[PATCH 2/4] net: qrtr: Assign unique node id for MHI endpoints

[Manivannan Sadhasivam via B4 Relay <devnull+manivannan.sadhasivam.oss.qualcomm.com@kernel.org>]

From: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>

Now that the QRTR driver allows using the unique node id for each device,
which is different from the node id received from the remote node, compute
a unique node id using a new API, qrtr_host_node_id().

This API takes the 'index' parameter and adds it to QRTR_NODE_HOST_BASE,
whose value is outside of the node id range used by the remote nodes (0 to
0xffff).

Finally, call the new API from MHI endpoint driver by passing the MHI
controller index as the parameter. The MHI controller index is unique for
each controller, thereby for each MHI endpoint device.

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
---
 MAINTAINERS        |  1 +
 include/net/qrtr.h | 21 +++++++++++++++++++++
 net/qrtr/mhi.c     |  4 +++-
 3 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/MAINTAINERS b/MAINTAINERS
index 3a19da74d00c..bc1af0cd8a8b 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -22504,6 +22504,7 @@ QUALCOMM IPC ROUTER (QRTR) DRIVER
 M:	Manivannan Sadhasivam <mani@kernel.org>
 L:	linux-arm-msm@vger.kernel.org
 S:	Maintained
+F:	include/net/qrtr.h
 F:	include/trace/events/qrtr.h
 F:	include/uapi/linux/qrtr.h
 F:	net/qrtr/
diff --git a/include/net/qrtr.h b/include/net/qrtr.h
new file mode 100644
index 000000000000..745d51b4a6ba
--- /dev/null
+++ b/include/net/qrtr.h
@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef _NET_QRTR_H
+#define _NET_QRTR_H
+
+#include <linux/types.h>
+
+/* The offset is chosen carefully to not collide with the node ids allocated by
+ * the remote nodes. All the remote nodes use node ids in range 0 to 0xffff.
+ */
+#define QRTR_NODE_HOST_BASE 0x10000u
+
+/* Compute host node id from a per-device index. The index must be unique
+ * among the host assigned endpoints and smaller than QRTR_NODE_HOST_BASE.
+ */
+static inline unsigned int qrtr_host_node_id(unsigned int index)
+{
+	return QRTR_NODE_HOST_BASE + index;
+}
+
+#endif /* _NET_QRTR_H */
diff --git a/net/qrtr/mhi.c b/net/qrtr/mhi.c
index 3990da1a65dc..c920ab61f848 100644
--- a/net/qrtr/mhi.c
+++ b/net/qrtr/mhi.c
@@ -6,6 +6,7 @@
 #include <linux/mhi.h>
 #include <linux/module.h>
 #include <linux/skbuff.h>
+#include <net/qrtr.h>
 #include <net/sock.h>
 
 #include "qrtr.h"
@@ -127,7 +128,8 @@ static int qcom_mhi_qrtr_probe(struct mhi_device *mhi_dev,
 	if (rc)
 		return rc;
 
-	rc = qrtr_endpoint_register(&qdev->ep, QRTR_EP_NID_AUTO);
+	rc = qrtr_endpoint_register(&qdev->ep,
+				    qrtr_host_node_id(mhi_dev->mhi_cntrl->index));
 	if (rc)
 		goto err_unprepare;
 

-- 
2.43.0