include/scsi/scsi_device.h - linux/kernel/git/mellanox/linux - Git at Google

 #ifndef _SCSI_SCSI_DEVICE_H
 #define _SCSI_SCSI_DEVICE_H

 #include <linux/device.h>
 #include <linux/list.h>
 #include <linux/spinlock.h>
 #include <linux/workqueue.h>
 #include <linux/blkdev.h>
 #include <asm/atomic.h>

 struct request_queue;
 struct scsi_cmnd;
 struct scsi_lun;
 struct scsi_sense_hdr;

 struct scsi_mode_data {
 	__u32	length;
 	__u16	block_descriptor_length;
 	__u8	medium_type;
 	__u8	device_specific;
 	__u8	header_length;
 	__u8	longlba:1;
 };

 /*
  * sdev state: If you alter this, you also need to alter scsi_sysfs.c
  * (for the ascii descriptions) and the state model enforcer:
  * scsi_lib:scsi_device_set_state().
  */
 enum scsi_device_state {
 	SDEV_CREATED = 1,	/* device created but not added to sysfs
 				 * Only internal commands allowed (for inq) */
 	SDEV_RUNNING,		/* device properly configured
 				 * All commands allowed */
 	SDEV_CANCEL,		/* beginning to delete device
 				 * Only error handler commands allowed */
 	SDEV_DEL,		/* device deleted
 				 * no commands allowed */
 	SDEV_QUIESCE,		/* Device quiescent.  No block commands
 				 * will be accepted, only specials (which
 				 * originate in the mid-layer) */
 	SDEV_OFFLINE,		/* Device offlined (by error handling or
 				 * user request */
 	SDEV_BLOCK,		/* Device blocked by scsi lld.  No scsi
 				 * commands from user or midlayer should be issued
 				 * to the scsi lld. */
 };

 enum scsi_device_event {
 	SDEV_EVT_MEDIA_CHANGE	= 1,	/* media has changed */

 	SDEV_EVT_LAST		= SDEV_EVT_MEDIA_CHANGE,
 	SDEV_EVT_MAXBITS	= SDEV_EVT_LAST + 1
 };

 struct scsi_event {
 	enum scsi_device_event	evt_type;
 	struct list_head	node;

 	/* put union of data structures, for non-simple event types,
 	 * here
 	 */
 };

 struct scsi_device {
 	struct Scsi_Host *host;
 	struct request_queue *request_queue;

 	/* the next two are protected by the host->host_lock */
 	struct list_head    siblings;   /* list of all devices on this host */
 	struct list_head    same_target_siblings; /* just the devices sharing same target id */

 	/* this is now protected by the request_queue->queue_lock */
 	unsigned int device_busy;	/* commands actually active on
 					 * low-level. protected by queue_lock. */
 	spinlock_t list_lock;
 	struct list_head cmd_list;	/* queue of in use SCSI Command structures */
 	struct list_head starved_entry;
 	struct scsi_cmnd *current_cmnd;	/* currently active command */
 	unsigned short queue_depth;	/* How deep of a queue we want */
 	unsigned short last_queue_full_depth; /* These two are used by */
 	unsigned short last_queue_full_count; /* scsi_track_queue_full() */
 	unsigned long last_queue_full_time;/* don't let QUEUE_FULLs on the same
 					   jiffie count on our counter, they
 					   could all be from the same event. */

 	unsigned int id, lun, channel;

 	unsigned int manufacturer;	/* Manufacturer of device, for using
 					 * vendor-specific cmd's */
 	unsigned sector_size;	/* size in bytes */

 	void *hostdata;		/* available to low-level driver */
 	char type;
 	char scsi_level;
 	char inq_periph_qual;	/* PQ from INQUIRY data */
 	unsigned char inquiry_len;	/* valid bytes in 'inquiry' */
 	unsigned char * inquiry;	/* INQUIRY response data */
 	const char * vendor;		/* [back_compat] point into 'inquiry' ... */
 	const char * model;		/* ... after scan; point to static string */
 	const char * rev;		/* ... "nullnullnullnull" before scan */
 	unsigned char current_tag;	/* current tag */
 	struct scsi_target      *sdev_target;   /* used only for single_lun */

 	unsigned int	sdev_bflags; /* black/white flags as also found in
 				 * scsi_devinfo.[hc]. For now used only to
 				 * pass settings from slave_alloc to scsi
 				 * core. */
 	unsigned writeable:1;
 	unsigned removable:1;
 	unsigned changed:1;	/* Data invalid due to media change */
 	unsigned busy:1;	/* Used to prevent races */
 	unsigned lockable:1;	/* Able to prevent media removal */
 	unsigned locked:1;      /* Media removal disabled */
 	unsigned borken:1;	/* Tell the Seagate driver to be
 				 * painfully slow on this device */
 	unsigned disconnect:1;	/* can disconnect */
 	unsigned soft_reset:1;	/* Uses soft reset option */
 	unsigned sdtr:1;	/* Device supports SDTR messages */
 	unsigned wdtr:1;	/* Device supports WDTR messages */
 	unsigned ppr:1;		/* Device supports PPR messages */
 	unsigned tagged_supported:1;	/* Supports SCSI-II tagged queuing */
 	unsigned simple_tags:1;	/* simple queue tag messages are enabled */
 	unsigned ordered_tags:1;/* ordered queue tag messages are enabled */
 	unsigned single_lun:1;	/* Indicates we should only allow I/O to
 				 * one of the luns for the device at a
 				 * time. */
 	unsigned was_reset:1;	/* There was a bus reset on the bus for
 				 * this device */
 	unsigned expecting_cc_ua:1; /* Expecting a CHECK_CONDITION/UNIT_ATTN
 				     * because we did a bus reset. */
 	unsigned use_10_for_rw:1; /* first try 10-byte read / write */
 	unsigned use_10_for_ms:1; /* first try 10-byte mode sense/select */
 	unsigned skip_ms_page_8:1;	/* do not use MODE SENSE page 0x08 */
 	unsigned skip_ms_page_3f:1;	/* do not use MODE SENSE page 0x3f */
 	unsigned use_192_bytes_for_3f:1; /* ask for 192 bytes from page 0x3f */
 	unsigned no_start_on_add:1;	/* do not issue start on add */
 	unsigned allow_restart:1; /* issue START_UNIT in error handler */
 	unsigned manage_start_stop:1;	/* Let HLD (sd) manage start/stop */
 	unsigned no_uld_attach:1; /* disable connecting to upper level drivers */
 	unsigned select_no_atn:1;
 	unsigned fix_capacity:1;	/* READ_CAPACITY is too high by 1 */
 	unsigned guess_capacity:1;	/* READ_CAPACITY might be too high by 1 */
 	unsigned retry_hwerror:1;	/* Retry HARDWARE_ERROR */

 	DECLARE_BITMAP(supported_events, SDEV_EVT_MAXBITS); /* supported events */
 	struct list_head event_list;	/* asserted events */
 	struct work_struct event_work;

 	unsigned int device_blocked;	/* Device returned QUEUE_FULL. */

 	unsigned int max_device_blocked; /* what device_blocked counts down from  */
 #define SCSI_DEFAULT_DEVICE_BLOCKED	3

 	atomic_t iorequest_cnt;
 	atomic_t iodone_cnt;
 	atomic_t ioerr_cnt;

 	int timeout;

 	struct device		sdev_gendev;
 	struct class_device	sdev_classdev;

 	struct execute_work	ew; /* used to get process context on put */

 	enum scsi_device_state sdev_state;
 	unsigned long		sdev_data[0];
 } __attribute__((aligned(sizeof(unsigned long))));
 #define	to_scsi_device(d)	\
 	container_of(d, struct scsi_device, sdev_gendev)
 #define	class_to_sdev(d)	\
 	container_of(d, struct scsi_device, sdev_classdev)
 #define transport_class_to_sdev(class_dev) \
 	to_scsi_device(class_dev->dev)

 #define sdev_printk(prefix, sdev, fmt, a...)	\
 	dev_printk(prefix, &(sdev)->sdev_gendev, fmt, ##a)

 #define scmd_printk(prefix, scmd, fmt, a...)				\
         (scmd)->request->rq_disk ?					\
 	sdev_printk(prefix, (scmd)->device, "[%s] " fmt,		\
 		    (scmd)->request->rq_disk->disk_name, ##a) :		\
 	sdev_printk(prefix, (scmd)->device, fmt, ##a)

 enum scsi_target_state {
 	STARGET_RUNNING = 1,
 	STARGET_DEL,
 };

 /*
  * scsi_target: representation of a scsi target, for now, this is only
  * used for single_lun devices. If no one has active IO to the target,
  * starget_sdev_user is NULL, else it points to the active sdev.
  */
 struct scsi_target {
 	struct scsi_device	*starget_sdev_user;
 	struct list_head	siblings;
 	struct list_head	devices;
 	struct device		dev;
 	unsigned int		reap_ref; /* protected by the host lock */
 	unsigned int		channel;
 	unsigned int		id; /* target id ... replace
 				     * scsi_device.id eventually */
 	unsigned int		create:1; /* signal that it needs to be added */
 	unsigned int		pdt_1f_for_no_lun;	/* PDT = 0x1f */
 						/* means no lun present */

 	char			scsi_level;
 	struct execute_work	ew;
 	enum scsi_target_state	state;
 	void 			*hostdata; /* available to low-level driver */
 	unsigned long		starget_data[0]; /* for the transport */
 	/* starget_data must be the last element!!!! */
 } __attribute__((aligned(sizeof(unsigned long))));

 #define to_scsi_target(d)	container_of(d, struct scsi_target, dev)
 static inline struct scsi_target *scsi_target(struct scsi_device *sdev)
 {
 	return to_scsi_target(sdev->sdev_gendev.parent);
 }
 #define transport_class_to_starget(class_dev) \
 	to_scsi_target(class_dev->dev)

 #define starget_printk(prefix, starget, fmt, a...)	\
 	dev_printk(prefix, &(starget)->dev, fmt, ##a)

 extern struct scsi_device *__scsi_add_device(struct Scsi_Host *,
 		uint, uint, uint, void *hostdata);
 extern int scsi_add_device(struct Scsi_Host *host, uint channel,
 			   uint target, uint lun);
 extern void scsi_remove_device(struct scsi_device *);

 extern int scsi_device_get(struct scsi_device *);
 extern void scsi_device_put(struct scsi_device *);
 extern struct scsi_device *scsi_device_lookup(struct Scsi_Host *,
 					      uint, uint, uint);
 extern struct scsi_device *__scsi_device_lookup(struct Scsi_Host *,
 						uint, uint, uint);
 extern struct scsi_device *scsi_device_lookup_by_target(struct scsi_target *,
 							uint);
 extern struct scsi_device *__scsi_device_lookup_by_target(struct scsi_target *,
 							  uint);
 extern void starget_for_each_device(struct scsi_target *, void *,
 		     void (*fn)(struct scsi_device *, void *));
 extern void __starget_for_each_device(struct scsi_target *, void *,
 				      void (*fn)(struct scsi_device *,
 						 void *));

 /* only exposed to implement shost_for_each_device */
 extern struct scsi_device *__scsi_iterate_devices(struct Scsi_Host *,
 						  struct scsi_device *);

 /**
  * shost_for_each_device - iterate over all devices of a host
  * @sdev: the &struct scsi_device to use as a cursor
  * @shost: the &struct scsi_host to iterate over
  *
  * Iterator that returns each device attached to @shost.  This loop
  * takes a reference on each device and releases it at the end.  If
  * you break out of the loop, you must call scsi_device_put(sdev).
  */
 #define shost_for_each_device(sdev, shost) \
 	for ((sdev) = __scsi_iterate_devices((shost), NULL); \
 	     (sdev); \
 	     (sdev) = __scsi_iterate_devices((shost), (sdev)))

 /**
  * __shost_for_each_device - iterate over all devices of a host (UNLOCKED)
  * @sdev: the &struct scsi_device to use as a cursor
  * @shost: the &struct scsi_host to iterate over
  *
  * Iterator that returns each device attached to @shost.  It does _not_
  * take a reference on the scsi_device, so the whole loop must be
  * protected by shost->host_lock.
  *
  * Note: The only reason to use this is because you need to access the
  * device list in interrupt context.  Otherwise you really want to use
  * shost_for_each_device instead.
  */
 #define __shost_for_each_device(sdev, shost) \
 	list_for_each_entry((sdev), &((shost)->__devices), siblings)

 extern void scsi_adjust_queue_depth(struct scsi_device *, int, int);
 extern int scsi_track_queue_full(struct scsi_device *, int);

 extern int scsi_set_medium_removal(struct scsi_device *, char);

 extern int scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage,
 			   unsigned char *buffer, int len, int timeout,
 			   int retries, struct scsi_mode_data *data,
 			   struct scsi_sense_hdr *);
 extern int scsi_mode_select(struct scsi_device *sdev, int pf, int sp,
 			    int modepage, unsigned char *buffer, int len,
 			    int timeout, int retries,
 			    struct scsi_mode_data *data,
 			    struct scsi_sense_hdr *);
 extern int scsi_test_unit_ready(struct scsi_device *sdev, int timeout,
 				int retries);
 extern int scsi_device_set_state(struct scsi_device *sdev,
 				 enum scsi_device_state state);
 extern struct scsi_event *sdev_evt_alloc(enum scsi_device_event evt_type,
 					  gfp_t gfpflags);
 extern void sdev_evt_send(struct scsi_device *sdev, struct scsi_event *evt);
 extern void sdev_evt_send_simple(struct scsi_device *sdev,
 			  enum scsi_device_event evt_type, gfp_t gfpflags);
 extern int scsi_device_quiesce(struct scsi_device *sdev);
 extern void scsi_device_resume(struct scsi_device *sdev);
 extern void scsi_target_quiesce(struct scsi_target *);
 extern void scsi_target_resume(struct scsi_target *);
 extern void scsi_scan_target(struct device *parent, unsigned int channel,
 			     unsigned int id, unsigned int lun, int rescan);
 extern void scsi_target_reap(struct scsi_target *);
 extern void scsi_target_block(struct device *);
 extern void scsi_target_unblock(struct device *);
 extern void scsi_remove_target(struct device *);
 extern void int_to_scsilun(unsigned int, struct scsi_lun *);
 extern int scsilun_to_int(struct scsi_lun *);
 extern const char *scsi_device_state_name(enum scsi_device_state);
 extern int scsi_is_sdev_device(const struct device *);
 extern int scsi_is_target_device(const struct device *);
 extern int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd,
 			int data_direction, void *buffer, unsigned bufflen,
 			unsigned char *sense, int timeout, int retries,
 			int flag);
 extern int scsi_execute_req(struct scsi_device *sdev, const unsigned char *cmd,
 			    int data_direction, void *buffer, unsigned bufflen,
 			    struct scsi_sense_hdr *, int timeout, int retries);
 extern int scsi_execute_async(struct scsi_device *sdev,
 			      const unsigned char *cmd, int cmd_len, int data_direction,
 			      void *buffer, unsigned bufflen, int use_sg,
 			      int timeout, int retries, void *privdata,
 			      void (*done)(void *, char *, int, int),
 			      gfp_t gfp);

 static inline int __must_check scsi_device_reprobe(struct scsi_device *sdev)
 {
 	return device_reprobe(&sdev->sdev_gendev);
 }

 static inline unsigned int sdev_channel(struct scsi_device *sdev)
 {
 	return sdev->channel;
 }

 static inline unsigned int sdev_id(struct scsi_device *sdev)
 {
 	return sdev->id;
 }

 #define scmd_id(scmd) sdev_id((scmd)->device)
 #define scmd_channel(scmd) sdev_channel((scmd)->device)

 static inline int scsi_device_online(struct scsi_device *sdev)
 {
 	return sdev->sdev_state != SDEV_OFFLINE;
 }

 /* accessor functions for the SCSI parameters */
 static inline int scsi_device_sync(struct scsi_device *sdev)
 {
 	return sdev->sdtr;
 }
 static inline int scsi_device_wide(struct scsi_device *sdev)
 {
 	return sdev->wdtr;
 }
 static inline int scsi_device_dt(struct scsi_device *sdev)
 {
 	return sdev->ppr;
 }
 static inline int scsi_device_dt_only(struct scsi_device *sdev)
 {
 	if (sdev->inquiry_len < 57)
 		return 0;
 	return (sdev->inquiry[56] & 0x0c) == 0x04;
 }
 static inline int scsi_device_ius(struct scsi_device *sdev)
 {
 	if (sdev->inquiry_len < 57)
 		return 0;
 	return sdev->inquiry[56] & 0x01;
 }
 static inline int scsi_device_qas(struct scsi_device *sdev)
 {
 	if (sdev->inquiry_len < 57)
 		return 0;
 	return sdev->inquiry[56] & 0x02;
 }

 #define MODULE_ALIAS_SCSI_DEVICE(type) \
 	MODULE_ALIAS("scsi:t-" __stringify(type) "*")
 #define SCSI_DEVICE_MODALIAS_FMT "scsi:t-0x%02x"

 #endif /* _SCSI_SCSI_DEVICE_H */
	#ifndef _SCSI_SCSI_DEVICE_H
	#define _SCSI_SCSI_DEVICE_H

	#include <linux/device.h>
	#include <linux/list.h>
	#include <linux/spinlock.h>
	#include <linux/workqueue.h>
	#include <linux/blkdev.h>
	#include <asm/atomic.h>

	struct request_queue;
	struct scsi_cmnd;
	struct scsi_lun;
	struct scsi_sense_hdr;

	struct scsi_mode_data {
	__u32 length;
	__u16 block_descriptor_length;
	__u8 medium_type;
	__u8 device_specific;
	__u8 header_length;
	__u8 longlba:1;
	};

	/*
	* sdev state: If you alter this, you also need to alter scsi_sysfs.c
	* (for the ascii descriptions) and the state model enforcer:
	* scsi_lib:scsi_device_set_state().
	*/
	enum scsi_device_state {
	SDEV_CREATED = 1, /* device created but not added to sysfs
	* Only internal commands allowed (for inq) */
	SDEV_RUNNING, /* device properly configured
	* All commands allowed */
	SDEV_CANCEL, /* beginning to delete device
	* Only error handler commands allowed */
	SDEV_DEL, /* device deleted
	* no commands allowed */
	SDEV_QUIESCE, /* Device quiescent. No block commands
	* will be accepted, only specials (which
	* originate in the mid-layer) */
	SDEV_OFFLINE, /* Device offlined (by error handling or
	* user request */
	SDEV_BLOCK, /* Device blocked by scsi lld. No scsi
	* commands from user or midlayer should be issued
	* to the scsi lld. */
	};

	enum scsi_device_event {
	SDEV_EVT_MEDIA_CHANGE = 1, /* media has changed */

	SDEV_EVT_LAST = SDEV_EVT_MEDIA_CHANGE,
	SDEV_EVT_MAXBITS = SDEV_EVT_LAST + 1
	};

	struct scsi_event {
	enum scsi_device_event evt_type;
	struct list_head node;

	/* put union of data structures, for non-simple event types,
	* here
	*/
	};

	struct scsi_device {
	struct Scsi_Host *host;
	struct request_queue *request_queue;

	/* the next two are protected by the host->host_lock */
	struct list_head siblings; /* list of all devices on this host */
	struct list_head same_target_siblings; /* just the devices sharing same target id */

	/* this is now protected by the request_queue->queue_lock */
	unsigned int device_busy; /* commands actually active on
	* low-level. protected by queue_lock. */
	spinlock_t list_lock;
	struct list_head cmd_list; /* queue of in use SCSI Command structures */
	struct list_head starved_entry;
	struct scsi_cmnd current_cmnd; / currently active command */
	unsigned short queue_depth; /* How deep of a queue we want */
	unsigned short last_queue_full_depth; /* These two are used by */
	unsigned short last_queue_full_count; /* scsi_track_queue_full() */
	unsigned long last_queue_full_time;/* don't let QUEUE_FULLs on the same
	jiffie count on our counter, they
	could all be from the same event. */

	unsigned int id, lun, channel;

	unsigned int manufacturer; /* Manufacturer of device, for using
	* vendor-specific cmd's */
	unsigned sector_size; /* size in bytes */

	void hostdata; / available to low-level driver */
	char type;
	char scsi_level;
	char inq_periph_qual; /* PQ from INQUIRY data */
	unsigned char inquiry_len; /* valid bytes in 'inquiry' */
	unsigned char * inquiry; /* INQUIRY response data */
	const char * vendor; /* [back_compat] point into 'inquiry' ... */
	const char * model; /* ... after scan; point to static string */
	const char * rev; /* ... "nullnullnullnull" before scan */
	unsigned char current_tag; /* current tag */
	struct scsi_target sdev_target; / used only for single_lun */

	unsigned int sdev_bflags; /* black/white flags as also found in
	* scsi_devinfo.[hc]. For now used only to
	* pass settings from slave_alloc to scsi
	* core. */
	unsigned writeable:1;
	unsigned removable:1;
	unsigned changed:1; /* Data invalid due to media change */
	unsigned busy:1; /* Used to prevent races */
	unsigned lockable:1; /* Able to prevent media removal */
	unsigned locked:1; /* Media removal disabled */
	unsigned borken:1; /* Tell the Seagate driver to be
	* painfully slow on this device */
	unsigned disconnect:1; /* can disconnect */
	unsigned soft_reset:1; /* Uses soft reset option */
	unsigned sdtr:1; /* Device supports SDTR messages */
	unsigned wdtr:1; /* Device supports WDTR messages */
	unsigned ppr:1; /* Device supports PPR messages */
	unsigned tagged_supported:1; /* Supports SCSI-II tagged queuing */
	unsigned simple_tags:1; /* simple queue tag messages are enabled */
	unsigned ordered_tags:1;/* ordered queue tag messages are enabled */
	unsigned single_lun:1; /* Indicates we should only allow I/O to
	* one of the luns for the device at a
	* time. */
	unsigned was_reset:1; /* There was a bus reset on the bus for
	* this device */
	unsigned expecting_cc_ua:1; /* Expecting a CHECK_CONDITION/UNIT_ATTN
	* because we did a bus reset. */
	unsigned use_10_for_rw:1; /* first try 10-byte read / write */
	unsigned use_10_for_ms:1; /* first try 10-byte mode sense/select */
	unsigned skip_ms_page_8:1; /* do not use MODE SENSE page 0x08 */
	unsigned skip_ms_page_3f:1; /* do not use MODE SENSE page 0x3f */
	unsigned use_192_bytes_for_3f:1; /* ask for 192 bytes from page 0x3f */
	unsigned no_start_on_add:1; /* do not issue start on add */
	unsigned allow_restart:1; /* issue START_UNIT in error handler */
	unsigned manage_start_stop:1; /* Let HLD (sd) manage start/stop */
	unsigned no_uld_attach:1; /* disable connecting to upper level drivers */
	unsigned select_no_atn:1;
	unsigned fix_capacity:1; /* READ_CAPACITY is too high by 1 */
	unsigned guess_capacity:1; /* READ_CAPACITY might be too high by 1 */
	unsigned retry_hwerror:1; /* Retry HARDWARE_ERROR */

	DECLARE_BITMAP(supported_events, SDEV_EVT_MAXBITS); /* supported events */
	struct list_head event_list; /* asserted events */
	struct work_struct event_work;

	unsigned int device_blocked; /* Device returned QUEUE_FULL. */

	unsigned int max_device_blocked; /* what device_blocked counts down from */
	#define SCSI_DEFAULT_DEVICE_BLOCKED 3

	atomic_t iorequest_cnt;
	atomic_t iodone_cnt;
	atomic_t ioerr_cnt;

	int timeout;

	struct device sdev_gendev;
	struct class_device sdev_classdev;

	struct execute_work ew; /* used to get process context on put */

	enum scsi_device_state sdev_state;
	unsigned long sdev_data[0];
	} __attribute__((aligned(sizeof(unsigned long))));
	#define to_scsi_device(d) \
	container_of(d, struct scsi_device, sdev_gendev)
	#define class_to_sdev(d) \
	container_of(d, struct scsi_device, sdev_classdev)
	#define transport_class_to_sdev(class_dev) \
	to_scsi_device(class_dev->dev)

	#define sdev_printk(prefix, sdev, fmt, a...) \
	dev_printk(prefix, &(sdev)->sdev_gendev, fmt, ##a)

	#define scmd_printk(prefix, scmd, fmt, a...) \
	(scmd)->request->rq_disk ? \
	sdev_printk(prefix, (scmd)->device, "[%s] " fmt, \
	(scmd)->request->rq_disk->disk_name, ##a) : \
	sdev_printk(prefix, (scmd)->device, fmt, ##a)

	enum scsi_target_state {
	STARGET_RUNNING = 1,
	STARGET_DEL,
	};

	/*
	* scsi_target: representation of a scsi target, for now, this is only
	* used for single_lun devices. If no one has active IO to the target,
	* starget_sdev_user is NULL, else it points to the active sdev.
	*/
	struct scsi_target {
	struct scsi_device *starget_sdev_user;
	struct list_head siblings;
	struct list_head devices;
	struct device dev;
	unsigned int reap_ref; /* protected by the host lock */
	unsigned int channel;
	unsigned int id; /* target id ... replace
	* scsi_device.id eventually */
	unsigned int create:1; /* signal that it needs to be added */
	unsigned int pdt_1f_for_no_lun; /* PDT = 0x1f */
	/* means no lun present */

	char scsi_level;
	struct execute_work ew;
	enum scsi_target_state state;
	void hostdata; / available to low-level driver */
	unsigned long starget_data[0]; /* for the transport */
	/* starget_data must be the last element!!!! */
	} __attribute__((aligned(sizeof(unsigned long))));

	#define to_scsi_target(d) container_of(d, struct scsi_target, dev)
	static inline struct scsi_target scsi_target(struct scsi_device sdev)
	{
	return to_scsi_target(sdev->sdev_gendev.parent);
	}
	#define transport_class_to_starget(class_dev) \
	to_scsi_target(class_dev->dev)

	#define starget_printk(prefix, starget, fmt, a...) \
	dev_printk(prefix, &(starget)->dev, fmt, ##a)

	extern struct scsi_device __scsi_add_device(struct Scsi_Host ,
	uint, uint, uint, void *hostdata);
	extern int scsi_add_device(struct Scsi_Host *host, uint channel,
	uint target, uint lun);
	extern void scsi_remove_device(struct scsi_device *);

	extern int scsi_device_get(struct scsi_device *);
	extern void scsi_device_put(struct scsi_device *);
	extern struct scsi_device scsi_device_lookup(struct Scsi_Host ,
	uint, uint, uint);
	extern struct scsi_device __scsi_device_lookup(struct Scsi_Host ,
	uint, uint, uint);
	extern struct scsi_device scsi_device_lookup_by_target(struct scsi_target ,
	uint);
	extern struct scsi_device __scsi_device_lookup_by_target(struct scsi_target ,
	uint);
	extern void starget_for_each_device(struct scsi_target , void ,
	void (fn)(struct scsi_device , void *));
	extern void __starget_for_each_device(struct scsi_target , void ,
	void (fn)(struct scsi_device ,
	void *));

	/* only exposed to implement shost_for_each_device */
	extern struct scsi_device __scsi_iterate_devices(struct Scsi_Host ,
	struct scsi_device *);

	/**
	* shost_for_each_device - iterate over all devices of a host
	* @sdev: the &struct scsi_device to use as a cursor
	* @shost: the &struct scsi_host to iterate over
	*
	* Iterator that returns each device attached to @shost. This loop
	* takes a reference on each device and releases it at the end. If
	* you break out of the loop, you must call scsi_device_put(sdev).
	*/
	#define shost_for_each_device(sdev, shost) \
	for ((sdev) = __scsi_iterate_devices((shost), NULL); \
	(sdev); \
	(sdev) = __scsi_iterate_devices((shost), (sdev)))

	/**
	* __shost_for_each_device - iterate over all devices of a host (UNLOCKED)
	* @sdev: the &struct scsi_device to use as a cursor
	* @shost: the &struct scsi_host to iterate over
	*
	* Iterator that returns each device attached to @shost. It does _not_
	* take a reference on the scsi_device, so the whole loop must be
	* protected by shost->host_lock.
	*
	* Note: The only reason to use this is because you need to access the
	* device list in interrupt context. Otherwise you really want to use
	* shost_for_each_device instead.
	*/
	#define __shost_for_each_device(sdev, shost) \
	list_for_each_entry((sdev), &((shost)->__devices), siblings)

	extern void scsi_adjust_queue_depth(struct scsi_device *, int, int);
	extern int scsi_track_queue_full(struct scsi_device *, int);

	extern int scsi_set_medium_removal(struct scsi_device *, char);

	extern int scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage,
	unsigned char *buffer, int len, int timeout,
	int retries, struct scsi_mode_data *data,
	struct scsi_sense_hdr *);
	extern int scsi_mode_select(struct scsi_device *sdev, int pf, int sp,
	int modepage, unsigned char *buffer, int len,
	int timeout, int retries,
	struct scsi_mode_data *data,
	struct scsi_sense_hdr *);
	extern int scsi_test_unit_ready(struct scsi_device *sdev, int timeout,
	int retries);
	extern int scsi_device_set_state(struct scsi_device *sdev,
	enum scsi_device_state state);
	extern struct scsi_event *sdev_evt_alloc(enum scsi_device_event evt_type,
	gfp_t gfpflags);
	extern void sdev_evt_send(struct scsi_device sdev, struct scsi_event evt);
	extern void sdev_evt_send_simple(struct scsi_device *sdev,
	enum scsi_device_event evt_type, gfp_t gfpflags);
	extern int scsi_device_quiesce(struct scsi_device *sdev);
	extern void scsi_device_resume(struct scsi_device *sdev);
	extern void scsi_target_quiesce(struct scsi_target *);
	extern void scsi_target_resume(struct scsi_target *);
	extern void scsi_scan_target(struct device *parent, unsigned int channel,
	unsigned int id, unsigned int lun, int rescan);
	extern void scsi_target_reap(struct scsi_target *);
	extern void scsi_target_block(struct device *);
	extern void scsi_target_unblock(struct device *);
	extern void scsi_remove_target(struct device *);
	extern void int_to_scsilun(unsigned int, struct scsi_lun *);
	extern int scsilun_to_int(struct scsi_lun *);
	extern const char *scsi_device_state_name(enum scsi_device_state);
	extern int scsi_is_sdev_device(const struct device *);
	extern int scsi_is_target_device(const struct device *);
	extern int scsi_execute(struct scsi_device sdev, const unsigned char cmd,
	int data_direction, void *buffer, unsigned bufflen,
	unsigned char *sense, int timeout, int retries,
	int flag);
	extern int scsi_execute_req(struct scsi_device sdev, const unsigned char cmd,
	int data_direction, void *buffer, unsigned bufflen,
	struct scsi_sense_hdr *, int timeout, int retries);
	extern int scsi_execute_async(struct scsi_device *sdev,
	const unsigned char *cmd, int cmd_len, int data_direction,
	void *buffer, unsigned bufflen, int use_sg,
	int timeout, int retries, void *privdata,
	void (done)(void , char *, int, int),
	gfp_t gfp);

	static inline int __must_check scsi_device_reprobe(struct scsi_device *sdev)
	{
	return device_reprobe(&sdev->sdev_gendev);
	}

	static inline unsigned int sdev_channel(struct scsi_device *sdev)
	{
	return sdev->channel;
	}

	static inline unsigned int sdev_id(struct scsi_device *sdev)
	{
	return sdev->id;
	}

	#define scmd_id(scmd) sdev_id((scmd)->device)
	#define scmd_channel(scmd) sdev_channel((scmd)->device)

	static inline int scsi_device_online(struct scsi_device *sdev)
	{
	return sdev->sdev_state != SDEV_OFFLINE;
	}

	/* accessor functions for the SCSI parameters */
	static inline int scsi_device_sync(struct scsi_device *sdev)
	{
	return sdev->sdtr;
	}
	static inline int scsi_device_wide(struct scsi_device *sdev)
	{
	return sdev->wdtr;
	}
	static inline int scsi_device_dt(struct scsi_device *sdev)
	{
	return sdev->ppr;
	}
	static inline int scsi_device_dt_only(struct scsi_device *sdev)
	{
	if (sdev->inquiry_len < 57)
	return 0;
	return (sdev->inquiry[56] & 0x0c) == 0x04;
	}
	static inline int scsi_device_ius(struct scsi_device *sdev)
	{
	if (sdev->inquiry_len < 57)
	return 0;
	return sdev->inquiry[56] & 0x01;
	}
	static inline int scsi_device_qas(struct scsi_device *sdev)
	{
	if (sdev->inquiry_len < 57)
	return 0;
	return sdev->inquiry[56] & 0x02;
	}

	#define MODULE_ALIAS_SCSI_DEVICE(type) \
	MODULE_ALIAS("scsi:t-" __stringify(type) "*")
	#define SCSI_DEVICE_MODALIAS_FMT "scsi:t-0x%02x"

	#endif /* _SCSI_SCSI_DEVICE_H */