Add in 2.4 ide-scsi

drivers/scsi/ide-scsi.c

+/*
+ * linux/drivers/scsi/ide-scsi.c	Version 0.9		Jul   4, 1999
+ *
+ * Copyright (C) 1996 - 1999 Gadi Oxman <gadio@netvision.net.il>
+ */
+
+/*
+ * Emulation of a SCSI host adapter for IDE ATAPI devices.
+ *
+ * With this driver, one can use the Linux SCSI drivers instead of the
+ * native IDE ATAPI drivers.
+ *
+ * Ver 0.1   Dec  3 96   Initial version.
+ * Ver 0.2   Jan 26 97   Fixed bug in cleanup_module() and added emulation
+ *                        of MODE_SENSE_6/MODE_SELECT_6 for cdroms. Thanks
+ *                        to Janos Farkas for pointing this out.
+ *                       Avoid using bitfields in structures for m68k.
+ *                       Added Scatter/Gather and DMA support.
+ * Ver 0.4   Dec  7 97   Add support for ATAPI PD/CD drives.
+ *                       Use variable timeout for each command.
+ * Ver 0.5   Jan  2 98   Fix previous PD/CD support.
+ *                       Allow disabling of SCSI-6 to SCSI-10 transformation.
+ * Ver 0.6   Jan 27 98   Allow disabling of SCSI command translation layer
+ *                        for access through /dev/sg.
+ *                       Fix MODE_SENSE_6/MODE_SELECT_6/INQUIRY translation.
+ * Ver 0.7   Dec 04 98   Ignore commands where lun != 0 to avoid multiple
+ *                        detection of devices with CONFIG_SCSI_MULTI_LUN
+ * Ver 0.8   Feb 05 99   Optical media need translation too. Reverse 0.7.
+ * Ver 0.9   Jul 04 99   Fix a bug in SG_SET_TRANSFORM.
+ * Ver 0.91  Jun 10 02   Fix "off by one" error in transforms
+ */
+
+#define IDESCSI_VERSION "0.9"
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/ioport.h>
+#include <linux/blkdev.h>
+#include <linux/errno.h>
+#include <linux/hdreg.h>
+#include <linux/slab.h>
+#include <linux/ide.h>
+
+#include <asm/io.h>
+#include <asm/bitops.h>
+#include <asm/uaccess.h>
+
+#include "scsi.h"
+#include "hosts.h"
+#include "sd.h"
+#include <scsi/sg.h>
+
+#define IDESCSI_DEBUG_LOG		0
+
+typedef struct idescsi_pc_s {
+	u8 c[12];				/* Actual packet bytes */
+	int request_transfer;			/* Bytes to transfer */
+	int actually_transferred;		/* Bytes actually transferred */
+	int buffer_size;			/* Size of our data buffer */
+	struct request *rq;			/* The corresponding request */
+	byte *buffer;				/* Data buffer */
+	byte *current_position;			/* Pointer into the above buffer */
+	struct scatterlist *sg;			/* Scatter gather table */
+	int b_count;				/* Bytes transferred from current entry */
+	Scsi_Cmnd *scsi_cmd;			/* SCSI command */
+	void (*done)(Scsi_Cmnd *);		/* Scsi completion routine */
+	unsigned long flags;			/* Status/Action flags */
+	unsigned long timeout;			/* Command timeout */
+} idescsi_pc_t;
+
+/*
+ *	Packet command status bits.
+ */
+#define PC_DMA_IN_PROGRESS		0	/* 1 while DMA in progress */
+#define PC_WRITING			1	/* Data direction */
+#define PC_TRANSFORM			2	/* transform SCSI commands */
+
+/*
+ *	SCSI command transformation layer
+ */
+#define IDESCSI_TRANSFORM		0	/* Enable/Disable transformation */
+#define IDESCSI_SG_TRANSFORM		1	/* /dev/sg transformation */
+
+/*
+ *	Log flags
+ */
+#define IDESCSI_LOG_CMD			0	/* Log SCSI commands */
+
+typedef struct {
+	ide_drive_t *drive;
+	idescsi_pc_t *pc;			/* Current packet command */
+	unsigned long flags;			/* Status/Action flags */
+	unsigned long transform;		/* SCSI cmd translation layer */
+	unsigned long log;			/* log flags */
+} idescsi_scsi_t;
+
+/*
+ *	Per ATAPI device status bits.
+ */
+#define IDESCSI_DRQ_INTERRUPT		0	/* DRQ interrupt device */
+
+/*
+ *	ide-scsi requests.
+ */
+#define IDESCSI_PC_RQ			90
+
+/*
+ *	Bits of the interrupt reason register.
+ */
+#define IDESCSI_IREASON_COD	0x1		/* Information transferred is command */
+#define IDESCSI_IREASON_IO	0x2		/* The device requests us to read */
+
+static void idescsi_discard_data (ide_drive_t *drive, unsigned int bcount)
+{
+	while (bcount--)
+		IN_BYTE (IDE_DATA_REG);
+}
+
+static void idescsi_output_zeros (ide_drive_t *drive, unsigned int bcount)
+{
+	while (bcount--)
+		OUT_BYTE (0, IDE_DATA_REG);
+}
+
+/*
+ *	PIO data transfer routines using the scatter gather table.
+ */
+static void idescsi_input_buffers (ide_drive_t *drive, idescsi_pc_t *pc, unsigned int bcount)
+{
+	int count;
+	char *buf;
+
+	while (bcount) {
+		if (pc->sg - (struct scatterlist *) pc->scsi_cmd->request_buffer > pc->scsi_cmd->use_sg) {
+			printk (KERN_ERR "ide-scsi: scatter gather table too small, discarding data\n");
+			idescsi_discard_data (drive, bcount);
+			return;
+		}
+		count = IDE_MIN (pc->sg->length - pc->b_count, bcount);
+		buf = page_address(pc->sg->page) + pc->sg->offset;
+		atapi_input_bytes (drive, buf + pc->b_count, count);
+		bcount -= count; pc->b_count += count;
+		if (pc->b_count == pc->sg->length) {
+			pc->sg++;
+			pc->b_count = 0;
+		}
+	}
+}
+
+static void idescsi_output_buffers (ide_drive_t *drive, idescsi_pc_t *pc, unsigned int bcount)
+{
+	int count;
+	char *buf;
+
+	while (bcount) {
+		if (pc->sg - (struct scatterlist *) pc->scsi_cmd->request_buffer > pc->scsi_cmd->use_sg) {
+			printk (KERN_ERR "ide-scsi: scatter gather table too small, padding with zeros\n");
+			idescsi_output_zeros (drive, bcount);
+			return;
+		}
+		count = IDE_MIN (pc->sg->length - pc->b_count, bcount);
+		buf = page_address(pc->sg->page) + pc->sg->offset;
+		atapi_output_bytes (drive, buf + pc->b_count, count);
+		bcount -= count; pc->b_count += count;
+		if (pc->b_count == pc->sg->length) {
+			pc->sg++;
+			pc->b_count = 0;
+		}
+	}
+}
+
+/*
+ *	Most of the SCSI commands are supported directly by ATAPI devices.
+ *	idescsi_transform_pc handles the few exceptions.
+ */
+static inline void idescsi_transform_pc1 (ide_drive_t *drive, idescsi_pc_t *pc)
+{
+	u8 *c = pc->c, *scsi_buf = pc->buffer, *sc = pc->scsi_cmd->cmnd;
+	char *atapi_buf;
+
+	if (!test_bit(PC_TRANSFORM, &pc->flags))
+		return;
+	if (drive->media == ide_cdrom || drive->media == ide_optical) {
+		if (c[0] == READ_6 || c[0] == WRITE_6) {
+			c[8] = c[4];		c[5] = c[3];		c[4] = c[2];
+			c[3] = c[1] & 0x1f;	c[2] = 0;		c[1] &= 0xe0;
+			c[0] += (READ_10 - READ_6);
+		}
+		if (c[0] == MODE_SENSE || c[0] == MODE_SELECT) {
+			unsigned short new_len;
+			if (!scsi_buf)
+				return;
+			if ((atapi_buf = kmalloc(pc->buffer_size + 4, GFP_ATOMIC)) == NULL)
+				return;
+			memset(atapi_buf, 0, pc->buffer_size + 4);
+			memset (c, 0, 12);
+			c[0] = sc[0] | 0x40;
+			c[1] = sc[1];
+			c[2] = sc[2];
+			new_len = sc[4] + 4;
+			c[8] = new_len;
+			c[9] = sc[5];
+			c[7] = new_len >> 8;
+			if (c[0] == MODE_SELECT_10) {
+				atapi_buf[1] = scsi_buf[0];	/* Mode data length */
+				atapi_buf[2] = scsi_buf[1];	/* Medium type */
+				atapi_buf[3] = scsi_buf[2];	/* Device specific parameter */
+				atapi_buf[7] = scsi_buf[3];	/* Block descriptor length */
+				memcpy(atapi_buf + 8, scsi_buf + 4, pc->buffer_size - 4);
+			}
+			pc->buffer = atapi_buf;
+			pc->request_transfer += 4;
+			pc->buffer_size += 4;
+		}
+	}
+}
+
+static inline void idescsi_transform_pc2 (ide_drive_t *drive, idescsi_pc_t *pc)
+{
+	u8 *atapi_buf = pc->buffer;
+	u8 *sc = pc->scsi_cmd->cmnd;
+	u8 *scsi_buf = pc->scsi_cmd->request_buffer;
+
+	if (!test_bit(PC_TRANSFORM, &pc->flags))
+		return;
+	if (drive->media == ide_cdrom || drive->media == ide_optical) {
+		if (pc->c[0] == MODE_SENSE_10 && sc[0] == MODE_SENSE) {
+			scsi_buf[0] = atapi_buf[1];		/* Mode data length */
+			scsi_buf[1] = atapi_buf[2];		/* Medium type */
+			scsi_buf[2] = atapi_buf[3];		/* Device specific parameter */
+			scsi_buf[3] = atapi_buf[7];		/* Block descriptor length */
+			memcpy(scsi_buf + 4, atapi_buf + 8, pc->request_transfer - 8);
+		}
+		if (pc->c[0] == INQUIRY) {
+			scsi_buf[2] |= 2;			/* ansi_revision */
+			scsi_buf[3] = (scsi_buf[3] & 0xf0) | 2;	/* response data format */
+		}
+	}
+	if (atapi_buf && atapi_buf != scsi_buf)
+		kfree(atapi_buf);
+}
+
+static inline void idescsi_free_bio (struct bio *bio)
+{
+	struct bio *bhp;
+
+	while (bio) {
+		bhp = bio;
+		bio = bio->bi_next;
+		bio_put(bhp);
+	}
+}
+
+static void hexdump(u8 *x, int len)
+{
+	int i;
+
+	printk("[ ");
+	for (i = 0; i < len; i++)
+		printk("%x ", x[i]);
+	printk("]\n");
+}
+
+static int idescsi_end_request (ide_drive_t *drive, int uptodate)
+{
+	idescsi_scsi_t *scsi = drive->driver_data;
+	struct request *rq = HWGROUP(drive)->rq;
+	idescsi_pc_t *pc = (idescsi_pc_t *) rq->special;
+	int log = test_bit(IDESCSI_LOG_CMD, &scsi->log);
+	struct Scsi_Host *host;
+	u8 *scsi_buf;
+	unsigned long flags;
+
+	if (!(rq->flags & REQ_SPECIAL)) {
+		ide_end_request(drive, uptodate);
+		return 0;
+	}
+	ide_end_drive_cmd (drive, 0, 0);
+	if (rq->errors >= ERROR_MAX) {
+		pc->scsi_cmd->result = DID_ERROR << 16;
+		if (log)
+			printk ("ide-scsi: %s: I/O error for %lu\n", drive->name, pc->scsi_cmd->serial_number);
+	} else if (rq->errors) {
+		pc->scsi_cmd->result = (CHECK_CONDITION << 1) | (DID_OK << 16);
+		if (log)
+			printk ("ide-scsi: %s: check condition for %lu\n", drive->name, pc->scsi_cmd->serial_number);
+	} else {
+		pc->scsi_cmd->result = DID_OK << 16;
+		idescsi_transform_pc2 (drive, pc);
+		if (log) {
+			printk ("ide-scsi: %s: suc %lu", drive->name, pc->scsi_cmd->serial_number);
+			if (!test_bit(PC_WRITING, &pc->flags) && pc->actually_transferred && pc->actually_transferred <= 1024 && pc->buffer) {
+				printk(", rst = ");
+				scsi_buf = pc->scsi_cmd->request_buffer;
+				hexdump(scsi_buf, IDE_MIN(16, pc->scsi_cmd->request_bufflen));
+			} else printk("\n");
+		}
+	}
+	host = pc->scsi_cmd->host;
+	spin_lock_irqsave(host->host_lock, flags);
+	pc->done(pc->scsi_cmd);
+	spin_unlock_irqrestore(host->host_lock, flags);
+	idescsi_free_bio (rq->bio);
+	kfree(pc); kfree(rq);
+	scsi->pc = NULL;
+	return 0;
+}
+
+static inline unsigned long get_timeout(idescsi_pc_t *pc)
+{
+	return IDE_MAX(WAIT_CMD, pc->timeout - jiffies);
+}
+
+/*
+ *	Our interrupt handler.
+ */
+static ide_startstop_t idescsi_pc_intr (ide_drive_t *drive)
+{
+	idescsi_scsi_t *scsi = drive->driver_data;
+	byte status, ireason;
+	int bcount;
+	idescsi_pc_t *pc=scsi->pc;
+	struct request *rq = pc->rq;
+	unsigned int temp;
+
+#if IDESCSI_DEBUG_LOG
+	printk (KERN_INFO "ide-scsi: Reached idescsi_pc_intr interrupt handler\n");
+#endif /* IDESCSI_DEBUG_LOG */
+
+	if (test_and_clear_bit (PC_DMA_IN_PROGRESS, &pc->flags)) {
+#if IDESCSI_DEBUG_LOG
+		printk ("ide-scsi: %s: DMA complete\n", drive->name);
+#endif /* IDESCSI_DEBUG_LOG */
+		pc->actually_transferred=pc->request_transfer;
+		(void) (HWIF(drive)->dmaproc(ide_dma_end, drive));
+	}
+
+	status = GET_STAT();						/* Clear the interrupt */
+
+	if ((status & DRQ_STAT) == 0) {					/* No more interrupts */
+		if (test_bit(IDESCSI_LOG_CMD, &scsi->log))
+			printk (KERN_INFO "Packet command completed, %d bytes transferred\n", pc->actually_transferred);
+		local_irq_enable();
+		if (status & ERR_STAT)
+			rq->errors++;
+		idescsi_end_request (drive, 1);
+		return ide_stopped;
+	}
+	bcount = IN_BYTE (IDE_BCOUNTH_REG) << 8 | IN_BYTE (IDE_BCOUNTL_REG);
+	ireason = IN_BYTE (IDE_IREASON_REG);
+
+	if (ireason & IDESCSI_IREASON_COD) {
+		printk (KERN_ERR "ide-scsi: CoD != 0 in idescsi_pc_intr\n");
+		return ide_do_reset (drive);
+	}
+	if (ireason & IDESCSI_IREASON_IO) {
+		temp = pc->actually_transferred + bcount;
+		if ( temp > pc->request_transfer) {
+			if (temp > pc->buffer_size) {
+				printk (KERN_ERR "ide-scsi: The scsi wants to send us more data than expected - discarding data\n");
+				temp = pc->buffer_size - pc->actually_transferred;
+				if (temp) {
+					clear_bit(PC_WRITING, &pc->flags);
+					if (pc->sg)
+						idescsi_input_buffers(drive, pc, temp);
+					else
+						atapi_input_bytes(drive, pc->current_position, temp);
+					printk(KERN_ERR "ide-scsi: transferred %d of %d bytes\n", temp, bcount);
+				}
+				pc->actually_transferred += temp;
+				pc->current_position += temp;
+				idescsi_discard_data (drive,bcount - temp);
+				ide_set_handler(drive, &idescsi_pc_intr, get_timeout(pc), NULL);
+				return ide_started;
+			}
+#if IDESCSI_DEBUG_LOG
+			printk (KERN_NOTICE "ide-scsi: The scsi wants to send us more data than expected - allowing transfer\n");
+#endif /* IDESCSI_DEBUG_LOG */
+		}
+	}
+	if (ireason & IDESCSI_IREASON_IO) {
+		clear_bit(PC_WRITING, &pc->flags);
+		if (pc->sg)
+			idescsi_input_buffers (drive, pc, bcount);
+		else
+			atapi_input_bytes (drive,pc->current_position,bcount);
+	} else {
+		set_bit(PC_WRITING, &pc->flags);
+		if (pc->sg)
+			idescsi_output_buffers (drive, pc, bcount);
+		else
+			atapi_output_bytes (drive,pc->current_position,bcount);
+	}
+	pc->actually_transferred+=bcount;				/* Update the current position */
+	pc->current_position+=bcount;
+
+	ide_set_handler(drive, &idescsi_pc_intr, get_timeout(pc), NULL);	/* And set the interrupt handler again */
+	return ide_started;
+}
+
+static ide_startstop_t idescsi_transfer_pc (ide_drive_t *drive)
+{
+	idescsi_scsi_t *scsi = drive->driver_data;
+	idescsi_pc_t *pc = scsi->pc;
+	byte ireason;
+	ide_startstop_t startstop;
+
+	if (ide_wait_stat (&startstop,drive,DRQ_STAT,BUSY_STAT,WAIT_READY)) {
+		printk (KERN_ERR "ide-scsi: Strange, packet command initiated yet DRQ isn't asserted\n");
+		return startstop;
+	}
+	ireason = IN_BYTE (IDE_IREASON_REG);
+	if ((ireason & (IDESCSI_IREASON_IO | IDESCSI_IREASON_COD)) != IDESCSI_IREASON_COD) {
+		printk (KERN_ERR "ide-scsi: (IO,CoD) != (0,1) while issuing a packet command\n");
+		return ide_do_reset (drive);
+	}
+	ide_set_handler(drive, &idescsi_pc_intr, get_timeout(pc), NULL);	/* Set the interrupt routine */
+	atapi_output_bytes (drive, scsi->pc->c, 12);			/* Send the actual packet */
+	return ide_started;
+}
+
+/*
+ *	Issue a packet command
+ */
+static ide_startstop_t idescsi_issue_pc (ide_drive_t *drive, idescsi_pc_t *pc)
+{
+	idescsi_scsi_t *scsi = drive->driver_data;
+	int bcount;
+	struct request *rq = pc->rq;
+	int dma_ok = 0;
+
+	scsi->pc=pc;							/* Set the current packet command */
+	pc->actually_transferred=0;					/* We haven't transferred any data yet */
+	pc->current_position=pc->buffer;
+	bcount = IDE_MIN (pc->request_transfer, 63 * 1024);		/* Request to transfer the entire buffer at once */
+
+	if (drive->using_dma && rq->bio)
+		dma_ok=!HWIF(drive)->dmaproc(test_bit (PC_WRITING, &pc->flags) ? ide_dma_write : ide_dma_read, drive);
+
+	SELECT_DRIVE(HWIF(drive), drive);
+	if (IDE_CONTROL_REG)
+		OUT_BYTE (drive->ctl,IDE_CONTROL_REG);
+	OUT_BYTE (dma_ok,IDE_FEATURE_REG);
+	OUT_BYTE (bcount >> 8,IDE_BCOUNTH_REG);
+	OUT_BYTE (bcount & 0xff,IDE_BCOUNTL_REG);
+
+	if (dma_ok) {
+		set_bit (PC_DMA_IN_PROGRESS, &pc->flags);
+		(void) (HWIF(drive)->dmaproc(ide_dma_begin, drive));
+	}
+	if (test_bit (IDESCSI_DRQ_INTERRUPT, &scsi->flags)) {
+		ide_set_handler (drive, &idescsi_transfer_pc, get_timeout(pc), NULL);
+		OUT_BYTE (WIN_PACKETCMD, IDE_COMMAND_REG);		/* Issue the packet command */
+		return ide_started;
+	} else {
+		OUT_BYTE (WIN_PACKETCMD, IDE_COMMAND_REG);
+		return idescsi_transfer_pc (drive);
+	}
+}
+
+/*
+ *	idescsi_do_request is our request handling function.
+ */
+static ide_startstop_t idescsi_do_request (ide_drive_t *drive, struct request *rq, unsigned long block)
+{
+#if IDESCSI_DEBUG_LOG
+	printk (KERN_INFO "rq_status: %d, rq_dev: %u, cmd: %d, errors: %d\n",rq->rq_status,(unsigned int) rq->rq_dev,rq->cmd,rq->errors);
+	printk (KERN_INFO "sector: %ld, nr_sectors: %ld, current_nr_sectors: %ld\n",rq->sector,rq->nr_sectors,rq->current_nr_sectors);
+#endif /* IDESCSI_DEBUG_LOG */
+
+	if (rq->flags & REQ_SPECIAL) {
+		return idescsi_issue_pc (drive, (idescsi_pc_t *) rq->special);
+	}
+	blk_dump_rq_flags(rq, "ide-scsi: unsup command");
+	idescsi_end_request (drive, 0);
+	return ide_stopped;
+}
+
+static int idescsi_open (struct inode *inode, struct file *filp, ide_drive_t *drive)
+{
+	MOD_INC_USE_COUNT;
+	return 0;
+}
+
+static void idescsi_ide_release (struct inode *inode, struct file *filp, ide_drive_t *drive)
+{
+	MOD_DEC_USE_COUNT;
+}
+
+static ide_drive_t *idescsi_drives[MAX_HWIFS * MAX_DRIVES];
+static int idescsi_initialized = 0;
+
+static void idescsi_add_settings(ide_drive_t *drive)
+{
+	idescsi_scsi_t *scsi = drive->driver_data;
+
+/*
+ *			drive	setting name	read/write	ioctl	ioctl		data type	min	max	mul_factor	div_factor	data pointer		set function
+ */
+	ide_add_setting(drive,	"bios_cyl",	SETTING_RW,	-1,	-1,		TYPE_INT,	0,	1023,	1,		1,		&drive->bios_cyl,	NULL);
+	ide_add_setting(drive,	"bios_head",	SETTING_RW,	-1,	-1,		TYPE_BYTE,	0,	255,	1,		1,		&drive->bios_head,	NULL);
+	ide_add_setting(drive,	"bios_sect",	SETTING_RW,	-1,	-1,		TYPE_BYTE,	0,	63,	1,		1,		&drive->bios_sect,	NULL);
+	ide_add_setting(drive,	"transform",	SETTING_RW,	-1,	-1,		TYPE_INT,	0,	3,	1,		1,		&scsi->transform,	NULL);
+	ide_add_setting(drive,	"log",		SETTING_RW,	-1,	-1,		TYPE_INT,	0,	1,	1,		1,		&scsi->log,		NULL);
+}
+
+/*
+ *	Driver initialization.
+ */
+static void idescsi_setup (ide_drive_t *drive, idescsi_scsi_t *scsi, int id)
+{
+	DRIVER(drive)->busy++;
+	idescsi_drives[id] = drive;
+	drive->driver_data = scsi;
+	drive->ready_stat = 0;
+	memset (scsi, 0, sizeof (idescsi_scsi_t));
+	scsi->drive = drive;
+	if (drive->id && (drive->id->config & 0x0060) == 0x20)
+		set_bit (IDESCSI_DRQ_INTERRUPT, &scsi->flags);
+	set_bit(IDESCSI_TRANSFORM, &scsi->transform);
+	clear_bit(IDESCSI_SG_TRANSFORM, &scsi->transform);
+#if IDESCSI_DEBUG_LOG
+	set_bit(IDESCSI_LOG_CMD, &scsi->log);
+#endif /* IDESCSI_DEBUG_LOG */
+	idescsi_add_settings(drive);
+}
+
+static int idescsi_cleanup (ide_drive_t *drive)
+{
+	idescsi_scsi_t *scsi = drive->driver_data;
+
+	if (ide_unregister_subdriver (drive))
+		return 1;
+	drive->driver_data = NULL;
+	kfree (scsi);
+	return 0;
+}
+
+/*
+ *	IDE subdriver functions, registered with ide.c
+ */
+static ide_driver_t idescsi_driver = {
+	name:			"ide-scsi",
+	version:		IDESCSI_VERSION,
+	media:			ide_scsi,
+	busy:			0,
+	supports_dma:		1,
+	supports_dsc_overlap:	0,
+	cleanup:		idescsi_cleanup,
+	standby:		NULL,
+	flushcache:		NULL,
+	do_request:		idescsi_do_request,
+	end_request:		idescsi_end_request,
+	ioctl:			NULL,
+	open:			idescsi_open,
+	release:		idescsi_ide_release,
+	media_change:		NULL,
+	revalidate:		NULL,
+	pre_reset:		NULL,
+	capacity:		NULL,
+	special:		NULL,
+	proc:			NULL,
+};
+
+int idescsi_init (void);
+static ide_module_t idescsi_module = {
+	IDE_DRIVER_MODULE,
+	idescsi_init,
+	&idescsi_driver,
+	NULL
+};
+
+/*
+ *	idescsi_init will register the driver for each scsi.
+ */
+int idescsi_init (void)
+{
+	ide_drive_t *drive;
+	idescsi_scsi_t *scsi;
+	byte media[] = {TYPE_DISK, TYPE_TAPE, TYPE_PROCESSOR, TYPE_WORM, TYPE_ROM, TYPE_SCANNER, TYPE_MOD, 255};
+	int i, failed, id;
+
+	if (idescsi_initialized)
+		return 0;
+	idescsi_initialized = 1;
+	for (i = 0; i < MAX_HWIFS * MAX_DRIVES; i++)
+		idescsi_drives[i] = NULL;
+	MOD_INC_USE_COUNT;
+	for (i = 0; media[i] != 255; i++) {
+		failed = 0;
+		while ((drive = ide_scan_devices (media[i], idescsi_driver.name, NULL, failed++)) != NULL) {
+
+			if ((scsi = (idescsi_scsi_t *) kmalloc (sizeof (idescsi_scsi_t), GFP_KERNEL)) == NULL) {
+				printk (KERN_ERR "ide-scsi: %s: Can't allocate a scsi structure\n", drive->name);
+				continue;
+			}
+			if (ide_register_subdriver (drive, &idescsi_driver, IDE_SUBDRIVER_VERSION)) {
+				printk (KERN_ERR "ide-scsi: %s: Failed to register the driver with ide.c\n", drive->name);
+				kfree (scsi);
+				continue;
+			}
+			for (id = 0; id < MAX_HWIFS * MAX_DRIVES && idescsi_drives[id]; id++);
+				idescsi_setup (drive, scsi, id);
+			failed--;
+		}
+	}
+	ide_register_module(&idescsi_module);
+	MOD_DEC_USE_COUNT;
+	return 0;
+}
+
+int idescsi_detect (Scsi_Host_Template *host_template)
+{
+	struct Scsi_Host *host;
+	int id;
+	int last_lun = 0;
+
+	host_template->proc_name = "ide-scsi";
+	host = scsi_register(host_template, 0);
+	if(host == NULL)
+		return 0;
+		
+	for (id = 0; id < MAX_HWIFS * MAX_DRIVES && idescsi_drives[id]; id++)
+		last_lun = IDE_MAX(last_lun, idescsi_drives[id]->last_lun);
+	host->max_id = id;
+	host->max_lun = last_lun + 1;
+	host->can_queue = host->cmd_per_lun * id;
+	return 1;
+}
+
+int idescsi_release (struct Scsi_Host *host)
+{
+	ide_drive_t *drive;
+	int id;
+
+	for (id = 0; id < MAX_HWIFS * MAX_DRIVES; id++) {
+		drive = idescsi_drives[id];
+		if (drive)
+			DRIVER(drive)->busy--;
+	}
+	return 0;
+}
+
+const char *idescsi_info (struct Scsi_Host *host)
+{
+	return "SCSI host adapter emulation for IDE ATAPI devices";
+}
+
+int idescsi_ioctl (Scsi_Device *dev, int cmd, void *arg)
+{
+	ide_drive_t *drive = idescsi_drives[dev->id];
+	idescsi_scsi_t *scsi = drive->driver_data;
+
+	if (cmd == SG_SET_TRANSFORM) {
+		if (arg)
+			set_bit(IDESCSI_SG_TRANSFORM, &scsi->transform);
+		else
+			clear_bit(IDESCSI_SG_TRANSFORM, &scsi->transform);
+		return 0;
+	} else if (cmd == SG_GET_TRANSFORM)
+		return put_user(test_bit(IDESCSI_SG_TRANSFORM, &scsi->transform), (int *) arg);
+	return -EINVAL;
+}
+
+static inline struct bio *idescsi_kmalloc_bio (int count)
+{
+	struct bio *bh, *bhp, *first_bh;
+
+	if ((first_bh = bhp = bh = bio_alloc(GFP_ATOMIC, 1)) == NULL)
+		goto abort;
+	bio_init(bh);
+	bh->bi_vcnt = 1;
+	while (--count) {
+		if ((bh = bio_alloc(GFP_ATOMIC, 1)) == NULL)
+			goto abort;
+		bio_init(bh);
+		bh->bi_vcnt = 1;
+		bhp->bi_next = bh;
+		bhp = bh;
+		bh->bi_next = NULL;
+	}
+	return first_bh;
+abort:
+	idescsi_free_bio (first_bh);
+	return NULL;
+}
+
+static inline int idescsi_set_direction (idescsi_pc_t *pc)
+{
+	switch (pc->c[0]) {
+		case READ_6: case READ_10: case READ_12:
+			clear_bit (PC_WRITING, &pc->flags);
+			return 0;
+		case WRITE_6: case WRITE_10: case WRITE_12:
+			set_bit (PC_WRITING, &pc->flags);
+			return 0;
+		default:
+			return 1;
+	}
+}
+
+static inline struct bio *idescsi_dma_bio(ide_drive_t *drive, idescsi_pc_t *pc)
+{
+	struct bio *bh = NULL, *first_bh = NULL;
+	int segments = pc->scsi_cmd->use_sg;
+	struct scatterlist *sg = pc->scsi_cmd->request_buffer;
+
+	if (!drive->using_dma || !pc->request_transfer || pc->request_transfer % 1024)
+		return NULL;
+	if (idescsi_set_direction(pc))
+		return NULL;
+	if (segments) {
+		if ((first_bh = bh = idescsi_kmalloc_bio (segments)) == NULL)
+			return NULL;
+#if IDESCSI_DEBUG_LOG
+		printk ("ide-scsi: %s: building DMA table, %d segments, %dkB total\n", drive->name, segments, pc->request_transfer >> 10);
+#endif /* IDESCSI_DEBUG_LOG */
+		while (segments--) {
+			bh->bi_io_vec[0].bv_page = sg->page;
+			bh->bi_io_vec[0].bv_len = sg->length;
+			bh->bi_io_vec[0].bv_offset = sg->offset;
+			bh->bi_size = sg->length;
+			bh = bh->bi_next;
+			sg++;
+		}
+	} else {
+		if ((first_bh = bh = idescsi_kmalloc_bio (1)) == NULL)
+			return NULL;
+#if IDESCSI_DEBUG_LOG
+		printk ("ide-scsi: %s: building DMA table for a single buffer (%dkB)\n", drive->name, pc->request_transfer >> 10);
+#endif /* IDESCSI_DEBUG_LOG */
+		bh->bi_io_vec[0].bv_page = virt_to_page(pc->scsi_cmd->request_buffer);
+		bh->bi_io_vec[0].bv_len = pc->request_transfer;
+		bh->bi_io_vec[0].bv_offset = (unsigned long) pc->scsi_cmd->request_buffer & ~PAGE_MASK;
+		bh->bi_size = pc->request_transfer;
+	}
+	return first_bh;
+}
+
+static inline int should_transform(ide_drive_t *drive, Scsi_Cmnd *cmd)
+{
+	idescsi_scsi_t *scsi = drive->driver_data;
+
+	if (major(cmd->request->rq_dev) == SCSI_GENERIC_MAJOR)
+		return test_bit(IDESCSI_SG_TRANSFORM, &scsi->transform);
+	return test_bit(IDESCSI_TRANSFORM, &scsi->transform);
+}
+
+int idescsi_queue (Scsi_Cmnd *cmd, void (*done)(Scsi_Cmnd *))
+{
+	ide_drive_t *drive = idescsi_drives[cmd->target];
+	idescsi_scsi_t *scsi;
+	struct request *rq = NULL;
+	idescsi_pc_t *pc = NULL;
+
+	if (!drive) {
+		printk (KERN_ERR "ide-scsi: drive id %d not present\n", cmd->target);
+		goto abort;
+	}
+	scsi = drive->driver_data;
+	pc = kmalloc (sizeof (idescsi_pc_t), GFP_ATOMIC);
+	rq = kmalloc (sizeof (struct request), GFP_ATOMIC);
+	if (rq == NULL || pc == NULL) {
+		printk (KERN_ERR "ide-scsi: %s: out of memory\n", drive->name);
+		goto abort;
+	}
+
+	memset (pc->c, 0, 12);
+	pc->flags = 0;
+	pc->rq = rq;
+	memcpy (pc->c, cmd->cmnd, cmd->cmd_len);
+	if (cmd->use_sg) {
+		pc->buffer = NULL;
+		pc->sg = cmd->request_buffer;
+	} else {
+		pc->buffer = cmd->request_buffer;
+		pc->sg = NULL;
+	}
+	pc->b_count = 0;
+	pc->request_transfer = pc->buffer_size = cmd->request_bufflen;
+	pc->scsi_cmd = cmd;
+	pc->done = done;
+	pc->timeout = jiffies + cmd->timeout_per_command;
+
+	if (should_transform(drive, cmd))
+		set_bit(PC_TRANSFORM, &pc->flags);
+	idescsi_transform_pc1 (drive, pc);
+
+	if (test_bit(IDESCSI_LOG_CMD, &scsi->log)) {
+		printk ("ide-scsi: %s: que %lu, cmd = ", drive->name, cmd->serial_number);
+		hexdump(cmd->cmnd, cmd->cmd_len);
+		if (memcmp(pc->c, cmd->cmnd, cmd->cmd_len)) {
+			printk ("ide-scsi: %s: que %lu, tsl = ", drive->name, cmd->serial_number);
+			hexdump(pc->c, 12);
+		}
+	}
+
+	ide_init_drive_cmd (rq);
+	rq->special = (char *) pc;
+	rq->bio = idescsi_dma_bio (drive, pc);
+	rq->flags = REQ_SPECIAL;
+	spin_unlock_irq(cmd->host->host_lock);
+	(void) ide_do_drive_cmd (drive, rq, ide_end);
+	spin_lock_irq(cmd->host->host_lock);
+	return 0;
+abort:
+	if (pc) kfree (pc);
+	if (rq) kfree (rq);
+	cmd->result = DID_ERROR << 16;
+	done(cmd);
+	return 0;
+}
+
+int idescsi_abort (Scsi_Cmnd *cmd)
+{
+	return SCSI_ABORT_SNOOZE;
+}
+
+int idescsi_reset (Scsi_Cmnd *cmd, unsigned int resetflags)
+{
+	return SCSI_RESET_SUCCESS;
+}
+
+static int idescsi_bios(Disk *disk, struct block_device *dev, int *parm)
+{
+	ide_drive_t *drive = idescsi_drives[disk->device->id];
+
+	if (drive->bios_cyl && drive->bios_head && drive->bios_sect) {
+		parm[0] = drive->bios_head;
+		parm[1] = drive->bios_sect;
+		parm[2] = drive->bios_cyl;
+	}
+	return 0;
+}
+
+static Scsi_Host_Template idescsi_template = {
+	module:		THIS_MODULE,
+	name:		"idescsi",
+	detect:		idescsi_detect,
+	release:	idescsi_release,
+	info:		idescsi_info,
+	ioctl:		idescsi_ioctl,
+	queuecommand:	idescsi_queue,
+	abort:		idescsi_abort,
+	reset:		idescsi_reset,
+	bios_param:	idescsi_bios,
+	can_queue:	10,
+	this_id:	-1,
+	sg_tablesize:	256,
+	cmd_per_lun:	5,
+	use_clustering:	DISABLE_CLUSTERING,
+	emulated:	1,
+};
+
+static int __init init_idescsi_module(void)
+{
+	idescsi_init();
+	scsi_register_host(&idescsi_template);
+	return 0;
+}
+
+static void __exit exit_idescsi_module(void)
+{
+	ide_drive_t *drive;
+	byte media[] = {TYPE_DISK, TYPE_TAPE, TYPE_PROCESSOR, TYPE_WORM, TYPE_ROM, TYPE_SCANNER, TYPE_MOD, 255};
+	int i, failed;
+
+	scsi_unregister_host(&idescsi_template);
+	for (i = 0; media[i] != 255; i++) {
+		failed = 0;
+		while ((drive = ide_scan_devices (media[i], idescsi_driver.name, &idescsi_driver, failed)) != NULL)
+			if (idescsi_cleanup (drive)) {
+				printk ("%s: exit_idescsi_module() called while still busy\n", drive->name);
+				failed++;
+			}
+	}
+	ide_unregister_module(&idescsi_module);
+}
+
+module_init(init_idescsi_module);
+module_exit(exit_idescsi_module);
+MODULE_LICENSE("GPL");