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 <[email protected]> --- 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 <[email protected]>"); +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
