include/linux/pktcdvd.h

   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 sucessfully 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
  95 struct 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
 115 struct packet_settings
 116 {
 117         __u8                    size;           /* packet size in (512 byte) sectors */
 118         __u8                    fp;             /* fixed packets */
 119         __u8                    link_loss;      /* the rest is specified
 120                                                  * as per Mt Fuji */
 121         __u8                    write_type;
 122         __u8                    track_mode;
 123         __u8                    block_mode;
 124 };
 125
 126 /*
 127  * Very crude stats for now
 128  */
 129 struct packet_stats
 130 {
 131         unsigned long           pkt_started;
 132         unsigned long           pkt_ended;
 133         unsigned long           secs_w;
 134         unsigned long           secs_rg;
 135         unsigned long           secs_r;
 136 };
 137
 138 struct packet_cdrw
 139 {
 140         struct list_head        pkt_free_list;
 141         struct list_head        pkt_active_list;
 142         spinlock_t              active_list_lock; /* Serialize access to pkt_active_list */
 143         struct task_struct      *thread;
 144         atomic_t                pending_bios;
 145 };
 146
 147 /*
 148  * Switch to high speed reading after reading this many kilobytes
 149  * with no interspersed writes.
 150  */
 151 #define HI_SPEED_SWITCH 512
 152
 153 struct packet_iosched
 154 {
 155         atomic_t                attention;      /* Set to non-zero when queue processing is needed */
 156         int                     writing;        /* Non-zero when writing, zero when reading */
 157         spinlock_t              lock;           /* Protecting read/write queue manipulations */
 158         struct bio              *read_queue;
 159         struct bio              *read_queue_tail;
 160         struct bio              *write_queue;
 161         struct bio              *write_queue_tail;
 162         int                     high_prio_read; /* An important read request has been queued */
 163         int                     successive_reads;
 164 };
 165
 166 /*
 167  * 32 buffers of 2048 bytes
 168  */
 169 #define PACKET_MAX_SIZE         32
 170 #define PAGES_PER_PACKET        (PACKET_MAX_SIZE * CD_FRAMESIZE / PAGE_SIZE)
 171 #define PACKET_MAX_SECTORS      (PACKET_MAX_SIZE * CD_FRAMESIZE >> 9)
 172
 173 enum packet_data_state {
 174         PACKET_IDLE_STATE,                      /* Not used at the moment */
 175         PACKET_WAITING_STATE,                   /* Waiting for more bios to arrive, so */
 176                                                 /* we don't have to do as much */
 177                                                 /* data gathering */
 178         PACKET_READ_WAIT_STATE,                 /* Waiting for reads to fill in holes */
 179         PACKET_WRITE_WAIT_STATE,                /* Waiting for the write to complete */
 180         PACKET_RECOVERY_STATE,                  /* Recover after read/write errors */
 181         PACKET_FINISHED_STATE,                  /* After write has finished */
 182
 183         PACKET_NUM_STATES                       /* Number of possible states */
 184 };
 185
 186 /*
 187  * Information needed for writing a single packet
 188  */
 189 struct pktcdvd_device;
 190
 191 struct packet_data
 192 {
 193         struct list_head        list;
 194
 195         spinlock_t              lock;           /* Lock protecting state transitions and */
 196                                                 /* orig_bios list */
 197
 198         struct bio              *orig_bios;     /* Original bios passed to pkt_make_request */
 199         struct bio              *orig_bios_tail;/* that will be handled by this packet */
 200         int                     write_size;     /* Total size of all bios in the orig_bios */
 201                                                 /* list, measured in number of frames */
 202
 203         struct bio              *w_bio;         /* The bio we will send to the real CD */
 204                                                 /* device once we have all data for the */
 205                                                 /* packet we are going to write */
 206         sector_t                sector;         /* First sector in this packet */
 207         int                     frames;         /* Number of frames in this packet */
 208
 209         enum packet_data_state  state;          /* Current state */
 210         atomic_t                run_sm;         /* Incremented whenever the state */
 211                                                 /* machine needs to be run */
 212         long                    sleep_time;     /* Set this to non-zero to make the state */
 213                                                 /* machine run after this many jiffies. */
 214
 215         atomic_t                io_wait;        /* Number of pending IO operations */
 216         atomic_t                io_errors;      /* Number of read/write errors during IO */
 217
 218         struct bio              *r_bios[PACKET_MAX_SIZE]; /* bios to use during data gathering */
 219         struct page             *pages[PAGES_PER_PACKET];
 220
 221         int                     cache_valid;    /* If non-zero, the data for the zone defined */
 222                                                 /* by the sector variable is completely cached */
 223                                                 /* in the pages[] vector. */
 224
 225         int                     id;             /* ID number for debugging */
 226         struct pktcdvd_device   *pd;
 227 };
 228
 229 struct pkt_rb_node {
 230         struct rb_node          rb_node;
 231         struct bio              *bio;
 232 };
 233
 234 struct packet_stacked_data
 235 {
 236         struct bio              *bio;           /* Original read request bio */
 237         struct pktcdvd_device   *pd;
 238 };
 239 #define PSD_POOL_SIZE           64
 240
 241 struct pktcdvd_device
 242 {
 243         struct block_device     *bdev;          /* dev attached */
 244         dev_t                   pkt_dev;        /* our dev */
 245         char                    name[20];
 246         struct packet_settings  settings;
 247         struct packet_stats     stats;
 248         int                     refcnt;         /* Open count */
 249         int                     write_speed;    /* current write speed, kB/s */
 250         int                     read_speed;     /* current read speed, kB/s */
 251         unsigned long           offset;         /* start offset */
 252         __u8                    mode_offset;    /* 0 / 8 */
 253         __u8                    type;
 254         unsigned long           flags;
 255         __u16                   mmc3_profile;
 256         __u32                   nwa;            /* next writable address */
 257         __u32                   lra;            /* last recorded address */
 258         struct packet_cdrw      cdrw;
 259         wait_queue_head_t       wqueue;
 260
 261         spinlock_t              lock;           /* Serialize access to bio_queue */
 262         struct rb_root          bio_queue;      /* Work queue of bios we need to handle */
 263         int                     bio_queue_size; /* Number of nodes in bio_queue */
 264         sector_t                current_sector; /* Keep track of where the elevator is */
 265         atomic_t                scan_queue;     /* Set to non-zero when pkt_handle_queue */
 266                                                 /* needs to be run. */
 267         mempool_t               *rb_pool;       /* mempool for pkt_rb_node allocations */
 268
 269         struct packet_iosched   iosched;
 270         struct gendisk          *disk;
 271 };
 272
 273 #endif /* __KERNEL__ */
 274
 275 #endif /* __PKTCDVD_H */