diff mbox series

[v2,25/29] media: mc: Add per-file-handle data support

Message ID 20231220103713.113386-26-sakari.ailus@linux.intel.com (mailing list archive)
State New
Headers show
Series Media device lifetime management | expand

Commit Message

Sakari Ailus Dec. 20, 2023, 10:37 a.m. UTC 
From: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

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@ideasonboard.com>

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@linux.intel.com>
---
 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

Comments

Hans Verkuil Feb. 5, 2024, 3:08 p.m. UTC | #1 
On 20/12/2023 11:37, Sakari Ailus wrote:
> From: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
> 
> 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@ideasonboard.com>
> 
> 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@linux.intel.com>

Acked-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

> ---
>  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 4ea05e42dafb..04d376015526 100644
> --- a/drivers/media/mc/mc-devnode.c
> +++ b/drivers/media/mc/mc-devnode.c
> @@ -150,6 +150,7 @@ 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
> @@ -170,17 +171,15 @@ 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;
>  }
>  
> @@ -189,8 +188,7 @@ 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 98e1892f1b51..83b8ea44463d 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 d050f54f252a..b0efdde4ffd8 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
>   * @media_dev:	pointer to struct &media_device
> @@ -137,7 +151,9 @@ 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 */
diff mbox series

Patch

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 4ea05e42dafb..04d376015526 100644
--- a/drivers/media/mc/mc-devnode.c
+++ b/drivers/media/mc/mc-devnode.c
@@ -150,6 +150,7 @@  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
@@ -170,17 +171,15 @@  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;
 }
 
@@ -189,8 +188,7 @@  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 98e1892f1b51..83b8ea44463d 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 d050f54f252a..b0efdde4ffd8 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
  * @media_dev:	pointer to struct &media_device
@@ -137,7 +151,9 @@  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 */