zfcp_scsi.c

linux-2.6.15.6

/* 
 * 
 * linux/drivers/s390/scsi/zfcp_scsi.c
 * 
 * FCP adapter driver for IBM eServer zSeries 
 * 
 * (C) Copyright IBM Corp. 2002, 2004
 *
 * Author(s): Martin Peschke <[e-mail]> 
 *            Raimund Schroeder <[e-mail]> 
 *            Aron Zeh
 *            Wolfgang Taphorn
 *            Stefan Bader <[e-mail]> 
 *            Heiko Carstens <[e-mail]> 
 *            Andreas Herrmann <[e-mail]>
 * 
 * This program is free software; you can redistribute it and/or modify 
 * it under the terms of the GNU General Public License as published by 
 * the Free Software Foundation; either version 2, or (at your option) 
 * any later version. 
 * 
 * This program is distributed in the hope that it will be useful, 
 * but WITHOUT ANY WARRANTY; without even the implied warranty of 
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the 
 * GNU General Public License for more details. 
 * 
 * You should have received a copy of the GNU General Public License 
 * along with this program; if not, write to the Free Software 
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 
 */

#define ZFCP_LOG_AREA			ZFCP_LOG_AREA_SCSI

#define ZFCP_SCSI_REVISION "$Revision: 1.74 $"

#include "zfcp_ext.h"

static void zfcp_scsi_slave_destroy(struct scsi_device *sdp);
static int zfcp_scsi_slave_alloc(struct scsi_device *sdp);
static int zfcp_scsi_slave_configure(struct scsi_device *sdp);
static int zfcp_scsi_queuecommand(struct scsi_cmnd *,
				  void (*done) (struct scsi_cmnd *));
static int zfcp_scsi_eh_abort_handler(struct scsi_cmnd *);
static int zfcp_scsi_eh_device_reset_handler(struct scsi_cmnd *);
static int zfcp_scsi_eh_bus_reset_handler(struct scsi_cmnd *);
static int zfcp_scsi_eh_host_reset_handler(struct scsi_cmnd *);
static int zfcp_task_management_function(struct zfcp_unit *, u8,
					 struct scsi_cmnd *);

static struct zfcp_unit *zfcp_unit_lookup(struct zfcp_adapter *, int, scsi_id_t,
					  scsi_lun_t);
static struct zfcp_port *zfcp_port_lookup(struct zfcp_adapter *, int,
					  scsi_id_t);

static struct device_attribute *zfcp_sysfs_sdev_attrs[];

struct scsi_transport_template *zfcp_transport_template;

struct zfcp_data zfcp_data = {
	.scsi_host_template = {
	      name:	               ZFCP_NAME,
	      proc_name:               "zfcp",
	      proc_info:               NULL,
	      detect:	               NULL,
	      slave_alloc:             zfcp_scsi_slave_alloc,
	      slave_configure:         zfcp_scsi_slave_configure,
	      slave_destroy:           zfcp_scsi_slave_destroy,
	      queuecommand:            zfcp_scsi_queuecommand,
	      eh_abort_handler:        zfcp_scsi_eh_abort_handler,
	      eh_device_reset_handler: zfcp_scsi_eh_device_reset_handler,
	      eh_bus_reset_handler:    zfcp_scsi_eh_bus_reset_handler,
	      eh_host_reset_handler:   zfcp_scsi_eh_host_reset_handler,
			               /* FIXME(openfcp): Tune */
	      can_queue:               4096,
	      this_id:	               0,
	      /*
	       * FIXME:
	       * one less? can zfcp_create_sbale cope with it?
	       */
	      sg_tablesize:            ZFCP_MAX_SBALES_PER_REQ,
	      cmd_per_lun:             1,
	      unchecked_isa_dma:       0,
	      use_clustering:          1,
	      sdev_attrs:              zfcp_sysfs_sdev_attrs,
	},
	.driver_version = ZFCP_VERSION,
	/* rest initialised with zeros */
};

/* Find start of Response Information in FCP response unit*/
char *
zfcp_get_fcp_rsp_info_ptr(struct fcp_rsp_iu *fcp_rsp_iu)
{
	char *fcp_rsp_info_ptr;

	fcp_rsp_info_ptr =
	    (unsigned char *) fcp_rsp_iu + (sizeof (struct fcp_rsp_iu));

	return fcp_rsp_info_ptr;
}

/* Find start of Sense Information in FCP response unit*/
char *
zfcp_get_fcp_sns_info_ptr(struct fcp_rsp_iu *fcp_rsp_iu)
{
	char *fcp_sns_info_ptr;

	fcp_sns_info_ptr =
	    (unsigned char *) fcp_rsp_iu + (sizeof (struct fcp_rsp_iu));
	if (fcp_rsp_iu->validity.bits.fcp_rsp_len_valid)
		fcp_sns_info_ptr = (char *) fcp_sns_info_ptr +
		    fcp_rsp_iu->fcp_rsp_len;

	return fcp_sns_info_ptr;
}

fcp_dl_t *
zfcp_get_fcp_dl_ptr(struct fcp_cmnd_iu * fcp_cmd)
{
	int additional_length = fcp_cmd->add_fcp_cdb_length << 2;
	fcp_dl_t *fcp_dl_addr;

	fcp_dl_addr = (fcp_dl_t *)
		((unsigned char *) fcp_cmd +
		 sizeof (struct fcp_cmnd_iu) + additional_length);
	/*
	 * fcp_dl_addr = start address of fcp_cmnd structure + 
	 * size of fixed part + size of dynamically sized add_dcp_cdb field
	 * SEE FCP-2 documentation
	 */
	return fcp_dl_addr;
}

fcp_dl_t
zfcp_get_fcp_dl(struct fcp_cmnd_iu * fcp_cmd)
{
	return *zfcp_get_fcp_dl_ptr(fcp_cmd);
}

void
zfcp_set_fcp_dl(struct fcp_cmnd_iu *fcp_cmd, fcp_dl_t fcp_dl)
{
	*zfcp_get_fcp_dl_ptr(fcp_cmd) = fcp_dl;
}

/*
 * note: it's a bit-or operation not an assignment
 * regarding the specified byte
 */
static inline void
set_byte(u32 * result, char status, char pos)
{
	*result |= status << (pos * 8);
}

void
set_host_byte(u32 * result, char status)
{
	set_byte(result, status, 2);
}

void
set_driver_byte(u32 * result, char status)
{
	set_byte(result, status, 3);
}

/*
 * function:	zfcp_scsi_slave_alloc
 *
 * purpose:
 *
 * returns:
 */

static int
zfcp_scsi_slave_alloc(struct scsi_device *sdp)
{
	struct zfcp_adapter *adapter;
	struct zfcp_unit *unit;
	unsigned long flags;
	int retval = -ENXIO;

	adapter = (struct zfcp_adapter *) sdp->host->hostdata[0];
	if (!adapter)
		goto out;

	read_lock_irqsave(&zfcp_data.config_lock, flags);
	unit = zfcp_unit_lookup(adapter, sdp->channel, sdp->id, sdp->lun);
	if (unit) {
		sdp->hostdata = unit;
		unit->device = sdp;
		zfcp_unit_get(unit);
		retval = 0;
	}
	read_unlock_irqrestore(&zfcp_data.config_lock, flags);
 out:
	return retval;
}

/*
 * function:	zfcp_scsi_slave_destroy
 *
 * purpose:
 *
 * returns:
 */

static void
zfcp_scsi_slave_destroy(struct scsi_device *sdpnt)
{
	struct zfcp_unit *unit = (struct zfcp_unit *) sdpnt->hostdata;

	if (unit) {
		sdpnt->hostdata = NULL;
		unit->device = NULL;
		zfcp_unit_put(unit);
	} else {
		ZFCP_LOG_NORMAL("bug: no unit associated with SCSI device at "
				"address %p\n", sdpnt);
	}
}

/* 
 * called from scsi midlayer to allow finetuning of a device.
 */
static int
zfcp_scsi_slave_configure(struct scsi_device *sdp)
{
	if (sdp->tagged_supported)
		scsi_adjust_queue_depth(sdp, MSG_SIMPLE_TAG, ZFCP_CMND_PER_LUN);
	else
		scsi_adjust_queue_depth(sdp, 0, 1);
	return 0;
}

/**
 * zfcp_scsi_command_fail - set result in scsi_cmnd and call scsi_done function
 * @scpnt: pointer to struct scsi_cmnd where result is set
 * @result: result to be set in scpnt (e.g. DID_ERROR)
 */
static void
zfcp_scsi_command_fail(struct scsi_cmnd *scpnt, int result)
{
	set_host_byte(&scpnt->result, result);
	if ((scpnt->device != NULL) && (scpnt->device->host != NULL))
		zfcp_scsi_dbf_event_result("fail", 4,
			(struct zfcp_adapter*) scpnt->device->host->hostdata[0],
			scpnt);
	/* return directly */
	scpnt->scsi_done(scpnt);
}

/**
 * zfcp_scsi_command_async - worker for zfcp_scsi_queuecommand and
 *	zfcp_scsi_command_sync
 * @adapter: adapter where scsi command is issued
 * @unit: unit to which scsi command is sent
 * @scpnt: scsi command to be sent
 * @timer: timer to be started if request is successfully initiated
 *
 * Note: In scsi_done function must be set in scpnt.
 */
int
zfcp_scsi_command_async(struct zfcp_adapter *adapter, struct zfcp_unit *unit,
			struct scsi_cmnd *scpnt, struct timer_list *timer)
{
	int tmp;
	int retval;

	retval = 0;

	BUG_ON((adapter == NULL) || (adapter != unit->port->adapter));
	BUG_ON(scpnt->scsi_done == NULL);

	if (unlikely(NULL == unit)) {
		zfcp_scsi_command_fail(scpnt, DID_NO_CONNECT);
		goto out;
	}

	if (unlikely(
	      atomic_test_mask(ZFCP_STATUS_COMMON_ERP_FAILED, &unit->status) ||
	     !atomic_test_mask(ZFCP_STATUS_COMMON_RUNNING, &unit->status))) {
		ZFCP_LOG_DEBUG("stopping SCSI I/O on unit 0x%016Lx on port "
			       "0x%016Lx on adapter %s\n",
			       unit->fcp_lun, unit->port->wwpn,
			       zfcp_get_busid_by_adapter(adapter));
		zfcp_scsi_command_fail(scpnt, DID_ERROR);
		goto out;
	}

	if (unlikely(
	     !atomic_test_mask(ZFCP_STATUS_COMMON_UNBLOCKED, &unit->status))) {
		ZFCP_LOG_DEBUG("adapter %s not ready or unit 0x%016Lx "
			       "on port 0x%016Lx in recovery\n",
			       zfcp_get_busid_by_unit(unit),
			       unit->fcp_lun, unit->port->wwpn);
		retval = SCSI_MLQUEUE_DEVICE_BUSY;
		goto out;
	}

	tmp = zfcp_fsf_send_fcp_command_task(adapter, unit, scpnt, timer,
					     ZFCP_REQ_AUTO_CLEANUP);

	if (unlikely(tmp < 0)) {
		ZFCP_LOG_DEBUG("error: initiation of Send FCP Cmnd failed\n");
		retval = SCSI_MLQUEUE_HOST_BUSY;
	}

out:
	return retval;
}

void
zfcp_scsi_command_sync_handler(struct scsi_cmnd *scpnt)
{
	struct completion *wait = (struct completion *) scpnt->SCp.ptr;
	complete(wait);
}


/**
 * zfcp_scsi_command_sync - send a SCSI command and wait for completion
 * @unit: unit where command is sent to
 * @scpnt: scsi command to be sent
 * @timer: timer to be started if request is successfully initiated
 * Return: 0
 *
 * Errors are indicated in scpnt->result
 */
int
zfcp_scsi_command_sync(struct zfcp_unit *unit, struct scsi_cmnd *scpnt,
		       struct timer_list *timer)
{
	int ret;
	DECLARE_COMPLETION(wait);

	scpnt->SCp.ptr = (void *) &wait;  /* silent re-use */
	scpnt->scsi_done = zfcp_scsi_command_sync_handler;
	ret = zfcp_scsi_command_async(unit->port->adapter, unit, scpnt, timer);
	if (ret == 0)
		wait_for_completion(&wait);

	scpnt->SCp.ptr = NULL;

	return 0;
}

/*
 * function:	zfcp_scsi_queuecommand
 *
 * purpose:	enqueues a SCSI command to the specified target device
 *
 * returns:	0 - success, SCSI command enqueued
 *		!0 - failure
 */
int
zfcp_scsi_queuecommand(struct scsi_cmnd *scpnt,
		       void (*done) (struct scsi_cmnd *))
{
	struct zfcp_unit *unit;
	struct zfcp_adapter *adapter;

	/* reset the status for this request */
	scpnt->result = 0;
	scpnt->host_scribble = NULL;
	scpnt->scsi_done = done;

	/*
	 * figure out adapter and target device
	 * (stored there by zfcp_scsi_slave_alloc)
	 */
	adapter = (struct zfcp_adapter *) scpnt->device->host->hostdata[0];
	unit = (struct zfcp_unit *) scpnt->device->hostdata;

	return zfcp_scsi_command_async(adapter, unit, scpnt, NULL);
}

/*
 * function:    zfcp_unit_lookup
 *
 * purpose:
 *
 * returns:
 *
 * context:	
 */
static struct zfcp_unit *
zfcp_unit_lookup(struct zfcp_adapter *adapter, int channel, scsi_id_t id,
		 scsi_lun_t lun)
{
	struct zfcp_port *port;
	struct zfcp_unit *unit, *retval = NULL;

	list_for_each_entry(port, &adapter->port_list_head, list) {
		if (!port->rport || (id != port->rport->scsi_target_id))
			continue;
		list_for_each_entry(unit, &port->unit_list_head, list) {
			if (lun == unit->scsi_lun) {
				retval = unit;
				goto out;
			}
		}
	}
 out:
	return retval;
}

static struct zfcp_port *
zfcp_port_lookup(struct zfcp_adapter *adapter, int channel, scsi_id_t id)
{
	struct zfcp_port *port;

	list_for_each_entry(port, &adapter->port_list_head, list) {
		if (port->rport && (id == port->rport->scsi_target_id))
			return port;
	}
	return (struct zfcp_port *) NULL;