]> git.ipfire.org Git - thirdparty/kernel/stable.git/blob - drivers/net/hyperv/netvsc.c
Merge tag 'gvt-fixes-2019-03-21' of https://github.com/intel/gvt-linux into drm-intel...
[thirdparty/kernel/stable.git] / drivers / net / hyperv / netvsc.c
1 /*
2 * Copyright (c) 2009, Microsoft Corporation.
3 *
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms and conditions of the GNU General Public License,
6 * version 2, as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
11 * more details.
12 *
13 * You should have received a copy of the GNU General Public License along with
14 * this program; if not, see <http://www.gnu.org/licenses/>.
15 *
16 * Authors:
17 * Haiyang Zhang <haiyangz@microsoft.com>
18 * Hank Janssen <hjanssen@microsoft.com>
19 */
20 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
21
22 #include <linux/kernel.h>
23 #include <linux/sched.h>
24 #include <linux/wait.h>
25 #include <linux/mm.h>
26 #include <linux/delay.h>
27 #include <linux/io.h>
28 #include <linux/slab.h>
29 #include <linux/netdevice.h>
30 #include <linux/if_ether.h>
31 #include <linux/vmalloc.h>
32 #include <linux/rtnetlink.h>
33 #include <linux/prefetch.h>
34
35 #include <asm/sync_bitops.h>
36
37 #include "hyperv_net.h"
38 #include "netvsc_trace.h"
39
40 /*
41 * Switch the data path from the synthetic interface to the VF
42 * interface.
43 */
44 void netvsc_switch_datapath(struct net_device *ndev, bool vf)
45 {
46 struct net_device_context *net_device_ctx = netdev_priv(ndev);
47 struct hv_device *dev = net_device_ctx->device_ctx;
48 struct netvsc_device *nv_dev = rtnl_dereference(net_device_ctx->nvdev);
49 struct nvsp_message *init_pkt = &nv_dev->channel_init_pkt;
50
51 memset(init_pkt, 0, sizeof(struct nvsp_message));
52 init_pkt->hdr.msg_type = NVSP_MSG4_TYPE_SWITCH_DATA_PATH;
53 if (vf)
54 init_pkt->msg.v4_msg.active_dp.active_datapath =
55 NVSP_DATAPATH_VF;
56 else
57 init_pkt->msg.v4_msg.active_dp.active_datapath =
58 NVSP_DATAPATH_SYNTHETIC;
59
60 trace_nvsp_send(ndev, init_pkt);
61
62 vmbus_sendpacket(dev->channel, init_pkt,
63 sizeof(struct nvsp_message),
64 (unsigned long)init_pkt,
65 VM_PKT_DATA_INBAND, 0);
66 }
67
68 /* Worker to setup sub channels on initial setup
69 * Initial hotplug event occurs in softirq context
70 * and can't wait for channels.
71 */
72 static void netvsc_subchan_work(struct work_struct *w)
73 {
74 struct netvsc_device *nvdev =
75 container_of(w, struct netvsc_device, subchan_work);
76 struct rndis_device *rdev;
77 int i, ret;
78
79 /* Avoid deadlock with device removal already under RTNL */
80 if (!rtnl_trylock()) {
81 schedule_work(w);
82 return;
83 }
84
85 rdev = nvdev->extension;
86 if (rdev) {
87 ret = rndis_set_subchannel(rdev->ndev, nvdev, NULL);
88 if (ret == 0) {
89 netif_device_attach(rdev->ndev);
90 } else {
91 /* fallback to only primary channel */
92 for (i = 1; i < nvdev->num_chn; i++)
93 netif_napi_del(&nvdev->chan_table[i].napi);
94
95 nvdev->max_chn = 1;
96 nvdev->num_chn = 1;
97 }
98 }
99
100 rtnl_unlock();
101 }
102
103 static struct netvsc_device *alloc_net_device(void)
104 {
105 struct netvsc_device *net_device;
106
107 net_device = kzalloc(sizeof(struct netvsc_device), GFP_KERNEL);
108 if (!net_device)
109 return NULL;
110
111 init_waitqueue_head(&net_device->wait_drain);
112 net_device->destroy = false;
113
114 net_device->max_pkt = RNDIS_MAX_PKT_DEFAULT;
115 net_device->pkt_align = RNDIS_PKT_ALIGN_DEFAULT;
116
117 init_completion(&net_device->channel_init_wait);
118 init_waitqueue_head(&net_device->subchan_open);
119 INIT_WORK(&net_device->subchan_work, netvsc_subchan_work);
120
121 return net_device;
122 }
123
124 static void free_netvsc_device(struct rcu_head *head)
125 {
126 struct netvsc_device *nvdev
127 = container_of(head, struct netvsc_device, rcu);
128 int i;
129
130 kfree(nvdev->extension);
131 vfree(nvdev->recv_buf);
132 vfree(nvdev->send_buf);
133 kfree(nvdev->send_section_map);
134
135 for (i = 0; i < VRSS_CHANNEL_MAX; i++)
136 vfree(nvdev->chan_table[i].mrc.slots);
137
138 kfree(nvdev);
139 }
140
141 static void free_netvsc_device_rcu(struct netvsc_device *nvdev)
142 {
143 call_rcu(&nvdev->rcu, free_netvsc_device);
144 }
145
146 static void netvsc_revoke_recv_buf(struct hv_device *device,
147 struct netvsc_device *net_device,
148 struct net_device *ndev)
149 {
150 struct nvsp_message *revoke_packet;
151 int ret;
152
153 /*
154 * If we got a section count, it means we received a
155 * SendReceiveBufferComplete msg (ie sent
156 * NvspMessage1TypeSendReceiveBuffer msg) therefore, we need
157 * to send a revoke msg here
158 */
159 if (net_device->recv_section_cnt) {
160 /* Send the revoke receive buffer */
161 revoke_packet = &net_device->revoke_packet;
162 memset(revoke_packet, 0, sizeof(struct nvsp_message));
163
164 revoke_packet->hdr.msg_type =
165 NVSP_MSG1_TYPE_REVOKE_RECV_BUF;
166 revoke_packet->msg.v1_msg.
167 revoke_recv_buf.id = NETVSC_RECEIVE_BUFFER_ID;
168
169 trace_nvsp_send(ndev, revoke_packet);
170
171 ret = vmbus_sendpacket(device->channel,
172 revoke_packet,
173 sizeof(struct nvsp_message),
174 (unsigned long)revoke_packet,
175 VM_PKT_DATA_INBAND, 0);
176 /* If the failure is because the channel is rescinded;
177 * ignore the failure since we cannot send on a rescinded
178 * channel. This would allow us to properly cleanup
179 * even when the channel is rescinded.
180 */
181 if (device->channel->rescind)
182 ret = 0;
183 /*
184 * If we failed here, we might as well return and
185 * have a leak rather than continue and a bugchk
186 */
187 if (ret != 0) {
188 netdev_err(ndev, "unable to send "
189 "revoke receive buffer to netvsp\n");
190 return;
191 }
192 net_device->recv_section_cnt = 0;
193 }
194 }
195
196 static void netvsc_revoke_send_buf(struct hv_device *device,
197 struct netvsc_device *net_device,
198 struct net_device *ndev)
199 {
200 struct nvsp_message *revoke_packet;
201 int ret;
202
203 /* Deal with the send buffer we may have setup.
204 * If we got a send section size, it means we received a
205 * NVSP_MSG1_TYPE_SEND_SEND_BUF_COMPLETE msg (ie sent
206 * NVSP_MSG1_TYPE_SEND_SEND_BUF msg) therefore, we need
207 * to send a revoke msg here
208 */
209 if (net_device->send_section_cnt) {
210 /* Send the revoke receive buffer */
211 revoke_packet = &net_device->revoke_packet;
212 memset(revoke_packet, 0, sizeof(struct nvsp_message));
213
214 revoke_packet->hdr.msg_type =
215 NVSP_MSG1_TYPE_REVOKE_SEND_BUF;
216 revoke_packet->msg.v1_msg.revoke_send_buf.id =
217 NETVSC_SEND_BUFFER_ID;
218
219 trace_nvsp_send(ndev, revoke_packet);
220
221 ret = vmbus_sendpacket(device->channel,
222 revoke_packet,
223 sizeof(struct nvsp_message),
224 (unsigned long)revoke_packet,
225 VM_PKT_DATA_INBAND, 0);
226
227 /* If the failure is because the channel is rescinded;
228 * ignore the failure since we cannot send on a rescinded
229 * channel. This would allow us to properly cleanup
230 * even when the channel is rescinded.
231 */
232 if (device->channel->rescind)
233 ret = 0;
234
235 /* If we failed here, we might as well return and
236 * have a leak rather than continue and a bugchk
237 */
238 if (ret != 0) {
239 netdev_err(ndev, "unable to send "
240 "revoke send buffer to netvsp\n");
241 return;
242 }
243 net_device->send_section_cnt = 0;
244 }
245 }
246
247 static void netvsc_teardown_recv_gpadl(struct hv_device *device,
248 struct netvsc_device *net_device,
249 struct net_device *ndev)
250 {
251 int ret;
252
253 if (net_device->recv_buf_gpadl_handle) {
254 ret = vmbus_teardown_gpadl(device->channel,
255 net_device->recv_buf_gpadl_handle);
256
257 /* If we failed here, we might as well return and have a leak
258 * rather than continue and a bugchk
259 */
260 if (ret != 0) {
261 netdev_err(ndev,
262 "unable to teardown receive buffer's gpadl\n");
263 return;
264 }
265 net_device->recv_buf_gpadl_handle = 0;
266 }
267 }
268
269 static void netvsc_teardown_send_gpadl(struct hv_device *device,
270 struct netvsc_device *net_device,
271 struct net_device *ndev)
272 {
273 int ret;
274
275 if (net_device->send_buf_gpadl_handle) {
276 ret = vmbus_teardown_gpadl(device->channel,
277 net_device->send_buf_gpadl_handle);
278
279 /* If we failed here, we might as well return and have a leak
280 * rather than continue and a bugchk
281 */
282 if (ret != 0) {
283 netdev_err(ndev,
284 "unable to teardown send buffer's gpadl\n");
285 return;
286 }
287 net_device->send_buf_gpadl_handle = 0;
288 }
289 }
290
291 int netvsc_alloc_recv_comp_ring(struct netvsc_device *net_device, u32 q_idx)
292 {
293 struct netvsc_channel *nvchan = &net_device->chan_table[q_idx];
294 int node = cpu_to_node(nvchan->channel->target_cpu);
295 size_t size;
296
297 size = net_device->recv_completion_cnt * sizeof(struct recv_comp_data);
298 nvchan->mrc.slots = vzalloc_node(size, node);
299 if (!nvchan->mrc.slots)
300 nvchan->mrc.slots = vzalloc(size);
301
302 return nvchan->mrc.slots ? 0 : -ENOMEM;
303 }
304
305 static int netvsc_init_buf(struct hv_device *device,
306 struct netvsc_device *net_device,
307 const struct netvsc_device_info *device_info)
308 {
309 struct nvsp_1_message_send_receive_buffer_complete *resp;
310 struct net_device *ndev = hv_get_drvdata(device);
311 struct nvsp_message *init_packet;
312 unsigned int buf_size;
313 size_t map_words;
314 int ret = 0;
315
316 /* Get receive buffer area. */
317 buf_size = device_info->recv_sections * device_info->recv_section_size;
318 buf_size = roundup(buf_size, PAGE_SIZE);
319
320 /* Legacy hosts only allow smaller receive buffer */
321 if (net_device->nvsp_version <= NVSP_PROTOCOL_VERSION_2)
322 buf_size = min_t(unsigned int, buf_size,
323 NETVSC_RECEIVE_BUFFER_SIZE_LEGACY);
324
325 net_device->recv_buf = vzalloc(buf_size);
326 if (!net_device->recv_buf) {
327 netdev_err(ndev,
328 "unable to allocate receive buffer of size %u\n",
329 buf_size);
330 ret = -ENOMEM;
331 goto cleanup;
332 }
333
334 net_device->recv_buf_size = buf_size;
335
336 /*
337 * Establish the gpadl handle for this buffer on this
338 * channel. Note: This call uses the vmbus connection rather
339 * than the channel to establish the gpadl handle.
340 */
341 ret = vmbus_establish_gpadl(device->channel, net_device->recv_buf,
342 buf_size,
343 &net_device->recv_buf_gpadl_handle);
344 if (ret != 0) {
345 netdev_err(ndev,
346 "unable to establish receive buffer's gpadl\n");
347 goto cleanup;
348 }
349
350 /* Notify the NetVsp of the gpadl handle */
351 init_packet = &net_device->channel_init_pkt;
352 memset(init_packet, 0, sizeof(struct nvsp_message));
353 init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_RECV_BUF;
354 init_packet->msg.v1_msg.send_recv_buf.
355 gpadl_handle = net_device->recv_buf_gpadl_handle;
356 init_packet->msg.v1_msg.
357 send_recv_buf.id = NETVSC_RECEIVE_BUFFER_ID;
358
359 trace_nvsp_send(ndev, init_packet);
360
361 /* Send the gpadl notification request */
362 ret = vmbus_sendpacket(device->channel, init_packet,
363 sizeof(struct nvsp_message),
364 (unsigned long)init_packet,
365 VM_PKT_DATA_INBAND,
366 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
367 if (ret != 0) {
368 netdev_err(ndev,
369 "unable to send receive buffer's gpadl to netvsp\n");
370 goto cleanup;
371 }
372
373 wait_for_completion(&net_device->channel_init_wait);
374
375 /* Check the response */
376 resp = &init_packet->msg.v1_msg.send_recv_buf_complete;
377 if (resp->status != NVSP_STAT_SUCCESS) {
378 netdev_err(ndev,
379 "Unable to complete receive buffer initialization with NetVsp - status %d\n",
380 resp->status);
381 ret = -EINVAL;
382 goto cleanup;
383 }
384
385 /* Parse the response */
386 netdev_dbg(ndev, "Receive sections: %u sub_allocs: size %u count: %u\n",
387 resp->num_sections, resp->sections[0].sub_alloc_size,
388 resp->sections[0].num_sub_allocs);
389
390 /* There should only be one section for the entire receive buffer */
391 if (resp->num_sections != 1 || resp->sections[0].offset != 0) {
392 ret = -EINVAL;
393 goto cleanup;
394 }
395
396 net_device->recv_section_size = resp->sections[0].sub_alloc_size;
397 net_device->recv_section_cnt = resp->sections[0].num_sub_allocs;
398
399 /* Setup receive completion ring */
400 net_device->recv_completion_cnt
401 = round_up(net_device->recv_section_cnt + 1,
402 PAGE_SIZE / sizeof(u64));
403 ret = netvsc_alloc_recv_comp_ring(net_device, 0);
404 if (ret)
405 goto cleanup;
406
407 /* Now setup the send buffer. */
408 buf_size = device_info->send_sections * device_info->send_section_size;
409 buf_size = round_up(buf_size, PAGE_SIZE);
410
411 net_device->send_buf = vzalloc(buf_size);
412 if (!net_device->send_buf) {
413 netdev_err(ndev, "unable to allocate send buffer of size %u\n",
414 buf_size);
415 ret = -ENOMEM;
416 goto cleanup;
417 }
418
419 /* Establish the gpadl handle for this buffer on this
420 * channel. Note: This call uses the vmbus connection rather
421 * than the channel to establish the gpadl handle.
422 */
423 ret = vmbus_establish_gpadl(device->channel, net_device->send_buf,
424 buf_size,
425 &net_device->send_buf_gpadl_handle);
426 if (ret != 0) {
427 netdev_err(ndev,
428 "unable to establish send buffer's gpadl\n");
429 goto cleanup;
430 }
431
432 /* Notify the NetVsp of the gpadl handle */
433 init_packet = &net_device->channel_init_pkt;
434 memset(init_packet, 0, sizeof(struct nvsp_message));
435 init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_SEND_BUF;
436 init_packet->msg.v1_msg.send_send_buf.gpadl_handle =
437 net_device->send_buf_gpadl_handle;
438 init_packet->msg.v1_msg.send_send_buf.id = NETVSC_SEND_BUFFER_ID;
439
440 trace_nvsp_send(ndev, init_packet);
441
442 /* Send the gpadl notification request */
443 ret = vmbus_sendpacket(device->channel, init_packet,
444 sizeof(struct nvsp_message),
445 (unsigned long)init_packet,
446 VM_PKT_DATA_INBAND,
447 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
448 if (ret != 0) {
449 netdev_err(ndev,
450 "unable to send send buffer's gpadl to netvsp\n");
451 goto cleanup;
452 }
453
454 wait_for_completion(&net_device->channel_init_wait);
455
456 /* Check the response */
457 if (init_packet->msg.v1_msg.
458 send_send_buf_complete.status != NVSP_STAT_SUCCESS) {
459 netdev_err(ndev, "Unable to complete send buffer "
460 "initialization with NetVsp - status %d\n",
461 init_packet->msg.v1_msg.
462 send_send_buf_complete.status);
463 ret = -EINVAL;
464 goto cleanup;
465 }
466
467 /* Parse the response */
468 net_device->send_section_size = init_packet->msg.
469 v1_msg.send_send_buf_complete.section_size;
470
471 /* Section count is simply the size divided by the section size. */
472 net_device->send_section_cnt = buf_size / net_device->send_section_size;
473
474 netdev_dbg(ndev, "Send section size: %d, Section count:%d\n",
475 net_device->send_section_size, net_device->send_section_cnt);
476
477 /* Setup state for managing the send buffer. */
478 map_words = DIV_ROUND_UP(net_device->send_section_cnt, BITS_PER_LONG);
479
480 net_device->send_section_map = kcalloc(map_words, sizeof(ulong), GFP_KERNEL);
481 if (net_device->send_section_map == NULL) {
482 ret = -ENOMEM;
483 goto cleanup;
484 }
485
486 goto exit;
487
488 cleanup:
489 netvsc_revoke_recv_buf(device, net_device, ndev);
490 netvsc_revoke_send_buf(device, net_device, ndev);
491 netvsc_teardown_recv_gpadl(device, net_device, ndev);
492 netvsc_teardown_send_gpadl(device, net_device, ndev);
493
494 exit:
495 return ret;
496 }
497
498 /* Negotiate NVSP protocol version */
499 static int negotiate_nvsp_ver(struct hv_device *device,
500 struct netvsc_device *net_device,
501 struct nvsp_message *init_packet,
502 u32 nvsp_ver)
503 {
504 struct net_device *ndev = hv_get_drvdata(device);
505 int ret;
506
507 memset(init_packet, 0, sizeof(struct nvsp_message));
508 init_packet->hdr.msg_type = NVSP_MSG_TYPE_INIT;
509 init_packet->msg.init_msg.init.min_protocol_ver = nvsp_ver;
510 init_packet->msg.init_msg.init.max_protocol_ver = nvsp_ver;
511 trace_nvsp_send(ndev, init_packet);
512
513 /* Send the init request */
514 ret = vmbus_sendpacket(device->channel, init_packet,
515 sizeof(struct nvsp_message),
516 (unsigned long)init_packet,
517 VM_PKT_DATA_INBAND,
518 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
519
520 if (ret != 0)
521 return ret;
522
523 wait_for_completion(&net_device->channel_init_wait);
524
525 if (init_packet->msg.init_msg.init_complete.status !=
526 NVSP_STAT_SUCCESS)
527 return -EINVAL;
528
529 if (nvsp_ver == NVSP_PROTOCOL_VERSION_1)
530 return 0;
531
532 /* NVSPv2 or later: Send NDIS config */
533 memset(init_packet, 0, sizeof(struct nvsp_message));
534 init_packet->hdr.msg_type = NVSP_MSG2_TYPE_SEND_NDIS_CONFIG;
535 init_packet->msg.v2_msg.send_ndis_config.mtu = ndev->mtu + ETH_HLEN;
536 init_packet->msg.v2_msg.send_ndis_config.capability.ieee8021q = 1;
537
538 if (nvsp_ver >= NVSP_PROTOCOL_VERSION_5) {
539 init_packet->msg.v2_msg.send_ndis_config.capability.sriov = 1;
540
541 /* Teaming bit is needed to receive link speed updates */
542 init_packet->msg.v2_msg.send_ndis_config.capability.teaming = 1;
543 }
544
545 if (nvsp_ver >= NVSP_PROTOCOL_VERSION_61)
546 init_packet->msg.v2_msg.send_ndis_config.capability.rsc = 1;
547
548 trace_nvsp_send(ndev, init_packet);
549
550 ret = vmbus_sendpacket(device->channel, init_packet,
551 sizeof(struct nvsp_message),
552 (unsigned long)init_packet,
553 VM_PKT_DATA_INBAND, 0);
554
555 return ret;
556 }
557
558 static int netvsc_connect_vsp(struct hv_device *device,
559 struct netvsc_device *net_device,
560 const struct netvsc_device_info *device_info)
561 {
562 struct net_device *ndev = hv_get_drvdata(device);
563 static const u32 ver_list[] = {
564 NVSP_PROTOCOL_VERSION_1, NVSP_PROTOCOL_VERSION_2,
565 NVSP_PROTOCOL_VERSION_4, NVSP_PROTOCOL_VERSION_5,
566 NVSP_PROTOCOL_VERSION_6, NVSP_PROTOCOL_VERSION_61
567 };
568 struct nvsp_message *init_packet;
569 int ndis_version, i, ret;
570
571 init_packet = &net_device->channel_init_pkt;
572
573 /* Negotiate the latest NVSP protocol supported */
574 for (i = ARRAY_SIZE(ver_list) - 1; i >= 0; i--)
575 if (negotiate_nvsp_ver(device, net_device, init_packet,
576 ver_list[i]) == 0) {
577 net_device->nvsp_version = ver_list[i];
578 break;
579 }
580
581 if (i < 0) {
582 ret = -EPROTO;
583 goto cleanup;
584 }
585
586 pr_debug("Negotiated NVSP version:%x\n", net_device->nvsp_version);
587
588 /* Send the ndis version */
589 memset(init_packet, 0, sizeof(struct nvsp_message));
590
591 if (net_device->nvsp_version <= NVSP_PROTOCOL_VERSION_4)
592 ndis_version = 0x00060001;
593 else
594 ndis_version = 0x0006001e;
595
596 init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_NDIS_VER;
597 init_packet->msg.v1_msg.
598 send_ndis_ver.ndis_major_ver =
599 (ndis_version & 0xFFFF0000) >> 16;
600 init_packet->msg.v1_msg.
601 send_ndis_ver.ndis_minor_ver =
602 ndis_version & 0xFFFF;
603
604 trace_nvsp_send(ndev, init_packet);
605
606 /* Send the init request */
607 ret = vmbus_sendpacket(device->channel, init_packet,
608 sizeof(struct nvsp_message),
609 (unsigned long)init_packet,
610 VM_PKT_DATA_INBAND, 0);
611 if (ret != 0)
612 goto cleanup;
613
614
615 ret = netvsc_init_buf(device, net_device, device_info);
616
617 cleanup:
618 return ret;
619 }
620
621 /*
622 * netvsc_device_remove - Callback when the root bus device is removed
623 */
624 void netvsc_device_remove(struct hv_device *device)
625 {
626 struct net_device *ndev = hv_get_drvdata(device);
627 struct net_device_context *net_device_ctx = netdev_priv(ndev);
628 struct netvsc_device *net_device
629 = rtnl_dereference(net_device_ctx->nvdev);
630 int i;
631
632 /*
633 * Revoke receive buffer. If host is pre-Win2016 then tear down
634 * receive buffer GPADL. Do the same for send buffer.
635 */
636 netvsc_revoke_recv_buf(device, net_device, ndev);
637 if (vmbus_proto_version < VERSION_WIN10)
638 netvsc_teardown_recv_gpadl(device, net_device, ndev);
639
640 netvsc_revoke_send_buf(device, net_device, ndev);
641 if (vmbus_proto_version < VERSION_WIN10)
642 netvsc_teardown_send_gpadl(device, net_device, ndev);
643
644 RCU_INIT_POINTER(net_device_ctx->nvdev, NULL);
645
646 /* And disassociate NAPI context from device */
647 for (i = 0; i < net_device->num_chn; i++)
648 netif_napi_del(&net_device->chan_table[i].napi);
649
650 /*
651 * At this point, no one should be accessing net_device
652 * except in here
653 */
654 netdev_dbg(ndev, "net device safe to remove\n");
655
656 /* Now, we can close the channel safely */
657 vmbus_close(device->channel);
658
659 /*
660 * If host is Win2016 or higher then we do the GPADL tear down
661 * here after VMBus is closed.
662 */
663 if (vmbus_proto_version >= VERSION_WIN10) {
664 netvsc_teardown_recv_gpadl(device, net_device, ndev);
665 netvsc_teardown_send_gpadl(device, net_device, ndev);
666 }
667
668 /* Release all resources */
669 free_netvsc_device_rcu(net_device);
670 }
671
672 #define RING_AVAIL_PERCENT_HIWATER 20
673 #define RING_AVAIL_PERCENT_LOWATER 10
674
675 static inline void netvsc_free_send_slot(struct netvsc_device *net_device,
676 u32 index)
677 {
678 sync_change_bit(index, net_device->send_section_map);
679 }
680
681 static void netvsc_send_tx_complete(struct net_device *ndev,
682 struct netvsc_device *net_device,
683 struct vmbus_channel *channel,
684 const struct vmpacket_descriptor *desc,
685 int budget)
686 {
687 struct sk_buff *skb = (struct sk_buff *)(unsigned long)desc->trans_id;
688 struct net_device_context *ndev_ctx = netdev_priv(ndev);
689 u16 q_idx = 0;
690 int queue_sends;
691
692 /* Notify the layer above us */
693 if (likely(skb)) {
694 const struct hv_netvsc_packet *packet
695 = (struct hv_netvsc_packet *)skb->cb;
696 u32 send_index = packet->send_buf_index;
697 struct netvsc_stats *tx_stats;
698
699 if (send_index != NETVSC_INVALID_INDEX)
700 netvsc_free_send_slot(net_device, send_index);
701 q_idx = packet->q_idx;
702
703 tx_stats = &net_device->chan_table[q_idx].tx_stats;
704
705 u64_stats_update_begin(&tx_stats->syncp);
706 tx_stats->packets += packet->total_packets;
707 tx_stats->bytes += packet->total_bytes;
708 u64_stats_update_end(&tx_stats->syncp);
709
710 napi_consume_skb(skb, budget);
711 }
712
713 queue_sends =
714 atomic_dec_return(&net_device->chan_table[q_idx].queue_sends);
715
716 if (unlikely(net_device->destroy)) {
717 if (queue_sends == 0)
718 wake_up(&net_device->wait_drain);
719 } else {
720 struct netdev_queue *txq = netdev_get_tx_queue(ndev, q_idx);
721
722 if (netif_tx_queue_stopped(txq) &&
723 (hv_get_avail_to_write_percent(&channel->outbound) >
724 RING_AVAIL_PERCENT_HIWATER || queue_sends < 1)) {
725 netif_tx_wake_queue(txq);
726 ndev_ctx->eth_stats.wake_queue++;
727 }
728 }
729 }
730
731 static void netvsc_send_completion(struct net_device *ndev,
732 struct netvsc_device *net_device,
733 struct vmbus_channel *incoming_channel,
734 const struct vmpacket_descriptor *desc,
735 int budget)
736 {
737 const struct nvsp_message *nvsp_packet = hv_pkt_data(desc);
738
739 switch (nvsp_packet->hdr.msg_type) {
740 case NVSP_MSG_TYPE_INIT_COMPLETE:
741 case NVSP_MSG1_TYPE_SEND_RECV_BUF_COMPLETE:
742 case NVSP_MSG1_TYPE_SEND_SEND_BUF_COMPLETE:
743 case NVSP_MSG5_TYPE_SUBCHANNEL:
744 /* Copy the response back */
745 memcpy(&net_device->channel_init_pkt, nvsp_packet,
746 sizeof(struct nvsp_message));
747 complete(&net_device->channel_init_wait);
748 break;
749
750 case NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE:
751 netvsc_send_tx_complete(ndev, net_device, incoming_channel,
752 desc, budget);
753 break;
754
755 default:
756 netdev_err(ndev,
757 "Unknown send completion type %d received!!\n",
758 nvsp_packet->hdr.msg_type);
759 }
760 }
761
762 static u32 netvsc_get_next_send_section(struct netvsc_device *net_device)
763 {
764 unsigned long *map_addr = net_device->send_section_map;
765 unsigned int i;
766
767 for_each_clear_bit(i, map_addr, net_device->send_section_cnt) {
768 if (sync_test_and_set_bit(i, map_addr) == 0)
769 return i;
770 }
771
772 return NETVSC_INVALID_INDEX;
773 }
774
775 static void netvsc_copy_to_send_buf(struct netvsc_device *net_device,
776 unsigned int section_index,
777 u32 pend_size,
778 struct hv_netvsc_packet *packet,
779 struct rndis_message *rndis_msg,
780 struct hv_page_buffer *pb,
781 bool xmit_more)
782 {
783 char *start = net_device->send_buf;
784 char *dest = start + (section_index * net_device->send_section_size)
785 + pend_size;
786 int i;
787 u32 padding = 0;
788 u32 page_count = packet->cp_partial ? packet->rmsg_pgcnt :
789 packet->page_buf_cnt;
790 u32 remain;
791
792 /* Add padding */
793 remain = packet->total_data_buflen & (net_device->pkt_align - 1);
794 if (xmit_more && remain) {
795 padding = net_device->pkt_align - remain;
796 rndis_msg->msg_len += padding;
797 packet->total_data_buflen += padding;
798 }
799
800 for (i = 0; i < page_count; i++) {
801 char *src = phys_to_virt(pb[i].pfn << PAGE_SHIFT);
802 u32 offset = pb[i].offset;
803 u32 len = pb[i].len;
804
805 memcpy(dest, (src + offset), len);
806 dest += len;
807 }
808
809 if (padding)
810 memset(dest, 0, padding);
811 }
812
813 static inline int netvsc_send_pkt(
814 struct hv_device *device,
815 struct hv_netvsc_packet *packet,
816 struct netvsc_device *net_device,
817 struct hv_page_buffer *pb,
818 struct sk_buff *skb)
819 {
820 struct nvsp_message nvmsg;
821 struct nvsp_1_message_send_rndis_packet *rpkt =
822 &nvmsg.msg.v1_msg.send_rndis_pkt;
823 struct netvsc_channel * const nvchan =
824 &net_device->chan_table[packet->q_idx];
825 struct vmbus_channel *out_channel = nvchan->channel;
826 struct net_device *ndev = hv_get_drvdata(device);
827 struct net_device_context *ndev_ctx = netdev_priv(ndev);
828 struct netdev_queue *txq = netdev_get_tx_queue(ndev, packet->q_idx);
829 u64 req_id;
830 int ret;
831 u32 ring_avail = hv_get_avail_to_write_percent(&out_channel->outbound);
832
833 nvmsg.hdr.msg_type = NVSP_MSG1_TYPE_SEND_RNDIS_PKT;
834 if (skb)
835 rpkt->channel_type = 0; /* 0 is RMC_DATA */
836 else
837 rpkt->channel_type = 1; /* 1 is RMC_CONTROL */
838
839 rpkt->send_buf_section_index = packet->send_buf_index;
840 if (packet->send_buf_index == NETVSC_INVALID_INDEX)
841 rpkt->send_buf_section_size = 0;
842 else
843 rpkt->send_buf_section_size = packet->total_data_buflen;
844
845 req_id = (ulong)skb;
846
847 if (out_channel->rescind)
848 return -ENODEV;
849
850 trace_nvsp_send_pkt(ndev, out_channel, rpkt);
851
852 if (packet->page_buf_cnt) {
853 if (packet->cp_partial)
854 pb += packet->rmsg_pgcnt;
855
856 ret = vmbus_sendpacket_pagebuffer(out_channel,
857 pb, packet->page_buf_cnt,
858 &nvmsg, sizeof(nvmsg),
859 req_id);
860 } else {
861 ret = vmbus_sendpacket(out_channel,
862 &nvmsg, sizeof(nvmsg),
863 req_id, VM_PKT_DATA_INBAND,
864 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
865 }
866
867 if (ret == 0) {
868 atomic_inc_return(&nvchan->queue_sends);
869
870 if (ring_avail < RING_AVAIL_PERCENT_LOWATER) {
871 netif_tx_stop_queue(txq);
872 ndev_ctx->eth_stats.stop_queue++;
873 }
874 } else if (ret == -EAGAIN) {
875 netif_tx_stop_queue(txq);
876 ndev_ctx->eth_stats.stop_queue++;
877 if (atomic_read(&nvchan->queue_sends) < 1) {
878 netif_tx_wake_queue(txq);
879 ndev_ctx->eth_stats.wake_queue++;
880 ret = -ENOSPC;
881 }
882 } else {
883 netdev_err(ndev,
884 "Unable to send packet pages %u len %u, ret %d\n",
885 packet->page_buf_cnt, packet->total_data_buflen,
886 ret);
887 }
888
889 return ret;
890 }
891
892 /* Move packet out of multi send data (msd), and clear msd */
893 static inline void move_pkt_msd(struct hv_netvsc_packet **msd_send,
894 struct sk_buff **msd_skb,
895 struct multi_send_data *msdp)
896 {
897 *msd_skb = msdp->skb;
898 *msd_send = msdp->pkt;
899 msdp->skb = NULL;
900 msdp->pkt = NULL;
901 msdp->count = 0;
902 }
903
904 /* RCU already held by caller */
905 int netvsc_send(struct net_device *ndev,
906 struct hv_netvsc_packet *packet,
907 struct rndis_message *rndis_msg,
908 struct hv_page_buffer *pb,
909 struct sk_buff *skb)
910 {
911 struct net_device_context *ndev_ctx = netdev_priv(ndev);
912 struct netvsc_device *net_device
913 = rcu_dereference_bh(ndev_ctx->nvdev);
914 struct hv_device *device = ndev_ctx->device_ctx;
915 int ret = 0;
916 struct netvsc_channel *nvchan;
917 u32 pktlen = packet->total_data_buflen, msd_len = 0;
918 unsigned int section_index = NETVSC_INVALID_INDEX;
919 struct multi_send_data *msdp;
920 struct hv_netvsc_packet *msd_send = NULL, *cur_send = NULL;
921 struct sk_buff *msd_skb = NULL;
922 bool try_batch, xmit_more;
923
924 /* If device is rescinded, return error and packet will get dropped. */
925 if (unlikely(!net_device || net_device->destroy))
926 return -ENODEV;
927
928 nvchan = &net_device->chan_table[packet->q_idx];
929 packet->send_buf_index = NETVSC_INVALID_INDEX;
930 packet->cp_partial = false;
931
932 /* Send control message directly without accessing msd (Multi-Send
933 * Data) field which may be changed during data packet processing.
934 */
935 if (!skb)
936 return netvsc_send_pkt(device, packet, net_device, pb, skb);
937
938 /* batch packets in send buffer if possible */
939 msdp = &nvchan->msd;
940 if (msdp->pkt)
941 msd_len = msdp->pkt->total_data_buflen;
942
943 try_batch = msd_len > 0 && msdp->count < net_device->max_pkt;
944 if (try_batch && msd_len + pktlen + net_device->pkt_align <
945 net_device->send_section_size) {
946 section_index = msdp->pkt->send_buf_index;
947
948 } else if (try_batch && msd_len + packet->rmsg_size <
949 net_device->send_section_size) {
950 section_index = msdp->pkt->send_buf_index;
951 packet->cp_partial = true;
952
953 } else if (pktlen + net_device->pkt_align <
954 net_device->send_section_size) {
955 section_index = netvsc_get_next_send_section(net_device);
956 if (unlikely(section_index == NETVSC_INVALID_INDEX)) {
957 ++ndev_ctx->eth_stats.tx_send_full;
958 } else {
959 move_pkt_msd(&msd_send, &msd_skb, msdp);
960 msd_len = 0;
961 }
962 }
963
964 /* Keep aggregating only if stack says more data is coming
965 * and not doing mixed modes send and not flow blocked
966 */
967 xmit_more = skb->xmit_more &&
968 !packet->cp_partial &&
969 !netif_xmit_stopped(netdev_get_tx_queue(ndev, packet->q_idx));
970
971 if (section_index != NETVSC_INVALID_INDEX) {
972 netvsc_copy_to_send_buf(net_device,
973 section_index, msd_len,
974 packet, rndis_msg, pb, xmit_more);
975
976 packet->send_buf_index = section_index;
977
978 if (packet->cp_partial) {
979 packet->page_buf_cnt -= packet->rmsg_pgcnt;
980 packet->total_data_buflen = msd_len + packet->rmsg_size;
981 } else {
982 packet->page_buf_cnt = 0;
983 packet->total_data_buflen += msd_len;
984 }
985
986 if (msdp->pkt) {
987 packet->total_packets += msdp->pkt->total_packets;
988 packet->total_bytes += msdp->pkt->total_bytes;
989 }
990
991 if (msdp->skb)
992 dev_consume_skb_any(msdp->skb);
993
994 if (xmit_more) {
995 msdp->skb = skb;
996 msdp->pkt = packet;
997 msdp->count++;
998 } else {
999 cur_send = packet;
1000 msdp->skb = NULL;
1001 msdp->pkt = NULL;
1002 msdp->count = 0;
1003 }
1004 } else {
1005 move_pkt_msd(&msd_send, &msd_skb, msdp);
1006 cur_send = packet;
1007 }
1008
1009 if (msd_send) {
1010 int m_ret = netvsc_send_pkt(device, msd_send, net_device,
1011 NULL, msd_skb);
1012
1013 if (m_ret != 0) {
1014 netvsc_free_send_slot(net_device,
1015 msd_send->send_buf_index);
1016 dev_kfree_skb_any(msd_skb);
1017 }
1018 }
1019
1020 if (cur_send)
1021 ret = netvsc_send_pkt(device, cur_send, net_device, pb, skb);
1022
1023 if (ret != 0 && section_index != NETVSC_INVALID_INDEX)
1024 netvsc_free_send_slot(net_device, section_index);
1025
1026 return ret;
1027 }
1028
1029 /* Send pending recv completions */
1030 static int send_recv_completions(struct net_device *ndev,
1031 struct netvsc_device *nvdev,
1032 struct netvsc_channel *nvchan)
1033 {
1034 struct multi_recv_comp *mrc = &nvchan->mrc;
1035 struct recv_comp_msg {
1036 struct nvsp_message_header hdr;
1037 u32 status;
1038 } __packed;
1039 struct recv_comp_msg msg = {
1040 .hdr.msg_type = NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE,
1041 };
1042 int ret;
1043
1044 while (mrc->first != mrc->next) {
1045 const struct recv_comp_data *rcd
1046 = mrc->slots + mrc->first;
1047
1048 msg.status = rcd->status;
1049 ret = vmbus_sendpacket(nvchan->channel, &msg, sizeof(msg),
1050 rcd->tid, VM_PKT_COMP, 0);
1051 if (unlikely(ret)) {
1052 struct net_device_context *ndev_ctx = netdev_priv(ndev);
1053
1054 ++ndev_ctx->eth_stats.rx_comp_busy;
1055 return ret;
1056 }
1057
1058 if (++mrc->first == nvdev->recv_completion_cnt)
1059 mrc->first = 0;
1060 }
1061
1062 /* receive completion ring has been emptied */
1063 if (unlikely(nvdev->destroy))
1064 wake_up(&nvdev->wait_drain);
1065
1066 return 0;
1067 }
1068
1069 /* Count how many receive completions are outstanding */
1070 static void recv_comp_slot_avail(const struct netvsc_device *nvdev,
1071 const struct multi_recv_comp *mrc,
1072 u32 *filled, u32 *avail)
1073 {
1074 u32 count = nvdev->recv_completion_cnt;
1075
1076 if (mrc->next >= mrc->first)
1077 *filled = mrc->next - mrc->first;
1078 else
1079 *filled = (count - mrc->first) + mrc->next;
1080
1081 *avail = count - *filled - 1;
1082 }
1083
1084 /* Add receive complete to ring to send to host. */
1085 static void enq_receive_complete(struct net_device *ndev,
1086 struct netvsc_device *nvdev, u16 q_idx,
1087 u64 tid, u32 status)
1088 {
1089 struct netvsc_channel *nvchan = &nvdev->chan_table[q_idx];
1090 struct multi_recv_comp *mrc = &nvchan->mrc;
1091 struct recv_comp_data *rcd;
1092 u32 filled, avail;
1093
1094 recv_comp_slot_avail(nvdev, mrc, &filled, &avail);
1095
1096 if (unlikely(filled > NAPI_POLL_WEIGHT)) {
1097 send_recv_completions(ndev, nvdev, nvchan);
1098 recv_comp_slot_avail(nvdev, mrc, &filled, &avail);
1099 }
1100
1101 if (unlikely(!avail)) {
1102 netdev_err(ndev, "Recv_comp full buf q:%hd, tid:%llx\n",
1103 q_idx, tid);
1104 return;
1105 }
1106
1107 rcd = mrc->slots + mrc->next;
1108 rcd->tid = tid;
1109 rcd->status = status;
1110
1111 if (++mrc->next == nvdev->recv_completion_cnt)
1112 mrc->next = 0;
1113 }
1114
1115 static int netvsc_receive(struct net_device *ndev,
1116 struct netvsc_device *net_device,
1117 struct netvsc_channel *nvchan,
1118 const struct vmpacket_descriptor *desc,
1119 const struct nvsp_message *nvsp)
1120 {
1121 struct net_device_context *net_device_ctx = netdev_priv(ndev);
1122 struct vmbus_channel *channel = nvchan->channel;
1123 const struct vmtransfer_page_packet_header *vmxferpage_packet
1124 = container_of(desc, const struct vmtransfer_page_packet_header, d);
1125 u16 q_idx = channel->offermsg.offer.sub_channel_index;
1126 char *recv_buf = net_device->recv_buf;
1127 u32 status = NVSP_STAT_SUCCESS;
1128 int i;
1129 int count = 0;
1130
1131 /* Make sure this is a valid nvsp packet */
1132 if (unlikely(nvsp->hdr.msg_type != NVSP_MSG1_TYPE_SEND_RNDIS_PKT)) {
1133 netif_err(net_device_ctx, rx_err, ndev,
1134 "Unknown nvsp packet type received %u\n",
1135 nvsp->hdr.msg_type);
1136 return 0;
1137 }
1138
1139 if (unlikely(vmxferpage_packet->xfer_pageset_id != NETVSC_RECEIVE_BUFFER_ID)) {
1140 netif_err(net_device_ctx, rx_err, ndev,
1141 "Invalid xfer page set id - expecting %x got %x\n",
1142 NETVSC_RECEIVE_BUFFER_ID,
1143 vmxferpage_packet->xfer_pageset_id);
1144 return 0;
1145 }
1146
1147 count = vmxferpage_packet->range_cnt;
1148
1149 /* Each range represents 1 RNDIS pkt that contains 1 ethernet frame */
1150 for (i = 0; i < count; i++) {
1151 u32 offset = vmxferpage_packet->ranges[i].byte_offset;
1152 u32 buflen = vmxferpage_packet->ranges[i].byte_count;
1153 void *data;
1154 int ret;
1155
1156 if (unlikely(offset + buflen > net_device->recv_buf_size)) {
1157 nvchan->rsc.cnt = 0;
1158 status = NVSP_STAT_FAIL;
1159 netif_err(net_device_ctx, rx_err, ndev,
1160 "Packet offset:%u + len:%u too big\n",
1161 offset, buflen);
1162
1163 continue;
1164 }
1165
1166 data = recv_buf + offset;
1167
1168 nvchan->rsc.is_last = (i == count - 1);
1169
1170 trace_rndis_recv(ndev, q_idx, data);
1171
1172 /* Pass it to the upper layer */
1173 ret = rndis_filter_receive(ndev, net_device,
1174 nvchan, data, buflen);
1175
1176 if (unlikely(ret != NVSP_STAT_SUCCESS))
1177 status = NVSP_STAT_FAIL;
1178 }
1179
1180 enq_receive_complete(ndev, net_device, q_idx,
1181 vmxferpage_packet->d.trans_id, status);
1182
1183 return count;
1184 }
1185
1186 static void netvsc_send_table(struct net_device *ndev,
1187 const struct nvsp_message *nvmsg)
1188 {
1189 struct net_device_context *net_device_ctx = netdev_priv(ndev);
1190 u32 count, *tab;
1191 int i;
1192
1193 count = nvmsg->msg.v5_msg.send_table.count;
1194 if (count != VRSS_SEND_TAB_SIZE) {
1195 netdev_err(ndev, "Received wrong send-table size:%u\n", count);
1196 return;
1197 }
1198
1199 tab = (u32 *)((unsigned long)&nvmsg->msg.v5_msg.send_table +
1200 nvmsg->msg.v5_msg.send_table.offset);
1201
1202 for (i = 0; i < count; i++)
1203 net_device_ctx->tx_table[i] = tab[i];
1204 }
1205
1206 static void netvsc_send_vf(struct net_device *ndev,
1207 const struct nvsp_message *nvmsg)
1208 {
1209 struct net_device_context *net_device_ctx = netdev_priv(ndev);
1210
1211 net_device_ctx->vf_alloc = nvmsg->msg.v4_msg.vf_assoc.allocated;
1212 net_device_ctx->vf_serial = nvmsg->msg.v4_msg.vf_assoc.serial;
1213 netdev_info(ndev, "VF slot %u %s\n",
1214 net_device_ctx->vf_serial,
1215 net_device_ctx->vf_alloc ? "added" : "removed");
1216 }
1217
1218 static void netvsc_receive_inband(struct net_device *ndev,
1219 const struct nvsp_message *nvmsg)
1220 {
1221 switch (nvmsg->hdr.msg_type) {
1222 case NVSP_MSG5_TYPE_SEND_INDIRECTION_TABLE:
1223 netvsc_send_table(ndev, nvmsg);
1224 break;
1225
1226 case NVSP_MSG4_TYPE_SEND_VF_ASSOCIATION:
1227 netvsc_send_vf(ndev, nvmsg);
1228 break;
1229 }
1230 }
1231
1232 static int netvsc_process_raw_pkt(struct hv_device *device,
1233 struct netvsc_channel *nvchan,
1234 struct netvsc_device *net_device,
1235 struct net_device *ndev,
1236 const struct vmpacket_descriptor *desc,
1237 int budget)
1238 {
1239 struct vmbus_channel *channel = nvchan->channel;
1240 const struct nvsp_message *nvmsg = hv_pkt_data(desc);
1241
1242 trace_nvsp_recv(ndev, channel, nvmsg);
1243
1244 switch (desc->type) {
1245 case VM_PKT_COMP:
1246 netvsc_send_completion(ndev, net_device, channel,
1247 desc, budget);
1248 break;
1249
1250 case VM_PKT_DATA_USING_XFER_PAGES:
1251 return netvsc_receive(ndev, net_device, nvchan,
1252 desc, nvmsg);
1253 break;
1254
1255 case VM_PKT_DATA_INBAND:
1256 netvsc_receive_inband(ndev, nvmsg);
1257 break;
1258
1259 default:
1260 netdev_err(ndev, "unhandled packet type %d, tid %llx\n",
1261 desc->type, desc->trans_id);
1262 break;
1263 }
1264
1265 return 0;
1266 }
1267
1268 static struct hv_device *netvsc_channel_to_device(struct vmbus_channel *channel)
1269 {
1270 struct vmbus_channel *primary = channel->primary_channel;
1271
1272 return primary ? primary->device_obj : channel->device_obj;
1273 }
1274
1275 /* Network processing softirq
1276 * Process data in incoming ring buffer from host
1277 * Stops when ring is empty or budget is met or exceeded.
1278 */
1279 int netvsc_poll(struct napi_struct *napi, int budget)
1280 {
1281 struct netvsc_channel *nvchan
1282 = container_of(napi, struct netvsc_channel, napi);
1283 struct netvsc_device *net_device = nvchan->net_device;
1284 struct vmbus_channel *channel = nvchan->channel;
1285 struct hv_device *device = netvsc_channel_to_device(channel);
1286 struct net_device *ndev = hv_get_drvdata(device);
1287 int work_done = 0;
1288 int ret;
1289
1290 /* If starting a new interval */
1291 if (!nvchan->desc)
1292 nvchan->desc = hv_pkt_iter_first(channel);
1293
1294 while (nvchan->desc && work_done < budget) {
1295 work_done += netvsc_process_raw_pkt(device, nvchan, net_device,
1296 ndev, nvchan->desc, budget);
1297 nvchan->desc = hv_pkt_iter_next(channel, nvchan->desc);
1298 }
1299
1300 /* Send any pending receive completions */
1301 ret = send_recv_completions(ndev, net_device, nvchan);
1302
1303 /* If it did not exhaust NAPI budget this time
1304 * and not doing busy poll
1305 * then re-enable host interrupts
1306 * and reschedule if ring is not empty
1307 * or sending receive completion failed.
1308 */
1309 if (work_done < budget &&
1310 napi_complete_done(napi, work_done) &&
1311 (ret || hv_end_read(&channel->inbound)) &&
1312 napi_schedule_prep(napi)) {
1313 hv_begin_read(&channel->inbound);
1314 __napi_schedule(napi);
1315 }
1316
1317 /* Driver may overshoot since multiple packets per descriptor */
1318 return min(work_done, budget);
1319 }
1320
1321 /* Call back when data is available in host ring buffer.
1322 * Processing is deferred until network softirq (NAPI)
1323 */
1324 void netvsc_channel_cb(void *context)
1325 {
1326 struct netvsc_channel *nvchan = context;
1327 struct vmbus_channel *channel = nvchan->channel;
1328 struct hv_ring_buffer_info *rbi = &channel->inbound;
1329
1330 /* preload first vmpacket descriptor */
1331 prefetch(hv_get_ring_buffer(rbi) + rbi->priv_read_index);
1332
1333 if (napi_schedule_prep(&nvchan->napi)) {
1334 /* disable interrupts from host */
1335 hv_begin_read(rbi);
1336
1337 __napi_schedule_irqoff(&nvchan->napi);
1338 }
1339 }
1340
1341 /*
1342 * netvsc_device_add - Callback when the device belonging to this
1343 * driver is added
1344 */
1345 struct netvsc_device *netvsc_device_add(struct hv_device *device,
1346 const struct netvsc_device_info *device_info)
1347 {
1348 int i, ret = 0;
1349 struct netvsc_device *net_device;
1350 struct net_device *ndev = hv_get_drvdata(device);
1351 struct net_device_context *net_device_ctx = netdev_priv(ndev);
1352
1353 net_device = alloc_net_device();
1354 if (!net_device)
1355 return ERR_PTR(-ENOMEM);
1356
1357 for (i = 0; i < VRSS_SEND_TAB_SIZE; i++)
1358 net_device_ctx->tx_table[i] = 0;
1359
1360 /* Because the device uses NAPI, all the interrupt batching and
1361 * control is done via Net softirq, not the channel handling
1362 */
1363 set_channel_read_mode(device->channel, HV_CALL_ISR);
1364
1365 /* If we're reopening the device we may have multiple queues, fill the
1366 * chn_table with the default channel to use it before subchannels are
1367 * opened.
1368 * Initialize the channel state before we open;
1369 * we can be interrupted as soon as we open the channel.
1370 */
1371
1372 for (i = 0; i < VRSS_CHANNEL_MAX; i++) {
1373 struct netvsc_channel *nvchan = &net_device->chan_table[i];
1374
1375 nvchan->channel = device->channel;
1376 nvchan->net_device = net_device;
1377 u64_stats_init(&nvchan->tx_stats.syncp);
1378 u64_stats_init(&nvchan->rx_stats.syncp);
1379 }
1380
1381 /* Enable NAPI handler before init callbacks */
1382 netif_napi_add(ndev, &net_device->chan_table[0].napi,
1383 netvsc_poll, NAPI_POLL_WEIGHT);
1384
1385 /* Open the channel */
1386 ret = vmbus_open(device->channel, netvsc_ring_bytes,
1387 netvsc_ring_bytes, NULL, 0,
1388 netvsc_channel_cb, net_device->chan_table);
1389
1390 if (ret != 0) {
1391 netdev_err(ndev, "unable to open channel: %d\n", ret);
1392 goto cleanup;
1393 }
1394
1395 /* Channel is opened */
1396 netdev_dbg(ndev, "hv_netvsc channel opened successfully\n");
1397
1398 napi_enable(&net_device->chan_table[0].napi);
1399
1400 /* Connect with the NetVsp */
1401 ret = netvsc_connect_vsp(device, net_device, device_info);
1402 if (ret != 0) {
1403 netdev_err(ndev,
1404 "unable to connect to NetVSP - %d\n", ret);
1405 goto close;
1406 }
1407
1408 /* Writing nvdev pointer unlocks netvsc_send(), make sure chn_table is
1409 * populated.
1410 */
1411 rcu_assign_pointer(net_device_ctx->nvdev, net_device);
1412
1413 return net_device;
1414
1415 close:
1416 RCU_INIT_POINTER(net_device_ctx->nvdev, NULL);
1417 napi_disable(&net_device->chan_table[0].napi);
1418
1419 /* Now, we can close the channel safely */
1420 vmbus_close(device->channel);
1421
1422 cleanup:
1423 netif_napi_del(&net_device->chan_table[0].napi);
1424 free_netvsc_device(&net_device->rcu);
1425
1426 return ERR_PTR(ret);
1427 }