hv_netvsc: remove locking in netvsc_send()
[cascardo/linux.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 <asm/sync_bitops.h>
33
34 #include "hyperv_net.h"
35
36
37 static struct netvsc_device *alloc_net_device(struct hv_device *device)
38 {
39         struct netvsc_device *net_device;
40         struct net_device *ndev = hv_get_drvdata(device);
41
42         net_device = kzalloc(sizeof(struct netvsc_device), GFP_KERNEL);
43         if (!net_device)
44                 return NULL;
45
46         net_device->cb_buffer = kzalloc(NETVSC_PACKET_SIZE, GFP_KERNEL);
47         if (!net_device->cb_buffer) {
48                 kfree(net_device);
49                 return NULL;
50         }
51
52         init_waitqueue_head(&net_device->wait_drain);
53         net_device->start_remove = false;
54         net_device->destroy = false;
55         net_device->dev = device;
56         net_device->ndev = ndev;
57         net_device->max_pkt = RNDIS_MAX_PKT_DEFAULT;
58         net_device->pkt_align = RNDIS_PKT_ALIGN_DEFAULT;
59
60         hv_set_drvdata(device, net_device);
61         return net_device;
62 }
63
64 static void free_netvsc_device(struct netvsc_device *nvdev)
65 {
66         kfree(nvdev->cb_buffer);
67         kfree(nvdev);
68 }
69
70 static struct netvsc_device *get_outbound_net_device(struct hv_device *device)
71 {
72         struct netvsc_device *net_device;
73
74         net_device = hv_get_drvdata(device);
75         if (net_device && net_device->destroy)
76                 net_device = NULL;
77
78         return net_device;
79 }
80
81 static struct netvsc_device *get_inbound_net_device(struct hv_device *device)
82 {
83         struct netvsc_device *net_device;
84
85         net_device = hv_get_drvdata(device);
86
87         if (!net_device)
88                 goto get_in_err;
89
90         if (net_device->destroy &&
91                 atomic_read(&net_device->num_outstanding_sends) == 0)
92                 net_device = NULL;
93
94 get_in_err:
95         return net_device;
96 }
97
98
99 static int netvsc_destroy_buf(struct netvsc_device *net_device)
100 {
101         struct nvsp_message *revoke_packet;
102         int ret = 0;
103         struct net_device *ndev = net_device->ndev;
104
105         /*
106          * If we got a section count, it means we received a
107          * SendReceiveBufferComplete msg (ie sent
108          * NvspMessage1TypeSendReceiveBuffer msg) therefore, we need
109          * to send a revoke msg here
110          */
111         if (net_device->recv_section_cnt) {
112                 /* Send the revoke receive buffer */
113                 revoke_packet = &net_device->revoke_packet;
114                 memset(revoke_packet, 0, sizeof(struct nvsp_message));
115
116                 revoke_packet->hdr.msg_type =
117                         NVSP_MSG1_TYPE_REVOKE_RECV_BUF;
118                 revoke_packet->msg.v1_msg.
119                 revoke_recv_buf.id = NETVSC_RECEIVE_BUFFER_ID;
120
121                 ret = vmbus_sendpacket(net_device->dev->channel,
122                                        revoke_packet,
123                                        sizeof(struct nvsp_message),
124                                        (unsigned long)revoke_packet,
125                                        VM_PKT_DATA_INBAND, 0);
126                 /*
127                  * If we failed here, we might as well return and
128                  * have a leak rather than continue and a bugchk
129                  */
130                 if (ret != 0) {
131                         netdev_err(ndev, "unable to send "
132                                 "revoke receive buffer to netvsp\n");
133                         return ret;
134                 }
135         }
136
137         /* Teardown the gpadl on the vsp end */
138         if (net_device->recv_buf_gpadl_handle) {
139                 ret = vmbus_teardown_gpadl(net_device->dev->channel,
140                            net_device->recv_buf_gpadl_handle);
141
142                 /* If we failed here, we might as well return and have a leak
143                  * rather than continue and a bugchk
144                  */
145                 if (ret != 0) {
146                         netdev_err(ndev,
147                                    "unable to teardown receive buffer's gpadl\n");
148                         return ret;
149                 }
150                 net_device->recv_buf_gpadl_handle = 0;
151         }
152
153         if (net_device->recv_buf) {
154                 /* Free up the receive buffer */
155                 vfree(net_device->recv_buf);
156                 net_device->recv_buf = NULL;
157         }
158
159         if (net_device->recv_section) {
160                 net_device->recv_section_cnt = 0;
161                 kfree(net_device->recv_section);
162                 net_device->recv_section = NULL;
163         }
164
165         /* Deal with the send buffer we may have setup.
166          * If we got a  send section size, it means we received a
167          * NVSP_MSG1_TYPE_SEND_SEND_BUF_COMPLETE msg (ie sent
168          * NVSP_MSG1_TYPE_SEND_SEND_BUF msg) therefore, we need
169          * to send a revoke msg here
170          */
171         if (net_device->send_section_size) {
172                 /* Send the revoke receive buffer */
173                 revoke_packet = &net_device->revoke_packet;
174                 memset(revoke_packet, 0, sizeof(struct nvsp_message));
175
176                 revoke_packet->hdr.msg_type =
177                         NVSP_MSG1_TYPE_REVOKE_SEND_BUF;
178                 revoke_packet->msg.v1_msg.revoke_send_buf.id =
179                         NETVSC_SEND_BUFFER_ID;
180
181                 ret = vmbus_sendpacket(net_device->dev->channel,
182                                        revoke_packet,
183                                        sizeof(struct nvsp_message),
184                                        (unsigned long)revoke_packet,
185                                        VM_PKT_DATA_INBAND, 0);
186                 /* If we failed here, we might as well return and
187                  * have a leak rather than continue and a bugchk
188                  */
189                 if (ret != 0) {
190                         netdev_err(ndev, "unable to send "
191                                    "revoke send buffer to netvsp\n");
192                         return ret;
193                 }
194         }
195         /* Teardown the gpadl on the vsp end */
196         if (net_device->send_buf_gpadl_handle) {
197                 ret = vmbus_teardown_gpadl(net_device->dev->channel,
198                                            net_device->send_buf_gpadl_handle);
199
200                 /* If we failed here, we might as well return and have a leak
201                  * rather than continue and a bugchk
202                  */
203                 if (ret != 0) {
204                         netdev_err(ndev,
205                                    "unable to teardown send buffer's gpadl\n");
206                         return ret;
207                 }
208                 net_device->send_buf_gpadl_handle = 0;
209         }
210         if (net_device->send_buf) {
211                 /* Free up the send buffer */
212                 vfree(net_device->send_buf);
213                 net_device->send_buf = NULL;
214         }
215         kfree(net_device->send_section_map);
216
217         return ret;
218 }
219
220 static int netvsc_init_buf(struct hv_device *device)
221 {
222         int ret = 0;
223         unsigned long t;
224         struct netvsc_device *net_device;
225         struct nvsp_message *init_packet;
226         struct net_device *ndev;
227         int node;
228
229         net_device = get_outbound_net_device(device);
230         if (!net_device)
231                 return -ENODEV;
232         ndev = net_device->ndev;
233
234         node = cpu_to_node(device->channel->target_cpu);
235         net_device->recv_buf = vzalloc_node(net_device->recv_buf_size, node);
236         if (!net_device->recv_buf)
237                 net_device->recv_buf = vzalloc(net_device->recv_buf_size);
238
239         if (!net_device->recv_buf) {
240                 netdev_err(ndev, "unable to allocate receive "
241                         "buffer of size %d\n", net_device->recv_buf_size);
242                 ret = -ENOMEM;
243                 goto cleanup;
244         }
245
246         /*
247          * Establish the gpadl handle for this buffer on this
248          * channel.  Note: This call uses the vmbus connection rather
249          * than the channel to establish the gpadl handle.
250          */
251         ret = vmbus_establish_gpadl(device->channel, net_device->recv_buf,
252                                     net_device->recv_buf_size,
253                                     &net_device->recv_buf_gpadl_handle);
254         if (ret != 0) {
255                 netdev_err(ndev,
256                         "unable to establish receive buffer's gpadl\n");
257                 goto cleanup;
258         }
259
260
261         /* Notify the NetVsp of the gpadl handle */
262         init_packet = &net_device->channel_init_pkt;
263
264         memset(init_packet, 0, sizeof(struct nvsp_message));
265
266         init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_RECV_BUF;
267         init_packet->msg.v1_msg.send_recv_buf.
268                 gpadl_handle = net_device->recv_buf_gpadl_handle;
269         init_packet->msg.v1_msg.
270                 send_recv_buf.id = NETVSC_RECEIVE_BUFFER_ID;
271
272         /* Send the gpadl notification request */
273         ret = vmbus_sendpacket(device->channel, init_packet,
274                                sizeof(struct nvsp_message),
275                                (unsigned long)init_packet,
276                                VM_PKT_DATA_INBAND,
277                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
278         if (ret != 0) {
279                 netdev_err(ndev,
280                         "unable to send receive buffer's gpadl to netvsp\n");
281                 goto cleanup;
282         }
283
284         t = wait_for_completion_timeout(&net_device->channel_init_wait, 5*HZ);
285         BUG_ON(t == 0);
286
287
288         /* Check the response */
289         if (init_packet->msg.v1_msg.
290             send_recv_buf_complete.status != NVSP_STAT_SUCCESS) {
291                 netdev_err(ndev, "Unable to complete receive buffer "
292                            "initialization with NetVsp - status %d\n",
293                            init_packet->msg.v1_msg.
294                            send_recv_buf_complete.status);
295                 ret = -EINVAL;
296                 goto cleanup;
297         }
298
299         /* Parse the response */
300
301         net_device->recv_section_cnt = init_packet->msg.
302                 v1_msg.send_recv_buf_complete.num_sections;
303
304         net_device->recv_section = kmemdup(
305                 init_packet->msg.v1_msg.send_recv_buf_complete.sections,
306                 net_device->recv_section_cnt *
307                 sizeof(struct nvsp_1_receive_buffer_section),
308                 GFP_KERNEL);
309         if (net_device->recv_section == NULL) {
310                 ret = -EINVAL;
311                 goto cleanup;
312         }
313
314         /*
315          * For 1st release, there should only be 1 section that represents the
316          * entire receive buffer
317          */
318         if (net_device->recv_section_cnt != 1 ||
319             net_device->recv_section->offset != 0) {
320                 ret = -EINVAL;
321                 goto cleanup;
322         }
323
324         /* Now setup the send buffer.
325          */
326         net_device->send_buf = vzalloc_node(net_device->send_buf_size, node);
327         if (!net_device->send_buf)
328                 net_device->send_buf = vzalloc(net_device->send_buf_size);
329         if (!net_device->send_buf) {
330                 netdev_err(ndev, "unable to allocate send "
331                            "buffer of size %d\n", net_device->send_buf_size);
332                 ret = -ENOMEM;
333                 goto cleanup;
334         }
335
336         /* Establish the gpadl handle for this buffer on this
337          * channel.  Note: This call uses the vmbus connection rather
338          * than the channel to establish the gpadl handle.
339          */
340         ret = vmbus_establish_gpadl(device->channel, net_device->send_buf,
341                                     net_device->send_buf_size,
342                                     &net_device->send_buf_gpadl_handle);
343         if (ret != 0) {
344                 netdev_err(ndev,
345                            "unable to establish send buffer's gpadl\n");
346                 goto cleanup;
347         }
348
349         /* Notify the NetVsp of the gpadl handle */
350         init_packet = &net_device->channel_init_pkt;
351         memset(init_packet, 0, sizeof(struct nvsp_message));
352         init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_SEND_BUF;
353         init_packet->msg.v1_msg.send_send_buf.gpadl_handle =
354                 net_device->send_buf_gpadl_handle;
355         init_packet->msg.v1_msg.send_send_buf.id = NETVSC_SEND_BUFFER_ID;
356
357         /* Send the gpadl notification request */
358         ret = vmbus_sendpacket(device->channel, init_packet,
359                                sizeof(struct nvsp_message),
360                                (unsigned long)init_packet,
361                                VM_PKT_DATA_INBAND,
362                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
363         if (ret != 0) {
364                 netdev_err(ndev,
365                            "unable to send send buffer's gpadl to netvsp\n");
366                 goto cleanup;
367         }
368
369         t = wait_for_completion_timeout(&net_device->channel_init_wait, 5*HZ);
370         BUG_ON(t == 0);
371
372         /* Check the response */
373         if (init_packet->msg.v1_msg.
374             send_send_buf_complete.status != NVSP_STAT_SUCCESS) {
375                 netdev_err(ndev, "Unable to complete send buffer "
376                            "initialization with NetVsp - status %d\n",
377                            init_packet->msg.v1_msg.
378                            send_send_buf_complete.status);
379                 ret = -EINVAL;
380                 goto cleanup;
381         }
382
383         /* Parse the response */
384         net_device->send_section_size = init_packet->msg.
385                                 v1_msg.send_send_buf_complete.section_size;
386
387         /* Section count is simply the size divided by the section size.
388          */
389         net_device->send_section_cnt =
390                 net_device->send_buf_size/net_device->send_section_size;
391
392         dev_info(&device->device, "Send section size: %d, Section count:%d\n",
393                  net_device->send_section_size, net_device->send_section_cnt);
394
395         /* Setup state for managing the send buffer. */
396         net_device->map_words = DIV_ROUND_UP(net_device->send_section_cnt,
397                                              BITS_PER_LONG);
398
399         net_device->send_section_map =
400                 kzalloc(net_device->map_words * sizeof(ulong), GFP_KERNEL);
401         if (net_device->send_section_map == NULL) {
402                 ret = -ENOMEM;
403                 goto cleanup;
404         }
405
406         goto exit;
407
408 cleanup:
409         netvsc_destroy_buf(net_device);
410
411 exit:
412         return ret;
413 }
414
415
416 /* Negotiate NVSP protocol version */
417 static int negotiate_nvsp_ver(struct hv_device *device,
418                               struct netvsc_device *net_device,
419                               struct nvsp_message *init_packet,
420                               u32 nvsp_ver)
421 {
422         int ret;
423         unsigned long t;
424
425         memset(init_packet, 0, sizeof(struct nvsp_message));
426         init_packet->hdr.msg_type = NVSP_MSG_TYPE_INIT;
427         init_packet->msg.init_msg.init.min_protocol_ver = nvsp_ver;
428         init_packet->msg.init_msg.init.max_protocol_ver = nvsp_ver;
429
430         /* Send the init request */
431         ret = vmbus_sendpacket(device->channel, init_packet,
432                                sizeof(struct nvsp_message),
433                                (unsigned long)init_packet,
434                                VM_PKT_DATA_INBAND,
435                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
436
437         if (ret != 0)
438                 return ret;
439
440         t = wait_for_completion_timeout(&net_device->channel_init_wait, 5*HZ);
441
442         if (t == 0)
443                 return -ETIMEDOUT;
444
445         if (init_packet->msg.init_msg.init_complete.status !=
446             NVSP_STAT_SUCCESS)
447                 return -EINVAL;
448
449         if (nvsp_ver == NVSP_PROTOCOL_VERSION_1)
450                 return 0;
451
452         /* NVSPv2 or later: Send NDIS config */
453         memset(init_packet, 0, sizeof(struct nvsp_message));
454         init_packet->hdr.msg_type = NVSP_MSG2_TYPE_SEND_NDIS_CONFIG;
455         init_packet->msg.v2_msg.send_ndis_config.mtu = net_device->ndev->mtu +
456                                                        ETH_HLEN;
457         init_packet->msg.v2_msg.send_ndis_config.capability.ieee8021q = 1;
458
459         if (nvsp_ver >= NVSP_PROTOCOL_VERSION_5)
460                 init_packet->msg.v2_msg.send_ndis_config.capability.sriov = 1;
461
462         ret = vmbus_sendpacket(device->channel, init_packet,
463                                 sizeof(struct nvsp_message),
464                                 (unsigned long)init_packet,
465                                 VM_PKT_DATA_INBAND, 0);
466
467         return ret;
468 }
469
470 static int netvsc_connect_vsp(struct hv_device *device)
471 {
472         int ret;
473         struct netvsc_device *net_device;
474         struct nvsp_message *init_packet;
475         int ndis_version;
476         struct net_device *ndev;
477         u32 ver_list[] = { NVSP_PROTOCOL_VERSION_1, NVSP_PROTOCOL_VERSION_2,
478                 NVSP_PROTOCOL_VERSION_4, NVSP_PROTOCOL_VERSION_5 };
479         int i, num_ver = 4; /* number of different NVSP versions */
480
481         net_device = get_outbound_net_device(device);
482         if (!net_device)
483                 return -ENODEV;
484         ndev = net_device->ndev;
485
486         init_packet = &net_device->channel_init_pkt;
487
488         /* Negotiate the latest NVSP protocol supported */
489         for (i = num_ver - 1; i >= 0; i--)
490                 if (negotiate_nvsp_ver(device, net_device, init_packet,
491                                        ver_list[i])  == 0) {
492                         net_device->nvsp_version = ver_list[i];
493                         break;
494                 }
495
496         if (i < 0) {
497                 ret = -EPROTO;
498                 goto cleanup;
499         }
500
501         pr_debug("Negotiated NVSP version:%x\n", net_device->nvsp_version);
502
503         /* Send the ndis version */
504         memset(init_packet, 0, sizeof(struct nvsp_message));
505
506         if (net_device->nvsp_version <= NVSP_PROTOCOL_VERSION_4)
507                 ndis_version = 0x00060001;
508         else
509                 ndis_version = 0x0006001e;
510
511         init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_NDIS_VER;
512         init_packet->msg.v1_msg.
513                 send_ndis_ver.ndis_major_ver =
514                                 (ndis_version & 0xFFFF0000) >> 16;
515         init_packet->msg.v1_msg.
516                 send_ndis_ver.ndis_minor_ver =
517                                 ndis_version & 0xFFFF;
518
519         /* Send the init request */
520         ret = vmbus_sendpacket(device->channel, init_packet,
521                                 sizeof(struct nvsp_message),
522                                 (unsigned long)init_packet,
523                                 VM_PKT_DATA_INBAND, 0);
524         if (ret != 0)
525                 goto cleanup;
526
527         /* Post the big receive buffer to NetVSP */
528         if (net_device->nvsp_version <= NVSP_PROTOCOL_VERSION_2)
529                 net_device->recv_buf_size = NETVSC_RECEIVE_BUFFER_SIZE_LEGACY;
530         else
531                 net_device->recv_buf_size = NETVSC_RECEIVE_BUFFER_SIZE;
532         net_device->send_buf_size = NETVSC_SEND_BUFFER_SIZE;
533
534         ret = netvsc_init_buf(device);
535
536 cleanup:
537         return ret;
538 }
539
540 static void netvsc_disconnect_vsp(struct netvsc_device *net_device)
541 {
542         netvsc_destroy_buf(net_device);
543 }
544
545 /*
546  * netvsc_device_remove - Callback when the root bus device is removed
547  */
548 int netvsc_device_remove(struct hv_device *device)
549 {
550         struct netvsc_device *net_device;
551         unsigned long flags;
552
553         net_device = hv_get_drvdata(device);
554
555         netvsc_disconnect_vsp(net_device);
556
557         /*
558          * Since we have already drained, we don't need to busy wait
559          * as was done in final_release_stor_device()
560          * Note that we cannot set the ext pointer to NULL until
561          * we have drained - to drain the outgoing packets, we need to
562          * allow incoming packets.
563          */
564
565         spin_lock_irqsave(&device->channel->inbound_lock, flags);
566         hv_set_drvdata(device, NULL);
567         spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
568
569         /*
570          * At this point, no one should be accessing net_device
571          * except in here
572          */
573         dev_notice(&device->device, "net device safe to remove\n");
574
575         /* Now, we can close the channel safely */
576         vmbus_close(device->channel);
577
578         /* Release all resources */
579         vfree(net_device->sub_cb_buf);
580         free_netvsc_device(net_device);
581         return 0;
582 }
583
584
585 #define RING_AVAIL_PERCENT_HIWATER 20
586 #define RING_AVAIL_PERCENT_LOWATER 10
587
588 /*
589  * Get the percentage of available bytes to write in the ring.
590  * The return value is in range from 0 to 100.
591  */
592 static inline u32 hv_ringbuf_avail_percent(
593                 struct hv_ring_buffer_info *ring_info)
594 {
595         u32 avail_read, avail_write;
596
597         hv_get_ringbuffer_availbytes(ring_info, &avail_read, &avail_write);
598
599         return avail_write * 100 / ring_info->ring_datasize;
600 }
601
602 static inline void netvsc_free_send_slot(struct netvsc_device *net_device,
603                                          u32 index)
604 {
605         sync_change_bit(index, net_device->send_section_map);
606 }
607
608 static void netvsc_send_completion(struct netvsc_device *net_device,
609                                    struct vmbus_channel *incoming_channel,
610                                    struct hv_device *device,
611                                    struct vmpacket_descriptor *packet)
612 {
613         struct nvsp_message *nvsp_packet;
614         struct hv_netvsc_packet *nvsc_packet;
615         struct net_device *ndev;
616         u32 send_index;
617
618         ndev = net_device->ndev;
619
620         nvsp_packet = (struct nvsp_message *)((unsigned long)packet +
621                         (packet->offset8 << 3));
622
623         if ((nvsp_packet->hdr.msg_type == NVSP_MSG_TYPE_INIT_COMPLETE) ||
624             (nvsp_packet->hdr.msg_type ==
625              NVSP_MSG1_TYPE_SEND_RECV_BUF_COMPLETE) ||
626             (nvsp_packet->hdr.msg_type ==
627              NVSP_MSG1_TYPE_SEND_SEND_BUF_COMPLETE) ||
628             (nvsp_packet->hdr.msg_type ==
629              NVSP_MSG5_TYPE_SUBCHANNEL)) {
630                 /* Copy the response back */
631                 memcpy(&net_device->channel_init_pkt, nvsp_packet,
632                        sizeof(struct nvsp_message));
633                 complete(&net_device->channel_init_wait);
634         } else if (nvsp_packet->hdr.msg_type ==
635                    NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE) {
636                 int num_outstanding_sends;
637                 u16 q_idx = 0;
638                 struct vmbus_channel *channel = device->channel;
639                 int queue_sends;
640
641                 /* Get the send context */
642                 nvsc_packet = (struct hv_netvsc_packet *)(unsigned long)
643                         packet->trans_id;
644
645                 /* Notify the layer above us */
646                 if (nvsc_packet) {
647                         send_index = nvsc_packet->send_buf_index;
648                         if (send_index != NETVSC_INVALID_INDEX)
649                                 netvsc_free_send_slot(net_device, send_index);
650                         q_idx = nvsc_packet->q_idx;
651                         channel = incoming_channel;
652                         netvsc_xmit_completion(nvsc_packet);
653                 }
654
655                 num_outstanding_sends =
656                         atomic_dec_return(&net_device->num_outstanding_sends);
657                 queue_sends = atomic_dec_return(&net_device->
658                                                 queue_sends[q_idx]);
659
660                 if (net_device->destroy && num_outstanding_sends == 0)
661                         wake_up(&net_device->wait_drain);
662
663                 if (netif_tx_queue_stopped(netdev_get_tx_queue(ndev, q_idx)) &&
664                     !net_device->start_remove &&
665                     (hv_ringbuf_avail_percent(&channel->outbound) >
666                      RING_AVAIL_PERCENT_HIWATER || queue_sends < 1))
667                                 netif_tx_wake_queue(netdev_get_tx_queue(
668                                                     ndev, q_idx));
669         } else {
670                 netdev_err(ndev, "Unknown send completion packet type- "
671                            "%d received!!\n", nvsp_packet->hdr.msg_type);
672         }
673
674 }
675
676 static u32 netvsc_get_next_send_section(struct netvsc_device *net_device)
677 {
678         unsigned long index;
679         u32 max_words = net_device->map_words;
680         unsigned long *map_addr = (unsigned long *)net_device->send_section_map;
681         u32 section_cnt = net_device->send_section_cnt;
682         int ret_val = NETVSC_INVALID_INDEX;
683         int i;
684         int prev_val;
685
686         for (i = 0; i < max_words; i++) {
687                 if (!~(map_addr[i]))
688                         continue;
689                 index = ffz(map_addr[i]);
690                 prev_val = sync_test_and_set_bit(index, &map_addr[i]);
691                 if (prev_val)
692                         continue;
693                 if ((index + (i * BITS_PER_LONG)) >= section_cnt)
694                         break;
695                 ret_val = (index + (i * BITS_PER_LONG));
696                 break;
697         }
698         return ret_val;
699 }
700
701 static u32 netvsc_copy_to_send_buf(struct netvsc_device *net_device,
702                                    unsigned int section_index,
703                                    u32 pend_size,
704                                    struct hv_netvsc_packet *packet,
705                                    struct rndis_message *rndis_msg)
706 {
707         char *start = net_device->send_buf;
708         char *dest = start + (section_index * net_device->send_section_size)
709                      + pend_size;
710         int i;
711         u32 msg_size = 0;
712         u32 padding = 0;
713         u32 remain = packet->total_data_buflen % net_device->pkt_align;
714         u32 page_count = packet->cp_partial ? packet->rmsg_pgcnt :
715                 packet->page_buf_cnt;
716
717         /* Add padding */
718         if (packet->is_data_pkt && packet->xmit_more && remain &&
719             !packet->cp_partial) {
720                 padding = net_device->pkt_align - remain;
721                 rndis_msg->msg_len += padding;
722                 packet->total_data_buflen += padding;
723         }
724
725         for (i = 0; i < page_count; i++) {
726                 char *src = phys_to_virt(packet->page_buf[i].pfn << PAGE_SHIFT);
727                 u32 offset = packet->page_buf[i].offset;
728                 u32 len = packet->page_buf[i].len;
729
730                 memcpy(dest, (src + offset), len);
731                 msg_size += len;
732                 dest += len;
733         }
734
735         if (padding) {
736                 memset(dest, 0, padding);
737                 msg_size += padding;
738         }
739
740         return msg_size;
741 }
742
743 static inline int netvsc_send_pkt(
744         struct hv_netvsc_packet *packet,
745         struct netvsc_device *net_device)
746 {
747         struct nvsp_message nvmsg;
748         u16 q_idx = packet->q_idx;
749         struct vmbus_channel *out_channel = net_device->chn_table[q_idx];
750         struct net_device *ndev = net_device->ndev;
751         u64 req_id;
752         int ret;
753         struct hv_page_buffer *pgbuf;
754         u32 ring_avail = hv_ringbuf_avail_percent(&out_channel->outbound);
755
756         nvmsg.hdr.msg_type = NVSP_MSG1_TYPE_SEND_RNDIS_PKT;
757         if (packet->is_data_pkt) {
758                 /* 0 is RMC_DATA; */
759                 nvmsg.msg.v1_msg.send_rndis_pkt.channel_type = 0;
760         } else {
761                 /* 1 is RMC_CONTROL; */
762                 nvmsg.msg.v1_msg.send_rndis_pkt.channel_type = 1;
763         }
764
765         nvmsg.msg.v1_msg.send_rndis_pkt.send_buf_section_index =
766                 packet->send_buf_index;
767         if (packet->send_buf_index == NETVSC_INVALID_INDEX)
768                 nvmsg.msg.v1_msg.send_rndis_pkt.send_buf_section_size = 0;
769         else
770                 nvmsg.msg.v1_msg.send_rndis_pkt.send_buf_section_size =
771                         packet->total_data_buflen;
772
773         if (packet->completion_func)
774                 req_id = (ulong)packet;
775         else
776                 req_id = 0;
777
778         if (out_channel->rescind)
779                 return -ENODEV;
780
781         /*
782          * It is possible that once we successfully place this packet
783          * on the ringbuffer, we may stop the queue. In that case, we want
784          * to notify the host independent of the xmit_more flag. We don't
785          * need to be precise here; in the worst case we may signal the host
786          * unnecessarily.
787          */
788         if (ring_avail < (RING_AVAIL_PERCENT_LOWATER + 1))
789                 packet->xmit_more = false;
790
791         if (packet->page_buf_cnt) {
792                 pgbuf = packet->cp_partial ? packet->page_buf +
793                         packet->rmsg_pgcnt : packet->page_buf;
794                 ret = vmbus_sendpacket_pagebuffer_ctl(out_channel,
795                                                       pgbuf,
796                                                       packet->page_buf_cnt,
797                                                       &nvmsg,
798                                                       sizeof(struct nvsp_message),
799                                                       req_id,
800                                                       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED,
801                                                       !packet->xmit_more);
802         } else {
803                 ret = vmbus_sendpacket_ctl(out_channel, &nvmsg,
804                                            sizeof(struct nvsp_message),
805                                            req_id,
806                                            VM_PKT_DATA_INBAND,
807                                            VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED,
808                                            !packet->xmit_more);
809         }
810
811         if (ret == 0) {
812                 atomic_inc(&net_device->num_outstanding_sends);
813                 atomic_inc(&net_device->queue_sends[q_idx]);
814
815                 if (ring_avail < RING_AVAIL_PERCENT_LOWATER) {
816                         netif_tx_stop_queue(netdev_get_tx_queue(ndev, q_idx));
817
818                         if (atomic_read(&net_device->
819                                 queue_sends[q_idx]) < 1)
820                                 netif_tx_wake_queue(netdev_get_tx_queue(
821                                                     ndev, q_idx));
822                 }
823         } else if (ret == -EAGAIN) {
824                 netif_tx_stop_queue(netdev_get_tx_queue(
825                                     ndev, q_idx));
826                 if (atomic_read(&net_device->queue_sends[q_idx]) < 1) {
827                         netif_tx_wake_queue(netdev_get_tx_queue(
828                                             ndev, q_idx));
829                         ret = -ENOSPC;
830                 }
831         } else {
832                 netdev_err(ndev, "Unable to send packet %p ret %d\n",
833                            packet, ret);
834         }
835
836         return ret;
837 }
838
839 int netvsc_send(struct hv_device *device,
840                 struct hv_netvsc_packet *packet,
841                 struct rndis_message *rndis_msg)
842 {
843         struct netvsc_device *net_device;
844         int ret = 0, m_ret = 0;
845         struct vmbus_channel *out_channel;
846         u16 q_idx = packet->q_idx;
847         u32 pktlen = packet->total_data_buflen, msd_len = 0;
848         unsigned int section_index = NETVSC_INVALID_INDEX;
849         struct multi_send_data *msdp;
850         struct hv_netvsc_packet *msd_send = NULL, *cur_send = NULL;
851         bool try_batch;
852
853         net_device = get_outbound_net_device(device);
854         if (!net_device)
855                 return -ENODEV;
856
857         out_channel = net_device->chn_table[q_idx];
858
859         packet->send_buf_index = NETVSC_INVALID_INDEX;
860         packet->cp_partial = false;
861
862         msdp = &net_device->msd[q_idx];
863
864         /* batch packets in send buffer if possible */
865         if (msdp->pkt)
866                 msd_len = msdp->pkt->total_data_buflen;
867
868         try_batch = packet->is_data_pkt && msd_len > 0 && msdp->count <
869                     net_device->max_pkt;
870
871         if (try_batch && msd_len + pktlen + net_device->pkt_align <
872             net_device->send_section_size) {
873                 section_index = msdp->pkt->send_buf_index;
874
875         } else if (try_batch && msd_len + packet->rmsg_size <
876                    net_device->send_section_size) {
877                 section_index = msdp->pkt->send_buf_index;
878                 packet->cp_partial = true;
879
880         } else if (packet->is_data_pkt && pktlen + net_device->pkt_align <
881                    net_device->send_section_size) {
882                 section_index = netvsc_get_next_send_section(net_device);
883                 if (section_index != NETVSC_INVALID_INDEX) {
884                                 msd_send = msdp->pkt;
885                                 msdp->pkt = NULL;
886                                 msdp->count = 0;
887                                 msd_len = 0;
888                 }
889         }
890
891         if (section_index != NETVSC_INVALID_INDEX) {
892                 netvsc_copy_to_send_buf(net_device,
893                                         section_index, msd_len,
894                                         packet, rndis_msg);
895
896                 packet->send_buf_index = section_index;
897
898                 if (packet->cp_partial) {
899                         packet->page_buf_cnt -= packet->rmsg_pgcnt;
900                         packet->total_data_buflen = msd_len + packet->rmsg_size;
901                 } else {
902                         packet->page_buf_cnt = 0;
903                         packet->total_data_buflen += msd_len;
904                 }
905
906                 if (msdp->pkt)
907                         netvsc_xmit_completion(msdp->pkt);
908
909                 if (packet->xmit_more && !packet->cp_partial) {
910                         msdp->pkt = packet;
911                         msdp->count++;
912                 } else {
913                         cur_send = packet;
914                         msdp->pkt = NULL;
915                         msdp->count = 0;
916                 }
917         } else {
918                 msd_send = msdp->pkt;
919                 msdp->pkt = NULL;
920                 msdp->count = 0;
921                 cur_send = packet;
922         }
923
924         if (msd_send) {
925                 m_ret = netvsc_send_pkt(msd_send, net_device);
926
927                 if (m_ret != 0) {
928                         netvsc_free_send_slot(net_device,
929                                               msd_send->send_buf_index);
930                         netvsc_xmit_completion(msd_send);
931                 }
932         }
933
934         if (cur_send)
935                 ret = netvsc_send_pkt(cur_send, net_device);
936
937         if (ret != 0 && section_index != NETVSC_INVALID_INDEX)
938                 netvsc_free_send_slot(net_device, section_index);
939
940         return ret;
941 }
942
943 static void netvsc_send_recv_completion(struct hv_device *device,
944                                         struct vmbus_channel *channel,
945                                         struct netvsc_device *net_device,
946                                         u64 transaction_id, u32 status)
947 {
948         struct nvsp_message recvcompMessage;
949         int retries = 0;
950         int ret;
951         struct net_device *ndev;
952
953         ndev = net_device->ndev;
954
955         recvcompMessage.hdr.msg_type =
956                                 NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE;
957
958         recvcompMessage.msg.v1_msg.send_rndis_pkt_complete.status = status;
959
960 retry_send_cmplt:
961         /* Send the completion */
962         ret = vmbus_sendpacket(channel, &recvcompMessage,
963                                sizeof(struct nvsp_message), transaction_id,
964                                VM_PKT_COMP, 0);
965         if (ret == 0) {
966                 /* success */
967                 /* no-op */
968         } else if (ret == -EAGAIN) {
969                 /* no more room...wait a bit and attempt to retry 3 times */
970                 retries++;
971                 netdev_err(ndev, "unable to send receive completion pkt"
972                         " (tid %llx)...retrying %d\n", transaction_id, retries);
973
974                 if (retries < 4) {
975                         udelay(100);
976                         goto retry_send_cmplt;
977                 } else {
978                         netdev_err(ndev, "unable to send receive "
979                                 "completion pkt (tid %llx)...give up retrying\n",
980                                 transaction_id);
981                 }
982         } else {
983                 netdev_err(ndev, "unable to send receive "
984                         "completion pkt - %llx\n", transaction_id);
985         }
986 }
987
988 static void netvsc_receive(struct netvsc_device *net_device,
989                         struct vmbus_channel *channel,
990                         struct hv_device *device,
991                         struct vmpacket_descriptor *packet)
992 {
993         struct vmtransfer_page_packet_header *vmxferpage_packet;
994         struct nvsp_message *nvsp_packet;
995         struct hv_netvsc_packet nv_pkt;
996         struct hv_netvsc_packet *netvsc_packet = &nv_pkt;
997         u32 status = NVSP_STAT_SUCCESS;
998         int i;
999         int count = 0;
1000         struct net_device *ndev;
1001         void *data;
1002
1003         ndev = net_device->ndev;
1004
1005         /*
1006          * All inbound packets other than send completion should be xfer page
1007          * packet
1008          */
1009         if (packet->type != VM_PKT_DATA_USING_XFER_PAGES) {
1010                 netdev_err(ndev, "Unknown packet type received - %d\n",
1011                            packet->type);
1012                 return;
1013         }
1014
1015         nvsp_packet = (struct nvsp_message *)((unsigned long)packet +
1016                         (packet->offset8 << 3));
1017
1018         /* Make sure this is a valid nvsp packet */
1019         if (nvsp_packet->hdr.msg_type !=
1020             NVSP_MSG1_TYPE_SEND_RNDIS_PKT) {
1021                 netdev_err(ndev, "Unknown nvsp packet type received-"
1022                         " %d\n", nvsp_packet->hdr.msg_type);
1023                 return;
1024         }
1025
1026         vmxferpage_packet = (struct vmtransfer_page_packet_header *)packet;
1027
1028         if (vmxferpage_packet->xfer_pageset_id != NETVSC_RECEIVE_BUFFER_ID) {
1029                 netdev_err(ndev, "Invalid xfer page set id - "
1030                            "expecting %x got %x\n", NETVSC_RECEIVE_BUFFER_ID,
1031                            vmxferpage_packet->xfer_pageset_id);
1032                 return;
1033         }
1034
1035         count = vmxferpage_packet->range_cnt;
1036
1037         /* Each range represents 1 RNDIS pkt that contains 1 ethernet frame */
1038         for (i = 0; i < count; i++) {
1039                 /* Initialize the netvsc packet */
1040                 netvsc_packet->status = NVSP_STAT_SUCCESS;
1041                 data = (void *)((unsigned long)net_device->
1042                         recv_buf + vmxferpage_packet->ranges[i].byte_offset);
1043                 netvsc_packet->total_data_buflen =
1044                                         vmxferpage_packet->ranges[i].byte_count;
1045
1046                 /* Pass it to the upper layer */
1047                 rndis_filter_receive(device, netvsc_packet, &data, channel);
1048
1049                 if (netvsc_packet->status != NVSP_STAT_SUCCESS)
1050                         status = NVSP_STAT_FAIL;
1051         }
1052
1053         netvsc_send_recv_completion(device, channel, net_device,
1054                                     vmxferpage_packet->d.trans_id, status);
1055 }
1056
1057
1058 static void netvsc_send_table(struct hv_device *hdev,
1059                               struct nvsp_message *nvmsg)
1060 {
1061         struct netvsc_device *nvscdev;
1062         struct net_device *ndev;
1063         int i;
1064         u32 count, *tab;
1065
1066         nvscdev = get_outbound_net_device(hdev);
1067         if (!nvscdev)
1068                 return;
1069         ndev = nvscdev->ndev;
1070
1071         count = nvmsg->msg.v5_msg.send_table.count;
1072         if (count != VRSS_SEND_TAB_SIZE) {
1073                 netdev_err(ndev, "Received wrong send-table size:%u\n", count);
1074                 return;
1075         }
1076
1077         tab = (u32 *)((unsigned long)&nvmsg->msg.v5_msg.send_table +
1078                       nvmsg->msg.v5_msg.send_table.offset);
1079
1080         for (i = 0; i < count; i++)
1081                 nvscdev->send_table[i] = tab[i];
1082 }
1083
1084 static void netvsc_send_vf(struct netvsc_device *nvdev,
1085                            struct nvsp_message *nvmsg)
1086 {
1087         nvdev->vf_alloc = nvmsg->msg.v4_msg.vf_assoc.allocated;
1088         nvdev->vf_serial = nvmsg->msg.v4_msg.vf_assoc.serial;
1089 }
1090
1091 static inline void netvsc_receive_inband(struct hv_device *hdev,
1092                                          struct netvsc_device *nvdev,
1093                                          struct nvsp_message *nvmsg)
1094 {
1095         switch (nvmsg->hdr.msg_type) {
1096         case NVSP_MSG5_TYPE_SEND_INDIRECTION_TABLE:
1097                 netvsc_send_table(hdev, nvmsg);
1098                 break;
1099
1100         case NVSP_MSG4_TYPE_SEND_VF_ASSOCIATION:
1101                 netvsc_send_vf(nvdev, nvmsg);
1102                 break;
1103         }
1104 }
1105
1106 void netvsc_channel_cb(void *context)
1107 {
1108         int ret;
1109         struct vmbus_channel *channel = (struct vmbus_channel *)context;
1110         struct hv_device *device;
1111         struct netvsc_device *net_device;
1112         u32 bytes_recvd;
1113         u64 request_id;
1114         struct vmpacket_descriptor *desc;
1115         unsigned char *buffer;
1116         int bufferlen = NETVSC_PACKET_SIZE;
1117         struct net_device *ndev;
1118         struct nvsp_message *nvmsg;
1119
1120         if (channel->primary_channel != NULL)
1121                 device = channel->primary_channel->device_obj;
1122         else
1123                 device = channel->device_obj;
1124
1125         net_device = get_inbound_net_device(device);
1126         if (!net_device)
1127                 return;
1128         ndev = net_device->ndev;
1129         buffer = get_per_channel_state(channel);
1130
1131         do {
1132                 ret = vmbus_recvpacket_raw(channel, buffer, bufferlen,
1133                                            &bytes_recvd, &request_id);
1134                 if (ret == 0) {
1135                         if (bytes_recvd > 0) {
1136                                 desc = (struct vmpacket_descriptor *)buffer;
1137                                 nvmsg = (struct nvsp_message *)((unsigned long)
1138                                          desc + (desc->offset8 << 3));
1139                                 switch (desc->type) {
1140                                 case VM_PKT_COMP:
1141                                         netvsc_send_completion(net_device,
1142                                                                 channel,
1143                                                                 device, desc);
1144                                         break;
1145
1146                                 case VM_PKT_DATA_USING_XFER_PAGES:
1147                                         netvsc_receive(net_device, channel,
1148                                                        device, desc);
1149                                         break;
1150
1151                                 case VM_PKT_DATA_INBAND:
1152                                         netvsc_receive_inband(device,
1153                                                               net_device,
1154                                                               nvmsg);
1155                                         break;
1156
1157                                 default:
1158                                         netdev_err(ndev,
1159                                                    "unhandled packet type %d, "
1160                                                    "tid %llx len %d\n",
1161                                                    desc->type, request_id,
1162                                                    bytes_recvd);
1163                                         break;
1164                                 }
1165
1166                         } else {
1167                                 /*
1168                                  * We are done for this pass.
1169                                  */
1170                                 break;
1171                         }
1172
1173                 } else if (ret == -ENOBUFS) {
1174                         if (bufferlen > NETVSC_PACKET_SIZE)
1175                                 kfree(buffer);
1176                         /* Handle large packet */
1177                         buffer = kmalloc(bytes_recvd, GFP_ATOMIC);
1178                         if (buffer == NULL) {
1179                                 /* Try again next time around */
1180                                 netdev_err(ndev,
1181                                            "unable to allocate buffer of size "
1182                                            "(%d)!!\n", bytes_recvd);
1183                                 break;
1184                         }
1185
1186                         bufferlen = bytes_recvd;
1187                 }
1188         } while (1);
1189
1190         if (bufferlen > NETVSC_PACKET_SIZE)
1191                 kfree(buffer);
1192         return;
1193 }
1194
1195 /*
1196  * netvsc_device_add - Callback when the device belonging to this
1197  * driver is added
1198  */
1199 int netvsc_device_add(struct hv_device *device, void *additional_info)
1200 {
1201         int ret = 0;
1202         int ring_size =
1203         ((struct netvsc_device_info *)additional_info)->ring_size;
1204         struct netvsc_device *net_device;
1205         struct net_device *ndev;
1206
1207         net_device = alloc_net_device(device);
1208         if (!net_device)
1209                 return -ENOMEM;
1210
1211         net_device->ring_size = ring_size;
1212
1213         /*
1214          * Coming into this function, struct net_device * is
1215          * registered as the driver private data.
1216          * In alloc_net_device(), we register struct netvsc_device *
1217          * as the driver private data and stash away struct net_device *
1218          * in struct netvsc_device *.
1219          */
1220         ndev = net_device->ndev;
1221
1222         /* Add netvsc_device context to netvsc_device */
1223         net_device->nd_ctx = netdev_priv(ndev);
1224
1225         /* Initialize the NetVSC channel extension */
1226         init_completion(&net_device->channel_init_wait);
1227
1228         set_per_channel_state(device->channel, net_device->cb_buffer);
1229
1230         /* Open the channel */
1231         ret = vmbus_open(device->channel, ring_size * PAGE_SIZE,
1232                          ring_size * PAGE_SIZE, NULL, 0,
1233                          netvsc_channel_cb, device->channel);
1234
1235         if (ret != 0) {
1236                 netdev_err(ndev, "unable to open channel: %d\n", ret);
1237                 goto cleanup;
1238         }
1239
1240         /* Channel is opened */
1241         pr_info("hv_netvsc channel opened successfully\n");
1242
1243         net_device->chn_table[0] = device->channel;
1244
1245         /* Connect with the NetVsp */
1246         ret = netvsc_connect_vsp(device);
1247         if (ret != 0) {
1248                 netdev_err(ndev,
1249                         "unable to connect to NetVSP - %d\n", ret);
1250                 goto close;
1251         }
1252
1253         return ret;
1254
1255 close:
1256         /* Now, we can close the channel safely */
1257         vmbus_close(device->channel);
1258
1259 cleanup:
1260         free_netvsc_device(net_device);
1261
1262         return ret;
1263 }