libata-scsi.c

来自「Linux Kernel 2.6.9 for OMAP1710」· C语言 代码 · 共 1,571 行 · 第 1/3 页

 *	Generate a generic MODE SENSE r/w error recovery page.
 *
 *	LOCKING:
 *	None.
 */

static unsigned int ata_msense_rw_recovery(u8 **ptr_io, const u8 *last)
{
	const u8 page[] = {
		0x1,			  /* page code */
		0xa,			  /* page length */
		(1 << 7) | (1 << 6),	  /* note auto r/w reallocation */
		0, 0, 0, 0, 0, 0, 0, 0, 0 /* 9 zeroes */
	};

	ata_msense_push(ptr_io, last, page, sizeof(page));
	return sizeof(page);
}

/**
 *	ata_scsiop_mode_sense - Simulate MODE SENSE 6, 10 commands
 *	@args: Port / device / SCSI command of interest.
 *	@rbuf: Response buffer, to which simulated SCSI cmd output is sent.
 *	@buflen: Response buffer length.
 *
 *	Simulate MODE SENSE commands.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host_set lock)
 */

unsigned int ata_scsiop_mode_sense(struct ata_scsi_args *args, u8 *rbuf,
				  unsigned int buflen)
{
	u8 *scsicmd = args->cmd->cmnd, *p, *last;
	struct ata_device *dev = args->dev;
	unsigned int page_control, six_byte, output_len;

	VPRINTK("ENTER\n");

	six_byte = (scsicmd[0] == MODE_SENSE);

	/* we only support saved and current values (which we treat
	 * in the same manner)
	 */
	page_control = scsicmd[2] >> 6;
	if ((page_control != 0) && (page_control != 3))
		return 1;

	if (six_byte)
		output_len = 4;
	else
		output_len = 8;

	p = rbuf + output_len;
	last = rbuf + buflen - 1;

	switch(scsicmd[2] & 0x3f) {
	case 0x01:		/* r/w error recovery */
		output_len += ata_msense_rw_recovery(&p, last);
		break;

	case 0x08:		/* caching */
		output_len += ata_msense_caching(dev, &p, last);
		break;

	case 0x0a: {		/* control mode */
		output_len += ata_msense_ctl_mode(&p, last);
		break;
		}

	case 0x3f:		/* all pages */
		output_len += ata_msense_rw_recovery(&p, last);
		output_len += ata_msense_caching(dev, &p, last);
		output_len += ata_msense_ctl_mode(&p, last);
		break;

	default:		/* invalid page code */
		return 1;
	}

	if (six_byte) {
		output_len--;
		rbuf[0] = output_len;
	} else {
		output_len -= 2;
		rbuf[0] = output_len >> 8;
		rbuf[1] = output_len;
	}

	return 0;
}

/**
 *	ata_scsiop_read_cap - Simulate READ CAPACITY[ 16] commands
 *	@args: Port / device / SCSI command of interest.
 *	@rbuf: Response buffer, to which simulated SCSI cmd output is sent.
 *	@buflen: Response buffer length.
 *
 *	Simulate READ CAPACITY commands.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host_set lock)
 */

unsigned int ata_scsiop_read_cap(struct ata_scsi_args *args, u8 *rbuf,
			        unsigned int buflen)
{
	u64 n_sectors = args->dev->n_sectors;
	u32 tmp;

	VPRINTK("ENTER\n");

	n_sectors--;		/* ATA TotalUserSectors - 1 */

	tmp = n_sectors;	/* note: truncates, if lba48 */
	if (args->cmd->cmnd[0] == READ_CAPACITY) {
		/* sector count, 32-bit */
		rbuf[0] = tmp >> (8 * 3);
		rbuf[1] = tmp >> (8 * 2);
		rbuf[2] = tmp >> (8 * 1);
		rbuf[3] = tmp;

		/* sector size */
		tmp = ATA_SECT_SIZE;
		rbuf[6] = tmp >> 8;
		rbuf[7] = tmp;

	} else {
		/* sector count, 64-bit */
		rbuf[2] = n_sectors >> (8 * 7);
		rbuf[3] = n_sectors >> (8 * 6);
		rbuf[4] = n_sectors >> (8 * 5);
		rbuf[5] = n_sectors >> (8 * 4);
		rbuf[6] = tmp >> (8 * 3);
		rbuf[7] = tmp >> (8 * 2);
		rbuf[8] = tmp >> (8 * 1);
		rbuf[9] = tmp;

		/* sector size */
		tmp = ATA_SECT_SIZE;
		rbuf[12] = tmp >> 8;
		rbuf[13] = tmp;
	}

	return 0;
}

/**
 *	ata_scsiop_report_luns - Simulate REPORT LUNS command
 *	@args: Port / device / SCSI command of interest.
 *	@rbuf: Response buffer, to which simulated SCSI cmd output is sent.
 *	@buflen: Response buffer length.
 *
 *	Simulate REPORT LUNS command.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host_set lock)
 */

unsigned int ata_scsiop_report_luns(struct ata_scsi_args *args, u8 *rbuf,
				   unsigned int buflen)
{
	VPRINTK("ENTER\n");
	rbuf[3] = 8;	/* just one lun, LUN 0, size 8 bytes */

	return 0;
}

/**
 *	ata_scsi_badcmd - End a SCSI request with an error
 *	@cmd: SCSI request to be handled
 *	@done: SCSI command completion function
 *	@asc: SCSI-defined additional sense code
 *	@ascq: SCSI-defined additional sense code qualifier
 *
 *	Helper function that completes a SCSI command with
 *	%SAM_STAT_CHECK_CONDITION, with a sense key %ILLEGAL_REQUEST
 *	and the specified additional sense codes.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host_set lock)
 */

void ata_scsi_badcmd(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *), u8 asc, u8 ascq)
{
	DPRINTK("ENTER\n");
	cmd->result = SAM_STAT_CHECK_CONDITION;

	cmd->sense_buffer[0] = 0x70;
	cmd->sense_buffer[2] = ILLEGAL_REQUEST;
	cmd->sense_buffer[7] = 14 - 8;	/* addnl. sense len. FIXME: correct? */
	cmd->sense_buffer[12] = asc;
	cmd->sense_buffer[13] = ascq;

	done(cmd);
}

static int atapi_qc_complete(struct ata_queued_cmd *qc, u8 drv_stat)
{
	struct scsi_cmnd *cmd = qc->scsicmd;

	if (unlikely(drv_stat & (ATA_ERR | ATA_BUSY | ATA_DRQ)))
		cmd->result = SAM_STAT_CHECK_CONDITION;
	else {
		u8 *scsicmd = cmd->cmnd;

		if (scsicmd[0] == INQUIRY) {
			u8 *buf = NULL;
			unsigned int buflen;

			buflen = ata_scsi_rbuf_get(cmd, &buf);
			buf[2] = 0x5;
			buf[3] = (buf[3] & 0xf0) | 2;
			ata_scsi_rbuf_put(cmd);
		}
		cmd->result = SAM_STAT_GOOD;
	}

	qc->scsidone(cmd);

	return 0;
}
/**
 *	atapi_xlat - Initialize PACKET taskfile
 *	@qc: command structure to be initialized
 *	@scsicmd: SCSI CDB associated with this PACKET command
 *
 *	LOCKING:
 *	spin_lock_irqsave(host_set lock)
 *
 *	RETURNS:
 *	Zero on success, non-zero on failure.
 */

static unsigned int atapi_xlat(struct ata_queued_cmd *qc, u8 *scsicmd)
{
	struct scsi_cmnd *cmd = qc->scsicmd;
	struct ata_device *dev = qc->dev;
	int using_pio = (dev->flags & ATA_DFLAG_PIO);
	int nodata = (cmd->sc_data_direction == SCSI_DATA_NONE);

	memcpy(&qc->cdb, scsicmd, qc->ap->cdb_len);

	qc->complete_fn = atapi_qc_complete;

	qc->tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
	if (cmd->sc_data_direction == SCSI_DATA_WRITE) {
		qc->tf.flags |= ATA_TFLAG_WRITE;
		DPRINTK("direction: write\n");
	}

	qc->tf.command = ATA_CMD_PACKET;

	/* no data, or PIO data xfer */
	if (using_pio || nodata) {
		if (nodata)
			qc->tf.protocol = ATA_PROT_ATAPI_NODATA;
		else
			qc->tf.protocol = ATA_PROT_ATAPI;
		qc->tf.lbam = (8 * 1024) & 0xff;
		qc->tf.lbah = (8 * 1024) >> 8;
	}

	/* DMA data xfer */
	else {
		qc->tf.protocol = ATA_PROT_ATAPI_DMA;
		qc->tf.feature |= ATAPI_PKT_DMA;

#ifdef ATAPI_ENABLE_DMADIR
		/* some SATA bridges need us to indicate data xfer direction */
		if (cmd->sc_data_direction != SCSI_DATA_WRITE)
			qc->tf.feature |= ATAPI_DMADIR;
#endif
	}

	return 0;
}

/**
 *	ata_scsi_find_dev - lookup ata_device from scsi_cmnd
 *	@ap: ATA port to which the device is attached
 *	@cmd: SCSI command to be sent to the device
 *
 *	Given various information provided in struct scsi_cmnd,
 *	map that onto an ATA bus, and using that mapping
 *	determine which ata_device is associated with the
 *	SCSI command to be sent.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host_set lock)
 *
 *	RETURNS:
 *	Associated ATA device, or %NULL if not found.
 */

static struct ata_device *
ata_scsi_find_dev(struct ata_port *ap, struct scsi_device *scsidev)
{
	struct ata_device *dev;

	/* skip commands not addressed to targets we simulate */
	if (likely(scsidev->id < ATA_MAX_DEVICES))
		dev = &ap->device[scsidev->id];
	else
		return NULL;

	if (unlikely((scsidev->channel != 0) ||
		     (scsidev->lun != 0)))
		return NULL;

	if (unlikely(!ata_dev_present(dev)))
		return NULL;

#ifndef ATA_ENABLE_ATAPI
	if (unlikely(dev->class == ATA_DEV_ATAPI))
		return NULL;
#endif

	return dev;
}

/**
 *	ata_get_xlat_func - check if SCSI to ATA translation is possible
 *	@dev: ATA device
 *	@cmd: SCSI command opcode to consider
 *
 *	Look up the SCSI command given, and determine whether the
 *	SCSI command is to be translated or simulated.
 *
 *	RETURNS:
 *	Pointer to translation function if possible, %NULL if not.
 */

static inline ata_xlat_func_t ata_get_xlat_func(struct ata_device *dev, u8 cmd)
{
	switch (cmd) {
	case READ_6:
	case READ_10:
	case READ_16:

	case WRITE_6:
	case WRITE_10:
	case WRITE_16:
		return ata_scsi_rw_xlat;

	case SYNCHRONIZE_CACHE:
		if (ata_try_flush_cache(dev))
			return ata_scsi_flush_xlat;
		break;

	case VERIFY:
	case VERIFY_16:
		return ata_scsi_verify_xlat;
	}

	return NULL;
}

/**
 *	ata_scsi_dump_cdb - dump SCSI command contents to dmesg
 *	@ap: ATA port to which the command was being sent
 *	@cmd: SCSI command to dump
 *
 *	Prints the contents of a SCSI command via printk().
 */

static inline void ata_scsi_dump_cdb(struct ata_port *ap,
				     struct scsi_cmnd *cmd)
{
#ifdef ATA_DEBUG
	struct scsi_device *scsidev = cmd->device;
	u8 *scsicmd = cmd->cmnd;

	DPRINTK("CDB (%u:%d,%d,%d) %02x %02x %02x %02x %02x %02x %02x %02x %02x\n",
		ap->id,
		scsidev->channel, scsidev->id, scsidev->lun,
		scsicmd[0], scsicmd[1], scsicmd[2], scsicmd[3],
		scsicmd[4], scsicmd[5], scsicmd[6], scsicmd[7],
		scsicmd[8]);
#endif
}

/**
 *	ata_scsi_queuecmd - Issue SCSI cdb to libata-managed device
 *	@cmd: SCSI command to be sent
 *	@done: Completion function, called when command is complete
 *
 *	In some cases, this function translates SCSI commands into
 *	ATA taskfiles, and queues the taskfiles to be sent to
 *	hardware.  In other cases, this function simulates a
 *	SCSI device by evaluating and responding to certain
 *	SCSI commands.  This creates the overall effect of
 *	ATA and ATAPI devices appearing as SCSI devices.
 *
 *	LOCKING:
 *	Releases scsi-layer-held lock, and obtains host_set lock.
 *
 *	RETURNS:
 *	Zero.
 */

int ata_scsi_queuecmd(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *))
{
	struct ata_port *ap;
	struct ata_device *dev;
	struct scsi_device *scsidev = cmd->device;

	ap = (struct ata_port *) &scsidev->host->hostdata[0];

	ata_scsi_dump_cdb(ap, cmd);

	dev = ata_scsi_find_dev(ap, scsidev);
	if (unlikely(!dev)) {
		cmd->result = (DID_BAD_TARGET << 16);
		done(cmd);
		goto out_unlock;
	}

	if (dev->class == ATA_DEV_ATA) {
		ata_xlat_func_t xlat_func = ata_get_xlat_func(dev,
							      cmd->cmnd[0]);

		if (xlat_func)
			ata_scsi_translate(ap, dev, cmd, done, xlat_func);
		else
			ata_scsi_simulate(ap, dev, cmd, done);
	} else
		ata_scsi_translate(ap, dev, cmd, done, atapi_xlat);

out_unlock:
	return 0;
}

/**
 *	ata_scsi_simulate - simulate SCSI command on ATA device
 *	@ap: Port to which ATA device is attached.
 *	@dev: Target device for CDB.
 *	@cmd: SCSI command being sent to device.
 *	@done: SCSI command completion function.
 *
 *	Interprets and directly executes a select list of SCSI commands
 *	that can be handled internally.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host_set lock)
 */

static void ata_scsi_simulate(struct ata_port *ap, struct ata_device *dev,
			      struct scsi_cmnd *cmd,
			      void (*done)(struct scsi_cmnd *))
{
	struct ata_scsi_args args;
	u8 *scsicmd = cmd->cmnd;

	args.ap = ap;
	args.dev = dev;
	args.cmd = cmd;
	args.done = done;

	switch(scsicmd[0]) {
		/* no-op's, complete with success */
		case SYNCHRONIZE_CACHE:
		case REZERO_UNIT:
		case SEEK_6:
		case SEEK_10:
		case TEST_UNIT_READY:
		case FORMAT_UNIT:		/* FIXME: correct? */
		case SEND_DIAGNOSTIC:		/* FIXME: correct? */
			ata_scsi_rbuf_fill(&args, ata_scsiop_noop);
			break;

		case INQUIRY:
			if (scsicmd[1] & 2)	           /* is CmdDt set?  */
				ata_bad_cdb(cmd, done);
			else if ((scsicmd[1] & 1) == 0)    /* is EVPD clear? */
				ata_scsi_rbuf_fill(&args, ata_scsiop_inq_std);
			else if (scsicmd[2] == 0x00)
				ata_scsi_rbuf_fill(&args, ata_scsiop_inq_00);
			else if (scsicmd[2] == 0x80)
				ata_scsi_rbuf_fill(&args, ata_scsiop_inq_80);
			else if (scsicmd[2] == 0x83)
				ata_scsi_rbuf_fill(&args, ata_scsiop_inq_83);
			else
				ata_bad_cdb(cmd, done);
			break;

		case MODE_SENSE:
		case MODE_SENSE_10:
			ata_scsi_rbuf_fill(&args, ata_scsiop_mode_sense);
			break;

		case MODE_SELECT:	/* unconditionally return */
		case MODE_SELECT_10:	/* bad-field-in-cdb */
			ata_bad_cdb(cmd, done);
			break;

		case READ_CAPACITY:
			ata_scsi_rbuf_fill(&args, ata_scsiop_read_cap);
			break;

		case SERVICE_ACTION_IN:
			if ((scsicmd[1] & 0x1f) == SAI_READ_CAPACITY_16)
				ata_scsi_rbuf_fill(&args, ata_scsiop_read_cap);
			else
				ata_bad_cdb(cmd, done);
			break;

		case REPORT_LUNS:
			ata_scsi_rbuf_fill(&args, ata_scsiop_report_luns);
			break;

		/* mandantory commands we haven't implemented yet */
		case REQUEST_SENSE:

		/* all other commands */
		default:
			ata_bad_scsiop(cmd, done);
			break;
	}
}