xref: /openbmc/linux/include/scsi/scsi_device.h (revision 727dede0)
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 /**
84  * struct scsi_vpd - SCSI Vital Product Data
85  * @rcu: For kfree_rcu().
86  * @len: Length in bytes of @data.
87  * @data: VPD data as defined in various T10 SCSI standard documents.
88  */
89 struct scsi_vpd {
90 	struct rcu_head	rcu;
91 	int		len;
92 	unsigned char	data[];
93 };
94 
95 struct scsi_device {
96 	struct Scsi_Host *host;
97 	struct request_queue *request_queue;
98 
99 	/* the next two are protected by the host->host_lock */
100 	struct list_head    siblings;   /* list of all devices on this host */
101 	struct list_head    same_target_siblings; /* just the devices sharing same target id */
102 
103 	atomic_t device_busy;		/* commands actually active on LLDD */
104 	atomic_t device_blocked;	/* Device returned QUEUE_FULL. */
105 
106 	spinlock_t list_lock;
107 	struct list_head cmd_list;	/* queue of in use SCSI Command structures */
108 	struct list_head starved_entry;
109 	unsigned short queue_depth;	/* How deep of a queue we want */
110 	unsigned short max_queue_depth;	/* max queue depth */
111 	unsigned short last_queue_full_depth; /* These two are used by */
112 	unsigned short last_queue_full_count; /* scsi_track_queue_full() */
113 	unsigned long last_queue_full_time;	/* last queue full time */
114 	unsigned long queue_ramp_up_period;	/* ramp up period in jiffies */
115 #define SCSI_DEFAULT_RAMP_UP_PERIOD	(120 * HZ)
116 
117 	unsigned long last_queue_ramp_up;	/* last queue ramp up time */
118 
119 	unsigned int id, channel;
120 	u64 lun;
121 	unsigned int manufacturer;	/* Manufacturer of device, for using
122 					 * vendor-specific cmd's */
123 	unsigned sector_size;	/* size in bytes */
124 
125 	void *hostdata;		/* available to low-level driver */
126 	unsigned char type;
127 	char scsi_level;
128 	char inq_periph_qual;	/* PQ from INQUIRY data */
129 	struct mutex inquiry_mutex;
130 	unsigned char inquiry_len;	/* valid bytes in 'inquiry' */
131 	unsigned char * inquiry;	/* INQUIRY response data */
132 	const char * vendor;		/* [back_compat] point into 'inquiry' ... */
133 	const char * model;		/* ... after scan; point to static string */
134 	const char * rev;		/* ... "nullnullnullnull" before scan */
135 
136 #define SCSI_VPD_PG_LEN                255
137 	struct scsi_vpd __rcu *vpd_pg83;
138 	struct scsi_vpd __rcu *vpd_pg80;
139 	unsigned char current_tag;	/* current tag */
140 	struct scsi_target      *sdev_target;   /* used only for single_lun */
141 
142 	unsigned int	sdev_bflags; /* black/white flags as also found in
143 				 * scsi_devinfo.[hc]. For now used only to
144 				 * pass settings from slave_alloc to scsi
145 				 * core. */
146 	unsigned int eh_timeout; /* Error handling timeout */
147 	unsigned removable:1;
148 	unsigned changed:1;	/* Data invalid due to media change */
149 	unsigned busy:1;	/* Used to prevent races */
150 	unsigned lockable:1;	/* Able to prevent media removal */
151 	unsigned locked:1;      /* Media removal disabled */
152 	unsigned borken:1;	/* Tell the Seagate driver to be
153 				 * painfully slow on this device */
154 	unsigned disconnect:1;	/* can disconnect */
155 	unsigned soft_reset:1;	/* Uses soft reset option */
156 	unsigned sdtr:1;	/* Device supports SDTR messages */
157 	unsigned wdtr:1;	/* Device supports WDTR messages */
158 	unsigned ppr:1;		/* Device supports PPR messages */
159 	unsigned tagged_supported:1;	/* Supports SCSI-II tagged queuing */
160 	unsigned simple_tags:1;	/* simple queue tag messages are enabled */
161 	unsigned was_reset:1;	/* There was a bus reset on the bus for
162 				 * this device */
163 	unsigned expecting_cc_ua:1; /* Expecting a CHECK_CONDITION/UNIT_ATTN
164 				     * because we did a bus reset. */
165 	unsigned use_10_for_rw:1; /* first try 10-byte read / write */
166 	unsigned use_10_for_ms:1; /* first try 10-byte mode sense/select */
167 	unsigned no_report_opcodes:1;	/* no REPORT SUPPORTED OPERATION CODES */
168 	unsigned no_write_same:1;	/* no WRITE SAME command */
169 	unsigned use_16_for_rw:1; /* Use read/write(16) over read/write(10) */
170 	unsigned skip_ms_page_8:1;	/* do not use MODE SENSE page 0x08 */
171 	unsigned skip_ms_page_3f:1;	/* do not use MODE SENSE page 0x3f */
172 	unsigned skip_vpd_pages:1;	/* do not read VPD pages */
173 	unsigned try_vpd_pages:1;	/* attempt to read VPD pages */
174 	unsigned use_192_bytes_for_3f:1; /* ask for 192 bytes from page 0x3f */
175 	unsigned no_start_on_add:1;	/* do not issue start on add */
176 	unsigned allow_restart:1; /* issue START_UNIT in error handler */
177 	unsigned manage_start_stop:1;	/* Let HLD (sd) manage start/stop */
178 	unsigned start_stop_pwr_cond:1;	/* Set power cond. in START_STOP_UNIT */
179 	unsigned no_uld_attach:1; /* disable connecting to upper level drivers */
180 	unsigned select_no_atn:1;
181 	unsigned fix_capacity:1;	/* READ_CAPACITY is too high by 1 */
182 	unsigned guess_capacity:1;	/* READ_CAPACITY might be too high by 1 */
183 	unsigned retry_hwerror:1;	/* Retry HARDWARE_ERROR */
184 	unsigned last_sector_bug:1;	/* do not use multisector accesses on
185 					   SD_LAST_BUGGY_SECTORS */
186 	unsigned no_read_disc_info:1;	/* Avoid READ_DISC_INFO cmds */
187 	unsigned no_read_capacity_16:1; /* Avoid READ_CAPACITY_16 cmds */
188 	unsigned try_rc_10_first:1;	/* Try READ_CAPACACITY_10 first */
189 	unsigned security_supported:1;	/* Supports Security Protocols */
190 	unsigned is_visible:1;	/* is the device visible in sysfs */
191 	unsigned wce_default_on:1;	/* Cache is ON by default */
192 	unsigned no_dif:1;	/* T10 PI (DIF) should be disabled */
193 	unsigned broken_fua:1;		/* Don't set FUA bit */
194 	unsigned lun_in_cdb:1;		/* Store LUN bits in CDB[1] */
195 	unsigned unmap_limit_for_ws:1;	/* Use the UNMAP limit for WRITE SAME */
196 
197 	atomic_t disk_events_disable_depth; /* disable depth for disk events */
198 
199 	DECLARE_BITMAP(supported_events, SDEV_EVT_MAXBITS); /* supported events */
200 	DECLARE_BITMAP(pending_events, SDEV_EVT_MAXBITS); /* pending events */
201 	struct list_head event_list;	/* asserted events */
202 	struct work_struct event_work;
203 
204 	unsigned int max_device_blocked; /* what device_blocked counts down from  */
205 #define SCSI_DEFAULT_DEVICE_BLOCKED	3
206 
207 	atomic_t iorequest_cnt;
208 	atomic_t iodone_cnt;
209 	atomic_t ioerr_cnt;
210 
211 	struct device		sdev_gendev,
212 				sdev_dev;
213 
214 	struct execute_work	ew; /* used to get process context on put */
215 	struct work_struct	requeue_work;
216 
217 	struct scsi_device_handler *handler;
218 	void			*handler_data;
219 
220 	unsigned char		access_state;
221 	struct mutex		state_mutex;
222 	enum scsi_device_state sdev_state;
223 	unsigned long		sdev_data[0];
224 } __attribute__((aligned(sizeof(unsigned long))));
225 
226 #define	to_scsi_device(d)	\
227 	container_of(d, struct scsi_device, sdev_gendev)
228 #define	class_to_sdev(d)	\
229 	container_of(d, struct scsi_device, sdev_dev)
230 #define transport_class_to_sdev(class_dev) \
231 	to_scsi_device(class_dev->parent)
232 
233 #define sdev_dbg(sdev, fmt, a...) \
234 	dev_dbg(&(sdev)->sdev_gendev, fmt, ##a)
235 
236 /*
237  * like scmd_printk, but the device name is passed in
238  * as a string pointer
239  */
240 __printf(4, 5) void
241 sdev_prefix_printk(const char *, const struct scsi_device *, const char *,
242 		const char *, ...);
243 
244 #define sdev_printk(l, sdev, fmt, a...)				\
245 	sdev_prefix_printk(l, sdev, NULL, fmt, ##a)
246 
247 __printf(3, 4) void
248 scmd_printk(const char *, const struct scsi_cmnd *, const char *, ...);
249 
250 #define scmd_dbg(scmd, fmt, a...)					   \
251 	do {								   \
252 		if ((scmd)->request->rq_disk)				   \
253 			sdev_dbg((scmd)->device, "[%s] " fmt,		   \
254 				 (scmd)->request->rq_disk->disk_name, ##a);\
255 		else							   \
256 			sdev_dbg((scmd)->device, fmt, ##a);		   \
257 	} while (0)
258 
259 enum scsi_target_state {
260 	STARGET_CREATED = 1,
261 	STARGET_RUNNING,
262 	STARGET_REMOVE,
263 	STARGET_CREATED_REMOVE,
264 	STARGET_DEL,
265 };
266 
267 /*
268  * scsi_target: representation of a scsi target, for now, this is only
269  * used for single_lun devices. If no one has active IO to the target,
270  * starget_sdev_user is NULL, else it points to the active sdev.
271  */
272 struct scsi_target {
273 	struct scsi_device	*starget_sdev_user;
274 	struct list_head	siblings;
275 	struct list_head	devices;
276 	struct device		dev;
277 	struct kref		reap_ref; /* last put renders target invisible */
278 	unsigned int		channel;
279 	unsigned int		id; /* target id ... replace
280 				     * scsi_device.id eventually */
281 	unsigned int		create:1; /* signal that it needs to be added */
282 	unsigned int		single_lun:1;	/* Indicates we should only
283 						 * allow I/O to one of the luns
284 						 * for the device at a time. */
285 	unsigned int		pdt_1f_for_no_lun:1;	/* PDT = 0x1f
286 						 * means no lun present. */
287 	unsigned int		no_report_luns:1;	/* Don't use
288 						 * REPORT LUNS for scanning. */
289 	unsigned int		expecting_lun_change:1;	/* A device has reported
290 						 * a 3F/0E UA, other devices on
291 						 * the same target will also. */
292 	/* commands actually active on LLD. */
293 	atomic_t		target_busy;
294 	atomic_t		target_blocked;
295 
296 	/*
297 	 * LLDs should set this in the slave_alloc host template callout.
298 	 * If set to zero then there is not limit.
299 	 */
300 	unsigned int		can_queue;
301 	unsigned int		max_target_blocked;
302 #define SCSI_DEFAULT_TARGET_BLOCKED	3
303 
304 	char			scsi_level;
305 	enum scsi_target_state	state;
306 	void 			*hostdata; /* available to low-level driver */
307 	unsigned long		starget_data[0]; /* for the transport */
308 	/* starget_data must be the last element!!!! */
309 } __attribute__((aligned(sizeof(unsigned long))));
310 
311 #define to_scsi_target(d)	container_of(d, struct scsi_target, dev)
312 static inline struct scsi_target *scsi_target(struct scsi_device *sdev)
313 {
314 	return to_scsi_target(sdev->sdev_gendev.parent);
315 }
316 #define transport_class_to_starget(class_dev) \
317 	to_scsi_target(class_dev->parent)
318 
319 #define starget_printk(prefix, starget, fmt, a...)	\
320 	dev_printk(prefix, &(starget)->dev, fmt, ##a)
321 
322 extern struct scsi_device *__scsi_add_device(struct Scsi_Host *,
323 		uint, uint, u64, void *hostdata);
324 extern int scsi_add_device(struct Scsi_Host *host, uint channel,
325 			   uint target, u64 lun);
326 extern int scsi_register_device_handler(struct scsi_device_handler *scsi_dh);
327 extern void scsi_remove_device(struct scsi_device *);
328 extern int scsi_unregister_device_handler(struct scsi_device_handler *scsi_dh);
329 void scsi_attach_vpd(struct scsi_device *sdev);
330 
331 extern struct scsi_device *scsi_device_from_queue(struct request_queue *q);
332 extern int __must_check scsi_device_get(struct scsi_device *);
333 extern void scsi_device_put(struct scsi_device *);
334 extern struct scsi_device *scsi_device_lookup(struct Scsi_Host *,
335 					      uint, uint, u64);
336 extern struct scsi_device *__scsi_device_lookup(struct Scsi_Host *,
337 						uint, uint, u64);
338 extern struct scsi_device *scsi_device_lookup_by_target(struct scsi_target *,
339 							u64);
340 extern struct scsi_device *__scsi_device_lookup_by_target(struct scsi_target *,
341 							  u64);
342 extern void starget_for_each_device(struct scsi_target *, void *,
343 		     void (*fn)(struct scsi_device *, void *));
344 extern void __starget_for_each_device(struct scsi_target *, void *,
345 				      void (*fn)(struct scsi_device *,
346 						 void *));
347 
348 /* only exposed to implement shost_for_each_device */
349 extern struct scsi_device *__scsi_iterate_devices(struct Scsi_Host *,
350 						  struct scsi_device *);
351 
352 /**
353  * shost_for_each_device - iterate over all devices of a host
354  * @sdev: the &struct scsi_device to use as a cursor
355  * @shost: the &struct scsi_host to iterate over
356  *
357  * Iterator that returns each device attached to @shost.  This loop
358  * takes a reference on each device and releases it at the end.  If
359  * you break out of the loop, you must call scsi_device_put(sdev).
360  */
361 #define shost_for_each_device(sdev, shost) \
362 	for ((sdev) = __scsi_iterate_devices((shost), NULL); \
363 	     (sdev); \
364 	     (sdev) = __scsi_iterate_devices((shost), (sdev)))
365 
366 /**
367  * __shost_for_each_device - iterate over all devices of a host (UNLOCKED)
368  * @sdev: the &struct scsi_device to use as a cursor
369  * @shost: the &struct scsi_host to iterate over
370  *
371  * Iterator that returns each device attached to @shost.  It does _not_
372  * take a reference on the scsi_device, so the whole loop must be
373  * protected by shost->host_lock.
374  *
375  * Note: The only reason to use this is because you need to access the
376  * device list in interrupt context.  Otherwise you really want to use
377  * shost_for_each_device instead.
378  */
379 #define __shost_for_each_device(sdev, shost) \
380 	list_for_each_entry((sdev), &((shost)->__devices), siblings)
381 
382 extern int scsi_change_queue_depth(struct scsi_device *, int);
383 extern int scsi_track_queue_full(struct scsi_device *, int);
384 
385 extern int scsi_set_medium_removal(struct scsi_device *, char);
386 
387 extern int scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage,
388 			   unsigned char *buffer, int len, int timeout,
389 			   int retries, struct scsi_mode_data *data,
390 			   struct scsi_sense_hdr *);
391 extern int scsi_mode_select(struct scsi_device *sdev, int pf, int sp,
392 			    int modepage, unsigned char *buffer, int len,
393 			    int timeout, int retries,
394 			    struct scsi_mode_data *data,
395 			    struct scsi_sense_hdr *);
396 extern int scsi_test_unit_ready(struct scsi_device *sdev, int timeout,
397 				int retries, struct scsi_sense_hdr *sshdr);
398 extern int scsi_get_vpd_page(struct scsi_device *, u8 page, unsigned char *buf,
399 			     int buf_len);
400 extern int scsi_report_opcode(struct scsi_device *sdev, unsigned char *buffer,
401 			      unsigned int len, unsigned char opcode);
402 extern int scsi_device_set_state(struct scsi_device *sdev,
403 				 enum scsi_device_state state);
404 extern struct scsi_event *sdev_evt_alloc(enum scsi_device_event evt_type,
405 					  gfp_t gfpflags);
406 extern void sdev_evt_send(struct scsi_device *sdev, struct scsi_event *evt);
407 extern void sdev_evt_send_simple(struct scsi_device *sdev,
408 			  enum scsi_device_event evt_type, gfp_t gfpflags);
409 extern int scsi_device_quiesce(struct scsi_device *sdev);
410 extern void scsi_device_resume(struct scsi_device *sdev);
411 extern void scsi_target_quiesce(struct scsi_target *);
412 extern void scsi_target_resume(struct scsi_target *);
413 extern void scsi_scan_target(struct device *parent, unsigned int channel,
414 			     unsigned int id, u64 lun,
415 			     enum scsi_scan_mode rescan);
416 extern void scsi_target_reap(struct scsi_target *);
417 extern void scsi_target_block(struct device *);
418 extern void scsi_target_unblock(struct device *, enum scsi_device_state);
419 extern void scsi_remove_target(struct device *);
420 extern const char *scsi_device_state_name(enum scsi_device_state);
421 extern int scsi_is_sdev_device(const struct device *);
422 extern int scsi_is_target_device(const struct device *);
423 extern void scsi_sanitize_inquiry_string(unsigned char *s, int len);
424 extern int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd,
425 			int data_direction, void *buffer, unsigned bufflen,
426 			unsigned char *sense, struct scsi_sense_hdr *sshdr,
427 			int timeout, int retries, u64 flags,
428 			req_flags_t rq_flags, int *resid);
429 static inline int scsi_execute_req(struct scsi_device *sdev,
430 	const unsigned char *cmd, int data_direction, void *buffer,
431 	unsigned bufflen, struct scsi_sense_hdr *sshdr, int timeout,
432 	int retries, int *resid)
433 {
434 	return scsi_execute(sdev, cmd, data_direction, buffer,
435 		bufflen, NULL, sshdr, timeout, retries,  0, 0, resid);
436 }
437 extern void sdev_disable_disk_events(struct scsi_device *sdev);
438 extern void sdev_enable_disk_events(struct scsi_device *sdev);
439 extern int scsi_vpd_lun_id(struct scsi_device *, char *, size_t);
440 extern int scsi_vpd_tpg_id(struct scsi_device *, int *);
441 
442 #ifdef CONFIG_PM
443 extern int scsi_autopm_get_device(struct scsi_device *);
444 extern void scsi_autopm_put_device(struct scsi_device *);
445 #else
446 static inline int scsi_autopm_get_device(struct scsi_device *d) { return 0; }
447 static inline void scsi_autopm_put_device(struct scsi_device *d) {}
448 #endif /* CONFIG_PM */
449 
450 static inline int __must_check scsi_device_reprobe(struct scsi_device *sdev)
451 {
452 	return device_reprobe(&sdev->sdev_gendev);
453 }
454 
455 static inline unsigned int sdev_channel(struct scsi_device *sdev)
456 {
457 	return sdev->channel;
458 }
459 
460 static inline unsigned int sdev_id(struct scsi_device *sdev)
461 {
462 	return sdev->id;
463 }
464 
465 #define scmd_id(scmd) sdev_id((scmd)->device)
466 #define scmd_channel(scmd) sdev_channel((scmd)->device)
467 
468 /*
469  * checks for positions of the SCSI state machine
470  */
471 static inline int scsi_device_online(struct scsi_device *sdev)
472 {
473 	return (sdev->sdev_state != SDEV_OFFLINE &&
474 		sdev->sdev_state != SDEV_TRANSPORT_OFFLINE &&
475 		sdev->sdev_state != SDEV_DEL);
476 }
477 static inline int scsi_device_blocked(struct scsi_device *sdev)
478 {
479 	return sdev->sdev_state == SDEV_BLOCK ||
480 		sdev->sdev_state == SDEV_CREATED_BLOCK;
481 }
482 static inline int scsi_device_created(struct scsi_device *sdev)
483 {
484 	return sdev->sdev_state == SDEV_CREATED ||
485 		sdev->sdev_state == SDEV_CREATED_BLOCK;
486 }
487 
488 int scsi_internal_device_block_nowait(struct scsi_device *sdev);
489 int scsi_internal_device_unblock_nowait(struct scsi_device *sdev,
490 					enum scsi_device_state new_state);
491 
492 /* accessor functions for the SCSI parameters */
493 static inline int scsi_device_sync(struct scsi_device *sdev)
494 {
495 	return sdev->sdtr;
496 }
497 static inline int scsi_device_wide(struct scsi_device *sdev)
498 {
499 	return sdev->wdtr;
500 }
501 static inline int scsi_device_dt(struct scsi_device *sdev)
502 {
503 	return sdev->ppr;
504 }
505 static inline int scsi_device_dt_only(struct scsi_device *sdev)
506 {
507 	if (sdev->inquiry_len < 57)
508 		return 0;
509 	return (sdev->inquiry[56] & 0x0c) == 0x04;
510 }
511 static inline int scsi_device_ius(struct scsi_device *sdev)
512 {
513 	if (sdev->inquiry_len < 57)
514 		return 0;
515 	return sdev->inquiry[56] & 0x01;
516 }
517 static inline int scsi_device_qas(struct scsi_device *sdev)
518 {
519 	if (sdev->inquiry_len < 57)
520 		return 0;
521 	return sdev->inquiry[56] & 0x02;
522 }
523 static inline int scsi_device_enclosure(struct scsi_device *sdev)
524 {
525 	return sdev->inquiry ? (sdev->inquiry[6] & (1<<6)) : 1;
526 }
527 
528 static inline int scsi_device_protection(struct scsi_device *sdev)
529 {
530 	if (sdev->no_dif)
531 		return 0;
532 
533 	return sdev->scsi_level > SCSI_2 && sdev->inquiry[5] & (1<<0);
534 }
535 
536 static inline int scsi_device_tpgs(struct scsi_device *sdev)
537 {
538 	return sdev->inquiry ? (sdev->inquiry[5] >> 4) & 0x3 : 0;
539 }
540 
541 /**
542  * scsi_device_supports_vpd - test if a device supports VPD pages
543  * @sdev: the &struct scsi_device to test
544  *
545  * If the 'try_vpd_pages' flag is set it takes precedence.
546  * Otherwise we will assume VPD pages are supported if the
547  * SCSI level is at least SPC-3 and 'skip_vpd_pages' is not set.
548  */
549 static inline int scsi_device_supports_vpd(struct scsi_device *sdev)
550 {
551 	/* Attempt VPD inquiry if the device blacklist explicitly calls
552 	 * for it.
553 	 */
554 	if (sdev->try_vpd_pages)
555 		return 1;
556 	/*
557 	 * Although VPD inquiries can go to SCSI-2 type devices,
558 	 * some USB ones crash on receiving them, and the pages
559 	 * we currently ask for are mandatory for SPC-2 and beyond
560 	 */
561 	if (sdev->scsi_level >= SCSI_SPC_2 && !sdev->skip_vpd_pages)
562 		return 1;
563 	return 0;
564 }
565 
566 #define MODULE_ALIAS_SCSI_DEVICE(type) \
567 	MODULE_ALIAS("scsi:t-" __stringify(type) "*")
568 #define SCSI_DEVICE_MODALIAS_FMT "scsi:t-0x%02x"
569 
570 #endif /* _SCSI_SCSI_DEVICE_H */
571