Target Driver Instance Initialization

The following sections describe target entry points.

tran_tgt_init() Entry Point

The tran_tgt_init(9E) entry point enables the HBA to allocate and initialize any per-target resources. tran_tgt_init() also enables the HBA to qualify the device's address as valid and supportable for that particular HBA. By returning DDI_FAILURE, the instance of the target driver for that device is not probed or attached.

tran_tgt_init() is not required. If tran_tgt_init() is not supplied, the framework attempts to probe and attach all possible instances of the appropriate target drivers.

static int
isp_tran_tgt_init(
    dev_info_t            *hba_dip,
    dev_info_t            *tgt_dip,
    scsi_hba_tran_t       *tran,
    struct scsi_device    *sd)
{
    return ((sd->sd_address.a_target < N_ISP_TARGETS_WIDE &&
        sd->sd_address.a_lun < 8) ? DDI_SUCCESS : DDI_FAILURE);
}

tran_tgt_probe() Entry Point

The tran_tgt_probe(9E) entry point enables the HBA to customize the operation of scsi_probe(9F), if necessary. This entry point is called only when the target driver calls scsi_probe().

The HBA driver can retain the normal operation of scsi_probe() by calling scsi_hba_probe(9F) and returning its return value.

This entry point is not required, and if not needed, the HBA driver should set the tran_tgt_probe vector in the scsi_hba_tran(9S) structure to point to scsi_hba_probe().

scsi_probe() allocates a scsi_inquiry(9S) structure and sets the sd_inq field of the scsi_device(9S) structure to point to the data in scsi_inquiry. scsi_hba_probe() handles this task automatically. scsi_unprobe(9F) then frees the scsi_inquiry data.

Except for the allocation of scsi_inquiry data, tran_tgt_probe() must be stateless, because the same SCSI device might call tran_tgt_probe() several times. Normally, allocation of scsi_inquiry data is handled by scsi_hba_probe().

The allocation of the scsi_inquiry(9S) structure is handled automatically by scsi_hba_probe(). This information is only of concern if you want custom scsi_probe() handling.

static int
isp_tran_tgt_probe(
    struct scsi_device    *sd,
    int                   (*callback)())
{
    /*
     * Perform any special probe customization needed.
     * Normal probe handling.
     */
    return (scsi_hba_probe(sd, callback));
}

tran_tgt_free() Entry Point

The tran_tgt_free(9E) entry point enables the HBA to perform any deallocation or clean-up procedures for an instance of a target. This entry point is optional.

static void
isp_tran_tgt_free(
    dev_info_t            *hba_dip,
    dev_info_t            *tgt_dip,
    scsi_hba_tran_t       *hba_tran,
    struct scsi_device    *sd)
{
    /*
     * Undo any special per-target initialization done
     * earlier in tran_tgt_init(9F) and tran_tgt_probe(9F)
     */
}