Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
[muen/linux.git] / drivers / scsi / storvsc_drv.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, write to the Free Software Foundation, Inc., 59 Temple
15  * Place - Suite 330, Boston, MA 02111-1307 USA.
16  *
17  * Authors:
18  *   Haiyang Zhang <haiyangz@microsoft.com>
19  *   Hank Janssen  <hjanssen@microsoft.com>
20  *   K. Y. Srinivasan <kys@microsoft.com>
21  */
22
23 #include <linux/kernel.h>
24 #include <linux/wait.h>
25 #include <linux/sched.h>
26 #include <linux/completion.h>
27 #include <linux/string.h>
28 #include <linux/mm.h>
29 #include <linux/delay.h>
30 #include <linux/init.h>
31 #include <linux/slab.h>
32 #include <linux/module.h>
33 #include <linux/device.h>
34 #include <linux/hyperv.h>
35 #include <linux/blkdev.h>
36 #include <scsi/scsi.h>
37 #include <scsi/scsi_cmnd.h>
38 #include <scsi/scsi_host.h>
39 #include <scsi/scsi_device.h>
40 #include <scsi/scsi_tcq.h>
41 #include <scsi/scsi_eh.h>
42 #include <scsi/scsi_devinfo.h>
43 #include <scsi/scsi_dbg.h>
44 #include <scsi/scsi_transport_fc.h>
45 #include <scsi/scsi_transport.h>
46
47 /*
48  * All wire protocol details (storage protocol between the guest and the host)
49  * are consolidated here.
50  *
51  * Begin protocol definitions.
52  */
53
54 /*
55  * Version history:
56  * V1 Beta: 0.1
57  * V1 RC < 2008/1/31: 1.0
58  * V1 RC > 2008/1/31:  2.0
59  * Win7: 4.2
60  * Win8: 5.1
61  * Win8.1: 6.0
62  * Win10: 6.2
63  */
64
65 #define VMSTOR_PROTO_VERSION(MAJOR_, MINOR_)    ((((MAJOR_) & 0xff) << 8) | \
66                                                 (((MINOR_) & 0xff)))
67
68 #define VMSTOR_PROTO_VERSION_WIN6       VMSTOR_PROTO_VERSION(2, 0)
69 #define VMSTOR_PROTO_VERSION_WIN7       VMSTOR_PROTO_VERSION(4, 2)
70 #define VMSTOR_PROTO_VERSION_WIN8       VMSTOR_PROTO_VERSION(5, 1)
71 #define VMSTOR_PROTO_VERSION_WIN8_1     VMSTOR_PROTO_VERSION(6, 0)
72 #define VMSTOR_PROTO_VERSION_WIN10      VMSTOR_PROTO_VERSION(6, 2)
73
74 /*  Packet structure describing virtual storage requests. */
75 enum vstor_packet_operation {
76         VSTOR_OPERATION_COMPLETE_IO             = 1,
77         VSTOR_OPERATION_REMOVE_DEVICE           = 2,
78         VSTOR_OPERATION_EXECUTE_SRB             = 3,
79         VSTOR_OPERATION_RESET_LUN               = 4,
80         VSTOR_OPERATION_RESET_ADAPTER           = 5,
81         VSTOR_OPERATION_RESET_BUS               = 6,
82         VSTOR_OPERATION_BEGIN_INITIALIZATION    = 7,
83         VSTOR_OPERATION_END_INITIALIZATION      = 8,
84         VSTOR_OPERATION_QUERY_PROTOCOL_VERSION  = 9,
85         VSTOR_OPERATION_QUERY_PROPERTIES        = 10,
86         VSTOR_OPERATION_ENUMERATE_BUS           = 11,
87         VSTOR_OPERATION_FCHBA_DATA              = 12,
88         VSTOR_OPERATION_CREATE_SUB_CHANNELS     = 13,
89         VSTOR_OPERATION_MAXIMUM                 = 13
90 };
91
92 /*
93  * WWN packet for Fibre Channel HBA
94  */
95
96 struct hv_fc_wwn_packet {
97         u8      primary_active;
98         u8      reserved1[3];
99         u8      primary_port_wwn[8];
100         u8      primary_node_wwn[8];
101         u8      secondary_port_wwn[8];
102         u8      secondary_node_wwn[8];
103 };
104
105
106
107 /*
108  * SRB Flag Bits
109  */
110
111 #define SRB_FLAGS_QUEUE_ACTION_ENABLE           0x00000002
112 #define SRB_FLAGS_DISABLE_DISCONNECT            0x00000004
113 #define SRB_FLAGS_DISABLE_SYNCH_TRANSFER        0x00000008
114 #define SRB_FLAGS_BYPASS_FROZEN_QUEUE           0x00000010
115 #define SRB_FLAGS_DISABLE_AUTOSENSE             0x00000020
116 #define SRB_FLAGS_DATA_IN                       0x00000040
117 #define SRB_FLAGS_DATA_OUT                      0x00000080
118 #define SRB_FLAGS_NO_DATA_TRANSFER              0x00000000
119 #define SRB_FLAGS_UNSPECIFIED_DIRECTION (SRB_FLAGS_DATA_IN | SRB_FLAGS_DATA_OUT)
120 #define SRB_FLAGS_NO_QUEUE_FREEZE               0x00000100
121 #define SRB_FLAGS_ADAPTER_CACHE_ENABLE          0x00000200
122 #define SRB_FLAGS_FREE_SENSE_BUFFER             0x00000400
123
124 /*
125  * This flag indicates the request is part of the workflow for processing a D3.
126  */
127 #define SRB_FLAGS_D3_PROCESSING                 0x00000800
128 #define SRB_FLAGS_IS_ACTIVE                     0x00010000
129 #define SRB_FLAGS_ALLOCATED_FROM_ZONE           0x00020000
130 #define SRB_FLAGS_SGLIST_FROM_POOL              0x00040000
131 #define SRB_FLAGS_BYPASS_LOCKED_QUEUE           0x00080000
132 #define SRB_FLAGS_NO_KEEP_AWAKE                 0x00100000
133 #define SRB_FLAGS_PORT_DRIVER_ALLOCSENSE        0x00200000
134 #define SRB_FLAGS_PORT_DRIVER_SENSEHASPORT      0x00400000
135 #define SRB_FLAGS_DONT_START_NEXT_PACKET        0x00800000
136 #define SRB_FLAGS_PORT_DRIVER_RESERVED          0x0F000000
137 #define SRB_FLAGS_CLASS_DRIVER_RESERVED         0xF0000000
138
139 #define SP_UNTAGGED                     ((unsigned char) ~0)
140 #define SRB_SIMPLE_TAG_REQUEST          0x20
141
142 /*
143  * Platform neutral description of a scsi request -
144  * this remains the same across the write regardless of 32/64 bit
145  * note: it's patterned off the SCSI_PASS_THROUGH structure
146  */
147 #define STORVSC_MAX_CMD_LEN                     0x10
148
149 #define POST_WIN7_STORVSC_SENSE_BUFFER_SIZE     0x14
150 #define PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE      0x12
151
152 #define STORVSC_SENSE_BUFFER_SIZE               0x14
153 #define STORVSC_MAX_BUF_LEN_WITH_PADDING        0x14
154
155 /*
156  * Sense buffer size changed in win8; have a run-time
157  * variable to track the size we should use.  This value will
158  * likely change during protocol negotiation but it is valid
159  * to start by assuming pre-Win8.
160  */
161 static int sense_buffer_size = PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE;
162
163 /*
164  * The storage protocol version is determined during the
165  * initial exchange with the host.  It will indicate which
166  * storage functionality is available in the host.
167 */
168 static int vmstor_proto_version;
169
170 #define STORVSC_LOGGING_NONE    0
171 #define STORVSC_LOGGING_ERROR   1
172 #define STORVSC_LOGGING_WARN    2
173
174 static int logging_level = STORVSC_LOGGING_ERROR;
175 module_param(logging_level, int, S_IRUGO|S_IWUSR);
176 MODULE_PARM_DESC(logging_level,
177         "Logging level, 0 - None, 1 - Error (default), 2 - Warning.");
178
179 static inline bool do_logging(int level)
180 {
181         return logging_level >= level;
182 }
183
184 #define storvsc_log(dev, level, fmt, ...)                       \
185 do {                                                            \
186         if (do_logging(level))                                  \
187                 dev_warn(&(dev)->device, fmt, ##__VA_ARGS__);   \
188 } while (0)
189
190 struct vmscsi_win8_extension {
191         /*
192          * The following were added in Windows 8
193          */
194         u16 reserve;
195         u8  queue_tag;
196         u8  queue_action;
197         u32 srb_flags;
198         u32 time_out_value;
199         u32 queue_sort_ey;
200 } __packed;
201
202 struct vmscsi_request {
203         u16 length;
204         u8 srb_status;
205         u8 scsi_status;
206
207         u8  port_number;
208         u8  path_id;
209         u8  target_id;
210         u8  lun;
211
212         u8  cdb_length;
213         u8  sense_info_length;
214         u8  data_in;
215         u8  reserved;
216
217         u32 data_transfer_length;
218
219         union {
220                 u8 cdb[STORVSC_MAX_CMD_LEN];
221                 u8 sense_data[STORVSC_SENSE_BUFFER_SIZE];
222                 u8 reserved_array[STORVSC_MAX_BUF_LEN_WITH_PADDING];
223         };
224         /*
225          * The following was added in win8.
226          */
227         struct vmscsi_win8_extension win8_extension;
228
229 } __attribute((packed));
230
231
232 /*
233  * The size of the vmscsi_request has changed in win8. The
234  * additional size is because of new elements added to the
235  * structure. These elements are valid only when we are talking
236  * to a win8 host.
237  * Track the correction to size we need to apply. This value
238  * will likely change during protocol negotiation but it is
239  * valid to start by assuming pre-Win8.
240  */
241 static int vmscsi_size_delta = sizeof(struct vmscsi_win8_extension);
242
243 /*
244  * The list of storage protocols in order of preference.
245  */
246 struct vmstor_protocol {
247         int protocol_version;
248         int sense_buffer_size;
249         int vmscsi_size_delta;
250 };
251
252
253 static const struct vmstor_protocol vmstor_protocols[] = {
254         {
255                 VMSTOR_PROTO_VERSION_WIN10,
256                 POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
257                 0
258         },
259         {
260                 VMSTOR_PROTO_VERSION_WIN8_1,
261                 POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
262                 0
263         },
264         {
265                 VMSTOR_PROTO_VERSION_WIN8,
266                 POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
267                 0
268         },
269         {
270                 VMSTOR_PROTO_VERSION_WIN7,
271                 PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE,
272                 sizeof(struct vmscsi_win8_extension),
273         },
274         {
275                 VMSTOR_PROTO_VERSION_WIN6,
276                 PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE,
277                 sizeof(struct vmscsi_win8_extension),
278         }
279 };
280
281
282 /*
283  * This structure is sent during the initialization phase to get the different
284  * properties of the channel.
285  */
286
287 #define STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL          0x1
288
289 struct vmstorage_channel_properties {
290         u32 reserved;
291         u16 max_channel_cnt;
292         u16 reserved1;
293
294         u32 flags;
295         u32   max_transfer_bytes;
296
297         u64  reserved2;
298 } __packed;
299
300 /*  This structure is sent during the storage protocol negotiations. */
301 struct vmstorage_protocol_version {
302         /* Major (MSW) and minor (LSW) version numbers. */
303         u16 major_minor;
304
305         /*
306          * Revision number is auto-incremented whenever this file is changed
307          * (See FILL_VMSTOR_REVISION macro above).  Mismatch does not
308          * definitely indicate incompatibility--but it does indicate mismatched
309          * builds.
310          * This is only used on the windows side. Just set it to 0.
311          */
312         u16 revision;
313 } __packed;
314
315 /* Channel Property Flags */
316 #define STORAGE_CHANNEL_REMOVABLE_FLAG          0x1
317 #define STORAGE_CHANNEL_EMULATED_IDE_FLAG       0x2
318
319 struct vstor_packet {
320         /* Requested operation type */
321         enum vstor_packet_operation operation;
322
323         /*  Flags - see below for values */
324         u32 flags;
325
326         /* Status of the request returned from the server side. */
327         u32 status;
328
329         /* Data payload area */
330         union {
331                 /*
332                  * Structure used to forward SCSI commands from the
333                  * client to the server.
334                  */
335                 struct vmscsi_request vm_srb;
336
337                 /* Structure used to query channel properties. */
338                 struct vmstorage_channel_properties storage_channel_properties;
339
340                 /* Used during version negotiations. */
341                 struct vmstorage_protocol_version version;
342
343                 /* Fibre channel address packet */
344                 struct hv_fc_wwn_packet wwn_packet;
345
346                 /* Number of sub-channels to create */
347                 u16 sub_channel_count;
348
349                 /* This will be the maximum of the union members */
350                 u8  buffer[0x34];
351         };
352 } __packed;
353
354 /*
355  * Packet Flags:
356  *
357  * This flag indicates that the server should send back a completion for this
358  * packet.
359  */
360
361 #define REQUEST_COMPLETION_FLAG 0x1
362
363 /* Matches Windows-end */
364 enum storvsc_request_type {
365         WRITE_TYPE = 0,
366         READ_TYPE,
367         UNKNOWN_TYPE,
368 };
369
370 /*
371  * SRB status codes and masks; a subset of the codes used here.
372  */
373
374 #define SRB_STATUS_AUTOSENSE_VALID      0x80
375 #define SRB_STATUS_QUEUE_FROZEN         0x40
376 #define SRB_STATUS_INVALID_LUN  0x20
377 #define SRB_STATUS_SUCCESS      0x01
378 #define SRB_STATUS_ABORTED      0x02
379 #define SRB_STATUS_ERROR        0x04
380 #define SRB_STATUS_DATA_OVERRUN 0x12
381
382 #define SRB_STATUS(status) \
383         (status & ~(SRB_STATUS_AUTOSENSE_VALID | SRB_STATUS_QUEUE_FROZEN))
384 /*
385  * This is the end of Protocol specific defines.
386  */
387
388 static int storvsc_ringbuffer_size = (256 * PAGE_SIZE);
389 static u32 max_outstanding_req_per_channel;
390
391 static int storvsc_vcpus_per_sub_channel = 4;
392
393 module_param(storvsc_ringbuffer_size, int, S_IRUGO);
394 MODULE_PARM_DESC(storvsc_ringbuffer_size, "Ring buffer size (bytes)");
395
396 module_param(storvsc_vcpus_per_sub_channel, int, S_IRUGO);
397 MODULE_PARM_DESC(storvsc_vcpus_per_sub_channel, "Ratio of VCPUs to subchannels");
398 /*
399  * Timeout in seconds for all devices managed by this driver.
400  */
401 static int storvsc_timeout = 180;
402
403 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
404 static struct scsi_transport_template *fc_transport_template;
405 #endif
406
407 static void storvsc_on_channel_callback(void *context);
408
409 #define STORVSC_MAX_LUNS_PER_TARGET                     255
410 #define STORVSC_MAX_TARGETS                             2
411 #define STORVSC_MAX_CHANNELS                            8
412
413 #define STORVSC_FC_MAX_LUNS_PER_TARGET                  255
414 #define STORVSC_FC_MAX_TARGETS                          128
415 #define STORVSC_FC_MAX_CHANNELS                         8
416
417 #define STORVSC_IDE_MAX_LUNS_PER_TARGET                 64
418 #define STORVSC_IDE_MAX_TARGETS                         1
419 #define STORVSC_IDE_MAX_CHANNELS                        1
420
421 struct storvsc_cmd_request {
422         struct scsi_cmnd *cmd;
423
424         struct hv_device *device;
425
426         /* Synchronize the request/response if needed */
427         struct completion wait_event;
428
429         struct vmbus_channel_packet_multipage_buffer mpb;
430         struct vmbus_packet_mpb_array *payload;
431         u32 payload_sz;
432
433         struct vstor_packet vstor_packet;
434 };
435
436
437 /* A storvsc device is a device object that contains a vmbus channel */
438 struct storvsc_device {
439         struct hv_device *device;
440
441         bool     destroy;
442         bool     drain_notify;
443         bool     open_sub_channel;
444         atomic_t num_outstanding_req;
445         struct Scsi_Host *host;
446
447         wait_queue_head_t waiting_to_drain;
448
449         /*
450          * Each unique Port/Path/Target represents 1 channel ie scsi
451          * controller. In reality, the pathid, targetid is always 0
452          * and the port is set by us
453          */
454         unsigned int port_number;
455         unsigned char path_id;
456         unsigned char target_id;
457
458         /*
459          * Max I/O, the device can support.
460          */
461         u32   max_transfer_bytes;
462         /*
463          * Number of sub-channels we will open.
464          */
465         u16 num_sc;
466         struct vmbus_channel **stor_chns;
467         /*
468          * Mask of CPUs bound to subchannels.
469          */
470         struct cpumask alloced_cpus;
471         /* Used for vsc/vsp channel reset process */
472         struct storvsc_cmd_request init_request;
473         struct storvsc_cmd_request reset_request;
474         /*
475          * Currently active port and node names for FC devices.
476          */
477         u64 node_name;
478         u64 port_name;
479 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
480         struct fc_rport *rport;
481 #endif
482 };
483
484 struct hv_host_device {
485         struct hv_device *dev;
486         unsigned int port;
487         unsigned char path;
488         unsigned char target;
489         struct workqueue_struct *handle_error_wq;
490         struct work_struct host_scan_work;
491         struct Scsi_Host *host;
492 };
493
494 struct storvsc_scan_work {
495         struct work_struct work;
496         struct Scsi_Host *host;
497         u8 lun;
498         u8 tgt_id;
499 };
500
501 static void storvsc_device_scan(struct work_struct *work)
502 {
503         struct storvsc_scan_work *wrk;
504         struct scsi_device *sdev;
505
506         wrk = container_of(work, struct storvsc_scan_work, work);
507
508         sdev = scsi_device_lookup(wrk->host, 0, wrk->tgt_id, wrk->lun);
509         if (!sdev)
510                 goto done;
511         scsi_rescan_device(&sdev->sdev_gendev);
512         scsi_device_put(sdev);
513
514 done:
515         kfree(wrk);
516 }
517
518 static void storvsc_host_scan(struct work_struct *work)
519 {
520         struct Scsi_Host *host;
521         struct scsi_device *sdev;
522         struct hv_host_device *host_device =
523                 container_of(work, struct hv_host_device, host_scan_work);
524
525         host = host_device->host;
526         /*
527          * Before scanning the host, first check to see if any of the
528          * currrently known devices have been hot removed. We issue a
529          * "unit ready" command against all currently known devices.
530          * This I/O will result in an error for devices that have been
531          * removed. As part of handling the I/O error, we remove the device.
532          *
533          * When a LUN is added or removed, the host sends us a signal to
534          * scan the host. Thus we are forced to discover the LUNs that
535          * may have been removed this way.
536          */
537         mutex_lock(&host->scan_mutex);
538         shost_for_each_device(sdev, host)
539                 scsi_test_unit_ready(sdev, 1, 1, NULL);
540         mutex_unlock(&host->scan_mutex);
541         /*
542          * Now scan the host to discover LUNs that may have been added.
543          */
544         scsi_scan_host(host);
545 }
546
547 static void storvsc_remove_lun(struct work_struct *work)
548 {
549         struct storvsc_scan_work *wrk;
550         struct scsi_device *sdev;
551
552         wrk = container_of(work, struct storvsc_scan_work, work);
553         if (!scsi_host_get(wrk->host))
554                 goto done;
555
556         sdev = scsi_device_lookup(wrk->host, 0, wrk->tgt_id, wrk->lun);
557
558         if (sdev) {
559                 scsi_remove_device(sdev);
560                 scsi_device_put(sdev);
561         }
562         scsi_host_put(wrk->host);
563
564 done:
565         kfree(wrk);
566 }
567
568
569 /*
570  * We can get incoming messages from the host that are not in response to
571  * messages that we have sent out. An example of this would be messages
572  * received by the guest to notify dynamic addition/removal of LUNs. To
573  * deal with potential race conditions where the driver may be in the
574  * midst of being unloaded when we might receive an unsolicited message
575  * from the host, we have implemented a mechanism to gurantee sequential
576  * consistency:
577  *
578  * 1) Once the device is marked as being destroyed, we will fail all
579  *    outgoing messages.
580  * 2) We permit incoming messages when the device is being destroyed,
581  *    only to properly account for messages already sent out.
582  */
583
584 static inline struct storvsc_device *get_out_stor_device(
585                                         struct hv_device *device)
586 {
587         struct storvsc_device *stor_device;
588
589         stor_device = hv_get_drvdata(device);
590
591         if (stor_device && stor_device->destroy)
592                 stor_device = NULL;
593
594         return stor_device;
595 }
596
597
598 static inline void storvsc_wait_to_drain(struct storvsc_device *dev)
599 {
600         dev->drain_notify = true;
601         wait_event(dev->waiting_to_drain,
602                    atomic_read(&dev->num_outstanding_req) == 0);
603         dev->drain_notify = false;
604 }
605
606 static inline struct storvsc_device *get_in_stor_device(
607                                         struct hv_device *device)
608 {
609         struct storvsc_device *stor_device;
610
611         stor_device = hv_get_drvdata(device);
612
613         if (!stor_device)
614                 goto get_in_err;
615
616         /*
617          * If the device is being destroyed; allow incoming
618          * traffic only to cleanup outstanding requests.
619          */
620
621         if (stor_device->destroy  &&
622                 (atomic_read(&stor_device->num_outstanding_req) == 0))
623                 stor_device = NULL;
624
625 get_in_err:
626         return stor_device;
627
628 }
629
630 static void handle_sc_creation(struct vmbus_channel *new_sc)
631 {
632         struct hv_device *device = new_sc->primary_channel->device_obj;
633         struct storvsc_device *stor_device;
634         struct vmstorage_channel_properties props;
635
636         stor_device = get_out_stor_device(device);
637         if (!stor_device)
638                 return;
639
640         if (stor_device->open_sub_channel == false)
641                 return;
642
643         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
644
645         vmbus_open(new_sc,
646                    storvsc_ringbuffer_size,
647                    storvsc_ringbuffer_size,
648                    (void *)&props,
649                    sizeof(struct vmstorage_channel_properties),
650                    storvsc_on_channel_callback, new_sc);
651
652         if (new_sc->state == CHANNEL_OPENED_STATE) {
653                 stor_device->stor_chns[new_sc->target_cpu] = new_sc;
654                 cpumask_set_cpu(new_sc->target_cpu, &stor_device->alloced_cpus);
655         }
656 }
657
658 static void  handle_multichannel_storage(struct hv_device *device, int max_chns)
659 {
660         struct storvsc_device *stor_device;
661         int num_cpus = num_online_cpus();
662         int num_sc;
663         struct storvsc_cmd_request *request;
664         struct vstor_packet *vstor_packet;
665         int ret, t;
666
667         num_sc = ((max_chns > num_cpus) ? num_cpus : max_chns);
668         stor_device = get_out_stor_device(device);
669         if (!stor_device)
670                 return;
671
672         stor_device->num_sc = num_sc;
673         request = &stor_device->init_request;
674         vstor_packet = &request->vstor_packet;
675
676         stor_device->open_sub_channel = true;
677         /*
678          * Establish a handler for dealing with subchannels.
679          */
680         vmbus_set_sc_create_callback(device->channel, handle_sc_creation);
681
682         /*
683          * Check to see if sub-channels have already been created. This
684          * can happen when this driver is re-loaded after unloading.
685          */
686
687         if (vmbus_are_subchannels_present(device->channel))
688                 return;
689
690         stor_device->open_sub_channel = false;
691         /*
692          * Request the host to create sub-channels.
693          */
694         memset(request, 0, sizeof(struct storvsc_cmd_request));
695         init_completion(&request->wait_event);
696         vstor_packet->operation = VSTOR_OPERATION_CREATE_SUB_CHANNELS;
697         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
698         vstor_packet->sub_channel_count = num_sc;
699
700         ret = vmbus_sendpacket(device->channel, vstor_packet,
701                                (sizeof(struct vstor_packet) -
702                                vmscsi_size_delta),
703                                (unsigned long)request,
704                                VM_PKT_DATA_INBAND,
705                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
706
707         if (ret != 0)
708                 return;
709
710         t = wait_for_completion_timeout(&request->wait_event, 10*HZ);
711         if (t == 0)
712                 return;
713
714         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
715             vstor_packet->status != 0)
716                 return;
717
718         /*
719          * Now that we created the sub-channels, invoke the check; this
720          * may trigger the callback.
721          */
722         stor_device->open_sub_channel = true;
723         vmbus_are_subchannels_present(device->channel);
724 }
725
726 static void cache_wwn(struct storvsc_device *stor_device,
727                       struct vstor_packet *vstor_packet)
728 {
729         /*
730          * Cache the currently active port and node ww names.
731          */
732         if (vstor_packet->wwn_packet.primary_active) {
733                 stor_device->node_name =
734                         wwn_to_u64(vstor_packet->wwn_packet.primary_node_wwn);
735                 stor_device->port_name =
736                         wwn_to_u64(vstor_packet->wwn_packet.primary_port_wwn);
737         } else {
738                 stor_device->node_name =
739                         wwn_to_u64(vstor_packet->wwn_packet.secondary_node_wwn);
740                 stor_device->port_name =
741                         wwn_to_u64(vstor_packet->wwn_packet.secondary_port_wwn);
742         }
743 }
744
745
746 static int storvsc_execute_vstor_op(struct hv_device *device,
747                                     struct storvsc_cmd_request *request,
748                                     bool status_check)
749 {
750         struct vstor_packet *vstor_packet;
751         int ret, t;
752
753         vstor_packet = &request->vstor_packet;
754
755         init_completion(&request->wait_event);
756         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
757
758         ret = vmbus_sendpacket(device->channel, vstor_packet,
759                                (sizeof(struct vstor_packet) -
760                                vmscsi_size_delta),
761                                (unsigned long)request,
762                                VM_PKT_DATA_INBAND,
763                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
764         if (ret != 0)
765                 return ret;
766
767         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
768         if (t == 0)
769                 return -ETIMEDOUT;
770
771         if (!status_check)
772                 return ret;
773
774         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
775             vstor_packet->status != 0)
776                 return -EINVAL;
777
778         return ret;
779 }
780
781 static int storvsc_channel_init(struct hv_device *device, bool is_fc)
782 {
783         struct storvsc_device *stor_device;
784         struct storvsc_cmd_request *request;
785         struct vstor_packet *vstor_packet;
786         int ret, i;
787         int max_chns;
788         bool process_sub_channels = false;
789
790         stor_device = get_out_stor_device(device);
791         if (!stor_device)
792                 return -ENODEV;
793
794         request = &stor_device->init_request;
795         vstor_packet = &request->vstor_packet;
796
797         /*
798          * Now, initiate the vsc/vsp initialization protocol on the open
799          * channel
800          */
801         memset(request, 0, sizeof(struct storvsc_cmd_request));
802         vstor_packet->operation = VSTOR_OPERATION_BEGIN_INITIALIZATION;
803         ret = storvsc_execute_vstor_op(device, request, true);
804         if (ret)
805                 return ret;
806         /*
807          * Query host supported protocol version.
808          */
809
810         for (i = 0; i < ARRAY_SIZE(vmstor_protocols); i++) {
811                 /* reuse the packet for version range supported */
812                 memset(vstor_packet, 0, sizeof(struct vstor_packet));
813                 vstor_packet->operation =
814                         VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;
815
816                 vstor_packet->version.major_minor =
817                         vmstor_protocols[i].protocol_version;
818
819                 /*
820                  * The revision number is only used in Windows; set it to 0.
821                  */
822                 vstor_packet->version.revision = 0;
823                 ret = storvsc_execute_vstor_op(device, request, false);
824                 if (ret != 0)
825                         return ret;
826
827                 if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO)
828                         return -EINVAL;
829
830                 if (vstor_packet->status == 0) {
831                         vmstor_proto_version =
832                                 vmstor_protocols[i].protocol_version;
833
834                         sense_buffer_size =
835                                 vmstor_protocols[i].sense_buffer_size;
836
837                         vmscsi_size_delta =
838                                 vmstor_protocols[i].vmscsi_size_delta;
839
840                         break;
841                 }
842         }
843
844         if (vstor_packet->status != 0)
845                 return -EINVAL;
846
847
848         memset(vstor_packet, 0, sizeof(struct vstor_packet));
849         vstor_packet->operation = VSTOR_OPERATION_QUERY_PROPERTIES;
850         ret = storvsc_execute_vstor_op(device, request, true);
851         if (ret != 0)
852                 return ret;
853
854         /*
855          * Check to see if multi-channel support is there.
856          * Hosts that implement protocol version of 5.1 and above
857          * support multi-channel.
858          */
859         max_chns = vstor_packet->storage_channel_properties.max_channel_cnt;
860
861         /*
862          * Allocate state to manage the sub-channels.
863          * We allocate an array based on the numbers of possible CPUs
864          * (Hyper-V does not support cpu online/offline).
865          * This Array will be sparseley populated with unique
866          * channels - primary + sub-channels.
867          * We will however populate all the slots to evenly distribute
868          * the load.
869          */
870         stor_device->stor_chns = kcalloc(num_possible_cpus(), sizeof(void *),
871                                          GFP_KERNEL);
872         if (stor_device->stor_chns == NULL)
873                 return -ENOMEM;
874
875         stor_device->stor_chns[device->channel->target_cpu] = device->channel;
876         cpumask_set_cpu(device->channel->target_cpu,
877                         &stor_device->alloced_cpus);
878
879         if (vmstor_proto_version >= VMSTOR_PROTO_VERSION_WIN8) {
880                 if (vstor_packet->storage_channel_properties.flags &
881                     STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL)
882                         process_sub_channels = true;
883         }
884         stor_device->max_transfer_bytes =
885                 vstor_packet->storage_channel_properties.max_transfer_bytes;
886
887         if (!is_fc)
888                 goto done;
889
890         /*
891          * For FC devices retrieve FC HBA data.
892          */
893         memset(vstor_packet, 0, sizeof(struct vstor_packet));
894         vstor_packet->operation = VSTOR_OPERATION_FCHBA_DATA;
895         ret = storvsc_execute_vstor_op(device, request, true);
896         if (ret != 0)
897                 return ret;
898
899         /*
900          * Cache the currently active port and node ww names.
901          */
902         cache_wwn(stor_device, vstor_packet);
903
904 done:
905
906         memset(vstor_packet, 0, sizeof(struct vstor_packet));
907         vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
908         ret = storvsc_execute_vstor_op(device, request, true);
909         if (ret != 0)
910                 return ret;
911
912         if (process_sub_channels)
913                 handle_multichannel_storage(device, max_chns);
914
915         return ret;
916 }
917
918 static void storvsc_handle_error(struct vmscsi_request *vm_srb,
919                                 struct scsi_cmnd *scmnd,
920                                 struct Scsi_Host *host,
921                                 u8 asc, u8 ascq)
922 {
923         struct storvsc_scan_work *wrk;
924         void (*process_err_fn)(struct work_struct *work);
925         struct hv_host_device *host_dev = shost_priv(host);
926         bool do_work = false;
927
928         switch (SRB_STATUS(vm_srb->srb_status)) {
929         case SRB_STATUS_ERROR:
930                 /*
931                  * Let upper layer deal with error when
932                  * sense message is present.
933                  */
934
935                 if (vm_srb->srb_status & SRB_STATUS_AUTOSENSE_VALID)
936                         break;
937                 /*
938                  * If there is an error; offline the device since all
939                  * error recovery strategies would have already been
940                  * deployed on the host side. However, if the command
941                  * were a pass-through command deal with it appropriately.
942                  */
943                 switch (scmnd->cmnd[0]) {
944                 case ATA_16:
945                 case ATA_12:
946                         set_host_byte(scmnd, DID_PASSTHROUGH);
947                         break;
948                 /*
949                  * On Some Windows hosts TEST_UNIT_READY command can return
950                  * SRB_STATUS_ERROR, let the upper level code deal with it
951                  * based on the sense information.
952                  */
953                 case TEST_UNIT_READY:
954                         break;
955                 default:
956                         set_host_byte(scmnd, DID_ERROR);
957                 }
958                 break;
959         case SRB_STATUS_INVALID_LUN:
960                 set_host_byte(scmnd, DID_NO_CONNECT);
961                 do_work = true;
962                 process_err_fn = storvsc_remove_lun;
963                 break;
964         case SRB_STATUS_ABORTED:
965                 if (vm_srb->srb_status & SRB_STATUS_AUTOSENSE_VALID &&
966                     (asc == 0x2a) && (ascq == 0x9)) {
967                         do_work = true;
968                         process_err_fn = storvsc_device_scan;
969                         /*
970                          * Retry the I/O that trigerred this.
971                          */
972                         set_host_byte(scmnd, DID_REQUEUE);
973                 }
974                 break;
975         }
976
977         if (!do_work)
978                 return;
979
980         /*
981          * We need to schedule work to process this error; schedule it.
982          */
983         wrk = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
984         if (!wrk) {
985                 set_host_byte(scmnd, DID_TARGET_FAILURE);
986                 return;
987         }
988
989         wrk->host = host;
990         wrk->lun = vm_srb->lun;
991         wrk->tgt_id = vm_srb->target_id;
992         INIT_WORK(&wrk->work, process_err_fn);
993         queue_work(host_dev->handle_error_wq, &wrk->work);
994 }
995
996
997 static void storvsc_command_completion(struct storvsc_cmd_request *cmd_request,
998                                        struct storvsc_device *stor_dev)
999 {
1000         struct scsi_cmnd *scmnd = cmd_request->cmd;
1001         struct scsi_sense_hdr sense_hdr;
1002         struct vmscsi_request *vm_srb;
1003         u32 data_transfer_length;
1004         struct Scsi_Host *host;
1005         u32 payload_sz = cmd_request->payload_sz;
1006         void *payload = cmd_request->payload;
1007
1008         host = stor_dev->host;
1009
1010         vm_srb = &cmd_request->vstor_packet.vm_srb;
1011         data_transfer_length = vm_srb->data_transfer_length;
1012
1013         scmnd->result = vm_srb->scsi_status;
1014
1015         if (scmnd->result) {
1016                 if (scsi_normalize_sense(scmnd->sense_buffer,
1017                                 SCSI_SENSE_BUFFERSIZE, &sense_hdr) &&
1018                     !(sense_hdr.sense_key == NOT_READY &&
1019                                  sense_hdr.asc == 0x03A) &&
1020                     do_logging(STORVSC_LOGGING_ERROR))
1021                         scsi_print_sense_hdr(scmnd->device, "storvsc",
1022                                              &sense_hdr);
1023         }
1024
1025         if (vm_srb->srb_status != SRB_STATUS_SUCCESS) {
1026                 storvsc_handle_error(vm_srb, scmnd, host, sense_hdr.asc,
1027                                          sense_hdr.ascq);
1028                 /*
1029                  * The Windows driver set data_transfer_length on
1030                  * SRB_STATUS_DATA_OVERRUN. On other errors, this value
1031                  * is untouched.  In these cases we set it to 0.
1032                  */
1033                 if (vm_srb->srb_status != SRB_STATUS_DATA_OVERRUN)
1034                         data_transfer_length = 0;
1035         }
1036
1037         scsi_set_resid(scmnd,
1038                 cmd_request->payload->range.len - data_transfer_length);
1039
1040         scmnd->scsi_done(scmnd);
1041
1042         if (payload_sz >
1043                 sizeof(struct vmbus_channel_packet_multipage_buffer))
1044                 kfree(payload);
1045 }
1046
1047 static void storvsc_on_io_completion(struct storvsc_device *stor_device,
1048                                   struct vstor_packet *vstor_packet,
1049                                   struct storvsc_cmd_request *request)
1050 {
1051         struct vstor_packet *stor_pkt;
1052         struct hv_device *device = stor_device->device;
1053
1054         stor_pkt = &request->vstor_packet;
1055
1056         /*
1057          * The current SCSI handling on the host side does
1058          * not correctly handle:
1059          * INQUIRY command with page code parameter set to 0x80
1060          * MODE_SENSE command with cmd[2] == 0x1c
1061          *
1062          * Setup srb and scsi status so this won't be fatal.
1063          * We do this so we can distinguish truly fatal failues
1064          * (srb status == 0x4) and off-line the device in that case.
1065          */
1066
1067         if ((stor_pkt->vm_srb.cdb[0] == INQUIRY) ||
1068            (stor_pkt->vm_srb.cdb[0] == MODE_SENSE)) {
1069                 vstor_packet->vm_srb.scsi_status = 0;
1070                 vstor_packet->vm_srb.srb_status = SRB_STATUS_SUCCESS;
1071         }
1072
1073
1074         /* Copy over the status...etc */
1075         stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
1076         stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
1077         stor_pkt->vm_srb.sense_info_length =
1078         vstor_packet->vm_srb.sense_info_length;
1079
1080         if (vstor_packet->vm_srb.scsi_status != 0 ||
1081             vstor_packet->vm_srb.srb_status != SRB_STATUS_SUCCESS)
1082                 storvsc_log(device, STORVSC_LOGGING_WARN,
1083                         "cmd 0x%x scsi status 0x%x srb status 0x%x\n",
1084                         stor_pkt->vm_srb.cdb[0],
1085                         vstor_packet->vm_srb.scsi_status,
1086                         vstor_packet->vm_srb.srb_status);
1087
1088         if ((vstor_packet->vm_srb.scsi_status & 0xFF) == 0x02) {
1089                 /* CHECK_CONDITION */
1090                 if (vstor_packet->vm_srb.srb_status &
1091                         SRB_STATUS_AUTOSENSE_VALID) {
1092                         /* autosense data available */
1093
1094                         storvsc_log(device, STORVSC_LOGGING_WARN,
1095                                 "stor pkt %p autosense data valid - len %d\n",
1096                                 request, vstor_packet->vm_srb.sense_info_length);
1097
1098                         memcpy(request->cmd->sense_buffer,
1099                                vstor_packet->vm_srb.sense_data,
1100                                vstor_packet->vm_srb.sense_info_length);
1101
1102                 }
1103         }
1104
1105         stor_pkt->vm_srb.data_transfer_length =
1106         vstor_packet->vm_srb.data_transfer_length;
1107
1108         storvsc_command_completion(request, stor_device);
1109
1110         if (atomic_dec_and_test(&stor_device->num_outstanding_req) &&
1111                 stor_device->drain_notify)
1112                 wake_up(&stor_device->waiting_to_drain);
1113
1114
1115 }
1116
1117 static void storvsc_on_receive(struct storvsc_device *stor_device,
1118                              struct vstor_packet *vstor_packet,
1119                              struct storvsc_cmd_request *request)
1120 {
1121         struct hv_host_device *host_dev;
1122         switch (vstor_packet->operation) {
1123         case VSTOR_OPERATION_COMPLETE_IO:
1124                 storvsc_on_io_completion(stor_device, vstor_packet, request);
1125                 break;
1126
1127         case VSTOR_OPERATION_REMOVE_DEVICE:
1128         case VSTOR_OPERATION_ENUMERATE_BUS:
1129                 host_dev = shost_priv(stor_device->host);
1130                 queue_work(
1131                         host_dev->handle_error_wq, &host_dev->host_scan_work);
1132                 break;
1133
1134         case VSTOR_OPERATION_FCHBA_DATA:
1135                 cache_wwn(stor_device, vstor_packet);
1136 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1137                 fc_host_node_name(stor_device->host) = stor_device->node_name;
1138                 fc_host_port_name(stor_device->host) = stor_device->port_name;
1139 #endif
1140                 break;
1141         default:
1142                 break;
1143         }
1144 }
1145
1146 static void storvsc_on_channel_callback(void *context)
1147 {
1148         struct vmbus_channel *channel = (struct vmbus_channel *)context;
1149         const struct vmpacket_descriptor *desc;
1150         struct hv_device *device;
1151         struct storvsc_device *stor_device;
1152
1153         if (channel->primary_channel != NULL)
1154                 device = channel->primary_channel->device_obj;
1155         else
1156                 device = channel->device_obj;
1157
1158         stor_device = get_in_stor_device(device);
1159         if (!stor_device)
1160                 return;
1161
1162         foreach_vmbus_pkt(desc, channel) {
1163                 void *packet = hv_pkt_data(desc);
1164                 struct storvsc_cmd_request *request;
1165
1166                 request = (struct storvsc_cmd_request *)
1167                         ((unsigned long)desc->trans_id);
1168
1169                 if (request == &stor_device->init_request ||
1170                     request == &stor_device->reset_request) {
1171                         memcpy(&request->vstor_packet, packet,
1172                                (sizeof(struct vstor_packet) - vmscsi_size_delta));
1173                         complete(&request->wait_event);
1174                 } else {
1175                         storvsc_on_receive(stor_device, packet, request);
1176                 }
1177         }
1178 }
1179
1180 static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size,
1181                                   bool is_fc)
1182 {
1183         struct vmstorage_channel_properties props;
1184         int ret;
1185
1186         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
1187
1188         ret = vmbus_open(device->channel,
1189                          ring_size,
1190                          ring_size,
1191                          (void *)&props,
1192                          sizeof(struct vmstorage_channel_properties),
1193                          storvsc_on_channel_callback, device->channel);
1194
1195         if (ret != 0)
1196                 return ret;
1197
1198         ret = storvsc_channel_init(device, is_fc);
1199
1200         return ret;
1201 }
1202
1203 static int storvsc_dev_remove(struct hv_device *device)
1204 {
1205         struct storvsc_device *stor_device;
1206
1207         stor_device = hv_get_drvdata(device);
1208
1209         stor_device->destroy = true;
1210
1211         /* Make sure flag is set before waiting */
1212         wmb();
1213
1214         /*
1215          * At this point, all outbound traffic should be disable. We
1216          * only allow inbound traffic (responses) to proceed so that
1217          * outstanding requests can be completed.
1218          */
1219
1220         storvsc_wait_to_drain(stor_device);
1221
1222         /*
1223          * Since we have already drained, we don't need to busy wait
1224          * as was done in final_release_stor_device()
1225          * Note that we cannot set the ext pointer to NULL until
1226          * we have drained - to drain the outgoing packets, we need to
1227          * allow incoming packets.
1228          */
1229         hv_set_drvdata(device, NULL);
1230
1231         /* Close the channel */
1232         vmbus_close(device->channel);
1233
1234         kfree(stor_device->stor_chns);
1235         kfree(stor_device);
1236         return 0;
1237 }
1238
1239 static struct vmbus_channel *get_og_chn(struct storvsc_device *stor_device,
1240                                         u16 q_num)
1241 {
1242         u16 slot = 0;
1243         u16 hash_qnum;
1244         struct cpumask alloced_mask;
1245         int num_channels, tgt_cpu;
1246
1247         if (stor_device->num_sc == 0)
1248                 return stor_device->device->channel;
1249
1250         /*
1251          * Our channel array is sparsley populated and we
1252          * initiated I/O on a processor/hw-q that does not
1253          * currently have a designated channel. Fix this.
1254          * The strategy is simple:
1255          * I. Ensure NUMA locality
1256          * II. Distribute evenly (best effort)
1257          * III. Mapping is persistent.
1258          */
1259
1260         cpumask_and(&alloced_mask, &stor_device->alloced_cpus,
1261                     cpumask_of_node(cpu_to_node(q_num)));
1262
1263         num_channels = cpumask_weight(&alloced_mask);
1264         if (num_channels == 0)
1265                 return stor_device->device->channel;
1266
1267         hash_qnum = q_num;
1268         while (hash_qnum >= num_channels)
1269                 hash_qnum -= num_channels;
1270
1271         for_each_cpu(tgt_cpu, &alloced_mask) {
1272                 if (slot == hash_qnum)
1273                         break;
1274                 slot++;
1275         }
1276
1277         stor_device->stor_chns[q_num] = stor_device->stor_chns[tgt_cpu];
1278
1279         return stor_device->stor_chns[q_num];
1280 }
1281
1282
1283 static int storvsc_do_io(struct hv_device *device,
1284                          struct storvsc_cmd_request *request, u16 q_num)
1285 {
1286         struct storvsc_device *stor_device;
1287         struct vstor_packet *vstor_packet;
1288         struct vmbus_channel *outgoing_channel;
1289         int ret = 0;
1290         struct cpumask alloced_mask;
1291         int tgt_cpu;
1292
1293         vstor_packet = &request->vstor_packet;
1294         stor_device = get_out_stor_device(device);
1295
1296         if (!stor_device)
1297                 return -ENODEV;
1298
1299
1300         request->device  = device;
1301         /*
1302          * Select an an appropriate channel to send the request out.
1303          */
1304
1305         if (stor_device->stor_chns[q_num] != NULL) {
1306                 outgoing_channel = stor_device->stor_chns[q_num];
1307                 if (outgoing_channel->target_cpu == smp_processor_id()) {
1308                         /*
1309                          * Ideally, we want to pick a different channel if
1310                          * available on the same NUMA node.
1311                          */
1312                         cpumask_and(&alloced_mask, &stor_device->alloced_cpus,
1313                                     cpumask_of_node(cpu_to_node(q_num)));
1314                         for_each_cpu(tgt_cpu, &alloced_mask) {
1315                                 if (tgt_cpu != outgoing_channel->target_cpu) {
1316                                         outgoing_channel =
1317                                         stor_device->stor_chns[tgt_cpu];
1318                                         break;
1319                                 }
1320                         }
1321                 }
1322         } else {
1323                 outgoing_channel = get_og_chn(stor_device, q_num);
1324         }
1325
1326
1327         vstor_packet->flags |= REQUEST_COMPLETION_FLAG;
1328
1329         vstor_packet->vm_srb.length = (sizeof(struct vmscsi_request) -
1330                                         vmscsi_size_delta);
1331
1332
1333         vstor_packet->vm_srb.sense_info_length = sense_buffer_size;
1334
1335
1336         vstor_packet->vm_srb.data_transfer_length =
1337         request->payload->range.len;
1338
1339         vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
1340
1341         if (request->payload->range.len) {
1342
1343                 ret = vmbus_sendpacket_mpb_desc(outgoing_channel,
1344                                 request->payload, request->payload_sz,
1345                                 vstor_packet,
1346                                 (sizeof(struct vstor_packet) -
1347                                 vmscsi_size_delta),
1348                                 (unsigned long)request);
1349         } else {
1350                 ret = vmbus_sendpacket(outgoing_channel, vstor_packet,
1351                                (sizeof(struct vstor_packet) -
1352                                 vmscsi_size_delta),
1353                                (unsigned long)request,
1354                                VM_PKT_DATA_INBAND,
1355                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1356         }
1357
1358         if (ret != 0)
1359                 return ret;
1360
1361         atomic_inc(&stor_device->num_outstanding_req);
1362
1363         return ret;
1364 }
1365
1366 static int storvsc_device_alloc(struct scsi_device *sdevice)
1367 {
1368         /*
1369          * Set blist flag to permit the reading of the VPD pages even when
1370          * the target may claim SPC-2 compliance. MSFT targets currently
1371          * claim SPC-2 compliance while they implement post SPC-2 features.
1372          * With this flag we can correctly handle WRITE_SAME_16 issues.
1373          *
1374          * Hypervisor reports SCSI_UNKNOWN type for DVD ROM device but
1375          * still supports REPORT LUN.
1376          */
1377         sdevice->sdev_bflags = BLIST_REPORTLUN2 | BLIST_TRY_VPD_PAGES;
1378
1379         return 0;
1380 }
1381
1382 static int storvsc_device_configure(struct scsi_device *sdevice)
1383 {
1384
1385         blk_queue_bounce_limit(sdevice->request_queue, BLK_BOUNCE_ANY);
1386
1387         blk_queue_rq_timeout(sdevice->request_queue, (storvsc_timeout * HZ));
1388
1389         /* Ensure there are no gaps in presented sgls */
1390         blk_queue_virt_boundary(sdevice->request_queue, PAGE_SIZE - 1);
1391
1392         sdevice->no_write_same = 1;
1393
1394         /*
1395          * If the host is WIN8 or WIN8 R2, claim conformance to SPC-3
1396          * if the device is a MSFT virtual device.  If the host is
1397          * WIN10 or newer, allow write_same.
1398          */
1399         if (!strncmp(sdevice->vendor, "Msft", 4)) {
1400                 switch (vmstor_proto_version) {
1401                 case VMSTOR_PROTO_VERSION_WIN8:
1402                 case VMSTOR_PROTO_VERSION_WIN8_1:
1403                         sdevice->scsi_level = SCSI_SPC_3;
1404                         break;
1405                 }
1406
1407                 if (vmstor_proto_version >= VMSTOR_PROTO_VERSION_WIN10)
1408                         sdevice->no_write_same = 0;
1409         }
1410
1411         return 0;
1412 }
1413
1414 static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
1415                            sector_t capacity, int *info)
1416 {
1417         sector_t nsect = capacity;
1418         sector_t cylinders = nsect;
1419         int heads, sectors_pt;
1420
1421         /*
1422          * We are making up these values; let us keep it simple.
1423          */
1424         heads = 0xff;
1425         sectors_pt = 0x3f;      /* Sectors per track */
1426         sector_div(cylinders, heads * sectors_pt);
1427         if ((sector_t)(cylinders + 1) * heads * sectors_pt < nsect)
1428                 cylinders = 0xffff;
1429
1430         info[0] = heads;
1431         info[1] = sectors_pt;
1432         info[2] = (int)cylinders;
1433
1434         return 0;
1435 }
1436
1437 static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
1438 {
1439         struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
1440         struct hv_device *device = host_dev->dev;
1441
1442         struct storvsc_device *stor_device;
1443         struct storvsc_cmd_request *request;
1444         struct vstor_packet *vstor_packet;
1445         int ret, t;
1446
1447
1448         stor_device = get_out_stor_device(device);
1449         if (!stor_device)
1450                 return FAILED;
1451
1452         request = &stor_device->reset_request;
1453         vstor_packet = &request->vstor_packet;
1454
1455         init_completion(&request->wait_event);
1456
1457         vstor_packet->operation = VSTOR_OPERATION_RESET_BUS;
1458         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
1459         vstor_packet->vm_srb.path_id = stor_device->path_id;
1460
1461         ret = vmbus_sendpacket(device->channel, vstor_packet,
1462                                (sizeof(struct vstor_packet) -
1463                                 vmscsi_size_delta),
1464                                (unsigned long)&stor_device->reset_request,
1465                                VM_PKT_DATA_INBAND,
1466                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1467         if (ret != 0)
1468                 return FAILED;
1469
1470         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
1471         if (t == 0)
1472                 return TIMEOUT_ERROR;
1473
1474
1475         /*
1476          * At this point, all outstanding requests in the adapter
1477          * should have been flushed out and return to us
1478          * There is a potential race here where the host may be in
1479          * the process of responding when we return from here.
1480          * Just wait for all in-transit packets to be accounted for
1481          * before we return from here.
1482          */
1483         storvsc_wait_to_drain(stor_device);
1484
1485         return SUCCESS;
1486 }
1487
1488 /*
1489  * The host guarantees to respond to each command, although I/O latencies might
1490  * be unbounded on Azure.  Reset the timer unconditionally to give the host a
1491  * chance to perform EH.
1492  */
1493 static enum blk_eh_timer_return storvsc_eh_timed_out(struct scsi_cmnd *scmnd)
1494 {
1495 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1496         if (scmnd->device->host->transportt == fc_transport_template)
1497                 return fc_eh_timed_out(scmnd);
1498 #endif
1499         return BLK_EH_RESET_TIMER;
1500 }
1501
1502 static bool storvsc_scsi_cmd_ok(struct scsi_cmnd *scmnd)
1503 {
1504         bool allowed = true;
1505         u8 scsi_op = scmnd->cmnd[0];
1506
1507         switch (scsi_op) {
1508         /* the host does not handle WRITE_SAME, log accident usage */
1509         case WRITE_SAME:
1510         /*
1511          * smartd sends this command and the host does not handle
1512          * this. So, don't send it.
1513          */
1514         case SET_WINDOW:
1515                 scmnd->result = ILLEGAL_REQUEST << 16;
1516                 allowed = false;
1517                 break;
1518         default:
1519                 break;
1520         }
1521         return allowed;
1522 }
1523
1524 static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
1525 {
1526         int ret;
1527         struct hv_host_device *host_dev = shost_priv(host);
1528         struct hv_device *dev = host_dev->dev;
1529         struct storvsc_cmd_request *cmd_request = scsi_cmd_priv(scmnd);
1530         int i;
1531         struct scatterlist *sgl;
1532         unsigned int sg_count = 0;
1533         struct vmscsi_request *vm_srb;
1534         struct scatterlist *cur_sgl;
1535         struct vmbus_packet_mpb_array  *payload;
1536         u32 payload_sz;
1537         u32 length;
1538
1539         if (vmstor_proto_version <= VMSTOR_PROTO_VERSION_WIN8) {
1540                 /*
1541                  * On legacy hosts filter unimplemented commands.
1542                  * Future hosts are expected to correctly handle
1543                  * unsupported commands. Furthermore, it is
1544                  * possible that some of the currently
1545                  * unsupported commands maybe supported in
1546                  * future versions of the host.
1547                  */
1548                 if (!storvsc_scsi_cmd_ok(scmnd)) {
1549                         scmnd->scsi_done(scmnd);
1550                         return 0;
1551                 }
1552         }
1553
1554         /* Setup the cmd request */
1555         cmd_request->cmd = scmnd;
1556
1557         vm_srb = &cmd_request->vstor_packet.vm_srb;
1558         vm_srb->win8_extension.time_out_value = 60;
1559
1560         vm_srb->win8_extension.srb_flags |=
1561                 SRB_FLAGS_DISABLE_SYNCH_TRANSFER;
1562
1563         if (scmnd->device->tagged_supported) {
1564                 vm_srb->win8_extension.srb_flags |=
1565                 (SRB_FLAGS_QUEUE_ACTION_ENABLE | SRB_FLAGS_NO_QUEUE_FREEZE);
1566                 vm_srb->win8_extension.queue_tag = SP_UNTAGGED;
1567                 vm_srb->win8_extension.queue_action = SRB_SIMPLE_TAG_REQUEST;
1568         }
1569
1570         /* Build the SRB */
1571         switch (scmnd->sc_data_direction) {
1572         case DMA_TO_DEVICE:
1573                 vm_srb->data_in = WRITE_TYPE;
1574                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_OUT;
1575                 break;
1576         case DMA_FROM_DEVICE:
1577                 vm_srb->data_in = READ_TYPE;
1578                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_IN;
1579                 break;
1580         case DMA_NONE:
1581                 vm_srb->data_in = UNKNOWN_TYPE;
1582                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_NO_DATA_TRANSFER;
1583                 break;
1584         default:
1585                 /*
1586                  * This is DMA_BIDIRECTIONAL or something else we are never
1587                  * supposed to see here.
1588                  */
1589                 WARN(1, "Unexpected data direction: %d\n",
1590                      scmnd->sc_data_direction);
1591                 return -EINVAL;
1592         }
1593
1594
1595         vm_srb->port_number = host_dev->port;
1596         vm_srb->path_id = scmnd->device->channel;
1597         vm_srb->target_id = scmnd->device->id;
1598         vm_srb->lun = scmnd->device->lun;
1599
1600         vm_srb->cdb_length = scmnd->cmd_len;
1601
1602         memcpy(vm_srb->cdb, scmnd->cmnd, vm_srb->cdb_length);
1603
1604         sgl = (struct scatterlist *)scsi_sglist(scmnd);
1605         sg_count = scsi_sg_count(scmnd);
1606
1607         length = scsi_bufflen(scmnd);
1608         payload = (struct vmbus_packet_mpb_array *)&cmd_request->mpb;
1609         payload_sz = sizeof(cmd_request->mpb);
1610
1611         if (sg_count) {
1612                 if (sg_count > MAX_PAGE_BUFFER_COUNT) {
1613
1614                         payload_sz = (sg_count * sizeof(u64) +
1615                                       sizeof(struct vmbus_packet_mpb_array));
1616                         payload = kzalloc(payload_sz, GFP_ATOMIC);
1617                         if (!payload)
1618                                 return SCSI_MLQUEUE_DEVICE_BUSY;
1619                 }
1620
1621                 payload->range.len = length;
1622                 payload->range.offset = sgl[0].offset;
1623
1624                 cur_sgl = sgl;
1625                 for (i = 0; i < sg_count; i++) {
1626                         payload->range.pfn_array[i] =
1627                                 page_to_pfn(sg_page((cur_sgl)));
1628                         cur_sgl = sg_next(cur_sgl);
1629                 }
1630         }
1631
1632         cmd_request->payload = payload;
1633         cmd_request->payload_sz = payload_sz;
1634
1635         /* Invokes the vsc to start an IO */
1636         ret = storvsc_do_io(dev, cmd_request, get_cpu());
1637         put_cpu();
1638
1639         if (ret == -EAGAIN) {
1640                 if (payload_sz > sizeof(cmd_request->mpb))
1641                         kfree(payload);
1642                 /* no more space */
1643                 return SCSI_MLQUEUE_DEVICE_BUSY;
1644         }
1645
1646         return 0;
1647 }
1648
1649 static struct scsi_host_template scsi_driver = {
1650         .module =               THIS_MODULE,
1651         .name =                 "storvsc_host_t",
1652         .cmd_size =             sizeof(struct storvsc_cmd_request),
1653         .bios_param =           storvsc_get_chs,
1654         .queuecommand =         storvsc_queuecommand,
1655         .eh_host_reset_handler =        storvsc_host_reset_handler,
1656         .proc_name =            "storvsc_host",
1657         .eh_timed_out =         storvsc_eh_timed_out,
1658         .slave_alloc =          storvsc_device_alloc,
1659         .slave_configure =      storvsc_device_configure,
1660         .cmd_per_lun =          2048,
1661         .this_id =              -1,
1662         .use_clustering =       ENABLE_CLUSTERING,
1663         /* Make sure we dont get a sg segment crosses a page boundary */
1664         .dma_boundary =         PAGE_SIZE-1,
1665         .no_write_same =        1,
1666         .track_queue_depth =    1,
1667 };
1668
1669 enum {
1670         SCSI_GUID,
1671         IDE_GUID,
1672         SFC_GUID,
1673 };
1674
1675 static const struct hv_vmbus_device_id id_table[] = {
1676         /* SCSI guid */
1677         { HV_SCSI_GUID,
1678           .driver_data = SCSI_GUID
1679         },
1680         /* IDE guid */
1681         { HV_IDE_GUID,
1682           .driver_data = IDE_GUID
1683         },
1684         /* Fibre Channel GUID */
1685         {
1686           HV_SYNTHFC_GUID,
1687           .driver_data = SFC_GUID
1688         },
1689         { },
1690 };
1691
1692 MODULE_DEVICE_TABLE(vmbus, id_table);
1693
1694 static int storvsc_probe(struct hv_device *device,
1695                         const struct hv_vmbus_device_id *dev_id)
1696 {
1697         int ret;
1698         int num_cpus = num_online_cpus();
1699         struct Scsi_Host *host;
1700         struct hv_host_device *host_dev;
1701         bool dev_is_ide = ((dev_id->driver_data == IDE_GUID) ? true : false);
1702         bool is_fc = ((dev_id->driver_data == SFC_GUID) ? true : false);
1703         int target = 0;
1704         struct storvsc_device *stor_device;
1705         int max_luns_per_target;
1706         int max_targets;
1707         int max_channels;
1708         int max_sub_channels = 0;
1709
1710         /*
1711          * Based on the windows host we are running on,
1712          * set state to properly communicate with the host.
1713          */
1714
1715         if (vmbus_proto_version < VERSION_WIN8) {
1716                 max_luns_per_target = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1717                 max_targets = STORVSC_IDE_MAX_TARGETS;
1718                 max_channels = STORVSC_IDE_MAX_CHANNELS;
1719         } else {
1720                 max_luns_per_target = STORVSC_MAX_LUNS_PER_TARGET;
1721                 max_targets = STORVSC_MAX_TARGETS;
1722                 max_channels = STORVSC_MAX_CHANNELS;
1723                 /*
1724                  * On Windows8 and above, we support sub-channels for storage.
1725                  * The number of sub-channels offerred is based on the number of
1726                  * VCPUs in the guest.
1727                  */
1728                 max_sub_channels = (num_cpus / storvsc_vcpus_per_sub_channel);
1729         }
1730
1731         scsi_driver.can_queue = (max_outstanding_req_per_channel *
1732                                  (max_sub_channels + 1));
1733
1734         host = scsi_host_alloc(&scsi_driver,
1735                                sizeof(struct hv_host_device));
1736         if (!host)
1737                 return -ENOMEM;
1738
1739         host_dev = shost_priv(host);
1740         memset(host_dev, 0, sizeof(struct hv_host_device));
1741
1742         host_dev->port = host->host_no;
1743         host_dev->dev = device;
1744         host_dev->host = host;
1745
1746
1747         stor_device = kzalloc(sizeof(struct storvsc_device), GFP_KERNEL);
1748         if (!stor_device) {
1749                 ret = -ENOMEM;
1750                 goto err_out0;
1751         }
1752
1753         stor_device->destroy = false;
1754         stor_device->open_sub_channel = false;
1755         init_waitqueue_head(&stor_device->waiting_to_drain);
1756         stor_device->device = device;
1757         stor_device->host = host;
1758         hv_set_drvdata(device, stor_device);
1759
1760         stor_device->port_number = host->host_no;
1761         ret = storvsc_connect_to_vsp(device, storvsc_ringbuffer_size, is_fc);
1762         if (ret)
1763                 goto err_out1;
1764
1765         host_dev->path = stor_device->path_id;
1766         host_dev->target = stor_device->target_id;
1767
1768         switch (dev_id->driver_data) {
1769         case SFC_GUID:
1770                 host->max_lun = STORVSC_FC_MAX_LUNS_PER_TARGET;
1771                 host->max_id = STORVSC_FC_MAX_TARGETS;
1772                 host->max_channel = STORVSC_FC_MAX_CHANNELS - 1;
1773 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1774                 host->transportt = fc_transport_template;
1775 #endif
1776                 break;
1777
1778         case SCSI_GUID:
1779                 host->max_lun = max_luns_per_target;
1780                 host->max_id = max_targets;
1781                 host->max_channel = max_channels - 1;
1782                 break;
1783
1784         default:
1785                 host->max_lun = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1786                 host->max_id = STORVSC_IDE_MAX_TARGETS;
1787                 host->max_channel = STORVSC_IDE_MAX_CHANNELS - 1;
1788                 break;
1789         }
1790         /* max cmd length */
1791         host->max_cmd_len = STORVSC_MAX_CMD_LEN;
1792
1793         /*
1794          * set the table size based on the info we got
1795          * from the host.
1796          */
1797         host->sg_tablesize = (stor_device->max_transfer_bytes >> PAGE_SHIFT);
1798         /*
1799          * Set the number of HW queues we are supporting.
1800          */
1801         if (stor_device->num_sc != 0)
1802                 host->nr_hw_queues = stor_device->num_sc + 1;
1803
1804         /*
1805          * Set the error handler work queue.
1806          */
1807         host_dev->handle_error_wq =
1808                         alloc_ordered_workqueue("storvsc_error_wq_%d",
1809                                                 WQ_MEM_RECLAIM,
1810                                                 host->host_no);
1811         if (!host_dev->handle_error_wq)
1812                 goto err_out2;
1813         INIT_WORK(&host_dev->host_scan_work, storvsc_host_scan);
1814         /* Register the HBA and start the scsi bus scan */
1815         ret = scsi_add_host(host, &device->device);
1816         if (ret != 0)
1817                 goto err_out3;
1818
1819         if (!dev_is_ide) {
1820                 scsi_scan_host(host);
1821         } else {
1822                 target = (device->dev_instance.b[5] << 8 |
1823                          device->dev_instance.b[4]);
1824                 ret = scsi_add_device(host, 0, target, 0);
1825                 if (ret)
1826                         goto err_out4;
1827         }
1828 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1829         if (host->transportt == fc_transport_template) {
1830                 struct fc_rport_identifiers ids = {
1831                         .roles = FC_PORT_ROLE_FCP_DUMMY_INITIATOR,
1832                 };
1833
1834                 fc_host_node_name(host) = stor_device->node_name;
1835                 fc_host_port_name(host) = stor_device->port_name;
1836                 stor_device->rport = fc_remote_port_add(host, 0, &ids);
1837                 if (!stor_device->rport) {
1838                         ret = -ENOMEM;
1839                         goto err_out4;
1840                 }
1841         }
1842 #endif
1843         return 0;
1844
1845 err_out4:
1846         scsi_remove_host(host);
1847
1848 err_out3:
1849         destroy_workqueue(host_dev->handle_error_wq);
1850
1851 err_out2:
1852         /*
1853          * Once we have connected with the host, we would need to
1854          * to invoke storvsc_dev_remove() to rollback this state and
1855          * this call also frees up the stor_device; hence the jump around
1856          * err_out1 label.
1857          */
1858         storvsc_dev_remove(device);
1859         goto err_out0;
1860
1861 err_out1:
1862         kfree(stor_device->stor_chns);
1863         kfree(stor_device);
1864
1865 err_out0:
1866         scsi_host_put(host);
1867         return ret;
1868 }
1869
1870 static int storvsc_remove(struct hv_device *dev)
1871 {
1872         struct storvsc_device *stor_device = hv_get_drvdata(dev);
1873         struct Scsi_Host *host = stor_device->host;
1874         struct hv_host_device *host_dev = shost_priv(host);
1875
1876 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1877         if (host->transportt == fc_transport_template) {
1878                 fc_remote_port_delete(stor_device->rport);
1879                 fc_remove_host(host);
1880         }
1881 #endif
1882         destroy_workqueue(host_dev->handle_error_wq);
1883         scsi_remove_host(host);
1884         storvsc_dev_remove(dev);
1885         scsi_host_put(host);
1886
1887         return 0;
1888 }
1889
1890 static struct hv_driver storvsc_drv = {
1891         .name = KBUILD_MODNAME,
1892         .id_table = id_table,
1893         .probe = storvsc_probe,
1894         .remove = storvsc_remove,
1895 };
1896
1897 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1898 static struct fc_function_template fc_transport_functions = {
1899         .show_host_node_name = 1,
1900         .show_host_port_name = 1,
1901 };
1902 #endif
1903
1904 static int __init storvsc_drv_init(void)
1905 {
1906         int ret;
1907
1908         /*
1909          * Divide the ring buffer data size (which is 1 page less
1910          * than the ring buffer size since that page is reserved for
1911          * the ring buffer indices) by the max request size (which is
1912          * vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
1913          */
1914         max_outstanding_req_per_channel =
1915                 ((storvsc_ringbuffer_size - PAGE_SIZE) /
1916                 ALIGN(MAX_MULTIPAGE_BUFFER_PACKET +
1917                 sizeof(struct vstor_packet) + sizeof(u64) -
1918                 vmscsi_size_delta,
1919                 sizeof(u64)));
1920
1921 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1922         fc_transport_template = fc_attach_transport(&fc_transport_functions);
1923         if (!fc_transport_template)
1924                 return -ENODEV;
1925 #endif
1926
1927         ret = vmbus_driver_register(&storvsc_drv);
1928
1929 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1930         if (ret)
1931                 fc_release_transport(fc_transport_template);
1932 #endif
1933
1934         return ret;
1935 }
1936
1937 static void __exit storvsc_drv_exit(void)
1938 {
1939         vmbus_driver_unregister(&storvsc_drv);
1940 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1941         fc_release_transport(fc_transport_template);
1942 #endif
1943 }
1944
1945 MODULE_LICENSE("GPL");
1946 MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
1947 module_init(storvsc_drv_init);
1948 module_exit(storvsc_drv_exit);