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Message-ID: <20250908090746.862407-3-danishanwar@ti.com>
Date: Mon, 8 Sep 2025 14:37:41 +0530
From: MD Danish Anwar <danishanwar@...com>
To: "David S. Miller" <davem@...emloft.net>,
Eric Dumazet
<edumazet@...gle.com>, Jakub Kicinski <kuba@...nel.org>,
Paolo Abeni
<pabeni@...hat.com>, Simon Horman <horms@...nel.org>,
Jonathan Corbet
<corbet@....net>, Nishanth Menon <nm@...com>,
Vignesh Raghavendra
<vigneshr@...com>,
Tero Kristo <kristo@...nel.org>, Rob Herring
<robh@...nel.org>,
Krzysztof Kozlowski <krzk+dt@...nel.org>,
Conor Dooley
<conor+dt@...nel.org>,
Andrew Lunn <andrew+netdev@...n.ch>,
MD Danish Anwar
<danishanwar@...com>,
Mengyuan Lou <mengyuanlou@...-swift.com>,
Luo Jie
<quic_luoj@...cinc.com>, Fan Gong <gongfan1@...wei.com>,
Lei Wei
<quic_leiwei@...cinc.com>,
Michael Ellerman <mpe@...erman.id.au>, Lee Trager
<lee@...ger.us>,
Lorenzo Bianconi <lorenzo@...nel.org>,
Parthiban Veerasooran
<Parthiban.Veerasooran@...rochip.com>,
Geert Uytterhoeven
<geert+renesas@...der.be>,
Lukas Bulwahn <lukas.bulwahn@...hat.com>
CC: <netdev@...r.kernel.org>, <linux-doc@...r.kernel.org>,
<linux-kernel@...r.kernel.org>, <linux-arm-kernel@...ts.infradead.org>,
<devicetree@...r.kernel.org>
Subject: [PATCH net-next v3 2/7] net: rpmsg-eth: Add basic rpmsg skeleton
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@...com>
---
drivers/net/ethernet/Kconfig | 10 +++
drivers/net/ethernet/Makefile | 1 +
drivers/net/ethernet/rpmsg_eth.c | 142 +++++++++++++++++++++++++++++++
drivers/net/ethernet/rpmsg_eth.h | 85 ++++++++++++++++++
4 files changed, 238 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..b375dfd9cf1c
--- /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/io.h>
+#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, *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;
+ }
+
+ /* Parse the memory-region phandle */
+ rmem_np = of_parse_phandle(np, "memory-region", common->data.shm_region_index);
+ of_node_put(np);
+ 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;
+ common->data = *(const struct rpmsg_eth_data *)rpdev->id.driver_data;
+ dev_err(dev, "shm_index = %d\n", common->data.shm_region_index);
+
+ 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 const struct rpmsg_eth_data ti_rpmsg_eth_data = {
+ .shm_region_index = 2,
+};
+
+static struct rpmsg_device_id rpmsg_eth_id_table[] = {
+ { .name = "ti.shm-eth", .driver_data = (kernel_ulong_t)&ti_rpmsg_eth_data },
+ {},
+};
+MODULE_DEVICE_TABLE(rpmsg, rpmsg_eth_id_table);
+
+static struct rpmsg_driver rpmsg_eth_rpmsg_client = {
+ .drv.name = KBUILD_MODNAME,
+ .id_table = rpmsg_eth_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@...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..7c8ae57fcf07
--- /dev/null
+++ b/drivers/net/ethernet/rpmsg_eth.h
@@ -0,0 +1,85 @@
+/* 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 prueth_pdata - RPMSG ETH device data
+ * @shm_region_index: Shared memory region index
+ */
+struct rpmsg_eth_data {
+ u8 shm_region_index;
+};
+
+/**
+ * struct rpmsg_eth_common - common structure for RPMSG Ethernet
+ * @rpdev: RPMSG device
+ * @port: Ethernet port
+ * @dev: Device
+ * @data: Vendor specific data
+ */
+struct rpmsg_eth_common {
+ struct rpmsg_device *rpdev;
+ struct rpmsg_eth_port *port;
+ struct device *dev;
+ struct rpmsg_eth_data data;
+};
+
+/**
+ * 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
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