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treewide: remove redundant IS_ERR() before error code check
[linux/fpc-iii.git] / drivers / net / xen-netback / netback.c
blob315dfc6ea29729285293525a2c66d461e99b645e
1 /*
2 * Back-end of the driver for virtual network devices. This portion of the
3 * driver exports a 'unified' network-device interface that can be accessed
4 * by any operating system that implements a compatible front end. A
5 * reference front-end implementation can be found in:
6 * drivers/net/xen-netfront.c
7 *
8 * Copyright (c) 2002-2005, K A Fraser
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License version 2
12 * as published by the Free Software Foundation; or, when distributed
13 * separately from the Linux kernel or incorporated into other
14 * software packages, subject to the following license:
15 *
16 * Permission is hereby granted, free of charge, to any person obtaining a copy
17 * of this source file (the "Software"), to deal in the Software without
18 * restriction, including without limitation the rights to use, copy, modify,
19 * merge, publish, distribute, sublicense, and/or sell copies of the Software,
20 * and to permit persons to whom the Software is furnished to do so, subject to
21 * the following conditions:
22 *
23 * The above copyright notice and this permission notice shall be included in
24 * all copies or substantial portions of the Software.
25 *
26 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
27 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
28 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
29 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
30 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
31 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
32 * IN THE SOFTWARE.
33 */
34
35 #include "common.h"
36
37 #include <linux/kthread.h>
38 #include <linux/if_vlan.h>
39 #include <linux/udp.h>
40 #include <linux/highmem.h>
41
42 #include <net/tcp.h>
43
44 #include <xen/xen.h>
45 #include <xen/events.h>
46 #include <xen/interface/memory.h>
47 #include <xen/page.h>
48
49 #include <asm/xen/hypercall.h>
50
51 /* Provide an option to disable split event channels at load time as
52 * event channels are limited resource. Split event channels are
53 * enabled by default.
54 */
55 bool separate_tx_rx_irq = true;
56 module_param(separate_tx_rx_irq, bool, 0644);
57
58 /* The time that packets can stay on the guest Rx internal queue
59 * before they are dropped.
60 */
61 unsigned int rx_drain_timeout_msecs = 10000;
62 module_param(rx_drain_timeout_msecs, uint, 0444);
63
64 /* The length of time before the frontend is considered unresponsive
65 * because it isn't providing Rx slots.
66 */
67 unsigned int rx_stall_timeout_msecs = 60000;
68 module_param(rx_stall_timeout_msecs, uint, 0444);
69
70 #define MAX_QUEUES_DEFAULT 8
71 unsigned int xenvif_max_queues;
72 module_param_named(max_queues, xenvif_max_queues, uint, 0644);
73 MODULE_PARM_DESC(max_queues,
74 "Maximum number of queues per virtual interface");
75
76 /*
77 * This is the maximum slots a skb can have. If a guest sends a skb
78 * which exceeds this limit it is considered malicious.
79 */
80 #define FATAL_SKB_SLOTS_DEFAULT 20
81 static unsigned int fatal_skb_slots = FATAL_SKB_SLOTS_DEFAULT;
82 module_param(fatal_skb_slots, uint, 0444);
83
84 /* The amount to copy out of the first guest Tx slot into the skb's
85 * linear area. If the first slot has more data, it will be mapped
86 * and put into the first frag.
87 *
88 * This is sized to avoid pulling headers from the frags for most
89 * TCP/IP packets.
90 */
91 #define XEN_NETBACK_TX_COPY_LEN 128
92
93 /* This is the maximum number of flows in the hash cache. */
94 #define XENVIF_HASH_CACHE_SIZE_DEFAULT 64
95 unsigned int xenvif_hash_cache_size = XENVIF_HASH_CACHE_SIZE_DEFAULT;
96 module_param_named(hash_cache_size, xenvif_hash_cache_size, uint, 0644);
97 MODULE_PARM_DESC(hash_cache_size, "Number of flows in the hash cache");
98
99 static void xenvif_idx_release(struct xenvif_queue *queue, u16 pending_idx,
100 u8 status);
101
102 static void make_tx_response(struct xenvif_queue *queue,
103 struct xen_netif_tx_request *txp,
104 unsigned int extra_count,
105 s8 st);
106 static void push_tx_responses(struct xenvif_queue *queue);
107
108 static inline int tx_work_todo(struct xenvif_queue *queue);
109
110 static inline unsigned long idx_to_pfn(struct xenvif_queue *queue,
111 u16 idx)
112 {
113 return page_to_pfn(queue->mmap_pages[idx]);
114 }
115
116 static inline unsigned long idx_to_kaddr(struct xenvif_queue *queue,
117 u16 idx)
118 {
119 return (unsigned long)pfn_to_kaddr(idx_to_pfn(queue, idx));
120 }
121
122 #define callback_param(vif, pending_idx) \
123 (vif->pending_tx_info[pending_idx].callback_struct)
124
125 /* Find the containing VIF's structure from a pointer in pending_tx_info array
126 */
127 static inline struct xenvif_queue *ubuf_to_queue(const struct ubuf_info *ubuf)
128 {
129 u16 pending_idx = ubuf->desc;
130 struct pending_tx_info *temp =
131 container_of(ubuf, struct pending_tx_info, callback_struct);
132 return container_of(temp - pending_idx,
133 struct xenvif_queue,
134 pending_tx_info[0]);
135 }
136
137 static u16 frag_get_pending_idx(skb_frag_t *frag)
138 {
139 return (u16)skb_frag_off(frag);
140 }
141
142 static void frag_set_pending_idx(skb_frag_t *frag, u16 pending_idx)
143 {
144 skb_frag_off_set(frag, pending_idx);
145 }
146
147 static inline pending_ring_idx_t pending_index(unsigned i)
148 {
149 return i & (MAX_PENDING_REQS-1);
150 }
151
152 void xenvif_kick_thread(struct xenvif_queue *queue)
153 {
154 wake_up(&queue->wq);
155 }
156
157 void xenvif_napi_schedule_or_enable_events(struct xenvif_queue *queue)
158 {
159 int more_to_do;
160
161 RING_FINAL_CHECK_FOR_REQUESTS(&queue->tx, more_to_do);
162
163 if (more_to_do)
164 napi_schedule(&queue->napi);
165 }
166
167 static void tx_add_credit(struct xenvif_queue *queue)
168 {
169 unsigned long max_burst, max_credit;
170
171 /*
172 * Allow a burst big enough to transmit a jumbo packet of up to 128kB.
173 * Otherwise the interface can seize up due to insufficient credit.
174 */
175 max_burst = max(131072UL, queue->credit_bytes);
176
177 /* Take care that adding a new chunk of credit doesn't wrap to zero. */
178 max_credit = queue->remaining_credit + queue->credit_bytes;
179 if (max_credit < queue->remaining_credit)
180 max_credit = ULONG_MAX; /* wrapped: clamp to ULONG_MAX */
181
182 queue->remaining_credit = min(max_credit, max_burst);
183 queue->rate_limited = false;
184 }
185
186 void xenvif_tx_credit_callback(struct timer_list *t)
187 {
188 struct xenvif_queue *queue = from_timer(queue, t, credit_timeout);
189 tx_add_credit(queue);
190 xenvif_napi_schedule_or_enable_events(queue);
191 }
192
193 static void xenvif_tx_err(struct xenvif_queue *queue,
194 struct xen_netif_tx_request *txp,
195 unsigned int extra_count, RING_IDX end)
196 {
197 RING_IDX cons = queue->tx.req_cons;
198 unsigned long flags;
199
200 do {
201 spin_lock_irqsave(&queue->response_lock, flags);
202 make_tx_response(queue, txp, extra_count, XEN_NETIF_RSP_ERROR);
203 push_tx_responses(queue);
204 spin_unlock_irqrestore(&queue->response_lock, flags);
205 if (cons == end)
206 break;
207 RING_COPY_REQUEST(&queue->tx, cons++, txp);
208 extra_count = 0; /* only the first frag can have extras */
209 } while (1);
210 queue->tx.req_cons = cons;
211 }
212
213 static void xenvif_fatal_tx_err(struct xenvif *vif)
214 {
215 netdev_err(vif->dev, "fatal error; disabling device\n");
216 vif->disabled = true;
217 /* Disable the vif from queue 0's kthread */
218 if (vif->num_queues)
219 xenvif_kick_thread(&vif->queues[0]);
220 }
221
222 static int xenvif_count_requests(struct xenvif_queue *queue,
223 struct xen_netif_tx_request *first,
224 unsigned int extra_count,
225 struct xen_netif_tx_request *txp,
226 int work_to_do)
227 {
228 RING_IDX cons = queue->tx.req_cons;
229 int slots = 0;
230 int drop_err = 0;
231 int more_data;
232
233 if (!(first->flags & XEN_NETTXF_more_data))
234 return 0;
235
236 do {
237 struct xen_netif_tx_request dropped_tx = { 0 };
238
239 if (slots >= work_to_do) {
240 netdev_err(queue->vif->dev,
241 "Asked for %d slots but exceeds this limit\n",
242 work_to_do);
243 xenvif_fatal_tx_err(queue->vif);
244 return -ENODATA;
245 }
246
247 /* This guest is really using too many slots and
248 * considered malicious.
249 */
250 if (unlikely(slots >= fatal_skb_slots)) {
251 netdev_err(queue->vif->dev,
252 "Malicious frontend using %d slots, threshold %u\n",
253 slots, fatal_skb_slots);
254 xenvif_fatal_tx_err(queue->vif);
255 return -E2BIG;
256 }
257
258 /* Xen network protocol had implicit dependency on
259 * MAX_SKB_FRAGS. XEN_NETBK_LEGACY_SLOTS_MAX is set to
260 * the historical MAX_SKB_FRAGS value 18 to honor the
261 * same behavior as before. Any packet using more than
262 * 18 slots but less than fatal_skb_slots slots is
263 * dropped
264 */
265 if (!drop_err && slots >= XEN_NETBK_LEGACY_SLOTS_MAX) {
266 if (net_ratelimit())
267 netdev_dbg(queue->vif->dev,
268 "Too many slots (%d) exceeding limit (%d), dropping packet\n",
269 slots, XEN_NETBK_LEGACY_SLOTS_MAX);
270 drop_err = -E2BIG;
271 }
272
273 if (drop_err)
274 txp = &dropped_tx;
275
276 RING_COPY_REQUEST(&queue->tx, cons + slots, txp);
277
278 /* If the guest submitted a frame >= 64 KiB then
279 * first->size overflowed and following slots will
280 * appear to be larger than the frame.
281 *
282 * This cannot be fatal error as there are buggy
283 * frontends that do this.
284 *
285 * Consume all slots and drop the packet.
286 */
287 if (!drop_err && txp->size > first->size) {
288 if (net_ratelimit())
289 netdev_dbg(queue->vif->dev,
290 "Invalid tx request, slot size %u > remaining size %u\n",
291 txp->size, first->size);
292 drop_err = -EIO;
293 }
294
295 first->size -= txp->size;
296 slots++;
297
298 if (unlikely((txp->offset + txp->size) > XEN_PAGE_SIZE)) {
299 netdev_err(queue->vif->dev, "Cross page boundary, txp->offset: %u, size: %u\n",
300 txp->offset, txp->size);
301 xenvif_fatal_tx_err(queue->vif);
302 return -EINVAL;
303 }
304
305 more_data = txp->flags & XEN_NETTXF_more_data;
306
307 if (!drop_err)
308 txp++;
309
310 } while (more_data);
311
312 if (drop_err) {
313 xenvif_tx_err(queue, first, extra_count, cons + slots);
314 return drop_err;
315 }
316
317 return slots;
318 }
319
320
321 struct xenvif_tx_cb {
322 u16 pending_idx;
323 };
324
325 #define XENVIF_TX_CB(skb) ((struct xenvif_tx_cb *)(skb)->cb)
326
327 static inline void xenvif_tx_create_map_op(struct xenvif_queue *queue,
328 u16 pending_idx,
329 struct xen_netif_tx_request *txp,
330 unsigned int extra_count,
331 struct gnttab_map_grant_ref *mop)
332 {
333 queue->pages_to_map[mop-queue->tx_map_ops] = queue->mmap_pages[pending_idx];
334 gnttab_set_map_op(mop, idx_to_kaddr(queue, pending_idx),
335 GNTMAP_host_map | GNTMAP_readonly,
336 txp->gref, queue->vif->domid);
337
338 memcpy(&queue->pending_tx_info[pending_idx].req, txp,
339 sizeof(*txp));
340 queue->pending_tx_info[pending_idx].extra_count = extra_count;
341 }
342
343 static inline struct sk_buff *xenvif_alloc_skb(unsigned int size)
344 {
345 struct sk_buff *skb =
346 alloc_skb(size + NET_SKB_PAD + NET_IP_ALIGN,
347 GFP_ATOMIC | __GFP_NOWARN);
348 if (unlikely(skb == NULL))
349 return NULL;
350
351 /* Packets passed to netif_rx() must have some headroom. */
352 skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN);
353
354 /* Initialize it here to avoid later surprises */
355 skb_shinfo(skb)->destructor_arg = NULL;
356
357 return skb;
358 }
359
360 static struct gnttab_map_grant_ref *xenvif_get_requests(struct xenvif_queue *queue,
361 struct sk_buff *skb,
362 struct xen_netif_tx_request *txp,
363 struct gnttab_map_grant_ref *gop,
364 unsigned int frag_overflow,
365 struct sk_buff *nskb)
366 {
367 struct skb_shared_info *shinfo = skb_shinfo(skb);
368 skb_frag_t *frags = shinfo->frags;
369 u16 pending_idx = XENVIF_TX_CB(skb)->pending_idx;
370 int start;
371 pending_ring_idx_t index;
372 unsigned int nr_slots;
373
374 nr_slots = shinfo->nr_frags;
375
376 /* Skip first skb fragment if it is on same page as header fragment. */
377 start = (frag_get_pending_idx(&shinfo->frags[0]) == pending_idx);
378
379 for (shinfo->nr_frags = start; shinfo->nr_frags < nr_slots;
380 shinfo->nr_frags++, txp++, gop++) {
381 index = pending_index(queue->pending_cons++);
382 pending_idx = queue->pending_ring[index];
383 xenvif_tx_create_map_op(queue, pending_idx, txp, 0, gop);
384 frag_set_pending_idx(&frags[shinfo->nr_frags], pending_idx);
385 }
386
387 if (frag_overflow) {
388
389 shinfo = skb_shinfo(nskb);
390 frags = shinfo->frags;
391
392 for (shinfo->nr_frags = 0; shinfo->nr_frags < frag_overflow;
393 shinfo->nr_frags++, txp++, gop++) {
394 index = pending_index(queue->pending_cons++);
395 pending_idx = queue->pending_ring[index];
396 xenvif_tx_create_map_op(queue, pending_idx, txp, 0,
397 gop);
398 frag_set_pending_idx(&frags[shinfo->nr_frags],
399 pending_idx);
400 }
401
402 skb_shinfo(skb)->frag_list = nskb;
403 }
404
405 return gop;
406 }
407
408 static inline void xenvif_grant_handle_set(struct xenvif_queue *queue,
409 u16 pending_idx,
410 grant_handle_t handle)
411 {
412 if (unlikely(queue->grant_tx_handle[pending_idx] !=
413 NETBACK_INVALID_HANDLE)) {
414 netdev_err(queue->vif->dev,
415 "Trying to overwrite active handle! pending_idx: 0x%x\n",
416 pending_idx);
417 BUG();
418 }
419 queue->grant_tx_handle[pending_idx] = handle;
420 }
421
422 static inline void xenvif_grant_handle_reset(struct xenvif_queue *queue,
423 u16 pending_idx)
424 {
425 if (unlikely(queue->grant_tx_handle[pending_idx] ==
426 NETBACK_INVALID_HANDLE)) {
427 netdev_err(queue->vif->dev,
428 "Trying to unmap invalid handle! pending_idx: 0x%x\n",
429 pending_idx);
430 BUG();
431 }
432 queue->grant_tx_handle[pending_idx] = NETBACK_INVALID_HANDLE;
433 }
434
435 static int xenvif_tx_check_gop(struct xenvif_queue *queue,
436 struct sk_buff *skb,
437 struct gnttab_map_grant_ref **gopp_map,
438 struct gnttab_copy **gopp_copy)
439 {
440 struct gnttab_map_grant_ref *gop_map = *gopp_map;
441 u16 pending_idx = XENVIF_TX_CB(skb)->pending_idx;
442 /* This always points to the shinfo of the skb being checked, which
443 * could be either the first or the one on the frag_list
444 */
445 struct skb_shared_info *shinfo = skb_shinfo(skb);
446 /* If this is non-NULL, we are currently checking the frag_list skb, and
447 * this points to the shinfo of the first one
448 */
449 struct skb_shared_info *first_shinfo = NULL;
450 int nr_frags = shinfo->nr_frags;
451 const bool sharedslot = nr_frags &&
452 frag_get_pending_idx(&shinfo->frags[0]) == pending_idx;
453 int i, err;
454
455 /* Check status of header. */
456 err = (*gopp_copy)->status;
457 if (unlikely(err)) {
458 if (net_ratelimit())
459 netdev_dbg(queue->vif->dev,
460 "Grant copy of header failed! status: %d pending_idx: %u ref: %u\n",
461 (*gopp_copy)->status,
462 pending_idx,
463 (*gopp_copy)->source.u.ref);
464 /* The first frag might still have this slot mapped */
465 if (!sharedslot)
466 xenvif_idx_release(queue, pending_idx,
467 XEN_NETIF_RSP_ERROR);
468 }
469 (*gopp_copy)++;
470
471 check_frags:
472 for (i = 0; i < nr_frags; i++, gop_map++) {
473 int j, newerr;
474
475 pending_idx = frag_get_pending_idx(&shinfo->frags[i]);
476
477 /* Check error status: if okay then remember grant handle. */
478 newerr = gop_map->status;
479
480 if (likely(!newerr)) {
481 xenvif_grant_handle_set(queue,
482 pending_idx,
483 gop_map->handle);
484 /* Had a previous error? Invalidate this fragment. */
485 if (unlikely(err)) {
486 xenvif_idx_unmap(queue, pending_idx);
487 /* If the mapping of the first frag was OK, but
488 * the header's copy failed, and they are
489 * sharing a slot, send an error
490 */
491 if (i == 0 && sharedslot)
492 xenvif_idx_release(queue, pending_idx,
493 XEN_NETIF_RSP_ERROR);
494 else
495 xenvif_idx_release(queue, pending_idx,
496 XEN_NETIF_RSP_OKAY);
497 }
498 continue;
499 }
500
501 /* Error on this fragment: respond to client with an error. */
502 if (net_ratelimit())
503 netdev_dbg(queue->vif->dev,
504 "Grant map of %d. frag failed! status: %d pending_idx: %u ref: %u\n",
505 i,
506 gop_map->status,
507 pending_idx,
508 gop_map->ref);
509
510 xenvif_idx_release(queue, pending_idx, XEN_NETIF_RSP_ERROR);
511
512 /* Not the first error? Preceding frags already invalidated. */
513 if (err)
514 continue;
515
516 /* First error: if the header haven't shared a slot with the
517 * first frag, release it as well.
518 */
519 if (!sharedslot)
520 xenvif_idx_release(queue,
521 XENVIF_TX_CB(skb)->pending_idx,
522 XEN_NETIF_RSP_OKAY);
523
524 /* Invalidate preceding fragments of this skb. */
525 for (j = 0; j < i; j++) {
526 pending_idx = frag_get_pending_idx(&shinfo->frags[j]);
527 xenvif_idx_unmap(queue, pending_idx);
528 xenvif_idx_release(queue, pending_idx,
529 XEN_NETIF_RSP_OKAY);
530 }
531
532 /* And if we found the error while checking the frag_list, unmap
533 * the first skb's frags
534 */
535 if (first_shinfo) {
536 for (j = 0; j < first_shinfo->nr_frags; j++) {
537 pending_idx = frag_get_pending_idx(&first_shinfo->frags[j]);
538 xenvif_idx_unmap(queue, pending_idx);
539 xenvif_idx_release(queue, pending_idx,
540 XEN_NETIF_RSP_OKAY);
541 }
542 }
543
544 /* Remember the error: invalidate all subsequent fragments. */
545 err = newerr;
546 }
547
548 if (skb_has_frag_list(skb) && !first_shinfo) {
549 first_shinfo = skb_shinfo(skb);
550 shinfo = skb_shinfo(skb_shinfo(skb)->frag_list);
551 nr_frags = shinfo->nr_frags;
552
553 goto check_frags;
554 }
555
556 *gopp_map = gop_map;
557 return err;
558 }
559
560 static void xenvif_fill_frags(struct xenvif_queue *queue, struct sk_buff *skb)
561 {
562 struct skb_shared_info *shinfo = skb_shinfo(skb);
563 int nr_frags = shinfo->nr_frags;
564 int i;
565 u16 prev_pending_idx = INVALID_PENDING_IDX;
566
567 for (i = 0; i < nr_frags; i++) {
568 skb_frag_t *frag = shinfo->frags + i;
569 struct xen_netif_tx_request *txp;
570 struct page *page;
571 u16 pending_idx;
572
573 pending_idx = frag_get_pending_idx(frag);
574
575 /* If this is not the first frag, chain it to the previous*/
576 if (prev_pending_idx == INVALID_PENDING_IDX)
577 skb_shinfo(skb)->destructor_arg =
578 &callback_param(queue, pending_idx);
579 else
580 callback_param(queue, prev_pending_idx).ctx =
581 &callback_param(queue, pending_idx);
582
583 callback_param(queue, pending_idx).ctx = NULL;
584 prev_pending_idx = pending_idx;
585
586 txp = &queue->pending_tx_info[pending_idx].req;
587 page = virt_to_page(idx_to_kaddr(queue, pending_idx));
588 __skb_fill_page_desc(skb, i, page, txp->offset, txp->size);
589 skb->len += txp->size;
590 skb->data_len += txp->size;
591 skb->truesize += txp->size;
592
593 /* Take an extra reference to offset network stack's put_page */
594 get_page(queue->mmap_pages[pending_idx]);
595 }
596 }
597
598 static int xenvif_get_extras(struct xenvif_queue *queue,
599 struct xen_netif_extra_info *extras,
600 unsigned int *extra_count,
601 int work_to_do)
602 {
603 struct xen_netif_extra_info extra;
604 RING_IDX cons = queue->tx.req_cons;
605
606 do {
607 if (unlikely(work_to_do-- <= 0)) {
608 netdev_err(queue->vif->dev, "Missing extra info\n");
609 xenvif_fatal_tx_err(queue->vif);
610 return -EBADR;
611 }
612
613 RING_COPY_REQUEST(&queue->tx, cons, &extra);
614
615 queue->tx.req_cons = ++cons;
616 (*extra_count)++;
617
618 if (unlikely(!extra.type ||
619 extra.type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
620 netdev_err(queue->vif->dev,
621 "Invalid extra type: %d\n", extra.type);
622 xenvif_fatal_tx_err(queue->vif);
623 return -EINVAL;
624 }
625
626 memcpy(&extras[extra.type - 1], &extra, sizeof(extra));
627 } while (extra.flags & XEN_NETIF_EXTRA_FLAG_MORE);
628
629 return work_to_do;
630 }
631
632 static int xenvif_set_skb_gso(struct xenvif *vif,
633 struct sk_buff *skb,
634 struct xen_netif_extra_info *gso)
635 {
636 if (!gso->u.gso.size) {
637 netdev_err(vif->dev, "GSO size must not be zero.\n");
638 xenvif_fatal_tx_err(vif);
639 return -EINVAL;
640 }
641
642 switch (gso->u.gso.type) {
643 case XEN_NETIF_GSO_TYPE_TCPV4:
644 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
645 break;
646 case XEN_NETIF_GSO_TYPE_TCPV6:
647 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
648 break;
649 default:
650 netdev_err(vif->dev, "Bad GSO type %d.\n", gso->u.gso.type);
651 xenvif_fatal_tx_err(vif);
652 return -EINVAL;
653 }
654
655 skb_shinfo(skb)->gso_size = gso->u.gso.size;
656 /* gso_segs will be calculated later */
657
658 return 0;
659 }
660
661 static int checksum_setup(struct xenvif_queue *queue, struct sk_buff *skb)
662 {
663 bool recalculate_partial_csum = false;
664
665 /* A GSO SKB must be CHECKSUM_PARTIAL. However some buggy
666 * peers can fail to set NETRXF_csum_blank when sending a GSO
667 * frame. In this case force the SKB to CHECKSUM_PARTIAL and
668 * recalculate the partial checksum.
669 */
670 if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) {
671 queue->stats.rx_gso_checksum_fixup++;
672 skb->ip_summed = CHECKSUM_PARTIAL;
673 recalculate_partial_csum = true;
674 }
675
676 /* A non-CHECKSUM_PARTIAL SKB does not require setup. */
677 if (skb->ip_summed != CHECKSUM_PARTIAL)
678 return 0;
679
680 return skb_checksum_setup(skb, recalculate_partial_csum);
681 }
682
683 static bool tx_credit_exceeded(struct xenvif_queue *queue, unsigned size)
684 {
685 u64 now = get_jiffies_64();
686 u64 next_credit = queue->credit_window_start +
687 msecs_to_jiffies(queue->credit_usec / 1000);
688
689 /* Timer could already be pending in rare cases. */
690 if (timer_pending(&queue->credit_timeout)) {
691 queue->rate_limited = true;
692 return true;
693 }
694
695 /* Passed the point where we can replenish credit? */
696 if (time_after_eq64(now, next_credit)) {
697 queue->credit_window_start = now;
698 tx_add_credit(queue);
699 }
700
701 /* Still too big to send right now? Set a callback. */
702 if (size > queue->remaining_credit) {
703 mod_timer(&queue->credit_timeout,
704 next_credit);
705 queue->credit_window_start = next_credit;
706 queue->rate_limited = true;
707
708 return true;
709 }
710
711 return false;
712 }
713
714 /* No locking is required in xenvif_mcast_add/del() as they are
715 * only ever invoked from NAPI poll. An RCU list is used because
716 * xenvif_mcast_match() is called asynchronously, during start_xmit.
717 */
718
719 static int xenvif_mcast_add(struct xenvif *vif, const u8 *addr)
720 {
721 struct xenvif_mcast_addr *mcast;
722
723 if (vif->fe_mcast_count == XEN_NETBK_MCAST_MAX) {
724 if (net_ratelimit())
725 netdev_err(vif->dev,
726 "Too many multicast addresses\n");
727 return -ENOSPC;
728 }
729
730 mcast = kzalloc(sizeof(*mcast), GFP_ATOMIC);
731 if (!mcast)
732 return -ENOMEM;
733
734 ether_addr_copy(mcast->addr, addr);
735 list_add_tail_rcu(&mcast->entry, &vif->fe_mcast_addr);
736 vif->fe_mcast_count++;
737
738 return 0;
739 }
740
741 static void xenvif_mcast_del(struct xenvif *vif, const u8 *addr)
742 {
743 struct xenvif_mcast_addr *mcast;
744
745 list_for_each_entry_rcu(mcast, &vif->fe_mcast_addr, entry) {
746 if (ether_addr_equal(addr, mcast->addr)) {
747 --vif->fe_mcast_count;
748 list_del_rcu(&mcast->entry);
749 kfree_rcu(mcast, rcu);
750 break;
751 }
752 }
753 }
754
755 bool xenvif_mcast_match(struct xenvif *vif, const u8 *addr)
756 {
757 struct xenvif_mcast_addr *mcast;
758
759 rcu_read_lock();
760 list_for_each_entry_rcu(mcast, &vif->fe_mcast_addr, entry) {
761 if (ether_addr_equal(addr, mcast->addr)) {
762 rcu_read_unlock();
763 return true;
764 }
765 }
766 rcu_read_unlock();
767
768 return false;
769 }
770
771 void xenvif_mcast_addr_list_free(struct xenvif *vif)
772 {
773 /* No need for locking or RCU here. NAPI poll and TX queue
774 * are stopped.
775 */
776 while (!list_empty(&vif->fe_mcast_addr)) {
777 struct xenvif_mcast_addr *mcast;
778
779 mcast = list_first_entry(&vif->fe_mcast_addr,
780 struct xenvif_mcast_addr,
781 entry);
782 --vif->fe_mcast_count;
783 list_del(&mcast->entry);
784 kfree(mcast);
785 }
786 }
787
788 static void xenvif_tx_build_gops(struct xenvif_queue *queue,
789 int budget,
790 unsigned *copy_ops,
791 unsigned *map_ops)
792 {
793 struct gnttab_map_grant_ref *gop = queue->tx_map_ops;
794 struct sk_buff *skb, *nskb;
795 int ret;
796 unsigned int frag_overflow;
797
798 while (skb_queue_len(&queue->tx_queue) < budget) {
799 struct xen_netif_tx_request txreq;
800 struct xen_netif_tx_request txfrags[XEN_NETBK_LEGACY_SLOTS_MAX];
801 struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX-1];
802 unsigned int extra_count;
803 u16 pending_idx;
804 RING_IDX idx;
805 int work_to_do;
806 unsigned int data_len;
807 pending_ring_idx_t index;
808
809 if (queue->tx.sring->req_prod - queue->tx.req_cons >
810 XEN_NETIF_TX_RING_SIZE) {
811 netdev_err(queue->vif->dev,
812 "Impossible number of requests. "
813 "req_prod %d, req_cons %d, size %ld\n",
814 queue->tx.sring->req_prod, queue->tx.req_cons,
815 XEN_NETIF_TX_RING_SIZE);
816 xenvif_fatal_tx_err(queue->vif);
817 break;
818 }
819
820 work_to_do = RING_HAS_UNCONSUMED_REQUESTS(&queue->tx);
821 if (!work_to_do)
822 break;
823
824 idx = queue->tx.req_cons;
825 rmb(); /* Ensure that we see the request before we copy it. */
826 RING_COPY_REQUEST(&queue->tx, idx, &txreq);
827
828 /* Credit-based scheduling. */
829 if (txreq.size > queue->remaining_credit &&
830 tx_credit_exceeded(queue, txreq.size))
831 break;
832
833 queue->remaining_credit -= txreq.size;
834
835 work_to_do--;
836 queue->tx.req_cons = ++idx;
837
838 memset(extras, 0, sizeof(extras));
839 extra_count = 0;
840 if (txreq.flags & XEN_NETTXF_extra_info) {
841 work_to_do = xenvif_get_extras(queue, extras,
842 &extra_count,
843 work_to_do);
844 idx = queue->tx.req_cons;
845 if (unlikely(work_to_do < 0))
846 break;
847 }
848
849 if (extras[XEN_NETIF_EXTRA_TYPE_MCAST_ADD - 1].type) {
850 struct xen_netif_extra_info *extra;
851
852 extra = &extras[XEN_NETIF_EXTRA_TYPE_MCAST_ADD - 1];
853 ret = xenvif_mcast_add(queue->vif, extra->u.mcast.addr);
854
855 make_tx_response(queue, &txreq, extra_count,
856 (ret == 0) ?
857 XEN_NETIF_RSP_OKAY :
858 XEN_NETIF_RSP_ERROR);
859 push_tx_responses(queue);
860 continue;
861 }
862
863 if (extras[XEN_NETIF_EXTRA_TYPE_MCAST_DEL - 1].type) {
864 struct xen_netif_extra_info *extra;
865
866 extra = &extras[XEN_NETIF_EXTRA_TYPE_MCAST_DEL - 1];
867 xenvif_mcast_del(queue->vif, extra->u.mcast.addr);
868
869 make_tx_response(queue, &txreq, extra_count,
870 XEN_NETIF_RSP_OKAY);
871 push_tx_responses(queue);
872 continue;
873 }
874
875 ret = xenvif_count_requests(queue, &txreq, extra_count,
876 txfrags, work_to_do);
877 if (unlikely(ret < 0))
878 break;
879
880 idx += ret;
881
882 if (unlikely(txreq.size < ETH_HLEN)) {
883 netdev_dbg(queue->vif->dev,
884 "Bad packet size: %d\n", txreq.size);
885 xenvif_tx_err(queue, &txreq, extra_count, idx);
886 break;
887 }
888
889 /* No crossing a page as the payload mustn't fragment. */
890 if (unlikely((txreq.offset + txreq.size) > XEN_PAGE_SIZE)) {
891 netdev_err(queue->vif->dev,
892 "txreq.offset: %u, size: %u, end: %lu\n",
893 txreq.offset, txreq.size,
894 (unsigned long)(txreq.offset&~XEN_PAGE_MASK) + txreq.size);
895 xenvif_fatal_tx_err(queue->vif);
896 break;
897 }
898
899 index = pending_index(queue->pending_cons);
900 pending_idx = queue->pending_ring[index];
901
902 data_len = (txreq.size > XEN_NETBACK_TX_COPY_LEN &&
903 ret < XEN_NETBK_LEGACY_SLOTS_MAX) ?
904 XEN_NETBACK_TX_COPY_LEN : txreq.size;
905
906 skb = xenvif_alloc_skb(data_len);
907 if (unlikely(skb == NULL)) {
908 netdev_dbg(queue->vif->dev,
909 "Can't allocate a skb in start_xmit.\n");
910 xenvif_tx_err(queue, &txreq, extra_count, idx);
911 break;
912 }
913
914 skb_shinfo(skb)->nr_frags = ret;
915 if (data_len < txreq.size)
916 skb_shinfo(skb)->nr_frags++;
917 /* At this point shinfo->nr_frags is in fact the number of
918 * slots, which can be as large as XEN_NETBK_LEGACY_SLOTS_MAX.
919 */
920 frag_overflow = 0;
921 nskb = NULL;
922 if (skb_shinfo(skb)->nr_frags > MAX_SKB_FRAGS) {
923 frag_overflow = skb_shinfo(skb)->nr_frags - MAX_SKB_FRAGS;
924 BUG_ON(frag_overflow > MAX_SKB_FRAGS);
925 skb_shinfo(skb)->nr_frags = MAX_SKB_FRAGS;
926 nskb = xenvif_alloc_skb(0);
927 if (unlikely(nskb == NULL)) {
928 skb_shinfo(skb)->nr_frags = 0;
929 kfree_skb(skb);
930 xenvif_tx_err(queue, &txreq, extra_count, idx);
931 if (net_ratelimit())
932 netdev_err(queue->vif->dev,
933 "Can't allocate the frag_list skb.\n");
934 break;
935 }
936 }
937
938 if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) {
939 struct xen_netif_extra_info *gso;
940 gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1];
941
942 if (xenvif_set_skb_gso(queue->vif, skb, gso)) {
943 /* Failure in xenvif_set_skb_gso is fatal. */
944 skb_shinfo(skb)->nr_frags = 0;
945 kfree_skb(skb);
946 kfree_skb(nskb);
947 break;
948 }
949 }
950
951 if (extras[XEN_NETIF_EXTRA_TYPE_HASH - 1].type) {
952 struct xen_netif_extra_info *extra;
953 enum pkt_hash_types type = PKT_HASH_TYPE_NONE;
954
955 extra = &extras[XEN_NETIF_EXTRA_TYPE_HASH - 1];
956
957 switch (extra->u.hash.type) {
958 case _XEN_NETIF_CTRL_HASH_TYPE_IPV4:
959 case _XEN_NETIF_CTRL_HASH_TYPE_IPV6:
960 type = PKT_HASH_TYPE_L3;
961 break;
962
963 case _XEN_NETIF_CTRL_HASH_TYPE_IPV4_TCP:
964 case _XEN_NETIF_CTRL_HASH_TYPE_IPV6_TCP:
965 type = PKT_HASH_TYPE_L4;
966 break;
967
968 default:
969 break;
970 }
971
972 if (type != PKT_HASH_TYPE_NONE)
973 skb_set_hash(skb,
974 *(u32 *)extra->u.hash.value,
975 type);
976 }
977
978 XENVIF_TX_CB(skb)->pending_idx = pending_idx;
979
980 __skb_put(skb, data_len);
981 queue->tx_copy_ops[*copy_ops].source.u.ref = txreq.gref;
982 queue->tx_copy_ops[*copy_ops].source.domid = queue->vif->domid;
983 queue->tx_copy_ops[*copy_ops].source.offset = txreq.offset;
984
985 queue->tx_copy_ops[*copy_ops].dest.u.gmfn =
986 virt_to_gfn(skb->data);
987 queue->tx_copy_ops[*copy_ops].dest.domid = DOMID_SELF;
988 queue->tx_copy_ops[*copy_ops].dest.offset =
989 offset_in_page(skb->data) & ~XEN_PAGE_MASK;
990
991 queue->tx_copy_ops[*copy_ops].len = data_len;
992 queue->tx_copy_ops[*copy_ops].flags = GNTCOPY_source_gref;
993
994 (*copy_ops)++;
995
996 if (data_len < txreq.size) {
997 frag_set_pending_idx(&skb_shinfo(skb)->frags[0],
998 pending_idx);
999 xenvif_tx_create_map_op(queue, pending_idx, &txreq,
1000 extra_count, gop);
1001 gop++;
1002 } else {
1003 frag_set_pending_idx(&skb_shinfo(skb)->frags[0],
1004 INVALID_PENDING_IDX);
1005 memcpy(&queue->pending_tx_info[pending_idx].req,
1006 &txreq, sizeof(txreq));
1007 queue->pending_tx_info[pending_idx].extra_count =
1008 extra_count;
1009 }
1010
1011 queue->pending_cons++;
1012
1013 gop = xenvif_get_requests(queue, skb, txfrags, gop,
1014 frag_overflow, nskb);
1015
1016 __skb_queue_tail(&queue->tx_queue, skb);
1017
1018 queue->tx.req_cons = idx;
1019
1020 if (((gop-queue->tx_map_ops) >= ARRAY_SIZE(queue->tx_map_ops)) ||
1021 (*copy_ops >= ARRAY_SIZE(queue->tx_copy_ops)))
1022 break;
1023 }
1024
1025 (*map_ops) = gop - queue->tx_map_ops;
1026 return;
1027 }
1028
1029 /* Consolidate skb with a frag_list into a brand new one with local pages on
1030 * frags. Returns 0 or -ENOMEM if can't allocate new pages.
1031 */
1032 static int xenvif_handle_frag_list(struct xenvif_queue *queue, struct sk_buff *skb)
1033 {
1034 unsigned int offset = skb_headlen(skb);
1035 skb_frag_t frags[MAX_SKB_FRAGS];
1036 int i, f;
1037 struct ubuf_info *uarg;
1038 struct sk_buff *nskb = skb_shinfo(skb)->frag_list;
1039
1040 queue->stats.tx_zerocopy_sent += 2;
1041 queue->stats.tx_frag_overflow++;
1042
1043 xenvif_fill_frags(queue, nskb);
1044 /* Subtract frags size, we will correct it later */
1045 skb->truesize -= skb->data_len;
1046 skb->len += nskb->len;
1047 skb->data_len += nskb->len;
1048
1049 /* create a brand new frags array and coalesce there */
1050 for (i = 0; offset < skb->len; i++) {
1051 struct page *page;
1052 unsigned int len;
1053
1054 BUG_ON(i >= MAX_SKB_FRAGS);
1055 page = alloc_page(GFP_ATOMIC);
1056 if (!page) {
1057 int j;
1058 skb->truesize += skb->data_len;
1059 for (j = 0; j < i; j++)
1060 put_page(skb_frag_page(&frags[j]));
1061 return -ENOMEM;
1062 }
1063
1064 if (offset + PAGE_SIZE < skb->len)
1065 len = PAGE_SIZE;
1066 else
1067 len = skb->len - offset;
1068 if (skb_copy_bits(skb, offset, page_address(page), len))
1069 BUG();
1070
1071 offset += len;
1072 __skb_frag_set_page(&frags[i], page);
1073 skb_frag_off_set(&frags[i], 0);
1074 skb_frag_size_set(&frags[i], len);
1075 }
1076
1077 /* Release all the original (foreign) frags. */
1078 for (f = 0; f < skb_shinfo(skb)->nr_frags; f++)
1079 skb_frag_unref(skb, f);
1080 uarg = skb_shinfo(skb)->destructor_arg;
1081 /* increase inflight counter to offset decrement in callback */
1082 atomic_inc(&queue->inflight_packets);
1083 uarg->callback(uarg, true);
1084 skb_shinfo(skb)->destructor_arg = NULL;
1085
1086 /* Fill the skb with the new (local) frags. */
1087 memcpy(skb_shinfo(skb)->frags, frags, i * sizeof(skb_frag_t));
1088 skb_shinfo(skb)->nr_frags = i;
1089 skb->truesize += i * PAGE_SIZE;
1090
1091 return 0;
1092 }
1093
1094 static int xenvif_tx_submit(struct xenvif_queue *queue)
1095 {
1096 struct gnttab_map_grant_ref *gop_map = queue->tx_map_ops;
1097 struct gnttab_copy *gop_copy = queue->tx_copy_ops;
1098 struct sk_buff *skb;
1099 int work_done = 0;
1100
1101 while ((skb = __skb_dequeue(&queue->tx_queue)) != NULL) {
1102 struct xen_netif_tx_request *txp;
1103 u16 pending_idx;
1104 unsigned data_len;
1105
1106 pending_idx = XENVIF_TX_CB(skb)->pending_idx;
1107 txp = &queue->pending_tx_info[pending_idx].req;
1108
1109 /* Check the remap error code. */
1110 if (unlikely(xenvif_tx_check_gop(queue, skb, &gop_map, &gop_copy))) {
1111 /* If there was an error, xenvif_tx_check_gop is
1112 * expected to release all the frags which were mapped,
1113 * so kfree_skb shouldn't do it again
1114 */
1115 skb_shinfo(skb)->nr_frags = 0;
1116 if (skb_has_frag_list(skb)) {
1117 struct sk_buff *nskb =
1118 skb_shinfo(skb)->frag_list;
1119 skb_shinfo(nskb)->nr_frags = 0;
1120 }
1121 kfree_skb(skb);
1122 continue;
1123 }
1124
1125 data_len = skb->len;
1126 callback_param(queue, pending_idx).ctx = NULL;
1127 if (data_len < txp->size) {
1128 /* Append the packet payload as a fragment. */
1129 txp->offset += data_len;
1130 txp->size -= data_len;
1131 } else {
1132 /* Schedule a response immediately. */
1133 xenvif_idx_release(queue, pending_idx,
1134 XEN_NETIF_RSP_OKAY);
1135 }
1136
1137 if (txp->flags & XEN_NETTXF_csum_blank)
1138 skb->ip_summed = CHECKSUM_PARTIAL;
1139 else if (txp->flags & XEN_NETTXF_data_validated)
1140 skb->ip_summed = CHECKSUM_UNNECESSARY;
1141
1142 xenvif_fill_frags(queue, skb);
1143
1144 if (unlikely(skb_has_frag_list(skb))) {
1145 struct sk_buff *nskb = skb_shinfo(skb)->frag_list;
1146 xenvif_skb_zerocopy_prepare(queue, nskb);
1147 if (xenvif_handle_frag_list(queue, skb)) {
1148 if (net_ratelimit())
1149 netdev_err(queue->vif->dev,
1150 "Not enough memory to consolidate frag_list!\n");
1151 xenvif_skb_zerocopy_prepare(queue, skb);
1152 kfree_skb(skb);
1153 continue;
1154 }
1155 /* Copied all the bits from the frag list -- free it. */
1156 skb_frag_list_init(skb);
1157 kfree_skb(nskb);
1158 }
1159
1160 skb->dev = queue->vif->dev;
1161 skb->protocol = eth_type_trans(skb, skb->dev);
1162 skb_reset_network_header(skb);
1163
1164 if (checksum_setup(queue, skb)) {
1165 netdev_dbg(queue->vif->dev,
1166 "Can't setup checksum in net_tx_action\n");
1167 /* We have to set this flag to trigger the callback */
1168 if (skb_shinfo(skb)->destructor_arg)
1169 xenvif_skb_zerocopy_prepare(queue, skb);
1170 kfree_skb(skb);
1171 continue;
1172 }
1173
1174 skb_probe_transport_header(skb);
1175
1176 /* If the packet is GSO then we will have just set up the
1177 * transport header offset in checksum_setup so it's now
1178 * straightforward to calculate gso_segs.
1179 */
1180 if (skb_is_gso(skb)) {
1181 int mss, hdrlen;
1182
1183 /* GSO implies having the L4 header. */
1184 WARN_ON_ONCE(!skb_transport_header_was_set(skb));
1185 if (unlikely(!skb_transport_header_was_set(skb))) {
1186 kfree_skb(skb);
1187 continue;
1188 }
1189
1190 mss = skb_shinfo(skb)->gso_size;
1191 hdrlen = skb_transport_header(skb) -
1192 skb_mac_header(skb) +
1193 tcp_hdrlen(skb);
1194
1195 skb_shinfo(skb)->gso_segs =
1196 DIV_ROUND_UP(skb->len - hdrlen, mss);
1197 }
1198
1199 queue->stats.rx_bytes += skb->len;
1200 queue->stats.rx_packets++;
1201
1202 work_done++;
1203
1204 /* Set this flag right before netif_receive_skb, otherwise
1205 * someone might think this packet already left netback, and
1206 * do a skb_copy_ubufs while we are still in control of the
1207 * skb. E.g. the __pskb_pull_tail earlier can do such thing.
1208 */
1209 if (skb_shinfo(skb)->destructor_arg) {
1210 xenvif_skb_zerocopy_prepare(queue, skb);
1211 queue->stats.tx_zerocopy_sent++;
1212 }
1213
1214 netif_receive_skb(skb);
1215 }
1216
1217 return work_done;
1218 }
1219
1220 void xenvif_zerocopy_callback(struct ubuf_info *ubuf, bool zerocopy_success)
1221 {
1222 unsigned long flags;
1223 pending_ring_idx_t index;
1224 struct xenvif_queue *queue = ubuf_to_queue(ubuf);
1225
1226 /* This is the only place where we grab this lock, to protect callbacks
1227 * from each other.
1228 */
1229 spin_lock_irqsave(&queue->callback_lock, flags);
1230 do {
1231 u16 pending_idx = ubuf->desc;
1232 ubuf = (struct ubuf_info *) ubuf->ctx;
1233 BUG_ON(queue->dealloc_prod - queue->dealloc_cons >=
1234 MAX_PENDING_REQS);
1235 index = pending_index(queue->dealloc_prod);
1236 queue->dealloc_ring[index] = pending_idx;
1237 /* Sync with xenvif_tx_dealloc_action:
1238 * insert idx then incr producer.
1239 */
1240 smp_wmb();
1241 queue->dealloc_prod++;
1242 } while (ubuf);
1243 spin_unlock_irqrestore(&queue->callback_lock, flags);
1244
1245 if (likely(zerocopy_success))
1246 queue->stats.tx_zerocopy_success++;
1247 else
1248 queue->stats.tx_zerocopy_fail++;
1249 xenvif_skb_zerocopy_complete(queue);
1250 }
1251
1252 static inline void xenvif_tx_dealloc_action(struct xenvif_queue *queue)
1253 {
1254 struct gnttab_unmap_grant_ref *gop;
1255 pending_ring_idx_t dc, dp;
1256 u16 pending_idx, pending_idx_release[MAX_PENDING_REQS];
1257 unsigned int i = 0;
1258
1259 dc = queue->dealloc_cons;
1260 gop = queue->tx_unmap_ops;
1261
1262 /* Free up any grants we have finished using */
1263 do {
1264 dp = queue->dealloc_prod;
1265
1266 /* Ensure we see all indices enqueued by all
1267 * xenvif_zerocopy_callback().
1268 */
1269 smp_rmb();
1270
1271 while (dc != dp) {
1272 BUG_ON(gop - queue->tx_unmap_ops >= MAX_PENDING_REQS);
1273 pending_idx =
1274 queue->dealloc_ring[pending_index(dc++)];
1275
1276 pending_idx_release[gop - queue->tx_unmap_ops] =
1277 pending_idx;
1278 queue->pages_to_unmap[gop - queue->tx_unmap_ops] =
1279 queue->mmap_pages[pending_idx];
1280 gnttab_set_unmap_op(gop,
1281 idx_to_kaddr(queue, pending_idx),
1282 GNTMAP_host_map,
1283 queue->grant_tx_handle[pending_idx]);
1284 xenvif_grant_handle_reset(queue, pending_idx);
1285 ++gop;
1286 }
1287
1288 } while (dp != queue->dealloc_prod);
1289
1290 queue->dealloc_cons = dc;
1291
1292 if (gop - queue->tx_unmap_ops > 0) {
1293 int ret;
1294 ret = gnttab_unmap_refs(queue->tx_unmap_ops,
1295 NULL,
1296 queue->pages_to_unmap,
1297 gop - queue->tx_unmap_ops);
1298 if (ret) {
1299 netdev_err(queue->vif->dev, "Unmap fail: nr_ops %tu ret %d\n",
1300 gop - queue->tx_unmap_ops, ret);
1301 for (i = 0; i < gop - queue->tx_unmap_ops; ++i) {
1302 if (gop[i].status != GNTST_okay)
1303 netdev_err(queue->vif->dev,
1304 " host_addr: 0x%llx handle: 0x%x status: %d\n",
1305 gop[i].host_addr,
1306 gop[i].handle,
1307 gop[i].status);
1308 }
1309 BUG();
1310 }
1311 }
1312
1313 for (i = 0; i < gop - queue->tx_unmap_ops; ++i)
1314 xenvif_idx_release(queue, pending_idx_release[i],
1315 XEN_NETIF_RSP_OKAY);
1316 }
1317
1318
1319 /* Called after netfront has transmitted */
1320 int xenvif_tx_action(struct xenvif_queue *queue, int budget)
1321 {
1322 unsigned nr_mops, nr_cops = 0;
1323 int work_done, ret;
1324
1325 if (unlikely(!tx_work_todo(queue)))
1326 return 0;
1327
1328 xenvif_tx_build_gops(queue, budget, &nr_cops, &nr_mops);
1329
1330 if (nr_cops == 0)
1331 return 0;
1332
1333 gnttab_batch_copy(queue->tx_copy_ops, nr_cops);
1334 if (nr_mops != 0) {
1335 ret = gnttab_map_refs(queue->tx_map_ops,
1336 NULL,
1337 queue->pages_to_map,
1338 nr_mops);
1339 BUG_ON(ret);
1340 }
1341
1342 work_done = xenvif_tx_submit(queue);
1343
1344 return work_done;
1345 }
1346
1347 static void xenvif_idx_release(struct xenvif_queue *queue, u16 pending_idx,
1348 u8 status)
1349 {
1350 struct pending_tx_info *pending_tx_info;
1351 pending_ring_idx_t index;
1352 unsigned long flags;
1353
1354 pending_tx_info = &queue->pending_tx_info[pending_idx];
1355
1356 spin_lock_irqsave(&queue->response_lock, flags);
1357
1358 make_tx_response(queue, &pending_tx_info->req,
1359 pending_tx_info->extra_count, status);
1360
1361 /* Release the pending index before pusing the Tx response so
1362 * its available before a new Tx request is pushed by the
1363 * frontend.
1364 */
1365 index = pending_index(queue->pending_prod++);
1366 queue->pending_ring[index] = pending_idx;
1367
1368 push_tx_responses(queue);
1369
1370 spin_unlock_irqrestore(&queue->response_lock, flags);
1371 }
1372
1373
1374 static void make_tx_response(struct xenvif_queue *queue,
1375 struct xen_netif_tx_request *txp,
1376 unsigned int extra_count,
1377 s8 st)
1378 {
1379 RING_IDX i = queue->tx.rsp_prod_pvt;
1380 struct xen_netif_tx_response *resp;
1381
1382 resp = RING_GET_RESPONSE(&queue->tx, i);
1383 resp->id = txp->id;
1384 resp->status = st;
1385
1386 while (extra_count-- != 0)
1387 RING_GET_RESPONSE(&queue->tx, ++i)->status = XEN_NETIF_RSP_NULL;
1388
1389 queue->tx.rsp_prod_pvt = ++i;
1390 }
1391
1392 static void push_tx_responses(struct xenvif_queue *queue)
1393 {
1394 int notify;
1395
1396 RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&queue->tx, notify);
1397 if (notify)
1398 notify_remote_via_irq(queue->tx_irq);
1399 }
1400
1401 void xenvif_idx_unmap(struct xenvif_queue *queue, u16 pending_idx)
1402 {
1403 int ret;
1404 struct gnttab_unmap_grant_ref tx_unmap_op;
1405
1406 gnttab_set_unmap_op(&tx_unmap_op,
1407 idx_to_kaddr(queue, pending_idx),
1408 GNTMAP_host_map,
1409 queue->grant_tx_handle[pending_idx]);
1410 xenvif_grant_handle_reset(queue, pending_idx);
1411
1412 ret = gnttab_unmap_refs(&tx_unmap_op, NULL,
1413 &queue->mmap_pages[pending_idx], 1);
1414 if (ret) {
1415 netdev_err(queue->vif->dev,
1416 "Unmap fail: ret: %d pending_idx: %d host_addr: %llx handle: 0x%x status: %d\n",
1417 ret,
1418 pending_idx,
1419 tx_unmap_op.host_addr,
1420 tx_unmap_op.handle,
1421 tx_unmap_op.status);
1422 BUG();
1423 }
1424 }
1425
1426 static inline int tx_work_todo(struct xenvif_queue *queue)
1427 {
1428 if (likely(RING_HAS_UNCONSUMED_REQUESTS(&queue->tx)))
1429 return 1;
1430
1431 return 0;
1432 }
1433
1434 static inline bool tx_dealloc_work_todo(struct xenvif_queue *queue)
1435 {
1436 return queue->dealloc_cons != queue->dealloc_prod;
1437 }
1438
1439 void xenvif_unmap_frontend_data_rings(struct xenvif_queue *queue)
1440 {
1441 if (queue->tx.sring)
1442 xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(queue->vif),
1443 queue->tx.sring);
1444 if (queue->rx.sring)
1445 xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(queue->vif),
1446 queue->rx.sring);
1447 }
1448
1449 int xenvif_map_frontend_data_rings(struct xenvif_queue *queue,
1450 grant_ref_t tx_ring_ref,
1451 grant_ref_t rx_ring_ref)
1452 {
1453 void *addr;
1454 struct xen_netif_tx_sring *txs;
1455 struct xen_netif_rx_sring *rxs;
1456 RING_IDX rsp_prod, req_prod;
1457 int err = -ENOMEM;
1458
1459 err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(queue->vif),
1460 &tx_ring_ref, 1, &addr);
1461 if (err)
1462 goto err;
1463
1464 txs = (struct xen_netif_tx_sring *)addr;
1465 rsp_prod = READ_ONCE(txs->rsp_prod);
1466 req_prod = READ_ONCE(txs->req_prod);
1467
1468 BACK_RING_ATTACH(&queue->tx, txs, rsp_prod, XEN_PAGE_SIZE);
1469
1470 err = -EIO;
1471 if (req_prod - rsp_prod > RING_SIZE(&queue->tx))
1472 goto err;
1473
1474 err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(queue->vif),
1475 &rx_ring_ref, 1, &addr);
1476 if (err)
1477 goto err;
1478
1479 rxs = (struct xen_netif_rx_sring *)addr;
1480 rsp_prod = READ_ONCE(rxs->rsp_prod);
1481 req_prod = READ_ONCE(rxs->req_prod);
1482
1483 BACK_RING_ATTACH(&queue->rx, rxs, rsp_prod, XEN_PAGE_SIZE);
1484
1485 err = -EIO;
1486 if (req_prod - rsp_prod > RING_SIZE(&queue->rx))
1487 goto err;
1488
1489 return 0;
1490
1491 err:
1492 xenvif_unmap_frontend_data_rings(queue);
1493 return err;
1494 }
1495
1496 static bool xenvif_dealloc_kthread_should_stop(struct xenvif_queue *queue)
1497 {
1498 /* Dealloc thread must remain running until all inflight
1499 * packets complete.
1500 */
1501 return kthread_should_stop() &&
1502 !atomic_read(&queue->inflight_packets);
1503 }
1504
1505 int xenvif_dealloc_kthread(void *data)
1506 {
1507 struct xenvif_queue *queue = data;
1508
1509 for (;;) {
1510 wait_event_interruptible(queue->dealloc_wq,
1511 tx_dealloc_work_todo(queue) ||
1512 xenvif_dealloc_kthread_should_stop(queue));
1513 if (xenvif_dealloc_kthread_should_stop(queue))
1514 break;
1515
1516 xenvif_tx_dealloc_action(queue);
1517 cond_resched();
1518 }
1519
1520 /* Unmap anything remaining*/
1521 if (tx_dealloc_work_todo(queue))
1522 xenvif_tx_dealloc_action(queue);
1523
1524 return 0;
1525 }
1526
1527 static void make_ctrl_response(struct xenvif *vif,
1528 const struct xen_netif_ctrl_request *req,
1529 u32 status, u32 data)
1530 {
1531 RING_IDX idx = vif->ctrl.rsp_prod_pvt;
1532 struct xen_netif_ctrl_response rsp = {
1533 .id = req->id,
1534 .type = req->type,
1535 .status = status,
1536 .data = data,
1537 };
1538
1539 *RING_GET_RESPONSE(&vif->ctrl, idx) = rsp;
1540 vif->ctrl.rsp_prod_pvt = ++idx;
1541 }
1542
1543 static void push_ctrl_response(struct xenvif *vif)
1544 {
1545 int notify;
1546
1547 RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&vif->ctrl, notify);
1548 if (notify)
1549 notify_remote_via_irq(vif->ctrl_irq);
1550 }
1551
1552 static void process_ctrl_request(struct xenvif *vif,
1553 const struct xen_netif_ctrl_request *req)
1554 {
1555 u32 status = XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED;
1556 u32 data = 0;
1557
1558 switch (req->type) {
1559 case XEN_NETIF_CTRL_TYPE_SET_HASH_ALGORITHM:
1560 status = xenvif_set_hash_alg(vif, req->data[0]);
1561 break;
1562
1563 case XEN_NETIF_CTRL_TYPE_GET_HASH_FLAGS:
1564 status = xenvif_get_hash_flags(vif, &data);
1565 break;
1566
1567 case XEN_NETIF_CTRL_TYPE_SET_HASH_FLAGS:
1568 status = xenvif_set_hash_flags(vif, req->data[0]);
1569 break;
1570
1571 case XEN_NETIF_CTRL_TYPE_SET_HASH_KEY:
1572 status = xenvif_set_hash_key(vif, req->data[0],
1573 req->data[1]);
1574 break;
1575
1576 case XEN_NETIF_CTRL_TYPE_GET_HASH_MAPPING_SIZE:
1577 status = XEN_NETIF_CTRL_STATUS_SUCCESS;
1578 data = XEN_NETBK_MAX_HASH_MAPPING_SIZE;
1579 break;
1580
1581 case XEN_NETIF_CTRL_TYPE_SET_HASH_MAPPING_SIZE:
1582 status = xenvif_set_hash_mapping_size(vif,
1583 req->data[0]);
1584 break;
1585
1586 case XEN_NETIF_CTRL_TYPE_SET_HASH_MAPPING:
1587 status = xenvif_set_hash_mapping(vif, req->data[0],
1588 req->data[1],
1589 req->data[2]);
1590 break;
1591
1592 default:
1593 break;
1594 }
1595
1596 make_ctrl_response(vif, req, status, data);
1597 push_ctrl_response(vif);
1598 }
1599
1600 static void xenvif_ctrl_action(struct xenvif *vif)
1601 {
1602 for (;;) {
1603 RING_IDX req_prod, req_cons;
1604
1605 req_prod = vif->ctrl.sring->req_prod;
1606 req_cons = vif->ctrl.req_cons;
1607
1608 /* Make sure we can see requests before we process them. */
1609 rmb();
1610
1611 if (req_cons == req_prod)
1612 break;
1613
1614 while (req_cons != req_prod) {
1615 struct xen_netif_ctrl_request req;
1616
1617 RING_COPY_REQUEST(&vif->ctrl, req_cons, &req);
1618 req_cons++;
1619
1620 process_ctrl_request(vif, &req);
1621 }
1622
1623 vif->ctrl.req_cons = req_cons;
1624 vif->ctrl.sring->req_event = req_cons + 1;
1625 }
1626 }
1627
1628 static bool xenvif_ctrl_work_todo(struct xenvif *vif)
1629 {
1630 if (likely(RING_HAS_UNCONSUMED_REQUESTS(&vif->ctrl)))
1631 return true;
1632
1633 return false;
1634 }
1635
1636 irqreturn_t xenvif_ctrl_irq_fn(int irq, void *data)
1637 {
1638 struct xenvif *vif = data;
1639
1640 while (xenvif_ctrl_work_todo(vif))
1641 xenvif_ctrl_action(vif);
1642
1643 return IRQ_HANDLED;
1644 }
1645
1646 static int __init netback_init(void)
1647 {
1648 int rc = 0;
1649
1650 if (!xen_domain())
1651 return -ENODEV;
1652
1653 /* Allow as many queues as there are CPUs but max. 8 if user has not
1654 * specified a value.
1655 */
1656 if (xenvif_max_queues == 0)
1657 xenvif_max_queues = min_t(unsigned int, MAX_QUEUES_DEFAULT,
1658 num_online_cpus());
1659
1660 if (fatal_skb_slots < XEN_NETBK_LEGACY_SLOTS_MAX) {
1661 pr_info("fatal_skb_slots too small (%d), bump it to XEN_NETBK_LEGACY_SLOTS_MAX (%d)\n",
1662 fatal_skb_slots, XEN_NETBK_LEGACY_SLOTS_MAX);
1663 fatal_skb_slots = XEN_NETBK_LEGACY_SLOTS_MAX;
1664 }
1665
1666 rc = xenvif_xenbus_init();
1667 if (rc)
1668 goto failed_init;
1669
1670 #ifdef CONFIG_DEBUG_FS
1671 xen_netback_dbg_root = debugfs_create_dir("xen-netback", NULL);
1672 #endif /* CONFIG_DEBUG_FS */
1673
1674 return 0;
1675
1676 failed_init:
1677 return rc;
1678 }
1679
1680 module_init(netback_init);
1681
1682 static void __exit netback_fini(void)
1683 {
1684 #ifdef CONFIG_DEBUG_FS
1685 debugfs_remove_recursive(xen_netback_dbg_root);
1686 #endif /* CONFIG_DEBUG_FS */
1687 xenvif_xenbus_fini();
1688 }
1689 module_exit(netback_fini);
1690
1691 MODULE_LICENSE("Dual BSD/GPL");
1692 MODULE_ALIAS("xen-backend:vif");
Linux with added FPC-III support