path: root/drivers/scsi/ide-scsi.c

/*
 * Copyright (C) 1996-1999  Gadi Oxman <gadio@netvision.net.il>
 * Copyright (C) 2004-2005  Bartlomiej Zolnierkiewicz
 */

/*
 * 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/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 <linux/delay.h>
#include <linux/mutex.h>
#include <linux/bitops.h>

#include <asm/io.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

/*
 *	SCSI command transformation layer
 */
#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;

	struct ide_atapi_pc *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 DEFINE_MUTEX(idescsi_ref_mutex);
/* Set by module param to skip cd */
static int idescsi_nocd;

#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;

	mutex_lock(&idescsi_ref_mutex);
	scsi = ide_scsi_g(disk);
	if (scsi)
		scsi_host_get(scsi->host);
	mutex_unlock(&idescsi_ref_mutex);
	return scsi;
}

static void ide_scsi_put(struct ide_scsi_obj *scsi)
{
	mutex_lock(&idescsi_ref_mutex);
	scsi_host_put(scsi->host);
	mutex_unlock(&idescsi_ref_mutex);
}

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

/*
 *	PIO data transfer routines using the scatter gather table.
 */
static void idescsi_input_buffers(ide_drive_t *drive, struct ide_atapi_pc *pc,
		unsigned int bcount)
{
	int count;
	char *buf;

	while (bcount) {
		count = min(pc->sg->length - pc->b_count, bcount);
		if (PageHighMem(sg_page(pc->sg))) {
			unsigned long flags;

			local_irq_save(flags);
			buf = kmap_atomic(sg_page(pc->sg), KM_IRQ0) +
					pc->sg->offset;
			drive->hwif->atapi_input_bytes(drive,
						buf + pc->b_count, count);
			kunmap_atomic(buf - pc->sg->offset, KM_IRQ0);
			local_irq_restore(flags);
		} else {
			buf = sg_virt(pc->sg);
			drive->hwif->atapi_input_bytes(drive,
						buf + pc->b_count, count);
		}
		bcount -= count; pc->b_count += count;
		if (pc->b_count == pc->sg->length) {
			if (!--pc->sg_cnt)
				break;
			pc->sg = sg_next(pc->sg);
			pc->b_count = 0;
		}
	}

	if (bcount) {
		printk (KERN_ERR "ide-scsi: scatter gather table too small, discarding data\n");
		ide_atapi_discard_data(drive, bcount);
	}
}

static void idescsi_output_buffers(ide_drive_t *drive, struct ide_atapi_pc *pc,
		unsigned int bcount)
{