xref: /linux/include/scsi/scsi_device.h (revision 841b86f3289dbe858daeceec36423d4ea286fac2)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _SCSI_SCSI_DEVICE_H
3 #define _SCSI_SCSI_DEVICE_H
4 
5 #include <linux/list.h>
6 #include <linux/spinlock.h>
7 #include <linux/workqueue.h>
8 #include <linux/blkdev.h>
9 #include <scsi/scsi.h>
10 #include <linux/atomic.h>
11 
12 struct device;
13 struct request_queue;
14 struct scsi_cmnd;
15 struct scsi_lun;
16 struct scsi_sense_hdr;
17 
18 struct scsi_mode_data {
19 	__u32	length;
20 	__u16	block_descriptor_length;
21 	__u8	medium_type;
22 	__u8	device_specific;
23 	__u8	header_length;
24 	__u8	longlba:1;
25 };
26 
27 /*
28  * sdev state: If you alter this, you also need to alter scsi_sysfs.c
29  * (for the ascii descriptions) and the state model enforcer:
30  * scsi_lib:scsi_device_set_state().
31  */
32 enum scsi_device_state {
33 	SDEV_CREATED = 1,	/* device created but not added to sysfs
34 				 * Only internal commands allowed (for inq) */
35 	SDEV_RUNNING,		/* device properly configured
36 				 * All commands allowed */
37 	SDEV_CANCEL,		/* beginning to delete device
38 				 * Only error handler commands allowed */
39 	SDEV_DEL,		/* device deleted
40 				 * no commands allowed */
41 	SDEV_QUIESCE,		/* Device quiescent.  No block commands
42 				 * will be accepted, only specials (which
43 				 * originate in the mid-layer) */
44 	SDEV_OFFLINE,		/* Device offlined (by error handling or
45 				 * user request */
46 	SDEV_TRANSPORT_OFFLINE,	/* Offlined by transport class error handler */
47 	SDEV_BLOCK,		/* Device blocked by scsi lld.  No
48 				 * scsi commands from user or midlayer
49 				 * should be issued to the scsi
50 				 * lld. */
51 	SDEV_CREATED_BLOCK,	/* same as above but for created devices */
52 };
53 
54 enum scsi_scan_mode {
55 	SCSI_SCAN_INITIAL = 0,
56 	SCSI_SCAN_RESCAN,
57 	SCSI_SCAN_MANUAL,
58 };
59 
60 enum scsi_device_event {
61 	SDEV_EVT_MEDIA_CHANGE	= 1,	/* media has changed */
62 	SDEV_EVT_INQUIRY_CHANGE_REPORTED,		/* 3F 03  UA reported */
63 	SDEV_EVT_CAPACITY_CHANGE_REPORTED,		/* 2A 09  UA reported */
64 	SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED,	/* 38 07  UA reported */
65 	SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED,	/* 2A 01  UA reported */
66 	SDEV_EVT_LUN_CHANGE_REPORTED,			/* 3F 0E  UA reported */
67 	SDEV_EVT_ALUA_STATE_CHANGE_REPORTED,		/* 2A 06  UA reported */
68 	SDEV_EVT_POWER_ON_RESET_OCCURRED,		/* 29 00  UA reported */
69 
70 	SDEV_EVT_FIRST		= SDEV_EVT_MEDIA_CHANGE,
71 	SDEV_EVT_LAST		= SDEV_EVT_POWER_ON_RESET_OCCURRED,
72 
73 	SDEV_EVT_MAXBITS	= SDEV_EVT_LAST + 1
74 };
75 
76 struct scsi_event {
77 	enum scsi_device_event	evt_type;
78 	struct list_head	node;
79 
80 	/* put union of data structures, for non-simple event types,
81 	 * here
82 	 */
83 };
84 
85 /**
86  * struct scsi_vpd - SCSI Vital Product Data
87  * @rcu: For kfree_rcu().
88  * @len: Length in bytes of @data.
89  * @data: VPD data as defined in various T10 SCSI standard documents.
90  */
91 struct scsi_vpd {
92 	struct rcu_head	rcu;
93 	int		len;
94 	unsigned char	data[];
95 };
96 
97 struct scsi_device {
98 	struct Scsi_Host *host;
99 	struct request_queue *request_queue;
100 
101 	/* the next two are protected by the host->host_lock */
102 	struct list_head    siblings;   /* list of all devices on this host */
103 	struct list_head    same_target_siblings; /* just the devices sharing same target id */
104 
105 	atomic_t device_busy;		/* commands actually active on LLDD */
106 	atomic_t device_blocked;	/* Device returned QUEUE_FULL. */
107 
108 	spinlock_t list_lock;
109 	struct list_head cmd_list;	/* queue of in use SCSI Command structures */
110 	struct list_head starved_entry;
111 	unsigned short queue_depth;	/* How deep of a queue we want */
112 	unsigned short max_queue_depth;	/* max queue depth */
113 	unsigned short last_queue_full_depth; /* These two are used by */
114 	unsigned short last_queue_full_count; /* scsi_track_queue_full() */
115 	unsigned long last_queue_full_time;	/* last queue full time */
116 	unsigned long queue_ramp_up_period;	/* ramp up period in jiffies */
117 #define SCSI_DEFAULT_RAMP_UP_PERIOD	(120 * HZ)
118 
119 	unsigned long last_queue_ramp_up;	/* last queue ramp up time */
120 
121 	unsigned int id, channel;
122 	u64 lun;
123 	unsigned int manufacturer;	/* Manufacturer of device, for using
124 					 * vendor-specific cmd's */
125 	unsigned sector_size;	/* size in bytes */
126 
127 	void *hostdata;		/* available to low-level driver */
128 	unsigned char type;
129 	char scsi_level;
130 	char inq_periph_qual;	/* PQ from INQUIRY data */
131 	struct mutex inquiry_mutex;
132 	unsigned char inquiry_len;	/* valid bytes in 'inquiry' */
133 	unsigned char * inquiry;	/* INQUIRY response data */
134 	const char * vendor;		/* [back_compat] point into 'inquiry' ... */
135 	const char * model;		/* ... after scan; point to static string */
136 	const char * rev;		/* ... "nullnullnullnull" before scan */
137 
138 #define SCSI_VPD_PG_LEN                255
139 	struct scsi_vpd __rcu *vpd_pg83;
140 	struct scsi_vpd __rcu *vpd_pg80;
141 	unsigned char current_tag;	/* current tag */
142 	struct scsi_target      *sdev_target;   /* used only for single_lun */
143 
144 	unsigned int	sdev_bflags; /* black/white flags as also found in
145 				 * scsi_devinfo.[hc]. For now used only to
146 				 * pass settings from slave_alloc to scsi
147 				 * core. */
148 	unsigned int eh_timeout; /* Error handling timeout */
149 	unsigned removable:1;
150 	unsigned changed:1;	/* Data invalid due to media change */
151 	unsigned busy:1;	/* Used to prevent races */
152 	unsigned lockable:1;	/* Able to prevent media removal */
153 	unsigned locked:1;      /* Media removal disabled */
154 	unsigned borken:1;	/* Tell the Seagate driver to be
155 				 * painfully slow on this device */
156 	unsigned disconnect:1;	/* can disconnect */
157 	unsigned soft_reset:1;	/* Uses soft reset option */
158 	unsigned sdtr:1;	/* Device supports SDTR messages */
159 	unsigned wdtr:1;	/* Device supports WDTR messages */
160 	unsigned ppr:1;		/* Device supports PPR messages */
161 	unsigned tagged_supported:1;	/* Supports SCSI-II tagged queuing */
162 	unsigned simple_tags:1;	/* simple queue tag messages are enabled */
163 	unsigned was_reset:1;	/* There was a bus reset on the bus for
164 				 * this device */
165 	unsigned expecting_cc_ua:1; /* Expecting a CHECK_CONDITION/UNIT_ATTN
166 				     * because we did a bus reset. */
167 	unsigned use_10_for_rw:1; /* first try 10-byte read / write */
168 	unsigned use_10_for_ms:1; /* first try 10-byte mode sense/select */
169 	unsigned no_report_opcodes:1;	/* no REPORT SUPPORTED OPERATION CODES */
170 	unsigned no_write_same:1;	/* no WRITE SAME command */
171 	unsigned use_16_for_rw:1; /* Use read/write(16) over read/write(10) */
172 	unsigned skip_ms_page_8:1;	/* do not use MODE SENSE page 0x08 */
173 	unsigned skip_ms_page_3f:1;	/* do not use MODE SENSE page 0x3f */
174 	unsigned skip_vpd_pages:1;	/* do not read VPD pages */
175 	unsigned try_vpd_pages:1;	/* attempt to read VPD pages */
176 	unsigned use_192_bytes_for_3f:1; /* ask for 192 bytes from page 0x3f */
177 	unsigned no_start_on_add:1;	/* do not issue start on add */
178 	unsigned allow_restart:1; /* issue START_UNIT in error handler */
179 	unsigned manage_start_stop:1;	/* Let HLD (sd) manage start/stop */
180 	unsigned start_stop_pwr_cond:1;	/* Set power cond. in START_STOP_UNIT */
181 	unsigned no_uld_attach:1; /* disable connecting to upper level drivers */
182 	unsigned select_no_atn:1;
183 	unsigned fix_capacity:1;	/* READ_CAPACITY is too high by 1 */
184 	unsigned guess_capacity:1;	/* READ_CAPACITY might be too high by 1 */
185 	unsigned retry_hwerror:1;	/* Retry HARDWARE_ERROR */
186 	unsigned last_sector_bug:1;	/* do not use multisector accesses on
187 					   SD_LAST_BUGGY_SECTORS */
188 	unsigned no_read_disc_info:1;	/* Avoid READ_DISC_INFO cmds */
189 	unsigned no_read_capacity_16:1; /* Avoid READ_CAPACITY_16 cmds */
190 	unsigned try_rc_10_first:1;	/* Try READ_CAPACACITY_10 first */
191 	unsigned security_supported:1;	/* Supports Security Protocols */
192 	unsigned is_visible:1;	/* is the device visible in sysfs */
193 	unsigned wce_default_on:1;	/* Cache is ON by default */
194 	unsigned no_dif:1;	/* T10 PI (DIF) should be disabled */
195 	unsigned broken_fua:1;		/* Don't set FUA bit */
196 	unsigned lun_in_cdb:1;		/* Store LUN bits in CDB[1] */
197 	unsigned unmap_limit_for_ws:1;	/* Use the UNMAP limit for WRITE SAME */
198 
199 	atomic_t disk_events_disable_depth; /* disable depth for disk events */
200 
201 	DECLARE_BITMAP(supported_events, SDEV_EVT_MAXBITS); /* supported events */
202 	DECLARE_BITMAP(pending_events, SDEV_EVT_MAXBITS); /* pending events */
203 	struct list_head event_list;	/* asserted events */
204 	struct work_struct event_work;
205 
206 	unsigned int max_device_blocked; /* what device_blocked counts down from  */
207 #define SCSI_DEFAULT_DEVICE_BLOCKED	3
208 
209 	atomic_t iorequest_cnt;
210 	atomic_t iodone_cnt;
211 	atomic_t ioerr_cnt;
212 
213 	struct device		sdev_gendev,
214 				sdev_dev;
215 
216 	struct execute_work	ew; /* used to get process context on put */
217 	struct work_struct	requeue_work;
218 
219 	struct scsi_device_handler *handler;
220 	void			*handler_data;
221 
222 	unsigned char		access_state;
223 	struct mutex		state_mutex;
224 	enum scsi_device_state sdev_state;
225 	struct task_struct	*quiesced_by;
226 	unsigned long		sdev_data[0];
227 } __attribute__((aligned(sizeof(unsigned long))));
228 
229 #define	to_scsi_device(d)	\
230 	container_of(d, struct scsi_device, sdev_gendev)
231 #define	class_to_sdev(d)	\
232 	container_of(d, struct scsi_device, sdev_dev)
233 #define transport_class_to_sdev(class_dev) \
234 	to_scsi_device(class_dev->parent)
235 
236 #define sdev_dbg(sdev, fmt, a...) \
237 	dev_dbg(&(sdev)->sdev_gendev, fmt, ##a)
238 
239 /*
240  * like scmd_printk, but the device name is passed in
241  * as a string pointer
242  */
243 __printf(4, 5) void
244 sdev_prefix_printk(const char *, const struct scsi_device *, const char *,
245 		const char *, ...);
246 
247 #define sdev_printk(l, sdev, fmt, a...)				\
248 	sdev_prefix_printk(l, sdev, NULL, fmt, ##a)
249 
250 __printf(3, 4) void
251 scmd_printk(const char *, const struct scsi_cmnd *, const char *, ...);
252 
253 #define scmd_dbg(scmd, fmt, a...)					   \
254 	do {								   \
255 		if ((scmd)->request->rq_disk)				   \
256 			sdev_dbg((scmd)->device, "[%s] " fmt,		   \
257 				 (scmd)->request->rq_disk->disk_name, ##a);\
258 		else							   \
259 			sdev_dbg((scmd)->device, fmt, ##a);		   \
260 	} while (0)
261 
262 enum scsi_target_state {
263 	STARGET_CREATED = 1,
264 	STARGET_RUNNING,
265 	STARGET_REMOVE,
266 	STARGET_CREATED_REMOVE,
267 	STARGET_DEL,
268 };
269 
270 /*
271  * scsi_target: representation of a scsi target, for now, this is only
272  * used for single_lun devices. If no one has active IO to the target,
273  * starget_sdev_user is NULL, else it points to the active sdev.
274  */
275 struct scsi_target {
276 	struct scsi_device	*starget_sdev_user;
277 	struct list_head	siblings;
278 	struct list_head	devices;
279 	struct device		dev;
280 	struct kref		reap_ref; /* last put renders target invisible */
281 	unsigned int		channel;
282 	unsigned int		id; /* target id ... replace
283 				     * scsi_device.id eventually */
284 	unsigned int		create:1; /* signal that it needs to be added */
285 	unsigned int		single_lun:1;	/* Indicates we should only
286 						 * allow I/O to one of the luns
287 						 * for the device at a time. */
288 	unsigned int		pdt_1f_for_no_lun:1;	/* PDT = 0x1f
289 						 * means no lun present. */
290 	unsigned int		no_report_luns:1;	/* Don't use
291 						 * REPORT LUNS for scanning. */
292 	unsigned int		expecting_lun_change:1;	/* A device has reported
293 						 * a 3F/0E UA, other devices on
294 						 * the same target will also. */
295 	/* commands actually active on LLD. */
296 	atomic_t		target_busy;
297 	atomic_t		target_blocked;
298 
299 	/*
300 	 * LLDs should set this in the slave_alloc host template callout.
301 	 * If set to zero then there is not limit.
302 	 */
303 	unsigned int		can_queue;
304 	unsigned int		max_target_blocked;
305 #define SCSI_DEFAULT_TARGET_BLOCKED	3
306 
307 	char			scsi_level;
308 	enum scsi_target_state	state;
309 	void 			*hostdata; /* available to low-level driver */
310 	unsigned long		starget_data[0]; /* for the transport */
311 	/* starget_data must be the last element!!!! */
312 } __attribute__((aligned(sizeof(unsigned long))));
313 
314 #define to_scsi_target(d)	container_of(d, struct scsi_target, dev)
315 static inline struct scsi_target *scsi_target(struct scsi_device *sdev)
316 {
317 	return to_scsi_target(sdev->sdev_gendev.parent);
318 }
319 #define transport_class_to_starget(class_dev) \
320 	to_scsi_target(class_dev->parent)
321 
322 #define starget_printk(prefix, starget, fmt, a...)	\
323 	dev_printk(prefix, &(starget)->dev, fmt, ##a)
324 
325 extern struct scsi_device *__scsi_add_device(struct Scsi_Host *,
326 		uint, uint, u64, void *hostdata);
327 extern int scsi_add_device(struct Scsi_Host *host, uint channel,
328 			   uint target, u64 lun);
329 extern int scsi_register_device_handler(struct scsi_device_handler *scsi_dh);
330 extern void scsi_remove_device(struct scsi_device *);
331 extern int scsi_unregister_device_handler(struct scsi_device_handler *scsi_dh);
332 void scsi_attach_vpd(struct scsi_device *sdev);
333 
334 extern struct scsi_device *scsi_device_from_queue(struct request_queue *q);
335 extern int __must_check scsi_device_get(struct scsi_device *);
336 extern void scsi_device_put(struct scsi_device *);
337 extern struct scsi_device *scsi_device_lookup(struct Scsi_Host *,
338 					      uint, uint, u64);
339 extern struct scsi_device *__scsi_device_lookup(struct Scsi_Host *,
340 						uint, uint, u64);
341 extern struct scsi_device *scsi_device_lookup_by_target(struct scsi_target *,
342 							u64);
343 extern struct scsi_device *__scsi_device_lookup_by_target(struct scsi_target *,
344 							  u64);
345 extern void starget_for_each_device(struct scsi_target *, void *,
346 		     void (*fn)(struct scsi_device *, void *));
347 extern void __starget_for_each_device(struct scsi_target *, void *,
348 				      void (*fn)(struct scsi_device *,
349 						 void *));
350 
351 /* only exposed to implement shost_for_each_device */
352 extern struct scsi_device *__scsi_iterate_devices(struct Scsi_Host *,
353 						  struct scsi_device *);
354 
355 /**
356  * shost_for_each_device - iterate over all devices of a host
357  * @sdev: the &struct scsi_device to use as a cursor
358  * @shost: the &struct scsi_host to iterate over
359  *
360  * Iterator that returns each device attached to @shost.  This loop
361  * takes a reference on each device and releases it at the end.  If
362  * you break out of the loop, you must call scsi_device_put(sdev).
363  */
364 #define shost_for_each_device(sdev, shost) \
365 	for ((sdev) = __scsi_iterate_devices((shost), NULL); \
366 	     (sdev); \
367 	     (sdev) = __scsi_iterate_devices((shost), (sdev)))
368 
369 /**
370  * __shost_for_each_device - iterate over all devices of a host (UNLOCKED)
371  * @sdev: the &struct scsi_device to use as a cursor
372  * @shost: the &struct scsi_host to iterate over
373  *
374  * Iterator that returns each device attached to @shost.  It does _not_
375  * take a reference on the scsi_device, so the whole loop must be
376  * protected by shost->host_lock.
377  *
378  * Note: The only reason to use this is because you need to access the
379  * device list in interrupt context.  Otherwise you really want to use
380  * shost_for_each_device instead.
381  */
382 #define __shost_for_each_device(sdev, shost) \
383 	list_for_each_entry((sdev), &((shost)->__devices), siblings)
384 
385 extern int scsi_change_queue_depth(struct scsi_device *, int);
386 extern int scsi_track_queue_full(struct scsi_device *, int);
387 
388 extern int scsi_set_medium_removal(struct scsi_device *, char);
389 
390 extern int scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage,
391 			   unsigned char *buffer, int len, int timeout,
392 			   int retries, struct scsi_mode_data *data,
393 			   struct scsi_sense_hdr *);
394 extern int scsi_mode_select(struct scsi_device *sdev, int pf, int sp,
395 			    int modepage, unsigned char *buffer, int len,
396 			    int timeout, int retries,
397 			    struct scsi_mode_data *data,
398 			    struct scsi_sense_hdr *);
399 extern int scsi_test_unit_ready(struct scsi_device *sdev, int timeout,
400 				int retries, struct scsi_sense_hdr *sshdr);
401 extern int scsi_get_vpd_page(struct scsi_device *, u8 page, unsigned char *buf,
402 			     int buf_len);
403 extern int scsi_report_opcode(struct scsi_device *sdev, unsigned char *buffer,
404 			      unsigned int len, unsigned char opcode);
405 extern int scsi_device_set_state(struct scsi_device *sdev,
406 				 enum scsi_device_state state);
407 extern struct scsi_event *sdev_evt_alloc(enum scsi_device_event evt_type,
408 					  gfp_t gfpflags);
409 extern void sdev_evt_send(struct scsi_device *sdev, struct scsi_event *evt);
410 extern void sdev_evt_send_simple(struct scsi_device *sdev,
411 			  enum scsi_device_event evt_type, gfp_t gfpflags);
412 extern int scsi_device_quiesce(struct scsi_device *sdev);
413 extern void scsi_device_resume(struct scsi_device *sdev);
414 extern void scsi_target_quiesce(struct scsi_target *);
415 extern void scsi_target_resume(struct scsi_target *);
416 extern void scsi_scan_target(struct device *parent, unsigned int channel,
417 			     unsigned int id, u64 lun,
418 			     enum scsi_scan_mode rescan);
419 extern void scsi_target_reap(struct scsi_target *);
420 extern void scsi_target_block(struct device *);
421 extern void scsi_target_unblock(struct device *, enum scsi_device_state);
422 extern void scsi_remove_target(struct device *);
423 extern const char *scsi_device_state_name(enum scsi_device_state);
424 extern int scsi_is_sdev_device(const struct device *);
425 extern int scsi_is_target_device(const struct device *);
426 extern void scsi_sanitize_inquiry_string(unsigned char *s, int len);
427 extern int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd,
428 			int data_direction, void *buffer, unsigned bufflen,
429 			unsigned char *sense, struct scsi_sense_hdr *sshdr,
430 			int timeout, int retries, u64 flags,
431 			req_flags_t rq_flags, int *resid);
432 static inline int scsi_execute_req(struct scsi_device *sdev,
433 	const unsigned char *cmd, int data_direction, void *buffer,
434 	unsigned bufflen, struct scsi_sense_hdr *sshdr, int timeout,
435 	int retries, int *resid)
436 {
437 	return scsi_execute(sdev, cmd, data_direction, buffer,
438 		bufflen, NULL, sshdr, timeout, retries,  0, 0, resid);
439 }
440 extern void sdev_disable_disk_events(struct scsi_device *sdev);
441 extern void sdev_enable_disk_events(struct scsi_device *sdev);
442 extern int scsi_vpd_lun_id(struct scsi_device *, char *, size_t);
443 extern int scsi_vpd_tpg_id(struct scsi_device *, int *);
444 
445 #ifdef CONFIG_PM
446 extern int scsi_autopm_get_device(struct scsi_device *);
447 extern void scsi_autopm_put_device(struct scsi_device *);
448 #else
449 static inline int scsi_autopm_get_device(struct scsi_device *d) { return 0; }
450 static inline void scsi_autopm_put_device(struct scsi_device *d) {}
451 #endif /* CONFIG_PM */
452 
453 static inline int __must_check scsi_device_reprobe(struct scsi_device *sdev)
454 {
455 	return device_reprobe(&sdev->sdev_gendev);
456 }
457 
458 static inline unsigned int sdev_channel(struct scsi_device *sdev)
459 {
460 	return sdev->channel;
461 }
462 
463 static inline unsigned int sdev_id(struct scsi_device *sdev)
464 {
465 	return sdev->id;
466 }
467 
468 #define scmd_id(scmd) sdev_id((scmd)->device)
469 #define scmd_channel(scmd) sdev_channel((scmd)->device)
470 
471 /*
472  * checks for positions of the SCSI state machine
473  */
474 static inline int scsi_device_online(struct scsi_device *sdev)
475 {
476 	return (sdev->sdev_state != SDEV_OFFLINE &&
477 		sdev->sdev_state != SDEV_TRANSPORT_OFFLINE &&
478 		sdev->sdev_state != SDEV_DEL);
479 }
480 static inline int scsi_device_blocked(struct scsi_device *sdev)
481 {
482 	return sdev->sdev_state == SDEV_BLOCK ||
483 		sdev->sdev_state == SDEV_CREATED_BLOCK;
484 }
485 static inline int scsi_device_created(struct scsi_device *sdev)
486 {
487 	return sdev->sdev_state == SDEV_CREATED ||
488 		sdev->sdev_state == SDEV_CREATED_BLOCK;
489 }
490 
491 int scsi_internal_device_block_nowait(struct scsi_device *sdev);
492 int scsi_internal_device_unblock_nowait(struct scsi_device *sdev,
493 					enum scsi_device_state new_state);
494 
495 /* accessor functions for the SCSI parameters */
496 static inline int scsi_device_sync(struct scsi_device *sdev)
497 {
498 	return sdev->sdtr;
499 }
500 static inline int scsi_device_wide(struct scsi_device *sdev)
501 {
502 	return sdev->wdtr;
503 }
504 static inline int scsi_device_dt(struct scsi_device *sdev)
505 {
506 	return sdev->ppr;
507 }
508 static inline int scsi_device_dt_only(struct scsi_device *sdev)
509 {
510 	if (sdev->inquiry_len < 57)
511 		return 0;
512 	return (sdev->inquiry[56] & 0x0c) == 0x04;
513 }
514 static inline int scsi_device_ius(struct scsi_device *sdev)
515 {
516 	if (sdev->inquiry_len < 57)
517 		return 0;
518 	return sdev->inquiry[56] & 0x01;
519 }
520 static inline int scsi_device_qas(struct scsi_device *sdev)
521 {
522 	if (sdev->inquiry_len < 57)
523 		return 0;
524 	return sdev->inquiry[56] & 0x02;
525 }
526 static inline int scsi_device_enclosure(struct scsi_device *sdev)
527 {
528 	return sdev->inquiry ? (sdev->inquiry[6] & (1<<6)) : 1;
529 }
530 
531 static inline int scsi_device_protection(struct scsi_device *sdev)
532 {
533 	if (sdev->no_dif)
534 		return 0;
535 
536 	return sdev->scsi_level > SCSI_2 && sdev->inquiry[5] & (1<<0);
537 }
538 
539 static inline int scsi_device_tpgs(struct scsi_device *sdev)
540 {
541 	return sdev->inquiry ? (sdev->inquiry[5] >> 4) & 0x3 : 0;
542 }
543 
544 /**
545  * scsi_device_supports_vpd - test if a device supports VPD pages
546  * @sdev: the &struct scsi_device to test
547  *
548  * If the 'try_vpd_pages' flag is set it takes precedence.
549  * Otherwise we will assume VPD pages are supported if the
550  * SCSI level is at least SPC-3 and 'skip_vpd_pages' is not set.
551  */
552 static inline int scsi_device_supports_vpd(struct scsi_device *sdev)
553 {
554 	/* Attempt VPD inquiry if the device blacklist explicitly calls
555 	 * for it.
556 	 */
557 	if (sdev->try_vpd_pages)
558 		return 1;
559 	/*
560 	 * Although VPD inquiries can go to SCSI-2 type devices,
561 	 * some USB ones crash on receiving them, and the pages
562 	 * we currently ask for are mandatory for SPC-2 and beyond
563 	 */
564 	if (sdev->scsi_level >= SCSI_SPC_2 && !sdev->skip_vpd_pages)
565 		return 1;
566 	return 0;
567 }
568 
569 #define MODULE_ALIAS_SCSI_DEVICE(type) \
570 	MODULE_ALIAS("scsi:t-" __stringify(type) "*")
571 #define SCSI_DEVICE_MODALIAS_FMT "scsi:t-0x%02x"
572 
573 #endif /* _SCSI_SCSI_DEVICE_H */
574