libata-scsi.c

linux 内核源代码

 *	termination.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host lock)
 *
 *	RETURNS:
 *	0 on success, SCSI_ML_QUEUE_DEVICE_BUSY if the command
 *	needs to be deferred.
 */
static int ata_scsi_translate(struct ata_device *dev, struct scsi_cmnd *cmd,
			      void (*done)(struct scsi_cmnd *),
			      ata_xlat_func_t xlat_func)
{
	struct ata_port *ap = dev->link->ap;
	struct ata_queued_cmd *qc;
	int rc;

	VPRINTK("ENTER\n");

	qc = ata_scsi_qc_new(dev, cmd, done);
	if (!qc)
		goto err_mem;

	/* data is present; dma-map it */
	if (cmd->sc_data_direction == DMA_FROM_DEVICE ||
	    cmd->sc_data_direction == DMA_TO_DEVICE) {
		if (unlikely(scsi_bufflen(cmd) < 1)) {
			ata_dev_printk(dev, KERN_WARNING,
				       "WARNING: zero len r/w req\n");
			goto err_did;
		}

		ata_sg_init(qc, scsi_sglist(cmd), scsi_sg_count(cmd));

		qc->dma_dir = cmd->sc_data_direction;
	}

	qc->complete_fn = ata_scsi_qc_complete;

	if (xlat_func(qc))
		goto early_finish;

	if (ap->ops->qc_defer) {
		if ((rc = ap->ops->qc_defer(qc)))
			goto defer;
	}

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

	VPRINTK("EXIT\n");
	return 0;

early_finish:
	ata_qc_free(qc);
	qc->scsidone(cmd);
	DPRINTK("EXIT - early finish (good or error)\n");
	return 0;

err_did:
	ata_qc_free(qc);
	cmd->result = (DID_ERROR << 16);
	qc->scsidone(cmd);
err_mem:
	DPRINTK("EXIT - internal\n");
	return 0;

defer:
	ata_qc_free(qc);
	DPRINTK("EXIT - defer\n");
	if (rc == ATA_DEFER_LINK)
		return SCSI_MLQUEUE_DEVICE_BUSY;
	else
		return SCSI_MLQUEUE_HOST_BUSY;
}

/**
 *	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 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;

	struct scatterlist *sg = scsi_sglist(cmd);

	if (sg) {
		buf = kmap_atomic(sg_page(sg), KM_IRQ0) + sg->offset;
		buflen = sg->length;
	} else {
		buf = NULL;
		buflen = 0;
	}

	*buf_out = buf;
	return buflen;
}

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

static inline void ata_scsi_rbuf_put(struct scsi_cmnd *cmd, u8 *buf)
{
	struct scatterlist *sg = scsi_sglist(cmd);
	if (sg)
		kunmap_atomic(buf - sg->offset, KM_IRQ0);
}

/**
 *	ata_scsi_rbuf_fill - wrapper for SCSI command simulators
 *	@args: device IDENTIFY data / 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 (0), or not (in which case cmd->result
 *	and sense buffer are assumed to be set).
 *
 *	LOCKING:
 *	spin_lock_irqsave(host 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);
	memset(rbuf, 0, buflen);
	rc = actor(args, rbuf, buflen);
	ata_scsi_rbuf_put(cmd, rbuf);

	if (rc == 0)
		cmd->result = SAM_STAT_GOOD;
	args->done(cmd);
}

/**
 *	ATA_SCSI_RBUF_SET - helper to set values in SCSI response buffer
 *	@idx: byte index into SCSI response buffer
 *	@val: value to set
 *
 *	To be used by SCSI command simulator functions.  This macros
 *	expects two local variables, u8 *rbuf and unsigned int buflen,
 *	are in scope.
 *
 *	LOCKING:
 *	None.
 */
#define ATA_SCSI_RBUF_SET(idx, val) do { \
		if ((idx) < buflen) rbuf[(idx)] = (u8)(val); \
	} while (0)

/**
 *	ata_scsiop_inq_std - Simulate INQUIRY command
 *	@args: device IDENTIFY data / 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-VPD INQUIRY command output.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host lock)
 */

unsigned int ata_scsiop_inq_std(struct ata_scsi_args *args, u8 *rbuf,
			       unsigned int buflen)
{
	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(args->id))
		hdr[1] |= (1 << 7);

	VPRINTK("ENTER\n");

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

	if (buflen > 35) {
		memcpy(&rbuf[8], "ATA     ", 8);
		ata_id_string(args->id, &rbuf[16], ATA_ID_PROD, 16);
		ata_id_string(args->id, &rbuf[32], ATA_ID_FW_REV, 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 VPD page 0, list of pages
 *	@args: device IDENTIFY data / SCSI command of interest.
 *	@rbuf: Response buffer, to which simulated SCSI cmd output is sent.
 *	@buflen: Response buffer length.
 *
 *	Returns list of inquiry VPD pages available.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host 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 VPD pages */

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

	return 0;
}

/**
 *	ata_scsiop_inq_80 - Simulate INQUIRY VPD page 80, device serial number
 *	@args: device IDENTIFY data / 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 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_ID_SERNO_LEN,	/* page len */
	};
	memcpy(rbuf, hdr, sizeof(hdr));

	if (buflen > (ATA_ID_SERNO_LEN + 4 - 1))
		ata_id_string(args->id, (unsigned char *) &rbuf[4],
			      ATA_ID_SERNO, ATA_ID_SERNO_LEN);

	return 0;
}

/**
 *	ata_scsiop_inq_83 - Simulate INQUIRY VPD page 83, device identity
 *	@args: device IDENTIFY data / SCSI command of interest.
 *	@rbuf: Response buffer, to which simulated SCSI cmd output is sent.
 *	@buflen: Response buffer length.
 *
 *	Yields two logical unit device identification designators:
 *	 - vendor specific ASCII containing the ATA serial number
 *	 - SAT defined "t10 vendor id based" containing ASCII vendor
 *	   name ("ATA     "), model and serial numbers.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host lock)
 */

unsigned int ata_scsiop_inq_83(struct ata_scsi_args *args, u8 *rbuf,
			      unsigned int buflen)
{
	int num;
	const int sat_model_serial_desc_len = 68;

	rbuf[1] = 0x83;			/* this page code */
	num = 4;

	if (buflen > (ATA_ID_SERNO_LEN + num + 3)) {
		/* piv=0, assoc=lu, code_set=ACSII, designator=vendor */
		rbuf[num + 0] = 2;
		rbuf[num + 3] = ATA_ID_SERNO_LEN;
		num += 4;
		ata_id_string(args->id, (unsigned char *) rbuf + num,
			      ATA_ID_SERNO, ATA_ID_SERNO_LEN);
		num += ATA_ID_SERNO_LEN;
	}
	if (buflen > (sat_model_serial_desc_len + num + 3)) {
		/* SAT defined lu model and serial numbers descriptor */
		/* piv=0, assoc=lu, code_set=ACSII, designator=t10 vendor id */
		rbuf[num + 0] = 2;
		rbuf[num + 1] = 1;
		rbuf[num + 3] = sat_model_serial_desc_len;
		num += 4;
		memcpy(rbuf + num, "ATA     ", 8);
		num += 8;
		ata_id_string(args->id, (unsigned char *) rbuf + num,
			      ATA_ID_PROD, ATA_ID_PROD_LEN);
		num += ATA_ID_PROD_LEN;
		ata_id_string(args->id, (unsigned char *) rbuf + num,
			      ATA_ID_SERNO, ATA_ID_SERNO_LEN);
		num += ATA_ID_SERNO_LEN;
	}
	rbuf[3] = num - 4;    /* page len (assume less than 256 bytes) */
	return 0;
}

/**
 *	ata_scsiop_inq_89 - Simulate INQUIRY VPD page 89, ATA info
 *	@args: device IDENTIFY data / SCSI command of interest.
 *	@rbuf: Response buffer, to which simulated SCSI cmd output is sent.
 *	@buflen: Response buffer length.
 *
 *	Yields SAT-specified ATA VPD page.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host lock)
 */

unsigned int ata_scsiop_inq_89(struct ata_scsi_args *args, u8 *rbuf,
			      unsigned int buflen)
{
	u8 pbuf[60];
	struct ata_taskfile tf;
	unsigned int i;

	if (!buflen)
		return 0;

	memset(&pbuf, 0, sizeof(pbuf));
	memset(&tf, 0, sizeof(tf));

	pbuf[1] = 0x89;			/* our page code */
	pbuf[2] = (0x238 >> 8);		/* page size fixed at 238h */
	pbuf[3] = (0x238 & 0xff);

	memcpy(&pbuf[8], "linux   ", 8);
	memcpy(&pbuf[16], "libata          ", 16);
	memcpy(&pbuf[32], DRV_VERSION, 4);
	ata_id_string(args->id, &pbuf[32], ATA_ID_FW_REV, 4);

	/* we don't store the ATA device signature, so we fake it */

	tf.command = ATA_DRDY;		/* really, this is Status reg */
	tf.lbal = 0x1;
	tf.nsect = 0x1;

	ata_tf_to_fis(&tf, 0, 1, &pbuf[36]);	/* TODO: PMP? */
	pbuf[36] = 0x34;		/* force D2H Reg FIS (34h) */

	pbuf[56] = ATA_CMD_ID_ATA;

	i = min(buflen, 60U);
	memcpy(rbuf, &pbuf[0], i);
	buflen -= i;

	if (!buflen)
		return 0;

	memcpy(&rbuf[60], &args->id[0], min(buflen, 512U));
	return 0;
}

/**
 *	ata_scsiop_noop - Command handler that simply returns success.
 *	@args: device IDENTIFY data / 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 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
 *	@id: device IDENTIFY data
 *	@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(u16 *id, u8 **ptr_io,
				       const u8 *last)
{
	u8 page[CACHE_MPAGE_LEN];

	memcpy(page, def_cache_mpage, sizeof(page));
	if (ata_id_wcache_enabled(id))
		page[2] |= (1 << 2);	/* write cache enable */
	if (!ata_id_rahead_enabled(id))
		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)
{
	ata_msense_push(ptr_io, last, def_control_mpage,
			sizeof(def_control_mpage));
	return sizeof(def_control_mpage);
}

/**
 *	ata_msense_rw_recovery - Simulate MODE SENSE r/w error recovery page
 *	@dev: Device associated with this MODE SENSE command