/home/hillier_g/checkout/most4linux/most-kernel/most-txbuf.h File Reference

Synchronous transmit buffer for MOST. More...

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Data Structures
struct	tx_buffer
Functions
tx_buffer *	txbuf_alloc (unsigned int writer_count, unsigned int frame_count, unsigned int bytes_per_frame)
void	txbuf_free (struct tx_buffer *ring)
ssize_t	txbuf_get (struct tx_buffer *ring, unsigned char *buffer, size_t bytes)
ssize_t	txbuf_put (struct tx_buffer *ring, int writer_index, struct frame_part frame_part, const char *buffer, size_t bytes, struct rtnrt_memcopy_desc *copy)
bool	txbuf_is_full (struct tx_buffer *ring, int writer_index)
void	txbuf_print_debug (struct tx_buffer *ring)

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Detailed Description

Synchronous transmit buffer for MOST.

Definition in file most-txbuf.h.

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Function Documentation

struct tx_buffer* txbuf_alloc	(	unsigned int	writer_count,
		unsigned int	frame_count,
		unsigned int	bytes_per_frame
	)

Parameters:

	writer_count	the number of writers
	frame_count	the number of frames that are in the ring buffer
	bytes_per_frame	the number of bytes needed per frame

Returns:

the allocated ring buffer or NULL if the ring buffer could not be allocated (an error message will be printed)

Definition at line 54 of file most-txbuf.c.

References tx_buffer::buffer, tx_buffer::bytes_per_frame, tx_buffer::frame_count, tx_buffer::full_count, ker_malloc, tx_buffer::lock, PR, pr_txbuf_debug, tx_buffer::readptr, rtnrt_err, rtnrt_lock_init, tx_buffer::writeptr, and tx_buffer::writer_count.

void txbuf_free

(

struct tx_buffer *

ring

)

Frees the ring buffer. Don't use ring after calling this function any more.

Parameters:

ring

the ring buffer

Definition at line 107 of file most-txbuf.c.

References tx_buffer::buffer.

ssize_t txbuf_get	(	struct tx_buffer *	ring,
		unsigned char *	buffer,
		size_t	bytes
	)

Reads element_count frames from the ring buffer.

Parameters:

	ring	the ring buffer
	buffer	the buffer to copy (usually a DMA buffer)
	bytes	the number of bytes that should be copied. If there are less than bytes elements in the ring, only the number of elements in the ring are copied

Returns:

the number of elements copied

Definition at line 120 of file most-txbuf.c.

References tx_buffer::buffer, tx_buffer::bytes_per_frame, tx_buffer::frame_count, tx_buffer::full_count, tx_buffer::lock, PR, tx_buffer::readptr, rtnrt_err, rtnrt_lock_get_irqsave, and rtnrt_lock_put_irqrestore.

Referenced by most_sync_int_handler(), and most_sync_rt_interrupt_handler().

ssize_t txbuf_put	(	struct tx_buffer *	ring,
		int	writer_index,
		struct frame_part	frame_part,
		const char *	buffer,
		size_t	bytes,
		struct rtnrt_memcopy_desc *	copy
	)

Puts bytes bytes in the ring.

Parameters:

	ring	the ring buffer
	writer_index	the index of the writer that wants to put data in the buffer. The index is not checked!
	frame_part	the part of the frame the user is interested
	buffer	userspace buffer from which the data is copied. The function uses the copy function that checks if it is valid memory, no additional checks must be done before
	bytes	the number of bytes that are in the userspace buffer
	copy	the copy descriptor, see description of struct rtnrt_memcopy_desc.

Returns:

the number of bytes that have been copied successfully

Definition at line 216 of file most-txbuf.c.

References tx_buffer::buffer, tx_buffer::bytes_per_frame, frame_part::count, tx_buffer::frame_count, tx_buffer::lock, frame_part::offset, PR, pr_txbuf_debug, tx_buffer::readptr, rtnrt_copy, rtnrt_err, rtnrt_lock_get_irqsave, rtnrt_lock_put_irqrestore, txbuf_update_full_frame_count(), and tx_buffer::writeptr.

Referenced by most_sync_write().

bool txbuf_is_full	(	struct tx_buffer *	ring,
		int	writer_index
	)

Checks if the buffer is full for the specified writer.

Parameters:

	ring	the ring buffer
	writer_index	the index of the writer

Definition at line 200 of file most-txbuf.c.

References tx_buffer::bytes_per_frame, tx_buffer::frame_count, tx_buffer::readptr, and tx_buffer::writeptr.

Referenced by most_sync_write().

void txbuf_print_debug

(

struct tx_buffer *

ring

)

Prints debug information (printk()) of the ring buffer. Don't call this function on large ring buffers because the whole buffer is printed in hex values and large buffers would fill the kernel ring buffer here and slowdown the whole system!

Parameters:

ring

the ring buffer

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