dmaengine: idxd: Expose ATS disable knob only when WQ ATS is supported

WQ Advanced Translation Service (ATS) can be controlled only when
WQ ATS is supported. The sysfs ATS disable knob should be visible only
when the features is supported.

Signed-off-by: Fenghua Yu <[e-mail]>
Reviewed-by: Dave Jiang <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Vinod Koul <[e-mail]>

drivers/dma/idxd/sysfs.c

···
 				    const char *buf, size_t count)
 {
 	struct idxd_wq *wq = confdev_to_wq(dev);
-	struct idxd_device *idxd = wq->idxd;
 	bool ats_dis;
 	int rc;
 
 	if (wq->state != IDXD_WQ_DISABLED)
 		return -EPERM;
-
-	if (!idxd->hw.wq_cap.wq_ats_support)
-		return -EOPNOTSUPP;
 
 	rc = kstrtobool(buf, &ats_dis);
 	if (rc < 0)
···
 		return 0;
 
 	if (idxd_wq_attr_invisible(prs_disable, wq_prs_support, attr, idxd))
+		return 0;
+
+	if (idxd_wq_attr_invisible(ats_disable, wq_ats_support, attr, idxd))
 		return 0;
 
 	return attr->mode;