diff mbox series

[v3,14/16] net: qrtr: Add MHI transport layer

Message ID 20200220095854.4804-15-manivannan.sadhasivam@linaro.org (mailing list archive)
State New, archived
Headers show
Series Add MHI bus support | expand

Commit Message

Manivannan Sadhasivam Feb. 20, 2020, 9:58 a.m. UTC
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.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 net/qrtr/Kconfig  |   7 ++
 net/qrtr/Makefile |   2 +
 net/qrtr/mhi.c    | 209 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 218 insertions(+)
 create mode 100644 net/qrtr/mhi.c

Comments

Greg Kroah-Hartman March 18, 2020, 2:42 p.m. UTC | #1
On Thu, Feb 20, 2020 at 03:28:52PM +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.
> 
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: netdev@vger.kernel.org
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> ---
>  net/qrtr/Kconfig  |   7 ++
>  net/qrtr/Makefile |   2 +
>  net/qrtr/mhi.c    | 209 ++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 218 insertions(+)
>  create mode 100644 net/qrtr/mhi.c

I stopped here in this series, as I do not feel comfortable merging
stuff under net/.

Can you get some review by the networking developers and then I will be
ok with taking it through my tree.

thanks,

greg k-h
Manivannan Sadhasivam March 18, 2020, 2:53 p.m. UTC | #2
Hi Greg,

On Wed, Mar 18, 2020 at 03:42:46PM +0100, Greg KH wrote:
> On Thu, Feb 20, 2020 at 03:28:52PM +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.
> > 
> > Cc: "David S. Miller" <davem@davemloft.net>
> > Cc: netdev@vger.kernel.org
> > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> > ---
> >  net/qrtr/Kconfig  |   7 ++
> >  net/qrtr/Makefile |   2 +
> >  net/qrtr/mhi.c    | 209 ++++++++++++++++++++++++++++++++++++++++++++++
> >  3 files changed, 218 insertions(+)
> >  create mode 100644 net/qrtr/mhi.c
> 
> I stopped here in this series, as I do not feel comfortable merging
> stuff under net/.
> 
> Can you get some review by the networking developers and then I will be
> ok with taking it through my tree.
> 

Sure.

Dave, can you please look into this patch? Greg merged the remaining patches
to his char-misc-testing branch. And if you can provide review, all can go
through Greg's tree.

Thanks,
Mani

> thanks,
> 
> greg k-h
diff mbox series

Patch

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 1c6d6c120fb7..3dc0a7c9d455 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..fcfba3673d59
--- /dev/null
+++ b/net/qrtr/mhi.c
@@ -0,0 +1,209 @@ 
+// 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;
+	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 QRTR to MHI */
+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);
+	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);
+}
+
+static void qcom_mhi_qrtr_status_callback(struct mhi_device *mhi_dev,
+					  enum mhi_callback 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);
+}
+
+/* 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);
+	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_skb(qdev->mhi_dev, DMA_TO_DEVICE, skb, skb->len,
+			   MHI_EOT);
+	if (rc) {
+		list_del(&pkt->node);
+		/* Reference count needs to be dropped 2 times */
+		kref_put(&pkt->refcount, qrtr_mhi_pkt_release);
+		kref_put(&pkt->refcount, qrtr_mhi_pkt_release);
+		kfree_skb(skb);
+		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;
+	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);
+
+	net_id = QRTR_EP_NID_AUTO;
+
+	INIT_LIST_HEAD(&qdev->ul_pkts);
+	spin_lock_init(&qdev->ul_lock);
+
+	dev_set_drvdata(&mhi_dev->dev, qdev);
+	rc = qrtr_endpoint_register(&qdev->ep, net_id);
+	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,
+	.status_cb = qcom_mhi_qrtr_status_callback,
+	.id_table = qcom_mhi_qrtr_id_table,
+	.driver = {
+		.name = "qcom_mhi_qrtr",
+	},
+};
+
+module_driver(qcom_mhi_qrtr_driver, mhi_driver_register,
+	      mhi_driver_unregister);
+
+MODULE_DESCRIPTION("Qualcomm IPC-Router MHI interface driver");
+MODULE_LICENSE("GPL v2");