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irqchip: crossbar: Introduce centralized check for crossbar write
[linux/fpc-iii.git] / drivers / net / xen-netfront.c
blob5a7872ac35661bd039633c4cb77102f40fa58dbb
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 #define TX_MAX_TARGET min_t(int, NET_TX_RING_SIZE, 256)
81
82 /* Queue name is interface name with "-qNNN" appended */
83 #define QUEUE_NAME_SIZE (IFNAMSIZ + 6)
84
85 /* IRQ name is queue name with "-tx" or "-rx" appended */
86 #define IRQ_NAME_SIZE (QUEUE_NAME_SIZE + 3)
87
88 struct netfront_stats {
89 u64 rx_packets;
90 u64 tx_packets;
91 u64 rx_bytes;
92 u64 tx_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 /* Receive-ring batched refills. */
141 #define RX_MIN_TARGET 8
142 #define RX_DFL_MIN_TARGET 64
143 #define RX_MAX_TARGET min_t(int, NET_RX_RING_SIZE, 256)
144 unsigned rx_min_target, rx_max_target, rx_target;
145 struct sk_buff_head rx_batch;
146
147 struct timer_list rx_refill_timer;
148
149 struct sk_buff *rx_skbs[NET_RX_RING_SIZE];
150 grant_ref_t gref_rx_head;
151 grant_ref_t grant_rx_ref[NET_RX_RING_SIZE];
152
153 unsigned long rx_pfn_array[NET_RX_RING_SIZE];
154 struct multicall_entry rx_mcl[NET_RX_RING_SIZE+1];
155 struct mmu_update rx_mmu[NET_RX_RING_SIZE];
156 };
157
158 struct netfront_info {
159 struct list_head list;
160 struct net_device *netdev;
161
162 struct xenbus_device *xbdev;
163
164 /* Multi-queue support */
165 struct netfront_queue *queues;
166
167 /* Statistics */
168 struct netfront_stats __percpu *stats;
169
170 atomic_t rx_gso_checksum_fixup;
171 };
172
173 struct netfront_rx_info {
174 struct xen_netif_rx_response rx;
175 struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX - 1];
176 };
177
178 static void skb_entry_set_link(union skb_entry *list, unsigned short id)
179 {
180 list->link = id;
181 }
182
183 static int skb_entry_is_link(const union skb_entry *list)
184 {
185 BUILD_BUG_ON(sizeof(list->skb) != sizeof(list->link));
186 return (unsigned long)list->skb < PAGE_OFFSET;
187 }
188
189 /*
190 * Access macros for acquiring freeing slots in tx_skbs[].
191 */
192
193 static void add_id_to_freelist(unsigned *head, union skb_entry *list,
194 unsigned short id)
195 {
196 skb_entry_set_link(&list[id], *head);
197 *head = id;
198 }
199
200 static unsigned short get_id_from_freelist(unsigned *head,
201 union skb_entry *list)
202 {
203 unsigned int id = *head;
204 *head = list[id].link;
205 return id;
206 }
207
208 static int xennet_rxidx(RING_IDX idx)
209 {
210 return idx & (NET_RX_RING_SIZE - 1);
211 }
212
213 static struct sk_buff *xennet_get_rx_skb(struct netfront_queue *queue,
214 RING_IDX ri)
215 {
216 int i = xennet_rxidx(ri);
217 struct sk_buff *skb = queue->rx_skbs[i];
218 queue->rx_skbs[i] = NULL;
219 return skb;
220 }
221
222 static grant_ref_t xennet_get_rx_ref(struct netfront_queue *queue,
223 RING_IDX ri)
224 {
225 int i = xennet_rxidx(ri);
226 grant_ref_t ref = queue->grant_rx_ref[i];
227 queue->grant_rx_ref[i] = GRANT_INVALID_REF;
228 return ref;
229 }
230
231 #ifdef CONFIG_SYSFS
232 static int xennet_sysfs_addif(struct net_device *netdev);
233 static void xennet_sysfs_delif(struct net_device *netdev);
234 #else /* !CONFIG_SYSFS */
235 #define xennet_sysfs_addif(dev) (0)
236 #define xennet_sysfs_delif(dev) do { } while (0)
237 #endif
238
239 static bool xennet_can_sg(struct net_device *dev)
240 {
241 return dev->features & NETIF_F_SG;
242 }
243
244
245 static void rx_refill_timeout(unsigned long data)
246 {
247 struct netfront_queue *queue = (struct netfront_queue *)data;
248 napi_schedule(&queue->napi);
249 }
250
251 static int netfront_tx_slot_available(struct netfront_queue *queue)
252 {
253 return (queue->tx.req_prod_pvt - queue->tx.rsp_cons) <
254 (TX_MAX_TARGET - MAX_SKB_FRAGS - 2);
255 }
256
257 static void xennet_maybe_wake_tx(struct netfront_queue *queue)
258 {
259 struct net_device *dev = queue->info->netdev;
260 struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, queue->id);
261
262 if (unlikely(netif_tx_queue_stopped(dev_queue)) &&
263 netfront_tx_slot_available(queue) &&
264 likely(netif_running(dev)))
265 netif_tx_wake_queue(netdev_get_tx_queue(dev, queue->id));
266 }
267
268 static void xennet_alloc_rx_buffers(struct netfront_queue *queue)
269 {
270 unsigned short id;
271 struct sk_buff *skb;
272 struct page *page;
273 int i, batch_target, notify;
274 RING_IDX req_prod = queue->rx.req_prod_pvt;
275 grant_ref_t ref;
276 unsigned long pfn;
277 void *vaddr;
278 struct xen_netif_rx_request *req;
279
280 if (unlikely(!netif_carrier_ok(queue->info->netdev)))
281 return;
282
283 /*
284 * Allocate skbuffs greedily, even though we batch updates to the
285 * receive ring. This creates a less bursty demand on the memory
286 * allocator, so should reduce the chance of failed allocation requests
287 * both for ourself and for other kernel subsystems.
288 */
289 batch_target = queue->rx_target - (req_prod - queue->rx.rsp_cons);
290 for (i = skb_queue_len(&queue->rx_batch); i < batch_target; i++) {
291 skb = __netdev_alloc_skb(queue->info->netdev,
292 RX_COPY_THRESHOLD + NET_IP_ALIGN,
293 GFP_ATOMIC | __GFP_NOWARN);
294 if (unlikely(!skb))
295 goto no_skb;
296
297 /* Align ip header to a 16 bytes boundary */
298 skb_reserve(skb, NET_IP_ALIGN);
299
300 page = alloc_page(GFP_ATOMIC | __GFP_NOWARN);
301 if (!page) {
302 kfree_skb(skb);
303 no_skb:
304 /* Could not allocate any skbuffs. Try again later. */
305 mod_timer(&queue->rx_refill_timer,
306 jiffies + (HZ/10));
307
308 /* Any skbuffs queued for refill? Force them out. */
309 if (i != 0)
310 goto refill;
311 break;
312 }
313
314 skb_add_rx_frag(skb, 0, page, 0, 0, PAGE_SIZE);
315 __skb_queue_tail(&queue->rx_batch, skb);
316 }
317
318 /* Is the batch large enough to be worthwhile? */
319 if (i < (queue->rx_target/2)) {
320 if (req_prod > queue->rx.sring->req_prod)
321 goto push;
322 return;
323 }
324
325 /* Adjust our fill target if we risked running out of buffers. */
326 if (((req_prod - queue->rx.sring->rsp_prod) < (queue->rx_target / 4)) &&
327 ((queue->rx_target *= 2) > queue->rx_max_target))
328 queue->rx_target = queue->rx_max_target;
329
330 refill:
331 for (i = 0; ; i++) {
332 skb = __skb_dequeue(&queue->rx_batch);
333 if (skb == NULL)
334 break;
335
336 skb->dev = queue->info->netdev;
337
338 id = xennet_rxidx(req_prod + i);
339
340 BUG_ON(queue->rx_skbs[id]);
341 queue->rx_skbs[id] = skb;
342
343 ref = gnttab_claim_grant_reference(&queue->gref_rx_head);
344 BUG_ON((signed short)ref < 0);
345 queue->grant_rx_ref[id] = ref;
346
347 pfn = page_to_pfn(skb_frag_page(&skb_shinfo(skb)->frags[0]));
348 vaddr = page_address(skb_frag_page(&skb_shinfo(skb)->frags[0]));
349
350 req = RING_GET_REQUEST(&queue->rx, req_prod + i);
351 gnttab_grant_foreign_access_ref(ref,
352 queue->info->xbdev->otherend_id,
353 pfn_to_mfn(pfn),
354 0);
355
356 req->id = id;
357 req->gref = ref;
358 }
359
360 wmb(); /* barrier so backend seens requests */
361
362 /* Above is a suitable barrier to ensure backend will see requests. */
363 queue->rx.req_prod_pvt = req_prod + i;
364 push:
365 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->rx, notify);
366 if (notify)
367 notify_remote_via_irq(queue->rx_irq);
368 }
369
370 static int xennet_open(struct net_device *dev)
371 {
372 struct netfront_info *np = netdev_priv(dev);
373 unsigned int num_queues = dev->real_num_tx_queues;
374 unsigned int i = 0;
375 struct netfront_queue *queue = NULL;
376
377 for (i = 0; i < num_queues; ++i) {
378 queue = &np->queues[i];
379 napi_enable(&queue->napi);
380
381 spin_lock_bh(&queue->rx_lock);
382 if (netif_carrier_ok(dev)) {
383 xennet_alloc_rx_buffers(queue);
384 queue->rx.sring->rsp_event = queue->rx.rsp_cons + 1;
385 if (RING_HAS_UNCONSUMED_RESPONSES(&queue->rx))
386 napi_schedule(&queue->napi);
387 }
388 spin_unlock_bh(&queue->rx_lock);
389 }
390
391 netif_tx_start_all_queues(dev);
392
393 return 0;
394 }
395
396 static void xennet_tx_buf_gc(struct netfront_queue *queue)
397 {
398 RING_IDX cons, prod;
399 unsigned short id;
400 struct sk_buff *skb;
401
402 BUG_ON(!netif_carrier_ok(queue->info->netdev));
403
404 do {
405 prod = queue->tx.sring->rsp_prod;
406 rmb(); /* Ensure we see responses up to 'rp'. */
407
408 for (cons = queue->tx.rsp_cons; cons != prod; cons++) {
409 struct xen_netif_tx_response *txrsp;
410
411 txrsp = RING_GET_RESPONSE(&queue->tx, cons);
412 if (txrsp->status == XEN_NETIF_RSP_NULL)
413 continue;
414
415 id = txrsp->id;
416 skb = queue->tx_skbs[id].skb;
417 if (unlikely(gnttab_query_foreign_access(
418 queue->grant_tx_ref[id]) != 0)) {
419 pr_alert("%s: warning -- grant still in use by backend domain\n",
420 __func__);
421 BUG();
422 }
423 gnttab_end_foreign_access_ref(
424 queue->grant_tx_ref[id], GNTMAP_readonly);
425 gnttab_release_grant_reference(
426 &queue->gref_tx_head, queue->grant_tx_ref[id]);
427 queue->grant_tx_ref[id] = GRANT_INVALID_REF;
428 queue->grant_tx_page[id] = NULL;
429 add_id_to_freelist(&queue->tx_skb_freelist, queue->tx_skbs, id);
430 dev_kfree_skb_irq(skb);
431 }
432
433 queue->tx.rsp_cons = prod;
434
435 /*
436 * Set a new event, then check for race with update of tx_cons.
437 * Note that it is essential to schedule a callback, no matter
438 * how few buffers are pending. Even if there is space in the
439 * transmit ring, higher layers may be blocked because too much
440 * data is outstanding: in such cases notification from Xen is
441 * likely to be the only kick that we'll get.
442 */
443 queue->tx.sring->rsp_event =
444 prod + ((queue->tx.sring->req_prod - prod) >> 1) + 1;
445 mb(); /* update shared area */
446 } while ((cons == prod) && (prod != queue->tx.sring->rsp_prod));
447
448 xennet_maybe_wake_tx(queue);
449 }
450
451 static void xennet_make_frags(struct sk_buff *skb, struct netfront_queue *queue,
452 struct xen_netif_tx_request *tx)
453 {
454 char *data = skb->data;
455 unsigned long mfn;
456 RING_IDX prod = queue->tx.req_prod_pvt;
457 int frags = skb_shinfo(skb)->nr_frags;
458 unsigned int offset = offset_in_page(data);
459 unsigned int len = skb_headlen(skb);
460 unsigned int id;
461 grant_ref_t ref;
462 int i;
463
464 /* While the header overlaps a page boundary (including being
465 larger than a page), split it it into page-sized chunks. */
466 while (len > PAGE_SIZE - offset) {
467 tx->size = PAGE_SIZE - offset;
468 tx->flags |= XEN_NETTXF_more_data;
469 len -= tx->size;
470 data += tx->size;
471 offset = 0;
472
473 id = get_id_from_freelist(&queue->tx_skb_freelist, queue->tx_skbs);
474 queue->tx_skbs[id].skb = skb_get(skb);
475 tx = RING_GET_REQUEST(&queue->tx, prod++);
476 tx->id = id;
477 ref = gnttab_claim_grant_reference(&queue->gref_tx_head);
478 BUG_ON((signed short)ref < 0);
479
480 mfn = virt_to_mfn(data);
481 gnttab_grant_foreign_access_ref(ref, queue->info->xbdev->otherend_id,
482 mfn, GNTMAP_readonly);
483
484 queue->grant_tx_page[id] = virt_to_page(data);
485 tx->gref = queue->grant_tx_ref[id] = ref;
486 tx->offset = offset;
487 tx->size = len;
488 tx->flags = 0;
489 }
490
491 /* Grant backend access to each skb fragment page. */
492 for (i = 0; i < frags; i++) {
493 skb_frag_t *frag = skb_shinfo(skb)->frags + i;
494 struct page *page = skb_frag_page(frag);
495
496 len = skb_frag_size(frag);
497 offset = frag->page_offset;
498
499 /* Data must not cross a page boundary. */
500 BUG_ON(len + offset > PAGE_SIZE<<compound_order(page));
501
502 /* Skip unused frames from start of page */
503 page += offset >> PAGE_SHIFT;
504 offset &= ~PAGE_MASK;
505
506 while (len > 0) {
507 unsigned long bytes;
508
509 BUG_ON(offset >= PAGE_SIZE);
510
511 bytes = PAGE_SIZE - offset;
512 if (bytes > len)
513 bytes = len;
514
515 tx->flags |= XEN_NETTXF_more_data;
516
517 id = get_id_from_freelist(&queue->tx_skb_freelist,
518 queue->tx_skbs);
519 queue->tx_skbs[id].skb = skb_get(skb);
520 tx = RING_GET_REQUEST(&queue->tx, prod++);
521 tx->id = id;
522 ref = gnttab_claim_grant_reference(&queue->gref_tx_head);
523 BUG_ON((signed short)ref < 0);
524
525 mfn = pfn_to_mfn(page_to_pfn(page));
526 gnttab_grant_foreign_access_ref(ref,
527 queue->info->xbdev->otherend_id,
528 mfn, GNTMAP_readonly);
529
530 queue->grant_tx_page[id] = page;
531 tx->gref = queue->grant_tx_ref[id] = ref;
532 tx->offset = offset;
533 tx->size = bytes;
534 tx->flags = 0;
535
536 offset += bytes;
537 len -= bytes;
538
539 /* Next frame */
540 if (offset == PAGE_SIZE && len) {
541 BUG_ON(!PageCompound(page));
542 page++;
543 offset = 0;
544 }
545 }
546 }
547
548 queue->tx.req_prod_pvt = prod;
549 }
550
551 /*
552 * Count how many ring slots are required to send the frags of this
553 * skb. Each frag might be a compound page.
554 */
555 static int xennet_count_skb_frag_slots(struct sk_buff *skb)
556 {
557 int i, frags = skb_shinfo(skb)->nr_frags;
558 int pages = 0;
559
560 for (i = 0; i < frags; i++) {
561 skb_frag_t *frag = skb_shinfo(skb)->frags + i;
562 unsigned long size = skb_frag_size(frag);
563 unsigned long offset = frag->page_offset;
564
565 /* Skip unused frames from start of page */
566 offset &= ~PAGE_MASK;
567
568 pages += PFN_UP(offset + size);
569 }
570
571 return pages;
572 }
573
574 static u16 xennet_select_queue(struct net_device *dev, struct sk_buff *skb,
575 void *accel_priv, select_queue_fallback_t fallback)
576 {
577 unsigned int num_queues = dev->real_num_tx_queues;
578 u32 hash;
579 u16 queue_idx;
580
581 /* First, check if there is only one queue */
582 if (num_queues == 1) {
583 queue_idx = 0;
584 } else {
585 hash = skb_get_hash(skb);
586 queue_idx = hash % num_queues;
587 }
588
589 return queue_idx;
590 }
591
592 static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev)
593 {
594 unsigned short id;
595 struct netfront_info *np = netdev_priv(dev);
596 struct netfront_stats *stats = this_cpu_ptr(np->stats);
597 struct xen_netif_tx_request *tx;
598 char *data = skb->data;
599 RING_IDX i;
600 grant_ref_t ref;
601 unsigned long mfn;
602 int notify;
603 int slots;
604 unsigned int offset = offset_in_page(data);
605 unsigned int len = skb_headlen(skb);
606 unsigned long flags;
607 struct netfront_queue *queue = NULL;
608 unsigned int num_queues = dev->real_num_tx_queues;
609 u16 queue_index;
610
611 /* Drop the packet if no queues are set up */
612 if (num_queues < 1)
613 goto drop;
614 /* Determine which queue to transmit this SKB on */
615 queue_index = skb_get_queue_mapping(skb);
616 queue = &np->queues[queue_index];
617
618 /* If skb->len is too big for wire format, drop skb and alert
619 * user about misconfiguration.
620 */
621 if (unlikely(skb->len > XEN_NETIF_MAX_TX_SIZE)) {
622 net_alert_ratelimited(
623 "xennet: skb->len = %u, too big for wire format\n",
624 skb->len);
625 goto drop;
626 }
627
628 slots = DIV_ROUND_UP(offset + len, PAGE_SIZE) +
629 xennet_count_skb_frag_slots(skb);
630 if (unlikely(slots > MAX_SKB_FRAGS + 1)) {
631 net_alert_ratelimited(
632 "xennet: skb rides the rocket: %d slots\n", slots);
633 goto drop;
634 }
635
636 spin_lock_irqsave(&queue->tx_lock, flags);
637
638 if (unlikely(!netif_carrier_ok(dev) ||
639 (slots > 1 && !xennet_can_sg(dev)) ||
640 netif_needs_gso(skb, netif_skb_features(skb)))) {
641 spin_unlock_irqrestore(&queue->tx_lock, flags);
642 goto drop;
643 }
644
645 i = queue->tx.req_prod_pvt;
646
647 id = get_id_from_freelist(&queue->tx_skb_freelist, queue->tx_skbs);
648 queue->tx_skbs[id].skb = skb;
649
650 tx = RING_GET_REQUEST(&queue->tx, i);
651
652 tx->id = id;
653 ref = gnttab_claim_grant_reference(&queue->gref_tx_head);
654 BUG_ON((signed short)ref < 0);
655 mfn = virt_to_mfn(data);
656 gnttab_grant_foreign_access_ref(
657 ref, queue->info->xbdev->otherend_id, mfn, GNTMAP_readonly);
658 queue->grant_tx_page[id] = virt_to_page(data);
659 tx->gref = queue->grant_tx_ref[id] = ref;
660 tx->offset = offset;
661 tx->size = len;
662
663 tx->flags = 0;
664 if (skb->ip_summed == CHECKSUM_PARTIAL)
665 /* local packet? */
666 tx->flags |= XEN_NETTXF_csum_blank | XEN_NETTXF_data_validated;
667 else if (skb->ip_summed == CHECKSUM_UNNECESSARY)
668 /* remote but checksummed. */
669 tx->flags |= XEN_NETTXF_data_validated;
670
671 if (skb_shinfo(skb)->gso_size) {
672 struct xen_netif_extra_info *gso;
673
674 gso = (struct xen_netif_extra_info *)
675 RING_GET_REQUEST(&queue->tx, ++i);
676
677 tx->flags |= XEN_NETTXF_extra_info;
678
679 gso->u.gso.size = skb_shinfo(skb)->gso_size;
680 gso->u.gso.type = (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) ?
681 XEN_NETIF_GSO_TYPE_TCPV6 :
682 XEN_NETIF_GSO_TYPE_TCPV4;
683 gso->u.gso.pad = 0;
684 gso->u.gso.features = 0;
685
686 gso->type = XEN_NETIF_EXTRA_TYPE_GSO;
687 gso->flags = 0;
688 }
689
690 queue->tx.req_prod_pvt = i + 1;
691
692 xennet_make_frags(skb, queue, tx);
693 tx->size = skb->len;
694
695 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->tx, notify);
696 if (notify)
697 notify_remote_via_irq(queue->tx_irq);
698
699 u64_stats_update_begin(&stats->syncp);
700 stats->tx_bytes += skb->len;
701 stats->tx_packets++;
702 u64_stats_update_end(&stats->syncp);
703
704 /* Note: It is not safe to access skb after xennet_tx_buf_gc()! */
705 xennet_tx_buf_gc(queue);
706
707 if (!netfront_tx_slot_available(queue))
708 netif_tx_stop_queue(netdev_get_tx_queue(dev, queue->id));
709
710 spin_unlock_irqrestore(&queue->tx_lock, flags);
711
712 return NETDEV_TX_OK;
713
714 drop:
715 dev->stats.tx_dropped++;
716 dev_kfree_skb_any(skb);
717 return NETDEV_TX_OK;
718 }
719
720 static int xennet_close(struct net_device *dev)
721 {
722 struct netfront_info *np = netdev_priv(dev);
723 unsigned int num_queues = dev->real_num_tx_queues;
724 unsigned int i;
725 struct netfront_queue *queue;
726 netif_tx_stop_all_queues(np->netdev);
727 for (i = 0; i < num_queues; ++i) {
728 queue = &np->queues[i];
729 napi_disable(&queue->napi);
730 }
731 return 0;
732 }
733
734 static void xennet_move_rx_slot(struct netfront_queue *queue, struct sk_buff *skb,
735 grant_ref_t ref)
736 {
737 int new = xennet_rxidx(queue->rx.req_prod_pvt);
738
739 BUG_ON(queue->rx_skbs[new]);
740 queue->rx_skbs[new] = skb;
741 queue->grant_rx_ref[new] = ref;
742 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->id = new;
743 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->gref = ref;
744 queue->rx.req_prod_pvt++;
745 }
746
747 static int xennet_get_extras(struct netfront_queue *queue,
748 struct xen_netif_extra_info *extras,
749 RING_IDX rp)
750
751 {
752 struct xen_netif_extra_info *extra;
753 struct device *dev = &queue->info->netdev->dev;
754 RING_IDX cons = queue->rx.rsp_cons;
755 int err = 0;
756
757 do {
758 struct sk_buff *skb;
759 grant_ref_t ref;
760
761 if (unlikely(cons + 1 == rp)) {
762 if (net_ratelimit())
763 dev_warn(dev, "Missing extra info\n");
764 err = -EBADR;
765 break;
766 }
767
768 extra = (struct xen_netif_extra_info *)
769 RING_GET_RESPONSE(&queue->rx, ++cons);
770
771 if (unlikely(!extra->type ||
772 extra->type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
773 if (net_ratelimit())
774 dev_warn(dev, "Invalid extra type: %d\n",
775 extra->type);
776 err = -EINVAL;
777 } else {
778 memcpy(&extras[extra->type - 1], extra,
779 sizeof(*extra));
780 }
781
782 skb = xennet_get_rx_skb(queue, cons);
783 ref = xennet_get_rx_ref(queue, cons);
784 xennet_move_rx_slot(queue, skb, ref);
785 } while (extra->flags & XEN_NETIF_EXTRA_FLAG_MORE);
786
787 queue->rx.rsp_cons = cons;
788 return err;
789 }
790
791 static int xennet_get_responses(struct netfront_queue *queue,
792 struct netfront_rx_info *rinfo, RING_IDX rp,
793 struct sk_buff_head *list)
794 {
795 struct xen_netif_rx_response *rx = &rinfo->rx;
796 struct xen_netif_extra_info *extras = rinfo->extras;
797 struct device *dev = &queue->info->netdev->dev;
798 RING_IDX cons = queue->rx.rsp_cons;
799 struct sk_buff *skb = xennet_get_rx_skb(queue, cons);
800 grant_ref_t ref = xennet_get_rx_ref(queue, cons);
801 int max = MAX_SKB_FRAGS + (rx->status <= RX_COPY_THRESHOLD);
802 int slots = 1;
803 int err = 0;
804 unsigned long ret;
805
806 if (rx->flags & XEN_NETRXF_extra_info) {
807 err = xennet_get_extras(queue, extras, rp);
808 cons = queue->rx.rsp_cons;
809 }
810
811 for (;;) {
812 if (unlikely(rx->status < 0 ||
813 rx->offset + rx->status > PAGE_SIZE)) {
814 if (net_ratelimit())
815 dev_warn(dev, "rx->offset: %x, size: %u\n",
816 rx->offset, rx->status);
817 xennet_move_rx_slot(queue, skb, ref);
818 err = -EINVAL;
819 goto next;
820 }
821
822 /*
823 * This definitely indicates a bug, either in this driver or in
824 * the backend driver. In future this should flag the bad
825 * situation to the system controller to reboot the backend.
826 */
827 if (ref == GRANT_INVALID_REF) {
828 if (net_ratelimit())
829 dev_warn(dev, "Bad rx response id %d.\n",
830 rx->id);
831 err = -EINVAL;
832 goto next;
833 }
834
835 ret = gnttab_end_foreign_access_ref(ref, 0);
836 BUG_ON(!ret);
837
838 gnttab_release_grant_reference(&queue->gref_rx_head, ref);
839
840 __skb_queue_tail(list, skb);
841
842 next:
843 if (!(rx->flags & XEN_NETRXF_more_data))
844 break;
845
846 if (cons + slots == rp) {
847 if (net_ratelimit())
848 dev_warn(dev, "Need more slots\n");
849 err = -ENOENT;
850 break;
851 }
852
853 rx = RING_GET_RESPONSE(&queue->rx, cons + slots);
854 skb = xennet_get_rx_skb(queue, cons + slots);
855 ref = xennet_get_rx_ref(queue, cons + slots);
856 slots++;
857 }
858
859 if (unlikely(slots > max)) {
860 if (net_ratelimit())
861 dev_warn(dev, "Too many slots\n");
862 err = -E2BIG;
863 }
864
865 if (unlikely(err))
866 queue->rx.rsp_cons = cons + slots;
867
868 return err;
869 }
870
871 static int xennet_set_skb_gso(struct sk_buff *skb,
872 struct xen_netif_extra_info *gso)
873 {
874 if (!gso->u.gso.size) {
875 if (net_ratelimit())
876 pr_warn("GSO size must not be zero\n");
877 return -EINVAL;
878 }
879
880 if (gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV4 &&
881 gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV6) {
882 if (net_ratelimit())
883 pr_warn("Bad GSO type %d\n", gso->u.gso.type);
884 return -EINVAL;
885 }
886
887 skb_shinfo(skb)->gso_size = gso->u.gso.size;
888 skb_shinfo(skb)->gso_type =
889 (gso->u.gso.type == XEN_NETIF_GSO_TYPE_TCPV4) ?
890 SKB_GSO_TCPV4 :
891 SKB_GSO_TCPV6;
892
893 /* Header must be checked, and gso_segs computed. */
894 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
895 skb_shinfo(skb)->gso_segs = 0;
896
897 return 0;
898 }
899
900 static RING_IDX xennet_fill_frags(struct netfront_queue *queue,
901 struct sk_buff *skb,
902 struct sk_buff_head *list)
903 {
904 struct skb_shared_info *shinfo = skb_shinfo(skb);
905 RING_IDX cons = queue->rx.rsp_cons;
906 struct sk_buff *nskb;
907
908 while ((nskb = __skb_dequeue(list))) {
909 struct xen_netif_rx_response *rx =
910 RING_GET_RESPONSE(&queue->rx, ++cons);
911 skb_frag_t *nfrag = &skb_shinfo(nskb)->frags[0];
912
913 if (shinfo->nr_frags == MAX_SKB_FRAGS) {
914 unsigned int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
915
916 BUG_ON(pull_to <= skb_headlen(skb));
917 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
918 }
919 BUG_ON(shinfo->nr_frags >= MAX_SKB_FRAGS);
920
921 skb_add_rx_frag(skb, shinfo->nr_frags, skb_frag_page(nfrag),
922 rx->offset, rx->status, PAGE_SIZE);
923
924 skb_shinfo(nskb)->nr_frags = 0;
925 kfree_skb(nskb);
926 }
927
928 return cons;
929 }
930
931 static int checksum_setup(struct net_device *dev, struct sk_buff *skb)
932 {
933 bool recalculate_partial_csum = false;
934
935 /*
936 * A GSO SKB must be CHECKSUM_PARTIAL. However some buggy
937 * peers can fail to set NETRXF_csum_blank when sending a GSO
938 * frame. In this case force the SKB to CHECKSUM_PARTIAL and
939 * recalculate the partial checksum.
940 */
941 if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) {
942 struct netfront_info *np = netdev_priv(dev);
943 atomic_inc(&np->rx_gso_checksum_fixup);
944 skb->ip_summed = CHECKSUM_PARTIAL;
945 recalculate_partial_csum = true;
946 }
947
948 /* A non-CHECKSUM_PARTIAL SKB does not require setup. */
949 if (skb->ip_summed != CHECKSUM_PARTIAL)
950 return 0;
951
952 return skb_checksum_setup(skb, recalculate_partial_csum);
953 }
954
955 static int handle_incoming_queue(struct netfront_queue *queue,
956 struct sk_buff_head *rxq)
957 {
958 struct netfront_stats *stats = this_cpu_ptr(queue->info->stats);
959 int packets_dropped = 0;
960 struct sk_buff *skb;
961
962 while ((skb = __skb_dequeue(rxq)) != NULL) {
963 int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
964
965 if (pull_to > skb_headlen(skb))
966 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
967
968 /* Ethernet work: Delayed to here as it peeks the header. */
969 skb->protocol = eth_type_trans(skb, queue->info->netdev);
970 skb_reset_network_header(skb);
971
972 if (checksum_setup(queue->info->netdev, skb)) {
973 kfree_skb(skb);
974 packets_dropped++;
975 queue->info->netdev->stats.rx_errors++;
976 continue;
977 }
978
979 u64_stats_update_begin(&stats->syncp);
980 stats->rx_packets++;
981 stats->rx_bytes += skb->len;
982 u64_stats_update_end(&stats->syncp);
983
984 /* Pass it up. */
985 napi_gro_receive(&queue->napi, skb);
986 }
987
988 return packets_dropped;
989 }
990
991 static int xennet_poll(struct napi_struct *napi, int budget)
992 {
993 struct netfront_queue *queue = container_of(napi, struct netfront_queue, napi);
994 struct net_device *dev = queue->info->netdev;
995 struct sk_buff *skb;
996 struct netfront_rx_info rinfo;
997 struct xen_netif_rx_response *rx = &rinfo.rx;
998 struct xen_netif_extra_info *extras = rinfo.extras;
999 RING_IDX i, rp;
1000 int work_done;
1001 struct sk_buff_head rxq;
1002 struct sk_buff_head errq;
1003 struct sk_buff_head tmpq;
1004 unsigned long flags;
1005 int err;
1006
1007 spin_lock(&queue->rx_lock);
1008
1009 skb_queue_head_init(&rxq);
1010 skb_queue_head_init(&errq);
1011 skb_queue_head_init(&tmpq);
1012
1013 rp = queue->rx.sring->rsp_prod;
1014 rmb(); /* Ensure we see queued responses up to 'rp'. */
1015
1016 i = queue->rx.rsp_cons;
1017 work_done = 0;
1018 while ((i != rp) && (work_done < budget)) {
1019 memcpy(rx, RING_GET_RESPONSE(&queue->rx, i), sizeof(*rx));
1020 memset(extras, 0, sizeof(rinfo.extras));
1021
1022 err = xennet_get_responses(queue, &rinfo, rp, &tmpq);
1023
1024 if (unlikely(err)) {
1025 err:
1026 while ((skb = __skb_dequeue(&tmpq)))
1027 __skb_queue_tail(&errq, skb);
1028 dev->stats.rx_errors++;
1029 i = queue->rx.rsp_cons;
1030 continue;
1031 }
1032
1033 skb = __skb_dequeue(&tmpq);
1034
1035 if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) {
1036 struct xen_netif_extra_info *gso;
1037 gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1];
1038
1039 if (unlikely(xennet_set_skb_gso(skb, gso))) {
1040 __skb_queue_head(&tmpq, skb);
1041 queue->rx.rsp_cons += skb_queue_len(&tmpq);
1042 goto err;
1043 }
1044 }
1045
1046 NETFRONT_SKB_CB(skb)->pull_to = rx->status;
1047 if (NETFRONT_SKB_CB(skb)->pull_to > RX_COPY_THRESHOLD)
1048 NETFRONT_SKB_CB(skb)->pull_to = RX_COPY_THRESHOLD;
1049
1050 skb_shinfo(skb)->frags[0].page_offset = rx->offset;
1051 skb_frag_size_set(&skb_shinfo(skb)->frags[0], rx->status);
1052 skb->data_len = rx->status;
1053 skb->len += rx->status;
1054
1055 i = xennet_fill_frags(queue, skb, &tmpq);
1056
1057 if (rx->flags & XEN_NETRXF_csum_blank)
1058 skb->ip_summed = CHECKSUM_PARTIAL;
1059 else if (rx->flags & XEN_NETRXF_data_validated)
1060 skb->ip_summed = CHECKSUM_UNNECESSARY;
1061
1062 __skb_queue_tail(&rxq, skb);
1063
1064 queue->rx.rsp_cons = ++i;
1065 work_done++;
1066 }
1067
1068 __skb_queue_purge(&errq);
1069
1070 work_done -= handle_incoming_queue(queue, &rxq);
1071
1072 /* If we get a callback with very few responses, reduce fill target. */
1073 /* NB. Note exponential increase, linear decrease. */
1074 if (((queue->rx.req_prod_pvt - queue->rx.sring->rsp_prod) >
1075 ((3*queue->rx_target) / 4)) &&
1076 (--queue->rx_target < queue->rx_min_target))
1077 queue->rx_target = queue->rx_min_target;
1078
1079 xennet_alloc_rx_buffers(queue);
1080
1081 if (work_done < budget) {
1082 int more_to_do = 0;
1083
1084 napi_gro_flush(napi, false);
1085
1086 local_irq_save(flags);
1087
1088 RING_FINAL_CHECK_FOR_RESPONSES(&queue->rx, more_to_do);
1089 if (!more_to_do)
1090 __napi_complete(napi);
1091
1092 local_irq_restore(flags);
1093 }
1094
1095 spin_unlock(&queue->rx_lock);
1096
1097 return work_done;
1098 }
1099
1100 static int xennet_change_mtu(struct net_device *dev, int mtu)
1101 {
1102 int max = xennet_can_sg(dev) ?
1103 XEN_NETIF_MAX_TX_SIZE - MAX_TCP_HEADER : ETH_DATA_LEN;
1104
1105 if (mtu > max)
1106 return -EINVAL;
1107 dev->mtu = mtu;
1108 return 0;
1109 }
1110
1111 static struct rtnl_link_stats64 *xennet_get_stats64(struct net_device *dev,
1112 struct rtnl_link_stats64 *tot)
1113 {
1114 struct netfront_info *np = netdev_priv(dev);
1115 int cpu;
1116
1117 for_each_possible_cpu(cpu) {
1118 struct netfront_stats *stats = per_cpu_ptr(np->stats, cpu);
1119 u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
1120 unsigned int start;
1121
1122 do {
1123 start = u64_stats_fetch_begin_irq(&stats->syncp);
1124
1125 rx_packets = stats->rx_packets;
1126 tx_packets = stats->tx_packets;
1127 rx_bytes = stats->rx_bytes;
1128 tx_bytes = stats->tx_bytes;
1129 } while (u64_stats_fetch_retry_irq(&stats->syncp, start));
1130
1131 tot->rx_packets += rx_packets;
1132 tot->tx_packets += tx_packets;
1133 tot->rx_bytes += rx_bytes;
1134 tot->tx_bytes += tx_bytes;
1135 }
1136
1137 tot->rx_errors = dev->stats.rx_errors;
1138 tot->tx_dropped = dev->stats.tx_dropped;
1139
1140 return tot;
1141 }
1142
1143 static void xennet_release_tx_bufs(struct netfront_queue *queue)
1144 {
1145 struct sk_buff *skb;
1146 int i;
1147
1148 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1149 /* Skip over entries which are actually freelist references */
1150 if (skb_entry_is_link(&queue->tx_skbs[i]))
1151 continue;
1152
1153 skb = queue->tx_skbs[i].skb;
1154 get_page(queue->grant_tx_page[i]);
1155 gnttab_end_foreign_access(queue->grant_tx_ref[i],
1156 GNTMAP_readonly,
1157 (unsigned long)page_address(queue->grant_tx_page[i]));
1158 queue->grant_tx_page[i] = NULL;
1159 queue->grant_tx_ref[i] = GRANT_INVALID_REF;
1160 add_id_to_freelist(&queue->tx_skb_freelist, queue->tx_skbs, i);
1161 dev_kfree_skb_irq(skb);
1162 }
1163 }
1164
1165 static void xennet_release_rx_bufs(struct netfront_queue *queue)
1166 {
1167 int id, ref;
1168
1169 spin_lock_bh(&queue->rx_lock);
1170
1171 for (id = 0; id < NET_RX_RING_SIZE; id++) {
1172 struct sk_buff *skb;
1173 struct page *page;
1174
1175 skb = queue->rx_skbs[id];
1176 if (!skb)
1177 continue;
1178
1179 ref = queue->grant_rx_ref[id];
1180 if (ref == GRANT_INVALID_REF)
1181 continue;
1182
1183 page = skb_frag_page(&skb_shinfo(skb)->frags[0]);
1184
1185 /* gnttab_end_foreign_access() needs a page ref until
1186 * foreign access is ended (which may be deferred).
1187 */
1188 get_page(page);
1189 gnttab_end_foreign_access(ref, 0,
1190 (unsigned long)page_address(page));
1191 queue->grant_rx_ref[id] = GRANT_INVALID_REF;
1192
1193 kfree_skb(skb);
1194 }
1195
1196 spin_unlock_bh(&queue->rx_lock);
1197 }
1198
1199 static void xennet_uninit(struct net_device *dev)
1200 {
1201 struct netfront_info *np = netdev_priv(dev);
1202 unsigned int num_queues = dev->real_num_tx_queues;
1203 struct netfront_queue *queue;
1204 unsigned int i;
1205
1206 for (i = 0; i < num_queues; ++i) {
1207 queue = &np->queues[i];
1208 xennet_release_tx_bufs(queue);
1209 xennet_release_rx_bufs(queue);
1210 gnttab_free_grant_references(queue->gref_tx_head);
1211 gnttab_free_grant_references(queue->gref_rx_head);
1212 }
1213 }
1214
1215 static netdev_features_t xennet_fix_features(struct net_device *dev,
1216 netdev_features_t features)
1217 {
1218 struct netfront_info *np = netdev_priv(dev);
1219 int val;
1220
1221 if (features & NETIF_F_SG) {
1222 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, "feature-sg",
1223 "%d", &val) < 0)
1224 val = 0;
1225
1226 if (!val)
1227 features &= ~NETIF_F_SG;
1228 }
1229
1230 if (features & NETIF_F_IPV6_CSUM) {
1231 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1232 "feature-ipv6-csum-offload", "%d", &val) < 0)
1233 val = 0;
1234
1235 if (!val)
1236 features &= ~NETIF_F_IPV6_CSUM;
1237 }
1238
1239 if (features & NETIF_F_TSO) {
1240 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1241 "feature-gso-tcpv4", "%d", &val) < 0)
1242 val = 0;
1243
1244 if (!val)
1245 features &= ~NETIF_F_TSO;
1246 }
1247
1248 if (features & NETIF_F_TSO6) {
1249 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1250 "feature-gso-tcpv6", "%d", &val) < 0)
1251 val = 0;
1252
1253 if (!val)
1254 features &= ~NETIF_F_TSO6;
1255 }
1256
1257 return features;
1258 }
1259
1260 static int xennet_set_features(struct net_device *dev,
1261 netdev_features_t features)
1262 {
1263 if (!(features & NETIF_F_SG) && dev->mtu > ETH_DATA_LEN) {
1264 netdev_info(dev, "Reducing MTU because no SG offload");
1265 dev->mtu = ETH_DATA_LEN;
1266 }
1267
1268 return 0;
1269 }
1270
1271 static irqreturn_t xennet_tx_interrupt(int irq, void *dev_id)
1272 {
1273 struct netfront_queue *queue = dev_id;
1274 unsigned long flags;
1275
1276 spin_lock_irqsave(&queue->tx_lock, flags);
1277 xennet_tx_buf_gc(queue);
1278 spin_unlock_irqrestore(&queue->tx_lock, flags);
1279
1280 return IRQ_HANDLED;
1281 }
1282
1283 static irqreturn_t xennet_rx_interrupt(int irq, void *dev_id)
1284 {
1285 struct netfront_queue *queue = dev_id;
1286 struct net_device *dev = queue->info->netdev;
1287
1288 if (likely(netif_carrier_ok(dev) &&
1289 RING_HAS_UNCONSUMED_RESPONSES(&queue->rx)))
1290 napi_schedule(&queue->napi);
1291
1292 return IRQ_HANDLED;
1293 }
1294
1295 static irqreturn_t xennet_interrupt(int irq, void *dev_id)
1296 {
1297 xennet_tx_interrupt(irq, dev_id);
1298 xennet_rx_interrupt(irq, dev_id);
1299 return IRQ_HANDLED;
1300 }
1301
1302 #ifdef CONFIG_NET_POLL_CONTROLLER
1303 static void xennet_poll_controller(struct net_device *dev)
1304 {
1305 /* Poll each queue */
1306 struct netfront_info *info = netdev_priv(dev);
1307 unsigned int num_queues = dev->real_num_tx_queues;
1308 unsigned int i;
1309 for (i = 0; i < num_queues; ++i)
1310 xennet_interrupt(0, &info->queues[i]);
1311 }
1312 #endif
1313
1314 static const struct net_device_ops xennet_netdev_ops = {
1315 .ndo_open = xennet_open,
1316 .ndo_uninit = xennet_uninit,
1317 .ndo_stop = xennet_close,
1318 .ndo_start_xmit = xennet_start_xmit,
1319 .ndo_change_mtu = xennet_change_mtu,
1320 .ndo_get_stats64 = xennet_get_stats64,
1321 .ndo_set_mac_address = eth_mac_addr,
1322 .ndo_validate_addr = eth_validate_addr,
1323 .ndo_fix_features = xennet_fix_features,
1324 .ndo_set_features = xennet_set_features,
1325 .ndo_select_queue = xennet_select_queue,
1326 #ifdef CONFIG_NET_POLL_CONTROLLER
1327 .ndo_poll_controller = xennet_poll_controller,
1328 #endif
1329 };
1330
1331 static struct net_device *xennet_create_dev(struct xenbus_device *dev)
1332 {
1333 int err;
1334 struct net_device *netdev;
1335 struct netfront_info *np;
1336
1337 netdev = alloc_etherdev_mq(sizeof(struct netfront_info), xennet_max_queues);
1338 if (!netdev)
1339 return ERR_PTR(-ENOMEM);
1340
1341 np = netdev_priv(netdev);
1342 np->xbdev = dev;
1343
1344 /* No need to use rtnl_lock() before the call below as it
1345 * happens before register_netdev().
1346 */
1347 netif_set_real_num_tx_queues(netdev, 0);
1348 np->queues = NULL;
1349
1350 err = -ENOMEM;
1351 np->stats = netdev_alloc_pcpu_stats(struct netfront_stats);
1352 if (np->stats == NULL)
1353 goto exit;
1354
1355 netdev->netdev_ops = &xennet_netdev_ops;
1356
1357 netdev->features = NETIF_F_IP_CSUM | NETIF_F_RXCSUM |
1358 NETIF_F_GSO_ROBUST;
1359 netdev->hw_features = NETIF_F_SG |
1360 NETIF_F_IPV6_CSUM |
1361 NETIF_F_TSO | NETIF_F_TSO6;
1362
1363 /*
1364 * Assume that all hw features are available for now. This set
1365 * will be adjusted by the call to netdev_update_features() in
1366 * xennet_connect() which is the earliest point where we can
1367 * negotiate with the backend regarding supported features.
1368 */
1369 netdev->features |= netdev->hw_features;
1370
1371 netdev->ethtool_ops = &xennet_ethtool_ops;
1372 SET_NETDEV_DEV(netdev, &dev->dev);
1373
1374 netif_set_gso_max_size(netdev, XEN_NETIF_MAX_TX_SIZE - MAX_TCP_HEADER);
1375
1376 np->netdev = netdev;
1377
1378 netif_carrier_off(netdev);
1379
1380 return netdev;
1381
1382 exit:
1383 free_netdev(netdev);
1384 return ERR_PTR(err);
1385 }
1386
1387 /**
1388 * Entry point to this code when a new device is created. Allocate the basic
1389 * structures and the ring buffers for communication with the backend, and
1390 * inform the backend of the appropriate details for those.
1391 */
1392 static int netfront_probe(struct xenbus_device *dev,
1393 const struct xenbus_device_id *id)
1394 {
1395 int err;
1396 struct net_device *netdev;
1397 struct netfront_info *info;
1398
1399 netdev = xennet_create_dev(dev);
1400 if (IS_ERR(netdev)) {
1401 err = PTR_ERR(netdev);
1402 xenbus_dev_fatal(dev, err, "creating netdev");
1403 return err;
1404 }
1405
1406 info = netdev_priv(netdev);
1407 dev_set_drvdata(&dev->dev, info);
1408
1409 err = register_netdev(info->netdev);
1410 if (err) {
1411 pr_warn("%s: register_netdev err=%d\n", __func__, err);
1412 goto fail;
1413 }
1414
1415 err = xennet_sysfs_addif(info->netdev);
1416 if (err) {
1417 unregister_netdev(info->netdev);
1418 pr_warn("%s: add sysfs failed err=%d\n", __func__, err);
1419 goto fail;
1420 }
1421
1422 return 0;
1423
1424 fail:
1425 free_netdev(netdev);
1426 dev_set_drvdata(&dev->dev, NULL);
1427 return err;
1428 }
1429
1430 static void xennet_end_access(int ref, void *page)
1431 {
1432 /* This frees the page as a side-effect */
1433 if (ref != GRANT_INVALID_REF)
1434 gnttab_end_foreign_access(ref, 0, (unsigned long)page);
1435 }
1436
1437 static void xennet_disconnect_backend(struct netfront_info *info)
1438 {
1439 unsigned int i = 0;
1440 struct netfront_queue *queue = NULL;
1441 unsigned int num_queues = info->netdev->real_num_tx_queues;
1442
1443 for (i = 0; i < num_queues; ++i) {
1444 /* Stop old i/f to prevent errors whilst we rebuild the state. */
1445 spin_lock_bh(&queue->rx_lock);
1446 spin_lock_irq(&queue->tx_lock);
1447 netif_carrier_off(queue->info->netdev);
1448 spin_unlock_irq(&queue->tx_lock);
1449 spin_unlock_bh(&queue->rx_lock);
1450
1451 if (queue->tx_irq && (queue->tx_irq == queue->rx_irq))
1452 unbind_from_irqhandler(queue->tx_irq, queue);
1453 if (queue->tx_irq && (queue->tx_irq != queue->rx_irq)) {
1454 unbind_from_irqhandler(queue->tx_irq, queue);
1455 unbind_from_irqhandler(queue->rx_irq, queue);
1456 }
1457 queue->tx_evtchn = queue->rx_evtchn = 0;
1458 queue->tx_irq = queue->rx_irq = 0;
1459
1460 /* End access and free the pages */
1461 xennet_end_access(queue->tx_ring_ref, queue->tx.sring);
1462 xennet_end_access(queue->rx_ring_ref, queue->rx.sring);
1463
1464 queue->tx_ring_ref = GRANT_INVALID_REF;
1465 queue->rx_ring_ref = GRANT_INVALID_REF;
1466 queue->tx.sring = NULL;
1467 queue->rx.sring = NULL;
1468 }
1469 }
1470
1471 /**
1472 * We are reconnecting to the backend, due to a suspend/resume, or a backend
1473 * driver restart. We tear down our netif structure and recreate it, but
1474 * leave the device-layer structures intact so that this is transparent to the
1475 * rest of the kernel.
1476 */
1477 static int netfront_resume(struct xenbus_device *dev)
1478 {
1479 struct netfront_info *info = dev_get_drvdata(&dev->dev);
1480
1481 dev_dbg(&dev->dev, "%s\n", dev->nodename);
1482
1483 xennet_disconnect_backend(info);
1484 return 0;
1485 }
1486
1487 static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[])
1488 {
1489 char *s, *e, *macstr;
1490 int i;
1491
1492 macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL);
1493 if (IS_ERR(macstr))
1494 return PTR_ERR(macstr);
1495
1496 for (i = 0; i < ETH_ALEN; i++) {
1497 mac[i] = simple_strtoul(s, &e, 16);
1498 if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) {
1499 kfree(macstr);
1500 return -ENOENT;
1501 }
1502 s = e+1;
1503 }
1504
1505 kfree(macstr);
1506 return 0;
1507 }
1508
1509 static int setup_netfront_single(struct netfront_queue *queue)
1510 {
1511 int err;
1512
1513 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn);
1514 if (err < 0)
1515 goto fail;
1516
1517 err = bind_evtchn_to_irqhandler(queue->tx_evtchn,
1518 xennet_interrupt,
1519 0, queue->info->netdev->name, queue);
1520 if (err < 0)
1521 goto bind_fail;
1522 queue->rx_evtchn = queue->tx_evtchn;
1523 queue->rx_irq = queue->tx_irq = err;
1524
1525 return 0;
1526
1527 bind_fail:
1528 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn);
1529 queue->tx_evtchn = 0;
1530 fail:
1531 return err;
1532 }
1533
1534 static int setup_netfront_split(struct netfront_queue *queue)
1535 {
1536 int err;
1537
1538 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn);
1539 if (err < 0)
1540 goto fail;
1541 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->rx_evtchn);
1542 if (err < 0)
1543 goto alloc_rx_evtchn_fail;
1544
1545 snprintf(queue->tx_irq_name, sizeof(queue->tx_irq_name),
1546 "%s-tx", queue->name);
1547 err = bind_evtchn_to_irqhandler(queue->tx_evtchn,
1548 xennet_tx_interrupt,
1549 0, queue->tx_irq_name, queue);
1550 if (err < 0)
1551 goto bind_tx_fail;
1552 queue->tx_irq = err;
1553
1554 snprintf(queue->rx_irq_name, sizeof(queue->rx_irq_name),
1555 "%s-rx", queue->name);
1556 err = bind_evtchn_to_irqhandler(queue->rx_evtchn,
1557 xennet_rx_interrupt,
1558 0, queue->rx_irq_name, queue);
1559 if (err < 0)
1560 goto bind_rx_fail;
1561 queue->rx_irq = err;
1562
1563 return 0;
1564
1565 bind_rx_fail:
1566 unbind_from_irqhandler(queue->tx_irq, queue);
1567 queue->tx_irq = 0;
1568 bind_tx_fail:
1569 xenbus_free_evtchn(queue->info->xbdev, queue->rx_evtchn);
1570 queue->rx_evtchn = 0;
1571 alloc_rx_evtchn_fail:
1572 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn);
1573 queue->tx_evtchn = 0;
1574 fail:
1575 return err;
1576 }
1577
1578 static int setup_netfront(struct xenbus_device *dev,
1579 struct netfront_queue *queue, unsigned int feature_split_evtchn)
1580 {
1581 struct xen_netif_tx_sring *txs;
1582 struct xen_netif_rx_sring *rxs;
1583 int err;
1584
1585 queue->tx_ring_ref = GRANT_INVALID_REF;
1586 queue->rx_ring_ref = GRANT_INVALID_REF;
1587 queue->rx.sring = NULL;
1588 queue->tx.sring = NULL;
1589
1590 txs = (struct xen_netif_tx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1591 if (!txs) {
1592 err = -ENOMEM;
1593 xenbus_dev_fatal(dev, err, "allocating tx ring page");
1594 goto fail;
1595 }
1596 SHARED_RING_INIT(txs);
1597 FRONT_RING_INIT(&queue->tx, txs, PAGE_SIZE);
1598
1599 err = xenbus_grant_ring(dev, virt_to_mfn(txs));
1600 if (err < 0)
1601 goto grant_tx_ring_fail;
1602 queue->tx_ring_ref = err;
1603
1604 rxs = (struct xen_netif_rx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1605 if (!rxs) {
1606 err = -ENOMEM;
1607 xenbus_dev_fatal(dev, err, "allocating rx ring page");
1608 goto alloc_rx_ring_fail;
1609 }
1610 SHARED_RING_INIT(rxs);
1611 FRONT_RING_INIT(&queue->rx, rxs, PAGE_SIZE);
1612
1613 err = xenbus_grant_ring(dev, virt_to_mfn(rxs));
1614 if (err < 0)
1615 goto grant_rx_ring_fail;
1616 queue->rx_ring_ref = err;
1617
1618 if (feature_split_evtchn)
1619 err = setup_netfront_split(queue);
1620 /* setup single event channel if
1621 * a) feature-split-event-channels == 0
1622 * b) feature-split-event-channels == 1 but failed to setup
1623 */
1624 if (!feature_split_evtchn || (feature_split_evtchn && err))
1625 err = setup_netfront_single(queue);
1626
1627 if (err)
1628 goto alloc_evtchn_fail;
1629
1630 return 0;
1631
1632 /* If we fail to setup netfront, it is safe to just revoke access to
1633 * granted pages because backend is not accessing it at this point.
1634 */
1635 alloc_evtchn_fail:
1636 gnttab_end_foreign_access_ref(queue->rx_ring_ref, 0);
1637 grant_rx_ring_fail:
1638 free_page((unsigned long)rxs);
1639 alloc_rx_ring_fail:
1640 gnttab_end_foreign_access_ref(queue->tx_ring_ref, 0);
1641 grant_tx_ring_fail:
1642 free_page((unsigned long)txs);
1643 fail:
1644 return err;
1645 }
1646
1647 /* Queue-specific initialisation
1648 * This used to be done in xennet_create_dev() but must now
1649 * be run per-queue.
1650 */
1651 static int xennet_init_queue(struct netfront_queue *queue)
1652 {
1653 unsigned short i;
1654 int err = 0;
1655
1656 spin_lock_init(&queue->tx_lock);
1657 spin_lock_init(&queue->rx_lock);
1658
1659 skb_queue_head_init(&queue->rx_batch);
1660 queue->rx_target = RX_DFL_MIN_TARGET;
1661 queue->rx_min_target = RX_DFL_MIN_TARGET;
1662 queue->rx_max_target = RX_MAX_TARGET;
1663
1664 init_timer(&queue->rx_refill_timer);
1665 queue->rx_refill_timer.data = (unsigned long)queue;
1666 queue->rx_refill_timer.function = rx_refill_timeout;
1667
1668 snprintf(queue->name, sizeof(queue->name), "%s-q%u",
1669 queue->info->netdev->name, queue->id);
1670
1671 /* Initialise tx_skbs as a free chain containing every entry. */
1672 queue->tx_skb_freelist = 0;
1673 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1674 skb_entry_set_link(&queue->tx_skbs[i], i+1);
1675 queue->grant_tx_ref[i] = GRANT_INVALID_REF;
1676 queue->grant_tx_page[i] = NULL;
1677 }
1678
1679 /* Clear out rx_skbs */
1680 for (i = 0; i < NET_RX_RING_SIZE; i++) {
1681 queue->rx_skbs[i] = NULL;
1682 queue->grant_rx_ref[i] = GRANT_INVALID_REF;
1683 }
1684
1685 /* A grant for every tx ring slot */
1686 if (gnttab_alloc_grant_references(TX_MAX_TARGET,
1687 &queue->gref_tx_head) < 0) {
1688 pr_alert("can't alloc tx grant refs\n");
1689 err = -ENOMEM;
1690 goto exit;
1691 }
1692
1693 /* A grant for every rx ring slot */
1694 if (gnttab_alloc_grant_references(RX_MAX_TARGET,
1695 &queue->gref_rx_head) < 0) {
1696 pr_alert("can't alloc rx grant refs\n");
1697 err = -ENOMEM;
1698 goto exit_free_tx;
1699 }
1700
1701 netif_napi_add(queue->info->netdev, &queue->napi, xennet_poll, 64);
1702
1703 return 0;
1704
1705 exit_free_tx:
1706 gnttab_free_grant_references(queue->gref_tx_head);
1707 exit:
1708 return err;
1709 }
1710
1711 static int write_queue_xenstore_keys(struct netfront_queue *queue,
1712 struct xenbus_transaction *xbt, int write_hierarchical)
1713 {
1714 /* Write the queue-specific keys into XenStore in the traditional
1715 * way for a single queue, or in a queue subkeys for multiple
1716 * queues.
1717 */
1718 struct xenbus_device *dev = queue->info->xbdev;
1719 int err;
1720 const char *message;
1721 char *path;
1722 size_t pathsize;
1723
1724 /* Choose the correct place to write the keys */
1725 if (write_hierarchical) {
1726 pathsize = strlen(dev->nodename) + 10;
1727 path = kzalloc(pathsize, GFP_KERNEL);
1728 if (!path) {
1729 err = -ENOMEM;
1730 message = "out of memory while writing ring references";
1731 goto error;
1732 }
1733 snprintf(path, pathsize, "%s/queue-%u",
1734 dev->nodename, queue->id);
1735 } else {
1736 path = (char *)dev->nodename;
1737 }
1738
1739 /* Write ring references */
1740 err = xenbus_printf(*xbt, path, "tx-ring-ref", "%u",
1741 queue->tx_ring_ref);
1742 if (err) {
1743 message = "writing tx-ring-ref";
1744 goto error;
1745 }
1746
1747 err = xenbus_printf(*xbt, path, "rx-ring-ref", "%u",
1748 queue->rx_ring_ref);
1749 if (err) {
1750 message = "writing rx-ring-ref";
1751 goto error;
1752 }
1753
1754 /* Write event channels; taking into account both shared
1755 * and split event channel scenarios.
1756 */
1757 if (queue->tx_evtchn == queue->rx_evtchn) {
1758 /* Shared event channel */
1759 err = xenbus_printf(*xbt, path,
1760 "event-channel", "%u", queue->tx_evtchn);
1761 if (err) {
1762 message = "writing event-channel";
1763 goto error;
1764 }
1765 } else {
1766 /* Split event channels */
1767 err = xenbus_printf(*xbt, path,
1768 "event-channel-tx", "%u", queue->tx_evtchn);
1769 if (err) {
1770 message = "writing event-channel-tx";
1771 goto error;
1772 }
1773
1774 err = xenbus_printf(*xbt, path,
1775 "event-channel-rx", "%u", queue->rx_evtchn);
1776 if (err) {
1777 message = "writing event-channel-rx";
1778 goto error;
1779 }
1780 }
1781
1782 if (write_hierarchical)
1783 kfree(path);
1784 return 0;
1785
1786 error:
1787 if (write_hierarchical)
1788 kfree(path);
1789 xenbus_dev_fatal(dev, err, "%s", message);
1790 return err;
1791 }
1792
1793 /* Common code used when first setting up, and when resuming. */
1794 static int talk_to_netback(struct xenbus_device *dev,
1795 struct netfront_info *info)
1796 {
1797 const char *message;
1798 struct xenbus_transaction xbt;
1799 int err;
1800 unsigned int feature_split_evtchn;
1801 unsigned int i = 0;
1802 unsigned int max_queues = 0;
1803 struct netfront_queue *queue = NULL;
1804 unsigned int num_queues = 1;
1805
1806 info->netdev->irq = 0;
1807
1808 /* Check if backend supports multiple queues */
1809 err = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
1810 "multi-queue-max-queues", "%u", &max_queues);
1811 if (err < 0)
1812 max_queues = 1;
1813 num_queues = min(max_queues, xennet_max_queues);
1814
1815 /* Check feature-split-event-channels */
1816 err = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
1817 "feature-split-event-channels", "%u",
1818 &feature_split_evtchn);
1819 if (err < 0)
1820 feature_split_evtchn = 0;
1821
1822 /* Read mac addr. */
1823 err = xen_net_read_mac(dev, info->netdev->dev_addr);
1824 if (err) {
1825 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
1826 goto out;
1827 }
1828
1829 /* Allocate array of queues */
1830 info->queues = kcalloc(num_queues, sizeof(struct netfront_queue), GFP_KERNEL);
1831 if (!info->queues) {
1832 err = -ENOMEM;
1833 goto out;
1834 }
1835 rtnl_lock();
1836 netif_set_real_num_tx_queues(info->netdev, num_queues);
1837 rtnl_unlock();
1838
1839 /* Create shared ring, alloc event channel -- for each queue */
1840 for (i = 0; i < num_queues; ++i) {
1841 queue = &info->queues[i];
1842 queue->id = i;
1843 queue->info = info;
1844 err = xennet_init_queue(queue);
1845 if (err) {
1846 /* xennet_init_queue() cleans up after itself on failure,
1847 * but we still have to clean up any previously initialised
1848 * queues. If i > 0, set num_queues to i, then goto
1849 * destroy_ring, which calls xennet_disconnect_backend()
1850 * to tidy up.
1851 */
1852 if (i > 0) {
1853 rtnl_lock();
1854 netif_set_real_num_tx_queues(info->netdev, i);
1855 rtnl_unlock();
1856 goto destroy_ring;
1857 } else {
1858 goto out;
1859 }
1860 }
1861 err = setup_netfront(dev, queue, feature_split_evtchn);
1862 if (err) {
1863 /* As for xennet_init_queue(), setup_netfront() will tidy
1864 * up the current 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_lock();
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 i, requeue_idx, err;
1976 struct sk_buff *skb;
1977 grant_ref_t ref;
1978 struct xen_netif_rx_request *req;
1979 unsigned int feature_rx_copy;
1980 unsigned int j = 0;
1981 struct netfront_queue *queue = NULL;
1982
1983 err = xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1984 "feature-rx-copy", "%u", &feature_rx_copy);
1985 if (err != 1)
1986 feature_rx_copy = 0;
1987
1988 if (!feature_rx_copy) {
1989 dev_info(&dev->dev,
1990 "backend does not support copying receive path\n");
1991 return -ENODEV;
1992 }
1993
1994 err = talk_to_netback(np->xbdev, np);
1995 if (err)
1996 return err;
1997
1998 /* talk_to_netback() sets the correct number of queues */
1999 num_queues = dev->real_num_tx_queues;
2000
2001 rtnl_lock();
2002 netdev_update_features(dev);
2003 rtnl_unlock();
2004
2005 /* By now, the queue structures have been set up */
2006 for (j = 0; j < num_queues; ++j) {
2007 queue = &np->queues[j];
2008 spin_lock_bh(&queue->rx_lock);
2009 spin_lock_irq(&queue->tx_lock);
2010
2011 /* Step 1: Discard all pending TX packet fragments. */
2012 xennet_release_tx_bufs(queue);
2013
2014 /* Step 2: Rebuild the RX buffer freelist and the RX ring itself. */
2015 for (requeue_idx = 0, i = 0; i < NET_RX_RING_SIZE; i++) {
2016 skb_frag_t *frag;
2017 const struct page *page;
2018 if (!queue->rx_skbs[i])
2019 continue;
2020
2021 skb = queue->rx_skbs[requeue_idx] = xennet_get_rx_skb(queue, i);
2022 ref = queue->grant_rx_ref[requeue_idx] = xennet_get_rx_ref(queue, i);
2023 req = RING_GET_REQUEST(&queue->rx, requeue_idx);
2024
2025 frag = &skb_shinfo(skb)->frags[0];
2026 page = skb_frag_page(frag);
2027 gnttab_grant_foreign_access_ref(
2028 ref, queue->info->xbdev->otherend_id,
2029 pfn_to_mfn(page_to_pfn(page)),
2030 0);
2031 req->gref = ref;
2032 req->id = requeue_idx;
2033
2034 requeue_idx++;
2035 }
2036
2037 queue->rx.req_prod_pvt = requeue_idx;
2038 }
2039
2040 /*
2041 * Step 3: All public and private state should now be sane. Get
2042 * ready to start sending and receiving packets and give the driver
2043 * domain a kick because we've probably just requeued some
2044 * packets.
2045 */
2046 netif_carrier_on(np->netdev);
2047 for (j = 0; j < num_queues; ++j) {
2048 queue = &np->queues[j];
2049 notify_remote_via_irq(queue->tx_irq);
2050 if (queue->tx_irq != queue->rx_irq)
2051 notify_remote_via_irq(queue->rx_irq);
2052 xennet_tx_buf_gc(queue);
2053 xennet_alloc_rx_buffers(queue);
2054
2055 spin_unlock_irq(&queue->tx_lock);
2056 spin_unlock_bh(&queue->rx_lock);
2057 }
2058
2059 return 0;
2060 }
2061
2062 /**
2063 * Callback received when the backend's state changes.
2064 */
2065 static void netback_changed(struct xenbus_device *dev,
2066 enum xenbus_state backend_state)
2067 {
2068 struct netfront_info *np = dev_get_drvdata(&dev->dev);
2069 struct net_device *netdev = np->netdev;
2070
2071 dev_dbg(&dev->dev, "%s\n", xenbus_strstate(backend_state));
2072
2073 switch (backend_state) {
2074 case XenbusStateInitialising:
2075 case XenbusStateInitialised:
2076 case XenbusStateReconfiguring:
2077 case XenbusStateReconfigured:
2078 case XenbusStateUnknown:
2079 break;
2080
2081 case XenbusStateInitWait:
2082 if (dev->state != XenbusStateInitialising)
2083 break;
2084 if (xennet_connect(netdev) != 0)
2085 break;
2086 xenbus_switch_state(dev, XenbusStateConnected);
2087 break;
2088
2089 case XenbusStateConnected:
2090 netdev_notify_peers(netdev);
2091 break;
2092
2093 case XenbusStateClosed:
2094 if (dev->state == XenbusStateClosed)
2095 break;
2096 /* Missed the backend's CLOSING state -- fallthrough */
2097 case XenbusStateClosing:
2098 xenbus_frontend_closed(dev);
2099 break;
2100 }
2101 }
2102
2103 static const struct xennet_stat {
2104 char name[ETH_GSTRING_LEN];
2105 u16 offset;
2106 } xennet_stats[] = {
2107 {
2108 "rx_gso_checksum_fixup",
2109 offsetof(struct netfront_info, rx_gso_checksum_fixup)
2110 },
2111 };
2112
2113 static int xennet_get_sset_count(struct net_device *dev, int string_set)
2114 {
2115 switch (string_set) {
2116 case ETH_SS_STATS:
2117 return ARRAY_SIZE(xennet_stats);
2118 default:
2119 return -EINVAL;
2120 }
2121 }
2122
2123 static void xennet_get_ethtool_stats(struct net_device *dev,
2124 struct ethtool_stats *stats, u64 * data)
2125 {
2126 void *np = netdev_priv(dev);
2127 int i;
2128
2129 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
2130 data[i] = atomic_read((atomic_t *)(np + xennet_stats[i].offset));
2131 }
2132
2133 static void xennet_get_strings(struct net_device *dev, u32 stringset, u8 * data)
2134 {
2135 int i;
2136
2137 switch (stringset) {
2138 case ETH_SS_STATS:
2139 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
2140 memcpy(data + i * ETH_GSTRING_LEN,
2141 xennet_stats[i].name, ETH_GSTRING_LEN);
2142 break;
2143 }
2144 }
2145
2146 static const struct ethtool_ops xennet_ethtool_ops =
2147 {
2148 .get_link = ethtool_op_get_link,
2149
2150 .get_sset_count = xennet_get_sset_count,
2151 .get_ethtool_stats = xennet_get_ethtool_stats,
2152 .get_strings = xennet_get_strings,
2153 };
2154
2155 #ifdef CONFIG_SYSFS
2156 static ssize_t show_rxbuf_min(struct device *dev,
2157 struct device_attribute *attr, char *buf)
2158 {
2159 struct net_device *netdev = to_net_dev(dev);
2160 struct netfront_info *info = netdev_priv(netdev);
2161 unsigned int num_queues = netdev->real_num_tx_queues;
2162
2163 if (num_queues)
2164 return sprintf(buf, "%u\n", info->queues[0].rx_min_target);
2165 else
2166 return sprintf(buf, "%u\n", RX_MIN_TARGET);
2167 }
2168
2169 static ssize_t store_rxbuf_min(struct device *dev,
2170 struct device_attribute *attr,
2171 const char *buf, size_t len)
2172 {
2173 struct net_device *netdev = to_net_dev(dev);
2174 struct netfront_info *np = netdev_priv(netdev);
2175 unsigned int num_queues = netdev->real_num_tx_queues;
2176 char *endp;
2177 unsigned long target;
2178 unsigned int i;
2179 struct netfront_queue *queue;
2180
2181 if (!capable(CAP_NET_ADMIN))
2182 return -EPERM;
2183
2184 target = simple_strtoul(buf, &endp, 0);
2185 if (endp == buf)
2186 return -EBADMSG;
2187
2188 if (target < RX_MIN_TARGET)
2189 target = RX_MIN_TARGET;
2190 if (target > RX_MAX_TARGET)
2191 target = RX_MAX_TARGET;
2192
2193 for (i = 0; i < num_queues; ++i) {
2194 queue = &np->queues[i];
2195 spin_lock_bh(&queue->rx_lock);
2196 if (target > queue->rx_max_target)
2197 queue->rx_max_target = target;
2198 queue->rx_min_target = target;
2199 if (target > queue->rx_target)
2200 queue->rx_target = target;
2201
2202 xennet_alloc_rx_buffers(queue);
2203
2204 spin_unlock_bh(&queue->rx_lock);
2205 }
2206 return len;
2207 }
2208
2209 static ssize_t show_rxbuf_max(struct device *dev,
2210 struct device_attribute *attr, char *buf)
2211 {
2212 struct net_device *netdev = to_net_dev(dev);
2213 struct netfront_info *info = netdev_priv(netdev);
2214 unsigned int num_queues = netdev->real_num_tx_queues;
2215
2216 if (num_queues)
2217 return sprintf(buf, "%u\n", info->queues[0].rx_max_target);
2218 else
2219 return sprintf(buf, "%u\n", RX_MAX_TARGET);
2220 }
2221
2222 static ssize_t store_rxbuf_max(struct device *dev,
2223 struct device_attribute *attr,
2224 const char *buf, size_t len)
2225 {
2226 struct net_device *netdev = to_net_dev(dev);
2227 struct netfront_info *np = netdev_priv(netdev);
2228 unsigned int num_queues = netdev->real_num_tx_queues;
2229 char *endp;
2230 unsigned long target;
2231 unsigned int i = 0;
2232 struct netfront_queue *queue = NULL;
2233
2234 if (!capable(CAP_NET_ADMIN))
2235 return -EPERM;
2236
2237 target = simple_strtoul(buf, &endp, 0);
2238 if (endp == buf)
2239 return -EBADMSG;
2240
2241 if (target < RX_MIN_TARGET)
2242 target = RX_MIN_TARGET;
2243 if (target > RX_MAX_TARGET)
2244 target = RX_MAX_TARGET;
2245
2246 for (i = 0; i < num_queues; ++i) {
2247 queue = &np->queues[i];
2248 spin_lock_bh(&queue->rx_lock);
2249 if (target < queue->rx_min_target)
2250 queue->rx_min_target = target;
2251 queue->rx_max_target = target;
2252 if (target < queue->rx_target)
2253 queue->rx_target = target;
2254
2255 xennet_alloc_rx_buffers(queue);
2256
2257 spin_unlock_bh(&queue->rx_lock);
2258 }
2259 return len;
2260 }
2261
2262 static ssize_t show_rxbuf_cur(struct device *dev,
2263 struct device_attribute *attr, char *buf)
2264 {
2265 struct net_device *netdev = to_net_dev(dev);
2266 struct netfront_info *info = netdev_priv(netdev);
2267 unsigned int num_queues = netdev->real_num_tx_queues;
2268
2269 if (num_queues)
2270 return sprintf(buf, "%u\n", info->queues[0].rx_target);
2271 else
2272 return sprintf(buf, "0\n");
2273 }
2274
2275 static struct device_attribute xennet_attrs[] = {
2276 __ATTR(rxbuf_min, S_IRUGO|S_IWUSR, show_rxbuf_min, store_rxbuf_min),
2277 __ATTR(rxbuf_max, S_IRUGO|S_IWUSR, show_rxbuf_max, store_rxbuf_max),
2278 __ATTR(rxbuf_cur, S_IRUGO, show_rxbuf_cur, NULL),
2279 };
2280
2281 static int xennet_sysfs_addif(struct net_device *netdev)
2282 {
2283 int i;
2284 int err;
2285
2286 for (i = 0; i < ARRAY_SIZE(xennet_attrs); i++) {
2287 err = device_create_file(&netdev->dev,
2288 &xennet_attrs[i]);
2289 if (err)
2290 goto fail;
2291 }
2292 return 0;
2293
2294 fail:
2295 while (--i >= 0)
2296 device_remove_file(&netdev->dev, &xennet_attrs[i]);
2297 return err;
2298 }
2299
2300 static void xennet_sysfs_delif(struct net_device *netdev)
2301 {
2302 int i;
2303
2304 for (i = 0; i < ARRAY_SIZE(xennet_attrs); i++)
2305 device_remove_file(&netdev->dev, &xennet_attrs[i]);
2306 }
2307
2308 #endif /* CONFIG_SYSFS */
2309
2310 static const struct xenbus_device_id netfront_ids[] = {
2311 { "vif" },
2312 { "" }
2313 };
2314
2315
2316 static int xennet_remove(struct xenbus_device *dev)
2317 {
2318 struct netfront_info *info = dev_get_drvdata(&dev->dev);
2319 unsigned int num_queues = info->netdev->real_num_tx_queues;
2320 struct netfront_queue *queue = NULL;
2321 unsigned int i = 0;
2322
2323 dev_dbg(&dev->dev, "%s\n", dev->nodename);
2324
2325 xennet_disconnect_backend(info);
2326
2327 xennet_sysfs_delif(info->netdev);
2328
2329 unregister_netdev(info->netdev);
2330
2331 for (i = 0; i < num_queues; ++i) {
2332 queue = &info->queues[i];
2333 del_timer_sync(&queue->rx_refill_timer);
2334 }
2335
2336 if (num_queues) {
2337 kfree(info->queues);
2338 info->queues = NULL;
2339 }
2340
2341 free_percpu(info->stats);
2342
2343 free_netdev(info->netdev);
2344
2345 return 0;
2346 }
2347
2348 static DEFINE_XENBUS_DRIVER(netfront, ,
2349 .probe = netfront_probe,
2350 .remove = xennet_remove,
2351 .resume = netfront_resume,
2352 .otherend_changed = netback_changed,
2353 );
2354
2355 static int __init netif_init(void)
2356 {
2357 if (!xen_domain())
2358 return -ENODEV;
2359
2360 if (!xen_has_pv_nic_devices())
2361 return -ENODEV;
2362
2363 pr_info("Initialising Xen virtual ethernet driver\n");
2364
2365 /* Allow as many queues as there are CPUs, by default */
2366 xennet_max_queues = num_online_cpus();
2367
2368 return xenbus_register_frontend(&netfront_driver);
2369 }
2370 module_init(netif_init);
2371
2372
2373 static void __exit netif_exit(void)
2374 {
2375 xenbus_unregister_driver(&netfront_driver);
2376 }
2377 module_exit(netif_exit);
2378
2379 MODULE_DESCRIPTION("Xen virtual network device frontend");
2380 MODULE_LICENSE("GPL");
2381 MODULE_ALIAS("xen:vif");
2382 MODULE_ALIAS("xennet");
Linux with added FPC-III support