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Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
[cris-mirror.git] / drivers / net / xen-netfront.c
blob3127bc8633ca511889e8098d1a996c30c6d28b3f
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_unload_q);
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 - MAX_SKB_FRAGS - 2);
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 wmb(); /* barrier so backend seens requests */
341
342 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->rx, notify);
343 if (notify)
344 notify_remote_via_irq(queue->rx_irq);
345 }
346
347 static int xennet_open(struct net_device *dev)
348 {
349 struct netfront_info *np = netdev_priv(dev);
350 unsigned int num_queues = dev->real_num_tx_queues;
351 unsigned int i = 0;
352 struct netfront_queue *queue = NULL;
353
354 if (!np->queues)
355 return -ENODEV;
356
357 for (i = 0; i < num_queues; ++i) {
358 queue = &np->queues[i];
359 napi_enable(&queue->napi);
360
361 spin_lock_bh(&queue->rx_lock);
362 if (netif_carrier_ok(dev)) {
363 xennet_alloc_rx_buffers(queue);
364 queue->rx.sring->rsp_event = queue->rx.rsp_cons + 1;
365 if (RING_HAS_UNCONSUMED_RESPONSES(&queue->rx))
366 napi_schedule(&queue->napi);
367 }
368 spin_unlock_bh(&queue->rx_lock);
369 }
370
371 netif_tx_start_all_queues(dev);
372
373 return 0;
374 }
375
376 static void xennet_tx_buf_gc(struct netfront_queue *queue)
377 {
378 RING_IDX cons, prod;
379 unsigned short id;
380 struct sk_buff *skb;
381 bool more_to_do;
382
383 BUG_ON(!netif_carrier_ok(queue->info->netdev));
384
385 do {
386 prod = queue->tx.sring->rsp_prod;
387 rmb(); /* Ensure we see responses up to 'rp'. */
388
389 for (cons = queue->tx.rsp_cons; cons != prod; cons++) {
390 struct xen_netif_tx_response *txrsp;
391
392 txrsp = RING_GET_RESPONSE(&queue->tx, cons);
393 if (txrsp->status == XEN_NETIF_RSP_NULL)
394 continue;
395
396 id = txrsp->id;
397 skb = queue->tx_skbs[id].skb;
398 if (unlikely(gnttab_query_foreign_access(
399 queue->grant_tx_ref[id]) != 0)) {
400 pr_alert("%s: warning -- grant still in use by backend domain\n",
401 __func__);
402 BUG();
403 }
404 gnttab_end_foreign_access_ref(
405 queue->grant_tx_ref[id], GNTMAP_readonly);
406 gnttab_release_grant_reference(
407 &queue->gref_tx_head, queue->grant_tx_ref[id]);
408 queue->grant_tx_ref[id] = GRANT_INVALID_REF;
409 queue->grant_tx_page[id] = NULL;
410 add_id_to_freelist(&queue->tx_skb_freelist, queue->tx_skbs, id);
411 dev_kfree_skb_irq(skb);
412 }
413
414 queue->tx.rsp_cons = prod;
415
416 RING_FINAL_CHECK_FOR_RESPONSES(&queue->tx, more_to_do);
417 } while (more_to_do);
418
419 xennet_maybe_wake_tx(queue);
420 }
421
422 struct xennet_gnttab_make_txreq {
423 struct netfront_queue *queue;
424 struct sk_buff *skb;
425 struct page *page;
426 struct xen_netif_tx_request *tx; /* Last request */
427 unsigned int size;
428 };
429
430 static void xennet_tx_setup_grant(unsigned long gfn, unsigned int offset,
431 unsigned int len, void *data)
432 {
433 struct xennet_gnttab_make_txreq *info = data;
434 unsigned int id;
435 struct xen_netif_tx_request *tx;
436 grant_ref_t ref;
437 /* convenient aliases */
438 struct page *page = info->page;
439 struct netfront_queue *queue = info->queue;
440 struct sk_buff *skb = info->skb;
441
442 id = get_id_from_freelist(&queue->tx_skb_freelist, queue->tx_skbs);
443 tx = RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++);
444 ref = gnttab_claim_grant_reference(&queue->gref_tx_head);
445 WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)(int)ref));
446
447 gnttab_grant_foreign_access_ref(ref, queue->info->xbdev->otherend_id,
448 gfn, GNTMAP_readonly);
449
450 queue->tx_skbs[id].skb = skb;
451 queue->grant_tx_page[id] = page;
452 queue->grant_tx_ref[id] = ref;
453
454 tx->id = id;
455 tx->gref = ref;
456 tx->offset = offset;
457 tx->size = len;
458 tx->flags = 0;
459
460 info->tx = tx;
461 info->size += tx->size;
462 }
463
464 static struct xen_netif_tx_request *xennet_make_first_txreq(
465 struct netfront_queue *queue, struct sk_buff *skb,
466 struct page *page, unsigned int offset, unsigned int len)
467 {
468 struct xennet_gnttab_make_txreq info = {
469 .queue = queue,
470 .skb = skb,
471 .page = page,
472 .size = 0,
473 };
474
475 gnttab_for_one_grant(page, offset, len, xennet_tx_setup_grant, &info);
476
477 return info.tx;
478 }
479
480 static void xennet_make_one_txreq(unsigned long gfn, unsigned int offset,
481 unsigned int len, void *data)
482 {
483 struct xennet_gnttab_make_txreq *info = data;
484
485 info->tx->flags |= XEN_NETTXF_more_data;
486 skb_get(info->skb);
487 xennet_tx_setup_grant(gfn, offset, len, data);
488 }
489
490 static struct xen_netif_tx_request *xennet_make_txreqs(
491 struct netfront_queue *queue, struct xen_netif_tx_request *tx,
492 struct sk_buff *skb, struct page *page,
493 unsigned int offset, unsigned int len)
494 {
495 struct xennet_gnttab_make_txreq info = {
496 .queue = queue,
497 .skb = skb,
498 .tx = tx,
499 };
500
501 /* Skip unused frames from start of page */
502 page += offset >> PAGE_SHIFT;
503 offset &= ~PAGE_MASK;
504
505 while (len) {
506 info.page = page;
507 info.size = 0;
508
509 gnttab_foreach_grant_in_range(page, offset, len,
510 xennet_make_one_txreq,
511 &info);
512
513 page++;
514 offset = 0;
515 len -= info.size;
516 }
517
518 return info.tx;
519 }
520
521 /*
522 * Count how many ring slots are required to send this skb. Each frag
523 * might be a compound page.
524 */
525 static int xennet_count_skb_slots(struct sk_buff *skb)
526 {
527 int i, frags = skb_shinfo(skb)->nr_frags;
528 int slots;
529
530 slots = gnttab_count_grant(offset_in_page(skb->data),
531 skb_headlen(skb));
532
533 for (i = 0; i < frags; i++) {
534 skb_frag_t *frag = skb_shinfo(skb)->frags + i;
535 unsigned long size = skb_frag_size(frag);
536 unsigned long offset = frag->page_offset;
537
538 /* Skip unused frames from start of page */
539 offset &= ~PAGE_MASK;
540
541 slots += gnttab_count_grant(offset, size);
542 }
543
544 return slots;
545 }
546
547 static u16 xennet_select_queue(struct net_device *dev, struct sk_buff *skb,
548 void *accel_priv, select_queue_fallback_t fallback)
549 {
550 unsigned int num_queues = dev->real_num_tx_queues;
551 u32 hash;
552 u16 queue_idx;
553
554 /* First, check if there is only one queue */
555 if (num_queues == 1) {
556 queue_idx = 0;
557 } else {
558 hash = skb_get_hash(skb);
559 queue_idx = hash % num_queues;
560 }
561
562 return queue_idx;
563 }
564
565 #define MAX_XEN_SKB_FRAGS (65536 / XEN_PAGE_SIZE + 1)
566
567 static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev)
568 {
569 struct netfront_info *np = netdev_priv(dev);
570 struct netfront_stats *tx_stats = this_cpu_ptr(np->tx_stats);
571 struct xen_netif_tx_request *tx, *first_tx;
572 unsigned int i;
573 int notify;
574 int slots;
575 struct page *page;
576 unsigned int offset;
577 unsigned int len;
578 unsigned long flags;
579 struct netfront_queue *queue = NULL;
580 unsigned int num_queues = dev->real_num_tx_queues;
581 u16 queue_index;
582 struct sk_buff *nskb;
583
584 /* Drop the packet if no queues are set up */
585 if (num_queues < 1)
586 goto drop;
587 /* Determine which queue to transmit this SKB on */
588 queue_index = skb_get_queue_mapping(skb);
589 queue = &np->queues[queue_index];
590
591 /* If skb->len is too big for wire format, drop skb and alert
592 * user about misconfiguration.
593 */
594 if (unlikely(skb->len > XEN_NETIF_MAX_TX_SIZE)) {
595 net_alert_ratelimited(
596 "xennet: skb->len = %u, too big for wire format\n",
597 skb->len);
598 goto drop;
599 }
600
601 slots = xennet_count_skb_slots(skb);
602 if (unlikely(slots > MAX_XEN_SKB_FRAGS + 1)) {
603 net_dbg_ratelimited("xennet: skb rides the rocket: %d slots, %d bytes\n",
604 slots, skb->len);
605 if (skb_linearize(skb))
606 goto drop;
607 }
608
609 page = virt_to_page(skb->data);
610 offset = offset_in_page(skb->data);
611
612 /* The first req should be at least ETH_HLEN size or the packet will be
613 * dropped by netback.
614 */
615 if (unlikely(PAGE_SIZE - offset < ETH_HLEN)) {
616 nskb = skb_copy(skb, GFP_ATOMIC);
617 if (!nskb)
618 goto drop;
619 dev_consume_skb_any(skb);
620 skb = nskb;
621 page = virt_to_page(skb->data);
622 offset = offset_in_page(skb->data);
623 }
624
625 len = skb_headlen(skb);
626
627 spin_lock_irqsave(&queue->tx_lock, flags);
628
629 if (unlikely(!netif_carrier_ok(dev) ||
630 (slots > 1 && !xennet_can_sg(dev)) ||
631 netif_needs_gso(skb, netif_skb_features(skb)))) {
632 spin_unlock_irqrestore(&queue->tx_lock, flags);
633 goto drop;
634 }
635
636 /* First request for the linear area. */
637 first_tx = tx = xennet_make_first_txreq(queue, skb,
638 page, offset, len);
639 offset += tx->size;
640 if (offset == PAGE_SIZE) {
641 page++;
642 offset = 0;
643 }
644 len -= tx->size;
645
646 if (skb->ip_summed == CHECKSUM_PARTIAL)
647 /* local packet? */
648 tx->flags |= XEN_NETTXF_csum_blank | XEN_NETTXF_data_validated;
649 else if (skb->ip_summed == CHECKSUM_UNNECESSARY)
650 /* remote but checksummed. */
651 tx->flags |= XEN_NETTXF_data_validated;
652
653 /* Optional extra info after the first request. */
654 if (skb_shinfo(skb)->gso_size) {
655 struct xen_netif_extra_info *gso;
656
657 gso = (struct xen_netif_extra_info *)
658 RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++);
659
660 tx->flags |= XEN_NETTXF_extra_info;
661
662 gso->u.gso.size = skb_shinfo(skb)->gso_size;
663 gso->u.gso.type = (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) ?
664 XEN_NETIF_GSO_TYPE_TCPV6 :
665 XEN_NETIF_GSO_TYPE_TCPV4;
666 gso->u.gso.pad = 0;
667 gso->u.gso.features = 0;
668
669 gso->type = XEN_NETIF_EXTRA_TYPE_GSO;
670 gso->flags = 0;
671 }
672
673 /* Requests for the rest of the linear area. */
674 tx = xennet_make_txreqs(queue, tx, skb, page, offset, len);
675
676 /* Requests for all the frags. */
677 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
678 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
679 tx = xennet_make_txreqs(queue, tx, skb,
680 skb_frag_page(frag), frag->page_offset,
681 skb_frag_size(frag));
682 }
683
684 /* First request has the packet length. */
685 first_tx->size = skb->len;
686
687 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->tx, notify);
688 if (notify)
689 notify_remote_via_irq(queue->tx_irq);
690
691 u64_stats_update_begin(&tx_stats->syncp);
692 tx_stats->bytes += skb->len;
693 tx_stats->packets++;
694 u64_stats_update_end(&tx_stats->syncp);
695
696 /* Note: It is not safe to access skb after xennet_tx_buf_gc()! */
697 xennet_tx_buf_gc(queue);
698
699 if (!netfront_tx_slot_available(queue))
700 netif_tx_stop_queue(netdev_get_tx_queue(dev, queue->id));
701
702 spin_unlock_irqrestore(&queue->tx_lock, flags);
703
704 return NETDEV_TX_OK;
705
706 drop:
707 dev->stats.tx_dropped++;
708 dev_kfree_skb_any(skb);
709 return NETDEV_TX_OK;
710 }
711
712 static int xennet_close(struct net_device *dev)
713 {
714 struct netfront_info *np = netdev_priv(dev);
715 unsigned int num_queues = dev->real_num_tx_queues;
716 unsigned int i;
717 struct netfront_queue *queue;
718 netif_tx_stop_all_queues(np->netdev);
719 for (i = 0; i < num_queues; ++i) {
720 queue = &np->queues[i];
721 napi_disable(&queue->napi);
722 }
723 return 0;
724 }
725
726 static void xennet_move_rx_slot(struct netfront_queue *queue, struct sk_buff *skb,
727 grant_ref_t ref)
728 {
729 int new = xennet_rxidx(queue->rx.req_prod_pvt);
730
731 BUG_ON(queue->rx_skbs[new]);
732 queue->rx_skbs[new] = skb;
733 queue->grant_rx_ref[new] = ref;
734 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->id = new;
735 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->gref = ref;
736 queue->rx.req_prod_pvt++;
737 }
738
739 static int xennet_get_extras(struct netfront_queue *queue,
740 struct xen_netif_extra_info *extras,
741 RING_IDX rp)
742
743 {
744 struct xen_netif_extra_info *extra;
745 struct device *dev = &queue->info->netdev->dev;
746 RING_IDX cons = queue->rx.rsp_cons;
747 int err = 0;
748
749 do {
750 struct sk_buff *skb;
751 grant_ref_t ref;
752
753 if (unlikely(cons + 1 == rp)) {
754 if (net_ratelimit())
755 dev_warn(dev, "Missing extra info\n");
756 err = -EBADR;
757 break;
758 }
759
760 extra = (struct xen_netif_extra_info *)
761 RING_GET_RESPONSE(&queue->rx, ++cons);
762
763 if (unlikely(!extra->type ||
764 extra->type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
765 if (net_ratelimit())
766 dev_warn(dev, "Invalid extra type: %d\n",
767 extra->type);
768 err = -EINVAL;
769 } else {
770 memcpy(&extras[extra->type - 1], extra,
771 sizeof(*extra));
772 }
773
774 skb = xennet_get_rx_skb(queue, cons);
775 ref = xennet_get_rx_ref(queue, cons);
776 xennet_move_rx_slot(queue, skb, ref);
777 } while (extra->flags & XEN_NETIF_EXTRA_FLAG_MORE);
778
779 queue->rx.rsp_cons = cons;
780 return err;
781 }
782
783 static int xennet_get_responses(struct netfront_queue *queue,
784 struct netfront_rx_info *rinfo, RING_IDX rp,
785 struct sk_buff_head *list)
786 {
787 struct xen_netif_rx_response *rx = &rinfo->rx;
788 struct xen_netif_extra_info *extras = rinfo->extras;
789 struct device *dev = &queue->info->netdev->dev;
790 RING_IDX cons = queue->rx.rsp_cons;
791 struct sk_buff *skb = xennet_get_rx_skb(queue, cons);
792 grant_ref_t ref = xennet_get_rx_ref(queue, cons);
793 int max = MAX_SKB_FRAGS + (rx->status <= RX_COPY_THRESHOLD);
794 int slots = 1;
795 int err = 0;
796 unsigned long ret;
797
798 if (rx->flags & XEN_NETRXF_extra_info) {
799 err = xennet_get_extras(queue, extras, rp);
800 cons = queue->rx.rsp_cons;
801 }
802
803 for (;;) {
804 if (unlikely(rx->status < 0 ||
805 rx->offset + rx->status > XEN_PAGE_SIZE)) {
806 if (net_ratelimit())
807 dev_warn(dev, "rx->offset: %u, size: %d\n",
808 rx->offset, rx->status);
809 xennet_move_rx_slot(queue, skb, ref);
810 err = -EINVAL;
811 goto next;
812 }
813
814 /*
815 * This definitely indicates a bug, either in this driver or in
816 * the backend driver. In future this should flag the bad
817 * situation to the system controller to reboot the backend.
818 */
819 if (ref == GRANT_INVALID_REF) {
820 if (net_ratelimit())
821 dev_warn(dev, "Bad rx response id %d.\n",
822 rx->id);
823 err = -EINVAL;
824 goto next;
825 }
826
827 ret = gnttab_end_foreign_access_ref(ref, 0);
828 BUG_ON(!ret);
829
830 gnttab_release_grant_reference(&queue->gref_rx_head, ref);
831
832 __skb_queue_tail(list, skb);
833
834 next:
835 if (!(rx->flags & XEN_NETRXF_more_data))
836 break;
837
838 if (cons + slots == rp) {
839 if (net_ratelimit())
840 dev_warn(dev, "Need more slots\n");
841 err = -ENOENT;
842 break;
843 }
844
845 rx = RING_GET_RESPONSE(&queue->rx, cons + slots);
846 skb = xennet_get_rx_skb(queue, cons + slots);
847 ref = xennet_get_rx_ref(queue, cons + slots);
848 slots++;
849 }
850
851 if (unlikely(slots > max)) {
852 if (net_ratelimit())
853 dev_warn(dev, "Too many slots\n");
854 err = -E2BIG;
855 }
856
857 if (unlikely(err))
858 queue->rx.rsp_cons = cons + slots;
859
860 return err;
861 }
862
863 static int xennet_set_skb_gso(struct sk_buff *skb,
864 struct xen_netif_extra_info *gso)
865 {
866 if (!gso->u.gso.size) {
867 if (net_ratelimit())
868 pr_warn("GSO size must not be zero\n");
869 return -EINVAL;
870 }
871
872 if (gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV4 &&
873 gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV6) {
874 if (net_ratelimit())
875 pr_warn("Bad GSO type %d\n", gso->u.gso.type);
876 return -EINVAL;
877 }
878
879 skb_shinfo(skb)->gso_size = gso->u.gso.size;
880 skb_shinfo(skb)->gso_type =
881 (gso->u.gso.type == XEN_NETIF_GSO_TYPE_TCPV4) ?
882 SKB_GSO_TCPV4 :
883 SKB_GSO_TCPV6;
884
885 /* Header must be checked, and gso_segs computed. */
886 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
887 skb_shinfo(skb)->gso_segs = 0;
888
889 return 0;
890 }
891
892 static RING_IDX xennet_fill_frags(struct netfront_queue *queue,
893 struct sk_buff *skb,
894 struct sk_buff_head *list)
895 {
896 struct skb_shared_info *shinfo = skb_shinfo(skb);
897 RING_IDX cons = queue->rx.rsp_cons;
898 struct sk_buff *nskb;
899
900 while ((nskb = __skb_dequeue(list))) {
901 struct xen_netif_rx_response *rx =
902 RING_GET_RESPONSE(&queue->rx, ++cons);
903 skb_frag_t *nfrag = &skb_shinfo(nskb)->frags[0];
904
905 if (shinfo->nr_frags == MAX_SKB_FRAGS) {
906 unsigned int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
907
908 BUG_ON(pull_to <= skb_headlen(skb));
909 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
910 }
911 BUG_ON(shinfo->nr_frags >= MAX_SKB_FRAGS);
912
913 skb_add_rx_frag(skb, shinfo->nr_frags, skb_frag_page(nfrag),
914 rx->offset, rx->status, PAGE_SIZE);
915
916 skb_shinfo(nskb)->nr_frags = 0;
917 kfree_skb(nskb);
918 }
919
920 return cons;
921 }
922
923 static int checksum_setup(struct net_device *dev, struct sk_buff *skb)
924 {
925 bool recalculate_partial_csum = false;
926
927 /*
928 * A GSO SKB must be CHECKSUM_PARTIAL. However some buggy
929 * peers can fail to set NETRXF_csum_blank when sending a GSO
930 * frame. In this case force the SKB to CHECKSUM_PARTIAL and
931 * recalculate the partial checksum.
932 */
933 if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) {
934 struct netfront_info *np = netdev_priv(dev);
935 atomic_inc(&np->rx_gso_checksum_fixup);
936 skb->ip_summed = CHECKSUM_PARTIAL;
937 recalculate_partial_csum = true;
938 }
939
940 /* A non-CHECKSUM_PARTIAL SKB does not require setup. */
941 if (skb->ip_summed != CHECKSUM_PARTIAL)
942 return 0;
943
944 return skb_checksum_setup(skb, recalculate_partial_csum);
945 }
946
947 static int handle_incoming_queue(struct netfront_queue *queue,
948 struct sk_buff_head *rxq)
949 {
950 struct netfront_stats *rx_stats = this_cpu_ptr(queue->info->rx_stats);
951 int packets_dropped = 0;
952 struct sk_buff *skb;
953
954 while ((skb = __skb_dequeue(rxq)) != NULL) {
955 int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
956
957 if (pull_to > skb_headlen(skb))
958 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
959
960 /* Ethernet work: Delayed to here as it peeks the header. */
961 skb->protocol = eth_type_trans(skb, queue->info->netdev);
962 skb_reset_network_header(skb);
963
964 if (checksum_setup(queue->info->netdev, skb)) {
965 kfree_skb(skb);
966 packets_dropped++;
967 queue->info->netdev->stats.rx_errors++;
968 continue;
969 }
970
971 u64_stats_update_begin(&rx_stats->syncp);
972 rx_stats->packets++;
973 rx_stats->bytes += skb->len;
974 u64_stats_update_end(&rx_stats->syncp);
975
976 /* Pass it up. */
977 napi_gro_receive(&queue->napi, skb);
978 }
979
980 return packets_dropped;
981 }
982
983 static int xennet_poll(struct napi_struct *napi, int budget)
984 {
985 struct netfront_queue *queue = container_of(napi, struct netfront_queue, napi);
986 struct net_device *dev = queue->info->netdev;
987 struct sk_buff *skb;
988 struct netfront_rx_info rinfo;
989 struct xen_netif_rx_response *rx = &rinfo.rx;
990 struct xen_netif_extra_info *extras = rinfo.extras;
991 RING_IDX i, rp;
992 int work_done;
993 struct sk_buff_head rxq;
994 struct sk_buff_head errq;
995 struct sk_buff_head tmpq;
996 int err;
997
998 spin_lock(&queue->rx_lock);
999
1000 skb_queue_head_init(&rxq);
1001 skb_queue_head_init(&errq);
1002 skb_queue_head_init(&tmpq);
1003
1004 rp = queue->rx.sring->rsp_prod;
1005 rmb(); /* Ensure we see queued responses up to 'rp'. */
1006
1007 i = queue->rx.rsp_cons;
1008 work_done = 0;
1009 while ((i != rp) && (work_done < budget)) {
1010 memcpy(rx, RING_GET_RESPONSE(&queue->rx, i), sizeof(*rx));
1011 memset(extras, 0, sizeof(rinfo.extras));
1012
1013 err = xennet_get_responses(queue, &rinfo, rp, &tmpq);
1014
1015 if (unlikely(err)) {
1016 err:
1017 while ((skb = __skb_dequeue(&tmpq)))
1018 __skb_queue_tail(&errq, skb);
1019 dev->stats.rx_errors++;
1020 i = queue->rx.rsp_cons;
1021 continue;
1022 }
1023
1024 skb = __skb_dequeue(&tmpq);
1025
1026 if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) {
1027 struct xen_netif_extra_info *gso;
1028 gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1];
1029
1030 if (unlikely(xennet_set_skb_gso(skb, gso))) {
1031 __skb_queue_head(&tmpq, skb);
1032 queue->rx.rsp_cons += skb_queue_len(&tmpq);
1033 goto err;
1034 }
1035 }
1036
1037 NETFRONT_SKB_CB(skb)->pull_to = rx->status;
1038 if (NETFRONT_SKB_CB(skb)->pull_to > RX_COPY_THRESHOLD)
1039 NETFRONT_SKB_CB(skb)->pull_to = RX_COPY_THRESHOLD;
1040
1041 skb_shinfo(skb)->frags[0].page_offset = rx->offset;
1042 skb_frag_size_set(&skb_shinfo(skb)->frags[0], rx->status);
1043 skb->data_len = rx->status;
1044 skb->len += rx->status;
1045
1046 i = xennet_fill_frags(queue, skb, &tmpq);
1047
1048 if (rx->flags & XEN_NETRXF_csum_blank)
1049 skb->ip_summed = CHECKSUM_PARTIAL;
1050 else if (rx->flags & XEN_NETRXF_data_validated)
1051 skb->ip_summed = CHECKSUM_UNNECESSARY;
1052
1053 __skb_queue_tail(&rxq, skb);
1054
1055 queue->rx.rsp_cons = ++i;
1056 work_done++;
1057 }
1058
1059 __skb_queue_purge(&errq);
1060
1061 work_done -= handle_incoming_queue(queue, &rxq);
1062
1063 xennet_alloc_rx_buffers(queue);
1064
1065 if (work_done < budget) {
1066 int more_to_do = 0;
1067
1068 napi_complete_done(napi, work_done);
1069
1070 RING_FINAL_CHECK_FOR_RESPONSES(&queue->rx, more_to_do);
1071 if (more_to_do)
1072 napi_schedule(napi);
1073 }
1074
1075 spin_unlock(&queue->rx_lock);
1076
1077 return work_done;
1078 }
1079
1080 static int xennet_change_mtu(struct net_device *dev, int mtu)
1081 {
1082 int max = xennet_can_sg(dev) ? XEN_NETIF_MAX_TX_SIZE : ETH_DATA_LEN;
1083
1084 if (mtu > max)
1085 return -EINVAL;
1086 dev->mtu = mtu;
1087 return 0;
1088 }
1089
1090 static void xennet_get_stats64(struct net_device *dev,
1091 struct rtnl_link_stats64 *tot)
1092 {
1093 struct netfront_info *np = netdev_priv(dev);
1094 int cpu;
1095
1096 for_each_possible_cpu(cpu) {
1097 struct netfront_stats *rx_stats = per_cpu_ptr(np->rx_stats, cpu);
1098 struct netfront_stats *tx_stats = per_cpu_ptr(np->tx_stats, cpu);
1099 u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
1100 unsigned int start;
1101
1102 do {
1103 start = u64_stats_fetch_begin_irq(&tx_stats->syncp);
1104 tx_packets = tx_stats->packets;
1105 tx_bytes = tx_stats->bytes;
1106 } while (u64_stats_fetch_retry_irq(&tx_stats->syncp, start));
1107
1108 do {
1109 start = u64_stats_fetch_begin_irq(&rx_stats->syncp);
1110 rx_packets = rx_stats->packets;
1111 rx_bytes = rx_stats->bytes;
1112 } while (u64_stats_fetch_retry_irq(&rx_stats->syncp, start));
1113
1114 tot->rx_packets += rx_packets;
1115 tot->tx_packets += tx_packets;
1116 tot->rx_bytes += rx_bytes;
1117 tot->tx_bytes += tx_bytes;
1118 }
1119
1120 tot->rx_errors = dev->stats.rx_errors;
1121 tot->tx_dropped = dev->stats.tx_dropped;
1122 }
1123
1124 static void xennet_release_tx_bufs(struct netfront_queue *queue)
1125 {
1126 struct sk_buff *skb;
1127 int i;
1128
1129 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1130 /* Skip over entries which are actually freelist references */
1131 if (skb_entry_is_link(&queue->tx_skbs[i]))
1132 continue;
1133
1134 skb = queue->tx_skbs[i].skb;
1135 get_page(queue->grant_tx_page[i]);
1136 gnttab_end_foreign_access(queue->grant_tx_ref[i],
1137 GNTMAP_readonly,
1138 (unsigned long)page_address(queue->grant_tx_page[i]));
1139 queue->grant_tx_page[i] = NULL;
1140 queue->grant_tx_ref[i] = GRANT_INVALID_REF;
1141 add_id_to_freelist(&queue->tx_skb_freelist, queue->tx_skbs, i);
1142 dev_kfree_skb_irq(skb);
1143 }
1144 }
1145
1146 static void xennet_release_rx_bufs(struct netfront_queue *queue)
1147 {
1148 int id, ref;
1149
1150 spin_lock_bh(&queue->rx_lock);
1151
1152 for (id = 0; id < NET_RX_RING_SIZE; id++) {
1153 struct sk_buff *skb;
1154 struct page *page;
1155
1156 skb = queue->rx_skbs[id];
1157 if (!skb)
1158 continue;
1159
1160 ref = queue->grant_rx_ref[id];
1161 if (ref == GRANT_INVALID_REF)
1162 continue;
1163
1164 page = skb_frag_page(&skb_shinfo(skb)->frags[0]);
1165
1166 /* gnttab_end_foreign_access() needs a page ref until
1167 * foreign access is ended (which may be deferred).
1168 */
1169 get_page(page);
1170 gnttab_end_foreign_access(ref, 0,
1171 (unsigned long)page_address(page));
1172 queue->grant_rx_ref[id] = GRANT_INVALID_REF;
1173
1174 kfree_skb(skb);
1175 }
1176
1177 spin_unlock_bh(&queue->rx_lock);
1178 }
1179
1180 static netdev_features_t xennet_fix_features(struct net_device *dev,
1181 netdev_features_t features)
1182 {
1183 struct netfront_info *np = netdev_priv(dev);
1184
1185 if (features & NETIF_F_SG &&
1186 !xenbus_read_unsigned(np->xbdev->otherend, "feature-sg", 0))
1187 features &= ~NETIF_F_SG;
1188
1189 if (features & NETIF_F_IPV6_CSUM &&
1190 !xenbus_read_unsigned(np->xbdev->otherend,
1191 "feature-ipv6-csum-offload", 0))
1192 features &= ~NETIF_F_IPV6_CSUM;
1193
1194 if (features & NETIF_F_TSO &&
1195 !xenbus_read_unsigned(np->xbdev->otherend, "feature-gso-tcpv4", 0))
1196 features &= ~NETIF_F_TSO;
1197
1198 if (features & NETIF_F_TSO6 &&
1199 !xenbus_read_unsigned(np->xbdev->otherend, "feature-gso-tcpv6", 0))
1200 features &= ~NETIF_F_TSO6;
1201
1202 return features;
1203 }
1204
1205 static int xennet_set_features(struct net_device *dev,
1206 netdev_features_t features)
1207 {
1208 if (!(features & NETIF_F_SG) && dev->mtu > ETH_DATA_LEN) {
1209 netdev_info(dev, "Reducing MTU because no SG offload");
1210 dev->mtu = ETH_DATA_LEN;
1211 }
1212
1213 return 0;
1214 }
1215
1216 static irqreturn_t xennet_tx_interrupt(int irq, void *dev_id)
1217 {
1218 struct netfront_queue *queue = dev_id;
1219 unsigned long flags;
1220
1221 spin_lock_irqsave(&queue->tx_lock, flags);
1222 xennet_tx_buf_gc(queue);
1223 spin_unlock_irqrestore(&queue->tx_lock, flags);
1224
1225 return IRQ_HANDLED;
1226 }
1227
1228 static irqreturn_t xennet_rx_interrupt(int irq, void *dev_id)
1229 {
1230 struct netfront_queue *queue = dev_id;
1231 struct net_device *dev = queue->info->netdev;
1232
1233 if (likely(netif_carrier_ok(dev) &&
1234 RING_HAS_UNCONSUMED_RESPONSES(&queue->rx)))
1235 napi_schedule(&queue->napi);
1236
1237 return IRQ_HANDLED;
1238 }
1239
1240 static irqreturn_t xennet_interrupt(int irq, void *dev_id)
1241 {
1242 xennet_tx_interrupt(irq, dev_id);
1243 xennet_rx_interrupt(irq, dev_id);
1244 return IRQ_HANDLED;
1245 }
1246
1247 #ifdef CONFIG_NET_POLL_CONTROLLER
1248 static void xennet_poll_controller(struct net_device *dev)
1249 {
1250 /* Poll each queue */
1251 struct netfront_info *info = netdev_priv(dev);
1252 unsigned int num_queues = dev->real_num_tx_queues;
1253 unsigned int i;
1254 for (i = 0; i < num_queues; ++i)
1255 xennet_interrupt(0, &info->queues[i]);
1256 }
1257 #endif
1258
1259 static const struct net_device_ops xennet_netdev_ops = {
1260 .ndo_open = xennet_open,
1261 .ndo_stop = xennet_close,
1262 .ndo_start_xmit = xennet_start_xmit,
1263 .ndo_change_mtu = xennet_change_mtu,
1264 .ndo_get_stats64 = xennet_get_stats64,
1265 .ndo_set_mac_address = eth_mac_addr,
1266 .ndo_validate_addr = eth_validate_addr,
1267 .ndo_fix_features = xennet_fix_features,
1268 .ndo_set_features = xennet_set_features,
1269 .ndo_select_queue = xennet_select_queue,
1270 #ifdef CONFIG_NET_POLL_CONTROLLER
1271 .ndo_poll_controller = xennet_poll_controller,
1272 #endif
1273 };
1274
1275 static void xennet_free_netdev(struct net_device *netdev)
1276 {
1277 struct netfront_info *np = netdev_priv(netdev);
1278
1279 free_percpu(np->rx_stats);
1280 free_percpu(np->tx_stats);
1281 free_netdev(netdev);
1282 }
1283
1284 static struct net_device *xennet_create_dev(struct xenbus_device *dev)
1285 {
1286 int err;
1287 struct net_device *netdev;
1288 struct netfront_info *np;
1289
1290 netdev = alloc_etherdev_mq(sizeof(struct netfront_info), xennet_max_queues);
1291 if (!netdev)
1292 return ERR_PTR(-ENOMEM);
1293
1294 np = netdev_priv(netdev);
1295 np->xbdev = dev;
1296
1297 np->queues = NULL;
1298
1299 err = -ENOMEM;
1300 np->rx_stats = netdev_alloc_pcpu_stats(struct netfront_stats);
1301 if (np->rx_stats == NULL)
1302 goto exit;
1303 np->tx_stats = netdev_alloc_pcpu_stats(struct netfront_stats);
1304 if (np->tx_stats == NULL)
1305 goto exit;
1306
1307 netdev->netdev_ops = &xennet_netdev_ops;
1308
1309 netdev->features = NETIF_F_IP_CSUM | NETIF_F_RXCSUM |
1310 NETIF_F_GSO_ROBUST;
1311 netdev->hw_features = NETIF_F_SG |
1312 NETIF_F_IPV6_CSUM |
1313 NETIF_F_TSO | NETIF_F_TSO6;
1314
1315 /*
1316 * Assume that all hw features are available for now. This set
1317 * will be adjusted by the call to netdev_update_features() in
1318 * xennet_connect() which is the earliest point where we can
1319 * negotiate with the backend regarding supported features.
1320 */
1321 netdev->features |= netdev->hw_features;
1322
1323 netdev->ethtool_ops = &xennet_ethtool_ops;
1324 netdev->min_mtu = ETH_MIN_MTU;
1325 netdev->max_mtu = XEN_NETIF_MAX_TX_SIZE;
1326 SET_NETDEV_DEV(netdev, &dev->dev);
1327
1328 np->netdev = netdev;
1329
1330 netif_carrier_off(netdev);
1331
1332 xenbus_switch_state(dev, XenbusStateInitialising);
1333 return netdev;
1334
1335 exit:
1336 xennet_free_netdev(netdev);
1337 return ERR_PTR(err);
1338 }
1339
1340 /**
1341 * Entry point to this code when a new device is created. Allocate the basic
1342 * structures and the ring buffers for communication with the backend, and
1343 * inform the backend of the appropriate details for those.
1344 */
1345 static int netfront_probe(struct xenbus_device *dev,
1346 const struct xenbus_device_id *id)
1347 {
1348 int err;
1349 struct net_device *netdev;
1350 struct netfront_info *info;
1351
1352 netdev = xennet_create_dev(dev);
1353 if (IS_ERR(netdev)) {
1354 err = PTR_ERR(netdev);
1355 xenbus_dev_fatal(dev, err, "creating netdev");
1356 return err;
1357 }
1358
1359 info = netdev_priv(netdev);
1360 dev_set_drvdata(&dev->dev, info);
1361 #ifdef CONFIG_SYSFS
1362 info->netdev->sysfs_groups[0] = &xennet_dev_group;
1363 #endif
1364
1365 return 0;
1366 }
1367
1368 static void xennet_end_access(int ref, void *page)
1369 {
1370 /* This frees the page as a side-effect */
1371 if (ref != GRANT_INVALID_REF)
1372 gnttab_end_foreign_access(ref, 0, (unsigned long)page);
1373 }
1374
1375 static void xennet_disconnect_backend(struct netfront_info *info)
1376 {
1377 unsigned int i = 0;
1378 unsigned int num_queues = info->netdev->real_num_tx_queues;
1379
1380 netif_carrier_off(info->netdev);
1381
1382 for (i = 0; i < num_queues && info->queues; ++i) {
1383 struct netfront_queue *queue = &info->queues[i];
1384
1385 del_timer_sync(&queue->rx_refill_timer);
1386
1387 if (queue->tx_irq && (queue->tx_irq == queue->rx_irq))
1388 unbind_from_irqhandler(queue->tx_irq, queue);
1389 if (queue->tx_irq && (queue->tx_irq != queue->rx_irq)) {
1390 unbind_from_irqhandler(queue->tx_irq, queue);
1391 unbind_from_irqhandler(queue->rx_irq, queue);
1392 }
1393 queue->tx_evtchn = queue->rx_evtchn = 0;
1394 queue->tx_irq = queue->rx_irq = 0;
1395
1396 if (netif_running(info->netdev))
1397 napi_synchronize(&queue->napi);
1398
1399 xennet_release_tx_bufs(queue);
1400 xennet_release_rx_bufs(queue);
1401 gnttab_free_grant_references(queue->gref_tx_head);
1402 gnttab_free_grant_references(queue->gref_rx_head);
1403
1404 /* End access and free the pages */
1405 xennet_end_access(queue->tx_ring_ref, queue->tx.sring);
1406 xennet_end_access(queue->rx_ring_ref, queue->rx.sring);
1407
1408 queue->tx_ring_ref = GRANT_INVALID_REF;
1409 queue->rx_ring_ref = GRANT_INVALID_REF;
1410 queue->tx.sring = NULL;
1411 queue->rx.sring = NULL;
1412 }
1413 }
1414
1415 /**
1416 * We are reconnecting to the backend, due to a suspend/resume, or a backend
1417 * driver restart. We tear down our netif structure and recreate it, but
1418 * leave the device-layer structures intact so that this is transparent to the
1419 * rest of the kernel.
1420 */
1421 static int netfront_resume(struct xenbus_device *dev)
1422 {
1423 struct netfront_info *info = dev_get_drvdata(&dev->dev);
1424
1425 dev_dbg(&dev->dev, "%s\n", dev->nodename);
1426
1427 xennet_disconnect_backend(info);
1428 return 0;
1429 }
1430
1431 static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[])
1432 {
1433 char *s, *e, *macstr;
1434 int i;
1435
1436 macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL);
1437 if (IS_ERR(macstr))
1438 return PTR_ERR(macstr);
1439
1440 for (i = 0; i < ETH_ALEN; i++) {
1441 mac[i] = simple_strtoul(s, &e, 16);
1442 if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) {
1443 kfree(macstr);
1444 return -ENOENT;
1445 }
1446 s = e+1;
1447 }
1448
1449 kfree(macstr);
1450 return 0;
1451 }
1452
1453 static int setup_netfront_single(struct netfront_queue *queue)
1454 {
1455 int err;
1456
1457 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn);
1458 if (err < 0)
1459 goto fail;
1460
1461 err = bind_evtchn_to_irqhandler(queue->tx_evtchn,
1462 xennet_interrupt,
1463 0, queue->info->netdev->name, queue);
1464 if (err < 0)
1465 goto bind_fail;
1466 queue->rx_evtchn = queue->tx_evtchn;
1467 queue->rx_irq = queue->tx_irq = err;
1468
1469 return 0;
1470
1471 bind_fail:
1472 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn);
1473 queue->tx_evtchn = 0;
1474 fail:
1475 return err;
1476 }
1477
1478 static int setup_netfront_split(struct netfront_queue *queue)
1479 {
1480 int err;
1481
1482 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn);
1483 if (err < 0)
1484 goto fail;
1485 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->rx_evtchn);
1486 if (err < 0)
1487 goto alloc_rx_evtchn_fail;
1488
1489 snprintf(queue->tx_irq_name, sizeof(queue->tx_irq_name),
1490 "%s-tx", queue->name);
1491 err = bind_evtchn_to_irqhandler(queue->tx_evtchn,
1492 xennet_tx_interrupt,
1493 0, queue->tx_irq_name, queue);
1494 if (err < 0)
1495 goto bind_tx_fail;
1496 queue->tx_irq = err;
1497
1498 snprintf(queue->rx_irq_name, sizeof(queue->rx_irq_name),
1499 "%s-rx", queue->name);
1500 err = bind_evtchn_to_irqhandler(queue->rx_evtchn,
1501 xennet_rx_interrupt,
1502 0, queue->rx_irq_name, queue);
1503 if (err < 0)
1504 goto bind_rx_fail;
1505 queue->rx_irq = err;
1506
1507 return 0;
1508
1509 bind_rx_fail:
1510 unbind_from_irqhandler(queue->tx_irq, queue);
1511 queue->tx_irq = 0;
1512 bind_tx_fail:
1513 xenbus_free_evtchn(queue->info->xbdev, queue->rx_evtchn);
1514 queue->rx_evtchn = 0;
1515 alloc_rx_evtchn_fail:
1516 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn);
1517 queue->tx_evtchn = 0;
1518 fail:
1519 return err;
1520 }
1521
1522 static int setup_netfront(struct xenbus_device *dev,
1523 struct netfront_queue *queue, unsigned int feature_split_evtchn)
1524 {
1525 struct xen_netif_tx_sring *txs;
1526 struct xen_netif_rx_sring *rxs;
1527 grant_ref_t gref;
1528 int err;
1529
1530 queue->tx_ring_ref = GRANT_INVALID_REF;
1531 queue->rx_ring_ref = GRANT_INVALID_REF;
1532 queue->rx.sring = NULL;
1533 queue->tx.sring = NULL;
1534
1535 txs = (struct xen_netif_tx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1536 if (!txs) {
1537 err = -ENOMEM;
1538 xenbus_dev_fatal(dev, err, "allocating tx ring page");
1539 goto fail;
1540 }
1541 SHARED_RING_INIT(txs);
1542 FRONT_RING_INIT(&queue->tx, txs, XEN_PAGE_SIZE);
1543
1544 err = xenbus_grant_ring(dev, txs, 1, &gref);
1545 if (err < 0)
1546 goto grant_tx_ring_fail;
1547 queue->tx_ring_ref = gref;
1548
1549 rxs = (struct xen_netif_rx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1550 if (!rxs) {
1551 err = -ENOMEM;
1552 xenbus_dev_fatal(dev, err, "allocating rx ring page");
1553 goto alloc_rx_ring_fail;
1554 }
1555 SHARED_RING_INIT(rxs);
1556 FRONT_RING_INIT(&queue->rx, rxs, XEN_PAGE_SIZE);
1557
1558 err = xenbus_grant_ring(dev, rxs, 1, &gref);
1559 if (err < 0)
1560 goto grant_rx_ring_fail;
1561 queue->rx_ring_ref = gref;
1562
1563 if (feature_split_evtchn)
1564 err = setup_netfront_split(queue);
1565 /* setup single event channel if
1566 * a) feature-split-event-channels == 0
1567 * b) feature-split-event-channels == 1 but failed to setup
1568 */
1569 if (!feature_split_evtchn || (feature_split_evtchn && err))
1570 err = setup_netfront_single(queue);
1571
1572 if (err)
1573 goto alloc_evtchn_fail;
1574
1575 return 0;
1576
1577 /* If we fail to setup netfront, it is safe to just revoke access to
1578 * granted pages because backend is not accessing it at this point.
1579 */
1580 alloc_evtchn_fail:
1581 gnttab_end_foreign_access_ref(queue->rx_ring_ref, 0);
1582 grant_rx_ring_fail:
1583 free_page((unsigned long)rxs);
1584 alloc_rx_ring_fail:
1585 gnttab_end_foreign_access_ref(queue->tx_ring_ref, 0);
1586 grant_tx_ring_fail:
1587 free_page((unsigned long)txs);
1588 fail:
1589 return err;
1590 }
1591
1592 /* Queue-specific initialisation
1593 * This used to be done in xennet_create_dev() but must now
1594 * be run per-queue.
1595 */
1596 static int xennet_init_queue(struct netfront_queue *queue)
1597 {
1598 unsigned short i;
1599 int err = 0;
1600
1601 spin_lock_init(&queue->tx_lock);
1602 spin_lock_init(&queue->rx_lock);
1603
1604 timer_setup(&queue->rx_refill_timer, rx_refill_timeout, 0);
1605
1606 snprintf(queue->name, sizeof(queue->name), "%s-q%u",
1607 queue->info->netdev->name, queue->id);
1608
1609 /* Initialise tx_skbs as a free chain containing every entry. */
1610 queue->tx_skb_freelist = 0;
1611 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1612 skb_entry_set_link(&queue->tx_skbs[i], i+1);
1613 queue->grant_tx_ref[i] = GRANT_INVALID_REF;
1614 queue->grant_tx_page[i] = NULL;
1615 }
1616
1617 /* Clear out rx_skbs */
1618 for (i = 0; i < NET_RX_RING_SIZE; i++) {
1619 queue->rx_skbs[i] = NULL;
1620 queue->grant_rx_ref[i] = GRANT_INVALID_REF;
1621 }
1622
1623 /* A grant for every tx ring slot */
1624 if (gnttab_alloc_grant_references(NET_TX_RING_SIZE,
1625 &queue->gref_tx_head) < 0) {
1626 pr_alert("can't alloc tx grant refs\n");
1627 err = -ENOMEM;
1628 goto exit;
1629 }
1630
1631 /* A grant for every rx ring slot */
1632 if (gnttab_alloc_grant_references(NET_RX_RING_SIZE,
1633 &queue->gref_rx_head) < 0) {
1634 pr_alert("can't alloc rx grant refs\n");
1635 err = -ENOMEM;
1636 goto exit_free_tx;
1637 }
1638
1639 return 0;
1640
1641 exit_free_tx:
1642 gnttab_free_grant_references(queue->gref_tx_head);
1643 exit:
1644 return err;
1645 }
1646
1647 static int write_queue_xenstore_keys(struct netfront_queue *queue,
1648 struct xenbus_transaction *xbt, int write_hierarchical)
1649 {
1650 /* Write the queue-specific keys into XenStore in the traditional
1651 * way for a single queue, or in a queue subkeys for multiple
1652 * queues.
1653 */
1654 struct xenbus_device *dev = queue->info->xbdev;
1655 int err;
1656 const char *message;
1657 char *path;
1658 size_t pathsize;
1659
1660 /* Choose the correct place to write the keys */
1661 if (write_hierarchical) {
1662 pathsize = strlen(dev->nodename) + 10;
1663 path = kzalloc(pathsize, GFP_KERNEL);
1664 if (!path) {
1665 err = -ENOMEM;
1666 message = "out of memory while writing ring references";
1667 goto error;
1668 }
1669 snprintf(path, pathsize, "%s/queue-%u",
1670 dev->nodename, queue->id);
1671 } else {
1672 path = (char *)dev->nodename;
1673 }
1674
1675 /* Write ring references */
1676 err = xenbus_printf(*xbt, path, "tx-ring-ref", "%u",
1677 queue->tx_ring_ref);
1678 if (err) {
1679 message = "writing tx-ring-ref";
1680 goto error;
1681 }
1682
1683 err = xenbus_printf(*xbt, path, "rx-ring-ref", "%u",
1684 queue->rx_ring_ref);
1685 if (err) {
1686 message = "writing rx-ring-ref";
1687 goto error;
1688 }
1689
1690 /* Write event channels; taking into account both shared
1691 * and split event channel scenarios.
1692 */
1693 if (queue->tx_evtchn == queue->rx_evtchn) {
1694 /* Shared event channel */
1695 err = xenbus_printf(*xbt, path,
1696 "event-channel", "%u", queue->tx_evtchn);
1697 if (err) {
1698 message = "writing event-channel";
1699 goto error;
1700 }
1701 } else {
1702 /* Split event channels */
1703 err = xenbus_printf(*xbt, path,
1704 "event-channel-tx", "%u", queue->tx_evtchn);
1705 if (err) {
1706 message = "writing event-channel-tx";
1707 goto error;
1708 }
1709
1710 err = xenbus_printf(*xbt, path,
1711 "event-channel-rx", "%u", queue->rx_evtchn);
1712 if (err) {
1713 message = "writing event-channel-rx";
1714 goto error;
1715 }
1716 }
1717
1718 if (write_hierarchical)
1719 kfree(path);
1720 return 0;
1721
1722 error:
1723 if (write_hierarchical)
1724 kfree(path);
1725 xenbus_dev_fatal(dev, err, "%s", message);
1726 return err;
1727 }
1728
1729 static void xennet_destroy_queues(struct netfront_info *info)
1730 {
1731 unsigned int i;
1732
1733 for (i = 0; i < info->netdev->real_num_tx_queues; i++) {
1734 struct netfront_queue *queue = &info->queues[i];
1735
1736 if (netif_running(info->netdev))
1737 napi_disable(&queue->napi);
1738 netif_napi_del(&queue->napi);
1739 }
1740
1741 kfree(info->queues);
1742 info->queues = NULL;
1743 }
1744
1745 static int xennet_create_queues(struct netfront_info *info,
1746 unsigned int *num_queues)
1747 {
1748 unsigned int i;
1749 int ret;
1750
1751 info->queues = kcalloc(*num_queues, sizeof(struct netfront_queue),
1752 GFP_KERNEL);
1753 if (!info->queues)
1754 return -ENOMEM;
1755
1756 for (i = 0; i < *num_queues; i++) {
1757 struct netfront_queue *queue = &info->queues[i];
1758
1759 queue->id = i;
1760 queue->info = info;
1761
1762 ret = xennet_init_queue(queue);
1763 if (ret < 0) {
1764 dev_warn(&info->xbdev->dev,
1765 "only created %d queues\n", i);
1766 *num_queues = i;
1767 break;
1768 }
1769
1770 netif_napi_add(queue->info->netdev, &queue->napi,
1771 xennet_poll, 64);
1772 if (netif_running(info->netdev))
1773 napi_enable(&queue->napi);
1774 }
1775
1776 netif_set_real_num_tx_queues(info->netdev, *num_queues);
1777
1778 if (*num_queues == 0) {
1779 dev_err(&info->xbdev->dev, "no queues\n");
1780 return -EINVAL;
1781 }
1782 return 0;
1783 }
1784
1785 /* Common code used when first setting up, and when resuming. */
1786 static int talk_to_netback(struct xenbus_device *dev,
1787 struct netfront_info *info)
1788 {
1789 const char *message;
1790 struct xenbus_transaction xbt;
1791 int err;
1792 unsigned int feature_split_evtchn;
1793 unsigned int i = 0;
1794 unsigned int max_queues = 0;
1795 struct netfront_queue *queue = NULL;
1796 unsigned int num_queues = 1;
1797
1798 info->netdev->irq = 0;
1799
1800 /* Check if backend supports multiple queues */
1801 max_queues = xenbus_read_unsigned(info->xbdev->otherend,
1802 "multi-queue-max-queues", 1);
1803 num_queues = min(max_queues, xennet_max_queues);
1804
1805 /* Check feature-split-event-channels */
1806 feature_split_evtchn = xenbus_read_unsigned(info->xbdev->otherend,
1807 "feature-split-event-channels", 0);
1808
1809 /* Read mac addr. */
1810 err = xen_net_read_mac(dev, info->netdev->dev_addr);
1811 if (err) {
1812 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
1813 goto out;
1814 }
1815
1816 rtnl_lock();
1817 if (info->queues)
1818 xennet_destroy_queues(info);
1819
1820 err = xennet_create_queues(info, &num_queues);
1821 if (err < 0) {
1822 xenbus_dev_fatal(dev, err, "creating queues");
1823 kfree(info->queues);
1824 info->queues = NULL;
1825 goto out;
1826 }
1827 rtnl_unlock();
1828
1829 /* Create shared ring, alloc event channel -- for each queue */
1830 for (i = 0; i < num_queues; ++i) {
1831 queue = &info->queues[i];
1832 err = setup_netfront(dev, queue, feature_split_evtchn);
1833 if (err)
1834 goto destroy_ring;
1835 }
1836
1837 again:
1838 err = xenbus_transaction_start(&xbt);
1839 if (err) {
1840 xenbus_dev_fatal(dev, err, "starting transaction");
1841 goto destroy_ring;
1842 }
1843
1844 if (xenbus_exists(XBT_NIL,
1845 info->xbdev->otherend, "multi-queue-max-queues")) {
1846 /* Write the number of queues */
1847 err = xenbus_printf(xbt, dev->nodename,
1848 "multi-queue-num-queues", "%u", num_queues);
1849 if (err) {
1850 message = "writing multi-queue-num-queues";
1851 goto abort_transaction_no_dev_fatal;
1852 }
1853 }
1854
1855 if (num_queues == 1) {
1856 err = write_queue_xenstore_keys(&info->queues[0], &xbt, 0); /* flat */
1857 if (err)
1858 goto abort_transaction_no_dev_fatal;
1859 } else {
1860 /* Write the keys for each queue */
1861 for (i = 0; i < num_queues; ++i) {
1862 queue = &info->queues[i];
1863 err = write_queue_xenstore_keys(queue, &xbt, 1); /* hierarchical */
1864 if (err)
1865 goto abort_transaction_no_dev_fatal;
1866 }
1867 }
1868
1869 /* The remaining keys are not queue-specific */
1870 err = xenbus_printf(xbt, dev->nodename, "request-rx-copy", "%u",
1871 1);
1872 if (err) {
1873 message = "writing request-rx-copy";
1874 goto abort_transaction;
1875 }
1876
1877 err = xenbus_printf(xbt, dev->nodename, "feature-rx-notify", "%d", 1);
1878 if (err) {
1879 message = "writing feature-rx-notify";
1880 goto abort_transaction;
1881 }
1882
1883 err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", 1);
1884 if (err) {
1885 message = "writing feature-sg";
1886 goto abort_transaction;
1887 }
1888
1889 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4", "%d", 1);
1890 if (err) {
1891 message = "writing feature-gso-tcpv4";
1892 goto abort_transaction;
1893 }
1894
1895 err = xenbus_write(xbt, dev->nodename, "feature-gso-tcpv6", "1");
1896 if (err) {
1897 message = "writing feature-gso-tcpv6";
1898 goto abort_transaction;
1899 }
1900
1901 err = xenbus_write(xbt, dev->nodename, "feature-ipv6-csum-offload",
1902 "1");
1903 if (err) {
1904 message = "writing feature-ipv6-csum-offload";
1905 goto abort_transaction;
1906 }
1907
1908 err = xenbus_transaction_end(xbt, 0);
1909 if (err) {
1910 if (err == -EAGAIN)
1911 goto again;
1912 xenbus_dev_fatal(dev, err, "completing transaction");
1913 goto destroy_ring;
1914 }
1915
1916 return 0;
1917
1918 abort_transaction:
1919 xenbus_dev_fatal(dev, err, "%s", message);
1920 abort_transaction_no_dev_fatal:
1921 xenbus_transaction_end(xbt, 1);
1922 destroy_ring:
1923 xennet_disconnect_backend(info);
1924 rtnl_lock();
1925 xennet_destroy_queues(info);
1926 out:
1927 rtnl_unlock();
1928 device_unregister(&dev->dev);
1929 return err;
1930 }
1931
1932 static int xennet_connect(struct net_device *dev)
1933 {
1934 struct netfront_info *np = netdev_priv(dev);
1935 unsigned int num_queues = 0;
1936 int err;
1937 unsigned int j = 0;
1938 struct netfront_queue *queue = NULL;
1939
1940 if (!xenbus_read_unsigned(np->xbdev->otherend, "feature-rx-copy", 0)) {
1941 dev_info(&dev->dev,
1942 "backend does not support copying receive path\n");
1943 return -ENODEV;
1944 }
1945
1946 err = talk_to_netback(np->xbdev, np);
1947 if (err)
1948 return err;
1949
1950 /* talk_to_netback() sets the correct number of queues */
1951 num_queues = dev->real_num_tx_queues;
1952
1953 rtnl_lock();
1954 netdev_update_features(dev);
1955 rtnl_unlock();
1956
1957 if (dev->reg_state == NETREG_UNINITIALIZED) {
1958 err = register_netdev(dev);
1959 if (err) {
1960 pr_warn("%s: register_netdev err=%d\n", __func__, err);
1961 device_unregister(&np->xbdev->dev);
1962 return err;
1963 }
1964 }
1965
1966 /*
1967 * All public and private state should now be sane. Get
1968 * ready to start sending and receiving packets and give the driver
1969 * domain a kick because we've probably just requeued some
1970 * packets.
1971 */
1972 netif_carrier_on(np->netdev);
1973 for (j = 0; j < num_queues; ++j) {
1974 queue = &np->queues[j];
1975
1976 notify_remote_via_irq(queue->tx_irq);
1977 if (queue->tx_irq != queue->rx_irq)
1978 notify_remote_via_irq(queue->rx_irq);
1979
1980 spin_lock_irq(&queue->tx_lock);
1981 xennet_tx_buf_gc(queue);
1982 spin_unlock_irq(&queue->tx_lock);
1983
1984 spin_lock_bh(&queue->rx_lock);
1985 xennet_alloc_rx_buffers(queue);
1986 spin_unlock_bh(&queue->rx_lock);
1987 }
1988
1989 return 0;
1990 }
1991
1992 /**
1993 * Callback received when the backend's state changes.
1994 */
1995 static void netback_changed(struct xenbus_device *dev,
1996 enum xenbus_state backend_state)
1997 {
1998 struct netfront_info *np = dev_get_drvdata(&dev->dev);
1999 struct net_device *netdev = np->netdev;
2000
2001 dev_dbg(&dev->dev, "%s\n", xenbus_strstate(backend_state));
2002
2003 switch (backend_state) {
2004 case XenbusStateInitialising:
2005 case XenbusStateInitialised:
2006 case XenbusStateReconfiguring:
2007 case XenbusStateReconfigured:
2008 break;
2009
2010 case XenbusStateUnknown:
2011 wake_up_all(&module_unload_q);
2012 break;
2013
2014 case XenbusStateInitWait:
2015 if (dev->state != XenbusStateInitialising)
2016 break;
2017 if (xennet_connect(netdev) != 0)
2018 break;
2019 xenbus_switch_state(dev, XenbusStateConnected);
2020 break;
2021
2022 case XenbusStateConnected:
2023 netdev_notify_peers(netdev);
2024 break;
2025
2026 case XenbusStateClosed:
2027 wake_up_all(&module_unload_q);
2028 if (dev->state == XenbusStateClosed)
2029 break;
2030 /* Missed the backend's CLOSING state -- fallthrough */
2031 case XenbusStateClosing:
2032 wake_up_all(&module_unload_q);
2033 xenbus_frontend_closed(dev);
2034 break;
2035 }
2036 }
2037
2038 static const struct xennet_stat {
2039 char name[ETH_GSTRING_LEN];
2040 u16 offset;
2041 } xennet_stats[] = {
2042 {
2043 "rx_gso_checksum_fixup",
2044 offsetof(struct netfront_info, rx_gso_checksum_fixup)
2045 },
2046 };
2047
2048 static int xennet_get_sset_count(struct net_device *dev, int string_set)
2049 {
2050 switch (string_set) {
2051 case ETH_SS_STATS:
2052 return ARRAY_SIZE(xennet_stats);
2053 default:
2054 return -EINVAL;
2055 }
2056 }
2057
2058 static void xennet_get_ethtool_stats(struct net_device *dev,
2059 struct ethtool_stats *stats, u64 * data)
2060 {
2061 void *np = netdev_priv(dev);
2062 int i;
2063
2064 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
2065 data[i] = atomic_read((atomic_t *)(np + xennet_stats[i].offset));
2066 }
2067
2068 static void xennet_get_strings(struct net_device *dev, u32 stringset, u8 * data)
2069 {
2070 int i;
2071
2072 switch (stringset) {
2073 case ETH_SS_STATS:
2074 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
2075 memcpy(data + i * ETH_GSTRING_LEN,
2076 xennet_stats[i].name, ETH_GSTRING_LEN);
2077 break;
2078 }
2079 }
2080
2081 static const struct ethtool_ops xennet_ethtool_ops =
2082 {
2083 .get_link = ethtool_op_get_link,
2084
2085 .get_sset_count = xennet_get_sset_count,
2086 .get_ethtool_stats = xennet_get_ethtool_stats,
2087 .get_strings = xennet_get_strings,
2088 };
2089
2090 #ifdef CONFIG_SYSFS
2091 static ssize_t show_rxbuf(struct device *dev,
2092 struct device_attribute *attr, char *buf)
2093 {
2094 return sprintf(buf, "%lu\n", NET_RX_RING_SIZE);
2095 }
2096
2097 static ssize_t store_rxbuf(struct device *dev,
2098 struct device_attribute *attr,
2099 const char *buf, size_t len)
2100 {
2101 char *endp;
2102 unsigned long target;
2103
2104 if (!capable(CAP_NET_ADMIN))
2105 return -EPERM;
2106
2107 target = simple_strtoul(buf, &endp, 0);
2108 if (endp == buf)
2109 return -EBADMSG;
2110
2111 /* rxbuf_min and rxbuf_max are no longer configurable. */
2112
2113 return len;
2114 }
2115
2116 static DEVICE_ATTR(rxbuf_min, S_IRUGO|S_IWUSR, show_rxbuf, store_rxbuf);
2117 static DEVICE_ATTR(rxbuf_max, S_IRUGO|S_IWUSR, show_rxbuf, store_rxbuf);
2118 static DEVICE_ATTR(rxbuf_cur, S_IRUGO, show_rxbuf, NULL);
2119
2120 static struct attribute *xennet_dev_attrs[] = {
2121 &dev_attr_rxbuf_min.attr,
2122 &dev_attr_rxbuf_max.attr,
2123 &dev_attr_rxbuf_cur.attr,
2124 NULL
2125 };
2126
2127 static const struct attribute_group xennet_dev_group = {
2128 .attrs = xennet_dev_attrs
2129 };
2130 #endif /* CONFIG_SYSFS */
2131
2132 static int xennet_remove(struct xenbus_device *dev)
2133 {
2134 struct netfront_info *info = dev_get_drvdata(&dev->dev);
2135
2136 dev_dbg(&dev->dev, "%s\n", dev->nodename);
2137
2138 if (xenbus_read_driver_state(dev->otherend) != XenbusStateClosed) {
2139 xenbus_switch_state(dev, XenbusStateClosing);
2140 wait_event(module_unload_q,
2141 xenbus_read_driver_state(dev->otherend) ==
2142 XenbusStateClosing ||
2143 xenbus_read_driver_state(dev->otherend) ==
2144 XenbusStateUnknown);
2145
2146 xenbus_switch_state(dev, XenbusStateClosed);
2147 wait_event(module_unload_q,
2148 xenbus_read_driver_state(dev->otherend) ==
2149 XenbusStateClosed ||
2150 xenbus_read_driver_state(dev->otherend) ==
2151 XenbusStateUnknown);
2152 }
2153
2154 xennet_disconnect_backend(info);
2155
2156 if (info->netdev->reg_state == NETREG_REGISTERED)
2157 unregister_netdev(info->netdev);
2158
2159 if (info->queues) {
2160 rtnl_lock();
2161 xennet_destroy_queues(info);
2162 rtnl_unlock();
2163 }
2164 xennet_free_netdev(info->netdev);
2165
2166 return 0;
2167 }
2168
2169 static const struct xenbus_device_id netfront_ids[] = {
2170 { "vif" },
2171 { "" }
2172 };
2173
2174 static struct xenbus_driver netfront_driver = {
2175 .ids = netfront_ids,
2176 .probe = netfront_probe,
2177 .remove = xennet_remove,
2178 .resume = netfront_resume,
2179 .otherend_changed = netback_changed,
2180 };
2181
2182 static int __init netif_init(void)
2183 {
2184 if (!xen_domain())
2185 return -ENODEV;
2186
2187 if (!xen_has_pv_nic_devices())
2188 return -ENODEV;
2189
2190 pr_info("Initialising Xen virtual ethernet driver\n");
2191
2192 /* Allow as many queues as there are CPUs inut max. 8 if user has not
2193 * specified a value.
2194 */
2195 if (xennet_max_queues == 0)
2196 xennet_max_queues = min_t(unsigned int, MAX_QUEUES_DEFAULT,
2197 num_online_cpus());
2198
2199 return xenbus_register_frontend(&netfront_driver);
2200 }
2201 module_init(netif_init);
2202
2203
2204 static void __exit netif_exit(void)
2205 {
2206 xenbus_unregister_driver(&netfront_driver);
2207 }
2208 module_exit(netif_exit);
2209
2210 MODULE_DESCRIPTION("Xen virtual network device frontend");
2211 MODULE_LICENSE("GPL");
2212 MODULE_ALIAS("xen:vif");
2213 MODULE_ALIAS("xennet");
CRIS linux kernel tree