/*
   *    tape device driver for 3480/3490E/3590 tapes.
   *
   *  S390 and zSeries version
   *    Copyright IBM Corp. 2001, 2009
   *    Author(s): Carsten Otte <cotte@de.ibm.com>
   *		 Tuan Ngo-Anh <ngoanh@de.ibm.com>
   *		 Martin Schwidefsky <schwidefsky@de.ibm.com>
   *		 Stefan Bader <shbader@de.ibm.com>
   */
  
  #ifndef _TAPE_H
  #define _TAPE_H
  
  #include <asm/ccwdev.h>
  #include <asm/debug.h>
  #include <asm/idals.h>
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/mtio.h>
  #include <linux/interrupt.h>
  #include <linux/workqueue.h>
  
  struct gendisk;
  
  /*
   * Define DBF_LIKE_HELL for lots of messages in the debug feature.
   */
  #define DBF_LIKE_HELL
  #ifdef  DBF_LIKE_HELL
  #define DBF_LH(level, str, ...) \
  do { \
  	debug_sprintf_event(TAPE_DBF_AREA, level, str, ## __VA_ARGS__); \
  } while (0)
  #else
  #define DBF_LH(level, str, ...) do {} while(0)
  #endif
  
  /*
   * macros s390 debug feature (dbf)
   */
  #define DBF_EVENT(d_level, d_str...) \
  do { \
  	debug_sprintf_event(TAPE_DBF_AREA, d_level, d_str); \
  } while (0)
  
  #define DBF_EXCEPTION(d_level, d_str...) \
  do { \
  	debug_sprintf_exception(TAPE_DBF_AREA, d_level, d_str); \
  } while (0)
  
  #define TAPE_VERSION_MAJOR 2
  #define TAPE_VERSION_MINOR 0
  #define TAPE_MAGIC "tape"
  
  #define TAPE_MINORS_PER_DEV 2	    /* two minors per device */
  #define TAPEBLOCK_HSEC_SIZE	2048
  #define TAPEBLOCK_HSEC_S2B	2
  #define TAPEBLOCK_RETRIES	5
  
  enum tape_medium_state {
  	MS_UNKNOWN,
  	MS_LOADED,
  	MS_UNLOADED,
  	MS_SIZE
  };
  
  enum tape_state {
  	TS_UNUSED=0,
  	TS_IN_USE,
  	TS_BLKUSE,
  	TS_INIT,
  	TS_NOT_OPER,
  	TS_SIZE
  };
  
  enum tape_op {
  	TO_BLOCK,	/* Block read */
  	TO_BSB,		/* Backward space block */
  	TO_BSF,		/* Backward space filemark */
  	TO_DSE,		/* Data security erase */
  	TO_FSB,		/* Forward space block */
  	TO_FSF,		/* Forward space filemark */
  	TO_LBL,		/* Locate block label */
  	TO_NOP,		/* No operation */
  	TO_RBA,		/* Read backward */
  	TO_RBI,		/* Read block information */
  	TO_RFO,		/* Read forward */
  	TO_REW,		/* Rewind tape */
  	TO_RUN,		/* Rewind and unload tape */
  	TO_WRI,		/* Write block */
  	TO_WTM,		/* Write tape mark */
  	TO_MSEN,	/* Medium sense */
  	TO_LOAD,	/* Load tape */
  	TO_READ_CONFIG, /* Read configuration data */
  	TO_READ_ATTMSG, /* Read attention message */
  	TO_DIS,		/* Tape display */
  	TO_ASSIGN,	/* Assign tape to channel path */
  	TO_UNASSIGN,	/* Unassign tape from channel path */
  	TO_CRYPT_ON,	/* Enable encrpytion */
  	TO_CRYPT_OFF,	/* Disable encrpytion */
  	TO_KEKL_SET,	/* Set KEK label */
  	TO_KEKL_QUERY,	/* Query KEK label */
  	TO_RDC,		/* Read device characteristics */
  	TO_SIZE,	/* #entries in tape_op_t */
  };
  
  /* Forward declaration */
  struct tape_device;
  
  /* tape_request->status can be: */
  enum tape_request_status {
  	TAPE_REQUEST_INIT,	/* request is ready to be processed */
  	TAPE_REQUEST_QUEUED,	/* request is queued to be processed */
  	TAPE_REQUEST_IN_IO,	/* request is currently in IO */
  	TAPE_REQUEST_DONE,	/* request is completed. */
  	TAPE_REQUEST_CANCEL,	/* request should be canceled. */
  	TAPE_REQUEST_LONG_BUSY, /* request has to be restarted after long busy */
  };
  
  /* Tape CCW request */
  struct tape_request {
  	struct list_head list;		/* list head for request queueing. */
  	struct tape_device *device;	/* tape device of this request */
  	struct ccw1 *cpaddr;		/* address of the channel program. */
  	void *cpdata;			/* pointer to ccw data. */
  	enum tape_request_status status;/* status of this request */
  	int options;			/* options for execution. */
  	int retries;			/* retry counter for error recovery. */
  	int rescnt;			/* residual count from devstat. */
  
  	/* Callback for delivering final status. */
  	void (*callback)(struct tape_request *, void *);
  	void *callback_data;
  
  	enum tape_op op;
  	int rc;
  };
  
  /* Function type for magnetic tape commands */
  typedef int (*tape_mtop_fn)(struct tape_device *, int);
  
  /* Size of the array containing the mtops for a discipline */
  #define TAPE_NR_MTOPS (MTMKPART+1)
  
  /* Tape Discipline */
  struct tape_discipline {
  	struct module *owner;
  	int  (*setup_device)(struct tape_device *);
  	void (*cleanup_device)(struct tape_device *);
  	int (*irq)(struct tape_device *, struct tape_request *, struct irb *);
  	struct tape_request *(*read_block)(struct tape_device *, size_t);
  	struct tape_request *(*write_block)(struct tape_device *, size_t);
  	void (*process_eov)(struct tape_device*);
  	/* ioctl function for additional ioctls. */
  	int (*ioctl_fn)(struct tape_device *, unsigned int, unsigned long);
  	/* Array of tape commands with TAPE_NR_MTOPS entries */
  	tape_mtop_fn *mtop_array;
  };
  
  /*
   * The discipline irq function either returns an error code (<0) which
   * means that the request has failed with an error or one of the following:
   */
  #define TAPE_IO_SUCCESS		0	/* request successful */
  #define TAPE_IO_PENDING		1	/* request still running */
  #define TAPE_IO_RETRY		2	/* retry to current request */
  #define TAPE_IO_STOP		3	/* stop the running request */
  #define TAPE_IO_LONG_BUSY	4	/* delay the running request */
  
  /* Char Frontend Data */
  struct tape_char_data {
  	struct idal_buffer *idal_buf;	/* idal buffer for user char data */
  	int block_size;			/*   of size block_size. */
  };
  
  /* Tape Info */
  struct tape_device {
  	/* entry in tape_device_list */
  	struct list_head		node;
  
  	int				cdev_id;
  	struct ccw_device *		cdev;
  	struct tape_class_device *	nt;
  	struct tape_class_device *	rt;
  
  	/* Device mutex to serialize tape commands. */
  	struct mutex			mutex;
  
  	/* Device discipline information. */
  	struct tape_discipline *	discipline;
  	void *				discdata;
  
  	/* Generic status flags */
  	long				tape_generic_status;
  
  	/* Device state information. */
  	wait_queue_head_t		state_change_wq;
  	enum tape_state			tape_state;
  	enum tape_medium_state		medium_state;
  	unsigned char *			modeset_byte;
  
  	/* Reference count. */
  	atomic_t			ref_count;
  
  	/* Request queue. */
  	struct list_head		req_queue;
  
  	/* Request wait queue. */
  	wait_queue_head_t		wait_queue;
  
  	/* Each tape device has (currently) two minor numbers. */
  	int				first_minor;
  
  	/* Number of tapemarks required for correct termination. */
  	int				required_tapemarks;
  
  	/* Block ID of the BOF */
  	unsigned int			bof;
  
  	/* Character device frontend data */
  	struct tape_char_data		char_data;
  
  	/* Function to start or stop the next request later. */
  	struct delayed_work		tape_dnr;
  
  	/* Timer for long busy */
  	struct timer_list		lb_timeout;
  
  };
  
  /* Externals from tape_core.c */
  extern struct tape_request *tape_alloc_request(int cplength, int datasize);
  extern void tape_free_request(struct tape_request *);
  extern int tape_do_io(struct tape_device *, struct tape_request *);
  extern int tape_do_io_async(struct tape_device *, struct tape_request *);
  extern int tape_do_io_interruptible(struct tape_device *, struct tape_request *);
  extern int tape_cancel_io(struct tape_device *, struct tape_request *);
  void tape_hotplug_event(struct tape_device *, int major, int action);
  
  static inline int
  tape_do_io_free(struct tape_device *device, struct tape_request *request)
  {
  	int rc;
  
  	rc = tape_do_io(device, request);
  	tape_free_request(request);
  	return rc;
  }
  
  static inline void
  tape_do_io_async_free(struct tape_device *device, struct tape_request *request)
  {
  	request->callback = (void *) tape_free_request;
  	request->callback_data = NULL;
  	tape_do_io_async(device, request);
  }
  
  extern int tape_oper_handler(int irq, int status);
  extern void tape_noper_handler(int irq, int status);
  extern int tape_open(struct tape_device *);
  extern int tape_release(struct tape_device *);
  extern int tape_mtop(struct tape_device *, int, int);
  extern void tape_state_set(struct tape_device *, enum tape_state);
  
  extern int tape_generic_online(struct tape_device *, struct tape_discipline *);
  extern int tape_generic_offline(struct ccw_device *);
  extern int tape_generic_pm_suspend(struct ccw_device *);
  
  /* Externals from tape_devmap.c */
  extern int tape_generic_probe(struct ccw_device *);
  extern void tape_generic_remove(struct ccw_device *);
  
  extern struct tape_device *tape_find_device(int devindex);
  extern struct tape_device *tape_get_device(struct tape_device *);
  extern void tape_put_device(struct tape_device *);
  
  /* Externals from tape_char.c */
  extern int tapechar_init(void);
  extern void tapechar_exit(void);
  extern int  tapechar_setup_device(struct tape_device *);
  extern void tapechar_cleanup_device(struct tape_device *);
  
  /* tape initialisation functions */
  #ifdef CONFIG_PROC_FS
  extern void tape_proc_init (void);
  extern void tape_proc_cleanup (void);
  #else
  static inline void tape_proc_init (void) {;}
  static inline void tape_proc_cleanup (void) {;}
  #endif
  
  /* a function for dumping device sense info */
  extern void tape_dump_sense_dbf(struct tape_device *, struct tape_request *,
  				struct irb *);
  
  /* functions for handling the status of a device */
  extern void tape_med_state_set(struct tape_device *, enum tape_medium_state);
  
  /* The debug area */
  extern debug_info_t *TAPE_DBF_AREA;
  
  /* functions for building ccws */
  static inline struct ccw1 *
  tape_ccw_cc(struct ccw1 *ccw, __u8 cmd_code, __u16 memsize, void *cda)
  {
  	ccw->cmd_code = cmd_code;
  	ccw->flags = CCW_FLAG_CC;
  	ccw->count = memsize;
  	ccw->cda = (__u32)(addr_t) cda;
  	return ccw + 1;
  }
  
  static inline struct ccw1 *
  tape_ccw_end(struct ccw1 *ccw, __u8 cmd_code, __u16 memsize, void *cda)
  {
  	ccw->cmd_code = cmd_code;
  	ccw->flags = 0;
  	ccw->count = memsize;
  	ccw->cda = (__u32)(addr_t) cda;
  	return ccw + 1;
  }
  
  static inline struct ccw1 *
  tape_ccw_cmd(struct ccw1 *ccw, __u8 cmd_code)
  {
  	ccw->cmd_code = cmd_code;
  	ccw->flags = 0;
  	ccw->count = 0;
  	ccw->cda = (__u32)(addr_t) &ccw->cmd_code;
  	return ccw + 1;
  }
  
  static inline struct ccw1 *
  tape_ccw_repeat(struct ccw1 *ccw, __u8 cmd_code, int count)
  {
  	while (count-- > 0) {
  		ccw->cmd_code = cmd_code;
  		ccw->flags = CCW_FLAG_CC;
  		ccw->count = 0;
  		ccw->cda = (__u32)(addr_t) &ccw->cmd_code;
  		ccw++;
  	}
  	return ccw;
  }
  
  static inline struct ccw1 *
  tape_ccw_cc_idal(struct ccw1 *ccw, __u8 cmd_code, struct idal_buffer *idal)
  {
  	ccw->cmd_code = cmd_code;
  	ccw->flags    = CCW_FLAG_CC;
  	idal_buffer_set_cda(idal, ccw);
  	return ccw++;
  }
  
  static inline struct ccw1 *
  tape_ccw_end_idal(struct ccw1 *ccw, __u8 cmd_code, struct idal_buffer *idal)
  {
  	ccw->cmd_code = cmd_code;
  	ccw->flags    = 0;
  	idal_buffer_set_cda(idal, ccw);
  	return ccw++;
  }
  
  /* Global vars */
  extern const char *tape_state_verbose[];
  extern const char *tape_op_verbose[];
  
  #endif /* for ifdef tape.h */