xref: /openbmc/linux/include/scsi/scsi_device.h (revision 4f6cce39)
1 #ifndef _SCSI_SCSI_DEVICE_H
2 #define _SCSI_SCSI_DEVICE_H
3 
4 #include <linux/list.h>
5 #include <linux/spinlock.h>
6 #include <linux/workqueue.h>
7 #include <linux/blkdev.h>
8 #include <scsi/scsi.h>
9 #include <linux/atomic.h>
10 
11 struct device;
12 struct request_queue;
13 struct scsi_cmnd;
14 struct scsi_lun;
15 struct scsi_sense_hdr;
16 
17 struct scsi_mode_data {
18 	__u32	length;
19 	__u16	block_descriptor_length;
20 	__u8	medium_type;
21 	__u8	device_specific;
22 	__u8	header_length;
23 	__u8	longlba:1;
24 };
25 
26 /*
27  * sdev state: If you alter this, you also need to alter scsi_sysfs.c
28  * (for the ascii descriptions) and the state model enforcer:
29  * scsi_lib:scsi_device_set_state().
30  */
31 enum scsi_device_state {
32 	SDEV_CREATED = 1,	/* device created but not added to sysfs
33 				 * Only internal commands allowed (for inq) */
34 	SDEV_RUNNING,		/* device properly configured
35 				 * All commands allowed */
36 	SDEV_CANCEL,		/* beginning to delete device
37 				 * Only error handler commands allowed */
38 	SDEV_DEL,		/* device deleted
39 				 * no commands allowed */
40 	SDEV_QUIESCE,		/* Device quiescent.  No block commands
41 				 * will be accepted, only specials (which
42 				 * originate in the mid-layer) */
43 	SDEV_OFFLINE,		/* Device offlined (by error handling or
44 				 * user request */
45 	SDEV_TRANSPORT_OFFLINE,	/* Offlined by transport class error handler */
46 	SDEV_BLOCK,		/* Device blocked by scsi lld.  No
47 				 * scsi commands from user or midlayer
48 				 * should be issued to the scsi
49 				 * lld. */
50 	SDEV_CREATED_BLOCK,	/* same as above but for created devices */
51 };
52 
53 enum scsi_scan_mode {
54 	SCSI_SCAN_INITIAL = 0,
55 	SCSI_SCAN_RESCAN,
56 	SCSI_SCAN_MANUAL,
57 };
58 
59 enum scsi_device_event {
60 	SDEV_EVT_MEDIA_CHANGE	= 1,	/* media has changed */
61 	SDEV_EVT_INQUIRY_CHANGE_REPORTED,		/* 3F 03  UA reported */
62 	SDEV_EVT_CAPACITY_CHANGE_REPORTED,		/* 2A 09  UA reported */
63 	SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED,	/* 38 07  UA reported */
64 	SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED,	/* 2A 01  UA reported */
65 	SDEV_EVT_LUN_CHANGE_REPORTED,			/* 3F 0E  UA reported */
66 	SDEV_EVT_ALUA_STATE_CHANGE_REPORTED,		/* 2A 06  UA reported */
67 
68 	SDEV_EVT_FIRST		= SDEV_EVT_MEDIA_CHANGE,
69 	SDEV_EVT_LAST		= SDEV_EVT_ALUA_STATE_CHANGE_REPORTED,
70 
71 	SDEV_EVT_MAXBITS	= SDEV_EVT_LAST + 1
72 };
73 
74 struct scsi_event {
75 	enum scsi_device_event	evt_type;
76 	struct list_head	node;
77 
78 	/* put union of data structures, for non-simple event types,
79 	 * here
80 	 */
81 };
82 
83 struct scsi_device {
84 	struct Scsi_Host *host;
85 	struct request_queue *request_queue;
86 
87 	/* the next two are protected by the host->host_lock */
88 	struct list_head    siblings;   /* list of all devices on this host */
89 	struct list_head    same_target_siblings; /* just the devices sharing same target id */
90 
91 	atomic_t device_busy;		/* commands actually active on LLDD */
92 	atomic_t device_blocked;	/* Device returned QUEUE_FULL. */
93 
94 	spinlock_t list_lock;
95 	struct list_head cmd_list;	/* queue of in use SCSI Command structures */
96 	struct list_head starved_entry;
97 	unsigned short queue_depth;	/* How deep of a queue we want */
98 	unsigned short max_queue_depth;	/* max queue depth */
99 	unsigned short last_queue_full_depth; /* These two are used by */
100 	unsigned short last_queue_full_count; /* scsi_track_queue_full() */
101 	unsigned long last_queue_full_time;	/* last queue full time */
102 	unsigned long queue_ramp_up_period;	/* ramp up period in jiffies */
103 #define SCSI_DEFAULT_RAMP_UP_PERIOD	(120 * HZ)
104 
105 	unsigned long last_queue_ramp_up;	/* last queue ramp up time */
106 
107 	unsigned int id, channel;
108 	u64 lun;
109 	unsigned int manufacturer;	/* Manufacturer of device, for using
110 					 * vendor-specific cmd's */
111 	unsigned sector_size;	/* size in bytes */
112 
113 	void *hostdata;		/* available to low-level driver */
114 	char type;
115 	char scsi_level;
116 	char inq_periph_qual;	/* PQ from INQUIRY data */
117 	struct mutex inquiry_mutex;
118 	unsigned char inquiry_len;	/* valid bytes in 'inquiry' */
119 	unsigned char * inquiry;	/* INQUIRY response data */
120 	const char * vendor;		/* [back_compat] point into 'inquiry' ... */
121 	const char * model;		/* ... after scan; point to static string */
122 	const char * rev;		/* ... "nullnullnullnull" before scan */
123 
124 #define SCSI_VPD_PG_LEN                255
125 	int vpd_pg83_len;
126 	unsigned char __rcu *vpd_pg83;
127 	int vpd_pg80_len;
128 	unsigned char __rcu *vpd_pg80;
129 	unsigned char current_tag;	/* current tag */
130 	struct scsi_target      *sdev_target;   /* used only for single_lun */
131 
132 	unsigned int	sdev_bflags; /* black/white flags as also found in
133 				 * scsi_devinfo.[hc]. For now used only to
134 				 * pass settings from slave_alloc to scsi
135 				 * core. */
136 	unsigned int eh_timeout; /* Error handling timeout */
137 	unsigned removable:1;
138 	unsigned changed:1;	/* Data invalid due to media change */
139 	unsigned busy:1;	/* Used to prevent races */
140 	unsigned lockable:1;	/* Able to prevent media removal */
141 	unsigned locked:1;      /* Media removal disabled */
142 	unsigned borken:1;	/* Tell the Seagate driver to be
143 				 * painfully slow on this device */
144 	unsigned disconnect:1;	/* can disconnect */
145 	unsigned soft_reset:1;	/* Uses soft reset option */
146 	unsigned sdtr:1;	/* Device supports SDTR messages */
147 	unsigned wdtr:1;	/* Device supports WDTR messages */
148 	unsigned ppr:1;		/* Device supports PPR messages */
149 	unsigned tagged_supported:1;	/* Supports SCSI-II tagged queuing */
150 	unsigned simple_tags:1;	/* simple queue tag messages are enabled */
151 	unsigned was_reset:1;	/* There was a bus reset on the bus for
152 				 * this device */
153 	unsigned expecting_cc_ua:1; /* Expecting a CHECK_CONDITION/UNIT_ATTN
154 				     * because we did a bus reset. */
155 	unsigned use_10_for_rw:1; /* first try 10-byte read / write */
156 	unsigned use_10_for_ms:1; /* first try 10-byte mode sense/select */
157 	unsigned no_report_opcodes:1;	/* no REPORT SUPPORTED OPERATION CODES */
158 	unsigned no_write_same:1;	/* no WRITE SAME command */
159 	unsigned use_16_for_rw:1; /* Use read/write(16) over read/write(10) */
160 	unsigned skip_ms_page_8:1;	/* do not use MODE SENSE page 0x08 */
161 	unsigned skip_ms_page_3f:1;	/* do not use MODE SENSE page 0x3f */
162 	unsigned skip_vpd_pages:1;	/* do not read VPD pages */
163 	unsigned try_vpd_pages:1;	/* attempt to read VPD pages */
164 	unsigned use_192_bytes_for_3f:1; /* ask for 192 bytes from page 0x3f */
165 	unsigned no_start_on_add:1;	/* do not issue start on add */
166 	unsigned allow_restart:1; /* issue START_UNIT in error handler */
167 	unsigned manage_start_stop:1;	/* Let HLD (sd) manage start/stop */
168 	unsigned start_stop_pwr_cond:1;	/* Set power cond. in START_STOP_UNIT */
169 	unsigned no_uld_attach:1; /* disable connecting to upper level drivers */
170 	unsigned select_no_atn:1;
171 	unsigned fix_capacity:1;	/* READ_CAPACITY is too high by 1 */
172 	unsigned guess_capacity:1;	/* READ_CAPACITY might be too high by 1 */
173 	unsigned retry_hwerror:1;	/* Retry HARDWARE_ERROR */
174 	unsigned last_sector_bug:1;	/* do not use multisector accesses on
175 					   SD_LAST_BUGGY_SECTORS */
176 	unsigned no_read_disc_info:1;	/* Avoid READ_DISC_INFO cmds */
177 	unsigned no_read_capacity_16:1; /* Avoid READ_CAPACITY_16 cmds */
178 	unsigned try_rc_10_first:1;	/* Try READ_CAPACACITY_10 first */
179 	unsigned is_visible:1;	/* is the device visible in sysfs */
180 	unsigned wce_default_on:1;	/* Cache is ON by default */
181 	unsigned no_dif:1;	/* T10 PI (DIF) should be disabled */
182 	unsigned broken_fua:1;		/* Don't set FUA bit */
183 	unsigned lun_in_cdb:1;		/* Store LUN bits in CDB[1] */
184 	unsigned synchronous_alua:1;	/* Synchronous ALUA commands */
185 
186 	atomic_t disk_events_disable_depth; /* disable depth for disk events */
187 
188 	DECLARE_BITMAP(supported_events, SDEV_EVT_MAXBITS); /* supported events */
189 	DECLARE_BITMAP(pending_events, SDEV_EVT_MAXBITS); /* pending events */
190 	struct list_head event_list;	/* asserted events */
191 	struct work_struct event_work;
192 
193 	unsigned int max_device_blocked; /* what device_blocked counts down from  */
194 #define SCSI_DEFAULT_DEVICE_BLOCKED	3
195 
196 	atomic_t iorequest_cnt;
197 	atomic_t iodone_cnt;
198 	atomic_t ioerr_cnt;
199 
200 	struct device		sdev_gendev,
201 				sdev_dev;
202 
203 	struct execute_work	ew; /* used to get process context on put */
204 	struct work_struct	requeue_work;
205 
206 	struct scsi_device_handler *handler;
207 	void			*handler_data;
208 
209 	unsigned char		access_state;
210 	enum scsi_device_state sdev_state;
211 	unsigned long		sdev_data[0];
212 } __attribute__((aligned(sizeof(unsigned long))));
213 
214 #define	to_scsi_device(d)	\
215 	container_of(d, struct scsi_device, sdev_gendev)
216 #define	class_to_sdev(d)	\
217 	container_of(d, struct scsi_device, sdev_dev)
218 #define transport_class_to_sdev(class_dev) \
219 	to_scsi_device(class_dev->parent)
220 
221 #define sdev_dbg(sdev, fmt, a...) \
222 	dev_dbg(&(sdev)->sdev_gendev, fmt, ##a)
223 
224 /*
225  * like scmd_printk, but the device name is passed in
226  * as a string pointer
227  */
228 __printf(4, 5) void
229 sdev_prefix_printk(const char *, const struct scsi_device *, const char *,
230 		const char *, ...);
231 
232 #define sdev_printk(l, sdev, fmt, a...)				\
233 	sdev_prefix_printk(l, sdev, NULL, fmt, ##a)
234 
235 __printf(3, 4) void
236 scmd_printk(const char *, const struct scsi_cmnd *, const char *, ...);
237 
238 #define scmd_dbg(scmd, fmt, a...)					   \
239 	do {								   \
240 		if ((scmd)->request->rq_disk)				   \
241 			sdev_dbg((scmd)->device, "[%s] " fmt,		   \
242 				 (scmd)->request->rq_disk->disk_name, ##a);\
243 		else							   \
244 			sdev_dbg((scmd)->device, fmt, ##a);		   \
245 	} while (0)
246 
247 enum scsi_target_state {
248 	STARGET_CREATED = 1,
249 	STARGET_RUNNING,
250 	STARGET_REMOVE,
251 	STARGET_DEL,
252 };
253 
254 /*
255  * scsi_target: representation of a scsi target, for now, this is only
256  * used for single_lun devices. If no one has active IO to the target,
257  * starget_sdev_user is NULL, else it points to the active sdev.
258  */
259 struct scsi_target {
260 	struct scsi_device	*starget_sdev_user;
261 	struct list_head	siblings;
262 	struct list_head	devices;
263 	struct device		dev;
264 	struct kref		reap_ref; /* last put renders target invisible */
265 	unsigned int		channel;
266 	unsigned int		id; /* target id ... replace
267 				     * scsi_device.id eventually */
268 	unsigned int		create:1; /* signal that it needs to be added */
269 	unsigned int		single_lun:1;	/* Indicates we should only
270 						 * allow I/O to one of the luns
271 						 * for the device at a time. */
272 	unsigned int		pdt_1f_for_no_lun:1;	/* PDT = 0x1f
273 						 * means no lun present. */
274 	unsigned int		no_report_luns:1;	/* Don't use
275 						 * REPORT LUNS for scanning. */
276 	unsigned int		expecting_lun_change:1;	/* A device has reported
277 						 * a 3F/0E UA, other devices on
278 						 * the same target will also. */
279 	/* commands actually active on LLD. */
280 	atomic_t		target_busy;
281 	atomic_t		target_blocked;
282 
283 	/*
284 	 * LLDs should set this in the slave_alloc host template callout.
285 	 * If set to zero then there is not limit.
286 	 */
287 	unsigned int		can_queue;
288 	unsigned int		max_target_blocked;
289 #define SCSI_DEFAULT_TARGET_BLOCKED	3
290 
291 	char			scsi_level;
292 	enum scsi_target_state	state;
293 	void 			*hostdata; /* available to low-level driver */
294 	unsigned long		starget_data[0]; /* for the transport */
295 	/* starget_data must be the last element!!!! */
296 } __attribute__((aligned(sizeof(unsigned long))));
297 
298 #define to_scsi_target(d)	container_of(d, struct scsi_target, dev)
299 static inline struct scsi_target *scsi_target(struct scsi_device *sdev)
300 {
301 	return to_scsi_target(sdev->sdev_gendev.parent);
302 }
303 #define transport_class_to_starget(class_dev) \
304 	to_scsi_target(class_dev->parent)
305 
306 #define starget_printk(prefix, starget, fmt, a...)	\
307 	dev_printk(prefix, &(starget)->dev, fmt, ##a)
308 
309 extern struct scsi_device *__scsi_add_device(struct Scsi_Host *,
310 		uint, uint, u64, void *hostdata);
311 extern int scsi_add_device(struct Scsi_Host *host, uint channel,
312 			   uint target, u64 lun);
313 extern int scsi_register_device_handler(struct scsi_device_handler *scsi_dh);
314 extern void scsi_remove_device(struct scsi_device *);
315 extern int scsi_unregister_device_handler(struct scsi_device_handler *scsi_dh);
316 void scsi_attach_vpd(struct scsi_device *sdev);
317 
318 extern struct scsi_device *scsi_device_from_queue(struct request_queue *q);
319 extern int scsi_device_get(struct scsi_device *);
320 extern void scsi_device_put(struct scsi_device *);
321 extern struct scsi_device *scsi_device_lookup(struct Scsi_Host *,
322 					      uint, uint, u64);
323 extern struct scsi_device *__scsi_device_lookup(struct Scsi_Host *,
324 						uint, uint, u64);
325 extern struct scsi_device *scsi_device_lookup_by_target(struct scsi_target *,
326 							u64);
327 extern struct scsi_device *__scsi_device_lookup_by_target(struct scsi_target *,
328 							  u64);
329 extern void starget_for_each_device(struct scsi_target *, void *,
330 		     void (*fn)(struct scsi_device *, void *));
331 extern void __starget_for_each_device(struct scsi_target *, void *,
332 				      void (*fn)(struct scsi_device *,
333 						 void *));
334 
335 /* only exposed to implement shost_for_each_device */
336 extern struct scsi_device *__scsi_iterate_devices(struct Scsi_Host *,
337 						  struct scsi_device *);
338 
339 /**
340  * shost_for_each_device - iterate over all devices of a host
341  * @sdev: the &struct scsi_device to use as a cursor
342  * @shost: the &struct scsi_host to iterate over
343  *
344  * Iterator that returns each device attached to @shost.  This loop
345  * takes a reference on each device and releases it at the end.  If
346  * you break out of the loop, you must call scsi_device_put(sdev).
347  */
348 #define shost_for_each_device(sdev, shost) \
349 	for ((sdev) = __scsi_iterate_devices((shost), NULL); \
350 	     (sdev); \
351 	     (sdev) = __scsi_iterate_devices((shost), (sdev)))
352 
353 /**
354  * __shost_for_each_device - iterate over all devices of a host (UNLOCKED)
355  * @sdev: the &struct scsi_device to use as a cursor
356  * @shost: the &struct scsi_host to iterate over
357  *
358  * Iterator that returns each device attached to @shost.  It does _not_
359  * take a reference on the scsi_device, so the whole loop must be
360  * protected by shost->host_lock.
361  *
362  * Note: The only reason to use this is because you need to access the
363  * device list in interrupt context.  Otherwise you really want to use
364  * shost_for_each_device instead.
365  */
366 #define __shost_for_each_device(sdev, shost) \
367 	list_for_each_entry((sdev), &((shost)->__devices), siblings)
368 
369 extern int scsi_change_queue_depth(struct scsi_device *, int);
370 extern int scsi_track_queue_full(struct scsi_device *, int);
371 
372 extern int scsi_set_medium_removal(struct scsi_device *, char);
373 
374 extern int scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage,
375 			   unsigned char *buffer, int len, int timeout,
376 			   int retries, struct scsi_mode_data *data,
377 			   struct scsi_sense_hdr *);
378 extern int scsi_mode_select(struct scsi_device *sdev, int pf, int sp,
379 			    int modepage, unsigned char *buffer, int len,
380 			    int timeout, int retries,
381 			    struct scsi_mode_data *data,
382 			    struct scsi_sense_hdr *);
383 extern int scsi_test_unit_ready(struct scsi_device *sdev, int timeout,
384 				int retries, struct scsi_sense_hdr *sshdr);
385 extern int scsi_get_vpd_page(struct scsi_device *, u8 page, unsigned char *buf,
386 			     int buf_len);
387 extern int scsi_report_opcode(struct scsi_device *sdev, unsigned char *buffer,
388 			      unsigned int len, unsigned char opcode);
389 extern int scsi_device_set_state(struct scsi_device *sdev,
390 				 enum scsi_device_state state);
391 extern struct scsi_event *sdev_evt_alloc(enum scsi_device_event evt_type,
392 					  gfp_t gfpflags);
393 extern void sdev_evt_send(struct scsi_device *sdev, struct scsi_event *evt);
394 extern void sdev_evt_send_simple(struct scsi_device *sdev,
395 			  enum scsi_device_event evt_type, gfp_t gfpflags);
396 extern int scsi_device_quiesce(struct scsi_device *sdev);
397 extern void scsi_device_resume(struct scsi_device *sdev);
398 extern void scsi_target_quiesce(struct scsi_target *);
399 extern void scsi_target_resume(struct scsi_target *);
400 extern void scsi_scan_target(struct device *parent, unsigned int channel,
401 			     unsigned int id, u64 lun,
402 			     enum scsi_scan_mode rescan);
403 extern void scsi_target_reap(struct scsi_target *);
404 extern void scsi_target_block(struct device *);
405 extern void scsi_target_unblock(struct device *, enum scsi_device_state);
406 extern void scsi_remove_target(struct device *);
407 extern const char *scsi_device_state_name(enum scsi_device_state);
408 extern int scsi_is_sdev_device(const struct device *);
409 extern int scsi_is_target_device(const struct device *);
410 extern void scsi_sanitize_inquiry_string(unsigned char *s, int len);
411 extern int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd,
412 			int data_direction, void *buffer, unsigned bufflen,
413 			unsigned char *sense, struct scsi_sense_hdr *sshdr,
414 			int timeout, int retries, u64 flags,
415 			req_flags_t rq_flags, int *resid);
416 static inline int scsi_execute_req(struct scsi_device *sdev,
417 	const unsigned char *cmd, int data_direction, void *buffer,
418 	unsigned bufflen, struct scsi_sense_hdr *sshdr, int timeout,
419 	int retries, int *resid)
420 {
421 	return scsi_execute(sdev, cmd, data_direction, buffer,
422 		bufflen, NULL, sshdr, timeout, retries,  0, 0, resid);
423 }
424 extern void sdev_disable_disk_events(struct scsi_device *sdev);
425 extern void sdev_enable_disk_events(struct scsi_device *sdev);
426 extern int scsi_vpd_lun_id(struct scsi_device *, char *, size_t);
427 extern int scsi_vpd_tpg_id(struct scsi_device *, int *);
428 
429 #ifdef CONFIG_PM
430 extern int scsi_autopm_get_device(struct scsi_device *);
431 extern void scsi_autopm_put_device(struct scsi_device *);
432 #else
433 static inline int scsi_autopm_get_device(struct scsi_device *d) { return 0; }
434 static inline void scsi_autopm_put_device(struct scsi_device *d) {}
435 #endif /* CONFIG_PM */
436 
437 static inline int __must_check scsi_device_reprobe(struct scsi_device *sdev)
438 {
439 	return device_reprobe(&sdev->sdev_gendev);
440 }
441 
442 static inline unsigned int sdev_channel(struct scsi_device *sdev)
443 {
444 	return sdev->channel;
445 }
446 
447 static inline unsigned int sdev_id(struct scsi_device *sdev)
448 {
449 	return sdev->id;
450 }
451 
452 #define scmd_id(scmd) sdev_id((scmd)->device)
453 #define scmd_channel(scmd) sdev_channel((scmd)->device)
454 
455 /*
456  * checks for positions of the SCSI state machine
457  */
458 static inline int scsi_device_online(struct scsi_device *sdev)
459 {
460 	return (sdev->sdev_state != SDEV_OFFLINE &&
461 		sdev->sdev_state != SDEV_TRANSPORT_OFFLINE &&
462 		sdev->sdev_state != SDEV_DEL);
463 }
464 static inline int scsi_device_blocked(struct scsi_device *sdev)
465 {
466 	return sdev->sdev_state == SDEV_BLOCK ||
467 		sdev->sdev_state == SDEV_CREATED_BLOCK;
468 }
469 static inline int scsi_device_created(struct scsi_device *sdev)
470 {
471 	return sdev->sdev_state == SDEV_CREATED ||
472 		sdev->sdev_state == SDEV_CREATED_BLOCK;
473 }
474 
475 int scsi_internal_device_block(struct scsi_device *sdev, bool wait);
476 int scsi_internal_device_unblock(struct scsi_device *sdev,
477 				 enum scsi_device_state new_state);
478 
479 /* accessor functions for the SCSI parameters */
480 static inline int scsi_device_sync(struct scsi_device *sdev)
481 {
482 	return sdev->sdtr;
483 }
484 static inline int scsi_device_wide(struct scsi_device *sdev)
485 {
486 	return sdev->wdtr;
487 }
488 static inline int scsi_device_dt(struct scsi_device *sdev)
489 {
490 	return sdev->ppr;
491 }
492 static inline int scsi_device_dt_only(struct scsi_device *sdev)
493 {
494 	if (sdev->inquiry_len < 57)
495 		return 0;
496 	return (sdev->inquiry[56] & 0x0c) == 0x04;
497 }
498 static inline int scsi_device_ius(struct scsi_device *sdev)
499 {
500 	if (sdev->inquiry_len < 57)
501 		return 0;
502 	return sdev->inquiry[56] & 0x01;
503 }
504 static inline int scsi_device_qas(struct scsi_device *sdev)
505 {
506 	if (sdev->inquiry_len < 57)
507 		return 0;
508 	return sdev->inquiry[56] & 0x02;
509 }
510 static inline int scsi_device_enclosure(struct scsi_device *sdev)
511 {
512 	return sdev->inquiry ? (sdev->inquiry[6] & (1<<6)) : 1;
513 }
514 
515 static inline int scsi_device_protection(struct scsi_device *sdev)
516 {
517 	if (sdev->no_dif)
518 		return 0;
519 
520 	return sdev->scsi_level > SCSI_2 && sdev->inquiry[5] & (1<<0);
521 }
522 
523 static inline int scsi_device_tpgs(struct scsi_device *sdev)
524 {
525 	return sdev->inquiry ? (sdev->inquiry[5] >> 4) & 0x3 : 0;
526 }
527 
528 /**
529  * scsi_device_supports_vpd - test if a device supports VPD pages
530  * @sdev: the &struct scsi_device to test
531  *
532  * If the 'try_vpd_pages' flag is set it takes precedence.
533  * Otherwise we will assume VPD pages are supported if the
534  * SCSI level is at least SPC-3 and 'skip_vpd_pages' is not set.
535  */
536 static inline int scsi_device_supports_vpd(struct scsi_device *sdev)
537 {
538 	/* Attempt VPD inquiry if the device blacklist explicitly calls
539 	 * for it.
540 	 */
541 	if (sdev->try_vpd_pages)
542 		return 1;
543 	/*
544 	 * Although VPD inquiries can go to SCSI-2 type devices,
545 	 * some USB ones crash on receiving them, and the pages
546 	 * we currently ask for are mandatory for SPC-2 and beyond
547 	 */
548 	if (sdev->scsi_level >= SCSI_SPC_2 && !sdev->skip_vpd_pages)
549 		return 1;
550 	return 0;
551 }
552 
553 #define MODULE_ALIAS_SCSI_DEVICE(type) \
554 	MODULE_ALIAS("scsi:t-" __stringify(type) "*")
555 #define SCSI_DEVICE_MODALIAS_FMT "scsi:t-0x%02x"
556 
557 #endif /* _SCSI_SCSI_DEVICE_H */
558