scsi_device.h

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#ifndef _SCSI_SCSI_DEVICE_H
#define _SCSI_SCSI_DEVICE_H

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

struct device;
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_TRANSPORT_OFFLINE, /* Offlined by transport class error handler */
    SDEV_BLOCK,     /* Device blocked by scsi lld.  No
                 * scsi commands from user or midlayer
                 * should be issued to the scsi
                 * lld. */
    SDEV_CREATED_BLOCK, /* same as above but for created devices */
};

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 max_queue_depth; /* max queue depth */
    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; /* last queue full time */
    unsigned long queue_ramp_up_period; /* ramp up period in jiffies */
#define SCSI_DEFAULT_RAMP_UP_PERIOD (120 * HZ)

    unsigned long last_queue_ramp_up;   /* last queue ramp up time */

    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 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 no_report_opcodes:1;   /* no REPORT SUPPORTED OPERATION CODES */
    unsigned no_write_same:1;   /* no WRITE SAME command */
    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 skip_vpd_pages:1;  /* do not read VPD pages */
    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 start_stop_pwr_cond:1; /* Set power cond. in START_STOP_UNIT */
    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 */
    unsigned last_sector_bug:1; /* do not use multisector accesses on
                       SD_LAST_BUGGY_SECTORS */
    unsigned no_read_disc_info:1;   /* Avoid READ_DISC_INFO cmds */
    unsigned no_read_capacity_16:1; /* Avoid READ_CAPACITY_16 cmds */
    unsigned try_rc_10_first:1; /* Try READ_CAPACACITY_10 first */
    unsigned is_visible:1;  /* is the device visible in sysfs */
    unsigned can_power_off:1; /* Device supports runtime power off */
    unsigned wce_default_on:1;  /* Cache is ON by default */
    unsigned no_dif:1;  /* T10 PI (DIF) should be disabled */

    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;

    struct device       sdev_gendev,
                sdev_dev;

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

    struct scsi_dh_data *scsi_dh_data;
    enum scsi_device_state sdev_state;
    unsigned long       sdev_data[0];
} __attribute__((aligned(sizeof(unsigned long))));

struct scsi_dh_devlist {
    char *vendor;
    char *model;
};

typedef void (*activate_complete)(void *, int);
struct scsi_device_handler {
    /* Used by the infrastructure */
    struct list_head list; /* list of scsi_device_handlers */

    /* Filled by the hardware handler */
    struct module *module;
    const char *name;
    const struct scsi_dh_devlist *devlist;
    int (*check_sense)(struct scsi_device *, struct scsi_sense_hdr *);
    int (*attach)(struct scsi_device *);
    void (*detach)(struct scsi_device *);
    int (*activate)(struct scsi_device *, activate_complete, void *);
    int (*prep_fn)(struct scsi_device *, struct request *);
    int (*set_params)(struct scsi_device *, const char *);
    bool (*match)(struct scsi_device *);
};

struct scsi_dh_data {
    struct scsi_device_handler *scsi_dh;
    struct scsi_device *sdev;
    struct kref kref;
    char buf[0];
};

#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_dev)
#define transport_class_to_sdev(class_dev) \
    to_scsi_device(class_dev->parent)

#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_CREATED = 1,
    STARGET_RUNNING,
    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        single_lun:1;   /* Indicates we should only
                         * allow I/O to one of the luns
                         * for the device at a time. */
    unsigned int        pdt_1f_for_no_lun:1;    /* PDT = 0x1f
                         * means no lun present. */
    unsigned int        no_report_luns:1;   /* Don't use
                         * REPORT LUNS for scanning. */
    /* commands actually active on LLD. protected by host lock. */
    unsigned int        target_busy;
    /*
     * LLDs should set this in the slave_alloc host template callout.
     * If set to zero then there is not limit.
     */
    unsigned int        can_queue;
    unsigned int        target_blocked;
    unsigned int        max_target_blocked;
#define SCSI_DEFAULT_TARGET_BLOCKED 3

    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->parent)

#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 int scsi_register_device_handler(struct scsi_device_handler *scsi_dh);
extern void scsi_remove_device(struct scsi_device *);
extern int scsi_unregister_device_handler(struct scsi_device_handler *scsi_dh);

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 *);

#define shost_for_each_device(sdev, shost) \
    for ((sdev) = __scsi_iterate_devices((shost), NULL); \
         (sdev); \
         (sdev) = __scsi_iterate_devices((shost), (sdev)))

#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, struct scsi_sense_hdr *sshdr);
extern int scsi_get_vpd_page(struct scsi_device *, u8 page, unsigned char *buf,
                 int buf_len);
extern int scsi_report_opcode(struct scsi_device *sdev, unsigned char *buffer,
                  unsigned int len, unsigned char opcode);
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 *, enum scsi_device_state);
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, int *resid);
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,
                int *resid);

#ifdef CONFIG_PM_RUNTIME
extern int scsi_autopm_get_device(struct scsi_device *);
extern void scsi_autopm_put_device(struct scsi_device *);
#else
static inline int scsi_autopm_get_device(struct scsi_device *d) { return 0; }
static inline void scsi_autopm_put_device(struct scsi_device *d) {}
#endif /* CONFIG_PM_RUNTIME */

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)

/*
 * checks for positions of the SCSI state machine
 */
static inline int scsi_device_online(struct scsi_device *sdev)
{
    return (sdev->sdev_state != SDEV_OFFLINE &&
        sdev->sdev_state != SDEV_TRANSPORT_OFFLINE &&
        sdev->sdev_state != SDEV_DEL);
}
static inline int scsi_device_blocked(struct scsi_device *sdev)
{
    return sdev->sdev_state == SDEV_BLOCK ||
        sdev->sdev_state == SDEV_CREATED_BLOCK;
}
static inline int scsi_device_created(struct scsi_device *sdev)
{
    return sdev->sdev_state == SDEV_CREATED ||
        sdev->sdev_state == SDEV_CREATED_BLOCK;
}

/* 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;
}
static inline int scsi_device_enclosure(struct scsi_device *sdev)
{
    return sdev->inquiry ? (sdev->inquiry[6] & (1<<6)) : 1;
}

static inline int scsi_device_protection(struct scsi_device *sdev)
{
    if (sdev->no_dif)
        return 0;

    return sdev->scsi_level > SCSI_2 && sdev->inquiry[5] & (1<<0);
}

static inline int scsi_device_tpgs(struct scsi_device *sdev)
{
    return sdev->inquiry ? (sdev->inquiry[5] >> 4) & 0x3 : 0;
}

#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 */