Re: [PATCH v3 2/3] net: qrtr: Add MHI transport layer

From: Manivannan Sadhasivam
Date: Mon May 04 2020 - 10:49:19 EST


Hi Dave,

On Mon, Apr 27, 2020 at 01:28:28PM +0530, Manivannan Sadhasivam wrote:
> MHI is the transport layer used for communicating to the external modems.
> Hence, this commit adds MHI transport layer support to QRTR for
> transferring the QMI messages over IPC Router.
>

Can you please review this driver? It'd be great if this ends up in v5.8
along with all other MHI patches.

Thanks,
Mani

> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
> Cc: netdev@xxxxxxxxxxxxxxx
> Reviewed-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
> ---
> net/qrtr/Kconfig | 7 +++
> net/qrtr/Makefile | 2 +
> net/qrtr/mhi.c | 127 ++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 136 insertions(+)
> create mode 100644 net/qrtr/mhi.c
>
> diff --git a/net/qrtr/Kconfig b/net/qrtr/Kconfig
> index 63f89cc6e82c..8eb876471564 100644
> --- a/net/qrtr/Kconfig
> +++ b/net/qrtr/Kconfig
> @@ -29,4 +29,11 @@ config QRTR_TUN
> implement endpoints of QRTR, for purpose of tunneling data to other
> hosts or testing purposes.
>
> +config QRTR_MHI
> + tristate "MHI IPC Router channels"
> + depends on MHI_BUS
> + help
> + Say Y here to support MHI based ipcrouter channels. MHI is the
> + transport used for communicating to external modems.
> +
> endif # QRTR
> diff --git a/net/qrtr/Makefile b/net/qrtr/Makefile
> index 32d4e923925d..1b1411d158a7 100644
> --- a/net/qrtr/Makefile
> +++ b/net/qrtr/Makefile
> @@ -5,3 +5,5 @@ obj-$(CONFIG_QRTR_SMD) += qrtr-smd.o
> qrtr-smd-y := smd.o
> obj-$(CONFIG_QRTR_TUN) += qrtr-tun.o
> qrtr-tun-y := tun.o
> +obj-$(CONFIG_QRTR_MHI) += qrtr-mhi.o
> +qrtr-mhi-y := mhi.o
> diff --git a/net/qrtr/mhi.c b/net/qrtr/mhi.c
> new file mode 100644
> index 000000000000..2a2abf5b070d
> --- /dev/null
> +++ b/net/qrtr/mhi.c
> @@ -0,0 +1,127 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2018-2020, The Linux Foundation. All rights reserved.
> + */
> +
> +#include <linux/mhi.h>
> +#include <linux/mod_devicetable.h>
> +#include <linux/module.h>
> +#include <linux/skbuff.h>
> +#include <net/sock.h>
> +
> +#include "qrtr.h"
> +
> +struct qrtr_mhi_dev {
> + struct qrtr_endpoint ep;
> + struct mhi_device *mhi_dev;
> + struct device *dev;
> +};
> +
> +/* From MHI to QRTR */
> +static void qcom_mhi_qrtr_dl_callback(struct mhi_device *mhi_dev,
> + struct mhi_result *mhi_res)
> +{
> + struct qrtr_mhi_dev *qdev = dev_get_drvdata(&mhi_dev->dev);
> + int rc;
> +
> + if (!qdev || mhi_res->transaction_status)
> + return;
> +
> + rc = qrtr_endpoint_post(&qdev->ep, mhi_res->buf_addr,
> + mhi_res->bytes_xferd);
> + if (rc == -EINVAL)
> + dev_err(qdev->dev, "invalid ipcrouter packet\n");
> +}
> +
> +/* From QRTR to MHI */
> +static void qcom_mhi_qrtr_ul_callback(struct mhi_device *mhi_dev,
> + struct mhi_result *mhi_res)
> +{
> + struct sk_buff *skb = (struct sk_buff *)mhi_res->buf_addr;
> +
> + if (skb->sk)
> + sock_put(skb->sk);
> + consume_skb(skb);
> +}
> +
> +/* Send data over MHI */
> +static int qcom_mhi_qrtr_send(struct qrtr_endpoint *ep, struct sk_buff *skb)
> +{
> + struct qrtr_mhi_dev *qdev = container_of(ep, struct qrtr_mhi_dev, ep);
> + int rc;
> +
> + rc = skb_linearize(skb);
> + if (rc)
> + goto free_skb;
> +
> + rc = mhi_queue_skb(qdev->mhi_dev, DMA_TO_DEVICE, skb, skb->len,
> + MHI_EOT);
> + if (rc)
> + goto free_skb;
> +
> + if (skb->sk)
> + sock_hold(skb->sk);
> +
> + return rc;
> +
> +free_skb:
> + kfree_skb(skb);
> +
> + return rc;
> +}
> +
> +static int qcom_mhi_qrtr_probe(struct mhi_device *mhi_dev,
> + const struct mhi_device_id *id)
> +{
> + struct qrtr_mhi_dev *qdev;
> + int rc;
> +
> + qdev = devm_kzalloc(&mhi_dev->dev, sizeof(*qdev), GFP_KERNEL);
> + if (!qdev)
> + return -ENOMEM;
> +
> + qdev->mhi_dev = mhi_dev;
> + qdev->dev = &mhi_dev->dev;
> + qdev->ep.xmit = qcom_mhi_qrtr_send;
> +
> + dev_set_drvdata(&mhi_dev->dev, qdev);
> + rc = qrtr_endpoint_register(&qdev->ep, QRTR_EP_NID_AUTO);
> + if (rc)
> + return rc;
> +
> + dev_dbg(qdev->dev, "Qualcomm MHI QRTR driver probed\n");
> +
> + return 0;
> +}
> +
> +static void qcom_mhi_qrtr_remove(struct mhi_device *mhi_dev)
> +{
> + struct qrtr_mhi_dev *qdev = dev_get_drvdata(&mhi_dev->dev);
> +
> + qrtr_endpoint_unregister(&qdev->ep);
> + dev_set_drvdata(&mhi_dev->dev, NULL);
> +}
> +
> +static const struct mhi_device_id qcom_mhi_qrtr_id_table[] = {
> + { .chan = "IPCR" },
> + {}
> +};
> +MODULE_DEVICE_TABLE(mhi, qcom_mhi_qrtr_id_table);
> +
> +static struct mhi_driver qcom_mhi_qrtr_driver = {
> + .probe = qcom_mhi_qrtr_probe,
> + .remove = qcom_mhi_qrtr_remove,
> + .dl_xfer_cb = qcom_mhi_qrtr_dl_callback,
> + .ul_xfer_cb = qcom_mhi_qrtr_ul_callback,
> + .id_table = qcom_mhi_qrtr_id_table,
> + .driver = {
> + .name = "qcom_mhi_qrtr",
> + },
> +};
> +
> +module_mhi_driver(qcom_mhi_qrtr_driver);
> +
> +MODULE_AUTHOR("Chris Lew <clew@xxxxxxxxxxxxxx>");
> +MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>");
> +MODULE_DESCRIPTION("Qualcomm IPC-Router MHI interface driver");
> +MODULE_LICENSE("GPL v2");
> --
> 2.17.1
>