linux: Add functions to set and clear etdas bit

src/libnvme.map

@@ -1,5 +1,8 @@
 # SPDX-License-Identifier: LGPL-2.1-or-later
 LIBNVME_UNRELEASED {
+	global:
+		nvme_set_etdas;
+		nvme_clear_etdas;
 };
 
 LIBNVME_1_14 {

src/nvme/linux.c

@@ -121,6 +121,53 @@ int nvme_fw_download_seq(int fd, __u32 size, __u32 xfer, __u32 offset,
 	return err;
 }
 
+int nvme_set_etdas(int fd, bool *changed)
+{
+	struct nvme_feat_host_behavior da4;
+	int err;
+
+	err = nvme_get_features_host_behavior(fd, 0, &da4, NULL);
+	if (err)
+		return err;
+
+	if (da4.etdas) {
+		*changed = false;
+		return 0;
+	}
+
+	da4.etdas = 1;
+
+	err = nvme_set_features_host_behavior(fd, 0, &da4);
+	if (err)
+		return err;
+
+	*changed = true;
+	return 0;
+}
+
+int nvme_clear_etdas(int fd, bool *changed)
+{
+	struct nvme_feat_host_behavior da4;
+	int err;
+
+	err = nvme_get_features_host_behavior(fd, 0, &da4, NULL);
+	if (err)
+		return err;
+
+	if (!da4.etdas) {
+		*changed = false;
+		return 0;
+	}
+
+	da4.etdas = 0;
+	err = nvme_set_features_host_behavior(fd, 0, &da4);
+	if (err)
+		return err;
+
+	*changed = true;
+	return 0;
+}
+
 int nvme_get_telemetry_max(int fd, enum nvme_telemetry_da *da, size_t *data_tx)
 {
 	_cleanup_free_ struct nvme_id_ctrl *id_ctrl = NULL;

src/nvme/linux.h

@@ -34,6 +34,28 @@
 int nvme_fw_download_seq(int fd, __u32 size, __u32 xfer, __u32 offset,
 			 void *buf);
 
+/**
+ * nvme_set_etdas() - Set the Extended Telemetry Data Area 4 Supported bit
+ * @fd:		File descriptor of nvme device
+ * @changed:	boolean to indicate whether or not the host
+ *		behavior support feature had been changed
+ *
+ * Return: The nvme command status if a response was received (see
+ * &enum nvme_status_field) or -1 with errno set otherwise.
+ */
+int nvme_set_etdas(int fd, bool *changed);
+
+/**
+ * nvme_clear_etdas() - Clear the Extended Telemetry Data Area 4 Supported bit
+ * @fd:		File descriptor of nvme device
+ * @changed:	boolean to indicate whether or not the host
+ *		behavior support feature had been changed
+ *
+ * Return: The nvme command status if a response was received (see
+ * &enum nvme_status_field) or -1 with errno set otherwise.
+ */
+int nvme_clear_etdas(int fd, bool *changed);
+
 /**
  * nvme_get_telemetry_max() - Get telemetry limits
  * @fd:		File descriptor of nvme device