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/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
  28 struct 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  */
  42 struct 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
  51 struct 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
  66 struct 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
  87 enum 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  */
 103 struct pktcdvd_device;
 104
 105 struct 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
 143 struct pkt_rb_node {
 144         struct rb_node          rb_node;
 145         struct bio              *bio;
 146 };
 147
 148 struct 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
 155 struct 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
 163 struct 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 */