path: root/drivers/scsi/scsi_debug.c

/*
 * 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://sg.danny.cz/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]
 */


#define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__

#include <linux/module.h>

#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/timer.h>
#include <linux/slab.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/scatterlist.h>
#include <linux/blkdev.h>
#include <linux/crc-t10dif.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/atomic.h>
#include <linux/hrtimer.h>

#include <net/checksum.h>

#include <asm/unaligned.h>

#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_host.h>
#include <scsi/scsicam.h>
#include <scsi/scsi_eh.h>
#include <scsi/scsi_tcq.h>
#include <scsi/scsi_dbg.h>

#include "sd.h"
#include "scsi_logging.h"

#define SCSI_DEBUG_VERSION "1.85"
static const char *scsi_debug_version_date = "20141022";

#define MY_NAME "scsi_debug"

/* Additional Sense Code (ASC) */
#define NO_ADDITIONAL_SENSE 0x0
#define LOGICAL_UNIT_NOT_READY 0x4
#define LOGICAL_UNIT_COMMUNICATION_FAILURE 0x8
#define UNRECOVERED_READ_ERR 0x11
#define PARAMETER_LIST_LENGTH_ERR 0x1a
#define INVALID_OPCODE 0x20
#define LBA_OUT_OF_RANGE 0x21
#define INVALID_FIELD_IN_CDB 0x24
#define INVALID_FIELD_IN_PARAM_LIST 0x26
#define UA_RESET_ASC 0x29
#define UA_CHANGED_ASC 0x2a
#define TARGET_CHANGED_ASC 0x3f
#define LUNS_CHANGED_ASCQ 0x0e
#define INSUFF_RES_ASC 0x55
#define INSUFF_RES_ASCQ 0x3
#define POWER_ON_RESET_ASCQ 0x0
#define BUS_RESET_ASCQ 0x2	/* scsi bus reset occurred */
#define MODE_CHANGED_ASCQ 0x1	/* mode parameters changed */
#define CAPACITY_CHANGED_ASCQ 0x9
#define SAVING_PARAMS_UNSUP 0x39
#define TRANSPORT_PROBLEM 0x4b
#define THRESHOLD_EXCEEDED 0x5d
#define LOW_POWER_COND_ON 0x5e
#define MISCOMPARE_VERIFY_ASC 0x1d
#define MICROCODE_CHANGED_ASCQ 0x1	/* with TARGET_CHANGED_ASC */
#define MICROCODE_CHANGED_WO_RESET_ASCQ 0x16

/* Additional Sense Code Qualifier (ASCQ) */
#define ACK_NAK_TO 0x3


/* 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_ATO 1
#define DEF_DELAY   1		/* if > 0 unit is a jiffy */
#define DEF_DEV_SIZE_MB   8
#define DEF_DIF 0
#define DEF_DIX 0
#define DEF_D_SENSE   0
#define DEF_EVERY_NTH   0
#define DEF_FAKE_RW	0
#define DEF_GUARD 0
#define DEF_HOST_LOCK 0
#define DEF_LBPU 0
#define DEF_LBPWS 0
#define DEF_LBPWS10 0
#define DEF_LBPRZ 1
#define DEF_LOWEST_ALIGNED 0
#define DEF_NDELAY   0		/* if > 0 unit is a nanosecond */
#define DEF_NO_LUN_0   0
#define DEF_NUM_PARTS   0
#define DEF_OPTS   0
#define DEF_OPT_BLKS 1024
#define DEF_PHYSBLK_EXP 0
#define DEF_PTYPE   0
#define DEF_REMOVABLE false
#define DEF_SCSI_LEVEL   6    /* INQUIRY, byte2 [6->SPC-4] */
#define DEF_SECTOR_SIZE 512
#define DEF_UNMAP_ALIGNMENT 0
#define DEF_UNMAP_GRANULARITY 1
#define DEF_UNMAP_MAX_BLOCKS 0xFFFFFFFF
#define DEF_UNMAP_MAX_DESC 256
#define DEF_VIRTUAL_GB   0
#define DEF_VPD_USE_HOSTNO 1
#define DEF_WRITESAME_LENGTH 0xFFFF
#define DEF_STRICT 0
#define DELAY_OVERRIDDEN -9999

/* 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
#define SCSI_DEBUG_OPT_DIF_ERR   32
#define SCSI_DEBUG_OPT_DIX_ERR   64
#define SCSI_DEBUG_OPT_MAC_TIMEOUT  128
#define SCSI_DEBUG_OPT_SHORT_TRANSFER	0x100
#define SCSI_DEBUG_OPT_Q_NOISE	0x200
#define SCSI_DEBUG_OPT_ALL_TSF	0x400
#define SCSI_DEBUG_OPT_RARE_TSF	0x800
#define SCSI_DEBUG_OPT_N_WCE	0x1000
#define SCSI_DEBUG_OPT_RESET_NOISE 0x2000
#define SCSI_DEBUG_OPT_NO_CDB_NOISE 0x4000
#define SCSI_DEBUG_OPT_ALL_NOISE (0x1 | 0x200 | 0x2000)
/* 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).
 */

/* As indicated in SAM-5 and SPC-4 Unit Attentions (UAs)are returned in
 * priority order. In the subset implemented here lower numbers have higher
 * priority. The UA numbers should be a sequence starting from 0 with
 * SDEBUG_NUM_UAS being 1 higher than the highest numbered UA. */
#define SDEBUG_UA_POR 0		/* Power on, reset, or bus device reset */
#define SDEBUG_UA_BUS_RESET 1
#define SDEBUG_UA_MODE_CHANGED 2
#define SDEBUG_UA_CAPACITY_CHANGED 3
#define SDEBUG_UA_LUNS_CHANGED 4
#define SDEBUG_UA_MICROCODE_CHANGED 5	/* simulate firmware change */
#define SDEBUG_UA_MICROCODE_CHANGED_WO_RESET 6
#define SDEBUG_NUM_UAS 7

/* for check_readiness() */
#define UAS_ONLY 1	/* check for UAs only */
#define UAS_TUR 0	/* if no UAs then check if media access possible */

/* 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 */
#define OPT_MEDIUM_ERR_NUM    10     /* number of consecutive medium errs */

/* 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

/* SCSI_DEBUG_CANQUEUE is the maximum number of commands that can be queued
 * (for response) at one time. Can be reduced by max_queue option. Command
 * responses are not queued when delay=0 and ndelay=0. The per-device
 * DEF_CMD_PER_LUN can be changed via sysfs:
 * /sys/class/scsi_device/<h:c:t:l>/device/queue_depth but cannot exceed
 * SCSI_DEBUG_CANQUEUE. */
#define SCSI_DEBUG_CANQUEUE_WORDS  9	/* a WORD is bits in a long */
#define SCSI_DEBUG_CANQUEUE  (SCSI_DEBUG_CANQUEUE_WORDS * BITS_PER_LONG)
#define DEF_CMD_PER_LUN  255

#if DEF_CMD_PER_LUN > SCSI_DEBUG_CANQUEUE
#warning "Expect DEF_CMD_PER_LUN <= SCSI_DEBUG_CANQUEUE"
#endif

/* SCSI opcodes (first byte of cdb) mapped onto these indexes */
enum sdeb_opcode_index {
	SDEB_I_INVALID_OPCODE =	0,
	SDEB_I_INQUIRY = 1,
	SDEB_I_REPORT_LUNS = 2,
	SDEB_I_REQUEST_SENSE = 3,
	SDEB_I_TEST_UNIT_READY = 4,
	SDEB_I_MODE_SENSE = 5,		/* 6, 10 */
	SDEB_I_MODE_SELECT = 6,		/* 6, 10 */
	SDEB_I_LOG_SENSE = 7,
	SDEB_I_READ_CAPACITY = 8,	/* 10; 16 is in SA_IN(16) */
	SDEB_I_READ = 9,		/* 6, 10, 12, 16 */
	SDEB_I_WRITE = 10,		/* 6, 10, 12, 16 */
	SDEB_I_START_STOP = 11,
	SDEB_I_SERV_ACT_IN = 12,	/* 12, 16 */
	SDEB_I_SERV_ACT_OUT = 13,	/* 12, 16 */
	SDEB_I_MAINT_IN = 14,
	SDEB_I_MAINT_OUT = 15,
	SDEB_I_VERIFY = 16,		/* 10 only */
	SDEB_I_VARIABLE_LEN = 17,
	SDEB_I_RESERVE = 18,		/* 6, 10 */
	SDEB_I_RELEASE = 19,		/* 6, 10 */
	SDEB_I_ALLOW_REMOVAL = 20,	/* PREVENT ALLOW MEDIUM REMOVAL */
	SDEB_I_REZERO_UNIT = 21,	/* REWIND in SSC */
	SDEB_I_ATA_PT = 22,		/* 12, 16 */
	SDEB_I_SEND_DIAG = 23,
	SDEB_I_UNMAP = 24,
	SDEB_I_XDWRITEREAD = 25,	/* 10 only */
	SDEB_I_WRITE_BUFFER = 26,
	SDEB_I_WRITE_SAME = 27,		/* 10, 16 */
	SDEB_I_SYNC_CACHE = 28,		/* 10 only */
	SDEB_I_COMP_WRITE = 29,
	SDEB_I_LAST_ELEMENT = 30,	/* keep this last */
};

static const unsigned char opcode_ind_arr[256] = {
/* 0x0; 0x0->0x1f: 6 byte cdbs */
	SDEB_I_TEST_UNIT_READY, SDEB_I_REZERO_UNIT, 0, SDEB_I_REQUEST_SENSE,
	    0, 0, 0, 0,
	SDEB_I_READ, 0, SDEB_I_WRITE, 0, 0, 0, 0, 0,
	0, 0, SDEB_I_INQUIRY, 0, 0, SDEB_I_MODE_SELECT, SDEB_I_RESERVE,
	    SDEB_I_RELEASE,
	0, 0, SDEB_I_MODE_SENSE, SDEB_I_START_STOP, 0, SDEB_I_SEND_DIAG,
	    SDEB_I_ALLOW_REMOVAL, 0,
/* 0x20; 0x20->0x3f: 10 byte cdbs */
	0, 0, 0, 0, 0, SDEB_I_READ_CAPACITY, 0, 0,
	SDEB_I_READ, 0, SDEB_I_WRITE, 0, 0, 0, 0, SDEB_I_VERIFY,
	0, 0, 0, 0, 0, SDEB_I_SYNC_CACHE, 0, 0,
	0, 0, 0, SDEB_I_WRITE_BUFFER, 0, 0, 0, 0,
/* 0x40; 0x40->0x5f: 10 byte cdbs */
	0, SDEB_I_WRITE_SAME, SDEB_I_UNMAP, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, SDEB_I_LOG_SENSE, 0, 0,
	0, 0, 0, SDEB_I_XDWRITEREAD, 0, SDEB_I_MODE_SELECT, SDEB_I_RESERVE,
	    SDEB_I_RELEASE,
	0, 0, SDEB_I_MODE_SENSE, 0, 0, 0, 0, 0,
/* 0x60; 0x60->0x7d are reserved */
	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, SDEB_I_VARIABLE_LEN,
/* 0x80; 0x80->0x9f: 16 byte cdbs */
	0, 0, 0, 0, 0, SDEB_I_ATA_PT, 0, 0,
	SDEB_I_READ, SDEB_I_COMP_WRITE, SDEB_I_WRITE, 0, 0, 0, 0, 0,
	0, 0, 0, SDEB_I_WRITE_SAME, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, SDEB_I_SERV_ACT_IN, SDEB_I_SERV_ACT_OUT,
/* 0xa0; 0xa0->0xbf: 12 byte cdbs */
	SDEB_I_REPORT_LUNS, SDEB_I_ATA_PT, 0, SDEB_I_MAINT_IN,
	     SDEB_I_MAINT_OUT, 0, 0, 0,
	SDEB_I_READ, SDEB_I_SERV_ACT_OUT, SDEB_I_WRITE, SDEB_I_SERV_ACT_IN,
	     0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0,
/* 0xc0; 0xc0->0xff: vendor specific */
	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,
};

#define F_D_IN			1
#define F_D_OUT			2
#define F_D_OUT_MAYBE		4	/* WRITE SAME, NDOB bit */
#define F_D_UNKN		8
#define F_RL_WLUN_OK		0x10
#define F_SKIP_UA		0x20
#define F_DELAY_OVERR		0x40
#define F_SA_LOW		0x80	/* cdb byte 1, bits 4 to 0 */
#define F_SA_HIGH		0x100	/* as used by variable length cdbs */
#define F_INV_OP		0x200
#define F_FAKE_RW		0x400
#define F_M_ACCESS		0x800	/* media access */

#define FF_RESPOND (F_RL_WLUN_OK | F_SKIP_UA | F_DELAY_OVERR)
#define FF_DIRECT_IO (F_M_ACCESS | F_FAKE_RW)
#define FF_SA (F_SA_HIGH | F_SA_LOW)

struct sdebug_dev_info;
static int resp_inquiry(struct scsi_cmnd *, struct sdebug_dev_info *);
static int resp_report_luns(struct scsi_cmnd *, struct sdebug_dev_info *);
static int resp_requests(struct scsi_cmnd *, struct sdebug_dev_info *);
static int resp_mode_sense(struct scsi_cmnd *, struct sdebug_dev_info *);
static int resp_mode_select(struct scsi_cmnd *, struct sdebug_dev_info *);
static int resp_log_sense(struct scsi_cmnd *, struct sdebug_dev_info *);
static int resp_readcap(struct scsi_cmnd *, struct sdebug_dev_info *);
static int resp_read_dt0(struct scsi_cmnd *, struct sdebug_dev_info *);
static int resp_write_dt0(struct scsi_cmnd *, struct sdebug_dev_info *);
static int resp_start_stop(struct scsi_cmnd *, struct sdebug_dev_info *);
static int resp_readcap16(struct scsi_cmnd *, struct sdebug_dev_info *);
static int resp_get_lba_status(struct scsi_cmnd *, struct sdebug_dev_info *);
static int resp_report_tgtpgs(struct scsi_cmnd *, struct sdebug_dev_info *);
static int resp_unmap(struct scsi_cmnd *, struct sdebug_dev_info *);
static int resp_rsup_opcodes(struct scsi_cmnd *, struct sdebug_dev_info *);
static int resp_rsup_tmfs(struct scsi_cmnd *, struct sdebug_dev_info *);
static int resp_write_same_10(struct scsi_cmnd *, struct sdebug_dev_info *);
static int resp_write_same_16(struct scsi_cmnd *, struct sdebug_dev_info *);
static int resp_xdwriteread_10(struct scsi_cmnd *, struct sdebug_dev_info *);
static int resp_comp_write(struct scsi_cmnd *, struct sdebug_dev_info *);
static int resp_write_buffer(struct scsi_cmnd *, struct sdebug_dev_info *);

struct opcode_info_t {
	u8 num_attached;	/* 0 if this is it (i.e. a leaf); use 0xff
				 * for terminating element */
	u8 opcode;		/* if num_attached > 0, preferred */
	u16 sa;			/* service action */
	u32 flags;		/* OR-ed set of SDEB_F_* */
	int (*pfp)(struct scsi_cmnd *, struct sdebug_dev_info *);
	const struct opcode_info_t *arrp;  /* num_attached elements or NULL */
	u8 len_mask[16];	/* len=len_mask[0], then mask for cdb[1]... */
				/* ignore cdb bytes after position 15 */
};

static const struct opcode_info_t msense_iarr[1] = {
	{0, 0x1a, 0, F_D_IN, NULL, NULL,
	    {6,  0xe8, 0xff, 0xff, 0xff, 0xc7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
};

static const struct opcode_info_t mselect_iarr[1] = {
	{0, 0x15, 0, F_D_OUT, NULL, NULL,
	    {6,  0xf1, 0, 0, 0xff, 0xc7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
};

static const struct opcode_info_t read_iarr[3] = {
	{0, 0x28, 0, F_D_IN | FF_DIRECT_IO, resp_read_dt0, NULL,/* READ(10) */
	    {10,  0xff, 0xff, 0xff, 0xff, 0xff, 0x1f, 0xff, 0xff, 0xc7, 0, 0,
	     0, 0, 0, 0} },
	{0, 0x8, 0, F_D_IN | FF_DIRECT_IO, resp_read_dt0, NULL, /* READ(6) */
	    {6,  0xff, 0xff, 0xff, 0xff, 0xc7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
	{0, 0xa8, 0, F_D_IN | FF_DIRECT_IO, resp_read_dt0, NULL,/* READ(12) */
	    {12,  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x9f,
	     0xc7, 0, 0, 0, 0} },
};

static const struct opcode_info_t write_iarr[3] = {
	{0, 0x2a, 0, F_D_OUT | FF_DIRECT_IO, resp_write_dt0, NULL,   /* 10 */
	    {10,  0xfb, 0xff, 0xff, 0xff, 0xff, 0x1f, 0xff, 0xff, 0xc7, 0, 0,
	     0, 0, 0, 0} },
	{0, 0xa, 0, F_D_OUT | FF_DIRECT_IO, resp_write_dt0, NULL,    /* 6 */
	    {6,  0xff, 0xff, 0xff, 0xff, 0xc7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
	{0, 0xaa, 0, F_D_OUT | FF_DIRECT_IO, resp_write_dt0, NULL,   /* 12 */
	    {12,  0xfb, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x9f,
	     0xc7, 0, 0, 0, 0} },
};

static const struct opcode_info_t sa_in_iarr[1] = {
	{0, 0x9e, 0x12, F_SA_LOW | F_D_IN, resp_get_lba_status, NULL,
	    {16,  0x12, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
	     0xff, 0xff, 0xff, 0, 0xc7} },
};

static const struct opcode_info_t vl_iarr[1] = {	/* VARIABLE LENGTH */
	{0, 0x7f, 0xb, F_SA_HIGH | F_D_OUT | FF_DIRECT_IO, resp_write_dt0,
	    NULL, {32,  0xc7, 0, 0, 0, 0, 0x1f, 0x18, 0x0, 0xb, 0xfa,
		   0, 0xff, 0xff, 0xff, 0xff} },	/* WRITE(32) */
};

static const struct opcode_info_t maint_in_iarr[2] = {
	{0, 0xa3, 0xc, F_SA_LOW | F_D_IN, resp_rsup_opcodes, NULL,
	    {12,  0xc, 0x87, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0,
	     0xc7, 0, 0, 0, 0} },
	{0, 0xa3, 0xd, F_SA_LOW | F_D_IN, resp_rsup_tmfs, NULL,
	    {12,  0xd, 0x80, 0, 0, 0, 0xff, 0xff, 0xff, 0xff, 0, 0xc7, 0, 0,
	     0, 0} },
};

static const struct opcode_info_t write_same_iarr[1] = {
	{0, 0x93, 0, F_D_OUT_MAYBE | FF_DIRECT_IO, resp_write_same_16, NULL,
	    {16,  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
	     0xff, 0xff, 0xff, 0x1f, 0xc7} },
};

static const struct opcode_info_t reserve_iarr[1] = {
	{0, 0x16, 0, F_D_OUT, NULL, NULL,	/* RESERVE(6) */
	    {6,  0x1f, 0xff, 0xff, 0xff, 0xc7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
};

static const struct opcode_info_t release_iarr[1] = {
	{0, 0x17, 0, F_D_OUT, NULL, NULL,	/* RELEASE(6) */
	    {6,  0x1f, 0xff, 0, 0, 0xc7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
};


/* This array is accessed via SDEB_I_* values. Make sure all are mapped,
 * plus the terminating elements for logic that scans this table such as
 * REPORT SUPPORTED OPERATION CODES. */
static const struct opcode_info_t opcode_info_arr[SDEB_I_LAST_ELEMENT + 1] = {
/* 0 */
	{0, 0, 0, F_INV_OP | FF_RESPOND, NULL, NULL,
	    {0,  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
	{0, 0x12, 0, FF_RESPOND | F_D_IN, resp_inquiry, NULL,
	    {6,  0xe3, 0xff, 0xff, 0xff, 0xc7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
	{0, 0xa0, 0, FF_RESPOND | F_D_IN, resp_report_luns, NULL,
	    {12,  0xe3, 0xff, 0, 0, 0, 0xff, 0xff, 0xff, 0xff, 0, 0xc7, 0, 0,
	     0, 0} },
	{0, 0x3, 0, FF_RESPOND | F_D_IN, resp_requests, NULL,
	    {6,  0xe1, 0, 0, 0xff, 0xc7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
	{0, 0x0, 0, F_M_ACCESS | F_RL_WLUN_OK, NULL, NULL,/* TEST UNIT READY */
	    {6,  0, 0, 0, 0, 0xc7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
	{1, 0x5a, 0, F_D_IN, resp_mode_sense, msense_iarr,
	    {10,  0xf8, 0xff, 0xff, 0, 0, 0, 0xff, 0xff, 0xc7, 0, 0, 0, 0, 0,
	     0} },
	{1, 0x55, 0, F_D_OUT, resp_mode_select, mselect_iarr,
	    {10,  0xf1, 0, 0, 0, 0, 0, 0xff, 0xff, 0xc7, 0, 0, 0, 0, 0, 0} },
	{0, 0x4d, 0, F_D_IN, resp_log_sense, NULL,
	    {10,  0xe3, 0xff, 0xff, 0, 0xff, 0xff, 0xff, 0xff, 0xc7, 0, 0, 0,
	     0, 0, 0} },
	{0, 0x25, 0, F_D_IN, resp_readcap, NULL,
	    {10,  0xe1, 0xff, 0xff, 0xff, 0xff, 0, 0, 0x1, 0xc7, 0, 0, 0, 0,
	     0, 0} },
	{3, 0x88, 0, F_D_IN | FF_DIRECT_IO, resp_read_dt0, read_iarr,
	    {16,  0xfe, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
	     0xff, 0xff, 0xff, 0x9f, 0xc7} },		/* READ(16) */
/* 10 */
	{3, 0x8a, 0, F_D_OUT | FF_DIRECT_IO, resp_write_dt0, write_iarr,
	    {16,  0xfa, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
	     0xff, 0xff, 0xff, 0x9f, 0xc7} },		/* WRITE(16) */
	{0, 0x1b, 0, 0, resp_start_stop, NULL,		/* START STOP UNIT */
	    {6,  0x1, 0, 0xf, 0xf7, 0xc7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
	{1, 0x9e, 0x10, F_SA_LOW | F_D_IN, resp_readcap16, sa_in_iarr,
	    {16,  0x10, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
	     0xff, 0xff, 0xff, 0x1, 0xc7} },	/* READ CAPACITY(16) */
	{0, 0, 0, F_INV_OP | FF_RESPOND, NULL, NULL, /* SA OUT */
	    {0,  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
	{2, 0xa3, 0xa, F_SA_LOW | F_D_IN, resp_report_tgtpgs, maint_in_iarr,
	    {12,  0xea, 0, 0, 0, 0, 0xff, 0xff, 0xff, 0xff, 0, 0xc7, 0, 0, 0,
	     0} },
	{0, 0, 0, F_INV_OP | FF_RESPOND, NULL, NULL, /* MAINT OUT */
	    {0,  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
	{0, 0x2f, 0, F_D_OUT_MAYBE | FF_DIRECT_IO, NULL, NULL, /* VERIFY(10) */
	    {10,  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xc7,
	     0, 0, 0, 0, 0, 0} },
	{1, 0x7f, 0x9, F_SA_HIGH | F_D_IN | FF_DIRECT_IO, resp_read_dt0,
	    vl_iarr, {32,  0xc7, 0, 0, 0, 0, 0x1f, 0x18, 0x0, 0x9, 0xfe, 0,
		      0xff, 0xff, 0xff, 0xff} },/* VARIABLE LENGTH, READ(32) */
	{1, 0x56, 0, F_D_OUT, NULL, reserve_iarr, /* RESERVE(10) */
	    {10,  0xff, 0xff, 0xff, 0, 0, 0, 0xff, 0xff, 0xc7, 0, 0, 0, 0, 0,
	     0} },
	{1, 0x57, 0, F_D_OUT, NULL, release_iarr, /* RELEASE(10) */
	    {10,  0x13, 0xff, 0xff, 0, 0, 0, 0xff, 0xff, 0xc7, 0, 0, 0, 0, 0,
	     0} },
/* 20 */
	{0, 0x1e, 0, 0, NULL, NULL, /* ALLOW REMOVAL */
	    {6,  0, 0, 0, 0x3, 0xc7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
	{0, 0x1, 0, 0, resp_start_stop, NULL, /* REWIND ?? */
	    {6,  0x1, 0, 0, 0, 0xc7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
	{0, 0, 0, F_INV_OP | FF_RESPOND, NULL, NULL, /* ATA_PT */
	    {0,  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
	{0, 0x1d, F_D_OUT, 0, NULL, NULL,	/* SEND DIAGNOSTIC */
	    {6,  0xf7, 0, 0xff, 0xff, 0xc7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
	{0, 0x42, 0, F_D_OUT | FF_DIRECT_IO, resp_unmap, NULL, /* UNMAP */
	    {10,  0x1, 0, 0, 0, 0, 0x1f, 0xff, 0xff, 0xc7, 0, 0, 0, 0, 0, 0} },
	{0, 0x53, 0, F_D_IN | F_D_OUT | FF_DIRECT_IO, resp_xdwriteread_10,
	    NULL, {10,  0xff, 0xff, 0xff, 0xff, 0xff, 0x1f, 0xff, 0xff, 0xc7,
		   0, 0, 0, 0, 0, 0} },
	{0, 0x3b, 0, F_D_OUT_MAYBE, resp_write_buffer, NULL,
	    {10,  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xc7, 0, 0,
	     0, 0, 0, 0} },			/* WRITE_BUFFER */
	{1, 0x41, 0, F_D_OUT_MAYBE | FF_DIRECT_IO, resp_write_same_10,
	    write_same_iarr, {10,  0xff, 0xff, 0xff, 0xff, 0xff, 0x1f, 0xff,
			      0xff, 0xc7, 0, 0, 0, 0, 0, 0} },
	{0, 0x35, 0, F_DELAY_OVERR | FF_DIRECT_IO, NULL, NULL, /* SYNC_CACHE */
	    {10,  0x7, 0xff, 0xff, 0xff, 0xff, 0x1f, 0xff, 0xff, 0xc7, 0, 0,
	     0, 0, 0, 0} },
	{0, 0x89, 0, F_D_OUT | FF_DIRECT_IO, resp_comp_write, NULL,
	    {16,  0xf8, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0, 0,
	     0, 0xff, 0x1f, 0xc7} },		/* COMPARE AND WRITE */

/* 30 */
	{0xff, 0, 0, 0, NULL, NULL,		/* terminating element */
	    {0,  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
};

struct sdebug_scmd_extra_t {
	bool inj_recovered;
	bool inj_transport;
	bool inj_dif;
	bool inj_dix;
	bool inj_short;
};

static int scsi_debug_add_host = DEF_NUM_HOST;
static int scsi_debug_ato = DEF_ATO;
static int scsi_debug_delay = DEF_DELAY;
static int scsi_debug_dev_size_mb = DEF_DEV_SIZE_MB;
static int scsi_debug_dif = DEF_DIF;
static int scsi_debug_dix = DEF_DIX;
static int scsi_debug_dsense = DEF_D_SENSE;
static int scsi_debug_every_nth = DEF_EVERY_NTH;
static int scsi_debug_fake_rw = DEF_FAKE_RW;
static unsigned int scsi_debug_guard = DEF_GUARD;
static int scsi_debug_lowest_aligned = DEF_LOWEST_ALIGNED;
static int scsi_debug_max_luns = DEF_MAX_LUNS;
static int scsi_debug_max_queue = SCSI_DEBUG_CANQUEUE;
static atomic_t retired_max_queue;	/* if > 0 then was prior max_queue */
static int scsi_debug_ndelay = DEF_NDELAY;
static int scsi_debug_no_lun_0 = DEF_NO_LUN_0;
static int scsi_debug_no_uld = 0;
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_opt_blks = DEF_OPT_BLKS;
static int scsi_debug_opts = DEF_OPTS;
static int scsi_debug_physblk_exp = DEF_PHYSBLK_EXP;
static int scsi_debug_ptype = DEF_PTYPE; /* SCSI peripheral type (0==disk) */
static int scsi_debug_scsi_level = DEF_SCSI_LEVEL;
static int scsi_debug_sector_size = DEF_SECTOR_SIZE;
static int scsi_debug_virtual_gb = DEF_VIRTUAL_GB;
static int scsi_debug_vpd_use_hostno = DEF_VPD_USE_HOSTNO;
static unsigned int scsi_debug_lbpu = DEF_LBPU;
static unsigned int scsi_debug_lbpws = DEF_LBPWS;
static unsigned int scsi_debug_lbpws10 = DEF_LBPWS10;
static unsigned int scsi_debug_lbprz = DEF_LBPRZ;
static unsigned int scsi_debug_unmap_alignment = DEF_UNMAP_ALIGNMENT;
static unsigned int scsi_debug_unmap_granularity = DEF_UNMAP_GRANULARITY;
static unsigned int scsi_debug_unmap_max_blocks = DEF_UNMAP_MAX_BLOCKS;
static unsigned int scsi_debug_unmap_max_desc = DEF_UNMAP_MAX_DESC;
static unsigned int scsi_debug_write_same_length = DEF_WRITESAME_LENGTH;
static bool scsi_debug_removable = DEF_REMOVABLE;
static bool scsi_debug_clustering;
static bool scsi_debug_host_lock = DEF_HOST_LOCK;
static bool scsi_debug_strict = DEF_STRICT;
static bool sdebug_any_injecting_opt;

static atomic_t sdebug_cmnd_count;
static atomic_t sdebug_completions;
static atomic_t sdebug_a_tsf;		/* counter of 'almost' TSFs */

#define DEV_READONLY(TGT)      (0)

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 */

#define SDEBUG_MAX_PARTS 4

#define SCSI_DEBUG_MAX_CMD_LEN 32

static unsigned int scsi_debug_lbp(void)
{
	return ((0 == scsi_debug_fake_rw) &&
		(scsi_debug_lbpu | scsi_debug_lbpws | scsi_debug_lbpws10));
}

struct sdebug_dev_info {
	struct list_head dev_list;
	unsigned int channel;
	unsigned int target;
	u64 lun;
	struct sdebug_host_info *sdbg_host;
	unsigned long uas_bm[1];
	atomic_t num_in_q;
	char stopped;		/* TODO: should be atomic */
	bool 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);


struct sdebug_hrtimer {		/* ... is derived from hrtimer */
	struct hrtimer hrt;	/* must be first element */
	int qa_indx;
};

struct sdebug_queued_cmd {
	/* in_use flagged by a bit in queued_in_use_bm[] */
	struct timer_list *cmnd_timerp;
	struct tasklet_struct *tletp;
	struct sdebug_hrtimer *sd_hrtp;
	struct scsi_cmnd * a_cmnd;
};
static struct sdebug_queued_cmd queued_arr[SCSI_DEBUG_CANQUEUE];
static unsigned long queued_in_use_bm[SCSI_DEBUG_CANQUEUE_WORDS];


static unsigned char * fake_storep;	/* ramdisk storage */
static struct sd_dif_tuple *dif_storep;	/* protection info */
static void *map_storep;		/* provisioning map */

static unsigned long map_size;
static int num_aborts;
static int num_dev_resets;
static int num_target_resets;
static int num_bus_resets;
static int num_host_resets;
static int dix_writes;
static int dix_reads;
static int dif_errors;

static DEFINE_SPINLOCK(queued_arr_lock);
static DEFINE_RWLOCK(atomic_rw);

static char sdebug_proc_name[] = MY_NAME;
static const char *my_name = MY_NAME;

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 const int illegal_condition_result =
	(DRIVER_SENSE << 24) | (DID_ABORT << 16) | SAM_STAT_CHECK_CONDITION;

static const int device_qfull_result =
	(DID_OK << 16) | (COMMAND_COMPLETE << 8) | SAM_STAT_TASK_SET_FULL;

static unsigned char caching_pg[] = {0x8, 18, 0x14, 0, 0xff, 0xff, 0, 0,
				     0xff, 0xff, 0xff, 0xff, 0x80, 0x14, 0, 0,
				     0, 0, 0, 0};
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};

static void *fake_store(unsigned long long lba)
{
	lba = do_div(lba, sdebug_store_sectors);

	return fake_storep + lba * scsi_debug_sector_size;
}

static struct sd_dif_tuple *dif_store(sector_t sector)
{
	sector = sector_div(sector, sdebug_store_sectors);

	return dif_storep + sector;
}

static int sdebug_add_adapter(void);
static void sdebug_remove_adapter(void);

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;
		/* scsi_debug_max_luns; */
		hpnt->max_lun = SCSI_W_LUN_REPORT_LUNS + 1;
	}
	spin_unlock(&sdebug_host_list_lock);
}

enum sdeb_cmd_data {SDEB_IN_DATA = 0, SDEB_IN_CDB = 1};

/* Set in_bit to -1 to indicate no bit position of invalid field */
static void
mk_sense_invalid_fld(struct scsi_cmnd *scp, enum sdeb_cmd_data c_d,
		     int in_byte, int in_bit)
{
	unsigned char *sbuff;
	u8 sks[4];
	int sl, asc;

	sbuff = scp->sense_buffer;
	if (!sbuff) {
		sdev_printk(KERN_ERR, scp->device,
			    "%s: sense_buffer is NULL\n", __func__);
		return;
	}
	asc = c_d ? INVALID_FIELD_IN_CDB : INVALID_FIELD_IN_PARAM_LIST;
	memset(sbuff, 0, SCSI_SENSE_BUFFERSIZE);
	scsi_build_sense_buffer(scsi_debug_dsense, sbuff, ILLEGAL_REQUEST,
				asc, 0);
	memset(sks, 0, sizeof(sks));
	sks[0] = 0x80;
	if (c_d)
		sks[0] |= 0x40;
	if (in_bit >= 0) {
		sks[0] |= 0x8;
		sks[0] |= 0x7 & in_bit;
	}
	put_unaligned_be16(in_byte, sks + 1);
	if (scsi_debug_dsense) {
		sl = sbuff[7] + 8;
		sbuff[7] = sl;
		sbuff[sl] = 0x2;
		sbuff[sl + 1] = 0x6;
		memcpy(sbuff + sl + 4, sks, 3);
	} else
		memcpy(sbuff + 15, sks, 3);
	if (SCSI_DEBUG_OPT_NOISE & scsi_debug_opts)
		sdev_printk(KERN_INFO, scp->device, "%s:  [sense_key,asc,ascq"
			    "]: [0x5,0x%x,0x0] %c byte=%d, bit=%d\n",
			    my_name, asc, c_d ? 'C' : 'D', in_byte, in_bit);
}

static void mk_sense_buffer(struct scsi_cmnd *scp, int key, int asc, int asq)
{
	unsigned char *sbuff;

	sbuff = scp->sense_buffer;
	if (!sbuff) {
		sdev_printk(KERN_ERR, scp->device,
			    "%s: sense_buffer is NULL\n", __func__);
		return;
	}
	memset(sbuff, 0, SCSI_SENSE_BUFFERSIZE);

	scsi_build_sense_buffer(scsi_debug_dsense, sbuff, key, asc, asq);

	if (SCSI_DEBUG_OPT_NOISE & scsi_debug_opts)
		sdev_printk(KERN_INFO, scp->device,
			    "%s:  [sense_key,asc,ascq]: [0x%x,0x%x,0x%x]\n",
			    my_name, key, asc, asq);
}

static void
mk_sense_invalid_opcode(struct scsi_cmnd *scp)
{
	mk_sense_buffer(scp, ILLEGAL_REQUEST, INVALID_OPCODE, 0);
}

static int scsi_debug_ioctl(struct scsi_device *dev, int cmd, void __user *arg)
{
	if (SCSI_DEBUG_OPT_NOISE & scsi_debug_opts) {
		if (0x1261 == cmd)
			sdev_printk(KERN_INFO, dev,
				    "%s: BLKFLSBUF [0x1261]\n", __func__);
		else if (0x5331 == cmd)
			sdev_printk(KERN_INFO, dev,
				    "%s: CDROM_GET_CAPABILITY [0x5331]\n",
				    __func__);
		else
			sdev_printk(KERN_INFO, dev, "%s: cmd=0x%x\n",
				    __func__, cmd);
	}
	return -EINVAL;
	/* return -ENOTTY; // correct return but upsets fdisk */
}

static void clear_luns_changed_on_target(struct sdebug_dev_info *devip)
{
	struct sdebug_host_info *sdhp;
	struct sdebug_dev_info *dp;

	spin_lock(&sdebug_host_list_lock);
	list_for_each_entry(sdhp, &sdebug_host_list, host_list) {
		list_for_each_entry(dp, &sdhp->dev_info_list, dev_list) {
			if ((devip->sdbg_host == dp->sdbg_host) &&
			    (devip->target == dp->target))
				clear_bit(SDEBUG_UA_LUNS_CHANGED, dp->uas_bm);
		}
	}
	spin_unlock(&sdebug_host_list_lock);
}

static int check_readiness(struct scsi_cmnd *SCpnt, int uas_only,
			   struct sdebug_dev_info * devip)
{
	int k;
	bool debug = !!(SCSI_DEBUG_OPT_NOISE & scsi_debug_opts);

	k = find_first_bit(devip->uas_bm, SDEBUG_NUM_UAS);
	if (k != SDEBUG_NUM_UAS) {
		const char *cp = NULL;

		switch (k) {
		case SDEBUG_UA_POR:
			mk_sense_buffer(SCpnt, UNIT_ATTENTION,
					UA_RESET_ASC, POWER_ON_RESET_ASCQ);
			if (debug)
				cp = "power on reset";
			break;
		case SDEBUG_UA_BUS_RESET:
			mk_sense_buffer(SCpnt, UNIT_ATTENTION,
					UA_RESET_ASC, BUS_RESET_ASCQ);
			if (debug)
				cp = "bus reset";
			break;
		case SDEBUG_UA_MODE_CHANGED:
			mk_sense_buffer(SCpnt, UNIT_ATTENTION,
					UA_CHANGED_ASC, MODE_CHANGED_ASCQ);
			if (debug)
				cp = "mode parameters changed";
			break;
		case SDEBUG_UA_CAPACITY_CHANGED:
			mk_sense_buffer(SCpnt, UNIT_ATTENTION,
					UA_CHANGED_ASC, CAPACITY_CHANGED_ASCQ);
			if (debug)
				cp = "capacity data changed";
			break;
		case SDEBUG_UA_MICROCODE_CHANGED:
			mk_sense_buffer(SCpnt, UNIT_ATTENTION,
				 TARGET_CHANGED_ASC, MICROCODE_CHANGED_ASCQ);
			if (debug)
				cp = "microcode has been changed";
			break;
		case SDEBUG_UA_MICROCODE_CHANGED_WO_RESET:
			mk_sense_buffer(SCpnt, UNIT_ATTENTION,
					TARGET_CHANGED_ASC,
					MICROCODE_CHANGED_WO_RESET_ASCQ);
			if (debug)
				cp = "microcode has been changed without reset";
			break;
		case SDEBUG_UA_LUNS_CHANGED:
			/*
			 * SPC-3 behavior is to report a UNIT ATTENTION with
			 * ASC/ASCQ REPORTED LUNS DATA HAS CHANGED on every LUN
			 * on the target, until a REPORT LUNS command is
			 * received.  SPC-4 behavior is to report it only once.
			 * NOTE:  scsi_debug_scsi_level does not use the same
			 * values as struct scsi_device->scsi_level.
			 */
			if (scsi_debug_scsi_level >= 6)	/* SPC-4 and above */
				clear_luns_changed_on_target(devip);
			mk_sense_buffer(SCpnt, UNIT_ATTENTION,
					TARGET_CHANGED_ASC,
					LUNS_CHANGED_ASCQ);
			if (debug)
				cp = "reported luns data has changed";
			break;
		default:
			pr_warn("%s: unexpected unit attention code=%d\n",
				__func__, k);
			if (debug)
				cp = "unknown";
			break;
		}
		clear_bit(k, devip->uas_bm);
		if (debug)
			sdev_printk(KERN_INFO, SCpnt->device,
				   "%s reports: Unit attention: %s\n",
				   my_name, cp);
		return check_condition_result;
	}
	if ((UAS_TUR == uas_only) && devip->stopped) {
		mk_sense_buffer(SCpnt, NOT_READY, LOGICAL_UNIT_NOT_READY,
				0x2);
		if (debug)
			sdev_printk(KERN_INFO, SCpnt->device,
				    "%s reports: Not ready: %s\n", my_name,
				    "initializing command required");
		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 act_len;
	struct scsi_data_buffer *sdb = scsi_in(scp);

	if (!sdb->length)
		return 0;
	if (!(scsi_bidi_cmnd(scp) || scp->sc_data_direction == DMA_FROM_DEVICE))
		return (DID_ERROR << 16);

	act_len = sg_copy_from_buffer(sdb->table.sgl, sdb->table.nents,
				      arr, arr_len);
	sdb->resid = scsi_bufflen(scp) - 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 arr_len)
{
	if (!scsi_bufflen(scp))
		return 0;
	if (!(scsi_bidi_cmnd(scp) || scp->sc_data_direction == DMA_TO_DEVICE))
		return -1;

	return scsi_sg_copy_to_buffer(scp, arr, arr_len);
}


static const char * inq_vendor_id = "Linux   ";
static const char * inq_product_id = "scsi_debug      ";
static const char *inq_product_rev = "0184";	/* version less '.' */

/* Device identification VPD page. Returns number of bytes placed in arr */
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