From: Laurent Pinchart <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx>
The media devnode core associates devnodes with files by storing the
devnode pointer in the file structure private_data field. In order to
allow tracking of per-file-handle data introduce a new media devnode
file handle structure that stores the devnode pointer, and store a
pointer to that structure in the file private_data field.
Users of the media devnode code (the only existing user being
media_device) are responsible for managing their own subclass of the
media_devnode_fh structure.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx>
Prepare struct media_device_fh to be used for maintaining file handle list
to avoid shuffling things here and there right after.
Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
Acked-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
---
drivers/media/mc/mc-device.c | 14 +++++++++++++-
drivers/media/mc/mc-devnode.c | 20 +++++++++-----------
include/media/media-device.h | 7 +++++++
include/media/media-devnode.h | 18 +++++++++++++++++-
include/media/media-fh.h | 32 ++++++++++++++++++++++++++++++++
5 files changed, 78 insertions(+), 13 deletions(-)
create mode 100644 include/media/media-fh.h
diff --git a/drivers/media/mc/mc-device.c b/drivers/media/mc/mc-device.c
index 10426c2796b6..67a39cb63f89 100644
--- a/drivers/media/mc/mc-device.c
+++ b/drivers/media/mc/mc-device.c
@@ -22,6 +22,7 @@
#include <media/media-device.h>
#include <media/media-devnode.h>
#include <media/media-entity.h>
+#include <media/media-fh.h>
#include <media/media-request.h>
#ifdef CONFIG_MEDIA_CONTROLLER
@@ -35,7 +36,6 @@
#define MEDIA_ENT_SUBTYPE_MASK 0x0000ffff
#define MEDIA_ENT_T_DEVNODE_UNKNOWN (MEDIA_ENT_F_OLD_BASE | \
MEDIA_ENT_SUBTYPE_MASK)
-
/* -----------------------------------------------------------------------------
* Userspace API
*/
@@ -47,11 +47,23 @@ static inline void __user *media_get_uptr(__u64 arg)
static int media_device_open(struct file *filp)
{
+ struct media_device_fh *fh;
+
+ fh = kzalloc(sizeof(*fh), GFP_KERNEL);
+ if (!fh)
+ return -ENOMEM;
+
+ filp->private_data = &fh->fh;
+
return 0;
}
static int media_device_close(struct file *filp)
{
+ struct media_device_fh *fh = media_device_fh(filp);
+
+ kfree(fh);
+
return 0;
}
diff --git a/drivers/media/mc/mc-devnode.c b/drivers/media/mc/mc-devnode.c
index 6fb3a202eb26..4fdb1572ff9b 100644
--- a/drivers/media/mc/mc-devnode.c
+++ b/drivers/media/mc/mc-devnode.c
@@ -133,6 +133,7 @@ static long media_compat_ioctl(struct file *filp, unsigned int cmd,
static int media_open(struct inode *inode, struct file *filp)
{
struct media_devnode *devnode;
+ struct media_devnode_fh *fh;
int ret;
/* Check if the media device is available. This needs to be done with
@@ -153,17 +154,15 @@ static int media_open(struct inode *inode, struct file *filp)
get_device(&devnode->dev);
mutex_unlock(&media_devnode_lock);
- filp->private_data = devnode;
-
- if (devnode->fops->open) {
- ret = devnode->fops->open(filp);
- if (ret) {
- put_device(&devnode->dev);
- filp->private_data = NULL;
- return ret;
- }
+ ret = devnode->fops->open(filp);
+ if (ret) {
+ put_device(&devnode->dev);
+ return ret;
}
+ fh = filp->private_data;
+ fh->devnode = devnode;
+
return 0;
}
@@ -172,8 +171,7 @@ static int media_release(struct inode *inode, struct file *filp)
{
struct media_devnode *devnode = media_devnode_data(filp);
- if (devnode->fops->release)
- devnode->fops->release(filp);
+ devnode->fops->release(filp);
filp->private_data = NULL;
diff --git a/include/media/media-device.h b/include/media/media-device.h
index fe4625f3f62b..f9f7c37e7d57 100644
--- a/include/media/media-device.h
+++ b/include/media/media-device.h
@@ -110,6 +110,10 @@ struct media_device_ops {
* other operations that stop or start streaming.
* @request_id: Used to generate unique request IDs
*
+ * @fh_list: List of file handles in the media device
+ * (struct media_device_fh.mdev_list).
+ * @fh_list_lock: Serialise access to fh_list list.
+ *
* This structure represents an abstract high-level media device. It allows easy
* access to entities and provides basic media device-level support. The
* structure can be allocated directly or embedded in a larger structure.
@@ -182,6 +186,9 @@ struct media_device {
struct mutex req_queue_mutex;
atomic_t request_id;
+
+ struct list_head fh_list;
+ spinlock_t fh_list_lock;
};
/* We don't need to include usb.h here */
diff --git a/include/media/media-devnode.h b/include/media/media-devnode.h
index 113c317e6a0e..e4e8552598eb 100644
--- a/include/media/media-devnode.h
+++ b/include/media/media-devnode.h
@@ -53,6 +53,20 @@ struct media_file_operations {
int (*release) (struct file *);
};
+/**
+ * struct media_devnode_fh - Media device node file handle
+ * @devnode: pointer to the media device node
+ *
+ * This structure serves as a base for per-file-handle data storage. Media
+ * device node users embed media_devnode_fh in their custom file handle data
+ * structures and store the media_devnode_fh in the file private_data in order
+ * to let the media device node core locate the media_devnode corresponding to a
+ * file handle.
+ */
+struct media_devnode_fh {
+ struct media_devnode *devnode;
+};
+
/**
* struct media_devnode - Media device node
* @fops: pointer to struct &media_file_operations with media device ops
@@ -136,7 +150,9 @@ void media_devnode_unregister(struct media_devnode *devnode);
*/
static inline struct media_devnode *media_devnode_data(struct file *filp)
{
- return filp->private_data;
+ struct media_devnode_fh *fh = filp->private_data;
+
+ return fh->devnode;
}
/**
diff --git a/include/media/media-fh.h b/include/media/media-fh.h
new file mode 100644
index 000000000000..6f00744b81d6
--- /dev/null
+++ b/include/media/media-fh.h
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Media device file handle
+ *
+ * Copyright (C) 2019--2023 Intel Corporation
+ */
+
+#ifndef MEDIA_FH_H
+#define MEDIA_FH_H
+
+#include <linux/list.h>
+#include <linux/file.h>
+
+#include <media/media-devnode.h>
+
+/**
+ * struct media_device_fh - File handle specific information on MC
+ *
+ * @fh: The media device file handle
+ * @mdev_list: This file handle in media device's list of file handles
+ */
+struct media_device_fh {
+ struct media_devnode_fh fh;
+ struct list_head mdev_list;
+};
+
+static inline struct media_device_fh *media_device_fh(struct file *filp)
+{
+ return container_of(filp->private_data, struct media_device_fh, fh);
+}
+
+#endif /* MEDIA_FH_H */
--
2.39.2
