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

 *	RETURNS:
 *	Zero on success, non-zero on error.
 */

static unsigned int ata_scsi_rw_xlat(struct ata_queued_cmd *qc, u8 *scsicmd)
{
	struct ata_taskfile *tf = &qc->tf;
	unsigned int lba48 = tf->flags & ATA_TFLAG_LBA48;

	tf->flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
	tf->protocol = qc->dev->xfer_protocol;
	tf->device |= ATA_LBA;

	if (scsicmd[0] == READ_10 || scsicmd[0] == READ_6 ||
	    scsicmd[0] == READ_16) {
		tf->command = qc->dev->read_cmd;
	} else {
		tf->command = qc->dev->write_cmd;
		tf->flags |= ATA_TFLAG_WRITE;
	}

	if (scsicmd[0] == READ_10 || scsicmd[0] == WRITE_10) {
		if (lba48) {
			tf->hob_nsect = scsicmd[7];
			tf->hob_lbal = scsicmd[2];

			qc->nsect = ((unsigned int)scsicmd[7] << 8) |
					scsicmd[8];
		} else {
			/* if we don't support LBA48 addressing, the request
			 * -may- be too large. */
			if ((scsicmd[2] & 0xf0) || scsicmd[7])
				return 1;

			/* stores LBA27:24 in lower 4 bits of device reg */
			tf->device |= scsicmd[2];

			qc->nsect = scsicmd[8];
		}

		tf->nsect = scsicmd[8];
		tf->lbal = scsicmd[5];
		tf->lbam = scsicmd[4];
		tf->lbah = scsicmd[3];

		VPRINTK("ten-byte command\n");
		return 0;
	}

	if (scsicmd[0] == READ_6 || scsicmd[0] == WRITE_6) {
		qc->nsect = tf->nsect = scsicmd[4];
		tf->lbal = scsicmd[3];
		tf->lbam = scsicmd[2];
		tf->lbah = scsicmd[1] & 0x1f; /* mask out reserved bits */

		VPRINTK("six-byte command\n");
		return 0;
	}

	if (scsicmd[0] == READ_16 || scsicmd[0] == WRITE_16) {
		/* rule out impossible LBAs and sector counts */
		if (scsicmd[2] || scsicmd[3] || scsicmd[10] || scsicmd[11])
			return 1;

		if (lba48) {
			tf->hob_nsect = scsicmd[12];
			tf->hob_lbal = scsicmd[6];
			tf->hob_lbam = scsicmd[5];
			tf->hob_lbah = scsicmd[4];

			qc->nsect = ((unsigned int)scsicmd[12] << 8) |
					scsicmd[13];
		} else {
			/* once again, filter out impossible non-zero values */
			if (scsicmd[4] || scsicmd[5] || scsicmd[12] ||
			    (scsicmd[6] & 0xf0))
				return 1;

			/* stores LBA27:24 in lower 4 bits of device reg */
			tf->device |= scsicmd[2];

			qc->nsect = scsicmd[13];
		}

		tf->nsect = scsicmd[13];
		tf->lbal = scsicmd[9];
		tf->lbam = scsicmd[8];
		tf->lbah = scsicmd[7];

		VPRINTK("sixteen-byte command\n");
		return 0;
	}

	DPRINTK("no-byte command\n");
	return 1;
}

static int ata_scsi_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)))
		ata_to_sense_error(qc, drv_stat);
	else
		cmd->result = SAM_STAT_GOOD;

	qc->scsidone(cmd);

	return 0;
}

/**
 *	ata_scsi_translate - Translate then issue SCSI command to ATA device
 *	@ap: ATA port to which the command is addressed
 *	@dev: ATA device to which the command is addressed
 *	@cmd: SCSI command to execute
 *	@done: SCSI command completion function
 *	@xlat_func: Actor which translates @cmd to an ATA taskfile
 *
 *	Our ->queuecommand() function has decided that the SCSI
 *	command issued can be directly translated into an ATA
 *	command, rather than handled internally.
 *
 *	This function sets up an ata_queued_cmd structure for the
 *	SCSI command, and sends that ata_queued_cmd to the hardware.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host_set lock)
 */

static void ata_scsi_translate(struct ata_port *ap, struct ata_device *dev,
			      struct scsi_cmnd *cmd,
			      void (*done)(struct scsi_cmnd *),
			      ata_xlat_func_t xlat_func)
{
	struct ata_queued_cmd *qc;
	u8 *scsicmd = cmd->cmnd;

	VPRINTK("ENTER\n");

	qc = ata_scsi_qc_new(ap, dev, cmd, done);
	if (!qc)
		return;

	/* data is present; dma-map it */
	if (cmd->sc_data_direction == SCSI_DATA_READ ||
	    cmd->sc_data_direction == SCSI_DATA_WRITE) {
		if (unlikely(cmd->request_bufflen < 1)) {
			printk(KERN_WARNING "ata%u(%u): WARNING: zero len r/w req\n",
			       ap->id, dev->devno);
			goto err_out;
		}

		if (cmd->use_sg)
			ata_sg_init(qc, cmd->request_buffer, cmd->use_sg);
		else
			ata_sg_init_one(qc, cmd->request_buffer,
					cmd->request_bufflen);

		qc->pci_dma_dir = scsi_to_pci_dma_dir(cmd->sc_data_direction);
	}

	qc->complete_fn = ata_scsi_qc_complete;

	if (xlat_func(qc, scsicmd))
		goto err_out;

	/* select device, send command to hardware */
	if (ata_qc_issue(qc))
		goto err_out;

	VPRINTK("EXIT\n");
	return;

err_out:
	ata_bad_cdb(cmd, done);
	DPRINTK("EXIT - badcmd\n");
}

/**
 *	ata_scsi_rbuf_get - Map response buffer.
 *	@cmd: SCSI command containing buffer to be mapped.
 *	@buf_out: Pointer to mapped area.
 *
 *	Maps buffer contained within SCSI command @cmd.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host_set lock)
 *
 *	RETURNS:
 *	Length of response buffer.
 */

static unsigned int ata_scsi_rbuf_get(struct scsi_cmnd *cmd, u8 **buf_out)
{
	u8 *buf;
	unsigned int buflen;

	if (cmd->use_sg) {
		struct scatterlist *sg;

		sg = (struct scatterlist *) cmd->request_buffer;
		buf = kmap_atomic(sg->page, KM_USER0) + sg->offset;
		buflen = sg->length;
	} else {
		buf = cmd->request_buffer;
		buflen = cmd->request_bufflen;
	}

	memset(buf, 0, buflen);
	*buf_out = buf;
	return buflen;
}

/**
 *	ata_scsi_rbuf_put - Unmap response buffer.
 *	@cmd: SCSI command containing buffer to be unmapped.
 *
 *	Unmaps response buffer contained within @cmd.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host_set lock)
 */

static inline void ata_scsi_rbuf_put(struct scsi_cmnd *cmd)
{
	if (cmd->use_sg) {
		struct scatterlist *sg;

		sg = (struct scatterlist *) cmd->request_buffer;
		kunmap_atomic(sg->page, KM_USER0);
	}
}

/**
 *	ata_scsi_rbuf_fill - wrapper for SCSI command simulators
 *	@args: Port / device / SCSI command of interest.
 *	@actor: Callback hook for desired SCSI command simulator
 *
 *	Takes care of the hard work of simulating a SCSI command...
 *	Mapping the response buffer, calling the command's handler,
 *	and handling the handler's return value.  This return value
 *	indicates whether the handler wishes the SCSI command to be
 *	completed successfully, or not.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host_set lock)
 */

void ata_scsi_rbuf_fill(struct ata_scsi_args *args,
		        unsigned int (*actor) (struct ata_scsi_args *args,
			     		   u8 *rbuf, unsigned int buflen))
{
	u8 *rbuf;
	unsigned int buflen, rc;
	struct scsi_cmnd *cmd = args->cmd;

	buflen = ata_scsi_rbuf_get(cmd, &rbuf);
	rc = actor(args, rbuf, buflen);
	ata_scsi_rbuf_put(cmd);

	if (rc)
		ata_bad_cdb(cmd, args->done);
	else {
		cmd->result = SAM_STAT_GOOD;
		args->done(cmd);
	}
}

/**
 *	ata_scsiop_inq_std - Simulate INQUIRY command
 *	@args: Port / device / SCSI command of interest.
 *	@rbuf: Response buffer, to which simulated SCSI cmd output is sent.
 *	@buflen: Response buffer length.
 *
 *	Returns standard device identification data associated
 *	with non-EVPD INQUIRY command output.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host_set lock)
 */

unsigned int ata_scsiop_inq_std(struct ata_scsi_args *args, u8 *rbuf,
			       unsigned int buflen)
{
	struct ata_device *dev = args->dev;

	u8 hdr[] = {
		TYPE_DISK,
		0,
		0x5,	/* claim SPC-3 version compatibility */
		2,
		95 - 4
	};

	/* set scsi removeable (RMB) bit per ata bit */
	if (ata_id_removeable(dev))
		hdr[1] |= (1 << 7);

	VPRINTK("ENTER\n");

	memcpy(rbuf, hdr, sizeof(hdr));

	if (buflen > 35) {
		memcpy(&rbuf[8], "ATA     ", 8);
		ata_dev_id_string(dev, &rbuf[16], ATA_ID_PROD_OFS, 16);
		ata_dev_id_string(dev, &rbuf[32], ATA_ID_FW_REV_OFS, 4);
		if (rbuf[32] == 0 || rbuf[32] == ' ')
			memcpy(&rbuf[32], "n/a ", 4);
	}

	if (buflen > 63) {
		const u8 versions[] = {
			0x60,	/* SAM-3 (no version claimed) */

			0x03,
			0x20,	/* SBC-2 (no version claimed) */

			0x02,
			0x60	/* SPC-3 (no version claimed) */
		};

		memcpy(rbuf + 59, versions, sizeof(versions));
	}

	return 0;
}

/**
 *	ata_scsiop_inq_00 - Simulate INQUIRY EVPD page 0, list of pages
 *	@args: Port / device / SCSI command of interest.
 *	@rbuf: Response buffer, to which simulated SCSI cmd output is sent.
 *	@buflen: Response buffer length.
 *
 *	Returns list of inquiry EVPD pages available.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host_set lock)
 */

unsigned int ata_scsiop_inq_00(struct ata_scsi_args *args, u8 *rbuf,
			      unsigned int buflen)
{
	const u8 pages[] = {
		0x00,	/* page 0x00, this page */
		0x80,	/* page 0x80, unit serial no page */
		0x83	/* page 0x83, device ident page */
	};
	rbuf[3] = sizeof(pages);	/* number of supported EVPD pages */

	if (buflen > 6)
		memcpy(rbuf + 4, pages, sizeof(pages));

	return 0;
}

/**
 *	ata_scsiop_inq_80 - Simulate INQUIRY EVPD page 80, device serial number
 *	@args: Port / device / SCSI command of interest.
 *	@rbuf: Response buffer, to which simulated SCSI cmd output is sent.
 *	@buflen: Response buffer length.
 *
 *	Returns ATA device serial number.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host_set lock)
 */

unsigned int ata_scsiop_inq_80(struct ata_scsi_args *args, u8 *rbuf,
			      unsigned int buflen)
{
	const u8 hdr[] = {
		0,
		0x80,			/* this page code */
		0,
		ATA_SERNO_LEN,		/* page len */
	};
	memcpy(rbuf, hdr, sizeof(hdr));

	if (buflen > (ATA_SERNO_LEN + 4))
		ata_dev_id_string(args->dev, (unsigned char *) &rbuf[4],
				  ATA_ID_SERNO_OFS, ATA_SERNO_LEN);

	return 0;
}

static const char *inq_83_str = "Linux ATA-SCSI simulator";

/**
 *	ata_scsiop_inq_83 - Simulate INQUIRY EVPD page 83, device identity
 *	@args: Port / device / SCSI command of interest.
 *	@rbuf: Response buffer, to which simulated SCSI cmd output is sent.
 *	@buflen: Response buffer length.
 *
 *	Returns device identification.  Currently hardcoded to
 *	return "Linux ATA-SCSI simulator".
 *
 *	LOCKING:
 *	spin_lock_irqsave(host_set lock)
 */

unsigned int ata_scsiop_inq_83(struct ata_scsi_args *args, u8 *rbuf,
			      unsigned int buflen)
{
	rbuf[1] = 0x83;			/* this page code */
	rbuf[3] = 4 + strlen(inq_83_str);	/* page len */

	/* our one and only identification descriptor (vendor-specific) */
	if (buflen > (strlen(inq_83_str) + 4 + 4)) {
		rbuf[4 + 0] = 2;	/* code set: ASCII */
		rbuf[4 + 3] = strlen(inq_83_str);
		memcpy(rbuf + 4 + 4, inq_83_str, strlen(inq_83_str));
	}

	return 0;
}

/**
 *	ata_scsiop_noop -
 *	@args: Port / device / SCSI command of interest.
 *	@rbuf: Response buffer, to which simulated SCSI cmd output is sent.
 *	@buflen: Response buffer length.
 *
 *	No operation.  Simply returns success to caller, to indicate
 *	that the caller should successfully complete this SCSI command.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host_set lock)
 */

unsigned int ata_scsiop_noop(struct ata_scsi_args *args, u8 *rbuf,
			    unsigned int buflen)
{
	VPRINTK("ENTER\n");
	return 0;
}

/**
 *	ata_msense_push - Push data onto MODE SENSE data output buffer
 *	@ptr_io: (input/output) Location to store more output data
 *	@last: End of output data buffer
 *	@buf: Pointer to BLOB being added to output buffer
 *	@buflen: Length of BLOB
 *
 *	Store MODE SENSE data on an output buffer.
 *
 *	LOCKING:
 *	None.
 */

static void ata_msense_push(u8 **ptr_io, const u8 *last,
			    const u8 *buf, unsigned int buflen)
{
	u8 *ptr = *ptr_io;

	if ((ptr + buflen - 1) > last)
		return;

	memcpy(ptr, buf, buflen);

	ptr += buflen;

	*ptr_io = ptr;
}

/**
 *	ata_msense_caching - Simulate MODE SENSE caching info page
 *	@dev: Device associated with this MODE SENSE command
 *	@ptr_io: (input/output) Location to store more output data
 *	@last: End of output data buffer
 *
 *	Generate a caching info page, which conditionally indicates
 *	write caching to the SCSI layer, depending on device
 *	capabilities.
 *
 *	LOCKING:
 *	None.
 */

static unsigned int ata_msense_caching(struct ata_device *dev, u8 **ptr_io,
				       const u8 *last)
{
	u8 page[] = {
		0x8,				/* page code */
		0x12,				/* page length */
		0, 0, 0, 0, 0, 0, 0, 0, 0, 0,	/* 10 zeroes */
		0, 0, 0, 0, 0, 0, 0, 0		/* 8 zeroes */
	};

	if (ata_id_wcache_enabled(dev))
		page[2] |= (1 << 2);	/* write cache enable */
	if (!ata_id_rahead_enabled(dev))
		page[12] |= (1 << 5);	/* disable read ahead */

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

/**
 *	ata_msense_ctl_mode - Simulate MODE SENSE control mode page
 *	@dev: Device associated with this MODE SENSE command
 *	@ptr_io: (input/output) Location to store more output data
 *	@last: End of output data buffer
 *
 *	Generate a generic MODE SENSE control mode page.
 *
 *	LOCKING:
 *	None.
 */

static unsigned int ata_msense_ctl_mode(u8 **ptr_io, const u8 *last)
{
	const u8 page[] = {0xa, 0xa, 2, 0, 0, 0, 0, 0, 0xff, 0xff, 0, 30};

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

/**
 *	ata_msense_rw_recovery - Simulate MODE SENSE r/w error recovery page
 *	@dev: Device associated with this MODE SENSE command
 *	@ptr_io: (input/output) Location to store more output data
 *	@last: End of output data buffer
 *