ide-scsi.c

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/*
 * linux/drivers/scsi/ide-scsi.c	Version 0.9		Jul   4, 1999
 *
 * Copyright (C) 1996 - 1999 Gadi Oxman <[e-mail]>
 */

/*
 * 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 <asm/io.h>
#include <asm/bitops.h>
#include <asm/uaccess.h>

#include "scsi.h"
#include <scsi/scsi_host.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 */
	Scsi_Cmnd *scsi_cmd;			/* SCSI command */
	void (*done)(Scsi_Cmnd *);		/* Scsi completion routine */
	unsigned long flags;			/* Status/Action flags */
	unsigned long timeout;			/* Command timeout */
} idescsi_pc_t;

/*
 *	Packet command status bits.
 */
#define PC_DMA_IN_PROGRESS		0	/* 1 while DMA in progress */
#define PC_WRITING			1	/* Data direction */
#define PC_TRANSFORM			2	/* transform SCSI commands */
#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_drive_t *drive;
	idescsi_pc_t *pc;			/* Current packet command */
	unsigned long flags;			/* Status/Action flags */
	unsigned long transform;		/* SCSI cmd translation layer */
	unsigned long log;			/* log flags */
} idescsi_scsi_t;

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;
		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;
		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 inline void idescsi_free_bio (struct bio *bio)
{
	struct bio *bhp;

	while (bio) {
		bhp = bio;
		bio = bio->bi_next;
		bio_put(bhp);
	}
}

static void hexdump(u8 *x, int len)
{
	int i;

	printk("[ ");
	for (i = 0; i < len; i++)
		printk("%x ", x[i]);
	printk("]\n");
}

static int idescsi_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);
	}
	return ide_do_drive_cmd(drive, rq, ide_preempt);
}

ide_startstop_t idescsi_atapi_error (ide_drive_t *drive, const char *msg, byte stat)
{
	struct request *rq;
	byte err;

	err = ide_dump_atapi_status(drive, msg, stat);

	if (drive == NULL || (rq = HWGROUP(drive)->rq) == NULL)
		return ide_stopped;

	/* retry only "normal" I/O: */
	if (rq->flags & (REQ_DRIVE_CMD | REQ_DRIVE_TASK | REQ_DRIVE_TASKFILE)) {
		rq->errors = 1;
		ide_end_drive_cmd(drive, stat, err);
		return ide_stopped;
	}

	if (HWIF(drive)->INB(IDE_STATUS_REG) & (BUSY_STAT|DRQ_STAT))
		/* force an abort */
		HWIF(drive)->OUTB(WIN_IDLEIMMEDIATE,IDE_COMMAND_REG);

	rq->errors++;
	DRIVER(drive)->end_request(drive, 0, 0);
	return ide_stopped;
}

ide_startstop_t idescsi_atapi_abort (ide_drive_t *drive, const char *msg)
{
	struct request *rq;

	if (drive == NULL || (rq = HWGROUP(drive)->rq) == NULL)
	       return ide_stopped;

	/* retry only "normal" I/O: */
	if (rq->flags & (REQ_DRIVE_CMD | REQ_DRIVE_TASK | REQ_DRIVE_TASKFILE)) {
		rq->errors = 1;
		ide_end_drive_cmd(drive, BUSY_STAT, 0);
		return ide_stopped;
	}

#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;
	DRIVER(drive)->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) |