net: add rpmsg sockets and a userland demo app

Warning: this is still completely preliminary and buggy.

It's only here to assist folks who needs this for development.

Signed-off-by: Ohad Ben-Cohen <[email protected]>

drivers/rpmsg/virtio_rpmsg_bus.c

@@ -51,6 +51,7 @@
  * @sendq:	wait queue of sending contexts waiting for a tx buffers
  * @sleepers:	number of senders that are waiting for a tx buffer
  * @ns_ept:	the bus's name service endpoint
+ * @id:		unique system-wide index id for this vproc
  *
  * This structure stores the rpmsg state of a given virtio remote processor
  * device (there might be several virtio proc devices for each physical
@@ -68,8 +69,15 @@ struct virtproc_info {
 	wait_queue_head_t sendq;
 	atomic_t sleepers;
 	struct rpmsg_endpoint *ns_ept;
+	int id;
 };
 
+int get_virtproc_id(struct virtproc_info *vrp)
+{
+	return vrp->id;
+}
+EXPORT_SYMBOL(get_virtproc_id);
+
 /**
  * struct rpmsg_channel_info - internal channel info representation
  * @name: name of service
@@ -133,6 +141,16 @@ rpmsg_show_attr(src, src, "0x%x\n");
 rpmsg_show_attr(dst, dst, "0x%x\n");
 rpmsg_show_attr(announce, announce ? "true" : "false", "%s\n");
 
+/*
+ * The virtio devices we are probed with represent remote processors
+ * on the system. We call them _virtual_ processors, because every physical
+ * remote processor might actually have several virtio devices.
+ *
+ * The idr below is used to assign each vproc a unique, system-wide, index id.
+ */
+static struct idr vprocs;
+static DEFINE_MUTEX(vprocs_mutex);
+
 /*
  * Unique (and free running) index for rpmsg devices.
  *
@@ -499,7 +517,7 @@ static int rpmsg_channel_match(struct device *dev, void *data)
  * this function will be used to create both static and dynamic
  * channels.
  */
-static struct rpmsg_channel *rpmsg_create_channel(struct virtproc_info *vrp,
+static struct rpmsg_channel *__rpmsg_create_channel(struct virtproc_info *vrp,
 				struct rpmsg_channel_info *chinfo)
 {
 	struct rpmsg_channel *rpdev;
@@ -555,7 +573,7 @@ static struct rpmsg_channel *rpmsg_create_channel(struct virtproc_info *vrp,
  * find an existing channel using its name + address properties,
  * and destroy it
  */
-static int rpmsg_destroy_channel(struct virtproc_info *vrp,
+static int __rpmsg_destroy_channel(struct virtproc_info *vrp,
 					struct rpmsg_channel_info *chinfo)
 {
 	struct virtio_device *vdev = vrp->vdev;
@@ -874,6 +892,25 @@ static void rpmsg_xmit_done(struct virtqueue *svq)
 	wake_up_interruptible(&vrp->sendq);
 }
 
+struct rpmsg_channel *rpmsg_create_channel(int vrp_id, const char *name,
+							int src, int dst)
+{
+	struct rpmsg_channel_info chinfo;
+	struct virtproc_info *vrp;
+
+	strncpy(chinfo.name, name, sizeof(chinfo.name));
+	chinfo.src = src;
+	chinfo.dst = dst;
+
+	/* TODO we probably want radix tree and fw-induced id numbers ? */
+	vrp = idr_find(&vprocs, vrp_id);
+	if (!vrp)
+		return NULL;
+
+	return __rpmsg_create_channel(vrp, &chinfo);
+}
+EXPORT_SYMBOL(rpmsg_create_channel);
+
 /* invoked when a name service announcement arrives */
 static void rpmsg_ns_cb(struct rpmsg_channel *rpdev, void *data, int len,
 							void *priv, u32 src)
@@ -917,13 +954,13 @@ static void rpmsg_ns_cb(struct rpmsg_channel *rpdev, void *data, int len,
 	chinfo.dst = msg->addr;
 
 	if (msg->flags & RPMSG_NS_DESTROY) {
-		ret = rpmsg_destroy_channel(vrp, &chinfo);
+		ret = __rpmsg_destroy_channel(vrp, &chinfo);
 		if (ret)
-			dev_err(dev, "rpmsg_destroy_channel failed: %d\n", ret);
+			dev_err(dev, "__rpmsg_destroy_channel err: %d\n", ret);
 	} else {
-		newch = rpmsg_create_channel(vrp, &chinfo);
+		newch = __rpmsg_create_channel(vrp, &chinfo);
 		if (!newch)
-			dev_err(dev, "rpmsg_create_channel failed\n");
+			dev_err(dev, "__rpmsg_create_channel failed\n");
 	}
 }
 
@@ -934,7 +971,7 @@ static int rpmsg_probe(struct virtio_device *vdev)
 	struct virtqueue *vqs[2];
 	struct virtproc_info *vrp;
 	void *bufs_va;
-	int err = 0, i;
+	int err = 0, i, vproc_id;
 
 	vrp = kzalloc(sizeof(*vrp), GFP_KERNEL);
 	if (!vrp)
@@ -947,10 +984,26 @@ static int rpmsg_probe(struct virtio_device *vdev)
 	mutex_init(&vrp->tx_lock);
 	init_waitqueue_head(&vrp->sendq);
 
+	if (!idr_pre_get(&vprocs, GFP_KERNEL))
+		goto free_vrp;
+
+	mutex_lock(&vprocs_mutex);
+
+	err = idr_get_new(&vprocs, vrp, &vproc_id);
+
+	mutex_unlock(&vprocs_mutex);
+
+	if (err) {
+		dev_err(&vdev->dev, "idr_get_new failed: %d\n", err);
+		goto free_vrp;
+	}
+
+	vrp->id = vproc_id;
+
 	/* We expect two virtqueues, rx and tx (and in this order) */
 	err = vdev->config->find_vqs(vdev, 2, vqs, vq_cbs, names);
 	if (err)
-		goto free_vrp;
+		goto rem_idr;
 
 	vrp->rvq = vqs[0];
 	vrp->svq = vqs[1];
@@ -1012,6 +1065,10 @@ static int rpmsg_probe(struct virtio_device *vdev)
 					bufs_va, vrp->bufs_dma);
 vqs_del:
 	vdev->config->del_vqs(vrp->vdev);
+rem_idr:
+	mutex_lock(&vprocs_mutex);
+	idr_remove(&vprocs, vproc_id);
+	mutex_unlock(&vprocs_mutex);
 free_vrp:
 	kfree(vrp);
 	return err;
@@ -1046,6 +1103,10 @@ static void __devexit rpmsg_remove(struct virtio_device *vdev)
 	dma_free_coherent(vdev->dev.parent->parent, RPMSG_TOTAL_BUF_SPACE,
 					vrp->rbufs, vrp->bufs_dma);
 
+	mutex_lock(&vprocs_mutex);
+	idr_remove(&vprocs, vrp->id);
+	mutex_unlock(&vprocs_mutex);
+
 	kfree(vrp);
 }
 
@@ -1072,6 +1133,8 @@ static int __init rpmsg_init(void)
 {
 	int ret;
 
+	idr_init(&vprocs);
+
 	ret = bus_register(&rpmsg_bus);
 	if (ret) {
 		pr_err("failed to register rpmsg bus: %d\n", ret);
@@ -1092,6 +1155,9 @@ static void __exit rpmsg_fini(void)
 {
 	unregister_virtio_driver(&virtio_ipc_driver);
 	bus_unregister(&rpmsg_bus);
+
+	idr_remove_all(&vprocs);
+	idr_destroy(&vprocs);
 }
 module_exit(rpmsg_fini);
 

include/linux/rpmsg.h

@@ -329,4 +329,8 @@ int rpmsg_trysend_offchannel(struct rpmsg_channel *rpdev, u32 src, u32 dst,
 	return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, false);
 }
 
+int get_virtproc_id(struct virtproc_info *vrp);
+struct rpmsg_channel *rpmsg_create_channel(int vrp_id, const char *name,
+							int src, int dst);
+
 #endif /* _LINUX_RPMSG_H */

include/linux/socket.h

@@ -195,7 +195,8 @@ struct ucred {
 #define AF_CAIF		37	/* CAIF sockets			*/
 #define AF_ALG		38	/* Algorithm sockets		*/
 #define AF_NFC		39	/* NFC sockets			*/
-#define AF_MAX		40	/* For now.. */
+#define AF_RPMSG	40	/* Remote-processor messaging   */
+#define AF_MAX		41	/* For now.. */
 
 /* Protocol families, same as address families. */
 #define PF_UNSPEC	AF_UNSPEC
@@ -238,6 +239,7 @@ struct ucred {
 #define PF_CAIF		AF_CAIF
 #define PF_ALG		AF_ALG
 #define PF_NFC		AF_NFC
+#define PF_RPMSG	AF_RPMSG
 #define PF_MAX		AF_MAX
 
 /* Maximum queue length specifiable by listen.  */
@@ -313,6 +315,7 @@ struct ucred {
 #define SOL_IUCV	277
 #define SOL_CAIF	278
 #define SOL_ALG		279
+#define SOL_RPMSG	280
 
 /* IPX options */
 #define IPX_TYPE	1

include/net/rpmsg.h

@@ -0,0 +1,58 @@
+/*
+ * Remote processor messaging sockets
+ *
+ * Copyright (C) 2011 Texas Instruments, Inc
+ *
+ * Ohad Ben-Cohen <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * 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.
+ */
+
+#ifndef __NET_RPMSG_H
+#define __NET_RPMSG_H
+
+#include <linux/types.h>
+#include <linux/socket.h>
+
+/* user space needs this */
+#ifndef AF_RPMSG
+#define AF_RPMSG	40
+#define PF_RPMSG	AF_RPMSG
+#endif
+
+/* Connection and socket states */
+enum {
+	RPMSG_CONNECTED = 1, /* wait_for_packet() wants this... */
+	RPMSG_OPEN,
+	RPMSG_LISTENING,
+	RPMSG_CLOSED,
+};
+
+struct sockaddr_rpmsg {
+	sa_family_t family;
+	__u32 vproc_id;
+	__u32 addr;
+};
+
+#define RPMSG_LOCALHOST ((__u32) ~0UL)
+
+#ifdef __KERNEL__
+
+#include <net/sock.h>
+#include <linux/rpmsg.h>
+
+struct rpmsg_socket {
+	struct sock sk;
+	struct rpmsg_channel *rpdev;
+	bool unregister_rpdev;
+};
+
+#endif /* __KERNEL__ */
+#endif /* __NET_RPMSG_H */

net/Makefile

@@ -70,3 +70,4 @@ obj-$(CONFIG_CEPH_LIB)		+= ceph/
 obj-$(CONFIG_BATMAN_ADV)	+= batman-adv/
 obj-$(CONFIG_NFC)		+= nfc/
 obj-$(CONFIG_OPENVSWITCH)	+= openvswitch/
+obj-$(CONFIG_RPMSG)		+= rpmsg/

net/rpmsg/Makefile

@@ -0,0 +1 @@
+obj-$(CONFIG_RPMSG)	+= rpmsg_proto.o