linux/include/linux/pktcdvd.h
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   1/*
   2 * Copyright (C) 2000 Jens Axboe <axboe@suse.de>
   3 * Copyright (C) 2001-2004 Peter Osterlund <petero2@telia.com>
   4 *
   5 * May be copied or modified under the terms of the GNU General Public
   6 * License.  See linux/COPYING for more information.
   7 *
   8 * Packet writing layer for ATAPI and SCSI CD-R, CD-RW, DVD-R, and
   9 * DVD-RW devices.
  10 *
  11 */
  12#ifndef __PKTCDVD_H
  13#define __PKTCDVD_H
  14
  15#include <linux/types.h>
  16
  17/*
  18 * 1 for normal debug messages, 2 is very verbose. 0 to turn it off.
  19 */
  20#define PACKET_DEBUG            1
  21
  22#define MAX_WRITERS             8
  23
  24#define PKT_RB_POOL_SIZE        512
  25
  26/*
  27 * How long we should hold a non-full packet before starting data gathering.
  28 */
  29#define PACKET_WAIT_TIME        (HZ * 5 / 1000)
  30
  31/*
  32 * use drive write caching -- we need deferred error handling to be
  33 * able to successfully recover with this option (drive will return good
  34 * status as soon as the cdb is validated).
  35 */
  36#if defined(CONFIG_CDROM_PKTCDVD_WCACHE)
  37#define USE_WCACHING            1
  38#else
  39#define USE_WCACHING            0
  40#endif
  41
  42/*
  43 * No user-servicable parts beyond this point ->
  44 */
  45
  46/*
  47 * device types
  48 */
  49#define PACKET_CDR              1
  50#define PACKET_CDRW             2
  51#define PACKET_DVDR             3
  52#define PACKET_DVDRW            4
  53
  54/*
  55 * flags
  56 */
  57#define PACKET_WRITABLE         1       /* pd is writable */
  58#define PACKET_NWA_VALID        2       /* next writable address valid */
  59#define PACKET_LRA_VALID        3       /* last recorded address valid */
  60#define PACKET_MERGE_SEGS       4       /* perform segment merging to keep */
  61                                        /* underlying cdrom device happy */
  62
  63/*
  64 * Disc status -- from READ_DISC_INFO
  65 */
  66#define PACKET_DISC_EMPTY       0
  67#define PACKET_DISC_INCOMPLETE  1
  68#define PACKET_DISC_COMPLETE    2
  69#define PACKET_DISC_OTHER       3
  70
  71/*
  72 * write type, and corresponding data block type
  73 */
  74#define PACKET_MODE1            1
  75#define PACKET_MODE2            2
  76#define PACKET_BLOCK_MODE1      8
  77#define PACKET_BLOCK_MODE2      10
  78
  79/*
  80 * Last session/border status
  81 */
  82#define PACKET_SESSION_EMPTY            0
  83#define PACKET_SESSION_INCOMPLETE       1
  84#define PACKET_SESSION_RESERVED         2
  85#define PACKET_SESSION_COMPLETE         3
  86
  87#define PACKET_MCN                      "4a656e734178626f65323030300000"
  88
  89#undef PACKET_USE_LS
  90
  91#define PKT_CTRL_CMD_SETUP      0
  92#define PKT_CTRL_CMD_TEARDOWN   1
  93#define PKT_CTRL_CMD_STATUS     2
  94
  95struct pkt_ctrl_command {
  96        __u32 command;                          /* in: Setup, teardown, status */
  97        __u32 dev_index;                        /* in/out: Device index */
  98        __u32 dev;                              /* in/out: Device nr for cdrw device */
  99        __u32 pkt_dev;                          /* in/out: Device nr for packet device */
 100        __u32 num_devices;                      /* out: Largest device index + 1 */
 101        __u32 padding;                          /* Not used */
 102};
 103
 104/*
 105 * packet ioctls
 106 */
 107#define PACKET_IOCTL_MAGIC      ('X')
 108#define PACKET_CTRL_CMD         _IOWR(PACKET_IOCTL_MAGIC, 1, struct pkt_ctrl_command)
 109
 110#ifdef __KERNEL__
 111#include <linux/blkdev.h>
 112#include <linux/completion.h>
 113#include <linux/cdrom.h>
 114#include <linux/kobject.h>
 115#include <linux/sysfs.h>
 116#include <linux/mempool.h>
 117
 118/* default bio write queue congestion marks */
 119#define PKT_WRITE_CONGESTION_ON    10000
 120#define PKT_WRITE_CONGESTION_OFF   9000
 121
 122
 123struct packet_settings
 124{
 125        __u32                   size;           /* packet size in (512 byte) sectors */
 126        __u8                    fp;             /* fixed packets */
 127        __u8                    link_loss;      /* the rest is specified
 128                                                 * as per Mt Fuji */
 129        __u8                    write_type;
 130        __u8                    track_mode;
 131        __u8                    block_mode;
 132};
 133
 134/*
 135 * Very crude stats for now
 136 */
 137struct packet_stats
 138{
 139        unsigned long           pkt_started;
 140        unsigned long           pkt_ended;
 141        unsigned long           secs_w;
 142        unsigned long           secs_rg;
 143        unsigned long           secs_r;
 144};
 145
 146struct packet_cdrw
 147{
 148        struct list_head        pkt_free_list;
 149        struct list_head        pkt_active_list;
 150        spinlock_t              active_list_lock; /* Serialize access to pkt_active_list */
 151        struct task_struct      *thread;
 152        atomic_t                pending_bios;
 153};
 154
 155/*
 156 * Switch to high speed reading after reading this many kilobytes
 157 * with no interspersed writes.
 158 */
 159#define HI_SPEED_SWITCH 512
 160
 161struct packet_iosched
 162{
 163        atomic_t                attention;      /* Set to non-zero when queue processing is needed */
 164        int                     writing;        /* Non-zero when writing, zero when reading */
 165        spinlock_t              lock;           /* Protecting read/write queue manipulations */
 166        struct bio_list         read_queue;
 167        struct bio_list         write_queue;
 168        sector_t                last_write;     /* The sector where the last write ended */
 169        int                     successive_reads;
 170};
 171
 172/*
 173 * 32 buffers of 2048 bytes
 174 */
 175#if (PAGE_SIZE % CD_FRAMESIZE) != 0
 176#error "PAGE_SIZE must be a multiple of CD_FRAMESIZE"
 177#endif
 178#define PACKET_MAX_SIZE         128
 179#define FRAMES_PER_PAGE         (PAGE_SIZE / CD_FRAMESIZE)
 180#define PACKET_MAX_SECTORS      (PACKET_MAX_SIZE * CD_FRAMESIZE >> 9)
 181
 182enum packet_data_state {
 183        PACKET_IDLE_STATE,                      /* Not used at the moment */
 184        PACKET_WAITING_STATE,                   /* Waiting for more bios to arrive, so */
 185                                                /* we don't have to do as much */
 186                                                /* data gathering */
 187        PACKET_READ_WAIT_STATE,                 /* Waiting for reads to fill in holes */
 188        PACKET_WRITE_WAIT_STATE,                /* Waiting for the write to complete */
 189        PACKET_RECOVERY_STATE,                  /* Recover after read/write errors */
 190        PACKET_FINISHED_STATE,                  /* After write has finished */
 191
 192        PACKET_NUM_STATES                       /* Number of possible states */
 193};
 194
 195/*
 196 * Information needed for writing a single packet
 197 */
 198struct pktcdvd_device;
 199
 200struct packet_data
 201{
 202        struct list_head        list;
 203
 204        spinlock_t              lock;           /* Lock protecting state transitions and */
 205                                                /* orig_bios list */
 206
 207        struct bio_list         orig_bios;      /* Original bios passed to pkt_make_request */
 208                                                /* that will be handled by this packet */
 209        int                     write_size;     /* Total size of all bios in the orig_bios */
 210                                                /* list, measured in number of frames */
 211
 212        struct bio              *w_bio;         /* The bio we will send to the real CD */
 213                                                /* device once we have all data for the */
 214                                                /* packet we are going to write */
 215        sector_t                sector;         /* First sector in this packet */
 216        int                     frames;         /* Number of frames in this packet */
 217
 218        enum packet_data_state  state;          /* Current state */
 219        atomic_t                run_sm;         /* Incremented whenever the state */
 220                                                /* machine needs to be run */
 221        long                    sleep_time;     /* Set this to non-zero to make the state */
 222                                                /* machine run after this many jiffies. */
 223
 224        atomic_t                io_wait;        /* Number of pending IO operations */
 225        atomic_t                io_errors;      /* Number of read/write errors during IO */
 226
 227        struct bio              *r_bios[PACKET_MAX_SIZE]; /* bios to use during data gathering */
 228        struct page             *pages[PACKET_MAX_SIZE / FRAMES_PER_PAGE];
 229
 230        int                     cache_valid;    /* If non-zero, the data for the zone defined */
 231                                                /* by the sector variable is completely cached */
 232                                                /* in the pages[] vector. */
 233
 234        int                     id;             /* ID number for debugging */
 235        struct pktcdvd_device   *pd;
 236};
 237
 238struct pkt_rb_node {
 239        struct rb_node          rb_node;
 240        struct bio              *bio;
 241};
 242
 243struct packet_stacked_data
 244{
 245        struct bio              *bio;           /* Original read request bio */
 246        struct pktcdvd_device   *pd;
 247};
 248#define PSD_POOL_SIZE           64
 249
 250struct pktcdvd_kobj
 251{
 252        struct kobject          kobj;
 253        struct pktcdvd_device   *pd;
 254};
 255#define to_pktcdvdkobj(_k) \
 256  ((struct pktcdvd_kobj*)container_of(_k,struct pktcdvd_kobj,kobj))
 257
 258struct pktcdvd_device
 259{
 260        struct block_device     *bdev;          /* dev attached */
 261        dev_t                   pkt_dev;        /* our dev */
 262        char                    name[20];
 263        struct packet_settings  settings;
 264        struct packet_stats     stats;
 265        int                     refcnt;         /* Open count */
 266        int                     write_speed;    /* current write speed, kB/s */
 267        int                     read_speed;     /* current read speed, kB/s */
 268        unsigned long           offset;         /* start offset */
 269        __u8                    mode_offset;    /* 0 / 8 */
 270        __u8                    type;
 271        unsigned long           flags;
 272        __u16                   mmc3_profile;
 273        __u32                   nwa;            /* next writable address */
 274        __u32                   lra;            /* last recorded address */
 275        struct packet_cdrw      cdrw;
 276        wait_queue_head_t       wqueue;
 277
 278        spinlock_t              lock;           /* Serialize access to bio_queue */
 279        struct rb_root          bio_queue;      /* Work queue of bios we need to handle */
 280        int                     bio_queue_size; /* Number of nodes in bio_queue */
 281        sector_t                current_sector; /* Keep track of where the elevator is */
 282        atomic_t                scan_queue;     /* Set to non-zero when pkt_handle_queue */
 283                                                /* needs to be run. */
 284        mempool_t               *rb_pool;       /* mempool for pkt_rb_node allocations */
 285
 286        struct packet_iosched   iosched;
 287        struct gendisk          *disk;
 288
 289        int                     write_congestion_off;
 290        int                     write_congestion_on;
 291
 292        struct device           *dev;           /* sysfs pktcdvd[0-7] dev */
 293        struct pktcdvd_kobj     *kobj_stat;     /* sysfs pktcdvd[0-7]/stat/     */
 294        struct pktcdvd_kobj     *kobj_wqueue;   /* sysfs pktcdvd[0-7]/write_queue/ */
 295
 296        struct dentry           *dfs_d_root;    /* debugfs: devname directory */
 297        struct dentry           *dfs_f_info;    /* debugfs: info file */
 298};
 299
 300#endif /* __KERNEL__ */
 301
 302#endif /* __PKTCDVD_H */
 303
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