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Message-ID: <26a85bae-1a33-dd1f-5e73-0ab6da100abf@quicinc.com>
Date:   Wed, 7 Jun 2023 10:27:47 -0600
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Subject: Re: [PATCH v2 1/2] net: Add MHI Endpoint network driver
Content-Language: en-US
To:     Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>,
        <davem@davemloft.net>, <edumazet@google.com>, <kuba@kernel.org>,
        <pabeni@redhat.com>
CC:     <mhi@lists.linux.dev>, <linux-arm-msm@vger.kernel.org>,
        <netdev@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <loic.poulain@linaro.org>
References: <20230607152427.108607-1-manivannan.sadhasivam@linaro.org>
 <20230607152427.108607-2-manivannan.sadhasivam@linaro.org>
From:   Jeffrey Hugo <quic_jhugo@quicinc.com>
In-Reply-To: <20230607152427.108607-2-manivannan.sadhasivam@linaro.org>
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On 6/7/2023 9:24 AM, Manivannan Sadhasivam wrote:
> Add a network driver for the Modem Host Interface (MHI) endpoint devices
> that provides network interfaces to the PCIe based Qualcomm endpoint
> devices supporting MHI bus. This driver allows the MHI endpoint devices to
> establish IP communication with the host machines (x86, ARM64) over MHI
> bus.
> 
> The driver currently supports only IP_SW0 MHI channel that can be used
> to route IP traffic from the endpoint CPU to host machine.
> 
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> ---
>   drivers/net/Kconfig      |   9 ++
>   drivers/net/Makefile     |   1 +
>   drivers/net/mhi_ep_net.c | 331 +++++++++++++++++++++++++++++++++++++++
>   3 files changed, 341 insertions(+)
>   create mode 100644 drivers/net/mhi_ep_net.c
> 
> diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
> index 368c6f5b327e..36b628e2e49f 100644
> --- a/drivers/net/Kconfig
> +++ b/drivers/net/Kconfig
> @@ -452,6 +452,15 @@ config MHI_NET
>   	  QCOM based WWAN modems for IP or QMAP/rmnet protocol (like SDX55).
>   	  Say Y or M.
>   
> +config MHI_EP_NET
> +	tristate "MHI Endpoint network driver"
> +	depends on MHI_BUS_EP
> +	help
> +	  This is the network driver for MHI bus implementation in endpoint
> +	  devices. It is used provide the network interface for QCOM endpoint
> +	  devices such as SDX55 modems.
> +	  Say Y or M.

What will the module be called if "m" is selected?

> +
>   endif # NET_CORE
>   
>   config SUNGEM_PHY
> diff --git a/drivers/net/Makefile b/drivers/net/Makefile
> index e26f98f897c5..b8e706a4150e 100644
> --- a/drivers/net/Makefile
> +++ b/drivers/net/Makefile
> @@ -40,6 +40,7 @@ obj-$(CONFIG_NLMON) += nlmon.o
>   obj-$(CONFIG_NET_VRF) += vrf.o
>   obj-$(CONFIG_VSOCKMON) += vsockmon.o
>   obj-$(CONFIG_MHI_NET) += mhi_net.o
> +obj-$(CONFIG_MHI_EP_NET) += mhi_ep_net.o
>   
>   #
>   # Networking Drivers
> diff --git a/drivers/net/mhi_ep_net.c b/drivers/net/mhi_ep_net.c
> new file mode 100644
> index 000000000000..0d7939caefc7
> --- /dev/null
> +++ b/drivers/net/mhi_ep_net.c
> @@ -0,0 +1,331 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * MHI Endpoint Network driver
> + *
> + * Based on drivers/net/mhi_net.c
> + *
> + * Copyright (c) 2023, Linaro Ltd.
> + * Author: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> + */
> +
> +#include <linux/if_arp.h>
> +#include <linux/mhi_ep.h>
> +#include <linux/mod_devicetable.h>
> +#include <linux/module.h>
> +#include <linux/netdevice.h>
> +#include <linux/skbuff.h>
> +#include <linux/u64_stats_sync.h>
> +
> +#define MHI_NET_MIN_MTU		ETH_MIN_MTU
> +#define MHI_NET_MAX_MTU		0xffff
> +
> +struct mhi_ep_net_stats {
> +	u64_stats_t rx_packets;
> +	u64_stats_t rx_bytes;
> +	u64_stats_t rx_errors;
> +	u64_stats_t tx_packets;
> +	u64_stats_t tx_bytes;
> +	u64_stats_t tx_errors;
> +	u64_stats_t tx_dropped;
> +	struct u64_stats_sync tx_syncp;
> +	struct u64_stats_sync rx_syncp;
> +};
> +
> +struct mhi_ep_net_dev {
> +	struct mhi_ep_device *mdev;
> +	struct net_device *ndev;
> +	struct mhi_ep_net_stats stats;
> +	struct workqueue_struct *xmit_wq;
> +	struct work_struct xmit_work;
> +	struct sk_buff_head tx_buffers;
> +	spinlock_t tx_lock; /* Lock for protecting tx_buffers */
> +	u32 mru;
> +};
> +
> +static void mhi_ep_net_dev_process_queue_packets(struct work_struct *work)
> +{
> +	struct mhi_ep_net_dev *mhi_ep_netdev = container_of(work,
> +			struct mhi_ep_net_dev, xmit_work);

Looks like this can fit all on one line to me.