dasd_int.h

linux-2.6.15.6

/* 
 * File...........: linux/drivers/s390/block/dasd_int.h
 * Author(s)......: Holger Smolinski <[e-mail]>
 *                  Horst Hummel <[e-mail]> 
 *		    Martin Schwidefsky <[e-mail]>
 * Bugreports.to..: <[e-mail]>
 * (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999,2000
 *
 * $Revision: 1.65 $
 */

#ifndef DASD_INT_H
#define DASD_INT_H

#ifdef __KERNEL__

/* erp debugging in dasd.c and dasd_3990_erp.c */
#define ERP_DEBUG


/* we keep old device allocation scheme; IOW, minors are still in 0..255 */
#define DASD_PER_MAJOR (1U << (MINORBITS - DASD_PARTN_BITS))
#define DASD_PARTN_MASK ((1 << DASD_PARTN_BITS) - 1)

/*
 * States a dasd device can have:
 *   new: the dasd_device structure is allocated.
 *   known: the discipline for the device is identified.
 *   basic: the device can do basic i/o.
 *   accept: the device is analysed (format is known).
 *   ready: partition detection is done and the device is can do block io.
 *   online: the device accepts requests from the block device queue.
 *
 * Things to do for startup state transitions:
 *   new -> known: find discipline for the device and create devfs entries.
 *   known -> basic: request irq line for the device.
 *   basic -> ready: do the initial analysis, e.g. format detection,
 *                   do block device setup and detect partitions.
 *   ready -> online: schedule the device tasklet.
 * Things to do for shutdown state transitions:
 *   online -> ready: just set the new device state.
 *   ready -> basic: flush requests from the block device layer, clear
 *                   partition information and reset format information.
 *   basic -> known: terminate all requests and free irq.
 *   known -> new: remove devfs entries and forget discipline.
 */

#define DASD_STATE_NEW	  0
#define DASD_STATE_KNOWN  1
#define DASD_STATE_BASIC  2
#define DASD_STATE_READY  3
#define DASD_STATE_ONLINE 4

#include <linux/module.h>
#include <linux/wait.h>
#include <linux/blkdev.h>
#include <linux/devfs_fs_kernel.h>
#include <linux/genhd.h>
#include <linux/hdreg.h>
#include <linux/interrupt.h>
#include <asm/ccwdev.h>
#include <linux/workqueue.h>
#include <asm/debug.h>
#include <asm/dasd.h>
#include <asm/idals.h>

/*
 * SECTION: Type definitions
 */
struct dasd_device;

typedef int (*dasd_ioctl_fn_t) (struct block_device *bdev, int no, long args);

struct dasd_ioctl {
	struct list_head list;
	struct module *owner;
	int no;
	dasd_ioctl_fn_t handler;
};

typedef enum {
	dasd_era_fatal = -1,	/* no chance to recover		     */
	dasd_era_none = 0,	/* don't recover, everything alright */
	dasd_era_msg = 1,	/* don't recover, just report...     */
	dasd_era_recover = 2	/* recovery action recommended	     */
} dasd_era_t;

/* BIT DEFINITIONS FOR SENSE DATA */
#define DASD_SENSE_BIT_0 0x80
#define DASD_SENSE_BIT_1 0x40
#define DASD_SENSE_BIT_2 0x20
#define DASD_SENSE_BIT_3 0x10

/*
 * SECTION: MACROs for klogd and s390 debug feature (dbf)
 */
#define DBF_DEV_EVENT(d_level, d_device, d_str, d_data...) \
do { \
	debug_sprintf_event(d_device->debug_area, \
			    d_level, \
			    d_str "\n", \
			    d_data); \
} while(0)

#define DBF_DEV_EXC(d_level, d_device, d_str, d_data...) \
do { \
	debug_sprintf_exception(d_device->debug_area, \
				d_level, \
				d_str "\n", \
				d_data); \
} while(0)

#define DBF_EVENT(d_level, d_str, d_data...)\
do { \
	debug_sprintf_event(dasd_debug_area, \
			    d_level,\
			    d_str "\n", \
			    d_data); \
} while(0)

#define DBF_EXC(d_level, d_str, d_data...)\
do { \
	debug_sprintf_exception(dasd_debug_area, \
				d_level,\
				d_str "\n", \
				d_data); \
} while(0)

/* definition of dbf debug levels */
#define	DBF_EMERG	0	/* system is unusable			*/
#define	DBF_ALERT	1	/* action must be taken immediately	*/
#define	DBF_CRIT	2	/* critical conditions			*/
#define	DBF_ERR		3	/* error conditions			*/
#define	DBF_WARNING	4	/* warning conditions			*/
#define	DBF_NOTICE	5	/* normal but significant condition	*/
#define	DBF_INFO	6	/* informational			*/
#define	DBF_DEBUG	6	/* debug-level messages			*/

/* messages to be written via klogd and dbf */
#define DEV_MESSAGE(d_loglevel,d_device,d_string,d_args...)\
do { \
	printk(d_loglevel PRINTK_HEADER " %s: " d_string "\n", \
	       d_device->cdev->dev.bus_id, d_args); \
	DBF_DEV_EVENT(DBF_ALERT, d_device, d_string, d_args); \
} while(0)

#define MESSAGE(d_loglevel,d_string,d_args...)\
do { \
	printk(d_loglevel PRINTK_HEADER " " d_string "\n", d_args); \
	DBF_EVENT(DBF_ALERT, d_string, d_args); \
} while(0)

/* messages to be written via klogd only */
#define DEV_MESSAGE_LOG(d_loglevel,d_device,d_string,d_args...)\
do { \
	printk(d_loglevel PRINTK_HEADER " %s: " d_string "\n", \
	       d_device->cdev->dev.bus_id, d_args); \
} while(0)

#define MESSAGE_LOG(d_loglevel,d_string,d_args...)\
do { \
	printk(d_loglevel PRINTK_HEADER " " d_string "\n", d_args); \
} while(0)

struct dasd_ccw_req {
	unsigned int magic;		/* Eye catcher */
        struct list_head list;		/* list_head for request queueing. */

	/* Where to execute what... */
	struct dasd_device *device;	/* device the request is for */
	struct ccw1 *cpaddr;		/* address of channel program */
	char status;	        	/* status of this request */
	short retries;			/* A retry counter */
	unsigned long flags;        	/* flags of this request */

	/* ... and how */
	unsigned long starttime;	/* jiffies time of request start */
	int expires;			/* expiration period in jiffies */
	char lpm;               	/* logical path mask */
	void *data;			/* pointer to data area */

	/* these are important for recovering erroneous requests          */
	struct irb irb;			/* device status in case of an error */
	struct dasd_ccw_req *refers;	/* ERP-chain queueing. */
	void *function; 		/* originating ERP action */

	/* these are for statistics only */
	unsigned long long buildclk;	/* TOD-clock of request generation */
	unsigned long long startclk;	/* TOD-clock of request start */
	unsigned long long stopclk;	/* TOD-clock of request interrupt */
	unsigned long long endclk;	/* TOD-clock of request termination */

        /* Callback that is called after reaching final status. */
        void (*callback)(struct dasd_ccw_req *, void *data);
        void *callback_data;
};

/* 
 * dasd_ccw_req -> status can be:
 */
#define DASD_CQR_FILLED   0x00	/* request is ready to be processed */
#define DASD_CQR_QUEUED   0x01	/* request is queued to be processed */
#define DASD_CQR_IN_IO    0x02	/* request is currently in IO */
#define DASD_CQR_DONE     0x03	/* request is completed successfully */
#define DASD_CQR_ERROR    0x04	/* request is completed with error */
#define DASD_CQR_FAILED   0x05	/* request is finally failed */
#define DASD_CQR_CLEAR    0x06	/* request is clear pending */

/* per dasd_ccw_req flags */
#define DASD_CQR_FLAGS_USE_ERP   0	/* use ERP for this request */

/* Signature for error recovery functions. */
typedef struct dasd_ccw_req *(*dasd_erp_fn_t) (struct dasd_ccw_req *);

/*
 * the struct dasd_discipline is
 * sth like a table of virtual functions, if you think of dasd_eckd
 * inheriting dasd...
 * no, currently we are not planning to reimplement the driver in C++
 */
struct dasd_discipline {
	struct module *owner;
	char ebcname[8];	/* a name used for tagging and printks */
	char name[8];		/* a name used for tagging and printks */
	int max_blocks;		/* maximum number of blocks to be chained */

	struct list_head list;	/* used for list of disciplines */

        /*
         * Device recognition functions. check_device is used to verify
         * the sense data and the information returned by read device
         * characteristics. It returns 0 if the discipline can be used
         * for the device in question.
         * do_analysis is used in the step from device state "basic" to
         * state "accept". It returns 0 if the device can be made ready,
         * it returns -EMEDIUMTYPE if the device can't be made ready or
         * -EAGAIN if do_analysis started a ccw that needs to complete
         * before the analysis may be repeated.
         */
        int (*check_device)(struct dasd_device *);
	int (*do_analysis) (struct dasd_device *);

        /*
         * Device operation functions. build_cp creates a ccw chain for
         * a block device request, start_io starts the request and
         * term_IO cancels it (e.g. in case of a timeout). format_device
         * returns a ccw chain to be used to format the device.
         */
	struct dasd_ccw_req *(*build_cp) (struct dasd_device *,
					  struct request *);
	int (*start_IO) (struct dasd_ccw_req *);
	int (*term_IO) (struct dasd_ccw_req *);
	struct dasd_ccw_req *(*format_device) (struct dasd_device *,
					       struct format_data_t *);
	int (*free_cp) (struct dasd_ccw_req *, struct request *);
        /*
         * Error recovery functions. examine_error() returns a value that
         * indicates what to do for an error condition. If examine_error()
         * returns 'dasd_era_recover' erp_action() is called to create a 
         * special error recovery ccw. erp_postaction() is called after
         * an error recovery ccw has finished its execution. dump_sense
         * is called for every error condition to print the sense data
         * to the console.
         */
	dasd_era_t(*examine_error) (struct dasd_ccw_req *, struct irb *);
	dasd_erp_fn_t(*erp_action) (struct dasd_ccw_req *);
	dasd_erp_fn_t(*erp_postaction) (struct dasd_ccw_req *);
	void (*dump_sense) (struct dasd_device *, struct dasd_ccw_req *,
			    struct irb *);

        /* i/o control functions. */
	int (*fill_geometry) (struct dasd_device *, struct hd_geometry *);
	int (*fill_info) (struct dasd_device *, struct dasd_information2_t *);
};

extern struct dasd_discipline *dasd_diag_discipline_pointer;

struct dasd_device {
	/* Block device stuff. */
	struct gendisk *gdp;
	request_queue_t *request_queue;
	spinlock_t request_queue_lock;
	struct block_device *bdev;
        unsigned int devindex;
	unsigned long blocks;		/* size of volume in blocks */
	unsigned int bp_block;		/* bytes per block */
	unsigned int s2b_shift;		/* log2 (bp_block/512) */
	unsigned long flags;		/* per device flags */
	unsigned short features;        /* copy of devmap-features (read-only!) */