drivers/scsi/device_handler/scsi_dh_emc.c - kernel/msm-4.19 - Gitiles

 /*
  * Target driver for EMC CLARiiON AX/CX-series hardware.
  * Based on code from Lars Marowsky-Bree <lmb@suse.de>
  * and Ed Goggin <egoggin@emc.com>.
  *
  * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
  * Copyright (C) 2006 Mike Christie
  *
  * 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; see the file COPYING.  If not, write to
  * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 #include <linux/slab.h>
 #include <linux/module.h>
 #include <scsi/scsi.h>
 #include <scsi/scsi_eh.h>
 #include <scsi/scsi_dh.h>
 #include <scsi/scsi_device.h>

 #define CLARIION_NAME			"emc"

 #define CLARIION_TRESPASS_PAGE		0x22
 #define CLARIION_BUFFER_SIZE		0xFC
 #define CLARIION_TIMEOUT		(60 * HZ)
 #define CLARIION_RETRIES		3
 #define CLARIION_UNBOUND_LU		-1
 #define CLARIION_SP_A			0
 #define CLARIION_SP_B			1

 /* Flags */
 #define CLARIION_SHORT_TRESPASS		1
 #define CLARIION_HONOR_RESERVATIONS	2

 /* LUN states */
 #define CLARIION_LUN_UNINITIALIZED	-1
 #define CLARIION_LUN_UNBOUND		0
 #define CLARIION_LUN_BOUND		1
 #define CLARIION_LUN_OWNED		2

 static unsigned char long_trespass[] = {
 	0, 0, 0, 0, 0, 0, 0, 0,
 	CLARIION_TRESPASS_PAGE,	/* Page code */
 	0x09,			/* Page length - 2 */
 	0x01,			/* Trespass code */
 	0xff, 0xff,		/* Trespass target */
 	0, 0, 0, 0, 0, 0	/* Reserved bytes / unknown */
 };

 static unsigned char short_trespass[] = {
 	0, 0, 0, 0,
 	CLARIION_TRESPASS_PAGE,	/* Page code */
 	0x02,			/* Page length - 2 */
 	0x01,			/* Trespass code */
 	0xff,			/* Trespass target */
 };

 static const char * lun_state[] =
 {
     "not bound",
     "bound",
     "owned",
 };

 struct clariion_dh_data {
 	/*
 	 * Flags:
 	 *  CLARIION_SHORT_TRESPASS
 	 * Use short trespass command (FC-series) or the long version
 	 * (default for AX/CX CLARiiON arrays).
 	 *
 	 *  CLARIION_HONOR_RESERVATIONS
 	 * Whether or not (default) to honor SCSI reservations when
 	 * initiating a switch-over.
 	 */
 	unsigned flags;
 	/*
 	 * I/O buffer for both MODE_SELECT and INQUIRY commands.
 	 */
 	unsigned char buffer[CLARIION_BUFFER_SIZE];
 	/*
 	 * LUN state
 	 */
 	int lun_state;
 	/*
 	 * SP Port number
 	 */
 	int port;
 	/*
 	 * which SP (A=0,B=1,UNBOUND=-1) is the default SP for this
 	 * path's mapped LUN
 	 */
 	int default_sp;
 	/*
 	 * which SP (A=0,B=1,UNBOUND=-1) is the active SP for this
 	 * path's mapped LUN
 	 */
 	int current_sp;
 };

 /*
  * Parse MODE_SELECT cmd reply.
  */
 static int trespass_endio(struct scsi_device *sdev,
 			  struct scsi_sense_hdr *sshdr)
 {
 	int err = SCSI_DH_IO;

 	sdev_printk(KERN_ERR, sdev, "%s: Found valid sense data 0x%2x, "
 		    "0x%2x, 0x%2x while sending CLARiiON trespass "
 		    "command.\n", CLARIION_NAME, sshdr->sense_key,
 		    sshdr->asc, sshdr->ascq);

 	if (sshdr->sense_key == 0x05 && sshdr->asc == 0x04 &&
 	    sshdr->ascq == 0x00) {
 		/*
 		 * Array based copy in progress -- do not send
 		 * mode_select or copy will be aborted mid-stream.
 		 */
 		sdev_printk(KERN_INFO, sdev, "%s: Array Based Copy in "
 			    "progress while sending CLARiiON trespass "
 			    "command.\n", CLARIION_NAME);
 		err = SCSI_DH_DEV_TEMP_BUSY;
 	} else if (sshdr->sense_key == 0x02 && sshdr->asc == 0x04 &&
 		   sshdr->ascq == 0x03) {
 		/*
 		 * LUN Not Ready - Manual Intervention Required
 		 * indicates in-progress ucode upgrade (NDU).
 		 */
 		sdev_printk(KERN_INFO, sdev, "%s: Detected in-progress "
 			    "ucode upgrade NDU operation while sending "
 			    "CLARiiON trespass command.\n", CLARIION_NAME);
 		err = SCSI_DH_DEV_TEMP_BUSY;
 	} else
 		err = SCSI_DH_DEV_FAILED;
 	return err;
 }

 static int parse_sp_info_reply(struct scsi_device *sdev,
 			       struct clariion_dh_data *csdev)
 {
 	int err = SCSI_DH_OK;

 	/* check for in-progress ucode upgrade (NDU) */
 	if (csdev->buffer[48] != 0) {
 		sdev_printk(KERN_NOTICE, sdev, "%s: Detected in-progress "
 			    "ucode upgrade NDU operation while finding "
 			    "current active SP.", CLARIION_NAME);
 		err = SCSI_DH_DEV_TEMP_BUSY;
 		goto out;
 	}
 	if (csdev->buffer[4] > 2) {
 		/* Invalid buffer format */
 		sdev_printk(KERN_NOTICE, sdev,
 			    "%s: invalid VPD page 0xC0 format\n",
 			    CLARIION_NAME);
 		err = SCSI_DH_NOSYS;
 		goto out;
 	}
 	switch (csdev->buffer[28] & 0x0f) {
 	case 6:
 		sdev_printk(KERN_NOTICE, sdev,
 			    "%s: ALUA failover mode detected\n",
 			    CLARIION_NAME);
 		break;
 	case 4:
 		/* Linux failover */
 		break;
 	default:
 		sdev_printk(KERN_WARNING, sdev,
 			    "%s: Invalid failover mode %d\n",
 			    CLARIION_NAME, csdev->buffer[28] & 0x0f);
 		err = SCSI_DH_NOSYS;
 		goto out;
 	}

 	csdev->default_sp = csdev->buffer[5];
 	csdev->lun_state = csdev->buffer[4];
 	csdev->current_sp = csdev->buffer[8];
 	csdev->port = csdev->buffer[7];
 	if (csdev->lun_state == CLARIION_LUN_OWNED)
 		sdev->access_state = SCSI_ACCESS_STATE_OPTIMAL;
 	else
 		sdev->access_state = SCSI_ACCESS_STATE_STANDBY;
 	if (csdev->default_sp == csdev->current_sp)
 		sdev->access_state |= SCSI_ACCESS_STATE_PREFERRED;
 out:
 	return err;
 }

 #define emc_default_str "FC (Legacy)"

 static char * parse_sp_model(struct scsi_device *sdev, unsigned char *buffer)
 {
 	unsigned char len = buffer[4] + 5;
 	char *sp_model = NULL;
 	unsigned char sp_len, serial_len;

 	if (len < 160) {
 		sdev_printk(KERN_WARNING, sdev,
 			    "%s: Invalid information section length %d\n",
 			    CLARIION_NAME, len);
 		/* Check for old FC arrays */
 		if (!strncmp(buffer + 8, "DGC", 3)) {
 			/* Old FC array, not supporting extended information */
 			sp_model = emc_default_str;
 		}
 		goto out;
 	}

 	/*
 	 * Parse extended information for SP model number
 	 */
 	serial_len = buffer[160];
 	if (serial_len == 0 || serial_len + 161 > len) {
 		sdev_printk(KERN_WARNING, sdev,
 			    "%s: Invalid array serial number length %d\n",
 			    CLARIION_NAME, serial_len);
 		goto out;
 	}
 	sp_len = buffer[99];
 	if (sp_len == 0 || serial_len + sp_len + 161 > len) {
 		sdev_printk(KERN_WARNING, sdev,
 			    "%s: Invalid model number length %d\n",
 			    CLARIION_NAME, sp_len);
 		goto out;
 	}
 	sp_model = &buffer[serial_len + 161];
 	/* Strip whitespace at the end */
 	while (sp_len > 1 && sp_model[sp_len - 1] == ' ')
 		sp_len--;

 	sp_model[sp_len] = '\0';

 out:
 	return sp_model;
 }

 static int send_trespass_cmd(struct scsi_device *sdev,
 			    struct clariion_dh_data *csdev)
 {
 	unsigned char *page22;
 	unsigned char cdb[COMMAND_SIZE(MODE_SELECT)];
 	int err, res = SCSI_DH_OK, len;
 	struct scsi_sense_hdr sshdr;
 	u64 req_flags = REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT |
 		REQ_FAILFAST_DRIVER;

 	if (csdev->flags & CLARIION_SHORT_TRESPASS) {
 		page22 = short_trespass;
 		if (!(csdev->flags & CLARIION_HONOR_RESERVATIONS))
 			/* Set Honor Reservations bit */
 			page22[6] |= 0x80;
 		len = sizeof(short_trespass);
 		cdb[0] = MODE_SELECT;
 		cdb[1] = 0x10;
 		cdb[4] = len;
 	} else {
 		page22 = long_trespass;
 		if (!(csdev->flags & CLARIION_HONOR_RESERVATIONS))
 			/* Set Honor Reservations bit */
 			page22[10] |= 0x80;
 		len = sizeof(long_trespass);
 		cdb[0] = MODE_SELECT_10;
 		cdb[8] = len;
 	}
 	BUG_ON((len > CLARIION_BUFFER_SIZE));
 	memcpy(csdev->buffer, page22, len);

 	err = scsi_execute_req_flags(sdev, cdb, DMA_TO_DEVICE,
 				     csdev->buffer, len, &sshdr,
 				     CLARIION_TIMEOUT * HZ, CLARIION_RETRIES,
 				     NULL, req_flags, 0);
 	if (err) {
 		if (scsi_sense_valid(&sshdr))
 			res = trespass_endio(sdev, &sshdr);
 		else {
 			sdev_printk(KERN_INFO, sdev,
 				    "%s: failed to send MODE SELECT: %x\n",
 				    CLARIION_NAME, err);
 			res = SCSI_DH_IO;
 		}
 	}

 	return res;
 }

 static int clariion_check_sense(struct scsi_device *sdev,
 				struct scsi_sense_hdr *sense_hdr)
 {
 	switch (sense_hdr->sense_key) {
 	case NOT_READY:
 		if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x03)
 			/*
 			 * LUN Not Ready - Manual Intervention Required
 			 * indicates this is a passive path.
 			 *
 			 * FIXME: However, if this is seen and EVPD C0
 			 * indicates that this is due to a NDU in
 			 * progress, we should set FAIL_PATH too.
 			 * This indicates we might have to do a SCSI
 			 * inquiry in the end_io path. Ugh.
 			 *
 			 * Can return FAILED only when we want the error
 			 * recovery process to kick in.
 			 */
 			return SUCCESS;
 		break;
 	case ILLEGAL_REQUEST:
 		if (sense_hdr->asc == 0x25 && sense_hdr->ascq == 0x01)
 			/*
 			 * An array based copy is in progress. Do not
 			 * fail the path, do not bypass to another PG,
 			 * do not retry. Fail the IO immediately.
 			 * (Actually this is the same conclusion as in
 			 * the default handler, but lets make sure.)
 			 *
 			 * Can return FAILED only when we want the error
 			 * recovery process to kick in.
 			 */
 			return SUCCESS;
 		break;
 	case UNIT_ATTENTION:
 		if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00)
 			/*
 			 * Unit Attention Code. This is the first IO
 			 * to the new path, so just retry.
 			 */
 			return ADD_TO_MLQUEUE;
 		break;
 	}

 	return SCSI_RETURN_NOT_HANDLED;
 }

 static int clariion_prep_fn(struct scsi_device *sdev, struct request *req)
 {
 	struct clariion_dh_data *h = sdev->handler_data;
 	int ret = BLKPREP_OK;

 	if (h->lun_state != CLARIION_LUN_OWNED) {
 		ret = BLKPREP_KILL;
 		req->rq_flags |= RQF_QUIET;
 	}
 	return ret;

 }

 static int clariion_std_inquiry(struct scsi_device *sdev,
 				struct clariion_dh_data *csdev)
 {
 	int err = SCSI_DH_OK;
 	char *sp_model;

 	sp_model = parse_sp_model(sdev, sdev->inquiry);
 	if (!sp_model) {
 		err = SCSI_DH_DEV_UNSUPP;
 		goto out;
 	}

 	/*
 	 * FC Series arrays do not support long trespass
 	 */
 	if (!strlen(sp_model) || !strncmp(sp_model, "FC",2))
 		csdev->flags |= CLARIION_SHORT_TRESPASS;

 	sdev_printk(KERN_INFO, sdev,
 		    "%s: detected Clariion %s, flags %x\n",
 		    CLARIION_NAME, sp_model, csdev->flags);
 out:
 	return err;
 }

 static int clariion_send_inquiry(struct scsi_device *sdev,
 				 struct clariion_dh_data *csdev)
 {
 	int err = SCSI_DH_IO;

 	if (!scsi_get_vpd_page(sdev, 0xC0, csdev->buffer,
 			       CLARIION_BUFFER_SIZE))
 		err = parse_sp_info_reply(sdev, csdev);

 	return err;
 }

 static int clariion_activate(struct scsi_device *sdev,
 				activate_complete fn, void *data)
 {
 	struct clariion_dh_data *csdev = sdev->handler_data;
 	int result;

 	result = clariion_send_inquiry(sdev, csdev);
 	if (result != SCSI_DH_OK)
 		goto done;

 	if (csdev->lun_state == CLARIION_LUN_OWNED)
 		goto done;

 	result = send_trespass_cmd(sdev, csdev);
 	if (result != SCSI_DH_OK)
 		goto done;
 	sdev_printk(KERN_INFO, sdev,"%s: %s trespass command sent\n",
 		    CLARIION_NAME,
 		    csdev->flags&CLARIION_SHORT_TRESPASS?"short":"long" );

 	/* Update status */
 	result = clariion_send_inquiry(sdev, csdev);
 	if (result != SCSI_DH_OK)
 		goto done;

 done:
 	sdev_printk(KERN_INFO, sdev,
 		    "%s: at SP %c Port %d (%s, default SP %c)\n",
 		    CLARIION_NAME, csdev->current_sp + 'A',
 		    csdev->port, lun_state[csdev->lun_state],
 		    csdev->default_sp + 'A');

 	if (fn)
 		fn(data, result);
 	return 0;
 }
 /*
  * params - parameters in the following format
  *      "no_of_params\0param1\0param2\0param3\0...\0"
  *      for example, string for 2 parameters with value 10 and 21
  *      is specified as "2\010\021\0".
  */
 static int clariion_set_params(struct scsi_device *sdev, const char *params)
 {
 	struct clariion_dh_data *csdev = sdev->handler_data;
 	unsigned int hr = 0, st = 0, argc;
 	const char *p = params;
 	int result = SCSI_DH_OK;

 	if ((sscanf(params, "%u", &argc) != 1) || (argc != 2))
 		return -EINVAL;

 	while (*p++)
 		;
 	if ((sscanf(p, "%u", &st) != 1) || (st > 1))
 		return -EINVAL;

 	while (*p++)
 		;
 	if ((sscanf(p, "%u", &hr) != 1) || (hr > 1))
 		return -EINVAL;

 	if (st)
 		csdev->flags |= CLARIION_SHORT_TRESPASS;
 	else
 		csdev->flags &= ~CLARIION_SHORT_TRESPASS;

 	if (hr)
 		csdev->flags |= CLARIION_HONOR_RESERVATIONS;
 	else
 		csdev->flags &= ~CLARIION_HONOR_RESERVATIONS;

 	/*
 	 * If this path is owned, we have to send a trespass command
 	 * with the new parameters. If not, simply return. Next trespass
 	 * command would use the parameters.
 	 */
 	if (csdev->lun_state != CLARIION_LUN_OWNED)
 		goto done;

 	csdev->lun_state = CLARIION_LUN_UNINITIALIZED;
 	result = send_trespass_cmd(sdev, csdev);
 	if (result != SCSI_DH_OK)
 		goto done;

 	/* Update status */
 	result = clariion_send_inquiry(sdev, csdev);

 done:
 	return result;
 }

 static int clariion_bus_attach(struct scsi_device *sdev)
 {
 	struct clariion_dh_data *h;
 	int err;

 	h = kzalloc(sizeof(*h) , GFP_KERNEL);
 	if (!h)
 		return -ENOMEM;
 	h->lun_state = CLARIION_LUN_UNINITIALIZED;
 	h->default_sp = CLARIION_UNBOUND_LU;
 	h->current_sp = CLARIION_UNBOUND_LU;

 	err = clariion_std_inquiry(sdev, h);
 	if (err != SCSI_DH_OK)
 		goto failed;

 	err = clariion_send_inquiry(sdev, h);
 	if (err != SCSI_DH_OK)
 		goto failed;

 	sdev_printk(KERN_INFO, sdev,
 		    "%s: connected to SP %c Port %d (%s, default SP %c)\n",
 		    CLARIION_NAME, h->current_sp + 'A',
 		    h->port, lun_state[h->lun_state],
 		    h->default_sp + 'A');

 	sdev->handler_data = h;
 	return 0;

 failed:
 	kfree(h);
 	return -EINVAL;
 }

 static void clariion_bus_detach(struct scsi_device *sdev)
 {
 	kfree(sdev->handler_data);
 	sdev->handler_data = NULL;
 }

 static struct scsi_device_handler clariion_dh = {
 	.name		= CLARIION_NAME,
 	.module		= THIS_MODULE,
 	.attach		= clariion_bus_attach,
 	.detach		= clariion_bus_detach,
 	.check_sense	= clariion_check_sense,
 	.activate	= clariion_activate,
 	.prep_fn	= clariion_prep_fn,
 	.set_params	= clariion_set_params,
 };

 static int __init clariion_init(void)
 {
 	int r;

 	r = scsi_register_device_handler(&clariion_dh);
 	if (r != 0)
 		printk(KERN_ERR "%s: Failed to register scsi device handler.",
 			CLARIION_NAME);
 	return r;
 }

 static void __exit clariion_exit(void)
 {
 	scsi_unregister_device_handler(&clariion_dh);
 }

 module_init(clariion_init);
 module_exit(clariion_exit);

 MODULE_DESCRIPTION("EMC CX/AX/FC-family driver");
 MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu>, Chandra Seetharaman <sekharan@us.ibm.com>");
 MODULE_LICENSE("GPL");
	/*
	* Target driver for EMC CLARiiON AX/CX-series hardware.
	* Based on code from Lars Marowsky-Bree <lmb@suse.de>
	* and Ed Goggin <egoggin@emc.com>.
	*
	* Copyright (C) 2006 Red Hat, Inc. All rights reserved.
	* Copyright (C) 2006 Mike Christie
	*
	* 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; see the file COPYING. If not, write to
	* the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
	*/
	#include <linux/slab.h>
	#include <linux/module.h>
	#include <scsi/scsi.h>
	#include <scsi/scsi_eh.h>
	#include <scsi/scsi_dh.h>
	#include <scsi/scsi_device.h>

	#define CLARIION_NAME "emc"

	#define CLARIION_TRESPASS_PAGE 0x22
	#define CLARIION_BUFFER_SIZE 0xFC
	#define CLARIION_TIMEOUT (60 * HZ)
	#define CLARIION_RETRIES 3
	#define CLARIION_UNBOUND_LU -1
	#define CLARIION_SP_A 0
	#define CLARIION_SP_B 1

	/* Flags */
	#define CLARIION_SHORT_TRESPASS 1
	#define CLARIION_HONOR_RESERVATIONS 2

	/* LUN states */
	#define CLARIION_LUN_UNINITIALIZED -1
	#define CLARIION_LUN_UNBOUND 0
	#define CLARIION_LUN_BOUND 1
	#define CLARIION_LUN_OWNED 2

	static unsigned char long_trespass[] = {
	0, 0, 0, 0, 0, 0, 0, 0,
	CLARIION_TRESPASS_PAGE, /* Page code */
	0x09, /* Page length - 2 */
	0x01, /* Trespass code */
	0xff, 0xff, /* Trespass target */
	0, 0, 0, 0, 0, 0 /* Reserved bytes / unknown */
	};

	static unsigned char short_trespass[] = {
	0, 0, 0, 0,
	CLARIION_TRESPASS_PAGE, /* Page code */
	0x02, /* Page length - 2 */
	0x01, /* Trespass code */
	0xff, /* Trespass target */
	};

	static const char * lun_state[] =
	{
	"not bound",
	"bound",
	"owned",
	};

	struct clariion_dh_data {
	/*
	* Flags:
	* CLARIION_SHORT_TRESPASS
	* Use short trespass command (FC-series) or the long version
	* (default for AX/CX CLARiiON arrays).
	*
	* CLARIION_HONOR_RESERVATIONS
	* Whether or not (default) to honor SCSI reservations when
	* initiating a switch-over.
	*/
	unsigned flags;
	/*
	* I/O buffer for both MODE_SELECT and INQUIRY commands.
	*/
	unsigned char buffer[CLARIION_BUFFER_SIZE];
	/*
	* LUN state
	*/
	int lun_state;
	/*
	* SP Port number
	*/
	int port;
	/*
	* which SP (A=0,B=1,UNBOUND=-1) is the default SP for this
	* path's mapped LUN
	*/
	int default_sp;
	/*
	* which SP (A=0,B=1,UNBOUND=-1) is the active SP for this
	* path's mapped LUN
	*/
	int current_sp;
	};

	/*
	* Parse MODE_SELECT cmd reply.
	*/
	static int trespass_endio(struct scsi_device *sdev,
	struct scsi_sense_hdr *sshdr)
	{
	int err = SCSI_DH_IO;

	sdev_printk(KERN_ERR, sdev, "%s: Found valid sense data 0x%2x, "
	"0x%2x, 0x%2x while sending CLARiiON trespass "
	"command.\n", CLARIION_NAME, sshdr->sense_key,
	sshdr->asc, sshdr->ascq);

	if (sshdr->sense_key == 0x05 && sshdr->asc == 0x04 &&
	sshdr->ascq == 0x00) {
	/*
	* Array based copy in progress -- do not send
	* mode_select or copy will be aborted mid-stream.
	*/
	sdev_printk(KERN_INFO, sdev, "%s: Array Based Copy in "
	"progress while sending CLARiiON trespass "
	"command.\n", CLARIION_NAME);
	err = SCSI_DH_DEV_TEMP_BUSY;
	} else if (sshdr->sense_key == 0x02 && sshdr->asc == 0x04 &&
	sshdr->ascq == 0x03) {
	/*
	* LUN Not Ready - Manual Intervention Required
	* indicates in-progress ucode upgrade (NDU).
	*/
	sdev_printk(KERN_INFO, sdev, "%s: Detected in-progress "
	"ucode upgrade NDU operation while sending "
	"CLARiiON trespass command.\n", CLARIION_NAME);
	err = SCSI_DH_DEV_TEMP_BUSY;
	} else
	err = SCSI_DH_DEV_FAILED;
	return err;
	}

	static int parse_sp_info_reply(struct scsi_device *sdev,
	struct clariion_dh_data *csdev)
	{
	int err = SCSI_DH_OK;

	/* check for in-progress ucode upgrade (NDU) */
	if (csdev->buffer[48] != 0) {
	sdev_printk(KERN_NOTICE, sdev, "%s: Detected in-progress "
	"ucode upgrade NDU operation while finding "
	"current active SP.", CLARIION_NAME);
	err = SCSI_DH_DEV_TEMP_BUSY;
	goto out;
	}
	if (csdev->buffer[4] > 2) {
	/* Invalid buffer format */
	sdev_printk(KERN_NOTICE, sdev,
	"%s: invalid VPD page 0xC0 format\n",
	CLARIION_NAME);
	err = SCSI_DH_NOSYS;
	goto out;
	}
	switch (csdev->buffer[28] & 0x0f) {
	case 6:
	sdev_printk(KERN_NOTICE, sdev,
	"%s: ALUA failover mode detected\n",
	CLARIION_NAME);
	break;
	case 4:
	/* Linux failover */
	break;
	default:
	sdev_printk(KERN_WARNING, sdev,
	"%s: Invalid failover mode %d\n",
	CLARIION_NAME, csdev->buffer[28] & 0x0f);
	err = SCSI_DH_NOSYS;
	goto out;
	}

	csdev->default_sp = csdev->buffer[5];
	csdev->lun_state = csdev->buffer[4];
	csdev->current_sp = csdev->buffer[8];
	csdev->port = csdev->buffer[7];
	if (csdev->lun_state == CLARIION_LUN_OWNED)
	sdev->access_state = SCSI_ACCESS_STATE_OPTIMAL;
	else
	sdev->access_state = SCSI_ACCESS_STATE_STANDBY;
	if (csdev->default_sp == csdev->current_sp)
	sdev->access_state \|= SCSI_ACCESS_STATE_PREFERRED;
	out:
	return err;
	}

	#define emc_default_str "FC (Legacy)"

	static char * parse_sp_model(struct scsi_device sdev, unsigned char buffer)
	{
	unsigned char len = buffer[4] + 5;
	char *sp_model = NULL;
	unsigned char sp_len, serial_len;

	if (len < 160) {
	sdev_printk(KERN_WARNING, sdev,
	"%s: Invalid information section length %d\n",
	CLARIION_NAME, len);
	/* Check for old FC arrays */
	if (!strncmp(buffer + 8, "DGC", 3)) {
	/* Old FC array, not supporting extended information */
	sp_model = emc_default_str;
	}
	goto out;
	}

	/*
	* Parse extended information for SP model number
	*/
	serial_len = buffer[160];
	if (serial_len == 0 \|\| serial_len + 161 > len) {
	sdev_printk(KERN_WARNING, sdev,
	"%s: Invalid array serial number length %d\n",
	CLARIION_NAME, serial_len);
	goto out;
	}
	sp_len = buffer[99];
	if (sp_len == 0 \|\| serial_len + sp_len + 161 > len) {
	sdev_printk(KERN_WARNING, sdev,
	"%s: Invalid model number length %d\n",
	CLARIION_NAME, sp_len);
	goto out;
	}
	sp_model = &buffer[serial_len + 161];
	/* Strip whitespace at the end */
	while (sp_len > 1 && sp_model[sp_len - 1] == ' ')
	sp_len--;

	sp_model[sp_len] = '\0';

	out:
	return sp_model;
	}

	static int send_trespass_cmd(struct scsi_device *sdev,
	struct clariion_dh_data *csdev)
	{
	unsigned char *page22;
	unsigned char cdb[COMMAND_SIZE(MODE_SELECT)];
	int err, res = SCSI_DH_OK, len;
	struct scsi_sense_hdr sshdr;
	u64 req_flags = REQ_FAILFAST_DEV \| REQ_FAILFAST_TRANSPORT \|
	REQ_FAILFAST_DRIVER;

	if (csdev->flags & CLARIION_SHORT_TRESPASS) {
	page22 = short_trespass;
	if (!(csdev->flags & CLARIION_HONOR_RESERVATIONS))
	/* Set Honor Reservations bit */
	page22[6] \|= 0x80;
	len = sizeof(short_trespass);
	cdb[0] = MODE_SELECT;
	cdb[1] = 0x10;
	cdb[4] = len;
	} else {
	page22 = long_trespass;
	if (!(csdev->flags & CLARIION_HONOR_RESERVATIONS))
	/* Set Honor Reservations bit */
	page22[10] \|= 0x80;
	len = sizeof(long_trespass);
	cdb[0] = MODE_SELECT_10;
	cdb[8] = len;
	}
	BUG_ON((len > CLARIION_BUFFER_SIZE));
	memcpy(csdev->buffer, page22, len);

	err = scsi_execute_req_flags(sdev, cdb, DMA_TO_DEVICE,
	csdev->buffer, len, &sshdr,
	CLARIION_TIMEOUT * HZ, CLARIION_RETRIES,
	NULL, req_flags, 0);
	if (err) {
	if (scsi_sense_valid(&sshdr))
	res = trespass_endio(sdev, &sshdr);
	else {
	sdev_printk(KERN_INFO, sdev,
	"%s: failed to send MODE SELECT: %x\n",
	CLARIION_NAME, err);
	res = SCSI_DH_IO;
	}
	}

	return res;
	}

	static int clariion_check_sense(struct scsi_device *sdev,
	struct scsi_sense_hdr *sense_hdr)
	{
	switch (sense_hdr->sense_key) {
	case NOT_READY:
	if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x03)
	/*
	* LUN Not Ready - Manual Intervention Required
	* indicates this is a passive path.
	*
	* FIXME: However, if this is seen and EVPD C0
	* indicates that this is due to a NDU in
	* progress, we should set FAIL_PATH too.
	* This indicates we might have to do a SCSI
	* inquiry in the end_io path. Ugh.
	*
	* Can return FAILED only when we want the error
	* recovery process to kick in.
	*/
	return SUCCESS;
	break;
	case ILLEGAL_REQUEST:
	if (sense_hdr->asc == 0x25 && sense_hdr->ascq == 0x01)
	/*
	* An array based copy is in progress. Do not
	* fail the path, do not bypass to another PG,
	* do not retry. Fail the IO immediately.
	* (Actually this is the same conclusion as in
	* the default handler, but lets make sure.)
	*
	* Can return FAILED only when we want the error
	* recovery process to kick in.
	*/
	return SUCCESS;
	break;
	case UNIT_ATTENTION:
	if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00)
	/*
	* Unit Attention Code. This is the first IO
	* to the new path, so just retry.
	*/
	return ADD_TO_MLQUEUE;
	break;
	}

	return SCSI_RETURN_NOT_HANDLED;
	}

	static int clariion_prep_fn(struct scsi_device sdev, struct request req)
	{
	struct clariion_dh_data *h = sdev->handler_data;
	int ret = BLKPREP_OK;

	if (h->lun_state != CLARIION_LUN_OWNED) {
	ret = BLKPREP_KILL;
	req->rq_flags \|= RQF_QUIET;
	}
	return ret;

	}

	static int clariion_std_inquiry(struct scsi_device *sdev,
	struct clariion_dh_data *csdev)
	{
	int err = SCSI_DH_OK;
	char *sp_model;

	sp_model = parse_sp_model(sdev, sdev->inquiry);
	if (!sp_model) {
	err = SCSI_DH_DEV_UNSUPP;
	goto out;
	}

	/*
	* FC Series arrays do not support long trespass
	*/
	if (!strlen(sp_model) \|\| !strncmp(sp_model, "FC",2))
	csdev->flags \|= CLARIION_SHORT_TRESPASS;

	sdev_printk(KERN_INFO, sdev,
	"%s: detected Clariion %s, flags %x\n",
	CLARIION_NAME, sp_model, csdev->flags);
	out:
	return err;
	}

	static int clariion_send_inquiry(struct scsi_device *sdev,
	struct clariion_dh_data *csdev)
	{
	int err = SCSI_DH_IO;

	if (!scsi_get_vpd_page(sdev, 0xC0, csdev->buffer,
	CLARIION_BUFFER_SIZE))
	err = parse_sp_info_reply(sdev, csdev);

	return err;
	}

	static int clariion_activate(struct scsi_device *sdev,
	activate_complete fn, void *data)
	{
	struct clariion_dh_data *csdev = sdev->handler_data;
	int result;

	result = clariion_send_inquiry(sdev, csdev);
	if (result != SCSI_DH_OK)
	goto done;

	if (csdev->lun_state == CLARIION_LUN_OWNED)
	goto done;

	result = send_trespass_cmd(sdev, csdev);
	if (result != SCSI_DH_OK)
	goto done;
	sdev_printk(KERN_INFO, sdev,"%s: %s trespass command sent\n",
	CLARIION_NAME,
	csdev->flags&CLARIION_SHORT_TRESPASS?"short":"long" );

	/* Update status */
	result = clariion_send_inquiry(sdev, csdev);
	if (result != SCSI_DH_OK)
	goto done;

	done:
	sdev_printk(KERN_INFO, sdev,
	"%s: at SP %c Port %d (%s, default SP %c)\n",
	CLARIION_NAME, csdev->current_sp + 'A',
	csdev->port, lun_state[csdev->lun_state],
	csdev->default_sp + 'A');

	if (fn)
	fn(data, result);
	return 0;
	}
	/*
	* params - parameters in the following format
	* "no_of_params\0param1\0param2\0param3\0...\0"
	* for example, string for 2 parameters with value 10 and 21
	* is specified as "2\010\021\0".
	*/
	static int clariion_set_params(struct scsi_device sdev, const char params)
	{
	struct clariion_dh_data *csdev = sdev->handler_data;
	unsigned int hr = 0, st = 0, argc;
	const char *p = params;
	int result = SCSI_DH_OK;

	if ((sscanf(params, "%u", &argc) != 1) \|\| (argc != 2))
	return -EINVAL;

	while (*p++)
	;
	if ((sscanf(p, "%u", &st) != 1) \|\| (st > 1))
	return -EINVAL;

	while (*p++)
	;
	if ((sscanf(p, "%u", &hr) != 1) \|\| (hr > 1))
	return -EINVAL;

	if (st)
	csdev->flags \|= CLARIION_SHORT_TRESPASS;
	else
	csdev->flags &= ~CLARIION_SHORT_TRESPASS;

	if (hr)
	csdev->flags \|= CLARIION_HONOR_RESERVATIONS;
	else
	csdev->flags &= ~CLARIION_HONOR_RESERVATIONS;

	/*
	* If this path is owned, we have to send a trespass command
	* with the new parameters. If not, simply return. Next trespass
	* command would use the parameters.
	*/
	if (csdev->lun_state != CLARIION_LUN_OWNED)
	goto done;

	csdev->lun_state = CLARIION_LUN_UNINITIALIZED;
	result = send_trespass_cmd(sdev, csdev);
	if (result != SCSI_DH_OK)
	goto done;

	/* Update status */
	result = clariion_send_inquiry(sdev, csdev);

	done:
	return result;
	}

	static int clariion_bus_attach(struct scsi_device *sdev)
	{
	struct clariion_dh_data *h;
	int err;

	h = kzalloc(sizeof(*h) , GFP_KERNEL);
	if (!h)
	return -ENOMEM;
	h->lun_state = CLARIION_LUN_UNINITIALIZED;
	h->default_sp = CLARIION_UNBOUND_LU;
	h->current_sp = CLARIION_UNBOUND_LU;

	err = clariion_std_inquiry(sdev, h);
	if (err != SCSI_DH_OK)
	goto failed;

	err = clariion_send_inquiry(sdev, h);
	if (err != SCSI_DH_OK)
	goto failed;

	sdev_printk(KERN_INFO, sdev,
	"%s: connected to SP %c Port %d (%s, default SP %c)\n",
	CLARIION_NAME, h->current_sp + 'A',
	h->port, lun_state[h->lun_state],
	h->default_sp + 'A');

	sdev->handler_data = h;
	return 0;

	failed:
	kfree(h);
	return -EINVAL;
	}

	static void clariion_bus_detach(struct scsi_device *sdev)
	{
	kfree(sdev->handler_data);
	sdev->handler_data = NULL;
	}

	static struct scsi_device_handler clariion_dh = {
	.name = CLARIION_NAME,
	.module = THIS_MODULE,
	.attach = clariion_bus_attach,
	.detach = clariion_bus_detach,
	.check_sense = clariion_check_sense,
	.activate = clariion_activate,
	.prep_fn = clariion_prep_fn,
	.set_params = clariion_set_params,
	};

	static int __init clariion_init(void)
	{
	int r;

	r = scsi_register_device_handler(&clariion_dh);
	if (r != 0)
	printk(KERN_ERR "%s: Failed to register scsi device handler.",
	CLARIION_NAME);
	return r;
	}

	static void __exit clariion_exit(void)
	{
	scsi_unregister_device_handler(&clariion_dh);
	}

	module_init(clariion_init);
	module_exit(clariion_exit);

	MODULE_DESCRIPTION("EMC CX/AX/FC-family driver");
	MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu>, Chandra Seetharaman <sekharan@us.ibm.com>");
	MODULE_LICENSE("GPL");