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. In the 8-bit field, the two high order bits
307	* are flags, while the remaining 6 bits are an integer status code. The
308	* definitions here include only the subset of the integer status codes that
309	* are tested for in this driver.
310	*/
311	#define SRB_STATUS_AUTOSENSE_VALID 0x80
312	#define SRB_STATUS_QUEUE_FROZEN 0x40
313
314	/* SRB status integer codes */
315	#define SRB_STATUS_SUCCESS 0x01
316	#define SRB_STATUS_ABORTED 0x02
317	#define SRB_STATUS_ERROR 0x04
318	#define SRB_STATUS_INVALID_REQUEST 0x06
319	#define SRB_STATUS_TIMEOUT 0x09
320	#define SRB_STATUS_SELECTION_TIMEOUT 0x0A
321	#define SRB_STATUS_BUS_RESET 0x0E
322	#define SRB_STATUS_DATA_OVERRUN 0x12
323	#define SRB_STATUS_INVALID_LUN 0x20
324	#define SRB_STATUS_INTERNAL_ERROR 0x30
325
326	#define SRB_STATUS(status) \
327	(status & ~(SRB_STATUS_AUTOSENSE_VALID | SRB_STATUS_QUEUE_FROZEN))
328	/*
329	* This is the end of Protocol specific defines.
330	*/
331
332	static int storvsc_ringbuffer_size = (128 * 1024);
333	static int aligned_ringbuffer_size;
334	static u32 max_outstanding_req_per_channel;
335	static int storvsc_change_queue_depth(struct scsi_device *sdev, int queue_depth);
336
337	static int storvsc_vcpus_per_sub_channel = 4;
338	static unsigned int storvsc_max_hw_queues;
339
340	module_param(storvsc_ringbuffer_size, int, S_IRUGO);
341	MODULE_PARM_DESC(storvsc_ringbuffer_size, "Ring buffer size (bytes)");
342
343	module_param(storvsc_max_hw_queues, uint, 0644);
344	MODULE_PARM_DESC(storvsc_max_hw_queues, "Maximum number of hardware queues");
345
346	module_param(storvsc_vcpus_per_sub_channel, int, S_IRUGO);
347	MODULE_PARM_DESC(storvsc_vcpus_per_sub_channel, "Ratio of VCPUs to subchannels");
348
349	static int ring_avail_percent_lowater = 10;
350	module_param(ring_avail_percent_lowater, int, S_IRUGO);
351	MODULE_PARM_DESC(ring_avail_percent_lowater,
352	"Select a channel if available ring size > this in percent");
353
354	/*
355	* Timeout in seconds for all devices managed by this driver.
356	*/
357	static int storvsc_timeout = 180;
358
359	#if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
360	static struct scsi_transport_template *fc_transport_template;
361	#endif
362
363	static struct scsi_host_template scsi_driver;
364	static void storvsc_on_channel_callback(void *context);
365
366	#define STORVSC_MAX_LUNS_PER_TARGET 255
367	#define STORVSC_MAX_TARGETS 2
368	#define STORVSC_MAX_CHANNELS 8
369
370	#define STORVSC_FC_MAX_LUNS_PER_TARGET 255
371	#define STORVSC_FC_MAX_TARGETS 128
372	#define STORVSC_FC_MAX_CHANNELS 8
373	#define STORVSC_FC_MAX_XFER_SIZE ((u32)(512 * 1024))
374
375	#define STORVSC_IDE_MAX_LUNS_PER_TARGET 64
376	#define STORVSC_IDE_MAX_TARGETS 1
377	#define STORVSC_IDE_MAX_CHANNELS 1
378
379	/*
380	* Upper bound on the size of a storvsc packet.
381	*/
382	#define STORVSC_MAX_PKT_SIZE (sizeof(struct vmpacket_descriptor) +\
383	sizeof(struct vstor_packet))
384
385	struct storvsc_cmd_request {
386	struct scsi_cmnd *cmd;
387
388	struct hv_device *device;
389
390	/* Synchronize the request/response if needed */
391	struct completion wait_event;
392
393	struct vmbus_channel_packet_multipage_buffer mpb;
394	struct vmbus_packet_mpb_array *payload;
395	u32 payload_sz;
396
397	struct vstor_packet vstor_packet;
398	};
399
400
401	/* A storvsc device is a device object that contains a vmbus channel */
402	struct storvsc_device {
403	struct hv_device *device;
404
405	bool destroy;
406	bool drain_notify;
407	atomic_t num_outstanding_req;
408	struct Scsi_Host *host;
409
410	wait_queue_head_t waiting_to_drain;
411
412	/*
413	* Each unique Port/Path/Target represents 1 channel ie scsi
414	* controller. In reality, the pathid, targetid is always 0
415	* and the port is set by us
416	*/
417	unsigned int port_number;
418	unsigned char path_id;
419	unsigned char target_id;
420
421	/*
422	* Max I/O, the device can support.
423	*/
424	u32 max_transfer_bytes;
425	/*
426	* Number of sub-channels we will open.
427	*/
428	u16 num_sc;
429	struct vmbus_channel **stor_chns;
430	/*
431	* Mask of CPUs bound to subchannels.
432	*/
433	struct cpumask alloced_cpus;
434	/*
435	* Serializes modifications of stor_chns[] from storvsc_do_io()
436	* and storvsc_change_target_cpu().
437	*/
438	spinlock_t lock;
439	/* Used for vsc/vsp channel reset process */
440	struct storvsc_cmd_request init_request;
441	struct storvsc_cmd_request reset_request;
442	/*
443	* Currently active port and node names for FC devices.
444	*/
445	u64 node_name;
446	u64 port_name;
447	#if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
448	struct fc_rport *rport;
449	#endif
450	};
451
452	struct hv_host_device {
453	struct hv_device *dev;
454	unsigned int port;
455	unsigned char path;
456	unsigned char target;
457	struct workqueue_struct *handle_error_wq;
458	struct work_struct host_scan_work;
459	struct Scsi_Host *host;
460	};
461
462	struct storvsc_scan_work {
463	struct work_struct work;
464	struct Scsi_Host *host;
465	u8 lun;
466	u8 tgt_id;
467	};
468
469	static void storvsc_device_scan(struct work_struct *work)
470	{
471	struct storvsc_scan_work *wrk;
472	struct scsi_device *sdev;
473
474	wrk = container_of(work, struct storvsc_scan_work, work);
475
476	sdev = scsi_device_lookup(wrk->host, 0, wrk->tgt_id, wrk->lun);
477	if (!sdev)
478	goto done;
479	scsi_rescan_device(sdev);
480	scsi_device_put(sdev);
481
482	done:
483	kfree(objp: wrk);
484	}
485
486	static void storvsc_host_scan(struct work_struct *work)
487	{
488	struct Scsi_Host *host;
489	struct scsi_device *sdev;
490	struct hv_host_device *host_device =
491	container_of(work, struct hv_host_device, host_scan_work);
492
493	host = host_device->host;
494	/*
495	* Before scanning the host, first check to see if any of the
496	* currently known devices have been hot removed. We issue a
497	* "unit ready" command against all currently known devices.
498	* This I/O will result in an error for devices that have been
499	* removed. As part of handling the I/O error, we remove the device.
500	*
501	* When a LUN is added or removed, the host sends us a signal to
502	* scan the host. Thus we are forced to discover the LUNs that
503	* may have been removed this way.
504	*/
505	mutex_lock(&host->scan_mutex);
506	shost_for_each_device(sdev, host)
507	scsi_test_unit_ready(sdev, timeout: 1, retries: 1, NULL);
508	mutex_unlock(lock: &host->scan_mutex);
509	/*
510	* Now scan the host to discover LUNs that may have been added.
511	*/
512	scsi_scan_host(host);
513	}
514
515	static void storvsc_remove_lun(struct work_struct *work)
516	{
517	struct storvsc_scan_work *wrk;
518	struct scsi_device *sdev;
519
520	wrk = container_of(work, struct storvsc_scan_work, work);
521	if (!scsi_host_get(wrk->host))
522	goto done;
523
524	sdev = scsi_device_lookup(wrk->host, 0, wrk->tgt_id, wrk->lun);
525
526	if (sdev) {
527	scsi_remove_device(sdev);
528	scsi_device_put(sdev);
529	}
530	scsi_host_put(t: wrk->host);
531
532	done:
533	kfree(objp: wrk);
534	}
535
536
537	/*
538	* We can get incoming messages from the host that are not in response to
539	* messages that we have sent out. An example of this would be messages
540	* received by the guest to notify dynamic addition/removal of LUNs. To
541	* deal with potential race conditions where the driver may be in the
542	* midst of being unloaded when we might receive an unsolicited message
543	* from the host, we have implemented a mechanism to gurantee sequential
544	* consistency:
545	*
546	* 1) Once the device is marked as being destroyed, we will fail all
547	* outgoing messages.
548	* 2) We permit incoming messages when the device is being destroyed,
549	* only to properly account for messages already sent out.
550	*/
551
552	static inline struct storvsc_device *get_out_stor_device(
553	struct hv_device *device)
554	{
555	struct storvsc_device *stor_device;
556
557	stor_device = hv_get_drvdata(dev: device);
558
559	if (stor_device && stor_device->destroy)
560	stor_device = NULL;
561
562	return stor_device;
563	}
564
565
566	static inline void storvsc_wait_to_drain(struct storvsc_device *dev)
567	{
568	dev->drain_notify = true;
569	wait_event(dev->waiting_to_drain,
570	atomic_read(&dev->num_outstanding_req) == 0);
571	dev->drain_notify = false;
572	}
573
574	static inline struct storvsc_device *get_in_stor_device(
575	struct hv_device *device)
576	{
577	struct storvsc_device *stor_device;
578
579	stor_device = hv_get_drvdata(dev: device);
580
581	if (!stor_device)
582	goto get_in_err;
583
584	/*
585	* If the device is being destroyed; allow incoming
586	* traffic only to cleanup outstanding requests.
587	*/
588
589	if (stor_device->destroy &&
590	(atomic_read(v: &stor_device->num_outstanding_req) == 0))
591	stor_device = NULL;
592
593	get_in_err:
594	return stor_device;
595
596	}
597
598	static void storvsc_change_target_cpu(struct vmbus_channel *channel, u32 old,
599	u32 new)
600	{
601	struct storvsc_device *stor_device;
602	struct vmbus_channel *cur_chn;
603	bool old_is_alloced = false;
604	struct hv_device *device;
605	unsigned long flags;
606	int cpu;
607
608	device = channel->primary_channel ?
609	channel->primary_channel->device_obj
610	: channel->device_obj;
611	stor_device = get_out_stor_device(device);
612	if (!stor_device)
613	return;
614
615	/* See storvsc_do_io() -> get_og_chn(). */
616	spin_lock_irqsave(&stor_device->lock, flags);
617
618	/*
619	* Determines if the storvsc device has other channels assigned to
620	* the "old" CPU to update the alloced_cpus mask and the stor_chns
621	* array.
622	*/
623	if (device->channel != channel && device->channel->target_cpu == old) {
624	cur_chn = device->channel;
625	old_is_alloced = true;
626	goto old_is_alloced;
627	}
628	list_for_each_entry(cur_chn, &device->channel->sc_list, sc_list) {
629	if (cur_chn == channel)
630	continue;
631	if (cur_chn->target_cpu == old) {
632	old_is_alloced = true;
633	goto old_is_alloced;
634	}
635	}
636
637	old_is_alloced:
638	if (old_is_alloced)
639	WRITE_ONCE(stor_device->stor_chns[old], cur_chn);
640	else
641	cpumask_clear_cpu(cpu: old, dstp: &stor_device->alloced_cpus);
642
643	/* "Flush" the stor_chns array. */
644	for_each_possible_cpu(cpu) {
645	if (stor_device->stor_chns[cpu] && !cpumask_test_cpu(
646	cpu, cpumask: &stor_device->alloced_cpus))
647	WRITE_ONCE(stor_device->stor_chns[cpu], NULL);
648	}
649
650	WRITE_ONCE(stor_device->stor_chns[new], channel);
651	cpumask_set_cpu(cpu: new, dstp: &stor_device->alloced_cpus);
652
653	spin_unlock_irqrestore(lock: &stor_device->lock, flags);
654	}
655
656	static u64 storvsc_next_request_id(struct vmbus_channel *channel, u64 rqst_addr)
657	{
658	struct storvsc_cmd_request *request =
659	(struct storvsc_cmd_request *)(unsigned long)rqst_addr;
660
661	if (rqst_addr == VMBUS_RQST_INIT)
662	return VMBUS_RQST_INIT;
663	if (rqst_addr == VMBUS_RQST_RESET)
664	return VMBUS_RQST_RESET;
665
666	/*
667	* Cannot return an ID of 0, which is reserved for an unsolicited
668	* message from Hyper-V.
669	*/
670	return (u64)blk_mq_unique_tag(rq: scsi_cmd_to_rq(scmd: request->cmd)) + 1;
671	}
672
673	static void handle_sc_creation(struct vmbus_channel *new_sc)
674	{
675	struct hv_device *device = new_sc->primary_channel->device_obj;
676	struct device *dev = &device->device;
677	struct storvsc_device *stor_device;
678	struct vmstorage_channel_properties props;
679	int ret;
680
681	stor_device = get_out_stor_device(device);
682	if (!stor_device)
683	return;
684
685	memset(&props, 0, sizeof(struct vmstorage_channel_properties));
686	new_sc->max_pkt_size = STORVSC_MAX_PKT_SIZE;
687
688	new_sc->next_request_id_callback = storvsc_next_request_id;
689
690	ret = vmbus_open(channel: new_sc,
691	send_ringbuffersize: aligned_ringbuffer_size,
692	recv_ringbuffersize: aligned_ringbuffer_size,
693	userdata: (void *)&props,
694	userdatalen: sizeof(struct vmstorage_channel_properties),
695	onchannel_callback: storvsc_on_channel_callback, context: new_sc);
696
697	/* In case vmbus_open() fails, we don't use the sub-channel. */
698	if (ret != 0) {
699	dev_err(dev, "Failed to open sub-channel: err=%d\n", ret);
700	return;
701	}
702
703	new_sc->change_target_cpu_callback = storvsc_change_target_cpu;
704
705	/* Add the sub-channel to the array of available channels. */
706	stor_device->stor_chns[new_sc->target_cpu] = new_sc;
707	cpumask_set_cpu(cpu: new_sc->target_cpu, dstp: &stor_device->alloced_cpus);
708	}
709
710	static void handle_multichannel_storage(struct hv_device *device, int max_chns)
711	{
712	struct device *dev = &device->device;
713	struct storvsc_device *stor_device;
714	int num_sc;
715	struct storvsc_cmd_request *request;
716	struct vstor_packet *vstor_packet;
717	int ret, t;
718
719	/*
720	* If the number of CPUs is artificially restricted, such as
721	* with maxcpus=1 on the kernel boot line, Hyper-V could offer
722	* sub-channels >= the number of CPUs. These sub-channels
723	* should not be created. The primary channel is already created
724	* and assigned to one CPU, so check against # CPUs - 1.
725	*/
726	num_sc = min((int)(num_online_cpus() - 1), max_chns);
727	if (!num_sc)
728	return;
729
730	stor_device = get_out_stor_device(device);
731	if (!stor_device)
732	return;
733
734	stor_device->num_sc = num_sc;
735	request = &stor_device->init_request;
736	vstor_packet = &request->vstor_packet;
737
738	/*
739	* Establish a handler for dealing with subchannels.
740	*/
741	vmbus_set_sc_create_callback(primary_channel: device->channel, sc_cr_cb: handle_sc_creation);
742
743	/*
744	* Request the host to create sub-channels.
745	*/
746	memset(request, 0, sizeof(struct storvsc_cmd_request));
747	init_completion(x: &request->wait_event);
748	vstor_packet->operation = VSTOR_OPERATION_CREATE_SUB_CHANNELS;
749	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
750	vstor_packet->sub_channel_count = num_sc;
751
752	ret = vmbus_sendpacket(channel: device->channel, buffer: vstor_packet,
753	bufferLen: sizeof(struct vstor_packet),
754	VMBUS_RQST_INIT,
755	type: VM_PKT_DATA_INBAND,
756	VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
757
758	if (ret != 0) {
759	dev_err(dev, "Failed to create sub-channel: err=%d\n", ret);
760	return;
761	}
762
763	t = wait_for_completion_timeout(x: &request->wait_event, timeout: 10*HZ);
764	if (t == 0) {
765	dev_err(dev, "Failed to create sub-channel: timed out\n");
766	return;
767	}
768
769	if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
770	vstor_packet->status != 0) {
771	dev_err(dev, "Failed to create sub-channel: op=%d, sts=%d\n",
772	vstor_packet->operation, vstor_packet->status);
773	return;
774	}
775
776	/*
777	* We need to do nothing here, because vmbus_process_offer()
778	* invokes channel->sc_creation_callback, which will open and use
779	* the sub-channel(s).
780	*/
781	}
782
783	static void cache_wwn(struct storvsc_device *stor_device,
784	struct vstor_packet *vstor_packet)
785	{
786	/*
787	* Cache the currently active port and node ww names.
788	*/
789	if (vstor_packet->wwn_packet.primary_active) {
790	stor_device->node_name =
791	wwn_to_u64(wwn: vstor_packet->wwn_packet.primary_node_wwn);
792	stor_device->port_name =
793	wwn_to_u64(wwn: vstor_packet->wwn_packet.primary_port_wwn);
794	} else {
795	stor_device->node_name =
796	wwn_to_u64(wwn: vstor_packet->wwn_packet.secondary_node_wwn);
797	stor_device->port_name =
798	wwn_to_u64(wwn: vstor_packet->wwn_packet.secondary_port_wwn);
799	}
800	}
801
802
803	static int storvsc_execute_vstor_op(struct hv_device *device,
804	struct storvsc_cmd_request *request,
805	bool status_check)
806	{
807	struct storvsc_device *stor_device;
808	struct vstor_packet *vstor_packet;
809	int ret, t;
810
811	stor_device = get_out_stor_device(device);
812	if (!stor_device)
813	return -ENODEV;
814
815	vstor_packet = &request->vstor_packet;
816
817	init_completion(x: &request->wait_event);
818	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
819
820	ret = vmbus_sendpacket(channel: device->channel, buffer: vstor_packet,
821	bufferLen: sizeof(struct vstor_packet),
822	VMBUS_RQST_INIT,
823	type: VM_PKT_DATA_INBAND,
824	VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
825	if (ret != 0)
826	return ret;
827
828	t = wait_for_completion_timeout(x: &request->wait_event, timeout: 5*HZ);
829	if (t == 0)
830	return -ETIMEDOUT;
831
832	if (!status_check)
833	return ret;
834
835	if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
836	vstor_packet->status != 0)
837	return -EINVAL;
838
839	return ret;
840	}
841
842	static int storvsc_channel_init(struct hv_device *device, bool is_fc)
843	{
844	struct storvsc_device *stor_device;
845	struct storvsc_cmd_request *request;
846	struct vstor_packet *vstor_packet;
847	int ret, i;
848	int max_chns;
849	bool process_sub_channels = false;
850
851	stor_device = get_out_stor_device(device);
852	if (!stor_device)
853	return -ENODEV;
854
855	request = &stor_device->init_request;
856	vstor_packet = &request->vstor_packet;
857
858	/*
859	* Now, initiate the vsc/vsp initialization protocol on the open
860	* channel
861	*/
862	memset(request, 0, sizeof(struct storvsc_cmd_request));
863	vstor_packet->operation = VSTOR_OPERATION_BEGIN_INITIALIZATION;
864	ret = storvsc_execute_vstor_op(device, request, status_check: true);
865	if (ret)
866	return ret;
867	/*
868	* Query host supported protocol version.
869	*/
870
871	for (i = 0; i < ARRAY_SIZE(protocol_version); i++) {
872	/* reuse the packet for version range supported */
873	memset(vstor_packet, 0, sizeof(struct vstor_packet));
874	vstor_packet->operation =
875	VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;
876
877	vstor_packet->version.major_minor = protocol_version[i];
878
879	/*
880	* The revision number is only used in Windows; set it to 0.
881	*/
882	vstor_packet->version.revision = 0;
883	ret = storvsc_execute_vstor_op(device, request, status_check: false);
884	if (ret != 0)
885	return ret;
886
887	if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO)
888	return -EINVAL;
889
890	if (vstor_packet->status == 0) {
891	vmstor_proto_version = protocol_version[i];
892
893	break;
894	}
895	}
896
897	if (vstor_packet->status != 0) {
898	dev_err(&device->device, "Obsolete Hyper-V version\n");
899	return -EINVAL;
900	}
901
902
903	memset(vstor_packet, 0, sizeof(struct vstor_packet));
904	vstor_packet->operation = VSTOR_OPERATION_QUERY_PROPERTIES;
905	ret = storvsc_execute_vstor_op(device, request, status_check: true);
906	if (ret != 0)
907	return ret;
908
909	/*
910	* Check to see if multi-channel support is there.
911	* Hosts that implement protocol version of 5.1 and above
912	* support multi-channel.
913	*/
914	max_chns = vstor_packet->storage_channel_properties.max_channel_cnt;
915
916	/*
917	* Allocate state to manage the sub-channels.
918	* We allocate an array based on the numbers of possible CPUs
919	* (Hyper-V does not support cpu online/offline).
920	* This Array will be sparseley populated with unique
921	* channels - primary + sub-channels.
922	* We will however populate all the slots to evenly distribute
923	* the load.
924	*/
925	stor_device->stor_chns = kcalloc(num_possible_cpus(), size: sizeof(void *),
926	GFP_KERNEL);
927	if (stor_device->stor_chns == NULL)
928	return -ENOMEM;
929
930	device->channel->change_target_cpu_callback = storvsc_change_target_cpu;
931
932	stor_device->stor_chns[device->channel->target_cpu] = device->channel;
933	cpumask_set_cpu(cpu: device->channel->target_cpu,
934	dstp: &stor_device->alloced_cpus);
935
936	if (vstor_packet->storage_channel_properties.flags &
937	STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL)
938	process_sub_channels = true;
939
940	stor_device->max_transfer_bytes =
941	vstor_packet->storage_channel_properties.max_transfer_bytes;
942
943	if (!is_fc)
944	goto done;
945
946	/*
947	* For FC devices retrieve FC HBA data.
948	*/
949	memset(vstor_packet, 0, sizeof(struct vstor_packet));
950	vstor_packet->operation = VSTOR_OPERATION_FCHBA_DATA;
951	ret = storvsc_execute_vstor_op(device, request, status_check: true);
952	if (ret != 0)
953	return ret;
954
955	/*
956	* Cache the currently active port and node ww names.
957	*/
958	cache_wwn(stor_device, vstor_packet);
959
960	done:
961
962	memset(vstor_packet, 0, sizeof(struct vstor_packet));
963	vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
964	ret = storvsc_execute_vstor_op(device, request, status_check: true);
965	if (ret != 0)
966	return ret;
967
968	if (process_sub_channels)
969	handle_multichannel_storage(device, max_chns);
970
971	return ret;
972	}
973
974	static void storvsc_handle_error(struct vmscsi_request *vm_srb,
975	struct scsi_cmnd *scmnd,
976	struct Scsi_Host *host,
977	u8 asc, u8 ascq)
978	{
979	struct storvsc_scan_work *wrk;
980	void (*process_err_fn)(struct work_struct *work);
981	struct hv_host_device *host_dev = shost_priv(shost: host);
982
983	switch (SRB_STATUS(vm_srb->srb_status)) {
984	case SRB_STATUS_ERROR:
985	case SRB_STATUS_ABORTED:
986	case SRB_STATUS_INVALID_REQUEST:
987	case SRB_STATUS_INTERNAL_ERROR:
988	case SRB_STATUS_TIMEOUT:
989	case SRB_STATUS_SELECTION_TIMEOUT:
990	case SRB_STATUS_BUS_RESET:
991	case SRB_STATUS_DATA_OVERRUN:
992	if (vm_srb->srb_status & SRB_STATUS_AUTOSENSE_VALID) {
993	/* Check for capacity change */
994	if ((asc == 0x2a) && (ascq == 0x9)) {
995	process_err_fn = storvsc_device_scan;
996	/* Retry the I/O that triggered this. */
997	set_host_byte(cmd: scmnd, status: DID_REQUEUE);
998	goto do_work;
999	}
1000
1001	/*
1002	* Check for "Operating parameters have changed"
1003	* due to Hyper-V changing the VHD/VHDX BlockSize
1004	* when adding/removing a differencing disk. This
1005	* causes discard_granularity to change, so do a
1006	* rescan to pick up the new granularity. We don't
1007	* want scsi_report_sense() to output a message
1008	* that a sysadmin wouldn't know what to do with.
1009	*/
1010	if ((asc == 0x3f) && (ascq != 0x03) &&
1011	(ascq != 0x0e)) {
1012	process_err_fn = storvsc_device_scan;
1013	set_host_byte(cmd: scmnd, status: DID_REQUEUE);
1014	goto do_work;
1015	}
1016
1017	/*
1018	* Otherwise, let upper layer deal with the
1019	* error when sense message is present
1020	*/
1021	return;
1022	}
1023
1024	/*
1025	* If there is an error; offline the device since all
1026	* error recovery strategies would have already been
1027	* deployed on the host side. However, if the command
1028	* were a pass-through command deal with it appropriately.
1029	*/
1030	switch (scmnd->cmnd[0]) {
1031	case ATA_16:
1032	case ATA_12:
1033	set_host_byte(cmd: scmnd, status: DID_PASSTHROUGH);
1034	break;
1035	/*
1036	* On some Hyper-V hosts TEST_UNIT_READY command can
1037	* return SRB_STATUS_ERROR. Let the upper level code
1038	* deal with it based on the sense information.
1039	*/
1040	case TEST_UNIT_READY:
1041	break;
1042	default:
1043	set_host_byte(cmd: scmnd, status: DID_ERROR);
1044	}
1045	return;
1046
1047	case SRB_STATUS_INVALID_LUN:
1048	set_host_byte(cmd: scmnd, status: DID_NO_CONNECT);
1049	process_err_fn = storvsc_remove_lun;
1050	goto do_work;
1051
1052	}
1053	return;
1054
1055	do_work:
1056	/*
1057	* We need to schedule work to process this error; schedule it.
1058	*/
1059	wrk = kmalloc(size: sizeof(struct storvsc_scan_work), GFP_ATOMIC);
1060	if (!wrk) {
1061	set_host_byte(cmd: scmnd, status: DID_BAD_TARGET);
1062	return;
1063	}
1064
1065	wrk->host = host;
1066	wrk->lun = vm_srb->lun;
1067	wrk->tgt_id = vm_srb->target_id;
1068	INIT_WORK(&wrk->work, process_err_fn);
1069	queue_work(wq: host_dev->handle_error_wq, work: &wrk->work);
1070	}
1071
1072
1073	static void storvsc_command_completion(struct storvsc_cmd_request *cmd_request,
1074	struct storvsc_device *stor_dev)
1075	{
1076	struct scsi_cmnd *scmnd = cmd_request->cmd;
1077	struct scsi_sense_hdr sense_hdr;
1078	struct vmscsi_request *vm_srb;
1079	u32 data_transfer_length;
1080	struct Scsi_Host *host;
1081	u32 payload_sz = cmd_request->payload_sz;
1082	void *payload = cmd_request->payload;
1083	bool sense_ok;
1084
1085	host = stor_dev->host;
1086
1087	vm_srb = &cmd_request->vstor_packet.vm_srb;
1088	data_transfer_length = vm_srb->data_transfer_length;
1089
1090	scmnd->result = vm_srb->scsi_status;
1091
1092	if (scmnd->result) {
1093	sense_ok = scsi_normalize_sense(sense_buffer: scmnd->sense_buffer,
1094	SCSI_SENSE_BUFFERSIZE, sshdr: &sense_hdr);
1095
1096	if (sense_ok && do_logging(STORVSC_LOGGING_WARN))
1097	scsi_print_sense_hdr(scmnd->device, "storvsc",
1098	&sense_hdr);
1099	}
1100
1101	if (vm_srb->srb_status != SRB_STATUS_SUCCESS) {
1102	storvsc_handle_error(vm_srb, scmnd, host, asc: sense_hdr.asc,
1103	ascq: sense_hdr.ascq);
1104	/*
1105	* The Windows driver set data_transfer_length on
1106	* SRB_STATUS_DATA_OVERRUN. On other errors, this value
1107	* is untouched. In these cases we set it to 0.
1108	*/
1109	if (vm_srb->srb_status != SRB_STATUS_DATA_OVERRUN)
1110	data_transfer_length = 0;
1111	}
1112
1113	/* Validate data_transfer_length (from Hyper-V) */
1114	if (data_transfer_length > cmd_request->payload->range.len)
1115	data_transfer_length = cmd_request->payload->range.len;
1116
1117	scsi_set_resid(cmd: scmnd,
1118	resid: cmd_request->payload->range.len - data_transfer_length);
1119
1120	scsi_done(cmd: scmnd);
1121
1122	if (payload_sz >
1123	sizeof(struct vmbus_channel_packet_multipage_buffer))
1124	kfree(objp: payload);
1125	}
1126
1127	static void storvsc_on_io_completion(struct storvsc_device *stor_device,
1128	struct vstor_packet *vstor_packet,
1129	struct storvsc_cmd_request *request)
1130	{
1131	struct vstor_packet *stor_pkt;
1132	struct hv_device *device = stor_device->device;
1133
1134	stor_pkt = &request->vstor_packet;
1135
1136	/*
1137	* The current SCSI handling on the host side does
1138	* not correctly handle:
1139	* INQUIRY command with page code parameter set to 0x80
1140	* MODE_SENSE command with cmd[2] == 0x1c
1141	*
1142	* Setup srb and scsi status so this won't be fatal.
1143	* We do this so we can distinguish truly fatal failues
1144	* (srb status == 0x4) and off-line the device in that case.
1145	*/
1146
1147	if ((stor_pkt->vm_srb.cdb[0] == INQUIRY) ||
1148	(stor_pkt->vm_srb.cdb[0] == MODE_SENSE)) {
1149	vstor_packet->vm_srb.scsi_status = 0;
1150	vstor_packet->vm_srb.srb_status = SRB_STATUS_SUCCESS;
1151	}
1152
1153	/* Copy over the status...etc */
1154	stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
1155	stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
1156
1157	/*
1158	* Copy over the sense_info_length, but limit to the known max
1159	* size if Hyper-V returns a bad value.
1160	*/
1161	stor_pkt->vm_srb.sense_info_length = min_t(u8, STORVSC_SENSE_BUFFER_SIZE,
1162	vstor_packet->vm_srb.sense_info_length);
1163
1164	if (vstor_packet->vm_srb.scsi_status != 0 ||
1165	vstor_packet->vm_srb.srb_status != SRB_STATUS_SUCCESS) {
1166
1167	/*
1168	* Log TEST_UNIT_READY errors only as warnings. Hyper-V can
1169	* return errors when detecting devices using TEST_UNIT_READY,
1170	* and logging these as errors produces unhelpful noise.
1171	*/
1172	int loglevel = (stor_pkt->vm_srb.cdb[0] == TEST_UNIT_READY) ?
1173	STORVSC_LOGGING_WARN : STORVSC_LOGGING_ERROR;
1174
1175	storvsc_log(device, loglevel,
1176	"tag#%d cmd 0x%x status: scsi 0x%x srb 0x%x hv 0x%x\n",
1177	scsi_cmd_to_rq(request->cmd)->tag,
1178	stor_pkt->vm_srb.cdb[0],
1179	vstor_packet->vm_srb.scsi_status,
1180	vstor_packet->vm_srb.srb_status,
1181	vstor_packet->status);
1182	}
1183
1184	if (vstor_packet->vm_srb.scsi_status == SAM_STAT_CHECK_CONDITION &&
1185	(vstor_packet->vm_srb.srb_status & SRB_STATUS_AUTOSENSE_VALID))
1186	memcpy(request->cmd->sense_buffer,
1187	vstor_packet->vm_srb.sense_data,
1188	stor_pkt->vm_srb.sense_info_length);
1189
1190	stor_pkt->vm_srb.data_transfer_length =
1191	vstor_packet->vm_srb.data_transfer_length;
1192
1193	storvsc_command_completion(cmd_request: request, stor_dev: stor_device);
1194
1195	if (atomic_dec_and_test(v: &stor_device->num_outstanding_req) &&
1196	stor_device->drain_notify)
1197	wake_up(&stor_device->waiting_to_drain);
1198	}
1199
1200	static void storvsc_on_receive(struct storvsc_device *stor_device,
1201	struct vstor_packet *vstor_packet,
1202	struct storvsc_cmd_request *request)
1203	{
1204	struct hv_host_device *host_dev;
1205	switch (vstor_packet->operation) {
1206	case VSTOR_OPERATION_COMPLETE_IO:
1207	storvsc_on_io_completion(stor_device, vstor_packet, request);
1208	break;
1209
1210	case VSTOR_OPERATION_REMOVE_DEVICE:
1211	case VSTOR_OPERATION_ENUMERATE_BUS:
1212	host_dev = shost_priv(shost: stor_device->host);
1213	queue_work(
1214	wq: host_dev->handle_error_wq, work: &host_dev->host_scan_work);
1215	break;
1216
1217	case VSTOR_OPERATION_FCHBA_DATA:
1218	cache_wwn(stor_device, vstor_packet);
1219	#if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1220	fc_host_node_name(stor_device->host) = stor_device->node_name;
1221	fc_host_port_name(stor_device->host) = stor_device->port_name;
1222	#endif
1223	break;
1224	default:
1225	break;
1226	}
1227	}
1228
1229	static void storvsc_on_channel_callback(void *context)
1230	{
1231	struct vmbus_channel *channel = (struct vmbus_channel *)context;
1232	const struct vmpacket_descriptor *desc;
1233	struct hv_device *device;
1234	struct storvsc_device *stor_device;
1235	struct Scsi_Host *shost;
1236	unsigned long time_limit = jiffies + msecs_to_jiffies(CALLBACK_TIMEOUT);
1237
1238	if (channel->primary_channel != NULL)
1239	device = channel->primary_channel->device_obj;
1240	else
1241	device = channel->device_obj;
1242
1243	stor_device = get_in_stor_device(device);
1244	if (!stor_device)
1245	return;
1246
1247	shost = stor_device->host;
1248
1249	foreach_vmbus_pkt(desc, channel) {
1250	struct vstor_packet *packet = hv_pkt_data(desc);
1251	struct storvsc_cmd_request *request = NULL;
1252	u32 pktlen = hv_pkt_datalen(desc);
1253	u64 rqst_id = desc->trans_id;
1254	u32 minlen = rqst_id ? sizeof(struct vstor_packet) :
1255	sizeof(enum vstor_packet_operation);
1256
1257	if (unlikely(time_after(jiffies, time_limit))) {
1258	hv_pkt_iter_close(channel);
1259	return;
1260	}
1261
1262	if (pktlen < minlen) {
1263	dev_err(&device->device,
1264	"Invalid pkt: id=%llu, len=%u, minlen=%u\n",
1265	rqst_id, pktlen, minlen);
1266	continue;
1267	}
1268
1269	if (rqst_id == VMBUS_RQST_INIT) {
1270	request = &stor_device->init_request;
1271	} else if (rqst_id == VMBUS_RQST_RESET) {
1272	request = &stor_device->reset_request;
1273	} else {
1274	/* Hyper-V can send an unsolicited message with ID of 0 */
1275	if (rqst_id == 0) {
1276	/*
1277	* storvsc_on_receive() looks at the vstor_packet in the message
1278	* from the ring buffer.
1279	*
1280	* - If the operation in the vstor_packet is COMPLETE_IO, then
1281	* we call storvsc_on_io_completion(), and dereference the
1282	* guest memory address. Make sure we don't call
1283	* storvsc_on_io_completion() with a guest memory address
1284	* that is zero if Hyper-V were to construct and send such
1285	* a bogus packet.
1286	*
1287	* - If the operation in the vstor_packet is FCHBA_DATA, then
1288	* we call cache_wwn(), and access the data payload area of
1289	* the packet (wwn_packet); however, there is no guarantee
1290	* that the packet is big enough to contain such area.
1291	* Future-proof the code by rejecting such a bogus packet.
1292	*/
1293	if (packet->operation == VSTOR_OPERATION_COMPLETE_IO ||
1294	packet->operation == VSTOR_OPERATION_FCHBA_DATA) {
1295	dev_err(&device->device, "Invalid packet with ID of 0\n");
1296	continue;
1297	}
1298	} else {
1299	struct scsi_cmnd *scmnd;
1300
1301	/* Transaction 'rqst_id' corresponds to tag 'rqst_id - 1' */
1302	scmnd = scsi_host_find_tag(shost, tag: rqst_id - 1);
1303	if (scmnd == NULL) {
1304	dev_err(&device->device, "Incorrect transaction ID\n");
1305	continue;
1306	}
1307	request = (struct storvsc_cmd_request *)scsi_cmd_priv(cmd: scmnd);
1308	scsi_dma_unmap(cmd: scmnd);
1309	}
1310
1311	storvsc_on_receive(stor_device, vstor_packet: packet, request);
1312	continue;
1313	}
1314
1315	memcpy(&request->vstor_packet, packet,
1316	sizeof(struct vstor_packet));
1317	complete(&request->wait_event);
1318	}
1319	}
1320
1321	static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size,
1322	bool is_fc)
1323	{
1324	struct vmstorage_channel_properties props;
1325	int ret;
1326
1327	memset(&props, 0, sizeof(struct vmstorage_channel_properties));
1328
1329	device->channel->max_pkt_size = STORVSC_MAX_PKT_SIZE;
1330	device->channel->next_request_id_callback = storvsc_next_request_id;
1331
1332	ret = vmbus_open(channel: device->channel,
1333	send_ringbuffersize: ring_size,
1334	recv_ringbuffersize: ring_size,
1335	userdata: (void *)&props,
1336	userdatalen: sizeof(struct vmstorage_channel_properties),
1337	onchannel_callback: storvsc_on_channel_callback, context: device->channel);
1338
1339	if (ret != 0)
1340	return ret;
1341
1342	ret = storvsc_channel_init(device, is_fc);
1343
1344	return ret;
1345	}
1346
1347	static int storvsc_dev_remove(struct hv_device *device)
1348	{
1349	struct storvsc_device *stor_device;
1350
1351	stor_device = hv_get_drvdata(dev: device);
1352
1353	stor_device->destroy = true;
1354
1355	/* Make sure flag is set before waiting */
1356	wmb();
1357
1358	/*
1359	* At this point, all outbound traffic should be disable. We
1360	* only allow inbound traffic (responses) to proceed so that
1361	* outstanding requests can be completed.
1362	*/
1363
1364	storvsc_wait_to_drain(dev: stor_device);
1365
1366	/*
1367	* Since we have already drained, we don't need to busy wait
1368	* as was done in final_release_stor_device()
1369	* Note that we cannot set the ext pointer to NULL until
1370	* we have drained - to drain the outgoing packets, we need to
1371	* allow incoming packets.
1372	*/
1373	hv_set_drvdata(dev: device, NULL);
1374
1375	/* Close the channel */
1376	vmbus_close(channel: device->channel);
1377
1378	kfree(objp: stor_device->stor_chns);
1379	kfree(objp: stor_device);
1380	return 0;
1381	}
1382
1383	static struct vmbus_channel *get_og_chn(struct storvsc_device *stor_device,
1384	u16 q_num)
1385	{
1386	u16 slot = 0;
1387	u16 hash_qnum;
1388	const struct cpumask *node_mask;
1389	int num_channels, tgt_cpu;
1390
1391	if (stor_device->num_sc == 0) {
1392	stor_device->stor_chns[q_num] = stor_device->device->channel;
1393	return stor_device->device->channel;
1394	}
1395
1396	/*
1397	* Our channel array is sparsley populated and we
1398	* initiated I/O on a processor/hw-q that does not
1399	* currently have a designated channel. Fix this.
1400	* The strategy is simple:
1401	* I. Ensure NUMA locality
1402	* II. Distribute evenly (best effort)
1403	*/
1404
1405	node_mask = cpumask_of_node(cpu_to_node(cpu: q_num));
1406
1407	num_channels = 0;
1408	for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1409	if (cpumask_test_cpu(cpu: tgt_cpu, cpumask: node_mask))
1410	num_channels++;
1411	}
1412	if (num_channels == 0) {
1413	stor_device->stor_chns[q_num] = stor_device->device->channel;
1414	return stor_device->device->channel;
1415	}
1416
1417	hash_qnum = q_num;
1418	while (hash_qnum >= num_channels)
1419	hash_qnum -= num_channels;
1420
1421	for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1422	if (!cpumask_test_cpu(cpu: tgt_cpu, cpumask: node_mask))
1423	continue;
1424	if (slot == hash_qnum)
1425	break;
1426	slot++;
1427	}
1428
1429	stor_device->stor_chns[q_num] = stor_device->stor_chns[tgt_cpu];
1430
1431	return stor_device->stor_chns[q_num];
1432	}
1433
1434
1435	static int storvsc_do_io(struct hv_device *device,
1436	struct storvsc_cmd_request *request, u16 q_num)
1437	{
1438	struct storvsc_device *stor_device;
1439	struct vstor_packet *vstor_packet;
1440	struct vmbus_channel *outgoing_channel, *channel;
1441	unsigned long flags;
1442	int ret = 0;
1443	const struct cpumask *node_mask;
1444	int tgt_cpu;
1445
1446	vstor_packet = &request->vstor_packet;
1447	stor_device = get_out_stor_device(device);
1448
1449	if (!stor_device)
1450	return -ENODEV;
1451
1452
1453	request->device = device;
1454	/*
1455	* Select an appropriate channel to send the request out.
1456	*/
1457	/* See storvsc_change_target_cpu(). */
1458	outgoing_channel = READ_ONCE(stor_device->stor_chns[q_num]);
1459	if (outgoing_channel != NULL) {
1460	if (outgoing_channel->target_cpu == q_num) {
1461	/*
1462	* Ideally, we want to pick a different channel if
1463	* available on the same NUMA node.
1464	*/
1465	node_mask = cpumask_of_node(cpu_to_node(cpu: q_num));
1466	for_each_cpu_wrap(tgt_cpu,
1467	&stor_device->alloced_cpus, q_num + 1) {
1468	if (!cpumask_test_cpu(cpu: tgt_cpu, cpumask: node_mask))
1469	continue;
1470	if (tgt_cpu == q_num)
1471	continue;
1472	channel = READ_ONCE(
1473	stor_device->stor_chns[tgt_cpu]);
1474	if (channel == NULL)
1475	continue;
1476	if (hv_get_avail_to_write_percent(
1477	rbi: &channel->outbound)
1478	> ring_avail_percent_lowater) {
1479	outgoing_channel = channel;
1480	goto found_channel;
1481	}
1482	}
1483
1484	/*
1485	* All the other channels on the same NUMA node are
1486	* busy. Try to use the channel on the current CPU
1487	*/
1488	if (hv_get_avail_to_write_percent(
1489	rbi: &outgoing_channel->outbound)
1490	> ring_avail_percent_lowater)
1491	goto found_channel;
1492
1493	/*
1494	* If we reach here, all the channels on the current
1495	* NUMA node are busy. Try to find a channel in
1496	* other NUMA nodes
1497	*/
1498	for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1499	if (cpumask_test_cpu(cpu: tgt_cpu, cpumask: node_mask))
1500	continue;
1501	channel = READ_ONCE(
1502	stor_device->stor_chns[tgt_cpu]);
1503	if (channel == NULL)
1504	continue;
1505	if (hv_get_avail_to_write_percent(
1506	rbi: &channel->outbound)
1507	> ring_avail_percent_lowater) {
1508	outgoing_channel = channel;
1509	goto found_channel;
1510	}
1511	}
1512	}
1513	} else {
1514	spin_lock_irqsave(&stor_device->lock, flags);
1515	outgoing_channel = stor_device->stor_chns[q_num];
1516	if (outgoing_channel != NULL) {
1517	spin_unlock_irqrestore(lock: &stor_device->lock, flags);
1518	goto found_channel;
1519	}
1520	outgoing_channel = get_og_chn(stor_device, q_num);
1521	spin_unlock_irqrestore(lock: &stor_device->lock, flags);
1522	}
1523
1524	found_channel:
1525	vstor_packet->flags |= REQUEST_COMPLETION_FLAG;
1526
1527	vstor_packet->vm_srb.length = sizeof(struct vmscsi_request);
1528
1529
1530	vstor_packet->vm_srb.sense_info_length = STORVSC_SENSE_BUFFER_SIZE;
1531
1532
1533	vstor_packet->vm_srb.data_transfer_length =
1534	request->payload->range.len;
1535
1536	vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
1537
1538	if (request->payload->range.len) {
1539
1540	ret = vmbus_sendpacket_mpb_desc(channel: outgoing_channel,
1541	mpb: request->payload, desc_size: request->payload_sz,
1542	buffer: vstor_packet,
1543	bufferlen: sizeof(struct vstor_packet),
1544	requestid: (unsigned long)request);
1545	} else {
1546	ret = vmbus_sendpacket(channel: outgoing_channel, buffer: vstor_packet,
1547	bufferLen: sizeof(struct vstor_packet),
1548	requestid: (unsigned long)request,
1549	type: VM_PKT_DATA_INBAND,
1550	VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1551	}
1552
1553	if (ret != 0)
1554	return ret;
1555
1556	atomic_inc(v: &stor_device->num_outstanding_req);
1557
1558	return ret;
1559	}
1560
1561	static int storvsc_device_alloc(struct scsi_device *sdevice)
1562	{
1563	/*
1564	* Set blist flag to permit the reading of the VPD pages even when
1565	* the target may claim SPC-2 compliance. MSFT targets currently
1566	* claim SPC-2 compliance while they implement post SPC-2 features.
1567	* With this flag we can correctly handle WRITE_SAME_16 issues.
1568	*
1569	* Hypervisor reports SCSI_UNKNOWN type for DVD ROM device but
1570	* still supports REPORT LUN.
1571	*/
1572	sdevice->sdev_bflags = BLIST_REPORTLUN2 | BLIST_TRY_VPD_PAGES;
1573
1574	return 0;
1575	}
1576
1577	static int storvsc_device_configure(struct scsi_device *sdevice)
1578	{
1579	blk_queue_rq_timeout(sdevice->request_queue, (storvsc_timeout * HZ));
1580
1581	/* storvsc devices don't support MAINTENANCE_IN SCSI cmd */
1582	sdevice->no_report_opcodes = 1;
1583	sdevice->no_write_same = 1;
1584
1585	/*
1586	* If the host is WIN8 or WIN8 R2, claim conformance to SPC-3
1587	* if the device is a MSFT virtual device. If the host is
1588	* WIN10 or newer, allow write_same.
1589	*/
1590	if (!strncmp(sdevice->vendor, "Msft", 4)) {
1591	switch (vmstor_proto_version) {
1592	case VMSTOR_PROTO_VERSION_WIN8:
1593	case VMSTOR_PROTO_VERSION_WIN8_1:
1594	sdevice->scsi_level = SCSI_SPC_3;
1595	break;
1596	}
1597
1598	if (vmstor_proto_version >= VMSTOR_PROTO_VERSION_WIN10)
1599	sdevice->no_write_same = 0;
1600	}
1601
1602	return 0;
1603	}
1604
1605	static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
1606	sector_t capacity, int *info)
1607	{
1608	sector_t nsect = capacity;
1609	sector_t cylinders = nsect;
1610	int heads, sectors_pt;
1611
1612	/*
1613	* We are making up these values; let us keep it simple.
1614	*/
1615	heads = 0xff;
1616	sectors_pt = 0x3f; /* Sectors per track */
1617	sector_div(cylinders, heads * sectors_pt);
1618	if ((sector_t)(cylinders + 1) * heads * sectors_pt < nsect)
1619	cylinders = 0xffff;
1620
1621	info[0] = heads;
1622	info[1] = sectors_pt;
1623	info[2] = (int)cylinders;
1624
1625	return 0;
1626	}
1627
1628	static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
1629	{
1630	struct hv_host_device *host_dev = shost_priv(shost: scmnd->device->host);
1631	struct hv_device *device = host_dev->dev;
1632
1633	struct storvsc_device *stor_device;
1634	struct storvsc_cmd_request *request;
1635	struct vstor_packet *vstor_packet;
1636	int ret, t;
1637
1638	stor_device = get_out_stor_device(device);
1639	if (!stor_device)
1640	return FAILED;
1641
1642	request = &stor_device->reset_request;
1643	vstor_packet = &request->vstor_packet;
1644	memset(vstor_packet, 0, sizeof(struct vstor_packet));
1645
1646	init_completion(x: &request->wait_event);
1647
1648	vstor_packet->operation = VSTOR_OPERATION_RESET_BUS;
1649	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
1650	vstor_packet->vm_srb.path_id = stor_device->path_id;
1651
1652	ret = vmbus_sendpacket(channel: device->channel, buffer: vstor_packet,
1653	bufferLen: sizeof(struct vstor_packet),
1654	VMBUS_RQST_RESET,
1655	type: VM_PKT_DATA_INBAND,
1656	VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1657	if (ret != 0)
1658	return FAILED;
1659
1660	t = wait_for_completion_timeout(x: &request->wait_event, timeout: 5*HZ);
1661	if (t == 0)
1662	return TIMEOUT_ERROR;
1663
1664
1665	/*
1666	* At this point, all outstanding requests in the adapter
1667	* should have been flushed out and return to us
1668	* There is a potential race here where the host may be in
1669	* the process of responding when we return from here.
1670	* Just wait for all in-transit packets to be accounted for
1671	* before we return from here.
1672	*/
1673	storvsc_wait_to_drain(dev: stor_device);
1674
1675	return SUCCESS;
1676	}
1677
1678	/*
1679	* The host guarantees to respond to each command, although I/O latencies might
1680	* be unbounded on Azure. Reset the timer unconditionally to give the host a
1681	* chance to perform EH.
1682	*/
1683	static enum scsi_timeout_action storvsc_eh_timed_out(struct scsi_cmnd *scmnd)
1684	{
1685	return SCSI_EH_RESET_TIMER;
1686	}
1687
1688	static bool storvsc_scsi_cmd_ok(struct scsi_cmnd *scmnd)
1689	{
1690	bool allowed = true;
1691	u8 scsi_op = scmnd->cmnd[0];
1692
1693	switch (scsi_op) {
1694	/* the host does not handle WRITE_SAME, log accident usage */
1695	case WRITE_SAME:
1696	/*
1697	* smartd sends this command and the host does not handle
1698	* this. So, don't send it.
1699	*/
1700	case SET_WINDOW:
1701	set_host_byte(cmd: scmnd, status: DID_ERROR);
1702	allowed = false;
1703	break;
1704	default:
1705	break;
1706	}
1707	return allowed;
1708	}
1709
1710	static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
1711	{
1712	int ret;
1713	struct hv_host_device *host_dev = shost_priv(shost: host);
1714	struct hv_device *dev = host_dev->dev;
1715	struct storvsc_cmd_request *cmd_request = scsi_cmd_priv(cmd: scmnd);
1716	struct scatterlist *sgl;
1717	struct vmscsi_request *vm_srb;
1718	struct vmbus_packet_mpb_array *payload;
1719	u32 payload_sz;
1720	u32 length;
1721
1722	if (vmstor_proto_version <= VMSTOR_PROTO_VERSION_WIN8) {
1723	/*
1724	* On legacy hosts filter unimplemented commands.
1725	* Future hosts are expected to correctly handle
1726	* unsupported commands. Furthermore, it is
1727	* possible that some of the currently
1728	* unsupported commands maybe supported in
1729	* future versions of the host.
1730	*/
1731	if (!storvsc_scsi_cmd_ok(scmnd)) {
1732	scsi_done(cmd: scmnd);
1733	return 0;
1734	}
1735	}
1736
1737	/* Setup the cmd request */
1738	cmd_request->cmd = scmnd;
1739
1740	memset(&cmd_request->vstor_packet, 0, sizeof(struct vstor_packet));
1741	vm_srb = &cmd_request->vstor_packet.vm_srb;
1742	vm_srb->time_out_value = 60;
1743
1744	vm_srb->srb_flags |=
1745	SRB_FLAGS_DISABLE_SYNCH_TRANSFER;
1746
1747	if (scmnd->device->tagged_supported) {
1748	vm_srb->srb_flags |=
1749	(SRB_FLAGS_QUEUE_ACTION_ENABLE | SRB_FLAGS_NO_QUEUE_FREEZE);
1750	vm_srb->queue_tag = SP_UNTAGGED;
1751	vm_srb->queue_action = SRB_SIMPLE_TAG_REQUEST;
1752	}
1753
1754	/* Build the SRB */
1755	switch (scmnd->sc_data_direction) {
1756	case DMA_TO_DEVICE:
1757	vm_srb->data_in = WRITE_TYPE;
1758	vm_srb->srb_flags |= SRB_FLAGS_DATA_OUT;
1759	break;
1760	case DMA_FROM_DEVICE:
1761	vm_srb->data_in = READ_TYPE;
1762	vm_srb->srb_flags |= SRB_FLAGS_DATA_IN;
1763	break;
1764	case DMA_NONE:
1765	vm_srb->data_in = UNKNOWN_TYPE;
1766	vm_srb->srb_flags |= SRB_FLAGS_NO_DATA_TRANSFER;
1767	break;
1768	default:
1769	/*
1770	* This is DMA_BIDIRECTIONAL or something else we are never
1771	* supposed to see here.
1772	*/
1773	WARN(1, "Unexpected data direction: %d\n",
1774	scmnd->sc_data_direction);
1775	return -EINVAL;
1776	}
1777
1778
1779	vm_srb->port_number = host_dev->port;
1780	vm_srb->path_id = scmnd->device->channel;
1781	vm_srb->target_id = scmnd->device->id;
1782	vm_srb->lun = scmnd->device->lun;
1783
1784	vm_srb->cdb_length = scmnd->cmd_len;
1785
1786	memcpy(vm_srb->cdb, scmnd->cmnd, vm_srb->cdb_length);
1787
1788	sgl = (struct scatterlist *)scsi_sglist(cmd: scmnd);
1789
1790	length = scsi_bufflen(cmd: scmnd);
1791	payload = (struct vmbus_packet_mpb_array *)&cmd_request->mpb;
1792	payload_sz = 0;
1793
1794	if (scsi_sg_count(cmd: scmnd)) {
1795	unsigned long offset_in_hvpg = offset_in_hvpage(sgl->offset);
1796	unsigned int hvpg_count = HVPFN_UP(offset_in_hvpg + length);
1797	struct scatterlist *sg;
1798	unsigned long hvpfn, hvpfns_to_add;
1799	int j, i = 0, sg_count;
1800
1801	payload_sz = (hvpg_count * sizeof(u64) +
1802	sizeof(struct vmbus_packet_mpb_array));
1803
1804	if (hvpg_count > MAX_PAGE_BUFFER_COUNT) {
1805	payload = kzalloc(size: payload_sz, GFP_ATOMIC);
1806	if (!payload)
1807	return SCSI_MLQUEUE_DEVICE_BUSY;
1808	}
1809
1810	payload->range.len = length;
1811	payload->range.offset = offset_in_hvpg;
1812
1813	sg_count = scsi_dma_map(cmd: scmnd);
1814	if (sg_count < 0) {
1815	ret = SCSI_MLQUEUE_DEVICE_BUSY;
1816	goto err_free_payload;
1817	}
1818
1819	for_each_sg(sgl, sg, sg_count, j) {
1820	/*
1821	* Init values for the current sgl entry. hvpfns_to_add
1822	* is in units of Hyper-V size pages. Handling the
1823	* PAGE_SIZE != HV_HYP_PAGE_SIZE case also handles
1824	* values of sgl->offset that are larger than PAGE_SIZE.
1825	* Such offsets are handled even on other than the first
1826	* sgl entry, provided they are a multiple of PAGE_SIZE.
1827	*/
1828	hvpfn = HVPFN_DOWN(sg_dma_address(sg));
1829	hvpfns_to_add = HVPFN_UP(sg_dma_address(sg) +
1830	sg_dma_len(sg)) - hvpfn;
1831
1832	/*
1833	* Fill the next portion of the PFN array with
1834	* sequential Hyper-V PFNs for the continguous physical
1835	* memory described by the sgl entry. The end of the
1836	* last sgl should be reached at the same time that
1837	* the PFN array is filled.
1838	*/
1839	while (hvpfns_to_add--)
1840	payload->range.pfn_array[i++] = hvpfn++;
1841	}
1842	}
1843
1844	cmd_request->payload = payload;
1845	cmd_request->payload_sz = payload_sz;
1846
1847	/* Invokes the vsc to start an IO */
1848	ret = storvsc_do_io(device: dev, request: cmd_request, get_cpu());
1849	put_cpu();
1850
1851	if (ret)
1852	scsi_dma_unmap(cmd: scmnd);
1853
1854	if (ret == -EAGAIN) {
1855	/* no more space */
1856	ret = SCSI_MLQUEUE_DEVICE_BUSY;
1857	goto err_free_payload;
1858	}
1859
1860	return 0;
1861
1862	err_free_payload:
1863	if (payload_sz > sizeof(cmd_request->mpb))
1864	kfree(objp: payload);
1865
1866	return ret;
1867	}
1868
1869	static struct scsi_host_template scsi_driver = {
1870	.module = THIS_MODULE,
1871	.name = "storvsc_host_t",
1872	.cmd_size = sizeof(struct storvsc_cmd_request),
1873	.bios_param = storvsc_get_chs,
1874	.queuecommand = storvsc_queuecommand,
1875	.eh_host_reset_handler = storvsc_host_reset_handler,
1876	.proc_name = "storvsc_host",
1877	.eh_timed_out = storvsc_eh_timed_out,
1878	.slave_alloc = storvsc_device_alloc,
1879	.slave_configure = storvsc_device_configure,
1880	.cmd_per_lun = 2048,
1881	.this_id = -1,
1882	/* Ensure there are no gaps in presented sgls */
1883	.virt_boundary_mask = HV_HYP_PAGE_SIZE - 1,
1884	.no_write_same = 1,
1885	.track_queue_depth = 1,
1886	.change_queue_depth = storvsc_change_queue_depth,
1887	};
1888
1889	enum {
1890	SCSI_GUID,
1891	IDE_GUID,
1892	SFC_GUID,
1893	};
1894
1895	static const struct hv_vmbus_device_id id_table[] = {
1896	/* SCSI guid */
1897	{ HV_SCSI_GUID,
1898	.driver_data = SCSI_GUID
1899	},
1900	/* IDE guid */
1901	{ HV_IDE_GUID,
1902	.driver_data = IDE_GUID
1903	},
1904	/* Fibre Channel GUID */
1905	{
1906	HV_SYNTHFC_GUID,
1907	.driver_data = SFC_GUID
1908	},
1909	{ },
1910	};
1911
1912	MODULE_DEVICE_TABLE(vmbus, id_table);
1913
1914	static const struct { guid_t guid; } fc_guid = { HV_SYNTHFC_GUID };
1915
1916	static bool hv_dev_is_fc(struct hv_device *hv_dev)
1917	{
1918	return guid_equal(u1: &fc_guid.guid, u2: &hv_dev->dev_type);
1919	}
1920
1921	static int storvsc_probe(struct hv_device *device,
1922	const struct hv_vmbus_device_id *dev_id)
1923	{
1924	int ret;
1925	int num_cpus = num_online_cpus();
1926	int num_present_cpus = num_present_cpus();
1927	struct Scsi_Host *host;
1928	struct hv_host_device *host_dev;
1929	bool dev_is_ide = ((dev_id->driver_data == IDE_GUID) ? true : false);
1930	bool is_fc = ((dev_id->driver_data == SFC_GUID) ? true : false);
1931	int target = 0;
1932	struct storvsc_device *stor_device;
1933	int max_sub_channels = 0;
1934	u32 max_xfer_bytes;
1935
1936	/*
1937	* We support sub-channels for storage on SCSI and FC controllers.
1938	* The number of sub-channels offerred is based on the number of
1939	* VCPUs in the guest.
1940	*/
1941	if (!dev_is_ide)
1942	max_sub_channels =
1943	(num_cpus - 1) / storvsc_vcpus_per_sub_channel;
1944
1945	scsi_driver.can_queue = max_outstanding_req_per_channel *
1946	(max_sub_channels + 1) *
1947	(100 - ring_avail_percent_lowater) / 100;
1948
1949	host = scsi_host_alloc(&scsi_driver,
1950	sizeof(struct hv_host_device));
1951	if (!host)
1952	return -ENOMEM;
1953
1954	host_dev = shost_priv(shost: host);
1955	memset(host_dev, 0, sizeof(struct hv_host_device));
1956
1957	host_dev->port = host->host_no;
1958	host_dev->dev = device;
1959	host_dev->host = host;
1960
1961
1962	stor_device = kzalloc(size: sizeof(struct storvsc_device), GFP_KERNEL);
1963	if (!stor_device) {
1964	ret = -ENOMEM;
1965	goto err_out0;
1966	}
1967
1968	stor_device->destroy = false;
1969	init_waitqueue_head(&stor_device->waiting_to_drain);
1970	stor_device->device = device;
1971	stor_device->host = host;
1972	spin_lock_init(&stor_device->lock);
1973	hv_set_drvdata(dev: device, data: stor_device);
1974	dma_set_min_align_mask(dev: &device->device, HV_HYP_PAGE_SIZE - 1);
1975
1976	stor_device->port_number = host->host_no;
1977	ret = storvsc_connect_to_vsp(device, ring_size: aligned_ringbuffer_size, is_fc);
1978	if (ret)
1979	goto err_out1;
1980
1981	host_dev->path = stor_device->path_id;
1982	host_dev->target = stor_device->target_id;
1983
1984	switch (dev_id->driver_data) {
1985	case SFC_GUID:
1986	host->max_lun = STORVSC_FC_MAX_LUNS_PER_TARGET;
1987	host->max_id = STORVSC_FC_MAX_TARGETS;
1988	host->max_channel = STORVSC_FC_MAX_CHANNELS - 1;
1989	#if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1990	host->transportt = fc_transport_template;
1991	#endif
1992	break;
1993
1994	case SCSI_GUID:
1995	host->max_lun = STORVSC_MAX_LUNS_PER_TARGET;
1996	host->max_id = STORVSC_MAX_TARGETS;
1997	host->max_channel = STORVSC_MAX_CHANNELS - 1;
1998	break;
1999
2000	default:
2001	host->max_lun = STORVSC_IDE_MAX_LUNS_PER_TARGET;
2002	host->max_id = STORVSC_IDE_MAX_TARGETS;
2003	host->max_channel = STORVSC_IDE_MAX_CHANNELS - 1;
2004	break;
2005	}
2006	/* max cmd length */
2007	host->max_cmd_len = STORVSC_MAX_CMD_LEN;
2008	/*
2009	* Any reasonable Hyper-V configuration should provide
2010	* max_transfer_bytes value aligning to HV_HYP_PAGE_SIZE,
2011	* protecting it from any weird value.
2012	*/
2013	max_xfer_bytes = round_down(stor_device->max_transfer_bytes, HV_HYP_PAGE_SIZE);
2014	if (is_fc)
2015	max_xfer_bytes = min(max_xfer_bytes, STORVSC_FC_MAX_XFER_SIZE);
2016
2017	/* max_hw_sectors_kb */
2018	host->max_sectors = max_xfer_bytes >> 9;
2019	/*
2020	* There are 2 requirements for Hyper-V storvsc sgl segments,
2021	* based on which the below calculation for max segments is
2022	* done:
2023	*
2024	* 1. Except for the first and last sgl segment, all sgl segments
2025	* should be align to HV_HYP_PAGE_SIZE, that also means the
2026	* maximum number of segments in a sgl can be calculated by
2027	* dividing the total max transfer length by HV_HYP_PAGE_SIZE.
2028	*
2029	* 2. Except for the first and last, each entry in the SGL must
2030	* have an offset that is a multiple of HV_HYP_PAGE_SIZE.
2031	*/
2032	host->sg_tablesize = (max_xfer_bytes >> HV_HYP_PAGE_SHIFT) + 1;
2033	/*
2034	* For non-IDE disks, the host supports multiple channels.
2035	* Set the number of HW queues we are supporting.
2036	*/
2037	if (!dev_is_ide) {
2038	if (storvsc_max_hw_queues > num_present_cpus) {
2039	storvsc_max_hw_queues = 0;
2040	storvsc_log(device, STORVSC_LOGGING_WARN,
2041	"Resetting invalid storvsc_max_hw_queues value to default.\n");
2042	}
2043	if (storvsc_max_hw_queues)
2044	host->nr_hw_queues = storvsc_max_hw_queues;
2045	else
2046	host->nr_hw_queues = num_present_cpus;
2047	}
2048
2049	/*
2050	* Set the error handler work queue.
2051	*/
2052	host_dev->handle_error_wq =
2053	alloc_ordered_workqueue("storvsc_error_wq_%d",
2054	0,
2055	host->host_no);
2056	if (!host_dev->handle_error_wq) {
2057	ret = -ENOMEM;
2058	goto err_out2;
2059	}
2060	INIT_WORK(&host_dev->host_scan_work, storvsc_host_scan);
2061	/* Register the HBA and start the scsi bus scan */
2062	ret = scsi_add_host(host, dev: &device->device);
2063	if (ret != 0)
2064	goto err_out3;
2065
2066	if (!dev_is_ide) {
2067	scsi_scan_host(host);
2068	} else {
2069	target = (device->dev_instance.b[5] << 8 |
2070	device->dev_instance.b[4]);
2071	ret = scsi_add_device(host, channel: 0, target, lun: 0);
2072	if (ret)
2073	goto err_out4;
2074	}
2075	#if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2076	if (host->transportt == fc_transport_template) {
2077	struct fc_rport_identifiers ids = {
2078	.roles = FC_PORT_ROLE_FCP_DUMMY_INITIATOR,
2079	};
2080
2081	fc_host_node_name(host) = stor_device->node_name;
2082	fc_host_port_name(host) = stor_device->port_name;
2083	stor_device->rport = fc_remote_port_add(shost: host, channel: 0, ids: &ids);
2084	if (!stor_device->rport) {
2085	ret = -ENOMEM;
2086	goto err_out4;
2087	}
2088	}
2089	#endif
2090	return 0;
2091
2092	err_out4:
2093	scsi_remove_host(host);
2094
2095	err_out3:
2096	destroy_workqueue(wq: host_dev->handle_error_wq);
2097
2098	err_out2:
2099	/*
2100	* Once we have connected with the host, we would need to
2101	* invoke storvsc_dev_remove() to rollback this state and
2102	* this call also frees up the stor_device; hence the jump around
2103	* err_out1 label.
2104	*/
2105	storvsc_dev_remove(device);
2106	goto err_out0;
2107
2108	err_out1:
2109	kfree(objp: stor_device->stor_chns);
2110	kfree(objp: stor_device);
2111
2112	err_out0:
2113	scsi_host_put(t: host);
2114	return ret;
2115	}
2116
2117	/* Change a scsi target's queue depth */
2118	static int storvsc_change_queue_depth(struct scsi_device *sdev, int queue_depth)
2119	{
2120	if (queue_depth > scsi_driver.can_queue)
2121	queue_depth = scsi_driver.can_queue;
2122
2123	return scsi_change_queue_depth(sdev, queue_depth);
2124	}
2125
2126	static void storvsc_remove(struct hv_device *dev)
2127	{
2128	struct storvsc_device *stor_device = hv_get_drvdata(dev);
2129	struct Scsi_Host *host = stor_device->host;
2130	struct hv_host_device *host_dev = shost_priv(shost: host);
2131
2132	#if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2133	if (host->transportt == fc_transport_template) {
2134	fc_remote_port_delete(rport: stor_device->rport);
2135	fc_remove_host(host);
2136	}
2137	#endif
2138	destroy_workqueue(wq: host_dev->handle_error_wq);
2139	scsi_remove_host(host);
2140	storvsc_dev_remove(device: dev);
2141	scsi_host_put(t: host);
2142	}
2143
2144	static int storvsc_suspend(struct hv_device *hv_dev)
2145	{
2146	struct storvsc_device *stor_device = hv_get_drvdata(dev: hv_dev);
2147	struct Scsi_Host *host = stor_device->host;
2148	struct hv_host_device *host_dev = shost_priv(shost: host);
2149
2150	storvsc_wait_to_drain(dev: stor_device);
2151
2152	drain_workqueue(wq: host_dev->handle_error_wq);
2153
2154	vmbus_close(channel: hv_dev->channel);
2155
2156	kfree(objp: stor_device->stor_chns);
2157	stor_device->stor_chns = NULL;
2158
2159	cpumask_clear(dstp: &stor_device->alloced_cpus);
2160
2161	return 0;
2162	}
2163
2164	static int storvsc_resume(struct hv_device *hv_dev)
2165	{
2166	int ret;
2167
2168	ret = storvsc_connect_to_vsp(device: hv_dev, ring_size: aligned_ringbuffer_size,
2169	is_fc: hv_dev_is_fc(hv_dev));
2170	return ret;
2171	}
2172
2173	static struct hv_driver storvsc_drv = {
2174	.name = KBUILD_MODNAME,
2175	.id_table = id_table,
2176	.probe = storvsc_probe,
2177	.remove = storvsc_remove,
2178	.suspend = storvsc_suspend,
2179	.resume = storvsc_resume,
2180	.driver = {
2181	.probe_type = PROBE_PREFER_ASYNCHRONOUS,
2182	},
2183	};
2184
2185	#if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2186	static struct fc_function_template fc_transport_functions = {
2187	.show_host_node_name = 1,
2188	.show_host_port_name = 1,
2189	};
2190	#endif
2191
2192	static int __init storvsc_drv_init(void)
2193	{
2194	int ret;
2195
2196	/*
2197	* Divide the ring buffer data size (which is 1 page less
2198	* than the ring buffer size since that page is reserved for
2199	* the ring buffer indices) by the max request size (which is
2200	* vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
2201	*/
2202	aligned_ringbuffer_size = VMBUS_RING_SIZE(storvsc_ringbuffer_size);
2203	max_outstanding_req_per_channel =
2204	((aligned_ringbuffer_size - PAGE_SIZE) /
2205	ALIGN(MAX_MULTIPAGE_BUFFER_PACKET +
2206	sizeof(struct vstor_packet) + sizeof(u64),
2207	sizeof(u64)));
2208
2209	#if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2210	fc_transport_template = fc_attach_transport(&fc_transport_functions);
2211	if (!fc_transport_template)
2212	return -ENODEV;
2213	#endif
2214
2215	ret = vmbus_driver_register(&storvsc_drv);
2216
2217	#if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2218	if (ret)
2219	fc_release_transport(fc_transport_template);
2220	#endif
2221
2222	return ret;
2223	}
2224
2225	static void __exit storvsc_drv_exit(void)
2226	{
2227	vmbus_driver_unregister(hv_driver: &storvsc_drv);
2228	#if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2229	fc_release_transport(fc_transport_template);
2230	#endif
2231	}
2232
2233	MODULE_LICENSE("GPL");
2234	MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
2235	module_init(storvsc_drv_init);
2236	module_exit(storvsc_drv_exit);
2237