net: Add Qualcomm IPC router

Add an implementation of Qualcomm's IPC router protocol, used to
communicate with service providing remote processors.
Signed-off-by: Courtney Cavin <courtney.cavin@sonymobile.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
[bjorn: Cope with 0 being a valid node id and implement RTM_NEWADDR]
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/socket.h

@@ -201,8 +201,9 @@ struct ucred {
 #define AF_NFC		39	/* NFC sockets			*/
 #define AF_VSOCK	40	/* vSockets			*/
 #define AF_KCM		41	/* Kernel Connection Multiplexor*/
+#define AF_QIPCRTR	42	/* Qualcomm IPC Router          */
 
-#define AF_MAX		42	/* For now.. */
+#define AF_MAX		43	/* For now.. */
 
 /* Protocol families, same as address families. */
 #define PF_UNSPEC	AF_UNSPEC
@@ -249,6 +250,7 @@ struct ucred {
 #define PF_NFC		AF_NFC
 #define PF_VSOCK	AF_VSOCK
 #define PF_KCM		AF_KCM
+#define PF_QIPCRTR	AF_QIPCRTR
 #define PF_MAX		AF_MAX
 
 /* Maximum queue length specifiable by listen.  */

include/uapi/linux/qrtr.h

+#ifndef _LINUX_QRTR_H
+#define _LINUX_QRTR_H
+
+#include <linux/socket.h>
+
+struct sockaddr_qrtr {
+	__kernel_sa_family_t sq_family;
+	__u32 sq_node;
+	__u32 sq_port;
+};
+
+#endif /* _LINUX_QRTR_H */

net/Kconfig

@@ -236,6 +236,7 @@ source "net/mpls/Kconfig"
 source "net/hsr/Kconfig"
 source "net/switchdev/Kconfig"
 source "net/l3mdev/Kconfig"
+source "net/qrtr/Kconfig"
 
 config RPS
 	bool

net/Makefile

@@ -78,3 +78,4 @@ endif
 ifneq ($(CONFIG_NET_L3_MASTER_DEV),)
 obj-y				+= l3mdev/
 endif
+obj-$(CONFIG_QRTR)		+= qrtr/

net/qrtr/Kconfig

+# Qualcomm IPC Router configuration
+#
+
+config QRTR
+	tristate "Qualcomm IPC Router support"
+	depends on ARCH_QCOM || COMPILE_TEST
+	---help---
+	  Say Y if you intend to use Qualcomm IPC router protocol.  The
+	  protocol is used to communicate with services provided by other
+	  hardware blocks in the system.
+
+	  In order to do service lookups, a userspace daemon is required to
+	  maintain a service listing.
+
+if QRTR
+
+config QRTR_SMD
+	tristate "SMD IPC Router channels"
+	depends on QCOM_SMD || COMPILE_TEST
+	---help---
+	  Say Y here to support SMD based ipcrouter channels.  SMD is the
+	  most common transport for IPC Router.
+
+endif # QRTR

net/qrtr/Makefile

+obj-$(CONFIG_QRTR) := qrtr.o
+obj-$(CONFIG_QRTR_SMD) += smd.o

net/qrtr/qrtr.h

+#ifndef __QRTR_H_
+#define __QRTR_H_
+
+#include <linux/types.h>
+
+struct sk_buff;
+
+/* endpoint node id auto assignment */
+#define QRTR_EP_NID_AUTO (-1)
+
+/**
+ * struct qrtr_endpoint - endpoint handle
+ * @xmit: Callback for outgoing packets
+ *
+ * The socket buffer passed to the xmit function becomes owned by the endpoint
+ * driver.  As such, when the driver is done with the buffer, it should
+ * call kfree_skb() on failure, or consume_skb() on success.
+ */
+struct qrtr_endpoint {
+	int (*xmit)(struct qrtr_endpoint *ep, struct sk_buff *skb);
+	/* private: not for endpoint use */
+	struct qrtr_node *node;
+};
+
+int qrtr_endpoint_register(struct qrtr_endpoint *ep, unsigned int nid);
+
+void qrtr_endpoint_unregister(struct qrtr_endpoint *ep);
+
+int qrtr_endpoint_post(struct qrtr_endpoint *ep, const void *data, size_t len);
+
+#endif

net/qrtr/smd.c

+/*
+ * Copyright (c) 2015, Sony Mobile Communications Inc.
+ * Copyright (c) 2013, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/soc/qcom/smd.h>
+
+#include "qrtr.h"
+
+struct qrtr_smd_dev {
+	struct qrtr_endpoint ep;
+	struct qcom_smd_channel *channel;
+};
+
+/* from smd to qrtr */
+static int qcom_smd_qrtr_callback(struct qcom_smd_device *sdev,
+				  const void *data, size_t len)
+{
+	struct qrtr_smd_dev *qdev = dev_get_drvdata(&sdev->dev);
+	int rc;
+
+	if (!qdev)
+		return -EAGAIN;
+
+	rc = qrtr_endpoint_post(&qdev->ep, data, len);
+	if (rc == -EINVAL) {
+		dev_err(&sdev->dev, "invalid ipcrouter packet\n");
+		/* return 0 to let smd drop the packet */
+		rc = 0;
+	}
+
+	return rc;
+}
+
+/* from qrtr to smd */
+static int qcom_smd_qrtr_send(struct qrtr_endpoint *ep, struct sk_buff *skb)
+{
+	struct qrtr_smd_dev *qdev = container_of(ep, struct qrtr_smd_dev, ep);
+	int rc;
+
+	rc = skb_linearize(skb);
+	if (rc)
+		goto out;
+
+	rc = qcom_smd_send(qdev->channel, skb->data, skb->len);
+
+out:
+	if (rc)
+		kfree_skb(skb);
+	else
+		consume_skb(skb);
+	return rc;
+}
+
+static int qcom_smd_qrtr_probe(struct qcom_smd_device *sdev)
+{
+	struct qrtr_smd_dev *qdev;
+	int rc;
+
+	qdev = devm_kzalloc(&sdev->dev, sizeof(*qdev), GFP_KERNEL);
+	if (!qdev)
+		return -ENOMEM;
+
+	qdev->channel = sdev->channel;
+	qdev->ep.xmit = qcom_smd_qrtr_send;
+
+	rc = qrtr_endpoint_register(&qdev->ep, QRTR_EP_NID_AUTO);
+	if (rc)
+		return rc;
+
+	dev_set_drvdata(&sdev->dev, qdev);
+
+	dev_dbg(&sdev->dev, "Qualcomm SMD QRTR driver probed\n");
+
+	return 0;
+}
+
+static void qcom_smd_qrtr_remove(struct qcom_smd_device *sdev)
+{
+	struct qrtr_smd_dev *qdev = dev_get_drvdata(&sdev->dev);
+
+	qrtr_endpoint_unregister(&qdev->ep);
+
+	dev_set_drvdata(&sdev->dev, NULL);
+}
+
+static const struct qcom_smd_id qcom_smd_qrtr_smd_match[] = {
+	{ "IPCRTR" },
+	{}
+};
+
+static struct qcom_smd_driver qcom_smd_qrtr_driver = {
+	.probe = qcom_smd_qrtr_probe,
+	.remove = qcom_smd_qrtr_remove,
+	.callback = qcom_smd_qrtr_callback,
+	.smd_match_table = qcom_smd_qrtr_smd_match,
+	.driver = {
+		.name = "qcom_smd_qrtr",
+		.owner = THIS_MODULE,
+	},
+};
+
+module_qcom_smd_driver(qcom_smd_qrtr_driver);
+
+MODULE_DESCRIPTION("Qualcomm IPC-Router SMD interface driver");
+MODULE_LICENSE("GPL v2");