/*
   * Copyright (C) 2000 Jens Axboe <axboe@suse.de>
   * Copyright (C) 2001-2004 Peter Osterlund <petero2@telia.com>
   *
   * May be copied or modified under the terms of the GNU General Public
   * License.  See linux/COPYING for more information.
   *
   * Packet writing layer for ATAPI and SCSI CD-R, CD-RW, DVD-R, and
   * DVD-RW devices.
   *
   */
  #ifndef __PKTCDVD_H
  #define __PKTCDVD_H
  
  #include <linux/types.h>
  
  /*
   * 1 for normal debug messages, 2 is very verbose. 0 to turn it off.
   */
  #define PACKET_DEBUG		1
  
  #define	MAX_WRITERS		8
  
  #define PKT_RB_POOL_SIZE	512
  
  /*
   * How long we should hold a non-full packet before starting data gathering.
   */
  #define PACKET_WAIT_TIME	(HZ * 5 / 1000)
  
  /*
   * use drive write caching -- we need deferred error handling to be

   * able to successfully recover with this option (drive will return good

   * status as soon as the cdb is validated).
   */
  #if defined(CONFIG_CDROM_PKTCDVD_WCACHE)
  #define USE_WCACHING		1
  #else
  #define USE_WCACHING		0
  #endif
  
  /*
   * No user-servicable parts beyond this point ->
   */
  
  /*
   * device types
   */
  #define PACKET_CDR		1
  #define	PACKET_CDRW		2
  #define PACKET_DVDR		3
  #define PACKET_DVDRW		4
  
  /*
   * flags
   */
  #define PACKET_WRITABLE		1	/* pd is writable */
  #define PACKET_NWA_VALID	2	/* next writable address valid */
  #define PACKET_LRA_VALID	3	/* last recorded address valid */
  #define PACKET_MERGE_SEGS	4	/* perform segment merging to keep */
  					/* underlying cdrom device happy */
  
  /*
   * Disc status -- from READ_DISC_INFO
   */
  #define PACKET_DISC_EMPTY	0
  #define PACKET_DISC_INCOMPLETE	1
  #define PACKET_DISC_COMPLETE	2
  #define PACKET_DISC_OTHER	3
  
  /*
   * write type, and corresponding data block type
   */
  #define PACKET_MODE1		1
  #define PACKET_MODE2		2
  #define PACKET_BLOCK_MODE1	8
  #define PACKET_BLOCK_MODE2	10
  
  /*
   * Last session/border status
   */
  #define PACKET_SESSION_EMPTY		0
  #define PACKET_SESSION_INCOMPLETE	1
  #define PACKET_SESSION_RESERVED		2
  #define PACKET_SESSION_COMPLETE		3
  
  #define PACKET_MCN			"4a656e734178626f65323030300000"
  
  #undef PACKET_USE_LS
  
  #define PKT_CTRL_CMD_SETUP	0
  #define PKT_CTRL_CMD_TEARDOWN	1
  #define PKT_CTRL_CMD_STATUS	2
  
  struct pkt_ctrl_command {
  	__u32 command;				/* in: Setup, teardown, status */
  	__u32 dev_index;			/* in/out: Device index */
  	__u32 dev;				/* in/out: Device nr for cdrw device */
  	__u32 pkt_dev;				/* in/out: Device nr for packet device */
  	__u32 num_devices;			/* out: Largest device index + 1 */
  	__u32 padding;				/* Not used */
  };
  
  /*
   * packet ioctls
   */
  #define PACKET_IOCTL_MAGIC	('X')
  #define PACKET_CTRL_CMD		_IOWR(PACKET_IOCTL_MAGIC, 1, struct pkt_ctrl_command)
  
  #ifdef __KERNEL__
  #include <linux/blkdev.h>
  #include <linux/completion.h>
  #include <linux/cdrom.h>

  #include <linux/kobject.h>
  #include <linux/sysfs.h>

  #include <linux/mempool.h>

  
  /* default bio write queue congestion marks */
  #define PKT_WRITE_CONGESTION_ON    10000
  #define PKT_WRITE_CONGESTION_OFF   9000

  struct packet_settings
  {

  	__u32			size;		/* packet size in (512 byte) sectors */

  	__u8			fp;		/* fixed packets */
  	__u8			link_loss;	/* the rest is specified
  						 * as per Mt Fuji */
  	__u8			write_type;
  	__u8			track_mode;
  	__u8			block_mode;
  };
  
  /*
   * Very crude stats for now
   */
  struct packet_stats
  {
  	unsigned long		pkt_started;
  	unsigned long		pkt_ended;
  	unsigned long		secs_w;
  	unsigned long		secs_rg;
  	unsigned long		secs_r;
  };
  
  struct packet_cdrw
  {
  	struct list_head	pkt_free_list;
  	struct list_head	pkt_active_list;
  	spinlock_t		active_list_lock; /* Serialize access to pkt_active_list */
  	struct task_struct	*thread;
  	atomic_t		pending_bios;
  };
  
  /*
   * Switch to high speed reading after reading this many kilobytes
   * with no interspersed writes.
   */
  #define HI_SPEED_SWITCH 512
  
  struct packet_iosched
  {
  	atomic_t		attention;	/* Set to non-zero when queue processing is needed */
  	int			writing;	/* Non-zero when writing, zero when reading */
  	spinlock_t		lock;		/* Protecting read/write queue manipulations */

  	struct bio_list		read_queue;
  	struct bio_list		write_queue;

  	sector_t		last_write;	/* The sector where the last write ended */

  	int			successive_reads;
  };
  
  /*
   * 32 buffers of 2048 bytes
   */

  #if (PAGE_SIZE % CD_FRAMESIZE) != 0
  #error "PAGE_SIZE must be a multiple of CD_FRAMESIZE"
  #endif

  #define PACKET_MAX_SIZE		128

  #define FRAMES_PER_PAGE		(PAGE_SIZE / CD_FRAMESIZE)

  #define PACKET_MAX_SECTORS	(PACKET_MAX_SIZE * CD_FRAMESIZE >> 9)
  
  enum packet_data_state {
  	PACKET_IDLE_STATE,			/* Not used at the moment */
  	PACKET_WAITING_STATE,			/* Waiting for more bios to arrive, so */
  						/* we don't have to do as much */
  						/* data gathering */
  	PACKET_READ_WAIT_STATE,			/* Waiting for reads to fill in holes */
  	PACKET_WRITE_WAIT_STATE,		/* Waiting for the write to complete */
  	PACKET_RECOVERY_STATE,			/* Recover after read/write errors */
  	PACKET_FINISHED_STATE,			/* After write has finished */
  
  	PACKET_NUM_STATES			/* Number of possible states */
  };
  
  /*
   * Information needed for writing a single packet
   */
  struct pktcdvd_device;
  
  struct packet_data
  {
  	struct list_head	list;
  
  	spinlock_t		lock;		/* Lock protecting state transitions and */
  						/* orig_bios list */

  	struct bio_list		orig_bios;	/* Original bios passed to pkt_make_request */
  						/* that will be handled by this packet */

  	int			write_size;	/* Total size of all bios in the orig_bios */
  						/* list, measured in number of frames */
  
  	struct bio		*w_bio;		/* The bio we will send to the real CD */
  						/* device once we have all data for the */
  						/* packet we are going to write */
  	sector_t		sector;		/* First sector in this packet */
  	int			frames;		/* Number of frames in this packet */
  
  	enum packet_data_state	state;		/* Current state */
  	atomic_t		run_sm;		/* Incremented whenever the state */
  						/* machine needs to be run */
  	long			sleep_time;	/* Set this to non-zero to make the state */
  						/* machine run after this many jiffies. */
  
  	atomic_t		io_wait;	/* Number of pending IO operations */
  	atomic_t		io_errors;	/* Number of read/write errors during IO */
  
  	struct bio		*r_bios[PACKET_MAX_SIZE]; /* bios to use during data gathering */

  	struct page		*pages[PACKET_MAX_SIZE / FRAMES_PER_PAGE];

  
  	int			cache_valid;	/* If non-zero, the data for the zone defined */
  						/* by the sector variable is completely cached */
  						/* in the pages[] vector. */
  
  	int			id;		/* ID number for debugging */
  	struct pktcdvd_device	*pd;
  };
  
  struct pkt_rb_node {
  	struct rb_node		rb_node;
  	struct bio		*bio;
  };
  
  struct packet_stacked_data
  {
  	struct bio		*bio;		/* Original read request bio */
  	struct pktcdvd_device	*pd;
  };
  #define PSD_POOL_SIZE		64

  struct pktcdvd_kobj
  {
  	struct kobject		kobj;
  	struct pktcdvd_device	*pd;
  };
  #define to_pktcdvdkobj(_k) \
    ((struct pktcdvd_kobj*)container_of(_k,struct pktcdvd_kobj,kobj))

  struct pktcdvd_device
  {
  	struct block_device	*bdev;		/* dev attached */
  	dev_t			pkt_dev;	/* our dev */
  	char			name[20];
  	struct packet_settings	settings;
  	struct packet_stats	stats;
  	int			refcnt;		/* Open count */
  	int			write_speed;	/* current write speed, kB/s */
  	int			read_speed;	/* current read speed, kB/s */
  	unsigned long		offset;		/* start offset */
  	__u8			mode_offset;	/* 0 / 8 */
  	__u8			type;
  	unsigned long		flags;
  	__u16			mmc3_profile;
  	__u32			nwa;		/* next writable address */
  	__u32			lra;		/* last recorded address */
  	struct packet_cdrw	cdrw;
  	wait_queue_head_t	wqueue;
  
  	spinlock_t		lock;		/* Serialize access to bio_queue */
  	struct rb_root		bio_queue;	/* Work queue of bios we need to handle */
  	int			bio_queue_size;	/* Number of nodes in bio_queue */
  	sector_t		current_sector;	/* Keep track of where the elevator is */
  	atomic_t		scan_queue;	/* Set to non-zero when pkt_handle_queue */
  						/* needs to be run. */
  	mempool_t		*rb_pool;	/* mempool for pkt_rb_node allocations */
  
  	struct packet_iosched   iosched;
  	struct gendisk		*disk;

  
  	int			write_congestion_off;
  	int			write_congestion_on;

  	struct device		*dev;		/* sysfs pktcdvd[0-7] dev */

  	struct pktcdvd_kobj	*kobj_stat;	/* sysfs pktcdvd[0-7]/stat/     */
  	struct pktcdvd_kobj	*kobj_wqueue;	/* sysfs pktcdvd[0-7]/write_queue/ */
  
  	struct dentry		*dfs_d_root;	/* debugfs: devname directory */
  	struct dentry		*dfs_f_info;	/* debugfs: info file */

  };
  
  #endif /* __KERNEL__ */
  
  #endif /* __PKTCDVD_H */