ide-scsi.c

linux 内核源代码

	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_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_slave_configure(struct scsi_device * sdp)
{
	/* Configure detected device */
	sdp->use_10_for_rw = 1;
	sdp->use_10_for_ms = 1;
	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 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) {
		scmd_printk (KERN_ERR, cmd, "drive not present\n");
		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);
	pc->buffer = NULL;
	pc->sg = scsi_sglist(cmd);
	pc->sg_cnt = scsi_sg_count(cmd);
	pc->b_count = 0;
	pc->request_transfer = pc->buffer_size = scsi_bufflen(cmd);
	pc->scsi_cmd = cmd;
	pc->done = done;
	pc->timeout = jiffies + cmd->timeout_per_command;

	if (test_bit(IDESCSI_LOG_CMD, &scsi->log)) {
		printk ("ide-scsi: %s: que %lu, cmd = ", drive->name, cmd->serial_number);
		ide_scsi_hex_dump(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);
			ide_scsi_hex_dump(pc->c, 12);
		}
	}

	ide_init_drive_cmd (rq);
	rq->special = (char *) pc;
	rq->cmd_type = REQ_TYPE_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:
	kfree (pc);
	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 (blk_sense_request(scsi->pc->rq))
			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(cmd->device->host->host_lock);
	spin_lock(&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);
		spin_unlock_irq(cmd->device->host->host_lock);
		return FAILED;
	}

	/* kill current request */
	blkdev_dequeue_request(req);
	end_that_request_last(req, 0);
	if (blk_sense_request(req))
		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, 0);
	}

	HWGROUP(drive)->rq = NULL;
	HWGROUP(drive)->handler = NULL;
	HWGROUP(drive)->busy = 1;		/* will set this to zero when ide reset finished */
	spin_unlock(&ide_lock);

	ide_do_reset(drive);

	/* ide_do_reset starts a polling handler which restarts itself every 50ms until the reset finishes */

	do {
		spin_unlock_irq(cmd->device->host->host_lock);
		msleep(50);
		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;
	}

	spin_unlock_irq(cmd->device->host->host_lock);
	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 ide_scsi_probe(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 (idescsi_nocd && drive->media == ide_cdrom)
		return -ENODEV;

	if (!strstr("ide-scsi", drive->driver_req) ||
	    !drive->present ||
	    drive->media == ide_disk ||
	    !(host = scsi_host_alloc(&idescsi_template,sizeof(idescsi_scsi_t))))
		return -ENODEV;

	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;
	ide_proc_register_driver(drive, &idescsi_driver);
	err = 0;
	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_proc_unregister_driver(drive, &idescsi_driver);

	put_disk(g);
out_host_put:
	scsi_host_put(host);
	return err;
}

static int __init init_idescsi_module(void)
{
	return driver_register(&idescsi_driver.gen_driver);
}

static void __exit exit_idescsi_module(void)
{
	driver_unregister(&idescsi_driver.gen_driver);
}

module_param(idescsi_nocd, int, 0600);
MODULE_PARM_DESC(idescsi_nocd, "Disable handling of CD-ROMs so they may be driven by ide-cd");
module_init(init_idescsi_module);
module_exit(exit_idescsi_module);
MODULE_LICENSE("GPL");