text: /*
   * vvvvvvvvvvvvvvvvvvvvvvv Original vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
   *  Copyright (C) 1992  Eric Youngdale
   *  Simulate a host adapter with 2 disks attached.  Do a lot of checking
   *  to make sure that we are not getting blocks mixed up, and PANIC if
   *  anything out of the ordinary is seen.
   * ^^^^^^^^^^^^^^^^^^^^^^^ Original ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   *
   *  This version is more generic, simulating a variable number of disk
   *  (or disk like devices) sharing a common amount of RAM. To be more
   *  realistic, the simulated devices have the transport attributes of
   *  SAS disks.
   *
   *
   *  For documentation see http://www.torque.net/sg/sdebug26.html
   *
   *   D. Gilbert (dpg) work for Magneto-Optical device test [20010421]
   *   dpg: work for devfs large number of disks [20010809]
   *        forked for lk 2.5 series [20011216, 20020101]
   *        use vmalloc() more inquiry+mode_sense [20020302]
   *        add timers for delayed responses [20020721]
   *   Patrick Mansfield <patmans@us.ibm.com> max_luns+scsi_level [20021031]
   *   Mike Anderson <andmike@us.ibm.com> sysfs work [20021118]
   *   dpg: change style of boot options to "scsi_debug.num_tgts=2" and
   *        module options to "modprobe scsi_debug num_tgts=2" [20021221]
   */
  
  #include <linux/module.h>
  
  #include <linux/kernel.h>
  #include <linux/errno.h>
  #include <linux/timer.h>
  #include <linux/types.h>
  #include <linux/string.h>
  #include <linux/genhd.h>
  #include <linux/fs.h>
  #include <linux/init.h>
  #include <linux/proc_fs.h>
  #include <linux/vmalloc.h>
  #include <linux/moduleparam.h>
  
  #include <linux/blkdev.h>
  #include "scsi.h"
  #include <scsi/scsi_host.h>
  #include <scsi/scsicam.h>
  
  #include <linux/stat.h>
  
  #include "scsi_logging.h"
  #include "scsi_debug.h"
  
  #define SCSI_DEBUG_VERSION "1.81"
  static const char * scsi_debug_version_date = "20070104";
  
  /* Additional Sense Code (ASC) */
  #define NO_ADDITIONAL_SENSE 0x0
  #define LOGICAL_UNIT_NOT_READY 0x4
  #define UNRECOVERED_READ_ERR 0x11
  #define PARAMETER_LIST_LENGTH_ERR 0x1a
  #define INVALID_OPCODE 0x20
  #define ADDR_OUT_OF_RANGE 0x21
  #define INVALID_FIELD_IN_CDB 0x24
  #define INVALID_FIELD_IN_PARAM_LIST 0x26
  #define POWERON_RESET 0x29
  #define SAVING_PARAMS_UNSUP 0x39
  #define TRANSPORT_PROBLEM 0x4b
  #define THRESHOLD_EXCEEDED 0x5d
  #define LOW_POWER_COND_ON 0x5e
  
  /* Additional Sense Code Qualifier (ASCQ) */
  #define ACK_NAK_TO 0x3
  
  #define SDEBUG_TAGGED_QUEUING 0 /* 0 | MSG_SIMPLE_TAG | MSG_ORDERED_TAG */
  
  /* Default values for driver parameters */
  #define DEF_NUM_HOST   1
  #define DEF_NUM_TGTS   1
  #define DEF_MAX_LUNS   1
  /* With these defaults, this driver will make 1 host with 1 target
   * (id 0) containing 1 logical unit (lun 0). That is 1 device.
   */
  #define DEF_DELAY   1
  #define DEF_DEV_SIZE_MB   8
  #define DEF_EVERY_NTH   0
  #define DEF_NUM_PARTS   0
  #define DEF_OPTS   0
  #define DEF_SCSI_LEVEL   5    /* INQUIRY, byte2 [5->SPC-3] */
  #define DEF_PTYPE   0
  #define DEF_D_SENSE   0
  #define DEF_NO_LUN_0   0
  #define DEF_VIRTUAL_GB   0
  #define DEF_FAKE_RW	0
  #define DEF_VPD_USE_HOSTNO 1
  
  /* bit mask values for scsi_debug_opts */
  #define SCSI_DEBUG_OPT_NOISE   1
  #define SCSI_DEBUG_OPT_MEDIUM_ERR   2
  #define SCSI_DEBUG_OPT_TIMEOUT   4
  #define SCSI_DEBUG_OPT_RECOVERED_ERR   8
  #define SCSI_DEBUG_OPT_TRANSPORT_ERR   16
  /* When "every_nth" > 0 then modulo "every_nth" commands:
   *   - a no response is simulated if SCSI_DEBUG_OPT_TIMEOUT is set
   *   - a RECOVERED_ERROR is simulated on successful read and write
   *     commands if SCSI_DEBUG_OPT_RECOVERED_ERR is set.
   *   - a TRANSPORT_ERROR is simulated on successful read and write
   *     commands if SCSI_DEBUG_OPT_TRANSPORT_ERR is set.
   *
   * When "every_nth" < 0 then after "- every_nth" commands:
   *   - a no response is simulated if SCSI_DEBUG_OPT_TIMEOUT is set
   *   - a RECOVERED_ERROR is simulated on successful read and write
   *     commands if SCSI_DEBUG_OPT_RECOVERED_ERR is set.
   *   - a TRANSPORT_ERROR is simulated on successful read and write
   *     commands if SCSI_DEBUG_OPT_TRANSPORT_ERR is set.
   * This will continue until some other action occurs (e.g. the user
   * writing a new value (other than -1 or 1) to every_nth via sysfs).
   */
  
  /* when 1==SCSI_DEBUG_OPT_MEDIUM_ERR, a medium error is simulated at this
   * sector on read commands: */
  #define OPT_MEDIUM_ERR_ADDR   0x1234 /* that's sector 4660 in decimal */
  
  /* If REPORT LUNS has luns >= 256 it can choose "flat space" (value 1)
   * or "peripheral device" addressing (value 0) */
  #define SAM2_LUN_ADDRESS_METHOD 0
  #define SAM2_WLUN_REPORT_LUNS 0xc101
  
  static int scsi_debug_add_host = DEF_NUM_HOST;
  static int scsi_debug_delay = DEF_DELAY;
  static int scsi_debug_dev_size_mb = DEF_DEV_SIZE_MB;
  static int scsi_debug_every_nth = DEF_EVERY_NTH;
  static int scsi_debug_max_luns = DEF_MAX_LUNS;
  static int scsi_debug_num_parts = DEF_NUM_PARTS;
  static int scsi_debug_num_tgts = DEF_NUM_TGTS; /* targets per host */
  static int scsi_debug_opts = DEF_OPTS;
  static int scsi_debug_scsi_level = DEF_SCSI_LEVEL;
  static int scsi_debug_ptype = DEF_PTYPE; /* SCSI peripheral type (0==disk) */
  static int scsi_debug_dsense = DEF_D_SENSE;
  static int scsi_debug_no_lun_0 = DEF_NO_LUN_0;
  static int scsi_debug_virtual_gb = DEF_VIRTUAL_GB;
  static int scsi_debug_fake_rw = DEF_FAKE_RW;
  static int scsi_debug_vpd_use_hostno = DEF_VPD_USE_HOSTNO;
  
  static int scsi_debug_cmnd_count = 0;
  
  #define DEV_READONLY(TGT)      (0)
  #define DEV_REMOVEABLE(TGT)    (0)
  
  static unsigned int sdebug_store_size;	/* in bytes */
  static unsigned int sdebug_store_sectors;
  static sector_t sdebug_capacity;	/* in sectors */
  
  /* old BIOS stuff, kernel may get rid of them but some mode sense pages
     may still need them */
  static int sdebug_heads;		/* heads per disk */
  static int sdebug_cylinders_per;	/* cylinders per surface */
  static int sdebug_sectors_per;		/* sectors per cylinder */
  
  /* default sector size is 512 bytes, 2**9 bytes */
  #define POW2_SECT_SIZE 9
  #define SECT_SIZE (1 << POW2_SECT_SIZE)
  #define SECT_SIZE_PER(TGT) SECT_SIZE
  
  #define SDEBUG_MAX_PARTS 4
  
  #define SDEBUG_SENSE_LEN 32
  
  struct sdebug_dev_info {
  	struct list_head dev_list;
  	unsigned char sense_buff[SDEBUG_SENSE_LEN];	/* weak nexus */
  	unsigned int channel;
  	unsigned int target;
  	unsigned int lun;
  	struct sdebug_host_info *sdbg_host;
  	unsigned int wlun;
  	char reset;
  	char stopped;
  	char used;
  };
  
  struct sdebug_host_info {
  	struct list_head host_list;
  	struct Scsi_Host *shost;
  	struct device dev;
  	struct list_head dev_info_list;
  };
  
  #define to_sdebug_host(d)	\
  	container_of(d, struct sdebug_host_info, dev)
  
  static LIST_HEAD(sdebug_host_list);
  static DEFINE_SPINLOCK(sdebug_host_list_lock);
  
  typedef void (* done_funct_t) (struct scsi_cmnd *);
  
  struct sdebug_queued_cmd {
  	int in_use;
  	struct timer_list cmnd_timer;
  	done_funct_t done_funct;
  	struct scsi_cmnd * a_cmnd;
  	int scsi_result;
  };
  static struct sdebug_queued_cmd queued_arr[SCSI_DEBUG_CANQUEUE];
  
  static struct scsi_host_template sdebug_driver_template = {
  	.proc_info =		scsi_debug_proc_info,
  	.name =			"SCSI DEBUG",
  	.info =			scsi_debug_info,
  	.slave_alloc =		scsi_debug_slave_alloc,
  	.slave_configure =	scsi_debug_slave_configure,
  	.slave_destroy =	scsi_debug_slave_destroy,
  	.ioctl =		scsi_debug_ioctl,
  	.queuecommand =		scsi_debug_queuecommand,
  	.eh_abort_handler =	scsi_debug_abort,
  	.eh_bus_reset_handler = scsi_debug_bus_reset,
  	.eh_device_reset_handler = scsi_debug_device_reset,
  	.eh_host_reset_handler = scsi_debug_host_reset,
  	.bios_param =		scsi_debug_biosparam,
  	.can_queue =		SCSI_DEBUG_CANQUEUE,
  	.this_id =		7,
  	.sg_tablesize =		256,
  	.cmd_per_lun =		16,
  	.max_sectors =		0xffff,
  	.unchecked_isa_dma = 	0,
  	.use_clustering = 	ENABLE_CLUSTERING,
  	.module =		THIS_MODULE,
  };
  
  static unsigned char * fake_storep;	/* ramdisk storage */
  
  static int num_aborts = 0;
  static int num_dev_resets = 0;
  static int num_bus_resets = 0;
  static int num_host_resets = 0;
  
  static DEFINE_SPINLOCK(queued_arr_lock);
  static DEFINE_RWLOCK(atomic_rw);
  
  static char sdebug_proc_name[] = "scsi_debug";
  
  static int sdebug_driver_probe(struct device *);
  static int sdebug_driver_remove(struct device *);
  static struct bus_type pseudo_lld_bus;
  
  static struct device_driver sdebug_driverfs_driver = {
  	.name 		= sdebug_proc_name,
  	.bus		= &pseudo_lld_bus,
  };
  
  static const int check_condition_result =
  		(DRIVER_SENSE << 24) | SAM_STAT_CHECK_CONDITION;
  
  static unsigned char ctrl_m_pg[] = {0xa, 10, 2, 0, 0, 0, 0, 0,
  				    0, 0, 0x2, 0x4b};
  static unsigned char iec_m_pg[] = {0x1c, 0xa, 0x08, 0, 0, 0, 0, 0,
  			           0, 0, 0x0, 0x0};
  
  /* function declarations */
  static int resp_inquiry(struct scsi_cmnd * SCpnt, int target,
  			struct sdebug_dev_info * devip);
  static int resp_requests(struct scsi_cmnd * SCpnt,
  			 struct sdebug_dev_info * devip);
  static int resp_start_stop(struct scsi_cmnd * scp,
  			   struct sdebug_dev_info * devip);
  static int resp_report_tgtpgs(struct scsi_cmnd * scp,
  			      struct sdebug_dev_info * devip);
  static int resp_readcap(struct scsi_cmnd * SCpnt,
  			struct sdebug_dev_info * devip);
  static int resp_readcap16(struct scsi_cmnd * SCpnt,
  			  struct sdebug_dev_info * devip);
  static int resp_mode_sense(struct scsi_cmnd * scp, int target,
  			   struct sdebug_dev_info * devip);
  static int resp_mode_select(struct scsi_cmnd * scp, int mselect6,
  			    struct sdebug_dev_info * devip);
  static int resp_log_sense(struct scsi_cmnd * scp,
  			  struct sdebug_dev_info * devip);
  static int resp_read(struct scsi_cmnd * SCpnt, unsigned long long lba,
  		     unsigned int num, struct sdebug_dev_info * devip);
  static int resp_write(struct scsi_cmnd * SCpnt, unsigned long long lba,
  		      unsigned int num, struct sdebug_dev_info * devip);
  static int resp_report_luns(struct scsi_cmnd * SCpnt,
  			    struct sdebug_dev_info * devip);
  static int fill_from_dev_buffer(struct scsi_cmnd * scp, unsigned char * arr,
                                  int arr_len);
  static int fetch_to_dev_buffer(struct scsi_cmnd * scp, unsigned char * arr,
                                 int max_arr_len);
  static void timer_intr_handler(unsigned long);
  static struct sdebug_dev_info * devInfoReg(struct scsi_device * sdev);
  static void mk_sense_buffer(struct sdebug_dev_info * devip, int key,
  			    int asc, int asq);
  static int check_readiness(struct scsi_cmnd * SCpnt, int reset_only,
  			   struct sdebug_dev_info * devip);
  static int schedule_resp(struct scsi_cmnd * cmnd,
  			 struct sdebug_dev_info * devip,
  			 done_funct_t done, int scsi_result, int delta_jiff);
  static void __init sdebug_build_parts(unsigned char * ramp);
  static void __init init_all_queued(void);
  static void stop_all_queued(void);
  static int stop_queued_cmnd(struct scsi_cmnd * cmnd);
  static int inquiry_evpd_83(unsigned char * arr, int port_group_id,
  			   int target_dev_id, int dev_id_num,
  			   const char * dev_id_str, int dev_id_str_len);
  static int inquiry_evpd_88(unsigned char * arr, int target_dev_id);
  static int do_create_driverfs_files(void);
  static void do_remove_driverfs_files(void);
  
  static int sdebug_add_adapter(void);
  static void sdebug_remove_adapter(void);
  static void sdebug_max_tgts_luns(void);
  
  static struct device pseudo_primary;
  static struct bus_type pseudo_lld_bus;
  
  
  static
  int scsi_debug_queuecommand(struct scsi_cmnd * SCpnt, done_funct_t done)
  {
  	unsigned char *cmd = (unsigned char *) SCpnt->cmnd;
  	int len, k, j;
  	unsigned int num;
  	unsigned long long lba;
  	int errsts = 0;
  	int target = SCpnt->device->id;
  	struct sdebug_dev_info * devip = NULL;
  	int inj_recovered = 0;
  	int inj_transport = 0;
  	int delay_override = 0;
  
  	if (done == NULL)
  		return 0;	/* assume mid level reprocessing command */
  
  	SCpnt->resid = 0;
  	if ((SCSI_DEBUG_OPT_NOISE & scsi_debug_opts) && cmd) {
  		printk(KERN_INFO "scsi_debug: cmd ");
  		for (k = 0, len = SCpnt->cmd_len; k < len; ++k)
  			printk("%02x ", (int)cmd[k]);
  		printk("\n");
  	}
          if(target == sdebug_driver_template.this_id) {
  		printk(KERN_INFO "scsi_debug: initiator's id used as "
  		       "target!\n");
  		return schedule_resp(SCpnt, NULL, done,
  				     DID_NO_CONNECT << 16, 0);
          }
  
  	if ((SCpnt->device->lun >= scsi_debug_max_luns) &&
  	    (SCpnt->device->lun != SAM2_WLUN_REPORT_LUNS))
  		return schedule_resp(SCpnt, NULL, done,
  				     DID_NO_CONNECT << 16, 0);
  	devip = devInfoReg(SCpnt->device);
  	if (NULL == devip)
  		return schedule_resp(SCpnt, NULL, done,
  				     DID_NO_CONNECT << 16, 0);
  
          if ((scsi_debug_every_nth != 0) &&
              (++scsi_debug_cmnd_count >= abs(scsi_debug_every_nth))) {
                  scsi_debug_cmnd_count = 0;
  		if (scsi_debug_every_nth < -1)
  			scsi_debug_every_nth = -1;
  		if (SCSI_DEBUG_OPT_TIMEOUT & scsi_debug_opts)
  			return 0; /* ignore command causing timeout */
  		else if (SCSI_DEBUG_OPT_RECOVERED_ERR & scsi_debug_opts)
  			inj_recovered = 1; /* to reads and writes below */
  		else if (SCSI_DEBUG_OPT_TRANSPORT_ERR & scsi_debug_opts)
  			inj_transport = 1; /* to reads and writes below */
          }
  
  	if (devip->wlun) {
  		switch (*cmd) {
  		case INQUIRY:
  		case REQUEST_SENSE:
  		case TEST_UNIT_READY:
  		case REPORT_LUNS:
  			break;  /* only allowable wlun commands */
  		default:
  			if (SCSI_DEBUG_OPT_NOISE & scsi_debug_opts)
  				printk(KERN_INFO "scsi_debug: Opcode: 0x%x "
  				       "not supported for wlun\n", *cmd);
  			mk_sense_buffer(devip, ILLEGAL_REQUEST,
  					INVALID_OPCODE, 0);
  			errsts = check_condition_result;
  			return schedule_resp(SCpnt, devip, done, errsts,
  					     0);
  		}
  	}
  
  	switch (*cmd) {
  	case INQUIRY:     /* mandatory, ignore unit attention */
  		delay_override = 1;
  		errsts = resp_inquiry(SCpnt, target, devip);
  		break;
  	case REQUEST_SENSE:	/* mandatory, ignore unit attention */
  		delay_override = 1;
  		errsts = resp_requests(SCpnt, devip);
  		break;
  	case REZERO_UNIT:	/* actually this is REWIND for SSC */
  	case START_STOP:
  		errsts = resp_start_stop(SCpnt, devip);
  		break;
  	case ALLOW_MEDIUM_REMOVAL:
  		if ((errsts = check_readiness(SCpnt, 1, devip)))
  			break;
  		if (SCSI_DEBUG_OPT_NOISE & scsi_debug_opts)
  			printk(KERN_INFO "scsi_debug: Medium removal %s\n",
  			        cmd[4] ? "inhibited" : "enabled");
  		break;
  	case SEND_DIAGNOSTIC:     /* mandatory */
  		errsts = check_readiness(SCpnt, 1, devip);
  		break;
  	case TEST_UNIT_READY:     /* mandatory */
  		delay_override = 1;
  		errsts = check_readiness(SCpnt, 0, devip);
  		break;
          case RESERVE:
  		errsts = check_readiness(SCpnt, 1, devip);
                  break;
          case RESERVE_10:
  		errsts = check_readiness(SCpnt, 1, devip);
                  break;
          case RELEASE:
  		errsts = check_readiness(SCpnt, 1, devip);
                  break;
          case RELEASE_10:
  		errsts = check_readiness(SCpnt, 1, devip);
                  break;
  	case READ_CAPACITY:
  		errsts = resp_readcap(SCpnt, devip);
  		break;
  	case SERVICE_ACTION_IN:
  		if (SAI_READ_CAPACITY_16 != cmd[1]) {
  			mk_sense_buffer(devip, ILLEGAL_REQUEST,
  					INVALID_OPCODE, 0);
  			errsts = check_condition_result;
  			break;
  		}
  		errsts = resp_readcap16(SCpnt, devip);
  		break;
  	case MAINTENANCE_IN:
  		if (MI_REPORT_TARGET_PGS != cmd[1]) {
  			mk_sense_buffer(devip, ILLEGAL_REQUEST,
  					INVALID_OPCODE, 0);
  			errsts = check_condition_result;
  			break;
  		}
  		errsts = resp_report_tgtpgs(SCpnt, devip);
  		break;
  	case READ_16:
  	case READ_12:
  	case READ_10:
  	case READ_6:
  		if ((errsts = check_readiness(SCpnt, 0, devip)))
  			break;
  		if (scsi_debug_fake_rw)
  			break;
  		if ((*cmd) == READ_16) {
  			for (lba = 0, j = 0; j < 8; ++j) {
  				if (j > 0)
  					lba <<= 8;
  				lba += cmd[2 + j];
  			}
  			num = cmd[13] + (cmd[12] << 8) +
  				(cmd[11] << 16) + (cmd[10] << 24);
  		} else if ((*cmd) == READ_12) {
  			lba = cmd[5] + (cmd[4] << 8) +
  				(cmd[3] << 16) + (cmd[2] << 24);
  			num = cmd[9] + (cmd[8] << 8) +
  				(cmd[7] << 16) + (cmd[6] << 24);
  		} else if ((*cmd) == READ_10) {
  			lba = cmd[5] + (cmd[4] << 8) +
  				(cmd[3] << 16) + (cmd[2] << 24);
  			num = cmd[8] + (cmd[7] << 8);
  		} else {	/* READ (6) */
  			lba = cmd[3] + (cmd[2] << 8) +
  				((cmd[1] & 0x1f) << 16);
  			num = (0 == cmd[4]) ? 256 : cmd[4];
  		}
  		errsts = resp_read(SCpnt, lba, num, devip);
  		if (inj_recovered && (0 == errsts)) {
  			mk_sense_buffer(devip, RECOVERED_ERROR,
  					THRESHOLD_EXCEEDED, 0);
  			errsts = check_condition_result;
  		} else if (inj_transport && (0 == errsts)) {
                          mk_sense_buffer(devip, ABORTED_COMMAND,
                                          TRANSPORT_PROBLEM, ACK_NAK_TO);
                          errsts = check_condition_result;
                  }
  		break;
  	case REPORT_LUNS:	/* mandatory, ignore unit attention */
  		delay_override = 1;
  		errsts = resp_report_luns(SCpnt, devip);
  		break;
  	case VERIFY:		/* 10 byte SBC-2 command */
  		errsts = check_readiness(SCpnt, 0, devip);
  		break;
  	case WRITE_16:
  	case WRITE_12:
  	case WRITE_10:
  	case WRITE_6:
  		if ((errsts = check_readiness(SCpnt, 0, devip)))
  			break;
  		if (scsi_debug_fake_rw)
  			break;
  		if ((*cmd) == WRITE_16) {
  			for (lba = 0, j = 0; j < 8; ++j) {
  				if (j > 0)
  					lba <<= 8;
  				lba += cmd[2 + j];
  			}
  			num = cmd[13] + (cmd[12] << 8) +
  				(cmd[11] << 16) + (cmd[10] << 24);
  		} else if ((*cmd) == WRITE_12) {
  			lba = cmd[5] + (cmd[4] << 8) +
  				(cmd[3] << 16) + (cmd[2] << 24);
  			num = cmd[9] + (cmd[8] << 8) +
  				(cmd[7] << 16) + (cmd[6] << 24);
  		} else if ((*cmd) == WRITE_10) {
  			lba = cmd[5] + (cmd[4] << 8) +
  				(cmd[3] << 16) + (cmd[2] << 24);
  			num = cmd[8] + (cmd[7] << 8);
  		} else {	/* WRITE (6) */
  			lba = cmd[3] + (cmd[2] << 8) +
  				((cmd[1] & 0x1f) << 16);
  			num = (0 == cmd[4]) ? 256 : cmd[4];
  		}
  		errsts = resp_write(SCpnt, lba, num, devip);
  		if (inj_recovered && (0 == errsts)) {
  			mk_sense_buffer(devip, RECOVERED_ERROR,
  					THRESHOLD_EXCEEDED, 0);
  			errsts = check_condition_result;
  		}
  		break;
  	case MODE_SENSE:
  	case MODE_SENSE_10:
  		errsts = resp_mode_sense(SCpnt, target, devip);
  		break;
  	case MODE_SELECT:
  		errsts = resp_mode_select(SCpnt, 1, devip);
  		break;
  	case MODE_SELECT_10:
  		errsts = resp_mode_select(SCpnt, 0, devip);
  		break;
  	case LOG_SENSE:
  		errsts = resp_log_sense(SCpnt, devip);
  		break;
  	case SYNCHRONIZE_CACHE:
  		delay_override = 1;
  		errsts = check_readiness(SCpnt, 0, devip);
  		break;
  	case WRITE_BUFFER:
  		errsts = check_readiness(SCpnt, 1, devip);
  		break;
  	default:
  		if (SCSI_DEBUG_OPT_NOISE & scsi_debug_opts)
  			printk(KERN_INFO "scsi_debug: Opcode: 0x%x not "
  			       "supported\n", *cmd);
  		if ((errsts = check_readiness(SCpnt, 1, devip)))
  			break;	/* Unit attention takes precedence */
  		mk_sense_buffer(devip, ILLEGAL_REQUEST, INVALID_OPCODE, 0);
  		errsts = check_condition_result;
  		break;
  	}
  	return schedule_resp(SCpnt, devip, done, errsts,
  			     (delay_override ? 0 : scsi_debug_delay));
  }
  
  static int scsi_debug_ioctl(struct scsi_device *dev, int cmd, void __user *arg)
  {
  	if (SCSI_DEBUG_OPT_NOISE & scsi_debug_opts) {
  		printk(KERN_INFO "scsi_debug: ioctl: cmd=0x%x\n", cmd);
  	}
  	return -EINVAL;
  	/* return -ENOTTY; // correct return but upsets fdisk */
  }
  
  static int check_readiness(struct scsi_cmnd * SCpnt, int reset_only,
  			   struct sdebug_dev_info * devip)
  {
  	if (devip->reset) {
  		if (SCSI_DEBUG_OPT_NOISE & scsi_debug_opts)
  			printk(KERN_INFO "scsi_debug: Reporting Unit "
  			       "attention: power on reset\n");
  		devip->reset = 0;
  		mk_sense_buffer(devip, UNIT_ATTENTION, POWERON_RESET, 0);
  		return check_condition_result;
  	}
  	if ((0 == reset_only) && devip->stopped) {
  		if (SCSI_DEBUG_OPT_NOISE & scsi_debug_opts)
  			printk(KERN_INFO "scsi_debug: Reporting Not "
  			       "ready: initializing command required\n");
  		mk_sense_buffer(devip, NOT_READY, LOGICAL_UNIT_NOT_READY,
  				0x2);
  		return check_condition_result;
  	}
  	return 0;
  }
  
  /* Returns 0 if ok else (DID_ERROR << 16). Sets scp->resid . */
  static int fill_from_dev_buffer(struct scsi_cmnd * scp, unsigned char * arr,
  				int arr_len)
  {
  	int k, req_len, act_len, len, active;
  	void * kaddr;
  	void * kaddr_off;
  	struct scatterlist * sgpnt;
  
  	if (0 == scp->request_bufflen)
  		return 0;
  	if (NULL == scp->request_buffer)
  		return (DID_ERROR << 16);
  	if (! ((scp->sc_data_direction == DMA_BIDIRECTIONAL) ||
  	      (scp->sc_data_direction == DMA_FROM_DEVICE)))
  		return (DID_ERROR << 16);
  	if (0 == scp->use_sg) {
  		req_len = scp->request_bufflen;
  		act_len = (req_len < arr_len) ? req_len : arr_len;
  		memcpy(scp->request_buffer, arr, act_len);
  		if (scp->resid)
  			scp->resid -= act_len;
  		else
  			scp->resid = req_len - act_len;
  		return 0;
  	}
  	sgpnt = (struct scatterlist *)scp->request_buffer;
  	active = 1;
  	for (k = 0, req_len = 0, act_len = 0; k < scp->use_sg; ++k, ++sgpnt) {
  		if (active) {
  			kaddr = (unsigned char *)
  				kmap_atomic(sgpnt->page, KM_USER0);
  			if (NULL == kaddr)
  				return (DID_ERROR << 16);
  			kaddr_off = (unsigned char *)kaddr + sgpnt->offset;
  			len = sgpnt->length;
  			if ((req_len + len) > arr_len) {
  				active = 0;
  				len = arr_len - req_len;
  			}
  			memcpy(kaddr_off, arr + req_len, len);
  			kunmap_atomic(kaddr, KM_USER0);
  			act_len += len;
  		}
  		req_len += sgpnt->length;
  	}
  	if (scp->resid)
  		scp->resid -= act_len;
  	else
  		scp->resid = req_len - act_len;
  	return 0;
  }
  
  /* Returns number of bytes fetched into 'arr' or -1 if error. */
  static int fetch_to_dev_buffer(struct scsi_cmnd * scp, unsigned char * arr,
  			       int max_arr_len)
  {
  	int k, req_len, len, fin;
  	void * kaddr;
  	void * kaddr_off;
  	struct scatterlist * sgpnt;
  
  	if (0 == scp->request_bufflen)
  		return 0;
  	if (NULL == scp->request_buffer)
  		return -1;
  	if (! ((scp->sc_data_direction == DMA_BIDIRECTIONAL) ||
  	      (scp->sc_data_direction == DMA_TO_DEVICE)))
  		return -1;
  	if (0 == scp->use_sg) {
  		req_len = scp->request_bufflen;
  		len = (req_len < max_arr_len) ? req_len : max_arr_len;
  		memcpy(arr, scp->request_buffer, len);
  		return len;
  	}
  	sgpnt = (struct scatterlist *)scp->request_buffer;
  	for (k = 0, req_len = 0, fin = 0; k < scp->use_sg; ++k, ++sgpnt) {
  		kaddr = (unsigned char *)kmap_atomic(sgpnt->page, KM_USER0);
  		if (NULL == kaddr)
  			return -1;
  		kaddr_off = (unsigned char *)kaddr + sgpnt->offset;
  		len = sgpnt->length;
  		if ((req_len + len) > max_arr_len) {
  			len = max_arr_len - req_len;
  			fin = 1;
  		}
  		memcpy(arr + req_len, kaddr_off, len);
  		kunmap_atomic(kaddr, KM_USER0);
  		if (fin)
  			return req_len + len;
  		req_len += sgpnt->length;
  	}
  	return req_len;
  }
  
  
  static const char * inq_vendor_id = "Linux   ";
  static const char * inq_product_id = "scsi_debug      ";
  static const char * inq_product_rev = "0004";
  
  static int inquiry_evpd_83(unsigned char * arr, int port_group_id,
  			   int target_dev_id, int dev_id_num,
  			   const char * dev_id_str,
  			   int dev_id_str_len)
  {
  	int num, port_a;
  	char b[32];
  
  	port_a = target_dev_id + 1;
  	/* T10 vendor identifier field format (faked) */
  	arr[0] = 0x2;	/* ASCII */
  	arr[1] = 0x1;
  	arr[2] = 0x0;
  	memcpy(&arr[4], inq_vendor_id, 8);
  	memcpy(&arr[12], inq_product_id, 16);
  	memcpy(&arr[28], dev_id_str, dev_id_str_len);
  	num = 8 + 16 + dev_id_str_len;
  	arr[3] = num;
  	num += 4;
  	if (dev_id_num >= 0) {
  		/* NAA-5, Logical unit identifier (binary) */
  		arr[num++] = 0x1;	/* binary (not necessarily sas) */
  		arr[num++] = 0x3;	/* PIV=0, lu, naa */
  		arr[num++] = 0x0;
  		arr[num++] = 0x8;
  		arr[num++] = 0x53;  /* naa-5 ieee company id=0x333333 (fake) */
  		arr[num++] = 0x33;
  		arr[num++] = 0x33;
  		arr[num++] = 0x30;
  		arr[num++] = (dev_id_num >> 24);
  		arr[num++] = (dev_id_num >> 16) & 0xff;
  		arr[num++] = (dev_id_num >> 8) & 0xff;
  		arr[num++] = dev_id_num & 0xff;
  		/* Target relative port number */
  		arr[num++] = 0x61;	/* proto=sas, binary */
  		arr[num++] = 0x94;	/* PIV=1, target port, rel port */
  		arr[num++] = 0x0;	/* reserved */
  		arr[num++] = 0x4;	/* length */
  		arr[num++] = 0x0;	/* reserved */
  		arr[num++] = 0x0;	/* reserved */
  		arr[num++] = 0x0;
  		arr[num++] = 0x1;	/* relative port A */
  	}
  	/* NAA-5, Target port identifier */
  	arr[num++] = 0x61;	/* proto=sas, binary */
  	arr[num++] = 0x93;	/* piv=1, target port, naa */
  	arr[num++] = 0x0;
  	arr[num++] = 0x8;
  	arr[num++] = 0x52;	/* naa-5, company id=0x222222 (fake) */
  	arr[num++] = 0x22;
  	arr[num++] = 0x22;
  	arr[num++] = 0x20;
  	arr[num++] = (port_a >> 24);
  	arr[num++] = (port_a >> 16) & 0xff;
  	arr[num++] = (port_a >> 8) & 0xff;
  	arr[num++] = port_a & 0xff;
  	/* NAA-5, Target port group identifier */
  	arr[num++] = 0x61;	/* proto=sas, binary */
  	arr[num++] = 0x95;	/* piv=1, target port group id */
  	arr[num++] = 0x0;
  	arr[num++] = 0x4;
  	arr[num++] = 0;
  	arr[num++] = 0;
  	arr[num++] = (port_group_id >> 8) & 0xff;
  	arr[num++] = port_group_id & 0xff;
  	/* NAA-5, Target device identifier */
  	arr[num++] = 0x61;	/* proto=sas, binary */
  	arr[num++] = 0xa3;	/* piv=1, target device, naa */
  	arr[num++] = 0x0;
  	arr[num++] = 0x8;
  	arr[num++] = 0x52;	/* naa-5, company id=0x222222 (fake) */
  	arr[num++] = 0x22;
  	arr[num++] = 0x22;
  	arr[num++] = 0x20;
  	arr[num++] = (target_dev_id >> 24);
  	arr[num++] = (target_dev_id >> 16) & 0xff;
  	arr[num++] = (target_dev_id >> 8) & 0xff;
  	arr[num++] = target_dev_id & 0xff;
  	/* SCSI name string: Target device identifier */
  	arr[num++] = 0x63;	/* proto=sas, UTF-8 */
  	arr[num++] = 0xa8;	/* piv=1, target device, SCSI name string */
  	arr[num++] = 0x0;
  	arr[num++] = 24;
  	memcpy(arr + num, "naa.52222220", 12);
  	num += 12;
  	snprintf(b, sizeof(b), "%08X", target_dev_id);
  	memcpy(arr + num, b, 8);
  	num += 8;
  	memset(arr + num, 0, 4);
  	num += 4;
  	return num;
  }
  
  
  static unsigned char vpd84_data[] = {
  /* from 4th byte */ 0x22,0x22,0x22,0x0,0xbb,0x0,
      0x22,0x22,0x22,0x0,0xbb,0x1,
      0x22,0x22,0x22,0x0,0xbb,0x2,
  };
  
  static int inquiry_evpd_84(unsigned char * arr)
  {
  	memcpy(arr, vpd84_data, sizeof(vpd84_data));
  	return sizeof(vpd84_data);
  }
  
  static int inquiry_evpd_85(unsigned char * arr)
  {
  	int num = 0;
  	const char * na1 = "https://www.kernel.org/config";
  	const char * na2 = "http://www.kernel.org/log";
  	int plen, olen;
  
  	arr[num++] = 0x1;	/* lu, storage config */
  	arr[num++] = 0x0;	/* reserved */
  	arr[num++] = 0x0;
  	olen = strlen(na1);
  	plen = olen + 1;
  	if (plen % 4)
  		plen = ((plen / 4) + 1) * 4;
  	arr[num++] = plen;	/* length, null termianted, padded */
  	memcpy(arr + num, na1, olen);
  	memset(arr + num + olen, 0, plen - olen);
  	num += plen;
  
  	arr[num++] = 0x4;	/* lu, logging */
  	arr[num++] = 0x0;	/* reserved */
  	arr[num++] = 0x0;
  	olen = strlen(na2);
  	plen = olen + 1;
  	if (plen % 4)
  		plen = ((plen / 4) + 1) * 4;
  	arr[num++] = plen;	/* length, null terminated, padded */
  	memcpy(arr + num, na2, olen);
  	memset(arr + num + olen, 0, plen - olen);
  	num += plen;
  
  	return num;
  }
  
  /* SCSI ports VPD page */
  static int inquiry_evpd_88(unsigned char * arr, int target_dev_id)
  {
  	int num = 0;
  	int port_a, port_b;
  
  	port_a = target_dev_id + 1;
  	port_b = port_a + 1;
  	arr[num++] = 0x0;	/* reserved */
  	arr[num++] = 0x0;	/* reserved */
  	arr[num++] = 0x0;
  	arr[num++] = 0x1;	/* relative port 1 (primary) */
  	memset(arr + num, 0, 6);
  	num += 6;
  	arr[num++] = 0x0;
  	arr[num++] = 12;	/* length tp descriptor */
  	/* naa-5 target port identifier (A) */
  	arr[num++] = 0x61;	/* proto=sas, binary */
  	arr[num++] = 0x93;	/* PIV=1, target port, NAA */
  	arr[num++] = 0x0;	/* reserved */
  	arr[num++] = 0x8;	/* length */
  	arr[num++] = 0x52;	/* NAA-5, company_id=0x222222 (fake) */
  	arr[num++] = 0x22;
  	arr[num++] = 0x22;
  	arr[num++] = 0x20;
  	arr[num++] = (port_a >> 24);
  	arr[num++] = (port_a >> 16) & 0xff;
  	arr[num++] = (port_a >> 8) & 0xff;
  	arr[num++] = port_a & 0xff;
  
  	arr[num++] = 0x0;	/* reserved */
  	arr[num++] = 0x0;	/* reserved */
  	arr[num++] = 0x0;
  	arr[num++] = 0x2;	/* relative port 2 (secondary) */
  	memset(arr + num, 0, 6);
  	num += 6;
  	arr[num++] = 0x0;
  	arr[num++] = 12;	/* length tp descriptor */
  	/* naa-5 target port identifier (B) */
  	arr[num++] = 0x61;	/* proto=sas, binary */
  	arr[num++] = 0x93;	/* PIV=1, target port, NAA */
  	arr[num++] = 0x0;	/* reserved */
  	arr[num++] = 0x8;	/* length */
  	arr[num++] = 0x52;	/* NAA-5, company_id=0x222222 (fake) */
  	arr[num++] = 0x22;
  	arr[num++] = 0x22;
  	arr[num++] = 0x20;
  	arr[num++] = (port_b >> 24);
  	arr[num++] = (port_b >> 16) & 0xff;
  	arr[num++] = (port_b >> 8) & 0xff;
  	arr[num++] = port_b & 0xff;
  
  	return num;
  }
  
  
  static unsigned char vpd89_data[] = {
  /* from 4th byte */ 0,0,0,0,
  'l','i','n','u','x',' ',' ',' ',
  'S','A','T',' ','s','c','s','i','_','d','e','b','u','g',' ',' ',
  '1','2','3','4',
  0x34,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,
  0xec,0,0,0,
  0x5a,0xc,0xff,0x3f,0x37,0xc8,0x10,0,0,0,0,0,0x3f,0,0,0,
  0,0,0,0,0x58,0x58,0x58,0x58,0x58,0x58,0x58,0x58,0x20,0x20,0x20,0x20,
  0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0,0,0,0x40,0x4,0,0x2e,0x33,
  0x38,0x31,0x20,0x20,0x20,0x20,0x54,0x53,0x38,0x33,0x30,0x30,0x33,0x31,
  0x53,0x41,
  0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,
  0x20,0x20,
  0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,
  0x10,0x80,
  0,0,0,0x2f,0,0,0,0x2,0,0x2,0x7,0,0xff,0xff,0x1,0,
  0x3f,0,0xc1,0xff,0x3e,0,0x10,0x1,0xb0,0xf8,0x50,0x9,0,0,0x7,0,
  0x3,0,0x78,0,0x78,0,0xf0,0,0x78,0,0,0,0,0,0,0,
  0,0,0,0,0,0,0,0,0x2,0,0,0,0,0,0,0,
  0x7e,0,0x1b,0,0x6b,0x34,0x1,0x7d,0x3,0x40,0x69,0x34,0x1,0x3c,0x3,0x40,
  0x7f,0x40,0,0,0,0,0xfe,0xfe,0,0,0,0,0,0xfe,0,0,
  0,0,0,0,0,0,0,0,0xb0,0xf8,0x50,0x9,0,0,0,0,
  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
  0x1,0,0xb0,0xf8,0x50,0x9,0xb0,0xf8,0x50,0x9,0x20,0x20,0x2,0,0xb6,0x42,
  0,0x80,0x8a,0,0x6,0x3c,0xa,0x3c,0xff,0xff,0xc6,0x7,0,0x1,0,0x8,
  0xf0,0xf,0,0x10,0x2,0,0x30,0,0,0,0,0,0,0,0x6,0xfe,
  0,0,0x2,0,0x50,0,0x8a,0,0x4f,0x95,0,0,0x21,0,0xb,0,
  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0xa5,0x51,
  };
  
  static int inquiry_evpd_89(unsigned char * arr)
  {
  	memcpy(arr, vpd89_data, sizeof(vpd89_data));
  	return sizeof(vpd89_data);
  }
  
  
  static unsigned char vpdb0_data[] = {
  	/* from 4th byte */ 0,0,0,4,
  	0,0,0x4,0,
  	0,0,0,64,
  };
  
  static int inquiry_evpd_b0(unsigned char * arr)
  {
  	memcpy(arr, vpdb0_data, sizeof(vpdb0_data));
  	if (sdebug_store_sectors > 0x400) {
  		arr[4] = (sdebug_store_sectors >> 24) & 0xff;
  		arr[5] = (sdebug_store_sectors >> 16) & 0xff;
  		arr[6] = (sdebug_store_sectors >> 8) & 0xff;
  		arr[7] = sdebug_store_sectors & 0xff;
  	}
  	return sizeof(vpdb0_data);
  }
  
  
  #define SDEBUG_LONG_INQ_SZ 96
  #define SDEBUG_MAX_INQ_ARR_SZ 584
  
  static int resp_inquiry(struct scsi_cmnd * scp, int target,
  			struct sdebug_dev_info * devip)
  {
  	unsigned char pq_pdt;
  	unsigned char * arr;
  	unsigned char *cmd = (unsigned char *)scp->cmnd;
  	int alloc_len, n, ret;
  
  	alloc_len = (cmd[3] << 8) + cmd[4];
  	arr = kzalloc(SDEBUG_MAX_INQ_ARR_SZ, GFP_ATOMIC);
  	if (! arr)
  		return DID_REQUEUE << 16;
  	if (devip->wlun)
  		pq_pdt = 0x1e;	/* present, wlun */
  	else if (scsi_debug_no_lun_0 && (0 == devip->lun))
  		pq_pdt = 0x7f;	/* not present, no device type */
  	else
  		pq_pdt = (scsi_debug_ptype & 0x1f);
  	arr[0] = pq_pdt;
  	if (0x2 & cmd[1]) {  /* CMDDT bit set */
  		mk_sense_buffer(devip, ILLEGAL_REQUEST, INVALID_FIELD_IN_CDB,
  			       	0);
  		kfree(arr);
  		return check_condition_result;
  	} else if (0x1 & cmd[1]) {  /* EVPD bit set */
  		int lu_id_num, port_group_id, target_dev_id, len;
  		char lu_id_str[6];
  		int host_no = devip->sdbg_host->shost->host_no;
  		
  		port_group_id = (((host_no + 1) & 0x7f) << 8) +
  		    (devip->channel & 0x7f);
  		if (0 == scsi_debug_vpd_use_hostno)
  			host_no = 0;
  		lu_id_num = devip->wlun ? -1 : (((host_no + 1) * 2000) +
  			    (devip->target * 1000) + devip->lun);
  		target_dev_id = ((host_no + 1) * 2000) +
  				 (devip->target * 1000) - 3;
  		len = scnprintf(lu_id_str, 6, "%d", lu_id_num);
  		if (0 == cmd[2]) { /* supported vital product data pages */
  			arr[1] = cmd[2];	/*sanity */
  			n = 4;
  			arr[n++] = 0x0;   /* this page */
  			arr[n++] = 0x80;  /* unit serial number */
  			arr[n++] = 0x83;  /* device identification */
  			arr[n++] = 0x84;  /* software interface ident. */
  			arr[n++] = 0x85;  /* management network addresses */
  			arr[n++] = 0x86;  /* extended inquiry */
  			arr[n++] = 0x87;  /* mode page policy */
  			arr[n++] = 0x88;  /* SCSI ports */
  			arr[n++] = 0x89;  /* ATA information */
  			arr[n++] = 0xb0;  /* Block limits (SBC) */
  			arr[3] = n - 4;	  /* number of supported VPD pages */
  		} else if (0x80 == cmd[2]) { /* unit serial number */
  			arr[1] = cmd[2];	/*sanity */
  			arr[3] = len;
  			memcpy(&arr[4], lu_id_str, len);
  		} else if (0x83 == cmd[2]) { /* device identification */
  			arr[1] = cmd[2];	/*sanity */
  			arr[3] = inquiry_evpd_83(&arr[4], port_group_id,
  						 target_dev_id, lu_id_num,
  						 lu_id_str, len);
  		} else if (0x84 == cmd[2]) { /* Software interface ident. */
  			arr[1] = cmd[2];	/*sanity */
  			arr[3] = inquiry_evpd_84(&arr[4]);
  		} else if (0x85 == cmd[2]) { /* Management network addresses */
  			arr[1] = cmd[2];	/*sanity */
  			arr[3] = inquiry_evpd_85(&arr[4]);
  		} else if (0x86 == cmd[2]) { /* extended inquiry */
  			arr[1] = cmd[2];	/*sanity */
  			arr[3] = 0x3c;	/* number of following entries */
  			arr[4] = 0x0;   /* no protection stuff */
  			arr[5] = 0x7;   /* head of q, ordered + simple q's */
  		} else if (0x87 == cmd[2]) { /* mode page policy */
  			arr[1] = cmd[2];	/*sanity */
  			arr[3] = 0x8;	/* number of following entries */
  			arr[4] = 0x2;	/* disconnect-reconnect mp */
  			arr[6] = 0x80;	/* mlus, shared */
  			arr[8] = 0x18;	 /* protocol specific lu */
  			arr[10] = 0x82;	 /* mlus, per initiator port */
  		} else if (0x88 == cmd[2]) { /* SCSI Ports */
  			arr[1] = cmd[2];	/*sanity */
  			arr[3] = inquiry_evpd_88(&arr[4], target_dev_id);
  		} else if (0x89 == cmd[2]) { /* ATA information */
  			arr[1] = cmd[2];        /*sanity */
  			n = inquiry_evpd_89(&arr[4]);
  			arr[2] = (n >> 8);
  			arr[3] = (n & 0xff);
  		} else if (0xb0 == cmd[2]) { /* Block limits (SBC) */
  			arr[1] = cmd[2];        /*sanity */
  			arr[3] = inquiry_evpd_b0(&arr[4]);
  		} else {
  			/* Illegal request, invalid field in cdb */
  			mk_sense_buffer(devip, ILLEGAL_REQUEST,
  					INVALID_FIELD_IN_CDB, 0);
  			kfree(arr);
  			return check_condition_result;
  		}
  		len = min(((arr[2] << 8) + arr[3]) + 4, alloc_len);
  		ret = fill_from_dev_buffer(scp, arr,
  			    min(len, SDEBUG_MAX_INQ_ARR_SZ));
  		kfree(arr);
  		return ret;
  	}
  	/* drops through here for a standard inquiry */
  	arr[1] = DEV_REMOVEABLE(target) ? 0x80 : 0;	/* Removable disk */
  	arr[2] = scsi_debug_scsi_level;
  	arr[3] = 2;    /* response_data_format==2 */
  	arr[4] = SDEBUG_LONG_INQ_SZ - 5;
  	if (0 == scsi_debug_vpd_use_hostno)
  		arr[5] = 0x10; /* claim: implicit TGPS */
  	arr[6] = 0x10; /* claim: MultiP */
  	/* arr[6] |= 0x40; ... claim: EncServ (enclosure services) */
  	arr[7] = 0xa; /* claim: LINKED + CMDQUE */
  	memcpy(&arr[8], inq_vendor_id, 8);
  	memcpy(&arr[16], inq_product_id, 16);
  	memcpy(&arr[32], inq_product_rev, 4);
  	/* version descriptors (2 bytes each) follow */
  	arr[58] = 0x0; arr[59] = 0x77; /* SAM-3 ANSI */
  	arr[60] = 0x3; arr[61] = 0x14;  /* SPC-3 ANSI */
  	n = 62;
  	if (scsi_debug_ptype == 0) {
  		arr[n++] = 0x3; arr[n++] = 0x3d; /* SBC-2 ANSI */
  	} else if (scsi_debug_ptype == 1) {
  		arr[n++] = 0x3; arr[n++] = 0x60; /* SSC-2 no version */
  	}
  	arr[n++] = 0xc; arr[n++] = 0xf;  /* SAS-1.1 rev 10 */
  	ret = fill_from_dev_buffer(scp, arr,
  			    min(alloc_len, SDEBUG_LONG_INQ_SZ));
  	kfree(arr);
  	return ret;
  }
  
  static int resp_requests(struct scsi_cmnd * scp,
  			 struct sdebug_dev_info * devip)
  {
  	unsigned char * sbuff;
  	unsigned char *cmd = (unsigned char *)scp->cmnd;
  	unsigned char arr[SDEBUG_SENSE_LEN];
  	int want_dsense;
  	int len = 18;
  
  	memset(arr, 0, sizeof(arr));
  	if (devip->reset == 1)
  		mk_sense_buffer(devip, 0, NO_ADDITIONAL_SENSE, 0);
  	want_dsense = !!(cmd[1] & 1) || scsi_debug_dsense;
  	sbuff = devip->sense_buff;
  	if ((iec_m_pg[2] & 0x4) && (6 == (iec_m_pg[3] & 0xf))) {
  		if (want_dsense) {
  			arr[0] = 0x72;
  			arr[1] = 0x0;		/* NO_SENSE in sense_key */
  			arr[2] = THRESHOLD_EXCEEDED;
  			arr[3] = 0xff;		/* TEST set and MRIE==6 */
  		} else {
  			arr[0] = 0x70;
  			arr[2] = 0x0;		/* NO_SENSE in sense_key */
  			arr[7] = 0xa;   	/* 18 byte sense buffer */
  			arr[12] = THRESHOLD_EXCEEDED;
  			arr[13] = 0xff;		/* TEST set and MRIE==6 */
  		}
  	} else {
  		memcpy(arr, sbuff, SDEBUG_SENSE_LEN);
  		if ((cmd[1] & 1) && (! scsi_debug_dsense)) {
  			/* DESC bit set and sense_buff in fixed format */
  			memset(arr, 0, sizeof(arr));
  			arr[0] = 0x72;
  			arr[1] = sbuff[2];     /* sense key */
  			arr[2] = sbuff[12];    /* asc */
  			arr[3] = sbuff[13];    /* ascq */
  			len = 8;
  		}
  	}
  	mk_sense_buffer(devip, 0, NO_ADDITIONAL_SENSE, 0);
  	return fill_from_dev_buffer(scp, arr, len);
  }
  
  static int resp_start_stop(struct scsi_cmnd * scp,
  			   struct sdebug_dev_info * devip)
  {
  	unsigned char *cmd = (unsigned char *)scp->cmnd;
  	int power_cond, errsts, start;
  
  	if ((errsts = check_readiness(scp, 1, devip)))
  		return errsts;
  	power_cond = (cmd[4] & 0xf0) >> 4;
  	if (power_cond) {
  		mk_sense_buffer(devip, ILLEGAL_REQUEST, INVALID_FIELD_IN_CDB,
  			       	0);
  		return check_condition_result;
  	}
  	start = cmd[4] & 1;
  	if (start == devip->stopped)
  		devip->stopped = !start;
  	return 0;
  }
  
  #define SDEBUG_READCAP_ARR_SZ 8
  static int resp_readcap(struct scsi_cmnd * scp,
  			struct sdebug_dev_info * devip)
  {
  	unsigned char arr[SDEBUG_READCAP_ARR_SZ];
  	unsigned int capac;
  	int errsts;
  
  	if ((errsts = check_readiness(scp, 1, devip)))
  		return errsts;
  	/* following just in case virtual_gb changed */
  	if (scsi_debug_virtual_gb > 0) {
  		sdebug_capacity = 2048 * 1024;
  		sdebug_capacity *= scsi_debug_virtual_gb;
  	} else
  		sdebug_capacity = sdebug_store_sectors;
  	memset(arr, 0, SDEBUG_READCAP_ARR_SZ);
  	if (sdebug_capacity < 0xffffffff) {
  		capac = (unsigned int)sdebug_capacity - 1;
  		arr[0] = (capac >> 24);
  		arr[1] = (capac >> 16) & 0xff;
  		arr[2] = (capac >> 8) & 0xff;
  		arr[3] = capac & 0xff;
  	} else {
  		arr[0] = 0xff;
  		arr[1] = 0xff;
  		arr[2] = 0xff;
  		arr[3] = 0xff;
  	}
  	arr[6] = (SECT_SIZE_PER(target) >> 8) & 0xff;
  	arr[7] = SECT_SIZE_PER(target) & 0xff;
  	return fill_from_dev_buffer(scp, arr, SDEBUG_READCAP_ARR_SZ);
  }
  
  #define SDEBUG_READCAP16_ARR_SZ 32
  static int resp_readcap16(struct scsi_cmnd * scp,
  			  struct sdebug_dev_info * devip)
  {
  	unsigned char *cmd = (unsigned char *)scp->cmnd;
  	unsigned char arr[SDEBUG_READCAP16_ARR_SZ];
  	unsigned long long capac;
  	int errsts, k, alloc_len;
  
  	if ((errsts = check_readiness(scp, 1, devip)))
  		return errsts;
  	alloc_len = ((cmd[10] << 24) + (cmd[11] << 16) + (cmd[12] << 8)
  		     + cmd[13]);
  	/* following just in case virtual_gb changed */
  	if (scsi_debug_virtual_gb > 0) {
  		sdebug_capacity = 2048 * 1024;
  		sdebug_capacity *= scsi_debug_virtual_gb;
  	} else
  		sdebug_capacity = sdebug_store_sectors;
  	memset(arr, 0, SDEBUG_READCAP16_ARR_SZ);
  	capac = sdebug_capacity - 1;
  	for (k = 0; k < 8; ++k, capac >>= 8)
  		arr[7 - k] = capac & 0xff;
  	arr[8] = (SECT_SIZE_PER(target) >> 24) & 0xff;
  	arr[9] = (SECT_SIZE_PER(target) >> 16) & 0xff;
  	arr[10] = (SECT_SIZE_PER(target) >> 8) & 0xff;
  	arr[11] = SECT_SIZE_PER(target) & 0xff;
  	return fill_from_dev_buffer(scp, arr,
  				    min(alloc_len, SDEBUG_READCAP16_ARR_SZ));
  }
  
  #define SDEBUG_MAX_TGTPGS_ARR_SZ 1412
  
  static int resp_report_tgtpgs(struct scsi_cmnd * scp,
  			      struct sdebug_dev_info * devip)
  {
  	unsigned char *cmd = (unsigned char *)scp->cmnd;
  	unsigned char * arr;
  	int host_no = devip->sdbg_host->shost->host_no;
  	int n, ret, alen, rlen;
  	int port_group_a, port_group_b, port_a, port_b;
  
  	alen = ((cmd[6] << 24) + (cmd[7] << 16) + (cmd[8] << 8)
  		+ cmd[9]);
  
  	arr = kzalloc(SDEBUG_MAX_TGTPGS_ARR_SZ, GFP_ATOMIC);
  	if (! arr)
  		return DID_REQUEUE << 16;
  	/*
  	 * EVPD page 0x88 states we have two ports, one
  	 * real and a fake port with no device connected.
  	 * So we create two port groups with one port each
  	 * and set the group with port B to unavailable.
  	 */
  	port_a = 0x1; /* relative port A */
  	port_b = 0x2; /* relative port B */
  	port_group_a = (((host_no + 1) & 0x7f) << 8) +
  	    (devip->channel & 0x7f);
  	port_group_b = (((host_no + 1) & 0x7f) << 8) +
  	    (devip->channel & 0x7f) + 0x80;
  
  	/*
  	 * The asymmetric access state is cycled according to the host_id.
  	 */
  	n = 4;
  	if (0 == scsi_debug_vpd_use_hostno) {
  	    arr[n++] = host_no % 3; /* Asymm access state */
  	    arr[n++] = 0x0F; /* claim: all states are supported */
  	} else {
  	    arr[n++] = 0x0; /* Active/Optimized path */
  	    arr[n++] = 0x01; /* claim: only support active/optimized paths */
  	}
  	arr[n++] = (port_group_a >> 8) & 0xff;
  	arr[n++] = port_group_a & 0xff;
  	arr[n++] = 0;    /* Reserved */
  	arr[n++] = 0;    /* Status code */
  	arr[n++] = 0;    /* Vendor unique */
  	arr[n++] = 0x1;  /* One port per group */
  	arr[n++] = 0;    /* Reserved */
  	arr[n++] = 0;    /* Reserved */
  	arr[n++] = (port_a >> 8) & 0xff;
  	arr[n++] = port_a & 0xff;
  	arr[n++] = 3;    /* Port unavailable */
  	arr[n++] = 0x08; /* claim: only unavailalbe paths are supported */
  	arr[n++] = (port_group_b >> 8) & 0xff;
  	arr[n++] = port_group_b & 0xff;
  	arr[n++] = 0;    /* Reserved */
  	arr[n++] = 0;    /* Status code */
  	arr[n++] = 0;    /* Vendor unique */
  	arr[n++] = 0x1;  /* One port per group */
  	arr[n++] = 0;    /* Reserved */
  	arr[n++] = 0;    /* Reserved */
  	arr[n++] = (port_b >> 8) & 0xff;
  	arr[n++] = port_b & 0xff;
  
  	rlen = n - 4;
  	arr[0] = (rlen >> 24) & 0xff;
  	arr[1] = (rlen >> 16) & 0xff;
  	arr[2] = (rlen >> 8) & 0xff;
  	arr[3] = rlen & 0xff;
  
  	/*
  	 * Return the smallest value of either
  	 * - The allocated length
  	 * - The constructed command length
  	 * - The maximum array size
  	 */
  	rlen = min(alen,n);
  	ret = fill_from_dev_buffer(scp, arr,
  				   min(rlen, SDEBUG_MAX_TGTPGS_ARR_SZ));
  	kfree(arr);
  	return ret;
  }
  
  /* <<Following mode page info copied from ST318451LW>> */
  
  static int resp_err_recov_pg(unsigned char * p, int pcontrol, int target)
  {	/* Read-Write Error Recovery page for mode_sense */
  	unsigned char err_recov_pg[] = {0x1, 0xa, 0xc0, 11, 240, 0, 0, 0,
  					5, 0, 0xff, 0xff};
  
  	memcpy(p, err_recov_pg, sizeof(err_recov_pg));
  	if (1 == pcontrol)
  		memset(p + 2, 0, sizeof(err_recov_pg) - 2);
  	return sizeof(err_recov_pg);
  }
  
  static int resp_disconnect_pg(unsigned char * p, int pcontrol, int target)
  { 	/* Disconnect-Reconnect page for mode_sense */
  	unsigned char disconnect_pg[] = {0x2, 0xe, 128, 128, 0, 10, 0, 0,
  					 0, 0, 0, 0, 0, 0, 0, 0};
  
  	memcpy(p, disconnect_pg, sizeof(disconnect_pg));
  	if (1 == pcontrol)
  		memset(p + 2, 0, sizeof(disconnect_pg) - 2);
  	return sizeof(disconnect_pg);
  }
  
  static int resp_format_pg(unsigned char * p, int pcontrol, int target)
  {       /* Format device page for mode_sense */
          unsigned char format_pg[] = {0x3, 0x16, 0, 0, 0, 0, 0, 0,
                                       0, 0, 0, 0, 0, 0, 0, 0,
                                       0, 0, 0, 0, 0x40, 0, 0, 0};
  
          memcpy(p, format_pg, sizeof(format_pg));
          p[10] = (sdebug_sectors_per >> 8) & 0xff;
          p[11] = sdebug_sectors_per & 0xff;
          p[12] = (SECT_SIZE >> 8) & 0xff;
          p[13] = SECT_SIZE & 0xff;
          if (DEV_REMOVEABLE(target))
                  p[20] |= 0x20; /* should agree with INQUIRY */
          if (1 == pcontrol)
                  memset(p + 2, 0, sizeof(format_pg) - 2);
          return sizeof(format_pg);
  }
  
  static int resp_caching_pg(unsigned char * p, int pcontrol, int target)
  { 	/* Caching page for mode_sense */
  	unsigned char caching_pg[] = {0x8, 18, 0x14, 0, 0xff, 0xff, 0, 0,
  		0xff, 0xff, 0xff, 0xff, 0x80, 0x14, 0, 0,     0, 0, 0, 0};
  
  	memcpy(p, caching_pg, sizeof(caching_pg));
  	if (1 == pcontrol)
  		memset(p + 2, 0, sizeof(caching_pg) - 2);
  	return sizeof(caching_pg);
  }
  
  static int resp_ctrl_m_pg(unsigned char * p, int pcontrol, int target)
  { 	/* Control mode page for mode_sense */
  	unsigned char ch_ctrl_m_pg[] = {/* 0xa, 10, */ 0x6, 0, 0, 0, 0, 0,
  				        0, 0, 0, 0};
  	unsigned char d_ctrl_m_pg[] = {0xa, 10, 2, 0, 0, 0, 0, 0,
  				     0, 0, 0x2, 0x4b};
  
  	if (scsi_debug_dsense)
  		ctrl_m_pg[2] |= 0x4;
  	else
  		ctrl_m_pg[2] &= ~0x4;
  	memcpy(p, ctrl_m_pg, sizeof(ctrl_m_pg));
  	if (1 == pcontrol)
  		memcpy(p + 2, ch_ctrl_m_pg, sizeof(ch_ctrl_m_pg));
  	else if (2 == pcontrol)
  		memcpy(p, d_ctrl_m_pg, sizeof(d_ctrl_m_pg));
  	return sizeof(ctrl_m_pg);
  }
  
  
  static int resp_iec_m_pg(unsigned char * p, int pcontrol, int target)
  {	/* Informational Exceptions control mode page for mode_sense */
  	unsigned char ch_iec_m_pg[] = {/* 0x1c, 0xa, */ 0x4, 0xf, 0, 0, 0, 0,
  				       0, 0, 0x0, 0x0};
  	unsigned char d_iec_m_pg[] = {0x1c, 0xa, 0x08, 0, 0, 0, 0, 0,
  				      0, 0, 0x0, 0x0};
  
  	memcpy(p, iec_m_pg, sizeof(iec_m_pg));
  	if (1 == pcontrol)
  		memcpy(p + 2, ch_iec_m_pg, sizeof(ch_iec_m_pg));
  	else if (2 == pcontrol)
  		memcpy(p, d_iec_m_pg, sizeof(d_iec_m_pg));
  	return sizeof(iec_m_pg);
  }
  
  static int resp_sas_sf_m_pg(unsigned char * p, int pcontrol, int target)
  {	/* SAS SSP mode page - short format for mode_sense */
  	unsigned char sas_sf_m_pg[] = {0x19, 0x6,
  		0x6, 0x0, 0x7, 0xd0, 0x0, 0x0};
  
  	memcpy(p, sas_sf_m_pg, sizeof(sas_sf_m_pg));
  	if (1 == pcontrol)
  		memset(p + 2, 0, sizeof(sas_sf_m_pg) - 2);
  	return sizeof(sas_sf_m_pg);
  }
  
  
  static int resp_sas_pcd_m_spg(unsigned char * p, int pcontrol, int target,
  			      int target_dev_id)
  {	/* SAS phy control and discover mode page for mode_sense */
  	unsigned char sas_pcd_m_pg[] = {0x59, 0x1, 0, 0x64, 0, 0x6, 0, 2,
  		    0, 0, 0, 0, 0x10, 0x9, 0x8, 0x0,
  		    0x52, 0x22, 0x22, 0x20, 0x0, 0x0, 0x0, 0x0,
  		    0x51, 0x11, 0x11, 0x10, 0x0, 0x0, 0x0, 0x1,
  		    0x2, 0, 0, 0, 0, 0, 0, 0,
  		    0x88, 0x99, 0, 0, 0, 0, 0, 0,
  		    0, 0, 0, 0, 0, 0, 0, 0,
  		    0, 1, 0, 0, 0x10, 0x9, 0x8, 0x0,
  		    0x52, 0x22, 0x22, 0x20, 0x0, 0x0, 0x0, 0x0,
  		    0x51, 0x11, 0x11, 0x10, 0x0, 0x0, 0x0, 0x1,
  		    0x3, 0, 0, 0, 0, 0, 0, 0,
  		    0x88, 0x99, 0, 0, 0, 0, 0, 0,
  		    0, 0, 0, 0, 0, 0, 0, 0,
  		};
  	int port_a, port_b;
  
  	port_a = target_dev_id + 1;
  	port_b = port_a + 1;
  	memcpy(p, sas_pcd_m_pg, sizeof(sas_pcd_m_pg));
  	p[20] = (port_a >> 24);
  	p[21] = (port_a >> 16) & 0xff;
  	p[22] = (port_a >> 8) & 0xff;
  	p[23] = port_a & 0xff;
  	p[48 + 20] = (port_b >> 24);
  	p[48 + 21] = (port_b >> 16) & 0xff;
  	p[48 + 22] = (port_b >> 8) & 0xff;
  	p[48 + 23] = port_b & 0xff;
  	if (1 == pcontrol)
  		memset(p + 4, 0, sizeof(sas_pcd_m_pg) - 4);
  	return sizeof(sas_pcd_m_pg);
  }
  
  static int resp_sas_sha_m_spg(unsigned char * p, int pcontrol)
  {	/* SAS SSP shared protocol specific port mode subpage */
  	unsigned char sas_sha_m_pg[] = {0x59, 0x2, 0, 0xc, 0, 0x6, 0x10, 0,
  		    0, 0, 0, 0, 0, 0, 0, 0,
  		};
  
  	memcpy(p, sas_sha_m_pg, sizeof(sas_sha_m_pg));
  	if (1 == pcontrol)
  		memset(p + 4, 0, sizeof(sas_sha_m_pg) - 4);
  	return sizeof(sas_sha_m_pg);
  }
  
  #define SDEBUG_MAX_MSENSE_SZ 256
  
  static int resp_mode_sense(struct scsi_cmnd * scp, int target,
  			   struct sdebug_dev_info * devip)
  {
  	unsigned char dbd, llbaa;
  	int pcontrol, pcode, subpcode, bd_len;
  	unsigned char dev_spec;
  	int k, alloc_len, msense_6, offset, len, errsts, target_dev_id;
  	unsigned char * ap;
  	unsigned char arr[SDEBUG_MAX_MSENSE_SZ];
  	unsigned char *cmd = (unsigned char *)scp->cmnd;
  
  	if ((errsts = check_readiness(scp, 1, devip)))
  		return errsts;
  	dbd = !!(cmd[1] & 0x8);
  	pcontrol = (cmd[2] & 0xc0) >> 6;
  	pcode = cmd[2] & 0x3f;
  	subpcode = cmd[3];
  	msense_6 = (MODE_SENSE == cmd[0]);
  	llbaa = msense_6 ? 0 : !!(cmd[1] & 0x10);
  	if ((0 == scsi_debug_ptype) && (0 == dbd))
  		bd_len = llbaa ? 16 : 8;
  	else
  		bd_len = 0;
  	alloc_len = msense_6 ? cmd[4] : ((cmd[7] << 8) | cmd[8]);
  	memset(arr, 0, SDEBUG_MAX_MSENSE_SZ);
  	if (0x3 == pcontrol) {  /* Saving values not supported */
  		mk_sense_buffer(devip, ILLEGAL_REQUEST, SAVING_PARAMS_UNSUP,
  			       	0);
  		return check_condition_result;
  	}
  	target_dev_id = ((devip->sdbg_host->shost->host_no + 1) * 2000) +
  			(devip->target * 1000) - 3;
  	/* set DPOFUA bit for disks */
  	if (0 == scsi_debug_ptype)
  		dev_spec = (DEV_READONLY(target) ? 0x80 : 0x0) | 0x10;
  	else
  		dev_spec = 0x0;
  	if (msense_6) {
  		arr[2] = dev_spec;
  		arr[3] = bd_len;
  		offset = 4;
  	} else {
  		arr[3] = dev_spec;
  		if (16 == bd_len)
  			arr[4] = 0x1;	/* set LONGLBA bit */
  		arr[7] = bd_len;	/* assume 255 or less */
  		offset = 8;
  	}
  	ap = arr + offset;
  	if ((bd_len > 0) && (0 == sdebug_capacity)) {
  		if (scsi_debug_virtual_gb > 0) {
  			sdebug_capacity = 2048 * 1024;
  			sdebug_capacity *= scsi_debug_virtual_gb;
  		} else
  			sdebug_capacity = sdebug_store_sectors;
  	}
  	if (8 == bd_len) {
  		if (sdebug_capacity > 0xfffffffe) {
  			ap[0] = 0xff;
  			ap[1] = 0xff;
  			ap[2] = 0xff;
  			ap[3] = 0xff;
  		} else {
  			ap[0] = (sdebug_capacity >> 24) & 0xff;
  			ap[1] = (sdebug_capacity >> 16) & 0xff;
  			ap[2] = (sdebug_capacity >> 8) & 0xff;
  			ap[3] = sdebug_capacity & 0xff;
  		}
          	ap[6] = (SECT_SIZE_PER(target) >> 8) & 0xff;
          	ap[7] = SECT_SIZE_PER(target) & 0xff;
  		offset += bd_len;
  		ap = arr + offset;
  	} else if (16 == bd_len) {
  		unsigned long long capac = sdebug_capacity;
  
          	for (k = 0; k < 8; ++k, capac >>= 8)
                  	ap[7 - k] = capac & 0xff;
          	ap[12] = (SECT_SIZE_PER(target) >> 24) & 0xff;
          	ap[13] = (SECT_SIZE_PER(target) >> 16) & 0xff;
          	ap[14] = (SECT_SIZE_PER(target) >> 8) & 0xff;
          	ap[15] = SECT_SIZE_PER(target) & 0xff;
  		offset += bd_len;
  		ap = arr + offset;
  	}
  
  	if ((subpcode > 0x0) && (subpcode < 0xff) && (0x19 != pcode)) {
  		/* TODO: Control Extension page */
  		mk_sense_buffer(devip, ILLEGAL_REQUEST, INVALID_FIELD_IN_CDB,
  			       	0);
  		return check_condition_result;
  	}
  	switch (pcode) {
  	case 0x1:	/* Read-Write error recovery page, direct access */
  		len = resp_err_recov_pg(ap, pcontrol, target);
  		offset += len;
  		break;
  	case 0x2:	/* Disconnect-Reconnect page, all devices */
  		len = resp_disconnect_pg(ap, pcontrol, target);
  		offset += len;
  		break;
          case 0x3:       /* Format device page, direct access */
                  len = resp_format_pg(ap, pcontrol, target);
                  offset += len;
                  break;
  	case 0x8:	/* Caching page, direct access */
  		len = resp_caching_pg(ap, pcontrol, target);
  		offset += len;
  		break;
  	case 0xa:	/* Control Mode page, all devices */
  		len = resp_ctrl_m_pg(ap, pcontrol, target);
  		offset += len;
  		break;
  	case 0x19:	/* if spc==1 then sas phy, control+discover */
  		if ((subpcode > 0x2) && (subpcode < 0xff)) {
  		        mk_sense_buffer(devip, ILLEGAL_REQUEST,
  					INVALID_FIELD_IN_CDB, 0);
  			return check_condition_result;
  	        }
  		len = 0;
  		if ((0x0 == subpcode) || (0xff == subpcode))
  			len += resp_sas_sf_m_pg(ap + len, pcontrol, target);
  		if ((0x1 == subpcode) || (0xff == subpcode))
  			len += resp_sas_pcd_m_spg(ap + len, pcontrol, target,
  						  target_dev_id);
  		if ((0x2 == subpcode) || (0xff == subpcode))
  			len += resp_sas_sha_m_spg(ap + len, pcontrol);
  		offset += len;
  		break;
  	case 0x1c:	/* Informational Exceptions Mode page, all devices */
  		len = resp_iec_m_pg(ap, pcontrol, target);
  		offset += len;
  		break;
  	case 0x3f:	/* Read all Mode pages */
  		if ((0 == subpcode) || (0xff == subpcode)) {
  			len = resp_err_recov_pg(ap, pcontrol, target);
  			len += resp_disconnect_pg(ap + len, pcontrol, target);
  			len += resp_format_pg(ap + len, pcontrol, target);
  			len += resp_caching_pg(ap + len, pcontrol, target);
  			len += resp_ctrl_m_pg(ap + len, pcontrol, target);
  			len += resp_sas_sf_m_pg(ap + len, pcontrol, target);
  			if (0xff == subpcode) {
  				len += resp_sas_pcd_m_spg(ap + len, pcontrol,
  						  target, target_dev_id);
  				len += resp_sas_sha_m_spg(ap + len, pcontrol);
  			}
  			len += resp_iec_m_pg(ap + len, pcontrol, target);
  		} else {
  			mk_sense_buffer(devip, ILLEGAL_REQUEST,
  					INVALID_FIELD_IN_CDB, 0);
  			return check_condition_result;
                  }
  		offset += len;
  		break;
  	default:
  		mk_sense_buffer(devip, ILLEGAL_REQUEST, INVALID_FIELD_IN_CDB,
  			       	0);
  		return check_condition_result;
  	}
  	if (msense_6)
  		arr[0] = offset - 1;
  	else {
  		arr[0] = ((offset - 2) >> 8) & 0xff;
  		arr[1] = (offset - 2) & 0xff;
  	}
  	return fill_from_dev_buffer(scp, arr, min(alloc_len, offset));
  }
  
  #define SDEBUG_MAX_MSELECT_SZ 512
  
  static int resp_mode_select(struct scsi_cmnd * scp, int mselect6,
  			    struct sdebug_dev_info * devip)
  {
  	int pf, sp, ps, md_len, bd_len, off, spf, pg_len;
  	int param_len, res, errsts, mpage;
  	unsigned char arr[SDEBUG_MAX_MSELECT_SZ];
  	unsigned char *cmd = (unsigned char *)scp->cmnd;
  
  	if ((errsts = check_readiness(scp, 1, devip)))
  		return errsts;
  	memset(arr, 0, sizeof(arr));
  	pf = cmd[1] & 0x10;
  	sp = cmd[1] & 0x1;
  	param_len = mselect6 ? cmd[4] : ((cmd[7] << 8) + cmd[8]);
  	if ((0 == pf) || sp || (param_len > SDEBUG_MAX_MSELECT_SZ)) {
  		mk_sense_buffer(devip, ILLEGAL_REQUEST,
  				INVALID_FIELD_IN_CDB, 0);
  		return check_condition_result;
  	}
          res = fetch_to_dev_buffer(scp, arr, param_len);
          if (-1 == res)
                  return (DID_ERROR << 16);
          else if ((res < param_len) &&
                   (SCSI_DEBUG_OPT_NOISE & scsi_debug_opts))
                  printk(KERN_INFO "scsi_debug: mode_select: cdb indicated=%d, "
                         " IO sent=%d bytes\n", param_len, res);
  	md_len = mselect6 ? (arr[0] + 1) : ((arr[0] << 8) + arr[1] + 2);
  	bd_len = mselect6 ? arr[3] : ((arr[6] << 8) + arr[7]);
  	if (md_len > 2) {
  		mk_sense_buffer(devip, ILLEGAL_REQUEST,
  				INVALID_FIELD_IN_PARAM_LIST, 0);
  		return check_condition_result;
  	}
  	off = bd_len + (mselect6 ? 4 : 8);
  	mpage = arr[off] & 0x3f;
  	ps = !!(arr[off] & 0x80);
  	if (ps) {
  		mk_sense_buffer(devip, ILLEGAL_REQUEST,
  				INVALID_FIELD_IN_PARAM_LIST, 0);
  		return check_condition_result;
  	}
  	spf = !!(arr[off] & 0x40);
  	pg_len = spf ? ((arr[off + 2] << 8) + arr[off + 3] + 4) :
  		       (arr[off + 1] + 2);
  	if ((pg_len + off) > param_len) {
  		mk_sense_buffer(devip, ILLEGAL_REQUEST,
  				PARAMETER_LIST_LENGTH_ERR, 0);
  		return check_condition_result;
  	}
  	switch (mpage) {
  	case 0xa:      /* Control Mode page */
  		if (ctrl_m_pg[1] == arr[off + 1]) {
  			memcpy(ctrl_m_pg + 2, arr + off + 2,
  			       sizeof(ctrl_m_pg) - 2);
  			scsi_debug_dsense = !!(ctrl_m_pg[2] & 0x4);
  			return 0;
  		}
  		break;
  	case 0x1c:      /* Informational Exceptions Mode page */
  		if (iec_m_pg[1] == arr[off + 1]) {
  			memcpy(iec_m_pg + 2, arr + off + 2,
  			       sizeof(iec_m_pg) - 2);
  			return 0;
  		}
  		break;
  	default:
  		break;
  	}
  	mk_sense_buffer(devip, ILLEGAL_REQUEST,
  			INVALID_FIELD_IN_PARAM_LIST, 0);
  	return check_condition_result;
  }
  
  static int resp_temp_l_pg(unsigned char * arr)
  {
  	unsigned char temp_l_pg[] = {0x0, 0x0, 0x3, 0x2, 0x0, 38,
  				     0x0, 0x1, 0x3, 0x2, 0x0, 65,
  		};
  
          memcpy(arr, temp_l_pg, sizeof(temp_l_pg));
          return sizeof(temp_l_pg);
  }
  
  static int resp_ie_l_pg(unsigned char * arr)
  {
  	unsigned char ie_l_pg[] = {0x0, 0x0, 0x3, 0x3, 0x0, 0x0, 38,
  		};
  
          memcpy(arr, ie_l_pg, sizeof(ie_l_pg));
  	if (iec_m_pg[2] & 0x4) {	/* TEST bit set */
  		arr[4] = THRESHOLD_EXCEEDED;
  		arr[5] = 0xff;
  	}
          return sizeof(ie_l_pg);
  }
  
  #define SDEBUG_MAX_LSENSE_SZ 512
  
  static int resp_log_sense(struct scsi_cmnd * scp,
                            struct sdebug_dev_info * devip)
  {
  	int ppc, sp, pcontrol, pcode, subpcode, alloc_len, errsts, len, n;
  	unsigned char arr[SDEBUG_MAX_LSENSE_SZ];
  	unsigned char *cmd = (unsigned char *)scp->cmnd;
  
  	if ((errsts = check_readiness(scp, 1, devip)))
  		return errsts;
  	memset(arr, 0, sizeof(arr));
  	ppc = cmd[1] & 0x2;
  	sp = cmd[1] & 0x1;
  	if (ppc || sp) {
  		mk_sense_buffer(devip, ILLEGAL_REQUEST,
  				INVALID_FIELD_IN_CDB, 0);
  		return check_condition_result;
  	}
  	pcontrol = (cmd[2] & 0xc0) >> 6;
  	pcode = cmd[2] & 0x3f;
  	subpcode = cmd[3] & 0xff;
  	alloc_len = (cmd[7] << 8) + cmd[8];
  	arr[0] = pcode;
  	if (0 == subpcode) {
  		switch (pcode) {
  		case 0x0:	/* Supported log pages log page */
  			n = 4;
  			arr[n++] = 0x0;		/* this page */
  			arr[n++] = 0xd;		/* Temperature */
  			arr[n++] = 0x2f;	/* Informational exceptions */
  			arr[3] = n - 4;
  			break;
  		case 0xd:	/* Temperature log page */
  			arr[3] = resp_temp_l_pg(arr + 4);
  			break;
  		case 0x2f:	/* Informational exceptions log page */
  			arr[3] = resp_ie_l_pg(arr + 4);
  			break;
  		default:
  			mk_sense_buffer(devip, ILLEGAL_REQUEST,
  					INVALID_FIELD_IN_CDB, 0);
  			return check_condition_result;
  		}
  	} else if (0xff == subpcode) {
  		arr[0] |= 0x40;
  		arr[1] = subpcode;
  		switch (pcode) {
  		case 0x0:	/* Supported log pages and subpages log page */
  			n = 4;
  			arr[n++] = 0x0;
  			arr[n++] = 0x0;		/* 0,0 page */
  			arr[n++] = 0x0;
  			arr[n++] = 0xff;	/* this page */
  			arr[n++] = 0xd;
  			arr[n++] = 0x0;		/* Temperature */
  			arr[n++] = 0x2f;
  			arr[n++] = 0x0;	/* Informational exceptions */
  			arr[3] = n - 4;
  			break;
  		case 0xd:	/* Temperature subpages */
  			n = 4;
  			arr[n++] = 0xd;
  			arr[n++] = 0x0;		/* Temperature */
  			arr[3] = n - 4;
  			break;
  		case 0x2f:	/* Informational exceptions subpages */
  			n = 4;
  			arr[n++] = 0x2f;
  			arr[n++] = 0x0;		/* Informational exceptions */
  			arr[3] = n - 4;
  			break;
  		default:
  			mk_sense_buffer(devip, ILLEGAL_REQUEST,
  					INVALID_FIELD_IN_CDB, 0);
  			return check_condition_result;
  		}
  	} else {
  		mk_sense_buffer(devip, ILLEGAL_REQUEST,
  				INVALID_FIELD_IN_CDB, 0);
  		return check_condition_result;
  	}
  	len = min(((arr[2] << 8) + arr[3]) + 4, alloc_len);
  	return fill_from_dev_buffer(scp, arr,
  		    min(len, SDEBUG_MAX_INQ_ARR_SZ));
  }
  
  static int resp_read(struct scsi_cmnd * SCpnt, unsigned long long lba,
  		     unsigned int num, struct sdebug_dev_info * devip)
  {
  	unsigned long iflags;
  	unsigned int block, from_bottom;
  	unsigned long long u;
  	int ret;
  
  	if (lba + num > sdebug_capacity) {
  		mk_sense_buffer(devip, ILLEGAL_REQUEST, ADDR_OUT_OF_RANGE,
  				0);
  		return check_condition_result;
  	}
  	/* transfer length excessive (tie in to block limits VPD page) */
  	if (num > sdebug_store_sectors) {
  		mk_sense_buffer(devip, ILLEGAL_REQUEST, INVALID_FIELD_IN_CDB,
  				0);
  		return check_condition_result;
  	}
  	if ((SCSI_DEBUG_OPT_MEDIUM_ERR & scsi_debug_opts) &&
  	    (lba <= OPT_MEDIUM_ERR_ADDR) &&
  	    ((lba + num) > OPT_MEDIUM_ERR_ADDR)) {
  		/* claim unrecoverable read error */
  		mk_sense_buffer(devip, MEDIUM_ERROR, UNRECOVERED_READ_ERR,
  				0);
  		/* set info field and valid bit for fixed descriptor */
  		if (0x70 == (devip->sense_buff[0] & 0x7f)) {
  			devip->sense_buff[0] |= 0x80;	/* Valid bit */
  			ret = OPT_MEDIUM_ERR_ADDR;
  			devip->sense_buff[3] = (ret >> 24) & 0xff;
  			devip->sense_buff[4] = (ret >> 16) & 0xff;
  			devip->sense_buff[5] = (ret >> 8) & 0xff;
  			devip->sense_buff[6] = ret & 0xff;
  		}
  		return check_condition_result;
  	}
  	read_lock_irqsave(&atomic_rw, iflags);
  	if ((lba + num) <= sdebug_store_sectors)
  		ret = fill_from_dev_buffer(SCpnt,
  					   fake_storep + (lba * SECT_SIZE),
  			   		   num * SECT_SIZE);
  	else {
  		/* modulo when one arg is 64 bits needs do_div() */
  		u = lba;
  		block = do_div(u, sdebug_store_sectors);
  		from_bottom = 0;
  		if ((block + num) > sdebug_store_sectors)
  			from_bottom = (block + num) - sdebug_store_sectors;
  		ret = fill_from_dev_buffer(SCpnt,
  					   fake_storep + (block * SECT_SIZE),
  			   		   (num - from_bottom) * SECT_SIZE);
  		if ((0 == ret) && (from_bottom > 0))
  			ret = fill_from_dev_buffer(SCpnt, fake_storep,
  						   from_bottom * SECT_SIZE);
  	}
  	read_unlock_irqrestore(&atomic_rw, iflags);
  	return ret;
  }
  
  static int resp_write(struct scsi_cmnd * SCpnt, unsigned long long lba,
  		      unsigned int num, struct sdebug_dev_info * devip)
  {
  	unsigned long iflags;
  	unsigned int block, to_bottom;
  	unsigned long long u;
  	int res;
  
  	if (lba + num > sdebug_capacity) {
  		mk_sense_buffer(devip, ILLEGAL_REQUEST, ADDR_OUT_OF_RANGE,
  			       	0);
  		return check_condition_result;
  	}
  	/* transfer length excessive (tie in to block limits VPD page) */
  	if (num > sdebug_store_sectors) {
  		mk_sense_buffer(devip, ILLEGAL_REQUEST, INVALID_FIELD_IN_CDB,
  				0);
  		return check_condition_result;
  	}
  
  	write_lock_irqsave(&atomic_rw, iflags);
  	if ((lba + num) <= sdebug_store_sectors)
  		res = fetch_to_dev_buffer(SCpnt,
  					  fake_storep + (lba * SECT_SIZE),
  			   		  num * SECT_SIZE);
  	else {
  		/* modulo when one arg is 64 bits needs do_div() */
  		u = lba;
  		block = do_div(u, sdebug_store_sectors);
  		to_bottom = 0;
  		if ((block + num) > sdebug_store_sectors)
  			to_bottom = (block + num) - sdebug_store_sectors;
  		res = fetch_to_dev_buffer(SCpnt,
  					  fake_storep + (block * SECT_SIZE),
  			   		  (num - to_bottom) * SECT_SIZE);
  		if ((0 == res) && (to_bottom > 0))
  			res = fetch_to_dev_buffer(SCpnt, fake_storep,
  						  to_bottom * SECT_SIZE);
  	}
  	write_unlock_irqrestore(&atomic_rw, iflags);
  	if (-1 == res)
  		return (DID_ERROR << 16);
  	else if ((res < (num * SECT_SIZE)) &&
  		 (SCSI_DEBUG_OPT_NOISE & scsi_debug_opts))
  		printk(KERN_INFO "scsi_debug: write: cdb indicated=%u, "
  		       " IO sent=%d bytes\n", num * SECT_SIZE, res);
  	return 0;
  }
  
  #define SDEBUG_RLUN_ARR_SZ 256
  
  static int resp_report_luns(struct scsi_cmnd * scp,
  			    struct sdebug_dev_info * devip)
  {
  	unsigned int alloc_len;
  	int lun_cnt, i, upper, num, n, wlun, lun;
  	unsigned char *cmd = (unsigned char *)scp->cmnd;
  	int select_report = (int)cmd[2];
  	struct scsi_lun *one_lun;
  	unsigned char arr[SDEBUG_RLUN_ARR_SZ];
  	unsigned char * max_addr;
  
  	alloc_len = cmd[9] + (cmd[8] << 8) + (cmd[7] << 16) + (cmd[6] << 24);
  	if ((alloc_len < 4) || (select_report > 2)) {
  		mk_sense_buffer(devip, ILLEGAL_REQUEST, INVALID_FIELD_IN_CDB,
  			       	0);
  		return check_condition_result;
  	}
  	/* can produce response with up to 16k luns (lun 0 to lun 16383) */
  	memset(arr, 0, SDEBUG_RLUN_ARR_SZ);
  	lun_cnt = scsi_debug_max_luns;
  	if (1 == select_report)
  		lun_cnt = 0;
  	else if (scsi_debug_no_lun_0 && (lun_cnt > 0))
  		--lun_cnt;
  	wlun = (select_report > 0) ? 1 : 0;
  	num = lun_cnt + wlun;
  	arr[2] = ((sizeof(struct scsi_lun) * num) >> 8) & 0xff;
  	arr[3] = (sizeof(struct scsi_lun) * num) & 0xff;
  	n = min((int)((SDEBUG_RLUN_ARR_SZ - 8) /
  			    sizeof(struct scsi_lun)), num);
  	if (n < num) {
  		wlun = 0;
  		lun_cnt = n;
  	}
  	one_lun = (struct scsi_lun *) &arr[8];
  	max_addr = arr + SDEBUG_RLUN_ARR_SZ;
  	for (i = 0, lun = (scsi_debug_no_lun_0 ? 1 : 0);
               ((i < lun_cnt) && ((unsigned char *)(one_lun + i) < max_addr));
  	     i++, lun++) {
  		upper = (lun >> 8) & 0x3f;
  		if (upper)
  			one_lun[i].scsi_lun[0] =
  			    (upper | (SAM2_LUN_ADDRESS_METHOD << 6));
  		one_lun[i].scsi_lun[1] = lun & 0xff;
  	}
  	if (wlun) {
  		one_lun[i].scsi_lun[0] = (SAM2_WLUN_REPORT_LUNS >> 8) & 0xff;
  		one_lun[i].scsi_lun[1] = SAM2_WLUN_REPORT_LUNS & 0xff;
  		i++;
  	}
  	alloc_len = (unsigned char *)(one_lun + i) - arr;
  	return fill_from_dev_buffer(scp, arr,
  				    min((int)alloc_len, SDEBUG_RLUN_ARR_SZ));
  }
  
  /* When timer goes off this function is called. */
  static void timer_intr_handler(unsigned long indx)
  {
  	struct sdebug_queued_cmd * sqcp;
  	unsigned long iflags;
  
  	if (indx >= SCSI_DEBUG_CANQUEUE) {
  		printk(KERN_ERR "scsi_debug:timer_intr_handler: indx too "
  		       "large\n");
  		return;
  	}
  	spin_lock_irqsave(&queued_arr_lock, iflags);
  	sqcp = &queued_arr[(int)indx];
  	if (! sqcp->in_use) {
  		printk(KERN_ERR "scsi_debug:timer_intr_handler: Unexpected "
  		       "interrupt\n");
  		spin_unlock_irqrestore(&queued_arr_lock, iflags);
  		return;
  	}
  	sqcp->in_use = 0;
  	if (sqcp->done_funct) {
  		sqcp->a_cmnd->result = sqcp->scsi_result;
  		sqcp->done_funct(sqcp->a_cmnd); /* callback to mid level */
  	}
  	sqcp->done_funct = NULL;
  	spin_unlock_irqrestore(&queued_arr_lock, iflags);
  }
  
  static int scsi_debug_slave_alloc(struct scsi_device * sdp)
  {
  	if (SCSI_DEBUG_OPT_NOISE & scsi_debug_opts)
  		printk(KERN_INFO "scsi_debug: slave_alloc <%u %u %u %u>\n",
  		       sdp->host->host_no, sdp->channel, sdp->id, sdp->lun);
  	return 0;
  }
  
  static int scsi_debug_slave_configure(struct scsi_device * sdp)
  {
  	struct sdebug_dev_info * devip;
  
  	if (SCSI_DEBUG_OPT_NOISE & scsi_debug_opts)
  		printk(KERN_INFO "scsi_debug: slave_configure <%u %u %u %u>\n",
  		       sdp->host->host_no, sdp->channel, sdp->id, sdp->lun);
  	if (sdp->host->max_cmd_len != SCSI_DEBUG_MAX_CMD_LEN)
  		sdp->host->max_cmd_len = SCSI_DEBUG_MAX_CMD_LEN;
  	devip = devInfoReg(sdp);
  	if (NULL == devip)
  		return 1;	/* no resources, will be marked offline */
  	sdp->hostdata = devip;
  	if (sdp->host->cmd_per_lun)
  		scsi_adjust_queue_depth(sdp, SDEBUG_TAGGED_QUEUING,
  					sdp->host->cmd_per_lun);
  	blk_queue_max_segment_size(sdp->request_queue, 256 * 1024);
  	return 0;
  }
  
  static void scsi_debug_slave_destroy(struct scsi_device * sdp)
  {
  	struct sdebug_dev_info * devip =
  				(struct sdebug_dev_info *)sdp->hostdata;
  
  	if (SCSI_DEBUG_OPT_NOISE & scsi_debug_opts)
  		printk(KERN_INFO "scsi_debug: slave_destroy <%u %u %u %u>\n",
  		       sdp->host->host_no, sdp->channel, sdp->id, sdp->lun);
  	if (devip) {
  		/* make this slot avaliable for re-use */
  		devip->used = 0;
  		sdp->hostdata = NULL;
  	}
  }
  
  static struct sdebug_dev_info * devInfoReg(struct scsi_device * sdev)
  {
  	struct sdebug_host_info * sdbg_host;
  	struct sdebug_dev_info * open_devip = NULL;
  	struct sdebug_dev_info * devip =
  			(struct sdebug_dev_info *)sdev->hostdata;
  
  	if (devip)
  		return devip;
  	sdbg_host = *(struct sdebug_host_info **) sdev->host->hostdata;
          if(! sdbg_host) {
                  printk(KERN_ERR "Host info NULL\n");
  		return NULL;
          }
  	list_for_each_entry(devip, &sdbg_host->dev_info_list, dev_list) {
  		if ((devip->used) && (devip->channel == sdev->channel) &&
                      (devip->target == sdev->id) &&
                      (devip->lun == sdev->lun))
                          return devip;
  		else {
  			if ((!devip->used) && (!open_devip))
  				open_devip = devip;
  		}
  	}
  	if (NULL == open_devip) { /* try and make a new one */
  		open_devip = kzalloc(sizeof(*open_devip),GFP_ATOMIC);
  		if (NULL == open_devip) {
  			printk(KERN_ERR "%s: out of memory at line %d\n",
  				__FUNCTION__, __LINE__);
  			return NULL;
  		}
  		open_devip->sdbg_host = sdbg_host;
  		list_add_tail(&open_devip->dev_list,
  		&sdbg_host->dev_info_list);
  	}
          if (open_devip) {
  		open_devip->channel = sdev->channel;
  		open_devip->target = sdev->id;
  		open_devip->lun = sdev->lun;
  		open_devip->sdbg_host = sdbg_host;
  		open_devip->reset = 1;
  		open_devip->used = 1;
  		memset(open_devip->sense_buff, 0, SDEBUG_SENSE_LEN);
  		if (scsi_debug_dsense)
  			open_devip->sense_buff[0] = 0x72;
  		else {
  			open_devip->sense_buff[0] = 0x70;
  			open_devip->sense_buff[7] = 0xa;
  		}
  		if (sdev->lun == SAM2_WLUN_REPORT_LUNS)
  			open_devip->wlun = SAM2_WLUN_REPORT_LUNS & 0xff;
  		return open_devip;
          }
          return NULL;
  }
  
  static void mk_sense_buffer(struct sdebug_dev_info * devip, int key,
  			    int asc, int asq)
  {
  	unsigned char * sbuff;
  
  	sbuff = devip->sense_buff;
  	memset(sbuff, 0, SDEBUG_SENSE_LEN);
  	if (scsi_debug_dsense) {
  		sbuff[0] = 0x72;  /* descriptor, current */
  		sbuff[1] = key;
  		sbuff[2] = asc;
  		sbuff[3] = asq;
  	} else {
  		sbuff[0] = 0x70;  /* fixed, current */
  		sbuff[2] = key;
  		sbuff[7] = 0xa;	  /* implies 18 byte sense buffer */
  		sbuff[12] = asc;
  		sbuff[13] = asq;
  	}
  	if (SCSI_DEBUG_OPT_NOISE & scsi_debug_opts)
  		printk(KERN_INFO "scsi_debug:    [sense_key,asc,ascq]: "
  		      "[0x%x,0x%x,0x%x]\n", key, asc, asq);
  }
  
  static int scsi_debug_abort(struct scsi_cmnd * SCpnt)
  {
  	if (SCSI_DEBUG_OPT_NOISE & scsi_debug_opts)
  		printk(KERN_INFO "scsi_debug: abort\n");
  	++num_aborts;
  	stop_queued_cmnd(SCpnt);
  	return SUCCESS;
  }
  
  static int scsi_debug_biosparam(struct scsi_device *sdev,
  		struct block_device * bdev, sector_t capacity, int *info)
  {
  	int res;
  	unsigned char *buf;
  
  	if (SCSI_DEBUG_OPT_NOISE & scsi_debug_opts)
  		printk(KERN_INFO "scsi_debug: biosparam\n");
  	buf = scsi_bios_ptable(bdev);
  	if (buf) {
  		res = scsi_partsize(buf, capacity,
  				    &info[2], &info[0], &info[1]);
  		kfree(buf);
  		if (! res)
  			return res;
  	}
  	info[0] = sdebug_heads;
  	info[1] = sdebug_sectors_per;
  	info[2] = sdebug_cylinders_per;
  	return 0;
  }
  
  static int scsi_debug_device_reset(struct scsi_cmnd * SCpnt)
  {
  	struct sdebug_dev_info * devip;
  
  	if (SCSI_DEBUG_OPT_NOISE & scsi_debug_opts)
  		printk(KERN_INFO "scsi_debug: device_reset\n");
  	++num_dev_resets;
  	if (SCpnt) {
  		devip = devInfoReg(SCpnt->device);
  		if (devip)
  			devip->reset = 1;
  	}
  	return SUCCESS;
  }
  
  static int scsi_debug_bus_reset(struct scsi_cmnd * SCpnt)
  {
  	struct sdebug_host_info *sdbg_host;
          struct sdebug_dev_info * dev_info;
          struct scsi_device * sdp;
          struct Scsi_Host * hp;
  
  	if (SCSI_DEBUG_OPT_NOISE & scsi_debug_opts)
  		printk(KERN_INFO "scsi_debug: bus_reset\n");
  	++num_bus_resets;
  	if (SCpnt && ((sdp = SCpnt->device)) && ((hp = sdp->host))) {
  		sdbg_host = *(struct sdebug_host_info **) hp->hostdata;
  		if (sdbg_host) {
  			list_for_each_entry(dev_info,
                                              &sdbg_host->dev_info_list,
                                              dev_list)
  				dev_info->reset = 1;
  		}
  	}
  	return SUCCESS;
  }
  
  static int scsi_debug_host_reset(struct scsi_cmnd * SCpnt)
  {
  	struct sdebug_host_info * sdbg_host;
          struct sdebug_dev_info * dev_info;
  
  	if (SCSI_DEBUG_OPT_NOISE & scsi_debug_opts)
  		printk(KERN_INFO "scsi_debug: host_reset\n");
  	++num_host_resets;
          spin_lock(&sdebug_host_list_lock);
          list_for_each_entry(sdbg_host, &sdebug_host_list, host_list) {
                  list_for_each_entry(dev_info, &sdbg_host->dev_info_list,
                                      dev_list)
                          dev_info->reset = 1;
          }
          spin_unlock(&sdebug_host_list_lock);
  	stop_all_queued();
  	return SUCCESS;
  }
  
  /* Returns 1 if found 'cmnd' and deleted its timer. else returns 0 */
  static int stop_queued_cmnd(struct scsi_cmnd * cmnd)
  {
  	unsigned long iflags;
  	int k;
  	struct sdebug_queued_cmd * sqcp;
  
  	spin_lock_irqsave(&queued_arr_lock, iflags);
  	for (k = 0; k < SCSI_DEBUG_CANQUEUE; ++k) {
  		sqcp = &queued_arr[k];
  		if (sqcp->in_use && (cmnd == sqcp->a_cmnd)) {
  			del_timer_sync(&sqcp->cmnd_timer);
  			sqcp->in_use = 0;
  			sqcp->a_cmnd = NULL;
  			break;
  		}
  	}
  	spin_unlock_irqrestore(&queued_arr_lock, iflags);
  	return (k < SCSI_DEBUG_CANQUEUE) ? 1 : 0;
  }
  
  /* Deletes (stops) timers of all queued commands */
  static void stop_all_queued(void)
  {
  	unsigned long iflags;
  	int k;
  	struct sdebug_queued_cmd * sqcp;
  
  	spin_lock_irqsave(&queued_arr_lock, iflags);
  	for (k = 0; k < SCSI_DEBUG_CANQUEUE; ++k) {
  		sqcp = &queued_arr[k];
  		if (sqcp->in_use && sqcp->a_cmnd) {
  			del_timer_sync(&sqcp->cmnd_timer);
  			sqcp->in_use = 0;
  			sqcp->a_cmnd = NULL;
  		}
  	}
  	spin_unlock_irqrestore(&queued_arr_lock, iflags);
  }
  
  /* Initializes timers in queued array */
  static void __init init_all_queued(void)
  {
  	unsigned long iflags;
  	int k;
  	struct sdebug_queued_cmd * sqcp;
  
  	spin_lock_irqsave(&queued_arr_lock, iflags);
  	for (k = 0; k < SCSI_DEBUG_CANQUEUE; ++k) {
  		sqcp = &queued_arr[k];
  		init_timer(&sqcp->cmnd_timer);
  		sqcp->in_use = 0;
  		sqcp->a_cmnd = NULL;
  	}
  	spin_unlock_irqrestore(&queued_arr_lock, iflags);
  }
  
  static void __init sdebug_build_parts(unsigned char * ramp)
  {
  	struct partition * pp;
  	int starts[SDEBUG_MAX_PARTS + 2];
  	int sectors_per_part, num_sectors, k;
  	int heads_by_sects, start_sec, end_sec;
  
  	/* assume partition table already zeroed */
  	if ((scsi_debug_num_parts < 1) || (sdebug_store_size < 1048576))
  		return;
  	if (scsi_debug_num_parts > SDEBUG_MAX_PARTS) {
  		scsi_debug_num_parts = SDEBUG_MAX_PARTS;
  		printk(KERN_WARNING "scsi_debug:build_parts: reducing "
  				    "partitions to %d\n", SDEBUG_MAX_PARTS);
  	}
  	num_sectors = (int)sdebug_store_sectors;
  	sectors_per_part = (num_sectors - sdebug_sectors_per)
  			   / scsi_debug_num_parts;
  	heads_by_sects = sdebug_heads * sdebug_sectors_per;
          starts[0] = sdebug_sectors_per;
  	for (k = 1; k < scsi_debug_num_parts; ++k)
  		starts[k] = ((k * sectors_per_part) / heads_by_sects)
  			    * heads_by_sects;
  	starts[scsi_debug_num_parts] = num_sectors;
  	starts[scsi_debug_num_parts + 1] = 0;
  
  	ramp[510] = 0x55;	/* magic partition markings */
  	ramp[511] = 0xAA;
  	pp = (struct partition *)(ramp + 0x1be);
  	for (k = 0; starts[k + 1]; ++k, ++pp) {
  		start_sec = starts[k];
  		end_sec = starts[k + 1] - 1;
  		pp->boot_ind = 0;
  
  		pp->cyl = start_sec / heads_by_sects;
  		pp->head = (start_sec - (pp->cyl * heads_by_sects))
  			   / sdebug_sectors_per;
  		pp->sector = (start_sec % sdebug_sectors_per) + 1;
  
  		pp->end_cyl = end_sec / heads_by_sects;
  		pp->end_head = (end_sec - (pp->end_cyl * heads_by_sects))
  			       / sdebug_sectors_per;
  		pp->end_sector = (end_sec % sdebug_sectors_per) + 1;
  
  		pp->start_sect = start_sec;
  		pp->nr_sects = end_sec - start_sec + 1;
  		pp->sys_ind = 0x83;	/* plain Linux partition */
  	}
  }
  
  static int schedule_resp(struct scsi_cmnd * cmnd,
  			 struct sdebug_dev_info * devip,
  			 done_funct_t done, int scsi_result, int delta_jiff)
  {
  	if ((SCSI_DEBUG_OPT_NOISE & scsi_debug_opts) && cmnd) {
  		if (scsi_result) {
  			struct scsi_device * sdp = cmnd->device;
  
  			printk(KERN_INFO "scsi_debug:    <%u %u %u %u> "
  			       "non-zero result=0x%x\n", sdp->host->host_no,
  			       sdp->channel, sdp->id, sdp->lun, scsi_result);
  		}
  	}
  	if (cmnd && devip) {
  		/* simulate autosense by this driver */
  		if (SAM_STAT_CHECK_CONDITION == (scsi_result & 0xff))
  			memcpy(cmnd->sense_buffer, devip->sense_buff,
  			       (SCSI_SENSE_BUFFERSIZE > SDEBUG_SENSE_LEN) ?
  			       SDEBUG_SENSE_LEN : SCSI_SENSE_BUFFERSIZE);
  	}
  	if (delta_jiff <= 0) {
  		if (cmnd)
  			cmnd->result = scsi_result;
  		if (done)
  			done(cmnd);
  		return 0;
  	} else {
  		unsigned long iflags;
  		int k;
  		struct sdebug_queued_cmd * sqcp = NULL;
  
  		spin_lock_irqsave(&queued_arr_lock, iflags);
  		for (k = 0; k < SCSI_DEBUG_CANQUEUE; ++k) {
  			sqcp = &queued_arr[k];
  			if (! sqcp->in_use)
  				break;
  		}
  		if (k >= SCSI_DEBUG_CANQUEUE) {
  			spin_unlock_irqrestore(&queued_arr_lock, iflags);
  			printk(KERN_WARNING "scsi_debug: can_queue exceeded\n");
  			return 1;	/* report busy to mid level */
  		}
  		sqcp->in_use = 1;
  		sqcp->a_cmnd = cmnd;
  		sqcp->scsi_result = scsi_result;
  		sqcp->done_funct = done;
  		sqcp->cmnd_timer.function = timer_intr_handler;
  		sqcp->cmnd_timer.data = k;
  		sqcp->cmnd_timer.expires = jiffies + delta_jiff;
  		add_timer(&sqcp->cmnd_timer);
  		spin_unlock_irqrestore(&queued_arr_lock, iflags);
  		if (cmnd)
  			cmnd->result = 0;
  		return 0;
  	}
  }
  
  /* Note: The following macros create attribute files in the
     /sys/module/scsi_debug/parameters directory. Unfortunately this
     driver is unaware of a change and cannot trigger auxiliary actions
     as it can when the corresponding attribute in the
     /sys/bus/pseudo/drivers/scsi_debug directory is changed.
   */
  module_param_named(add_host, scsi_debug_add_host, int, S_IRUGO | S_IWUSR);
  module_param_named(delay, scsi_debug_delay, int, S_IRUGO | S_IWUSR);
  module_param_named(dev_size_mb, scsi_debug_dev_size_mb, int, S_IRUGO);
  module_param_named(dsense, scsi_debug_dsense, int, S_IRUGO | S_IWUSR);
  module_param_named(every_nth, scsi_debug_every_nth, int, S_IRUGO | S_IWUSR);
  module_param_named(fake_rw, scsi_debug_fake_rw, int, S_IRUGO | S_IWUSR);
  module_param_named(max_luns, scsi_debug_max_luns, int, S_IRUGO | S_IWUSR);
  module_param_named(no_lun_0, scsi_debug_no_lun_0, int, S_IRUGO | S_IWUSR);
  module_param_named(num_parts, scsi_debug_num_parts, int, S_IRUGO);
  module_param_named(num_tgts, scsi_debug_num_tgts, int, S_IRUGO | S_IWUSR);
  module_param_named(opts, scsi_debug_opts, int, S_IRUGO | S_IWUSR);
  module_param_named(ptype, scsi_debug_ptype, int, S_IRUGO | S_IWUSR);
  module_param_named(scsi_level, scsi_debug_scsi_level, int, S_IRUGO);
  module_param_named(virtual_gb, scsi_debug_virtual_gb, int, S_IRUGO | S_IWUSR);
  module_param_named(vpd_use_hostno, scsi_debug_vpd_use_hostno, int,
  		   S_IRUGO | S_IWUSR);
  
  MODULE_AUTHOR("Eric Youngdale + Douglas Gilbert");
  MODULE_DESCRIPTION("SCSI debug adapter driver");
  MODULE_LICENSE("GPL");
  MODULE_VERSION(SCSI_DEBUG_VERSION);
  
  MODULE_PARM_DESC(add_host, "0..127 hosts allowed(def=1)");
  MODULE_PARM_DESC(delay, "# of jiffies to delay response(def=1)");
  MODULE_PARM_DESC(dev_size_mb, "size in MB of ram shared by devs(def=8)");
  MODULE_PARM_DESC(dsense, "use descriptor sense format(def=0 -> fixed)");
  MODULE_PARM_DESC(every_nth, "timeout every nth command(def=100)");
  MODULE_PARM_DESC(fake_rw, "fake reads/writes instead of copying (def=0)");
  MODULE_PARM_DESC(max_luns, "number of LUNs per target to simulate(def=1)");
  MODULE_PARM_DESC(no_lun_0, "no LU number 0 (def=0 -> have lun 0)");
  MODULE_PARM_DESC(num_parts, "number of partitions(def=0)");
  MODULE_PARM_DESC(num_tgts, "number of targets per host to simulate(def=1)");
  MODULE_PARM_DESC(opts, "1->noise, 2->medium_err, 4->timeout, 8->recovered_err... (def=0)");
  MODULE_PARM_DESC(ptype, "SCSI peripheral type(def=0[disk])");
  MODULE_PARM_DESC(scsi_level, "SCSI level to simulate(def=5[SPC-3])");
  MODULE_PARM_DESC(virtual_gb, "virtual gigabyte size (def=0 -> use dev_size_mb)");
  MODULE_PARM_DESC(vpd_use_hostno, "0 -> dev ids ignore hostno (def=1 -> unique dev ids)");
  
  
  static char sdebug_info[256];
  
  static const char * scsi_debug_info(struct Scsi_Host * shp)
  {
  	sprintf(sdebug_info, "scsi_debug, version %s [%s], "
  		"dev_size_mb=%d, opts=0x%x", SCSI_DEBUG_VERSION,
  		scsi_debug_version_date, scsi_debug_dev_size_mb,
  		scsi_debug_opts);
  	return sdebug_info;
  }
  
  /* scsi_debug_proc_info
   * Used if the driver currently has no own support for /proc/scsi
   */
  static int scsi_debug_proc_info(struct Scsi_Host *host, char *buffer, char **start, off_t offset,
  				int length, int inout)
  {
  	int len, pos, begin;
  	int orig_length;
  
  	orig_length = length;
  
  	if (inout == 1) {
  		char arr[16];
  		int minLen = length > 15 ? 15 : length;
  
  		if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
  			return -EACCES;
  		memcpy(arr, buffer, minLen);
  		arr[minLen] = '\0';
  		if (1 != sscanf(arr, "%d", &pos))
  			return -EINVAL;
  		scsi_debug_opts = pos;
  		if (scsi_debug_every_nth != 0)
                          scsi_debug_cmnd_count = 0;
  		return length;
  	}
  	begin = 0;
  	pos = len = sprintf(buffer, "scsi_debug adapter driver, version "
  	    "%s [%s]\n"
  	    "num_tgts=%d, shared (ram) size=%d MB, opts=0x%x, "
  	    "every_nth=%d(curr:%d)\n"
  	    "delay=%d, max_luns=%d, scsi_level=%d\n"
  	    "sector_size=%d bytes, cylinders=%d, heads=%d, sectors=%d\n"
  	    "number of aborts=%d, device_reset=%d, bus_resets=%d, "
  	    "host_resets=%d\n",
  	    SCSI_DEBUG_VERSION, scsi_debug_version_date, scsi_debug_num_tgts,
  	    scsi_debug_dev_size_mb, scsi_debug_opts, scsi_debug_every_nth,
  	    scsi_debug_cmnd_count, scsi_debug_delay,
  	    scsi_debug_max_luns, scsi_debug_scsi_level,
  	    SECT_SIZE, sdebug_cylinders_per, sdebug_heads, sdebug_sectors_per,
  	    num_aborts, num_dev_resets, num_bus_resets, num_host_resets);
  	if (pos < offset) {
  		len = 0;
  		begin = pos;
  	}
  	*start = buffer + (offset - begin);	/* Start of wanted data */
  	len -= (offset - begin);
  	if (len > length)
  		len = length;
  	return len;
  }
  
  static ssize_t sdebug_delay_show(struct device_driver * ddp, char * buf)
  {
          return scnprintf(buf, PAGE_SIZE, "%d\n", scsi_debug_delay);
  }
  
  static ssize_t sdebug_delay_store(struct device_driver * ddp,
  				  const char * buf, size_t count)
  {
          int delay;
  	char work[20];
  
          if (1 == sscanf(buf, "%10s", work)) {
  		if ((1 == sscanf(work, "%d", &delay)) && (delay >= 0)) {
  			scsi_debug_delay = delay;
  			return count;
  		}
  	}
  	return -EINVAL;
  }
  DRIVER_ATTR(delay, S_IRUGO | S_IWUSR, sdebug_delay_show,
  	    sdebug_delay_store);
  
  static ssize_t sdebug_opts_show(struct device_driver * ddp, char * buf)
  {
          return scnprintf(buf, PAGE_SIZE, "0x%x\n", scsi_debug_opts);
  }
  
  static ssize_t sdebug_opts_store(struct device_driver * ddp,
  				 const char * buf, size_t count)
  {
          int opts;
  	char work[20];
  
          if (1 == sscanf(buf, "%10s", work)) {
  		if (0 == strnicmp(work,"0x", 2)) {
  			if (1 == sscanf(&work[2], "%x", &opts))
  				goto opts_done;
  		} else {
  			if (1 == sscanf(work, "%d", &opts))
  				goto opts_done;
  		}
  	}
  	return -EINVAL;
  opts_done:
  	scsi_debug_opts = opts;
  	scsi_debug_cmnd_count = 0;
  	return count;
  }
  DRIVER_ATTR(opts, S_IRUGO | S_IWUSR, sdebug_opts_show,
  	    sdebug_opts_store);
  
  static ssize_t sdebug_ptype_show(struct device_driver * ddp, char * buf)
  {
          return scnprintf(buf, PAGE_SIZE, "%d\n", scsi_debug_ptype);
  }
  static ssize_t sdebug_ptype_store(struct device_driver * ddp,
  				  const char * buf, size_t count)
  {
          int n;
  
  	if ((count > 0) && (1 == sscanf(buf, "%d", &n)) && (n >= 0)) {
  		scsi_debug_ptype = n;
  		return count;
  	}
  	return -EINVAL;
  }
  DRIVER_ATTR(ptype, S_IRUGO | S_IWUSR, sdebug_ptype_show, sdebug_ptype_store);
  
  static ssize_t sdebug_dsense_show(struct device_driver * ddp, char * buf)
  {
          return scnprintf(buf, PAGE_SIZE, "%d\n", scsi_debug_dsense);
  }
  static ssize_t sdebug_dsense_store(struct device_driver * ddp,
  				  const char * buf, size_t count)
  {
          int n;
  
  	if ((count > 0) && (1 == sscanf(buf, "%d", &n)) && (n >= 0)) {
  		scsi_debug_dsense = n;
  		return count;
  	}
  	return -EINVAL;
  }
  DRIVER_ATTR(dsense, S_IRUGO | S_IWUSR, sdebug_dsense_show,
  	    sdebug_dsense_store);
  
  static ssize_t sdebug_fake_rw_show(struct device_driver * ddp, char * buf)
  {
          return scnprintf(buf, PAGE_SIZE, "%d\n", scsi_debug_fake_rw);
  }
  static ssize_t sdebug_fake_rw_store(struct device_driver * ddp,
  				    const char * buf, size_t count)
  {
          int n;
  
  	if ((count > 0) && (1 == sscanf(buf, "%d", &n)) && (n >= 0)) {
  		scsi_debug_fake_rw = n;
  		return count;
  	}
  	return -EINVAL;
  }
  DRIVER_ATTR(fake_rw, S_IRUGO | S_IWUSR, sdebug_fake_rw_show,
  	    sdebug_fake_rw_store);
  
  static ssize_t sdebug_no_lun_0_show(struct device_driver * ddp, char * buf)
  {
          return scnprintf(buf, PAGE_SIZE, "%d\n", scsi_debug_no_lun_0);
  }
  static ssize_t sdebug_no_lun_0_store(struct device_driver * ddp,
  				     const char * buf, size_t count)
  {
          int n;
  
  	if ((count > 0) && (1 == sscanf(buf, "%d", &n)) && (n >= 0)) {
  		scsi_debug_no_lun_0 = n;
  		return count;
  	}
  	return -EINVAL;
  }
  DRIVER_ATTR(no_lun_0, S_IRUGO | S_IWUSR, sdebug_no_lun_0_show,
  	    sdebug_no_lun_0_store);
  
  static ssize_t sdebug_num_tgts_show(struct device_driver * ddp, char * buf)
  {
          return scnprintf(buf, PAGE_SIZE, "%d\n", scsi_debug_num_tgts);
  }
  static ssize_t sdebug_num_tgts_store(struct device_driver * ddp,
  				     const char * buf, size_t count)
  {
          int n;
  
  	if ((count > 0) && (1 == sscanf(buf, "%d", &n)) && (n >= 0)) {
  		scsi_debug_num_tgts = n;
  		sdebug_max_tgts_luns();
  		return count;
  	}
  	return -EINVAL;
  }
  DRIVER_ATTR(num_tgts, S_IRUGO | S_IWUSR, sdebug_num_tgts_show,
  	    sdebug_num_tgts_store);
  
  static ssize_t sdebug_dev_size_mb_show(struct device_driver * ddp, char * buf)
  {
          return scnprintf(buf, PAGE_SIZE, "%d\n", scsi_debug_dev_size_mb);
  }
  DRIVER_ATTR(dev_size_mb, S_IRUGO, sdebug_dev_size_mb_show, NULL);
  
  static ssize_t sdebug_num_parts_show(struct device_driver * ddp, char * buf)
  {
          return scnprintf(buf, PAGE_SIZE, "%d\n", scsi_debug_num_parts);
  }
  DRIVER_ATTR(num_parts, S_IRUGO, sdebug_num_parts_show, NULL);
  
  static ssize_t sdebug_every_nth_show(struct device_driver * ddp, char * buf)
  {
          return scnprintf(buf, PAGE_SIZE, "%d\n", scsi_debug_every_nth);
  }
  static ssize_t sdebug_every_nth_store(struct device_driver * ddp,
  				      const char * buf, size_t count)
  {
          int nth;
  
  	if ((count > 0) && (1 == sscanf(buf, "%d", &nth))) {
  		scsi_debug_every_nth = nth;
  		scsi_debug_cmnd_count = 0;
  		return count;
  	}
  	return -EINVAL;
  }
  DRIVER_ATTR(every_nth, S_IRUGO | S_IWUSR, sdebug_every_nth_show,
  	    sdebug_every_nth_store);
  
  static ssize_t sdebug_max_luns_show(struct device_driver * ddp, char * buf)
  {
          return scnprintf(buf, PAGE_SIZE, "%d\n", scsi_debug_max_luns);
  }
  static ssize_t sdebug_max_luns_store(struct device_driver * ddp,
  				     const char * buf, size_t count)
  {
          int n;
  
  	if ((count > 0) && (1 == sscanf(buf, "%d", &n)) && (n >= 0)) {
  		scsi_debug_max_luns = n;
  		sdebug_max_tgts_luns();
  		return count;
  	}
  	return -EINVAL;
  }
  DRIVER_ATTR(max_luns, S_IRUGO | S_IWUSR, sdebug_max_luns_show,
  	    sdebug_max_luns_store);
  
  static ssize_t sdebug_scsi_level_show(struct device_driver * ddp, char * buf)
  {
          return scnprintf(buf, PAGE_SIZE, "%d\n", scsi_debug_scsi_level);
  }
  DRIVER_ATTR(scsi_level, S_IRUGO, sdebug_scsi_level_show, NULL);
  
  static ssize_t sdebug_virtual_gb_show(struct device_driver * ddp, char * buf)
  {
          return scnprintf(buf, PAGE_SIZE, "%d\n", scsi_debug_virtual_gb);
  }
  static ssize_t sdebug_virtual_gb_store(struct device_driver * ddp,
  				       const char * buf, size_t count)
  {
          int n;
  
  	if ((count > 0) && (1 == sscanf(buf, "%d", &n)) && (n >= 0)) {
  		scsi_debug_virtual_gb = n;
  		if (scsi_debug_virtual_gb > 0) {
  			sdebug_capacity = 2048 * 1024;
  			sdebug_capacity *= scsi_debug_virtual_gb;
  		} else
  			sdebug_capacity = sdebug_store_sectors;
  		return count;
  	}
  	return -EINVAL;
  }
  DRIVER_ATTR(virtual_gb, S_IRUGO | S_IWUSR, sdebug_virtual_gb_show,
  	    sdebug_virtual_gb_store);
  
  static ssize_t sdebug_add_host_show(struct device_driver * ddp, char * buf)
  {
          return scnprintf(buf, PAGE_SIZE, "%d\n", scsi_debug_add_host);
  }
  
  static ssize_t sdebug_add_host_store(struct device_driver * ddp,
  				     const char * buf, size_t count)
  {
          int delta_hosts;
  	char work[20];
  
          if (1 != sscanf(buf, "%10s", work))
  		return -EINVAL;
  	{	/* temporary hack around sscanf() problem with -ve nums */
  		int neg = 0;
  
  		if ('-' == *work)
  			neg = 1;
  		if (1 != sscanf(work + neg, "%d", &delta_hosts))
  			return -EINVAL;
  		if (neg)
  			delta_hosts = -delta_hosts;
  	}
  	if (delta_hosts > 0) {
  		do {
  			sdebug_add_adapter();
  		} while (--delta_hosts);
  	} else if (delta_hosts < 0) {
  		do {
  			sdebug_remove_adapter();
  		} while (++delta_hosts);
  	}
  	return count;
  }
  DRIVER_ATTR(add_host, S_IRUGO | S_IWUSR, sdebug_add_host_show, 
  	    sdebug_add_host_store);
  
  static ssize_t sdebug_vpd_use_hostno_show(struct device_driver * ddp,
  					  char * buf)
  {
  	return scnprintf(buf, PAGE_SIZE, "%d\n", scsi_debug_vpd_use_hostno);
  }
  static ssize_t sdebug_vpd_use_hostno_store(struct device_driver * ddp,
  					   const char * buf, size_t count)
  {
  	int n;
  
  	if ((count > 0) && (1 == sscanf(buf, "%d", &n)) && (n >= 0)) {
  		scsi_debug_vpd_use_hostno = n;
  		return count;
  	}
  	return -EINVAL;
  }
  DRIVER_ATTR(vpd_use_hostno, S_IRUGO | S_IWUSR, sdebug_vpd_use_hostno_show,
  	    sdebug_vpd_use_hostno_store);
  
  /* Note: The following function creates attribute files in the
     /sys/bus/pseudo/drivers/scsi_debug directory. The advantage of these
     files (over those found in the /sys/module/scsi_debug/parameters
     directory) is that auxiliary actions can be triggered when an attribute
     is changed. For example see: sdebug_add_host_store() above.
   */
  static int do_create_driverfs_files(void)
  {
  	int ret;
  
  	ret = driver_create_file(&sdebug_driverfs_driver, &driver_attr_add_host);
  	ret |= driver_create_file(&sdebug_driverfs_driver, &driver_attr_delay);
  	ret |= driver_create_file(&sdebug_driverfs_driver, &driver_attr_dev_size_mb);
  	ret |= driver_create_file(&sdebug_driverfs_driver, &driver_attr_dsense);
  	ret |= driver_create_file(&sdebug_driverfs_driver, &driver_attr_every_nth);
  	ret |= driver_create_file(&sdebug_driverfs_driver, &driver_attr_fake_rw);
  	ret |= driver_create_file(&sdebug_driverfs_driver, &driver_attr_max_luns);
  	ret |= driver_create_file(&sdebug_driverfs_driver, &driver_attr_no_lun_0);
  	ret |= driver_create_file(&sdebug_driverfs_driver, &driver_attr_num_parts);
  	ret |= driver_create_file(&sdebug_driverfs_driver, &driver_attr_num_tgts);
  	ret |= driver_create_file(&sdebug_driverfs_driver, &driver_attr_ptype);
  	ret |= driver_create_file(&sdebug_driverfs_driver, &driver_attr_opts);
  	ret |= driver_create_file(&sdebug_driverfs_driver, &driver_attr_scsi_level);
  	ret |= driver_create_file(&sdebug_driverfs_driver, &driver_attr_virtual_gb);
  	ret |= driver_create_file(&sdebug_driverfs_driver, &driver_attr_vpd_use_hostno);
  	return ret;
  }
  
  static void do_remove_driverfs_files(void)
  {
  	driver_remove_file(&sdebug_driverfs_driver, &driver_attr_vpd_use_hostno);
  	driver_remove_file(&sdebug_driverfs_driver, &driver_attr_virtual_gb);
  	driver_remove_file(&sdebug_driverfs_driver, &driver_attr_scsi_level);
  	driver_remove_file(&sdebug_driverfs_driver, &driver_attr_opts);
  	driver_remove_file(&sdebug_driverfs_driver, &driver_attr_ptype);
  	driver_remove_file(&sdebug_driverfs_driver, &driver_attr_num_tgts);
  	driver_remove_file(&sdebug_driverfs_driver, &driver_attr_num_parts);
  	driver_remove_file(&sdebug_driverfs_driver, &driver_attr_no_lun_0);
  	driver_remove_file(&sdebug_driverfs_driver, &driver_attr_max_luns);
  	driver_remove_file(&sdebug_driverfs_driver, &driver_attr_fake_rw);
  	driver_remove_file(&sdebug_driverfs_driver, &driver_attr_every_nth);
  	driver_remove_file(&sdebug_driverfs_driver, &driver_attr_dsense);
  	driver_remove_file(&sdebug_driverfs_driver, &driver_attr_dev_size_mb);
  	driver_remove_file(&sdebug_driverfs_driver, &driver_attr_delay);
  	driver_remove_file(&sdebug_driverfs_driver, &driver_attr_add_host);
  }
  
  static int __init scsi_debug_init(void)
  {
  	unsigned int sz;
  	int host_to_add;
  	int k;
  	int ret;
  
  	if (scsi_debug_dev_size_mb < 1)
  		scsi_debug_dev_size_mb = 1;  /* force minimum 1 MB ramdisk */
  	sdebug_store_size = (unsigned int)scsi_debug_dev_size_mb * 1048576;
  	sdebug_store_sectors = sdebug_store_size / SECT_SIZE;
  	if (scsi_debug_virtual_gb > 0) {
  		sdebug_capacity = 2048 * 1024;
  		sdebug_capacity *= scsi_debug_virtual_gb;
  	} else
  		sdebug_capacity = sdebug_store_sectors;
  
  	/* play around with geometry, don't waste too much on track 0 */
  	sdebug_heads = 8;
  	sdebug_sectors_per = 32;
  	if (scsi_debug_dev_size_mb >= 16)
  		sdebug_heads = 32;
  	else if (scsi_debug_dev_size_mb >= 256)
  		sdebug_heads = 64;
  	sdebug_cylinders_per = (unsigned long)sdebug_capacity /
  			       (sdebug_sectors_per * sdebug_heads);
  	if (sdebug_cylinders_per >= 1024) {
  		/* other LLDs do this; implies >= 1GB ram disk ... */
  		sdebug_heads = 255;
  		sdebug_sectors_per = 63;
  		sdebug_cylinders_per = (unsigned long)sdebug_capacity /
  			       (sdebug_sectors_per * sdebug_heads);
  	}
  
  	sz = sdebug_store_size;
  	fake_storep = vmalloc(sz);
  	if (NULL == fake_storep) {
  		printk(KERN_ERR "scsi_debug_init: out of memory, 1\n");
  		return -ENOMEM;
  	}
  	memset(fake_storep, 0, sz);
  	if (scsi_debug_num_parts > 0)
  		sdebug_build_parts(fake_storep);
  
  	ret = device_register(&pseudo_primary);
  	if (ret < 0) {
  		printk(KERN_WARNING "scsi_debug: device_register error: %d\n",
  			ret);
  		goto free_vm;
  	}
  	ret = bus_register(&pseudo_lld_bus);
  	if (ret < 0) {
  		printk(KERN_WARNING "scsi_debug: bus_register error: %d\n",
  			ret);
  		goto dev_unreg;
  	}
  	ret = driver_register(&sdebug_driverfs_driver);
  	if (ret < 0) {
  		printk(KERN_WARNING "scsi_debug: driver_register error: %d\n",
  			ret);
  		goto bus_unreg;
  	}
  	ret = do_create_driverfs_files();
  	if (ret < 0) {
  		printk(KERN_WARNING "scsi_debug: driver_create_file error: %d\n",
  			ret);
  		goto del_files;
  	}
  
  	init_all_queued();
  
  	sdebug_driver_template.proc_name = (char *)sdebug_proc_name;
  
  	host_to_add = scsi_debug_add_host;
          scsi_debug_add_host = 0;
  
          for (k = 0; k < host_to_add; k++) {
                  if (sdebug_add_adapter()) {
                          printk(KERN_ERR "scsi_debug_init: "
                                 "sdebug_add_adapter failed k=%d\n", k);
                          break;
                  }
          }
  
  	if (SCSI_DEBUG_OPT_NOISE & scsi_debug_opts) {
  		printk(KERN_INFO "scsi_debug_init: built %d host(s)\n",
  		       scsi_debug_add_host);
  	}
  	return 0;
  
  del_files:
  	do_remove_driverfs_files();
  	driver_unregister(&sdebug_driverfs_driver);
  bus_unreg:
  	bus_unregister(&pseudo_lld_bus);
  dev_unreg:
  	device_unregister(&pseudo_primary);
  free_vm:
  	vfree(fake_storep);
  
  	return ret;
  }
  
  static void __exit scsi_debug_exit(void)
  {
  	int k = scsi_debug_add_host;
  
  	stop_all_queued();
  	for (; k; k--)
  		sdebug_remove_adapter();
  	do_remove_driverfs_files();
  	driver_unregister(&sdebug_driverfs_driver);
  	bus_unregister(&pseudo_lld_bus);
  	device_unregister(&pseudo_primary);
  
  	vfree(fake_storep);
  }
  
  device_initcall(scsi_debug_init);
  module_exit(scsi_debug_exit);
  
  static void pseudo_0_release(struct device * dev)
  {
  	if (SCSI_DEBUG_OPT_NOISE & scsi_debug_opts)
  		printk(KERN_INFO "scsi_debug: pseudo_0_release() called\n");
  }
  
  static struct device pseudo_primary = {
  	.bus_id		= "pseudo_0",
  	.release	= pseudo_0_release,
  };
  
  static int pseudo_lld_bus_match(struct device *dev,
                            struct device_driver *dev_driver)
  {
          return 1;
  }
  
  static struct bus_type pseudo_lld_bus = {
          .name = "pseudo",
          .match = pseudo_lld_bus_match,
  	.probe = sdebug_driver_probe,
  	.remove = sdebug_driver_remove,
  };
  
  static void sdebug_release_adapter(struct device * dev)
  {
          struct sdebug_host_info *sdbg_host;
  
  	sdbg_host = to_sdebug_host(dev);
          kfree(sdbg_host);
  }
  
  static int sdebug_add_adapter(void)
  {
  	int k, devs_per_host;
          int error = 0;
          struct sdebug_host_info *sdbg_host;
          struct sdebug_dev_info *sdbg_devinfo;
          struct list_head *lh, *lh_sf;
  
          sdbg_host = kzalloc(sizeof(*sdbg_host),GFP_KERNEL);
          if (NULL == sdbg_host) {
                  printk(KERN_ERR "%s: out of memory at line %d\n",
                         __FUNCTION__, __LINE__);
                  return -ENOMEM;
          }
  
          INIT_LIST_HEAD(&sdbg_host->dev_info_list);
  
  	devs_per_host = scsi_debug_num_tgts * scsi_debug_max_luns;
          for (k = 0; k < devs_per_host; k++) {
                  sdbg_devinfo = kzalloc(sizeof(*sdbg_devinfo),GFP_KERNEL);
                  if (NULL == sdbg_devinfo) {
                          printk(KERN_ERR "%s: out of memory at line %d\n",
                                 __FUNCTION__, __LINE__);
                          error = -ENOMEM;
  			goto clean;
                  }
                  sdbg_devinfo->sdbg_host = sdbg_host;
                  list_add_tail(&sdbg_devinfo->dev_list,
                                &sdbg_host->dev_info_list);
          }
  
          spin_lock(&sdebug_host_list_lock);
          list_add_tail(&sdbg_host->host_list, &sdebug_host_list);
          spin_unlock(&sdebug_host_list_lock);
  
          sdbg_host->dev.bus = &pseudo_lld_bus;
          sdbg_host->dev.parent = &pseudo_primary;
          sdbg_host->dev.release = &sdebug_release_adapter;
          sprintf(sdbg_host->dev.bus_id, "adapter%d", scsi_debug_add_host);
  
          error = device_register(&sdbg_host->dev);
  
          if (error)
  		goto clean;
  
  	++scsi_debug_add_host;
          return error;
  
  clean:
  	list_for_each_safe(lh, lh_sf, &sdbg_host->dev_info_list) {
  		sdbg_devinfo = list_entry(lh, struct sdebug_dev_info,
  					  dev_list);
  		list_del(&sdbg_devinfo->dev_list);
  		kfree(sdbg_devinfo);
  	}
  
  	kfree(sdbg_host);
          return error;
  }
  
  static void sdebug_remove_adapter(void)
  {
          struct sdebug_host_info * sdbg_host = NULL;
  
          spin_lock(&sdebug_host_list_lock);
          if (!list_empty(&sdebug_host_list)) {
                  sdbg_host = list_entry(sdebug_host_list.prev,
                                         struct sdebug_host_info, host_list);
  		list_del(&sdbg_host->host_list);
  	}
          spin_unlock(&sdebug_host_list_lock);
  
  	if (!sdbg_host)
  		return;
  
          device_unregister(&sdbg_host->dev);
          --scsi_debug_add_host;
  }
  
  static int sdebug_driver_probe(struct device * dev)
  {
          int error = 0;
          struct sdebug_host_info *sdbg_host;
          struct Scsi_Host *hpnt;
  
  	sdbg_host = to_sdebug_host(dev);
  
          hpnt = scsi_host_alloc(&sdebug_driver_template, sizeof(sdbg_host));
          if (NULL == hpnt) {
                  printk(KERN_ERR "%s: scsi_register failed\n", __FUNCTION__);
                  error = -ENODEV;
  		return error;
          }
  
          sdbg_host->shost = hpnt;
  	*((struct sdebug_host_info **)hpnt->hostdata) = sdbg_host;
  	if ((hpnt->this_id >= 0) && (scsi_debug_num_tgts > hpnt->this_id))
  		hpnt->max_id = scsi_debug_num_tgts + 1;
  	else
  		hpnt->max_id = scsi_debug_num_tgts;
  	hpnt->max_lun = SAM2_WLUN_REPORT_LUNS;	/* = scsi_debug_max_luns; */
  
          error = scsi_add_host(hpnt, &sdbg_host->dev);
          if (error) {
                  printk(KERN_ERR "%s: scsi_add_host failed\n", __FUNCTION__);
                  error = -ENODEV;
  		scsi_host_put(hpnt);
          } else
  		scsi_scan_host(hpnt);
  
  
          return error;
  }
  
  static int sdebug_driver_remove(struct device * dev)
  {
          struct list_head *lh, *lh_sf;
          struct sdebug_host_info *sdbg_host;
          struct sdebug_dev_info *sdbg_devinfo;
  
  	sdbg_host = to_sdebug_host(dev);
  
  	if (!sdbg_host) {
  		printk(KERN_ERR "%s: Unable to locate host info\n",
  		       __FUNCTION__);
  		return -ENODEV;
  	}
  
          scsi_remove_host(sdbg_host->shost);
  
          list_for_each_safe(lh, lh_sf, &sdbg_host->dev_info_list) {
                  sdbg_devinfo = list_entry(lh, struct sdebug_dev_info,
                                            dev_list);
                  list_del(&sdbg_devinfo->dev_list);
                  kfree(sdbg_devinfo);
          }
  
          scsi_host_put(sdbg_host->shost);
          return 0;
  }
  
  static void sdebug_max_tgts_luns(void)
  {
  	struct sdebug_host_info * sdbg_host;
  	struct Scsi_Host *hpnt;
  
  	spin_lock(&sdebug_host_list_lock);
  	list_for_each_entry(sdbg_host, &sdebug_host_list, host_list) {
  		hpnt = sdbg_host->shost;
  		if ((hpnt->this_id >= 0) &&
  		    (scsi_debug_num_tgts > hpnt->this_id))
  			hpnt->max_id = scsi_debug_num_tgts + 1;
  		else
  			hpnt->max_id = scsi_debug_num_tgts;
  		hpnt->max_lun = SAM2_WLUN_REPORT_LUNS; /* scsi_debug_max_luns; */
  	}
  	spin_unlock(&sdebug_host_list_lock);
  }
  