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Merge branch 'perf/hw_breakpoints' into perf/core
[deliverable/linux.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 <asm/xen/page.h>
49 #include <xen/xen.h>
50 #include <xen/xenbus.h>
51 #include <xen/events.h>
52 #include <xen/page.h>
53 #include <xen/platform_pci.h>
54 #include <xen/grant_table.h>
55
56 #include <xen/interface/io/netif.h>
57 #include <xen/interface/memory.h>
58 #include <xen/interface/grant_table.h>
59
60 /* Module parameters */
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, PAGE_SIZE)
79 #define NET_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, PAGE_SIZE)
80
81 /* Minimum number of Rx slots (includes slot for GSO metadata). */
82 #define NET_RX_SLOTS_MIN (XEN_NETIF_NR_SLOTS_MIN + 1)
83
84 /* Queue name is interface name with "-qNNN" appended */
85 #define QUEUE_NAME_SIZE (IFNAMSIZ + 6)
86
87 /* IRQ name is queue name with "-tx" or "-rx" appended */
88 #define IRQ_NAME_SIZE (QUEUE_NAME_SIZE + 3)
89
90 struct netfront_stats {
91 u64 packets;
92 u64 bytes;
93 struct u64_stats_sync syncp;
94 };
95
96 struct netfront_info;
97
98 struct netfront_queue {
99 unsigned int id; /* Queue ID, 0-based */
100 char name[QUEUE_NAME_SIZE]; /* DEVNAME-qN */
101 struct netfront_info *info;
102
103 struct napi_struct napi;
104
105 /* Split event channels support, tx_* == rx_* when using
106 * single event channel.
107 */
108 unsigned int tx_evtchn, rx_evtchn;
109 unsigned int tx_irq, rx_irq;
110 /* Only used when split event channels support is enabled */
111 char tx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-tx */
112 char rx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-rx */
113
114 spinlock_t tx_lock;
115 struct xen_netif_tx_front_ring tx;
116 int tx_ring_ref;
117
118 /*
119 * {tx,rx}_skbs store outstanding skbuffs. Free tx_skb entries
120 * are linked from tx_skb_freelist through skb_entry.link.
121 *
122 * NB. Freelist index entries are always going to be less than
123 * PAGE_OFFSET, whereas pointers to skbs will always be equal or
124 * greater than PAGE_OFFSET: we use this property to distinguish
125 * them.
126 */
127 union skb_entry {
128 struct sk_buff *skb;
129 unsigned long link;
130 } tx_skbs[NET_TX_RING_SIZE];
131 grant_ref_t gref_tx_head;
132 grant_ref_t grant_tx_ref[NET_TX_RING_SIZE];
133 struct page *grant_tx_page[NET_TX_RING_SIZE];
134 unsigned tx_skb_freelist;
135
136 spinlock_t rx_lock ____cacheline_aligned_in_smp;
137 struct xen_netif_rx_front_ring rx;
138 int rx_ring_ref;
139
140 struct timer_list rx_refill_timer;
141
142 struct sk_buff *rx_skbs[NET_RX_RING_SIZE];
143 grant_ref_t gref_rx_head;
144 grant_ref_t grant_rx_ref[NET_RX_RING_SIZE];
145
146 unsigned long rx_pfn_array[NET_RX_RING_SIZE];
147 struct multicall_entry rx_mcl[NET_RX_RING_SIZE+1];
148 struct mmu_update rx_mmu[NET_RX_RING_SIZE];
149 };
150
151 struct netfront_info {
152 struct list_head list;
153 struct net_device *netdev;
154
155 struct xenbus_device *xbdev;
156
157 /* Multi-queue support */
158 struct netfront_queue *queues;
159
160 /* Statistics */
161 struct netfront_stats __percpu *rx_stats;
162 struct netfront_stats __percpu *tx_stats;
163
164 atomic_t rx_gso_checksum_fixup;
165 };
166
167 struct netfront_rx_info {
168 struct xen_netif_rx_response rx;
169 struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX - 1];
170 };
171
172 static void skb_entry_set_link(union skb_entry *list, unsigned short id)
173 {
174 list->link = id;
175 }
176
177 static int skb_entry_is_link(const union skb_entry *list)
178 {
179 BUILD_BUG_ON(sizeof(list->skb) != sizeof(list->link));
180 return (unsigned long)list->skb < PAGE_OFFSET;
181 }
182
183 /*
184 * Access macros for acquiring freeing slots in tx_skbs[].
185 */
186
187 static void add_id_to_freelist(unsigned *head, union skb_entry *list,
188 unsigned short id)
189 {
190 skb_entry_set_link(&list[id], *head);
191 *head = id;
192 }
193
194 static unsigned short get_id_from_freelist(unsigned *head,
195 union skb_entry *list)
196 {
197 unsigned int id = *head;
198 *head = list[id].link;
199 return id;
200 }
201
202 static int xennet_rxidx(RING_IDX idx)
203 {
204 return idx & (NET_RX_RING_SIZE - 1);
205 }
206
207 static struct sk_buff *xennet_get_rx_skb(struct netfront_queue *queue,
208 RING_IDX ri)
209 {
210 int i = xennet_rxidx(ri);
211 struct sk_buff *skb = queue->rx_skbs[i];
212 queue->rx_skbs[i] = NULL;
213 return skb;
214 }
215
216 static grant_ref_t xennet_get_rx_ref(struct netfront_queue *queue,
217 RING_IDX ri)
218 {
219 int i = xennet_rxidx(ri);
220 grant_ref_t ref = queue->grant_rx_ref[i];
221 queue->grant_rx_ref[i] = GRANT_INVALID_REF;
222 return ref;
223 }
224
225 #ifdef CONFIG_SYSFS
226 static int xennet_sysfs_addif(struct net_device *netdev);
227 static void xennet_sysfs_delif(struct net_device *netdev);
228 #else /* !CONFIG_SYSFS */
229 #define xennet_sysfs_addif(dev) (0)
230 #define xennet_sysfs_delif(dev) do { } while (0)
231 #endif
232
233 static bool xennet_can_sg(struct net_device *dev)
234 {
235 return dev->features & NETIF_F_SG;
236 }
237
238
239 static void rx_refill_timeout(unsigned long data)
240 {
241 struct netfront_queue *queue = (struct netfront_queue *)data;
242 napi_schedule(&queue->napi);
243 }
244
245 static int netfront_tx_slot_available(struct netfront_queue *queue)
246 {
247 return (queue->tx.req_prod_pvt - queue->tx.rsp_cons) <
248 (NET_TX_RING_SIZE - MAX_SKB_FRAGS - 2);
249 }
250
251 static void xennet_maybe_wake_tx(struct netfront_queue *queue)
252 {
253 struct net_device *dev = queue->info->netdev;
254 struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, queue->id);
255
256 if (unlikely(netif_tx_queue_stopped(dev_queue)) &&
257 netfront_tx_slot_available(queue) &&
258 likely(netif_running(dev)))
259 netif_tx_wake_queue(netdev_get_tx_queue(dev, queue->id));
260 }
261
262
263 static struct sk_buff *xennet_alloc_one_rx_buffer(struct netfront_queue *queue)
264 {
265 struct sk_buff *skb;
266 struct page *page;
267
268 skb = __netdev_alloc_skb(queue->info->netdev,
269 RX_COPY_THRESHOLD + NET_IP_ALIGN,
270 GFP_ATOMIC | __GFP_NOWARN);
271 if (unlikely(!skb))
272 return NULL;
273
274 page = alloc_page(GFP_ATOMIC | __GFP_NOWARN);
275 if (!page) {
276 kfree_skb(skb);
277 return NULL;
278 }
279 skb_add_rx_frag(skb, 0, page, 0, 0, PAGE_SIZE);
280
281 /* Align ip header to a 16 bytes boundary */
282 skb_reserve(skb, NET_IP_ALIGN);
283 skb->dev = queue->info->netdev;
284
285 return skb;
286 }
287
288
289 static void xennet_alloc_rx_buffers(struct netfront_queue *queue)
290 {
291 RING_IDX req_prod = queue->rx.req_prod_pvt;
292 int notify;
293
294 if (unlikely(!netif_carrier_ok(queue->info->netdev)))
295 return;
296
297 for (req_prod = queue->rx.req_prod_pvt;
298 req_prod - queue->rx.rsp_cons < NET_RX_RING_SIZE;
299 req_prod++) {
300 struct sk_buff *skb;
301 unsigned short id;
302 grant_ref_t ref;
303 unsigned long pfn;
304 struct xen_netif_rx_request *req;
305
306 skb = xennet_alloc_one_rx_buffer(queue);
307 if (!skb)
308 break;
309
310 id = xennet_rxidx(req_prod);
311
312 BUG_ON(queue->rx_skbs[id]);
313 queue->rx_skbs[id] = skb;
314
315 ref = gnttab_claim_grant_reference(&queue->gref_rx_head);
316 BUG_ON((signed short)ref < 0);
317 queue->grant_rx_ref[id] = ref;
318
319 pfn = page_to_pfn(skb_frag_page(&skb_shinfo(skb)->frags[0]));
320
321 req = RING_GET_REQUEST(&queue->rx, req_prod);
322 gnttab_grant_foreign_access_ref(ref,
323 queue->info->xbdev->otherend_id,
324 pfn_to_mfn(pfn),
325 0);
326
327 req->id = id;
328 req->gref = ref;
329 }
330
331 queue->rx.req_prod_pvt = req_prod;
332
333 /* Not enough requests? Try again later. */
334 if (req_prod - queue->rx.rsp_cons < NET_RX_SLOTS_MIN) {
335 mod_timer(&queue->rx_refill_timer, jiffies + (HZ/10));
336 return;
337 }
338
339 wmb(); /* barrier so backend seens requests */
340
341 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->rx, notify);
342 if (notify)
343 notify_remote_via_irq(queue->rx_irq);
344 }
345
346 static int xennet_open(struct net_device *dev)
347 {
348 struct netfront_info *np = netdev_priv(dev);
349 unsigned int num_queues = dev->real_num_tx_queues;
350 unsigned int i = 0;
351 struct netfront_queue *queue = NULL;
352
353 for (i = 0; i < num_queues; ++i) {
354 queue = &np->queues[i];
355 napi_enable(&queue->napi);
356
357 spin_lock_bh(&queue->rx_lock);
358 if (netif_carrier_ok(dev)) {
359 xennet_alloc_rx_buffers(queue);
360 queue->rx.sring->rsp_event = queue->rx.rsp_cons + 1;
361 if (RING_HAS_UNCONSUMED_RESPONSES(&queue->rx))
362 napi_schedule(&queue->napi);
363 }
364 spin_unlock_bh(&queue->rx_lock);
365 }
366
367 netif_tx_start_all_queues(dev);
368
369 return 0;
370 }
371
372 static void xennet_tx_buf_gc(struct netfront_queue *queue)
373 {
374 RING_IDX cons, prod;
375 unsigned short id;
376 struct sk_buff *skb;
377
378 BUG_ON(!netif_carrier_ok(queue->info->netdev));
379
380 do {
381 prod = queue->tx.sring->rsp_prod;
382 rmb(); /* Ensure we see responses up to 'rp'. */
383
384 for (cons = queue->tx.rsp_cons; cons != prod; cons++) {
385 struct xen_netif_tx_response *txrsp;
386
387 txrsp = RING_GET_RESPONSE(&queue->tx, cons);
388 if (txrsp->status == XEN_NETIF_RSP_NULL)
389 continue;
390
391 id = txrsp->id;
392 skb = queue->tx_skbs[id].skb;
393 if (unlikely(gnttab_query_foreign_access(
394 queue->grant_tx_ref[id]) != 0)) {
395 pr_alert("%s: warning -- grant still in use by backend domain\n",
396 __func__);
397 BUG();
398 }
399 gnttab_end_foreign_access_ref(
400 queue->grant_tx_ref[id], GNTMAP_readonly);
401 gnttab_release_grant_reference(
402 &queue->gref_tx_head, queue->grant_tx_ref[id]);
403 queue->grant_tx_ref[id] = GRANT_INVALID_REF;
404 queue->grant_tx_page[id] = NULL;
405 add_id_to_freelist(&queue->tx_skb_freelist, queue->tx_skbs, id);
406 dev_kfree_skb_irq(skb);
407 }
408
409 queue->tx.rsp_cons = prod;
410
411 /*
412 * Set a new event, then check for race with update of tx_cons.
413 * Note that it is essential to schedule a callback, no matter
414 * how few buffers are pending. Even if there is space in the
415 * transmit ring, higher layers may be blocked because too much
416 * data is outstanding: in such cases notification from Xen is
417 * likely to be the only kick that we'll get.
418 */
419 queue->tx.sring->rsp_event =
420 prod + ((queue->tx.sring->req_prod - prod) >> 1) + 1;
421 mb(); /* update shared area */
422 } while ((cons == prod) && (prod != queue->tx.sring->rsp_prod));
423
424 xennet_maybe_wake_tx(queue);
425 }
426
427 static void xennet_make_frags(struct sk_buff *skb, struct netfront_queue *queue,
428 struct xen_netif_tx_request *tx)
429 {
430 char *data = skb->data;
431 unsigned long mfn;
432 RING_IDX prod = queue->tx.req_prod_pvt;
433 int frags = skb_shinfo(skb)->nr_frags;
434 unsigned int offset = offset_in_page(data);
435 unsigned int len = skb_headlen(skb);
436 unsigned int id;
437 grant_ref_t ref;
438 int i;
439
440 /* While the header overlaps a page boundary (including being
441 larger than a page), split it it into page-sized chunks. */
442 while (len > PAGE_SIZE - offset) {
443 tx->size = PAGE_SIZE - offset;
444 tx->flags |= XEN_NETTXF_more_data;
445 len -= tx->size;
446 data += tx->size;
447 offset = 0;
448
449 id = get_id_from_freelist(&queue->tx_skb_freelist, queue->tx_skbs);
450 queue->tx_skbs[id].skb = skb_get(skb);
451 tx = RING_GET_REQUEST(&queue->tx, prod++);
452 tx->id = id;
453 ref = gnttab_claim_grant_reference(&queue->gref_tx_head);
454 BUG_ON((signed short)ref < 0);
455
456 mfn = virt_to_mfn(data);
457 gnttab_grant_foreign_access_ref(ref, queue->info->xbdev->otherend_id,
458 mfn, GNTMAP_readonly);
459
460 queue->grant_tx_page[id] = virt_to_page(data);
461 tx->gref = queue->grant_tx_ref[id] = ref;
462 tx->offset = offset;
463 tx->size = len;
464 tx->flags = 0;
465 }
466
467 /* Grant backend access to each skb fragment page. */
468 for (i = 0; i < frags; i++) {
469 skb_frag_t *frag = skb_shinfo(skb)->frags + i;
470 struct page *page = skb_frag_page(frag);
471
472 len = skb_frag_size(frag);
473 offset = frag->page_offset;
474
475 /* Skip unused frames from start of page */
476 page += offset >> PAGE_SHIFT;
477 offset &= ~PAGE_MASK;
478
479 while (len > 0) {
480 unsigned long bytes;
481
482 bytes = PAGE_SIZE - offset;
483 if (bytes > len)
484 bytes = len;
485
486 tx->flags |= XEN_NETTXF_more_data;
487
488 id = get_id_from_freelist(&queue->tx_skb_freelist,
489 queue->tx_skbs);
490 queue->tx_skbs[id].skb = skb_get(skb);
491 tx = RING_GET_REQUEST(&queue->tx, prod++);
492 tx->id = id;
493 ref = gnttab_claim_grant_reference(&queue->gref_tx_head);
494 BUG_ON((signed short)ref < 0);
495
496 mfn = pfn_to_mfn(page_to_pfn(page));
497 gnttab_grant_foreign_access_ref(ref,
498 queue->info->xbdev->otherend_id,
499 mfn, GNTMAP_readonly);
500
501 queue->grant_tx_page[id] = page;
502 tx->gref = queue->grant_tx_ref[id] = ref;
503 tx->offset = offset;
504 tx->size = bytes;
505 tx->flags = 0;
506
507 offset += bytes;
508 len -= bytes;
509
510 /* Next frame */
511 if (offset == PAGE_SIZE && len) {
512 BUG_ON(!PageCompound(page));
513 page++;
514 offset = 0;
515 }
516 }
517 }
518
519 queue->tx.req_prod_pvt = prod;
520 }
521
522 /*
523 * Count how many ring slots are required to send the frags of this
524 * skb. Each frag might be a compound page.
525 */
526 static int xennet_count_skb_frag_slots(struct sk_buff *skb)
527 {
528 int i, frags = skb_shinfo(skb)->nr_frags;
529 int pages = 0;
530
531 for (i = 0; i < frags; i++) {
532 skb_frag_t *frag = skb_shinfo(skb)->frags + i;
533 unsigned long size = skb_frag_size(frag);
534 unsigned long offset = frag->page_offset;
535
536 /* Skip unused frames from start of page */
537 offset &= ~PAGE_MASK;
538
539 pages += PFN_UP(offset + size);
540 }
541
542 return pages;
543 }
544
545 static u16 xennet_select_queue(struct net_device *dev, struct sk_buff *skb,
546 void *accel_priv, select_queue_fallback_t fallback)
547 {
548 unsigned int num_queues = dev->real_num_tx_queues;
549 u32 hash;
550 u16 queue_idx;
551
552 /* First, check if there is only one queue */
553 if (num_queues == 1) {
554 queue_idx = 0;
555 } else {
556 hash = skb_get_hash(skb);
557 queue_idx = hash % num_queues;
558 }
559
560 return queue_idx;
561 }
562
563 static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev)
564 {
565 unsigned short id;
566 struct netfront_info *np = netdev_priv(dev);
567 struct netfront_stats *tx_stats = this_cpu_ptr(np->tx_stats);
568 struct xen_netif_tx_request *tx;
569 char *data = skb->data;
570 RING_IDX i;
571 grant_ref_t ref;
572 unsigned long mfn;
573 int notify;
574 int slots;
575 unsigned int offset = offset_in_page(data);
576 unsigned int len = skb_headlen(skb);
577 unsigned long flags;
578 struct netfront_queue *queue = NULL;
579 unsigned int num_queues = dev->real_num_tx_queues;
580 u16 queue_index;
581
582 /* Drop the packet if no queues are set up */
583 if (num_queues < 1)
584 goto drop;
585 /* Determine which queue to transmit this SKB on */
586 queue_index = skb_get_queue_mapping(skb);
587 queue = &np->queues[queue_index];
588
589 /* If skb->len is too big for wire format, drop skb and alert
590 * user about misconfiguration.
591 */
592 if (unlikely(skb->len > XEN_NETIF_MAX_TX_SIZE)) {
593 net_alert_ratelimited(
594 "xennet: skb->len = %u, too big for wire format\n",
595 skb->len);
596 goto drop;
597 }
598
599 slots = DIV_ROUND_UP(offset + len, PAGE_SIZE) +
600 xennet_count_skb_frag_slots(skb);
601 if (unlikely(slots > MAX_SKB_FRAGS + 1)) {
602 net_dbg_ratelimited("xennet: skb rides the rocket: %d slots, %d bytes\n",
603 slots, skb->len);
604 if (skb_linearize(skb))
605 goto drop;
606 data = skb->data;
607 offset = offset_in_page(data);
608 len = skb_headlen(skb);
609 }
610
611 spin_lock_irqsave(&queue->tx_lock, flags);
612
613 if (unlikely(!netif_carrier_ok(dev) ||
614 (slots > 1 && !xennet_can_sg(dev)) ||
615 netif_needs_gso(dev, skb, netif_skb_features(skb)))) {
616 spin_unlock_irqrestore(&queue->tx_lock, flags);
617 goto drop;
618 }
619
620 i = queue->tx.req_prod_pvt;
621
622 id = get_id_from_freelist(&queue->tx_skb_freelist, queue->tx_skbs);
623 queue->tx_skbs[id].skb = skb;
624
625 tx = RING_GET_REQUEST(&queue->tx, i);
626
627 tx->id = id;
628 ref = gnttab_claim_grant_reference(&queue->gref_tx_head);
629 BUG_ON((signed short)ref < 0);
630 mfn = virt_to_mfn(data);
631 gnttab_grant_foreign_access_ref(
632 ref, queue->info->xbdev->otherend_id, mfn, GNTMAP_readonly);
633 queue->grant_tx_page[id] = virt_to_page(data);
634 tx->gref = queue->grant_tx_ref[id] = ref;
635 tx->offset = offset;
636 tx->size = len;
637
638 tx->flags = 0;
639 if (skb->ip_summed == CHECKSUM_PARTIAL)
640 /* local packet? */
641 tx->flags |= XEN_NETTXF_csum_blank | XEN_NETTXF_data_validated;
642 else if (skb->ip_summed == CHECKSUM_UNNECESSARY)
643 /* remote but checksummed. */
644 tx->flags |= XEN_NETTXF_data_validated;
645
646 if (skb_shinfo(skb)->gso_size) {
647 struct xen_netif_extra_info *gso;
648
649 gso = (struct xen_netif_extra_info *)
650 RING_GET_REQUEST(&queue->tx, ++i);
651
652 tx->flags |= XEN_NETTXF_extra_info;
653
654 gso->u.gso.size = skb_shinfo(skb)->gso_size;
655 gso->u.gso.type = (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) ?
656 XEN_NETIF_GSO_TYPE_TCPV6 :
657 XEN_NETIF_GSO_TYPE_TCPV4;
658 gso->u.gso.pad = 0;
659 gso->u.gso.features = 0;
660
661 gso->type = XEN_NETIF_EXTRA_TYPE_GSO;
662 gso->flags = 0;
663 }
664
665 queue->tx.req_prod_pvt = i + 1;
666
667 xennet_make_frags(skb, queue, tx);
668 tx->size = skb->len;
669
670 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->tx, notify);
671 if (notify)
672 notify_remote_via_irq(queue->tx_irq);
673
674 u64_stats_update_begin(&tx_stats->syncp);
675 tx_stats->bytes += skb->len;
676 tx_stats->packets++;
677 u64_stats_update_end(&tx_stats->syncp);
678
679 /* Note: It is not safe to access skb after xennet_tx_buf_gc()! */
680 xennet_tx_buf_gc(queue);
681
682 if (!netfront_tx_slot_available(queue))
683 netif_tx_stop_queue(netdev_get_tx_queue(dev, queue->id));
684
685 spin_unlock_irqrestore(&queue->tx_lock, flags);
686
687 return NETDEV_TX_OK;
688
689 drop:
690 dev->stats.tx_dropped++;
691 dev_kfree_skb_any(skb);
692 return NETDEV_TX_OK;
693 }
694
695 static int xennet_close(struct net_device *dev)
696 {
697 struct netfront_info *np = netdev_priv(dev);
698 unsigned int num_queues = dev->real_num_tx_queues;
699 unsigned int i;
700 struct netfront_queue *queue;
701 netif_tx_stop_all_queues(np->netdev);
702 for (i = 0; i < num_queues; ++i) {
703 queue = &np->queues[i];
704 napi_disable(&queue->napi);
705 }
706 return 0;
707 }
708
709 static void xennet_move_rx_slot(struct netfront_queue *queue, struct sk_buff *skb,
710 grant_ref_t ref)
711 {
712 int new = xennet_rxidx(queue->rx.req_prod_pvt);
713
714 BUG_ON(queue->rx_skbs[new]);
715 queue->rx_skbs[new] = skb;
716 queue->grant_rx_ref[new] = ref;
717 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->id = new;
718 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->gref = ref;
719 queue->rx.req_prod_pvt++;
720 }
721
722 static int xennet_get_extras(struct netfront_queue *queue,
723 struct xen_netif_extra_info *extras,
724 RING_IDX rp)
725
726 {
727 struct xen_netif_extra_info *extra;
728 struct device *dev = &queue->info->netdev->dev;
729 RING_IDX cons = queue->rx.rsp_cons;
730 int err = 0;
731
732 do {
733 struct sk_buff *skb;
734 grant_ref_t ref;
735
736 if (unlikely(cons + 1 == rp)) {
737 if (net_ratelimit())
738 dev_warn(dev, "Missing extra info\n");
739 err = -EBADR;
740 break;
741 }
742
743 extra = (struct xen_netif_extra_info *)
744 RING_GET_RESPONSE(&queue->rx, ++cons);
745
746 if (unlikely(!extra->type ||
747 extra->type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
748 if (net_ratelimit())
749 dev_warn(dev, "Invalid extra type: %d\n",
750 extra->type);
751 err = -EINVAL;
752 } else {
753 memcpy(&extras[extra->type - 1], extra,
754 sizeof(*extra));
755 }
756
757 skb = xennet_get_rx_skb(queue, cons);
758 ref = xennet_get_rx_ref(queue, cons);
759 xennet_move_rx_slot(queue, skb, ref);
760 } while (extra->flags & XEN_NETIF_EXTRA_FLAG_MORE);
761
762 queue->rx.rsp_cons = cons;
763 return err;
764 }
765
766 static int xennet_get_responses(struct netfront_queue *queue,
767 struct netfront_rx_info *rinfo, RING_IDX rp,
768 struct sk_buff_head *list)
769 {
770 struct xen_netif_rx_response *rx = &rinfo->rx;
771 struct xen_netif_extra_info *extras = rinfo->extras;
772 struct device *dev = &queue->info->netdev->dev;
773 RING_IDX cons = queue->rx.rsp_cons;
774 struct sk_buff *skb = xennet_get_rx_skb(queue, cons);
775 grant_ref_t ref = xennet_get_rx_ref(queue, cons);
776 int max = MAX_SKB_FRAGS + (rx->status <= RX_COPY_THRESHOLD);
777 int slots = 1;
778 int err = 0;
779 unsigned long ret;
780
781 if (rx->flags & XEN_NETRXF_extra_info) {
782 err = xennet_get_extras(queue, extras, rp);
783 cons = queue->rx.rsp_cons;
784 }
785
786 for (;;) {
787 if (unlikely(rx->status < 0 ||
788 rx->offset + rx->status > PAGE_SIZE)) {
789 if (net_ratelimit())
790 dev_warn(dev, "rx->offset: %x, size: %u\n",
791 rx->offset, rx->status);
792 xennet_move_rx_slot(queue, skb, ref);
793 err = -EINVAL;
794 goto next;
795 }
796
797 /*
798 * This definitely indicates a bug, either in this driver or in
799 * the backend driver. In future this should flag the bad
800 * situation to the system controller to reboot the backend.
801 */
802 if (ref == GRANT_INVALID_REF) {
803 if (net_ratelimit())
804 dev_warn(dev, "Bad rx response id %d.\n",
805 rx->id);
806 err = -EINVAL;
807 goto next;
808 }
809
810 ret = gnttab_end_foreign_access_ref(ref, 0);
811 BUG_ON(!ret);
812
813 gnttab_release_grant_reference(&queue->gref_rx_head, ref);
814
815 __skb_queue_tail(list, skb);
816
817 next:
818 if (!(rx->flags & XEN_NETRXF_more_data))
819 break;
820
821 if (cons + slots == rp) {
822 if (net_ratelimit())
823 dev_warn(dev, "Need more slots\n");
824 err = -ENOENT;
825 break;
826 }
827
828 rx = RING_GET_RESPONSE(&queue->rx, cons + slots);
829 skb = xennet_get_rx_skb(queue, cons + slots);
830 ref = xennet_get_rx_ref(queue, cons + slots);
831 slots++;
832 }
833
834 if (unlikely(slots > max)) {
835 if (net_ratelimit())
836 dev_warn(dev, "Too many slots\n");
837 err = -E2BIG;
838 }
839
840 if (unlikely(err))
841 queue->rx.rsp_cons = cons + slots;
842
843 return err;
844 }
845
846 static int xennet_set_skb_gso(struct sk_buff *skb,
847 struct xen_netif_extra_info *gso)
848 {
849 if (!gso->u.gso.size) {
850 if (net_ratelimit())
851 pr_warn("GSO size must not be zero\n");
852 return -EINVAL;
853 }
854
855 if (gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV4 &&
856 gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV6) {
857 if (net_ratelimit())
858 pr_warn("Bad GSO type %d\n", gso->u.gso.type);
859 return -EINVAL;
860 }
861
862 skb_shinfo(skb)->gso_size = gso->u.gso.size;
863 skb_shinfo(skb)->gso_type =
864 (gso->u.gso.type == XEN_NETIF_GSO_TYPE_TCPV4) ?
865 SKB_GSO_TCPV4 :
866 SKB_GSO_TCPV6;
867
868 /* Header must be checked, and gso_segs computed. */
869 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
870 skb_shinfo(skb)->gso_segs = 0;
871
872 return 0;
873 }
874
875 static RING_IDX xennet_fill_frags(struct netfront_queue *queue,
876 struct sk_buff *skb,
877 struct sk_buff_head *list)
878 {
879 struct skb_shared_info *shinfo = skb_shinfo(skb);
880 RING_IDX cons = queue->rx.rsp_cons;
881 struct sk_buff *nskb;
882
883 while ((nskb = __skb_dequeue(list))) {
884 struct xen_netif_rx_response *rx =
885 RING_GET_RESPONSE(&queue->rx, ++cons);
886 skb_frag_t *nfrag = &skb_shinfo(nskb)->frags[0];
887
888 if (shinfo->nr_frags == MAX_SKB_FRAGS) {
889 unsigned int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
890
891 BUG_ON(pull_to <= skb_headlen(skb));
892 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
893 }
894 BUG_ON(shinfo->nr_frags >= MAX_SKB_FRAGS);
895
896 skb_add_rx_frag(skb, shinfo->nr_frags, skb_frag_page(nfrag),
897 rx->offset, rx->status, PAGE_SIZE);
898
899 skb_shinfo(nskb)->nr_frags = 0;
900 kfree_skb(nskb);
901 }
902
903 return cons;
904 }
905
906 static int checksum_setup(struct net_device *dev, struct sk_buff *skb)
907 {
908 bool recalculate_partial_csum = false;
909
910 /*
911 * A GSO SKB must be CHECKSUM_PARTIAL. However some buggy
912 * peers can fail to set NETRXF_csum_blank when sending a GSO
913 * frame. In this case force the SKB to CHECKSUM_PARTIAL and
914 * recalculate the partial checksum.
915 */
916 if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) {
917 struct netfront_info *np = netdev_priv(dev);
918 atomic_inc(&np->rx_gso_checksum_fixup);
919 skb->ip_summed = CHECKSUM_PARTIAL;
920 recalculate_partial_csum = true;
921 }
922
923 /* A non-CHECKSUM_PARTIAL SKB does not require setup. */
924 if (skb->ip_summed != CHECKSUM_PARTIAL)
925 return 0;
926
927 return skb_checksum_setup(skb, recalculate_partial_csum);
928 }
929
930 static int handle_incoming_queue(struct netfront_queue *queue,
931 struct sk_buff_head *rxq)
932 {
933 struct netfront_stats *rx_stats = this_cpu_ptr(queue->info->rx_stats);
934 int packets_dropped = 0;
935 struct sk_buff *skb;
936
937 while ((skb = __skb_dequeue(rxq)) != NULL) {
938 int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
939
940 if (pull_to > skb_headlen(skb))
941 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
942
943 /* Ethernet work: Delayed to here as it peeks the header. */
944 skb->protocol = eth_type_trans(skb, queue->info->netdev);
945 skb_reset_network_header(skb);
946
947 if (checksum_setup(queue->info->netdev, skb)) {
948 kfree_skb(skb);
949 packets_dropped++;
950 queue->info->netdev->stats.rx_errors++;
951 continue;
952 }
953
954 u64_stats_update_begin(&rx_stats->syncp);
955 rx_stats->packets++;
956 rx_stats->bytes += skb->len;
957 u64_stats_update_end(&rx_stats->syncp);
958
959 /* Pass it up. */
960 napi_gro_receive(&queue->napi, skb);
961 }
962
963 return packets_dropped;
964 }
965
966 static int xennet_poll(struct napi_struct *napi, int budget)
967 {
968 struct netfront_queue *queue = container_of(napi, struct netfront_queue, napi);
969 struct net_device *dev = queue->info->netdev;
970 struct sk_buff *skb;
971 struct netfront_rx_info rinfo;
972 struct xen_netif_rx_response *rx = &rinfo.rx;
973 struct xen_netif_extra_info *extras = rinfo.extras;
974 RING_IDX i, rp;
975 int work_done;
976 struct sk_buff_head rxq;
977 struct sk_buff_head errq;
978 struct sk_buff_head tmpq;
979 int err;
980
981 spin_lock(&queue->rx_lock);
982
983 skb_queue_head_init(&rxq);
984 skb_queue_head_init(&errq);
985 skb_queue_head_init(&tmpq);
986
987 rp = queue->rx.sring->rsp_prod;
988 rmb(); /* Ensure we see queued responses up to 'rp'. */
989
990 i = queue->rx.rsp_cons;
991 work_done = 0;
992 while ((i != rp) && (work_done < budget)) {
993 memcpy(rx, RING_GET_RESPONSE(&queue->rx, i), sizeof(*rx));
994 memset(extras, 0, sizeof(rinfo.extras));
995
996 err = xennet_get_responses(queue, &rinfo, rp, &tmpq);
997
998 if (unlikely(err)) {
999 err:
1000 while ((skb = __skb_dequeue(&tmpq)))
1001 __skb_queue_tail(&errq, skb);
1002 dev->stats.rx_errors++;
1003 i = queue->rx.rsp_cons;
1004 continue;
1005 }
1006
1007 skb = __skb_dequeue(&tmpq);
1008
1009 if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) {
1010 struct xen_netif_extra_info *gso;
1011 gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1];
1012
1013 if (unlikely(xennet_set_skb_gso(skb, gso))) {
1014 __skb_queue_head(&tmpq, skb);
1015 queue->rx.rsp_cons += skb_queue_len(&tmpq);
1016 goto err;
1017 }
1018 }
1019
1020 NETFRONT_SKB_CB(skb)->pull_to = rx->status;
1021 if (NETFRONT_SKB_CB(skb)->pull_to > RX_COPY_THRESHOLD)
1022 NETFRONT_SKB_CB(skb)->pull_to = RX_COPY_THRESHOLD;
1023
1024 skb_shinfo(skb)->frags[0].page_offset = rx->offset;
1025 skb_frag_size_set(&skb_shinfo(skb)->frags[0], rx->status);
1026 skb->data_len = rx->status;
1027 skb->len += rx->status;
1028
1029 i = xennet_fill_frags(queue, skb, &tmpq);
1030
1031 if (rx->flags & XEN_NETRXF_csum_blank)
1032 skb->ip_summed = CHECKSUM_PARTIAL;
1033 else if (rx->flags & XEN_NETRXF_data_validated)
1034 skb->ip_summed = CHECKSUM_UNNECESSARY;
1035
1036 __skb_queue_tail(&rxq, skb);
1037
1038 queue->rx.rsp_cons = ++i;
1039 work_done++;
1040 }
1041
1042 __skb_queue_purge(&errq);
1043
1044 work_done -= handle_incoming_queue(queue, &rxq);
1045
1046 xennet_alloc_rx_buffers(queue);
1047
1048 if (work_done < budget) {
1049 int more_to_do = 0;
1050
1051 napi_complete(napi);
1052
1053 RING_FINAL_CHECK_FOR_RESPONSES(&queue->rx, more_to_do);
1054 if (more_to_do)
1055 napi_schedule(napi);
1056 }
1057
1058 spin_unlock(&queue->rx_lock);
1059
1060 return work_done;
1061 }
1062
1063 static int xennet_change_mtu(struct net_device *dev, int mtu)
1064 {
1065 int max = xennet_can_sg(dev) ?
1066 XEN_NETIF_MAX_TX_SIZE - MAX_TCP_HEADER : ETH_DATA_LEN;
1067
1068 if (mtu > max)
1069 return -EINVAL;
1070 dev->mtu = mtu;
1071 return 0;
1072 }
1073
1074 static struct rtnl_link_stats64 *xennet_get_stats64(struct net_device *dev,
1075 struct rtnl_link_stats64 *tot)
1076 {
1077 struct netfront_info *np = netdev_priv(dev);
1078 int cpu;
1079
1080 for_each_possible_cpu(cpu) {
1081 struct netfront_stats *rx_stats = per_cpu_ptr(np->rx_stats, cpu);
1082 struct netfront_stats *tx_stats = per_cpu_ptr(np->tx_stats, cpu);
1083 u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
1084 unsigned int start;
1085
1086 do {
1087 start = u64_stats_fetch_begin_irq(&tx_stats->syncp);
1088 tx_packets = tx_stats->packets;
1089 tx_bytes = tx_stats->bytes;
1090 } while (u64_stats_fetch_retry_irq(&tx_stats->syncp, start));
1091
1092 do {
1093 start = u64_stats_fetch_begin_irq(&rx_stats->syncp);
1094 rx_packets = rx_stats->packets;
1095 rx_bytes = rx_stats->bytes;
1096 } while (u64_stats_fetch_retry_irq(&rx_stats->syncp, start));
1097
1098 tot->rx_packets += rx_packets;
1099 tot->tx_packets += tx_packets;
1100 tot->rx_bytes += rx_bytes;
1101 tot->tx_bytes += tx_bytes;
1102 }
1103
1104 tot->rx_errors = dev->stats.rx_errors;
1105 tot->tx_dropped = dev->stats.tx_dropped;
1106
1107 return tot;
1108 }
1109
1110 static void xennet_release_tx_bufs(struct netfront_queue *queue)
1111 {
1112 struct sk_buff *skb;
1113 int i;
1114
1115 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1116 /* Skip over entries which are actually freelist references */
1117 if (skb_entry_is_link(&queue->tx_skbs[i]))
1118 continue;
1119
1120 skb = queue->tx_skbs[i].skb;
1121 get_page(queue->grant_tx_page[i]);
1122 gnttab_end_foreign_access(queue->grant_tx_ref[i],
1123 GNTMAP_readonly,
1124 (unsigned long)page_address(queue->grant_tx_page[i]));
1125 queue->grant_tx_page[i] = NULL;
1126 queue->grant_tx_ref[i] = GRANT_INVALID_REF;
1127 add_id_to_freelist(&queue->tx_skb_freelist, queue->tx_skbs, i);
1128 dev_kfree_skb_irq(skb);
1129 }
1130 }
1131
1132 static void xennet_release_rx_bufs(struct netfront_queue *queue)
1133 {
1134 int id, ref;
1135
1136 spin_lock_bh(&queue->rx_lock);
1137
1138 for (id = 0; id < NET_RX_RING_SIZE; id++) {
1139 struct sk_buff *skb;
1140 struct page *page;
1141
1142 skb = queue->rx_skbs[id];
1143 if (!skb)
1144 continue;
1145
1146 ref = queue->grant_rx_ref[id];
1147 if (ref == GRANT_INVALID_REF)
1148 continue;
1149
1150 page = skb_frag_page(&skb_shinfo(skb)->frags[0]);
1151
1152 /* gnttab_end_foreign_access() needs a page ref until
1153 * foreign access is ended (which may be deferred).
1154 */
1155 get_page(page);
1156 gnttab_end_foreign_access(ref, 0,
1157 (unsigned long)page_address(page));
1158 queue->grant_rx_ref[id] = GRANT_INVALID_REF;
1159
1160 kfree_skb(skb);
1161 }
1162
1163 spin_unlock_bh(&queue->rx_lock);
1164 }
1165
1166 static netdev_features_t xennet_fix_features(struct net_device *dev,
1167 netdev_features_t features)
1168 {
1169 struct netfront_info *np = netdev_priv(dev);
1170 int val;
1171
1172 if (features & NETIF_F_SG) {
1173 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, "feature-sg",
1174 "%d", &val) < 0)
1175 val = 0;
1176
1177 if (!val)
1178 features &= ~NETIF_F_SG;
1179 }
1180
1181 if (features & NETIF_F_IPV6_CSUM) {
1182 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1183 "feature-ipv6-csum-offload", "%d", &val) < 0)
1184 val = 0;
1185
1186 if (!val)
1187 features &= ~NETIF_F_IPV6_CSUM;
1188 }
1189
1190 if (features & NETIF_F_TSO) {
1191 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1192 "feature-gso-tcpv4", "%d", &val) < 0)
1193 val = 0;
1194
1195 if (!val)
1196 features &= ~NETIF_F_TSO;
1197 }
1198
1199 if (features & NETIF_F_TSO6) {
1200 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1201 "feature-gso-tcpv6", "%d", &val) < 0)
1202 val = 0;
1203
1204 if (!val)
1205 features &= ~NETIF_F_TSO6;
1206 }
1207
1208 return features;
1209 }
1210
1211 static int xennet_set_features(struct net_device *dev,
1212 netdev_features_t features)
1213 {
1214 if (!(features & NETIF_F_SG) && dev->mtu > ETH_DATA_LEN) {
1215 netdev_info(dev, "Reducing MTU because no SG offload");
1216 dev->mtu = ETH_DATA_LEN;
1217 }
1218
1219 return 0;
1220 }
1221
1222 static irqreturn_t xennet_tx_interrupt(int irq, void *dev_id)
1223 {
1224 struct netfront_queue *queue = dev_id;
1225 unsigned long flags;
1226
1227 spin_lock_irqsave(&queue->tx_lock, flags);
1228 xennet_tx_buf_gc(queue);
1229 spin_unlock_irqrestore(&queue->tx_lock, flags);
1230
1231 return IRQ_HANDLED;
1232 }
1233
1234 static irqreturn_t xennet_rx_interrupt(int irq, void *dev_id)
1235 {
1236 struct netfront_queue *queue = dev_id;
1237 struct net_device *dev = queue->info->netdev;
1238
1239 if (likely(netif_carrier_ok(dev) &&
1240 RING_HAS_UNCONSUMED_RESPONSES(&queue->rx)))
1241 napi_schedule(&queue->napi);
1242
1243 return IRQ_HANDLED;
1244 }
1245
1246 static irqreturn_t xennet_interrupt(int irq, void *dev_id)
1247 {
1248 xennet_tx_interrupt(irq, dev_id);
1249 xennet_rx_interrupt(irq, dev_id);
1250 return IRQ_HANDLED;
1251 }
1252
1253 #ifdef CONFIG_NET_POLL_CONTROLLER
1254 static void xennet_poll_controller(struct net_device *dev)
1255 {
1256 /* Poll each queue */
1257 struct netfront_info *info = netdev_priv(dev);
1258 unsigned int num_queues = dev->real_num_tx_queues;
1259 unsigned int i;
1260 for (i = 0; i < num_queues; ++i)
1261 xennet_interrupt(0, &info->queues[i]);
1262 }
1263 #endif
1264
1265 static const struct net_device_ops xennet_netdev_ops = {
1266 .ndo_open = xennet_open,
1267 .ndo_stop = xennet_close,
1268 .ndo_start_xmit = xennet_start_xmit,
1269 .ndo_change_mtu = xennet_change_mtu,
1270 .ndo_get_stats64 = xennet_get_stats64,
1271 .ndo_set_mac_address = eth_mac_addr,
1272 .ndo_validate_addr = eth_validate_addr,
1273 .ndo_fix_features = xennet_fix_features,
1274 .ndo_set_features = xennet_set_features,
1275 .ndo_select_queue = xennet_select_queue,
1276 #ifdef CONFIG_NET_POLL_CONTROLLER
1277 .ndo_poll_controller = xennet_poll_controller,
1278 #endif
1279 };
1280
1281 static void xennet_free_netdev(struct net_device *netdev)
1282 {
1283 struct netfront_info *np = netdev_priv(netdev);
1284
1285 free_percpu(np->rx_stats);
1286 free_percpu(np->tx_stats);
1287 free_netdev(netdev);
1288 }
1289
1290 static struct net_device *xennet_create_dev(struct xenbus_device *dev)
1291 {
1292 int err;
1293 struct net_device *netdev;
1294 struct netfront_info *np;
1295
1296 netdev = alloc_etherdev_mq(sizeof(struct netfront_info), xennet_max_queues);
1297 if (!netdev)
1298 return ERR_PTR(-ENOMEM);
1299
1300 np = netdev_priv(netdev);
1301 np->xbdev = dev;
1302
1303 /* No need to use rtnl_lock() before the call below as it
1304 * happens before register_netdev().
1305 */
1306 netif_set_real_num_tx_queues(netdev, 0);
1307 np->queues = NULL;
1308
1309 err = -ENOMEM;
1310 np->rx_stats = netdev_alloc_pcpu_stats(struct netfront_stats);
1311 if (np->rx_stats == NULL)
1312 goto exit;
1313 np->tx_stats = netdev_alloc_pcpu_stats(struct netfront_stats);
1314 if (np->tx_stats == NULL)
1315 goto exit;
1316
1317 netdev->netdev_ops = &xennet_netdev_ops;
1318
1319 netdev->features = NETIF_F_IP_CSUM | NETIF_F_RXCSUM |
1320 NETIF_F_GSO_ROBUST;
1321 netdev->hw_features = NETIF_F_SG |
1322 NETIF_F_IPV6_CSUM |
1323 NETIF_F_TSO | NETIF_F_TSO6;
1324
1325 /*
1326 * Assume that all hw features are available for now. This set
1327 * will be adjusted by the call to netdev_update_features() in
1328 * xennet_connect() which is the earliest point where we can
1329 * negotiate with the backend regarding supported features.
1330 */
1331 netdev->features |= netdev->hw_features;
1332
1333 netdev->ethtool_ops = &xennet_ethtool_ops;
1334 SET_NETDEV_DEV(netdev, &dev->dev);
1335
1336 netif_set_gso_max_size(netdev, XEN_NETIF_MAX_TX_SIZE - MAX_TCP_HEADER);
1337
1338 np->netdev = netdev;
1339
1340 netif_carrier_off(netdev);
1341
1342 return netdev;
1343
1344 exit:
1345 xennet_free_netdev(netdev);
1346 return ERR_PTR(err);
1347 }
1348
1349 /**
1350 * Entry point to this code when a new device is created. Allocate the basic
1351 * structures and the ring buffers for communication with the backend, and
1352 * inform the backend of the appropriate details for those.
1353 */
1354 static int netfront_probe(struct xenbus_device *dev,
1355 const struct xenbus_device_id *id)
1356 {
1357 int err;
1358 struct net_device *netdev;
1359 struct netfront_info *info;
1360
1361 netdev = xennet_create_dev(dev);
1362 if (IS_ERR(netdev)) {
1363 err = PTR_ERR(netdev);
1364 xenbus_dev_fatal(dev, err, "creating netdev");
1365 return err;
1366 }
1367
1368 info = netdev_priv(netdev);
1369 dev_set_drvdata(&dev->dev, info);
1370
1371 err = register_netdev(info->netdev);
1372 if (err) {
1373 pr_warn("%s: register_netdev err=%d\n", __func__, err);
1374 goto fail;
1375 }
1376
1377 err = xennet_sysfs_addif(info->netdev);
1378 if (err) {
1379 unregister_netdev(info->netdev);
1380 pr_warn("%s: add sysfs failed err=%d\n", __func__, err);
1381 goto fail;
1382 }
1383
1384 return 0;
1385
1386 fail:
1387 xennet_free_netdev(netdev);
1388 dev_set_drvdata(&dev->dev, NULL);
1389 return err;
1390 }
1391
1392 static void xennet_end_access(int ref, void *page)
1393 {
1394 /* This frees the page as a side-effect */
1395 if (ref != GRANT_INVALID_REF)
1396 gnttab_end_foreign_access(ref, 0, (unsigned long)page);
1397 }
1398
1399 static void xennet_disconnect_backend(struct netfront_info *info)
1400 {
1401 unsigned int i = 0;
1402 unsigned int num_queues = info->netdev->real_num_tx_queues;
1403
1404 netif_carrier_off(info->netdev);
1405
1406 for (i = 0; i < num_queues; ++i) {
1407 struct netfront_queue *queue = &info->queues[i];
1408
1409 if (queue->tx_irq && (queue->tx_irq == queue->rx_irq))
1410 unbind_from_irqhandler(queue->tx_irq, queue);
1411 if (queue->tx_irq && (queue->tx_irq != queue->rx_irq)) {
1412 unbind_from_irqhandler(queue->tx_irq, queue);
1413 unbind_from_irqhandler(queue->rx_irq, queue);
1414 }
1415 queue->tx_evtchn = queue->rx_evtchn = 0;
1416 queue->tx_irq = queue->rx_irq = 0;
1417
1418 napi_synchronize(&queue->napi);
1419
1420 xennet_release_tx_bufs(queue);
1421 xennet_release_rx_bufs(queue);
1422 gnttab_free_grant_references(queue->gref_tx_head);
1423 gnttab_free_grant_references(queue->gref_rx_head);
1424
1425 /* End access and free the pages */
1426 xennet_end_access(queue->tx_ring_ref, queue->tx.sring);
1427 xennet_end_access(queue->rx_ring_ref, queue->rx.sring);
1428
1429 queue->tx_ring_ref = GRANT_INVALID_REF;
1430 queue->rx_ring_ref = GRANT_INVALID_REF;
1431 queue->tx.sring = NULL;
1432 queue->rx.sring = NULL;
1433 }
1434 }
1435
1436 /**
1437 * We are reconnecting to the backend, due to a suspend/resume, or a backend
1438 * driver restart. We tear down our netif structure and recreate it, but
1439 * leave the device-layer structures intact so that this is transparent to the
1440 * rest of the kernel.
1441 */
1442 static int netfront_resume(struct xenbus_device *dev)
1443 {
1444 struct netfront_info *info = dev_get_drvdata(&dev->dev);
1445
1446 dev_dbg(&dev->dev, "%s\n", dev->nodename);
1447
1448 xennet_disconnect_backend(info);
1449 return 0;
1450 }
1451
1452 static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[])
1453 {
1454 char *s, *e, *macstr;
1455 int i;
1456
1457 macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL);
1458 if (IS_ERR(macstr))
1459 return PTR_ERR(macstr);
1460
1461 for (i = 0; i < ETH_ALEN; i++) {
1462 mac[i] = simple_strtoul(s, &e, 16);
1463 if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) {
1464 kfree(macstr);
1465 return -ENOENT;
1466 }
1467 s = e+1;
1468 }
1469
1470 kfree(macstr);
1471 return 0;
1472 }
1473
1474 static int setup_netfront_single(struct netfront_queue *queue)
1475 {
1476 int err;
1477
1478 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn);
1479 if (err < 0)
1480 goto fail;
1481
1482 err = bind_evtchn_to_irqhandler(queue->tx_evtchn,
1483 xennet_interrupt,
1484 0, queue->info->netdev->name, queue);
1485 if (err < 0)
1486 goto bind_fail;
1487 queue->rx_evtchn = queue->tx_evtchn;
1488 queue->rx_irq = queue->tx_irq = err;
1489
1490 return 0;
1491
1492 bind_fail:
1493 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn);
1494 queue->tx_evtchn = 0;
1495 fail:
1496 return err;
1497 }
1498
1499 static int setup_netfront_split(struct netfront_queue *queue)
1500 {
1501 int err;
1502
1503 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn);
1504 if (err < 0)
1505 goto fail;
1506 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->rx_evtchn);
1507 if (err < 0)
1508 goto alloc_rx_evtchn_fail;
1509
1510 snprintf(queue->tx_irq_name, sizeof(queue->tx_irq_name),
1511 "%s-tx", queue->name);
1512 err = bind_evtchn_to_irqhandler(queue->tx_evtchn,
1513 xennet_tx_interrupt,
1514 0, queue->tx_irq_name, queue);
1515 if (err < 0)
1516 goto bind_tx_fail;
1517 queue->tx_irq = err;
1518
1519 snprintf(queue->rx_irq_name, sizeof(queue->rx_irq_name),
1520 "%s-rx", queue->name);
1521 err = bind_evtchn_to_irqhandler(queue->rx_evtchn,
1522 xennet_rx_interrupt,
1523 0, queue->rx_irq_name, queue);
1524 if (err < 0)
1525 goto bind_rx_fail;
1526 queue->rx_irq = err;
1527
1528 return 0;
1529
1530 bind_rx_fail:
1531 unbind_from_irqhandler(queue->tx_irq, queue);
1532 queue->tx_irq = 0;
1533 bind_tx_fail:
1534 xenbus_free_evtchn(queue->info->xbdev, queue->rx_evtchn);
1535 queue->rx_evtchn = 0;
1536 alloc_rx_evtchn_fail:
1537 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn);
1538 queue->tx_evtchn = 0;
1539 fail:
1540 return err;
1541 }
1542
1543 static int setup_netfront(struct xenbus_device *dev,
1544 struct netfront_queue *queue, unsigned int feature_split_evtchn)
1545 {
1546 struct xen_netif_tx_sring *txs;
1547 struct xen_netif_rx_sring *rxs;
1548 int err;
1549
1550 queue->tx_ring_ref = GRANT_INVALID_REF;
1551 queue->rx_ring_ref = GRANT_INVALID_REF;
1552 queue->rx.sring = NULL;
1553 queue->tx.sring = NULL;
1554
1555 txs = (struct xen_netif_tx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1556 if (!txs) {
1557 err = -ENOMEM;
1558 xenbus_dev_fatal(dev, err, "allocating tx ring page");
1559 goto fail;
1560 }
1561 SHARED_RING_INIT(txs);
1562 FRONT_RING_INIT(&queue->tx, txs, PAGE_SIZE);
1563
1564 err = xenbus_grant_ring(dev, virt_to_mfn(txs));
1565 if (err < 0)
1566 goto grant_tx_ring_fail;
1567 queue->tx_ring_ref = err;
1568
1569 rxs = (struct xen_netif_rx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1570 if (!rxs) {
1571 err = -ENOMEM;
1572 xenbus_dev_fatal(dev, err, "allocating rx ring page");
1573 goto alloc_rx_ring_fail;
1574 }
1575 SHARED_RING_INIT(rxs);
1576 FRONT_RING_INIT(&queue->rx, rxs, PAGE_SIZE);
1577
1578 err = xenbus_grant_ring(dev, virt_to_mfn(rxs));
1579 if (err < 0)
1580 goto grant_rx_ring_fail;
1581 queue->rx_ring_ref = err;
1582
1583 if (feature_split_evtchn)
1584 err = setup_netfront_split(queue);
1585 /* setup single event channel if
1586 * a) feature-split-event-channels == 0
1587 * b) feature-split-event-channels == 1 but failed to setup
1588 */
1589 if (!feature_split_evtchn || (feature_split_evtchn && err))
1590 err = setup_netfront_single(queue);
1591
1592 if (err)
1593 goto alloc_evtchn_fail;
1594
1595 return 0;
1596
1597 /* If we fail to setup netfront, it is safe to just revoke access to
1598 * granted pages because backend is not accessing it at this point.
1599 */
1600 alloc_evtchn_fail:
1601 gnttab_end_foreign_access_ref(queue->rx_ring_ref, 0);
1602 grant_rx_ring_fail:
1603 free_page((unsigned long)rxs);
1604 alloc_rx_ring_fail:
1605 gnttab_end_foreign_access_ref(queue->tx_ring_ref, 0);
1606 grant_tx_ring_fail:
1607 free_page((unsigned long)txs);
1608 fail:
1609 return err;
1610 }
1611
1612 /* Queue-specific initialisation
1613 * This used to be done in xennet_create_dev() but must now
1614 * be run per-queue.
1615 */
1616 static int xennet_init_queue(struct netfront_queue *queue)
1617 {
1618 unsigned short i;
1619 int err = 0;
1620
1621 spin_lock_init(&queue->tx_lock);
1622 spin_lock_init(&queue->rx_lock);
1623
1624 init_timer(&queue->rx_refill_timer);
1625 queue->rx_refill_timer.data = (unsigned long)queue;
1626 queue->rx_refill_timer.function = rx_refill_timeout;
1627
1628 snprintf(queue->name, sizeof(queue->name), "%s-q%u",
1629 queue->info->netdev->name, queue->id);
1630
1631 /* Initialise tx_skbs as a free chain containing every entry. */
1632 queue->tx_skb_freelist = 0;
1633 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1634 skb_entry_set_link(&queue->tx_skbs[i], i+1);
1635 queue->grant_tx_ref[i] = GRANT_INVALID_REF;
1636 queue->grant_tx_page[i] = NULL;
1637 }
1638
1639 /* Clear out rx_skbs */
1640 for (i = 0; i < NET_RX_RING_SIZE; i++) {
1641 queue->rx_skbs[i] = NULL;
1642 queue->grant_rx_ref[i] = GRANT_INVALID_REF;
1643 }
1644
1645 /* A grant for every tx ring slot */
1646 if (gnttab_alloc_grant_references(NET_TX_RING_SIZE,
1647 &queue->gref_tx_head) < 0) {
1648 pr_alert("can't alloc tx grant refs\n");
1649 err = -ENOMEM;
1650 goto exit;
1651 }
1652
1653 /* A grant for every rx ring slot */
1654 if (gnttab_alloc_grant_references(NET_RX_RING_SIZE,
1655 &queue->gref_rx_head) < 0) {
1656 pr_alert("can't alloc rx grant refs\n");
1657 err = -ENOMEM;
1658 goto exit_free_tx;
1659 }
1660
1661 return 0;
1662
1663 exit_free_tx:
1664 gnttab_free_grant_references(queue->gref_tx_head);
1665 exit:
1666 return err;
1667 }
1668
1669 static int write_queue_xenstore_keys(struct netfront_queue *queue,
1670 struct xenbus_transaction *xbt, int write_hierarchical)
1671 {
1672 /* Write the queue-specific keys into XenStore in the traditional
1673 * way for a single queue, or in a queue subkeys for multiple
1674 * queues.
1675 */
1676 struct xenbus_device *dev = queue->info->xbdev;
1677 int err;
1678 const char *message;
1679 char *path;
1680 size_t pathsize;
1681
1682 /* Choose the correct place to write the keys */
1683 if (write_hierarchical) {
1684 pathsize = strlen(dev->nodename) + 10;
1685 path = kzalloc(pathsize, GFP_KERNEL);
1686 if (!path) {
1687 err = -ENOMEM;
1688 message = "out of memory while writing ring references";
1689 goto error;
1690 }
1691 snprintf(path, pathsize, "%s/queue-%u",
1692 dev->nodename, queue->id);
1693 } else {
1694 path = (char *)dev->nodename;
1695 }
1696
1697 /* Write ring references */
1698 err = xenbus_printf(*xbt, path, "tx-ring-ref", "%u",
1699 queue->tx_ring_ref);
1700 if (err) {
1701 message = "writing tx-ring-ref";
1702 goto error;
1703 }
1704
1705 err = xenbus_printf(*xbt, path, "rx-ring-ref", "%u",
1706 queue->rx_ring_ref);
1707 if (err) {
1708 message = "writing rx-ring-ref";
1709 goto error;
1710 }
1711
1712 /* Write event channels; taking into account both shared
1713 * and split event channel scenarios.
1714 */
1715 if (queue->tx_evtchn == queue->rx_evtchn) {
1716 /* Shared event channel */
1717 err = xenbus_printf(*xbt, path,
1718 "event-channel", "%u", queue->tx_evtchn);
1719 if (err) {
1720 message = "writing event-channel";
1721 goto error;
1722 }
1723 } else {
1724 /* Split event channels */
1725 err = xenbus_printf(*xbt, path,
1726 "event-channel-tx", "%u", queue->tx_evtchn);
1727 if (err) {
1728 message = "writing event-channel-tx";
1729 goto error;
1730 }
1731
1732 err = xenbus_printf(*xbt, path,
1733 "event-channel-rx", "%u", queue->rx_evtchn);
1734 if (err) {
1735 message = "writing event-channel-rx";
1736 goto error;
1737 }
1738 }
1739
1740 if (write_hierarchical)
1741 kfree(path);
1742 return 0;
1743
1744 error:
1745 if (write_hierarchical)
1746 kfree(path);
1747 xenbus_dev_fatal(dev, err, "%s", message);
1748 return err;
1749 }
1750
1751 static void xennet_destroy_queues(struct netfront_info *info)
1752 {
1753 unsigned int i;
1754
1755 rtnl_lock();
1756
1757 for (i = 0; i < info->netdev->real_num_tx_queues; i++) {
1758 struct netfront_queue *queue = &info->queues[i];
1759
1760 if (netif_running(info->netdev))
1761 napi_disable(&queue->napi);
1762 netif_napi_del(&queue->napi);
1763 }
1764
1765 rtnl_unlock();
1766
1767 kfree(info->queues);
1768 info->queues = NULL;
1769 }
1770
1771 static int xennet_create_queues(struct netfront_info *info,
1772 unsigned int num_queues)
1773 {
1774 unsigned int i;
1775 int ret;
1776
1777 info->queues = kcalloc(num_queues, sizeof(struct netfront_queue),
1778 GFP_KERNEL);
1779 if (!info->queues)
1780 return -ENOMEM;
1781
1782 rtnl_lock();
1783
1784 for (i = 0; i < num_queues; i++) {
1785 struct netfront_queue *queue = &info->queues[i];
1786
1787 queue->id = i;
1788 queue->info = info;
1789
1790 ret = xennet_init_queue(queue);
1791 if (ret < 0) {
1792 dev_warn(&info->netdev->dev,
1793 "only created %d queues\n", i);
1794 num_queues = i;
1795 break;
1796 }
1797
1798 netif_napi_add(queue->info->netdev, &queue->napi,
1799 xennet_poll, 64);
1800 if (netif_running(info->netdev))
1801 napi_enable(&queue->napi);
1802 }
1803
1804 netif_set_real_num_tx_queues(info->netdev, num_queues);
1805
1806 rtnl_unlock();
1807
1808 if (num_queues == 0) {
1809 dev_err(&info->netdev->dev, "no queues\n");
1810 return -EINVAL;
1811 }
1812 return 0;
1813 }
1814
1815 /* Common code used when first setting up, and when resuming. */
1816 static int talk_to_netback(struct xenbus_device *dev,
1817 struct netfront_info *info)
1818 {
1819 const char *message;
1820 struct xenbus_transaction xbt;
1821 int err;
1822 unsigned int feature_split_evtchn;
1823 unsigned int i = 0;
1824 unsigned int max_queues = 0;
1825 struct netfront_queue *queue = NULL;
1826 unsigned int num_queues = 1;
1827
1828 info->netdev->irq = 0;
1829
1830 /* Check if backend supports multiple queues */
1831 err = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
1832 "multi-queue-max-queues", "%u", &max_queues);
1833 if (err < 0)
1834 max_queues = 1;
1835 num_queues = min(max_queues, xennet_max_queues);
1836
1837 /* Check feature-split-event-channels */
1838 err = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
1839 "feature-split-event-channels", "%u",
1840 &feature_split_evtchn);
1841 if (err < 0)
1842 feature_split_evtchn = 0;
1843
1844 /* Read mac addr. */
1845 err = xen_net_read_mac(dev, info->netdev->dev_addr);
1846 if (err) {
1847 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
1848 goto out;
1849 }
1850
1851 if (info->queues)
1852 xennet_destroy_queues(info);
1853
1854 err = xennet_create_queues(info, num_queues);
1855 if (err < 0)
1856 goto destroy_ring;
1857
1858 /* Create shared ring, alloc event channel -- for each queue */
1859 for (i = 0; i < num_queues; ++i) {
1860 queue = &info->queues[i];
1861 err = setup_netfront(dev, queue, feature_split_evtchn);
1862 if (err) {
1863 /* setup_netfront() will tidy up the current
1864 * queue on error, but we need to clean up
1865 * those already allocated.
1866 */
1867 if (i > 0) {
1868 rtnl_lock();
1869 netif_set_real_num_tx_queues(info->netdev, i);
1870 rtnl_unlock();
1871 goto destroy_ring;
1872 } else {
1873 goto out;
1874 }
1875 }
1876 }
1877
1878 again:
1879 err = xenbus_transaction_start(&xbt);
1880 if (err) {
1881 xenbus_dev_fatal(dev, err, "starting transaction");
1882 goto destroy_ring;
1883 }
1884
1885 if (num_queues == 1) {
1886 err = write_queue_xenstore_keys(&info->queues[0], &xbt, 0); /* flat */
1887 if (err)
1888 goto abort_transaction_no_dev_fatal;
1889 } else {
1890 /* Write the number of queues */
1891 err = xenbus_printf(xbt, dev->nodename, "multi-queue-num-queues",
1892 "%u", num_queues);
1893 if (err) {
1894 message = "writing multi-queue-num-queues";
1895 goto abort_transaction_no_dev_fatal;
1896 }
1897
1898 /* Write the keys for each queue */
1899 for (i = 0; i < num_queues; ++i) {
1900 queue = &info->queues[i];
1901 err = write_queue_xenstore_keys(queue, &xbt, 1); /* hierarchical */
1902 if (err)
1903 goto abort_transaction_no_dev_fatal;
1904 }
1905 }
1906
1907 /* The remaining keys are not queue-specific */
1908 err = xenbus_printf(xbt, dev->nodename, "request-rx-copy", "%u",
1909 1);
1910 if (err) {
1911 message = "writing request-rx-copy";
1912 goto abort_transaction;
1913 }
1914
1915 err = xenbus_printf(xbt, dev->nodename, "feature-rx-notify", "%d", 1);
1916 if (err) {
1917 message = "writing feature-rx-notify";
1918 goto abort_transaction;
1919 }
1920
1921 err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", 1);
1922 if (err) {
1923 message = "writing feature-sg";
1924 goto abort_transaction;
1925 }
1926
1927 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4", "%d", 1);
1928 if (err) {
1929 message = "writing feature-gso-tcpv4";
1930 goto abort_transaction;
1931 }
1932
1933 err = xenbus_write(xbt, dev->nodename, "feature-gso-tcpv6", "1");
1934 if (err) {
1935 message = "writing feature-gso-tcpv6";
1936 goto abort_transaction;
1937 }
1938
1939 err = xenbus_write(xbt, dev->nodename, "feature-ipv6-csum-offload",
1940 "1");
1941 if (err) {
1942 message = "writing feature-ipv6-csum-offload";
1943 goto abort_transaction;
1944 }
1945
1946 err = xenbus_transaction_end(xbt, 0);
1947 if (err) {
1948 if (err == -EAGAIN)
1949 goto again;
1950 xenbus_dev_fatal(dev, err, "completing transaction");
1951 goto destroy_ring;
1952 }
1953
1954 return 0;
1955
1956 abort_transaction:
1957 xenbus_dev_fatal(dev, err, "%s", message);
1958 abort_transaction_no_dev_fatal:
1959 xenbus_transaction_end(xbt, 1);
1960 destroy_ring:
1961 xennet_disconnect_backend(info);
1962 kfree(info->queues);
1963 info->queues = NULL;
1964 rtnl_lock();
1965 netif_set_real_num_tx_queues(info->netdev, 0);
1966 rtnl_unlock();
1967 out:
1968 return err;
1969 }
1970
1971 static int xennet_connect(struct net_device *dev)
1972 {
1973 struct netfront_info *np = netdev_priv(dev);
1974 unsigned int num_queues = 0;
1975 int err;
1976 unsigned int feature_rx_copy;
1977 unsigned int j = 0;
1978 struct netfront_queue *queue = NULL;
1979
1980 err = xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1981 "feature-rx-copy", "%u", &feature_rx_copy);
1982 if (err != 1)
1983 feature_rx_copy = 0;
1984
1985 if (!feature_rx_copy) {
1986 dev_info(&dev->dev,
1987 "backend does not support copying receive path\n");
1988 return -ENODEV;
1989 }
1990
1991 err = talk_to_netback(np->xbdev, np);
1992 if (err)
1993 return err;
1994
1995 /* talk_to_netback() sets the correct number of queues */
1996 num_queues = dev->real_num_tx_queues;
1997
1998 rtnl_lock();
1999 netdev_update_features(dev);
2000 rtnl_unlock();
2001
2002 /*
2003 * All public and private state should now be sane. Get
2004 * ready to start sending and receiving packets and give the driver
2005 * domain a kick because we've probably just requeued some
2006 * packets.
2007 */
2008 netif_carrier_on(np->netdev);
2009 for (j = 0; j < num_queues; ++j) {
2010 queue = &np->queues[j];
2011
2012 notify_remote_via_irq(queue->tx_irq);
2013 if (queue->tx_irq != queue->rx_irq)
2014 notify_remote_via_irq(queue->rx_irq);
2015
2016 spin_lock_irq(&queue->tx_lock);
2017 xennet_tx_buf_gc(queue);
2018 spin_unlock_irq(&queue->tx_lock);
2019
2020 spin_lock_bh(&queue->rx_lock);
2021 xennet_alloc_rx_buffers(queue);
2022 spin_unlock_bh(&queue->rx_lock);
2023 }
2024
2025 return 0;
2026 }
2027
2028 /**
2029 * Callback received when the backend's state changes.
2030 */
2031 static void netback_changed(struct xenbus_device *dev,
2032 enum xenbus_state backend_state)
2033 {
2034 struct netfront_info *np = dev_get_drvdata(&dev->dev);
2035 struct net_device *netdev = np->netdev;
2036
2037 dev_dbg(&dev->dev, "%s\n", xenbus_strstate(backend_state));
2038
2039 switch (backend_state) {
2040 case XenbusStateInitialising:
2041 case XenbusStateInitialised:
2042 case XenbusStateReconfiguring:
2043 case XenbusStateReconfigured:
2044 case XenbusStateUnknown:
2045 break;
2046
2047 case XenbusStateInitWait:
2048 if (dev->state != XenbusStateInitialising)
2049 break;
2050 if (xennet_connect(netdev) != 0)
2051 break;
2052 xenbus_switch_state(dev, XenbusStateConnected);
2053 break;
2054
2055 case XenbusStateConnected:
2056 netdev_notify_peers(netdev);
2057 break;
2058
2059 case XenbusStateClosed:
2060 if (dev->state == XenbusStateClosed)
2061 break;
2062 /* Missed the backend's CLOSING state -- fallthrough */
2063 case XenbusStateClosing:
2064 xenbus_frontend_closed(dev);
2065 break;
2066 }
2067 }
2068
2069 static const struct xennet_stat {
2070 char name[ETH_GSTRING_LEN];
2071 u16 offset;
2072 } xennet_stats[] = {
2073 {
2074 "rx_gso_checksum_fixup",
2075 offsetof(struct netfront_info, rx_gso_checksum_fixup)
2076 },
2077 };
2078
2079 static int xennet_get_sset_count(struct net_device *dev, int string_set)
2080 {
2081 switch (string_set) {
2082 case ETH_SS_STATS:
2083 return ARRAY_SIZE(xennet_stats);
2084 default:
2085 return -EINVAL;
2086 }
2087 }
2088
2089 static void xennet_get_ethtool_stats(struct net_device *dev,
2090 struct ethtool_stats *stats, u64 * data)
2091 {
2092 void *np = netdev_priv(dev);
2093 int i;
2094
2095 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
2096 data[i] = atomic_read((atomic_t *)(np + xennet_stats[i].offset));
2097 }
2098
2099 static void xennet_get_strings(struct net_device *dev, u32 stringset, u8 * data)
2100 {
2101 int i;
2102
2103 switch (stringset) {
2104 case ETH_SS_STATS:
2105 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
2106 memcpy(data + i * ETH_GSTRING_LEN,
2107 xennet_stats[i].name, ETH_GSTRING_LEN);
2108 break;
2109 }
2110 }
2111
2112 static const struct ethtool_ops xennet_ethtool_ops =
2113 {
2114 .get_link = ethtool_op_get_link,
2115
2116 .get_sset_count = xennet_get_sset_count,
2117 .get_ethtool_stats = xennet_get_ethtool_stats,
2118 .get_strings = xennet_get_strings,
2119 };
2120
2121 #ifdef CONFIG_SYSFS
2122 static ssize_t show_rxbuf(struct device *dev,
2123 struct device_attribute *attr, char *buf)
2124 {
2125 return sprintf(buf, "%lu\n", NET_RX_RING_SIZE);
2126 }
2127
2128 static ssize_t store_rxbuf(struct device *dev,
2129 struct device_attribute *attr,
2130 const char *buf, size_t len)
2131 {
2132 char *endp;
2133 unsigned long target;
2134
2135 if (!capable(CAP_NET_ADMIN))
2136 return -EPERM;
2137
2138 target = simple_strtoul(buf, &endp, 0);
2139 if (endp == buf)
2140 return -EBADMSG;
2141
2142 /* rxbuf_min and rxbuf_max are no longer configurable. */
2143
2144 return len;
2145 }
2146
2147 static struct device_attribute xennet_attrs[] = {
2148 __ATTR(rxbuf_min, S_IRUGO|S_IWUSR, show_rxbuf, store_rxbuf),
2149 __ATTR(rxbuf_max, S_IRUGO|S_IWUSR, show_rxbuf, store_rxbuf),
2150 __ATTR(rxbuf_cur, S_IRUGO, show_rxbuf, NULL),
2151 };
2152
2153 static int xennet_sysfs_addif(struct net_device *netdev)
2154 {
2155 int i;
2156 int err;
2157
2158 for (i = 0; i < ARRAY_SIZE(xennet_attrs); i++) {
2159 err = device_create_file(&netdev->dev,
2160 &xennet_attrs[i]);
2161 if (err)
2162 goto fail;
2163 }
2164 return 0;
2165
2166 fail:
2167 while (--i >= 0)
2168 device_remove_file(&netdev->dev, &xennet_attrs[i]);
2169 return err;
2170 }
2171
2172 static void xennet_sysfs_delif(struct net_device *netdev)
2173 {
2174 int i;
2175
2176 for (i = 0; i < ARRAY_SIZE(xennet_attrs); i++)
2177 device_remove_file(&netdev->dev, &xennet_attrs[i]);
2178 }
2179
2180 #endif /* CONFIG_SYSFS */
2181
2182 static int xennet_remove(struct xenbus_device *dev)
2183 {
2184 struct netfront_info *info = dev_get_drvdata(&dev->dev);
2185 unsigned int num_queues = info->netdev->real_num_tx_queues;
2186 struct netfront_queue *queue = NULL;
2187 unsigned int i = 0;
2188
2189 dev_dbg(&dev->dev, "%s\n", dev->nodename);
2190
2191 xennet_disconnect_backend(info);
2192
2193 xennet_sysfs_delif(info->netdev);
2194
2195 unregister_netdev(info->netdev);
2196
2197 for (i = 0; i < num_queues; ++i) {
2198 queue = &info->queues[i];
2199 del_timer_sync(&queue->rx_refill_timer);
2200 }
2201
2202 if (num_queues) {
2203 kfree(info->queues);
2204 info->queues = NULL;
2205 }
2206
2207 xennet_free_netdev(info->netdev);
2208
2209 return 0;
2210 }
2211
2212 static const struct xenbus_device_id netfront_ids[] = {
2213 { "vif" },
2214 { "" }
2215 };
2216
2217 static struct xenbus_driver netfront_driver = {
2218 .ids = netfront_ids,
2219 .probe = netfront_probe,
2220 .remove = xennet_remove,
2221 .resume = netfront_resume,
2222 .otherend_changed = netback_changed,
2223 };
2224
2225 static int __init netif_init(void)
2226 {
2227 if (!xen_domain())
2228 return -ENODEV;
2229
2230 if (!xen_has_pv_nic_devices())
2231 return -ENODEV;
2232
2233 pr_info("Initialising Xen virtual ethernet driver\n");
2234
2235 /* Allow as many queues as there are CPUs, by default */
2236 xennet_max_queues = num_online_cpus();
2237
2238 return xenbus_register_frontend(&netfront_driver);
2239 }
2240 module_init(netif_init);
2241
2242
2243 static void __exit netif_exit(void)
2244 {
2245 xenbus_unregister_driver(&netfront_driver);
2246 }
2247 module_exit(netif_exit);
2248
2249 MODULE_DESCRIPTION("Xen virtual network device frontend");
2250 MODULE_LICENSE("GPL");
2251 MODULE_ALIAS("xen:vif");
2252 MODULE_ALIAS("xennet");
Linux kernel - Deliverables
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