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Commit 61a6bc5b authored by Chris Lew's avatar Chris Lew
Browse files

net: qrtr: Introduce MHI transport for qrtr 



MHI is used to communicate with external modems. Add MHI support for
QRTR to support QMI traffic between an external modem and the local
processor.

This change squashes the following commits from msm-4.14:
  commit cb30e68df75b ("qrtr: Introduce MHI transport for qrtr")
  commit 09915150093b ("qrtr: mhi: Configure IPC mhi channel to autostart")
  commit 76663f56fb8c ("net: qrtr: mhi: Create list for pending ul
                       transfers")
  commit 7be78c8d6afa ("net: qrtr: mhi: Register for early notifications")
  commit c0e7627fca46 ("net: qrtr: mhi: Use spin_lock_bh in
                       qcom_mhi_qrtr_send")
  commit e5f6a6769ceb ("net: qrtr: Add forwarding support based on net id")
  commit a42f90b127d8 ("net: qrtr: Make qrtr rx threads as RT priorities")
  commit 3358eee17fec ("net: qrtr: Send HELLO message on endpoint
		       register")

This change squashes the following commits from msm-4.19:
  commit 35ea4352871d ("net: qrtr: mhi: check whether ul pkt list is
		       empty")

Change-Id: I8d3ba9e9d48a7c37e21031c2ad1f27329dfdab6d
Signed-off-by: default avatarChris Lew <clew@codeaurora.org>
parent 1ee0801d

net/qrtr/Kconfig

+9 −0
Original line number Diff line number Diff line
@@ -40,4 +40,13 @@ 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 || (COMPILE_TEST && MHI_BUS=n)

	help

	  Say Y here to support MHI based ipcrouter channels.  MHI is the

	  transport used for external modem connections for IPC Router. The

	  MHI transport fakes synchronous sends by waiting for the uplink

	  callback from the MHI framework before returing to qrtr core.



endif # QRTR

net/qrtr/Makefile

+2 −0
Original line number Diff line number Diff line
@@ -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

net/qrtr/mhi.c

0 → 100644
+215 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-only

/* Copyright (c) 2018-2020, The Linux Foundation. All rights reserved. */



#include <linux/module.h>

#include <linux/skbuff.h>

#include <linux/mod_devicetable.h>

#include <linux/mhi.h>

#include <net/sock.h>

#include <linux/of.h>



#include "qrtr.h"



struct qrtr_mhi_dev {

	struct qrtr_endpoint ep;

	struct mhi_device *mhi_dev;

	struct device *dev;

	spinlock_t ul_lock;		/* lock to protect ul_pkts */

	struct list_head ul_pkts;

	atomic_t in_reset;

};



struct qrtr_mhi_pkt {

	struct list_head node;

	struct sk_buff *skb;

	struct kref refcount;

	struct completion done;

};



static void qrtr_mhi_pkt_release(struct kref *ref)

{

	struct qrtr_mhi_pkt *pkt = container_of(ref, struct qrtr_mhi_pkt,

						refcount);

	struct sock *sk = pkt->skb->sk;



	consume_skb(pkt->skb);

	if (sk)

		sock_put(sk);

	kfree(pkt);

}



/* 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 mhi to qrtr */

static void qcom_mhi_qrtr_ul_callback(struct mhi_device *mhi_dev,

				      struct mhi_result *mhi_res)

{

	struct qrtr_mhi_dev *qdev = dev_get_drvdata(&mhi_dev->dev);

	struct qrtr_mhi_pkt *pkt;

	unsigned long flags;



	spin_lock_irqsave(&qdev->ul_lock, flags);

	if (list_empty(&qdev->ul_pkts)) {

		spin_unlock_irqrestore(&qdev->ul_lock, flags);

		dev_err(qdev->dev, "ul_pkt list is empty\n");

		return;

	}

	pkt = list_first_entry(&qdev->ul_pkts, struct qrtr_mhi_pkt, node);

	list_del(&pkt->node);

	complete_all(&pkt->done);



	kref_put(&pkt->refcount, qrtr_mhi_pkt_release);

	spin_unlock_irqrestore(&qdev->ul_lock, flags);

}



/* fatal error */

static void qcom_mhi_qrtr_status_callback(struct mhi_device *mhi_dev,

					  enum MHI_CB mhi_cb)

{

	struct qrtr_mhi_dev *qdev = dev_get_drvdata(&mhi_dev->dev);

	struct qrtr_mhi_pkt *pkt;

	unsigned long flags;



	if (mhi_cb != MHI_CB_FATAL_ERROR)

		return;



	atomic_inc(&qdev->in_reset);

	spin_lock_irqsave(&qdev->ul_lock, flags);

	list_for_each_entry(pkt, &qdev->ul_pkts, node)

		complete_all(&pkt->done);

	spin_unlock_irqrestore(&qdev->ul_lock, flags);

}



/* from qrtr to 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);

	struct qrtr_mhi_pkt *pkt;

	int rc;



	rc = skb_linearize(skb);

	if (rc) {

		kfree_skb(skb);

		return rc;

	}



	pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);

	if (!pkt) {

		kfree_skb(skb);

		return -ENOMEM;

	}



	init_completion(&pkt->done);

	kref_init(&pkt->refcount);

	kref_get(&pkt->refcount);

	pkt->skb = skb;



	spin_lock_bh(&qdev->ul_lock);

	list_add_tail(&pkt->node, &qdev->ul_pkts);

	rc = mhi_queue_transfer(qdev->mhi_dev, DMA_TO_DEVICE, skb, skb->len,

				MHI_EOT);

	if (rc) {

		list_del(&pkt->node);

		kfree_skb(skb);

		kfree(pkt);

		spin_unlock_bh(&qdev->ul_lock);

		return rc;

	}

	spin_unlock_bh(&qdev->ul_lock);

	if (skb->sk)

		sock_hold(skb->sk);



	rc = wait_for_completion_interruptible_timeout(&pkt->done, HZ * 5);

	if (atomic_read(&qdev->in_reset))

		rc = -ECONNRESET;

	else if (rc == 0)

		rc = -ETIMEDOUT;

	else if (rc > 0)

		rc = 0;



	kref_put(&pkt->refcount, qrtr_mhi_pkt_release);

	return rc;

}



static int qcom_mhi_qrtr_probe(struct mhi_device *mhi_dev,

			       const struct mhi_device_id *id)

{

	struct qrtr_mhi_dev *qdev;

	u32 net_id;

	bool rt;

	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;

	atomic_set(&qdev->in_reset, 0);



	rc = of_property_read_u32(mhi_dev->dev.of_node, "qcom,net-id", &net_id);

	if (rc < 0)

		net_id = QRTR_EP_NET_ID_AUTO;



	rt = of_property_read_bool(mhi_dev->dev.of_node, "qcom,low-latency");



	INIT_LIST_HEAD(&qdev->ul_pkts);

	spin_lock_init(&qdev->ul_lock);



	rc = qrtr_endpoint_register(&qdev->ep, net_id, rt);

	if (rc)

		return rc;



	dev_set_drvdata(&mhi_dev->dev, qdev);



	dev_dbg(qdev->dev, "QTI 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_mhi_match[] = {

	{ .chan = "IPCR" },

	{}

};



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,

	.status_cb = qcom_mhi_qrtr_status_callback,

	.id_table = qcom_mhi_qrtr_mhi_match,

	.driver = {

		.name = "qcom_mhi_qrtr",

		.owner = THIS_MODULE,

	},

};



module_driver(qcom_mhi_qrtr_driver, mhi_driver_register,

	      mhi_driver_unregister);



MODULE_DESCRIPTION("QTI IPC-Router MHI interface driver");

MODULE_LICENSE("GPL v2");