path: root/drivers/s390/block/dasd_int.h

/*
 * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
 *		    Horst Hummel <Horst.Hummel@de.ibm.com>
 *		    Martin Schwidefsky <schwidefsky@de.ibm.com>
 * Bugreports.to..: <Linux390@de.ibm.com>
 * Copyright IBM Corp. 1999, 2009
 */

#ifndef DASD_INT_H
#define DASD_INT_H

/* 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.
 *   unfmt: the device could not be analyzed (format is unknown).
 *   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_UNFMT  3
#define DASD_STATE_READY  4
#define DASD_STATE_ONLINE 5

#include <linux/module.h>
#include <linux/wait.h>
#include <linux/blkdev.h>
#include <linux/genhd.h>
#include <linux/hdreg.h>
#include <linux/interrupt.h>
#include <linux/log2.h>
#include <asm/ccwdev.h>
#include <linux/workqueue.h>
#include <asm/debug.h>
#include <asm/dasd.h>
#include <asm/idals.h>

/* DASD discipline magic */
#define DASD_ECKD_MAGIC 0xC5C3D2C4
#define DASD_DIAG_MAGIC 0xC4C9C1C7
#define DASD_FBA_MAGIC 0xC6C2C140

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

/* 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

/* BIT DEFINITIONS FOR SIM SENSE */
#define DASD_SIM_SENSE 0x0F
#define DASD_SIM_MSG_TO_OP 0x03
#define DASD_SIM_LOG 0x0C

/* lock class for nested cdev lock */
#define CDEV_NESTED_FIRST 1
#define CDEV_NESTED_SECOND 2

/*
 * 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_EVENT_DEVID(d_level, d_cdev, d_str, d_data...)	\
do { \
	struct ccw_dev_id __dev_id;			\
	ccw_device_get_id(d_cdev, &__dev_id);		\
	debug_sprintf_event(dasd_debug_area,		\
			    d_level,					\
			    "0.%x.%04x " d_str "\n",			\
			    __dev_id.ssid, __dev_id.devno, 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)

/* limit size for an errorstring */
#define ERRORLENGTH 30

/* 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", \
	       dev_name(&d_device->cdev->dev), 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", \
	       dev_name(&d_device->cdev->dev), 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 devlist;	/* for dasd_device request queue */
	struct list_head blocklist;	/* for dasd_block request queue */

	/* Where to execute what... */
	struct dasd_block *block;	/* the originating block device */
	struct dasd_device *memdev;	/* the device used to allocate this */
	struct dasd_device *startdev;	/* device the request is started on */
	struct dasd_device *basedev;	/* base device if no block->base */
	void *cpaddr;			/* address of ccw or tcw */
	unsigned char cpmode;		/* 0 = cmd mode, 1 = itcw */
	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 */
	unsigned long expires;		/* expiration period in jiffies */
	char lpm;			/* logical path mask */
	void *data;			/* pointer to data area */

	/* these are important for recovering erroneous requests          */
	int intrc;			/* internal error, e.g. from start_IO */
	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_DONE		0x01	/* request is completed successfully */
#define DASD_CQR_NEED_ERP	0x02	/* request needs recovery action */
#define DASD_CQR_IN_ERP 	0x03	/* request is in recovery */
#define DASD_CQR_FAILED 	0x04	/* request is finally failed */
#define DASD_CQR_TERMINATED	0x05	/* request was stopped by driver */

#define DASD_CQR_QUEUED 	0x80	/* request is queued to be processed */
#define DASD_CQR_IN_IO		0x81	/* request is currently in IO */
#define DASD_CQR_ERROR		0x82	/* request is completed with error */
#define DASD_CQR_CLEAR_PENDING	0x83	/* request is clear pending */
#define DASD_CQR_CLEARED	0x84	/* request was cleared */
#define DASD_CQR_SUCCESS	0x85	/* request was successful */

/* default expiration time*/
#define DASD_EXPIRES	  300
#define DASD_EXPIRES_MAX  40000000
#define DASD_RETRIES	  256
#define DASD_RETRIES_MAX  32768

/* per dasd_ccw_req flags */
#define DASD_CQR_FLAGS_USE_ERP   0	/* use ERP for this request */
#define DASD_CQR_FLAGS_FAILFAST  1	/* FAILFAST */
#define DASD_CQR_VERIFY_PATH	 2	/* path verification request */
#define DASD_CQR_ALLOW_SLOCK	 3	/* Try this request even when lock was
					 * stolen. Should not be combined with
					 * DASD_CQR_FLAGS_USE_ERP
					 */

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

/*
 * Unique identifier for dasd device.
 */
#define UA_NOT_CONFIGURED  0x00
#define UA_BASE_DEVICE	   0x01
#define UA_BASE_PAV_ALIAS  0x02
#define UA_HYPER_PAV_ALIAS 0x03

struct dasd_uid {
	__u8 type;
	char vendor[4];
	char serial[15];
	__u16 ssid;
	__u8 real_unit_addr;
	__u8 base_unit_addr;
	char vduit[33];
};

/*
 * 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. uncheck_device is called during
	 * device shutdown to deregister a device from its discipline.
	 */
	int (*check_device) (struct dasd_device *);
	void (*uncheck_device) (struct dasd_device *);

	/*
	 * 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 (*do_analysis) (struct dasd_block *);

	/*
	 * This function is called, when new paths become available.
	 * Disciplins may use this callback to do necessary setup work,
	 * e.g. verify that new path is compatible with the current
	 * configuration.
	 */
	int (*verify_path)(struct dasd_device *, __u8);

	/*
	 * Last things to do when a device is set online, and first things
	 * when it is set offline.
	 */
	int (*basic_to_ready) (struct dasd_device *);
	int (*online_to_ready) (struct dasd_device *);
	int (*basic_to_known)(struct dasd_device *);

	/* (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.
	 * handle_terminated_request allows to examine a cqr and prepare
	 * it for retry.
	 */
	struct dasd_ccw_req *(</