summaryrefslogtreecommitdiffstats
path: root/drivers/rpmsg/rpmsg_char.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
commit4352b8aee98005853aa63f57d6377282de17a33f (patch)
tree27614d7a9ef05c32d089004e104364ce42324837 /drivers/rpmsg/rpmsg_char.c
downloadlinux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz
linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni: "A new driver this cycle, for the AMD AXI I3C controller. There are also new features such as IBI wakeup support, SETAASA device discovery and ACPI support for the the DAA methods, meaning we can now communicate with the SPD devices on DDR5 modules. New driver: - AMD AXI I3C master controller Subsystem: - I3C Common Command Code (CCC) handling improvements, especially around GET CCCs - SETAASA device discovery support - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as well as I2C devices on I3C bus - IBI-based wakeup support Drivers: - dw: SETAASA support - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C controller support, PIO queue management support for HCI v1.2 - renesas: improve suspend to RAM support, add runtime PM support" * tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits) i3c: dw: reduce do_daa time if there's no client i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2 i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode i3c: dw: rename "pclk" to "apb" to match dt-binding i3c: dw: make struct dw_i3c_cmd smaller i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding i3c: renesas: Don't register devices when ENTDAA times out i3c: master: dw-i3c-master: fix OD timing for first broadcast i3c: mipi-i3c-hci: Advertise IBI wakeup capability i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev() i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI i3c: master: Reject IBI requests from non-IBI-capable devices i3c: master: Add helper to query bus wakeup requirements i3c: master: Report wakeup events for IBIs i3c: master: Support IBI-based wakeup capability i3c: master: Fix potential UAF in i3c_device_match() i3c: master: Fix potential UAF in i3c_device_uevent() i3c: Make dev->desc locking assumptions explicit i3c: master: Fix use-after-free of master->this ...
Diffstat (limited to 'drivers/rpmsg/rpmsg_char.c')
-rw-r--r--drivers/rpmsg/rpmsg_char.c582
1 files changed, 582 insertions, 0 deletions
diff --git a/drivers/rpmsg/rpmsg_char.c b/drivers/rpmsg/rpmsg_char.c
new file mode 100644
index 000000000..bff5aefee
--- /dev/null
+++ b/drivers/rpmsg/rpmsg_char.c
@@ -0,0 +1,582 @@
+// 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
+ * 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.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#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_char.h"
+#include "rpmsg_internal.h"
+
+#define RPMSG_DEV_MAX (MINORMASK + 1)
+
+static dev_t rpmsg_major;
+
+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)
+
+/**
+ * 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
+ * @default_ept: set to channel default endpoint if the default endpoint should be re-used
+ * on device open to prevent endpoint address update.
+ * @remote_flow_restricted: to indicate if the remote has requested for flow to be limited
+ * @remote_flow_updated: to indicate if the flow control has been requested
+ */
+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;
+ struct rpmsg_endpoint *default_ept;
+
+ spinlock_t queue_lock;
+ struct sk_buff_head queue;
+ wait_queue_head_t readq;
+
+ bool remote_flow_restricted;
+ bool remote_flow_updated;
+};
+
+int rpmsg_chrdev_eptdev_destroy(struct device *dev, void *data)
+{
+ struct rpmsg_eptdev *eptdev = dev_to_eptdev(dev);
+
+ mutex_lock(&eptdev->ept_lock);
+ eptdev->rpdev = NULL;
+ if (eptdev->ept) {
+ /* The default endpoint is released by the rpmsg core */
+ if (!eptdev->default_ept)
+ rpmsg_destroy_ept(eptdev->ept);
+ eptdev->ept = NULL;
+ }
+ mutex_unlock(&eptdev->ept_lock);
+
+ /* wake up any blocked readers */
+ wake_up_interruptible(&eptdev->readq);
+
+ cdev_device_del(&eptdev->cdev, &eptdev->dev);
+ put_device(&eptdev->dev);
+
+ 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)
+{
+ struct rpmsg_eptdev *eptdev = priv;
+ struct sk_buff *skb;
+
+ if (!eptdev)
+ return 0;
+
+ skb = alloc_skb(len, GFP_ATOMIC);
+ if (!skb)
+ return -ENOMEM;
+
+ skb_put_data(skb, 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_ept_flow_cb(struct rpmsg_device *rpdev, void *priv, bool enable)
+{
+ struct rpmsg_eptdev *eptdev = priv;
+
+ if (!eptdev)
+ return 0;
+
+ eptdev->remote_flow_restricted = enable;
+ eptdev->remote_flow_updated = true;
+
+ 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;
+
+ mutex_lock(&eptdev->ept_lock);
+ if (eptdev->ept) {
+ mutex_unlock(&eptdev->ept_lock);
+ return -EBUSY;
+ }
+
+ if (!eptdev->rpdev) {
+ mutex_unlock(&eptdev->ept_lock);
+ return -ENETRESET;
+ }
+
+ get_device(dev);
+
+ /*
+ * 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);
+ mutex_unlock(&eptdev->ept_lock);
+ return -EINVAL;
+ }
+
+ ept->flow_cb = rpmsg_ept_flow_cb;
+ eptdev->ept = ept;
+ filp->private_data = eptdev;
+ mutex_unlock(&eptdev->ept_lock);
+
+ 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;
+
+ /* Close the endpoint, if it's not already destroyed by the parent */
+ mutex_lock(&eptdev->ept_lock);
+ if (eptdev->ept) {
+ if (!eptdev->default_ept)
+ rpmsg_destroy_ept(eptdev->ept);
+ eptdev->ept = NULL;
+ }
+ mutex_unlock(&eptdev->ept_lock);
+ eptdev->remote_flow_updated = false;
+
+ /* Discard all SKBs */
+ skb_queue_purge(&eptdev->queue);
+
+ put_device(dev);
+
+ return 0;
+}
+
+static ssize_t rpmsg_eptdev_read_iter(struct kiocb *iocb, struct iov_iter *to)
+{
+ struct file *filp = iocb->ki_filp;
+ 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);
+ spin_unlock_irqrestore(&eptdev->queue_lock, flags);
+ if (!skb)
+ return -EFAULT;
+
+ use = min_t(size_t, iov_iter_count(to), skb->len);
+ if (copy_to_iter(skb->data, use, to) != use)
+ use = -EFAULT;
+
+ kfree_skb(skb);
+
+ return use;
+}
+
+static ssize_t rpmsg_eptdev_write_iter(struct kiocb *iocb,
+ struct iov_iter *from)
+{
+ struct file *filp = iocb->ki_filp;
+ struct rpmsg_eptdev *eptdev = filp->private_data;
+ size_t len = iov_iter_count(from);
+ void *kbuf;
+ int ret;
+
+ kbuf = kzalloc(len, GFP_KERNEL);
+ if (!kbuf)
+ return -ENOMEM;
+
+ if (!copy_from_iter_full(kbuf, len, from)) {
+ ret = -EFAULT;
+ goto free_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_trysendto(eptdev->ept, kbuf, len, eptdev->chinfo.dst);
+ if (ret == -ENOMEM)
+ ret = -EAGAIN;
+ } else {
+ ret = rpmsg_sendto(eptdev->ept, kbuf, len, eptdev->chinfo.dst);
+ }
+
+unlock_eptdev:
+ mutex_unlock(&eptdev->ept_lock);
+
+free_kbuf:
+ kfree(kbuf);
+ return ret < 0 ? ret : len;
+}
+
+static __poll_t rpmsg_eptdev_poll(struct file *filp, poll_table *wait)
+{
+ struct rpmsg_eptdev *eptdev = filp->private_data;
+ __poll_t mask = 0;
+
+ if (!eptdev->ept)
+ return EPOLLERR;
+
+ poll_wait(filp, &eptdev->readq, wait);
+
+ if (!skb_queue_empty(&eptdev->queue))
+ mask |= EPOLLIN | EPOLLRDNORM;
+
+ if (eptdev->remote_flow_updated)
+ mask |= EPOLLPRI;
+
+ mutex_lock(&eptdev->ept_lock);
+ mask |= rpmsg_poll(eptdev->ept, filp, wait);
+ mutex_unlock(&eptdev->ept_lock);
+
+ return mask;
+}
+
+static long rpmsg_eptdev_ioctl(struct file *fp, unsigned int cmd,
+ unsigned long arg)
+{
+ struct rpmsg_eptdev *eptdev = fp->private_data;
+
+ bool set;
+ int ret;
+
+ switch (cmd) {
+ case RPMSG_GET_OUTGOING_FLOWCONTROL:
+ eptdev->remote_flow_updated = false;
+ ret = put_user(eptdev->remote_flow_restricted, (int __user *)arg);
+ break;
+ case RPMSG_SET_INCOMING_FLOWCONTROL:
+ if (arg > 1) {
+ ret = -EINVAL;
+ break;
+ }
+ set = !!arg;
+ ret = rpmsg_set_flow_control(eptdev->ept, set, eptdev->chinfo.dst);
+ break;
+ case RPMSG_DESTROY_EPT_IOCTL:
+ /* Don't allow to destroy a default endpoint. */
+ if (eptdev->default_ept) {
+ ret = -EINVAL;
+ break;
+ }
+ ret = rpmsg_chrdev_eptdev_destroy(&eptdev->dev, NULL);
+ break;
+ default:
+ ret = -EINVAL;
+ }
+
+ return ret;
+}
+
+static const struct file_operations rpmsg_eptdev_fops = {
+ .owner = THIS_MODULE,
+ .open = rpmsg_eptdev_open,
+ .release = rpmsg_eptdev_release,
+ .read_iter = rpmsg_eptdev_read_iter,
+ .write_iter = rpmsg_eptdev_write_iter,
+ .poll = rpmsg_eptdev_poll,
+ .unlocked_ioctl = rpmsg_eptdev_ioctl,
+ .compat_ioctl = compat_ptr_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_free(&rpmsg_ept_ida, dev->id);
+ ida_free(&rpmsg_minor_ida, MINOR(eptdev->dev.devt));
+ kfree(eptdev);
+}
+
+static struct rpmsg_eptdev *rpmsg_chrdev_eptdev_alloc(struct rpmsg_device *rpdev,
+ struct device *parent)
+{
+ struct rpmsg_eptdev *eptdev;
+ struct device *dev;
+
+ eptdev = kzalloc_obj(*eptdev);
+ if (!eptdev)
+ return ERR_PTR(-ENOMEM);
+
+ dev = &eptdev->dev;
+ eptdev->rpdev = rpdev;
+
+ 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 = 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_alloc_max(&rpmsg_minor_ida, RPMSG_DEV_MAX - 1, GFP_KERNEL);
+ if (ret < 0)
+ goto free_eptdev;
+ dev->devt = MKDEV(MAJOR(rpmsg_major), ret);
+
+ ret = ida_alloc(&rpmsg_ept_ida, GFP_KERNEL);
+ if (ret < 0)
+ goto free_minor_ida;
+ dev->id = ret;
+ dev_set_name(dev, "rpmsg%d", ret);
+
+ ret = cdev_device_add(&eptdev->cdev, &eptdev->dev);
+ if (ret)
+ goto free_ept_ida;
+
+ /* We can now rely on the release function for cleanup */
+ dev->release = rpmsg_eptdev_release_device;
+
+ return ret;
+
+free_ept_ida:
+ ida_free(&rpmsg_ept_ida, dev->id);
+free_minor_ida:
+ ida_free(&rpmsg_minor_ida, MINOR(dev->devt));
+free_eptdev:
+ put_device(dev);
+ kfree(eptdev);
+
+ return ret;
+}
+
+int rpmsg_chrdev_eptdev_create(struct rpmsg_device *rpdev, struct device *parent,
+ struct rpmsg_channel_info chinfo)
+{
+ struct rpmsg_eptdev *eptdev;
+
+ eptdev = rpmsg_chrdev_eptdev_alloc(rpdev, parent);
+ if (IS_ERR(eptdev))
+ return PTR_ERR(eptdev);
+
+ return rpmsg_chrdev_eptdev_add(eptdev, chinfo);
+}
+EXPORT_SYMBOL(rpmsg_chrdev_eptdev_create);
+
+static int rpmsg_chrdev_probe(struct rpmsg_device *rpdev)
+{
+ struct rpmsg_channel_info chinfo;
+ struct rpmsg_eptdev *eptdev;
+ struct device *dev = &rpdev->dev;
+ int ret;
+
+ memcpy(chinfo.name, rpdev->id.name, RPMSG_NAME_SIZE);
+ chinfo.src = rpdev->src;
+ chinfo.dst = rpdev->dst;
+
+ eptdev = rpmsg_chrdev_eptdev_alloc(rpdev, dev);
+ if (IS_ERR(eptdev))
+ return PTR_ERR(eptdev);
+
+ /* Set the default_ept to the rpmsg device endpoint */
+ eptdev->default_ept = rpdev->ept;
+
+ ret = rpmsg_chrdev_eptdev_add(eptdev, chinfo);
+
+ if (ret)
+ return ret;
+ /*
+ * The rpmsg_ept_cb uses *priv parameter to get its rpmsg_eptdev context.
+ * Stored it in default_ept *priv field.
+ */
+ eptdev->default_ept->priv = eptdev;
+
+ return 0;
+}
+
+static void rpmsg_chrdev_remove(struct rpmsg_device *rpdev)
+{
+ int ret;
+
+ ret = device_for_each_child(&rpdev->dev, NULL, rpmsg_chrdev_eptdev_destroy);
+ if (ret)
+ dev_warn(&rpdev->dev, "failed to destroy endpoints: %d\n", ret);
+}
+
+static struct rpmsg_device_id rpmsg_chrdev_id_table[] = {
+ { .name = "rpmsg-raw" },
+ { .name = "rpmsg_chrdev" },
+ { },
+};
+MODULE_DEVICE_TABLE(rpmsg, rpmsg_chrdev_id_table);
+
+static struct rpmsg_driver rpmsg_chrdev_driver = {
+ .probe = rpmsg_chrdev_probe,
+ .remove = rpmsg_chrdev_remove,
+ .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_char");
+ if (ret < 0) {
+ pr_err("failed to allocate char dev region\n");
+ return ret;
+ }
+
+ ret = register_rpmsg_driver(&rpmsg_chrdev_driver);
+ if (ret < 0) {
+ 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);
+
+static void rpmsg_chrdev_exit(void)
+{
+ unregister_rpmsg_driver(&rpmsg_chrdev_driver);
+ unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
+}
+module_exit(rpmsg_chrdev_exit);
+
+MODULE_DESCRIPTION("RPMSG device interface");
+MODULE_LICENSE("GPL v2");