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staging/android: Add some more kerneldoc to ashmem.c 

I am sorry if I have interpreted anything incorrectly here. This is my
second day really attempting to understand the Ashmem system.

I can not finish documenting this class at this stage - There is still
more that I have to learn. For now, however, it will have to do.

Signed-off-by: Cruz Julian Bishop <cruzjbishop@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Cruz Julian Bishop 2013-09-03 22:05:08 +10:00 committed by Greg Kroah-Hartman
parent 4d2c9d5ddc
commit 781114ced2
1 changed files with 37 additions and 3 deletions
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40
drivers/staging/android/ashmem.c
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@ -196,10 +196,17 @@ static void range_del(struct ashmem_range *range)
kmem_cache_free(ashmem_range_cachep, range);
}
/*
* range_shrink - shrinks a range
/**
* range_shrink() - Shrinks an ashmem_range
* @range: The associated ashmem_range being shrunk
* @start: The starting byte of the new range
* @end: The ending byte of the new range
*
* Caller must hold ashmem_mutex.
* This does not modify the data inside the existing range in any way - It
* simply shrinks the boundaries of the range.
*
* Theoretically, with a little tweaking, this could eventually be changed
* to range_resize, and expand the lru_count if the new range is larger.
*/
static inline void range_shrink(struct ashmem_range *range,
size_t start, size_t end)
@ -213,6 +220,16 @@ static inline void range_shrink(struct ashmem_range *range,
lru_count -= pre - range_size(range);
}
/**
* ashmem_open() - Opens an Anonymous Shared Memory structure
* @inode: The backing file's index node(?)
* @file: The backing file
*
* Please note that the ashmem_area is not returned by this function - It is
* instead written to "file->private_data".
*
* Return: 0 if successful, or another code if unsuccessful.
*/
static int ashmem_open(struct inode *inode, struct file *file)
{
struct ashmem_area *asma;
@ -234,6 +251,14 @@ static int ashmem_open(struct inode *inode, struct file *file)
return 0;
}
/**
* ashmem_release() - Releases an Anonymous Shared Memory structure
* @ignored: The backing file's Index Node(?) - It is ignored here.
* @file: The backing file
*
* Return: 0 if successful. If it is anything else, go have a coffee and
* try again.
*/
static int ashmem_release(struct inode *ignored, struct file *file)
{
struct ashmem_area *asma = file->private_data;
@ -251,6 +276,15 @@ static int ashmem_release(struct inode *ignored, struct file *file)
return 0;
}
/**
* ashmem_read() - Reads a set of bytes from an Ashmem-enabled file
* @file: The associated backing file.
* @buf: The buffer of data being written to
* @len: The number of bytes being read
* @pos: The position of the first byte to read.
*
* Return: 0 if successful, or another return code if not.
*/
static ssize_t ashmem_read(struct file *file, char __user *buf,
size_t len, loff_t *pos)
{