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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2009, Microsoft Corporation.
4 *
5 * Authors:
6 * Haiyang Zhang <haiyangz@microsoft.com>
7 * Hank Janssen <hjanssen@microsoft.com>
8 */
9#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10
11#include <linux/kernel.h>
12#include <linux/sched.h>
13#include <linux/wait.h>
14#include <linux/mm.h>
15#include <linux/delay.h>
16#include <linux/io.h>
17#include <linux/slab.h>
18#include <linux/netdevice.h>
19#include <linux/if_ether.h>
20#include <linux/vmalloc.h>
21#include <linux/rtnetlink.h>
22#include <linux/prefetch.h>
23
24#include <asm/sync_bitops.h>
25
26#include "hyperv_net.h"
27#include "netvsc_trace.h"
28
29/*
30 * Switch the data path from the synthetic interface to the VF
31 * interface.
32 */
33void netvsc_switch_datapath(struct net_device *ndev, bool vf)
34{
35 struct net_device_context *net_device_ctx = netdev_priv(ndev);
36 struct hv_device *dev = net_device_ctx->device_ctx;
37 struct netvsc_device *nv_dev = rtnl_dereference(net_device_ctx->nvdev);
38 struct nvsp_message *init_pkt = &nv_dev->channel_init_pkt;
39
40 memset(init_pkt, 0, sizeof(struct nvsp_message));
41 init_pkt->hdr.msg_type = NVSP_MSG4_TYPE_SWITCH_DATA_PATH;
42 if (vf)
43 init_pkt->msg.v4_msg.active_dp.active_datapath =
44 NVSP_DATAPATH_VF;
45 else
46 init_pkt->msg.v4_msg.active_dp.active_datapath =
47 NVSP_DATAPATH_SYNTHETIC;
48
49 trace_nvsp_send(ndev, init_pkt);
50
51 vmbus_sendpacket(dev->channel, init_pkt,
52 sizeof(struct nvsp_message),
53 (unsigned long)init_pkt,
54 VM_PKT_DATA_INBAND, 0);
55}
56
57/* Worker to setup sub channels on initial setup
58 * Initial hotplug event occurs in softirq context
59 * and can't wait for channels.
60 */
61static void netvsc_subchan_work(struct work_struct *w)
62{
63 struct netvsc_device *nvdev =
64 container_of(w, struct netvsc_device, subchan_work);
65 struct rndis_device *rdev;
66 int i, ret;
67
68 /* Avoid deadlock with device removal already under RTNL */
69 if (!rtnl_trylock()) {
70 schedule_work(w);
71 return;
72 }
73
74 rdev = nvdev->extension;
75 if (rdev) {
76 ret = rndis_set_subchannel(rdev->ndev, nvdev, NULL);
77 if (ret == 0) {
78 netif_device_attach(rdev->ndev);
79 } else {
80 /* fallback to only primary channel */
81 for (i = 1; i < nvdev->num_chn; i++)
82 netif_napi_del(&nvdev->chan_table[i].napi);
83
84 nvdev->max_chn = 1;
85 nvdev->num_chn = 1;
86 }
87 }
88
89 rtnl_unlock();
90}
91
92static struct netvsc_device *alloc_net_device(void)
93{
94 struct netvsc_device *net_device;
95
96 net_device = kzalloc(sizeof(struct netvsc_device), GFP_KERNEL);
97 if (!net_device)
98 return NULL;
99
100 init_waitqueue_head(&net_device->wait_drain);
101 net_device->destroy = false;
102 net_device->tx_disable = false;
103
104 net_device->max_pkt = RNDIS_MAX_PKT_DEFAULT;
105 net_device->pkt_align = RNDIS_PKT_ALIGN_DEFAULT;
106
107 init_completion(&net_device->channel_init_wait);
108 init_waitqueue_head(&net_device->subchan_open);
109 INIT_WORK(&net_device->subchan_work, netvsc_subchan_work);
110
111 return net_device;
112}
113
114static void free_netvsc_device(struct rcu_head *head)
115{
116 struct netvsc_device *nvdev
117 = container_of(head, struct netvsc_device, rcu);
118 int i;
119
120 kfree(nvdev->extension);
121 vfree(nvdev->recv_buf);
122 vfree(nvdev->send_buf);
123 kfree(nvdev->send_section_map);
124
125 for (i = 0; i < VRSS_CHANNEL_MAX; i++)
126 vfree(nvdev->chan_table[i].mrc.slots);
127
128 kfree(nvdev);
129}
130
131static void free_netvsc_device_rcu(struct netvsc_device *nvdev)
132{
133 call_rcu(&nvdev->rcu, free_netvsc_device);
134}
135
136static void netvsc_revoke_recv_buf(struct hv_device *device,
137 struct netvsc_device *net_device,
138 struct net_device *ndev)
139{
140 struct nvsp_message *revoke_packet;
141 int ret;
142
143 /*
144 * If we got a section count, it means we received a
145 * SendReceiveBufferComplete msg (ie sent
146 * NvspMessage1TypeSendReceiveBuffer msg) therefore, we need
147 * to send a revoke msg here
148 */
149 if (net_device->recv_section_cnt) {
150 /* Send the revoke receive buffer */
151 revoke_packet = &net_device->revoke_packet;
152 memset(revoke_packet, 0, sizeof(struct nvsp_message));
153
154 revoke_packet->hdr.msg_type =
155 NVSP_MSG1_TYPE_REVOKE_RECV_BUF;
156 revoke_packet->msg.v1_msg.
157 revoke_recv_buf.id = NETVSC_RECEIVE_BUFFER_ID;
158
159 trace_nvsp_send(ndev, revoke_packet);
160
161 ret = vmbus_sendpacket(device->channel,
162 revoke_packet,
163 sizeof(struct nvsp_message),
164 (unsigned long)revoke_packet,
165 VM_PKT_DATA_INBAND, 0);
166 /* If the failure is because the channel is rescinded;
167 * ignore the failure since we cannot send on a rescinded
168 * channel. This would allow us to properly cleanup
169 * even when the channel is rescinded.
170 */
171 if (device->channel->rescind)
172 ret = 0;
173 /*
174 * If we failed here, we might as well return and
175 * have a leak rather than continue and a bugchk
176 */
177 if (ret != 0) {
178 netdev_err(ndev, "unable to send "
179 "revoke receive buffer to netvsp\n");
180 return;
181 }
182 net_device->recv_section_cnt = 0;
183 }
184}
185
186static void netvsc_revoke_send_buf(struct hv_device *device,
187 struct netvsc_device *net_device,
188 struct net_device *ndev)
189{
190 struct nvsp_message *revoke_packet;
191 int ret;
192
193 /* Deal with the send buffer we may have setup.
194 * If we got a send section size, it means we received a
195 * NVSP_MSG1_TYPE_SEND_SEND_BUF_COMPLETE msg (ie sent
196 * NVSP_MSG1_TYPE_SEND_SEND_BUF msg) therefore, we need
197 * to send a revoke msg here
198 */
199 if (net_device->send_section_cnt) {
200 /* Send the revoke receive buffer */
201 revoke_packet = &net_device->revoke_packet;
202 memset(revoke_packet, 0, sizeof(struct nvsp_message));
203
204 revoke_packet->hdr.msg_type =
205 NVSP_MSG1_TYPE_REVOKE_SEND_BUF;
206 revoke_packet->msg.v1_msg.revoke_send_buf.id =
207 NETVSC_SEND_BUFFER_ID;
208
209 trace_nvsp_send(ndev, revoke_packet);
210
211 ret = vmbus_sendpacket(device->channel,
212 revoke_packet,
213 sizeof(struct nvsp_message),
214 (unsigned long)revoke_packet,
215 VM_PKT_DATA_INBAND, 0);
216
217 /* If the failure is because the channel is rescinded;
218 * ignore the failure since we cannot send on a rescinded
219 * channel. This would allow us to properly cleanup
220 * even when the channel is rescinded.
221 */
222 if (device->channel->rescind)
223 ret = 0;
224
225 /* If we failed here, we might as well return and
226 * have a leak rather than continue and a bugchk
227 */
228 if (ret != 0) {
229 netdev_err(ndev, "unable to send "
230 "revoke send buffer to netvsp\n");
231 return;
232 }
233 net_device->send_section_cnt = 0;
234 }
235}
236
237static void netvsc_teardown_recv_gpadl(struct hv_device *device,
238 struct netvsc_device *net_device,
239 struct net_device *ndev)
240{
241 int ret;
242
243 if (net_device->recv_buf_gpadl_handle) {
244 ret = vmbus_teardown_gpadl(device->channel,
245 net_device->recv_buf_gpadl_handle);
246
247 /* If we failed here, we might as well return and have a leak
248 * rather than continue and a bugchk
249 */
250 if (ret != 0) {
251 netdev_err(ndev,
252 "unable to teardown receive buffer's gpadl\n");
253 return;
254 }
255 net_device->recv_buf_gpadl_handle = 0;
256 }
257}
258
259static void netvsc_teardown_send_gpadl(struct hv_device *device,
260 struct netvsc_device *net_device,
261 struct net_device *ndev)
262{
263 int ret;
264
265 if (net_device->send_buf_gpadl_handle) {
266 ret = vmbus_teardown_gpadl(device->channel,
267 net_device->send_buf_gpadl_handle);
268
269 /* If we failed here, we might as well return and have a leak
270 * rather than continue and a bugchk
271 */
272 if (ret != 0) {
273 netdev_err(ndev,
274 "unable to teardown send buffer's gpadl\n");
275 return;
276 }
277 net_device->send_buf_gpadl_handle = 0;
278 }
279}
280
281int netvsc_alloc_recv_comp_ring(struct netvsc_device *net_device, u32 q_idx)
282{
283 struct netvsc_channel *nvchan = &net_device->chan_table[q_idx];
284 int node = cpu_to_node(nvchan->channel->target_cpu);
285 size_t size;
286
287 size = net_device->recv_completion_cnt * sizeof(struct recv_comp_data);
288 nvchan->mrc.slots = vzalloc_node(size, node);
289 if (!nvchan->mrc.slots)
290 nvchan->mrc.slots = vzalloc(size);
291
292 return nvchan->mrc.slots ? 0 : -ENOMEM;
293}
294
295static int netvsc_init_buf(struct hv_device *device,
296 struct netvsc_device *net_device,
297 const struct netvsc_device_info *device_info)
298{
299 struct nvsp_1_message_send_receive_buffer_complete *resp;
300 struct net_device *ndev = hv_get_drvdata(device);
301 struct nvsp_message *init_packet;
302 unsigned int buf_size;
303 size_t map_words;
304 int ret = 0;
305
306 /* Get receive buffer area. */
307 buf_size = device_info->recv_sections * device_info->recv_section_size;
308 buf_size = roundup(buf_size, PAGE_SIZE);
309
310 /* Legacy hosts only allow smaller receive buffer */
311 if (net_device->nvsp_version <= NVSP_PROTOCOL_VERSION_2)
312 buf_size = min_t(unsigned int, buf_size,
313 NETVSC_RECEIVE_BUFFER_SIZE_LEGACY);
314
315 net_device->recv_buf = vzalloc(buf_size);
316 if (!net_device->recv_buf) {
317 netdev_err(ndev,
318 "unable to allocate receive buffer of size %u\n",
319 buf_size);
320 ret = -ENOMEM;
321 goto cleanup;
322 }
323
324 net_device->recv_buf_size = buf_size;
325
326 /*
327 * Establish the gpadl handle for this buffer on this
328 * channel. Note: This call uses the vmbus connection rather
329 * than the channel to establish the gpadl handle.
330 */
331 ret = vmbus_establish_gpadl(device->channel, net_device->recv_buf,
332 buf_size,
333 &net_device->recv_buf_gpadl_handle);
334 if (ret != 0) {
335 netdev_err(ndev,
336 "unable to establish receive buffer's gpadl\n");
337 goto cleanup;
338 }
339
340 /* Notify the NetVsp of the gpadl handle */
341 init_packet = &net_device->channel_init_pkt;
342 memset(init_packet, 0, sizeof(struct nvsp_message));
343 init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_RECV_BUF;
344 init_packet->msg.v1_msg.send_recv_buf.
345 gpadl_handle = net_device->recv_buf_gpadl_handle;
346 init_packet->msg.v1_msg.
347 send_recv_buf.id = NETVSC_RECEIVE_BUFFER_ID;
348
349 trace_nvsp_send(ndev, init_packet);
350
351 /* Send the gpadl notification request */
352 ret = vmbus_sendpacket(device->channel, init_packet,
353 sizeof(struct nvsp_message),
354 (unsigned long)init_packet,
355 VM_PKT_DATA_INBAND,
356 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
357 if (ret != 0) {
358 netdev_err(ndev,
359 "unable to send receive buffer's gpadl to netvsp\n");
360 goto cleanup;
361 }
362
363 wait_for_completion(&net_device->channel_init_wait);
364
365 /* Check the response */
366 resp = &init_packet->msg.v1_msg.send_recv_buf_complete;
367 if (resp->status != NVSP_STAT_SUCCESS) {
368 netdev_err(ndev,
369 "Unable to complete receive buffer initialization with NetVsp - status %d\n",
370 resp->status);
371 ret = -EINVAL;
372 goto cleanup;
373 }
374
375 /* Parse the response */
376 netdev_dbg(ndev, "Receive sections: %u sub_allocs: size %u count: %u\n",
377 resp->num_sections, resp->sections[0].sub_alloc_size,
378 resp->sections[0].num_sub_allocs);
379
380 /* There should only be one section for the entire receive buffer */
381 if (resp->num_sections != 1 || resp->sections[0].offset != 0) {
382 ret = -EINVAL;
383 goto cleanup;
384 }
385
386 net_device->recv_section_size = resp->sections[0].sub_alloc_size;
387 net_device->recv_section_cnt = resp->sections[0].num_sub_allocs;
388
389 /* Setup receive completion ring */
390 net_device->recv_completion_cnt
391 = round_up(net_device->recv_section_cnt + 1,
392 PAGE_SIZE / sizeof(u64));
393 ret = netvsc_alloc_recv_comp_ring(net_device, 0);
394 if (ret)
395 goto cleanup;
396
397 /* Now setup the send buffer. */
398 buf_size = device_info->send_sections * device_info->send_section_size;
399 buf_size = round_up(buf_size, PAGE_SIZE);
400
401 net_device->send_buf = vzalloc(buf_size);
402 if (!net_device->send_buf) {
403 netdev_err(ndev, "unable to allocate send buffer of size %u\n",
404 buf_size);
405 ret = -ENOMEM;
406 goto cleanup;
407 }
408
409 /* Establish the gpadl handle for this buffer on this
410 * channel. Note: This call uses the vmbus connection rather
411 * than the channel to establish the gpadl handle.
412 */
413 ret = vmbus_establish_gpadl(device->channel, net_device->send_buf,
414 buf_size,
415 &net_device->send_buf_gpadl_handle);
416 if (ret != 0) {
417 netdev_err(ndev,
418 "unable to establish send buffer's gpadl\n");
419 goto cleanup;
420 }
421
422 /* Notify the NetVsp of the gpadl handle */
423 init_packet = &net_device->channel_init_pkt;
424 memset(init_packet, 0, sizeof(struct nvsp_message));
425 init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_SEND_BUF;
426 init_packet->msg.v1_msg.send_send_buf.gpadl_handle =
427 net_device->send_buf_gpadl_handle;
428 init_packet->msg.v1_msg.send_send_buf.id = NETVSC_SEND_BUFFER_ID;
429
430 trace_nvsp_send(ndev, init_packet);
431
432 /* Send the gpadl notification request */
433 ret = vmbus_sendpacket(device->channel, init_packet,
434 sizeof(struct nvsp_message),
435 (unsigned long)init_packet,
436 VM_PKT_DATA_INBAND,
437 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
438 if (ret != 0) {
439 netdev_err(ndev,
440 "unable to send send buffer's gpadl to netvsp\n");
441 goto cleanup;
442 }
443
444 wait_for_completion(&net_device->channel_init_wait);
445
446 /* Check the response */
447 if (init_packet->msg.v1_msg.
448 send_send_buf_complete.status != NVSP_STAT_SUCCESS) {
449 netdev_err(ndev, "Unable to complete send buffer "
450 "initialization with NetVsp - status %d\n",
451 init_packet->msg.v1_msg.
452 send_send_buf_complete.status);
453 ret = -EINVAL;
454 goto cleanup;
455 }
456
457 /* Parse the response */
458 net_device->send_section_size = init_packet->msg.
459 v1_msg.send_send_buf_complete.section_size;
460
461 /* Section count is simply the size divided by the section size. */
462 net_device->send_section_cnt = buf_size / net_device->send_section_size;
463
464 netdev_dbg(ndev, "Send section size: %d, Section count:%d\n",
465 net_device->send_section_size, net_device->send_section_cnt);
466
467 /* Setup state for managing the send buffer. */
468 map_words = DIV_ROUND_UP(net_device->send_section_cnt, BITS_PER_LONG);
469
470 net_device->send_section_map = kcalloc(map_words, sizeof(ulong), GFP_KERNEL);
471 if (net_device->send_section_map == NULL) {
472 ret = -ENOMEM;
473 goto cleanup;
474 }
475
476 goto exit;
477
478cleanup:
479 netvsc_revoke_recv_buf(device, net_device, ndev);
480 netvsc_revoke_send_buf(device, net_device, ndev);
481 netvsc_teardown_recv_gpadl(device, net_device, ndev);
482 netvsc_teardown_send_gpadl(device, net_device, ndev);
483
484exit:
485 return ret;
486}
487
488/* Negotiate NVSP protocol version */
489static int negotiate_nvsp_ver(struct hv_device *device,
490 struct netvsc_device *net_device,
491 struct nvsp_message *init_packet,
492 u32 nvsp_ver)
493{
494 struct net_device *ndev = hv_get_drvdata(device);
495 int ret;
496
497 memset(init_packet, 0, sizeof(struct nvsp_message));
498 init_packet->hdr.msg_type = NVSP_MSG_TYPE_INIT;
499 init_packet->msg.init_msg.init.min_protocol_ver = nvsp_ver;
500 init_packet->msg.init_msg.init.max_protocol_ver = nvsp_ver;
501 trace_nvsp_send(ndev, init_packet);
502
503 /* Send the init request */
504 ret = vmbus_sendpacket(device->channel, init_packet,
505 sizeof(struct nvsp_message),
506 (unsigned long)init_packet,
507 VM_PKT_DATA_INBAND,
508 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
509
510 if (ret != 0)
511 return ret;
512
513 wait_for_completion(&net_device->channel_init_wait);
514
515 if (init_packet->msg.init_msg.init_complete.status !=
516 NVSP_STAT_SUCCESS)
517 return -EINVAL;
518
519 if (nvsp_ver == NVSP_PROTOCOL_VERSION_1)
520 return 0;
521
522 /* NVSPv2 or later: Send NDIS config */
523 memset(init_packet, 0, sizeof(struct nvsp_message));
524 init_packet->hdr.msg_type = NVSP_MSG2_TYPE_SEND_NDIS_CONFIG;
525 init_packet->msg.v2_msg.send_ndis_config.mtu = ndev->mtu + ETH_HLEN;
526 init_packet->msg.v2_msg.send_ndis_config.capability.ieee8021q = 1;
527
528 if (nvsp_ver >= NVSP_PROTOCOL_VERSION_5) {
529 init_packet->msg.v2_msg.send_ndis_config.capability.sriov = 1;
530
531 /* Teaming bit is needed to receive link speed updates */
532 init_packet->msg.v2_msg.send_ndis_config.capability.teaming = 1;
533 }
534
535 if (nvsp_ver >= NVSP_PROTOCOL_VERSION_61)
536 init_packet->msg.v2_msg.send_ndis_config.capability.rsc = 1;
537
538 trace_nvsp_send(ndev, init_packet);
539
540 ret = vmbus_sendpacket(device->channel, init_packet,
541 sizeof(struct nvsp_message),
542 (unsigned long)init_packet,
543 VM_PKT_DATA_INBAND, 0);
544
545 return ret;
546}
547
548static int netvsc_connect_vsp(struct hv_device *device,
549 struct netvsc_device *net_device,
550 const struct netvsc_device_info *device_info)
551{
552 struct net_device *ndev = hv_get_drvdata(device);
553 static const u32 ver_list[] = {
554 NVSP_PROTOCOL_VERSION_1, NVSP_PROTOCOL_VERSION_2,
555 NVSP_PROTOCOL_VERSION_4, NVSP_PROTOCOL_VERSION_5,
556 NVSP_PROTOCOL_VERSION_6, NVSP_PROTOCOL_VERSION_61
557 };
558 struct nvsp_message *init_packet;
559 int ndis_version, i, ret;
560
561 init_packet = &net_device->channel_init_pkt;
562
563 /* Negotiate the latest NVSP protocol supported */
564 for (i = ARRAY_SIZE(ver_list) - 1; i >= 0; i--)
565 if (negotiate_nvsp_ver(device, net_device, init_packet,
566 ver_list[i]) == 0) {
567 net_device->nvsp_version = ver_list[i];
568 break;
569 }
570
571 if (i < 0) {
572 ret = -EPROTO;
573 goto cleanup;
574 }
575
576 pr_debug("Negotiated NVSP version:%x\n", net_device->nvsp_version);
577
578 /* Send the ndis version */
579 memset(init_packet, 0, sizeof(struct nvsp_message));
580
581 if (net_device->nvsp_version <= NVSP_PROTOCOL_VERSION_4)
582 ndis_version = 0x00060001;
583 else
584 ndis_version = 0x0006001e;
585
586 init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_NDIS_VER;
587 init_packet->msg.v1_msg.
588 send_ndis_ver.ndis_major_ver =
589 (ndis_version & 0xFFFF0000) >> 16;
590 init_packet->msg.v1_msg.
591 send_ndis_ver.ndis_minor_ver =
592 ndis_version & 0xFFFF;
593
594 trace_nvsp_send(ndev, init_packet);
595
596 /* Send the init request */
597 ret = vmbus_sendpacket(device->channel, init_packet,
598 sizeof(struct nvsp_message),
599 (unsigned long)init_packet,
600 VM_PKT_DATA_INBAND, 0);
601 if (ret != 0)
602 goto cleanup;
603
604
605 ret = netvsc_init_buf(device, net_device, device_info);
606
607cleanup:
608 return ret;
609}
610
611/*
612 * netvsc_device_remove - Callback when the root bus device is removed
613 */
614void netvsc_device_remove(struct hv_device *device)
615{
616 struct net_device *ndev = hv_get_drvdata(device);
617 struct net_device_context *net_device_ctx = netdev_priv(ndev);
618 struct netvsc_device *net_device
619 = rtnl_dereference(net_device_ctx->nvdev);
620 int i;
621
622 /*
623 * Revoke receive buffer. If host is pre-Win2016 then tear down
624 * receive buffer GPADL. Do the same for send buffer.
625 */
626 netvsc_revoke_recv_buf(device, net_device, ndev);
627 if (vmbus_proto_version < VERSION_WIN10)
628 netvsc_teardown_recv_gpadl(device, net_device, ndev);
629
630 netvsc_revoke_send_buf(device, net_device, ndev);
631 if (vmbus_proto_version < VERSION_WIN10)
632 netvsc_teardown_send_gpadl(device, net_device, ndev);
633
634 RCU_INIT_POINTER(net_device_ctx->nvdev, NULL);
635
636 /* And disassociate NAPI context from device */
637 for (i = 0; i < net_device->num_chn; i++)
638 netif_napi_del(&net_device->chan_table[i].napi);
639
640 /*
641 * At this point, no one should be accessing net_device
642 * except in here
643 */
644 netdev_dbg(ndev, "net device safe to remove\n");
645
646 /* Now, we can close the channel safely */
647 vmbus_close(device->channel);
648
649 /*
650 * If host is Win2016 or higher then we do the GPADL tear down
651 * here after VMBus is closed.
652 */
653 if (vmbus_proto_version >= VERSION_WIN10) {
654 netvsc_teardown_recv_gpadl(device, net_device, ndev);
655 netvsc_teardown_send_gpadl(device, net_device, ndev);
656 }
657
658 /* Release all resources */
659 free_netvsc_device_rcu(net_device);
660}
661
662#define RING_AVAIL_PERCENT_HIWATER 20
663#define RING_AVAIL_PERCENT_LOWATER 10
664
665static inline void netvsc_free_send_slot(struct netvsc_device *net_device,
666 u32 index)
667{
668 sync_change_bit(index, net_device->send_section_map);
669}
670
671static void netvsc_send_tx_complete(struct net_device *ndev,
672 struct netvsc_device *net_device,
673 struct vmbus_channel *channel,
674 const struct vmpacket_descriptor *desc,
675 int budget)
676{
677 struct sk_buff *skb = (struct sk_buff *)(unsigned long)desc->trans_id;
678 struct net_device_context *ndev_ctx = netdev_priv(ndev);
679 u16 q_idx = 0;
680 int queue_sends;
681
682 /* Notify the layer above us */
683 if (likely(skb)) {
684 const struct hv_netvsc_packet *packet
685 = (struct hv_netvsc_packet *)skb->cb;
686 u32 send_index = packet->send_buf_index;
687 struct netvsc_stats *tx_stats;
688
689 if (send_index != NETVSC_INVALID_INDEX)
690 netvsc_free_send_slot(net_device, send_index);
691 q_idx = packet->q_idx;
692
693 tx_stats = &net_device->chan_table[q_idx].tx_stats;
694
695 u64_stats_update_begin(&tx_stats->syncp);
696 tx_stats->packets += packet->total_packets;
697 tx_stats->bytes += packet->total_bytes;
698 u64_stats_update_end(&tx_stats->syncp);
699
700 napi_consume_skb(skb, budget);
701 }
702
703 queue_sends =
704 atomic_dec_return(&net_device->chan_table[q_idx].queue_sends);
705
706 if (unlikely(net_device->destroy)) {
707 if (queue_sends == 0)
708 wake_up(&net_device->wait_drain);
709 } else {
710 struct netdev_queue *txq = netdev_get_tx_queue(ndev, q_idx);
711
712 if (netif_tx_queue_stopped(txq) && !net_device->tx_disable &&
713 (hv_get_avail_to_write_percent(&channel->outbound) >
714 RING_AVAIL_PERCENT_HIWATER || queue_sends < 1)) {
715 netif_tx_wake_queue(txq);
716 ndev_ctx->eth_stats.wake_queue++;
717 }
718 }
719}
720
721static void netvsc_send_completion(struct net_device *ndev,
722 struct netvsc_device *net_device,
723 struct vmbus_channel *incoming_channel,
724 const struct vmpacket_descriptor *desc,
725 int budget)
726{
727 const struct nvsp_message *nvsp_packet = hv_pkt_data(desc);
728
729 switch (nvsp_packet->hdr.msg_type) {
730 case NVSP_MSG_TYPE_INIT_COMPLETE:
731 case NVSP_MSG1_TYPE_SEND_RECV_BUF_COMPLETE:
732 case NVSP_MSG1_TYPE_SEND_SEND_BUF_COMPLETE:
733 case NVSP_MSG5_TYPE_SUBCHANNEL:
734 /* Copy the response back */
735 memcpy(&net_device->channel_init_pkt, nvsp_packet,
736 sizeof(struct nvsp_message));
737 complete(&net_device->channel_init_wait);
738 break;
739
740 case NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE:
741 netvsc_send_tx_complete(ndev, net_device, incoming_channel,
742 desc, budget);
743 break;
744
745 default:
746 netdev_err(ndev,
747 "Unknown send completion type %d received!!\n",
748 nvsp_packet->hdr.msg_type);
749 }
750}
751
752static u32 netvsc_get_next_send_section(struct netvsc_device *net_device)
753{
754 unsigned long *map_addr = net_device->send_section_map;
755 unsigned int i;
756
757 for_each_clear_bit(i, map_addr, net_device->send_section_cnt) {
758 if (sync_test_and_set_bit(i, map_addr) == 0)
759 return i;
760 }
761
762 return NETVSC_INVALID_INDEX;
763}
764
765static void netvsc_copy_to_send_buf(struct netvsc_device *net_device,
766 unsigned int section_index,
767 u32 pend_size,
768 struct hv_netvsc_packet *packet,
769 struct rndis_message *rndis_msg,
770 struct hv_page_buffer *pb,
771 bool xmit_more)
772{
773 char *start = net_device->send_buf;
774 char *dest = start + (section_index * net_device->send_section_size)
775 + pend_size;
776 int i;
777 u32 padding = 0;
778 u32 page_count = packet->cp_partial ? packet->rmsg_pgcnt :
779 packet->page_buf_cnt;
780 u32 remain;
781
782 /* Add padding */
783 remain = packet->total_data_buflen & (net_device->pkt_align - 1);
784 if (xmit_more && remain) {
785 padding = net_device->pkt_align - remain;
786 rndis_msg->msg_len += padding;
787 packet->total_data_buflen += padding;
788 }
789
790 for (i = 0; i < page_count; i++) {
791 char *src = phys_to_virt(pb[i].pfn << PAGE_SHIFT);
792 u32 offset = pb[i].offset;
793 u32 len = pb[i].len;
794
795 memcpy(dest, (src + offset), len);
796 dest += len;
797 }
798
799 if (padding)
800 memset(dest, 0, padding);
801}
802
803static inline int netvsc_send_pkt(
804 struct hv_device *device,
805 struct hv_netvsc_packet *packet,
806 struct netvsc_device *net_device,
807 struct hv_page_buffer *pb,
808 struct sk_buff *skb)
809{
810 struct nvsp_message nvmsg;
811 struct nvsp_1_message_send_rndis_packet *rpkt =
812 &nvmsg.msg.v1_msg.send_rndis_pkt;
813 struct netvsc_channel * const nvchan =
814 &net_device->chan_table[packet->q_idx];
815 struct vmbus_channel *out_channel = nvchan->channel;
816 struct net_device *ndev = hv_get_drvdata(device);
817 struct net_device_context *ndev_ctx = netdev_priv(ndev);
818 struct netdev_queue *txq = netdev_get_tx_queue(ndev, packet->q_idx);
819 u64 req_id;
820 int ret;
821 u32 ring_avail = hv_get_avail_to_write_percent(&out_channel->outbound);
822
823 nvmsg.hdr.msg_type = NVSP_MSG1_TYPE_SEND_RNDIS_PKT;
824 if (skb)
825 rpkt->channel_type = 0; /* 0 is RMC_DATA */
826 else
827 rpkt->channel_type = 1; /* 1 is RMC_CONTROL */
828
829 rpkt->send_buf_section_index = packet->send_buf_index;
830 if (packet->send_buf_index == NETVSC_INVALID_INDEX)
831 rpkt->send_buf_section_size = 0;
832 else
833 rpkt->send_buf_section_size = packet->total_data_buflen;
834
835 req_id = (ulong)skb;
836
837 if (out_channel->rescind)
838 return -ENODEV;
839
840 trace_nvsp_send_pkt(ndev, out_channel, rpkt);
841
842 if (packet->page_buf_cnt) {
843 if (packet->cp_partial)
844 pb += packet->rmsg_pgcnt;
845
846 ret = vmbus_sendpacket_pagebuffer(out_channel,
847 pb, packet->page_buf_cnt,
848 &nvmsg, sizeof(nvmsg),
849 req_id);
850 } else {
851 ret = vmbus_sendpacket(out_channel,
852 &nvmsg, sizeof(nvmsg),
853 req_id, VM_PKT_DATA_INBAND,
854 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
855 }
856
857 if (ret == 0) {
858 atomic_inc_return(&nvchan->queue_sends);
859
860 if (ring_avail < RING_AVAIL_PERCENT_LOWATER) {
861 netif_tx_stop_queue(txq);
862 ndev_ctx->eth_stats.stop_queue++;
863 }
864 } else if (ret == -EAGAIN) {
865 netif_tx_stop_queue(txq);
866 ndev_ctx->eth_stats.stop_queue++;
867 } else {
868 netdev_err(ndev,
869 "Unable to send packet pages %u len %u, ret %d\n",
870 packet->page_buf_cnt, packet->total_data_buflen,
871 ret);
872 }
873
874 if (netif_tx_queue_stopped(txq) &&
875 atomic_read(&nvchan->queue_sends) < 1 &&
876 !net_device->tx_disable) {
877 netif_tx_wake_queue(txq);
878 ndev_ctx->eth_stats.wake_queue++;
879 if (ret == -EAGAIN)
880 ret = -ENOSPC;
881 }
882
883 return ret;
884}
885
886/* Move packet out of multi send data (msd), and clear msd */
887static inline void move_pkt_msd(struct hv_netvsc_packet **msd_send,
888 struct sk_buff **msd_skb,
889 struct multi_send_data *msdp)
890{
891 *msd_skb = msdp->skb;
892 *msd_send = msdp->pkt;
893 msdp->skb = NULL;
894 msdp->pkt = NULL;
895 msdp->count = 0;
896}
897
898/* RCU already held by caller */
899int netvsc_send(struct net_device *ndev,
900 struct hv_netvsc_packet *packet,
901 struct rndis_message *rndis_msg,
902 struct hv_page_buffer *pb,
903 struct sk_buff *skb)
904{
905 struct net_device_context *ndev_ctx = netdev_priv(ndev);
906 struct netvsc_device *net_device
907 = rcu_dereference_bh(ndev_ctx->nvdev);
908 struct hv_device *device = ndev_ctx->device_ctx;
909 int ret = 0;
910 struct netvsc_channel *nvchan;
911 u32 pktlen = packet->total_data_buflen, msd_len = 0;
912 unsigned int section_index = NETVSC_INVALID_INDEX;
913 struct multi_send_data *msdp;
914 struct hv_netvsc_packet *msd_send = NULL, *cur_send = NULL;
915 struct sk_buff *msd_skb = NULL;
916 bool try_batch, xmit_more;
917
918 /* If device is rescinded, return error and packet will get dropped. */
919 if (unlikely(!net_device || net_device->destroy))
920 return -ENODEV;
921
922 nvchan = &net_device->chan_table[packet->q_idx];
923 packet->send_buf_index = NETVSC_INVALID_INDEX;
924 packet->cp_partial = false;
925
926 /* Send control message directly without accessing msd (Multi-Send
927 * Data) field which may be changed during data packet processing.
928 */
929 if (!skb)
930 return netvsc_send_pkt(device, packet, net_device, pb, skb);
931
932 /* batch packets in send buffer if possible */
933 msdp = &nvchan->msd;
934 if (msdp->pkt)
935 msd_len = msdp->pkt->total_data_buflen;
936
937 try_batch = msd_len > 0 && msdp->count < net_device->max_pkt;
938 if (try_batch && msd_len + pktlen + net_device->pkt_align <
939 net_device->send_section_size) {
940 section_index = msdp->pkt->send_buf_index;
941
942 } else if (try_batch && msd_len + packet->rmsg_size <
943 net_device->send_section_size) {
944 section_index = msdp->pkt->send_buf_index;
945 packet->cp_partial = true;
946
947 } else if (pktlen + net_device->pkt_align <
948 net_device->send_section_size) {
949 section_index = netvsc_get_next_send_section(net_device);
950 if (unlikely(section_index == NETVSC_INVALID_INDEX)) {
951 ++ndev_ctx->eth_stats.tx_send_full;
952 } else {
953 move_pkt_msd(&msd_send, &msd_skb, msdp);
954 msd_len = 0;
955 }
956 }
957
958 /* Keep aggregating only if stack says more data is coming
959 * and not doing mixed modes send and not flow blocked
960 */
961 xmit_more = netdev_xmit_more() &&
962 !packet->cp_partial &&
963 !netif_xmit_stopped(netdev_get_tx_queue(ndev, packet->q_idx));
964
965 if (section_index != NETVSC_INVALID_INDEX) {
966 netvsc_copy_to_send_buf(net_device,
967 section_index, msd_len,
968 packet, rndis_msg, pb, xmit_more);
969
970 packet->send_buf_index = section_index;
971
972 if (packet->cp_partial) {
973 packet->page_buf_cnt -= packet->rmsg_pgcnt;
974 packet->total_data_buflen = msd_len + packet->rmsg_size;
975 } else {
976 packet->page_buf_cnt = 0;
977 packet->total_data_buflen += msd_len;
978 }
979
980 if (msdp->pkt) {
981 packet->total_packets += msdp->pkt->total_packets;
982 packet->total_bytes += msdp->pkt->total_bytes;
983 }
984
985 if (msdp->skb)
986 dev_consume_skb_any(msdp->skb);
987
988 if (xmit_more) {
989 msdp->skb = skb;
990 msdp->pkt = packet;
991 msdp->count++;
992 } else {
993 cur_send = packet;
994 msdp->skb = NULL;
995 msdp->pkt = NULL;
996 msdp->count = 0;
997 }
998 } else {
999 move_pkt_msd(&msd_send, &msd_skb, msdp);
1000 cur_send = packet;
1001 }
1002
1003 if (msd_send) {
1004 int m_ret = netvsc_send_pkt(device, msd_send, net_device,
1005 NULL, msd_skb);
1006
1007 if (m_ret != 0) {
1008 netvsc_free_send_slot(net_device,
1009 msd_send->send_buf_index);
1010 dev_kfree_skb_any(msd_skb);
1011 }
1012 }
1013
1014 if (cur_send)
1015 ret = netvsc_send_pkt(device, cur_send, net_device, pb, skb);
1016
1017 if (ret != 0 && section_index != NETVSC_INVALID_INDEX)
1018 netvsc_free_send_slot(net_device, section_index);
1019
1020 return ret;
1021}
1022
1023/* Send pending recv completions */
1024static int send_recv_completions(struct net_device *ndev,
1025 struct netvsc_device *nvdev,
1026 struct netvsc_channel *nvchan)
1027{
1028 struct multi_recv_comp *mrc = &nvchan->mrc;
1029 struct recv_comp_msg {
1030 struct nvsp_message_header hdr;
1031 u32 status;
1032 } __packed;
1033 struct recv_comp_msg msg = {
1034 .hdr.msg_type = NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE,
1035 };
1036 int ret;
1037
1038 while (mrc->first != mrc->next) {
1039 const struct recv_comp_data *rcd
1040 = mrc->slots + mrc->first;
1041
1042 msg.status = rcd->status;
1043 ret = vmbus_sendpacket(nvchan->channel, &msg, sizeof(msg),
1044 rcd->tid, VM_PKT_COMP, 0);
1045 if (unlikely(ret)) {
1046 struct net_device_context *ndev_ctx = netdev_priv(ndev);
1047
1048 ++ndev_ctx->eth_stats.rx_comp_busy;
1049 return ret;
1050 }
1051
1052 if (++mrc->first == nvdev->recv_completion_cnt)
1053 mrc->first = 0;
1054 }
1055
1056 /* receive completion ring has been emptied */
1057 if (unlikely(nvdev->destroy))
1058 wake_up(&nvdev->wait_drain);
1059
1060 return 0;
1061}
1062
1063/* Count how many receive completions are outstanding */
1064static void recv_comp_slot_avail(const struct netvsc_device *nvdev,
1065 const struct multi_recv_comp *mrc,
1066 u32 *filled, u32 *avail)
1067{
1068 u32 count = nvdev->recv_completion_cnt;
1069
1070 if (mrc->next >= mrc->first)
1071 *filled = mrc->next - mrc->first;
1072 else
1073 *filled = (count - mrc->first) + mrc->next;
1074
1075 *avail = count - *filled - 1;
1076}
1077
1078/* Add receive complete to ring to send to host. */
1079static void enq_receive_complete(struct net_device *ndev,
1080 struct netvsc_device *nvdev, u16 q_idx,
1081 u64 tid, u32 status)
1082{
1083 struct netvsc_channel *nvchan = &nvdev->chan_table[q_idx];
1084 struct multi_recv_comp *mrc = &nvchan->mrc;
1085 struct recv_comp_data *rcd;
1086 u32 filled, avail;
1087
1088 recv_comp_slot_avail(nvdev, mrc, &filled, &avail);
1089
1090 if (unlikely(filled > NAPI_POLL_WEIGHT)) {
1091 send_recv_completions(ndev, nvdev, nvchan);
1092 recv_comp_slot_avail(nvdev, mrc, &filled, &avail);
1093 }
1094
1095 if (unlikely(!avail)) {
1096 netdev_err(ndev, "Recv_comp full buf q:%hd, tid:%llx\n",
1097 q_idx, tid);
1098 return;
1099 }
1100
1101 rcd = mrc->slots + mrc->next;
1102 rcd->tid = tid;
1103 rcd->status = status;
1104
1105 if (++mrc->next == nvdev->recv_completion_cnt)
1106 mrc->next = 0;
1107}
1108
1109static int netvsc_receive(struct net_device *ndev,
1110 struct netvsc_device *net_device,
1111 struct netvsc_channel *nvchan,
1112 const struct vmpacket_descriptor *desc,
1113 const struct nvsp_message *nvsp)
1114{
1115 struct net_device_context *net_device_ctx = netdev_priv(ndev);
1116 struct vmbus_channel *channel = nvchan->channel;
1117 const struct vmtransfer_page_packet_header *vmxferpage_packet
1118 = container_of(desc, const struct vmtransfer_page_packet_header, d);
1119 u16 q_idx = channel->offermsg.offer.sub_channel_index;
1120 char *recv_buf = net_device->recv_buf;
1121 u32 status = NVSP_STAT_SUCCESS;
1122 int i;
1123 int count = 0;
1124
1125 /* Make sure this is a valid nvsp packet */
1126 if (unlikely(nvsp->hdr.msg_type != NVSP_MSG1_TYPE_SEND_RNDIS_PKT)) {
1127 netif_err(net_device_ctx, rx_err, ndev,
1128 "Unknown nvsp packet type received %u\n",
1129 nvsp->hdr.msg_type);
1130 return 0;
1131 }
1132
1133 if (unlikely(vmxferpage_packet->xfer_pageset_id != NETVSC_RECEIVE_BUFFER_ID)) {
1134 netif_err(net_device_ctx, rx_err, ndev,
1135 "Invalid xfer page set id - expecting %x got %x\n",
1136 NETVSC_RECEIVE_BUFFER_ID,
1137 vmxferpage_packet->xfer_pageset_id);
1138 return 0;
1139 }
1140
1141 count = vmxferpage_packet->range_cnt;
1142
1143 /* Each range represents 1 RNDIS pkt that contains 1 ethernet frame */
1144 for (i = 0; i < count; i++) {
1145 u32 offset = vmxferpage_packet->ranges[i].byte_offset;
1146 u32 buflen = vmxferpage_packet->ranges[i].byte_count;
1147 void *data;
1148 int ret;
1149
1150 if (unlikely(offset + buflen > net_device->recv_buf_size)) {
1151 nvchan->rsc.cnt = 0;
1152 status = NVSP_STAT_FAIL;
1153 netif_err(net_device_ctx, rx_err, ndev,
1154 "Packet offset:%u + len:%u too big\n",
1155 offset, buflen);
1156
1157 continue;
1158 }
1159
1160 data = recv_buf + offset;
1161
1162 nvchan->rsc.is_last = (i == count - 1);
1163
1164 trace_rndis_recv(ndev, q_idx, data);
1165
1166 /* Pass it to the upper layer */
1167 ret = rndis_filter_receive(ndev, net_device,
1168 nvchan, data, buflen);
1169
1170 if (unlikely(ret != NVSP_STAT_SUCCESS))
1171 status = NVSP_STAT_FAIL;
1172 }
1173
1174 enq_receive_complete(ndev, net_device, q_idx,
1175 vmxferpage_packet->d.trans_id, status);
1176
1177 return count;
1178}
1179
1180static void netvsc_send_table(struct net_device *ndev,
1181 struct netvsc_device *nvscdev,
1182 const struct nvsp_message *nvmsg,
1183 u32 msglen)
1184{
1185 struct net_device_context *net_device_ctx = netdev_priv(ndev);
1186 u32 count, offset, *tab;
1187 int i;
1188
1189 count = nvmsg->msg.v5_msg.send_table.count;
1190 offset = nvmsg->msg.v5_msg.send_table.offset;
1191
1192 if (count != VRSS_SEND_TAB_SIZE) {
1193 netdev_err(ndev, "Received wrong send-table size:%u\n", count);
1194 return;
1195 }
1196
1197 /* If negotiated version <= NVSP_PROTOCOL_VERSION_6, the offset may be
1198 * wrong due to a host bug. So fix the offset here.
1199 */
1200 if (nvscdev->nvsp_version <= NVSP_PROTOCOL_VERSION_6 &&
1201 msglen >= sizeof(struct nvsp_message_header) +
1202 sizeof(union nvsp_6_message_uber) + count * sizeof(u32))
1203 offset = sizeof(struct nvsp_message_header) +
1204 sizeof(union nvsp_6_message_uber);
1205
1206 /* Boundary check for all versions */
1207 if (offset > msglen - count * sizeof(u32)) {
1208 netdev_err(ndev, "Received send-table offset too big:%u\n",
1209 offset);
1210 return;
1211 }
1212
1213 tab = (void *)nvmsg + offset;
1214
1215 for (i = 0; i < count; i++)
1216 net_device_ctx->tx_table[i] = tab[i];
1217}
1218
1219static void netvsc_send_vf(struct net_device *ndev,
1220 const struct nvsp_message *nvmsg)
1221{
1222 struct net_device_context *net_device_ctx = netdev_priv(ndev);
1223
1224 net_device_ctx->vf_alloc = nvmsg->msg.v4_msg.vf_assoc.allocated;
1225 net_device_ctx->vf_serial = nvmsg->msg.v4_msg.vf_assoc.serial;
1226 netdev_info(ndev, "VF slot %u %s\n",
1227 net_device_ctx->vf_serial,
1228 net_device_ctx->vf_alloc ? "added" : "removed");
1229}
1230
1231static void netvsc_receive_inband(struct net_device *ndev,
1232 struct netvsc_device *nvscdev,
1233 const struct nvsp_message *nvmsg,
1234 u32 msglen)
1235{
1236 switch (nvmsg->hdr.msg_type) {
1237 case NVSP_MSG5_TYPE_SEND_INDIRECTION_TABLE:
1238 netvsc_send_table(ndev, nvscdev, nvmsg, msglen);
1239 break;
1240
1241 case NVSP_MSG4_TYPE_SEND_VF_ASSOCIATION:
1242 netvsc_send_vf(ndev, nvmsg);
1243 break;
1244 }
1245}
1246
1247static int netvsc_process_raw_pkt(struct hv_device *device,
1248 struct netvsc_channel *nvchan,
1249 struct netvsc_device *net_device,
1250 struct net_device *ndev,
1251 const struct vmpacket_descriptor *desc,
1252 int budget)
1253{
1254 struct vmbus_channel *channel = nvchan->channel;
1255 const struct nvsp_message *nvmsg = hv_pkt_data(desc);
1256 u32 msglen = hv_pkt_datalen(desc);
1257
1258 trace_nvsp_recv(ndev, channel, nvmsg);
1259
1260 switch (desc->type) {
1261 case VM_PKT_COMP:
1262 netvsc_send_completion(ndev, net_device, channel,
1263 desc, budget);
1264 break;
1265
1266 case VM_PKT_DATA_USING_XFER_PAGES:
1267 return netvsc_receive(ndev, net_device, nvchan,
1268 desc, nvmsg);
1269 break;
1270
1271 case VM_PKT_DATA_INBAND:
1272 netvsc_receive_inband(ndev, net_device, nvmsg, msglen);
1273 break;
1274
1275 default:
1276 netdev_err(ndev, "unhandled packet type %d, tid %llx\n",
1277 desc->type, desc->trans_id);
1278 break;
1279 }
1280
1281 return 0;
1282}
1283
1284static struct hv_device *netvsc_channel_to_device(struct vmbus_channel *channel)
1285{
1286 struct vmbus_channel *primary = channel->primary_channel;
1287
1288 return primary ? primary->device_obj : channel->device_obj;
1289}
1290
1291/* Network processing softirq
1292 * Process data in incoming ring buffer from host
1293 * Stops when ring is empty or budget is met or exceeded.
1294 */
1295int netvsc_poll(struct napi_struct *napi, int budget)
1296{
1297 struct netvsc_channel *nvchan
1298 = container_of(napi, struct netvsc_channel, napi);
1299 struct netvsc_device *net_device = nvchan->net_device;
1300 struct vmbus_channel *channel = nvchan->channel;
1301 struct hv_device *device = netvsc_channel_to_device(channel);
1302 struct net_device *ndev = hv_get_drvdata(device);
1303 int work_done = 0;
1304 int ret;
1305
1306 /* If starting a new interval */
1307 if (!nvchan->desc)
1308 nvchan->desc = hv_pkt_iter_first(channel);
1309
1310 while (nvchan->desc && work_done < budget) {
1311 work_done += netvsc_process_raw_pkt(device, nvchan, net_device,
1312 ndev, nvchan->desc, budget);
1313 nvchan->desc = hv_pkt_iter_next(channel, nvchan->desc);
1314 }
1315
1316 /* Send any pending receive completions */
1317 ret = send_recv_completions(ndev, net_device, nvchan);
1318
1319 /* If it did not exhaust NAPI budget this time
1320 * and not doing busy poll
1321 * then re-enable host interrupts
1322 * and reschedule if ring is not empty
1323 * or sending receive completion failed.
1324 */
1325 if (work_done < budget &&
1326 napi_complete_done(napi, work_done) &&
1327 (ret || hv_end_read(&channel->inbound)) &&
1328 napi_schedule_prep(napi)) {
1329 hv_begin_read(&channel->inbound);
1330 __napi_schedule(napi);
1331 }
1332
1333 /* Driver may overshoot since multiple packets per descriptor */
1334 return min(work_done, budget);
1335}
1336
1337/* Call back when data is available in host ring buffer.
1338 * Processing is deferred until network softirq (NAPI)
1339 */
1340void netvsc_channel_cb(void *context)
1341{
1342 struct netvsc_channel *nvchan = context;
1343 struct vmbus_channel *channel = nvchan->channel;
1344 struct hv_ring_buffer_info *rbi = &channel->inbound;
1345
1346 /* preload first vmpacket descriptor */
1347 prefetch(hv_get_ring_buffer(rbi) + rbi->priv_read_index);
1348
1349 if (napi_schedule_prep(&nvchan->napi)) {
1350 /* disable interrupts from host */
1351 hv_begin_read(rbi);
1352
1353 __napi_schedule_irqoff(&nvchan->napi);
1354 }
1355}
1356
1357/*
1358 * netvsc_device_add - Callback when the device belonging to this
1359 * driver is added
1360 */
1361struct netvsc_device *netvsc_device_add(struct hv_device *device,
1362 const struct netvsc_device_info *device_info)
1363{
1364 int i, ret = 0;
1365 struct netvsc_device *net_device;
1366 struct net_device *ndev = hv_get_drvdata(device);
1367 struct net_device_context *net_device_ctx = netdev_priv(ndev);
1368
1369 net_device = alloc_net_device();
1370 if (!net_device)
1371 return ERR_PTR(-ENOMEM);
1372
1373 for (i = 0; i < VRSS_SEND_TAB_SIZE; i++)
1374 net_device_ctx->tx_table[i] = 0;
1375
1376 /* Because the device uses NAPI, all the interrupt batching and
1377 * control is done via Net softirq, not the channel handling
1378 */
1379 set_channel_read_mode(device->channel, HV_CALL_ISR);
1380
1381 /* If we're reopening the device we may have multiple queues, fill the
1382 * chn_table with the default channel to use it before subchannels are
1383 * opened.
1384 * Initialize the channel state before we open;
1385 * we can be interrupted as soon as we open the channel.
1386 */
1387
1388 for (i = 0; i < VRSS_CHANNEL_MAX; i++) {
1389 struct netvsc_channel *nvchan = &net_device->chan_table[i];
1390
1391 nvchan->channel = device->channel;
1392 nvchan->net_device = net_device;
1393 u64_stats_init(&nvchan->tx_stats.syncp);
1394 u64_stats_init(&nvchan->rx_stats.syncp);
1395 }
1396
1397 /* Enable NAPI handler before init callbacks */
1398 netif_napi_add(ndev, &net_device->chan_table[0].napi,
1399 netvsc_poll, NAPI_POLL_WEIGHT);
1400
1401 /* Open the channel */
1402 ret = vmbus_open(device->channel, netvsc_ring_bytes,
1403 netvsc_ring_bytes, NULL, 0,
1404 netvsc_channel_cb, net_device->chan_table);
1405
1406 if (ret != 0) {
1407 netdev_err(ndev, "unable to open channel: %d\n", ret);
1408 goto cleanup;
1409 }
1410
1411 /* Channel is opened */
1412 netdev_dbg(ndev, "hv_netvsc channel opened successfully\n");
1413
1414 napi_enable(&net_device->chan_table[0].napi);
1415
1416 /* Connect with the NetVsp */
1417 ret = netvsc_connect_vsp(device, net_device, device_info);
1418 if (ret != 0) {
1419 netdev_err(ndev,
1420 "unable to connect to NetVSP - %d\n", ret);
1421 goto close;
1422 }
1423
1424 /* Writing nvdev pointer unlocks netvsc_send(), make sure chn_table is
1425 * populated.
1426 */
1427 rcu_assign_pointer(net_device_ctx->nvdev, net_device);
1428
1429 return net_device;
1430
1431close:
1432 RCU_INIT_POINTER(net_device_ctx->nvdev, NULL);
1433 napi_disable(&net_device->chan_table[0].napi);
1434
1435 /* Now, we can close the channel safely */
1436 vmbus_close(device->channel);
1437
1438cleanup:
1439 netif_napi_del(&net_device->chan_table[0].napi);
1440 free_netvsc_device(&net_device->rcu);
1441
1442 return ERR_PTR(ret);
1443}
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2009, Microsoft Corporation.
4 *
5 * Authors:
6 * Haiyang Zhang <haiyangz@microsoft.com>
7 * Hank Janssen <hjanssen@microsoft.com>
8 */
9#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10
11#include <linux/kernel.h>
12#include <linux/sched.h>
13#include <linux/wait.h>
14#include <linux/mm.h>
15#include <linux/delay.h>
16#include <linux/io.h>
17#include <linux/slab.h>
18#include <linux/netdevice.h>
19#include <linux/if_ether.h>
20#include <linux/vmalloc.h>
21#include <linux/rtnetlink.h>
22#include <linux/prefetch.h>
23#include <linux/filter.h>
24
25#include <asm/sync_bitops.h>
26#include <asm/mshyperv.h>
27
28#include "hyperv_net.h"
29#include "netvsc_trace.h"
30
31/*
32 * Switch the data path from the synthetic interface to the VF
33 * interface.
34 */
35int netvsc_switch_datapath(struct net_device *ndev, bool vf)
36{
37 struct net_device_context *net_device_ctx = netdev_priv(ndev);
38 struct hv_device *dev = net_device_ctx->device_ctx;
39 struct netvsc_device *nv_dev = rtnl_dereference(net_device_ctx->nvdev);
40 struct nvsp_message *init_pkt = &nv_dev->channel_init_pkt;
41 int ret, retry = 0;
42
43 /* Block sending traffic to VF if it's about to be gone */
44 if (!vf)
45 net_device_ctx->data_path_is_vf = vf;
46
47 memset(init_pkt, 0, sizeof(struct nvsp_message));
48 init_pkt->hdr.msg_type = NVSP_MSG4_TYPE_SWITCH_DATA_PATH;
49 if (vf)
50 init_pkt->msg.v4_msg.active_dp.active_datapath =
51 NVSP_DATAPATH_VF;
52 else
53 init_pkt->msg.v4_msg.active_dp.active_datapath =
54 NVSP_DATAPATH_SYNTHETIC;
55
56again:
57 trace_nvsp_send(ndev, init_pkt);
58
59 ret = vmbus_sendpacket(dev->channel, init_pkt,
60 sizeof(struct nvsp_message),
61 (unsigned long)init_pkt, VM_PKT_DATA_INBAND,
62 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
63
64 /* If failed to switch to/from VF, let data_path_is_vf stay false,
65 * so we use synthetic path to send data.
66 */
67 if (ret) {
68 if (ret != -EAGAIN) {
69 netdev_err(ndev,
70 "Unable to send sw datapath msg, err: %d\n",
71 ret);
72 return ret;
73 }
74
75 if (retry++ < RETRY_MAX) {
76 usleep_range(RETRY_US_LO, RETRY_US_HI);
77 goto again;
78 } else {
79 netdev_err(
80 ndev,
81 "Retry failed to send sw datapath msg, err: %d\n",
82 ret);
83 return ret;
84 }
85 }
86
87 wait_for_completion(&nv_dev->channel_init_wait);
88 net_device_ctx->data_path_is_vf = vf;
89
90 return 0;
91}
92
93/* Worker to setup sub channels on initial setup
94 * Initial hotplug event occurs in softirq context
95 * and can't wait for channels.
96 */
97static void netvsc_subchan_work(struct work_struct *w)
98{
99 struct netvsc_device *nvdev =
100 container_of(w, struct netvsc_device, subchan_work);
101 struct rndis_device *rdev;
102 int i, ret;
103
104 /* Avoid deadlock with device removal already under RTNL */
105 if (!rtnl_trylock()) {
106 schedule_work(w);
107 return;
108 }
109
110 rdev = nvdev->extension;
111 if (rdev) {
112 ret = rndis_set_subchannel(rdev->ndev, nvdev, NULL);
113 if (ret == 0) {
114 netif_device_attach(rdev->ndev);
115 } else {
116 /* fallback to only primary channel */
117 for (i = 1; i < nvdev->num_chn; i++)
118 netif_napi_del(&nvdev->chan_table[i].napi);
119
120 nvdev->max_chn = 1;
121 nvdev->num_chn = 1;
122 }
123 }
124
125 rtnl_unlock();
126}
127
128static struct netvsc_device *alloc_net_device(void)
129{
130 struct netvsc_device *net_device;
131
132 net_device = kzalloc(sizeof(struct netvsc_device), GFP_KERNEL);
133 if (!net_device)
134 return NULL;
135
136 init_waitqueue_head(&net_device->wait_drain);
137 net_device->destroy = false;
138 net_device->tx_disable = true;
139
140 net_device->max_pkt = RNDIS_MAX_PKT_DEFAULT;
141 net_device->pkt_align = RNDIS_PKT_ALIGN_DEFAULT;
142
143 init_completion(&net_device->channel_init_wait);
144 init_waitqueue_head(&net_device->subchan_open);
145 INIT_WORK(&net_device->subchan_work, netvsc_subchan_work);
146
147 return net_device;
148}
149
150static void free_netvsc_device(struct rcu_head *head)
151{
152 struct netvsc_device *nvdev
153 = container_of(head, struct netvsc_device, rcu);
154 int i;
155
156 kfree(nvdev->extension);
157
158 if (!nvdev->recv_buf_gpadl_handle.decrypted)
159 vfree(nvdev->recv_buf);
160 if (!nvdev->send_buf_gpadl_handle.decrypted)
161 vfree(nvdev->send_buf);
162 bitmap_free(nvdev->send_section_map);
163
164 for (i = 0; i < VRSS_CHANNEL_MAX; i++) {
165 xdp_rxq_info_unreg(&nvdev->chan_table[i].xdp_rxq);
166 kfree(nvdev->chan_table[i].recv_buf);
167 vfree(nvdev->chan_table[i].mrc.slots);
168 }
169
170 kfree(nvdev);
171}
172
173static void free_netvsc_device_rcu(struct netvsc_device *nvdev)
174{
175 call_rcu(&nvdev->rcu, free_netvsc_device);
176}
177
178static void netvsc_revoke_recv_buf(struct hv_device *device,
179 struct netvsc_device *net_device,
180 struct net_device *ndev)
181{
182 struct nvsp_message *revoke_packet;
183 int ret;
184
185 /*
186 * If we got a section count, it means we received a
187 * SendReceiveBufferComplete msg (ie sent
188 * NvspMessage1TypeSendReceiveBuffer msg) therefore, we need
189 * to send a revoke msg here
190 */
191 if (net_device->recv_section_cnt) {
192 /* Send the revoke receive buffer */
193 revoke_packet = &net_device->revoke_packet;
194 memset(revoke_packet, 0, sizeof(struct nvsp_message));
195
196 revoke_packet->hdr.msg_type =
197 NVSP_MSG1_TYPE_REVOKE_RECV_BUF;
198 revoke_packet->msg.v1_msg.
199 revoke_recv_buf.id = NETVSC_RECEIVE_BUFFER_ID;
200
201 trace_nvsp_send(ndev, revoke_packet);
202
203 ret = vmbus_sendpacket(device->channel,
204 revoke_packet,
205 sizeof(struct nvsp_message),
206 VMBUS_RQST_ID_NO_RESPONSE,
207 VM_PKT_DATA_INBAND, 0);
208 /* If the failure is because the channel is rescinded;
209 * ignore the failure since we cannot send on a rescinded
210 * channel. This would allow us to properly cleanup
211 * even when the channel is rescinded.
212 */
213 if (device->channel->rescind)
214 ret = 0;
215 /*
216 * If we failed here, we might as well return and
217 * have a leak rather than continue and a bugchk
218 */
219 if (ret != 0) {
220 netdev_err(ndev, "unable to send "
221 "revoke receive buffer to netvsp\n");
222 return;
223 }
224 net_device->recv_section_cnt = 0;
225 }
226}
227
228static void netvsc_revoke_send_buf(struct hv_device *device,
229 struct netvsc_device *net_device,
230 struct net_device *ndev)
231{
232 struct nvsp_message *revoke_packet;
233 int ret;
234
235 /* Deal with the send buffer we may have setup.
236 * If we got a send section size, it means we received a
237 * NVSP_MSG1_TYPE_SEND_SEND_BUF_COMPLETE msg (ie sent
238 * NVSP_MSG1_TYPE_SEND_SEND_BUF msg) therefore, we need
239 * to send a revoke msg here
240 */
241 if (net_device->send_section_cnt) {
242 /* Send the revoke receive buffer */
243 revoke_packet = &net_device->revoke_packet;
244 memset(revoke_packet, 0, sizeof(struct nvsp_message));
245
246 revoke_packet->hdr.msg_type =
247 NVSP_MSG1_TYPE_REVOKE_SEND_BUF;
248 revoke_packet->msg.v1_msg.revoke_send_buf.id =
249 NETVSC_SEND_BUFFER_ID;
250
251 trace_nvsp_send(ndev, revoke_packet);
252
253 ret = vmbus_sendpacket(device->channel,
254 revoke_packet,
255 sizeof(struct nvsp_message),
256 VMBUS_RQST_ID_NO_RESPONSE,
257 VM_PKT_DATA_INBAND, 0);
258
259 /* If the failure is because the channel is rescinded;
260 * ignore the failure since we cannot send on a rescinded
261 * channel. This would allow us to properly cleanup
262 * even when the channel is rescinded.
263 */
264 if (device->channel->rescind)
265 ret = 0;
266
267 /* If we failed here, we might as well return and
268 * have a leak rather than continue and a bugchk
269 */
270 if (ret != 0) {
271 netdev_err(ndev, "unable to send "
272 "revoke send buffer to netvsp\n");
273 return;
274 }
275 net_device->send_section_cnt = 0;
276 }
277}
278
279static void netvsc_teardown_recv_gpadl(struct hv_device *device,
280 struct netvsc_device *net_device,
281 struct net_device *ndev)
282{
283 int ret;
284
285 if (net_device->recv_buf_gpadl_handle.gpadl_handle) {
286 ret = vmbus_teardown_gpadl(device->channel,
287 &net_device->recv_buf_gpadl_handle);
288
289 /* If we failed here, we might as well return and have a leak
290 * rather than continue and a bugchk
291 */
292 if (ret != 0) {
293 netdev_err(ndev,
294 "unable to teardown receive buffer's gpadl\n");
295 return;
296 }
297 }
298}
299
300static void netvsc_teardown_send_gpadl(struct hv_device *device,
301 struct netvsc_device *net_device,
302 struct net_device *ndev)
303{
304 int ret;
305
306 if (net_device->send_buf_gpadl_handle.gpadl_handle) {
307 ret = vmbus_teardown_gpadl(device->channel,
308 &net_device->send_buf_gpadl_handle);
309
310 /* If we failed here, we might as well return and have a leak
311 * rather than continue and a bugchk
312 */
313 if (ret != 0) {
314 netdev_err(ndev,
315 "unable to teardown send buffer's gpadl\n");
316 return;
317 }
318 }
319}
320
321int netvsc_alloc_recv_comp_ring(struct netvsc_device *net_device, u32 q_idx)
322{
323 struct netvsc_channel *nvchan = &net_device->chan_table[q_idx];
324 int node = cpu_to_node(nvchan->channel->target_cpu);
325 size_t size;
326
327 size = net_device->recv_completion_cnt * sizeof(struct recv_comp_data);
328 nvchan->mrc.slots = vzalloc_node(size, node);
329 if (!nvchan->mrc.slots)
330 nvchan->mrc.slots = vzalloc(size);
331
332 return nvchan->mrc.slots ? 0 : -ENOMEM;
333}
334
335static int netvsc_init_buf(struct hv_device *device,
336 struct netvsc_device *net_device,
337 const struct netvsc_device_info *device_info)
338{
339 struct nvsp_1_message_send_receive_buffer_complete *resp;
340 struct net_device *ndev = hv_get_drvdata(device);
341 struct nvsp_message *init_packet;
342 unsigned int buf_size;
343 int i, ret = 0;
344
345 /* Get receive buffer area. */
346 buf_size = device_info->recv_sections * device_info->recv_section_size;
347 buf_size = roundup(buf_size, PAGE_SIZE);
348
349 /* Legacy hosts only allow smaller receive buffer */
350 if (net_device->nvsp_version <= NVSP_PROTOCOL_VERSION_2)
351 buf_size = min_t(unsigned int, buf_size,
352 NETVSC_RECEIVE_BUFFER_SIZE_LEGACY);
353
354 net_device->recv_buf = vzalloc(buf_size);
355 if (!net_device->recv_buf) {
356 netdev_err(ndev,
357 "unable to allocate receive buffer of size %u\n",
358 buf_size);
359 ret = -ENOMEM;
360 goto cleanup;
361 }
362
363 net_device->recv_buf_size = buf_size;
364
365 /*
366 * Establish the gpadl handle for this buffer on this
367 * channel. Note: This call uses the vmbus connection rather
368 * than the channel to establish the gpadl handle.
369 */
370 ret = vmbus_establish_gpadl(device->channel, net_device->recv_buf,
371 buf_size,
372 &net_device->recv_buf_gpadl_handle);
373 if (ret != 0) {
374 netdev_err(ndev,
375 "unable to establish receive buffer's gpadl\n");
376 goto cleanup;
377 }
378
379 /* Notify the NetVsp of the gpadl handle */
380 init_packet = &net_device->channel_init_pkt;
381 memset(init_packet, 0, sizeof(struct nvsp_message));
382 init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_RECV_BUF;
383 init_packet->msg.v1_msg.send_recv_buf.
384 gpadl_handle = net_device->recv_buf_gpadl_handle.gpadl_handle;
385 init_packet->msg.v1_msg.
386 send_recv_buf.id = NETVSC_RECEIVE_BUFFER_ID;
387
388 trace_nvsp_send(ndev, init_packet);
389
390 /* Send the gpadl notification request */
391 ret = vmbus_sendpacket(device->channel, init_packet,
392 sizeof(struct nvsp_message),
393 (unsigned long)init_packet,
394 VM_PKT_DATA_INBAND,
395 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
396 if (ret != 0) {
397 netdev_err(ndev,
398 "unable to send receive buffer's gpadl to netvsp\n");
399 goto cleanup;
400 }
401
402 wait_for_completion(&net_device->channel_init_wait);
403
404 /* Check the response */
405 resp = &init_packet->msg.v1_msg.send_recv_buf_complete;
406 if (resp->status != NVSP_STAT_SUCCESS) {
407 netdev_err(ndev,
408 "Unable to complete receive buffer initialization with NetVsp - status %d\n",
409 resp->status);
410 ret = -EINVAL;
411 goto cleanup;
412 }
413
414 /* Parse the response */
415 netdev_dbg(ndev, "Receive sections: %u sub_allocs: size %u count: %u\n",
416 resp->num_sections, resp->sections[0].sub_alloc_size,
417 resp->sections[0].num_sub_allocs);
418
419 /* There should only be one section for the entire receive buffer */
420 if (resp->num_sections != 1 || resp->sections[0].offset != 0) {
421 ret = -EINVAL;
422 goto cleanup;
423 }
424
425 net_device->recv_section_size = resp->sections[0].sub_alloc_size;
426 net_device->recv_section_cnt = resp->sections[0].num_sub_allocs;
427
428 /* Ensure buffer will not overflow */
429 if (net_device->recv_section_size < NETVSC_MTU_MIN || (u64)net_device->recv_section_size *
430 (u64)net_device->recv_section_cnt > (u64)buf_size) {
431 netdev_err(ndev, "invalid recv_section_size %u\n",
432 net_device->recv_section_size);
433 ret = -EINVAL;
434 goto cleanup;
435 }
436
437 for (i = 0; i < VRSS_CHANNEL_MAX; i++) {
438 struct netvsc_channel *nvchan = &net_device->chan_table[i];
439
440 nvchan->recv_buf = kzalloc(net_device->recv_section_size, GFP_KERNEL);
441 if (nvchan->recv_buf == NULL) {
442 ret = -ENOMEM;
443 goto cleanup;
444 }
445 }
446
447 /* Setup receive completion ring.
448 * Add 1 to the recv_section_cnt because at least one entry in a
449 * ring buffer has to be empty.
450 */
451 net_device->recv_completion_cnt = net_device->recv_section_cnt + 1;
452 ret = netvsc_alloc_recv_comp_ring(net_device, 0);
453 if (ret)
454 goto cleanup;
455
456 /* Now setup the send buffer. */
457 buf_size = device_info->send_sections * device_info->send_section_size;
458 buf_size = round_up(buf_size, PAGE_SIZE);
459
460 net_device->send_buf = vzalloc(buf_size);
461 if (!net_device->send_buf) {
462 netdev_err(ndev, "unable to allocate send buffer of size %u\n",
463 buf_size);
464 ret = -ENOMEM;
465 goto cleanup;
466 }
467 net_device->send_buf_size = buf_size;
468
469 /* Establish the gpadl handle for this buffer on this
470 * channel. Note: This call uses the vmbus connection rather
471 * than the channel to establish the gpadl handle.
472 */
473 ret = vmbus_establish_gpadl(device->channel, net_device->send_buf,
474 buf_size,
475 &net_device->send_buf_gpadl_handle);
476 if (ret != 0) {
477 netdev_err(ndev,
478 "unable to establish send buffer's gpadl\n");
479 goto cleanup;
480 }
481
482 /* Notify the NetVsp of the gpadl handle */
483 init_packet = &net_device->channel_init_pkt;
484 memset(init_packet, 0, sizeof(struct nvsp_message));
485 init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_SEND_BUF;
486 init_packet->msg.v1_msg.send_send_buf.gpadl_handle =
487 net_device->send_buf_gpadl_handle.gpadl_handle;
488 init_packet->msg.v1_msg.send_send_buf.id = NETVSC_SEND_BUFFER_ID;
489
490 trace_nvsp_send(ndev, init_packet);
491
492 /* Send the gpadl notification request */
493 ret = vmbus_sendpacket(device->channel, init_packet,
494 sizeof(struct nvsp_message),
495 (unsigned long)init_packet,
496 VM_PKT_DATA_INBAND,
497 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
498 if (ret != 0) {
499 netdev_err(ndev,
500 "unable to send send buffer's gpadl to netvsp\n");
501 goto cleanup;
502 }
503
504 wait_for_completion(&net_device->channel_init_wait);
505
506 /* Check the response */
507 if (init_packet->msg.v1_msg.
508 send_send_buf_complete.status != NVSP_STAT_SUCCESS) {
509 netdev_err(ndev, "Unable to complete send buffer "
510 "initialization with NetVsp - status %d\n",
511 init_packet->msg.v1_msg.
512 send_send_buf_complete.status);
513 ret = -EINVAL;
514 goto cleanup;
515 }
516
517 /* Parse the response */
518 net_device->send_section_size = init_packet->msg.
519 v1_msg.send_send_buf_complete.section_size;
520 if (net_device->send_section_size < NETVSC_MTU_MIN) {
521 netdev_err(ndev, "invalid send_section_size %u\n",
522 net_device->send_section_size);
523 ret = -EINVAL;
524 goto cleanup;
525 }
526
527 /* Section count is simply the size divided by the section size. */
528 net_device->send_section_cnt = buf_size / net_device->send_section_size;
529
530 netdev_dbg(ndev, "Send section size: %d, Section count:%d\n",
531 net_device->send_section_size, net_device->send_section_cnt);
532
533 /* Setup state for managing the send buffer. */
534 net_device->send_section_map = bitmap_zalloc(net_device->send_section_cnt,
535 GFP_KERNEL);
536 if (!net_device->send_section_map) {
537 ret = -ENOMEM;
538 goto cleanup;
539 }
540
541 goto exit;
542
543cleanup:
544 netvsc_revoke_recv_buf(device, net_device, ndev);
545 netvsc_revoke_send_buf(device, net_device, ndev);
546 netvsc_teardown_recv_gpadl(device, net_device, ndev);
547 netvsc_teardown_send_gpadl(device, net_device, ndev);
548
549exit:
550 return ret;
551}
552
553/* Negotiate NVSP protocol version */
554static int negotiate_nvsp_ver(struct hv_device *device,
555 struct netvsc_device *net_device,
556 struct nvsp_message *init_packet,
557 u32 nvsp_ver)
558{
559 struct net_device *ndev = hv_get_drvdata(device);
560 int ret;
561
562 memset(init_packet, 0, sizeof(struct nvsp_message));
563 init_packet->hdr.msg_type = NVSP_MSG_TYPE_INIT;
564 init_packet->msg.init_msg.init.min_protocol_ver = nvsp_ver;
565 init_packet->msg.init_msg.init.max_protocol_ver = nvsp_ver;
566 trace_nvsp_send(ndev, init_packet);
567
568 /* Send the init request */
569 ret = vmbus_sendpacket(device->channel, init_packet,
570 sizeof(struct nvsp_message),
571 (unsigned long)init_packet,
572 VM_PKT_DATA_INBAND,
573 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
574
575 if (ret != 0)
576 return ret;
577
578 wait_for_completion(&net_device->channel_init_wait);
579
580 if (init_packet->msg.init_msg.init_complete.status !=
581 NVSP_STAT_SUCCESS)
582 return -EINVAL;
583
584 if (nvsp_ver == NVSP_PROTOCOL_VERSION_1)
585 return 0;
586
587 /* NVSPv2 or later: Send NDIS config */
588 memset(init_packet, 0, sizeof(struct nvsp_message));
589 init_packet->hdr.msg_type = NVSP_MSG2_TYPE_SEND_NDIS_CONFIG;
590 init_packet->msg.v2_msg.send_ndis_config.mtu = ndev->mtu + ETH_HLEN;
591 init_packet->msg.v2_msg.send_ndis_config.capability.ieee8021q = 1;
592
593 if (nvsp_ver >= NVSP_PROTOCOL_VERSION_5) {
594 if (hv_is_isolation_supported())
595 netdev_info(ndev, "SR-IOV not advertised by guests on the host supporting isolation\n");
596 else
597 init_packet->msg.v2_msg.send_ndis_config.capability.sriov = 1;
598
599 /* Teaming bit is needed to receive link speed updates */
600 init_packet->msg.v2_msg.send_ndis_config.capability.teaming = 1;
601 }
602
603 if (nvsp_ver >= NVSP_PROTOCOL_VERSION_61)
604 init_packet->msg.v2_msg.send_ndis_config.capability.rsc = 1;
605
606 trace_nvsp_send(ndev, init_packet);
607
608 ret = vmbus_sendpacket(device->channel, init_packet,
609 sizeof(struct nvsp_message),
610 VMBUS_RQST_ID_NO_RESPONSE,
611 VM_PKT_DATA_INBAND, 0);
612
613 return ret;
614}
615
616static int netvsc_connect_vsp(struct hv_device *device,
617 struct netvsc_device *net_device,
618 const struct netvsc_device_info *device_info)
619{
620 struct net_device *ndev = hv_get_drvdata(device);
621 static const u32 ver_list[] = {
622 NVSP_PROTOCOL_VERSION_1, NVSP_PROTOCOL_VERSION_2,
623 NVSP_PROTOCOL_VERSION_4, NVSP_PROTOCOL_VERSION_5,
624 NVSP_PROTOCOL_VERSION_6, NVSP_PROTOCOL_VERSION_61
625 };
626 struct nvsp_message *init_packet;
627 int ndis_version, i, ret;
628
629 init_packet = &net_device->channel_init_pkt;
630
631 /* Negotiate the latest NVSP protocol supported */
632 for (i = ARRAY_SIZE(ver_list) - 1; i >= 0; i--)
633 if (negotiate_nvsp_ver(device, net_device, init_packet,
634 ver_list[i]) == 0) {
635 net_device->nvsp_version = ver_list[i];
636 break;
637 }
638
639 if (i < 0) {
640 ret = -EPROTO;
641 goto cleanup;
642 }
643
644 if (hv_is_isolation_supported() && net_device->nvsp_version < NVSP_PROTOCOL_VERSION_61) {
645 netdev_err(ndev, "Invalid NVSP version 0x%x (expected >= 0x%x) from the host supporting isolation\n",
646 net_device->nvsp_version, NVSP_PROTOCOL_VERSION_61);
647 ret = -EPROTO;
648 goto cleanup;
649 }
650
651 pr_debug("Negotiated NVSP version:%x\n", net_device->nvsp_version);
652
653 /* Send the ndis version */
654 memset(init_packet, 0, sizeof(struct nvsp_message));
655
656 if (net_device->nvsp_version <= NVSP_PROTOCOL_VERSION_4)
657 ndis_version = 0x00060001;
658 else
659 ndis_version = 0x0006001e;
660
661 init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_NDIS_VER;
662 init_packet->msg.v1_msg.
663 send_ndis_ver.ndis_major_ver =
664 (ndis_version & 0xFFFF0000) >> 16;
665 init_packet->msg.v1_msg.
666 send_ndis_ver.ndis_minor_ver =
667 ndis_version & 0xFFFF;
668
669 trace_nvsp_send(ndev, init_packet);
670
671 /* Send the init request */
672 ret = vmbus_sendpacket(device->channel, init_packet,
673 sizeof(struct nvsp_message),
674 VMBUS_RQST_ID_NO_RESPONSE,
675 VM_PKT_DATA_INBAND, 0);
676 if (ret != 0)
677 goto cleanup;
678
679
680 ret = netvsc_init_buf(device, net_device, device_info);
681
682cleanup:
683 return ret;
684}
685
686/*
687 * netvsc_device_remove - Callback when the root bus device is removed
688 */
689void netvsc_device_remove(struct hv_device *device)
690{
691 struct net_device *ndev = hv_get_drvdata(device);
692 struct net_device_context *net_device_ctx = netdev_priv(ndev);
693 struct netvsc_device *net_device
694 = rtnl_dereference(net_device_ctx->nvdev);
695 int i;
696
697 /*
698 * Revoke receive buffer. If host is pre-Win2016 then tear down
699 * receive buffer GPADL. Do the same for send buffer.
700 */
701 netvsc_revoke_recv_buf(device, net_device, ndev);
702 if (vmbus_proto_version < VERSION_WIN10)
703 netvsc_teardown_recv_gpadl(device, net_device, ndev);
704
705 netvsc_revoke_send_buf(device, net_device, ndev);
706 if (vmbus_proto_version < VERSION_WIN10)
707 netvsc_teardown_send_gpadl(device, net_device, ndev);
708
709 RCU_INIT_POINTER(net_device_ctx->nvdev, NULL);
710
711 /* Disable NAPI and disassociate its context from the device. */
712 for (i = 0; i < net_device->num_chn; i++) {
713 /* See also vmbus_reset_channel_cb(). */
714 /* only disable enabled NAPI channel */
715 if (i < ndev->real_num_rx_queues)
716 napi_disable(&net_device->chan_table[i].napi);
717
718 netif_napi_del(&net_device->chan_table[i].napi);
719 }
720
721 /*
722 * At this point, no one should be accessing net_device
723 * except in here
724 */
725 netdev_dbg(ndev, "net device safe to remove\n");
726
727 /* Now, we can close the channel safely */
728 vmbus_close(device->channel);
729
730 /*
731 * If host is Win2016 or higher then we do the GPADL tear down
732 * here after VMBus is closed.
733 */
734 if (vmbus_proto_version >= VERSION_WIN10) {
735 netvsc_teardown_recv_gpadl(device, net_device, ndev);
736 netvsc_teardown_send_gpadl(device, net_device, ndev);
737 }
738
739 /* Release all resources */
740 free_netvsc_device_rcu(net_device);
741}
742
743#define RING_AVAIL_PERCENT_HIWATER 20
744#define RING_AVAIL_PERCENT_LOWATER 10
745
746static inline void netvsc_free_send_slot(struct netvsc_device *net_device,
747 u32 index)
748{
749 sync_change_bit(index, net_device->send_section_map);
750}
751
752static void netvsc_send_tx_complete(struct net_device *ndev,
753 struct netvsc_device *net_device,
754 struct vmbus_channel *channel,
755 const struct vmpacket_descriptor *desc,
756 int budget)
757{
758 struct net_device_context *ndev_ctx = netdev_priv(ndev);
759 struct sk_buff *skb;
760 u16 q_idx = 0;
761 int queue_sends;
762 u64 cmd_rqst;
763
764 cmd_rqst = channel->request_addr_callback(channel, desc->trans_id);
765 if (cmd_rqst == VMBUS_RQST_ERROR) {
766 netdev_err(ndev, "Invalid transaction ID %llx\n", desc->trans_id);
767 return;
768 }
769
770 skb = (struct sk_buff *)(unsigned long)cmd_rqst;
771
772 /* Notify the layer above us */
773 if (likely(skb)) {
774 struct hv_netvsc_packet *packet
775 = (struct hv_netvsc_packet *)skb->cb;
776 u32 send_index = packet->send_buf_index;
777 struct netvsc_stats_tx *tx_stats;
778
779 if (send_index != NETVSC_INVALID_INDEX)
780 netvsc_free_send_slot(net_device, send_index);
781 q_idx = packet->q_idx;
782
783 tx_stats = &net_device->chan_table[q_idx].tx_stats;
784
785 u64_stats_update_begin(&tx_stats->syncp);
786 tx_stats->packets += packet->total_packets;
787 tx_stats->bytes += packet->total_bytes;
788 u64_stats_update_end(&tx_stats->syncp);
789
790 netvsc_dma_unmap(ndev_ctx->device_ctx, packet);
791 napi_consume_skb(skb, budget);
792 }
793
794 queue_sends =
795 atomic_dec_return(&net_device->chan_table[q_idx].queue_sends);
796
797 if (unlikely(net_device->destroy)) {
798 if (queue_sends == 0)
799 wake_up(&net_device->wait_drain);
800 } else {
801 struct netdev_queue *txq = netdev_get_tx_queue(ndev, q_idx);
802
803 if (netif_tx_queue_stopped(txq) && !net_device->tx_disable &&
804 (hv_get_avail_to_write_percent(&channel->outbound) >
805 RING_AVAIL_PERCENT_HIWATER || queue_sends < 1)) {
806 netif_tx_wake_queue(txq);
807 ndev_ctx->eth_stats.wake_queue++;
808 }
809 }
810}
811
812static void netvsc_send_completion(struct net_device *ndev,
813 struct netvsc_device *net_device,
814 struct vmbus_channel *incoming_channel,
815 const struct vmpacket_descriptor *desc,
816 int budget)
817{
818 const struct nvsp_message *nvsp_packet;
819 u32 msglen = hv_pkt_datalen(desc);
820 struct nvsp_message *pkt_rqst;
821 u64 cmd_rqst;
822 u32 status;
823
824 /* First check if this is a VMBUS completion without data payload */
825 if (!msglen) {
826 cmd_rqst = incoming_channel->request_addr_callback(incoming_channel,
827 desc->trans_id);
828 if (cmd_rqst == VMBUS_RQST_ERROR) {
829 netdev_err(ndev, "Invalid transaction ID %llx\n", desc->trans_id);
830 return;
831 }
832
833 pkt_rqst = (struct nvsp_message *)(uintptr_t)cmd_rqst;
834 switch (pkt_rqst->hdr.msg_type) {
835 case NVSP_MSG4_TYPE_SWITCH_DATA_PATH:
836 complete(&net_device->channel_init_wait);
837 break;
838
839 default:
840 netdev_err(ndev, "Unexpected VMBUS completion!!\n");
841 }
842 return;
843 }
844
845 /* Ensure packet is big enough to read header fields */
846 if (msglen < sizeof(struct nvsp_message_header)) {
847 netdev_err(ndev, "nvsp_message length too small: %u\n", msglen);
848 return;
849 }
850
851 nvsp_packet = hv_pkt_data(desc);
852 switch (nvsp_packet->hdr.msg_type) {
853 case NVSP_MSG_TYPE_INIT_COMPLETE:
854 if (msglen < sizeof(struct nvsp_message_header) +
855 sizeof(struct nvsp_message_init_complete)) {
856 netdev_err(ndev, "nvsp_msg length too small: %u\n",
857 msglen);
858 return;
859 }
860 break;
861
862 case NVSP_MSG1_TYPE_SEND_RECV_BUF_COMPLETE:
863 if (msglen < sizeof(struct nvsp_message_header) +
864 sizeof(struct nvsp_1_message_send_receive_buffer_complete)) {
865 netdev_err(ndev, "nvsp_msg1 length too small: %u\n",
866 msglen);
867 return;
868 }
869 break;
870
871 case NVSP_MSG1_TYPE_SEND_SEND_BUF_COMPLETE:
872 if (msglen < sizeof(struct nvsp_message_header) +
873 sizeof(struct nvsp_1_message_send_send_buffer_complete)) {
874 netdev_err(ndev, "nvsp_msg1 length too small: %u\n",
875 msglen);
876 return;
877 }
878 break;
879
880 case NVSP_MSG5_TYPE_SUBCHANNEL:
881 if (msglen < sizeof(struct nvsp_message_header) +
882 sizeof(struct nvsp_5_subchannel_complete)) {
883 netdev_err(ndev, "nvsp_msg5 length too small: %u\n",
884 msglen);
885 return;
886 }
887 break;
888
889 case NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE:
890 if (msglen < sizeof(struct nvsp_message_header) +
891 sizeof(struct nvsp_1_message_send_rndis_packet_complete)) {
892 if (net_ratelimit())
893 netdev_err(ndev, "nvsp_rndis_pkt_complete length too small: %u\n",
894 msglen);
895 return;
896 }
897
898 /* If status indicates an error, output a message so we know
899 * there's a problem. But process the completion anyway so the
900 * resources are released.
901 */
902 status = nvsp_packet->msg.v1_msg.send_rndis_pkt_complete.status;
903 if (status != NVSP_STAT_SUCCESS && net_ratelimit())
904 netdev_err(ndev, "nvsp_rndis_pkt_complete error status: %x\n",
905 status);
906
907 netvsc_send_tx_complete(ndev, net_device, incoming_channel,
908 desc, budget);
909 return;
910
911 default:
912 netdev_err(ndev,
913 "Unknown send completion type %d received!!\n",
914 nvsp_packet->hdr.msg_type);
915 return;
916 }
917
918 /* Copy the response back */
919 memcpy(&net_device->channel_init_pkt, nvsp_packet,
920 sizeof(struct nvsp_message));
921 complete(&net_device->channel_init_wait);
922}
923
924static u32 netvsc_get_next_send_section(struct netvsc_device *net_device)
925{
926 unsigned long *map_addr = net_device->send_section_map;
927 unsigned int i;
928
929 for_each_clear_bit(i, map_addr, net_device->send_section_cnt) {
930 if (sync_test_and_set_bit(i, map_addr) == 0)
931 return i;
932 }
933
934 return NETVSC_INVALID_INDEX;
935}
936
937static void netvsc_copy_to_send_buf(struct netvsc_device *net_device,
938 unsigned int section_index,
939 u32 pend_size,
940 struct hv_netvsc_packet *packet,
941 struct rndis_message *rndis_msg,
942 struct hv_page_buffer *pb,
943 bool xmit_more)
944{
945 char *start = net_device->send_buf;
946 char *dest = start + (section_index * net_device->send_section_size)
947 + pend_size;
948 int i;
949 u32 padding = 0;
950 u32 page_count = packet->cp_partial ? packet->rmsg_pgcnt :
951 packet->page_buf_cnt;
952 u32 remain;
953
954 /* Add padding */
955 remain = packet->total_data_buflen & (net_device->pkt_align - 1);
956 if (xmit_more && remain) {
957 padding = net_device->pkt_align - remain;
958 rndis_msg->msg_len += padding;
959 packet->total_data_buflen += padding;
960 }
961
962 for (i = 0; i < page_count; i++) {
963 char *src = phys_to_virt(pb[i].pfn << HV_HYP_PAGE_SHIFT);
964 u32 offset = pb[i].offset;
965 u32 len = pb[i].len;
966
967 memcpy(dest, (src + offset), len);
968 dest += len;
969 }
970
971 if (padding)
972 memset(dest, 0, padding);
973}
974
975void netvsc_dma_unmap(struct hv_device *hv_dev,
976 struct hv_netvsc_packet *packet)
977{
978 int i;
979
980 if (!hv_is_isolation_supported())
981 return;
982
983 if (!packet->dma_range)
984 return;
985
986 for (i = 0; i < packet->page_buf_cnt; i++)
987 dma_unmap_single(&hv_dev->device, packet->dma_range[i].dma,
988 packet->dma_range[i].mapping_size,
989 DMA_TO_DEVICE);
990
991 kfree(packet->dma_range);
992}
993
994/* netvsc_dma_map - Map swiotlb bounce buffer with data page of
995 * packet sent by vmbus_sendpacket_pagebuffer() in the Isolation
996 * VM.
997 *
998 * In isolation VM, netvsc send buffer has been marked visible to
999 * host and so the data copied to send buffer doesn't need to use
1000 * bounce buffer. The data pages handled by vmbus_sendpacket_pagebuffer()
1001 * may not be copied to send buffer and so these pages need to be
1002 * mapped with swiotlb bounce buffer. netvsc_dma_map() is to do
1003 * that. The pfns in the struct hv_page_buffer need to be converted
1004 * to bounce buffer's pfn. The loop here is necessary because the
1005 * entries in the page buffer array are not necessarily full
1006 * pages of data. Each entry in the array has a separate offset and
1007 * len that may be non-zero, even for entries in the middle of the
1008 * array. And the entries are not physically contiguous. So each
1009 * entry must be individually mapped rather than as a contiguous unit.
1010 * So not use dma_map_sg() here.
1011 */
1012static int netvsc_dma_map(struct hv_device *hv_dev,
1013 struct hv_netvsc_packet *packet,
1014 struct hv_page_buffer *pb)
1015{
1016 u32 page_count = packet->page_buf_cnt;
1017 dma_addr_t dma;
1018 int i;
1019
1020 if (!hv_is_isolation_supported())
1021 return 0;
1022
1023 packet->dma_range = kcalloc(page_count,
1024 sizeof(*packet->dma_range),
1025 GFP_ATOMIC);
1026 if (!packet->dma_range)
1027 return -ENOMEM;
1028
1029 for (i = 0; i < page_count; i++) {
1030 char *src = phys_to_virt((pb[i].pfn << HV_HYP_PAGE_SHIFT)
1031 + pb[i].offset);
1032 u32 len = pb[i].len;
1033
1034 dma = dma_map_single(&hv_dev->device, src, len,
1035 DMA_TO_DEVICE);
1036 if (dma_mapping_error(&hv_dev->device, dma)) {
1037 kfree(packet->dma_range);
1038 return -ENOMEM;
1039 }
1040
1041 /* pb[].offset and pb[].len are not changed during dma mapping
1042 * and so not reassign.
1043 */
1044 packet->dma_range[i].dma = dma;
1045 packet->dma_range[i].mapping_size = len;
1046 pb[i].pfn = dma >> HV_HYP_PAGE_SHIFT;
1047 }
1048
1049 return 0;
1050}
1051
1052static inline int netvsc_send_pkt(
1053 struct hv_device *device,
1054 struct hv_netvsc_packet *packet,
1055 struct netvsc_device *net_device,
1056 struct hv_page_buffer *pb,
1057 struct sk_buff *skb)
1058{
1059 struct nvsp_message nvmsg;
1060 struct nvsp_1_message_send_rndis_packet *rpkt =
1061 &nvmsg.msg.v1_msg.send_rndis_pkt;
1062 struct netvsc_channel * const nvchan =
1063 &net_device->chan_table[packet->q_idx];
1064 struct vmbus_channel *out_channel = nvchan->channel;
1065 struct net_device *ndev = hv_get_drvdata(device);
1066 struct net_device_context *ndev_ctx = netdev_priv(ndev);
1067 struct netdev_queue *txq = netdev_get_tx_queue(ndev, packet->q_idx);
1068 u64 req_id;
1069 int ret;
1070 u32 ring_avail = hv_get_avail_to_write_percent(&out_channel->outbound);
1071
1072 memset(&nvmsg, 0, sizeof(struct nvsp_message));
1073 nvmsg.hdr.msg_type = NVSP_MSG1_TYPE_SEND_RNDIS_PKT;
1074 if (skb)
1075 rpkt->channel_type = 0; /* 0 is RMC_DATA */
1076 else
1077 rpkt->channel_type = 1; /* 1 is RMC_CONTROL */
1078
1079 rpkt->send_buf_section_index = packet->send_buf_index;
1080 if (packet->send_buf_index == NETVSC_INVALID_INDEX)
1081 rpkt->send_buf_section_size = 0;
1082 else
1083 rpkt->send_buf_section_size = packet->total_data_buflen;
1084
1085 req_id = (ulong)skb;
1086
1087 if (out_channel->rescind)
1088 return -ENODEV;
1089
1090 trace_nvsp_send_pkt(ndev, out_channel, rpkt);
1091
1092 packet->dma_range = NULL;
1093 if (packet->page_buf_cnt) {
1094 if (packet->cp_partial)
1095 pb += packet->rmsg_pgcnt;
1096
1097 ret = netvsc_dma_map(ndev_ctx->device_ctx, packet, pb);
1098 if (ret) {
1099 ret = -EAGAIN;
1100 goto exit;
1101 }
1102
1103 ret = vmbus_sendpacket_pagebuffer(out_channel,
1104 pb, packet->page_buf_cnt,
1105 &nvmsg, sizeof(nvmsg),
1106 req_id);
1107
1108 if (ret)
1109 netvsc_dma_unmap(ndev_ctx->device_ctx, packet);
1110 } else {
1111 ret = vmbus_sendpacket(out_channel,
1112 &nvmsg, sizeof(nvmsg),
1113 req_id, VM_PKT_DATA_INBAND,
1114 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1115 }
1116
1117exit:
1118 if (ret == 0) {
1119 atomic_inc_return(&nvchan->queue_sends);
1120
1121 if (ring_avail < RING_AVAIL_PERCENT_LOWATER) {
1122 netif_tx_stop_queue(txq);
1123 ndev_ctx->eth_stats.stop_queue++;
1124 }
1125 } else if (ret == -EAGAIN) {
1126 netif_tx_stop_queue(txq);
1127 ndev_ctx->eth_stats.stop_queue++;
1128 } else {
1129 netdev_err(ndev,
1130 "Unable to send packet pages %u len %u, ret %d\n",
1131 packet->page_buf_cnt, packet->total_data_buflen,
1132 ret);
1133 }
1134
1135 if (netif_tx_queue_stopped(txq) &&
1136 atomic_read(&nvchan->queue_sends) < 1 &&
1137 !net_device->tx_disable) {
1138 netif_tx_wake_queue(txq);
1139 ndev_ctx->eth_stats.wake_queue++;
1140 if (ret == -EAGAIN)
1141 ret = -ENOSPC;
1142 }
1143
1144 return ret;
1145}
1146
1147/* Move packet out of multi send data (msd), and clear msd */
1148static inline void move_pkt_msd(struct hv_netvsc_packet **msd_send,
1149 struct sk_buff **msd_skb,
1150 struct multi_send_data *msdp)
1151{
1152 *msd_skb = msdp->skb;
1153 *msd_send = msdp->pkt;
1154 msdp->skb = NULL;
1155 msdp->pkt = NULL;
1156 msdp->count = 0;
1157}
1158
1159/* RCU already held by caller */
1160/* Batching/bouncing logic is designed to attempt to optimize
1161 * performance.
1162 *
1163 * For small, non-LSO packets we copy the packet to a send buffer
1164 * which is pre-registered with the Hyper-V side. This enables the
1165 * hypervisor to avoid remapping the aperture to access the packet
1166 * descriptor and data.
1167 *
1168 * If we already started using a buffer and the netdev is transmitting
1169 * a burst of packets, keep on copying into the buffer until it is
1170 * full or we are done collecting a burst. If there is an existing
1171 * buffer with space for the RNDIS descriptor but not the packet, copy
1172 * the RNDIS descriptor to the buffer, keeping the packet in place.
1173 *
1174 * If we do batching and send more than one packet using a single
1175 * NetVSC message, free the SKBs of the packets copied, except for the
1176 * last packet. This is done to streamline the handling of the case
1177 * where the last packet only had the RNDIS descriptor copied to the
1178 * send buffer, with the data pointers included in the NetVSC message.
1179 */
1180int netvsc_send(struct net_device *ndev,
1181 struct hv_netvsc_packet *packet,
1182 struct rndis_message *rndis_msg,
1183 struct hv_page_buffer *pb,
1184 struct sk_buff *skb,
1185 bool xdp_tx)
1186{
1187 struct net_device_context *ndev_ctx = netdev_priv(ndev);
1188 struct netvsc_device *net_device
1189 = rcu_dereference_bh(ndev_ctx->nvdev);
1190 struct hv_device *device = ndev_ctx->device_ctx;
1191 int ret = 0;
1192 struct netvsc_channel *nvchan;
1193 u32 pktlen = packet->total_data_buflen, msd_len = 0;
1194 unsigned int section_index = NETVSC_INVALID_INDEX;
1195 struct multi_send_data *msdp;
1196 struct hv_netvsc_packet *msd_send = NULL, *cur_send = NULL;
1197 struct sk_buff *msd_skb = NULL;
1198 bool try_batch, xmit_more;
1199
1200 /* If device is rescinded, return error and packet will get dropped. */
1201 if (unlikely(!net_device || net_device->destroy))
1202 return -ENODEV;
1203
1204 nvchan = &net_device->chan_table[packet->q_idx];
1205 packet->send_buf_index = NETVSC_INVALID_INDEX;
1206 packet->cp_partial = false;
1207
1208 /* Send a control message or XDP packet directly without accessing
1209 * msd (Multi-Send Data) field which may be changed during data packet
1210 * processing.
1211 */
1212 if (!skb || xdp_tx)
1213 return netvsc_send_pkt(device, packet, net_device, pb, skb);
1214
1215 /* batch packets in send buffer if possible */
1216 msdp = &nvchan->msd;
1217 if (msdp->pkt)
1218 msd_len = msdp->pkt->total_data_buflen;
1219
1220 try_batch = msd_len > 0 && msdp->count < net_device->max_pkt;
1221 if (try_batch && msd_len + pktlen + net_device->pkt_align <
1222 net_device->send_section_size) {
1223 section_index = msdp->pkt->send_buf_index;
1224
1225 } else if (try_batch && msd_len + packet->rmsg_size <
1226 net_device->send_section_size) {
1227 section_index = msdp->pkt->send_buf_index;
1228 packet->cp_partial = true;
1229
1230 } else if (pktlen + net_device->pkt_align <
1231 net_device->send_section_size) {
1232 section_index = netvsc_get_next_send_section(net_device);
1233 if (unlikely(section_index == NETVSC_INVALID_INDEX)) {
1234 ++ndev_ctx->eth_stats.tx_send_full;
1235 } else {
1236 move_pkt_msd(&msd_send, &msd_skb, msdp);
1237 msd_len = 0;
1238 }
1239 }
1240
1241 /* Keep aggregating only if stack says more data is coming
1242 * and not doing mixed modes send and not flow blocked
1243 */
1244 xmit_more = netdev_xmit_more() &&
1245 !packet->cp_partial &&
1246 !netif_xmit_stopped(netdev_get_tx_queue(ndev, packet->q_idx));
1247
1248 if (section_index != NETVSC_INVALID_INDEX) {
1249 netvsc_copy_to_send_buf(net_device,
1250 section_index, msd_len,
1251 packet, rndis_msg, pb, xmit_more);
1252
1253 packet->send_buf_index = section_index;
1254
1255 if (packet->cp_partial) {
1256 packet->page_buf_cnt -= packet->rmsg_pgcnt;
1257 packet->total_data_buflen = msd_len + packet->rmsg_size;
1258 } else {
1259 packet->page_buf_cnt = 0;
1260 packet->total_data_buflen += msd_len;
1261 }
1262
1263 if (msdp->pkt) {
1264 packet->total_packets += msdp->pkt->total_packets;
1265 packet->total_bytes += msdp->pkt->total_bytes;
1266 }
1267
1268 if (msdp->skb)
1269 dev_consume_skb_any(msdp->skb);
1270
1271 if (xmit_more) {
1272 msdp->skb = skb;
1273 msdp->pkt = packet;
1274 msdp->count++;
1275 } else {
1276 cur_send = packet;
1277 msdp->skb = NULL;
1278 msdp->pkt = NULL;
1279 msdp->count = 0;
1280 }
1281 } else {
1282 move_pkt_msd(&msd_send, &msd_skb, msdp);
1283 cur_send = packet;
1284 }
1285
1286 if (msd_send) {
1287 int m_ret = netvsc_send_pkt(device, msd_send, net_device,
1288 NULL, msd_skb);
1289
1290 if (m_ret != 0) {
1291 netvsc_free_send_slot(net_device,
1292 msd_send->send_buf_index);
1293 dev_kfree_skb_any(msd_skb);
1294 }
1295 }
1296
1297 if (cur_send)
1298 ret = netvsc_send_pkt(device, cur_send, net_device, pb, skb);
1299
1300 if (ret != 0 && section_index != NETVSC_INVALID_INDEX)
1301 netvsc_free_send_slot(net_device, section_index);
1302
1303 return ret;
1304}
1305
1306/* Send pending recv completions */
1307static int send_recv_completions(struct net_device *ndev,
1308 struct netvsc_device *nvdev,
1309 struct netvsc_channel *nvchan)
1310{
1311 struct multi_recv_comp *mrc = &nvchan->mrc;
1312 struct recv_comp_msg {
1313 struct nvsp_message_header hdr;
1314 u32 status;
1315 } __packed;
1316 struct recv_comp_msg msg = {
1317 .hdr.msg_type = NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE,
1318 };
1319 int ret;
1320
1321 while (mrc->first != mrc->next) {
1322 const struct recv_comp_data *rcd
1323 = mrc->slots + mrc->first;
1324
1325 msg.status = rcd->status;
1326 ret = vmbus_sendpacket(nvchan->channel, &msg, sizeof(msg),
1327 rcd->tid, VM_PKT_COMP, 0);
1328 if (unlikely(ret)) {
1329 struct net_device_context *ndev_ctx = netdev_priv(ndev);
1330
1331 ++ndev_ctx->eth_stats.rx_comp_busy;
1332 return ret;
1333 }
1334
1335 if (++mrc->first == nvdev->recv_completion_cnt)
1336 mrc->first = 0;
1337 }
1338
1339 /* receive completion ring has been emptied */
1340 if (unlikely(nvdev->destroy))
1341 wake_up(&nvdev->wait_drain);
1342
1343 return 0;
1344}
1345
1346/* Count how many receive completions are outstanding */
1347static void recv_comp_slot_avail(const struct netvsc_device *nvdev,
1348 const struct multi_recv_comp *mrc,
1349 u32 *filled, u32 *avail)
1350{
1351 u32 count = nvdev->recv_completion_cnt;
1352
1353 if (mrc->next >= mrc->first)
1354 *filled = mrc->next - mrc->first;
1355 else
1356 *filled = (count - mrc->first) + mrc->next;
1357
1358 *avail = count - *filled - 1;
1359}
1360
1361/* Add receive complete to ring to send to host. */
1362static void enq_receive_complete(struct net_device *ndev,
1363 struct netvsc_device *nvdev, u16 q_idx,
1364 u64 tid, u32 status)
1365{
1366 struct netvsc_channel *nvchan = &nvdev->chan_table[q_idx];
1367 struct multi_recv_comp *mrc = &nvchan->mrc;
1368 struct recv_comp_data *rcd;
1369 u32 filled, avail;
1370
1371 recv_comp_slot_avail(nvdev, mrc, &filled, &avail);
1372
1373 if (unlikely(filled > NAPI_POLL_WEIGHT)) {
1374 send_recv_completions(ndev, nvdev, nvchan);
1375 recv_comp_slot_avail(nvdev, mrc, &filled, &avail);
1376 }
1377
1378 if (unlikely(!avail)) {
1379 netdev_err(ndev, "Recv_comp full buf q:%hd, tid:%llx\n",
1380 q_idx, tid);
1381 return;
1382 }
1383
1384 rcd = mrc->slots + mrc->next;
1385 rcd->tid = tid;
1386 rcd->status = status;
1387
1388 if (++mrc->next == nvdev->recv_completion_cnt)
1389 mrc->next = 0;
1390}
1391
1392static int netvsc_receive(struct net_device *ndev,
1393 struct netvsc_device *net_device,
1394 struct netvsc_channel *nvchan,
1395 const struct vmpacket_descriptor *desc)
1396{
1397 struct net_device_context *net_device_ctx = netdev_priv(ndev);
1398 struct vmbus_channel *channel = nvchan->channel;
1399 const struct vmtransfer_page_packet_header *vmxferpage_packet
1400 = container_of(desc, const struct vmtransfer_page_packet_header, d);
1401 const struct nvsp_message *nvsp = hv_pkt_data(desc);
1402 u32 msglen = hv_pkt_datalen(desc);
1403 u16 q_idx = channel->offermsg.offer.sub_channel_index;
1404 char *recv_buf = net_device->recv_buf;
1405 u32 status = NVSP_STAT_SUCCESS;
1406 int i;
1407 int count = 0;
1408
1409 /* Ensure packet is big enough to read header fields */
1410 if (msglen < sizeof(struct nvsp_message_header)) {
1411 netif_err(net_device_ctx, rx_err, ndev,
1412 "invalid nvsp header, length too small: %u\n",
1413 msglen);
1414 return 0;
1415 }
1416
1417 /* Make sure this is a valid nvsp packet */
1418 if (unlikely(nvsp->hdr.msg_type != NVSP_MSG1_TYPE_SEND_RNDIS_PKT)) {
1419 netif_err(net_device_ctx, rx_err, ndev,
1420 "Unknown nvsp packet type received %u\n",
1421 nvsp->hdr.msg_type);
1422 return 0;
1423 }
1424
1425 /* Validate xfer page pkt header */
1426 if ((desc->offset8 << 3) < sizeof(struct vmtransfer_page_packet_header)) {
1427 netif_err(net_device_ctx, rx_err, ndev,
1428 "Invalid xfer page pkt, offset too small: %u\n",
1429 desc->offset8 << 3);
1430 return 0;
1431 }
1432
1433 if (unlikely(vmxferpage_packet->xfer_pageset_id != NETVSC_RECEIVE_BUFFER_ID)) {
1434 netif_err(net_device_ctx, rx_err, ndev,
1435 "Invalid xfer page set id - expecting %x got %x\n",
1436 NETVSC_RECEIVE_BUFFER_ID,
1437 vmxferpage_packet->xfer_pageset_id);
1438 return 0;
1439 }
1440
1441 count = vmxferpage_packet->range_cnt;
1442
1443 /* Check count for a valid value */
1444 if (NETVSC_XFER_HEADER_SIZE(count) > desc->offset8 << 3) {
1445 netif_err(net_device_ctx, rx_err, ndev,
1446 "Range count is not valid: %d\n",
1447 count);
1448 return 0;
1449 }
1450
1451 /* Each range represents 1 RNDIS pkt that contains 1 ethernet frame */
1452 for (i = 0; i < count; i++) {
1453 u32 offset = vmxferpage_packet->ranges[i].byte_offset;
1454 u32 buflen = vmxferpage_packet->ranges[i].byte_count;
1455 void *data;
1456 int ret;
1457
1458 if (unlikely(offset > net_device->recv_buf_size ||
1459 buflen > net_device->recv_buf_size - offset)) {
1460 nvchan->rsc.cnt = 0;
1461 status = NVSP_STAT_FAIL;
1462 netif_err(net_device_ctx, rx_err, ndev,
1463 "Packet offset:%u + len:%u too big\n",
1464 offset, buflen);
1465
1466 continue;
1467 }
1468
1469 /* We're going to copy (sections of) the packet into nvchan->recv_buf;
1470 * make sure that nvchan->recv_buf is large enough to hold the packet.
1471 */
1472 if (unlikely(buflen > net_device->recv_section_size)) {
1473 nvchan->rsc.cnt = 0;
1474 status = NVSP_STAT_FAIL;
1475 netif_err(net_device_ctx, rx_err, ndev,
1476 "Packet too big: buflen=%u recv_section_size=%u\n",
1477 buflen, net_device->recv_section_size);
1478
1479 continue;
1480 }
1481
1482 data = recv_buf + offset;
1483
1484 nvchan->rsc.is_last = (i == count - 1);
1485
1486 trace_rndis_recv(ndev, q_idx, data);
1487
1488 /* Pass it to the upper layer */
1489 ret = rndis_filter_receive(ndev, net_device,
1490 nvchan, data, buflen);
1491
1492 if (unlikely(ret != NVSP_STAT_SUCCESS)) {
1493 /* Drop incomplete packet */
1494 nvchan->rsc.cnt = 0;
1495 status = NVSP_STAT_FAIL;
1496 }
1497 }
1498
1499 enq_receive_complete(ndev, net_device, q_idx,
1500 vmxferpage_packet->d.trans_id, status);
1501
1502 return count;
1503}
1504
1505static void netvsc_send_table(struct net_device *ndev,
1506 struct netvsc_device *nvscdev,
1507 const struct nvsp_message *nvmsg,
1508 u32 msglen)
1509{
1510 struct net_device_context *net_device_ctx = netdev_priv(ndev);
1511 u32 count, offset, *tab;
1512 int i;
1513
1514 /* Ensure packet is big enough to read send_table fields */
1515 if (msglen < sizeof(struct nvsp_message_header) +
1516 sizeof(struct nvsp_5_send_indirect_table)) {
1517 netdev_err(ndev, "nvsp_v5_msg length too small: %u\n", msglen);
1518 return;
1519 }
1520
1521 count = nvmsg->msg.v5_msg.send_table.count;
1522 offset = nvmsg->msg.v5_msg.send_table.offset;
1523
1524 if (count != VRSS_SEND_TAB_SIZE) {
1525 netdev_err(ndev, "Received wrong send-table size:%u\n", count);
1526 return;
1527 }
1528
1529 /* If negotiated version <= NVSP_PROTOCOL_VERSION_6, the offset may be
1530 * wrong due to a host bug. So fix the offset here.
1531 */
1532 if (nvscdev->nvsp_version <= NVSP_PROTOCOL_VERSION_6 &&
1533 msglen >= sizeof(struct nvsp_message_header) +
1534 sizeof(union nvsp_6_message_uber) + count * sizeof(u32))
1535 offset = sizeof(struct nvsp_message_header) +
1536 sizeof(union nvsp_6_message_uber);
1537
1538 /* Boundary check for all versions */
1539 if (msglen < count * sizeof(u32) || offset > msglen - count * sizeof(u32)) {
1540 netdev_err(ndev, "Received send-table offset too big:%u\n",
1541 offset);
1542 return;
1543 }
1544
1545 tab = (void *)nvmsg + offset;
1546
1547 for (i = 0; i < count; i++)
1548 net_device_ctx->tx_table[i] = tab[i];
1549}
1550
1551static void netvsc_send_vf(struct net_device *ndev,
1552 const struct nvsp_message *nvmsg,
1553 u32 msglen)
1554{
1555 struct net_device_context *net_device_ctx = netdev_priv(ndev);
1556
1557 /* Ensure packet is big enough to read its fields */
1558 if (msglen < sizeof(struct nvsp_message_header) +
1559 sizeof(struct nvsp_4_send_vf_association)) {
1560 netdev_err(ndev, "nvsp_v4_msg length too small: %u\n", msglen);
1561 return;
1562 }
1563
1564 net_device_ctx->vf_alloc = nvmsg->msg.v4_msg.vf_assoc.allocated;
1565 net_device_ctx->vf_serial = nvmsg->msg.v4_msg.vf_assoc.serial;
1566
1567 if (net_device_ctx->vf_alloc)
1568 complete(&net_device_ctx->vf_add);
1569
1570 netdev_info(ndev, "VF slot %u %s\n",
1571 net_device_ctx->vf_serial,
1572 net_device_ctx->vf_alloc ? "added" : "removed");
1573}
1574
1575static void netvsc_receive_inband(struct net_device *ndev,
1576 struct netvsc_device *nvscdev,
1577 const struct vmpacket_descriptor *desc)
1578{
1579 const struct nvsp_message *nvmsg = hv_pkt_data(desc);
1580 u32 msglen = hv_pkt_datalen(desc);
1581
1582 /* Ensure packet is big enough to read header fields */
1583 if (msglen < sizeof(struct nvsp_message_header)) {
1584 netdev_err(ndev, "inband nvsp_message length too small: %u\n", msglen);
1585 return;
1586 }
1587
1588 switch (nvmsg->hdr.msg_type) {
1589 case NVSP_MSG5_TYPE_SEND_INDIRECTION_TABLE:
1590 netvsc_send_table(ndev, nvscdev, nvmsg, msglen);
1591 break;
1592
1593 case NVSP_MSG4_TYPE_SEND_VF_ASSOCIATION:
1594 if (hv_is_isolation_supported())
1595 netdev_err(ndev, "Ignore VF_ASSOCIATION msg from the host supporting isolation\n");
1596 else
1597 netvsc_send_vf(ndev, nvmsg, msglen);
1598 break;
1599 }
1600}
1601
1602static int netvsc_process_raw_pkt(struct hv_device *device,
1603 struct netvsc_channel *nvchan,
1604 struct netvsc_device *net_device,
1605 struct net_device *ndev,
1606 const struct vmpacket_descriptor *desc,
1607 int budget)
1608{
1609 struct vmbus_channel *channel = nvchan->channel;
1610 const struct nvsp_message *nvmsg = hv_pkt_data(desc);
1611
1612 trace_nvsp_recv(ndev, channel, nvmsg);
1613
1614 switch (desc->type) {
1615 case VM_PKT_COMP:
1616 netvsc_send_completion(ndev, net_device, channel, desc, budget);
1617 break;
1618
1619 case VM_PKT_DATA_USING_XFER_PAGES:
1620 return netvsc_receive(ndev, net_device, nvchan, desc);
1621
1622 case VM_PKT_DATA_INBAND:
1623 netvsc_receive_inband(ndev, net_device, desc);
1624 break;
1625
1626 default:
1627 netdev_err(ndev, "unhandled packet type %d, tid %llx\n",
1628 desc->type, desc->trans_id);
1629 break;
1630 }
1631
1632 return 0;
1633}
1634
1635static struct hv_device *netvsc_channel_to_device(struct vmbus_channel *channel)
1636{
1637 struct vmbus_channel *primary = channel->primary_channel;
1638
1639 return primary ? primary->device_obj : channel->device_obj;
1640}
1641
1642/* Network processing softirq
1643 * Process data in incoming ring buffer from host
1644 * Stops when ring is empty or budget is met or exceeded.
1645 */
1646int netvsc_poll(struct napi_struct *napi, int budget)
1647{
1648 struct netvsc_channel *nvchan
1649 = container_of(napi, struct netvsc_channel, napi);
1650 struct netvsc_device *net_device = nvchan->net_device;
1651 struct vmbus_channel *channel = nvchan->channel;
1652 struct hv_device *device = netvsc_channel_to_device(channel);
1653 struct net_device *ndev = hv_get_drvdata(device);
1654 int work_done = 0;
1655 int ret;
1656
1657 /* If starting a new interval */
1658 if (!nvchan->desc)
1659 nvchan->desc = hv_pkt_iter_first(channel);
1660
1661 nvchan->xdp_flush = false;
1662
1663 while (nvchan->desc && work_done < budget) {
1664 work_done += netvsc_process_raw_pkt(device, nvchan, net_device,
1665 ndev, nvchan->desc, budget);
1666 nvchan->desc = hv_pkt_iter_next(channel, nvchan->desc);
1667 }
1668
1669 if (nvchan->xdp_flush)
1670 xdp_do_flush();
1671
1672 /* Send any pending receive completions */
1673 ret = send_recv_completions(ndev, net_device, nvchan);
1674
1675 /* If it did not exhaust NAPI budget this time
1676 * and not doing busy poll
1677 * then re-enable host interrupts
1678 * and reschedule if ring is not empty
1679 * or sending receive completion failed.
1680 */
1681 if (work_done < budget &&
1682 napi_complete_done(napi, work_done) &&
1683 (ret || hv_end_read(&channel->inbound)) &&
1684 napi_schedule_prep(napi)) {
1685 hv_begin_read(&channel->inbound);
1686 __napi_schedule(napi);
1687 }
1688
1689 /* Driver may overshoot since multiple packets per descriptor */
1690 return min(work_done, budget);
1691}
1692
1693/* Call back when data is available in host ring buffer.
1694 * Processing is deferred until network softirq (NAPI)
1695 */
1696void netvsc_channel_cb(void *context)
1697{
1698 struct netvsc_channel *nvchan = context;
1699 struct vmbus_channel *channel = nvchan->channel;
1700 struct hv_ring_buffer_info *rbi = &channel->inbound;
1701
1702 /* preload first vmpacket descriptor */
1703 prefetch(hv_get_ring_buffer(rbi) + rbi->priv_read_index);
1704
1705 if (napi_schedule_prep(&nvchan->napi)) {
1706 /* disable interrupts from host */
1707 hv_begin_read(rbi);
1708
1709 __napi_schedule_irqoff(&nvchan->napi);
1710 }
1711}
1712
1713/*
1714 * netvsc_device_add - Callback when the device belonging to this
1715 * driver is added
1716 */
1717struct netvsc_device *netvsc_device_add(struct hv_device *device,
1718 const struct netvsc_device_info *device_info)
1719{
1720 int i, ret = 0;
1721 struct netvsc_device *net_device;
1722 struct net_device *ndev = hv_get_drvdata(device);
1723 struct net_device_context *net_device_ctx = netdev_priv(ndev);
1724
1725 net_device = alloc_net_device();
1726 if (!net_device)
1727 return ERR_PTR(-ENOMEM);
1728
1729 for (i = 0; i < VRSS_SEND_TAB_SIZE; i++)
1730 net_device_ctx->tx_table[i] = 0;
1731
1732 /* Because the device uses NAPI, all the interrupt batching and
1733 * control is done via Net softirq, not the channel handling
1734 */
1735 set_channel_read_mode(device->channel, HV_CALL_ISR);
1736
1737 /* If we're reopening the device we may have multiple queues, fill the
1738 * chn_table with the default channel to use it before subchannels are
1739 * opened.
1740 * Initialize the channel state before we open;
1741 * we can be interrupted as soon as we open the channel.
1742 */
1743
1744 for (i = 0; i < VRSS_CHANNEL_MAX; i++) {
1745 struct netvsc_channel *nvchan = &net_device->chan_table[i];
1746
1747 nvchan->channel = device->channel;
1748 nvchan->net_device = net_device;
1749 u64_stats_init(&nvchan->tx_stats.syncp);
1750 u64_stats_init(&nvchan->rx_stats.syncp);
1751
1752 ret = xdp_rxq_info_reg(&nvchan->xdp_rxq, ndev, i, 0);
1753
1754 if (ret) {
1755 netdev_err(ndev, "xdp_rxq_info_reg fail: %d\n", ret);
1756 goto cleanup2;
1757 }
1758
1759 ret = xdp_rxq_info_reg_mem_model(&nvchan->xdp_rxq,
1760 MEM_TYPE_PAGE_SHARED, NULL);
1761
1762 if (ret) {
1763 netdev_err(ndev, "xdp reg_mem_model fail: %d\n", ret);
1764 goto cleanup2;
1765 }
1766 }
1767
1768 /* Enable NAPI handler before init callbacks */
1769 netif_napi_add(ndev, &net_device->chan_table[0].napi, netvsc_poll);
1770
1771 /* Open the channel */
1772 device->channel->next_request_id_callback = vmbus_next_request_id;
1773 device->channel->request_addr_callback = vmbus_request_addr;
1774 device->channel->rqstor_size = netvsc_rqstor_size(netvsc_ring_bytes);
1775 device->channel->max_pkt_size = NETVSC_MAX_PKT_SIZE;
1776
1777 ret = vmbus_open(device->channel, netvsc_ring_bytes,
1778 netvsc_ring_bytes, NULL, 0,
1779 netvsc_channel_cb, net_device->chan_table);
1780
1781 if (ret != 0) {
1782 netdev_err(ndev, "unable to open channel: %d\n", ret);
1783 goto cleanup;
1784 }
1785
1786 /* Channel is opened */
1787 netdev_dbg(ndev, "hv_netvsc channel opened successfully\n");
1788
1789 napi_enable(&net_device->chan_table[0].napi);
1790
1791 /* Connect with the NetVsp */
1792 ret = netvsc_connect_vsp(device, net_device, device_info);
1793 if (ret != 0) {
1794 netdev_err(ndev,
1795 "unable to connect to NetVSP - %d\n", ret);
1796 goto close;
1797 }
1798
1799 /* Writing nvdev pointer unlocks netvsc_send(), make sure chn_table is
1800 * populated.
1801 */
1802 rcu_assign_pointer(net_device_ctx->nvdev, net_device);
1803
1804 return net_device;
1805
1806close:
1807 RCU_INIT_POINTER(net_device_ctx->nvdev, NULL);
1808 napi_disable(&net_device->chan_table[0].napi);
1809
1810 /* Now, we can close the channel safely */
1811 vmbus_close(device->channel);
1812
1813cleanup:
1814 netif_napi_del(&net_device->chan_table[0].napi);
1815
1816cleanup2:
1817 free_netvsc_device(&net_device->rcu);
1818
1819 return ERR_PTR(ret);
1820}