root/drivers/scsi/st.h

INCLUDED FROM

   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 */
  12 struct 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 
  24 struct scsi_tape;
  25 
  26 /* scsi tape command */
  27 struct 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. */
  37 struct 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 */
  60 struct 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 */
  86 struct 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 */
  97 struct 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 */
 120 struct 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