1 files changed, 90 insertions, 148 deletions

diff --git a/drivers/rpmsg/rpmsg_char.c b/drivers/rpmsg/rpmsg_char.c
index 5663cf799c95..b6183d4f62a2 100644
--- a/drivers/rpmsg/rpmsg_char.c
+++ b/drivers/rpmsg/rpmsg_char.c
@@ -1,5 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0
 /*
+ * Copyright (C) 2022, STMicroelectronics
  * Copyright (c) 2016, Linaro Ltd.
  * Copyright (c) 2012, Michal Simek <monstr@monstr.eu>
  * Copyright (c) 2012, PetaLogix
@@ -25,33 +26,19 @@
 #include <linux/uaccess.h>
 #include <uapi/linux/rpmsg.h>
 
+#include "rpmsg_char.h"
+#include "rpmsg_internal.h"
+
 #define RPMSG_DEV_MAX	(MINORMASK + 1)
 
 static dev_t rpmsg_major;
-static struct class *rpmsg_class;
 
-static DEFINE_IDA(rpmsg_ctrl_ida);
 static DEFINE_IDA(rpmsg_ept_ida);
 static DEFINE_IDA(rpmsg_minor_ida);
 
 #define dev_to_eptdev(dev) container_of(dev, struct rpmsg_eptdev, dev)
 #define cdev_to_eptdev(i_cdev) container_of(i_cdev, struct rpmsg_eptdev, cdev)
 
-#define dev_to_ctrldev(dev) container_of(dev, struct rpmsg_ctrldev, dev)
-#define cdev_to_ctrldev(i_cdev) container_of(i_cdev, struct rpmsg_ctrldev, cdev)
-
-/**
- * struct rpmsg_ctrldev - control device for instantiating endpoint devices
- * @rpdev:	underlaying rpmsg device
- * @cdev:	cdev for the ctrl device
- * @dev:	device for the ctrl device
- */
-struct rpmsg_ctrldev {
-	struct rpmsg_device *rpdev;
-	struct cdev cdev;
-	struct device dev;
-};
-
 /**
  * struct rpmsg_eptdev - endpoint device context
  * @dev:	endpoint device
@@ -63,6 +50,8 @@ struct rpmsg_ctrldev {
  * @queue_lock:	synchronization of @queue operations
  * @queue:	incoming message queue
  * @readq:	wait object for incoming queue
+ * @default_ept: set to channel default endpoint if the default endpoint should be re-used
+ *              on device open to prevent endpoint address update.
  */
 struct rpmsg_eptdev {
 	struct device dev;
@@ -73,13 +62,15 @@ struct rpmsg_eptdev {
 
 	struct mutex ept_lock;
 	struct rpmsg_endpoint *ept;
+	struct rpmsg_endpoint *default_ept;
 
 	spinlock_t queue_lock;
 	struct sk_buff_head queue;
 	wait_queue_head_t readq;
+
 };
 
-static int rpmsg_eptdev_destroy(struct device *dev, void *data)
+int rpmsg_chrdev_eptdev_destroy(struct device *dev, void *data)
 {
 	struct rpmsg_eptdev *eptdev = dev_to_eptdev(dev);
 
@@ -98,6 +89,7 @@ static int rpmsg_eptdev_destroy(struct device *dev, void *data)
 
 	return 0;
 }
+EXPORT_SYMBOL(rpmsg_chrdev_eptdev_destroy);
 
 static int rpmsg_ept_cb(struct rpmsg_device *rpdev, void *buf, int len,
 			void *priv, u32 addr)
@@ -133,7 +125,15 @@ static int rpmsg_eptdev_open(struct inode *inode, struct file *filp)
 
 	get_device(dev);
 
-	ept = rpmsg_create_ept(rpdev, rpmsg_ept_cb, eptdev, eptdev->chinfo);
+	/*
+	 * If the default_ept is set, the rpmsg device default endpoint is used.
+	 * Else a new endpoint is created on open that will be destroyed on release.
+	 */
+	if (eptdev->default_ept)
+		ept = eptdev->default_ept;
+	else
+		ept = rpmsg_create_ept(rpdev, rpmsg_ept_cb, eptdev, eptdev->chinfo);
+
 	if (!ept) {
 		dev_err(dev, "failed to open %s\n", eptdev->chinfo.name);
 		put_device(dev);
@@ -154,7 +154,8 @@ static int rpmsg_eptdev_release(struct inode *inode, struct file *filp)
 	/* Close the endpoint, if it's not already destroyed by the parent */
 	mutex_lock(&eptdev->ept_lock);
 	if (eptdev->ept) {
-		rpmsg_destroy_ept(eptdev->ept);
+		if (!eptdev->default_ept)
+			rpmsg_destroy_ept(eptdev->ept);
 		eptdev->ept = NULL;
 	}
 	mutex_unlock(&eptdev->ept_lock);
@@ -242,10 +243,13 @@ static ssize_t rpmsg_eptdev_write_iter(struct kiocb *iocb,
 		goto unlock_eptdev;
 	}
 
-	if (filp->f_flags & O_NONBLOCK)
+	if (filp->f_flags & O_NONBLOCK) {
 		ret = rpmsg_trysendto(eptdev->ept, kbuf, len, eptdev->chinfo.dst);
-	else
+		if (ret == -ENOMEM)
+			ret = -EAGAIN;
+	} else {
 		ret = rpmsg_sendto(eptdev->ept, kbuf, len, eptdev->chinfo.dst);
+	}
 
 unlock_eptdev:
 	mutex_unlock(&eptdev->ept_lock);
@@ -281,7 +285,11 @@ static long rpmsg_eptdev_ioctl(struct file *fp, unsigned int cmd,
 	if (cmd != RPMSG_DESTROY_EPT_IOCTL)
 		return -EINVAL;
 
-	return rpmsg_eptdev_destroy(&eptdev->dev, NULL);
+	/* Don't allow to destroy a default endpoint. */
+	if (eptdev->default_ept)
+		return -EINVAL;
+
+	return rpmsg_chrdev_eptdev_destroy(&eptdev->dev, NULL);
 }
 
 static const struct file_operations rpmsg_eptdev_fops = {
@@ -339,21 +347,18 @@ static void rpmsg_eptdev_release_device(struct device *dev)
 	kfree(eptdev);
 }
 
-static int rpmsg_eptdev_create(struct rpmsg_ctrldev *ctrldev,
-			       struct rpmsg_channel_info chinfo)
+static struct rpmsg_eptdev *rpmsg_chrdev_eptdev_alloc(struct rpmsg_device *rpdev,
+						      struct device *parent)
 {
-	struct rpmsg_device *rpdev = ctrldev->rpdev;
 	struct rpmsg_eptdev *eptdev;
 	struct device *dev;
-	int ret;
 
 	eptdev = kzalloc(sizeof(*eptdev), GFP_KERNEL);
 	if (!eptdev)
-		return -ENOMEM;
+		return ERR_PTR(-ENOMEM);
 
 	dev = &eptdev->dev;
 	eptdev->rpdev = rpdev;
-	eptdev->chinfo = chinfo;
 
 	mutex_init(&eptdev->ept_lock);
 	spin_lock_init(&eptdev->queue_lock);
@@ -362,13 +367,23 @@ static int rpmsg_eptdev_create(struct rpmsg_ctrldev *ctrldev,
 
 	device_initialize(dev);
 	dev->class = rpmsg_class;
-	dev->parent = &ctrldev->dev;
+	dev->parent = parent;
 	dev->groups = rpmsg_eptdev_groups;
 	dev_set_drvdata(dev, eptdev);
 
 	cdev_init(&eptdev->cdev, &rpmsg_eptdev_fops);
 	eptdev->cdev.owner = THIS_MODULE;
 
+	return eptdev;
+}
+
+static int rpmsg_chrdev_eptdev_add(struct rpmsg_eptdev *eptdev, struct rpmsg_channel_info chinfo)
+{
+	struct device *dev = &eptdev->dev;
+	int ret;
+
+	eptdev->chinfo = chinfo;
+
 	ret = ida_simple_get(&rpmsg_minor_ida, 0, RPMSG_DEV_MAX, GFP_KERNEL);
 	if (ret < 0)
 		goto free_eptdev;
@@ -400,163 +415,91 @@ free_eptdev:
 	return ret;
 }
 
-static int rpmsg_ctrldev_open(struct inode *inode, struct file *filp)
-{
-	struct rpmsg_ctrldev *ctrldev = cdev_to_ctrldev(inode->i_cdev);
-
-	get_device(&ctrldev->dev);
-	filp->private_data = ctrldev;
-
-	return 0;
-}
-
-static int rpmsg_ctrldev_release(struct inode *inode, struct file *filp)
-{
-	struct rpmsg_ctrldev *ctrldev = cdev_to_ctrldev(inode->i_cdev);
-
-	put_device(&ctrldev->dev);
-
-	return 0;
-}
-
-static long rpmsg_ctrldev_ioctl(struct file *fp, unsigned int cmd,
-				unsigned long arg)
+int rpmsg_chrdev_eptdev_create(struct rpmsg_device *rpdev, struct device *parent,
+			       struct rpmsg_channel_info chinfo)
 {
-	struct rpmsg_ctrldev *ctrldev = fp->private_data;
-	void __user *argp = (void __user *)arg;
-	struct rpmsg_endpoint_info eptinfo;
-	struct rpmsg_channel_info chinfo;
-
-	if (cmd != RPMSG_CREATE_EPT_IOCTL)
-		return -EINVAL;
-
-	if (copy_from_user(&eptinfo, argp, sizeof(eptinfo)))
-		return -EFAULT;
-
-	memcpy(chinfo.name, eptinfo.name, RPMSG_NAME_SIZE);
-	chinfo.name[RPMSG_NAME_SIZE-1] = '\0';
-	chinfo.src = eptinfo.src;
-	chinfo.dst = eptinfo.dst;
-
-	return rpmsg_eptdev_create(ctrldev, chinfo);
-};
+	struct rpmsg_eptdev *eptdev;
+	int ret;
 
-static const struct file_operations rpmsg_ctrldev_fops = {
-	.owner = THIS_MODULE,
-	.open = rpmsg_ctrldev_open,
-	.release = rpmsg_ctrldev_release,
-	.unlocked_ioctl = rpmsg_ctrldev_ioctl,
-	.compat_ioctl = compat_ptr_ioctl,
-};
+	eptdev = rpmsg_chrdev_eptdev_alloc(rpdev, parent);
+	if (IS_ERR(eptdev))
+		return PTR_ERR(eptdev);
 
-static void rpmsg_ctrldev_release_device(struct device *dev)
-{
-	struct rpmsg_ctrldev *ctrldev = dev_to_ctrldev(dev);
+	ret = rpmsg_chrdev_eptdev_add(eptdev, chinfo);
 
-	ida_simple_remove(&rpmsg_ctrl_ida, dev->id);
-	ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt));
-	kfree(ctrldev);
+	return ret;
 }
+EXPORT_SYMBOL(rpmsg_chrdev_eptdev_create);
 
 static int rpmsg_chrdev_probe(struct rpmsg_device *rpdev)
 {
-	struct rpmsg_ctrldev *ctrldev;
-	struct device *dev;
-	int ret;
-
-	ctrldev = kzalloc(sizeof(*ctrldev), GFP_KERNEL);
-	if (!ctrldev)
-		return -ENOMEM;
-
-	ctrldev->rpdev = rpdev;
-
-	dev = &ctrldev->dev;
-	device_initialize(dev);
-	dev->parent = &rpdev->dev;
-	dev->class = rpmsg_class;
-
-	cdev_init(&ctrldev->cdev, &rpmsg_ctrldev_fops);
-	ctrldev->cdev.owner = THIS_MODULE;
-
-	ret = ida_simple_get(&rpmsg_minor_ida, 0, RPMSG_DEV_MAX, GFP_KERNEL);
-	if (ret < 0)
-		goto free_ctrldev;
-	dev->devt = MKDEV(MAJOR(rpmsg_major), ret);
-
-	ret = ida_simple_get(&rpmsg_ctrl_ida, 0, 0, GFP_KERNEL);
-	if (ret < 0)
-		goto free_minor_ida;
-	dev->id = ret;
-	dev_set_name(&ctrldev->dev, "rpmsg_ctrl%d", ret);
+	struct rpmsg_channel_info chinfo;
+	struct rpmsg_eptdev *eptdev;
+	struct device *dev = &rpdev->dev;
 
-	ret = cdev_device_add(&ctrldev->cdev, &ctrldev->dev);
-	if (ret)
-		goto free_ctrl_ida;
+	memcpy(chinfo.name, rpdev->id.name, RPMSG_NAME_SIZE);
+	chinfo.src = rpdev->src;
+	chinfo.dst = rpdev->dst;
 
-	/* We can now rely on the release function for cleanup */
-	dev->release = rpmsg_ctrldev_release_device;
+	eptdev = rpmsg_chrdev_eptdev_alloc(rpdev, dev);
+	if (IS_ERR(eptdev))
+		return PTR_ERR(eptdev);
 
-	dev_set_drvdata(&rpdev->dev, ctrldev);
+	/* Set the default_ept to the rpmsg device endpoint */
+	eptdev->default_ept = rpdev->ept;
 
-	return ret;
+	/*
+	 * The rpmsg_ept_cb uses *priv parameter to get its rpmsg_eptdev context.
+	 * Storedit in default_ept *priv field.
+	 */
+	eptdev->default_ept->priv = eptdev;
 
-free_ctrl_ida:
-	ida_simple_remove(&rpmsg_ctrl_ida, dev->id);
-free_minor_ida:
-	ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt));
-free_ctrldev:
-	put_device(dev);
-	kfree(ctrldev);
-
-	return ret;
+	return rpmsg_chrdev_eptdev_add(eptdev, chinfo);
 }
 
 static void rpmsg_chrdev_remove(struct rpmsg_device *rpdev)
 {
-	struct rpmsg_ctrldev *ctrldev = dev_get_drvdata(&rpdev->dev);
 	int ret;
 
-	/* Destroy all endpoints */
-	ret = device_for_each_child(&ctrldev->dev, NULL, rpmsg_eptdev_destroy);
+	ret = device_for_each_child(&rpdev->dev, NULL, rpmsg_chrdev_eptdev_destroy);
 	if (ret)
-		dev_warn(&rpdev->dev, "failed to nuke endpoints: %d\n", ret);
-
-	cdev_device_del(&ctrldev->cdev, &ctrldev->dev);
-	put_device(&ctrldev->dev);
+		dev_warn(&rpdev->dev, "failed to destroy endpoints: %d\n", ret);
 }
 
+static struct rpmsg_device_id rpmsg_chrdev_id_table[] = {
+	{ .name	= "rpmsg-raw" },
+	{ },
+};
+
 static struct rpmsg_driver rpmsg_chrdev_driver = {
 	.probe = rpmsg_chrdev_probe,
 	.remove = rpmsg_chrdev_remove,
-	.drv = {
-		.name = "rpmsg_chrdev",
-	},
+	.callback = rpmsg_ept_cb,
+	.id_table = rpmsg_chrdev_id_table,
+	.drv.name = "rpmsg_chrdev",
 };
 
 static int rpmsg_chrdev_init(void)
 {
 	int ret;
 
-	ret = alloc_chrdev_region(&rpmsg_major, 0, RPMSG_DEV_MAX, "rpmsg");
+	ret = alloc_chrdev_region(&rpmsg_major, 0, RPMSG_DEV_MAX, "rpmsg_char");
 	if (ret < 0) {
 		pr_err("failed to allocate char dev region\n");
 		return ret;
 	}
 
-	rpmsg_class = class_create(THIS_MODULE, "rpmsg");
-	if (IS_ERR(rpmsg_class)) {
-		pr_err("failed to create rpmsg class\n");
-		unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
-		return PTR_ERR(rpmsg_class);
-	}
-
 	ret = register_rpmsg_driver(&rpmsg_chrdev_driver);
 	if (ret < 0) {
-		pr_err("failed to register rpmsg driver\n");
-		class_destroy(rpmsg_class);
-		unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
+		pr_err("rpmsg: failed to register rpmsg raw driver\n");
+		goto free_region;
 	}
 
+	return 0;
+
+free_region:
+	unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
+
 	return ret;
 }
 postcore_initcall(rpmsg_chrdev_init);
@@ -564,7 +507,6 @@ postcore_initcall(rpmsg_chrdev_init);
 static void rpmsg_chrdev_exit(void)
 {
 	unregister_rpmsg_driver(&rpmsg_chrdev_driver);
-	class_destroy(rpmsg_class);
 	unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
 }
 module_exit(rpmsg_chrdev_exit);