[PATCH net-next v2 0/8] Add RPMSG Ethernet Driver

[PATCH net-next v2 0/8] Add RPMSG Ethernet Driver

[MD Danish Anwar]

This patch series introduces the RPMSG Ethernet driver, which provides a
virtual Ethernet interface for communication between a host processor and
a remote processor using the RPMSG framework. The driver enables
Ethernet-like packet transmission and reception over shared memory,
facilitating inter-core communication in systems with heterogeneous
processors.

Key features of this driver:

1. Virtual Ethernet interface using RPMSG framework
2. Shared memory-based packet transmission and reception
3. Support for multicast address filtering
4. Dynamic MAC address assignment
5. NAPI support for efficient packet processing
6. State machine for managing interface states

The series begins by adding device tree binding documentation, continues
with  core driver implementation, and concludes with platform-specific DTS
changes for the TI K3 AM64 SoC. The driver is designed to be generic and
can be used by any vendor that implements compatible firmware for their
remote processors.

This driver is designed to be generic and vendor-agnostic. Vendors can
develop firmware for the remote processor to make it compatible with this
driver by adhering to the shared memory layout and communication protocol
described in the documentation.

This patch series has been tested on a TI AM64xx platform with a
compatible remote processor firmware. Feedback and suggestions for
improvement are welcome.

Changes since v1:
- Added dt binding for rpmsg-eth node similar to `qcom,glink-edge.yaml`
  and `google,cros-ec.yaml`
- Added phandle to rpmsg-eth node to dt binding `ti,k3-r5f-rproc.yaml`
- In the driver, shared memory region is now obtained from the rpmsg-eth
  node in device tree.
- Dropped base address from rpmsg callback. Since base address is obtained
  from device tree, no need for rpmsg callback to share this base address
  again.
- Dropped usage of pointers and strictly using only offsets while
  communicating to firmware.
- Updated documentation based on the changes in driver and bindings.
- Added "Naming convention" section to documentation to clarify naming and
  various terms used in the driver and documentation.
- Kept the naming should be consistent throughout the documentation and
  driver as suggested by Andrew Lunn <andrew@lunn.ch>
- Added device tree patch in the series to clarify how the changes will be
  done in device tree and how the driver will use device tree information.

v1 https://lore.kernel.org/all/20250723080322.3047826-1-danishanwar@ti.com/

MD Danish Anwar (8):
  dt-bindings: net: ti,rpmsg-eth: Add DT binding for RPMSG ETH
  dt-bindings: remoteproc: k3-r5f: Add rpmsg-eth subnode
  net: rpmsg-eth: Add Documentation for RPMSG-ETH Driver
  net: rpmsg-eth: Add basic rpmsg skeleton
  net: rpmsg-eth: Register device as netdev
  net: rpmsg-eth: Add netdev ops
  net: rpmsg-eth: Add support for multicast filtering
  arch: arm64: dts: k3-am64*: Add rpmsg-eth node

 .../devicetree/bindings/net/ti,rpmsg-eth.yaml |  38 ++
 .../bindings/remoteproc/ti,k3-r5f-rproc.yaml  |   6 +
 .../device_drivers/ethernet/index.rst         |   1 +
 .../device_drivers/ethernet/rpmsg_eth.rst     | 368 ++++++++++
 arch/arm64/boot/dts/ti/k3-am642-evm.dts       |  11 +-
 drivers/net/ethernet/Kconfig                  |  10 +
 drivers/net/ethernet/Makefile                 |   1 +
 drivers/net/ethernet/rpmsg_eth.c              | 639 ++++++++++++++++++
 drivers/net/ethernet/rpmsg_eth.h              | 283 ++++++++
 9 files changed, 1356 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/devicetree/bindings/net/ti,rpmsg-eth.yaml
 create mode 100644 Documentation/networking/device_drivers/ethernet/rpmsg_eth.rst
 create mode 100644 drivers/net/ethernet/rpmsg_eth.c
 create mode 100644 drivers/net/ethernet/rpmsg_eth.h


base-commit: 2fd4161d0d2547650d9559d57fc67b4e0a26a9e3
-- 
2.34.1

[PATCH net-next v2 1/8] dt-bindings: net: ti,rpmsg-eth: Add DT binding for RPMSG ETH

[MD Danish Anwar]

Add device tree binding documentation for Texas Instruments RPMsg Ethernet
channels. This binding describes the shared memory communication interface
between host processor and a remote processor for Ethernet packet exchange.

The binding defines the required 'memory-region' property that references
the dedicated shared memory area used for exchanging Ethernet packets
between processors.

Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
---
 .../devicetree/bindings/net/ti,rpmsg-eth.yaml | 38 +++++++++++++++++++
 1 file changed, 38 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/net/ti,rpmsg-eth.yaml

diff --git a/Documentation/devicetree/bindings/net/ti,rpmsg-eth.yaml b/Documentation/devicetree/bindings/net/ti,rpmsg-eth.yaml
new file mode 100644
index 000000000000..1c86d5c020b0
--- /dev/null
+++ b/Documentation/devicetree/bindings/net/ti,rpmsg-eth.yaml
@@ -0,0 +1,38 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/net/ti,rpmsg-eth.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Texas Instruments RPMsg channel nodes for Ethernet communication
+
+description: |
+  RPMsg Ethernet subnode represents the communication interface between host
+  processor and a remote processor.
+
+maintainers:
+  - MD Danish Anwar <danishanwar@ti.com>
+
+properties:
+  memory-region:
+    $ref: /schemas/types.yaml#/definitions/phandle
+    description: |
+      Phandle to the shared memory region used for communication between the
+      host processor and the remote processor.
+      This shared memory region is used to exchange Ethernet packets.
+
+required:
+  - memory-region
+
+additionalProperties: false
+
+examples:
+  - |
+    main_r5fss0_core0 {
+        mboxes = <&mailbox0_cluster2 &mbox_main_r5fss0_core0>;
+        memory-region = <&main_r5fss0_core0_dma_memory_region>,
+                        <&main_r5fss0_core0_memory_region>;
+        rpmsg-eth {
+            memory-region = <&main_r5fss0_core0_memory_region_shm>;
+        };
+    };
-- 
2.34.1

[PATCH net-next v2 2/8] dt-bindings: remoteproc: k3-r5f: Add rpmsg-eth subnode

[MD Danish Anwar]

Extend the Texas Instruments K3 R5F remoteproc device tree bindings to
include a 'rpmsg-eth' subnode.

This extension allows the RPMsg Ethernet to be defined as a subnode of
K3 R5F remoteproc nodes, enabling the configuration of shared memory-based
Ethernet communication between the host and remote processors.

Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
---
 .../devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml     | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Documentation/devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml b/Documentation/devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml
index a492f74a8608..4dbd708ec8ee 100644
--- a/Documentation/devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml
+++ b/Documentation/devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml
@@ -210,6 +210,12 @@ patternProperties:
           should be defined as per the generic bindings in,
           Documentation/devicetree/bindings/sram/sram.yaml
 
+      rpmsg-eth:
+        $ref: /schemas/net/ti,rpmsg-eth.yaml
+        description:
+          RPMsg Ethernet subnode which represents the communication interface
+          between host processor and remote processor.
+
     required:
       - compatible
       - reg
-- 
2.34.1

[PATCH net-next v2 3/8] net: rpmsg-eth: Add Documentation for RPMSG-ETH Driver

[MD Danish Anwar]

Add documentation for the RPMSG Based Virtual Ethernet Driver (rpmsg-eth).
The documentation describes the driver's architecture, shared memory
layout, RPMSG communication protocol, and requirements for vendor firmware
to interoperate with the driver. It details the use of a magic number for
shared memory validation, outlines the information exchanged between the
host and remote processor, and provides a how-to guide for vendors to
implement compatible firmware.

Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
---
 .../device_drivers/ethernet/index.rst         |   1 +
 .../device_drivers/ethernet/rpmsg_eth.rst     | 368 ++++++++++++++++++
 2 files changed, 369 insertions(+)
 create mode 100644 Documentation/networking/device_drivers/ethernet/rpmsg_eth.rst

diff --git a/Documentation/networking/device_drivers/ethernet/index.rst b/Documentation/networking/device_drivers/ethernet/index.rst
index 0b0a3eef6aae..20513a595af1 100644
--- a/Documentation/networking/device_drivers/ethernet/index.rst
+++ b/Documentation/networking/device_drivers/ethernet/index.rst
@@ -51,6 +51,7 @@ Contents:
    netronome/nfp
    pensando/ionic
    qualcomm/ppe/ppe
+   rpmsg_eth
    smsc/smc9
    stmicro/stmmac
    ti/cpsw
diff --git a/Documentation/networking/device_drivers/ethernet/rpmsg_eth.rst b/Documentation/networking/device_drivers/ethernet/rpmsg_eth.rst
new file mode 100644
index 000000000000..f39363645df3
--- /dev/null
+++ b/Documentation/networking/device_drivers/ethernet/rpmsg_eth.rst
@@ -0,0 +1,368 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+===================================
+RPMSG Based Virtual Ethernet Driver
+===================================
+
+Overview
+========
+
+The RPMSG Based Virtual Ethernet Driver provides a virtual Ethernet interface for
+communication between a host processor and a remote processor using the RPMSG
+framework. This driver enables Ethernet-like packet transmission and reception
+over shared memory, facilitating inter-core communication in systems with
+heterogeneous processors.
+
+The driver is designed to work with the RPMSG framework, which is part of the
+Linux Remote Processor (remoteproc) subsystem. It uses shared memory for data
+exchange and supports features like multicast address management, dynamic MAC
+address assignment, and efficient packet processing using NAPI.
+
+This driver is generic and can be used by any vendor. Vendors can develop their
+own firmware for the remote processor to make it compatible with this driver.
+The firmware must adhere to the shared memory layout, RPMSG communication
+protocol, and data exchange requirements described in this documentation.
+
+Naming Convention
+=================
+
+Throughout this documentation and in the driver implementation, the following naming
+convention is used to describe the direction of communication:
+
+- **Firmware**: The firmware / RTOS binary running on the remote core. This takes the primary role.
+- **Driver**: The Linux driver running on the host core. This takes the secondary role.
+
+This convention is important for understanding the data flow and the responsibilities
+of each side in the communication channel.
+
+Key Features
+============
+
+- Virtual Ethernet interface using RPMSG.
+- Shared memory-based packet transmission and reception.
+- Support for multicast address management.
+- Dynamic MAC address assignment.
+- NAPI (New API) support for efficient packet processing.
+- State machine for managing interface states.
+- Workqueue-based asynchronous operations.
+- Support for notifications and responses from the firmware.
+
+Magic Number
+============
+
+A **magic number** is used in the shared memory layout to validate that the
+memory region is correctly initialized and accessible by both driver and the
+firmware. This value is a unique constant ``0xABCDABCD`` that is written to
+specific locations (such as the head and tail structures) in the shared memory
+by the firmware and checked by the driver during the handshake process.
+
+Purpose of the Magic Number
+---------------------------
+
+- **Validation:** Ensures that the shared memory region has been properly set up
+  and is not corrupted or uninitialized.
+- **Synchronization:** Both driver and firmware must agree on the magic number
+  value, which helps detect mismatches in memory layout or protocol version.
+- **Error Detection:** If the driver detects an incorrect magic number during
+  initialization or runtime, it can abort the handshake and report an error,
+  preventing undefined behavior.
+
+Implementation Details
+----------------------
+
+- The magic number is defined as a macro in the driver source (e.g.,
+  ``#define RPMSG_ETH_SHM_MAGIC_NUM 0xABCDABCD``).
+- The firmware must write this value to the ``magic_num`` field of the head and
+  tail structures in the shared memory region.
+- During the handshake, the Linux driver reads these fields and compares them to
+  the expected value. If any mismatch is detected, the driver will log an error
+  and refuse to proceed.
+
+Example Usage in Shared Memory
+------------------------------
+
+.. code-block:: text
+
+      Shared Memory Layout:
+      ---------------------------
+      |   MAGIC_NUM (0xABCDABCD) |   <-- rpmsg_eth_shm_head
+      |          HEAD            |
+      ---------------------------
+      |   MAGIC_NUM (0xABCDABCD) |   <-- rpmsg_eth_shm_tail
+      |          TAIL            |
+      ---------------------------
+
+The magic number must be present in both the head and tail structures for the
+handshake to succeed.
+
+Firmware developers must ensure that the correct magic number is written to the
+appropriate locations in shared memory before the Linux driver attempts to
+initialize the interface.
+
+Shared Memory Layout
+====================
+
+The RPMSG Based Virtual Ethernet Driver uses a shared memory region to exchange
+data between driver and firmware. The shared memory is divided into transmit
+and receive regions, each with its own `head` and `tail` indices to track the
+buffer state. The base address of this shared memory is configured in the
+device tree. See :ref:`Configuration <rpmsg_config>` for details.
+
+Shared Memory Parameters
+------------------------
+
+The following parameters are exchanged between the driver and the firmware to
+configure the shared memory layout:
+
+1. **num_pkt_bufs**:
+
+   - The total number of packet buffers available in the shared memory.
+   - This determines the maximum number of packets that can be stored in the
+     shared memory at any given time.
+
+2. **buff_slot_size**:
+
+   - The size of each buffer slot in the shared memory.
+   - This includes space for the packet length, metadata, and the actual packet
+     data.
+
+3. **tx_offset**:
+
+   - The offset from the `base_addr` where the transmit buffers begin.
+   - This is used by driver to write packets for transmission.
+
+4. **rx_offset**:
+
+   - The offset from the `base_addr` where the receive buffers begin.
+   - This is used by driver to read packets received from the firmware.
+
+Shared Memory Structure
+-----------------------
+
+The shared memory layout is as follows:
+
+.. code-block:: text
+
+      Shared Memory Layout:
+      ---------------------------
+      |        MAGIC_NUM        |   rpmsg_eth_shm_head
+      |        HEAD_IDX         |
+      ---------------------------
+      |        MAGIC_NUM        |
+      |        PKT_1_LEN        |
+      |          PKT_1          |
+      ---------------------------
+      |           ...           |
+      ---------------------------
+      |        MAGIC_NUM        |
+      |        TAIL_IDX         |   rpmsg_eth_shm_tail
+      ---------------------------
+
+1. **MAGIC_NUM**:
+
+   - A unique identifier used to validate the shared memory region.
+   - Ensures that the memory region is correctly initialized and accessible.
+
+2. **HEAD Index**:
+
+   - Tracks the start of the buffer for packet transmission or reception.
+   - Updated by the producer (Driver or firmware) after writing a packet.
+
+3. **TAIL Index**:
+
+   - Tracks the end of the buffer for packet transmission or reception.
+   - Updated by the consumer (Driver or firmware) after reading a packet.
+
+4. **Packet Buffers**:
+
+   - Each packet buffer contains:
+
+      - **Packet Length**: A 4-byte field indicating the size of the packet.
+      - **Packet Data**: The actual Ethernet frame data.
+
+5. **Buffer Size**:
+
+   - Each buffer has a fixed size defined by `RPMSG_ETH_BUFFER_SIZE`, which
+     includes space for the packet length and data.
+
+Buffer Management
+-----------------
+
+- The driver and firmware use a circular buffer mechanism to manage the shared
+  memory.
+- The `head` and `tail` indices are used to determine the number of packets
+  available for processing:
+
+   .. code-block:: c
+
+         num_pkts = head - tail;
+         num_pkts = num_pkts >= 0 ? num_pkts : (num_pkts + max_buffers);
+
+- The producer writes packets to the buffer and increments the `head` index.
+- The consumer reads packets from the buffer and increments the `tail` index.
+
+RPMSG Communication
+===================
+
+The driver uses RPMSG channels to exchange control messages with the firmware.
+These messages are used to manage the state of the Ethernet interface,
+configure settings, notify events, and exchange runtime information.
+
+Information Exchanged Between RPMSG Channels
+--------------------------------------------
+
+1. **Requests from Driver to Firmware**:
+
+   - `RPMSG_ETH_REQ_SHM_INFO`: Request shared memory information, such as
+     ``num_pkt_bufs``, ``buff_slot_size``, ``tx_offset``, and
+     ``rx_offset``.
+   - `RPMSG_ETH_REQ_SET_MAC_ADDR`: Set the MAC address of the Ethernet
+     interface.
+   - `RPMSG_ETH_REQ_ADD_MC_ADDR`: Add a multicast address to the firmware's
+     filter list.
+   - `RPMSG_ETH_REQ_DEL_MC_ADDR`: Remove a multicast address from firmware's
+     filter list.
+
+2. **Responses from Firmware to Driver**:
+
+   - `RPMSG_ETH_RESP_SET_MAC_ADDR`: Acknowledge the MAC address configuration.
+   - `RPMSG_ETH_RESP_ADD_MC_ADDR`: Acknowledge the addition of a multicast
+     address.
+   - `RPMSG_ETH_RESP_DEL_MC_ADDR`: Acknowledge the removal of a multicast
+     address.
+   - `RPMSG_ETH_RESP_SHM_INFO`: Respond with shared memory information such as
+     ``num_pkt_bufs``, ``buff_slot_size``, ``tx_offset``, and
+     ``rx_offset``.
+
+3. **Notifications from Firmware to Driver**:
+
+   - `RPMSG_ETH_NOTIFY_PORT_UP`: Notify that the Ethernet port is up and ready
+     for communication.
+   - `RPMSG_ETH_NOTIFY_PORT_DOWN`: Notify that the Ethernet port is down.
+   - `RPMSG_ETH_NOTIFY_REMOTE_READY`: Notify that the firmware is ready for
+     communication.
+
+4. **Runtime Information Exchanged**:
+
+   - **Link State**: Notifications about link state changes (e.g., link up or
+     link down).
+   - **Statistics**: Runtime statistics such as transmitted/received packets,
+     errors, and dropped packets.
+   - **Error Notifications**: Notifications about errors like buffer overflows
+     or invalid packets.
+   - **Configuration Updates**: Notifications about changes in configuration,
+     such as updated MTU or VLAN settings.
+
+How-To Guide for Vendors
+========================
+
+This section provides a guide for vendors to develop firmware for the remote
+processor that is compatible with the RPMSG Based Virtual Ethernet Driver.
+
+1. **Implement Shared Memory Layout**:
+
+   - Allocate a shared memory region for packet transmission and reception.
+   - Initialize the `MAGIC_NUM`, `num_pkt_bufs`, `buff_slot_size`, `tx_offset`,
+     and `rx_offset`.
+
+2. **Magic Number Requirements**
+
+   - The firmware must write a unique magic number ``0xABCDABCD`` to the
+     `magic_num` field of both the head and tail structures in the shared
+     memory region.
+   - This magic number is used by the Linux driver to validate that the shared
+     memory region is correctly initialized and accessible.
+   - If the driver detects an incorrect magic number during the handshake, it
+     will abort initialization and report an error.
+   - Vendors must ensure the magic number matches the value expected by the
+     Linux driver, see the `RPMSG_ETH_SHM_MAGIC_NUM` macro in the driver
+     source.
+
+3. **Handle RPMSG Requests**:
+
+   - Implement handlers for the following RPMSG requests:
+
+      - `RPMSG_ETH_REQ_SHM_INFO`
+      - `RPMSG_ETH_REQ_SET_MAC_ADDR`
+      - `RPMSG_ETH_REQ_ADD_MC_ADDR`
+      - `RPMSG_ETH_REQ_DEL_MC_ADDR`
+
+4. **Send RPMSG Notifications**:
+
+   - Notify the Driver about the state of the Ethernet interface using the
+     notifications described above.
+
+5. **Send Runtime Information**:
+
+   - Implement mechanisms to send runtime information such as link state
+     changes, statistics, and error notifications.
+
+6. **Implement Packet Processing**:
+
+   - Process packets in the shared memory transmit and receive buffers.
+
+7. **Test the Firmware**:
+
+   - Use the RPMSG Based Virtual Ethernet Driver on the host to test packet
+     transmission and reception.
+
+.. _rpmsg_config:
+
+Configuration
+=============
+
+The driver relies on the device tree for configuration. The RPMsg Ethernet device
+is specified as a child node of the remote processor device, and it references a
+shared memory region.
+
+Example Device Tree Node
+------------------------
+The RPMsg Ethernet device is represented by the ``rpmsg-eth`` node, which is a
+child of the remote processor device. The shared memory region is specified
+using the ``memory-region`` property, which references a ``shared-dma-pool`` node.
+
+Here is an example of how the device tree node might look:
+
+.. code-block:: dts
+
+    <memory_region> {
+        compatible = "shared-dma-pool";
+        reg = <base_address size>;
+    };
+
+    <rproc_device> {
+        rpmsg-eth {
+            memory-region = <&<memory_region>>;
+        };
+    };
+
+In this example, ``<rproc_device>`` is the remote processor device node, and
+``<memory_region>`` is the shared memory region node. The ``rpmsg-eth`` node is
+a child of the remote processor device node, and it references the shared memory
+region node using the ``memory-region`` property.
+
+Vendors can create their own RPMsg Ethernet device node by replacing
+``<rproc_device>`` with their remote processor device node, and
+``<memory_region>`` with their shared memory region node.
+
+Limitations
+===========
+
+- The driver assumes a specific shared memory layout and may not work with other
+  configurations.
+- The driver currently supports only one transmit and one receive queue.
+- The current implementation only supports Linux driver running on the "host"
+  core as secondary and firmware running on the "remote" core as primary. It
+  does not support Linux-to-Linux communication where Linux driver would run on
+  both ends.
+
+References
+==========
+
+- :doc:`RPMSG Framework documentation </staging/rpmsg>`
+- :doc:`Network device documentation </networking/index>`
+
+Authors
+=======
+
+- MD Danish Anwar <danishanwar@ti.com>
-- 
2.34.1

[PATCH net-next v2 4/8] net: rpmsg-eth: Add basic rpmsg skeleton

[MD Danish Anwar]

Introduces a basic RPMSG Ethernet driver and add it's basic skeleton.
Add support for creating virtual Ethernet devices over RPMSG channels,
allowing user-space programs to send and receive messages using a
standard Ethernet protocol. The driver includes message handling,
probe, and remove functions, along with necessary data structures.

Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
---
 drivers/net/ethernet/Kconfig     |  10 +++
 drivers/net/ethernet/Makefile    |   1 +
 drivers/net/ethernet/rpmsg_eth.c | 142 +++++++++++++++++++++++++++++++
 drivers/net/ethernet/rpmsg_eth.h |  75 ++++++++++++++++
 4 files changed, 228 insertions(+)
 create mode 100644 drivers/net/ethernet/rpmsg_eth.c
 create mode 100644 drivers/net/ethernet/rpmsg_eth.h

diff --git a/drivers/net/ethernet/Kconfig b/drivers/net/ethernet/Kconfig
index f86d4557d8d7..a73a45a9ef3d 100644
--- a/drivers/net/ethernet/Kconfig
+++ b/drivers/net/ethernet/Kconfig
@@ -170,6 +170,16 @@ config OA_TC6
 	  To know the implementation details, refer documentation in
 	  <file:Documentation/networking/oa-tc6-framework.rst>.
 
+config RPMSG_ETH
+	tristate "RPMsg Based Virtual Ethernet driver"
+	depends on RPMSG
+	help
+	  This makes it possible for user-space programs to send and receive
+	  rpmsg messages as a standard eth protocol.
+
+	  To compile this driver as a module, choose M here: the module will be
+	  called rpmsg_eth.
+
 source "drivers/net/ethernet/packetengines/Kconfig"
 source "drivers/net/ethernet/pasemi/Kconfig"
 source "drivers/net/ethernet/pensando/Kconfig"
diff --git a/drivers/net/ethernet/Makefile b/drivers/net/ethernet/Makefile
index 67182339469a..aebd15993e3c 100644
--- a/drivers/net/ethernet/Makefile
+++ b/drivers/net/ethernet/Makefile
@@ -107,3 +107,4 @@ obj-$(CONFIG_NET_VENDOR_XIRCOM) += xircom/
 obj-$(CONFIG_NET_VENDOR_SYNOPSYS) += synopsys/
 obj-$(CONFIG_NET_VENDOR_PENSANDO) += pensando/
 obj-$(CONFIG_OA_TC6) += oa_tc6.o
+obj-$(CONFIG_RPMSG_ETH) += rpmsg_eth.o
diff --git a/drivers/net/ethernet/rpmsg_eth.c b/drivers/net/ethernet/rpmsg_eth.c
new file mode 100644
index 000000000000..4cfd9ff2f142
--- /dev/null
+++ b/drivers/net/ethernet/rpmsg_eth.c
@@ -0,0 +1,142 @@
+// SPDX-License-Identifier: GPL-2.0
+/* RPMsg Based Virtual Ethernet Driver
+ *
+ * Copyright (C) 2025 Texas Instruments Incorporated - https://www.ti.com/
+ */
+
+#include <linux/of.h>
+#include <linux/of_reserved_mem.h>
+#include <linux/remoteproc.h>
+#include "rpmsg_eth.h"
+
+static int rpmsg_eth_rpmsg_cb(struct rpmsg_device *rpdev, void *data, int len,
+			      void *priv, u32 src)
+{
+	struct rpmsg_eth_common *common = dev_get_drvdata(&rpdev->dev);
+	struct message *msg = (struct message *)data;
+	u32 msg_type = msg->msg_hdr.msg_type;
+	int ret = 0;
+
+	switch (msg_type) {
+	case RPMSG_ETH_REQUEST_MSG:
+	case RPMSG_ETH_RESPONSE_MSG:
+	case RPMSG_ETH_NOTIFY_MSG:
+		dev_dbg(common->dev, "Msg type = %d, Src Id = %d\n",
+			msg_type, msg->msg_hdr.src_id);
+		break;
+	default:
+		dev_err(common->dev, "Invalid msg type\n");
+		ret = -EINVAL;
+		break;
+	}
+	return ret;
+}
+
+/**
+ * rpmsg_eth_get_shm_info - Retrieve shared memory region for RPMsg Ethernet
+ * @common: Pointer to rpmsg_eth_common structure
+ *
+ * This function locates and maps the reserved memory region for the RPMsg
+ * Ethernet device by traversing the device tree hierarchy. It first identifies
+ * the associated remote processor (rproc), then locates the "rpmsg-eth" child
+ * node within the rproc's device tree node, and finally retrieves the
+ * "memory-region" phandle that points to the reserved memory region.
+ * Once found, the shared memory region is mapped into the
+ * kernel's virtual address space using devm_ioremap()
+ *
+ * Return: 0 on success, negative error code on failure.
+ */
+static int rpmsg_eth_get_shm_info(struct rpmsg_eth_common *common)
+{
+	struct device_node *np, *rpmsg_eth_node, *rmem_np;
+	struct reserved_mem *rmem;
+	struct rproc *rproc;
+
+	/* Get the remote processor associated with this device */
+	rproc = rproc_get_by_child(&common->rpdev->dev);
+	if (!rproc) {
+		dev_err(common->dev, "rpmsg eth device not child of rproc\n");
+		return -EINVAL;
+	}
+
+	/* Get the device node from rproc or its parent */
+	np = rproc->dev.of_node ?: (rproc->dev.parent ? rproc->dev.parent->of_node : NULL);
+	if (!np) {
+		dev_err(common->dev, "Cannot find rproc device node\n");
+		return -ENODEV;
+	}
+
+	/* Get the rpmsg-eth child node */
+	rpmsg_eth_node = of_get_child_by_name(np, "rpmsg-eth");
+	if (!rpmsg_eth_node) {
+		dev_err(common->dev, "Couldn't get rpmsg-eth node from np\n");
+		return -ENODEV;
+	}
+
+	/* Parse the memory-region phandle */
+	rmem_np = of_parse_phandle(rpmsg_eth_node, "memory-region", 0);
+	of_node_put(rpmsg_eth_node);
+	if (!rmem_np)
+		return -EINVAL;
+
+	/* Lookup the reserved memory region */
+	rmem = of_reserved_mem_lookup(rmem_np);
+	of_node_put(rmem_np);
+	if (!rmem)
+		return -EINVAL;
+
+	common->port->shm = devm_ioremap(common->dev, rmem->base, rmem->size);
+	if (IS_ERR(common->port->shm))
+		return PTR_ERR(common->port->shm);
+
+	common->port->buf_size = rmem->size;
+
+	return 0;
+}
+
+static int rpmsg_eth_probe(struct rpmsg_device *rpdev)
+{
+	struct device *dev = &rpdev->dev;
+	struct rpmsg_eth_common *common;
+	int ret = 0;
+
+	common = devm_kzalloc(&rpdev->dev, sizeof(*common), GFP_KERNEL);
+	if (!common)
+		return -ENOMEM;
+
+	dev_set_drvdata(dev, common);
+
+	common->port = devm_kzalloc(dev, sizeof(*common->port), GFP_KERNEL);
+	common->dev = dev;
+	common->rpdev = rpdev;
+
+	ret = rpmsg_eth_get_shm_info(common);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static void rpmsg_eth_remove(struct rpmsg_device *rpdev)
+{
+	dev_dbg(&rpdev->dev, "rpmsg-eth client driver is removed\n");
+}
+
+static struct rpmsg_device_id rpmsg_eth_rpmsg_id_table[] = {
+	{ .name = "shm-eth" },
+	{},
+};
+MODULE_DEVICE_TABLE(rpmsg, rpmsg_eth_rpmsg_id_table);
+
+static struct rpmsg_driver rpmsg_eth_rpmsg_client = {
+	.drv.name = KBUILD_MODNAME,
+	.id_table = rpmsg_eth_rpmsg_id_table,
+	.probe = rpmsg_eth_probe,
+	.callback = rpmsg_eth_rpmsg_cb,
+	.remove = rpmsg_eth_remove,
+};
+module_rpmsg_driver(rpmsg_eth_rpmsg_client);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("MD Danish Anwar <danishanwar@ti.com>");
+MODULE_DESCRIPTION("RPMsg Based Virtual Ethernet driver");
diff --git a/drivers/net/ethernet/rpmsg_eth.h b/drivers/net/ethernet/rpmsg_eth.h
new file mode 100644
index 000000000000..12be1c35eff8
--- /dev/null
+++ b/drivers/net/ethernet/rpmsg_eth.h
@@ -0,0 +1,75 @@
+/* SPDX-License-Identifier: GPL-2.0
+ * RPMsg Based Virtual Ethernet Driver common header
+ *
+ * Copyright (C) 2025 Texas Instruments Incorporated - https://www.ti.com/
+ */
+
+#ifndef __RPMSG_ETH_H__
+#define __RPMSG_ETH_H__
+
+#include <linux/errno.h>
+#include <linux/etherdevice.h>
+#include <linux/if_ether.h>
+#include <linux/if_vlan.h>
+#include <linux/jiffies.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/rpmsg.h>
+
+#define RPMSG_ETH_SHM_MAGIC_NUM 0xABCDABCD
+
+enum rpmsg_eth_msg_type {
+	RPMSG_ETH_REQUEST_MSG = 0,
+	RPMSG_ETH_RESPONSE_MSG,
+	RPMSG_ETH_NOTIFY_MSG,
+};
+
+/**
+ * struct message_header - message header structure for RPMSG Ethernet
+ * @src_id: Source endpoint ID
+ * @msg_type: Message type
+ */
+struct message_header {
+	u32 src_id;
+	u32 msg_type;
+} __packed;
+
+/**
+ * struct message - RPMSG Ethernet message structure
+ *
+ * @msg_hdr: Message header contains source and destination endpoint and
+ *          the type of message
+ *
+ * This structure is used to send and receive messages between the RPMSG
+ * Ethernet ports.
+ */
+struct message {
+	struct message_header msg_hdr;
+} __packed;
+
+/**
+ * struct rpmsg_eth_common - common structure for RPMSG Ethernet
+ * @rpdev: RPMSG device
+ * @port: Ethernet port
+ * @dev: Device
+ */
+struct rpmsg_eth_common {
+	struct rpmsg_device *rpdev;
+	struct rpmsg_eth_port *port;
+	struct device *dev;
+};
+
+/**
+ * struct rpmsg_eth_port - Ethernet port structure for RPMSG Ethernet
+ * @common: Pointer to the common RPMSG Ethernet structure
+ * @shm: Shared memory region mapping
+ * @buf_size: Size (in bytes) of the shared memory buffer for this port
+ */
+struct rpmsg_eth_port {
+	struct rpmsg_eth_common *common;
+	void __iomem *shm;
+	phys_addr_t buf_size;
+};
+
+#endif /* __RPMSG_ETH_H__ */
-- 
2.34.1

[PATCH net-next v2 5/8] net: rpmsg-eth: Register device as netdev

[MD Danish Anwar]

Register the rpmsg-eth device as a netdev and enhance the rpmsg callback
function to handle shared memory for tx and rx buffers. Introduce
structures for shared memory layout, including head, buffer, and tail
indices. Add initialization for the netdev, including setting up MAC
address, MTU, and netdev operations. Allocate memory for tx and rx
buffers and map shared memory regions. Update the probe function to
initialize the netdev and set the device state. Add necessary headers,
constants, and enums for shared memory and state management. Define
shared memory layout and buffer structures for efficient data handling.
Implement helper macros for accessing private data and shared memory
buffers. Ensure proper error handling during memory allocation and
device registration.

Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
---
 drivers/net/ethernet/rpmsg_eth.c | 120 ++++++++++++++++++-
 drivers/net/ethernet/rpmsg_eth.h | 194 +++++++++++++++++++++++++++++++
 2 files changed, 312 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/rpmsg_eth.c b/drivers/net/ethernet/rpmsg_eth.c
index 4cfd9ff2f142..b6fe5628933d 100644
--- a/drivers/net/ethernet/rpmsg_eth.c
+++ b/drivers/net/ethernet/rpmsg_eth.c
@@ -9,20 +9,89 @@
 #include <linux/remoteproc.h>
 #include "rpmsg_eth.h"
 
+/**
+ * rpmsg_eth_validate_handshake - Validate handshake parameters from remote
+ * @port: Pointer to rpmsg_eth_port structure
+ * @shm_info: Pointer to shared memory info received from remote
+ *
+ * Checks buffer size, magic numbers, and TX/RX offsets in the handshake
+ * response to ensure they match expected values and are within valid ranges.
+ *
+ * Return: 0 on success, -EINVAL on validation failure.
+ */
+static int rpmsg_eth_validate_handshake(struct rpmsg_eth_port *port,
+					struct rpmsg_eth_shm *shm_info)
+{
+	if (shm_info->buff_slot_size != RPMSG_ETH_BUFFER_SIZE) {
+		dev_err(port->common->dev, "Buffer configuration mismatch in handshake: expected_buf_size=%lu, received_buf_size=%d\n",
+			RPMSG_ETH_BUFFER_SIZE,
+			shm_info->buff_slot_size);
+		return -EINVAL;
+	}
+
+	if (readl(port->shm + port->tx_offset + HEAD_MAGIC_NUM_OFFSET) != RPMSG_ETH_SHM_MAGIC_NUM ||
+	    readl(port->shm + port->rx_offset + HEAD_MAGIC_NUM_OFFSET) != RPMSG_ETH_SHM_MAGIC_NUM ||
+	    readl(port->shm + port->tx_offset + TAIL_MAGIC_NUM_OFFSET(port->tx_max_buffers)) != RPMSG_ETH_SHM_MAGIC_NUM ||
+	    readl(port->shm + port->rx_offset + TAIL_MAGIC_NUM_OFFSET(port->rx_max_buffers)) != RPMSG_ETH_SHM_MAGIC_NUM) {
+		dev_err(port->common->dev, "Magic number mismatch in handshake at head/tail\n");
+		return -EINVAL;
+	}
+
+	if (shm_info->tx_offset >= port->buf_size ||
+	    shm_info->rx_offset >= port->buf_size) {
+		dev_err(port->common->dev, "TX/RX offset out of range in handshake: tx_offset=0x%x, rx_offset=0x%x, size=0x%llx\n",
+			shm_info->tx_offset,
+			shm_info->rx_offset,
+			port->buf_size);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 static int rpmsg_eth_rpmsg_cb(struct rpmsg_device *rpdev, void *data, int len,
 			      void *priv, u32 src)
 {
 	struct rpmsg_eth_common *common = dev_get_drvdata(&rpdev->dev);
 	struct message *msg = (struct message *)data;
+	struct rpmsg_eth_port *port = common->port;
 	u32 msg_type = msg->msg_hdr.msg_type;
+	u32 rpmsg_type;
 	int ret = 0;
 
 	switch (msg_type) {
 	case RPMSG_ETH_REQUEST_MSG:
+		rpmsg_type = msg->req_msg.type;
+		dev_dbg(common->dev, "Msg type = %d, RPMsg type = %d, Src Id = %d, Msg Id = %d\n",
+			msg_type, rpmsg_type, msg->msg_hdr.src_id, msg->req_msg.id);
+		break;
 	case RPMSG_ETH_RESPONSE_MSG:
+		rpmsg_type = msg->resp_msg.type;
+		dev_dbg(common->dev, "Msg type = %d, RPMsg type = %d, Src Id = %d, Msg Id = %d\n",
+			msg_type, rpmsg_type, msg->msg_hdr.src_id, msg->resp_msg.id);
+		switch (rpmsg_type) {
+		case RPMSG_ETH_RESP_SHM_INFO:
+			/* Retrieve Tx and Rx shared memory info from msg */
+			port->tx_offset = msg->resp_msg.shm_info.tx_offset;
+			port->rx_offset = msg->resp_msg.shm_info.rx_offset;
+			port->tx_max_buffers =
+				msg->resp_msg.shm_info.num_pkt_bufs;
+			port->rx_max_buffers =
+				msg->resp_msg.shm_info.num_pkt_bufs;
+
+			/* Handshake validation */
+			ret = rpmsg_eth_validate_handshake(port, &msg->resp_msg.shm_info);
+			if (ret) {
+				dev_err(common->dev, "RPMSG handshake failed %d\n", ret);
+				return ret;
+			}
+			break;
+		}
+		break;
 	case RPMSG_ETH_NOTIFY_MSG:
-		dev_dbg(common->dev, "Msg type = %d, Src Id = %d\n",
-			msg_type, msg->msg_hdr.src_id);
+		rpmsg_type = msg->notify_msg.type;
+		dev_dbg(common->dev, "Msg type = %d, RPMsg type = %d, Src Id = %d, Msg Id = %d\n",
+			msg_type, rpmsg_type, msg->msg_hdr.src_id, msg->notify_msg.id);
 		break;
 	default:
 		dev_err(common->dev, "Invalid msg type\n");
@@ -94,6 +163,47 @@ static int rpmsg_eth_get_shm_info(struct rpmsg_eth_common *common)
 	return 0;
 }
 
+static int rpmsg_eth_init_ndev(struct rpmsg_eth_common *common)
+{
+	struct device *dev = &common->rpdev->dev;
+	struct rpmsg_eth_ndev_priv *ndev_priv;
+	struct rpmsg_eth_port *port;
+	static u32 port_id;
+	int err = 0;
+
+	port = common->port;
+	port->common = common;
+	port->port_id = port_id++;
+
+	port->ndev = devm_alloc_etherdev_mqs(common->dev, sizeof(*ndev_priv),
+					     RPMSG_ETH_MAX_TX_QUEUES,
+					     RPMSG_ETH_MAX_RX_QUEUES);
+
+	if (!port->ndev) {
+		dev_err(dev, "error allocating net_device\n");
+		return -ENOMEM;
+	}
+
+	ndev_priv = netdev_priv(port->ndev);
+	ndev_priv->port = port;
+	SET_NETDEV_DEV(port->ndev, dev);
+
+	port->ndev->min_mtu = RPMSG_ETH_MIN_PACKET_SIZE;
+	port->ndev->max_mtu = MAX_MTU;
+
+	if (!is_valid_ether_addr(port->ndev->dev_addr)) {
+		eth_hw_addr_random(port->ndev);
+		dev_dbg(dev, "Using random MAC address %pM\n", port->ndev->dev_addr);
+	}
+
+	netif_carrier_off(port->ndev);
+	err = register_netdev(port->ndev);
+	if (err)
+		dev_err(dev, "error registering rpmsg_eth net device %d\n", err);
+
+	return err;
+}
+
 static int rpmsg_eth_probe(struct rpmsg_device *rpdev)
 {
 	struct device *dev = &rpdev->dev;
@@ -109,11 +219,17 @@ static int rpmsg_eth_probe(struct rpmsg_device *rpdev)
 	common->port = devm_kzalloc(dev, sizeof(*common->port), GFP_KERNEL);
 	common->dev = dev;
 	common->rpdev = rpdev;
+	common->state = RPMSG_ETH_STATE_PROBE;
 
 	ret = rpmsg_eth_get_shm_info(common);
 	if (ret)
 		return ret;
 
+	/* Register the network device */
+	ret = rpmsg_eth_init_ndev(common);
+	if (ret)
+		return ret;
+
 	return 0;
 }
 
diff --git a/drivers/net/ethernet/rpmsg_eth.h b/drivers/net/ethernet/rpmsg_eth.h
index 12be1c35eff8..0c2ae89fbfbf 100644
--- a/drivers/net/ethernet/rpmsg_eth.h
+++ b/drivers/net/ethernet/rpmsg_eth.h
@@ -18,6 +18,34 @@
 #include <linux/rpmsg.h>
 
 #define RPMSG_ETH_SHM_MAGIC_NUM 0xABCDABCD
+#define RPMSG_ETH_MIN_PACKET_SIZE ETH_ZLEN
+#define RPMSG_ETH_PACKET_BUFFER_SIZE   1540
+#define MAX_MTU   (RPMSG_ETH_PACKET_BUFFER_SIZE - (ETH_HLEN + ETH_FCS_LEN + VLAN_HLEN))
+
+#define RPMSG_ETH_MAX_TX_QUEUES 1
+#define RPMSG_ETH_MAX_RX_QUEUES 1
+#define PKT_LEN_SIZE_TYPE sizeof(u32)
+#define MAGIC_NUM_SIZE_TYPE sizeof(u32)
+
+/* 4 bytes to hold packet length and RPMSG_ETH_PACKET_BUFFER_SIZE to hold packet */
+#define RPMSG_ETH_BUFFER_SIZE \
+	(RPMSG_ETH_PACKET_BUFFER_SIZE + PKT_LEN_SIZE_TYPE + MAGIC_NUM_SIZE_TYPE)
+
+#define RX_POLL_TIMEOUT_JIFFIES usecs_to_jiffies(1000)
+#define RX_POLL_JIFFIES (jiffies + RX_POLL_TIMEOUT_JIFFIES)
+#define STATE_MACHINE_TIME_JIFFIES msecs_to_jiffies(100)
+#define RPMSG_ETH_REQ_TIMEOUT_JIFFIES msecs_to_jiffies(100)
+
+#define HEAD_MAGIC_NUM_OFFSET 0x0
+#define HEAD_IDX_OFFSET (HEAD_MAGIC_NUM_OFFSET + MAGIC_NUM_SIZE_TYPE)
+#define PKT_START_OFFSET(n) \
+	((HEAD_IDX_OFFSET + MAGIC_NUM_SIZE_TYPE) + ((n) * RPMSG_ETH_BUFFER_SIZE))
+#define TAIL_MAGIC_NUM_OFFSET(n) PKT_START_OFFSET((n))
+#define TAIL_IDX_OFFSET(n) (TAIL_MAGIC_NUM_OFFSET((n)) + MAGIC_NUM_SIZE_TYPE)
+
+#define rpmsg_eth_ndev_to_priv(ndev) ((struct rpmsg_eth_ndev_priv *)netdev_priv(ndev))
+#define rpmsg_eth_ndev_to_port(ndev) (rpmsg_eth_ndev_to_priv(ndev)->port)
+#define rpmsg_eth_ndev_to_common(ndev) (rpmsg_eth_ndev_to_port(ndev)->common)
 
 enum rpmsg_eth_msg_type {
 	RPMSG_ETH_REQUEST_MSG = 0,
@@ -25,6 +53,87 @@ enum rpmsg_eth_msg_type {
 	RPMSG_ETH_NOTIFY_MSG,
 };
 
+enum rpmsg_eth_rpmsg_type {
+	/* Request types */
+	RPMSG_ETH_REQ_SHM_INFO = 0,
+	RPMSG_ETH_REQ_SET_MAC_ADDR,
+
+	/* Response types */
+	RPMSG_ETH_RESP_SHM_INFO,
+	RPMSG_ETH_RESP_SET_MAC_ADDR,
+
+	/* Notification types */
+	RPMSG_ETH_NOTIFY_PORT_UP,
+	RPMSG_ETH_NOTIFY_PORT_DOWN,
+	RPMSG_ETH_NOTIFY_PORT_READY,
+	RPMSG_ETH_NOTIFY_REMOTE_READY,
+};
+
+/**
+ * struct rpmsg_eth_shm - Shared memory layout for RPMsg Ethernet
+ * @num_pkt_bufs: Number of packet buffers available in the shared memory
+ * @buff_slot_size: Size of each buffer slot in bytes
+ * @tx_offset: Offset for the transmit buffer region within the shared memory
+ * @rx_offset: Offset for the receive buffer region within the shared memory
+ *
+ * This structure defines the layout of the shared memory used for
+ * communication between the host and the remote processor in an RPMsg
+ * Ethernet driver. It specifies the configuration and memory offsets
+ * required for transmitting and receiving Ethernet packets.
+ */
+struct rpmsg_eth_shm {
+	u32 num_pkt_bufs;
+	u32 buff_slot_size;
+	u32 tx_offset;
+	u32 rx_offset;
+} __packed;
+
+/**
+ * struct rpmsg_eth_mac_addr - MAC address information for RPMSG Ethernet
+ * @addr: MAC address
+ */
+struct rpmsg_eth_mac_addr {
+	char addr[ETH_ALEN];
+} __packed;
+
+/**
+ * struct request_message - request message structure for RPMSG Ethernet
+ * @type: Request Type
+ * @id: Request ID
+ * @mac_addr: MAC address (if request type is MAC address related)
+ */
+struct request_message {
+	u32 type;
+	u32 id;
+	union {
+		struct rpmsg_eth_mac_addr mac_addr;
+	};
+} __packed;
+
+/**
+ * struct response_message - response message structure for RPMSG Ethernet
+ * @type: Response Type
+ * @id: Response ID
+ * @shm_info: rpmsg shared memory info
+ */
+struct response_message {
+	u32 type;
+	u32 id;
+	union {
+		struct rpmsg_eth_shm shm_info;
+	};
+} __packed;
+
+/**
+ * struct notify_message - notification message structure for RPMSG Ethernet
+ * @type: Notify Type
+ * @id: Notify ID
+ */
+struct notify_message {
+	u32 type;
+	u32 id;
+} __packed;
+
 /**
  * struct message_header - message header structure for RPMSG Ethernet
  * @src_id: Source endpoint ID
@@ -40,22 +149,89 @@ struct message_header {
  *
  * @msg_hdr: Message header contains source and destination endpoint and
  *          the type of message
+ * @req_msg: Request message structure contains the request type and ID
+ * @resp_msg: Response message structure contains the response type and ID
+ * @notify_msg: Notification message structure contains the notify type and ID
  *
  * This structure is used to send and receive messages between the RPMSG
  * Ethernet ports.
  */
 struct message {
 	struct message_header msg_hdr;
+	union {
+		struct request_message req_msg;
+		struct response_message resp_msg;
+		struct notify_message notify_msg;
+	};
 } __packed;
 
+/*      Shared Memory Layout
+ *
+ *	---------------------------	*****************
+ *	|        MAGIC_NUM        |	 rpmsg_eth_shm_head
+ *	|        HEAD_IDX         |
+ *	---------------------------	*****************
+ *	|        MAGIC_NUM        |
+ *	|        PKT_1_LEN        |
+ *	|          PKT_1          |
+ *	---------------------------
+ *	|        MAGIC_NUM        |
+ *	|        PKT_2_LEN        |	 rpmsg_eth_shm_buf
+ *	|          PKT_2          |
+ *	---------------------------
+ *	|           .             |
+ *	|           .             |
+ *	---------------------------
+ *	|        MAGIC_NUM        |
+ *	|        PKT_N_LEN        |
+ *	|          PKT_N          |
+ *	---------------------------	****************
+ *	|        MAGIC_NUM        |      rpmsg_eth_shm_tail
+ *	|        TAIL_IDX         |
+ *	---------------------------	****************
+ */
+
+enum rpmsg_eth_state {
+	RPMSG_ETH_STATE_PROBE,
+	RPMSG_ETH_STATE_OPEN,
+	RPMSG_ETH_STATE_CLOSE,
+	RPMSG_ETH_STATE_READY,
+	RPMSG_ETH_STATE_RUNNING,
+
+};
+
 /**
  * struct rpmsg_eth_common - common structure for RPMSG Ethernet
  * @rpdev: RPMSG device
+ * @send_msg: Send message
+ * @recv_msg: Receive message
  * @port: Ethernet port
  * @dev: Device
+ * @state: Interface state
+ * @state_work: Delayed work for state machine
  */
 struct rpmsg_eth_common {
 	struct rpmsg_device *rpdev;
+	/** @send_msg_lock: Lock for sending RPMSG */
+	spinlock_t send_msg_lock;
+	/** @recv_msg_lock: Lock for receiving RPMSG */
+	spinlock_t recv_msg_lock;
+	struct message send_msg;
+	struct message recv_msg;
+	struct rpmsg_eth_port *port;
+	struct device *dev;
+	enum rpmsg_eth_state state;
+	/** @state_lock: Lock for changing interface state */
+	struct mutex state_lock;
+	struct delayed_work state_work;
+};
+
+/**
+ * struct rpmsg_eth_ndev_priv - private structure for RPMSG Ethernet net device
+ * @port: Ethernet port
+ * @dev: Device
+ */
+struct rpmsg_eth_ndev_priv {
 	struct rpmsg_eth_port *port;
 	struct device *dev;
 };
@@ -64,12 +240,30 @@ struct rpmsg_eth_common {
  * struct rpmsg_eth_port - Ethernet port structure for RPMSG Ethernet
  * @common: Pointer to the common RPMSG Ethernet structure
  * @shm: Shared memory region mapping
+ * @tx_offset: Offset for TX region in shared memory
+ * @rx_offset: Offset for RX region in shared memory
  * @buf_size: Size (in bytes) of the shared memory buffer for this port
+ * @rx_timer: Timer for rx polling
+ * @rx_napi: NAPI structure for rx polling
+ * @local_mac_addr: Local MAC address
+ * @ndev: Network device
+ * @tx_max_buffers: Maximum number of tx buffers
+ * @rx_max_buffers: Maximum number of rx buffers
+ * @port_id: Port ID
  */
 struct rpmsg_eth_port {
 	struct rpmsg_eth_common *common;
 	void __iomem *shm;
+	u32 tx_offset;
+	u32 rx_offset;
 	phys_addr_t buf_size;
+	struct timer_list rx_timer;
+	struct napi_struct rx_napi;
+	u8 local_mac_addr[ETH_ALEN];
+	struct net_device *ndev;
+	u32 tx_max_buffers;
+	u32 rx_max_buffers;
+	u32 port_id;
 };
 
 #endif /* __RPMSG_ETH_H__ */
-- 
2.34.1

[PATCH net-next v2 6/8] net: rpmsg-eth: Add netdev ops

[MD Danish Anwar]

Add netdev ops for rpmsg-eth driver. This patch introduces the netdev
operations for the rpmsg-eth driver, enabling the driver to interact
with the Linux networking stack. The following functionalities are
implemented:

1. `ndo_open` and `ndo_stop`:
	- Handles the initialization and cleanup of the network device
	  during open and stop operations.
	- Manages the state transitions of the rpmsg-eth driver.

2. `ndo_start_xmit`:
	- Implements the transmit functionality by copying data from the
	  skb to the shared memory buffer and updating the head index.

3. `ndo_set_mac_address`:
	- Allows setting the MAC address of the network device and sends
	  the updated MAC address to the remote processor.

4. RX Path:
	- Adds a timer-based mechanism to poll for received packets in
	  shared memory.
	- Implements NAPI-based packet processing to handle received
	  packets efficiently.

5. State Machine:
	- Introduces a state machine to manage the driver's state
	  transitions, such as PROBE, OPEN, READY, and RUNNING.

6. Initialization:
	- Adds necessary initialization for locks, timers, and work
	  structures.
	- Registers the network device and sets up NAPI and RX timer.

7. Cleanup:
	- Ensures proper cleanup of resources during driver removal,
	  including NAPI and timers.

This patch enhances the rpmsg-eth driver to function as a fully
operational network device in the Linux kernel.

Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
---
 drivers/net/ethernet/rpmsg_eth.c | 318 +++++++++++++++++++++++++++++++
 drivers/net/ethernet/rpmsg_eth.h |   2 +
 2 files changed, 320 insertions(+)

diff --git a/drivers/net/ethernet/rpmsg_eth.c b/drivers/net/ethernet/rpmsg_eth.c
index b6fe5628933d..a2248e21cf22 100644
--- a/drivers/net/ethernet/rpmsg_eth.c
+++ b/drivers/net/ethernet/rpmsg_eth.c
@@ -49,6 +49,109 @@ static int rpmsg_eth_validate_handshake(struct rpmsg_eth_port *port,
 	return 0;
 }
 
+static int create_request(struct rpmsg_eth_common *common,
+			  enum rpmsg_eth_rpmsg_type rpmsg_type)
+{
+	struct message *msg = &common->send_msg;
+	int ret = 0;
+
+	msg->msg_hdr.src_id = common->port->port_id;
+	msg->req_msg.type = rpmsg_type;
+
+	switch (rpmsg_type) {
+	case RPMSG_ETH_REQ_SHM_INFO:
+		msg->msg_hdr.msg_type = RPMSG_ETH_REQUEST_MSG;
+		break;
+	case RPMSG_ETH_REQ_SET_MAC_ADDR:
+		msg->msg_hdr.msg_type = RPMSG_ETH_REQUEST_MSG;
+		ether_addr_copy(msg->req_msg.mac_addr.addr,
+				common->port->ndev->dev_addr);
+		break;
+	case RPMSG_ETH_NOTIFY_PORT_UP:
+	case RPMSG_ETH_NOTIFY_PORT_DOWN:
+		msg->msg_hdr.msg_type = RPMSG_ETH_NOTIFY_MSG;
+		break;
+	default:
+		ret = -EINVAL;
+		dev_err(common->dev, "Invalid RPMSG request\n");
+	}
+	return ret;
+}
+
+static int rpmsg_eth_create_send_request(struct rpmsg_eth_common *common,
+					 enum rpmsg_eth_rpmsg_type rpmsg_type,
+					 bool wait)
+{
+	unsigned long flags;
+	int ret = 0;
+
+	if (wait)
+		reinit_completion(&common->sync_msg);
+
+	spin_lock_irqsave(&common->send_msg_lock, flags);
+	ret = create_request(common, rpmsg_type);
+	if (ret)
+		goto release_lock;
+
+	ret = rpmsg_send(common->rpdev->ept, (void *)(&common->send_msg),
+			 sizeof(common->send_msg));
+	if (ret) {
+		dev_err(common->dev, "Failed to send RPMSG message\n");
+		goto release_lock;
+	}
+
+	spin_unlock_irqrestore(&common->send_msg_lock, flags);
+	if (wait) {
+		ret = wait_for_completion_timeout(&common->sync_msg,
+						  RPMSG_ETH_REQ_TIMEOUT_JIFFIES);
+
+		if (!ret) {
+			dev_err(common->dev, "Failed to receive response within %ld jiffies\n",
+				RPMSG_ETH_REQ_TIMEOUT_JIFFIES);
+			return -ETIMEDOUT;
+		}
+		ret = 0;
+	}
+	return ret;
+release_lock:
+	spin_unlock_irqrestore(&common->send_msg_lock, flags);
+	return ret;
+}
+
+static void rpmsg_eth_state_machine(struct work_struct *work)
+{
+	struct delayed_work *dwork = to_delayed_work(work);
+	struct rpmsg_eth_common *common;
+	struct rpmsg_eth_port *port;
+	int ret;
+
+	common = container_of(dwork, struct rpmsg_eth_common, state_work);
+	port = common->port;
+
+	mutex_lock(&common->state_lock);
+
+	switch (common->state) {
+	case RPMSG_ETH_STATE_PROBE:
+		break;
+	case RPMSG_ETH_STATE_OPEN:
+		rpmsg_eth_create_send_request(common, RPMSG_ETH_REQ_SHM_INFO, false);
+		break;
+	case RPMSG_ETH_STATE_CLOSE:
+		break;
+	case RPMSG_ETH_STATE_READY:
+		ret = rpmsg_eth_create_send_request(common, RPMSG_ETH_REQ_SET_MAC_ADDR, false);
+		if (!ret) {
+			napi_enable(&port->rx_napi);
+			netif_carrier_on(port->ndev);
+			mod_timer(&port->rx_timer, RX_POLL_TIMEOUT_JIFFIES);
+		}
+		break;
+	case RPMSG_ETH_STATE_RUNNING:
+		break;
+	}
+	mutex_unlock(&common->state_lock);
+}
+
 static int rpmsg_eth_rpmsg_cb(struct rpmsg_device *rpdev, void *data, int len,
 			      void *priv, u32 src)
 {
@@ -85,6 +188,17 @@ static int rpmsg_eth_rpmsg_cb(struct rpmsg_device *rpdev, void *data, int len,
 				dev_err(common->dev, "RPMSG handshake failed %d\n", ret);
 				return ret;
 			}
+
+			mutex_lock(&common->state_lock);
+			common->state = RPMSG_ETH_STATE_READY;
+			mutex_unlock(&common->state_lock);
+
+			mod_delayed_work(system_wq,
+					 &common->state_work,
+					 STATE_MACHINE_TIME_JIFFIES);
+
+			break;
+		case RPMSG_ETH_RESP_SET_MAC_ADDR:
 			break;
 		}
 		break;
@@ -92,6 +206,20 @@ static int rpmsg_eth_rpmsg_cb(struct rpmsg_device *rpdev, void *data, int len,
 		rpmsg_type = msg->notify_msg.type;
 		dev_dbg(common->dev, "Msg type = %d, RPMsg type = %d, Src Id = %d, Msg Id = %d\n",
 			msg_type, rpmsg_type, msg->msg_hdr.src_id, msg->notify_msg.id);
+		switch (rpmsg_type) {
+		case RPMSG_ETH_NOTIFY_REMOTE_READY:
+			mutex_lock(&common->state_lock);
+			common->state = RPMSG_ETH_STATE_RUNNING;
+			mutex_unlock(&common->state_lock);
+
+			mod_delayed_work(system_wq,
+					 &common->state_work,
+					 STATE_MACHINE_TIME_JIFFIES);
+			break;
+		case RPMSG_ETH_NOTIFY_PORT_UP:
+		case RPMSG_ETH_NOTIFY_PORT_DOWN:
+			break;
+		}
 		break;
 	default:
 		dev_err(common->dev, "Invalid msg type\n");
@@ -163,6 +291,181 @@ static int rpmsg_eth_get_shm_info(struct rpmsg_eth_common *common)
 	return 0;
 }
 
+static void rpmsg_eth_rx_timer(struct timer_list *timer)
+{
+	struct rpmsg_eth_port *port = timer_container_of(port, timer, rx_timer);
+	struct napi_struct *napi;
+	int num_pkts = 0;
+	u32 head, tail;
+
+	head = readl(port->shm + port->rx_offset + HEAD_IDX_OFFSET);
+	tail = readl(port->shm + port->rx_offset +
+		     TAIL_IDX_OFFSET(port->rx_max_buffers));
+
+	num_pkts = tail - head;
+	num_pkts = num_pkts >= 0 ? num_pkts :
+				   (num_pkts + port->rx_max_buffers);
+
+	napi = &port->rx_napi;
+	if (num_pkts && likely(napi_schedule_prep(napi)))
+		__napi_schedule(napi);
+	else
+		mod_timer(&port->rx_timer, RX_POLL_JIFFIES);
+}
+
+static int rpmsg_eth_rx_packets(struct napi_struct *napi, int budget)
+{
+	struct rpmsg_eth_port *port = container_of(napi, struct rpmsg_eth_port, rx_napi);
+	u32 count, process_pkts;
+	struct sk_buff *skb;
+	u32 head, tail;
+	int num_pkts;
+	u32 pkt_len;
+
+	head = readl(port->shm + port->rx_offset + HEAD_IDX_OFFSET);
+	tail = readl(port->shm + port->rx_offset +
+		     TAIL_IDX_OFFSET(port->rx_max_buffers));
+
+	num_pkts = head - tail;
+
+	num_pkts = num_pkts >= 0 ? num_pkts :
+				   (num_pkts + port->rx_max_buffers);
+	process_pkts = min(num_pkts, budget);
+	count = 0;
+	while (count < process_pkts) {
+		memcpy_fromio((void *)&pkt_len,
+			      port->shm + port->rx_offset + MAGIC_NUM_SIZE_TYPE +
+			      PKT_START_OFFSET((tail + count) % port->rx_max_buffers),
+			      PKT_LEN_SIZE_TYPE);
+		/* Start building the skb */
+		skb = napi_alloc_skb(napi, pkt_len);
+		if (!skb) {
+			port->ndev->stats.rx_dropped++;
+			goto rx_dropped;
+		}
+
+		skb->dev = port->ndev;
+		skb_put(skb, pkt_len);
+		memcpy_fromio((void *)skb->data,
+			      port->shm + port->rx_offset + PKT_LEN_SIZE_TYPE +
+			      MAGIC_NUM_SIZE_TYPE +
+			      PKT_START_OFFSET((tail + count) % port->rx_max_buffers),
+			      pkt_len);
+
+		skb->protocol = eth_type_trans(skb, port->ndev);
+
+		/* Push skb into network stack */
+		napi_gro_receive(napi, skb);
+
+		count++;
+		port->ndev->stats.rx_packets++;
+		port->ndev->stats.rx_bytes += skb->len;
+	}
+
+rx_dropped:
+
+	if (num_pkts) {
+		writel((tail + count) % port->rx_max_buffers,
+		       port->shm + port->rx_offset +
+		       TAIL_IDX_OFFSET(port->rx_max_buffers));
+
+		if (num_pkts < budget && napi_complete_done(napi, count))
+			mod_timer(&port->rx_timer, RX_POLL_TIMEOUT_JIFFIES);
+	}
+
+	return count;
+}
+
+static int rpmsg_eth_ndo_open(struct net_device *ndev)
+{
+	struct rpmsg_eth_common *common = rpmsg_eth_ndev_to_common(ndev);
+
+	mutex_lock(&common->state_lock);
+	common->state = RPMSG_ETH_STATE_OPEN;
+	mutex_unlock(&common->state_lock);
+	mod_delayed_work(system_wq, &common->state_work, msecs_to_jiffies(100));
+
+	return 0;
+}
+
+static int rpmsg_eth_ndo_stop(struct net_device *ndev)
+{
+	struct rpmsg_eth_common *common = rpmsg_eth_ndev_to_common(ndev);
+	struct rpmsg_eth_port *port = rpmsg_eth_ndev_to_port(ndev);
+
+	mutex_lock(&common->state_lock);
+	common->state = RPMSG_ETH_STATE_CLOSE;
+	mutex_unlock(&common->state_lock);
+
+	netif_carrier_off(port->ndev);
+
+	cancel_delayed_work_sync(&common->state_work);
+	timer_delete_sync(&port->rx_timer);
+	napi_disable(&port->rx_napi);
+
+	return 0;
+}
+
+static netdev_tx_t rpmsg_eth_start_xmit(struct sk_buff *skb, struct net_device *ndev)
+{
+	struct rpmsg_eth_port *port = rpmsg_eth_ndev_to_port(ndev);
+	u32 head, tail;
+	int num_pkts;
+	u32 len;
+
+	len = skb_headlen(skb);
+	head = readl(port->shm + port->tx_offset + HEAD_IDX_OFFSET);
+	tail = readl(port->shm + port->tx_offset +
+		     TAIL_IDX_OFFSET(port->tx_max_buffers));
+
+	/* If the buffer queue is full, then drop packet */
+	num_pkts = head - tail;
+	num_pkts = num_pkts >= 0 ? num_pkts :
+				   (num_pkts + port->tx_max_buffers);
+
+	if ((num_pkts + 1) == port->tx_max_buffers) {
+		netdev_warn(ndev, "Tx buffer full %d\n", num_pkts);
+		goto ring_full;
+	}
+	/* Copy length */
+	memcpy_toio(port->shm + port->tx_offset + PKT_START_OFFSET(head) + MAGIC_NUM_SIZE_TYPE,
+		    (void *)&len, PKT_LEN_SIZE_TYPE);
+	/* Copy data to shared mem */
+	memcpy_toio(port->shm + port->tx_offset + PKT_START_OFFSET(head) + MAGIC_NUM_SIZE_TYPE +
+		    PKT_LEN_SIZE_TYPE, (void *)skb->data, len);
+	writel((head + 1) % port->tx_max_buffers,
+	       port->shm + port->tx_offset + HEAD_IDX_OFFSET);
+
+	ndev->stats.tx_packets++;
+	ndev->stats.tx_bytes += skb->len;
+
+	dev_consume_skb_any(skb);
+	return NETDEV_TX_OK;
+
+ring_full:
+	return NETDEV_TX_BUSY;
+}
+
+static int rpmsg_eth_set_mac_address(struct net_device *ndev, void *addr)
+{
+	struct rpmsg_eth_common *common = rpmsg_eth_ndev_to_common(ndev);
+	int ret;
+
+	ret = eth_mac_addr(ndev, addr);
+
+	if (ret < 0)
+		return ret;
+	ret = rpmsg_eth_create_send_request(common, RPMSG_ETH_REQ_SET_MAC_ADDR, false);
+	return ret;
+}
+
+static const struct net_device_ops rpmsg_eth_netdev_ops = {
+	.ndo_open = rpmsg_eth_ndo_open,
+	.ndo_stop = rpmsg_eth_ndo_stop,
+	.ndo_start_xmit = rpmsg_eth_start_xmit,
+	.ndo_set_mac_address = rpmsg_eth_set_mac_address,
+};
+
 static int rpmsg_eth_init_ndev(struct rpmsg_eth_common *common)
 {
 	struct device *dev = &common->rpdev->dev;
@@ -186,6 +489,7 @@ static int rpmsg_eth_init_ndev(struct rpmsg_eth_common *common)
 
 	ndev_priv = netdev_priv(port->ndev);
 	ndev_priv->port = port;
+	port->ndev->netdev_ops = &rpmsg_eth_netdev_ops;
 	SET_NETDEV_DEV(port->ndev, dev);
 
 	port->ndev->min_mtu = RPMSG_ETH_MIN_PACKET_SIZE;
@@ -197,6 +501,8 @@ static int rpmsg_eth_init_ndev(struct rpmsg_eth_common *common)
 	}
 
 	netif_carrier_off(port->ndev);
+	netif_napi_add(port->ndev, &port->rx_napi, rpmsg_eth_rx_packets);
+	timer_setup(&port->rx_timer, rpmsg_eth_rx_timer, 0);
 	err = register_netdev(port->ndev);
 	if (err)
 		dev_err(dev, "error registering rpmsg_eth net device %d\n", err);
@@ -225,6 +531,12 @@ static int rpmsg_eth_probe(struct rpmsg_device *rpdev)
 	if (ret)
 		return ret;
 
+	spin_lock_init(&common->send_msg_lock);
+	spin_lock_init(&common->recv_msg_lock);
+	mutex_init(&common->state_lock);
+	INIT_DELAYED_WORK(&common->state_work, rpmsg_eth_state_machine);
+	init_completion(&common->sync_msg);
+
 	/* Register the network device */
 	ret = rpmsg_eth_init_ndev(common);
 	if (ret)
@@ -235,6 +547,12 @@ static int rpmsg_eth_probe(struct rpmsg_device *rpdev)
 
 static void rpmsg_eth_remove(struct rpmsg_device *rpdev)
 {
+	struct rpmsg_eth_common *common = dev_get_drvdata(&rpdev->dev);
+	struct rpmsg_eth_port *port = common->port;
+
+	netif_napi_del(&port->rx_napi);
+	timer_delete_sync(&port->rx_timer);
+
 	dev_dbg(&rpdev->dev, "rpmsg-eth client driver is removed\n");
 }
 
diff --git a/drivers/net/ethernet/rpmsg_eth.h b/drivers/net/ethernet/rpmsg_eth.h
index 0c2ae89fbfbf..992d05bd9386 100644
--- a/drivers/net/ethernet/rpmsg_eth.h
+++ b/drivers/net/ethernet/rpmsg_eth.h
@@ -209,6 +209,7 @@ enum rpmsg_eth_state {
  * @dev: Device
  * @state: Interface state
  * @state_work: Delayed work for state machine
+ * @sync_msg: Completion for synchronous message
  */
 struct rpmsg_eth_common {
 	struct rpmsg_device *rpdev;
@@ -224,6 +225,7 @@ struct rpmsg_eth_common {
 	/** @state_lock: Lock for changing interface state */
 	struct mutex state_lock;
 	struct delayed_work state_work;
+	struct completion sync_msg;
 };
 
 /**
-- 
2.34.1

[PATCH net-next v2 7/8] net: rpmsg-eth: Add support for multicast filtering

[MD Danish Anwar]

Add support for multicast filtering for RPMSG ETH driver. Implement the
ndo_set_rx_mode callback as icve_set_rx_mode() API. rx_mode_workqueue is
initialized in rpmsg_eth_probe() and queued in rpmsg_eth_set_rx_mode().

Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
---
 drivers/net/ethernet/rpmsg_eth.c | 63 ++++++++++++++++++++++++++++++++
 drivers/net/ethernet/rpmsg_eth.h | 12 ++++++
 2 files changed, 75 insertions(+)

diff --git a/drivers/net/ethernet/rpmsg_eth.c b/drivers/net/ethernet/rpmsg_eth.c
index a2248e21cf22..e26b1d8f1752 100644
--- a/drivers/net/ethernet/rpmsg_eth.c
+++ b/drivers/net/ethernet/rpmsg_eth.c
@@ -67,6 +67,11 @@ static int create_request(struct rpmsg_eth_common *common,
 		ether_addr_copy(msg->req_msg.mac_addr.addr,
 				common->port->ndev->dev_addr);
 		break;
+	case RPMSG_ETH_REQ_ADD_MC_ADDR:
+	case RPMSG_ETH_REQ_DEL_MC_ADDR:
+		ether_addr_copy(msg->req_msg.mac_addr.addr,
+				common->mcast_addr);
+		break;
 	case RPMSG_ETH_NOTIFY_PORT_UP:
 	case RPMSG_ETH_NOTIFY_PORT_DOWN:
 		msg->msg_hdr.msg_type = RPMSG_ETH_NOTIFY_MSG;
@@ -118,6 +123,22 @@ static int rpmsg_eth_create_send_request(struct rpmsg_eth_common *common,
 	return ret;
 }
 
+static int rpmsg_eth_add_mc_addr(struct net_device *ndev, const u8 *addr)
+{
+	struct rpmsg_eth_common *common = rpmsg_eth_ndev_to_common(ndev);
+
+	ether_addr_copy(common->mcast_addr, addr);
+	return rpmsg_eth_create_send_request(common, RPMSG_ETH_REQ_ADD_MC_ADDR, true);
+}
+
+static int rpmsg_eth_del_mc_addr(struct net_device *ndev, const u8 *addr)
+{
+	struct rpmsg_eth_common *common = rpmsg_eth_ndev_to_common(ndev);
+
+	ether_addr_copy(common->mcast_addr, addr);
+	return rpmsg_eth_create_send_request(common, RPMSG_ETH_REQ_DEL_MC_ADDR, true);
+}
+
 static void rpmsg_eth_state_machine(struct work_struct *work)
 {
 	struct delayed_work *dwork = to_delayed_work(work);
@@ -200,6 +221,10 @@ static int rpmsg_eth_rpmsg_cb(struct rpmsg_device *rpdev, void *data, int len,
 			break;
 		case RPMSG_ETH_RESP_SET_MAC_ADDR:
 			break;
+		case RPMSG_ETH_RESP_ADD_MC_ADDR:
+		case RPMSG_ETH_RESP_DEL_MC_ADDR:
+			complete(&common->sync_msg);
+			break;
 		}
 		break;
 	case RPMSG_ETH_NOTIFY_MSG:
@@ -399,10 +424,15 @@ static int rpmsg_eth_ndo_stop(struct net_device *ndev)
 
 	netif_carrier_off(port->ndev);
 
+	__dev_mc_unsync(ndev, rpmsg_eth_del_mc_addr);
+	__hw_addr_init(&common->mc_list);
+
 	cancel_delayed_work_sync(&common->state_work);
 	timer_delete_sync(&port->rx_timer);
 	napi_disable(&port->rx_napi);
 
+	cancel_work_sync(&common->rx_mode_work);
+
 	return 0;
 }
 
@@ -459,10 +489,35 @@ static int rpmsg_eth_set_mac_address(struct net_device *ndev, void *addr)
 	return ret;
 }
 
+static void rpmsg_eth_ndo_set_rx_mode_work(struct work_struct *work)
+{
+	struct rpmsg_eth_common *common;
+	struct net_device *ndev;
+
+	common = container_of(work, struct rpmsg_eth_common, rx_mode_work);
+	ndev = common->port->ndev;
+
+	/* make a mc list copy */
+	netif_addr_lock_bh(ndev);
+	__hw_addr_sync(&common->mc_list, &ndev->mc, ndev->addr_len);
+	netif_addr_unlock_bh(ndev);
+
+	__hw_addr_sync_dev(&common->mc_list, ndev, rpmsg_eth_add_mc_addr,
+			   rpmsg_eth_del_mc_addr);
+}
+
+static void rpmsg_eth_set_rx_mode(struct net_device *ndev)
+{
+	struct rpmsg_eth_common *common = rpmsg_eth_ndev_to_common(ndev);
+
+	queue_work(common->cmd_wq, &common->rx_mode_work);
+}
+
 static const struct net_device_ops rpmsg_eth_netdev_ops = {
 	.ndo_open = rpmsg_eth_ndo_open,
 	.ndo_stop = rpmsg_eth_ndo_stop,
 	.ndo_start_xmit = rpmsg_eth_start_xmit,
+	.ndo_set_rx_mode = rpmsg_eth_set_rx_mode,
 	.ndo_set_mac_address = rpmsg_eth_set_mac_address,
 };
 
@@ -537,6 +592,13 @@ static int rpmsg_eth_probe(struct rpmsg_device *rpdev)
 	INIT_DELAYED_WORK(&common->state_work, rpmsg_eth_state_machine);
 	init_completion(&common->sync_msg);
 
+	__hw_addr_init(&common->mc_list);
+	INIT_WORK(&common->rx_mode_work, rpmsg_eth_ndo_set_rx_mode_work);
+	common->cmd_wq = create_singlethread_workqueue("rpmsg_eth_rx_work");
+	if (!common->cmd_wq) {
+		dev_err(dev, "Failure requesting workqueue\n");
+		return -ENOMEM;
+	}
 	/* Register the network device */
 	ret = rpmsg_eth_init_ndev(common);
 	if (ret)
@@ -552,6 +614,7 @@ static void rpmsg_eth_remove(struct rpmsg_device *rpdev)
 
 	netif_napi_del(&port->rx_napi);
 	timer_delete_sync(&port->rx_timer);
+	destroy_workqueue(common->cmd_wq);
 
 	dev_dbg(&rpdev->dev, "rpmsg-eth client driver is removed\n");
 }
diff --git a/drivers/net/ethernet/rpmsg_eth.h b/drivers/net/ethernet/rpmsg_eth.h
index 992d05bd9386..995c5a9c1034 100644
--- a/drivers/net/ethernet/rpmsg_eth.h
+++ b/drivers/net/ethernet/rpmsg_eth.h
@@ -57,10 +57,14 @@ enum rpmsg_eth_rpmsg_type {
 	/* Request types */
 	RPMSG_ETH_REQ_SHM_INFO = 0,
 	RPMSG_ETH_REQ_SET_MAC_ADDR,
+	RPMSG_ETH_REQ_ADD_MC_ADDR,
+	RPMSG_ETH_REQ_DEL_MC_ADDR,
 
 	/* Response types */
 	RPMSG_ETH_RESP_SHM_INFO,
 	RPMSG_ETH_RESP_SET_MAC_ADDR,
+	RPMSG_ETH_RESP_ADD_MC_ADDR,
+	RPMSG_ETH_RESP_DEL_MC_ADDR,
 
 	/* Notification types */
 	RPMSG_ETH_NOTIFY_PORT_UP,
@@ -210,6 +214,10 @@ enum rpmsg_eth_state {
  * @state: Interface state
  * @state_work: Delayed work for state machine
  * @sync_msg: Completion for synchronous message
+ * @rx_mode_work: Work structure for rx mode
+ * @cmd_wq: Workqueue for commands
+ * @mc_list: List of multicast addresses
+ * @mcast_addr: Multicast address filter
  */
 struct rpmsg_eth_common {
 	struct rpmsg_device *rpdev;
@@ -226,6 +234,10 @@ struct rpmsg_eth_common {
 	struct mutex state_lock;
 	struct delayed_work state_work;
 	struct completion sync_msg;
+	struct work_struct rx_mode_work;
+	struct workqueue_struct *cmd_wq;
+	struct netdev_hw_addr_list mc_list;
+	u8 mcast_addr[ETH_ALEN];
 };
 
 /**
-- 
2.34.1

[PATCH net-next v2 8/8] arch: arm64: dts: k3-am64*: Add rpmsg-eth node

[MD Danish Anwar]

Add rpmsg-eth node to main_r5fss0_core0. This node describes the memory
region to be used for rpmsg ethernet communication. The commit adds
below changes,

- Adding new reserved memory region main_r5fss0_core0_memory_region_shm
- Adding rpmsg-eth node to main_r5fss0_core0 with memory-region as
  main_r5fss0_core0_memory_region_shm

Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
---
 arch/arm64/boot/dts/ti/k3-am642-evm.dts | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/ti/k3-am642-evm.dts b/arch/arm64/boot/dts/ti/k3-am642-evm.dts
index e01866372293..1e5ee9ac9966 100644
--- a/arch/arm64/boot/dts/ti/k3-am642-evm.dts
+++ b/arch/arm64/boot/dts/ti/k3-am642-evm.dts
@@ -61,7 +61,13 @@ main_r5fss0_core0_dma_memory_region: r5f-dma-memory@a0000000 {
 
 		main_r5fss0_core0_memory_region: r5f-memory@a0100000 {
 			compatible = "shared-dma-pool";
-			reg = <0x00 0xa0100000 0x00 0xf00000>;
+			reg = <0x00 0xa0100000 0x00 0x300000>;
+			no-map;
+		};
+
+		main_r5fss0_core0_memory_region_shm: r5f-shm-memory@a0400000 {
+			compatible = "shared-dma-pool";
+			reg = <0x00 0xa0400000 0x00 0xc00000>;
 			no-map;
 		};
 
@@ -768,6 +774,9 @@ &main_r5fss0_core0 {
 	mboxes = <&mailbox0_cluster2 &mbox_main_r5fss0_core0>;
 	memory-region = <&main_r5fss0_core0_dma_memory_region>,
 			<&main_r5fss0_core0_memory_region>;
+	rpmsg-eth {
+		memory-region = <&main_r5fss0_core0_memory_region_shm>;
+	};
 };
 
 &main_r5fss0_core1 {
-- 
2.34.1

Re: [PATCH net-next v2 1/8] dt-bindings: net: ti,rpmsg-eth: Add DT binding for RPMSG ETH

[Krzysztof Kozlowski]

On Tue, Sep 02, 2025 at 02:37:39PM +0530, MD Danish Anwar wrote:
> Add device tree binding documentation for Texas Instruments RPMsg Ethernet
> channels. This binding describes the shared memory communication interface
> between host processor and a remote processor for Ethernet packet exchange.
> 
> The binding defines the required 'memory-region' property that references
> the dedicated shared memory area used for exchanging Ethernet packets
> between processors.
> 
> Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
> ---
>  .../devicetree/bindings/net/ti,rpmsg-eth.yaml | 38 +++++++++++++++++++
>  1 file changed, 38 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/net/ti,rpmsg-eth.yaml
> 
> diff --git a/Documentation/devicetree/bindings/net/ti,rpmsg-eth.yaml b/Documentation/devicetree/bindings/net/ti,rpmsg-eth.yaml
> new file mode 100644
> index 000000000000..1c86d5c020b0
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/net/ti,rpmsg-eth.yaml
> @@ -0,0 +1,38 @@
> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/net/ti,rpmsg-eth.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Texas Instruments RPMsg channel nodes for Ethernet communication
> +
> +description: |
> +  RPMsg Ethernet subnode represents the communication interface between host
> +  processor and a remote processor.
> +
> +maintainers:
> +  - MD Danish Anwar <danishanwar@ti.com>
> +
> +properties:
> +  memory-region:
> +    $ref: /schemas/types.yaml#/definitions/phandle
> +    description: |
> +      Phandle to the shared memory region used for communication between the
> +      host processor and the remote processor.
> +      This shared memory region is used to exchange Ethernet packets.
> +
> +required:
> +  - memory-region
> +
> +additionalProperties: false

This cannot be really tested and is pointless binding... Really, one
property does not make it a device node.


> +
> +examples:
> +  - |
> +    main_r5fss0_core0 {
> +        mboxes = <&mailbox0_cluster2 &mbox_main_r5fss0_core0>;
> +        memory-region = <&main_r5fss0_core0_dma_memory_region>,
> +                        <&main_r5fss0_core0_memory_region>;

All this is irrelevant, drop.

> +        rpmsg-eth {
> +            memory-region = <&main_r5fss0_core0_memory_region_shm>;
> +        };
> +    };
> -- 
> 2.34.1
> 

Re: [PATCH net-next v2 1/8] dt-bindings: net: ti,rpmsg-eth: Add DT binding for RPMSG ETH

[Krzysztof Kozlowski]

On Tue, Sep 02, 2025 at 02:37:39PM +0530, MD Danish Anwar wrote:
> Add device tree binding documentation for Texas Instruments RPMsg Ethernet
> channels. This binding describes the shared memory communication interface
> between host processor and a remote processor for Ethernet packet exchange.
> 
> The binding defines the required 'memory-region' property that references

Describe the hardware, not "this binding".

A nit, subject: drop second/last, redundant "DT binding". The
"dt-bindings" prefix is already stating that these are bindings.
See also:
https://elixir.bootlin.com/linux/v6.17-rc3/source/Documentation/devicetree/bindings/submitting-patches.rst#L18

Best regards,
Krzysztof

Re: [PATCH net-next v2 2/8] dt-bindings: remoteproc: k3-r5f: Add rpmsg-eth subnode

[Krzysztof Kozlowski]

On Tue, Sep 02, 2025 at 02:37:40PM +0530, MD Danish Anwar wrote:
> Extend the Texas Instruments K3 R5F remoteproc device tree bindings to
> include a 'rpmsg-eth' subnode.
> 
> This extension allows the RPMsg Ethernet to be defined as a subnode of
> K3 R5F remoteproc nodes, enabling the configuration of shared memory-based
> Ethernet communication between the host and remote processors.
> 
> Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
> ---
>  .../devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml     | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml b/Documentation/devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml
> index a492f74a8608..4dbd708ec8ee 100644
> --- a/Documentation/devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml
> +++ b/Documentation/devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml
> @@ -210,6 +210,12 @@ patternProperties:
>            should be defined as per the generic bindings in,
>            Documentation/devicetree/bindings/sram/sram.yaml
>  
> +      rpmsg-eth:
> +        $ref: /schemas/net/ti,rpmsg-eth.yaml

No, not a separate device. Please read slides from my DT for beginners
talk from OSSE25. This is EXACTLY the case I covered there - what not to
do.

Best regards,
Krzysztof

Re: [PATCH net-next v2 1/8] dt-bindings: net: ti,rpmsg-eth: Add DT binding for RPMSG ETH

[MD Danish Anwar]

Hi Krzysztof,

On 03/09/25 12:48 pm, Krzysztof Kozlowski wrote:
> On Tue, Sep 02, 2025 at 02:37:39PM +0530, MD Danish Anwar wrote:
>> Add device tree binding documentation for Texas Instruments RPMsg Ethernet
>> channels. This binding describes the shared memory communication interface
>> between host processor and a remote processor for Ethernet packet exchange.
>>
>> The binding defines the required 'memory-region' property that references
>> the dedicated shared memory area used for exchanging Ethernet packets
>> between processors.
>>
>> Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
>> ---
>>  .../devicetree/bindings/net/ti,rpmsg-eth.yaml | 38 +++++++++++++++++++
>>  1 file changed, 38 insertions(+)
>>  create mode 100644 Documentation/devicetree/bindings/net/ti,rpmsg-eth.yaml
>>
>> diff --git a/Documentation/devicetree/bindings/net/ti,rpmsg-eth.yaml b/Documentation/devicetree/bindings/net/ti,rpmsg-eth.yaml
>> new file mode 100644
>> index 000000000000..1c86d5c020b0
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/net/ti,rpmsg-eth.yaml
>> @@ -0,0 +1,38 @@
>> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/net/ti,rpmsg-eth.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: Texas Instruments RPMsg channel nodes for Ethernet communication
>> +
>> +description: |
>> +  RPMsg Ethernet subnode represents the communication interface between host
>> +  processor and a remote processor.
>> +
>> +maintainers:
>> +  - MD Danish Anwar <danishanwar@ti.com>
>> +
>> +properties:
>> +  memory-region:
>> +    $ref: /schemas/types.yaml#/definitions/phandle
>> +    description: |
>> +      Phandle to the shared memory region used for communication between the
>> +      host processor and the remote processor.
>> +      This shared memory region is used to exchange Ethernet packets.
>> +
>> +required:
>> +  - memory-region
>> +
>> +additionalProperties: false
> 
> This cannot be really tested and is pointless binding... Really, one
> property does not make it a device node.
> 
> 

I tried to do something similar to google,cros-ec.yaml and
qcom,glink-edge.yaml

They are also rpmsg related and used by other vendors. I created similar
to that as my use case seems similar to them.

The only difference being I only need one property.


-- 
Thanks and Regards,
Danish

Re: [PATCH net-next v2 2/8] dt-bindings: remoteproc: k3-r5f: Add rpmsg-eth subnode

[MD Danish Anwar]

On 03/09/25 12:49 pm, Krzysztof Kozlowski wrote:
> On Tue, Sep 02, 2025 at 02:37:40PM +0530, MD Danish Anwar wrote:
>> Extend the Texas Instruments K3 R5F remoteproc device tree bindings to
>> include a 'rpmsg-eth' subnode.
>>
>> This extension allows the RPMsg Ethernet to be defined as a subnode of
>> K3 R5F remoteproc nodes, enabling the configuration of shared memory-based
>> Ethernet communication between the host and remote processors.
>>
>> Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
>> ---
>>  .../devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml     | 6 ++++++
>>  1 file changed, 6 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml b/Documentation/devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml
>> index a492f74a8608..4dbd708ec8ee 100644
>> --- a/Documentation/devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml
>> +++ b/Documentation/devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml
>> @@ -210,6 +210,12 @@ patternProperties:
>>            should be defined as per the generic bindings in,
>>            Documentation/devicetree/bindings/sram/sram.yaml
>>  
>> +      rpmsg-eth:
>> +        $ref: /schemas/net/ti,rpmsg-eth.yaml
> 
> No, not a separate device. Please read slides from my DT for beginners

I had synced with Andrew and we came to the conclusion that including
rpmsg-eth this way will follow the DT guidelines and should be okay.

I have another approach to handle this.

Instead of a new binding and node. I can just add a new phandle to the
rproc binding. Phandle name `shared-mem-region` or `rpmsg-eth-region`

Below is the device tree and dt binding diff for the same.

diff --git
a/Documentation/devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml
b/Documentation/devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml
index a492f74a8608..c02c99a5a768 100644
--- a/Documentation/devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml
+++ b/Documentation/devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml
@@ -210,6 +210,16 @@ patternProperties:
           should be defined as per the generic bindings in,
           Documentation/devicetree/bindings/sram/sram.yaml

+      rpmsg-eth-region:
+        $ref: /schemas/types.yaml#/definitions/phandle
+        description: |
+          phandle to the reserved memory nodes to be associated with the
+          remoteproc device for rpmsg eth communication. The reserved
memory
+          nodes should be carveout nodes, and should be defined with a
"no-map"
+          property as per the bindings in
+
Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt
+        additionalItems: true
+
     required:
       - compatible
       - reg
diff --git a/arch/arm64/boot/dts/ti/k3-am642-evm.dts
b/arch/arm64/boot/dts/ti/k3-am642-evm.dts
index e01866372293..e70dc542c6be 100644
--- a/arch/arm64/boot/dts/ti/k3-am642-evm.dts
+++ b/arch/arm64/boot/dts/ti/k3-am642-evm.dts
@@ -61,7 +61,13 @@ main_r5fss0_core0_dma_memory_region:
r5f-dma-memory@a0000000 {

 		main_r5fss0_core0_memory_region: r5f-memory@a0100000 {
 			compatible = "shared-dma-pool";
-			reg = <0x00 0xa0100000 0x00 0xf00000>;
+			reg = <0x00 0xa0100000 0x00 0x300000>;
+			no-map;
+		};
+
+		main_r5fss0_core0_memory_region_shm: r5f-shm-memory@a0400000 {
+			compatible = "shared-dma-pool";
+			reg = <0x00 0xa0400000 0x00 0xc00000>;
 			no-map;
 		};

@@ -768,6 +774,7 @@ &main_r5fss0_core0 {
 	mboxes = <&mailbox0_cluster2 &mbox_main_r5fss0_core0>;
 	memory-region = <&main_r5fss0_core0_dma_memory_region>,
 			<&main_r5fss0_core0_memory_region>;
+	rpmsg-eth-region = <&main_r5fss0_core0_memory_region_shm>;
 };

 &main_r5fss0_core1 {


In this approach I am creating a new phandle to a memory region that
will be used by my device.

Can you please let me know if this approach looks okay to you? Or it you
have any other suggestion on how to handle this?

> talk from OSSE25. This is EXACTLY the case I covered there - what not to
> do.

Sure I will have a look at that.

-- 
Thanks and Regards,
Danish

Re: [PATCH net-next v2 2/8] dt-bindings: remoteproc: k3-r5f: Add rpmsg-eth subnode

[Krzysztof Kozlowski]

On 03/09/2025 09:57, MD Danish Anwar wrote:
>>> Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
>>> ---
>>>  .../devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml     | 6 ++++++
>>>  1 file changed, 6 insertions(+)
>>>
>>> diff --git a/Documentation/devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml b/Documentation/devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml
>>> index a492f74a8608..4dbd708ec8ee 100644
>>> --- a/Documentation/devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml
>>> +++ b/Documentation/devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml
>>> @@ -210,6 +210,12 @@ patternProperties:
>>>            should be defined as per the generic bindings in,
>>>            Documentation/devicetree/bindings/sram/sram.yaml
>>>  
>>> +      rpmsg-eth:
>>> +        $ref: /schemas/net/ti,rpmsg-eth.yaml
>>
>> No, not a separate device. Please read slides from my DT for beginners
> 
> I had synced with Andrew and we came to the conclusion that including
> rpmsg-eth this way will follow the DT guidelines and should be okay.

... and did you check the guidelines? Instead of repeating something not
related to my comment rather bring argument matching the comment.


...

> @@ -768,6 +774,7 @@ &main_r5fss0_core0 {
>  	mboxes = <&mailbox0_cluster2 &mbox_main_r5fss0_core0>;
>  	memory-region = <&main_r5fss0_core0_dma_memory_region>,
>  			<&main_r5fss0_core0_memory_region>;
> +	rpmsg-eth-region = <&main_r5fss0_core0_memory_region_shm>;

You already have here memory-region, so use that one.

>  };
> 
>  &main_r5fss0_core1 {
> 
> 
> In this approach I am creating a new phandle to a memory region that
> will be used by my device.



Best regards,
Krzysztof

Re: [PATCH net-next v2 2/8] dt-bindings: remoteproc: k3-r5f: Add rpmsg-eth subnode

[Anwar, Md Danish]

On 9/3/2025 6:24 PM, Krzysztof Kozlowski wrote:
> On 03/09/2025 09:57, MD Danish Anwar wrote:
>>>> Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
>>>> ---
>>>>  .../devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml     | 6 ++++++
>>>>  1 file changed, 6 insertions(+)
>>>>
>>>> diff --git a/Documentation/devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml b/Documentation/devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml
>>>> index a492f74a8608..4dbd708ec8ee 100644
>>>> --- a/Documentation/devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml
>>>> +++ b/Documentation/devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml
>>>> @@ -210,6 +210,12 @@ patternProperties:
>>>>            should be defined as per the generic bindings in,
>>>>            Documentation/devicetree/bindings/sram/sram.yaml
>>>>  
>>>> +      rpmsg-eth:
>>>> +        $ref: /schemas/net/ti,rpmsg-eth.yaml
>>>
>>> No, not a separate device. Please read slides from my DT for beginners
>>
>> I had synced with Andrew and we came to the conclusion that including
>> rpmsg-eth this way will follow the DT guidelines and should be okay.
> 
> ... and did you check the guidelines? Instead of repeating something not
> related to my comment rather bring argument matching the comment.
> 
> 
> ...
> 
>> @@ -768,6 +774,7 @@ &main_r5fss0_core0 {
>>  	mboxes = <&mailbox0_cluster2 &mbox_main_r5fss0_core0>;
>>  	memory-region = <&main_r5fss0_core0_dma_memory_region>,
>>  			<&main_r5fss0_core0_memory_region>;
>> +	rpmsg-eth-region = <&main_r5fss0_core0_memory_region_shm>;
> 
> You already have here memory-region, so use that one.
> 

There is a problem with using memory-region. If I add
`main_r5fss0_core0_memory_region_shm` to memory region, to get this
phandle from driver I would have to use
	
	of_parse_phandle(np, "memory-region", 2)

Where 2 is the index for this region. But the problem is how would the
driver know this index. This index can vary for different vendors and
their rproc device.

If some other vendor tries to use this driver but their memory-region
has 3 existing entries. so this this entry will be the 4th one.

But the driver code won't work for this. We need to have a way to know
which index to look for in existing memory-region which can defer from
vendor to vendor.

So to avoid this, I thought of using a new memory region. Which will
have only 1 entry specifically for this case, and the driver can always

	of_parse_phandle(np, "rpmsg-eth-region", 0)

to get the memory region.

>>  };
>>
>>  &main_r5fss0_core1 {
>>
>>
>> In this approach I am creating a new phandle to a memory region that
>> will be used by my device.
> 
> 
> 
> Best regards,
> Krzysztof

-- 
Thanks and Regards,
Md Danish Anwar

Re: [PATCH net-next v2 2/8] dt-bindings: remoteproc: k3-r5f: Add rpmsg-eth subnode

[Andrew Lunn]

> >>  	mboxes = <&mailbox0_cluster2 &mbox_main_r5fss0_core0>;
> >>  	memory-region = <&main_r5fss0_core0_dma_memory_region>,
> >>  			<&main_r5fss0_core0_memory_region>;
> >> +	rpmsg-eth-region = <&main_r5fss0_core0_memory_region_shm>;
> > 
> > You already have here memory-region, so use that one.
> > 
> 
> There is a problem with using memory-region. If I add
> `main_r5fss0_core0_memory_region_shm` to memory region, to get this
> phandle from driver I would have to use
> 	
> 	of_parse_phandle(np, "memory-region", 2)
> 
> Where 2 is the index for this region. But the problem is how would the
> driver know this index. This index can vary for different vendors and
> their rproc device.
> 
> If some other vendor tries to use this driver but their memory-region
> has 3 existing entries. so this this entry will be the 4th one.

Just adding to this, there is nothing really TI specific in this
system. We want the design so that any vendor can use it, just by
adding the needed nodes to their rpmsg node, indicating there is a
compatible implementation on the other end, and an indication of where
the shared memory is.

Logically, it is a different shared memory. memory-region above is for
the rpmsg mechanism itself. A second shared memory is used for the
Ethernet drivers where it can place Ethernet frames. The Ethernet
frames themselves are not transported over rpmsg. The rpmsg is just
used for the control path, not the data path.

	Andrew

Re: [PATCH net-next v2 2/8] dt-bindings: remoteproc: k3-r5f: Add rpmsg-eth subnode

[Krzysztof Kozlowski]

On 03/09/2025 15:32, Anwar, Md Danish wrote:
> 
> 
> On 9/3/2025 6:24 PM, Krzysztof Kozlowski wrote:
>> On 03/09/2025 09:57, MD Danish Anwar wrote:
>>>>> Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
>>>>> ---
>>>>>  .../devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml     | 6 ++++++
>>>>>  1 file changed, 6 insertions(+)
>>>>>
>>>>> diff --git a/Documentation/devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml b/Documentation/devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml
>>>>> index a492f74a8608..4dbd708ec8ee 100644
>>>>> --- a/Documentation/devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml
>>>>> +++ b/Documentation/devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml
>>>>> @@ -210,6 +210,12 @@ patternProperties:
>>>>>            should be defined as per the generic bindings in,
>>>>>            Documentation/devicetree/bindings/sram/sram.yaml
>>>>>  
>>>>> +      rpmsg-eth:
>>>>> +        $ref: /schemas/net/ti,rpmsg-eth.yaml
>>>>
>>>> No, not a separate device. Please read slides from my DT for beginners
>>>
>>> I had synced with Andrew and we came to the conclusion that including
>>> rpmsg-eth this way will follow the DT guidelines and should be okay.
>>
>> ... and did you check the guidelines? Instead of repeating something not
>> related to my comment rather bring argument matching the comment.
>>
>>
>> ...
>>
>>> @@ -768,6 +774,7 @@ &main_r5fss0_core0 {
>>>  	mboxes = <&mailbox0_cluster2 &mbox_main_r5fss0_core0>;
>>>  	memory-region = <&main_r5fss0_core0_dma_memory_region>,
>>>  			<&main_r5fss0_core0_memory_region>;
>>> +	rpmsg-eth-region = <&main_r5fss0_core0_memory_region_shm>;
>>
>> You already have here memory-region, so use that one.
>>
> 
> There is a problem with using memory-region. If I add
> `main_r5fss0_core0_memory_region_shm` to memory region, to get this
> phandle from driver I would have to use
> 	
> 	of_parse_phandle(np, "memory-region", 2)
> 
> Where 2 is the index for this region. But the problem is how would the
> driver know this index. This index can vary for different vendors and
> their rproc device.

Index is fixed, cannot be anything else. Cannot vary.


> 
> If some other vendor tries to use this driver but their memory-region
> has 3 existing entries. so this this entry will be the 4th one.

None of these are reasons to add completely new node in DT. You use
arguments of drivers in hardware description. Really, can you read the
slides I asked for already?

> 
> But the driver code won't work for this. We need to have a way to know

Driver code can easily work with this. Multiple choices from using names
up to having driver match data with index.

> which index to look for in existing memory-region which can defer from
> vendor to vendor.
> 
> So to avoid this, I thought of using a new memory region. Which will
> have only 1 entry specifically for this case, and the driver can always
> 
> 	of_parse_phandle(np, "rpmsg-eth-region", 0)
> 
> to get the memory region.

Please don't drag the discussion. Look:

Q: I need a child node for my device to instantiate Linux driver"
A: NO

Q: I need new “vendor,foo-prop” property
A: Please look at existing common properties from common schemas or
devices representing similar class

Or actually let's start with most important:

"What Could You Put into DTS?"
Answers:
1. "Not the Linux Device Driver model"
2. "No Linux driver choices"

And that's exactly what you do and how you argue.

Best regards,
Krzysztof

Re: [PATCH net-next v2 2/8] dt-bindings: remoteproc: k3-r5f: Add rpmsg-eth subnode

[Krzysztof Kozlowski]

On 03/09/2025 16:06, Andrew Lunn wrote:
>>>>  	mboxes = <&mailbox0_cluster2 &mbox_main_r5fss0_core0>;
>>>>  	memory-region = <&main_r5fss0_core0_dma_memory_region>,
>>>>  			<&main_r5fss0_core0_memory_region>;
>>>> +	rpmsg-eth-region = <&main_r5fss0_core0_memory_region_shm>;
>>>
>>> You already have here memory-region, so use that one.
>>>
>>
>> There is a problem with using memory-region. If I add
>> `main_r5fss0_core0_memory_region_shm` to memory region, to get this
>> phandle from driver I would have to use
>> 	
>> 	of_parse_phandle(np, "memory-region", 2)
>>
>> Where 2 is the index for this region. But the problem is how would the
>> driver know this index. This index can vary for different vendors and
>> their rproc device.
>>
>> If some other vendor tries to use this driver but their memory-region
>> has 3 existing entries. so this this entry will be the 4th one.
> 
> Just adding to this, there is nothing really TI specific in this
> system. We want the design so that any vendor can use it, just by
> adding the needed nodes to their rpmsg node, indicating there is a
> compatible implementation on the other end, and an indication of where
> the shared memory is.

I don't know your drivers, but I still do not see here a problem with
'memory-region'. You just need to tell this common code which
memory-region phandle by index or name is the one for rpmsg.

> 
> Logically, it is a different shared memory. memory-region above is for
> the rpmsg mechanism itself. A second shared memory is used for the
> Ethernet drivers where it can place Ethernet frames. The Ethernet
> frames themselves are not transported over rpmsg. The rpmsg is just
> used for the control path, not the data path.

It is still "shared-dma-pool", right? Nothing in the bindings says that
all memory-region phandles are equal or the same. Just like phandles for
clocks. Some clocks need to be enabled for entire lifetime of the
device, some are toggled on-off during runtime PM.

Best regards,
Krzysztof