759 }
760
761 extra = (struct xen_netif_extra_info *)
762 RING_GET_RESPONSE(&queue->rx, ++cons);
763
764 if (unlikely(!extra->type ||
765 extra->type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
766 if (net_ratelimit())
767 dev_warn(dev, "Invalid extra type: %d\n",
768 extra->type);
769 err = -EINVAL;
770 } else {
771 memcpy(&extras[extra->type - 1], extra,
772 sizeof(*extra));
773 }
774
775 skb = xennet_get_rx_skb(queue, cons);
776 ref = xennet_get_rx_ref(queue, cons);
777 xennet_move_rx_slot(queue, skb, ref);
778 } while (extra->flags & XEN_NETIF_EXTRA_FLAG_MORE);
779
780 queue->rx.rsp_cons = cons;
781 return err;
782 }
783
784 static int xennet_get_responses(struct netfront_queue *queue,
785 struct netfront_rx_info *rinfo, RING_IDX rp,
786 struct sk_buff_head *list)
787 {
788 struct xen_netif_rx_response *rx = &rinfo->rx;
789 struct xen_netif_extra_info *extras = rinfo->extras;
790 struct device *dev = &queue->info->netdev->dev;
791 RING_IDX cons = queue->rx.rsp_cons;
792 struct sk_buff *skb = xennet_get_rx_skb(queue, cons);
793 grant_ref_t ref = xennet_get_rx_ref(queue, cons);
794 int max = XEN_NETIF_NR_SLOTS_MIN + (rx->status <= RX_COPY_THRESHOLD);
795 int slots = 1;
796 int err = 0;
797 unsigned long ret;
798
799 if (rx->flags & XEN_NETRXF_extra_info) {
800 err = xennet_get_extras(queue, extras, rp);
801 cons = queue->rx.rsp_cons;
802 }
803
804 for (;;) {
805 if (unlikely(rx->status < 0 ||
806 rx->offset + rx->status > XEN_PAGE_SIZE)) {
807 if (net_ratelimit())
808 dev_warn(dev, "rx->offset: %u, size: %d\n",
809 rx->offset, rx->status);
810 xennet_move_rx_slot(queue, skb, ref);
811 err = -EINVAL;
812 goto next;
813 }
814
815 /*
816 * This definitely indicates a bug, either in this driver or in
817 * the backend driver. In future this should flag the bad
818 * situation to the system controller to reboot the backend.
819 */
820 if (ref == GRANT_INVALID_REF) {
821 if (net_ratelimit())
822 dev_warn(dev, "Bad rx response id %d.\n",
823 rx->id);
824 err = -EINVAL;
825 goto next;
826 }
827
828 ret = gnttab_end_foreign_access_ref(ref, 0);
829 BUG_ON(!ret);
830
831 gnttab_release_grant_reference(&queue->gref_rx_head, ref);
832
833 __skb_queue_tail(list, skb);
834
835 next:
836 if (!(rx->flags & XEN_NETRXF_more_data))
837 break;
838
839 if (cons + slots == rp) {
840 if (net_ratelimit())
841 dev_warn(dev, "Need more slots\n");
842 err = -ENOENT;
843 break;
844 }
845
846 rx = RING_GET_RESPONSE(&queue->rx, cons + slots);
847 skb = xennet_get_rx_skb(queue, cons + slots);
848 ref = xennet_get_rx_ref(queue, cons + slots);
849 slots++;
850 }
851
852 if (unlikely(slots > max)) {
853 if (net_ratelimit())
854 dev_warn(dev, "Too many slots\n");
855 err = -E2BIG;
856 }
857
858 if (unlikely(err))
859 queue->rx.rsp_cons = cons + slots;
860
861 return err;
862 }
863
864 static int xennet_set_skb_gso(struct sk_buff *skb,
865 struct xen_netif_extra_info *gso)
866 {
867 if (!gso->u.gso.size) {
868 if (net_ratelimit())
869 pr_warn("GSO size must not be zero\n");
870 return -EINVAL;
871 }
872
873 if (gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV4 &&
874 gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV6) {
875 if (net_ratelimit())
876 pr_warn("Bad GSO type %d\n", gso->u.gso.type);
877 return -EINVAL;
878 }
879
880 skb_shinfo(skb)->gso_size = gso->u.gso.size;
881 skb_shinfo(skb)->gso_type =
882 (gso->u.gso.type == XEN_NETIF_GSO_TYPE_TCPV4) ?
883 SKB_GSO_TCPV4 :
884 SKB_GSO_TCPV6;
885
886 /* Header must be checked, and gso_segs computed. */
887 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
888 skb_shinfo(skb)->gso_segs = 0;
889
890 return 0;
891 }
892
893 static RING_IDX xennet_fill_frags(struct netfront_queue *queue,
894 struct sk_buff *skb,
895 struct sk_buff_head *list)
896 {
897 struct skb_shared_info *shinfo = skb_shinfo(skb);
898 RING_IDX cons = queue->rx.rsp_cons;
899 struct sk_buff *nskb;
900
901 while ((nskb = __skb_dequeue(list))) {
902 struct xen_netif_rx_response *rx =
903 RING_GET_RESPONSE(&queue->rx, ++cons);
904 skb_frag_t *nfrag = &skb_shinfo(nskb)->frags[0];
905
906 if (shinfo->nr_frags == MAX_SKB_FRAGS) {
907 unsigned int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
908
909 BUG_ON(pull_to <= skb_headlen(skb));
910 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
911 }
912 BUG_ON(shinfo->nr_frags >= MAX_SKB_FRAGS);
913
914 skb_add_rx_frag(skb, shinfo->nr_frags, skb_frag_page(nfrag),
915 rx->offset, rx->status, PAGE_SIZE);
916
917 skb_shinfo(nskb)->nr_frags = 0;
918 kfree_skb(nskb);
919 }
920
921 return cons;
922 }
923
924 static int checksum_setup(struct net_device *dev, struct sk_buff *skb)
925 {
926 bool recalculate_partial_csum = false;
927
928 /*
929 * A GSO SKB must be CHECKSUM_PARTIAL. However some buggy
930 * peers can fail to set NETRXF_csum_blank when sending a GSO
931 * frame. In this case force the SKB to CHECKSUM_PARTIAL and
932 * recalculate the partial checksum.
933 */
934 if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) {
935 struct netfront_info *np = netdev_priv(dev);
936 atomic_inc(&np->rx_gso_checksum_fixup);
937 skb->ip_summed = CHECKSUM_PARTIAL;
938 recalculate_partial_csum = true;
939 }
940
941 /* A non-CHECKSUM_PARTIAL SKB does not require setup. */
942 if (skb->ip_summed != CHECKSUM_PARTIAL)
943 return 0;
944
945 return skb_checksum_setup(skb, recalculate_partial_csum);
946 }
947
948 static int handle_incoming_queue(struct netfront_queue *queue,
949 struct sk_buff_head *rxq)
950 {
951 struct netfront_stats *rx_stats = this_cpu_ptr(queue->info->rx_stats);
952 int packets_dropped = 0;
953 struct sk_buff *skb;
954
955 while ((skb = __skb_dequeue(rxq)) != NULL) {
956 int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
957
958 if (pull_to > skb_headlen(skb))
959 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
960
961 /* Ethernet work: Delayed to here as it peeks the header. */
962 skb->protocol = eth_type_trans(skb, queue->info->netdev);
963 skb_reset_network_header(skb);
964
965 if (checksum_setup(queue->info->netdev, skb)) {
966 kfree_skb(skb);
967 packets_dropped++;
968 queue->info->netdev->stats.rx_errors++;
969 continue;
970 }
971
972 u64_stats_update_begin(&rx_stats->syncp);
973 rx_stats->packets++;
974 rx_stats->bytes += skb->len;
975 u64_stats_update_end(&rx_stats->syncp);
976
977 /* Pass it up. */
978 napi_gro_receive(&queue->napi, skb);
979 }
980
981 return packets_dropped;
982 }
983
984 static int xennet_poll(struct napi_struct *napi, int budget)
985 {
986 struct netfront_queue *queue = container_of(napi, struct netfront_queue, napi);
987 struct net_device *dev = queue->info->netdev;
988 struct sk_buff *skb;
989 struct netfront_rx_info rinfo;
990 struct xen_netif_rx_response *rx = &rinfo.rx;
991 struct xen_netif_extra_info *extras = rinfo.extras;
992 RING_IDX i, rp;
993 int work_done;
994 struct sk_buff_head rxq;
995 struct sk_buff_head errq;
996 struct sk_buff_head tmpq;
997 int err;
998
999 spin_lock(&queue->rx_lock);
1000
1001 skb_queue_head_init(&rxq);
1002 skb_queue_head_init(&errq);
1003 skb_queue_head_init(&tmpq);
1004
1005 rp = queue->rx.sring->rsp_prod;
1006 rmb(); /* Ensure we see queued responses up to 'rp'. */
1007
1008 i = queue->rx.rsp_cons;
1009 work_done = 0;
1010 while ((i != rp) && (work_done < budget)) {
1011 memcpy(rx, RING_GET_RESPONSE(&queue->rx, i), sizeof(*rx));
1012 memset(extras, 0, sizeof(rinfo.extras));
1013
1014 err = xennet_get_responses(queue, &rinfo, rp, &tmpq);
1015
1016 if (unlikely(err)) {
1017 err:
1018 while ((skb = __skb_dequeue(&tmpq)))
1019 __skb_queue_tail(&errq, skb);
1020 dev->stats.rx_errors++;
1021 i = queue->rx.rsp_cons;
1022 continue;
1023 }
1024
1025 skb = __skb_dequeue(&tmpq);
1026
1027 if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) {
1028 struct xen_netif_extra_info *gso;
1029 gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1];
1030
1031 if (unlikely(xennet_set_skb_gso(skb, gso))) {
1032 __skb_queue_head(&tmpq, skb);
1033 queue->rx.rsp_cons += skb_queue_len(&tmpq);
1034 goto err;
1035 }
1036 }
1037
1038 NETFRONT_SKB_CB(skb)->pull_to = rx->status;
1039 if (NETFRONT_SKB_CB(skb)->pull_to > RX_COPY_THRESHOLD)
1040 NETFRONT_SKB_CB(skb)->pull_to = RX_COPY_THRESHOLD;
1041
1042 skb_shinfo(skb)->frags[0].page_offset = rx->offset;
1043 skb_frag_size_set(&skb_shinfo(skb)->frags[0], rx->status);
1044 skb->data_len = rx->status;
1045 skb->len += rx->status;
1046
1047 i = xennet_fill_frags(queue, skb, &tmpq);
1048
1049 if (rx->flags & XEN_NETRXF_csum_blank)
1050 skb->ip_summed = CHECKSUM_PARTIAL;
1051 else if (rx->flags & XEN_NETRXF_data_validated)
1052 skb->ip_summed = CHECKSUM_UNNECESSARY;
1053
1054 __skb_queue_tail(&rxq, skb);
1055
1056 queue->rx.rsp_cons = ++i;
1057 work_done++;
1058 }
1059
1060 __skb_queue_purge(&errq);
1061
1062 work_done -= handle_incoming_queue(queue, &rxq);
1063
1064 xennet_alloc_rx_buffers(queue);
1065
1066 if (work_done < budget) {
1067 int more_to_do = 0;
1068
1069 napi_complete_done(napi, work_done);
1070
1071 RING_FINAL_CHECK_FOR_RESPONSES(&queue->rx, more_to_do);
1072 if (more_to_do)
1073 napi_schedule(napi);
1074 }
1075
1076 spin_unlock(&queue->rx_lock);
1077
1078 return work_done;
1079 }
1080
1081 static int xennet_change_mtu(struct net_device *dev, int mtu)
1082 {
1083 int max = xennet_can_sg(dev) ? XEN_NETIF_MAX_TX_SIZE : ETH_DATA_LEN;
1084
1085 if (mtu > max)
1086 return -EINVAL;
1087 dev->mtu = mtu;
1088 return 0;
1089 }
1090
1091 static void xennet_get_stats64(struct net_device *dev,
1092 struct rtnl_link_stats64 *tot)
1093 {
1094 struct netfront_info *np = netdev_priv(dev);
1095 int cpu;
1096
1097 for_each_possible_cpu(cpu) {
1098 struct netfront_stats *rx_stats = per_cpu_ptr(np->rx_stats, cpu);
1099 struct netfront_stats *tx_stats = per_cpu_ptr(np->tx_stats, cpu);
1100 u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
1101 unsigned int start;
1102
1103 do {
1104 start = u64_stats_fetch_begin_irq(&tx_stats->syncp);
1105 tx_packets = tx_stats->packets;
1106 tx_bytes = tx_stats->bytes;
1107 } while (u64_stats_fetch_retry_irq(&tx_stats->syncp, start));
1108
1109 do {
1110 start = u64_stats_fetch_begin_irq(&rx_stats->syncp);
1111 rx_packets = rx_stats->packets;
1112 rx_bytes = rx_stats->bytes;
1113 } while (u64_stats_fetch_retry_irq(&rx_stats->syncp, start));
1114
1115 tot->rx_packets += rx_packets;
1116 tot->tx_packets += tx_packets;
1117 tot->rx_bytes += rx_bytes;
1118 tot->tx_bytes += tx_bytes;
1119 }
1120
1121 tot->rx_errors = dev->stats.rx_errors;
1122 tot->tx_dropped = dev->stats.tx_dropped;
1123 }
1124
1125 static void xennet_release_tx_bufs(struct netfront_queue *queue)
1126 {
1127 struct sk_buff *skb;
1128 int i;
1129
1130 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1131 /* Skip over entries which are actually freelist references */
1132 if (skb_entry_is_link(&queue->tx_skbs[i]))
1133 continue;
1134
1135 skb = queue->tx_skbs[i].skb;
1136 get_page(queue->grant_tx_page[i]);
1137 gnttab_end_foreign_access(queue->grant_tx_ref[i],
1138 GNTMAP_readonly,
1139 (unsigned long)page_address(queue->grant_tx_page[i]));
1140 queue->grant_tx_page[i] = NULL;
1141 queue->grant_tx_ref[i] = GRANT_INVALID_REF;
1142 add_id_to_freelist(&queue->tx_skb_freelist, queue->tx_skbs, i);
1143 dev_kfree_skb_irq(skb);
1144 }
1145 }
1146
1147 static void xennet_release_rx_bufs(struct netfront_queue *queue)
1148 {
1149 int id, ref;
1150
1151 spin_lock_bh(&queue->rx_lock);
1152
1153 for (id = 0; id < NET_RX_RING_SIZE; id++) {
1154 struct sk_buff *skb;
1155 struct page *page;
1156
1157 skb = queue->rx_skbs[id];
1158 if (!skb)
1159 continue;
1160
1161 ref = queue->grant_rx_ref[id];
1162 if (ref == GRANT_INVALID_REF)
1163 continue;
1164
1165 page = skb_frag_page(&skb_shinfo(skb)->frags[0]);
1166
1167 /* gnttab_end_foreign_access() needs a page ref until
1168 * foreign access is ended (which may be deferred).
1169 */
1170 get_page(page);
1171 gnttab_end_foreign_access(ref, 0,
1172 (unsigned long)page_address(page));
1173 queue->grant_rx_ref[id] = GRANT_INVALID_REF;
1174
1175 kfree_skb(skb);
1176 }
1177
1178 spin_unlock_bh(&queue->rx_lock);
1179 }
1180
1181 static netdev_features_t xennet_fix_features(struct net_device *dev,
1182 netdev_features_t features)
1183 {
1184 struct netfront_info *np = netdev_priv(dev);
1185
1186 if (features & NETIF_F_SG &&
1187 !xenbus_read_unsigned(np->xbdev->otherend, "feature-sg", 0))
1188 features &= ~NETIF_F_SG;
1189
1190 if (features & NETIF_F_IPV6_CSUM &&
1191 !xenbus_read_unsigned(np->xbdev->otherend,
1192 "feature-ipv6-csum-offload", 0))
1193 features &= ~NETIF_F_IPV6_CSUM;
1194
1195 if (features & NETIF_F_TSO &&
1196 !xenbus_read_unsigned(np->xbdev->otherend, "feature-gso-tcpv4", 0))
1197 features &= ~NETIF_F_TSO;
1198
1199 if (features & NETIF_F_TSO6 &&
1200 !xenbus_read_unsigned(np->xbdev->otherend, "feature-gso-tcpv6", 0))
1201 features &= ~NETIF_F_TSO6;
1202
1203 return features;
1204 }
1205
1206 static int xennet_set_features(struct net_device *dev,
1207 netdev_features_t features)
1208 {
1209 if (!(features & NETIF_F_SG) && dev->mtu > ETH_DATA_LEN) {
1210 netdev_info(dev, "Reducing MTU because no SG offload");
1211 dev->mtu = ETH_DATA_LEN;
1212 }
1213
1214 return 0;
1215 }
1216
1217 static irqreturn_t xennet_tx_interrupt(int irq, void *dev_id)
1218 {
1219 struct netfront_queue *queue = dev_id;
1220 unsigned long flags;
1221
1222 spin_lock_irqsave(&queue->tx_lock, flags);
1223 xennet_tx_buf_gc(queue);
1224 spin_unlock_irqrestore(&queue->tx_lock, flags);
1225
1226 return IRQ_HANDLED;
1227 }
1228
1229 static irqreturn_t xennet_rx_interrupt(int irq, void *dev_id)
1230 {
1231 struct netfront_queue *queue = dev_id;
1232 struct net_device *dev = queue->info->netdev;
1233
1234 if (likely(netif_carrier_ok(dev) &&
1235 RING_HAS_UNCONSUMED_RESPONSES(&queue->rx)))
1236 napi_schedule(&queue->napi);
1237
1238 return IRQ_HANDLED;
1239 }
1240
1241 static irqreturn_t xennet_interrupt(int irq, void *dev_id)
1242 {
1243 xennet_tx_interrupt(irq, dev_id);
1244 xennet_rx_interrupt(irq, dev_id);
1245 return IRQ_HANDLED;
1246 }
1247
1248 #ifdef CONFIG_NET_POLL_CONTROLLER
1249 static void xennet_poll_controller(struct net_device *dev)
1250 {
1251 /* Poll each queue */
1252 struct netfront_info *info = netdev_priv(dev);
1253 unsigned int num_queues = dev->real_num_tx_queues;
1254 unsigned int i;
1255 for (i = 0; i < num_queues; ++i)
1256 xennet_interrupt(0, &info->queues[i]);
1257 }
1258 #endif
1259
1260 static const struct net_device_ops xennet_netdev_ops = {
1261 .ndo_open = xennet_open,
1262 .ndo_stop = xennet_close,
1263 .ndo_start_xmit = xennet_start_xmit,
1264 .ndo_change_mtu = xennet_change_mtu,
1265 .ndo_get_stats64 = xennet_get_stats64,
1266 .ndo_set_mac_address = eth_mac_addr,
1267 .ndo_validate_addr = eth_validate_addr,
1268 .ndo_fix_features = xennet_fix_features,
1269 .ndo_set_features = xennet_set_features,
1270 .ndo_select_queue = xennet_select_queue,
1271 #ifdef CONFIG_NET_POLL_CONTROLLER
1272 .ndo_poll_controller = xennet_poll_controller,
1273 #endif
1274 };
1275
1276 static void xennet_free_netdev(struct net_device *netdev)
1277 {
1278 struct netfront_info *np = netdev_priv(netdev);
1279
1280 free_percpu(np->rx_stats);
1281 free_percpu(np->tx_stats);
1282 free_netdev(netdev);
1283 }
1284
1285 static struct net_device *xennet_create_dev(struct xenbus_device *dev)
1286 {
1287 int err;
1288 struct net_device *netdev;
1289 struct netfront_info *np;
1290
1291 netdev = alloc_etherdev_mq(sizeof(struct netfront_info), xennet_max_queues);
1292 if (!netdev)
1293 return ERR_PTR(-ENOMEM);
1294
1295 np = netdev_priv(netdev);
1296 np->xbdev = dev;
1297
1298 np->queues = NULL;
1299
1300 err = -ENOMEM;
1301 np->rx_stats = netdev_alloc_pcpu_stats(struct netfront_stats);
1302 if (np->rx_stats == NULL)
1303 goto exit;
1304 np->tx_stats = netdev_alloc_pcpu_stats(struct netfront_stats);
1305 if (np->tx_stats == NULL)
1306 goto exit;
1307
1308 netdev->netdev_ops = &xennet_netdev_ops;
1309
1310 netdev->features = NETIF_F_IP_CSUM | NETIF_F_RXCSUM |
1311 NETIF_F_GSO_ROBUST;
1312 netdev->hw_features = NETIF_F_SG |
1313 NETIF_F_IPV6_CSUM |
1314 NETIF_F_TSO | NETIF_F_TSO6;
1315
1316 /*
1317 * Assume that all hw features are available for now. This set
1318 * will be adjusted by the call to netdev_update_features() in
1319 * xennet_connect() which is the earliest point where we can
1320 * negotiate with the backend regarding supported features.
1321 */
1322 netdev->features |= netdev->hw_features;
1323
1324 netdev->ethtool_ops = &xennet_ethtool_ops;
1325 netdev->min_mtu = ETH_MIN_MTU;
1326 netdev->max_mtu = XEN_NETIF_MAX_TX_SIZE;
1327 SET_NETDEV_DEV(netdev, &dev->dev);
1328
1329 np->netdev = netdev;
1330
1331 netif_carrier_off(netdev);
1332
1333 xenbus_switch_state(dev, XenbusStateInitialising);
1334 wait_event(module_load_q,
1335 xenbus_read_driver_state(dev->otherend) !=
1336 XenbusStateClosed &&
1337 xenbus_read_driver_state(dev->otherend) !=
1338 XenbusStateUnknown);
1339 return netdev;
1340
1341 exit:
1342 xennet_free_netdev(netdev);
1343 return ERR_PTR(err);
1344 }
1345
1346 /**
1347 * Entry point to this code when a new device is created. Allocate the basic
1348 * structures and the ring buffers for communication with the backend, and
1349 * inform the backend of the appropriate details for those.
1350 */
1351 static int netfront_probe(struct xenbus_device *dev,
1352 const struct xenbus_device_id *id)
1353 {
1354 int err;
1355 struct net_device *netdev;
1356 struct netfront_info *info;
1357
1358 netdev = xennet_create_dev(dev);
1359 if (IS_ERR(netdev)) {
1360 err = PTR_ERR(netdev);
1361 xenbus_dev_fatal(dev, err, "creating netdev");
1362 return err;
1363 }
1364
1365 info = netdev_priv(netdev);
1366 dev_set_drvdata(&dev->dev, info);
1367 #ifdef CONFIG_SYSFS
1368 info->netdev->sysfs_groups[0] = &xennet_dev_group;
1369 #endif
1370
1371 return 0;
1372 }
1373
1374 static void xennet_end_access(int ref, void *page)
1375 {
1376 /* This frees the page as a side-effect */
1377 if (ref != GRANT_INVALID_REF)
1378 gnttab_end_foreign_access(ref, 0, (unsigned long)page);
1379 }
1380
1381 static void xennet_disconnect_backend(struct netfront_info *info)
1382 {
1383 unsigned int i = 0;
1384 unsigned int num_queues = info->netdev->real_num_tx_queues;
1385
1386 netif_carrier_off(info->netdev);
1387
1388 for (i = 0; i < num_queues && info->queues; ++i) {
1389 struct netfront_queue *queue = &info->queues[i];
1390
1391 del_timer_sync(&queue->rx_refill_timer);
1392
1393 if (queue->tx_irq && (queue->tx_irq == queue->rx_irq))
1394 unbind_from_irqhandler(queue->tx_irq, queue);
1395 if (queue->tx_irq && (queue->tx_irq != queue->rx_irq)) {
1396 unbind_from_irqhandler(queue->tx_irq, queue);
1397 unbind_from_irqhandler(queue->rx_irq, queue);
1398 }
1399 queue->tx_evtchn = queue->rx_evtchn = 0;
1400 queue->tx_irq = queue->rx_irq = 0;
1401
1402 if (netif_running(info->netdev))
1403 napi_synchronize(&queue->napi);
1404
1405 xennet_release_tx_bufs(queue);
1406 xennet_release_rx_bufs(queue);
1407 gnttab_free_grant_references(queue->gref_tx_head);
1408 gnttab_free_grant_references(queue->gref_rx_head);
1409
1410 /* End access and free the pages */
1411 xennet_end_access(queue->tx_ring_ref, queue->tx.sring);
1412 xennet_end_access(queue->rx_ring_ref, queue->rx.sring);
1413
1414 queue->tx_ring_ref = GRANT_INVALID_REF;
1415 queue->rx_ring_ref = GRANT_INVALID_REF;
1416 queue->tx.sring = NULL;
1417 queue->rx.sring = NULL;
1418 }
1419 }
1420
1421 /**
1422 * We are reconnecting to the backend, due to a suspend/resume, or a backend
1423 * driver restart. We tear down our netif structure and recreate it, but
1424 * leave the device-layer structures intact so that this is transparent to the
1425 * rest of the kernel.
1426 */
1427 static int netfront_resume(struct xenbus_device *dev)
1428 {
1429 struct netfront_info *info = dev_get_drvdata(&dev->dev);
1430
1431 dev_dbg(&dev->dev, "%s\n", dev->nodename);
1432
1433 xennet_disconnect_backend(info);
1434 return 0;
1435 }
1436
1437 static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[])
1438 {
1439 char *s, *e, *macstr;
1440 int i;
1441
1442 macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL);
1443 if (IS_ERR(macstr))
1444 return PTR_ERR(macstr);
1445
1446 for (i = 0; i < ETH_ALEN; i++) {
1447 mac[i] = simple_strtoul(s, &e, 16);
1448 if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) {
1449 kfree(macstr);
1450 return -ENOENT;
1451 }
1452 s = e+1;
1453 }
1454
1455 kfree(macstr);
1456 return 0;
1457 }
1458
1459 static int setup_netfront_single(struct netfront_queue *queue)
1460 {
1461 int err;
1462
1463 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn);
1464 if (err < 0)
1465 goto fail;
1466
1467 err = bind_evtchn_to_irqhandler(queue->tx_evtchn,
1468 xennet_interrupt,
1469 0, queue->info->netdev->name, queue);
1470 if (err < 0)
1471 goto bind_fail;
1472 queue->rx_evtchn = queue->tx_evtchn;
1473 queue->rx_irq = queue->tx_irq = err;
1474
1475 return 0;
1476
1477 bind_fail:
1478 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn);
1479 queue->tx_evtchn = 0;
1480 fail:
1481 return err;
1482 }
1483
1484 static int setup_netfront_split(struct netfront_queue *queue)
1485 {
1486 int err;
1487
1488 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn);
1489 if (err < 0)
1490 goto fail;
1491 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->rx_evtchn);
1492 if (err < 0)
1493 goto alloc_rx_evtchn_fail;
1494
1495 snprintf(queue->tx_irq_name, sizeof(queue->tx_irq_name),
1496 "%s-tx", queue->name);
1497 err = bind_evtchn_to_irqhandler(queue->tx_evtchn,
1498 xennet_tx_interrupt,
1499 0, queue->tx_irq_name, queue);
1500 if (err < 0)
1501 goto bind_tx_fail;
1502 queue->tx_irq = err;
1503
1504 snprintf(queue->rx_irq_name, sizeof(queue->rx_irq_name),
1505 "%s-rx", queue->name);
1506 err = bind_evtchn_to_irqhandler(queue->rx_evtchn,
1507 xennet_rx_interrupt,
1508 0, queue->rx_irq_name, queue);
1509 if (err < 0)
1510 goto bind_rx_fail;
1511 queue->rx_irq = err;
1512
1513 return 0;
1514
1515 bind_rx_fail:
1516 unbind_from_irqhandler(queue->tx_irq, queue);
1517 queue->tx_irq = 0;
1518 bind_tx_fail:
1519 xenbus_free_evtchn(queue->info->xbdev, queue->rx_evtchn);
1520 queue->rx_evtchn = 0;
1521 alloc_rx_evtchn_fail:
1522 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn);
1523 queue->tx_evtchn = 0;
1524 fail:
1525 return err;
1526 }
1527
1528 static int setup_netfront(struct xenbus_device *dev,
1529 struct netfront_queue *queue, unsigned int feature_split_evtchn)
1530 {
1531 struct xen_netif_tx_sring *txs;
1532 struct xen_netif_rx_sring *rxs;
1533 grant_ref_t gref;
1534 int err;
1535
1536 queue->tx_ring_ref = GRANT_INVALID_REF;
1537 queue->rx_ring_ref = GRANT_INVALID_REF;
1538 queue->rx.sring = NULL;
1539 queue->tx.sring = NULL;
1540
1541 txs = (struct xen_netif_tx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1542 if (!txs) {
1543 err = -ENOMEM;
1544 xenbus_dev_fatal(dev, err, "allocating tx ring page");
1545 goto fail;
1546 }
1547 SHARED_RING_INIT(txs);
1548 FRONT_RING_INIT(&queue->tx, txs, XEN_PAGE_SIZE);
1549
1550 err = xenbus_grant_ring(dev, txs, 1, &gref);
1551 if (err < 0)
1552 goto grant_tx_ring_fail;
1553 queue->tx_ring_ref = gref;
1554
1555 rxs = (struct xen_netif_rx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1556 if (!rxs) {
1557 err = -ENOMEM;
1558 xenbus_dev_fatal(dev, err, "allocating rx ring page");
1559 goto alloc_rx_ring_fail;
1560 }
1561 SHARED_RING_INIT(rxs);
1562 FRONT_RING_INIT(&queue->rx, rxs, XEN_PAGE_SIZE);
1563
1564 err = xenbus_grant_ring(dev, rxs, 1, &gref);
1565 if (err < 0)
1566 goto grant_rx_ring_fail;
1567 queue->rx_ring_ref = gref;
1568
1569 if (feature_split_evtchn)
1570 err = setup_netfront_split(queue);
1571 /* setup single event channel if
1572 * a) feature-split-event-channels == 0
1573 * b) feature-split-event-channels == 1 but failed to setup
1574 */
1575 if (!feature_split_evtchn || (feature_split_evtchn && err))
1576 err = setup_netfront_single(queue);
1577
1578 if (err)
1579 goto alloc_evtchn_fail;
1580
1581 return 0;
1582
1583 /* If we fail to setup netfront, it is safe to just revoke access to
1584 * granted pages because backend is not accessing it at this point.
1585 */
1586 alloc_evtchn_fail:
1587 gnttab_end_foreign_access_ref(queue->rx_ring_ref, 0);
1588 grant_rx_ring_fail:
1589 free_page((unsigned long)rxs);
1590 alloc_rx_ring_fail:
1591 gnttab_end_foreign_access_ref(queue->tx_ring_ref, 0);
1592 grant_tx_ring_fail:
1593 free_page((unsigned long)txs);
1594 fail:
1595 return err;
1596 }
1597
1598 /* Queue-specific initialisation
1599 * This used to be done in xennet_create_dev() but must now
1600 * be run per-queue.
1601 */
1602 static int xennet_init_queue(struct netfront_queue *queue)
1603 {
1604 unsigned short i;
1605 int err = 0;
1606
1607 spin_lock_init(&queue->tx_lock);
1608 spin_lock_init(&queue->rx_lock);
1609
1610 timer_setup(&queue->rx_refill_timer, rx_refill_timeout, 0);
1611
1612 snprintf(queue->name, sizeof(queue->name), "%s-q%u",
1613 queue->info->netdev->name, queue->id);
1614
1615 /* Initialise tx_skbs as a free chain containing every entry. */
1616 queue->tx_skb_freelist = 0;
1617 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1618 skb_entry_set_link(&queue->tx_skbs[i], i+1);
1619 queue->grant_tx_ref[i] = GRANT_INVALID_REF;
1620 queue->grant_tx_page[i] = NULL;
1621 }
1622
1623 /* Clear out rx_skbs */
1624 for (i = 0; i < NET_RX_RING_SIZE; i++) {
1625 queue->rx_skbs[i] = NULL;
1626 queue->grant_rx_ref[i] = GRANT_INVALID_REF;
1627 }
1628
1629 /* A grant for every tx ring slot */
1630 if (gnttab_alloc_grant_references(NET_TX_RING_SIZE,
1631 &queue->gref_tx_head) < 0) {
1632 pr_alert("can't alloc tx grant refs\n");
1633 err = -ENOMEM;
1634 goto exit;
1635 }
1636
1637 /* A grant for every rx ring slot */
1638 if (gnttab_alloc_grant_references(NET_RX_RING_SIZE,
1639 &queue->gref_rx_head) < 0) {
1640 pr_alert("can't alloc rx grant refs\n");
1641 err = -ENOMEM;
1642 goto exit_free_tx;
1643 }
1644
1645 return 0;
1646
1647 exit_free_tx:
1648 gnttab_free_grant_references(queue->gref_tx_head);
1649 exit:
1650 return err;
1651 }
1652
1653 static int write_queue_xenstore_keys(struct netfront_queue *queue,
1654 struct xenbus_transaction *xbt, int write_hierarchical)
1655 {
1656 /* Write the queue-specific keys into XenStore in the traditional
1657 * way for a single queue, or in a queue subkeys for multiple
1658 * queues.
1659 */
1660 struct xenbus_device *dev = queue->info->xbdev;
1661 int err;
1662 const char *message;
1663 char *path;
1664 size_t pathsize;
1665
1666 /* Choose the correct place to write the keys */
1667 if (write_hierarchical) {
1668 pathsize = strlen(dev->nodename) + 10;
1669 path = kzalloc(pathsize, GFP_KERNEL);
1670 if (!path) {
1671 err = -ENOMEM;
1672 message = "out of memory while writing ring references";
1673 goto error;
1674 }
1675 snprintf(path, pathsize, "%s/queue-%u",
1676 dev->nodename, queue->id);
1677 } else {
1678 path = (char *)dev->nodename;
1679 }
1680
1681 /* Write ring references */
1682 err = xenbus_printf(*xbt, path, "tx-ring-ref", "%u",
1683 queue->tx_ring_ref);
1684 if (err) {
1685 message = "writing tx-ring-ref";
1686 goto error;
1687 }
1688
1689 err = xenbus_printf(*xbt, path, "rx-ring-ref", "%u",
1690 queue->rx_ring_ref);
1691 if (err) {
1692 message = "writing rx-ring-ref";
1693 goto error;
1694 }
1695
1696 /* Write event channels; taking into account both shared
1697 * and split event channel scenarios.
1698 */
1699 if (queue->tx_evtchn == queue->rx_evtchn) {
1700 /* Shared event channel */
1701 err = xenbus_printf(*xbt, path,
1702 "event-channel", "%u", queue->tx_evtchn);
1703 if (err) {
1704 message = "writing event-channel";
1705 goto error;
1706 }
1707 } else {
1708 /* Split event channels */
1709 err = xenbus_printf(*xbt, path,
1710 "event-channel-tx", "%u", queue->tx_evtchn);
1711 if (err) {
1712 message = "writing event-channel-tx";
1713 goto error;
1714 }
1715
1716 err = xenbus_printf(*xbt, path,
1717 "event-channel-rx", "%u", queue->rx_evtchn);
1718 if (err) {
1719 message = "writing event-channel-rx";
1720 goto error;
1721 }
1722 }
1723
1724 if (write_hierarchical)
1725 kfree(path);
1726 return 0;
1727
1728 error:
1729 if (write_hierarchical)
1730 kfree(path);
1731 xenbus_dev_fatal(dev, err, "%s", message);
1732 return err;
1733 }
1734
1735 static void xennet_destroy_queues(struct netfront_info *info)
1736 {
1737 unsigned int i;
1738
1739 for (i = 0; i < info->netdev->real_num_tx_queues; i++) {
1740 struct netfront_queue *queue = &info->queues[i];
1741
1742 if (netif_running(info->netdev))
1743 napi_disable(&queue->napi);
1744 netif_napi_del(&queue->napi);
1745 }
1746
1747 kfree(info->queues);
1748 info->queues = NULL;
1749 }
1750
1751 static int xennet_create_queues(struct netfront_info *info,
1752 unsigned int *num_queues)
1753 {
1754 unsigned int i;
1755 int ret;
1756
1757 info->queues = kcalloc(*num_queues, sizeof(struct netfront_queue),
1758 GFP_KERNEL);
1759 if (!info->queues)
1760 return -ENOMEM;
1761
1762 for (i = 0; i < *num_queues; i++) {
1763 struct netfront_queue *queue = &info->queues[i];
1764
1765 queue->id = i;
1766 queue->info = info;
1767
1768 ret = xennet_init_queue(queue);
1769 if (ret < 0) {
1770 dev_warn(&info->xbdev->dev,
1771 "only created %d queues\n", i);
1772 *num_queues = i;
1773 break;
1774 }
1775
1776 netif_napi_add(queue->info->netdev, &queue->napi,
1777 xennet_poll, 64);
1778 if (netif_running(info->netdev))
1779 napi_enable(&queue->napi);
1780 }
1781
1782 netif_set_real_num_tx_queues(info->netdev, *num_queues);
1783
1784 if (*num_queues == 0) {
1785 dev_err(&info->xbdev->dev, "no queues\n");
1786 return -EINVAL;
1787 }
1788 return 0;
1789 }
1790
1791 /* Common code used when first setting up, and when resuming. */
1792 static int talk_to_netback(struct xenbus_device *dev,
1793 struct netfront_info *info)
1794 {
1795 const char *message;
1796 struct xenbus_transaction xbt;
1797 int err;
1798 unsigned int feature_split_evtchn;
1799 unsigned int i = 0;
1800 unsigned int max_queues = 0;
1801 struct netfront_queue *queue = NULL;
1802 unsigned int num_queues = 1;
1803
1804 info->netdev->irq = 0;
1805
1806 /* Check if backend supports multiple queues */
1807 max_queues = xenbus_read_unsigned(info->xbdev->otherend,
1808 "multi-queue-max-queues", 1);
1809 num_queues = min(max_queues, xennet_max_queues);
1810
1811 /* Check feature-split-event-channels */
1812 feature_split_evtchn = xenbus_read_unsigned(info->xbdev->otherend,
1813 "feature-split-event-channels", 0);
1814
1815 /* Read mac addr. */
1816 err = xen_net_read_mac(dev, info->netdev->dev_addr);
1817 if (err) {
1818 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
1819 goto out_unlocked;
1820 }
1821
1822 rtnl_lock();
1823 if (info->queues)
1824 xennet_destroy_queues(info);
1825
1826 err = xennet_create_queues(info, &num_queues);
1827 if (err < 0) {
1828 xenbus_dev_fatal(dev, err, "creating queues");
1829 kfree(info->queues);
1830 info->queues = NULL;
1831 goto out;
1832 }
1833 rtnl_unlock();
1834
1835 /* Create shared ring, alloc event channel -- for each queue */
1836 for (i = 0; i < num_queues; ++i) {
1837 queue = &info->queues[i];
1838 err = setup_netfront(dev, queue, feature_split_evtchn);
1839 if (err)
1840 goto destroy_ring;
1841 }
1842
1843 again:
1844 err = xenbus_transaction_start(&xbt);
1845 if (err) {
1846 xenbus_dev_fatal(dev, err, "starting transaction");
1847 goto destroy_ring;
1848 }
1849
1850 if (xenbus_exists(XBT_NIL,
1851 info->xbdev->otherend, "multi-queue-max-queues")) {
1852 /* Write the number of queues */
1853 err = xenbus_printf(xbt, dev->nodename,
1854 "multi-queue-num-queues", "%u", num_queues);
1855 if (err) {
1856 message = "writing multi-queue-num-queues";
1857 goto abort_transaction_no_dev_fatal;
1858 }
1859 }
1860
1861 if (num_queues == 1) {
1862 err = write_queue_xenstore_keys(&info->queues[0], &xbt, 0); /* flat */
1863 if (err)
1864 goto abort_transaction_no_dev_fatal;
1865 } else {
1866 /* Write the keys for each queue */
1867 for (i = 0; i < num_queues; ++i) {
1868 queue = &info->queues[i];
1869 err = write_queue_xenstore_keys(queue, &xbt, 1); /* hierarchical */
1870 if (err)
1871 goto abort_transaction_no_dev_fatal;
1872 }
1873 }
1874
1875 /* The remaining keys are not queue-specific */
1876 err = xenbus_printf(xbt, dev->nodename, "request-rx-copy", "%u",
1877 1);
1878 if (err) {
1879 message = "writing request-rx-copy";
1880 goto abort_transaction;
1881 }
1882
1883 err = xenbus_printf(xbt, dev->nodename, "feature-rx-notify", "%d", 1);
1884 if (err) {
1885 message = "writing feature-rx-notify";
1886 goto abort_transaction;
1887 }
1888
1889 err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", 1);
1890 if (err) {
1891 message = "writing feature-sg";
1892 goto abort_transaction;
1893 }
1894
1895 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4", "%d", 1);
1896 if (err) {
1897 message = "writing feature-gso-tcpv4";
1898 goto abort_transaction;
1899 }
1900
1901 err = xenbus_write(xbt, dev->nodename, "feature-gso-tcpv6", "1");
1902 if (err) {
1903 message = "writing feature-gso-tcpv6";
1904 goto abort_transaction;
1905 }
1906
1907 err = xenbus_write(xbt, dev->nodename, "feature-ipv6-csum-offload",
1908 "1");
1909 if (err) {
1910 message = "writing feature-ipv6-csum-offload";
1911 goto abort_transaction;
1912 }
1913
1914 err = xenbus_transaction_end(xbt, 0);
1915 if (err) {
1916 if (err == -EAGAIN)
1917 goto again;
1918 xenbus_dev_fatal(dev, err, "completing transaction");
1919 goto destroy_ring;
1920 }
1921
1922 return 0;
1923
1924 abort_transaction:
1925 xenbus_dev_fatal(dev, err, "%s", message);
1926 abort_transaction_no_dev_fatal:
1927 xenbus_transaction_end(xbt, 1);
1928 destroy_ring:
1929 xennet_disconnect_backend(info);
1930 rtnl_lock();
1931 xennet_destroy_queues(info);
1932 out:
1933 rtnl_unlock();
1934 out_unlocked:
1935 device_unregister(&dev->dev);
1936 return err;
1937 }
1938
1939 static int xennet_connect(struct net_device *dev)
1940 {
1941 struct netfront_info *np = netdev_priv(dev);
1942 unsigned int num_queues = 0;
1943 int err;
1944 unsigned int j = 0;
1945 struct netfront_queue *queue = NULL;
1946
1947 if (!xenbus_read_unsigned(np->xbdev->otherend, "feature-rx-copy", 0)) {
1948 dev_info(&dev->dev,
1949 "backend does not support copying receive path\n");
1950 return -ENODEV;
1951 }
1952
1953 err = talk_to_netback(np->xbdev, np);
1954 if (err)
1955 return err;
1956
1957 /* talk_to_netback() sets the correct number of queues */
1958 num_queues = dev->real_num_tx_queues;
1959
1960 if (dev->reg_state == NETREG_UNINITIALIZED) {
1961 err = register_netdev(dev);
1962 if (err) {
1963 pr_warn("%s: register_netdev err=%d\n", __func__, err);
1964 device_unregister(&np->xbdev->dev);
1965 return err;
1966 }
1967 }
1968
1969 rtnl_lock();
1970 netdev_update_features(dev);
1971 rtnl_unlock();
1972
1973 /*
1974 * All public and private state should now be sane. Get
1975 * ready to start sending and receiving packets and give the driver
1976 * domain a kick because we've probably just requeued some
1977 * packets.
1978 */
1979 netif_carrier_on(np->netdev);
1980 for (j = 0; j < num_queues; ++j) {
1981 queue = &np->queues[j];
1982
1983 notify_remote_via_irq(queue->tx_irq);
1984 if (queue->tx_irq != queue->rx_irq)
1985 notify_remote_via_irq(queue->rx_irq);
1986
1987 spin_lock_irq(&queue->tx_lock);
1988 xennet_tx_buf_gc(queue);
1989 spin_unlock_irq(&queue->tx_lock);
1990
1991 spin_lock_bh(&queue->rx_lock);
1992 xennet_alloc_rx_buffers(queue);
1993 spin_unlock_bh(&queue->rx_lock);
1994 }
1995
1996 return 0;
1997 }
1998
1999 /**
2000 * Callback received when the backend's state changes.
2001 */
2002 static void netback_changed(struct xenbus_device *dev,
2003 enum xenbus_state backend_state)
2004 {
2005 struct netfront_info *np = dev_get_drvdata(&dev->dev);
2006 struct net_device *netdev = np->netdev;
2007
2008 dev_dbg(&dev->dev, "%s\n", xenbus_strstate(backend_state));
2009
2010 switch (backend_state) {
2011 case XenbusStateInitialising:
2012 case XenbusStateInitialised:
2013 case XenbusStateReconfiguring:
2014 case XenbusStateReconfigured:
2015 break;
2016
2017 case XenbusStateUnknown:
2018 wake_up_all(&module_unload_q);
2019 break;
2020
2021 case XenbusStateInitWait:
2022 if (dev->state != XenbusStateInitialising)
2023 break;
2024 if (xennet_connect(netdev) != 0)
2025 break;
2026 xenbus_switch_state(dev, XenbusStateConnected);
2027 break;
2028
2029 case XenbusStateConnected:
2030 netdev_notify_peers(netdev);
2031 break;
2032
2033 case XenbusStateClosed:
2034 wake_up_all(&module_unload_q);
2035 if (dev->state == XenbusStateClosed)
2036 break;
2037 /* Missed the backend's CLOSING state -- fallthrough */
2038 case XenbusStateClosing:
2039 wake_up_all(&module_unload_q);
2040 xenbus_frontend_closed(dev);
2041 break;
2042 }
2043 }
2044
2045 static const struct xennet_stat {
2046 char name[ETH_GSTRING_LEN];
2047 u16 offset;
2048 } xennet_stats[] = {
2049 {
2050 "rx_gso_checksum_fixup",
2051 offsetof(struct netfront_info, rx_gso_checksum_fixup)
2052 },
2053 };
2054
2055 static int xennet_get_sset_count(struct net_device *dev, int string_set)
2056 {
2057 switch (string_set) {
2058 case ETH_SS_STATS:
2059 return ARRAY_SIZE(xennet_stats);
2060 default:
2061 return -EINVAL;
2062 }
2063 }
2064
2065 static void xennet_get_ethtool_stats(struct net_device *dev,
2066 struct ethtool_stats *stats, u64 * data)
2067 {
2068 void *np = netdev_priv(dev);
2069 int i;
2070
2071 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
2072 data[i] = atomic_read((atomic_t *)(np + xennet_stats[i].offset));
2073 }
2074
2075 static void xennet_get_strings(struct net_device *dev, u32 stringset, u8 * data)
2076 {
2077 int i;
2078
2079 switch (stringset) {
2080 case ETH_SS_STATS:
2081 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
2082 memcpy(data + i * ETH_GSTRING_LEN,
2083 xennet_stats[i].name, ETH_GSTRING_LEN);
2084 break;
2085 }
2086 }
2087
2088 static const struct ethtool_ops xennet_ethtool_ops =
2089 {
2090 .get_link = ethtool_op_get_link,
2091
2092 .get_sset_count = xennet_get_sset_count,
2093 .get_ethtool_stats = xennet_get_ethtool_stats,
2094 .get_strings = xennet_get_strings,
2095 };
2096
2097 #ifdef CONFIG_SYSFS
2098 static ssize_t show_rxbuf(struct device *dev,
2099 struct device_attribute *attr, char *buf)
2100 {
2101 return sprintf(buf, "%lu\n", NET_RX_RING_SIZE);
2102 }
2103
2104 static ssize_t store_rxbuf(struct device *dev,
2105 struct device_attribute *attr,
2106 const char *buf, size_t len)
2107 {
2108 char *endp;
2109 unsigned long target;
2110
2111 if (!capable(CAP_NET_ADMIN))
2112 return -EPERM;
2113
2114 target = simple_strtoul(buf, &endp, 0);
2115 if (endp == buf)
2116 return -EBADMSG;
2117
2118 /* rxbuf_min and rxbuf_max are no longer configurable. */
2119
2120 return len;
2121 }
2122
2123 static DEVICE_ATTR(rxbuf_min, S_IRUGO|S_IWUSR, show_rxbuf, store_rxbuf);
2124 static DEVICE_ATTR(rxbuf_max, S_IRUGO|S_IWUSR, show_rxbuf, store_rxbuf);
2125 static DEVICE_ATTR(rxbuf_cur, S_IRUGO, show_rxbuf, NULL);
2126
2127 static struct attribute *xennet_dev_attrs[] = {
2128 &dev_attr_rxbuf_min.attr,
2129 &dev_attr_rxbuf_max.attr,
2130 &dev_attr_rxbuf_cur.attr,
2131 NULL
2132 };
2133
2134 static const struct attribute_group xennet_dev_group = {
2135 .attrs = xennet_dev_attrs
2136 };
2137 #endif /* CONFIG_SYSFS */
2138
2139 static int xennet_remove(struct xenbus_device *dev)
2140 {
2141 struct netfront_info *info = dev_get_drvdata(&dev->dev);
2142
2143 dev_dbg(&dev->dev, "%s\n", dev->nodename);
2144
2145 if (xenbus_read_driver_state(dev->otherend) != XenbusStateClosed) {
2146 xenbus_switch_state(dev, XenbusStateClosing);
2147 wait_event(module_unload_q,
2148 xenbus_read_driver_state(dev->otherend) ==
2149 XenbusStateClosing ||
2150 xenbus_read_driver_state(dev->otherend) ==
2151 XenbusStateUnknown);
2152
2153 xenbus_switch_state(dev, XenbusStateClosed);
2154 wait_event(module_unload_q,
2155 xenbus_read_driver_state(dev->otherend) ==
2156 XenbusStateClosed ||
2157 xenbus_read_driver_state(dev->otherend) ==
2158 XenbusStateUnknown);
2159 }
2160
2161 xennet_disconnect_backend(info);
2162
2163 if (info->netdev->reg_state == NETREG_REGISTERED)
2164 unregister_netdev(info->netdev);
2165
2166 if (info->queues) {
2167 rtnl_lock();
2168 xennet_destroy_queues(info);
2169 rtnl_unlock();
2170 }
2171 xennet_free_netdev(info->netdev);
2172
2173 return 0;
2174 }
2175
2176 static const struct xenbus_device_id netfront_ids[] = {
2177 { "vif" },
2178 { "" }
2179 };
2180
2181 static struct xenbus_driver netfront_driver = {
2182 .ids = netfront_ids,
2183 .probe = netfront_probe,
2184 .remove = xennet_remove,
2185 .resume = netfront_resume,
2186 .otherend_changed = netback_changed,
2187 };
2188
2189 static int __init netif_init(void)
2190 {
2191 if (!xen_domain())
2192 return -ENODEV;
2193
2194 if (!xen_has_pv_nic_devices())
2195 return -ENODEV;
2196
2197 pr_info("Initialising Xen virtual ethernet driver\n");
2198
2199 /* Allow as many queues as there are CPUs inut max. 8 if user has not
2200 * specified a value.
2201 */
2202 if (xennet_max_queues == 0)
2203 xennet_max_queues = min_t(unsigned int, MAX_QUEUES_DEFAULT,
2204 num_online_cpus());
2205
2206 return xenbus_register_frontend(&netfront_driver);
2207 }
2208 module_init(netif_init);
2209
2210
2211 static void __exit netif_exit(void)
2212 {
2213 xenbus_unregister_driver(&netfront_driver);
2214 }
2215 module_exit(netif_exit);
2216
2217 MODULE_DESCRIPTION("Xen virtual network device frontend");
2218 MODULE_LICENSE("GPL");
2219 MODULE_ALIAS("xen:vif");
2220 MODULE_ALIAS("xennet");
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