Commit aacda375 authored by Tejun Heo's avatar Tejun Heo Committed by Jeff Garzik
Browse files

libata: implement ata_qc_raw_nbytes() 



Implement ata_qc_raw_nbytes() which determines the raw user-requested
size of a PC command.

Signed-off-by: default avatarTejun Heo <htejun@gmail.com>
Signed-off-by: default avatarJeff Garzik <jeff@garzik.org>
parent cc7feea3

drivers/ata/libata-scsi.c

+11 −3
Original line number Diff line number Diff line
@@ -527,6 +527,14 @@ static struct ata_queued_cmd *ata_scsi_qc_new(struct ata_device *dev, 
	return qc;

}



static void ata_qc_set_pc_nbytes(struct ata_queued_cmd *qc)

{

	struct scsi_cmnd *scmd = qc->scsicmd;



	qc->extrabytes = scmd->request->extra_len;

	qc->nbytes = scsi_bufflen(scmd) + qc->extrabytes;

}



/**

 *	ata_dump_status - user friendly display of error info

 *	@id: id of the port in question
@@ -2539,7 +2547,7 @@ static unsigned int atapi_xlat(struct ata_queued_cmd *qc) 
	}



	qc->tf.command = ATA_CMD_PACKET;

	qc->nbytes = scsi_bufflen(scmd) + scmd->request->extra_len;

	ata_qc_set_pc_nbytes(qc);



	/* check whether ATAPI DMA is safe */

	if (!using_pio && ata_check_atapi_dma(qc))
@@ -2550,7 +2558,7 @@ static unsigned int atapi_xlat(struct ata_queued_cmd *qc) 
	 * want to set it properly, and for DMA where it is

	 * effectively meaningless.

	 */

	nbytes = min(scmd->request->data_len, (unsigned int)63 * 1024);

	nbytes = min(ata_qc_raw_nbytes(qc), (unsigned int)63 * 1024);



	/* Most ATAPI devices which honor transfer chunk size don't

	 * behave according to the spec when odd chunk size which
@@ -2876,7 +2884,7 @@ static unsigned int ata_scsi_pass_thru(struct ata_queued_cmd *qc) 
	 * TODO: find out if we need to do more here to

	 *       cover scatter/gather case.

	 */

	qc->nbytes = scsi_bufflen(scmd) + scmd->request->extra_len;

	ata_qc_set_pc_nbytes(qc);



	/* request result TF and be quiet about device error */

	qc->flags |= ATA_QCFLAG_RESULT_TF | ATA_QCFLAG_QUIET;

include/linux/libata.h

+7 −1
Original line number Diff line number Diff line
@@ -463,6 +463,7 @@ struct ata_queued_cmd { 
	unsigned int		sect_size;



	unsigned int		nbytes;

	unsigned int		extrabytes;

	unsigned int		curbytes;



	struct scatterlist	*cursg;
@@ -1336,6 +1337,11 @@ static inline struct ata_queued_cmd *ata_qc_from_tag(struct ata_port *ap, 
	return NULL;

}



static inline unsigned int ata_qc_raw_nbytes(struct ata_queued_cmd *qc)

{

	return qc->nbytes - min(qc->extrabytes, qc->nbytes);

}



static inline void ata_tf_init(struct ata_device *dev, struct ata_taskfile *tf)

{

	memset(tf, 0, sizeof(*tf));
@@ -1354,7 +1360,7 @@ static inline void ata_qc_reinit(struct ata_queued_cmd *qc) 
	qc->flags = 0;

	qc->cursg = NULL;

	qc->cursg_ofs = 0;

	qc->nbytes = qc->curbytes = 0;

	qc->nbytes = qc->extrabytes = qc->curbytes = 0;

	qc->n_elem = 0;

	qc->err_mask = 0;

	qc->sect_size = ATA_SECT_SIZE;