Merge branches 'acpi-scan', 'acpi-resource', 'acpi-apei', 'acpi-extlog' and 'acpi...
[sfrench/cifs-2.6.git] / drivers / scsi / storvsc_drv.c
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2009, Microsoft Corporation.
4  *
5  * Authors:
6  *   Haiyang Zhang <haiyangz@microsoft.com>
7  *   Hank Janssen  <hjanssen@microsoft.com>
8  *   K. Y. Srinivasan <kys@microsoft.com>
9  */
10
11 #include <linux/kernel.h>
12 #include <linux/wait.h>
13 #include <linux/sched.h>
14 #include <linux/completion.h>
15 #include <linux/string.h>
16 #include <linux/mm.h>
17 #include <linux/delay.h>
18 #include <linux/init.h>
19 #include <linux/slab.h>
20 #include <linux/module.h>
21 #include <linux/device.h>
22 #include <linux/hyperv.h>
23 #include <linux/blkdev.h>
24 #include <linux/dma-mapping.h>
25
26 #include <scsi/scsi.h>
27 #include <scsi/scsi_cmnd.h>
28 #include <scsi/scsi_host.h>
29 #include <scsi/scsi_device.h>
30 #include <scsi/scsi_tcq.h>
31 #include <scsi/scsi_eh.h>
32 #include <scsi/scsi_devinfo.h>
33 #include <scsi/scsi_dbg.h>
34 #include <scsi/scsi_transport_fc.h>
35 #include <scsi/scsi_transport.h>
36
37 /*
38  * All wire protocol details (storage protocol between the guest and the host)
39  * are consolidated here.
40  *
41  * Begin protocol definitions.
42  */
43
44 /*
45  * Version history:
46  * V1 Beta: 0.1
47  * V1 RC < 2008/1/31: 1.0
48  * V1 RC > 2008/1/31:  2.0
49  * Win7: 4.2
50  * Win8: 5.1
51  * Win8.1: 6.0
52  * Win10: 6.2
53  */
54
55 #define VMSTOR_PROTO_VERSION(MAJOR_, MINOR_)    ((((MAJOR_) & 0xff) << 8) | \
56                                                 (((MINOR_) & 0xff)))
57 #define VMSTOR_PROTO_VERSION_WIN6       VMSTOR_PROTO_VERSION(2, 0)
58 #define VMSTOR_PROTO_VERSION_WIN7       VMSTOR_PROTO_VERSION(4, 2)
59 #define VMSTOR_PROTO_VERSION_WIN8       VMSTOR_PROTO_VERSION(5, 1)
60 #define VMSTOR_PROTO_VERSION_WIN8_1     VMSTOR_PROTO_VERSION(6, 0)
61 #define VMSTOR_PROTO_VERSION_WIN10      VMSTOR_PROTO_VERSION(6, 2)
62
63 /* channel callback timeout in ms */
64 #define CALLBACK_TIMEOUT               2
65
66 /*  Packet structure describing virtual storage requests. */
67 enum vstor_packet_operation {
68         VSTOR_OPERATION_COMPLETE_IO             = 1,
69         VSTOR_OPERATION_REMOVE_DEVICE           = 2,
70         VSTOR_OPERATION_EXECUTE_SRB             = 3,
71         VSTOR_OPERATION_RESET_LUN               = 4,
72         VSTOR_OPERATION_RESET_ADAPTER           = 5,
73         VSTOR_OPERATION_RESET_BUS               = 6,
74         VSTOR_OPERATION_BEGIN_INITIALIZATION    = 7,
75         VSTOR_OPERATION_END_INITIALIZATION      = 8,
76         VSTOR_OPERATION_QUERY_PROTOCOL_VERSION  = 9,
77         VSTOR_OPERATION_QUERY_PROPERTIES        = 10,
78         VSTOR_OPERATION_ENUMERATE_BUS           = 11,
79         VSTOR_OPERATION_FCHBA_DATA              = 12,
80         VSTOR_OPERATION_CREATE_SUB_CHANNELS     = 13,
81         VSTOR_OPERATION_MAXIMUM                 = 13
82 };
83
84 /*
85  * WWN packet for Fibre Channel HBA
86  */
87
88 struct hv_fc_wwn_packet {
89         u8      primary_active;
90         u8      reserved1[3];
91         u8      primary_port_wwn[8];
92         u8      primary_node_wwn[8];
93         u8      secondary_port_wwn[8];
94         u8      secondary_node_wwn[8];
95 };
96
97
98
99 /*
100  * SRB Flag Bits
101  */
102
103 #define SRB_FLAGS_QUEUE_ACTION_ENABLE           0x00000002
104 #define SRB_FLAGS_DISABLE_DISCONNECT            0x00000004
105 #define SRB_FLAGS_DISABLE_SYNCH_TRANSFER        0x00000008
106 #define SRB_FLAGS_BYPASS_FROZEN_QUEUE           0x00000010
107 #define SRB_FLAGS_DISABLE_AUTOSENSE             0x00000020
108 #define SRB_FLAGS_DATA_IN                       0x00000040
109 #define SRB_FLAGS_DATA_OUT                      0x00000080
110 #define SRB_FLAGS_NO_DATA_TRANSFER              0x00000000
111 #define SRB_FLAGS_UNSPECIFIED_DIRECTION (SRB_FLAGS_DATA_IN | SRB_FLAGS_DATA_OUT)
112 #define SRB_FLAGS_NO_QUEUE_FREEZE               0x00000100
113 #define SRB_FLAGS_ADAPTER_CACHE_ENABLE          0x00000200
114 #define SRB_FLAGS_FREE_SENSE_BUFFER             0x00000400
115
116 /*
117  * This flag indicates the request is part of the workflow for processing a D3.
118  */
119 #define SRB_FLAGS_D3_PROCESSING                 0x00000800
120 #define SRB_FLAGS_IS_ACTIVE                     0x00010000
121 #define SRB_FLAGS_ALLOCATED_FROM_ZONE           0x00020000
122 #define SRB_FLAGS_SGLIST_FROM_POOL              0x00040000
123 #define SRB_FLAGS_BYPASS_LOCKED_QUEUE           0x00080000
124 #define SRB_FLAGS_NO_KEEP_AWAKE                 0x00100000
125 #define SRB_FLAGS_PORT_DRIVER_ALLOCSENSE        0x00200000
126 #define SRB_FLAGS_PORT_DRIVER_SENSEHASPORT      0x00400000
127 #define SRB_FLAGS_DONT_START_NEXT_PACKET        0x00800000
128 #define SRB_FLAGS_PORT_DRIVER_RESERVED          0x0F000000
129 #define SRB_FLAGS_CLASS_DRIVER_RESERVED         0xF0000000
130
131 #define SP_UNTAGGED                     ((unsigned char) ~0)
132 #define SRB_SIMPLE_TAG_REQUEST          0x20
133
134 /*
135  * Platform neutral description of a scsi request -
136  * this remains the same across the write regardless of 32/64 bit
137  * note: it's patterned off the SCSI_PASS_THROUGH structure
138  */
139 #define STORVSC_MAX_CMD_LEN                     0x10
140
141 /* Sense buffer size is the same for all versions since Windows 8 */
142 #define STORVSC_SENSE_BUFFER_SIZE               0x14
143 #define STORVSC_MAX_BUF_LEN_WITH_PADDING        0x14
144
145 /*
146  * The storage protocol version is determined during the
147  * initial exchange with the host.  It will indicate which
148  * storage functionality is available in the host.
149 */
150 static int vmstor_proto_version;
151
152 #define STORVSC_LOGGING_NONE    0
153 #define STORVSC_LOGGING_ERROR   1
154 #define STORVSC_LOGGING_WARN    2
155
156 static int logging_level = STORVSC_LOGGING_ERROR;
157 module_param(logging_level, int, S_IRUGO|S_IWUSR);
158 MODULE_PARM_DESC(logging_level,
159         "Logging level, 0 - None, 1 - Error (default), 2 - Warning.");
160
161 static inline bool do_logging(int level)
162 {
163         return logging_level >= level;
164 }
165
166 #define storvsc_log(dev, level, fmt, ...)                       \
167 do {                                                            \
168         if (do_logging(level))                                  \
169                 dev_warn(&(dev)->device, fmt, ##__VA_ARGS__);   \
170 } while (0)
171
172 struct vmscsi_request {
173         u16 length;
174         u8 srb_status;
175         u8 scsi_status;
176
177         u8  port_number;
178         u8  path_id;
179         u8  target_id;
180         u8  lun;
181
182         u8  cdb_length;
183         u8  sense_info_length;
184         u8  data_in;
185         u8  reserved;
186
187         u32 data_transfer_length;
188
189         union {
190                 u8 cdb[STORVSC_MAX_CMD_LEN];
191                 u8 sense_data[STORVSC_SENSE_BUFFER_SIZE];
192                 u8 reserved_array[STORVSC_MAX_BUF_LEN_WITH_PADDING];
193         };
194         /*
195          * The following was added in win8.
196          */
197         u16 reserve;
198         u8  queue_tag;
199         u8  queue_action;
200         u32 srb_flags;
201         u32 time_out_value;
202         u32 queue_sort_ey;
203
204 } __attribute((packed));
205
206 /*
207  * The list of windows version in order of preference.
208  */
209
210 static const int protocol_version[] = {
211                 VMSTOR_PROTO_VERSION_WIN10,
212                 VMSTOR_PROTO_VERSION_WIN8_1,
213                 VMSTOR_PROTO_VERSION_WIN8,
214 };
215
216
217 /*
218  * This structure is sent during the initialization phase to get the different
219  * properties of the channel.
220  */
221
222 #define STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL          0x1
223
224 struct vmstorage_channel_properties {
225         u32 reserved;
226         u16 max_channel_cnt;
227         u16 reserved1;
228
229         u32 flags;
230         u32   max_transfer_bytes;
231
232         u64  reserved2;
233 } __packed;
234
235 /*  This structure is sent during the storage protocol negotiations. */
236 struct vmstorage_protocol_version {
237         /* Major (MSW) and minor (LSW) version numbers. */
238         u16 major_minor;
239
240         /*
241          * Revision number is auto-incremented whenever this file is changed
242          * (See FILL_VMSTOR_REVISION macro above).  Mismatch does not
243          * definitely indicate incompatibility--but it does indicate mismatched
244          * builds.
245          * This is only used on the windows side. Just set it to 0.
246          */
247         u16 revision;
248 } __packed;
249
250 /* Channel Property Flags */
251 #define STORAGE_CHANNEL_REMOVABLE_FLAG          0x1
252 #define STORAGE_CHANNEL_EMULATED_IDE_FLAG       0x2
253
254 struct vstor_packet {
255         /* Requested operation type */
256         enum vstor_packet_operation operation;
257
258         /*  Flags - see below for values */
259         u32 flags;
260
261         /* Status of the request returned from the server side. */
262         u32 status;
263
264         /* Data payload area */
265         union {
266                 /*
267                  * Structure used to forward SCSI commands from the
268                  * client to the server.
269                  */
270                 struct vmscsi_request vm_srb;
271
272                 /* Structure used to query channel properties. */
273                 struct vmstorage_channel_properties storage_channel_properties;
274
275                 /* Used during version negotiations. */
276                 struct vmstorage_protocol_version version;
277
278                 /* Fibre channel address packet */
279                 struct hv_fc_wwn_packet wwn_packet;
280
281                 /* Number of sub-channels to create */
282                 u16 sub_channel_count;
283
284                 /* This will be the maximum of the union members */
285                 u8  buffer[0x34];
286         };
287 } __packed;
288
289 /*
290  * Packet Flags:
291  *
292  * This flag indicates that the server should send back a completion for this
293  * packet.
294  */
295
296 #define REQUEST_COMPLETION_FLAG 0x1
297
298 /* Matches Windows-end */
299 enum storvsc_request_type {
300         WRITE_TYPE = 0,
301         READ_TYPE,
302         UNKNOWN_TYPE,
303 };
304
305 /*
306  * SRB status codes and masks; a subset of the codes used here.
307  */
308
309 #define SRB_STATUS_AUTOSENSE_VALID      0x80
310 #define SRB_STATUS_QUEUE_FROZEN         0x40
311 #define SRB_STATUS_INVALID_LUN  0x20
312 #define SRB_STATUS_SUCCESS      0x01
313 #define SRB_STATUS_ABORTED      0x02
314 #define SRB_STATUS_ERROR        0x04
315 #define SRB_STATUS_DATA_OVERRUN 0x12
316
317 #define SRB_STATUS(status) \
318         (status & ~(SRB_STATUS_AUTOSENSE_VALID | SRB_STATUS_QUEUE_FROZEN))
319 /*
320  * This is the end of Protocol specific defines.
321  */
322
323 static int storvsc_ringbuffer_size = (128 * 1024);
324 static u32 max_outstanding_req_per_channel;
325 static int storvsc_change_queue_depth(struct scsi_device *sdev, int queue_depth);
326
327 static int storvsc_vcpus_per_sub_channel = 4;
328 static unsigned int storvsc_max_hw_queues;
329
330 module_param(storvsc_ringbuffer_size, int, S_IRUGO);
331 MODULE_PARM_DESC(storvsc_ringbuffer_size, "Ring buffer size (bytes)");
332
333 module_param(storvsc_max_hw_queues, uint, 0644);
334 MODULE_PARM_DESC(storvsc_max_hw_queues, "Maximum number of hardware queues");
335
336 module_param(storvsc_vcpus_per_sub_channel, int, S_IRUGO);
337 MODULE_PARM_DESC(storvsc_vcpus_per_sub_channel, "Ratio of VCPUs to subchannels");
338
339 static int ring_avail_percent_lowater = 10;
340 module_param(ring_avail_percent_lowater, int, S_IRUGO);
341 MODULE_PARM_DESC(ring_avail_percent_lowater,
342                 "Select a channel if available ring size > this in percent");
343
344 /*
345  * Timeout in seconds for all devices managed by this driver.
346  */
347 static int storvsc_timeout = 180;
348
349 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
350 static struct scsi_transport_template *fc_transport_template;
351 #endif
352
353 static struct scsi_host_template scsi_driver;
354 static void storvsc_on_channel_callback(void *context);
355
356 #define STORVSC_MAX_LUNS_PER_TARGET                     255
357 #define STORVSC_MAX_TARGETS                             2
358 #define STORVSC_MAX_CHANNELS                            8
359
360 #define STORVSC_FC_MAX_LUNS_PER_TARGET                  255
361 #define STORVSC_FC_MAX_TARGETS                          128
362 #define STORVSC_FC_MAX_CHANNELS                         8
363
364 #define STORVSC_IDE_MAX_LUNS_PER_TARGET                 64
365 #define STORVSC_IDE_MAX_TARGETS                         1
366 #define STORVSC_IDE_MAX_CHANNELS                        1
367
368 /*
369  * Upper bound on the size of a storvsc packet.
370  */
371 #define STORVSC_MAX_PKT_SIZE (sizeof(struct vmpacket_descriptor) +\
372                               sizeof(struct vstor_packet))
373
374 struct storvsc_cmd_request {
375         struct scsi_cmnd *cmd;
376
377         struct hv_device *device;
378
379         /* Synchronize the request/response if needed */
380         struct completion wait_event;
381
382         struct vmbus_channel_packet_multipage_buffer mpb;
383         struct vmbus_packet_mpb_array *payload;
384         u32 payload_sz;
385
386         struct vstor_packet vstor_packet;
387 };
388
389
390 /* A storvsc device is a device object that contains a vmbus channel */
391 struct storvsc_device {
392         struct hv_device *device;
393
394         bool     destroy;
395         bool     drain_notify;
396         atomic_t num_outstanding_req;
397         struct Scsi_Host *host;
398
399         wait_queue_head_t waiting_to_drain;
400
401         /*
402          * Each unique Port/Path/Target represents 1 channel ie scsi
403          * controller. In reality, the pathid, targetid is always 0
404          * and the port is set by us
405          */
406         unsigned int port_number;
407         unsigned char path_id;
408         unsigned char target_id;
409
410         /*
411          * Max I/O, the device can support.
412          */
413         u32   max_transfer_bytes;
414         /*
415          * Number of sub-channels we will open.
416          */
417         u16 num_sc;
418         struct vmbus_channel **stor_chns;
419         /*
420          * Mask of CPUs bound to subchannels.
421          */
422         struct cpumask alloced_cpus;
423         /*
424          * Serializes modifications of stor_chns[] from storvsc_do_io()
425          * and storvsc_change_target_cpu().
426          */
427         spinlock_t lock;
428         /* Used for vsc/vsp channel reset process */
429         struct storvsc_cmd_request init_request;
430         struct storvsc_cmd_request reset_request;
431         /*
432          * Currently active port and node names for FC devices.
433          */
434         u64 node_name;
435         u64 port_name;
436 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
437         struct fc_rport *rport;
438 #endif
439 };
440
441 struct hv_host_device {
442         struct hv_device *dev;
443         unsigned int port;
444         unsigned char path;
445         unsigned char target;
446         struct workqueue_struct *handle_error_wq;
447         struct work_struct host_scan_work;
448         struct Scsi_Host *host;
449 };
450
451 struct storvsc_scan_work {
452         struct work_struct work;
453         struct Scsi_Host *host;
454         u8 lun;
455         u8 tgt_id;
456 };
457
458 static void storvsc_device_scan(struct work_struct *work)
459 {
460         struct storvsc_scan_work *wrk;
461         struct scsi_device *sdev;
462
463         wrk = container_of(work, struct storvsc_scan_work, work);
464
465         sdev = scsi_device_lookup(wrk->host, 0, wrk->tgt_id, wrk->lun);
466         if (!sdev)
467                 goto done;
468         scsi_rescan_device(&sdev->sdev_gendev);
469         scsi_device_put(sdev);
470
471 done:
472         kfree(wrk);
473 }
474
475 static void storvsc_host_scan(struct work_struct *work)
476 {
477         struct Scsi_Host *host;
478         struct scsi_device *sdev;
479         struct hv_host_device *host_device =
480                 container_of(work, struct hv_host_device, host_scan_work);
481
482         host = host_device->host;
483         /*
484          * Before scanning the host, first check to see if any of the
485          * currently known devices have been hot removed. We issue a
486          * "unit ready" command against all currently known devices.
487          * This I/O will result in an error for devices that have been
488          * removed. As part of handling the I/O error, we remove the device.
489          *
490          * When a LUN is added or removed, the host sends us a signal to
491          * scan the host. Thus we are forced to discover the LUNs that
492          * may have been removed this way.
493          */
494         mutex_lock(&host->scan_mutex);
495         shost_for_each_device(sdev, host)
496                 scsi_test_unit_ready(sdev, 1, 1, NULL);
497         mutex_unlock(&host->scan_mutex);
498         /*
499          * Now scan the host to discover LUNs that may have been added.
500          */
501         scsi_scan_host(host);
502 }
503
504 static void storvsc_remove_lun(struct work_struct *work)
505 {
506         struct storvsc_scan_work *wrk;
507         struct scsi_device *sdev;
508
509         wrk = container_of(work, struct storvsc_scan_work, work);
510         if (!scsi_host_get(wrk->host))
511                 goto done;
512
513         sdev = scsi_device_lookup(wrk->host, 0, wrk->tgt_id, wrk->lun);
514
515         if (sdev) {
516                 scsi_remove_device(sdev);
517                 scsi_device_put(sdev);
518         }
519         scsi_host_put(wrk->host);
520
521 done:
522         kfree(wrk);
523 }
524
525
526 /*
527  * We can get incoming messages from the host that are not in response to
528  * messages that we have sent out. An example of this would be messages
529  * received by the guest to notify dynamic addition/removal of LUNs. To
530  * deal with potential race conditions where the driver may be in the
531  * midst of being unloaded when we might receive an unsolicited message
532  * from the host, we have implemented a mechanism to gurantee sequential
533  * consistency:
534  *
535  * 1) Once the device is marked as being destroyed, we will fail all
536  *    outgoing messages.
537  * 2) We permit incoming messages when the device is being destroyed,
538  *    only to properly account for messages already sent out.
539  */
540
541 static inline struct storvsc_device *get_out_stor_device(
542                                         struct hv_device *device)
543 {
544         struct storvsc_device *stor_device;
545
546         stor_device = hv_get_drvdata(device);
547
548         if (stor_device && stor_device->destroy)
549                 stor_device = NULL;
550
551         return stor_device;
552 }
553
554
555 static inline void storvsc_wait_to_drain(struct storvsc_device *dev)
556 {
557         dev->drain_notify = true;
558         wait_event(dev->waiting_to_drain,
559                    atomic_read(&dev->num_outstanding_req) == 0);
560         dev->drain_notify = false;
561 }
562
563 static inline struct storvsc_device *get_in_stor_device(
564                                         struct hv_device *device)
565 {
566         struct storvsc_device *stor_device;
567
568         stor_device = hv_get_drvdata(device);
569
570         if (!stor_device)
571                 goto get_in_err;
572
573         /*
574          * If the device is being destroyed; allow incoming
575          * traffic only to cleanup outstanding requests.
576          */
577
578         if (stor_device->destroy  &&
579                 (atomic_read(&stor_device->num_outstanding_req) == 0))
580                 stor_device = NULL;
581
582 get_in_err:
583         return stor_device;
584
585 }
586
587 static void storvsc_change_target_cpu(struct vmbus_channel *channel, u32 old,
588                                       u32 new)
589 {
590         struct storvsc_device *stor_device;
591         struct vmbus_channel *cur_chn;
592         bool old_is_alloced = false;
593         struct hv_device *device;
594         unsigned long flags;
595         int cpu;
596
597         device = channel->primary_channel ?
598                         channel->primary_channel->device_obj
599                                 : channel->device_obj;
600         stor_device = get_out_stor_device(device);
601         if (!stor_device)
602                 return;
603
604         /* See storvsc_do_io() -> get_og_chn(). */
605         spin_lock_irqsave(&stor_device->lock, flags);
606
607         /*
608          * Determines if the storvsc device has other channels assigned to
609          * the "old" CPU to update the alloced_cpus mask and the stor_chns
610          * array.
611          */
612         if (device->channel != channel && device->channel->target_cpu == old) {
613                 cur_chn = device->channel;
614                 old_is_alloced = true;
615                 goto old_is_alloced;
616         }
617         list_for_each_entry(cur_chn, &device->channel->sc_list, sc_list) {
618                 if (cur_chn == channel)
619                         continue;
620                 if (cur_chn->target_cpu == old) {
621                         old_is_alloced = true;
622                         goto old_is_alloced;
623                 }
624         }
625
626 old_is_alloced:
627         if (old_is_alloced)
628                 WRITE_ONCE(stor_device->stor_chns[old], cur_chn);
629         else
630                 cpumask_clear_cpu(old, &stor_device->alloced_cpus);
631
632         /* "Flush" the stor_chns array. */
633         for_each_possible_cpu(cpu) {
634                 if (stor_device->stor_chns[cpu] && !cpumask_test_cpu(
635                                         cpu, &stor_device->alloced_cpus))
636                         WRITE_ONCE(stor_device->stor_chns[cpu], NULL);
637         }
638
639         WRITE_ONCE(stor_device->stor_chns[new], channel);
640         cpumask_set_cpu(new, &stor_device->alloced_cpus);
641
642         spin_unlock_irqrestore(&stor_device->lock, flags);
643 }
644
645 static u64 storvsc_next_request_id(struct vmbus_channel *channel, u64 rqst_addr)
646 {
647         struct storvsc_cmd_request *request =
648                 (struct storvsc_cmd_request *)(unsigned long)rqst_addr;
649
650         if (rqst_addr == VMBUS_RQST_INIT)
651                 return VMBUS_RQST_INIT;
652         if (rqst_addr == VMBUS_RQST_RESET)
653                 return VMBUS_RQST_RESET;
654
655         /*
656          * Cannot return an ID of 0, which is reserved for an unsolicited
657          * message from Hyper-V.
658          */
659         return (u64)blk_mq_unique_tag(scsi_cmd_to_rq(request->cmd)) + 1;
660 }
661
662 static void handle_sc_creation(struct vmbus_channel *new_sc)
663 {
664         struct hv_device *device = new_sc->primary_channel->device_obj;
665         struct device *dev = &device->device;
666         struct storvsc_device *stor_device;
667         struct vmstorage_channel_properties props;
668         int ret;
669
670         stor_device = get_out_stor_device(device);
671         if (!stor_device)
672                 return;
673
674         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
675         new_sc->max_pkt_size = STORVSC_MAX_PKT_SIZE;
676
677         new_sc->next_request_id_callback = storvsc_next_request_id;
678
679         ret = vmbus_open(new_sc,
680                          storvsc_ringbuffer_size,
681                          storvsc_ringbuffer_size,
682                          (void *)&props,
683                          sizeof(struct vmstorage_channel_properties),
684                          storvsc_on_channel_callback, new_sc);
685
686         /* In case vmbus_open() fails, we don't use the sub-channel. */
687         if (ret != 0) {
688                 dev_err(dev, "Failed to open sub-channel: err=%d\n", ret);
689                 return;
690         }
691
692         new_sc->change_target_cpu_callback = storvsc_change_target_cpu;
693
694         /* Add the sub-channel to the array of available channels. */
695         stor_device->stor_chns[new_sc->target_cpu] = new_sc;
696         cpumask_set_cpu(new_sc->target_cpu, &stor_device->alloced_cpus);
697 }
698
699 static void  handle_multichannel_storage(struct hv_device *device, int max_chns)
700 {
701         struct device *dev = &device->device;
702         struct storvsc_device *stor_device;
703         int num_sc;
704         struct storvsc_cmd_request *request;
705         struct vstor_packet *vstor_packet;
706         int ret, t;
707
708         /*
709          * If the number of CPUs is artificially restricted, such as
710          * with maxcpus=1 on the kernel boot line, Hyper-V could offer
711          * sub-channels >= the number of CPUs. These sub-channels
712          * should not be created. The primary channel is already created
713          * and assigned to one CPU, so check against # CPUs - 1.
714          */
715         num_sc = min((int)(num_online_cpus() - 1), max_chns);
716         if (!num_sc)
717                 return;
718
719         stor_device = get_out_stor_device(device);
720         if (!stor_device)
721                 return;
722
723         stor_device->num_sc = num_sc;
724         request = &stor_device->init_request;
725         vstor_packet = &request->vstor_packet;
726
727         /*
728          * Establish a handler for dealing with subchannels.
729          */
730         vmbus_set_sc_create_callback(device->channel, handle_sc_creation);
731
732         /*
733          * Request the host to create sub-channels.
734          */
735         memset(request, 0, sizeof(struct storvsc_cmd_request));
736         init_completion(&request->wait_event);
737         vstor_packet->operation = VSTOR_OPERATION_CREATE_SUB_CHANNELS;
738         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
739         vstor_packet->sub_channel_count = num_sc;
740
741         ret = vmbus_sendpacket(device->channel, vstor_packet,
742                                sizeof(struct vstor_packet),
743                                VMBUS_RQST_INIT,
744                                VM_PKT_DATA_INBAND,
745                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
746
747         if (ret != 0) {
748                 dev_err(dev, "Failed to create sub-channel: err=%d\n", ret);
749                 return;
750         }
751
752         t = wait_for_completion_timeout(&request->wait_event, 10*HZ);
753         if (t == 0) {
754                 dev_err(dev, "Failed to create sub-channel: timed out\n");
755                 return;
756         }
757
758         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
759             vstor_packet->status != 0) {
760                 dev_err(dev, "Failed to create sub-channel: op=%d, sts=%d\n",
761                         vstor_packet->operation, vstor_packet->status);
762                 return;
763         }
764
765         /*
766          * We need to do nothing here, because vmbus_process_offer()
767          * invokes channel->sc_creation_callback, which will open and use
768          * the sub-channel(s).
769          */
770 }
771
772 static void cache_wwn(struct storvsc_device *stor_device,
773                       struct vstor_packet *vstor_packet)
774 {
775         /*
776          * Cache the currently active port and node ww names.
777          */
778         if (vstor_packet->wwn_packet.primary_active) {
779                 stor_device->node_name =
780                         wwn_to_u64(vstor_packet->wwn_packet.primary_node_wwn);
781                 stor_device->port_name =
782                         wwn_to_u64(vstor_packet->wwn_packet.primary_port_wwn);
783         } else {
784                 stor_device->node_name =
785                         wwn_to_u64(vstor_packet->wwn_packet.secondary_node_wwn);
786                 stor_device->port_name =
787                         wwn_to_u64(vstor_packet->wwn_packet.secondary_port_wwn);
788         }
789 }
790
791
792 static int storvsc_execute_vstor_op(struct hv_device *device,
793                                     struct storvsc_cmd_request *request,
794                                     bool status_check)
795 {
796         struct storvsc_device *stor_device;
797         struct vstor_packet *vstor_packet;
798         int ret, t;
799
800         stor_device = get_out_stor_device(device);
801         if (!stor_device)
802                 return -ENODEV;
803
804         vstor_packet = &request->vstor_packet;
805
806         init_completion(&request->wait_event);
807         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
808
809         ret = vmbus_sendpacket(device->channel, vstor_packet,
810                                sizeof(struct vstor_packet),
811                                VMBUS_RQST_INIT,
812                                VM_PKT_DATA_INBAND,
813                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
814         if (ret != 0)
815                 return ret;
816
817         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
818         if (t == 0)
819                 return -ETIMEDOUT;
820
821         if (!status_check)
822                 return ret;
823
824         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
825             vstor_packet->status != 0)
826                 return -EINVAL;
827
828         return ret;
829 }
830
831 static int storvsc_channel_init(struct hv_device *device, bool is_fc)
832 {
833         struct storvsc_device *stor_device;
834         struct storvsc_cmd_request *request;
835         struct vstor_packet *vstor_packet;
836         int ret, i;
837         int max_chns;
838         bool process_sub_channels = false;
839
840         stor_device = get_out_stor_device(device);
841         if (!stor_device)
842                 return -ENODEV;
843
844         request = &stor_device->init_request;
845         vstor_packet = &request->vstor_packet;
846
847         /*
848          * Now, initiate the vsc/vsp initialization protocol on the open
849          * channel
850          */
851         memset(request, 0, sizeof(struct storvsc_cmd_request));
852         vstor_packet->operation = VSTOR_OPERATION_BEGIN_INITIALIZATION;
853         ret = storvsc_execute_vstor_op(device, request, true);
854         if (ret)
855                 return ret;
856         /*
857          * Query host supported protocol version.
858          */
859
860         for (i = 0; i < ARRAY_SIZE(protocol_version); i++) {
861                 /* reuse the packet for version range supported */
862                 memset(vstor_packet, 0, sizeof(struct vstor_packet));
863                 vstor_packet->operation =
864                         VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;
865
866                 vstor_packet->version.major_minor = protocol_version[i];
867
868                 /*
869                  * The revision number is only used in Windows; set it to 0.
870                  */
871                 vstor_packet->version.revision = 0;
872                 ret = storvsc_execute_vstor_op(device, request, false);
873                 if (ret != 0)
874                         return ret;
875
876                 if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO)
877                         return -EINVAL;
878
879                 if (vstor_packet->status == 0) {
880                         vmstor_proto_version = protocol_version[i];
881
882                         break;
883                 }
884         }
885
886         if (vstor_packet->status != 0) {
887                 dev_err(&device->device, "Obsolete Hyper-V version\n");
888                 return -EINVAL;
889         }
890
891
892         memset(vstor_packet, 0, sizeof(struct vstor_packet));
893         vstor_packet->operation = VSTOR_OPERATION_QUERY_PROPERTIES;
894         ret = storvsc_execute_vstor_op(device, request, true);
895         if (ret != 0)
896                 return ret;
897
898         /*
899          * Check to see if multi-channel support is there.
900          * Hosts that implement protocol version of 5.1 and above
901          * support multi-channel.
902          */
903         max_chns = vstor_packet->storage_channel_properties.max_channel_cnt;
904
905         /*
906          * Allocate state to manage the sub-channels.
907          * We allocate an array based on the numbers of possible CPUs
908          * (Hyper-V does not support cpu online/offline).
909          * This Array will be sparseley populated with unique
910          * channels - primary + sub-channels.
911          * We will however populate all the slots to evenly distribute
912          * the load.
913          */
914         stor_device->stor_chns = kcalloc(num_possible_cpus(), sizeof(void *),
915                                          GFP_KERNEL);
916         if (stor_device->stor_chns == NULL)
917                 return -ENOMEM;
918
919         device->channel->change_target_cpu_callback = storvsc_change_target_cpu;
920
921         stor_device->stor_chns[device->channel->target_cpu] = device->channel;
922         cpumask_set_cpu(device->channel->target_cpu,
923                         &stor_device->alloced_cpus);
924
925         if (vstor_packet->storage_channel_properties.flags &
926             STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL)
927                 process_sub_channels = true;
928
929         stor_device->max_transfer_bytes =
930                 vstor_packet->storage_channel_properties.max_transfer_bytes;
931
932         if (!is_fc)
933                 goto done;
934
935         /*
936          * For FC devices retrieve FC HBA data.
937          */
938         memset(vstor_packet, 0, sizeof(struct vstor_packet));
939         vstor_packet->operation = VSTOR_OPERATION_FCHBA_DATA;
940         ret = storvsc_execute_vstor_op(device, request, true);
941         if (ret != 0)
942                 return ret;
943
944         /*
945          * Cache the currently active port and node ww names.
946          */
947         cache_wwn(stor_device, vstor_packet);
948
949 done:
950
951         memset(vstor_packet, 0, sizeof(struct vstor_packet));
952         vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
953         ret = storvsc_execute_vstor_op(device, request, true);
954         if (ret != 0)
955                 return ret;
956
957         if (process_sub_channels)
958                 handle_multichannel_storage(device, max_chns);
959
960         return ret;
961 }
962
963 static void storvsc_handle_error(struct vmscsi_request *vm_srb,
964                                 struct scsi_cmnd *scmnd,
965                                 struct Scsi_Host *host,
966                                 u8 asc, u8 ascq)
967 {
968         struct storvsc_scan_work *wrk;
969         void (*process_err_fn)(struct work_struct *work);
970         struct hv_host_device *host_dev = shost_priv(host);
971
972         /*
973          * In some situations, Hyper-V sets multiple bits in the
974          * srb_status, such as ABORTED and ERROR. So process them
975          * individually, with the most specific bits first.
976          */
977
978         if (vm_srb->srb_status & SRB_STATUS_INVALID_LUN) {
979                 set_host_byte(scmnd, DID_NO_CONNECT);
980                 process_err_fn = storvsc_remove_lun;
981                 goto do_work;
982         }
983
984         if (vm_srb->srb_status & SRB_STATUS_ABORTED) {
985                 if (vm_srb->srb_status & SRB_STATUS_AUTOSENSE_VALID &&
986                     /* Capacity data has changed */
987                     (asc == 0x2a) && (ascq == 0x9)) {
988                         process_err_fn = storvsc_device_scan;
989                         /*
990                          * Retry the I/O that triggered this.
991                          */
992                         set_host_byte(scmnd, DID_REQUEUE);
993                         goto do_work;
994                 }
995         }
996
997         if (vm_srb->srb_status & SRB_STATUS_ERROR) {
998                 /*
999                  * Let upper layer deal with error when
1000                  * sense message is present.
1001                  */
1002                 if (vm_srb->srb_status & SRB_STATUS_AUTOSENSE_VALID)
1003                         return;
1004
1005                 /*
1006                  * If there is an error; offline the device since all
1007                  * error recovery strategies would have already been
1008                  * deployed on the host side. However, if the command
1009                  * were a pass-through command deal with it appropriately.
1010                  */
1011                 switch (scmnd->cmnd[0]) {
1012                 case ATA_16:
1013                 case ATA_12:
1014                         set_host_byte(scmnd, DID_PASSTHROUGH);
1015                         break;
1016                 /*
1017                  * On some Hyper-V hosts TEST_UNIT_READY command can
1018                  * return SRB_STATUS_ERROR. Let the upper level code
1019                  * deal with it based on the sense information.
1020                  */
1021                 case TEST_UNIT_READY:
1022                         break;
1023                 default:
1024                         set_host_byte(scmnd, DID_ERROR);
1025                 }
1026         }
1027         return;
1028
1029 do_work:
1030         /*
1031          * We need to schedule work to process this error; schedule it.
1032          */
1033         wrk = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
1034         if (!wrk) {
1035                 set_host_byte(scmnd, DID_BAD_TARGET);
1036                 return;
1037         }
1038
1039         wrk->host = host;
1040         wrk->lun = vm_srb->lun;
1041         wrk->tgt_id = vm_srb->target_id;
1042         INIT_WORK(&wrk->work, process_err_fn);
1043         queue_work(host_dev->handle_error_wq, &wrk->work);
1044 }
1045
1046
1047 static void storvsc_command_completion(struct storvsc_cmd_request *cmd_request,
1048                                        struct storvsc_device *stor_dev)
1049 {
1050         struct scsi_cmnd *scmnd = cmd_request->cmd;
1051         struct scsi_sense_hdr sense_hdr;
1052         struct vmscsi_request *vm_srb;
1053         u32 data_transfer_length;
1054         struct Scsi_Host *host;
1055         u32 payload_sz = cmd_request->payload_sz;
1056         void *payload = cmd_request->payload;
1057         bool sense_ok;
1058
1059         host = stor_dev->host;
1060
1061         vm_srb = &cmd_request->vstor_packet.vm_srb;
1062         data_transfer_length = vm_srb->data_transfer_length;
1063
1064         scmnd->result = vm_srb->scsi_status;
1065
1066         if (scmnd->result) {
1067                 sense_ok = scsi_normalize_sense(scmnd->sense_buffer,
1068                                 SCSI_SENSE_BUFFERSIZE, &sense_hdr);
1069
1070                 if (sense_ok && do_logging(STORVSC_LOGGING_WARN))
1071                         scsi_print_sense_hdr(scmnd->device, "storvsc",
1072                                              &sense_hdr);
1073         }
1074
1075         if (vm_srb->srb_status != SRB_STATUS_SUCCESS) {
1076                 storvsc_handle_error(vm_srb, scmnd, host, sense_hdr.asc,
1077                                          sense_hdr.ascq);
1078                 /*
1079                  * The Windows driver set data_transfer_length on
1080                  * SRB_STATUS_DATA_OVERRUN. On other errors, this value
1081                  * is untouched.  In these cases we set it to 0.
1082                  */
1083                 if (vm_srb->srb_status != SRB_STATUS_DATA_OVERRUN)
1084                         data_transfer_length = 0;
1085         }
1086
1087         /* Validate data_transfer_length (from Hyper-V) */
1088         if (data_transfer_length > cmd_request->payload->range.len)
1089                 data_transfer_length = cmd_request->payload->range.len;
1090
1091         scsi_set_resid(scmnd,
1092                 cmd_request->payload->range.len - data_transfer_length);
1093
1094         scsi_done(scmnd);
1095
1096         if (payload_sz >
1097                 sizeof(struct vmbus_channel_packet_multipage_buffer))
1098                 kfree(payload);
1099 }
1100
1101 static void storvsc_on_io_completion(struct storvsc_device *stor_device,
1102                                   struct vstor_packet *vstor_packet,
1103                                   struct storvsc_cmd_request *request)
1104 {
1105         struct vstor_packet *stor_pkt;
1106         struct hv_device *device = stor_device->device;
1107
1108         stor_pkt = &request->vstor_packet;
1109
1110         /*
1111          * The current SCSI handling on the host side does
1112          * not correctly handle:
1113          * INQUIRY command with page code parameter set to 0x80
1114          * MODE_SENSE command with cmd[2] == 0x1c
1115          *
1116          * Setup srb and scsi status so this won't be fatal.
1117          * We do this so we can distinguish truly fatal failues
1118          * (srb status == 0x4) and off-line the device in that case.
1119          */
1120
1121         if ((stor_pkt->vm_srb.cdb[0] == INQUIRY) ||
1122            (stor_pkt->vm_srb.cdb[0] == MODE_SENSE)) {
1123                 vstor_packet->vm_srb.scsi_status = 0;
1124                 vstor_packet->vm_srb.srb_status = SRB_STATUS_SUCCESS;
1125         }
1126
1127         /* Copy over the status...etc */
1128         stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
1129         stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
1130
1131         /*
1132          * Copy over the sense_info_length, but limit to the known max
1133          * size if Hyper-V returns a bad value.
1134          */
1135         stor_pkt->vm_srb.sense_info_length = min_t(u8, STORVSC_SENSE_BUFFER_SIZE,
1136                 vstor_packet->vm_srb.sense_info_length);
1137
1138         if (vstor_packet->vm_srb.scsi_status != 0 ||
1139             vstor_packet->vm_srb.srb_status != SRB_STATUS_SUCCESS) {
1140
1141                 /*
1142                  * Log TEST_UNIT_READY errors only as warnings. Hyper-V can
1143                  * return errors when detecting devices using TEST_UNIT_READY,
1144                  * and logging these as errors produces unhelpful noise.
1145                  */
1146                 int loglevel = (stor_pkt->vm_srb.cdb[0] == TEST_UNIT_READY) ?
1147                         STORVSC_LOGGING_WARN : STORVSC_LOGGING_ERROR;
1148
1149                 storvsc_log(device, loglevel,
1150                         "tag#%d cmd 0x%x status: scsi 0x%x srb 0x%x hv 0x%x\n",
1151                         scsi_cmd_to_rq(request->cmd)->tag,
1152                         stor_pkt->vm_srb.cdb[0],
1153                         vstor_packet->vm_srb.scsi_status,
1154                         vstor_packet->vm_srb.srb_status,
1155                         vstor_packet->status);
1156         }
1157
1158         if (vstor_packet->vm_srb.scsi_status == SAM_STAT_CHECK_CONDITION &&
1159             (vstor_packet->vm_srb.srb_status & SRB_STATUS_AUTOSENSE_VALID))
1160                 memcpy(request->cmd->sense_buffer,
1161                        vstor_packet->vm_srb.sense_data,
1162                        stor_pkt->vm_srb.sense_info_length);
1163
1164         stor_pkt->vm_srb.data_transfer_length =
1165                 vstor_packet->vm_srb.data_transfer_length;
1166
1167         storvsc_command_completion(request, stor_device);
1168
1169         if (atomic_dec_and_test(&stor_device->num_outstanding_req) &&
1170                 stor_device->drain_notify)
1171                 wake_up(&stor_device->waiting_to_drain);
1172 }
1173
1174 static void storvsc_on_receive(struct storvsc_device *stor_device,
1175                              struct vstor_packet *vstor_packet,
1176                              struct storvsc_cmd_request *request)
1177 {
1178         struct hv_host_device *host_dev;
1179         switch (vstor_packet->operation) {
1180         case VSTOR_OPERATION_COMPLETE_IO:
1181                 storvsc_on_io_completion(stor_device, vstor_packet, request);
1182                 break;
1183
1184         case VSTOR_OPERATION_REMOVE_DEVICE:
1185         case VSTOR_OPERATION_ENUMERATE_BUS:
1186                 host_dev = shost_priv(stor_device->host);
1187                 queue_work(
1188                         host_dev->handle_error_wq, &host_dev->host_scan_work);
1189                 break;
1190
1191         case VSTOR_OPERATION_FCHBA_DATA:
1192                 cache_wwn(stor_device, vstor_packet);
1193 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1194                 fc_host_node_name(stor_device->host) = stor_device->node_name;
1195                 fc_host_port_name(stor_device->host) = stor_device->port_name;
1196 #endif
1197                 break;
1198         default:
1199                 break;
1200         }
1201 }
1202
1203 static void storvsc_on_channel_callback(void *context)
1204 {
1205         struct vmbus_channel *channel = (struct vmbus_channel *)context;
1206         const struct vmpacket_descriptor *desc;
1207         struct hv_device *device;
1208         struct storvsc_device *stor_device;
1209         struct Scsi_Host *shost;
1210         unsigned long time_limit = jiffies + msecs_to_jiffies(CALLBACK_TIMEOUT);
1211
1212         if (channel->primary_channel != NULL)
1213                 device = channel->primary_channel->device_obj;
1214         else
1215                 device = channel->device_obj;
1216
1217         stor_device = get_in_stor_device(device);
1218         if (!stor_device)
1219                 return;
1220
1221         shost = stor_device->host;
1222
1223         foreach_vmbus_pkt(desc, channel) {
1224                 struct vstor_packet *packet = hv_pkt_data(desc);
1225                 struct storvsc_cmd_request *request = NULL;
1226                 u32 pktlen = hv_pkt_datalen(desc);
1227                 u64 rqst_id = desc->trans_id;
1228                 u32 minlen = rqst_id ? sizeof(struct vstor_packet) :
1229                         sizeof(enum vstor_packet_operation);
1230
1231                 if (unlikely(time_after(jiffies, time_limit))) {
1232                         hv_pkt_iter_close(channel);
1233                         return;
1234                 }
1235
1236                 if (pktlen < minlen) {
1237                         dev_err(&device->device,
1238                                 "Invalid pkt: id=%llu, len=%u, minlen=%u\n",
1239                                 rqst_id, pktlen, minlen);
1240                         continue;
1241                 }
1242
1243                 if (rqst_id == VMBUS_RQST_INIT) {
1244                         request = &stor_device->init_request;
1245                 } else if (rqst_id == VMBUS_RQST_RESET) {
1246                         request = &stor_device->reset_request;
1247                 } else {
1248                         /* Hyper-V can send an unsolicited message with ID of 0 */
1249                         if (rqst_id == 0) {
1250                                 /*
1251                                  * storvsc_on_receive() looks at the vstor_packet in the message
1252                                  * from the ring buffer.
1253                                  *
1254                                  * - If the operation in the vstor_packet is COMPLETE_IO, then
1255                                  *   we call storvsc_on_io_completion(), and dereference the
1256                                  *   guest memory address.  Make sure we don't call
1257                                  *   storvsc_on_io_completion() with a guest memory address
1258                                  *   that is zero if Hyper-V were to construct and send such
1259                                  *   a bogus packet.
1260                                  *
1261                                  * - If the operation in the vstor_packet is FCHBA_DATA, then
1262                                  *   we call cache_wwn(), and access the data payload area of
1263                                  *   the packet (wwn_packet); however, there is no guarantee
1264                                  *   that the packet is big enough to contain such area.
1265                                  *   Future-proof the code by rejecting such a bogus packet.
1266                                  */
1267                                 if (packet->operation == VSTOR_OPERATION_COMPLETE_IO ||
1268                                     packet->operation == VSTOR_OPERATION_FCHBA_DATA) {
1269                                         dev_err(&device->device, "Invalid packet with ID of 0\n");
1270                                         continue;
1271                                 }
1272                         } else {
1273                                 struct scsi_cmnd *scmnd;
1274
1275                                 /* Transaction 'rqst_id' corresponds to tag 'rqst_id - 1' */
1276                                 scmnd = scsi_host_find_tag(shost, rqst_id - 1);
1277                                 if (scmnd == NULL) {
1278                                         dev_err(&device->device, "Incorrect transaction ID\n");
1279                                         continue;
1280                                 }
1281                                 request = (struct storvsc_cmd_request *)scsi_cmd_priv(scmnd);
1282                                 scsi_dma_unmap(scmnd);
1283                         }
1284
1285                         storvsc_on_receive(stor_device, packet, request);
1286                         continue;
1287                 }
1288
1289                 memcpy(&request->vstor_packet, packet,
1290                        sizeof(struct vstor_packet));
1291                 complete(&request->wait_event);
1292         }
1293 }
1294
1295 static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size,
1296                                   bool is_fc)
1297 {
1298         struct vmstorage_channel_properties props;
1299         int ret;
1300
1301         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
1302
1303         device->channel->max_pkt_size = STORVSC_MAX_PKT_SIZE;
1304         device->channel->next_request_id_callback = storvsc_next_request_id;
1305
1306         ret = vmbus_open(device->channel,
1307                          ring_size,
1308                          ring_size,
1309                          (void *)&props,
1310                          sizeof(struct vmstorage_channel_properties),
1311                          storvsc_on_channel_callback, device->channel);
1312
1313         if (ret != 0)
1314                 return ret;
1315
1316         ret = storvsc_channel_init(device, is_fc);
1317
1318         return ret;
1319 }
1320
1321 static int storvsc_dev_remove(struct hv_device *device)
1322 {
1323         struct storvsc_device *stor_device;
1324
1325         stor_device = hv_get_drvdata(device);
1326
1327         stor_device->destroy = true;
1328
1329         /* Make sure flag is set before waiting */
1330         wmb();
1331
1332         /*
1333          * At this point, all outbound traffic should be disable. We
1334          * only allow inbound traffic (responses) to proceed so that
1335          * outstanding requests can be completed.
1336          */
1337
1338         storvsc_wait_to_drain(stor_device);
1339
1340         /*
1341          * Since we have already drained, we don't need to busy wait
1342          * as was done in final_release_stor_device()
1343          * Note that we cannot set the ext pointer to NULL until
1344          * we have drained - to drain the outgoing packets, we need to
1345          * allow incoming packets.
1346          */
1347         hv_set_drvdata(device, NULL);
1348
1349         /* Close the channel */
1350         vmbus_close(device->channel);
1351
1352         kfree(stor_device->stor_chns);
1353         kfree(stor_device);
1354         return 0;
1355 }
1356
1357 static struct vmbus_channel *get_og_chn(struct storvsc_device *stor_device,
1358                                         u16 q_num)
1359 {
1360         u16 slot = 0;
1361         u16 hash_qnum;
1362         const struct cpumask *node_mask;
1363         int num_channels, tgt_cpu;
1364
1365         if (stor_device->num_sc == 0) {
1366                 stor_device->stor_chns[q_num] = stor_device->device->channel;
1367                 return stor_device->device->channel;
1368         }
1369
1370         /*
1371          * Our channel array is sparsley populated and we
1372          * initiated I/O on a processor/hw-q that does not
1373          * currently have a designated channel. Fix this.
1374          * The strategy is simple:
1375          * I. Ensure NUMA locality
1376          * II. Distribute evenly (best effort)
1377          */
1378
1379         node_mask = cpumask_of_node(cpu_to_node(q_num));
1380
1381         num_channels = 0;
1382         for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1383                 if (cpumask_test_cpu(tgt_cpu, node_mask))
1384                         num_channels++;
1385         }
1386         if (num_channels == 0) {
1387                 stor_device->stor_chns[q_num] = stor_device->device->channel;
1388                 return stor_device->device->channel;
1389         }
1390
1391         hash_qnum = q_num;
1392         while (hash_qnum >= num_channels)
1393                 hash_qnum -= num_channels;
1394
1395         for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1396                 if (!cpumask_test_cpu(tgt_cpu, node_mask))
1397                         continue;
1398                 if (slot == hash_qnum)
1399                         break;
1400                 slot++;
1401         }
1402
1403         stor_device->stor_chns[q_num] = stor_device->stor_chns[tgt_cpu];
1404
1405         return stor_device->stor_chns[q_num];
1406 }
1407
1408
1409 static int storvsc_do_io(struct hv_device *device,
1410                          struct storvsc_cmd_request *request, u16 q_num)
1411 {
1412         struct storvsc_device *stor_device;
1413         struct vstor_packet *vstor_packet;
1414         struct vmbus_channel *outgoing_channel, *channel;
1415         unsigned long flags;
1416         int ret = 0;
1417         const struct cpumask *node_mask;
1418         int tgt_cpu;
1419
1420         vstor_packet = &request->vstor_packet;
1421         stor_device = get_out_stor_device(device);
1422
1423         if (!stor_device)
1424                 return -ENODEV;
1425
1426
1427         request->device  = device;
1428         /*
1429          * Select an appropriate channel to send the request out.
1430          */
1431         /* See storvsc_change_target_cpu(). */
1432         outgoing_channel = READ_ONCE(stor_device->stor_chns[q_num]);
1433         if (outgoing_channel != NULL) {
1434                 if (outgoing_channel->target_cpu == q_num) {
1435                         /*
1436                          * Ideally, we want to pick a different channel if
1437                          * available on the same NUMA node.
1438                          */
1439                         node_mask = cpumask_of_node(cpu_to_node(q_num));
1440                         for_each_cpu_wrap(tgt_cpu,
1441                                  &stor_device->alloced_cpus, q_num + 1) {
1442                                 if (!cpumask_test_cpu(tgt_cpu, node_mask))
1443                                         continue;
1444                                 if (tgt_cpu == q_num)
1445                                         continue;
1446                                 channel = READ_ONCE(
1447                                         stor_device->stor_chns[tgt_cpu]);
1448                                 if (channel == NULL)
1449                                         continue;
1450                                 if (hv_get_avail_to_write_percent(
1451                                                         &channel->outbound)
1452                                                 > ring_avail_percent_lowater) {
1453                                         outgoing_channel = channel;
1454                                         goto found_channel;
1455                                 }
1456                         }
1457
1458                         /*
1459                          * All the other channels on the same NUMA node are
1460                          * busy. Try to use the channel on the current CPU
1461                          */
1462                         if (hv_get_avail_to_write_percent(
1463                                                 &outgoing_channel->outbound)
1464                                         > ring_avail_percent_lowater)
1465                                 goto found_channel;
1466
1467                         /*
1468                          * If we reach here, all the channels on the current
1469                          * NUMA node are busy. Try to find a channel in
1470                          * other NUMA nodes
1471                          */
1472                         for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1473                                 if (cpumask_test_cpu(tgt_cpu, node_mask))
1474                                         continue;
1475                                 channel = READ_ONCE(
1476                                         stor_device->stor_chns[tgt_cpu]);
1477                                 if (channel == NULL)
1478                                         continue;
1479                                 if (hv_get_avail_to_write_percent(
1480                                                         &channel->outbound)
1481                                                 > ring_avail_percent_lowater) {
1482                                         outgoing_channel = channel;
1483                                         goto found_channel;
1484                                 }
1485                         }
1486                 }
1487         } else {
1488                 spin_lock_irqsave(&stor_device->lock, flags);
1489                 outgoing_channel = stor_device->stor_chns[q_num];
1490                 if (outgoing_channel != NULL) {
1491                         spin_unlock_irqrestore(&stor_device->lock, flags);
1492                         goto found_channel;
1493                 }
1494                 outgoing_channel = get_og_chn(stor_device, q_num);
1495                 spin_unlock_irqrestore(&stor_device->lock, flags);
1496         }
1497
1498 found_channel:
1499         vstor_packet->flags |= REQUEST_COMPLETION_FLAG;
1500
1501         vstor_packet->vm_srb.length = sizeof(struct vmscsi_request);
1502
1503
1504         vstor_packet->vm_srb.sense_info_length = STORVSC_SENSE_BUFFER_SIZE;
1505
1506
1507         vstor_packet->vm_srb.data_transfer_length =
1508         request->payload->range.len;
1509
1510         vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
1511
1512         if (request->payload->range.len) {
1513
1514                 ret = vmbus_sendpacket_mpb_desc(outgoing_channel,
1515                                 request->payload, request->payload_sz,
1516                                 vstor_packet,
1517                                 sizeof(struct vstor_packet),
1518                                 (unsigned long)request);
1519         } else {
1520                 ret = vmbus_sendpacket(outgoing_channel, vstor_packet,
1521                                sizeof(struct vstor_packet),
1522                                (unsigned long)request,
1523                                VM_PKT_DATA_INBAND,
1524                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1525         }
1526
1527         if (ret != 0)
1528                 return ret;
1529
1530         atomic_inc(&stor_device->num_outstanding_req);
1531
1532         return ret;
1533 }
1534
1535 static int storvsc_device_alloc(struct scsi_device *sdevice)
1536 {
1537         /*
1538          * Set blist flag to permit the reading of the VPD pages even when
1539          * the target may claim SPC-2 compliance. MSFT targets currently
1540          * claim SPC-2 compliance while they implement post SPC-2 features.
1541          * With this flag we can correctly handle WRITE_SAME_16 issues.
1542          *
1543          * Hypervisor reports SCSI_UNKNOWN type for DVD ROM device but
1544          * still supports REPORT LUN.
1545          */
1546         sdevice->sdev_bflags = BLIST_REPORTLUN2 | BLIST_TRY_VPD_PAGES;
1547
1548         return 0;
1549 }
1550
1551 static int storvsc_device_configure(struct scsi_device *sdevice)
1552 {
1553         blk_queue_rq_timeout(sdevice->request_queue, (storvsc_timeout * HZ));
1554
1555         sdevice->no_write_same = 1;
1556
1557         /*
1558          * If the host is WIN8 or WIN8 R2, claim conformance to SPC-3
1559          * if the device is a MSFT virtual device.  If the host is
1560          * WIN10 or newer, allow write_same.
1561          */
1562         if (!strncmp(sdevice->vendor, "Msft", 4)) {
1563                 switch (vmstor_proto_version) {
1564                 case VMSTOR_PROTO_VERSION_WIN8:
1565                 case VMSTOR_PROTO_VERSION_WIN8_1:
1566                         sdevice->scsi_level = SCSI_SPC_3;
1567                         break;
1568                 }
1569
1570                 if (vmstor_proto_version >= VMSTOR_PROTO_VERSION_WIN10)
1571                         sdevice->no_write_same = 0;
1572         }
1573
1574         return 0;
1575 }
1576
1577 static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
1578                            sector_t capacity, int *info)
1579 {
1580         sector_t nsect = capacity;
1581         sector_t cylinders = nsect;
1582         int heads, sectors_pt;
1583
1584         /*
1585          * We are making up these values; let us keep it simple.
1586          */
1587         heads = 0xff;
1588         sectors_pt = 0x3f;      /* Sectors per track */
1589         sector_div(cylinders, heads * sectors_pt);
1590         if ((sector_t)(cylinders + 1) * heads * sectors_pt < nsect)
1591                 cylinders = 0xffff;
1592
1593         info[0] = heads;
1594         info[1] = sectors_pt;
1595         info[2] = (int)cylinders;
1596
1597         return 0;
1598 }
1599
1600 static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
1601 {
1602         struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
1603         struct hv_device *device = host_dev->dev;
1604
1605         struct storvsc_device *stor_device;
1606         struct storvsc_cmd_request *request;
1607         struct vstor_packet *vstor_packet;
1608         int ret, t;
1609
1610         stor_device = get_out_stor_device(device);
1611         if (!stor_device)
1612                 return FAILED;
1613
1614         request = &stor_device->reset_request;
1615         vstor_packet = &request->vstor_packet;
1616         memset(vstor_packet, 0, sizeof(struct vstor_packet));
1617
1618         init_completion(&request->wait_event);
1619
1620         vstor_packet->operation = VSTOR_OPERATION_RESET_BUS;
1621         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
1622         vstor_packet->vm_srb.path_id = stor_device->path_id;
1623
1624         ret = vmbus_sendpacket(device->channel, vstor_packet,
1625                                sizeof(struct vstor_packet),
1626                                VMBUS_RQST_RESET,
1627                                VM_PKT_DATA_INBAND,
1628                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1629         if (ret != 0)
1630                 return FAILED;
1631
1632         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
1633         if (t == 0)
1634                 return TIMEOUT_ERROR;
1635
1636
1637         /*
1638          * At this point, all outstanding requests in the adapter
1639          * should have been flushed out and return to us
1640          * There is a potential race here where the host may be in
1641          * the process of responding when we return from here.
1642          * Just wait for all in-transit packets to be accounted for
1643          * before we return from here.
1644          */
1645         storvsc_wait_to_drain(stor_device);
1646
1647         return SUCCESS;
1648 }
1649
1650 /*
1651  * The host guarantees to respond to each command, although I/O latencies might
1652  * be unbounded on Azure.  Reset the timer unconditionally to give the host a
1653  * chance to perform EH.
1654  */
1655 static enum blk_eh_timer_return storvsc_eh_timed_out(struct scsi_cmnd *scmnd)
1656 {
1657 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1658         if (scmnd->device->host->transportt == fc_transport_template)
1659                 return fc_eh_timed_out(scmnd);
1660 #endif
1661         return BLK_EH_RESET_TIMER;
1662 }
1663
1664 static bool storvsc_scsi_cmd_ok(struct scsi_cmnd *scmnd)
1665 {
1666         bool allowed = true;
1667         u8 scsi_op = scmnd->cmnd[0];
1668
1669         switch (scsi_op) {
1670         /* the host does not handle WRITE_SAME, log accident usage */
1671         case WRITE_SAME:
1672         /*
1673          * smartd sends this command and the host does not handle
1674          * this. So, don't send it.
1675          */
1676         case SET_WINDOW:
1677                 set_host_byte(scmnd, DID_ERROR);
1678                 allowed = false;
1679                 break;
1680         default:
1681                 break;
1682         }
1683         return allowed;
1684 }
1685
1686 static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
1687 {
1688         int ret;
1689         struct hv_host_device *host_dev = shost_priv(host);
1690         struct hv_device *dev = host_dev->dev;
1691         struct storvsc_cmd_request *cmd_request = scsi_cmd_priv(scmnd);
1692         struct scatterlist *sgl;
1693         struct vmscsi_request *vm_srb;
1694         struct vmbus_packet_mpb_array  *payload;
1695         u32 payload_sz;
1696         u32 length;
1697
1698         if (vmstor_proto_version <= VMSTOR_PROTO_VERSION_WIN8) {
1699                 /*
1700                  * On legacy hosts filter unimplemented commands.
1701                  * Future hosts are expected to correctly handle
1702                  * unsupported commands. Furthermore, it is
1703                  * possible that some of the currently
1704                  * unsupported commands maybe supported in
1705                  * future versions of the host.
1706                  */
1707                 if (!storvsc_scsi_cmd_ok(scmnd)) {
1708                         scsi_done(scmnd);
1709                         return 0;
1710                 }
1711         }
1712
1713         /* Setup the cmd request */
1714         cmd_request->cmd = scmnd;
1715
1716         memset(&cmd_request->vstor_packet, 0, sizeof(struct vstor_packet));
1717         vm_srb = &cmd_request->vstor_packet.vm_srb;
1718         vm_srb->time_out_value = 60;
1719
1720         vm_srb->srb_flags |=
1721                 SRB_FLAGS_DISABLE_SYNCH_TRANSFER;
1722
1723         if (scmnd->device->tagged_supported) {
1724                 vm_srb->srb_flags |=
1725                 (SRB_FLAGS_QUEUE_ACTION_ENABLE | SRB_FLAGS_NO_QUEUE_FREEZE);
1726                 vm_srb->queue_tag = SP_UNTAGGED;
1727                 vm_srb->queue_action = SRB_SIMPLE_TAG_REQUEST;
1728         }
1729
1730         /* Build the SRB */
1731         switch (scmnd->sc_data_direction) {
1732         case DMA_TO_DEVICE:
1733                 vm_srb->data_in = WRITE_TYPE;
1734                 vm_srb->srb_flags |= SRB_FLAGS_DATA_OUT;
1735                 break;
1736         case DMA_FROM_DEVICE:
1737                 vm_srb->data_in = READ_TYPE;
1738                 vm_srb->srb_flags |= SRB_FLAGS_DATA_IN;
1739                 break;
1740         case DMA_NONE:
1741                 vm_srb->data_in = UNKNOWN_TYPE;
1742                 vm_srb->srb_flags |= SRB_FLAGS_NO_DATA_TRANSFER;
1743                 break;
1744         default:
1745                 /*
1746                  * This is DMA_BIDIRECTIONAL or something else we are never
1747                  * supposed to see here.
1748                  */
1749                 WARN(1, "Unexpected data direction: %d\n",
1750                      scmnd->sc_data_direction);
1751                 return -EINVAL;
1752         }
1753
1754
1755         vm_srb->port_number = host_dev->port;
1756         vm_srb->path_id = scmnd->device->channel;
1757         vm_srb->target_id = scmnd->device->id;
1758         vm_srb->lun = scmnd->device->lun;
1759
1760         vm_srb->cdb_length = scmnd->cmd_len;
1761
1762         memcpy(vm_srb->cdb, scmnd->cmnd, vm_srb->cdb_length);
1763
1764         sgl = (struct scatterlist *)scsi_sglist(scmnd);
1765
1766         length = scsi_bufflen(scmnd);
1767         payload = (struct vmbus_packet_mpb_array *)&cmd_request->mpb;
1768         payload_sz = sizeof(cmd_request->mpb);
1769
1770         if (scsi_sg_count(scmnd)) {
1771                 unsigned long offset_in_hvpg = offset_in_hvpage(sgl->offset);
1772                 unsigned int hvpg_count = HVPFN_UP(offset_in_hvpg + length);
1773                 struct scatterlist *sg;
1774                 unsigned long hvpfn, hvpfns_to_add;
1775                 int j, i = 0, sg_count;
1776
1777                 if (hvpg_count > MAX_PAGE_BUFFER_COUNT) {
1778
1779                         payload_sz = (hvpg_count * sizeof(u64) +
1780                                       sizeof(struct vmbus_packet_mpb_array));
1781                         payload = kzalloc(payload_sz, GFP_ATOMIC);
1782                         if (!payload)
1783                                 return SCSI_MLQUEUE_DEVICE_BUSY;
1784                 }
1785
1786                 payload->range.len = length;
1787                 payload->range.offset = offset_in_hvpg;
1788
1789                 sg_count = scsi_dma_map(scmnd);
1790                 if (sg_count < 0) {
1791                         ret = SCSI_MLQUEUE_DEVICE_BUSY;
1792                         goto err_free_payload;
1793                 }
1794
1795                 for_each_sg(sgl, sg, sg_count, j) {
1796                         /*
1797                          * Init values for the current sgl entry. hvpfns_to_add
1798                          * is in units of Hyper-V size pages. Handling the
1799                          * PAGE_SIZE != HV_HYP_PAGE_SIZE case also handles
1800                          * values of sgl->offset that are larger than PAGE_SIZE.
1801                          * Such offsets are handled even on other than the first
1802                          * sgl entry, provided they are a multiple of PAGE_SIZE.
1803                          */
1804                         hvpfn = HVPFN_DOWN(sg_dma_address(sg));
1805                         hvpfns_to_add = HVPFN_UP(sg_dma_address(sg) +
1806                                                  sg_dma_len(sg)) - hvpfn;
1807
1808                         /*
1809                          * Fill the next portion of the PFN array with
1810                          * sequential Hyper-V PFNs for the continguous physical
1811                          * memory described by the sgl entry. The end of the
1812                          * last sgl should be reached at the same time that
1813                          * the PFN array is filled.
1814                          */
1815                         while (hvpfns_to_add--)
1816                                 payload->range.pfn_array[i++] = hvpfn++;
1817                 }
1818         }
1819
1820         cmd_request->payload = payload;
1821         cmd_request->payload_sz = payload_sz;
1822
1823         /* Invokes the vsc to start an IO */
1824         ret = storvsc_do_io(dev, cmd_request, get_cpu());
1825         put_cpu();
1826
1827         if (ret == -EAGAIN) {
1828                 /* no more space */
1829                 ret = SCSI_MLQUEUE_DEVICE_BUSY;
1830                 goto err_free_payload;
1831         }
1832
1833         return 0;
1834
1835 err_free_payload:
1836         if (payload_sz > sizeof(cmd_request->mpb))
1837                 kfree(payload);
1838
1839         return ret;
1840 }
1841
1842 static struct scsi_host_template scsi_driver = {
1843         .module =               THIS_MODULE,
1844         .name =                 "storvsc_host_t",
1845         .cmd_size =             sizeof(struct storvsc_cmd_request),
1846         .bios_param =           storvsc_get_chs,
1847         .queuecommand =         storvsc_queuecommand,
1848         .eh_host_reset_handler =        storvsc_host_reset_handler,
1849         .proc_name =            "storvsc_host",
1850         .eh_timed_out =         storvsc_eh_timed_out,
1851         .slave_alloc =          storvsc_device_alloc,
1852         .slave_configure =      storvsc_device_configure,
1853         .cmd_per_lun =          2048,
1854         .this_id =              -1,
1855         /* Ensure there are no gaps in presented sgls */
1856         .virt_boundary_mask =   HV_HYP_PAGE_SIZE - 1,
1857         .no_write_same =        1,
1858         .track_queue_depth =    1,
1859         .change_queue_depth =   storvsc_change_queue_depth,
1860 };
1861
1862 enum {
1863         SCSI_GUID,
1864         IDE_GUID,
1865         SFC_GUID,
1866 };
1867
1868 static const struct hv_vmbus_device_id id_table[] = {
1869         /* SCSI guid */
1870         { HV_SCSI_GUID,
1871           .driver_data = SCSI_GUID
1872         },
1873         /* IDE guid */
1874         { HV_IDE_GUID,
1875           .driver_data = IDE_GUID
1876         },
1877         /* Fibre Channel GUID */
1878         {
1879           HV_SYNTHFC_GUID,
1880           .driver_data = SFC_GUID
1881         },
1882         { },
1883 };
1884
1885 MODULE_DEVICE_TABLE(vmbus, id_table);
1886
1887 static const struct { guid_t guid; } fc_guid = { HV_SYNTHFC_GUID };
1888
1889 static bool hv_dev_is_fc(struct hv_device *hv_dev)
1890 {
1891         return guid_equal(&fc_guid.guid, &hv_dev->dev_type);
1892 }
1893
1894 static int storvsc_probe(struct hv_device *device,
1895                         const struct hv_vmbus_device_id *dev_id)
1896 {
1897         int ret;
1898         int num_cpus = num_online_cpus();
1899         int num_present_cpus = num_present_cpus();
1900         struct Scsi_Host *host;
1901         struct hv_host_device *host_dev;
1902         bool dev_is_ide = ((dev_id->driver_data == IDE_GUID) ? true : false);
1903         bool is_fc = ((dev_id->driver_data == SFC_GUID) ? true : false);
1904         int target = 0;
1905         struct storvsc_device *stor_device;
1906         int max_sub_channels = 0;
1907         u32 max_xfer_bytes;
1908
1909         /*
1910          * We support sub-channels for storage on SCSI and FC controllers.
1911          * The number of sub-channels offerred is based on the number of
1912          * VCPUs in the guest.
1913          */
1914         if (!dev_is_ide)
1915                 max_sub_channels =
1916                         (num_cpus - 1) / storvsc_vcpus_per_sub_channel;
1917
1918         scsi_driver.can_queue = max_outstanding_req_per_channel *
1919                                 (max_sub_channels + 1) *
1920                                 (100 - ring_avail_percent_lowater) / 100;
1921
1922         host = scsi_host_alloc(&scsi_driver,
1923                                sizeof(struct hv_host_device));
1924         if (!host)
1925                 return -ENOMEM;
1926
1927         host_dev = shost_priv(host);
1928         memset(host_dev, 0, sizeof(struct hv_host_device));
1929
1930         host_dev->port = host->host_no;
1931         host_dev->dev = device;
1932         host_dev->host = host;
1933
1934
1935         stor_device = kzalloc(sizeof(struct storvsc_device), GFP_KERNEL);
1936         if (!stor_device) {
1937                 ret = -ENOMEM;
1938                 goto err_out0;
1939         }
1940
1941         stor_device->destroy = false;
1942         init_waitqueue_head(&stor_device->waiting_to_drain);
1943         stor_device->device = device;
1944         stor_device->host = host;
1945         spin_lock_init(&stor_device->lock);
1946         hv_set_drvdata(device, stor_device);
1947         dma_set_min_align_mask(&device->device, HV_HYP_PAGE_SIZE - 1);
1948
1949         stor_device->port_number = host->host_no;
1950         ret = storvsc_connect_to_vsp(device, storvsc_ringbuffer_size, is_fc);
1951         if (ret)
1952                 goto err_out1;
1953
1954         host_dev->path = stor_device->path_id;
1955         host_dev->target = stor_device->target_id;
1956
1957         switch (dev_id->driver_data) {
1958         case SFC_GUID:
1959                 host->max_lun = STORVSC_FC_MAX_LUNS_PER_TARGET;
1960                 host->max_id = STORVSC_FC_MAX_TARGETS;
1961                 host->max_channel = STORVSC_FC_MAX_CHANNELS - 1;
1962 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1963                 host->transportt = fc_transport_template;
1964 #endif
1965                 break;
1966
1967         case SCSI_GUID:
1968                 host->max_lun = STORVSC_MAX_LUNS_PER_TARGET;
1969                 host->max_id = STORVSC_MAX_TARGETS;
1970                 host->max_channel = STORVSC_MAX_CHANNELS - 1;
1971                 break;
1972
1973         default:
1974                 host->max_lun = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1975                 host->max_id = STORVSC_IDE_MAX_TARGETS;
1976                 host->max_channel = STORVSC_IDE_MAX_CHANNELS - 1;
1977                 break;
1978         }
1979         /* max cmd length */
1980         host->max_cmd_len = STORVSC_MAX_CMD_LEN;
1981         /*
1982          * Any reasonable Hyper-V configuration should provide
1983          * max_transfer_bytes value aligning to HV_HYP_PAGE_SIZE,
1984          * protecting it from any weird value.
1985          */
1986         max_xfer_bytes = round_down(stor_device->max_transfer_bytes, HV_HYP_PAGE_SIZE);
1987         /* max_hw_sectors_kb */
1988         host->max_sectors = max_xfer_bytes >> 9;
1989         /*
1990          * There are 2 requirements for Hyper-V storvsc sgl segments,
1991          * based on which the below calculation for max segments is
1992          * done:
1993          *
1994          * 1. Except for the first and last sgl segment, all sgl segments
1995          *    should be align to HV_HYP_PAGE_SIZE, that also means the
1996          *    maximum number of segments in a sgl can be calculated by
1997          *    dividing the total max transfer length by HV_HYP_PAGE_SIZE.
1998          *
1999          * 2. Except for the first and last, each entry in the SGL must
2000          *    have an offset that is a multiple of HV_HYP_PAGE_SIZE.
2001          */
2002         host->sg_tablesize = (max_xfer_bytes >> HV_HYP_PAGE_SHIFT) + 1;
2003         /*
2004          * For non-IDE disks, the host supports multiple channels.
2005          * Set the number of HW queues we are supporting.
2006          */
2007         if (!dev_is_ide) {
2008                 if (storvsc_max_hw_queues > num_present_cpus) {
2009                         storvsc_max_hw_queues = 0;
2010                         storvsc_log(device, STORVSC_LOGGING_WARN,
2011                                 "Resetting invalid storvsc_max_hw_queues value to default.\n");
2012                 }
2013                 if (storvsc_max_hw_queues)
2014                         host->nr_hw_queues = storvsc_max_hw_queues;
2015                 else
2016                         host->nr_hw_queues = num_present_cpus;
2017         }
2018
2019         /*
2020          * Set the error handler work queue.
2021          */
2022         host_dev->handle_error_wq =
2023                         alloc_ordered_workqueue("storvsc_error_wq_%d",
2024                                                 0,
2025                                                 host->host_no);
2026         if (!host_dev->handle_error_wq) {
2027                 ret = -ENOMEM;
2028                 goto err_out2;
2029         }
2030         INIT_WORK(&host_dev->host_scan_work, storvsc_host_scan);
2031         /* Register the HBA and start the scsi bus scan */
2032         ret = scsi_add_host(host, &device->device);
2033         if (ret != 0)
2034                 goto err_out3;
2035
2036         if (!dev_is_ide) {
2037                 scsi_scan_host(host);
2038         } else {
2039                 target = (device->dev_instance.b[5] << 8 |
2040                          device->dev_instance.b[4]);
2041                 ret = scsi_add_device(host, 0, target, 0);
2042                 if (ret)
2043                         goto err_out4;
2044         }
2045 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2046         if (host->transportt == fc_transport_template) {
2047                 struct fc_rport_identifiers ids = {
2048                         .roles = FC_PORT_ROLE_FCP_DUMMY_INITIATOR,
2049                 };
2050
2051                 fc_host_node_name(host) = stor_device->node_name;
2052                 fc_host_port_name(host) = stor_device->port_name;
2053                 stor_device->rport = fc_remote_port_add(host, 0, &ids);
2054                 if (!stor_device->rport) {
2055                         ret = -ENOMEM;
2056                         goto err_out4;
2057                 }
2058         }
2059 #endif
2060         return 0;
2061
2062 err_out4:
2063         scsi_remove_host(host);
2064
2065 err_out3:
2066         destroy_workqueue(host_dev->handle_error_wq);
2067
2068 err_out2:
2069         /*
2070          * Once we have connected with the host, we would need to
2071          * invoke storvsc_dev_remove() to rollback this state and
2072          * this call also frees up the stor_device; hence the jump around
2073          * err_out1 label.
2074          */
2075         storvsc_dev_remove(device);
2076         goto err_out0;
2077
2078 err_out1:
2079         kfree(stor_device->stor_chns);
2080         kfree(stor_device);
2081
2082 err_out0:
2083         scsi_host_put(host);
2084         return ret;
2085 }
2086
2087 /* Change a scsi target's queue depth */
2088 static int storvsc_change_queue_depth(struct scsi_device *sdev, int queue_depth)
2089 {
2090         if (queue_depth > scsi_driver.can_queue)
2091                 queue_depth = scsi_driver.can_queue;
2092
2093         return scsi_change_queue_depth(sdev, queue_depth);
2094 }
2095
2096 static int storvsc_remove(struct hv_device *dev)
2097 {
2098         struct storvsc_device *stor_device = hv_get_drvdata(dev);
2099         struct Scsi_Host *host = stor_device->host;
2100         struct hv_host_device *host_dev = shost_priv(host);
2101
2102 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2103         if (host->transportt == fc_transport_template) {
2104                 fc_remote_port_delete(stor_device->rport);
2105                 fc_remove_host(host);
2106         }
2107 #endif
2108         destroy_workqueue(host_dev->handle_error_wq);
2109         scsi_remove_host(host);
2110         storvsc_dev_remove(dev);
2111         scsi_host_put(host);
2112
2113         return 0;
2114 }
2115
2116 static int storvsc_suspend(struct hv_device *hv_dev)
2117 {
2118         struct storvsc_device *stor_device = hv_get_drvdata(hv_dev);
2119         struct Scsi_Host *host = stor_device->host;
2120         struct hv_host_device *host_dev = shost_priv(host);
2121
2122         storvsc_wait_to_drain(stor_device);
2123
2124         drain_workqueue(host_dev->handle_error_wq);
2125
2126         vmbus_close(hv_dev->channel);
2127
2128         kfree(stor_device->stor_chns);
2129         stor_device->stor_chns = NULL;
2130
2131         cpumask_clear(&stor_device->alloced_cpus);
2132
2133         return 0;
2134 }
2135
2136 static int storvsc_resume(struct hv_device *hv_dev)
2137 {
2138         int ret;
2139
2140         ret = storvsc_connect_to_vsp(hv_dev, storvsc_ringbuffer_size,
2141                                      hv_dev_is_fc(hv_dev));
2142         return ret;
2143 }
2144
2145 static struct hv_driver storvsc_drv = {
2146         .name = KBUILD_MODNAME,
2147         .id_table = id_table,
2148         .probe = storvsc_probe,
2149         .remove = storvsc_remove,
2150         .suspend = storvsc_suspend,
2151         .resume = storvsc_resume,
2152         .driver = {
2153                 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
2154         },
2155 };
2156
2157 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2158 static struct fc_function_template fc_transport_functions = {
2159         .show_host_node_name = 1,
2160         .show_host_port_name = 1,
2161 };
2162 #endif
2163
2164 static int __init storvsc_drv_init(void)
2165 {
2166         int ret;
2167
2168         /*
2169          * Divide the ring buffer data size (which is 1 page less
2170          * than the ring buffer size since that page is reserved for
2171          * the ring buffer indices) by the max request size (which is
2172          * vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
2173          */
2174         max_outstanding_req_per_channel =
2175                 ((storvsc_ringbuffer_size - PAGE_SIZE) /
2176                 ALIGN(MAX_MULTIPAGE_BUFFER_PACKET +
2177                 sizeof(struct vstor_packet) + sizeof(u64),
2178                 sizeof(u64)));
2179
2180 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2181         fc_transport_template = fc_attach_transport(&fc_transport_functions);
2182         if (!fc_transport_template)
2183                 return -ENODEV;
2184 #endif
2185
2186         ret = vmbus_driver_register(&storvsc_drv);
2187
2188 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2189         if (ret)
2190                 fc_release_transport(fc_transport_template);
2191 #endif
2192
2193         return ret;
2194 }
2195
2196 static void __exit storvsc_drv_exit(void)
2197 {
2198         vmbus_driver_unregister(&storvsc_drv);
2199 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2200         fc_release_transport(fc_transport_template);
2201 #endif
2202 }
2203
2204 MODULE_LICENSE("GPL");
2205 MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
2206 module_init(storvsc_drv_init);
2207 module_exit(storvsc_drv_exit);