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");