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cpufreq/amd-pstate: Stop caching EPP
[pf-kernel.git] / drivers / net / xen-netback / netback.c
blob5836995d6774bc3c9e810bf5c14492f8df248b3f
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 #include <linux/skbuff_ref.h>
42
43 #include <net/tcp.h>
44
45 #include <xen/xen.h>
46 #include <xen/events.h>
47 #include <xen/interface/memory.h>
48 #include <xen/page.h>
49
50 #include <asm/xen/hypercall.h>
51
52 /* Provide an option to disable split event channels at load time as
53 * event channels are limited resource. Split event channels are
54 * enabled by default.
55 */
56 bool separate_tx_rx_irq = true;
57 module_param(separate_tx_rx_irq, bool, 0644);
58
59 /* The time that packets can stay on the guest Rx internal queue
60 * before they are dropped.
61 */
62 unsigned int rx_drain_timeout_msecs = 10000;
63 module_param(rx_drain_timeout_msecs, uint, 0444);
64
65 /* The length of time before the frontend is considered unresponsive
66 * because it isn't providing Rx slots.
67 */
68 unsigned int rx_stall_timeout_msecs = 60000;
69 module_param(rx_stall_timeout_msecs, uint, 0444);
70
71 #define MAX_QUEUES_DEFAULT 8
72 unsigned int xenvif_max_queues;
73 module_param_named(max_queues, xenvif_max_queues, uint, 0644);
74 MODULE_PARM_DESC(max_queues,
75 "Maximum number of queues per virtual interface");
76
77 /*
78 * This is the maximum slots a skb can have. If a guest sends a skb
79 * which exceeds this limit it is considered malicious.
80 */
81 #define FATAL_SKB_SLOTS_DEFAULT 20
82 static unsigned int fatal_skb_slots = FATAL_SKB_SLOTS_DEFAULT;
83 module_param(fatal_skb_slots, uint, 0444);
84
85 /* The amount to copy out of the first guest Tx slot into the skb's
86 * linear area. If the first slot has more data, it will be mapped
87 * and put into the first frag.
88 *
89 * This is sized to avoid pulling headers from the frags for most
90 * TCP/IP packets.
91 */
92 #define XEN_NETBACK_TX_COPY_LEN 128
93
94 /* This is the maximum number of flows in the hash cache. */
95 #define XENVIF_HASH_CACHE_SIZE_DEFAULT 64
96 unsigned int xenvif_hash_cache_size = XENVIF_HASH_CACHE_SIZE_DEFAULT;
97 module_param_named(hash_cache_size, xenvif_hash_cache_size, uint, 0644);
98 MODULE_PARM_DESC(hash_cache_size, "Number of flows in the hash cache");
99
100 /* The module parameter tells that we have to put data
101 * for xen-netfront with the XDP_PACKET_HEADROOM offset
102 * needed for XDP processing
103 */
104 bool provides_xdp_headroom = true;
105 module_param(provides_xdp_headroom, bool, 0644);
106
107 static void xenvif_idx_release(struct xenvif_queue *queue, u16 pending_idx,
108 s8 status);
109
110 static void make_tx_response(struct xenvif_queue *queue,
111 const struct xen_netif_tx_request *txp,
112 unsigned int extra_count,
113 s8 status);
114
115 static void xenvif_idx_unmap(struct xenvif_queue *queue, u16 pending_idx);
116
117 static inline int tx_work_todo(struct xenvif_queue *queue);
118
119 static inline unsigned long idx_to_pfn(struct xenvif_queue *queue,
120 u16 idx)
121 {
122 return page_to_pfn(queue->mmap_pages[idx]);
123 }
124
125 static inline unsigned long idx_to_kaddr(struct xenvif_queue *queue,
126 u16 idx)
127 {
128 return (unsigned long)pfn_to_kaddr(idx_to_pfn(queue, idx));
129 }
130
131 #define callback_param(vif, pending_idx) \
132 (vif->pending_tx_info[pending_idx].callback_struct)
133
134 /* Find the containing VIF's structure from a pointer in pending_tx_info array
135 */
136 static inline struct xenvif_queue *ubuf_to_queue(const struct ubuf_info_msgzc *ubuf)
137 {
138 u16 pending_idx = ubuf->desc;
139 struct pending_tx_info *temp =
140 container_of(ubuf, struct pending_tx_info, callback_struct);
141 return container_of(temp - pending_idx,
142 struct xenvif_queue,
143 pending_tx_info[0]);
144 }
145
146 static u16 frag_get_pending_idx(skb_frag_t *frag)
147 {
148 return (u16)skb_frag_off(frag);
149 }
150
151 static void frag_set_pending_idx(skb_frag_t *frag, u16 pending_idx)
152 {
153 skb_frag_off_set(frag, pending_idx);
154 }
155
156 static inline pending_ring_idx_t pending_index(unsigned i)
157 {
158 return i & (MAX_PENDING_REQS-1);
159 }
160
161 void xenvif_kick_thread(struct xenvif_queue *queue)
162 {
163 wake_up(&queue->wq);
164 }
165
166 void xenvif_napi_schedule_or_enable_events(struct xenvif_queue *queue)
167 {
168 int more_to_do;
169
170 RING_FINAL_CHECK_FOR_REQUESTS(&queue->tx, more_to_do);
171
172 if (more_to_do)
173 napi_schedule(&queue->napi);
174 else if (atomic_fetch_andnot(NETBK_TX_EOI | NETBK_COMMON_EOI,
175 &queue->eoi_pending) &
176 (NETBK_TX_EOI | NETBK_COMMON_EOI))
177 xen_irq_lateeoi(queue->tx_irq, 0);
178 }
179
180 static void tx_add_credit(struct xenvif_queue *queue)
181 {
182 unsigned long max_burst, max_credit;
183
184 /*
185 * Allow a burst big enough to transmit a jumbo packet of up to 128kB.
186 * Otherwise the interface can seize up due to insufficient credit.
187 */
188 max_burst = max(131072UL, queue->credit_bytes);
189
190 /* Take care that adding a new chunk of credit doesn't wrap to zero. */
191 max_credit = queue->remaining_credit + queue->credit_bytes;
192 if (max_credit < queue->remaining_credit)
193 max_credit = ULONG_MAX; /* wrapped: clamp to ULONG_MAX */
194
195 queue->remaining_credit = min(max_credit, max_burst);
196 queue->rate_limited = false;
197 }
198
199 void xenvif_tx_credit_callback(struct timer_list *t)
200 {
201 struct xenvif_queue *queue = from_timer(queue, t, credit_timeout);
202 tx_add_credit(queue);
203 xenvif_napi_schedule_or_enable_events(queue);
204 }
205
206 static void xenvif_tx_err(struct xenvif_queue *queue,
207 struct xen_netif_tx_request *txp,
208 unsigned int extra_count, RING_IDX end)
209 {
210 RING_IDX cons = queue->tx.req_cons;
211
212 do {
213 make_tx_response(queue, txp, extra_count, XEN_NETIF_RSP_ERROR);
214 if (cons == end)
215 break;
216 RING_COPY_REQUEST(&queue->tx, cons++, txp);
217 extra_count = 0; /* only the first frag can have extras */
218 } while (1);
219 queue->tx.req_cons = cons;
220 }
221
222 static void xenvif_fatal_tx_err(struct xenvif *vif)
223 {
224 netdev_err(vif->dev, "fatal error; disabling device\n");
225 vif->disabled = true;
226 /* Disable the vif from queue 0's kthread */
227 if (vif->num_queues)
228 xenvif_kick_thread(&vif->queues[0]);
229 }
230
231 static int xenvif_count_requests(struct xenvif_queue *queue,
232 struct xen_netif_tx_request *first,
233 unsigned int extra_count,
234 struct xen_netif_tx_request *txp,
235 int work_to_do)
236 {
237 RING_IDX cons = queue->tx.req_cons;
238 int slots = 0;
239 int drop_err = 0;
240 int more_data;
241
242 if (!(first->flags & XEN_NETTXF_more_data))
243 return 0;
244
245 do {
246 struct xen_netif_tx_request dropped_tx = { 0 };
247
248 if (slots >= work_to_do) {
249 netdev_err(queue->vif->dev,
250 "Asked for %d slots but exceeds this limit\n",
251 work_to_do);
252 xenvif_fatal_tx_err(queue->vif);
253 return -ENODATA;
254 }
255
256 /* This guest is really using too many slots and
257 * considered malicious.
258 */
259 if (unlikely(slots >= fatal_skb_slots)) {
260 netdev_err(queue->vif->dev,
261 "Malicious frontend using %d slots, threshold %u\n",
262 slots, fatal_skb_slots);
263 xenvif_fatal_tx_err(queue->vif);
264 return -E2BIG;
265 }
266
267 /* Xen network protocol had implicit dependency on
268 * MAX_SKB_FRAGS. XEN_NETBK_LEGACY_SLOTS_MAX is set to
269 * the historical MAX_SKB_FRAGS value 18 to honor the
270 * same behavior as before. Any packet using more than
271 * 18 slots but less than fatal_skb_slots slots is
272 * dropped
273 */
274 if (!drop_err && slots >= XEN_NETBK_LEGACY_SLOTS_MAX) {
275 if (net_ratelimit())
276 netdev_dbg(queue->vif->dev,
277 "Too many slots (%d) exceeding limit (%d), dropping packet\n",
278 slots, XEN_NETBK_LEGACY_SLOTS_MAX);
279 drop_err = -E2BIG;
280 }
281
282 if (drop_err)
283 txp = &dropped_tx;
284
285 RING_COPY_REQUEST(&queue->tx, cons + slots, txp);
286
287 /* If the guest submitted a frame >= 64 KiB then
288 * first->size overflowed and following slots will
289 * appear to be larger than the frame.
290 *
291 * This cannot be fatal error as there are buggy
292 * frontends that do this.
293 *
294 * Consume all slots and drop the packet.
295 */
296 if (!drop_err && txp->size > first->size) {
297 if (net_ratelimit())
298 netdev_dbg(queue->vif->dev,
299 "Invalid tx request, slot size %u > remaining size %u\n",
300 txp->size, first->size);
301 drop_err = -EIO;
302 }
303
304 first->size -= txp->size;
305 slots++;
306
307 if (unlikely((txp->offset + txp->size) > XEN_PAGE_SIZE)) {
308 netdev_err(queue->vif->dev, "Cross page boundary, txp->offset: %u, size: %u\n",
309 txp->offset, txp->size);
310 xenvif_fatal_tx_err(queue->vif);
311 return -EINVAL;
312 }
313
314 more_data = txp->flags & XEN_NETTXF_more_data;
315
316 if (!drop_err)
317 txp++;
318
319 } while (more_data);
320
321 if (drop_err) {
322 xenvif_tx_err(queue, first, extra_count, cons + slots);
323 return drop_err;
324 }
325
326 return slots;
327 }
328
329
330 struct xenvif_tx_cb {
331 u16 copy_pending_idx[XEN_NETBK_LEGACY_SLOTS_MAX + 1];
332 u8 copy_count;
333 u32 split_mask;
334 };
335
336 #define XENVIF_TX_CB(skb) ((struct xenvif_tx_cb *)(skb)->cb)
337 #define copy_pending_idx(skb, i) (XENVIF_TX_CB(skb)->copy_pending_idx[i])
338 #define copy_count(skb) (XENVIF_TX_CB(skb)->copy_count)
339
340 static inline void xenvif_tx_create_map_op(struct xenvif_queue *queue,
341 u16 pending_idx,
342 struct xen_netif_tx_request *txp,
343 unsigned int extra_count,
344 struct gnttab_map_grant_ref *mop)
345 {
346 queue->pages_to_map[mop-queue->tx_map_ops] = queue->mmap_pages[pending_idx];
347 gnttab_set_map_op(mop, idx_to_kaddr(queue, pending_idx),
348 GNTMAP_host_map | GNTMAP_readonly,
349 txp->gref, queue->vif->domid);
350
351 memcpy(&queue->pending_tx_info[pending_idx].req, txp,
352 sizeof(*txp));
353 queue->pending_tx_info[pending_idx].extra_count = extra_count;
354 }
355
356 static inline struct sk_buff *xenvif_alloc_skb(unsigned int size)
357 {
358 struct sk_buff *skb =
359 alloc_skb(size + NET_SKB_PAD + NET_IP_ALIGN,
360 GFP_ATOMIC | __GFP_NOWARN);
361
362 BUILD_BUG_ON(sizeof(*XENVIF_TX_CB(skb)) > sizeof(skb->cb));
363 if (unlikely(skb == NULL))
364 return NULL;
365
366 /* Packets passed to netif_rx() must have some headroom. */
367 skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN);
368
369 /* Initialize it here to avoid later surprises */
370 skb_shinfo(skb)->destructor_arg = NULL;
371
372 return skb;
373 }
374
375 static void xenvif_get_requests(struct xenvif_queue *queue,
376 struct sk_buff *skb,
377 struct xen_netif_tx_request *first,
378 struct xen_netif_tx_request *txfrags,
379 unsigned *copy_ops,
380 unsigned *map_ops,
381 unsigned int frag_overflow,
382 struct sk_buff *nskb,
383 unsigned int extra_count,
384 unsigned int data_len)
385 {
386 struct skb_shared_info *shinfo = skb_shinfo(skb);
387 skb_frag_t *frags = shinfo->frags;
388 u16 pending_idx;
389 pending_ring_idx_t index;
390 unsigned int nr_slots;
391 struct gnttab_copy *cop = queue->tx_copy_ops + *copy_ops;
392 struct gnttab_map_grant_ref *gop = queue->tx_map_ops + *map_ops;
393 struct xen_netif_tx_request *txp = first;
394
395 nr_slots = shinfo->nr_frags + frag_overflow + 1;
396
397 copy_count(skb) = 0;
398 XENVIF_TX_CB(skb)->split_mask = 0;
399
400 /* Create copy ops for exactly data_len bytes into the skb head. */
401 __skb_put(skb, data_len);
402 while (data_len > 0) {
403 int amount = data_len > txp->size ? txp->size : data_len;
404 bool split = false;
405
406 cop->source.u.ref = txp->gref;
407 cop->source.domid = queue->vif->domid;
408 cop->source.offset = txp->offset;
409
410 cop->dest.domid = DOMID_SELF;
411 cop->dest.offset = (offset_in_page(skb->data +
412 skb_headlen(skb) -
413 data_len)) & ~XEN_PAGE_MASK;
414 cop->dest.u.gmfn = virt_to_gfn(skb->data + skb_headlen(skb)
415 - data_len);
416
417 /* Don't cross local page boundary! */
418 if (cop->dest.offset + amount > XEN_PAGE_SIZE) {
419 amount = XEN_PAGE_SIZE - cop->dest.offset;
420 XENVIF_TX_CB(skb)->split_mask |= 1U << copy_count(skb);
421 split = true;
422 }
423
424 cop->len = amount;
425 cop->flags = GNTCOPY_source_gref;
426
427 index = pending_index(queue->pending_cons);
428 pending_idx = queue->pending_ring[index];
429 callback_param(queue, pending_idx).ctx = NULL;
430 copy_pending_idx(skb, copy_count(skb)) = pending_idx;
431 if (!split)
432 copy_count(skb)++;
433
434 cop++;
435 data_len -= amount;
436
437 if (amount == txp->size) {
438 /* The copy op covered the full tx_request */
439
440 memcpy(&queue->pending_tx_info[pending_idx].req,
441 txp, sizeof(*txp));
442 queue->pending_tx_info[pending_idx].extra_count =
443 (txp == first) ? extra_count : 0;
444
445 if (txp == first)
446 txp = txfrags;
447 else
448 txp++;
449 queue->pending_cons++;
450 nr_slots--;
451 } else {
452 /* The copy op partially covered the tx_request.
453 * The remainder will be mapped or copied in the next
454 * iteration.
455 */
456 txp->offset += amount;
457 txp->size -= amount;
458 }
459 }
460
461 for (shinfo->nr_frags = 0; nr_slots > 0 && shinfo->nr_frags < MAX_SKB_FRAGS;
462 nr_slots--) {
463 if (unlikely(!txp->size)) {
464 make_tx_response(queue, txp, 0, XEN_NETIF_RSP_OKAY);
465 ++txp;
466 continue;
467 }
468
469 index = pending_index(queue->pending_cons++);
470 pending_idx = queue->pending_ring[index];
471 xenvif_tx_create_map_op(queue, pending_idx, txp,
472 txp == first ? extra_count : 0, gop);
473 frag_set_pending_idx(&frags[shinfo->nr_frags], pending_idx);
474 ++shinfo->nr_frags;
475 ++gop;
476
477 if (txp == first)
478 txp = txfrags;
479 else
480 txp++;
481 }
482
483 if (nr_slots > 0) {
484
485 shinfo = skb_shinfo(nskb);
486 frags = shinfo->frags;
487
488 for (shinfo->nr_frags = 0; shinfo->nr_frags < nr_slots; ++txp) {
489 if (unlikely(!txp->size)) {
490 make_tx_response(queue, txp, 0,
491 XEN_NETIF_RSP_OKAY);
492 continue;
493 }
494
495 index = pending_index(queue->pending_cons++);
496 pending_idx = queue->pending_ring[index];
497 xenvif_tx_create_map_op(queue, pending_idx, txp, 0,
498 gop);
499 frag_set_pending_idx(&frags[shinfo->nr_frags],
500 pending_idx);
501 ++shinfo->nr_frags;
502 ++gop;
503 }
504
505 if (shinfo->nr_frags) {
506 skb_shinfo(skb)->frag_list = nskb;
507 nskb = NULL;
508 }
509 }
510
511 if (nskb) {
512 /* A frag_list skb was allocated but it is no longer needed
513 * because enough slots were converted to copy ops above or some
514 * were empty.
515 */
516 kfree_skb(nskb);
517 }
518
519 (*copy_ops) = cop - queue->tx_copy_ops;
520 (*map_ops) = gop - queue->tx_map_ops;
521 }
522
523 static inline void xenvif_grant_handle_set(struct xenvif_queue *queue,
524 u16 pending_idx,
525 grant_handle_t handle)
526 {
527 if (unlikely(queue->grant_tx_handle[pending_idx] !=
528 NETBACK_INVALID_HANDLE)) {
529 netdev_err(queue->vif->dev,
530 "Trying to overwrite active handle! pending_idx: 0x%x\n",
531 pending_idx);
532 BUG();
533 }
534 queue->grant_tx_handle[pending_idx] = handle;
535 }
536
537 static inline void xenvif_grant_handle_reset(struct xenvif_queue *queue,
538 u16 pending_idx)
539 {
540 if (unlikely(queue->grant_tx_handle[pending_idx] ==
541 NETBACK_INVALID_HANDLE)) {
542 netdev_err(queue->vif->dev,
543 "Trying to unmap invalid handle! pending_idx: 0x%x\n",
544 pending_idx);
545 BUG();
546 }
547 queue->grant_tx_handle[pending_idx] = NETBACK_INVALID_HANDLE;
548 }
549
550 static int xenvif_tx_check_gop(struct xenvif_queue *queue,
551 struct sk_buff *skb,
552 struct gnttab_map_grant_ref **gopp_map,
553 struct gnttab_copy **gopp_copy)
554 {
555 struct gnttab_map_grant_ref *gop_map = *gopp_map;
556 u16 pending_idx;
557 /* This always points to the shinfo of the skb being checked, which
558 * could be either the first or the one on the frag_list
559 */
560 struct skb_shared_info *shinfo = skb_shinfo(skb);
561 /* If this is non-NULL, we are currently checking the frag_list skb, and
562 * this points to the shinfo of the first one
563 */
564 struct skb_shared_info *first_shinfo = NULL;
565 int nr_frags = shinfo->nr_frags;
566 const bool sharedslot = nr_frags &&
567 frag_get_pending_idx(&shinfo->frags[0]) ==
568 copy_pending_idx(skb, copy_count(skb) - 1);
569 int i, err = 0;
570
571 for (i = 0; i < copy_count(skb); i++) {
572 int newerr;
573
574 /* Check status of header. */
575 pending_idx = copy_pending_idx(skb, i);
576
577 newerr = (*gopp_copy)->status;
578
579 /* Split copies need to be handled together. */
580 if (XENVIF_TX_CB(skb)->split_mask & (1U << i)) {
581 (*gopp_copy)++;
582 if (!newerr)
583 newerr = (*gopp_copy)->status;
584 }
585 if (likely(!newerr)) {
586 /* The first frag might still have this slot mapped */
587 if (i < copy_count(skb) - 1 || !sharedslot)
588 xenvif_idx_release(queue, pending_idx,
589 XEN_NETIF_RSP_OKAY);
590 } else {
591 err = newerr;
592 if (net_ratelimit())
593 netdev_dbg(queue->vif->dev,
594 "Grant copy of header failed! status: %d pending_idx: %u ref: %u\n",
595 (*gopp_copy)->status,
596 pending_idx,
597 (*gopp_copy)->source.u.ref);
598 /* The first frag might still have this slot mapped */
599 if (i < copy_count(skb) - 1 || !sharedslot)
600 xenvif_idx_release(queue, pending_idx,
601 XEN_NETIF_RSP_ERROR);
602 }
603 (*gopp_copy)++;
604 }
605
606 check_frags:
607 for (i = 0; i < nr_frags; i++, gop_map++) {
608 int j, newerr;
609
610 pending_idx = frag_get_pending_idx(&shinfo->frags[i]);
611
612 /* Check error status: if okay then remember grant handle. */
613 newerr = gop_map->status;
614
615 if (likely(!newerr)) {
616 xenvif_grant_handle_set(queue,
617 pending_idx,
618 gop_map->handle);
619 /* Had a previous error? Invalidate this fragment. */
620 if (unlikely(err)) {
621 xenvif_idx_unmap(queue, pending_idx);
622 /* If the mapping of the first frag was OK, but
623 * the header's copy failed, and they are
624 * sharing a slot, send an error
625 */
626 if (i == 0 && !first_shinfo && sharedslot)
627 xenvif_idx_release(queue, pending_idx,
628 XEN_NETIF_RSP_ERROR);
629 else
630 xenvif_idx_release(queue, pending_idx,
631 XEN_NETIF_RSP_OKAY);
632 }
633 continue;
634 }
635
636 /* Error on this fragment: respond to client with an error. */
637 if (net_ratelimit())
638 netdev_dbg(queue->vif->dev,
639 "Grant map of %d. frag failed! status: %d pending_idx: %u ref: %u\n",
640 i,
641 gop_map->status,
642 pending_idx,
643 gop_map->ref);
644
645 xenvif_idx_release(queue, pending_idx, XEN_NETIF_RSP_ERROR);
646
647 /* Not the first error? Preceding frags already invalidated. */
648 if (err)
649 continue;
650
651 /* Invalidate preceding fragments of this skb. */
652 for (j = 0; j < i; j++) {
653 pending_idx = frag_get_pending_idx(&shinfo->frags[j]);
654 xenvif_idx_unmap(queue, pending_idx);
655 xenvif_idx_release(queue, pending_idx,
656 XEN_NETIF_RSP_OKAY);
657 }
658
659 /* And if we found the error while checking the frag_list, unmap
660 * the first skb's frags
661 */
662 if (first_shinfo) {
663 for (j = 0; j < first_shinfo->nr_frags; j++) {
664 pending_idx = frag_get_pending_idx(&first_shinfo->frags[j]);
665 xenvif_idx_unmap(queue, pending_idx);
666 xenvif_idx_release(queue, pending_idx,
667 XEN_NETIF_RSP_OKAY);
668 }
669 }
670
671 /* Remember the error: invalidate all subsequent fragments. */
672 err = newerr;
673 }
674
675 if (skb_has_frag_list(skb) && !first_shinfo) {
676 first_shinfo = shinfo;
677 shinfo = skb_shinfo(shinfo->frag_list);
678 nr_frags = shinfo->nr_frags;
679
680 goto check_frags;
681 }
682
683 *gopp_map = gop_map;
684 return err;
685 }
686
687 static void xenvif_fill_frags(struct xenvif_queue *queue, struct sk_buff *skb)
688 {
689 struct skb_shared_info *shinfo = skb_shinfo(skb);
690 int nr_frags = shinfo->nr_frags;
691 int i;
692 u16 prev_pending_idx = INVALID_PENDING_IDX;
693
694 for (i = 0; i < nr_frags; i++) {
695 skb_frag_t *frag = shinfo->frags + i;
696 struct xen_netif_tx_request *txp;
697 struct page *page;
698 u16 pending_idx;
699
700 pending_idx = frag_get_pending_idx(frag);
701
702 /* If this is not the first frag, chain it to the previous*/
703 if (prev_pending_idx == INVALID_PENDING_IDX)
704 skb_shinfo(skb)->destructor_arg =
705 &callback_param(queue, pending_idx);
706 else
707 callback_param(queue, prev_pending_idx).ctx =
708 &callback_param(queue, pending_idx);
709
710 callback_param(queue, pending_idx).ctx = NULL;
711 prev_pending_idx = pending_idx;
712
713 txp = &queue->pending_tx_info[pending_idx].req;
714 page = virt_to_page((void *)idx_to_kaddr(queue, pending_idx));
715 __skb_fill_page_desc(skb, i, page, txp->offset, txp->size);
716 skb->len += txp->size;
717 skb->data_len += txp->size;
718 skb->truesize += txp->size;
719
720 /* Take an extra reference to offset network stack's put_page */
721 get_page(queue->mmap_pages[pending_idx]);
722 }
723 }
724
725 static int xenvif_get_extras(struct xenvif_queue *queue,
726 struct xen_netif_extra_info *extras,
727 unsigned int *extra_count,
728 int work_to_do)
729 {
730 struct xen_netif_extra_info extra;
731 RING_IDX cons = queue->tx.req_cons;
732
733 do {
734 if (unlikely(work_to_do-- <= 0)) {
735 netdev_err(queue->vif->dev, "Missing extra info\n");
736 xenvif_fatal_tx_err(queue->vif);
737 return -EBADR;
738 }
739
740 RING_COPY_REQUEST(&queue->tx, cons, &extra);
741
742 queue->tx.req_cons = ++cons;
743 (*extra_count)++;
744
745 if (unlikely(!extra.type ||
746 extra.type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
747 netdev_err(queue->vif->dev,
748 "Invalid extra type: %d\n", extra.type);
749 xenvif_fatal_tx_err(queue->vif);
750 return -EINVAL;
751 }
752
753 memcpy(&extras[extra.type - 1], &extra, sizeof(extra));
754 } while (extra.flags & XEN_NETIF_EXTRA_FLAG_MORE);
755
756 return work_to_do;
757 }
758
759 static int xenvif_set_skb_gso(struct xenvif *vif,
760 struct sk_buff *skb,
761 struct xen_netif_extra_info *gso)
762 {
763 if (!gso->u.gso.size) {
764 netdev_err(vif->dev, "GSO size must not be zero.\n");
765 xenvif_fatal_tx_err(vif);
766 return -EINVAL;
767 }
768
769 switch (gso->u.gso.type) {
770 case XEN_NETIF_GSO_TYPE_TCPV4:
771 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
772 break;
773 case XEN_NETIF_GSO_TYPE_TCPV6:
774 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
775 break;
776 default:
777 netdev_err(vif->dev, "Bad GSO type %d.\n", gso->u.gso.type);
778 xenvif_fatal_tx_err(vif);
779 return -EINVAL;
780 }
781
782 skb_shinfo(skb)->gso_size = gso->u.gso.size;
783 /* gso_segs will be calculated later */
784
785 return 0;
786 }
787
788 static int checksum_setup(struct xenvif_queue *queue, struct sk_buff *skb)
789 {
790 bool recalculate_partial_csum = false;
791
792 /* A GSO SKB must be CHECKSUM_PARTIAL. However some buggy
793 * peers can fail to set NETRXF_csum_blank when sending a GSO
794 * frame. In this case force the SKB to CHECKSUM_PARTIAL and
795 * recalculate the partial checksum.
796 */
797 if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) {
798 queue->stats.rx_gso_checksum_fixup++;
799 skb->ip_summed = CHECKSUM_PARTIAL;
800 recalculate_partial_csum = true;
801 }
802
803 /* A non-CHECKSUM_PARTIAL SKB does not require setup. */
804 if (skb->ip_summed != CHECKSUM_PARTIAL)
805 return 0;
806
807 return skb_checksum_setup(skb, recalculate_partial_csum);
808 }
809
810 static bool tx_credit_exceeded(struct xenvif_queue *queue, unsigned size)
811 {
812 u64 now = get_jiffies_64();
813 u64 next_credit = queue->credit_window_start +
814 msecs_to_jiffies(queue->credit_usec / 1000);
815
816 /* Timer could already be pending in rare cases. */
817 if (timer_pending(&queue->credit_timeout)) {
818 queue->rate_limited = true;
819 return true;
820 }
821
822 /* Passed the point where we can replenish credit? */
823 if (time_after_eq64(now, next_credit)) {
824 queue->credit_window_start = now;
825 tx_add_credit(queue);
826 }
827
828 /* Still too big to send right now? Set a callback. */
829 if (size > queue->remaining_credit) {
830 mod_timer(&queue->credit_timeout,
831 next_credit);
832 queue->credit_window_start = next_credit;
833 queue->rate_limited = true;
834
835 return true;
836 }
837
838 return false;
839 }
840
841 /* No locking is required in xenvif_mcast_add/del() as they are
842 * only ever invoked from NAPI poll. An RCU list is used because
843 * xenvif_mcast_match() is called asynchronously, during start_xmit.
844 */
845
846 static int xenvif_mcast_add(struct xenvif *vif, const u8 *addr)
847 {
848 struct xenvif_mcast_addr *mcast;
849
850 if (vif->fe_mcast_count == XEN_NETBK_MCAST_MAX) {
851 if (net_ratelimit())
852 netdev_err(vif->dev,
853 "Too many multicast addresses\n");
854 return -ENOSPC;
855 }
856
857 mcast = kzalloc(sizeof(*mcast), GFP_ATOMIC);
858 if (!mcast)
859 return -ENOMEM;
860
861 ether_addr_copy(mcast->addr, addr);
862 list_add_tail_rcu(&mcast->entry, &vif->fe_mcast_addr);
863 vif->fe_mcast_count++;
864
865 return 0;
866 }
867
868 static void xenvif_mcast_del(struct xenvif *vif, const u8 *addr)
869 {
870 struct xenvif_mcast_addr *mcast;
871
872 list_for_each_entry_rcu(mcast, &vif->fe_mcast_addr, entry) {
873 if (ether_addr_equal(addr, mcast->addr)) {
874 --vif->fe_mcast_count;
875 list_del_rcu(&mcast->entry);
876 kfree_rcu(mcast, rcu);
877 break;
878 }
879 }
880 }
881
882 bool xenvif_mcast_match(struct xenvif *vif, const u8 *addr)
883 {
884 struct xenvif_mcast_addr *mcast;
885
886 rcu_read_lock();
887 list_for_each_entry_rcu(mcast, &vif->fe_mcast_addr, entry) {
888 if (ether_addr_equal(addr, mcast->addr)) {
889 rcu_read_unlock();
890 return true;
891 }
892 }
893 rcu_read_unlock();
894
895 return false;
896 }
897
898 void xenvif_mcast_addr_list_free(struct xenvif *vif)
899 {
900 /* No need for locking or RCU here. NAPI poll and TX queue
901 * are stopped.
902 */
903 while (!list_empty(&vif->fe_mcast_addr)) {
904 struct xenvif_mcast_addr *mcast;
905
906 mcast = list_first_entry(&vif->fe_mcast_addr,
907 struct xenvif_mcast_addr,
908 entry);
909 --vif->fe_mcast_count;
910 list_del(&mcast->entry);
911 kfree(mcast);
912 }
913 }
914
915 static void xenvif_tx_build_gops(struct xenvif_queue *queue,
916 int budget,
917 unsigned *copy_ops,
918 unsigned *map_ops)
919 {
920 struct sk_buff *skb, *nskb;
921 int ret;
922 unsigned int frag_overflow;
923
924 while (skb_queue_len(&queue->tx_queue) < budget) {
925 struct xen_netif_tx_request txreq;
926 struct xen_netif_tx_request txfrags[XEN_NETBK_LEGACY_SLOTS_MAX];
927 struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX-1];
928 unsigned int extra_count;
929 RING_IDX idx;
930 int work_to_do;
931 unsigned int data_len;
932
933 if (queue->tx.sring->req_prod - queue->tx.req_cons >
934 XEN_NETIF_TX_RING_SIZE) {
935 netdev_err(queue->vif->dev,
936 "Impossible number of requests. "
937 "req_prod %d, req_cons %d, size %ld\n",
938 queue->tx.sring->req_prod, queue->tx.req_cons,
939 XEN_NETIF_TX_RING_SIZE);
940 xenvif_fatal_tx_err(queue->vif);
941 break;
942 }
943
944 work_to_do = XEN_RING_NR_UNCONSUMED_REQUESTS(&queue->tx);
945 if (!work_to_do)
946 break;
947
948 idx = queue->tx.req_cons;
949 rmb(); /* Ensure that we see the request before we copy it. */
950 RING_COPY_REQUEST(&queue->tx, idx, &txreq);
951
952 /* Credit-based scheduling. */
953 if (txreq.size > queue->remaining_credit &&
954 tx_credit_exceeded(queue, txreq.size))
955 break;
956
957 queue->remaining_credit -= txreq.size;
958
959 work_to_do--;
960 queue->tx.req_cons = ++idx;
961
962 memset(extras, 0, sizeof(extras));
963 extra_count = 0;
964 if (txreq.flags & XEN_NETTXF_extra_info) {
965 work_to_do = xenvif_get_extras(queue, extras,
966 &extra_count,
967 work_to_do);
968 idx = queue->tx.req_cons;
969 if (unlikely(work_to_do < 0))
970 break;
971 }
972
973 if (extras[XEN_NETIF_EXTRA_TYPE_MCAST_ADD - 1].type) {
974 struct xen_netif_extra_info *extra;
975
976 extra = &extras[XEN_NETIF_EXTRA_TYPE_MCAST_ADD - 1];
977 ret = xenvif_mcast_add(queue->vif, extra->u.mcast.addr);
978
979 make_tx_response(queue, &txreq, extra_count,
980 (ret == 0) ?
981 XEN_NETIF_RSP_OKAY :
982 XEN_NETIF_RSP_ERROR);
983 continue;
984 }
985
986 if (extras[XEN_NETIF_EXTRA_TYPE_MCAST_DEL - 1].type) {
987 struct xen_netif_extra_info *extra;
988
989 extra = &extras[XEN_NETIF_EXTRA_TYPE_MCAST_DEL - 1];
990 xenvif_mcast_del(queue->vif, extra->u.mcast.addr);
991
992 make_tx_response(queue, &txreq, extra_count,
993 XEN_NETIF_RSP_OKAY);
994 continue;
995 }
996
997 data_len = (txreq.size > XEN_NETBACK_TX_COPY_LEN) ?
998 XEN_NETBACK_TX_COPY_LEN : txreq.size;
999
1000 ret = xenvif_count_requests(queue, &txreq, extra_count,
1001 txfrags, work_to_do);
1002
1003 if (unlikely(ret < 0))
1004 break;
1005
1006 idx += ret;
1007
1008 if (unlikely(txreq.size < ETH_HLEN)) {
1009 netdev_dbg(queue->vif->dev,
1010 "Bad packet size: %d\n", txreq.size);
1011 xenvif_tx_err(queue, &txreq, extra_count, idx);
1012 break;
1013 }
1014
1015 /* No crossing a page as the payload mustn't fragment. */
1016 if (unlikely((txreq.offset + txreq.size) > XEN_PAGE_SIZE)) {
1017 netdev_err(queue->vif->dev, "Cross page boundary, txreq.offset: %u, size: %u\n",
1018 txreq.offset, txreq.size);
1019 xenvif_fatal_tx_err(queue->vif);
1020 break;
1021 }
1022
1023 if (ret >= XEN_NETBK_LEGACY_SLOTS_MAX - 1 && data_len < txreq.size)
1024 data_len = txreq.size;
1025
1026 skb = xenvif_alloc_skb(data_len);
1027 if (unlikely(skb == NULL)) {
1028 netdev_dbg(queue->vif->dev,
1029 "Can't allocate a skb in start_xmit.\n");
1030 xenvif_tx_err(queue, &txreq, extra_count, idx);
1031 break;
1032 }
1033
1034 skb_shinfo(skb)->nr_frags = ret;
1035 /* At this point shinfo->nr_frags is in fact the number of
1036 * slots, which can be as large as XEN_NETBK_LEGACY_SLOTS_MAX.
1037 */
1038 frag_overflow = 0;
1039 nskb = NULL;
1040 if (skb_shinfo(skb)->nr_frags > MAX_SKB_FRAGS) {
1041 frag_overflow = skb_shinfo(skb)->nr_frags - MAX_SKB_FRAGS;
1042 BUG_ON(frag_overflow > MAX_SKB_FRAGS);
1043 skb_shinfo(skb)->nr_frags = MAX_SKB_FRAGS;
1044 nskb = xenvif_alloc_skb(0);
1045 if (unlikely(nskb == NULL)) {
1046 skb_shinfo(skb)->nr_frags = 0;
1047 kfree_skb(skb);
1048 xenvif_tx_err(queue, &txreq, extra_count, idx);
1049 if (net_ratelimit())
1050 netdev_err(queue->vif->dev,
1051 "Can't allocate the frag_list skb.\n");
1052 break;
1053 }
1054 }
1055
1056 if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) {
1057 struct xen_netif_extra_info *gso;
1058 gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1];
1059
1060 if (xenvif_set_skb_gso(queue->vif, skb, gso)) {
1061 /* Failure in xenvif_set_skb_gso is fatal. */
1062 skb_shinfo(skb)->nr_frags = 0;
1063 kfree_skb(skb);
1064 kfree_skb(nskb);
1065 break;
1066 }
1067 }
1068
1069 if (extras[XEN_NETIF_EXTRA_TYPE_HASH - 1].type) {
1070 struct xen_netif_extra_info *extra;
1071 enum pkt_hash_types type = PKT_HASH_TYPE_NONE;
1072
1073 extra = &extras[XEN_NETIF_EXTRA_TYPE_HASH - 1];
1074
1075 switch (extra->u.hash.type) {
1076 case _XEN_NETIF_CTRL_HASH_TYPE_IPV4:
1077 case _XEN_NETIF_CTRL_HASH_TYPE_IPV6:
1078 type = PKT_HASH_TYPE_L3;
1079 break;
1080
1081 case _XEN_NETIF_CTRL_HASH_TYPE_IPV4_TCP:
1082 case _XEN_NETIF_CTRL_HASH_TYPE_IPV6_TCP:
1083 type = PKT_HASH_TYPE_L4;
1084 break;
1085
1086 default:
1087 break;
1088 }
1089
1090 if (type != PKT_HASH_TYPE_NONE)
1091 skb_set_hash(skb,
1092 *(u32 *)extra->u.hash.value,
1093 type);
1094 }
1095
1096 xenvif_get_requests(queue, skb, &txreq, txfrags, copy_ops,
1097 map_ops, frag_overflow, nskb, extra_count,
1098 data_len);
1099
1100 __skb_queue_tail(&queue->tx_queue, skb);
1101
1102 queue->tx.req_cons = idx;
1103 }
1104
1105 return;
1106 }
1107
1108 /* Consolidate skb with a frag_list into a brand new one with local pages on
1109 * frags. Returns 0 or -ENOMEM if can't allocate new pages.
1110 */
1111 static int xenvif_handle_frag_list(struct xenvif_queue *queue, struct sk_buff *skb)
1112 {
1113 unsigned int offset = skb_headlen(skb);
1114 skb_frag_t frags[MAX_SKB_FRAGS];
1115 int i, f;
1116 struct ubuf_info *uarg;
1117 struct sk_buff *nskb = skb_shinfo(skb)->frag_list;
1118
1119 queue->stats.tx_zerocopy_sent += 2;
1120 queue->stats.tx_frag_overflow++;
1121
1122 xenvif_fill_frags(queue, nskb);
1123 /* Subtract frags size, we will correct it later */
1124 skb->truesize -= skb->data_len;
1125 skb->len += nskb->len;
1126 skb->data_len += nskb->len;
1127
1128 /* create a brand new frags array and coalesce there */
1129 for (i = 0; offset < skb->len; i++) {
1130 struct page *page;
1131 unsigned int len;
1132
1133 BUG_ON(i >= MAX_SKB_FRAGS);
1134 page = alloc_page(GFP_ATOMIC);
1135 if (!page) {
1136 int j;
1137 skb->truesize += skb->data_len;
1138 for (j = 0; j < i; j++)
1139 put_page(skb_frag_page(&frags[j]));
1140 return -ENOMEM;
1141 }
1142
1143 if (offset + PAGE_SIZE < skb->len)
1144 len = PAGE_SIZE;
1145 else
1146 len = skb->len - offset;
1147 if (skb_copy_bits(skb, offset, page_address(page), len))
1148 BUG();
1149
1150 offset += len;
1151 skb_frag_fill_page_desc(&frags[i], page, 0, len);
1152 }
1153
1154 /* Release all the original (foreign) frags. */
1155 for (f = 0; f < skb_shinfo(skb)->nr_frags; f++)
1156 skb_frag_unref(skb, f);
1157 uarg = skb_shinfo(skb)->destructor_arg;
1158 /* increase inflight counter to offset decrement in callback */
1159 atomic_inc(&queue->inflight_packets);
1160 uarg->ops->complete(NULL, uarg, true);
1161 skb_shinfo(skb)->destructor_arg = NULL;
1162
1163 /* Fill the skb with the new (local) frags. */
1164 memcpy(skb_shinfo(skb)->frags, frags, i * sizeof(skb_frag_t));
1165 skb_shinfo(skb)->nr_frags = i;
1166 skb->truesize += i * PAGE_SIZE;
1167
1168 return 0;
1169 }
1170
1171 static int xenvif_tx_submit(struct xenvif_queue *queue)
1172 {
1173 struct gnttab_map_grant_ref *gop_map = queue->tx_map_ops;
1174 struct gnttab_copy *gop_copy = queue->tx_copy_ops;
1175 struct sk_buff *skb;
1176 int work_done = 0;
1177
1178 while ((skb = __skb_dequeue(&queue->tx_queue)) != NULL) {
1179 struct xen_netif_tx_request *txp;
1180 u16 pending_idx;
1181
1182 pending_idx = copy_pending_idx(skb, 0);
1183 txp = &queue->pending_tx_info[pending_idx].req;
1184
1185 /* Check the remap error code. */
1186 if (unlikely(xenvif_tx_check_gop(queue, skb, &gop_map, &gop_copy))) {
1187 /* If there was an error, xenvif_tx_check_gop is
1188 * expected to release all the frags which were mapped,
1189 * so kfree_skb shouldn't do it again
1190 */
1191 skb_shinfo(skb)->nr_frags = 0;
1192 if (skb_has_frag_list(skb)) {
1193 struct sk_buff *nskb =
1194 skb_shinfo(skb)->frag_list;
1195 skb_shinfo(nskb)->nr_frags = 0;
1196 }
1197 kfree_skb(skb);
1198 continue;
1199 }
1200
1201 if (txp->flags & XEN_NETTXF_csum_blank)
1202 skb->ip_summed = CHECKSUM_PARTIAL;
1203 else if (txp->flags & XEN_NETTXF_data_validated)
1204 skb->ip_summed = CHECKSUM_UNNECESSARY;
1205
1206 xenvif_fill_frags(queue, skb);
1207
1208 if (unlikely(skb_has_frag_list(skb))) {
1209 struct sk_buff *nskb = skb_shinfo(skb)->frag_list;
1210 xenvif_skb_zerocopy_prepare(queue, nskb);
1211 if (xenvif_handle_frag_list(queue, skb)) {
1212 if (net_ratelimit())
1213 netdev_err(queue->vif->dev,
1214 "Not enough memory to consolidate frag_list!\n");
1215 xenvif_skb_zerocopy_prepare(queue, skb);
1216 kfree_skb(skb);
1217 continue;
1218 }
1219 /* Copied all the bits from the frag list -- free it. */
1220 skb_frag_list_init(skb);
1221 kfree_skb(nskb);
1222 }
1223
1224 skb->dev = queue->vif->dev;
1225 skb->protocol = eth_type_trans(skb, skb->dev);
1226 skb_reset_network_header(skb);
1227
1228 if (checksum_setup(queue, skb)) {
1229 netdev_dbg(queue->vif->dev,
1230 "Can't setup checksum in net_tx_action\n");
1231 /* We have to set this flag to trigger the callback */
1232 if (skb_shinfo(skb)->destructor_arg)
1233 xenvif_skb_zerocopy_prepare(queue, skb);
1234 kfree_skb(skb);
1235 continue;
1236 }
1237
1238 skb_probe_transport_header(skb);
1239
1240 /* If the packet is GSO then we will have just set up the
1241 * transport header offset in checksum_setup so it's now
1242 * straightforward to calculate gso_segs.
1243 */
1244 if (skb_is_gso(skb)) {
1245 int mss, hdrlen;
1246
1247 /* GSO implies having the L4 header. */
1248 WARN_ON_ONCE(!skb_transport_header_was_set(skb));
1249 if (unlikely(!skb_transport_header_was_set(skb))) {
1250 kfree_skb(skb);
1251 continue;
1252 }
1253
1254 mss = skb_shinfo(skb)->gso_size;
1255 hdrlen = skb_tcp_all_headers(skb);
1256
1257 skb_shinfo(skb)->gso_segs =
1258 DIV_ROUND_UP(skb->len - hdrlen, mss);
1259 }
1260
1261 queue->stats.rx_bytes += skb->len;
1262 queue->stats.rx_packets++;
1263
1264 work_done++;
1265
1266 /* Set this flag right before netif_receive_skb, otherwise
1267 * someone might think this packet already left netback, and
1268 * do a skb_copy_ubufs while we are still in control of the
1269 * skb. E.g. the __pskb_pull_tail earlier can do such thing.
1270 */
1271 if (skb_shinfo(skb)->destructor_arg) {
1272 xenvif_skb_zerocopy_prepare(queue, skb);
1273 queue->stats.tx_zerocopy_sent++;
1274 }
1275
1276 netif_receive_skb(skb);
1277 }
1278
1279 return work_done;
1280 }
1281
1282 static void xenvif_zerocopy_callback(struct sk_buff *skb,
1283 struct ubuf_info *ubuf_base,
1284 bool zerocopy_success)
1285 {
1286 unsigned long flags;
1287 pending_ring_idx_t index;
1288 struct ubuf_info_msgzc *ubuf = uarg_to_msgzc(ubuf_base);
1289 struct xenvif_queue *queue = ubuf_to_queue(ubuf);
1290
1291 /* This is the only place where we grab this lock, to protect callbacks
1292 * from each other.
1293 */
1294 spin_lock_irqsave(&queue->callback_lock, flags);
1295 do {
1296 u16 pending_idx = ubuf->desc;
1297 ubuf = (struct ubuf_info_msgzc *) ubuf->ctx;
1298 BUG_ON(queue->dealloc_prod - queue->dealloc_cons >=
1299 MAX_PENDING_REQS);
1300 index = pending_index(queue->dealloc_prod);
1301 queue->dealloc_ring[index] = pending_idx;
1302 /* Sync with xenvif_tx_dealloc_action:
1303 * insert idx then incr producer.
1304 */
1305 smp_wmb();
1306 queue->dealloc_prod++;
1307 } while (ubuf);
1308 spin_unlock_irqrestore(&queue->callback_lock, flags);
1309
1310 if (likely(zerocopy_success))
1311 queue->stats.tx_zerocopy_success++;
1312 else
1313 queue->stats.tx_zerocopy_fail++;
1314 xenvif_skb_zerocopy_complete(queue);
1315 }
1316
1317 const struct ubuf_info_ops xenvif_ubuf_ops = {
1318 .complete = xenvif_zerocopy_callback,
1319 };
1320
1321 static inline void xenvif_tx_dealloc_action(struct xenvif_queue *queue)
1322 {
1323 struct gnttab_unmap_grant_ref *gop;
1324 pending_ring_idx_t dc, dp;
1325 u16 pending_idx, pending_idx_release[MAX_PENDING_REQS];
1326 unsigned int i = 0;
1327
1328 dc = queue->dealloc_cons;
1329 gop = queue->tx_unmap_ops;
1330
1331 /* Free up any grants we have finished using */
1332 do {
1333 dp = queue->dealloc_prod;
1334
1335 /* Ensure we see all indices enqueued by all
1336 * xenvif_zerocopy_callback().
1337 */
1338 smp_rmb();
1339
1340 while (dc != dp) {
1341 BUG_ON(gop - queue->tx_unmap_ops >= MAX_PENDING_REQS);
1342 pending_idx =
1343 queue->dealloc_ring[pending_index(dc++)];
1344
1345 pending_idx_release[gop - queue->tx_unmap_ops] =
1346 pending_idx;
1347 queue->pages_to_unmap[gop - queue->tx_unmap_ops] =
1348 queue->mmap_pages[pending_idx];
1349 gnttab_set_unmap_op(gop,
1350 idx_to_kaddr(queue, pending_idx),
1351 GNTMAP_host_map,
1352 queue->grant_tx_handle[pending_idx]);
1353 xenvif_grant_handle_reset(queue, pending_idx);
1354 ++gop;
1355 }
1356
1357 } while (dp != queue->dealloc_prod);
1358
1359 queue->dealloc_cons = dc;
1360
1361 if (gop - queue->tx_unmap_ops > 0) {
1362 int ret;
1363 ret = gnttab_unmap_refs(queue->tx_unmap_ops,
1364 NULL,
1365 queue->pages_to_unmap,
1366 gop - queue->tx_unmap_ops);
1367 if (ret) {
1368 netdev_err(queue->vif->dev, "Unmap fail: nr_ops %tu ret %d\n",
1369 gop - queue->tx_unmap_ops, ret);
1370 for (i = 0; i < gop - queue->tx_unmap_ops; ++i) {
1371 if (gop[i].status != GNTST_okay)
1372 netdev_err(queue->vif->dev,
1373 " host_addr: 0x%llx handle: 0x%x status: %d\n",
1374 gop[i].host_addr,
1375 gop[i].handle,
1376 gop[i].status);
1377 }
1378 BUG();
1379 }
1380 }
1381
1382 for (i = 0; i < gop - queue->tx_unmap_ops; ++i)
1383 xenvif_idx_release(queue, pending_idx_release[i],
1384 XEN_NETIF_RSP_OKAY);
1385 }
1386
1387
1388 /* Called after netfront has transmitted */
1389 int xenvif_tx_action(struct xenvif_queue *queue, int budget)
1390 {
1391 unsigned nr_mops = 0, nr_cops = 0;
1392 int work_done, ret;
1393
1394 if (unlikely(!tx_work_todo(queue)))
1395 return 0;
1396
1397 xenvif_tx_build_gops(queue, budget, &nr_cops, &nr_mops);
1398
1399 if (nr_cops == 0)
1400 return 0;
1401
1402 gnttab_batch_copy(queue->tx_copy_ops, nr_cops);
1403 if (nr_mops != 0) {
1404 ret = gnttab_map_refs(queue->tx_map_ops,
1405 NULL,
1406 queue->pages_to_map,
1407 nr_mops);
1408 if (ret) {
1409 unsigned int i;
1410
1411 netdev_err(queue->vif->dev, "Map fail: nr %u ret %d\n",
1412 nr_mops, ret);
1413 for (i = 0; i < nr_mops; ++i)
1414 WARN_ON_ONCE(queue->tx_map_ops[i].status ==
1415 GNTST_okay);
1416 }
1417 }
1418
1419 work_done = xenvif_tx_submit(queue);
1420
1421 return work_done;
1422 }
1423
1424 static void _make_tx_response(struct xenvif_queue *queue,
1425 const struct xen_netif_tx_request *txp,
1426 unsigned int extra_count,
1427 s8 status)
1428 {
1429 RING_IDX i = queue->tx.rsp_prod_pvt;
1430 struct xen_netif_tx_response *resp;
1431
1432 resp = RING_GET_RESPONSE(&queue->tx, i);
1433 resp->id = txp->id;
1434 resp->status = status;
1435
1436 while (extra_count-- != 0)
1437 RING_GET_RESPONSE(&queue->tx, ++i)->status = XEN_NETIF_RSP_NULL;
1438
1439 queue->tx.rsp_prod_pvt = ++i;
1440 }
1441
1442 static void push_tx_responses(struct xenvif_queue *queue)
1443 {
1444 int notify;
1445
1446 RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&queue->tx, notify);
1447 if (notify)
1448 notify_remote_via_irq(queue->tx_irq);
1449 }
1450
1451 static void xenvif_idx_release(struct xenvif_queue *queue, u16 pending_idx,
1452 s8 status)
1453 {
1454 struct pending_tx_info *pending_tx_info;
1455 pending_ring_idx_t index;
1456 unsigned long flags;
1457
1458 pending_tx_info = &queue->pending_tx_info[pending_idx];
1459
1460 spin_lock_irqsave(&queue->response_lock, flags);
1461
1462 _make_tx_response(queue, &pending_tx_info->req,
1463 pending_tx_info->extra_count, status);
1464
1465 /* Release the pending index before pusing the Tx response so
1466 * its available before a new Tx request is pushed by the
1467 * frontend.
1468 */
1469 index = pending_index(queue->pending_prod++);
1470 queue->pending_ring[index] = pending_idx;
1471
1472 push_tx_responses(queue);
1473
1474 spin_unlock_irqrestore(&queue->response_lock, flags);
1475 }
1476
1477 static void make_tx_response(struct xenvif_queue *queue,
1478 const struct xen_netif_tx_request *txp,
1479 unsigned int extra_count,
1480 s8 status)
1481 {
1482 unsigned long flags;
1483
1484 spin_lock_irqsave(&queue->response_lock, flags);
1485
1486 _make_tx_response(queue, txp, extra_count, status);
1487 push_tx_responses(queue);
1488
1489 spin_unlock_irqrestore(&queue->response_lock, flags);
1490 }
1491
1492 static void xenvif_idx_unmap(struct xenvif_queue *queue, u16 pending_idx)
1493 {
1494 int ret;
1495 struct gnttab_unmap_grant_ref tx_unmap_op;
1496
1497 gnttab_set_unmap_op(&tx_unmap_op,
1498 idx_to_kaddr(queue, pending_idx),
1499 GNTMAP_host_map,
1500 queue->grant_tx_handle[pending_idx]);
1501 xenvif_grant_handle_reset(queue, pending_idx);
1502
1503 ret = gnttab_unmap_refs(&tx_unmap_op, NULL,
1504 &queue->mmap_pages[pending_idx], 1);
1505 if (ret) {
1506 netdev_err(queue->vif->dev,
1507 "Unmap fail: ret: %d pending_idx: %d host_addr: %llx handle: 0x%x status: %d\n",
1508 ret,
1509 pending_idx,
1510 tx_unmap_op.host_addr,
1511 tx_unmap_op.handle,
1512 tx_unmap_op.status);
1513 BUG();
1514 }
1515 }
1516
1517 static inline int tx_work_todo(struct xenvif_queue *queue)
1518 {
1519 if (likely(RING_HAS_UNCONSUMED_REQUESTS(&queue->tx)))
1520 return 1;
1521
1522 return 0;
1523 }
1524
1525 static inline bool tx_dealloc_work_todo(struct xenvif_queue *queue)
1526 {
1527 return queue->dealloc_cons != queue->dealloc_prod;
1528 }
1529
1530 void xenvif_unmap_frontend_data_rings(struct xenvif_queue *queue)
1531 {
1532 if (queue->tx.sring)
1533 xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(queue->vif),
1534 queue->tx.sring);
1535 if (queue->rx.sring)
1536 xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(queue->vif),
1537 queue->rx.sring);
1538 }
1539
1540 int xenvif_map_frontend_data_rings(struct xenvif_queue *queue,
1541 grant_ref_t tx_ring_ref,
1542 grant_ref_t rx_ring_ref)
1543 {
1544 void *addr;
1545 struct xen_netif_tx_sring *txs;
1546 struct xen_netif_rx_sring *rxs;
1547 RING_IDX rsp_prod, req_prod;
1548 int err;
1549
1550 err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(queue->vif),
1551 &tx_ring_ref, 1, &addr);
1552 if (err)
1553 goto err;
1554
1555 txs = (struct xen_netif_tx_sring *)addr;
1556 rsp_prod = READ_ONCE(txs->rsp_prod);
1557 req_prod = READ_ONCE(txs->req_prod);
1558
1559 BACK_RING_ATTACH(&queue->tx, txs, rsp_prod, XEN_PAGE_SIZE);
1560
1561 err = -EIO;
1562 if (req_prod - rsp_prod > RING_SIZE(&queue->tx))
1563 goto err;
1564
1565 err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(queue->vif),
1566 &rx_ring_ref, 1, &addr);
1567 if (err)
1568 goto err;
1569
1570 rxs = (struct xen_netif_rx_sring *)addr;
1571 rsp_prod = READ_ONCE(rxs->rsp_prod);
1572 req_prod = READ_ONCE(rxs->req_prod);
1573
1574 BACK_RING_ATTACH(&queue->rx, rxs, rsp_prod, XEN_PAGE_SIZE);
1575
1576 err = -EIO;
1577 if (req_prod - rsp_prod > RING_SIZE(&queue->rx))
1578 goto err;
1579
1580 return 0;
1581
1582 err:
1583 xenvif_unmap_frontend_data_rings(queue);
1584 return err;
1585 }
1586
1587 static bool xenvif_dealloc_kthread_should_stop(struct xenvif_queue *queue)
1588 {
1589 /* Dealloc thread must remain running until all inflight
1590 * packets complete.
1591 */
1592 return kthread_should_stop() &&
1593 !atomic_read(&queue->inflight_packets);
1594 }
1595
1596 int xenvif_dealloc_kthread(void *data)
1597 {
1598 struct xenvif_queue *queue = data;
1599
1600 for (;;) {
1601 wait_event_interruptible(queue->dealloc_wq,
1602 tx_dealloc_work_todo(queue) ||
1603 xenvif_dealloc_kthread_should_stop(queue));
1604 if (xenvif_dealloc_kthread_should_stop(queue))
1605 break;
1606
1607 xenvif_tx_dealloc_action(queue);
1608 cond_resched();
1609 }
1610
1611 /* Unmap anything remaining*/
1612 if (tx_dealloc_work_todo(queue))
1613 xenvif_tx_dealloc_action(queue);
1614
1615 return 0;
1616 }
1617
1618 static void make_ctrl_response(struct xenvif *vif,
1619 const struct xen_netif_ctrl_request *req,
1620 u32 status, u32 data)
1621 {
1622 RING_IDX idx = vif->ctrl.rsp_prod_pvt;
1623 struct xen_netif_ctrl_response rsp = {
1624 .id = req->id,
1625 .type = req->type,
1626 .status = status,
1627 .data = data,
1628 };
1629
1630 *RING_GET_RESPONSE(&vif->ctrl, idx) = rsp;
1631 vif->ctrl.rsp_prod_pvt = ++idx;
1632 }
1633
1634 static void push_ctrl_response(struct xenvif *vif)
1635 {
1636 int notify;
1637
1638 RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&vif->ctrl, notify);
1639 if (notify)
1640 notify_remote_via_irq(vif->ctrl_irq);
1641 }
1642
1643 static void process_ctrl_request(struct xenvif *vif,
1644 const struct xen_netif_ctrl_request *req)
1645 {
1646 u32 status = XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED;
1647 u32 data = 0;
1648
1649 switch (req->type) {
1650 case XEN_NETIF_CTRL_TYPE_SET_HASH_ALGORITHM:
1651 status = xenvif_set_hash_alg(vif, req->data[0]);
1652 break;
1653
1654 case XEN_NETIF_CTRL_TYPE_GET_HASH_FLAGS:
1655 status = xenvif_get_hash_flags(vif, &data);
1656 break;
1657
1658 case XEN_NETIF_CTRL_TYPE_SET_HASH_FLAGS:
1659 status = xenvif_set_hash_flags(vif, req->data[0]);
1660 break;
1661
1662 case XEN_NETIF_CTRL_TYPE_SET_HASH_KEY:
1663 status = xenvif_set_hash_key(vif, req->data[0],
1664 req->data[1]);
1665 break;
1666
1667 case XEN_NETIF_CTRL_TYPE_GET_HASH_MAPPING_SIZE:
1668 status = XEN_NETIF_CTRL_STATUS_SUCCESS;
1669 data = XEN_NETBK_MAX_HASH_MAPPING_SIZE;
1670 break;
1671
1672 case XEN_NETIF_CTRL_TYPE_SET_HASH_MAPPING_SIZE:
1673 status = xenvif_set_hash_mapping_size(vif,
1674 req->data[0]);
1675 break;
1676
1677 case XEN_NETIF_CTRL_TYPE_SET_HASH_MAPPING:
1678 status = xenvif_set_hash_mapping(vif, req->data[0],
1679 req->data[1],
1680 req->data[2]);
1681 break;
1682
1683 default:
1684 break;
1685 }
1686
1687 make_ctrl_response(vif, req, status, data);
1688 push_ctrl_response(vif);
1689 }
1690
1691 static void xenvif_ctrl_action(struct xenvif *vif)
1692 {
1693 for (;;) {
1694 RING_IDX req_prod, req_cons;
1695
1696 req_prod = vif->ctrl.sring->req_prod;
1697 req_cons = vif->ctrl.req_cons;
1698
1699 /* Make sure we can see requests before we process them. */
1700 rmb();
1701
1702 if (req_cons == req_prod)
1703 break;
1704
1705 while (req_cons != req_prod) {
1706 struct xen_netif_ctrl_request req;
1707
1708 RING_COPY_REQUEST(&vif->ctrl, req_cons, &req);
1709 req_cons++;
1710
1711 process_ctrl_request(vif, &req);
1712 }
1713
1714 vif->ctrl.req_cons = req_cons;
1715 vif->ctrl.sring->req_event = req_cons + 1;
1716 }
1717 }
1718
1719 static bool xenvif_ctrl_work_todo(struct xenvif *vif)
1720 {
1721 if (likely(RING_HAS_UNCONSUMED_REQUESTS(&vif->ctrl)))
1722 return true;
1723
1724 return false;
1725 }
1726
1727 irqreturn_t xenvif_ctrl_irq_fn(int irq, void *data)
1728 {
1729 struct xenvif *vif = data;
1730 unsigned int eoi_flag = XEN_EOI_FLAG_SPURIOUS;
1731
1732 while (xenvif_ctrl_work_todo(vif)) {
1733 xenvif_ctrl_action(vif);
1734 eoi_flag = 0;
1735 }
1736
1737 xen_irq_lateeoi(irq, eoi_flag);
1738
1739 return IRQ_HANDLED;
1740 }
1741
1742 static int __init netback_init(void)
1743 {
1744 int rc = 0;
1745
1746 if (!xen_domain())
1747 return -ENODEV;
1748
1749 /* Allow as many queues as there are CPUs but max. 8 if user has not
1750 * specified a value.
1751 */
1752 if (xenvif_max_queues == 0)
1753 xenvif_max_queues = min_t(unsigned int, MAX_QUEUES_DEFAULT,
1754 num_online_cpus());
1755
1756 if (fatal_skb_slots < XEN_NETBK_LEGACY_SLOTS_MAX) {
1757 pr_info("fatal_skb_slots too small (%d), bump it to XEN_NETBK_LEGACY_SLOTS_MAX (%d)\n",
1758 fatal_skb_slots, XEN_NETBK_LEGACY_SLOTS_MAX);
1759 fatal_skb_slots = XEN_NETBK_LEGACY_SLOTS_MAX;
1760 }
1761
1762 rc = xenvif_xenbus_init();
1763 if (rc)
1764 goto failed_init;
1765
1766 #ifdef CONFIG_DEBUG_FS
1767 xen_netback_dbg_root = debugfs_create_dir("xen-netback", NULL);
1768 #endif /* CONFIG_DEBUG_FS */
1769
1770 return 0;
1771
1772 failed_init:
1773 return rc;
1774 }
1775
1776 module_init(netback_init);
1777
1778 static void __exit netback_fini(void)
1779 {
1780 #ifdef CONFIG_DEBUG_FS
1781 debugfs_remove_recursive(xen_netback_dbg_root);
1782 #endif /* CONFIG_DEBUG_FS */
1783 xenvif_xenbus_fini();
1784 }
1785 module_exit(netback_fini);
1786
1787 MODULE_DESCRIPTION("Xen backend network device module");
1788 MODULE_LICENSE("Dual BSD/GPL");
1789 MODULE_ALIAS("xen-backend:vif");
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