Re: [PATCH RFC v2 06/18] libata-scsi: Add ata_scsi_queue_internal()

Damien Le Moal
2022-06-13T07:12:52Z

On 6/9/22 19:29, John Garry wrote:
> Add a function to handle queued ATA internal SCSI cmnds - does much the
> same as ata_exec_internal_sg() does (which will be fixed up later to
> actually queue internal cmnds through this function).
>
> Signed-off-by: John Garry <john.garry@huawei.com>
> ---
> drivers/ata/libata-scsi.c | 47 ++++++++++++++++++++++++++++++++++++++-
> include/linux/libata.h | 6 +++++
> 2 files changed, 52 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
> index 42cecf95a4e5..baac35dd17ca 100644
> --- a/drivers/ata/libata-scsi.c
> +++ b/drivers/ata/libata-scsi.c
> @@ -3963,6 +3963,49 @@ static inline ata_xlat_func_t ata_get_xlat_func(struct ata_device *dev, u8 cmd)
> return NULL;
> }
>
> +static unsigned int ata_scsi_queue_internal(struct scsi_cmnd *scmd,
> + struct ata_device *dev)
> +{
> + struct ata_link *link = dev->link;
> + struct ata_port *ap = link->ap;
> + struct ata_queued_cmd *qc;
> +
> + /* no internal command while frozen */
> + if (ap->pflags & ATA_PFLAG_FROZEN)
> + goto did_err;
> +
> + /* initialize internal qc */
> + qc = __ata_qc_from_tag(ap, ATA_TAG_INTERNAL);
> + link->preempted_tag = link->active_tag;
> + link->preempted_sactive = link->sactive;
> + ap->preempted_qc_active = ap->qc_active;
> + ap->preempted_nr_active_links = ap->nr_active_links;
> + link->active_tag = ATA_TAG_POISON;
> + link->sactive = 0;
> + ap->qc_active = 0;
> + ap->nr_active_links = 0;> +
> + if (qc->dma_dir != DMA_NONE) {
> + int n_elem;
> +
> + n_elem = 1;
> + qc->n_elem = n_elem;
> + qc->sg = scsi_sglist(scmd);
> + qc->nbytes = qc->sg->length;
> + ata_sg_init(qc, qc->sg, n_elem);
> + }
> +
> + scmd->submitter = SUBMITTED_BY_BLOCK_LAYER;
> +
> + ata_qc_issue(qc);
> +
> + return 0;
> +did_err:
> + scmd->result = (DID_ERROR << 16);
> + scsi_done(scmd);
> + return 0;
> +}
> +
> int __ata_scsi_queuecmd(struct scsi_cmnd *scmd, struct ata_device *dev)
> {
> u8 scsi_op = scmd->cmnd[0];
> @@ -3971,7 +4014,9 @@ int __ata_scsi_queuecmd(struct scsi_cmnd *scmd, struct ata_device *dev)
> if (unlikely(!scmd->cmd_len))
> goto bad_cdb_len;
>
> - if (dev->class == ATA_DEV_ATA || dev->class == ATA_DEV_ZAC) {
> + if (scsi_is_reserved_cmd(scmd)) {
> + return ata_scsi_queue_internal(scmd, dev);
> + } else if (dev->class == ATA_DEV_ATA || dev->class == ATA_DEV_ZAC) {

No need for the else here.

> if (unlikely(scmd->cmd_len > dev->cdb_len))
> goto bad_cdb_len;
>
> diff --git a/include/linux/libata.h b/include/linux/libata.h
> index 732de9014626..43f4bcfe9a5f 100644
> --- a/include/linux/libata.h
> +++ b/include/linux/libata.h
> @@ -767,7 +767,9 @@ struct ata_link {
>
> struct device tdev;
> unsigned int active_tag; /* active tag on this link */
> + unsigned int preempted_tag;
> u32 sactive; /* active NCQ commands */
> + u32 preempted_sactive;
>
> unsigned int flags; /* ATA_LFLAG_xxx */
>
> @@ -861,6 +863,10 @@ struct ata_port {
> #ifdef CONFIG_ATA_ACPI
> struct ata_acpi_gtm __acpi_init_gtm; /* use ata_acpi_init_gtm() */
> #endif
> +
> + u64 preempted_qc_active;
> + int preempted_nr_active_links;
> +
> /* owned by EH */
> u8 sector_buf[ATA_SECT_SIZE] ____cacheline_aligned;
> };

--
Damien Le Moal
Western Digital Research