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: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
This commit is contained in:
Tejun Heo 2008-03-18 17:47:43 +09:00 committed by Jeff Garzik
parent cc7feea39b
commit aacda37538
2 changed files with 18 additions and 4 deletions

View file

@ -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;

View file

@ -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;