linux/drivers/scsi/st.h
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   1
   2#ifndef _ST_H
   3#define _ST_H
   4
   5#include <linux/completion.h>
   6#include <linux/mutex.h>
   7#include <linux/kref.h>
   8#include <scsi/scsi_cmnd.h>
   9
  10/* Descriptor for analyzed sense data */
  11struct st_cmdstatus {
  12        int midlevel_result;
  13        struct scsi_sense_hdr sense_hdr;
  14        int have_sense;
  15        int residual;
  16        u64 uremainder64;
  17        u8 flags;
  18        u8 remainder_valid;
  19        u8 fixed_format;
  20        u8 deferred;
  21};
  22
  23struct scsi_tape;
  24
  25/* scsi tape command */
  26struct st_request {
  27        unsigned char cmd[MAX_COMMAND_SIZE];
  28        unsigned char sense[SCSI_SENSE_BUFFERSIZE];
  29        int result;
  30        struct scsi_tape *stp;
  31        struct completion *waiting;
  32        struct bio *bio;
  33};
  34
  35/* The tape buffer descriptor. */
  36struct st_buffer {
  37        unsigned char dma;      /* DMA-able buffer */
  38        unsigned char cleared;  /* internal buffer cleared after open? */
  39        unsigned short do_dio;  /* direct i/o set up? */
  40        int buffer_size;
  41        int buffer_blocks;
  42        int buffer_bytes;
  43        int read_pointer;
  44        int writing;
  45        int syscall_result;
  46        struct st_request *last_SRpnt;
  47        struct st_cmdstatus cmdstat;
  48        struct page **reserved_pages;
  49        int reserved_page_order;
  50        struct page **mapped_pages;
  51        struct rq_map_data map_data;
  52        unsigned char *b_data;
  53        unsigned short use_sg;  /* zero or max number of s/g segments for this adapter */
  54        unsigned short sg_segs;         /* number of segments in s/g list */
  55        unsigned short frp_segs;        /* number of buffer segments */
  56};
  57
  58/* The tape mode definition */
  59struct st_modedef {
  60        unsigned char defined;
  61        unsigned char sysv;     /* SYS V semantics? */
  62        unsigned char do_async_writes;
  63        unsigned char do_buffer_writes;
  64        unsigned char do_read_ahead;
  65        unsigned char defaults_for_writes;
  66        unsigned char default_compression;      /* 0 = don't touch, etc */
  67        short default_density;  /* Forced density, -1 = no value */
  68        int default_blksize;    /* Forced blocksize, -1 = no value */
  69        struct scsi_tape *tape;
  70        struct device *devs[2];  /* Auto-rewind and non-rewind devices */
  71        struct cdev *cdevs[2];  /* Auto-rewind and non-rewind devices */
  72};
  73
  74/* Number of modes can be changed by changing ST_NBR_MODE_BITS. The maximum
  75   number of modes is 16 (ST_NBR_MODE_BITS 4) */
  76#define ST_NBR_MODE_BITS 2
  77#define ST_NBR_MODES (1 << ST_NBR_MODE_BITS)
  78#define ST_MODE_SHIFT (7 - ST_NBR_MODE_BITS)
  79#define ST_MODE_MASK ((ST_NBR_MODES - 1) << ST_MODE_SHIFT)
  80
  81#define ST_MAX_TAPES (1 << (20 - (ST_NBR_MODE_BITS + 1)))
  82#define ST_MAX_TAPE_ENTRIES  (ST_MAX_TAPES << (ST_NBR_MODE_BITS + 1))
  83
  84/* The status related to each partition */
  85struct st_partstat {
  86        unsigned char rw;
  87        unsigned char eof;
  88        unsigned char at_sm;
  89        unsigned char last_block_valid;
  90        u32 last_block_visited;
  91        int drv_block;          /* The block where the drive head is */
  92        int drv_file;
  93};
  94
  95/* Tape statistics */
  96struct scsi_tape_stats {
  97        atomic64_t read_byte_cnt;  /* bytes read */
  98        atomic64_t write_byte_cnt; /* bytes written */
  99        atomic64_t in_flight;      /* Number of I/Os in flight */
 100        atomic64_t read_cnt;       /* Count of read requests */
 101        atomic64_t write_cnt;      /* Count of write requests */
 102        atomic64_t other_cnt;      /* Count of other requests either
 103                                    * implicit or from user space
 104                                    * ioctl. */
 105        atomic64_t resid_cnt;      /* Count of resid_len > 0 */
 106        atomic64_t tot_read_time;  /* ktime spent completing reads */
 107        atomic64_t tot_write_time; /* ktime spent completing writes */
 108        atomic64_t tot_io_time;    /* ktime spent doing any I/O */
 109        ktime_t read_time;         /* holds ktime request was queued */
 110        ktime_t write_time;        /* holds ktime request was queued */
 111        ktime_t other_time;        /* holds ktime request was queued */
 112        atomic_t last_read_size;   /* Number of bytes issued for last read */
 113        atomic_t last_write_size;  /* Number of bytes issued for last write */
 114};
 115
 116#define ST_NBR_PARTITIONS 4
 117
 118/* The tape drive descriptor */
 119struct scsi_tape {
 120        struct scsi_driver *driver;
 121        struct scsi_device *device;
 122        struct mutex lock;      /* For serialization */
 123        struct completion wait; /* For SCSI commands */
 124        struct st_buffer *buffer;
 125        int index;
 126
 127        /* Drive characteristics */
 128        unsigned char omit_blklims;
 129        unsigned char do_auto_lock;
 130        unsigned char can_bsr;
 131        unsigned char can_partitions;
 132        unsigned char two_fm;
 133        unsigned char fast_mteom;
 134        unsigned char immediate;
 135        unsigned char restr_dma;
 136        unsigned char scsi2_logical;
 137        unsigned char default_drvbuffer;        /* 0xff = don't touch, value 3 bits */
 138        unsigned char cln_mode;                 /* 0 = none, otherwise sense byte nbr */
 139        unsigned char cln_sense_value;
 140        unsigned char cln_sense_mask;
 141        unsigned char use_pf;                   /* Set Page Format bit in all mode selects? */
 142        unsigned char try_dio;                  /* try direct i/o in general? */
 143        unsigned char try_dio_now;              /* try direct i/o before next close? */
 144        unsigned char c_algo;                   /* compression algorithm */
 145        unsigned char pos_unknown;                      /* after reset position unknown */
 146        unsigned char sili;                     /* use SILI when reading in variable b mode */
 147        unsigned char immediate_filemark;       /* write filemark immediately */
 148        int tape_type;
 149        int long_timeout;       /* timeout for commands known to take long time */
 150
 151        /* Mode characteristics */
 152        struct st_modedef modes[ST_NBR_MODES];
 153        int current_mode;
 154
 155        /* Status variables */
 156        int partition;
 157        int new_partition;
 158        int nbr_partitions;     /* zero until partition support enabled */
 159        struct st_partstat ps[ST_NBR_PARTITIONS];
 160        unsigned char dirty;
 161        unsigned char ready;
 162        unsigned char write_prot;
 163        unsigned char drv_write_prot;
 164        unsigned char in_use;
 165        unsigned char blksize_changed;
 166        unsigned char density_changed;
 167        unsigned char compression_changed;
 168        unsigned char drv_buffer;
 169        unsigned char density;
 170        unsigned char door_locked;
 171        unsigned char autorew_dev;   /* auto-rewind device */
 172        unsigned char rew_at_close;  /* rewind necessary at close */
 173        unsigned char inited;
 174        unsigned char cleaning_req;  /* cleaning requested? */
 175        int block_size;
 176        int min_block;
 177        int max_block;
 178        int recover_count;     /* From tape opening */
 179        int recover_reg;       /* From last status call */
 180
 181#if DEBUG
 182        unsigned char write_pending;
 183        int nbr_finished;
 184        int nbr_waits;
 185        int nbr_requests;
 186        int nbr_dio;
 187        int nbr_pages;
 188        unsigned char last_cmnd[6];
 189        unsigned char last_sense[16];
 190#endif
 191        struct gendisk *disk;
 192        struct kref     kref;
 193        struct scsi_tape_stats *stats;
 194};
 195
 196/* Bit masks for use_pf */
 197#define USE_PF      1
 198#define PF_TESTED   2
 199
 200/* Values of eof */
 201#define ST_NOEOF        0
 202#define ST_FM_HIT       1
 203#define ST_FM           2
 204#define ST_EOM_OK       3
 205#define ST_EOM_ERROR    4
 206#define ST_EOD_1        5
 207#define ST_EOD_2        6
 208#define ST_EOD          7
 209/* EOD hit while reading => ST_EOD_1 => return zero => ST_EOD_2 =>
 210   return zero => ST_EOD, return ENOSPC */
 211/* When writing: ST_EOM_OK == early warning found, write OK
 212                 ST_EOD_1  == allow trying new write after early warning
 213                 ST_EOM_ERROR == early warning found, not able to write all */
 214
 215/* Values of rw */
 216#define ST_IDLE         0
 217#define ST_READING      1
 218#define ST_WRITING      2
 219
 220/* Values of ready state */
 221#define ST_READY        0
 222#define ST_NOT_READY    1
 223#define ST_NO_TAPE      2
 224
 225/* Values for door lock state */
 226#define ST_UNLOCKED     0
 227#define ST_LOCKED_EXPLICIT 1
 228#define ST_LOCKED_AUTO  2
 229#define ST_LOCK_FAILS   3
 230
 231/* Positioning SCSI-commands for Tandberg, etc. drives */
 232#define QFA_REQUEST_BLOCK       0x02
 233#define QFA_SEEK_BLOCK          0x0c
 234
 235/* Setting the binary options */
 236#define ST_DONT_TOUCH  0
 237#define ST_NO          1
 238#define ST_YES         2
 239
 240#define EXTENDED_SENSE_START  18
 241
 242/* Masks for some conditions in the sense data */
 243#define SENSE_FMK   0x80
 244#define SENSE_EOM   0x40
 245#define SENSE_ILI   0x20
 246
 247#endif
 248