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