include/scsi/scsi_device.h

   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 __must_check 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 */