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 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 scsi2_logical;
 136        unsigned char default_drvbuffer;        /* 0xff = don't touch, value 3 bits */
 137        unsigned char cln_mode;                 /* 0 = none, otherwise sense byte nbr */
 138        unsigned char cln_sense_value;
 139        unsigned char cln_sense_mask;
 140        unsigned char use_pf;                   /* Set Page Format bit in all mode selects? */
 141        unsigned char try_dio;                  /* try direct i/o in general? */
 142        unsigned char try_dio_now;              /* try direct i/o before next close? */
 143        unsigned char c_algo;                   /* compression algorithm */
 144        unsigned char pos_unknown;                      /* after reset position unknown */
 145        unsigned char sili;                     /* use SILI when reading in variable b mode */
 146        unsigned char immediate_filemark;       /* write filemark immediately */
 147        int tape_type;
 148        int long_timeout;       /* timeout for commands known to take long time */
 149
 150        /* Mode characteristics */
 151        struct st_modedef modes[ST_NBR_MODES];
 152        int current_mode;
 153
 154        /* Status variables */
 155        int partition;
 156        int new_partition;
 157        int nbr_partitions;     /* zero until partition support enabled */
 158        struct st_partstat ps[ST_NBR_PARTITIONS];
 159        unsigned char dirty;
 160        unsigned char ready;
 161        unsigned char write_prot;
 162        unsigned char drv_write_prot;
 163        unsigned char in_use;
 164        unsigned char blksize_changed;
 165        unsigned char density_changed;
 166        unsigned char compression_changed;
 167        unsigned char drv_buffer;
 168        unsigned char density;
 169        unsigned char door_locked;
 170        unsigned char autorew_dev;   /* auto-rewind device */
 171        unsigned char rew_at_close;  /* rewind necessary at close */
 172        unsigned char inited;
 173        unsigned char cleaning_req;  /* cleaning requested? */
 174        int block_size;
 175        int min_block;
 176        int max_block;
 177        int recover_count;     /* From tape opening */
 178        int recover_reg;       /* From last status call */
 179
 180#if DEBUG
 181        unsigned char write_pending;
 182        int nbr_finished;
 183        int nbr_waits;
 184        int nbr_requests;
 185        int nbr_dio;
 186        int nbr_pages;
 187        unsigned char last_cmnd[6];
 188        unsigned char last_sense[16];
 189#endif
 190        char name[DISK_NAME_LEN];
 191        struct kref     kref;
 192        struct scsi_tape_stats *stats;
 193};
 194
 195/* Bit masks for use_pf */
 196#define USE_PF      1
 197#define PF_TESTED   2
 198
 199/* Values of eof */
 200#define ST_NOEOF        0
 201#define ST_FM_HIT       1
 202#define ST_FM           2
 203#define ST_EOM_OK       3
 204#define ST_EOM_ERROR    4
 205#define ST_EOD_1        5
 206#define ST_EOD_2        6
 207#define ST_EOD          7
 208/* EOD hit while reading => ST_EOD_1 => return zero => ST_EOD_2 =>
 209   return zero => ST_EOD, return ENOSPC */
 210/* When writing: ST_EOM_OK == early warning found, write OK
 211                 ST_EOD_1  == allow trying new write after early warning
 212                 ST_EOM_ERROR == early warning found, not able to write all */
 213
 214/* Values of rw */
 215#define ST_IDLE         0
 216#define ST_READING      1
 217#define ST_WRITING      2
 218
 219/* Values of ready state */
 220#define ST_READY        0
 221#define ST_NOT_READY    1
 222#define ST_NO_TAPE      2
 223
 224/* Values for door lock state */
 225#define ST_UNLOCKED     0
 226#define ST_LOCKED_EXPLICIT 1
 227#define ST_LOCKED_AUTO  2
 228#define ST_LOCK_FAILS   3
 229
 230/* Positioning SCSI-commands for Tandberg, etc. drives */
 231#define QFA_REQUEST_BLOCK       0x02
 232#define QFA_SEEK_BLOCK          0x0c
 233
 234/* Setting the binary options */
 235#define ST_DONT_TOUCH  0
 236#define ST_NO          1
 237#define ST_YES         2
 238
 239#define EXTENDED_SENSE_START  18
 240
 241/* Masks for some conditions in the sense data */
 242#define SENSE_FMK   0x80
 243#define SENSE_EOM   0x40
 244#define SENSE_ILI   0x20
 245
 246#endif
 247