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/blkdev.h>
  16#include <linux/completion.h>
  17#include <linux/cdrom.h>
  18#include <linux/kobject.h>
  19#include <linux/sysfs.h>
  20#include <linux/mempool.h>
  21#include <uapi/linux/pktcdvd.h>
  22
  23/* default bio write queue congestion marks */
  24#define PKT_WRITE_CONGESTION_ON    10000
  25#define PKT_WRITE_CONGESTION_OFF   9000
  26
  27
  28struct packet_settings
  29{
  30        __u32                   size;           /* packet size in (512 byte) sectors */
  31        __u8                    fp;             /* fixed packets */
  32        __u8                    link_loss;      /* the rest is specified
  33                                                 * as per Mt Fuji */
  34        __u8                    write_type;
  35        __u8                    track_mode;
  36        __u8                    block_mode;
  37};
  38
  39/*
  40 * Very crude stats for now
  41 */
  42struct packet_stats
  43{
  44        unsigned long           pkt_started;
  45        unsigned long           pkt_ended;
  46        unsigned long           secs_w;
  47        unsigned long           secs_rg;
  48        unsigned long           secs_r;
  49};
  50
  51struct packet_cdrw
  52{
  53        struct list_head        pkt_free_list;
  54        struct list_head        pkt_active_list;
  55        spinlock_t              active_list_lock; /* Serialize access to pkt_active_list */
  56        struct task_struct      *thread;
  57        atomic_t                pending_bios;
  58};
  59
  60/*
  61 * Switch to high speed reading after reading this many kilobytes
  62 * with no interspersed writes.
  63 */
  64#define HI_SPEED_SWITCH 512
  65
  66struct packet_iosched
  67{
  68        atomic_t                attention;      /* Set to non-zero when queue processing is needed */
  69        int                     writing;        /* Non-zero when writing, zero when reading */
  70        spinlock_t              lock;           /* Protecting read/write queue manipulations */
  71        struct bio_list         read_queue;
  72        struct bio_list         write_queue;
  73        sector_t                last_write;     /* The sector where the last write ended */
  74        int                     successive_reads;
  75};
  76
  77/*
  78 * 32 buffers of 2048 bytes
  79 */
  80#if (PAGE_SIZE % CD_FRAMESIZE) != 0
  81#error "PAGE_SIZE must be a multiple of CD_FRAMESIZE"
  82#endif
  83#define PACKET_MAX_SIZE         128
  84#define FRAMES_PER_PAGE         (PAGE_SIZE / CD_FRAMESIZE)
  85#define PACKET_MAX_SECTORS      (PACKET_MAX_SIZE * CD_FRAMESIZE >> 9)
  86
  87enum packet_data_state {
  88        PACKET_IDLE_STATE,                      /* Not used at the moment */
  89        PACKET_WAITING_STATE,                   /* Waiting for more bios to arrive, so */
  90                                                /* we don't have to do as much */
  91                                                /* data gathering */
  92        PACKET_READ_WAIT_STATE,                 /* Waiting for reads to fill in holes */
  93        PACKET_WRITE_WAIT_STATE,                /* Waiting for the write to complete */
  94        PACKET_RECOVERY_STATE,                  /* Recover after read/write errors */
  95        PACKET_FINISHED_STATE,                  /* After write has finished */
  96
  97        PACKET_NUM_STATES                       /* Number of possible states */
  98};
  99
 100/*
 101 * Information needed for writing a single packet
 102 */
 103struct pktcdvd_device;
 104
 105struct packet_data
 106{
 107        struct list_head        list;
 108
 109        spinlock_t              lock;           /* Lock protecting state transitions and */
 110                                                /* orig_bios list */
 111
 112        struct bio_list         orig_bios;      /* Original bios passed to pkt_make_request */
 113                                                /* that will be handled by this packet */
 114        int                     write_size;     /* Total size of all bios in the orig_bios */
 115                                                /* list, measured in number of frames */
 116
 117        struct bio              *w_bio;         /* The bio we will send to the real CD */
 118                                                /* device once we have all data for the */
 119                                                /* packet we are going to write */
 120        sector_t                sector;         /* First sector in this packet */
 121        int                     frames;         /* Number of frames in this packet */
 122
 123        enum packet_data_state  state;          /* Current state */
 124        atomic_t                run_sm;         /* Incremented whenever the state */
 125                                                /* machine needs to be run */
 126        long                    sleep_time;     /* Set this to non-zero to make the state */
 127                                                /* machine run after this many jiffies. */
 128
 129        atomic_t                io_wait;        /* Number of pending IO operations */
 130        atomic_t                io_errors;      /* Number of read/write errors during IO */
 131
 132        struct bio              *r_bios[PACKET_MAX_SIZE]; /* bios to use during data gathering */
 133        struct page             *pages[PACKET_MAX_SIZE / FRAMES_PER_PAGE];
 134
 135        int                     cache_valid;    /* If non-zero, the data for the zone defined */
 136                                                /* by the sector variable is completely cached */
 137                                                /* in the pages[] vector. */
 138
 139        int                     id;             /* ID number for debugging */
 140        struct pktcdvd_device   *pd;
 141};
 142
 143struct pkt_rb_node {
 144        struct rb_node          rb_node;
 145        struct bio              *bio;
 146};
 147
 148struct packet_stacked_data
 149{
 150        struct bio              *bio;           /* Original read request bio */
 151        struct pktcdvd_device   *pd;
 152};
 153#define PSD_POOL_SIZE           64
 154
 155struct pktcdvd_kobj
 156{
 157        struct kobject          kobj;
 158        struct pktcdvd_device   *pd;
 159};
 160#define to_pktcdvdkobj(_k) \
 161  ((struct pktcdvd_kobj*)container_of(_k,struct pktcdvd_kobj,kobj))
 162
 163struct pktcdvd_device
 164{
 165        struct block_device     *bdev;          /* dev attached */
 166        dev_t                   pkt_dev;        /* our dev */
 167        char                    name[20];
 168        struct packet_settings  settings;
 169        struct packet_stats     stats;
 170        int                     refcnt;         /* Open count */
 171        int                     write_speed;    /* current write speed, kB/s */
 172        int                     read_speed;     /* current read speed, kB/s */
 173        unsigned long           offset;         /* start offset */
 174        __u8                    mode_offset;    /* 0 / 8 */
 175        __u8                    type;
 176        unsigned long           flags;
 177        __u16                   mmc3_profile;
 178        __u32                   nwa;            /* next writable address */
 179        __u32                   lra;            /* last recorded address */
 180        struct packet_cdrw      cdrw;
 181        wait_queue_head_t       wqueue;
 182
 183        spinlock_t              lock;           /* Serialize access to bio_queue */
 184        struct rb_root          bio_queue;      /* Work queue of bios we need to handle */
 185        int                     bio_queue_size; /* Number of nodes in bio_queue */
 186        sector_t                current_sector; /* Keep track of where the elevator is */
 187        atomic_t                scan_queue;     /* Set to non-zero when pkt_handle_queue */
 188                                                /* needs to be run. */
 189        mempool_t               *rb_pool;       /* mempool for pkt_rb_node allocations */
 190
 191        struct packet_iosched   iosched;
 192        struct gendisk          *disk;
 193
 194        int                     write_congestion_off;
 195        int                     write_congestion_on;
 196
 197        struct device           *dev;           /* sysfs pktcdvd[0-7] dev */
 198        struct pktcdvd_kobj     *kobj_stat;     /* sysfs pktcdvd[0-7]/stat/     */
 199        struct pktcdvd_kobj     *kobj_wqueue;   /* sysfs pktcdvd[0-7]/write_queue/ */
 200
 201        struct dentry           *dfs_d_root;    /* debugfs: devname directory */
 202        struct dentry           *dfs_f_info;    /* debugfs: info file */
 203};
 204
 205#endif /* __PKTCDVD_H */
 206
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