zfcp_scsi.c

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/* 
 * 
 * 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]> 
 * 
 * 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

/* this drivers version (do not edit !!! generated and updated by cvs) */
#define ZFCP_SCSI_REVISION "$Revision: 1.65 $"

#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);

static struct zfcp_unit *zfcp_unit_lookup(struct zfcp_adapter *, int, scsi_id_t,
					  scsi_lun_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,
	}
	/* 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 = -ENODEV;

	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);
	zfcp_cmd_dbf_event_scsi("failing", scpnt);
	/* return directly */
	scpnt->scsi_done(scpnt);
}

/**
 * zfcp_scsi_command_async - worker for zfcp_scsi_queuecommand and
 *	zfcp_scsi_command_sync
 * @adapter: adapter for where scsi command is issued
 * @unit: unit to which scsi command is sent
 * @scpnt: scsi command to be sent
 *
 * 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)
{
	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,
					     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
 * returns 0, errors are indicated by scsi_cmnd->result
 */
int
zfcp_scsi_command_sync(struct zfcp_unit *unit, struct scsi_cmnd *scpnt)
{
	DECLARE_COMPLETION(wait);

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

	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);
}

/*
 * 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 (id != port->scsi_id)
			continue;
		list_for_each_entry(unit, &port->unit_list_head, list) {
			if (lun == unit->scsi_lun) {
				retval = unit;
				goto out;
			}
		}
	}
 out:
	return retval;
}

/*
 * function:	zfcp_scsi_eh_abort_handler
 *
 * purpose:	tries to abort the specified (timed out) SCSI command
 *
 * note: 	We do not need to care for a SCSI command which completes
 *		normally but late during this abort routine runs.
 *		We are allowed to return late commands to the SCSI stack.
 *		It tracks the state of commands and will handle late commands.
 *		(Usually, the normal completion of late commands is ignored with
 *		respect to the running abort operation. Grep for 'done_late'
 *		in the SCSI stacks sources.)
 *
 * returns:	SUCCESS	- command has been aborted and cleaned up in internal
 *			  bookkeeping,
 *			  SCSI stack won't be called for aborted command
 *		FAILED	- otherwise
 */
int
zfcp_scsi_eh_abort_handler(struct scsi_cmnd *scpnt)
{
	int retval = SUCCESS;
	struct zfcp_fsf_req *new_fsf_req, *old_fsf_req;
	struct zfcp_adapter *adapter = (struct zfcp_adapter *) scpnt->device->host->hostdata[0];
	struct zfcp_unit *unit = (struct zfcp_unit *) scpnt->device->hostdata;
	struct zfcp_port *port = unit->port;
	struct Scsi_Host *scsi_host = scpnt->device->host;
	union zfcp_req_data *req_data = NULL;
	unsigned long flags;
	u32 status = 0;

	/* the components of a abort_dbf record (fixed size record) */
	u64 dbf_scsi_cmnd = (unsigned long) scpnt;
	char dbf_opcode[ZFCP_ABORT_DBF_LENGTH];
	wwn_t dbf_wwn = port->wwpn;
	fcp_lun_t dbf_fcp_lun = unit->fcp_lun;
	u64 dbf_retries = scpnt->retries;
	u64 dbf_allowed = scpnt->allowed;
	u64 dbf_timeout = 0;
	u64 dbf_fsf_req = 0;
	u64 dbf_fsf_status = 0;
	u64 dbf_fsf_qual[2] = { 0, 0 };
	char dbf_result[ZFCP_ABORT_DBF_LENGTH] = { "##undef" };

	memset(dbf_opcode, 0, ZFCP_ABORT_DBF_LENGTH);
	memcpy(dbf_opcode,
	       scpnt->cmnd,
	       min(scpnt->cmd_len, (unsigned char) ZFCP_ABORT_DBF_LENGTH));

	ZFCP_LOG_INFO("aborting scsi_cmnd=%p on adapter %s\n",
		      scpnt, zfcp_get_busid_by_adapter(adapter));

	spin_unlock_irq(scsi_host->host_lock);

	/*
	 * Race condition between normal (late) completion and abort has
	 * to be avoided.
	 * The entirity of all accesses to scsi_req have to be atomic.
	 * scsi_req is usually part of the fsf_req and thus we block the
	 * release of fsf_req as long as we need to access scsi_req.