linux/drivers/scsi/st.h
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   1/* SPDX-License-Identifier: GPL-2.0 */
   2
   3#ifndef _ST_H
   4#define _ST_H
   5
   6#include <linux/completion.h>
   7#include <linux/mutex.h>
   8#include <linux/kref.h>
   9#include <scsi/scsi_cmnd.h>
  10
  11/* Descriptor for analyzed sense data */
  12struct st_cmdstatus {
  13        int midlevel_result;
  14        struct scsi_sense_hdr sense_hdr;
  15        int have_sense;
  16        int residual;
  17        u64 uremainder64;
  18        u8 flags;
  19        u8 remainder_valid;
  20        u8 fixed_format;
  21        u8 deferred;
  22};
  23
  24struct scsi_tape;
  25
  26/* scsi tape command */
  27struct st_request {
  28        unsigned char cmd[MAX_COMMAND_SIZE];
  29        unsigned char sense[SCSI_SENSE_BUFFERSIZE];
  30        int result;
  31        struct scsi_tape *stp;
  32        struct completion *waiting;
  33        struct bio *bio;
  34};
  35
  36/* The tape buffer descriptor. */
  37struct st_buffer {
  38        unsigned char dma;      /* DMA-able buffer */
  39        unsigned char cleared;  /* internal buffer cleared after open? */
  40        unsigned short do_dio;  /* direct i/o set up? */
  41        int buffer_size;
  42        int buffer_blocks;
  43        int buffer_bytes;
  44        int read_pointer;
  45        int writing;
  46        int syscall_result;
  47        struct st_request *last_SRpnt;
  48        struct st_cmdstatus cmdstat;
  49        struct page **reserved_pages;
  50        int reserved_page_order;
  51        struct page **mapped_pages;
  52        struct rq_map_data map_data;
  53        unsigned char *b_data;
  54        unsigned short use_sg;  /* zero or max number of s/g segments for this adapter */
  55        unsigned short sg_segs;         /* number of segments in s/g list */
  56        unsigned short frp_segs;        /* number of buffer segments */
  57};
  58
  59/* The tape mode definition */
  60struct st_modedef {
  61        unsigned char defined;
  62        unsigned char sysv;     /* SYS V semantics? */
  63        unsigned char do_async_writes;
  64        unsigned char do_buffer_writes;
  65        unsigned char do_read_ahead;
  66        unsigned char defaults_for_writes;
  67        unsigned char default_compression;      /* 0 = don't touch, etc */
  68        short default_density;  /* Forced density, -1 = no value */
  69        int default_blksize;    /* Forced blocksize, -1 = no value */
  70        struct scsi_tape *tape;
  71        struct device *devs[2];  /* Auto-rewind and non-rewind devices */
  72        struct cdev *cdevs[2];  /* Auto-rewind and non-rewind devices */
  73};
  74
  75/* Number of modes can be changed by changing ST_NBR_MODE_BITS. The maximum
  76   number of modes is 16 (ST_NBR_MODE_BITS 4) */
  77#define ST_NBR_MODE_BITS 2
  78#define ST_NBR_MODES (1 << ST_NBR_MODE_BITS)
  79#define ST_MODE_SHIFT (7 - ST_NBR_MODE_BITS)
  80#define ST_MODE_MASK ((ST_NBR_MODES - 1) << ST_MODE_SHIFT)
  81
  82#define ST_MAX_TAPES (1 << (20 - (ST_NBR_MODE_BITS + 1)))
  83#define ST_MAX_TAPE_ENTRIES  (ST_MAX_TAPES << (ST_NBR_MODE_BITS + 1))
  84
  85/* The status related to each partition */
  86struct st_partstat {
  87        unsigned char rw;
  88        unsigned char eof;
  89        unsigned char at_sm;
  90        unsigned char last_block_valid;
  91        u32 last_block_visited;
  92        int drv_block;          /* The block where the drive head is */
  93        int drv_file;
  94};
  95
  96/* Tape statistics */
  97struct scsi_tape_stats {
  98        atomic64_t read_byte_cnt;  /* bytes read */
  99        atomic64_t write_byte_cnt; /* bytes written */
 100        atomic64_t in_flight;      /* Number of I/Os in flight */
 101        atomic64_t read_cnt;       /* Count of read requests */
 102        atomic64_t write_cnt;      /* Count of write requests */
 103        atomic64_t other_cnt;      /* Count of other requests either
 104                                    * implicit or from user space
 105                                    * ioctl. */
 106        atomic64_t resid_cnt;      /* Count of resid_len > 0 */
 107        atomic64_t tot_read_time;  /* ktime spent completing reads */
 108        atomic64_t tot_write_time; /* ktime spent completing writes */
 109        atomic64_t tot_io_time;    /* ktime spent doing any I/O */
 110        ktime_t read_time;         /* holds ktime request was queued */
 111        ktime_t write_time;        /* holds ktime request was queued */
 112        ktime_t other_time;        /* holds ktime request was queued */
 113        atomic_t last_read_size;   /* Number of bytes issued for last read */
 114        atomic_t last_write_size;  /* Number of bytes issued for last write */
 115};
 116
 117#define ST_NBR_PARTITIONS 4
 118
 119/* The tape drive descriptor */
 120struct scsi_tape {
 121        struct scsi_driver *driver;
 122        struct scsi_device *device;
 123        struct mutex lock;      /* For serialization */
 124        struct completion wait; /* For SCSI commands */
 125        struct st_buffer *buffer;
 126        int index;
 127
 128        /* Drive characteristics */
 129        unsigned char omit_blklims;
 130        unsigned char do_auto_lock;
 131        unsigned char can_bsr;
 132        unsigned char can_partitions;
 133        unsigned char two_fm;
 134        unsigned char fast_mteom;
 135        unsigned char immediate;
 136        unsigned char restr_dma;
 137        unsigned char scsi2_logical;
 138        unsigned char default_drvbuffer;        /* 0xff = don't touch, value 3 bits */
 139        unsigned char cln_mode;                 /* 0 = none, otherwise sense byte nbr */
 140        unsigned char cln_sense_value;
 141        unsigned char cln_sense_mask;
 142        unsigned char use_pf;                   /* Set Page Format bit in all mode selects? */
 143        unsigned char try_dio;                  /* try direct i/o in general? */
 144        unsigned char try_dio_now;              /* try direct i/o before next close? */
 145        unsigned char c_algo;                   /* compression algorithm */
 146        unsigned char pos_unknown;                      /* after reset position unknown */
 147        unsigned char sili;                     /* use SILI when reading in variable b mode */
 148        unsigned char immediate_filemark;       /* write filemark immediately */
 149        int tape_type;
 150        int long_timeout;       /* timeout for commands known to take long time */
 151
 152        /* Mode characteristics */
 153        struct st_modedef modes[ST_NBR_MODES];
 154        int current_mode;
 155
 156        /* Status variables */
 157        int partition;
 158        int new_partition;
 159        int nbr_partitions;     /* zero until partition support enabled */
 160        struct st_partstat ps[ST_NBR_PARTITIONS];
 161        unsigned char dirty;
 162        unsigned char ready;
 163        unsigned char write_prot;
 164        unsigned char drv_write_prot;
 165        unsigned char in_use;
 166        unsigned char blksize_changed;
 167        unsigned char density_changed;
 168        unsigned char compression_changed;
 169        unsigned char drv_buffer;
 170        unsigned char density;
 171        unsigned char door_locked;
 172        unsigned char autorew_dev;   /* auto-rewind device */
 173        unsigned char rew_at_close;  /* rewind necessary at close */
 174        unsigned char inited;
 175        unsigned char cleaning_req;  /* cleaning requested? */
 176        int block_size;
 177        int min_block;
 178        int max_block;
 179        int recover_count;     /* From tape opening */
 180        int recover_reg;       /* From last status call */
 181
 182#if DEBUG
 183        unsigned char write_pending;
 184        int nbr_finished;
 185        int nbr_waits;
 186        int nbr_requests;
 187        int nbr_dio;
 188        int nbr_pages;
 189        unsigned char last_cmnd[6];
 190        unsigned char last_sense[16];
 191#endif
 192        struct gendisk *disk;
 193        struct kref     kref;
 194        struct scsi_tape_stats *stats;
 195};
 196
 197/* Bit masks for use_pf */
 198#define USE_PF      1
 199#define PF_TESTED   2
 200
 201/* Values of eof */
 202#define ST_NOEOF        0
 203#define ST_FM_HIT       1
 204#define ST_FM           2
 205#define ST_EOM_OK       3
 206#define ST_EOM_ERROR    4
 207#define ST_EOD_1        5
 208#define ST_EOD_2        6
 209#define ST_EOD          7
 210/* EOD hit while reading => ST_EOD_1 => return zero => ST_EOD_2 =>
 211   return zero => ST_EOD, return ENOSPC */
 212/* When writing: ST_EOM_OK == early warning found, write OK
 213                 ST_EOD_1  == allow trying new write after early warning
 214                 ST_EOM_ERROR == early warning found, not able to write all */
 215
 216/* Values of rw */
 217#define ST_IDLE         0
 218#define ST_READING      1
 219#define ST_WRITING      2
 220
 221/* Values of ready state */
 222#define ST_READY        0
 223#define ST_NOT_READY    1
 224#define ST_NO_TAPE      2
 225
 226/* Values for door lock state */
 227#define ST_UNLOCKED     0
 228#define ST_LOCKED_EXPLICIT 1
 229#define ST_LOCKED_AUTO  2
 230#define ST_LOCK_FAILS   3
 231
 232/* Positioning SCSI-commands for Tandberg, etc. drives */
 233#define QFA_REQUEST_BLOCK       0x02
 234#define QFA_SEEK_BLOCK          0x0c
 235
 236/* Setting the binary options */
 237#define ST_DONT_TOUCH  0
 238#define ST_NO          1
 239#define ST_YES         2
 240
 241#define EXTENDED_SENSE_START  18
 242
 243/* Masks for some conditions in the sense data */
 244#define SENSE_FMK   0x80
 245#define SENSE_EOM   0x40
 246#define SENSE_ILI   0x20
 247
 248#endif
 249