/* 
 * File...........: linux/drivers/s390/block/dasd_3990_erp.c
 * Author(s)......: Horst  Hummel    <Horst.Hummel@de.ibm.com> 
 *                  Holger Smolinski <Holger.Smolinski@de.ibm.com>
 * Bugreports.to..: <Linux390@de.ibm.com>
 * (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 2000, 2001
 *
 * $Revision: 1.52.2.5 $
 *
 * History of changes:
 * 05/14/01 fixed PL030160GTO (BUG() in erp_action_5)
 */

#include <asm/ccwcache.h>
#include <asm/idals.h>
#include <asm/s390io.h>
#include <linux/timer.h>

#include "dasd_int.h"
#include "dasd_eckd.h"
#include "dasd_3990_erp.h"

#ifdef PRINTK_HEADER
#undef PRINTK_HEADER
#endif				/* PRINTK_HEADER */
#define PRINTK_HEADER "dasd_erp(3990): "

/*
 ***************************************************************************** 
 * SECTION DEBUG ROUTINES
 ***************************************************************************** 
 */
void
log_erp_chain (ccw_req_t *cqr,
               int       caller,
               __u32     cpa)
{
        ccw_req_t     *loop_cqr = cqr;
	dasd_device_t *device   = cqr->device;

        int     i;
        char    *nl, 
                *end_cqr,
                *begin, 
                *end,
                buffer[80];
        
        /* dump sense data */
        if (device->discipline            && 
            device->discipline->dump_sense  ) {

                device->discipline->dump_sense (device, 
                                                cqr);
        }

        /* log the channel program */
        while (loop_cqr != NULL) {
                
                DEV_MESSAGE_LOG (KERN_ERR, device, 
                             "(%s) ERP chain report for req: %p",
                             caller == 0 ? "EXAMINE" : "ACTION",
                             loop_cqr);
                
                nl      = (char *) loop_cqr;
                end_cqr = nl + sizeof (ccw_req_t); 
                
                while (nl < end_cqr) {

                        sprintf (buffer,
                                 "%p: %02x%02x%02x%02x"
                                 " %02x%02x%02x%02x"
                                 " %02x%02x%02x%02x"
                                 " %02x%02x%02x%02x",
                                 nl,
                                 nl[0], nl[1], nl[2], nl[3],
                                 nl[4], nl[5], nl[6], nl[7],
                                 nl[8], nl[9], nl[10], nl[11],
                                 nl[12], nl[13], nl[14], nl[15]);
        
                        DEV_MESSAGE_LOG (KERN_ERR, device, "%s", 
                                     buffer);
                        nl +=16;
                }        
               	
		DEV_MESSAGE_LOG (KERN_ERR, device,
				"DATA area is at: %p",
				loop_cqr->data);
		nl      = (char *) loop_cqr->data;
		end_cqr = nl + loop_cqr->datasize;

                while (nl < end_cqr) {
					 
                        sprintf (buffer,
                                 "%p: %02x%02x%02x%02x"
                                 " %02x%02x%02x%02x"
                                 " %02x%02x%02x%02x"
                                 " %02x%02x%02x%02x",
                                  nl,
                                  nl[0], nl[1], nl[2], nl[3],
                                  nl[4], nl[5], nl[6], nl[7],
                                  nl[8], nl[9], nl[10], nl[11],
                                 nl[12], nl[13], nl[14], nl[15]);

                        DEV_MESSAGE_LOG (KERN_ERR, device, "%s",
                                     buffer);
                        nl +=16;
              }
	       	
                nl  = (char *) loop_cqr->cpaddr;
                
                if (loop_cqr->cplength > 40) { /* log only parts of the CP */

                        DEV_MESSAGE_LOG (KERN_ERR, device, "%s",
                                      "Start of channel program:");
                        
                        for (i = 0; i < 20; i += 2) { 
                                
                                sprintf (buffer,
                                         "%p: %02x%02x%02x%02x"
                                         " %02x%02x%02x%02x"
                                         " %02x%02x%02x%02x"
                                         " %02x%02x%02x%02x",
                                         nl,
                                         nl[0], nl[1], nl[2], nl[3],
                                         nl[4], nl[5], nl[6], nl[7],
                                         nl[8], nl[9], nl[10], nl[11],
                                         nl[12], nl[13], nl[14], nl[15]);
                                
                                DEV_MESSAGE_LOG (KERN_ERR, device, "%s",
                                             buffer);
                                nl += 16;
                        }
                        
                        DEV_MESSAGE_LOG (KERN_ERR, device, "%s",
                                     "End of channel program:");
                        
                        nl  = (char *) loop_cqr->cpaddr;
                        nl  += ((loop_cqr->cplength - 10) * 8);
                        
                        for (i = 0; i < 20; i += 2) { 
                                
                                sprintf (buffer,
                                         "%p: %02x%02x%02x%02x"
                                         " %02x%02x%02x%02x"
                                         " %02x%02x%02x%02x"
                                         " %02x%02x%02x%02x",
                                         nl,
                                         nl[0], nl[1], nl[2], nl[3],
                                         nl[4], nl[5], nl[6], nl[7],
                                         nl[8], nl[9], nl[10], nl[11],
                                         nl[12], nl[13], nl[14], nl[15]);
                                
                                DEV_MESSAGE_LOG (KERN_ERR, device, "%s",
                                             buffer);
                                nl += 16;
                        }
                        
                } else { /* log the whole CP */
                        
                        DEV_MESSAGE_LOG (KERN_ERR, device, "%s",
                                      "Channel program (complete):");
                        
                        for (i = 0; i < (loop_cqr->cplength + 4); i += 2) { 
                                
                                sprintf (buffer,
                                         "%p: %02x%02x%02x%02x"
                                         " %02x%02x%02x%02x"
                                         " %02x%02x%02x%02x"
                                         " %02x%02x%02x%02x",
                                         nl,
                                         nl[0], nl[1], nl[2], nl[3],
                                         nl[4], nl[5], nl[6], nl[7],
                                         nl[8], nl[9], nl[10], nl[11],
                                         nl[12], nl[13], nl[14], nl[15]);
                                
                                DEV_MESSAGE_LOG (KERN_ERR, device, "%s",
                                             buffer);
                                nl += 16;
                        }
                }

                /* log bytes arround failed CCW if not already done */ 
                begin = (char *) loop_cqr->cpaddr;
                end   = begin + ((loop_cqr->cplength+4) * 8);
                nl = (void *)(long)cpa;

                if (loop_cqr == cqr) {  /* log only once */
 
                        /* if not whole CP logged OR CCW outside logged CP */
                        if ((loop_cqr->cplength > 40) ||   
                            ((nl < begin        ) &&
                             (nl > end          )   )   ) {
                        
                                nl -= 10*8;     /* start some bytes before */
                                
                                DEV_MESSAGE_LOG (KERN_ERR, device, 
                                             "Failed CCW (%p) (area):",
                                             (void *)(long)cpa);
                                
                                for (i = 0; i < 20; i += 2) { 
                                        
                                        sprintf (buffer,
                                                 "%p: %02x%02x%02x%02x"
                                                 " %02x%02x%02x%02x"
                                                 " %02x%02x%02x%02x"
                                                 " %02x%02x%02x%02x",
                                                 nl,
                                                 nl[0], nl[1], nl[2], nl[3],
                                                 nl[4], nl[5], nl[6], nl[7],
                                                 nl[8], nl[9], nl[10], nl[11],
                                                 nl[12], nl[13], nl[14], nl[15]);

                                        DEV_MESSAGE_LOG (KERN_ERR, device, 
                                                         "%s", buffer);
                                        nl += 16;
                                }
                        } else {
                                DEV_MESSAGE_LOG (KERN_ERR, device, 
                                                 "Failed CCW (%p) already "
                                                 "logged",
                                             (void *)(long)cpa);
                        }
                }
                loop_cqr = loop_cqr->refers;
        }
} /* end log_erp_chain */

/*
 ***************************************************************************** 
 * SECTION ERP EXAMINATION
 ***************************************************************************** 
 */

/*
 * DASD_3990_ERP_EXAMINE_24 
 *
 * DESCRIPTION
 *   Checks only for fatal (unrecoverable) error. 
 *   A detailed examination of the sense data is done later outside
 *   the interrupt handler.
 *
 *   Each bit configuration leading to an action code 2 (Exit with
 *   programming error or unusual condition indication)
 *   are handled as fatal errorīs.
 * 
 *   All other configurations are handled as recoverable errors.
 *
 * RETURN VALUES
 *   dasd_era_fatal     for all fatal (unrecoverable errors)
 *   dasd_era_recover   for all others.
 */
dasd_era_t
dasd_3990_erp_examine_24 (ccw_req_t *cqr,
                          char      *sense)
{

        dasd_device_t *device = cqr->device;
        
	/* check for 'Command Reject' */
	if ((  sense[0] & SNS0_CMD_REJECT       ) &&
	    (!(sense[2] & SNS2_ENV_DATA_PRESENT))   ) {

                DEV_MESSAGE (KERN_ERR, device, "%s",
                             "EXAMINE 24: Command Reject detected - "
                             "fatal error");

                return dasd_era_fatal;
	}

	/* check for 'Invalid Track Format' */
	if ((  sense[1] & SNS1_INV_TRACK_FORMAT ) &&
            (!(sense[2] & SNS2_ENV_DATA_PRESENT))   ) {

                DEV_MESSAGE (KERN_ERR, device, "%s",
                             "EXAMINE 24: Invalid Track Format detected "
                             "- fatal error");

                return dasd_era_fatal;
	}

	/* check for 'No Record Found' */
	if (sense[1] & SNS1_NO_REC_FOUND) {
                
                DEV_MESSAGE (KERN_ERR, device,
                             "EXAMINE 24: No Record Found detected %s",
                             cqr == device->init_cqr ? " " :
                             "- fatal error");

                return dasd_era_fatal;
	}

	/* return recoverable for all others */
  	return dasd_era_recover;
} /* END dasd_3990_erp_examine_24 */

/*
 * DASD_3990_ERP_EXAMINE_32 
 *
 * DESCRIPTION
 *   Checks only for fatal/no/recoverable error. 
 *   A detailed examination of the sense data is done later outside
 *   the interrupt handler.
 *
 * RETURN VALUES
 *   dasd_era_none      no error 
 *   dasd_era_fatal     for all fatal (unrecoverable errors)
 *   dasd_era_recover   for recoverable others.
 */
dasd_era_t
dasd_3990_erp_examine_32 (ccw_req_t *cqr,
                          char      *sense)
{

        dasd_device_t *device = cqr->device;

	switch (sense[25]) {
	case 0x00:
		return dasd_era_none;

	case 0x01:
                DEV_MESSAGE (KERN_ERR, device, "%s",
                             "EXAMINE 32: fatal error");

		return dasd_era_fatal;

	default:

		return dasd_era_recover;
	}

} /* end dasd_3990_erp_examine_32 */

/*
 * DASD_3990_ERP_EXAMINE 
 *
 * DESCRIPTION
 *   Checks only for fatal/no/recover error. 
 *   A detailed examination of the sense data is done later outside
 *   the interrupt handler.
 *
 *   The logic is based on the 'IBM 3990 Storage Control  Reference' manual
 *   'Chapter 7. Error Recovery Procedures'.
 *
 * RETURN VALUES
 *   dasd_era_none      no error 
 *   dasd_era_fatal     for all fatal (unrecoverable errors)
 *   dasd_era_recover   for all others.
 */
dasd_era_t
dasd_3990_erp_examine (ccw_req_t *cqr, 
                       devstat_t *stat)
{

	char          *sense  = stat->ii.sense.data;
        dasd_era_t     era    = dasd_era_recover;
        dasd_device_t *device = cqr->device;

	/* check for successful execution first */
	if (stat->cstat == 0x00                                 &&
	    stat->dstat == (DEV_STAT_CHN_END | DEV_STAT_DEV_END)  )
		return dasd_era_none;

	/* distinguish between 24 and 32 byte sense data */
	if (sense[27] & DASD_SENSE_BIT_0) {

		era = dasd_3990_erp_examine_24 (cqr,
                                                sense);

	} else {

		era = dasd_3990_erp_examine_32 (cqr,
                                                sense);

	} 

        /* log the erp chain if fatal error occurred */
        if ((era == dasd_era_fatal  ) &&
            (cqr != device->init_cqr)   ){

                log_erp_chain (cqr, 
                               0, 
                               stat->cpa);
        }
        
        return era;

} /* END dasd_3990_erp_examine */

/*
 ***************************************************************************** 
 * SECTION ERP HANDLING
 ***************************************************************************** 
 */
/*
 ***************************************************************************** 
 * 24 and 32 byte sense ERP functions
 ***************************************************************************** 
 */

/*
 * DASD_3990_ERP_CLEANUP 
 *
 * DESCRIPTION
 *   Removes the already build but not neccessary ERP request and sets
 *   the status of the original cqr / erp to the given (final) status
 *
 *  PARAMETER
 *   erp                request to be blocked
 *   final_status       either CQR_STATUS_DONE or CQR_STATUS_FAILED 
 *
 * RETURN VALUES
 *   cqr                original cqr               
 */
ccw_req_t *
dasd_3990_erp_cleanup (ccw_req_t *erp,
                       char      final_status)
{

        ccw_req_t *cqr = erp->refers;
        
        dasd_free_request (erp, erp->device);

        check_then_set (&cqr->status,
                        CQR_STATUS_ERROR,
                        final_status);

        return cqr;

} /* end dasd_3990_erp_cleanup */ 

/*
 * DASD_3990_ERP_BLOCK_QUEUE 
 *
 * DESCRIPTION
 *   Block the given device request queue to prevent from further
 *   processing until the started timer has expired or an related
 *   interrupt was received.
 */
void
dasd_3990_erp_block_queue (ccw_req_t     *erp,
                           unsigned long expires)
{

	dasd_device_t *device = erp->device;

        DEV_MESSAGE (KERN_INFO, device,
                     "blocking request queue for %is",
                     (int) expires);

        device->stopped |= DASD_STOPPED_PENDING;

        check_then_set (&erp->status,
                        CQR_STATUS_ERROR,
                        CQR_STATUS_QUEUED);

        /* restart queue after some time */
        if (!timer_pending(&device->blocking_timer)) {
                init_timer(&device->blocking_timer);
                device->blocking_timer.function = dasd_3990_erp_restart_queue; 
                device->blocking_timer.data     = (unsigned long) device;
                device->blocking_timer.expires  = jiffies + (expires * HZ);
                add_timer(&device->blocking_timer); 
        } else {
                mod_timer(&device->blocking_timer, jiffies + (expires * HZ));
        }

} /* end dasd_3990_erp_block_queue */ 

/*
 * DASD_3990_ERP_RESTART_QUEUE 
 *
 * DESCRIPTION
 *   Restarts request queue of current device.
 *   This has to be done if either an related interrupt was received, or 
 *   the timer has expired.
 */
void
dasd_3990_erp_restart_queue (unsigned long device_ptr)
{

	dasd_device_t *device = (dasd_device_t *) device_ptr;
	unsigned long flags;
        
        /* get the needed locks to modify the request queue */
	s390irq_spin_lock_irqsave (device->devinfo.irq, 
                                   flags);

        /* 'restart' the device queue */
        DEV_MESSAGE (KERN_INFO, device, "%s",
                     "request queue restarted by MIH");

        device->stopped &= ~DASD_STOPPED_PENDING;

        s390irq_spin_unlock_irqrestore (device->devinfo.irq, 
                                        flags);
        dasd_schedule_bh (device);

} /* end dasd_3990_erp_restart_queue */

/*
 * DASD_3990_ERP_INT_REQ 
 *
 * DESCRIPTION
 *   Handles 'Intervention Required' error.
 *   This means either device offline or not installed.
 *
 * PARAMETER
 *   erp                current erp
 * RETURN VALUES
 *   erp                modified erp
 */
ccw_req_t *
dasd_3990_erp_int_req (ccw_req_t *erp)
{

	dasd_device_t *device = erp->device;

        /* first time set initial retry counter and erp_function */
        /* and retry once without blocking queue                 */
        /* (this enables easier enqueing of the cqr)             */
        if (erp->function != dasd_3990_erp_int_req) {

                erp->retries  = 256;
                erp->function = dasd_3990_erp_int_req;

        } else {

                /* issue a message and wait for 'device ready' interrupt */
                DEV_MESSAGE (KERN_ERR, device, "%s",
                             "is offline or not installed - "
                             "INTERVENTION REQUIRED!!");
                
                dasd_3990_erp_block_queue (erp,
                                           60);
        }

	return erp;

} /* end dasd_3990_erp_int_req */

/*
 * DASD_3990_ERP_ALTERNATE_PATH 
 *
 * DESCRIPTION
 *   Repeat the operation on a different channel path.
 *   If all alternate paths have been tried, the request is posted with a
 *   permanent error.
 *
 *  PARAMETER
 *   erp                pointer to the current ERP
 *
 * RETURN VALUES
 *   erp                modified pointer to the ERP
 *
 */
void
dasd_3990_erp_alternate_path (ccw_req_t *erp)
{

	dasd_device_t *device = erp->device;
        int irq = device->devinfo.irq;

        /* try alternate valid path */
        erp->lpm     &= ~(erp->dstat->lpum);
        erp->options |= DOIO_VALID_LPM;		/* use LPM for DO_IO */

	if ((erp->lpm & ioinfo[irq]->opm) != 0x00) {

		DEV_MESSAGE (KERN_DEBUG, device,
                             "try alternate lpm=%x (lpum=%x / opm=%x)",
                             erp->lpm,
                             erp->dstat->lpum,
                             ioinfo[irq]->opm);

		/* reset status to queued to handle the request again... */
		if (erp->status > CQR_STATUS_QUEUED)
                        erp->status = CQR_STATUS_QUEUED;

                erp->retries = 1;
                
	} else {
         
                DEV_MESSAGE (KERN_ERR, device,
                             "No alternate channel path left (lpum=%x / "
                             "opm=%x) -> permanent error",
                             erp->dstat->lpum,
                             ioinfo[irq]->opm);

                /* post request with permanent error */
		if (erp->status > CQR_STATUS_QUEUED)
                        erp->status = CQR_STATUS_FAILED;
        }
        
} /* end dasd_3990_erp_alternate_path */

/*
 * DASD_3990_ERP_DCTL
 *
 * DESCRIPTION
 *   Setup cqr to do the Diagnostic Control (DCTL) command with an 
 *   Inhibit Write subcommand (0x20) and the given modifier.
 *
 *  PARAMETER
 *   erp                pointer to the current (failed) ERP
 *   modifier           subcommand modifier
 *   
 * RETURN VALUES
 *   dctl_cqr           pointer to NEW dctl_cqr 
 *
 */
ccw_req_t *
dasd_3990_erp_DCTL (ccw_req_t *erp,
                    char      modifier)
{

	dasd_device_t *device = erp->device;
	DCTL_data_t   *DCTL_data;
        ccw1_t        *ccw;
        ccw_req_t     *dctl_cqr = dasd_alloc_request ((char *) &erp->magic,
                                                      1,
                                                      sizeof(DCTL_data_t),
                                                      erp->device);
        
	if (!dctl_cqr) {

                DEV_MESSAGE (KERN_ERR, device, "%s",
                             "Unable to allocate DCTL-CQR");
                
                check_then_set (&erp->status,
                                CQR_STATUS_ERROR,
                                CQR_STATUS_FAILED);

		return erp;
        }

	DCTL_data = dctl_cqr->data;

        DCTL_data->subcommand = 0x02; /* Inhibit Write */
        DCTL_data->modifier   = modifier;

	ccw = dctl_cqr->cpaddr;
	memset (ccw, 0, sizeof (ccw1_t));
        ccw->cmd_code = CCW_CMD_DCTL;
        ccw->count    = 4;
        if (dasd_set_normalized_cda(ccw, 
                                    __pa (DCTL_data), dctl_cqr, erp->device)) {
                dasd_free_request (dctl_cqr, erp->device);

                DEV_MESSAGE (KERN_ERR, device, "%s",
                             "Unable to allocate DCTL-CQR");

                check_then_set (&erp->status,
                                CQR_STATUS_ERROR,
                                CQR_STATUS_FAILED);
		return erp;
        }
        dctl_cqr->function = dasd_3990_erp_DCTL;
        dctl_cqr->refers   = erp;
        dctl_cqr->device   = erp->device;
        dctl_cqr->magic    = erp->magic;
        dctl_cqr->lpm      = LPM_ANYPATH;
        dctl_cqr->expires  = 5 * TOD_MIN;
        dctl_cqr->retries  = 2;

	dctl_cqr->buildclk = get_clock ();

        dctl_cqr->status = CQR_STATUS_FILLED;

	return dctl_cqr;

} /* end dasd_3990_erp_DCTL */

/*
 * DASD_3990_ERP_ACTION_1 
 *
 * DESCRIPTION
 *   Setup ERP to do the ERP action 1 (see Reference manual).
 *   Repeat the operation on a different channel path.
 *   If all alternate paths have been tried, the request is posted with a
 *   permanent error.
 *   Note: duplex handling is not implemented (yet).
 *
 *  PARAMETER
 *   erp                pointer to the current ERP
 *
 * RETURN VALUES
 *   erp                pointer to the ERP
 *
 */
ccw_req_t *
dasd_3990_erp_action_1 (ccw_req_t *erp)
{

        erp->function = dasd_3990_erp_action_1;

        dasd_3990_erp_alternate_path (erp);

	return erp;

} /* end dasd_3990_erp_action_1 */

/*
 * DASD_3990_ERP_ACTION_4 
 *
 * DESCRIPTION
 *   Setup ERP to do the ERP action 4 (see Reference manual).
 *   Set the current request to PENDING to block the CQR queue for that device
 *   until the state change interrupt appears.
 *   Use a timer (20 seconds) to retry the cqr if the interrupt is still missing.
 *
 *  PARAMETER
 *   sense              sense data of the actual error
 *   erp                pointer to the current ERP
 *
 * RETURN VALUES
 *   erp                pointer to the ERP
 *
 */
ccw_req_t *
dasd_3990_erp_action_4 (ccw_req_t *erp,
			char      *sense)
{

	dasd_device_t *device = erp->device;

        /* first time set initial retry counter and erp_function    */
        /* and retry once without waiting for state change pending  */
        /* interrupt (this enables easier enqueing of the cqr)      */
        if (erp->function != dasd_3990_erp_action_4) {

                erp->retries  = 256; 
                erp->function = dasd_3990_erp_action_4;

        } else {

                if (sense[25] == 0x1D) {	/* state change pending */
                        
                        DEV_MESSAGE (KERN_INFO, device,
                                     "waiting for state change pending "
                                     "interrupt, %d retries left",
                                     erp->retries);

                        dasd_3990_erp_block_queue (erp,
                                                   30);
                } else if (sense[25] == 0x1E) {	/* busy */
                        DEV_MESSAGE (KERN_INFO, device,
                                     "busy - redriving request later, "
                                     "%d retries left",
                                     erp->retries);
                        dasd_3990_erp_block_queue (erp, 1);
                } else {
			DEV_MESSAGE (KERN_INFO, device, 
                                     "redriving request immediately, "
                                     "%d retries left", 
                                     erp->retries);
                        /* no state change pending - retry */
                        check_then_set (&erp->status,
                                        CQR_STATUS_ERROR,
                                        CQR_STATUS_QUEUED);
                }
        }
	return erp;

} /* end dasd_3990_erp_action_4 */

/*
 ***************************************************************************** 
 * 24 byte sense ERP functions (only)
 ***************************************************************************** 
 */

/*
 * DASD_3990_ERP_ACTION_5 
 *
 * DESCRIPTION
 *   Setup ERP to do the ERP action 5 (see Reference manual).
 *   NOTE: Further handling is done in xxx_further_erp after the retries.
 *
 *  PARAMETER
 *   erp                pointer to the current ERP
 *
 * RETURN VALUES
 *   erp                pointer to the ERP
 *
 */
ccw_req_t *
dasd_3990_erp_action_5 (ccw_req_t *erp)
{

        /* first of all retry */
        erp->retries = 10;
        erp->function = dasd_3990_erp_action_5;

        return erp;

} /* end dasd_3990_erp_action_5 */

/*
 * DASD_3990_HANDLE_ENV_DATA
 *
 * DESCRIPTION
 *   Handles 24 byte 'Environmental data present'.
 *   Does a analysis of the sense data (message Format)
 *   and prints the error messages.
 *
 * PARAMETER
 *   sense              current sense data
 *   
 * RETURN VALUES
 *   void
 */
void
dasd_3990_handle_env_data (ccw_req_t *erp,
                           char      *sense)
{

        dasd_device_t *device = erp->device;
	char msg_format       = (sense[7] & 0xF0);
	char msg_no           = (sense[7] & 0x0F);
        

	switch (msg_format) {
	case 0x00:	/* Format 0 - Program or System Checks */

		if (sense[1] & 0x10) {	/* check message to operator bit */

			switch (msg_no) {
			case 0x00:	/* No Message */
				break;
			case 0x01:
                                DEV_MESSAGE (KERN_WARNING, device, "%s",
                                             "FORMAT 0 - Invalid Command");
				break;
			case 0x02:
                                DEV_MESSAGE (KERN_WARNING, device, "%s",
                                             "FORMAT 0 - Invalid Command "
                                             "Sequence");
				break;
			case 0x03:
                                DEV_MESSAGE (KERN_WARNING, device, "%s",
                                             "FORMAT 0 - CCW Count less than "
                                             "required");
				break;
			case 0x04:
                                DEV_MESSAGE (KERN_WARNING, device, "%s",
                                             "FORMAT 0 - Invalid Parameter");
				break;
			case 0x05:
                                DEV_MESSAGE (KERN_WARNING, device, "%s",
                                             "FORMAT 0 - Diagnostic of Sepecial"
                                             " Command Violates File Mask");
				break;
			case 0x07:
                                DEV_MESSAGE (KERN_WARNING, device, "%s",
                                             "FORMAT 0 - Channel Returned with "
                                             "Incorrect retry CCW");
				break;
			case 0x08:
                                DEV_MESSAGE (KERN_WARNING, device, "%s",
                                             "FORMAT 0 - Reset Notification");
				break;
			case 0x09:
                                DEV_MESSAGE (KERN_WARNING, device, "%s",
                                             "FORMAT 0 - Storage Path Restart");
				break;
			case 0x0A:
                                DEV_MESSAGE (KERN_WARNING, device,
                                             "FORMAT 0 - Channel requested "
                                             "... %02x",
                                             sense[8]);
				break;
			case 0x0B:
                                DEV_MESSAGE (KERN_WARNING, device, "%s",
                                             "FORMAT 0 - Invalid Defective/"
                                             "Alternate Track Pointer");
				break;
			case 0x0C:
                                DEV_MESSAGE (KERN_WARNING, device, "%s",
                                             "FORMAT 0 - DPS Installation "
                                             "Check");
				break;
			case 0x0E:
                                DEV_MESSAGE (KERN_WARNING, device, "%s",
                                             "FORMAT 0 - Command Invalid on "
                                             "Secondary Address");
				break;
			case 0x0F:
                                DEV_MESSAGE (KERN_WARNING, device,
                                             "FORMAT 0 - Status Not As "
                                             "Required: reason %02x",
                                             sense[8]);
				break;
			default:
                                DEV_MESSAGE (KERN_WARNING, device, "%s",
                                             "FORMAT 0 - Reseved");
			}
		} else {
			switch (msg_no) {
			case 0x00:	/* No Message */
				break;
			case 0x01:
                                DEV_MESSAGE (KERN_WARNING, device, "%s",
                                             "FORMAT 0 - Device Error Source");
				break;
			case 0x02:
                                DEV_MESSAGE (KERN_WARNING, device, "%s",
                                             "FORMAT 0 - Reserved");
				break;
			case 0x03:
                                DEV_MESSAGE (KERN_WARNING, device,
                                             "FORMAT 0 - Device Fenced - "
                                             "device = %02x",
                                             sense[4]);
				break;
			case 0x04:
                                DEV_MESSAGE (KERN_WARNING, device, "%s",
                                             "FORMAT 0 - Data Pinned for "
                                             "Device");
				break;
			default:
                                DEV_MESSAGE (KERN_WARNING, device, "%s",
                                             "FORMAT 0 - Reserved");
			}
                }
                break;
		
	case 0x10:	/* Format 1 - Device Equipment Checks */
		switch (msg_no) {
		case 0x00:	/* No Message */
			break;
		case 0x01:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 1 - Device Status 1 not as "
                                     "expected");
			break;
		case 0x03:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 1 - Index missing");
			break;
		case 0x04:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 1 - Interruption cannot be reset");
			break;
		case 0x05:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 1 - Device did not respond to "
                                     "selection");
			break;
		case 0x06:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 1 - Device check-2 error or Set "
                                     "Sector is not complete");
			break;
		case 0x07:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 1 - Head address does not "
                                     "compare");
			break;
		case 0x08:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 1 - Device status 1 not valid");
			break;
		case 0x09:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 1 - Device not ready");
			break;
		case 0x0A:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 1 - Track physical address did "
                                     "not compare");
			break;
		case 0x0B:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 1 - Missing device address bit");
			break;
		case 0x0C:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 1 - Drive motor switch is off");
			break;
		case 0x0D:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 1 - Seek incomplete");
			break;
		case 0x0E:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 1 - Cylinder address did not "
                                     "compare");
			break;
		case 0x0F:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 1 - Offset active cannot be "
                                     "reset");
			break;
		default:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 1 - Reserved");
		}
                break;		
                        
	case 0x20:	/* Format 2 - 3990 Equipment Checks */
		switch (msg_no) {
		case 0x08:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 2 - 3990 check-2 error");
			break;
		case 0x0E:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 2 - Support facility errors");
			break;
		case 0x0F:
                        DEV_MESSAGE (KERN_WARNING, device,
                                     "FORMAT 2 - Microcode detected error %02x",
                                     sense[8]);
			break;
		default:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 2 - Reserved");
		}
                break;		

	case 0x30:	/* Format 3 - 3990 Control Checks */
		switch (msg_no) {
		case 0x0F:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 3 - Allegiance terminated");
			break;
		default:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 3 - Reserved");
		}
                break;		

	case 0x40:	/* Format 4 - Data Checks */
		switch (msg_no) {
		case 0x00:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 4 - Home address area error");
			break;
		case 0x01:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 4 - Count area error");
			break;
		case 0x02:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 4 - Key area error");
			break;
		case 0x03:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 4 - Data area error");
			break;
		case 0x04:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 4 - No sync byte in home address "
                                      "area");
			break;
		case 0x05:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 4 - No sync byte in count address "
                                     "area");
			break;
		case 0x06:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 4 - No sync byte in key area");
			break;
		case 0x07:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 4 - No sync byte in data area");
			break;
		case 0x08:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 4 - Home address area error; "
                                     "offset active");
			break;
		case 0x09:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 4 - Count area error; offset "
                                     "active");
			break;
		case 0x0A:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 4 - Key area error; offset "
                                     "active");
			break;
		case 0x0B:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 4 - Data area error; "
                                     "offset active");
			break;
		case 0x0C:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 4 - No sync byte in home "
                                     "address area; offset active");
			break;
		case 0x0D:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 4 - No syn byte in count "
                                     "address area; offset active");
			break;
		case 0x0E:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 4 - No sync byte in key area; "
                                     "offset active");
			break;
		case 0x0F:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 4 - No syn byte in data area; "
                                     "offset active");
			break;
		default:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 4 - Reserved");
		}
                break;		

	case 0x50:	/* Format 5 - Data Check with displacement information */
		switch (msg_no) {
		case 0x00:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 5 - Data Check in the "
                                     "home address area");
			break;
		case 0x01:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 5 - Data Check in the count area");
			break;
		case 0x02:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 5 - Data Check in the key area");
			break;
		case 0x03:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 5 - Data Check in the data area");
			break;
		case 0x08:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 5 - Data Check in the "
                                     "home address area; offset active");
			break;
		case 0x09:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 5 - Data Check in the count area; "
                                     "offset active");
			break;
		case 0x0A:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 5 - Data Check in the key area; "
                                     "offset active");
			break;
		case 0x0B:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 5 - Data Check in the data area; "
                                     "offset active");
			break;
		default:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 5 - Reserved");
		}
                break;		

	case 0x60:	/* Format 6 - Usage Statistics/Overrun Errors */
		switch (msg_no) {
		case 0x00:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 6 - Overrun on channel A");
			break;
		case 0x01:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 6 - Overrun on channel B");
			break;
		case 0x02:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 6 - Overrun on channel C");
			break;
		case 0x03:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 6 - Overrun on channel D");
			break;
		case 0x04:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 6 - Overrun on channel E");
			break;
		case 0x05:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 6 - Overrun on channel F");
			break;
		case 0x06:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 6 - Overrun on channel G");
			break;
		case 0x07:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 6 - Overrun on channel H");
			break;
		default:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 6 - Reserved");
		}
                break;		

	case 0x70:	/* Format 7 - Device Connection Control Checks */
		switch (msg_no) {
		case 0x00:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 7 - RCC initiated by a connection "
                                     "check alert");
			break;
		case 0x01:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 7 - RCC 1 sequence not "
                                     "successful");
			break;
		case 0x02:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 7 - RCC 1 and RCC 2 sequences not "
                                     "successful");
			break;
		case 0x03:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 7 - Invalid tag-in during "
                                     "selection sequence");
			break;
		case 0x04:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 7 - extra RCC required");
			break;
		case 0x05:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 7 - Invalid DCC selection "
                                     "response or timeout");
			break;
		case 0x06:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 7 - Missing end operation; device "
                                     "transfer complete");
			break;
		case 0x07:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 7 - Missing end operation; device "
                                     "transfer incomplete");
			break;
		case 0x08:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 7 - Invalid tag-in for an "
                                     "immediate command sequence");
			break;
		case 0x09:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 7 - Invalid tag-in for an "
                                     "extended command sequence");
			break;
		case 0x0A:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 7 - 3990 microcode time out when "
                                     "stopping selection");
			break;
		case 0x0B:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 7 - No response to selection "
                                     "after a poll interruption");
			break;
		case 0x0C:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 7 - Permanent path error (DASD "
                                     "controller not available)");
			break;
		case 0x0D:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 7 - DASD controller not available"
                                     " on disconnected command chain");
			break;
		default:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 7 - Reserved");
		}
                break;		

	case 0x80:	/* Format 8 - Additional Device Equipment Checks */
		switch (msg_no) {
		case 0x00:	/* No Message */
		case 0x01:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 8 - Error correction code "
                                     "hardware fault");
			break;
		case 0x03:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 8 - Unexpected end operation "
                                     "response code");
			break;
		case 0x04:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 8 - End operation with transfer "
                                     "count not zero");
			break;
		case 0x05:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 8 - End operation with transfer "
                                     "count zero");
			break;
		case 0x06:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 8 - DPS checks after a system "
                                     "reset or selective reset");
			break;
		case 0x07:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 8 - DPS cannot be filled");
			break;
		case 0x08:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 8 - Short busy time-out during "
                                     "device selection");
			break;
		case 0x09:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 8 - DASD controller failed to "
                                     "set or reset the long busy latch");
			break;
		case 0x0A:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 8 - No interruption from device "
                                     "during a command chain");
			break;
		default:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 8 - Reserved");
		}
                break;		

	case 0x90:	/* Format 9 - Device Read, Write, and Seek Checks */
		switch (msg_no) {
		case 0x00:
			break;	/* No Message */
		case 0x06:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 9 - Device check-2 error");
			break;
		case 0x07:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 9 - Head address did not compare");
			break;
		case 0x0A:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 9 - Track physical address did "
                                     "not compare while oriented");
			break;
		case 0x0E:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 9 - Cylinder address did not "
                                     "compare");
			break;
		default:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT 9 - Reserved");
		}
                break;		

	case 0xF0:		/* Format F - Cache Storage Checks */
		switch (msg_no) {
		case 0x00:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT F - Operation Terminated");
			break;
		case 0x01:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT F - Subsystem Processing Error");
			break;
		case 0x02:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT F - Cache or nonvolatile storage "
                                     "equipment failure");
			break;
		case 0x04:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT F - Caching terminated");
			break;
		case 0x06:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT F - Cache fast write access not "
                                     "authorized");
			break;
		case 0x07:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT F - Track format incorrect");
			break;
		case 0x09:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT F - Caching reinitiated");
			break;
		case 0x0A:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT F - Nonvolatile storage "
                                     "terminated");
			break;
		case 0x0B:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT F - Volume is suspended duplex");
			break;
		case 0x0C:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT F - Subsystem status connot be "
                                     "determined");
			break;
		case 0x0D:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT F - Caching status reset to "
                                     "default");
			break;
		case 0x0E:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT F - DASD Fast Write inhibited");
			break;
		default:
                        DEV_MESSAGE (KERN_WARNING, device, "%s",
                                     "FORMAT D - Reserved");
		}
                break;		

	default:	/* unknown message format - should not happen */
                DEV_MESSAGE (KERN_WARNING, device,
                             "unknown message format %02x",
                             msg_format);
                
	} /* end switch message format */
        
} /* end dasd_3990_handle_env_data */

/*
 * DASD_3990_ERP_COM_REJ
 *
 * DESCRIPTION
 *   Handles 24 byte 'Command Reject' error.
 *
 * PARAMETER
 *   erp                current erp_head
 *   sense              current sense data
 * 
 * RETURN VALUES
 *   erp                'new' erp_head - pointer to new ERP 
 */
ccw_req_t *
dasd_3990_erp_com_rej (ccw_req_t *erp,
		       char      *sense)
{

	dasd_device_t *device = erp->device;

        erp->function = dasd_3990_erp_com_rej;

	/* env data present (ACTION 10 - retry should work) */
	if (sense[2] & SNS2_ENV_DATA_PRESENT) {

                DEV_MESSAGE (KERN_DEBUG, device, "%s",
                             "Command Reject - environmental data present");

		dasd_3990_handle_env_data (erp,
                                           sense);

		erp->retries = 5;

	} else {
		/* fatal error -  set status to FAILED */
                DEV_MESSAGE (KERN_ERR, device, "%s",
                             "Command Reject - Fatal error");

                erp = dasd_3990_erp_cleanup (erp,
                                             CQR_STATUS_FAILED);
	}

	return erp;

} /* end dasd_3990_erp_com_rej */

/*
 * DASD_3990_ERP_BUS_OUT 
 *
 * DESCRIPTION
 *   Handles 24 byte 'Bus Out Parity Check' error.
 *
 * PARAMETER
 *   erp                current erp_head
 * RETURN VALUES
 *   erp                new erp_head - pointer to new ERP
 */
ccw_req_t *
dasd_3990_erp_bus_out (ccw_req_t *erp)
{

	dasd_device_t *device = erp->device;

        /* first time set initial retry counter and erp_function */
        /* and retry once without blocking queue                 */
        /* (this enables easier enqueing of the cqr)             */
        if (erp->function != dasd_3990_erp_bus_out) {
                erp->retries  = 256;
                erp->function = dasd_3990_erp_bus_out;

        } else {

                /* issue a message and wait for 'device ready' interrupt */
                DEV_MESSAGE (KERN_DEBUG, device, "%s",
                             "bus out parity error or BOPC requested by "
                             "channel");
                
                dasd_3990_erp_block_queue (erp,
                                           60);
                
        }

	return erp;

} /* end dasd_3990_erp_bus_out */

/*
 * DASD_3990_ERP_EQUIP_CHECK
 *
 * DESCRIPTION
 *   Handles 24 byte 'Equipment Check' error.
 *
 * PARAMETER
 *   erp                current erp_head
 * RETURN VALUES
 *   erp                new erp_head - pointer to new ERP
 */
ccw_req_t *
dasd_3990_erp_equip_check (ccw_req_t *erp,
			   char      *sense)
{

	dasd_device_t *device = erp->device;

	erp->function = dasd_3990_erp_equip_check;

	if (sense[1] & SNS1_WRITE_INHIBITED) {

		DEV_MESSAGE (KERN_DEBUG, device, "%s",
                             "Write inhibited path encountered");

		/* vary path offline */
		DEV_MESSAGE (KERN_ERR, device, "%s",
                             "Path should be varied off-line. "
                             "This is not implemented yet \n - please report "
                             "to linux390@de.ibm.com");

		erp = dasd_3990_erp_action_1 (erp);

	} else if (sense[2] & SNS2_ENV_DATA_PRESENT) {
                
                DEV_MESSAGE (KERN_DEBUG, device, "%s",
                             "Equipment Check - "
                             "environmental data present");
                
                dasd_3990_handle_env_data (erp,
                                           sense);
                
                erp = dasd_3990_erp_action_4 (erp,
                                              sense);
                
        } else if (sense[1] & SNS1_PERM_ERR) {

                DEV_MESSAGE (KERN_DEBUG, device, "%s",
                             "Equipment Check - retry exhausted or "
                             "undesirable");
                
                erp = dasd_3990_erp_action_1 (erp);
                
        } else {
                /* all other equipment checks - Action 5 */
                /* rest is done when retries == 0 */
                DEV_MESSAGE (KERN_DEBUG, device, "%s",
                             "Equipment check or processing error");
                
                erp = dasd_3990_erp_action_5 (erp);
        }
        
        return erp;
        
} /* end dasd_3990_erp_equip_check */

/*
 * DASD_3990_ERP_DATA_CHECK
 *
 * DESCRIPTION
 *   Handles 24 byte 'Data Check' error.
 *
 * PARAMETER
 *   erp                current erp_head
 * RETURN VALUES
 *   erp                new erp_head - pointer to new ERP
 */
ccw_req_t *
dasd_3990_erp_data_check (ccw_req_t *erp,
			  char      *sense)
{

	dasd_device_t *device = erp->device;

	erp->function = dasd_3990_erp_data_check;

	if (sense[2] & SNS2_CORRECTABLE) {	/* correctable data check */

		/* issue message that the data has been corrected */
		DEV_MESSAGE (KERN_EMERG, device, "%s",
                             "Data recovered during retry with PCI "
                             "fetch mode active");

                /* not possible to handle this situation in Linux */    
                panic("No way to inform appliction about the possibly "
                      "incorret data");

	} else if (sense[2] & SNS2_ENV_DATA_PRESENT) {

		DEV_MESSAGE (KERN_DEBUG, device, "%s",
                             "Uncorrectable data check recovered secondary "
                             "addr of duplex pair");

		erp = dasd_3990_erp_action_4 (erp,
					      sense);

	} else if (sense[1] & SNS1_PERM_ERR) {

		DEV_MESSAGE (KERN_DEBUG, device, "%s",
                             "Uncorrectable data check with internal "
                             "retry exhausted");

		erp = dasd_3990_erp_action_1 (erp);

	} else {
		/* all other data checks */
		DEV_MESSAGE (KERN_DEBUG, device, "%s",
                             "Uncorrectable data check with retry count "
                             "exhausted...");

		erp = dasd_3990_erp_action_5 (erp);
	}

	return erp;

} /* end dasd_3990_erp_data_check */

/*
 * DASD_3990_ERP_OVERRUN
 *
 * DESCRIPTION
 *   Handles 24 byte 'Overrun' error.
 *
 * PARAMETER
 *   erp                current erp_head
 * RETURN VALUES
 *   erp                new erp_head - pointer to new ERP
 */
ccw_req_t *
dasd_3990_erp_overrun (ccw_req_t *erp,
		       char      *sense)
{

	dasd_device_t *device = erp->device;

	erp->function = dasd_3990_erp_overrun;

        DEV_MESSAGE (KERN_DEBUG, device, "%s",
                     "Overrun - service overrun or overrun"
                     " error requested by channel");

        erp = dasd_3990_erp_action_5 (erp);

	return erp;

} /* end dasd_3990_erp_overrun */

/*
 * DASD_3990_ERP_INV_FORMAT
 *
 * DESCRIPTION
 *   Handles 24 byte 'Invalid Track Format' error.
 *
 * PARAMETER
 *   erp                current erp_head
 * RETURN VALUES
 *   erp                new erp_head - pointer to new ERP
 */
ccw_req_t *
dasd_3990_erp_inv_format (ccw_req_t *erp,
			  char      *sense)
{

	dasd_device_t *device = erp->device;

	erp->function = dasd_3990_erp_inv_format;

	if (sense[2] & SNS2_ENV_DATA_PRESENT) {

		DEV_MESSAGE (KERN_DEBUG, device, "%s",
                             "Track format error when destaging or "
                             "staging data");

		dasd_3990_handle_env_data (erp,
                                           sense);

		erp = dasd_3990_erp_action_4 (erp,
					      sense);

	} else {
		DEV_MESSAGE (KERN_ERR, device, "%s",
                             "Invalid Track Format - Fatal error should have "
                             "been handled within the interrupt handler");

                erp= dasd_3990_erp_cleanup (erp,
                                            CQR_STATUS_FAILED);
        }

	return erp;

} /* end dasd_3990_erp_inv_format */

/*
 * DASD_3990_ERP_EOC
 *
 * DESCRIPTION
 *   Handles 24 byte 'End-of-Cylinder' error.
 *
 * PARAMETER
 *   erp                already added default erp
 * RETURN VALUES
 *   erp                pointer to original (failed) cqr.
 */
ccw_req_t *
dasd_3990_erp_EOC (ccw_req_t *default_erp,
		   char      *sense)
{

	dasd_device_t *device = default_erp->device;

        DEV_MESSAGE (KERN_ERR, device, "%s",
                     "End-of-Cylinder - must never happen");

        /* implement action 7 - BUG */
        return dasd_3990_erp_cleanup (default_erp,
                                      CQR_STATUS_FAILED);

} /* end dasd_3990_erp_EOC */

/*
 * DASD_3990_ERP_ENV_DATA
 *
 * DESCRIPTION
 *   Handles 24 byte 'Environmental-Data Present' error.
 *
 * PARAMETER
 *   erp                current erp_head
 * RETURN VALUES
 *   erp                new erp_head - pointer to new ERP
 */
ccw_req_t *
dasd_3990_erp_env_data (ccw_req_t *erp,
			char      *sense)
{

	dasd_device_t *device = erp->device;

	erp->function = dasd_3990_erp_env_data;

        DEV_MESSAGE (KERN_DEBUG, device, "%s",
                     "Environmental data present");

        dasd_3990_handle_env_data (erp,
                                   sense);

        /* don't retry on disabled interface */
        if (sense[7] != 0x0F) {

                erp = dasd_3990_erp_action_4 (erp,
                                              sense);
        } else {

                erp = dasd_3990_erp_cleanup (erp,
                                             CQR_STATUS_IN_IO);
        }

	return erp;

} /* end dasd_3990_erp_env_data */

/*
 * DASD_3990_ERP_NO_REC
 *
 * DESCRIPTION
 *   Handles 24 byte 'No Record Found' error.
 *
 * PARAMETER
 *   erp                already added default ERP
 *              
 * RETURN VALUES
 *   erp                new erp_head - pointer to new ERP
 */
ccw_req_t *
dasd_3990_erp_no_rec (ccw_req_t *default_erp,
		      char      *sense)
{

	dasd_device_t *device = default_erp->device;

        DEV_MESSAGE (KERN_ERR, device, "%s",
                     "No Record Found - Fatal error should "
                     "have been handled within the interrupt handler");

        return dasd_3990_erp_cleanup (default_erp,
                                      CQR_STATUS_FAILED);

} /* end dasd_3990_erp_no_rec */

/*
 * DASD_3990_ERP_FILE_PROT
 *
 * DESCRIPTION
 *   Handles 24 byte 'File Protected' error.
 *   Note: Seek related recovery is not implemented because
 *         wee don't use the seek command yet.
 *
 * PARAMETER
 *   erp                current erp_head
 * RETURN VALUES
 *   erp                new erp_head - pointer to new ERP
 */
ccw_req_t *
dasd_3990_erp_file_prot (ccw_req_t *erp)
{

	dasd_device_t *device = erp->device;

        DEV_MESSAGE (KERN_ERR, device, "%s",
                     "File Protected");

        return dasd_3990_erp_cleanup (erp,
                                      CQR_STATUS_FAILED);

} /* end dasd_3990_erp_file_prot */

/*
 * DASD_3990_ERP_INSPECT_24 
 *
 * DESCRIPTION
 *   Does a detailed inspection of the 24 byte sense data
 *   and sets up a related error recovery action.  
 *
 * PARAMETER
 *   sense              sense data of the actual error
 *   erp                pointer to the currently created default ERP
 *
 * RETURN VALUES
 *   erp                pointer to the (addtitional) ERP
 */
ccw_req_t *
dasd_3990_erp_inspect_24 (ccw_req_t *erp,
                          char      *sense)
{

	ccw_req_t *erp_filled = NULL;

	/* Check sense for ....    */
	/* 'Command Reject'        */
	if ((erp_filled == NULL) &&
	    (sense[0] & SNS0_CMD_REJECT)) {
		erp_filled = dasd_3990_erp_com_rej (erp,
						    sense);
	}
	/* 'Intervention Required' */
	if ((erp_filled == NULL) &&
	    (sense[0] & SNS0_INTERVENTION_REQ)) {
		erp_filled = dasd_3990_erp_int_req (erp);
	}
	/* 'Bus Out Parity Check'  */
	if ((erp_filled == NULL) &&
	    (sense[0] & SNS0_BUS_OUT_CHECK)) {
		erp_filled = dasd_3990_erp_bus_out (erp);
	}
	/* 'Equipment Check'       */
	if ((erp_filled == NULL) &&
	    (sense[0] & SNS0_EQUIPMENT_CHECK)) {
		erp_filled = dasd_3990_erp_equip_check (erp,
							sense);
	}
	/* 'Data Check'            */
	if ((erp_filled == NULL) &&
	    (sense[0] & SNS0_DATA_CHECK)) {
		erp_filled = dasd_3990_erp_data_check (erp,
						       sense);
	}
	/* 'Overrun'               */
	if ((erp_filled == NULL) &&
	    (sense[0] & SNS0_OVERRUN)) {
		erp_filled = dasd_3990_erp_overrun (erp,
						    sense);
	}
	/* 'Invalid Track Format'  */
	if ((erp_filled == NULL) &&
	    (sense[1] & SNS1_INV_TRACK_FORMAT)) {
		erp_filled = dasd_3990_erp_inv_format (erp,
						       sense);
	}
	/* 'End-of-Cylinder'       */
	if ((erp_filled == NULL) &&
	    (sense[1] & SNS1_EOC)) {
		erp_filled = dasd_3990_erp_EOC (erp,
						sense);
	}
	/* 'Environmental Data'    */
	if ((erp_filled == NULL) &&
	    (sense[2] & SNS2_ENV_DATA_PRESENT)) {
		erp_filled = dasd_3990_erp_env_data (erp,
						     sense);
	}
	/* 'No Record Found'       */
	if ((erp_filled == NULL) &&
	    (sense[1] & SNS1_NO_REC_FOUND)) {
		erp_filled = dasd_3990_erp_no_rec (erp,
						   sense);
	}
	/* 'File Protected'        */
	if ((erp_filled == NULL) &&
	    (sense[1] & SNS1_FILE_PROTECTED)) {
		erp_filled = dasd_3990_erp_file_prot (erp);
	}
	/* other (unknown) error - do default ERP */
	if (erp_filled == NULL) {

		erp_filled = erp;	
	}

	return erp_filled;

} /* END dasd_3990_erp_inspect_24 */

/*
 ***************************************************************************** 
 * 32 byte sense ERP functions (only)
 ***************************************************************************** 
 */

/*
 * DASD_3990_ERPACTION_10_32 
 *
 * DESCRIPTION
 *   Handles 32 byte 'Action 10' of Single Program Action Codes.
 *   Just retry and if retry doesn't work, return with error.
 *
 * PARAMETER
 *   erp                current erp_head
 *   sense              current sense data 
 * RETURN VALUES
 *   erp                modified erp_head
 */
ccw_req_t *
dasd_3990_erp_action_10_32 (ccw_req_t *erp,
                            char      *sense)
{

	dasd_device_t *device = erp->device;

        erp->retries  = 256;
        erp->function = dasd_3990_erp_action_10_32;

	DEV_MESSAGE (KERN_DEBUG, device, "%s",
                     "Perform logging requested");

	return erp;

} /* end dasd_3990_erp_action_10_32 */

/*
 * DASD_3990_ERP_ACTION_1B_32
 *
 * DESCRIPTION
 *   Handles 32 byte 'Action 1B' of Single Program Action Codes.
 *   A write operation could not be finished because of an unexpected 
 *   condition.
 *   The already created 'default erp' is used to get the link to 
 *   the erp chain, but it can not be used for this recovery 
 *   action because it contains no DE/LO data space.
 *
 * PARAMETER
 *   default_erp        already added default erp.
 *   sense              current sense data 
 *
 * RETURN VALUES
 *   erp                new erp or 
 *                      default_erp in case of imprecise ending or error
 */
ccw_req_t *
dasd_3990_erp_action_1B_32 (ccw_req_t *default_erp,
                            char      *sense)
{

	dasd_device_t  *device = default_erp->device;
        __u32          cpa     = 0;
        ccw_req_t      *cqr;
	ccw_req_t      *erp;
	DE_eckd_data_t *DE_data;
	char           *LO_data;   /* LO_eckd_data_t */
        ccw1_t         *ccw;

	DEV_MESSAGE (KERN_DEBUG, device, "%s",
                     "Write not finished because of unexpected condition");
        
        default_erp->function = dasd_3990_erp_action_1B_32;

        /* determine the original cqr */
        cqr = default_erp; 

        while (cqr->refers != NULL){
                cqr = cqr->refers;
        }

        /* for imprecise ending just do default erp */
        if (sense[1] & 0x01) {

                DEV_MESSAGE (KERN_DEBUG, device, "%s",
                             "Imprecise ending is set - just retry");

                return default_erp;
        } 
         
        /* determine the address of the CCW to be restarted */
        /* Imprecise ending is not set -> addr from IRB-SCSW */
        cpa = default_erp->refers->dstat->cpa;    
        
        if (cpa == 0) {
                
                DEV_MESSAGE (KERN_DEBUG, device, "%s",
                             "Unable to determine address of the CCW "
                             "to be restarted");
                
                return dasd_3990_erp_cleanup (default_erp,
                                              CQR_STATUS_FAILED);
        }
        
	/* Build new ERP request including DE/LO */
	erp = dasd_alloc_request ((char *) &cqr->magic,
                                  2 + 1,                    /* DE/LO + TIC */
                                  sizeof (DE_eckd_data_t) +
                                  sizeof (LO_eckd_data_t),
                                  device);

	if (!erp) {

                DEV_MESSAGE (KERN_ERR, device, "%s",
                             "Unable to allocate ERP");
                
                return dasd_3990_erp_cleanup (default_erp,
                                              CQR_STATUS_FAILED);
	}
        
        /* use original DE */
	DE_data = erp->data;
        memcpy (DE_data, 
                cqr->data, 
                sizeof (DE_eckd_data_t));
        
        /* create LO */
	LO_data = erp->data + sizeof (DE_eckd_data_t);
        
        if ((sense[3]  == 0x01) &&
            (LO_data[1] & 0x01)   ){

                DEV_MESSAGE (KERN_ERR, device, "%s",
                             "BUG - this should not happen");

                return dasd_3990_erp_cleanup (default_erp,
                                              CQR_STATUS_FAILED);
        }

        if ((sense[7] & 0x3F) == 0x01) {
                /* operation code is WRITE DATA -> data area orientation */
                LO_data[0] = 0x81;

        } else if ((sense[7] & 0x3F) == 0x03) {
                /* operation code is FORMAT WRITE -> index orientation */
                LO_data[0] = 0xC3;

        } else {
                LO_data[0] = sense[7];  /* operation */
        }

        LO_data[1] = sense[8];  /* auxiliary */
        LO_data[2] = sense[9];  
        LO_data[3] = sense[3];  /* count */ 
        LO_data[4] = sense[29]; /* seek_addr.cyl */
        LO_data[5] = sense[30]; /* seek_addr.cyl 2nd byte */
        LO_data[7] = sense[31]; /* seek_addr.head 2nd byte */  

        memcpy (&(LO_data[8]), &(sense[11]), 8);   

        /* create DE ccw */    
        ccw = erp->cpaddr;
	memset (ccw, 0, sizeof (ccw1_t));
	ccw->cmd_code = DASD_ECKD_CCW_DEFINE_EXTENT;
	ccw->flags    = CCW_FLAG_CC;
	ccw->count    = 16;
	if (dasd_set_normalized_cda (ccw,
                                     __pa (DE_data), erp, device)) {
                dasd_free_request (erp, device);
                DEV_MESSAGE (KERN_ERR, device, "%s",
                             "Unable to allocate ERP");

                return dasd_3990_erp_cleanup (default_erp,
                                              CQR_STATUS_FAILED);
        }

        /* create LO ccw */    
        ccw++;
	memset (ccw, 0, sizeof (ccw1_t));
	ccw->cmd_code = DASD_ECKD_CCW_LOCATE_RECORD;
	ccw->flags    = CCW_FLAG_CC;
	ccw->count    = 16;
	if (dasd_set_normalized_cda (ccw, 
                                     __pa (LO_data), erp, device)){
                dasd_free_request (erp, device);
                DEV_MESSAGE (KERN_ERR, device, "%s",
                             "Unable to allocate ERP");
                
                return dasd_3990_erp_cleanup (default_erp,
                                              CQR_STATUS_FAILED);
        }
        
        /* TIC to the failed ccw */
        ccw++;
	ccw->cmd_code = CCW_CMD_TIC;
	ccw->cda      = cpa;

        /* fill erp related fields */
        erp->function = dasd_3990_erp_action_1B_32;
	erp->refers   = default_erp->refers;
	erp->device   = device;
	erp->magic    = default_erp->magic;
	erp->lpm      = 0xFF;
	erp->expires  = 0;
	erp->retries  = 256;
	erp->status   = CQR_STATUS_FILLED;
        
        /* remove the default erp */
        dasd_free_request (default_erp, device);
        
	return erp;
        
} /* end dasd_3990_erp_action_1B_32 */

/*
 * DASD_3990_UPDATE_1B
 *
 * DESCRIPTION
 *   Handles the update to the 32 byte 'Action 1B' of Single Program 
 *   Action Codes in case the first action was not successful.
 *   The already created 'previous_erp' is the currently not successful
 *   ERP. 
 *
 * PARAMETER
 *   previous_erp       already created previous erp.
 *   sense              current sense data 
 * RETURN VALUES
 *   erp                modified erp 
 */
ccw_req_t *
dasd_3990_update_1B (ccw_req_t *previous_erp,
                     char      *sense)
{

	dasd_device_t  *device = previous_erp->device;
        __u32          cpa     = 0;
        ccw_req_t      *cqr;
	ccw_req_t      *erp;
	char           *LO_data;   /* LO_eckd_data_t */
        ccw1_t         *ccw;

	DEV_MESSAGE (KERN_DEBUG, device, "%s",
                     "Write not finished because of unexpected condition"
                     " - follow on");
        
        /* determine the original cqr */
        cqr = previous_erp;

        while (cqr->refers != NULL){
                cqr = cqr->refers;
        }
         
        /* for imprecise ending just do default erp */
        if (sense[1] & 0x01) {

                DEV_MESSAGE (KERN_DEBUG, device, "%s",
                             "Imprecise ending is set - just retry");

                check_then_set (&previous_erp->status,
                                CQR_STATUS_ERROR,
                                CQR_STATUS_QUEUED);

                return previous_erp;
        } 
         
        /* determine the address of the CCW to be restarted */
        /* Imprecise ending is not set -> addr from IRB-SCSW */
        cpa = previous_erp->dstat->cpa;    
        
        if (cpa == 0) {
                
                DEV_MESSAGE (KERN_DEBUG, device, "%s",
                             "Unable to determine address of the CCW "
                             "to be restarted");
                
                check_then_set (&previous_erp->status,
                                CQR_STATUS_ERROR,
                                CQR_STATUS_FAILED);
                
                return previous_erp;
        }
        
        erp = previous_erp;

	/* update the LO with the new returned sense data  */
	LO_data = erp->data + sizeof (DE_eckd_data_t);
        
        if ((sense[3]  == 0x01) &&
            (LO_data[1] & 0x01)   ){

                DEV_MESSAGE (KERN_ERR, device, "%s",
                             "BUG - this should not happen");

                check_then_set (&previous_erp->status,
                                CQR_STATUS_ERROR,
                                CQR_STATUS_FAILED);
                
                return previous_erp;
        }

        if ((sense[7] & 0x3F) == 0x01) {
                /* operation code is WRITE DATA -> data area orientation */
                LO_data[0] = 0x81;

        } else if ((sense[7] & 0x3F) == 0x03) {
                /* operation code is FORMAT WRITE -> index orientation */
                LO_data[0] = 0xC3;

        } else {
                LO_data[0] = sense[7];  /* operation */
        }

        LO_data[1] = sense[8];  /* auxiliary */
        LO_data[2] = sense[9];  
        LO_data[3] = sense[3];  /* count */ 
        LO_data[4] = sense[29]; /* seek_addr.cyl */
        LO_data[5] = sense[30]; /* seek_addr.cyl 2nd byte */
        LO_data[7] = sense[31]; /* seek_addr.head 2nd byte */  

        memcpy (&(LO_data[8]), &(sense[11]), 8);   

        /* TIC to the failed ccw */
        ccw = erp->cpaddr;  /* addr of DE ccw */
        ccw++;              /* addr of LE ccw */
        ccw++;              /* addr of TIC ccw */ 
	ccw->cda = cpa;

	check_then_set (&erp->status,
                        CQR_STATUS_ERROR,
                        CQR_STATUS_QUEUED);
        
	return erp;
        
} /* end dasd_3990_update_1B */

/*
 * DASD_3990_ERP_COMPOUND_RETRY 
 *
 * DESCRIPTION
 *   Handles the compound ERP action retry code.
 *   NOTE: At least one retry is done even if zero is specified
 *         by the sense data. This makes enqueueing of the request
 *         easier.
 *
 * PARAMETER
 *   sense              sense data of the actual error
 *   erp                pointer to the currently created ERP
 *
 * RETURN VALUES
 *   erp                modified ERP pointer
 *
 */
void
dasd_3990_erp_compound_retry (ccw_req_t *erp,
                              char      *sense)
{

        switch (sense[25] & 0x03) { 
        case 0x00:	/* no not retry */
                erp->retries = 1; 
                break;            
                
        case 0x01:	/* retry 2 times */
                erp->retries = 2;
                break;
                
        case 0x02:	/* retry 10 times */
                erp->retries = 10;
                break;
                
        case 0x03:	/* retry 256 times */
                erp->retries = 256;
                break;
                
        default:
                BUG();
        }
        
        erp->function = dasd_3990_erp_compound_retry;
        
} /* end dasd_3990_erp_compound_retry */

/*
 * DASD_3990_ERP_COMPOUND_PATH 
 *
 * DESCRIPTION
 *   Handles the compound ERP action for retry on alternate
 *   channel path.
 *
 * PARAMETER
 *   sense              sense data of the actual error
 *   erp                pointer to the currently created ERP
 *
 * RETURN VALUES
 *   erp                modified ERP pointer
 *
 */
void
dasd_3990_erp_compound_path (ccw_req_t *erp,
                             char      *sense)
{
        
        if (sense[25] & DASD_SENSE_BIT_3) {
                dasd_3990_erp_alternate_path (erp);
                
                if (erp->status == CQR_STATUS_FAILED) {
                        /* reset the lpm and the status to be able to 
                         * try further actions. */
                        
                        erp->lpm = LPM_ANYPATH;
                        
                        check_then_set (&erp->status,
                                        CQR_STATUS_FAILED,
                                        CQR_STATUS_ERROR);
                        
                }
        }
        
        erp->function = dasd_3990_erp_compound_path;

} /* end dasd_3990_erp_compound_path */

/*
 * DASD_3990_ERP_COMPOUND_CODE 
 *
 * DESCRIPTION
 *   Handles the compound ERP action for retry code.
 *
 * PARAMETER
 *   sense              sense data of the actual error
 *   erp                pointer to the currently created ERP
 *
 * RETURN VALUES
 *   erp                NEW ERP pointer
 *
 */
ccw_req_t *
dasd_3990_erp_compound_code (ccw_req_t *erp,
                             char      *sense)
{
        
        if (sense[25] & DASD_SENSE_BIT_2) {

                switch (sense[28]) {
                case 0x17:
                        /* issue a Diagnostic Control command with an 
                         * Inhibit Write subcommand and controler modifier */
                        erp = dasd_3990_erp_DCTL (erp,
                                                  0x20);
                        break;
                        
                case 0x25:
                        /* wait for 5 seconds and retry again */
                        erp->retries = 1;
                        
                        dasd_3990_erp_block_queue (erp,
                                                   5);
                        break;
                        
                default:
                        ; /* should not happen - continue */

                }
        }

        erp->function = dasd_3990_erp_compound_code;

        return erp;

} /* end dasd_3990_erp_compound_code */

/*
 * DASD_3990_ERP_COMPOUND_CONFIG 
 *
 * DESCRIPTION
 *   Handles the compound ERP action for configruation
 *   dependent error.
 *   Note: duplex handling is not implemented (yet).
 *
 * PARAMETER
 *   sense              sense data of the actual error
 *   erp                pointer to the currently created ERP
 *
 * RETURN VALUES
 *   erp                modified ERP pointer
 *
 */
void
dasd_3990_erp_compound_config (ccw_req_t *erp,
                               char      *sense)
{

        if ((sense[25] & DASD_SENSE_BIT_1) && 
            (sense[26] & DASD_SENSE_BIT_2)   ) {	

                /* set to suspended duplex state then restart */
                dasd_device_t *device  = erp->device;

                DEV_MESSAGE (KERN_ERR, device, "%s",      
                             "Set device to suspended duplex state should be "
                             "done!\n"
                             "This is not implemented yet (for compound ERP)"
                             " - please report to linux390@de.ibm.com");
                
        }

        erp->function = dasd_3990_erp_compound_config;

} /* end dasd_3990_erp_compound_config */

/*
 * DASD_3990_ERP_COMPOUND 
 *
 * DESCRIPTION
 *   Does the further compound program action if 
 *   compound retry was not successful.
 *
 * PARAMETER
 *   sense              sense data of the actual error
 *   erp                pointer to the current (failed) ERP
 *
 * RETURN VALUES
 *   erp                (additional) ERP pointer
 *
 */
ccw_req_t *
dasd_3990_erp_compound (ccw_req_t *erp,
                        char      *sense)
{

        if ((erp->function == dasd_3990_erp_compound_retry) &&
            (erp->status   == CQR_STATUS_ERROR            )   ) {
                
                dasd_3990_erp_compound_path (erp,
                                             sense);
        }

        if ((erp->function == dasd_3990_erp_compound_path) &&
            (erp->status   == CQR_STATUS_ERROR           )    ){

                erp = dasd_3990_erp_compound_code (erp,
                                                   sense);
        }

        if ((erp->function == dasd_3990_erp_compound_code) && 
            (erp->status   == CQR_STATUS_ERROR           )   ) {
                
                dasd_3990_erp_compound_config (erp,
                                               sense);
        }

        /* if no compound action ERP specified, the request failed */
        if (erp->status == CQR_STATUS_ERROR) {

                check_then_set (&erp->status,
                                CQR_STATUS_ERROR,
                                CQR_STATUS_FAILED);
        }

        return erp;
        
} /* end dasd_3990_erp_compound */

/*
 * DASD_3990_ERP_INSPECT_32 
 *
 * DESCRIPTION
 *   Does a detailed inspection of the 32 byte sense data
 *   and sets up a related error recovery action.  
 *
 * PARAMETER
 *   sense              sense data of the actual error
 *   erp                pointer to the currently created default ERP
 *
 * RETURN VALUES
 *   erp_filled         pointer to the ERP
 *
 */
ccw_req_t *
dasd_3990_erp_inspect_32 ( ccw_req_t *erp,
                           char      *sense )
{

	dasd_device_t *device = erp->device;

	erp->function = dasd_3990_erp_inspect_32;

	if (sense[25] & DASD_SENSE_BIT_0) {

		/* compound program action codes (byte25 bit 0 == '1') */
                dasd_3990_erp_compound_retry (erp,
                                              sense);

	} else {

		/* single program action codes (byte25 bit 0 == '0') */
		switch (sense[25]) {

		case 0x00:	/* success */
                        DEV_MESSAGE (KERN_DEBUG, device,
                                     "ERP called for successful request %p"
                                     " - NO ERP necessary",
                                     erp);
                        
                        erp = dasd_3990_erp_cleanup (erp,
                                                     CQR_STATUS_DONE);

                        break;
                        
		case 0x01:	/* fatal error */
                        DEV_MESSAGE (KERN_ERR, device, "%s",
                                     "Fatal error should have been "
                                     "handled within the interrupt handler");

                        erp = dasd_3990_erp_cleanup (erp,
                                                     CQR_STATUS_FAILED);
                        break;

		case 0x02:	/* intervention required */
		case 0x03:	/* intervention required during dual copy */
                        erp = dasd_3990_erp_int_req (erp);
                        break;

		case 0x0F:	/* length mismatch during update write command */
                        DEV_MESSAGE (KERN_ERR, device, "%s",
                                     "update write command error - should not "
                                     "happen;\n"
                                     "Please send this message together with "
                                     "the above sense data to linux390@de."
                                     "ibm.com");

                        erp = dasd_3990_erp_cleanup (erp,
                                                     CQR_STATUS_FAILED);
                        break;

		case 0x10:	/* logging required for other channel program */
                        erp = dasd_3990_erp_action_10_32 (erp,
                                                    sense);
                        break;

		case 0x15:	/* next track outside defined extend */
                        DEV_MESSAGE (KERN_ERR, device, "%s",
                                     "next track outside defined extend - "
                                     "should not happen;\n"
                                     "Please send this message together with "
                                     "the above sense data to linux390@de."
                                     "ibm.com");

                        erp= dasd_3990_erp_cleanup (erp,
                                                    CQR_STATUS_FAILED);
                        break;

		case 0x1B:	/* unexpected condition during write */

                        erp = dasd_3990_erp_action_1B_32 (erp,
                                                          sense);
                        break;

		case 0x1C:	/* invalid data */
                        DEV_MESSAGE (KERN_EMERG, device, "%s",
                                     "Data recovered during retry with PCI "
                                     "fetch mode active");
                        
                        /* not possible to handle this situation in Linux */    
                        panic("Invalid data - No way to inform application "
                              "about the possibly incorrect data");
			break;

		case 0x1D:	/* state-change pending */
                        DEV_MESSAGE (KERN_DEBUG, device, "%s",
                                     "A State change pending condition exists "
                                     "for the subsystem or device");

                        erp = dasd_3990_erp_action_4 (erp,
                                                      sense);
			break;

		case 0x1E:	/* busy */
                        DEV_MESSAGE (KERN_DEBUG, device, "%s",
                                     "Busy condition exists "
                                     "for the subsystem or device");
                        erp = dasd_3990_erp_action_4 (erp, sense);
			break;
		default:	
                        ;       /* all others errors - default erp  */
		}
	}

	return erp;

} /* end dasd_3990_erp_inspect_32 */

/*
 ***************************************************************************** 
 * main ERP control fuctions (24 and 32 byte sense)
 ***************************************************************************** 
 */

/*
 * DASD_3990_ERP_INSPECT
 *
 * DESCRIPTION
 *   Does a detailed inspection for sense data by calling either
 *   the 24-byte or the 32-byte inspection routine.
 *
 * PARAMETER
 *   erp                pointer to the currently created default ERP
 * RETURN VALUES
 *   erp_new            contens was possibly modified 
 */
ccw_req_t *
dasd_3990_erp_inspect (ccw_req_t *erp)
{

	ccw_req_t *erp_new = NULL;
	/* sense data are located in the refers record of the */
	/* already set up new ERP !                           */
	char *sense = erp->refers->dstat->ii.sense.data;

	/* distinguish between 24 and 32 byte sense data */
	if (sense[27] & DASD_SENSE_BIT_0) {

		/* inspect the 24 byte sense data */
		erp_new = dasd_3990_erp_inspect_24 (erp,
                                                    sense);

	} else {

		/* inspect the 32 byte sense data */
		erp_new = dasd_3990_erp_inspect_32 (erp,
                                                    sense);

	} /* end distinguish between 24 and 32 byte sense data */

	return erp_new;

} /* END dasd_3990_erp_inspect */

/*
 * DASD_3990_ERP_ADD_ERP
 * 
 * DESCRIPTION
 *   This funtion adds an additional request block (ERP) to the head of
 *   the given cqr (or erp).
 *   This erp is initialized as an default erp (retry TIC)
 *
 * PARAMETER
 *   cqr                head of the current ERP-chain (or single cqr if 
 *                      first error)
 * RETURN VALUES
 *   erp                pointer to new ERP-chain head
 */
ccw_req_t *
dasd_3990_erp_add_erp (ccw_req_t *cqr)
{

	dasd_device_t *device = cqr->device;
	ccw1_t *ccw;

	/* allocate additional request block */
	ccw_req_t *erp = dasd_alloc_request ((char *) &cqr->magic, 2, 0, cqr->device);

	if (!erp) {
                if (cqr->retries <= 0) {
                        DEV_MESSAGE (KERN_ERR, device, "%s",
                                     "Unable to allocate ERP request "
                                     "(NO retries left)");
                
                        check_then_set (&cqr->status,
                                        CQR_STATUS_ERROR,
                                        CQR_STATUS_FAILED);

                        cqr->stopclk = get_clock ();

                } else {
                        DEV_MESSAGE (KERN_ERR, device,
                                     "Unable to allocate ERP request "
                                     "(%i retries left)",
                                     cqr->retries);
                
                        if (!timer_pending(&device->timer)) {
                                init_timer (&device->timer);
                                device->timer.function = dasd_schedule_bh_timed;
                                device->timer.data     = (unsigned long) device;
                                device->timer.expires  = jiffies + (HZ << 3);
                                add_timer (&device->timer);
                        } else {
                                mod_timer(&device->timer, jiffies + (HZ << 3));
                        }
                }
                return cqr;
	}

	/* initialize request with default TIC to current ERP/CQR */
	ccw = erp->cpaddr;
	ccw->cmd_code = CCW_CMD_NOOP;
	ccw->flags = CCW_FLAG_CC;
	ccw++;
	ccw->cmd_code = CCW_CMD_TIC;
	ccw->cda      = (long)(cqr->cpaddr);
	erp->function = dasd_3990_erp_add_erp;
	erp->refers   = cqr;
	erp->device   = cqr->device;
	erp->magic    = cqr->magic;
	erp->lpm      = 0xFF;
	erp->expires  = 0;
	erp->retries  = 256;

	erp->status = CQR_STATUS_FILLED;

	return erp;
}

/*
 * DASD_3990_ERP_ADDITIONAL_ERP 
 * 
 * DESCRIPTION
 *   An additional ERP is needed to handle the current error.
 *   Add ERP to the head of the ERP-chain containing the ERP processing
 *   determined based on the sense data.
 *
 * PARAMETER
 *   cqr                head of the current ERP-chain (or single cqr if 
 *                      first error)
 *
 * RETURN VALUES
 *   erp                pointer to new ERP-chain head
 */
ccw_req_t *
dasd_3990_erp_additional_erp (ccw_req_t *cqr)
{

	ccw_req_t *erp = NULL;

	/* add erp and initialize with default TIC */
	erp = dasd_3990_erp_add_erp (cqr);

	/* inspect sense, determine specific ERP if possible */
        if (erp != cqr) {

                erp = dasd_3990_erp_inspect (erp);
        }

	return erp;

} /* end dasd_3990_erp_additional_erp */

/*
 * DASD_3990_ERP_ERROR_MATCH
 *
 * DESCRIPTION
 *   Check if the device status of the given cqr is the same.
 *   This means that the failed CCW and the relevant sense data
 *   must match.
 *   I don't distinguish between 24 and 32 byte sense because in case of
 *   24 byte sense byte 25 and 27 is set as well.
 *
 * PARAMETER
 *   cqr1               first cqr, which will be compared with the 
 *   cqr2               second cqr.
 *
 * RETURN VALUES
 *   match              'boolean' for match found
 *                      returns 1 if match found, otherwise 0.
 */
int
dasd_3990_erp_error_match (ccw_req_t *cqr1,
			   ccw_req_t *cqr2)
{

	/* check failed CCW */
	if (cqr1->dstat->cpa !=
	    cqr2->dstat->cpa) {
	//	return 0;	/* CCW doesn't match */
	}

	/* check sense data; byte 0-2,25,27 */
	if (!((memcmp (cqr1->dstat->ii.sense.data,
			cqr2->dstat->ii.sense.data,
			3) == 0) &&
	      (cqr1->dstat->ii.sense.data[27] ==
	       cqr2->dstat->ii.sense.data[27]   ) &&
	      (cqr1->dstat->ii.sense.data[25] ==
	       cqr2->dstat->ii.sense.data[25]   )   )) {

		return 0;	/* sense doesn't match */
	}

	return 1;		/* match */

} /* end dasd_3990_erp_error_match */

/*
 * DASD_3990_ERP_IN_ERP
 *
 * DESCRIPTION
 *   check if the current error already happened before.
 *   quick exit if current cqr is not an ERP (cqr->refers=NULL)
 *
 * PARAMETER
 *   cqr                failed cqr (either original cqr or already an erp)
 *
 * RETURN VALUES
 *   erp                erp-pointer to the already defined error 
 *                      recovery procedure OR
 *                      NULL if a 'new' error occurred.
 */
ccw_req_t *
dasd_3990_erp_in_erp (ccw_req_t *cqr)
{

	ccw_req_t *erp_head  = cqr,	/* save erp chain head */
                  *erp_match = NULL;	/* save erp chain head */
	int match = 0;		/* 'boolean' for matching error found */

	if (cqr->refers == NULL) {	/* return if not in erp */
		return NULL;
	}

	/* check the erp/cqr chain for current error */
	do {
		match = dasd_3990_erp_error_match (erp_head,
						   cqr->refers);
		erp_match = cqr;	 /* save possible matching erp  */
		cqr       = cqr->refers; /* check next erp/cqr in queue */

	} while ((cqr->refers != NULL) &&
		 (!match             )   );

	if (!match) {
		return NULL; 	/* no match was found */
	}

        return erp_match;	/* return address of matching erp */

} /* END dasd_3990_erp_in_erp */

/*
 * DASD_3990_ERP_FURTHER_ERP (24 & 32 byte sense)
 *
 * DESCRIPTION
 *   No retry is left for the current ERP. Check what has to be done 
 *   with the ERP.
 *     - do further defined ERP action or
 *     - wait for interrupt or  
 *     - exit with permanent error
 *
 * PARAMETER
 *   erp                ERP which is in progress wiht no retry left
 *
 * RETURN VALUES
 *   erp                modified/additional ERP
 */
ccw_req_t *
dasd_3990_erp_further_erp (ccw_req_t *erp)
{

        dasd_device_t *device = erp->device;
        char          *sense  = erp->dstat->ii.sense.data;
        
        /* check for 24 byte sense ERP */
	if ((erp->function == dasd_3990_erp_bus_out ) ||
            (erp->function == dasd_3990_erp_action_1) ||
            (erp->function == dasd_3990_erp_action_4)   ){
                
                erp = dasd_3990_erp_action_1 (erp);
                
	} else if (erp->function == dasd_3990_erp_action_5) {
                
                /* retries have not been successful */
                /* prepare erp for retry on different channel path */
                erp = dasd_3990_erp_action_1 (erp);
                
                if (!(sense[ 2] & DASD_SENSE_BIT_0)) {

                        /* issue a Diagnostic Control command with an 
                         * Inhibit Write subcommand */

                        switch (sense[25]) {
                        case 0x17:
                        case 0x57: { /* controller */
                                erp = dasd_3990_erp_DCTL (erp,
                                                          0x20);
                                break;
                        }
                        case 0x18:
                        case 0x58: { /* channel path */
                                erp = dasd_3990_erp_DCTL (erp,
                                                          0x40);
                                break;
                        }
                        case 0x19:
                        case 0x59: { /* storage director */
                                erp = dasd_3990_erp_DCTL (erp,
                                                          0x80);
                                break;
                        }
                        default:
                                DEV_MESSAGE (KERN_DEBUG, device,
                                             "invalid subcommand modifier 0x%x "
                                             "for Diagnostic Control Command",
                                             sense[25]);
                        }
                } 

        /* check for 32 byte sense ERP */
	} else if ((erp->function == dasd_3990_erp_compound_retry ) ||
                   (erp->function == dasd_3990_erp_compound_path  ) ||
                   (erp->function == dasd_3990_erp_compound_code  ) ||
                   (erp->function == dasd_3990_erp_compound_config)   ) {
                
                erp = dasd_3990_erp_compound (erp,
                                              sense);

	} else {
                /* no retry left and no additional special handling necessary */
                DEV_MESSAGE (KERN_ERR, device,
                             "no retries left for erp %p - "
                             "set status to FAILED",
                             erp);

		check_then_set (&erp->status,
                                CQR_STATUS_ERROR,
                                CQR_STATUS_FAILED);
	}

	return erp; 

} /* end dasd_3990_erp_further_erp */

/*
 * DASD_3990_ERP_HANDLE_MATCH_ERP 
 *
 * DESCRIPTION
 *   An error occurred again and an ERP has been detected which is already
 *   used to handle this error (e.g. retries). 
 *   All prior ERP's are asumed to be successful and therefore removed
 *   from queue.
 *   If retry counter of matching erp is already 0, it is checked if further 
 *   action is needed (besides retry) or if the ERP has failed.
 *
 * PARAMETER
 *   erp_head           first ERP in ERP-chain
 *   erp                ERP that handles the actual error.
 *                      (matching erp)
 *
 * RETURN VALUES
 *   erp                modified/additional ERP
 */
ccw_req_t *
dasd_3990_erp_handle_match_erp (ccw_req_t *erp_head,
				ccw_req_t *erp)
{

	dasd_device_t *device   = erp_head->device;
	ccw_req_t     *erp_done = erp_head;  /* finished req */
        ccw_req_t     *erp_free = NULL;      /* req to be freed */    
        
	/* loop over successful ERPs and remove them from chanq */
	while (erp_done != erp) {

                if (erp_done == NULL) 	/* end of chain reached */
                        panic (PRINTK_HEADER "Programming error in ERP! The "
                               "original request was lost\n");

		/* remove the request from the device queue */
		dasd_chanq_deq (&device->queue,
				erp_done);
                
                erp_free = erp_done;
		erp_done = erp_done->refers;
                
		/* free the finished erp request */
		dasd_free_request (erp_free, erp_free->device);

	} /* end while */

        if (erp->retries > 0) {
                
                char *sense = erp->refers->dstat->ii.sense.data;
                
                /* check for special retries */
                if (erp->function == dasd_3990_erp_action_4) {
                        
                        erp = dasd_3990_erp_action_4 (erp,
                                                      sense);
                        
                } else if (erp->function == dasd_3990_erp_action_1B_32) {
                        
                        erp = dasd_3990_update_1B (erp,
                                                   sense);

                } else if (erp->function == dasd_3990_erp_int_req) {

                        erp = dasd_3990_erp_int_req (erp);
                        
                } else {
                        /* simple retry   */
                        DEV_MESSAGE (KERN_DEBUG, device,
                                     "%i retries left for erp %p",
                                     erp->retries,
                                     erp);
                        
                        /* handle the request again... */
                        check_then_set (&erp->status,
                                        CQR_STATUS_ERROR,
                                        CQR_STATUS_QUEUED);
                }
                
        } else {
                /* no retry left - check for further necessary action    */
                /* if no further actions, handle rest as permanent error */
                erp = dasd_3990_erp_further_erp (erp);
	}

        return erp;
        
} /* end dasd_3990_erp_handle_match_erp */

/*
 * DASD_3990_ERP_ACTION
 *
 * DESCRIPTION
 *   controll routine for 3990 erp actions.
 *   Has to be called with the queue lock (namely the s390_irq_lock) acquired.
 *
 * PARAMETER
 *   cqr                failed cqr (either original cqr or already an erp)
 *
 * RETURN VALUES
 *   erp                erp-pointer to the head of the ERP action chain.
 *                      This means:
 *                       - either a ptr to an additional ERP cqr or
 *                       - the original given cqr (which's status might 
 *                         be modified)
 */
ccw_req_t *
dasd_3990_erp_action (ccw_req_t *cqr)
{

	ccw_req_t     *erp    = NULL;
	dasd_device_t *device = cqr->device;
        __u32         cpa     = cqr->dstat->cpa;    

#ifdef ERP_DEBUG 
	/* print current erp_chain */
        DEV_MESSAGE (KERN_DEBUG, device, "%s",
                     "ERP chain at BEGINNING of ERP-ACTION");
        {
                ccw_req_t *temp_erp = NULL;

                for (temp_erp = cqr; 
                     temp_erp != NULL; 
                     temp_erp = temp_erp->refers){

                        DEV_MESSAGE (KERN_DEBUG, device,
                                     "      erp %p refers to %p",
                                     temp_erp,
                                     temp_erp->refers);
                }
        } 
#endif /* ERP_DEBUG */

	/* double-check if current erp/cqr was successfull */
	if ((cqr->dstat->cstat == 0x00                                 ) &&
	    (cqr->dstat->dstat == (DEV_STAT_CHN_END | DEV_STAT_DEV_END))   ) {

                DEV_MESSAGE (KERN_DEBUG, device,
                             "ERP called for successful request %p"
                             " - NO ERP necessary",
                             cqr);
                
                check_then_set (&cqr->status,
                                CQR_STATUS_ERROR,
                                CQR_STATUS_DONE);

		return cqr;
	}
	/* check if sense data are available */
	if (!cqr->dstat->ii.sense.data) {
		DEV_MESSAGE (KERN_DEBUG, device,
                             "ERP called witout sense data avail ..."
                             "request %p - NO ERP possible",
                             cqr);

                check_then_set (&cqr->status,
                                CQR_STATUS_ERROR,
                                CQR_STATUS_FAILED);

		return cqr; 

	}

	/* check if error happened before */
	erp = dasd_3990_erp_in_erp (cqr);

	if (erp == NULL) {
		/* no matching erp found - set up erp */
		erp = dasd_3990_erp_additional_erp (cqr);
	} else {
		/* matching erp found - set all leading erp's to DONE */
		erp = dasd_3990_erp_handle_match_erp (cqr, 
                                                      erp);
	}

#ifdef ERP_DEBUG
	/* print current erp_chain */
        DEV_MESSAGE (KERN_DEBUG, device, "%s",
                     "ERP chain at END of ERP-ACTION");
        {
                ccw_req_t *temp_erp = NULL;
                for (temp_erp = erp; 
                     temp_erp != NULL; 
                     temp_erp = temp_erp->refers) {

                        DEV_MESSAGE (KERN_DEBUG, device,
                                     "      erp %p refers to %p",
                                     temp_erp,
                                     temp_erp->refers);
                }
        }
#endif /* ERP_DEBUG */

        if (erp->status == CQR_STATUS_FAILED) {

                log_erp_chain (erp,
                               1,
                               cpa);
        }

        /* enqueue added ERP request */
        if ((erp != device->queue.head ) &&
            (erp->status == CQR_STATUS_FILLED)   ){

                dasd_chanq_enq_head (&device->queue,
                                     erp);
        } else {
                if ((erp->status == CQR_STATUS_FILLED ) ||
                    (erp != device->queue.head)) {
                        /* something strange happened - log error and panic */
                        /* print current erp_chain */
                        DEV_MESSAGE (KERN_DEBUG, device, "%s",
                                     "ERP chain at END of ERP-ACTION");
                        {
                                ccw_req_t *temp_erp = NULL;
                                for (temp_erp = erp; 
                                     temp_erp != NULL; 
                                     temp_erp = temp_erp->refers) {

                                        DEV_MESSAGE (KERN_DEBUG, device,
                                                     "      erp %p (function %p)"
                                                     " refers to %p",
                                                     temp_erp,
                                                     temp_erp->function,
                                                     temp_erp->refers);
                                }
                        }
                        panic ("Problems with ERP chain!!! "
                               "Please report to linux390@de.ibm.com");
                }

        }

	return erp;

} /* end dasd_3990_erp_action */

/*
 * Overrides for Emacs so that we follow Linus's tabbing style.
 * Emacs will notice this stuff at the end of the file and automatically
 * adjust the settings for this buffer only.  This must remain at the end
 * of the file.
 * ---------------------------------------------------------------------------
 * Local variables:
 * c-indent-level: 4 
 * c-brace-imaginary-offset: 0
 * c-brace-offset: -4
 * c-argdecl-indent: 4
 * c-label-offset: -4
 * c-continued-statement-offset: 4
 * c-continued-brace-offset: 0
 * indent-tabs-mode: nil
 * tab-width: 8
 * End:
 */
