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 <fenghua.yu@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/20230712174436.3435088-2-fenghua.yu@intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

Author: Fenghua Yu

drivers/dma/idxd/sysfs.c

@@ -1088,16 +1088,12 @@ static ssize_t wq_ats_disable_store(struct device *dev, struct device_attribute
 				    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 rc;
@@ -1316,6 +1312,9 @@ static umode_t idxd_wq_attr_visible(struct kobject *kobj,
 	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;
 }