libata-scsi.c

linux 内核源代码

 *	@ptr_io: (input/output) Location to store more output data
 *	@last: End of output data buffer
 *
 *	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)
{

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

/*
 * We can turn this into a real blacklist if it's needed, for now just
 * blacklist any Maxtor BANC1G10 revision firmware
 */
static int ata_dev_supports_fua(u16 *id)
{
	unsigned char model[ATA_ID_PROD_LEN + 1], fw[ATA_ID_FW_REV_LEN + 1];

	if (!libata_fua)
		return 0;
	if (!ata_id_has_fua(id))
		return 0;

	ata_id_c_string(id, model, ATA_ID_PROD, sizeof(model));
	ata_id_c_string(id, fw, ATA_ID_FW_REV, sizeof(fw));

	if (strcmp(model, "Maxtor"))
		return 1;
	if (strcmp(fw, "BANC1G10"))
		return 1;

	return 0; /* blacklisted */
}

/**
 *	ata_scsiop_mode_sense - Simulate MODE SENSE 6, 10 commands
 *	@args: device IDENTIFY data / SCSI command of interest.
 *	@rbuf: Response buffer, to which simulated SCSI cmd output is sent.
 *	@buflen: Response buffer length.
 *
 *	Simulate MODE SENSE commands. Assume this is invoked for direct
 *	access devices (e.g. disks) only. There should be no block
 *	descriptor for other device types.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host lock)
 */

unsigned int ata_scsiop_mode_sense(struct ata_scsi_args *args, u8 *rbuf,
				  unsigned int buflen)
{
	struct ata_device *dev = args->dev;
	u8 *scsicmd = args->cmd->cmnd, *p, *last;
	const u8 sat_blk_desc[] = {
		0, 0, 0, 0,	/* number of blocks: sat unspecified */
		0,
		0, 0x2, 0x0	/* block length: 512 bytes */
	};
	u8 pg, spg;
	unsigned int ebd, page_control, six_byte, output_len, alloc_len, minlen;
	u8 dpofua;

	VPRINTK("ENTER\n");

	six_byte = (scsicmd[0] == MODE_SENSE);
	ebd = !(scsicmd[1] & 0x8);      /* dbd bit inverted == edb */
	/*
	 * LLBA bit in msense(10) ignored (compliant)
	 */

	page_control = scsicmd[2] >> 6;
	switch (page_control) {
	case 0: /* current */
		break;  /* supported */
	case 3: /* saved */
		goto saving_not_supp;
	case 1: /* changeable */
	case 2: /* defaults */
	default:
		goto invalid_fld;
	}

	if (six_byte) {
		output_len = 4 + (ebd ? 8 : 0);
		alloc_len = scsicmd[4];
	} else {
		output_len = 8 + (ebd ? 8 : 0);
		alloc_len = (scsicmd[7] << 8) + scsicmd[8];
	}
	minlen = (alloc_len < buflen) ? alloc_len : buflen;

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

	pg = scsicmd[2] & 0x3f;
	spg = scsicmd[3];
	/*
	 * No mode subpages supported (yet) but asking for _all_
	 * subpages may be valid
	 */
	if (spg && (spg != ALL_SUB_MPAGES))
		goto invalid_fld;

	switch(pg) {
	case RW_RECOVERY_MPAGE:
		output_len += ata_msense_rw_recovery(&p, last);
		break;

	case CACHE_MPAGE:
		output_len += ata_msense_caching(args->id, &p, last);
		break;

	case CONTROL_MPAGE: {
		output_len += ata_msense_ctl_mode(&p, last);
		break;
		}

	case ALL_MPAGES:
		output_len += ata_msense_rw_recovery(&p, last);
		output_len += ata_msense_caching(args->id, &p, last);
		output_len += ata_msense_ctl_mode(&p, last);
		break;

	default:		/* invalid page code */
		goto invalid_fld;
	}

	if (minlen < 1)
		return 0;

	dpofua = 0;
	if (ata_dev_supports_fua(args->id) && (dev->flags & ATA_DFLAG_LBA48) &&
	    (!(dev->flags & ATA_DFLAG_PIO) || dev->multi_count))
		dpofua = 1 << 4;

	if (six_byte) {
		output_len--;
		rbuf[0] = output_len;
		if (minlen > 2)
			rbuf[2] |= dpofua;
		if (ebd) {
			if (minlen > 3)
				rbuf[3] = sizeof(sat_blk_desc);
			if (minlen > 11)
				memcpy(rbuf + 4, sat_blk_desc,
				       sizeof(sat_blk_desc));
		}
	} else {
		output_len -= 2;
		rbuf[0] = output_len >> 8;
		if (minlen > 1)
			rbuf[1] = output_len;
		if (minlen > 3)
			rbuf[3] |= dpofua;
		if (ebd) {
			if (minlen > 7)
				rbuf[7] = sizeof(sat_blk_desc);
			if (minlen > 15)
				memcpy(rbuf + 8, sat_blk_desc,
				       sizeof(sat_blk_desc));
		}
	}
	return 0;

invalid_fld:
	ata_scsi_set_sense(args->cmd, ILLEGAL_REQUEST, 0x24, 0x0);
	/* "Invalid field in cbd" */
	return 1;

saving_not_supp:
	ata_scsi_set_sense(args->cmd, ILLEGAL_REQUEST, 0x39, 0x0);
	 /* "Saving parameters not supported" */
	return 1;
}

/**
 *	ata_scsiop_read_cap - Simulate READ CAPACITY[ 16] commands
 *	@args: device IDENTIFY data / SCSI command of interest.
 *	@rbuf: Response buffer, to which simulated SCSI cmd output is sent.
 *	@buflen: Response buffer length.
 *
 *	Simulate READ CAPACITY commands.
 *
 *	LOCKING:
 *	None.
 */
unsigned int ata_scsiop_read_cap(struct ata_scsi_args *args, u8 *rbuf,
				 unsigned int buflen)
{
	u64 last_lba = args->dev->n_sectors - 1; /* LBA of the last block */

	VPRINTK("ENTER\n");

	if (args->cmd->cmnd[0] == READ_CAPACITY) {
		if (last_lba >= 0xffffffffULL)
			last_lba = 0xffffffff;

		/* sector count, 32-bit */
		ATA_SCSI_RBUF_SET(0, last_lba >> (8 * 3));
		ATA_SCSI_RBUF_SET(1, last_lba >> (8 * 2));
		ATA_SCSI_RBUF_SET(2, last_lba >> (8 * 1));
		ATA_SCSI_RBUF_SET(3, last_lba);

		/* sector size */
		ATA_SCSI_RBUF_SET(6, ATA_SECT_SIZE >> 8);
		ATA_SCSI_RBUF_SET(7, ATA_SECT_SIZE);
	} else {
		/* sector count, 64-bit */
		ATA_SCSI_RBUF_SET(0, last_lba >> (8 * 7));
		ATA_SCSI_RBUF_SET(1, last_lba >> (8 * 6));
		ATA_SCSI_RBUF_SET(2, last_lba >> (8 * 5));
		ATA_SCSI_RBUF_SET(3, last_lba >> (8 * 4));
		ATA_SCSI_RBUF_SET(4, last_lba >> (8 * 3));
		ATA_SCSI_RBUF_SET(5, last_lba >> (8 * 2));
		ATA_SCSI_RBUF_SET(6, last_lba >> (8 * 1));
		ATA_SCSI_RBUF_SET(7, last_lba);

		/* sector size */
		ATA_SCSI_RBUF_SET(10, ATA_SECT_SIZE >> 8);
		ATA_SCSI_RBUF_SET(11, ATA_SECT_SIZE);
	}

	return 0;
}

/**
 *	ata_scsiop_report_luns - Simulate REPORT LUNS command
 *	@args: device IDENTIFY data / 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 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_set_sense - Set SCSI sense data and status
 *	@cmd: SCSI request to be handled
 *	@sk: SCSI-defined sense key
 *	@asc: SCSI-defined additional sense code
 *	@ascq: SCSI-defined additional sense code qualifier
 *
 *	Helper function that builds a valid fixed format, current
 *	response code and the given sense key (sk), additional sense
 *	code (asc) and additional sense code qualifier (ascq) with
 *	a SCSI command status of %SAM_STAT_CHECK_CONDITION and
 *	DRIVER_SENSE set in the upper bits of scsi_cmnd::result .
 *
 *	LOCKING:
 *	Not required
 */

void ata_scsi_set_sense(struct scsi_cmnd *cmd, u8 sk, u8 asc, u8 ascq)
{
	cmd->result = (DRIVER_SENSE << 24) | SAM_STAT_CHECK_CONDITION;

	cmd->sense_buffer[0] = 0x70;	/* fixed format, current */
	cmd->sense_buffer[2] = sk;
	cmd->sense_buffer[7] = 18 - 8;	/* additional sense length */
	cmd->sense_buffer[12] = asc;
	cmd->sense_buffer[13] = ascq;
}

/**
 *	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 lock)
 */

void ata_scsi_badcmd(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *), u8 asc, u8 ascq)
{
	DPRINTK("ENTER\n");
	ata_scsi_set_sense(cmd, ILLEGAL_REQUEST, asc, ascq);

	done(cmd);
}

static void atapi_sense_complete(struct ata_queued_cmd *qc)
{
	if (qc->err_mask && ((qc->err_mask & AC_ERR_DEV) == 0)) {
		/* FIXME: not quite right; we don't want the
		 * translation of taskfile registers into
		 * a sense descriptors, since that's only
		 * correct for ATA, not ATAPI
		 */
		ata_gen_passthru_sense(qc);
	}

	qc->scsidone(qc->scsicmd);
	ata_qc_free(qc);
}

/* is it pointless to prefer PIO for "safety reasons"? */
static inline int ata_pio_use_silly(struct ata_port *ap)
{
	return (ap->flags & ATA_FLAG_PIO_DMA);
}

static void atapi_request_sense(struct ata_queued_cmd *qc)
{
	struct ata_port *ap = qc->ap;
	struct scsi_cmnd *cmd = qc->scsicmd;

	DPRINTK("ATAPI request sense\n");

	/* FIXME: is this needed? */
	memset(cmd->sense_buffer, 0, sizeof(cmd->sense_buffer));

	ap->ops->tf_read(ap, &qc->tf);

	/* fill these in, for the case where they are -not- overwritten */
	cmd->sense_buffer[0] = 0x70;
	cmd->sense_buffer[2] = qc->tf.feature >> 4;

	ata_qc_reinit(qc);

	ata_sg_init_one(qc, cmd->sense_buffer, sizeof(cmd->sense_buffer));
	qc->dma_dir = DMA_FROM_DEVICE;

	memset(&qc->cdb, 0, qc->dev->cdb_len);
	qc->cdb[0] = REQUEST_SENSE;
	qc->cdb[4] = SCSI_SENSE_BUFFERSIZE;

	qc->tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
	qc->tf.command = ATA_CMD_PACKET;

	if (ata_pio_use_silly(ap)) {
		qc->tf.protocol = ATA_PROT_ATAPI_DMA;
		qc->tf.feature |= ATAPI_PKT_DMA;
	} else {
		qc->tf.protocol = ATA_PROT_ATAPI;
		qc->tf.lbam = SCSI_SENSE_BUFFERSIZE;
		qc->tf.lbah = 0;
	}
	qc->nbytes = SCSI_SENSE_BUFFERSIZE;

	qc->complete_fn = atapi_sense_complete;

	ata_qc_issue(qc);

	DPRINTK("EXIT\n");
}

static void atapi_qc_complete(struct ata_queued_cmd *qc)
{
	struct scsi_cmnd *cmd = qc->scsicmd;
	unsigned int err_mask = qc->err_mask;

	VPRINTK("ENTER, err_mask 0x%X\n", err_mask);

	/* handle completion from new EH */
	if (unlikely(qc->ap->ops->error_handler &&
		     (err_mask || qc->flags & ATA_QCFLAG_SENSE_VALID))) {

		if (!(qc->flags & ATA_QCFLAG_SENSE_VALID)) {
			/* FIXME: not quite right; we don't want the
			 * translation of taskfile registers into a
			 * sense descriptors, since that's only
			 * correct for ATA, not ATAPI
			 */
			ata_gen_passthru_sense(qc);
		}

		/* SCSI EH automatically locks door if sdev->locked is
		 * set.  Sometimes door lock request continues to
		 * fail, for example, when no media is present.  This
		 * creates a loop - SCSI EH issues door lock which
		 * fails and gets invoked again to acquire sense data
		 * for the failed command.
		 *
		 * If door lock fails, always clear sdev->locked to
		 * avoid this infinite loop.
		 */
		if (qc->cdb[0] == ALLOW_MEDIUM_REMOVAL)
			qc->dev->sdev->locked = 0;

		qc->scsicmd->result = SAM_STAT_CHECK_CONDITION;
		qc->scsidone(cmd);
		ata_qc_free(qc);
		return;
	}

	/* successful completion or old EH failure path */
	if (unlikely(err_mask & AC_ERR_DEV)) {
		cmd->result = SAM_STAT_CHECK_CONDITION;
		atapi_request_sense(qc);
		return;
	} else if (unlikely(err_mask)) {
		/* FIXME: not quite right; we don't want the
		 * translation of taskfile registers into
		 * a sense descriptors, since that's only
		 * correct for ATA, not ATAPI
		 */
		ata_gen_passthru_sense(qc);
	} else {
		u8 *scsicmd = cmd->cmnd;

		if ((scsicmd[0] == INQUIRY) && ((scsicmd[1] & 0x03) == 0)) {
			u8 *buf = NULL;
			unsigned int buflen;

			buflen = ata_scsi_rbuf_get(cmd, &buf);

	/* ATAPI devices typically report zero for their SCSI version,
	 * and sometimes deviate from the spec WRT response data
	 * format.  If SCSI version is reported as zero like normal,
	 * then we make the following fixups:  1) Fake MMC-5 version,
	 * to indicate to the Linux scsi midlayer this is a modern
	 * device.  2) Ensure response data format / ATAPI information
	 * are always correct.
	 */
			if (buf[2] == 0) {
				buf[2] = 0x5;
				buf[3] = 0x32;
			}

			ata_scsi_rbuf_put(cmd, buf);
		}

		cmd->result = SAM_STAT_GOOD;
	}

	qc->scsidone(cmd);
	ata_qc_free(qc);
}
/**
 *	atapi_xlat - Initialize PACKET taskfile
 *	@qc: command structure to be initialized
 *
 *	LOCKING:
 *	spin_lock_irqsave(host lock)
 *
 *	RETURNS:
 *	Zero on success, non-zero on failure.
 */
static unsigned int atapi_xlat(struct ata_queued_cmd *qc)
{
	struct scsi_cmnd *scmd = qc->scsicmd;
	struct ata_device *dev = qc->dev;
	int using_pio = (dev->flags & ATA_DFLAG_PIO);
	int nodata = (scmd->sc_data_direction == DMA_NONE);
	unsigned int nbytes;

	memset(qc->cdb, 0, dev->cdb_len);
	memcpy(qc->cdb, scmd->cmnd, scmd->cmd_len);

	qc->complete_fn = atapi_qc_complete;

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

	qc->tf.command = ATA_CMD_PACKET;
	qc->nbytes = scsi_bufflen(scmd);

	/* check whether ATAPI DMA is safe */
	if (!using_pio && ata_check_atapi_dma(qc))
		using_pio = 1;

	/* Some controller variants snoop this value for Packet
	 * transfers to do state machine and FIFO management.  Thus we
	 * want to set it properly, and for DMA where it is
	 * effectively meaningless.
	 */
	nbytes = min(qc->nbytes, (unsigned int)63 * 1024);

	/* Most ATAPI devices which honor transfer chunk size don't
	 * behave according to the spec when odd chunk size which
	 * matches the transfer length is specified.  If the number of