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-rw-r--r--drivers/rpmsg/rpmsg_char.c585
1 files changed, 585 insertions, 0 deletions
diff --git a/drivers/rpmsg/rpmsg_char.c b/drivers/rpmsg/rpmsg_char.c
new file mode 100644
index 000000000000..a78b6b79cea4
--- /dev/null
+++ b/drivers/rpmsg/rpmsg_char.c
@@ -0,0 +1,585 @@
+/*
+ * Copyright (c) 2016, Linaro Ltd.
+ * Copyright (c) 2012, Michal Simek <monstr@monstr.eu>
+ * Copyright (c) 2012, PetaLogix
+ * Copyright (c) 2011, Texas Instruments, Inc.
+ * Copyright (c) 2011, Google, Inc.
+ *
+ * Based on rpmsg performance statistics driver by Michal Simek, which in turn
+ * was based on TI & Google OMX rpmsg driver.
+ *
+ * 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/cdev.h>
+#include <linux/device.h>
+#include <linux/fs.h>
+#include <linux/idr.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/poll.h>
+#include <linux/rpmsg.h>
+#include <linux/skbuff.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <uapi/linux/rpmsg.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
+ * @cdev: cdev for the endpoint device
+ * @rpdev: underlaying rpmsg device
+ * @chinfo: info used to open the endpoint
+ * @ept_lock: synchronization of @ept modifications
+ * @ept: rpmsg endpoint reference, when open
+ * @queue_lock: synchronization of @queue operations
+ * @queue: incoming message queue
+ * @readq: wait object for incoming queue
+ */
+struct rpmsg_eptdev {
+ struct device dev;
+ struct cdev cdev;
+
+ struct rpmsg_device *rpdev;
+ struct rpmsg_channel_info chinfo;
+
+ struct mutex ept_lock;
+ struct rpmsg_endpoint *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)
+{
+ struct rpmsg_eptdev *eptdev = dev_to_eptdev(dev);
+
+ mutex_lock(&eptdev->ept_lock);
+ if (eptdev->ept) {
+ rpmsg_destroy_ept(eptdev->ept);
+ eptdev->ept = NULL;
+ }
+ mutex_unlock(&eptdev->ept_lock);
+
+ /* wake up any blocked readers */
+ wake_up_interruptible(&eptdev->readq);
+
+ device_del(&eptdev->dev);
+ put_device(&eptdev->dev);
+
+ return 0;
+}
+
+static int rpmsg_ept_cb(struct rpmsg_device *rpdev, void *buf, int len,
+ void *priv, u32 addr)
+{
+ struct rpmsg_eptdev *eptdev = priv;
+ struct sk_buff *skb;
+
+ skb = alloc_skb(len, GFP_ATOMIC);
+ if (!skb)
+ return -ENOMEM;
+
+ memcpy(skb_put(skb, len), buf, len);
+
+ spin_lock(&eptdev->queue_lock);
+ skb_queue_tail(&eptdev->queue, skb);
+ spin_unlock(&eptdev->queue_lock);
+
+ /* wake up any blocking processes, waiting for new data */
+ wake_up_interruptible(&eptdev->readq);
+
+ return 0;
+}
+
+static int rpmsg_eptdev_open(struct inode *inode, struct file *filp)
+{
+ struct rpmsg_eptdev *eptdev = cdev_to_eptdev(inode->i_cdev);
+ struct rpmsg_endpoint *ept;
+ struct rpmsg_device *rpdev = eptdev->rpdev;
+ struct device *dev = &eptdev->dev;
+
+ get_device(dev);
+
+ 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);
+ return -EINVAL;
+ }
+
+ eptdev->ept = ept;
+ filp->private_data = eptdev;
+
+ return 0;
+}
+
+static int rpmsg_eptdev_release(struct inode *inode, struct file *filp)
+{
+ struct rpmsg_eptdev *eptdev = cdev_to_eptdev(inode->i_cdev);
+ struct device *dev = &eptdev->dev;
+ struct sk_buff *skb;
+
+ /* 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);
+ eptdev->ept = NULL;
+ }
+ mutex_unlock(&eptdev->ept_lock);
+
+ /* Discard all SKBs */
+ while (!skb_queue_empty(&eptdev->queue)) {
+ skb = skb_dequeue(&eptdev->queue);
+ kfree_skb(skb);
+ }
+
+ put_device(dev);
+
+ return 0;
+}
+
+static ssize_t rpmsg_eptdev_read(struct file *filp, char __user *buf,
+ size_t len, loff_t *f_pos)
+{
+ struct rpmsg_eptdev *eptdev = filp->private_data;
+ unsigned long flags;
+ struct sk_buff *skb;
+ int use;
+
+ if (!eptdev->ept)
+ return -EPIPE;
+
+ spin_lock_irqsave(&eptdev->queue_lock, flags);
+
+ /* Wait for data in the queue */
+ if (skb_queue_empty(&eptdev->queue)) {
+ spin_unlock_irqrestore(&eptdev->queue_lock, flags);
+
+ if (filp->f_flags & O_NONBLOCK)
+ return -EAGAIN;
+
+ /* Wait until we get data or the endpoint goes away */
+ if (wait_event_interruptible(eptdev->readq,
+ !skb_queue_empty(&eptdev->queue) ||
+ !eptdev->ept))
+ return -ERESTARTSYS;
+
+ /* We lost the endpoint while waiting */
+ if (!eptdev->ept)
+ return -EPIPE;
+
+ spin_lock_irqsave(&eptdev->queue_lock, flags);
+ }
+
+ skb = skb_dequeue(&eptdev->queue);
+ if (!skb)
+ return -EFAULT;
+
+ spin_unlock_irqrestore(&eptdev->queue_lock, flags);
+
+ use = min_t(size_t, len, skb->len);
+ if (copy_to_user(buf, skb->data, use))
+ use = -EFAULT;
+
+ kfree_skb(skb);
+
+ return use;
+}
+
+static ssize_t rpmsg_eptdev_write(struct file *filp, const char __user *buf,
+ size_t len, loff_t *f_pos)
+{
+ struct rpmsg_eptdev *eptdev = filp->private_data;
+ void *kbuf;
+ int ret;
+
+ kbuf = memdup_user(buf, len);
+ if (IS_ERR(kbuf))
+ return PTR_ERR(kbuf);
+
+ if (mutex_lock_interruptible(&eptdev->ept_lock)) {
+ ret = -ERESTARTSYS;
+ goto free_kbuf;
+ }
+
+ if (!eptdev->ept) {
+ ret = -EPIPE;
+ goto unlock_eptdev;
+ }
+
+ if (filp->f_flags & O_NONBLOCK)
+ ret = rpmsg_trysend(eptdev->ept, kbuf, len);
+ else
+ ret = rpmsg_send(eptdev->ept, kbuf, len);
+
+unlock_eptdev:
+ mutex_unlock(&eptdev->ept_lock);
+
+free_kbuf:
+ kfree(kbuf);
+ return ret < 0 ? ret : len;
+}
+
+static unsigned int rpmsg_eptdev_poll(struct file *filp, poll_table *wait)
+{
+ struct rpmsg_eptdev *eptdev = filp->private_data;
+ unsigned int mask = 0;
+
+ if (!eptdev->ept)
+ return POLLERR;
+
+ poll_wait(filp, &eptdev->readq, wait);
+
+ if (!skb_queue_empty(&eptdev->queue))
+ mask |= POLLIN | POLLRDNORM;
+
+ mask |= rpmsg_poll(eptdev->ept, filp, wait);
+
+ return mask;
+}
+
+static long rpmsg_eptdev_ioctl(struct file *fp, unsigned int cmd,
+ unsigned long arg)
+{
+ struct rpmsg_eptdev *eptdev = fp->private_data;
+
+ if (cmd != RPMSG_DESTROY_EPT_IOCTL)
+ return -EINVAL;
+
+ return rpmsg_eptdev_destroy(&eptdev->dev, NULL);
+}
+
+static const struct file_operations rpmsg_eptdev_fops = {
+ .owner = THIS_MODULE,
+ .open = rpmsg_eptdev_open,
+ .release = rpmsg_eptdev_release,
+ .read = rpmsg_eptdev_read,
+ .write = rpmsg_eptdev_write,
+ .poll = rpmsg_eptdev_poll,
+ .unlocked_ioctl = rpmsg_eptdev_ioctl,
+};
+
+static ssize_t name_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct rpmsg_eptdev *eptdev = dev_get_drvdata(dev);
+
+ return sprintf(buf, "%s\n", eptdev->chinfo.name);
+}
+static DEVICE_ATTR_RO(name);
+
+static ssize_t src_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct rpmsg_eptdev *eptdev = dev_get_drvdata(dev);
+
+ return sprintf(buf, "%d\n", eptdev->chinfo.src);
+}
+static DEVICE_ATTR_RO(src);
+
+static ssize_t dst_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct rpmsg_eptdev *eptdev = dev_get_drvdata(dev);
+
+ return sprintf(buf, "%d\n", eptdev->chinfo.dst);
+}
+static DEVICE_ATTR_RO(dst);
+
+static struct attribute *rpmsg_eptdev_attrs[] = {
+ &dev_attr_name.attr,
+ &dev_attr_src.attr,
+ &dev_attr_dst.attr,
+ NULL
+};
+ATTRIBUTE_GROUPS(rpmsg_eptdev);
+
+static void rpmsg_eptdev_release_device(struct device *dev)
+{
+ struct rpmsg_eptdev *eptdev = dev_to_eptdev(dev);
+
+ ida_simple_remove(&rpmsg_ept_ida, dev->id);
+ ida_simple_remove(&rpmsg_minor_ida, MINOR(eptdev->dev.devt));
+ cdev_del(&eptdev->cdev);
+ kfree(eptdev);
+}
+
+static int rpmsg_eptdev_create(struct rpmsg_ctrldev *ctrldev,
+ struct rpmsg_channel_info chinfo)
+{
+ 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;
+
+ dev = &eptdev->dev;
+ eptdev->rpdev = rpdev;
+ eptdev->chinfo = chinfo;
+
+ mutex_init(&eptdev->ept_lock);
+ spin_lock_init(&eptdev->queue_lock);
+ skb_queue_head_init(&eptdev->queue);
+ init_waitqueue_head(&eptdev->readq);
+
+ device_initialize(dev);
+ dev->class = rpmsg_class;
+ dev->parent = &ctrldev->dev;
+ dev->groups = rpmsg_eptdev_groups;
+ dev_set_drvdata(dev, eptdev);
+
+ cdev_init(&eptdev->cdev, &rpmsg_eptdev_fops);
+ eptdev->cdev.owner = THIS_MODULE;
+
+ ret = ida_simple_get(&rpmsg_minor_ida, 0, RPMSG_DEV_MAX, GFP_KERNEL);
+ if (ret < 0)
+ goto free_eptdev;
+ dev->devt = MKDEV(MAJOR(rpmsg_major), ret);
+
+ ret = ida_simple_get(&rpmsg_ept_ida, 0, 0, GFP_KERNEL);
+ if (ret < 0)
+ goto free_minor_ida;
+ dev->id = ret;
+ dev_set_name(dev, "rpmsg%d", ret);
+
+ ret = cdev_add(&eptdev->cdev, dev->devt, 1);
+ if (ret)
+ goto free_ept_ida;
+
+ /* We can now rely on the release function for cleanup */
+ dev->release = rpmsg_eptdev_release_device;
+
+ ret = device_add(dev);
+ if (ret) {
+ dev_err(dev, "device_register failed: %d\n", ret);
+ put_device(dev);
+ }
+
+ return ret;
+
+free_ept_ida:
+ ida_simple_remove(&rpmsg_ept_ida, dev->id);
+free_minor_ida:
+ ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt));
+free_eptdev:
+ put_device(dev);
+ kfree(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)
+{
+ 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);
+};
+
+static const struct file_operations rpmsg_ctrldev_fops = {
+ .owner = THIS_MODULE,
+ .open = rpmsg_ctrldev_open,
+ .release = rpmsg_ctrldev_release,
+ .unlocked_ioctl = rpmsg_ctrldev_ioctl,
+};
+
+static void rpmsg_ctrldev_release_device(struct device *dev)
+{
+ struct rpmsg_ctrldev *ctrldev = dev_to_ctrldev(dev);
+
+ ida_simple_remove(&rpmsg_ctrl_ida, dev->id);
+ ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt));
+ cdev_del(&ctrldev->cdev);
+ kfree(ctrldev);
+}
+
+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);
+
+ ret = cdev_add(&ctrldev->cdev, dev->devt, 1);
+ if (ret)
+ goto free_ctrl_ida;
+
+ /* We can now rely on the release function for cleanup */
+ dev->release = rpmsg_ctrldev_release_device;
+
+ ret = device_add(dev);
+ if (ret) {
+ dev_err(&rpdev->dev, "device_register failed: %d\n", ret);
+ put_device(dev);
+ }
+
+ dev_set_drvdata(&rpdev->dev, ctrldev);
+
+ return ret;
+
+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;
+}
+
+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);
+ if (ret)
+ dev_warn(&rpdev->dev, "failed to nuke endpoints: %d\n", ret);
+
+ device_del(&ctrldev->dev);
+ put_device(&ctrldev->dev);
+}
+
+static struct rpmsg_driver rpmsg_chrdev_driver = {
+ .probe = rpmsg_chrdev_probe,
+ .remove = rpmsg_chrdev_remove,
+ .drv = {
+ .name = "rpmsg_chrdev",
+ },
+};
+
+static int rpmsg_char_init(void)
+{
+ int ret;
+
+ ret = alloc_chrdev_region(&rpmsg_major, 0, RPMSG_DEV_MAX, "rpmsg");
+ if (ret < 0) {
+ pr_err("rpmsg: 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("rpmsgchr: failed to register rpmsg driver\n");
+ class_destroy(rpmsg_class);
+ unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
+ }
+
+ return ret;
+}
+postcore_initcall(rpmsg_char_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);
+MODULE_LICENSE("GPL v2");

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