Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 1174 insertions, 0 deletions

diff --git a/drivers/scsi/ide-scsi.c b/drivers/scsi/ide-scsi.c
new file mode 100644
index 000000000000..2e2486b035dd
--- /dev/null
+++ b/drivers/scsi/ide-scsi.c
@@ -0,0 +1,1174 @@
+/*
+ * 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
+ * Ver 0.92  Dec 31 02   Implement new SCSI mid level API
+ */
+
+#define IDESCSI_VERSION "0.92"
+
+#include <linux/module.h>
+#include <linux/config.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 <linux/scatterlist.h>
+
+#include <asm/io.h>
+#include <asm/bitops.h>
+#include <asm/uaccess.h>
+
+#include <scsi/scsi.h>
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_device.h>
+#include <scsi/scsi_host.h>
+#include <scsi/scsi_tcq.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 */
+	u8 *buffer;				/* Data buffer */
+	u8 *current_position;			/* Pointer into the above buffer */
+	struct scatterlist *sg;			/* Scatter gather table */
+	int b_count;				/* Bytes transferred from current entry */
+	struct scsi_cmnd *scsi_cmd;		/* SCSI command */
+	void (*done)(struct 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 */
+#define PC_TIMEDOUT			3	/* command timed out */
+#define PC_DMA_OK			4	/* Use DMA */
+
+/*
+ *	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_scsi_obj {
+	ide_drive_t		*drive;
+	ide_driver_t		*driver;
+	struct gendisk		*disk;
+	struct Scsi_Host	*host;
+
+	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;
+
+static DECLARE_MUTEX(idescsi_ref_sem);
+
+#define ide_scsi_g(disk) \
+	container_of((disk)->private_data, struct ide_scsi_obj, driver)
+
+static struct ide_scsi_obj *ide_scsi_get(struct gendisk *disk)
+{
+	struct ide_scsi_obj *scsi = NULL;
+
+	down(&idescsi_ref_sem);
+	scsi = ide_scsi_g(disk);
+	if (scsi)
+		scsi_host_get(scsi->host);
+	up(&idescsi_ref_sem);
+	return scsi;
+}
+
+static void ide_scsi_put(struct ide_scsi_obj *scsi)
+{
+	down(&idescsi_ref_sem);
+	scsi_host_put(scsi->host);
+	up(&idescsi_ref_sem);
+}
+
+static inline idescsi_scsi_t *scsihost_to_idescsi(struct Scsi_Host *host)
+{
+	return (idescsi_scsi_t*) (&host[1]);
+}
+
+static inline idescsi_scsi_t *drive_to_idescsi(ide_drive_t *ide_drive)
+{
+	return scsihost_to_idescsi(ide_drive->driver_data);
+}
+
+/*
+ *	Per ATAPI device status bits.
+ */
+#define IDESCSI_DRQ_INTERRUPT		0	/* DRQ interrupt device */
+
+/*
+ *	ide-scsi requests.
+ */
+#define IDESCSI_PC_RQ			90
+
+static void idescsi_discard_data (ide_drive_t *drive, unsigned int bcount)
+{
+	while (bcount--)
+		(void) HWIF(drive)->INB(IDE_DATA_REG);
+}
+
+static void idescsi_output_zeros (ide_drive_t *drive, unsigned int bcount)
+{
+	while (bcount--)
+		HWIF(drive)->OUTB(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 = min(pc->sg->length - pc->b_count, bcount);
+		buf = page_address(pc->sg->page) + pc->sg->offset;
+		drive->hwif->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 = min(pc->sg->length - pc->b_count, bcount);
+		buf = page_address(pc->sg->page) + pc->sg->offset;
+		drive->hwif->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[7] = new_len >> 8;
+			c[9] = sc[5];
+			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 void hexdump(u8 *x, int len)
+{
+	int i;
+
+	printk("[ ");
+	for (i = 0; i < len; i++)
+		printk("%x ", x[i]);
+	printk("]\n");
+}
+
+static int idescsi_check_condition(ide_drive_t *drive, struct request *failed_command)
+{
+	idescsi_scsi_t *scsi = drive_to_idescsi(drive);
+	idescsi_pc_t   *pc;
+	struct request *rq;
+	u8             *buf;
+
+	/* stuff a sense request in front of our current request */
+	pc = kmalloc (sizeof (idescsi_pc_t), GFP_ATOMIC);
+	rq = kmalloc (sizeof (struct request), GFP_ATOMIC);
+	buf = kmalloc(SCSI_SENSE_BUFFERSIZE, GFP_ATOMIC);
+	if (pc == NULL || rq == NULL || buf == NULL) {
+		if (pc) kfree(pc);
+		if (rq) kfree(rq);
+		if (buf) kfree(buf);
+		return -ENOMEM;
+	}
+	memset (pc, 0, sizeof (idescsi_pc_t));
+	memset (buf, 0, SCSI_SENSE_BUFFERSIZE);
+	ide_init_drive_cmd(rq);
+	rq->special = (char *) pc;
+	pc->rq = rq;
+	pc->buffer = buf;
+	pc->c[0] = REQUEST_SENSE;
+	pc->c[4] = pc->request_transfer = pc->buffer_size = SCSI_SENSE_BUFFERSIZE;
+	rq->flags = REQ_SENSE;
+	pc->timeout = jiffies + WAIT_READY;
+	/* NOTE! Save the failed packet command in "rq->buffer" */
+	rq->buffer = (void *) failed_command->special;
+	pc->scsi_cmd = ((idescsi_pc_t *) failed_command->special)->scsi_cmd;
+	if (test_bit(IDESCSI_LOG_CMD, &scsi->log)) {
+		printk ("ide-scsi: %s: queue cmd = ", drive->name);
+		hexdump(pc->c, 6);
+	}
+	rq->rq_disk = scsi->disk;
+	return ide_do_drive_cmd(drive, rq, ide_preempt);
+}
+
+static int idescsi_end_request(ide_drive_t *, int, int);
+
+static ide_startstop_t
+idescsi_atapi_error(ide_drive_t *drive, struct request *rq, u8 stat, u8 err)
+{
+	if (HWIF(drive)->INB(IDE_STATUS_REG) & (BUSY_STAT|DRQ_STAT))
+		/* force an abort */
+		HWIF(drive)->OUTB(WIN_IDLEIMMEDIATE,IDE_COMMAND_REG);
+
+	rq->errors++;
+
+	idescsi_end_request(drive, 0, 0);
+
+	return ide_stopped;
+}
+
+static ide_startstop_t
+idescsi_atapi_abort(ide_drive_t *drive, struct request *rq)
+{
+#if IDESCSI_DEBUG_LOG
+	printk(KERN_WARNING "idescsi_atapi_abort called for %lu\n",
+			((idescsi_pc_t *) rq->special)->scsi_cmd->serial_number);
+#endif
+	rq->errors |= ERROR_MAX;
+
+	idescsi_end_request(drive, 0, 0);
+
+	return ide_stopped;
+}
+
+static int idescsi_end_request (ide_drive_t *drive, int uptodate, int nrsecs)
+{
+	idescsi_scsi_t *scsi = drive_to_idescsi(drive);
+	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|REQ_SENSE))) {
+		ide_end_request(drive, uptodate, nrsecs);
+		return 0;
+	}
+	ide_end_drive_cmd (drive, 0, 0);
+	if (rq->flags & REQ_SENSE) {
+		idescsi_pc_t *opc = (idescsi_pc_t *) rq->buffer;
+		if (log) {
+			printk ("ide-scsi: %s: wrap up check %lu, rst = ", drive->name, opc->scsi_cmd->serial_number);
+			hexdump(pc->buffer,16);
+		}
+		memcpy((void *) opc->scsi_cmd->sense_buffer, pc->buffer, SCSI_SENSE_BUFFERSIZE);
+		kfree(pc->buffer);
+		kfree(pc);
+		kfree(rq);
+		pc = opc;
+		rq = pc->rq;
+		pc->scsi_cmd->result = (CHECK_CONDITION << 1) |
+					((test_bit(PC_TIMEDOUT, &pc->flags)?DID_TIME_OUT:DID_OK) << 16);
+	} else if (test_bit(PC_TIMEDOUT, &pc->flags)) {
+		if (log)
+			printk (KERN_WARNING "ide-scsi: %s: timed out for %lu\n",
+					drive->name, pc->scsi_cmd->serial_number);
+		pc->scsi_cmd->result = DID_TIME_OUT << 16;
+	} else 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) {
+		if (log)
+			printk ("ide-scsi: %s: check condition for %lu\n", drive->name, pc->scsi_cmd->serial_number);
+		if (!idescsi_check_condition(drive, rq))
+			/* we started a request sense, so we'll be back, exit for now */
+			return 0;
+		pc->scsi_cmd->result = (CHECK_CONDITION << 1) | (DID_OK << 16);
+	} 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, min_t(unsigned, 16, pc->scsi_cmd->request_bufflen));
+			} else printk("\n");
+		}
+	}
+	host = pc->scsi_cmd->device->host;
+	spin_lock_irqsave(host->host_lock, flags);
+	pc->done(pc->scsi_cmd);
+	spin_unlock_irqrestore(host->host_lock, flags);
+	kfree(pc);
+	kfree(rq);
+	scsi->pc = NULL;
+	return 0;
+}
+
+static inline unsigned long get_timeout(idescsi_pc_t *pc)
+{
+	return max_t(unsigned long, WAIT_CMD, pc->timeout - jiffies);
+}
+
+static int idescsi_expiry(ide_drive_t *drive)
+{
+	idescsi_scsi_t *scsi = drive->driver_data;
+	idescsi_pc_t   *pc   = scsi->pc;
+
+#if IDESCSI_DEBUG_LOG
+	printk(KERN_WARNING "idescsi_expiry called for %lu at %lu\n", pc->scsi_cmd->serial_number, jiffies);
+#endif
+	set_bit(PC_TIMEDOUT, &pc->flags);
+
+	return 0;					/* we do not want the ide subsystem to retry */
+}
+
+/*
+ *	Our interrupt handler.
+ */
+static ide_startstop_t idescsi_pc_intr (ide_drive_t *drive)
+{
+	idescsi_scsi_t *scsi = drive_to_idescsi(drive);
+	idescsi_pc_t *pc=scsi->pc;
+	struct request *rq = pc->rq;
+	atapi_bcount_t bcount;
+	atapi_status_t status;
+	atapi_ireason_t ireason;
+	atapi_feature_t feature;
+
+	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_bit(PC_TIMEDOUT, &pc->flags)){
+#if IDESCSI_DEBUG_LOG
+		printk(KERN_WARNING "idescsi_pc_intr: got timed out packet  %lu at %lu\n",
+				pc->scsi_cmd->serial_number, jiffies);
+#endif
+		/* end this request now - scsi should retry it*/
+		idescsi_end_request (drive, 1, 0);
+		return ide_stopped;
+	}
+	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)->ide_dma_end(drive);
+	}
+
+	feature.all = 0;
+	/* Clear the interrupt */
+	status.all = HWIF(drive)->INB(IDE_STATUS_REG);
+
+	if (!status.b.drq) {
+		/* 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.b.check)
+			rq->errors++;
+		idescsi_end_request (drive, 1, 0);
+		return ide_stopped;
+	}
+	bcount.b.low	= HWIF(drive)->INB(IDE_BCOUNTL_REG);
+	bcount.b.high	= HWIF(drive)->INB(IDE_BCOUNTH_REG);
+	ireason.all	= HWIF(drive)->INB(IDE_IREASON_REG);
+
+	if (ireason.b.cod) {
+		printk(KERN_ERR "ide-scsi: CoD != 0 in idescsi_pc_intr\n");
+		return ide_do_reset (drive);
+	}
+	if (ireason.b.io) {
+		temp = pc->actually_transferred + bcount.all;
+		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
+						drive->hwif->atapi_input_bytes(drive, pc->current_position, temp);
+					printk(KERN_ERR "ide-scsi: transferred %d of %d bytes\n", temp, bcount.all);
+				}
+				pc->actually_transferred += temp;
+				pc->current_position += temp;
+				idescsi_discard_data(drive, bcount.all - temp);
+				ide_set_handler(drive, &idescsi_pc_intr, get_timeout(pc), idescsi_expiry);
+				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.b.io) {
+		clear_bit(PC_WRITING, &pc->flags);
+		if (pc->sg)
+			idescsi_input_buffers(drive, pc, bcount.all);
+		else
+			HWIF(drive)->atapi_input_bytes(drive, pc->current_position, bcount.all);
+	} else {
+		set_bit(PC_WRITING, &pc->flags);
+		if (pc->sg)
+			idescsi_output_buffers (drive, pc, bcount.all);
+		else
+			HWIF(drive)->atapi_output_bytes(drive, pc->current_position, bcount.all);
+	}
+	/* Update the current position */
+	pc->actually_transferred += bcount.all;
+	pc->current_position += bcount.all;
+
+	/* And set the interrupt handler again */
+	ide_set_handler(drive, &idescsi_pc_intr, get_timeout(pc), idescsi_expiry);
+	return ide_started;
+}
+
+static ide_startstop_t idescsi_transfer_pc(ide_drive_t *drive)
+{
+	ide_hwif_t *hwif = drive->hwif;
+	idescsi_scsi_t *scsi = drive_to_idescsi(drive);
+	idescsi_pc_t *pc = scsi->pc;
+	atapi_ireason_t 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.all	= HWIF(drive)->INB(IDE_IREASON_REG);
+	if (!ireason.b.cod || ireason.b.io) {
+		printk(KERN_ERR "ide-scsi: (IO,CoD) != (0,1) while "
+				"issuing a packet command\n");
+		return ide_do_reset (drive);
+	}
+	if (HWGROUP(drive)->handler != NULL)
+		BUG();
+	/* Set the interrupt routine */
+	ide_set_handler(drive, &idescsi_pc_intr, get_timeout(pc), idescsi_expiry);
+	/* Send the actual packet */
+	drive->hwif->atapi_output_bytes(drive, scsi->pc->c, 12);
+	if (test_bit (PC_DMA_OK, &pc->flags)) {
+		set_bit (PC_DMA_IN_PROGRESS, &pc->flags);
+		hwif->dma_start(drive);
+	}
+	return ide_started;
+}
+
+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 int idescsi_map_sg(ide_drive_t *drive, idescsi_pc_t *pc)
+{
+	ide_hwif_t *hwif = drive->hwif;
+	struct scatterlist *sg, *scsi_sg;
+	int segments;
+
+	if (!pc->request_transfer || pc->request_transfer % 1024)
+		return 1;
+
+	if (idescsi_set_direction(pc))
+		return 1;
+
+	sg = hwif->sg_table;
+	scsi_sg = pc->scsi_cmd->request_buffer;
+	segments = pc->scsi_cmd->use_sg;
+
+	if (segments > hwif->sg_max_nents)
+		return 1;
+
+	if (!segments) {
+		hwif->sg_nents = 1;
+		sg_init_one(sg, pc->scsi_cmd->request_buffer, pc->request_transfer);
+	} else {
+		hwif->sg_nents = segments;
+		memcpy(sg, scsi_sg, sizeof(*sg) * segments);
+	}
+
+	return 0;
+}
+
+/*
+ *	Issue a packet command
+ */
+static ide_startstop_t idescsi_issue_pc (ide_drive_t *drive, idescsi_pc_t *pc)
+{
+	idescsi_scsi_t *scsi = drive_to_idescsi(drive);
+	ide_hwif_t *hwif = drive->hwif;
+	atapi_feature_t feature;
+	atapi_bcount_t bcount;
+
+	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.all = min(pc->request_transfer, 63 * 1024);		/* Request to transfer the entire buffer at once */
+
+	feature.all = 0;
+	if (drive->using_dma && !idescsi_map_sg(drive, pc)) {
+		hwif->sg_mapped = 1;
+		feature.b.dma = !hwif->dma_setup(drive);
+		hwif->sg_mapped = 0;
+	}
+
+	SELECT_DRIVE(drive);
+	if (IDE_CONTROL_REG)
+		HWIF(drive)->OUTB(drive->ctl, IDE_CONTROL_REG);
+
+	HWIF(drive)->OUTB(feature.all, IDE_FEATURE_REG);
+	HWIF(drive)->OUTB(bcount.b.high, IDE_BCOUNTH_REG);
+	HWIF(drive)->OUTB(bcount.b.low, IDE_BCOUNTL_REG);
+
+	if (feature.b.dma)
+		set_bit(PC_DMA_OK, &pc->flags);
+
+	if (test_bit(IDESCSI_DRQ_INTERRUPT, &scsi->flags)) {
+		if (HWGROUP(drive)->handler != NULL)
+			BUG();
+		ide_set_handler(drive, &idescsi_transfer_pc,
+				get_timeout(pc), idescsi_expiry);
+		/* Issue the packet command */
+		HWIF(drive)->OUTB(WIN_PACKETCMD, IDE_COMMAND_REG);
+		return ide_started;
+	} else {
+		/* Issue the packet command */
+		HWIF(drive)->OUTB(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, sector_t block)
+{
+#if IDESCSI_DEBUG_LOG
+	printk (KERN_INFO "rq_status: %d, dev: %s, cmd: %x, errors: %d\n",rq->rq_status, rq->rq_disk->disk_name,rq->cmd[0],rq->errors);
+	printk (KERN_INFO "sector: %ld, nr_sectors: %ld, current_nr_sectors: %d\n",rq->sector,rq->nr_sectors,rq->current_nr_sectors);
+#endif /* IDESCSI_DEBUG_LOG */
+
+	if (rq->flags & (REQ_SPECIAL|REQ_SENSE)) {
+		return idescsi_issue_pc (drive, (idescsi_pc_t *) rq->special);
+	}
+	blk_dump_rq_flags(rq, "ide-scsi: unsup command");
+	idescsi_end_request (drive, 0, 0);
+	return ide_stopped;
+}
+
+static void idescsi_add_settings(ide_drive_t *drive)
+{
+	idescsi_scsi_t *scsi = drive_to_idescsi(drive);
+
+/*
+ *			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)
+{
+	DRIVER(drive)->busy++;
+	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);
+	DRIVER(drive)->busy--;
+}
+
+static int idescsi_cleanup (ide_drive_t *drive)
+{
+	struct Scsi_Host *scsihost = drive->driver_data;
+	struct ide_scsi_obj *scsi = scsihost_to_idescsi(scsihost);
+	struct gendisk *g = scsi->disk;
+
+	if (ide_unregister_subdriver(drive))
+		return 1;
+
+	ide_unregister_region(g);
+
+	drive->driver_data = NULL;
+	g->private_data = NULL;
+	put_disk(g);
+
+	scsi_remove_host(scsihost);
+	ide_scsi_put(scsi);
+
+	return 0;
+}
+
+static int idescsi_attach(ide_drive_t *drive);
+
+#ifdef CONFIG_PROC_FS
+static ide_proc_entry_t idescsi_proc[] = {
+	{ "capacity", S_IFREG|S_IRUGO, proc_ide_read_capacity, NULL },
+	{ NULL, 0, NULL, NULL }
+};
+#else
+# define idescsi_proc	NULL
+#endif
+
+/*
+ *	IDE subdriver functions, registered with ide.c
+ */
+static ide_driver_t idescsi_driver = {
+	.owner			= THIS_MODULE,
+	.name			= "ide-scsi",
+	.version		= IDESCSI_VERSION,
+	.media			= ide_scsi,
+	.busy			= 0,
+	.supports_dsc_overlap	= 0,
+	.proc			= idescsi_proc,
+	.attach			= idescsi_attach,
+	.cleanup		= idescsi_cleanup,
+	.do_request		= idescsi_do_request,
+	.end_request		= idescsi_end_request,
+	.error                  = idescsi_atapi_error,
+	.abort                  = idescsi_atapi_abort,
+	.drives			= LIST_HEAD_INIT(idescsi_driver.drives),
+};
+
+static int idescsi_ide_open(struct inode *inode, struct file *filp)
+{
+	struct gendisk *disk = inode->i_bdev->bd_disk;
+	struct ide_scsi_obj *scsi;
+	ide_drive_t *drive;
+
+	if (!(scsi = ide_scsi_get(disk)))
+		return -ENXIO;
+
+	drive = scsi->drive;
+
+	drive->usage++;
+
+	return 0;
+}
+
+static int idescsi_ide_release(struct inode *inode, struct file *filp)
+{
+	struct gendisk *disk = inode->i_bdev->bd_disk;
+	struct ide_scsi_obj *scsi = ide_scsi_g(disk);
+	ide_drive_t *drive = scsi->drive;
+
+	drive->usage--;
+
+	ide_scsi_put(scsi);
+
+	return 0;
+}
+
+static int idescsi_ide_ioctl(struct inode *inode, struct file *file,
+			unsigned int cmd, unsigned long arg)
+{
+	struct block_device *bdev = inode->i_bdev;
+	struct ide_scsi_obj *scsi = ide_scsi_g(bdev->bd_disk);
+	return generic_ide_ioctl(scsi->drive, file, bdev, cmd, arg);
+}
+
+static struct block_device_operations idescsi_ops = {
+	.owner		= THIS_MODULE,
+	.open		= idescsi_ide_open,
+	.release	= idescsi_ide_release,
+	.ioctl		= idescsi_ide_ioctl,
+};
+
+static int idescsi_attach(ide_drive_t *drive);
+
+static int idescsi_slave_configure(struct scsi_device * sdp)
+{
+	/* Configure detected device */
+	scsi_adjust_queue_depth(sdp, MSG_SIMPLE_TAG, sdp->host->cmd_per_lun);
+	return 0;
+}
+
+static const char *idescsi_info (struct Scsi_Host *host)
+{
+	return "SCSI host adapter emulation for IDE ATAPI devices";
+}
+
+static int idescsi_ioctl (struct scsi_device *dev, int cmd, void __user *arg)
+{
+	idescsi_scsi_t *scsi = scsihost_to_idescsi(dev->host);
+
+	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 __user *) arg);
+	return -EINVAL;
+}
+
+static inline int should_transform(ide_drive_t *drive, struct scsi_cmnd *cmd)
+{
+	idescsi_scsi_t *scsi = drive_to_idescsi(drive);
+
+	/* this was a layering violation and we can't support it
+	   anymore, sorry. */
+#if 0
+	struct gendisk *disk = cmd->request->rq_disk;
+
+	if (disk) {
+		struct Scsi_Device_Template **p = disk->private_data;
+		if (strcmp((*p)->scsi_driverfs_driver.name, "sg") == 0)
+			return test_bit(IDESCSI_SG_TRANSFORM, &scsi->transform);
+	}
+#endif
+	return test_bit(IDESCSI_TRANSFORM, &scsi->transform);
+}
+
+static int idescsi_queue (struct scsi_cmnd *cmd,
+		void (*done)(struct scsi_cmnd *))
+{
+	struct Scsi_Host *host = cmd->device->host;
+	idescsi_scsi_t *scsi = scsihost_to_idescsi(host);
+	ide_drive_t *drive = scsi->drive;
+	struct request *rq = NULL;
+	idescsi_pc_t *pc = NULL;
+
+	if (!drive) {
+		printk (KERN_ERR "ide-scsi: drive id %d not present\n", cmd->device->id);
+		goto abort;
+	}
+	scsi = drive_to_idescsi(drive);
+	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->flags = REQ_SPECIAL;
+	spin_unlock_irq(host->host_lock);
+	rq->rq_disk = scsi->disk;
+	(void) ide_do_drive_cmd (drive, rq, ide_end);
+	spin_lock_irq(host->host_lock);
+	return 0;
+abort:
+	if (pc) kfree (pc);
+	if (rq) kfree (rq);
+	cmd->result = DID_ERROR << 16;
+	done(cmd);
+	return 0;
+}
+
+static int idescsi_eh_abort (struct scsi_cmnd *cmd)
+{
+	idescsi_scsi_t *scsi  = scsihost_to_idescsi(cmd->device->host);
+	ide_drive_t    *drive = scsi->drive;
+	int		busy;
+	int             ret   = FAILED;
+
+	/* In idescsi_eh_abort we try to gently pry our command from the ide subsystem */
+
+	if (test_bit(IDESCSI_LOG_CMD, &scsi->log))
+		printk (KERN_WARNING "ide-scsi: abort called for %lu\n", cmd->serial_number);
+
+	if (!drive) {
+		printk (KERN_WARNING "ide-scsi: Drive not set in idescsi_eh_abort\n");
+		WARN_ON(1);
+		goto no_drive;
+	}
+
+	/* First give it some more time, how much is "right" is hard to say :-( */
+
+	busy = ide_wait_not_busy(HWIF(drive), 100);	/* FIXME - uses mdelay which causes latency? */
+	if (test_bit(IDESCSI_LOG_CMD, &scsi->log))
+		printk (KERN_WARNING "ide-scsi: drive did%s become ready\n", busy?" not":"");
+
+	spin_lock_irq(&ide_lock);
+
+	/* If there is no pc running we're done (our interrupt took care of it) */
+	if (!scsi->pc) {
+		ret = SUCCESS;
+		goto ide_unlock;
+	}
+
+	/* It's somewhere in flight. Does ide subsystem agree? */
+	if (scsi->pc->scsi_cmd->serial_number == cmd->serial_number && !busy &&
+	    elv_queue_empty(drive->queue) && HWGROUP(drive)->rq != scsi->pc->rq) {
+		/*
+		 * FIXME - not sure this condition can ever occur
+		 */
+		printk (KERN_ERR "ide-scsi: cmd aborted!\n");
+
+		if (scsi->pc->rq->flags & REQ_SENSE)
+			kfree(scsi->pc->buffer);
+		kfree(scsi->pc->rq);
+		kfree(scsi->pc);
+		scsi->pc = NULL;
+
+		ret = SUCCESS;
+	}
+
+ide_unlock:
+	spin_unlock_irq(&ide_lock);
+no_drive:
+	if (test_bit(IDESCSI_LOG_CMD, &scsi->log))
+		printk (KERN_WARNING "ide-scsi: abort returns %s\n", ret == SUCCESS?"success":"failed");
+
+	return ret;
+}
+
+static int idescsi_eh_reset (struct scsi_cmnd *cmd)
+{
+	struct request *req;
+	idescsi_scsi_t *scsi  = scsihost_to_idescsi(cmd->device->host);
+	ide_drive_t    *drive = scsi->drive;
+	int             ready = 0;
+	int             ret   = SUCCESS;
+
+	/* In idescsi_eh_reset we forcefully remove the command from the ide subsystem and reset the device. */
+
+	if (test_bit(IDESCSI_LOG_CMD, &scsi->log))
+		printk (KERN_WARNING "ide-scsi: reset called for %lu\n", cmd->serial_number);
+
+	if (!drive) {
+		printk (KERN_WARNING "ide-scsi: Drive not set in idescsi_eh_reset\n");
+		WARN_ON(1);
+		return FAILED;
+	}
+
+	spin_lock_irq(&ide_lock);
+
+	if (!scsi->pc || (req = scsi->pc->rq) != HWGROUP(drive)->rq || !HWGROUP(drive)->handler) {
+		printk (KERN_WARNING "ide-scsi: No active request in idescsi_eh_reset\n");
+		spin_unlock(&ide_lock);
+		return FAILED;
+	}
+
+	/* kill current request */
+	blkdev_dequeue_request(req);
+	end_that_request_last(req);
+	if (req->flags & REQ_SENSE)
+		kfree(scsi->pc->buffer);
+	kfree(scsi->pc);
+	scsi->pc = NULL;
+	kfree(req);
+
+	/* now nuke the drive queue */
+	while ((req = elv_next_request(drive->queue))) {
+		blkdev_dequeue_request(req);
+		end_that_request_last(req);
+	}
+
+	HWGROUP(drive)->rq = NULL;
+	HWGROUP(drive)->handler = NULL;
+	HWGROUP(drive)->busy = 1;		/* will set this to zero when ide reset finished */
+	spin_unlock_irq(&ide_lock);
+
+	ide_do_reset(drive);
+
+	/* ide_do_reset starts a polling handler which restarts itself every 50ms until the reset finishes */
+
+	do {
+		set_current_state(TASK_UNINTERRUPTIBLE);
+		spin_unlock_irq(cmd->device->host->host_lock);
+		schedule_timeout(HZ/20);
+		spin_lock_irq(cmd->device->host->host_lock);
+	} while ( HWGROUP(drive)->handler );
+
+	ready = drive_is_ready(drive);
+	HWGROUP(drive)->busy--;
+	if (!ready) {
+		printk (KERN_ERR "ide-scsi: reset failed!\n");
+		ret = FAILED;
+	}
+
+	return ret;
+}
+
+static int idescsi_bios(struct scsi_device *sdev, struct block_device *bdev,
+		sector_t capacity, int *parm)
+{
+	idescsi_scsi_t *idescsi = scsihost_to_idescsi(sdev->host);
+	ide_drive_t *drive = idescsi->drive;
+
+	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 struct scsi_host_template idescsi_template = {
+	.module			= THIS_MODULE,
+	.name			= "idescsi",
+	.info			= idescsi_info,
+	.slave_configure        = idescsi_slave_configure,
+	.ioctl			= idescsi_ioctl,
+	.queuecommand		= idescsi_queue,
+	.eh_abort_handler	= idescsi_eh_abort,
+	.eh_host_reset_handler  = idescsi_eh_reset,
+	.bios_param		= idescsi_bios,
+	.can_queue		= 40,
+	.this_id		= -1,
+	.sg_tablesize		= 256,
+	.cmd_per_lun		= 5,
+	.max_sectors		= 128,
+	.use_clustering		= DISABLE_CLUSTERING,
+	.emulated		= 1,
+	.proc_name		= "ide-scsi",
+};
+
+static int idescsi_attach(ide_drive_t *drive)
+{
+	idescsi_scsi_t *idescsi;
+	struct Scsi_Host *host;
+	struct gendisk *g;
+	static int warned;
+	int err = -ENOMEM;
+
+	if (!warned && drive->media == ide_cdrom) {
+		printk(KERN_WARNING "ide-scsi is deprecated for cd burning! Use ide-cd and give dev=/dev/hdX as device\n");
+		warned = 1;
+	}
+
+	if (!strstr("ide-scsi", drive->driver_req) ||
+	    !drive->present ||
+	    drive->media == ide_disk ||
+	    !(host = scsi_host_alloc(&idescsi_template,sizeof(idescsi_scsi_t))))
+		return 1;
+
+	g = alloc_disk(1 << PARTN_BITS);
+	if (!g)
+		goto out_host_put;
+
+	ide_init_disk(g, drive);
+
+	host->max_id = 1;
+
+#if IDESCSI_DEBUG_LOG
+	if (drive->id->last_lun)
+		printk(KERN_NOTICE "%s: id->last_lun=%u\n", drive->name, drive->id->last_lun);
+#endif
+	if ((drive->id->last_lun & 0x7) != 7)
+		host->max_lun = (drive->id->last_lun & 0x7) + 1;
+	else
+		host->max_lun = 1;
+
+	drive->driver_data = host;
+	idescsi = scsihost_to_idescsi(host);
+	idescsi->drive = drive;
+	idescsi->driver = &idescsi_driver;
+	idescsi->host = host;
+	idescsi->disk = g;
+	g->private_data = &idescsi->driver;
+	err = ide_register_subdriver(drive, &idescsi_driver);
+	if (!err) {
+		idescsi_setup (drive, idescsi);
+		g->fops = &idescsi_ops;
+		ide_register_region(g);
+		err = scsi_add_host(host, &drive->gendev);
+		if (!err) {
+			scsi_scan_host(host);
+			return 0;
+		}
+		/* fall through on error */
+		ide_unregister_region(g);
+		ide_unregister_subdriver(drive);
+	}
+
+	put_disk(g);
+out_host_put:
+	scsi_host_put(host);
+	return err;
+}
+
+static int __init init_idescsi_module(void)
+{
+	return ide_register_driver(&idescsi_driver);
+}
+
+static void __exit exit_idescsi_module(void)
+{
+	ide_unregister_driver(&idescsi_driver);
+}
+
+module_init(init_idescsi_module);
+module_exit(exit_idescsi_module);
+MODULE_LICENSE("GPL");