Update Linux to v5.10.109
Sourced from [1]
[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.10.109.tar.xz
Change-Id: I19bca9fc6762d4e63bcf3e4cba88bbe560d9c76c
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/drivers/most/most_cdev.c b/drivers/most/most_cdev.c
new file mode 100644
index 0000000..0448807
--- /dev/null
+++ b/drivers/most/most_cdev.c
@@ -0,0 +1,543 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * cdev.c - Character device component for Mostcore
+ *
+ * Copyright (C) 2013-2015 Microchip Technology Germany II GmbH & Co. KG
+ */
+
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include <linux/device.h>
+#include <linux/cdev.h>
+#include <linux/poll.h>
+#include <linux/kfifo.h>
+#include <linux/uaccess.h>
+#include <linux/idr.h>
+#include <linux/most.h>
+
+#define CHRDEV_REGION_SIZE 50
+
+static struct cdev_component {
+ dev_t devno;
+ struct ida minor_id;
+ unsigned int major;
+ struct class *class;
+ struct most_component cc;
+} comp;
+
+struct comp_channel {
+ wait_queue_head_t wq;
+ spinlock_t unlink; /* synchronization lock to unlink channels */
+ struct cdev cdev;
+ struct device *dev;
+ struct mutex io_mutex;
+ struct most_interface *iface;
+ struct most_channel_config *cfg;
+ unsigned int channel_id;
+ dev_t devno;
+ size_t mbo_offs;
+ DECLARE_KFIFO_PTR(fifo, typeof(struct mbo *));
+ int access_ref;
+ struct list_head list;
+};
+
+#define to_channel(d) container_of(d, struct comp_channel, cdev)
+static struct list_head channel_list;
+static spinlock_t ch_list_lock;
+
+static inline bool ch_has_mbo(struct comp_channel *c)
+{
+ return channel_has_mbo(c->iface, c->channel_id, &comp.cc) > 0;
+}
+
+static inline struct mbo *ch_get_mbo(struct comp_channel *c, struct mbo **mbo)
+{
+ if (!kfifo_peek(&c->fifo, mbo)) {
+ *mbo = most_get_mbo(c->iface, c->channel_id, &comp.cc);
+ if (*mbo)
+ kfifo_in(&c->fifo, mbo, 1);
+ }
+ return *mbo;
+}
+
+static struct comp_channel *get_channel(struct most_interface *iface, int id)
+{
+ struct comp_channel *c, *tmp;
+ unsigned long flags;
+
+ spin_lock_irqsave(&ch_list_lock, flags);
+ list_for_each_entry_safe(c, tmp, &channel_list, list) {
+ if ((c->iface == iface) && (c->channel_id == id)) {
+ spin_unlock_irqrestore(&ch_list_lock, flags);
+ return c;
+ }
+ }
+ spin_unlock_irqrestore(&ch_list_lock, flags);
+ return NULL;
+}
+
+static void stop_channel(struct comp_channel *c)
+{
+ struct mbo *mbo;
+
+ while (kfifo_out((struct kfifo *)&c->fifo, &mbo, 1))
+ most_put_mbo(mbo);
+ most_stop_channel(c->iface, c->channel_id, &comp.cc);
+}
+
+static void destroy_cdev(struct comp_channel *c)
+{
+ unsigned long flags;
+
+ device_destroy(comp.class, c->devno);
+ cdev_del(&c->cdev);
+ spin_lock_irqsave(&ch_list_lock, flags);
+ list_del(&c->list);
+ spin_unlock_irqrestore(&ch_list_lock, flags);
+}
+
+static void destroy_channel(struct comp_channel *c)
+{
+ ida_simple_remove(&comp.minor_id, MINOR(c->devno));
+ kfifo_free(&c->fifo);
+ kfree(c);
+}
+
+/**
+ * comp_open - implements the syscall to open the device
+ * @inode: inode pointer
+ * @filp: file pointer
+ *
+ * This stores the channel pointer in the private data field of
+ * the file structure and activates the channel within the core.
+ */
+static int comp_open(struct inode *inode, struct file *filp)
+{
+ struct comp_channel *c;
+ int ret;
+
+ c = to_channel(inode->i_cdev);
+ filp->private_data = c;
+
+ if (((c->cfg->direction == MOST_CH_RX) &&
+ ((filp->f_flags & O_ACCMODE) != O_RDONLY)) ||
+ ((c->cfg->direction == MOST_CH_TX) &&
+ ((filp->f_flags & O_ACCMODE) != O_WRONLY))) {
+ return -EACCES;
+ }
+
+ mutex_lock(&c->io_mutex);
+ if (!c->dev) {
+ mutex_unlock(&c->io_mutex);
+ return -ENODEV;
+ }
+
+ if (c->access_ref) {
+ mutex_unlock(&c->io_mutex);
+ return -EBUSY;
+ }
+
+ c->mbo_offs = 0;
+ ret = most_start_channel(c->iface, c->channel_id, &comp.cc);
+ if (!ret)
+ c->access_ref = 1;
+ mutex_unlock(&c->io_mutex);
+ return ret;
+}
+
+/**
+ * comp_close - implements the syscall to close the device
+ * @inode: inode pointer
+ * @filp: file pointer
+ *
+ * This stops the channel within the core.
+ */
+static int comp_close(struct inode *inode, struct file *filp)
+{
+ struct comp_channel *c = to_channel(inode->i_cdev);
+
+ mutex_lock(&c->io_mutex);
+ spin_lock(&c->unlink);
+ c->access_ref = 0;
+ spin_unlock(&c->unlink);
+ if (c->dev) {
+ stop_channel(c);
+ mutex_unlock(&c->io_mutex);
+ } else {
+ mutex_unlock(&c->io_mutex);
+ destroy_channel(c);
+ }
+ return 0;
+}
+
+/**
+ * comp_write - implements the syscall to write to the device
+ * @filp: file pointer
+ * @buf: pointer to user buffer
+ * @count: number of bytes to write
+ * @offset: offset from where to start writing
+ */
+static ssize_t comp_write(struct file *filp, const char __user *buf,
+ size_t count, loff_t *offset)
+{
+ int ret;
+ size_t to_copy, left;
+ struct mbo *mbo = NULL;
+ struct comp_channel *c = filp->private_data;
+
+ mutex_lock(&c->io_mutex);
+ while (c->dev && !ch_get_mbo(c, &mbo)) {
+ mutex_unlock(&c->io_mutex);
+
+ if ((filp->f_flags & O_NONBLOCK))
+ return -EAGAIN;
+ if (wait_event_interruptible(c->wq, ch_has_mbo(c) || !c->dev))
+ return -ERESTARTSYS;
+ mutex_lock(&c->io_mutex);
+ }
+
+ if (unlikely(!c->dev)) {
+ ret = -ENODEV;
+ goto unlock;
+ }
+
+ to_copy = min(count, c->cfg->buffer_size - c->mbo_offs);
+ left = copy_from_user(mbo->virt_address + c->mbo_offs, buf, to_copy);
+ if (left == to_copy) {
+ ret = -EFAULT;
+ goto unlock;
+ }
+
+ c->mbo_offs += to_copy - left;
+ if (c->mbo_offs >= c->cfg->buffer_size ||
+ c->cfg->data_type == MOST_CH_CONTROL ||
+ c->cfg->data_type == MOST_CH_ASYNC) {
+ kfifo_skip(&c->fifo);
+ mbo->buffer_length = c->mbo_offs;
+ c->mbo_offs = 0;
+ most_submit_mbo(mbo);
+ }
+
+ ret = to_copy - left;
+unlock:
+ mutex_unlock(&c->io_mutex);
+ return ret;
+}
+
+/**
+ * comp_read - implements the syscall to read from the device
+ * @filp: file pointer
+ * @buf: pointer to user buffer
+ * @count: number of bytes to read
+ * @offset: offset from where to start reading
+ */
+static ssize_t
+comp_read(struct file *filp, char __user *buf, size_t count, loff_t *offset)
+{
+ size_t to_copy, not_copied, copied;
+ struct mbo *mbo = NULL;
+ struct comp_channel *c = filp->private_data;
+
+ mutex_lock(&c->io_mutex);
+ while (c->dev && !kfifo_peek(&c->fifo, &mbo)) {
+ mutex_unlock(&c->io_mutex);
+ if (filp->f_flags & O_NONBLOCK)
+ return -EAGAIN;
+ if (wait_event_interruptible(c->wq,
+ (!kfifo_is_empty(&c->fifo) ||
+ (!c->dev))))
+ return -ERESTARTSYS;
+ mutex_lock(&c->io_mutex);
+ }
+
+ /* make sure we don't submit to gone devices */
+ if (unlikely(!c->dev)) {
+ mutex_unlock(&c->io_mutex);
+ return -ENODEV;
+ }
+
+ to_copy = min_t(size_t,
+ count,
+ mbo->processed_length - c->mbo_offs);
+
+ not_copied = copy_to_user(buf,
+ mbo->virt_address + c->mbo_offs,
+ to_copy);
+
+ copied = to_copy - not_copied;
+
+ c->mbo_offs += copied;
+ if (c->mbo_offs >= mbo->processed_length) {
+ kfifo_skip(&c->fifo);
+ most_put_mbo(mbo);
+ c->mbo_offs = 0;
+ }
+ mutex_unlock(&c->io_mutex);
+ return copied;
+}
+
+static __poll_t comp_poll(struct file *filp, poll_table *wait)
+{
+ struct comp_channel *c = filp->private_data;
+ __poll_t mask = 0;
+
+ poll_wait(filp, &c->wq, wait);
+
+ mutex_lock(&c->io_mutex);
+ if (c->cfg->direction == MOST_CH_RX) {
+ if (!c->dev || !kfifo_is_empty(&c->fifo))
+ mask |= EPOLLIN | EPOLLRDNORM;
+ } else {
+ if (!c->dev || !kfifo_is_empty(&c->fifo) || ch_has_mbo(c))
+ mask |= EPOLLOUT | EPOLLWRNORM;
+ }
+ mutex_unlock(&c->io_mutex);
+ return mask;
+}
+
+/**
+ * Initialization of struct file_operations
+ */
+static const struct file_operations channel_fops = {
+ .owner = THIS_MODULE,
+ .read = comp_read,
+ .write = comp_write,
+ .open = comp_open,
+ .release = comp_close,
+ .poll = comp_poll,
+};
+
+/**
+ * comp_disconnect_channel - disconnect a channel
+ * @iface: pointer to interface instance
+ * @channel_id: channel index
+ *
+ * This frees allocated memory and removes the cdev that represents this
+ * channel in user space.
+ */
+static int comp_disconnect_channel(struct most_interface *iface, int channel_id)
+{
+ struct comp_channel *c;
+
+ c = get_channel(iface, channel_id);
+ if (!c)
+ return -EINVAL;
+
+ mutex_lock(&c->io_mutex);
+ spin_lock(&c->unlink);
+ c->dev = NULL;
+ spin_unlock(&c->unlink);
+ destroy_cdev(c);
+ if (c->access_ref) {
+ stop_channel(c);
+ wake_up_interruptible(&c->wq);
+ mutex_unlock(&c->io_mutex);
+ } else {
+ mutex_unlock(&c->io_mutex);
+ destroy_channel(c);
+ }
+ return 0;
+}
+
+/**
+ * comp_rx_completion - completion handler for rx channels
+ * @mbo: pointer to buffer object that has completed
+ *
+ * This searches for the channel linked to this MBO and stores it in the local
+ * fifo buffer.
+ */
+static int comp_rx_completion(struct mbo *mbo)
+{
+ struct comp_channel *c;
+
+ if (!mbo)
+ return -EINVAL;
+
+ c = get_channel(mbo->ifp, mbo->hdm_channel_id);
+ if (!c)
+ return -EINVAL;
+
+ spin_lock(&c->unlink);
+ if (!c->access_ref || !c->dev) {
+ spin_unlock(&c->unlink);
+ return -ENODEV;
+ }
+ kfifo_in(&c->fifo, &mbo, 1);
+ spin_unlock(&c->unlink);
+#ifdef DEBUG_MESG
+ if (kfifo_is_full(&c->fifo))
+ dev_warn(c->dev, "Fifo is full\n");
+#endif
+ wake_up_interruptible(&c->wq);
+ return 0;
+}
+
+/**
+ * comp_tx_completion - completion handler for tx channels
+ * @iface: pointer to interface instance
+ * @channel_id: channel index/ID
+ *
+ * This wakes sleeping processes in the wait-queue.
+ */
+static int comp_tx_completion(struct most_interface *iface, int channel_id)
+{
+ struct comp_channel *c;
+
+ c = get_channel(iface, channel_id);
+ if (!c)
+ return -EINVAL;
+
+ if ((channel_id < 0) || (channel_id >= iface->num_channels)) {
+ dev_warn(c->dev, "Channel ID out of range\n");
+ return -EINVAL;
+ }
+
+ wake_up_interruptible(&c->wq);
+ return 0;
+}
+
+/**
+ * comp_probe - probe function of the driver module
+ * @iface: pointer to interface instance
+ * @channel_id: channel index/ID
+ * @cfg: pointer to actual channel configuration
+ * @name: name of the device to be created
+ *
+ * This allocates achannel object and creates the device node in /dev
+ *
+ * Returns 0 on success or error code otherwise.
+ */
+static int comp_probe(struct most_interface *iface, int channel_id,
+ struct most_channel_config *cfg, char *name, char *args)
+{
+ struct comp_channel *c;
+ unsigned long cl_flags;
+ int retval;
+ int current_minor;
+
+ if (!cfg || !name)
+ return -EINVAL;
+
+ c = get_channel(iface, channel_id);
+ if (c)
+ return -EEXIST;
+
+ current_minor = ida_simple_get(&comp.minor_id, 0, 0, GFP_KERNEL);
+ if (current_minor < 0)
+ return current_minor;
+
+ c = kzalloc(sizeof(*c), GFP_KERNEL);
+ if (!c) {
+ retval = -ENOMEM;
+ goto err_remove_ida;
+ }
+
+ c->devno = MKDEV(comp.major, current_minor);
+ cdev_init(&c->cdev, &channel_fops);
+ c->cdev.owner = THIS_MODULE;
+ retval = cdev_add(&c->cdev, c->devno, 1);
+ if (retval < 0)
+ goto err_free_c;
+ c->iface = iface;
+ c->cfg = cfg;
+ c->channel_id = channel_id;
+ c->access_ref = 0;
+ spin_lock_init(&c->unlink);
+ INIT_KFIFO(c->fifo);
+ retval = kfifo_alloc(&c->fifo, cfg->num_buffers, GFP_KERNEL);
+ if (retval)
+ goto err_del_cdev_and_free_channel;
+ init_waitqueue_head(&c->wq);
+ mutex_init(&c->io_mutex);
+ spin_lock_irqsave(&ch_list_lock, cl_flags);
+ list_add_tail(&c->list, &channel_list);
+ spin_unlock_irqrestore(&ch_list_lock, cl_flags);
+ c->dev = device_create(comp.class, NULL, c->devno, NULL, "%s", name);
+
+ if (IS_ERR(c->dev)) {
+ retval = PTR_ERR(c->dev);
+ goto err_free_kfifo_and_del_list;
+ }
+ kobject_uevent(&c->dev->kobj, KOBJ_ADD);
+ return 0;
+
+err_free_kfifo_and_del_list:
+ kfifo_free(&c->fifo);
+ list_del(&c->list);
+err_del_cdev_and_free_channel:
+ cdev_del(&c->cdev);
+err_free_c:
+ kfree(c);
+err_remove_ida:
+ ida_simple_remove(&comp.minor_id, current_minor);
+ return retval;
+}
+
+static struct cdev_component comp = {
+ .cc = {
+ .mod = THIS_MODULE,
+ .name = "cdev",
+ .probe_channel = comp_probe,
+ .disconnect_channel = comp_disconnect_channel,
+ .rx_completion = comp_rx_completion,
+ .tx_completion = comp_tx_completion,
+ },
+};
+
+static int __init mod_init(void)
+{
+ int err;
+
+ comp.class = class_create(THIS_MODULE, "most_cdev");
+ if (IS_ERR(comp.class))
+ return PTR_ERR(comp.class);
+
+ INIT_LIST_HEAD(&channel_list);
+ spin_lock_init(&ch_list_lock);
+ ida_init(&comp.minor_id);
+
+ err = alloc_chrdev_region(&comp.devno, 0, CHRDEV_REGION_SIZE, "cdev");
+ if (err < 0)
+ goto dest_ida;
+ comp.major = MAJOR(comp.devno);
+ err = most_register_component(&comp.cc);
+ if (err)
+ goto free_cdev;
+ err = most_register_configfs_subsys(&comp.cc);
+ if (err)
+ goto deregister_comp;
+ return 0;
+
+deregister_comp:
+ most_deregister_component(&comp.cc);
+free_cdev:
+ unregister_chrdev_region(comp.devno, CHRDEV_REGION_SIZE);
+dest_ida:
+ ida_destroy(&comp.minor_id);
+ class_destroy(comp.class);
+ return err;
+}
+
+static void __exit mod_exit(void)
+{
+ struct comp_channel *c, *tmp;
+
+ most_deregister_configfs_subsys(&comp.cc);
+ most_deregister_component(&comp.cc);
+
+ list_for_each_entry_safe(c, tmp, &channel_list, list) {
+ destroy_cdev(c);
+ destroy_channel(c);
+ }
+ unregister_chrdev_region(comp.devno, CHRDEV_REGION_SIZE);
+ ida_destroy(&comp.minor_id);
+ class_destroy(comp.class);
+}
+
+module_init(mod_init);
+module_exit(mod_exit);
+MODULE_AUTHOR("Christian Gromm <christian.gromm@microchip.com>");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("character device component for mostcore");