virtio: document functions better.

The old documentation is left over from when we used a structure with
strategy pointers.

And move the documentation to the C file as per kernel practice.
Though I disagree...

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Reviewed-by: Christoph Hellwig <hch@lst.de>
This commit is contained in:
Rusty Russell 2012-01-12 15:44:42 +10:30
parent 1e214a5c1a
commit 5dfc17628d
2 changed files with 91 additions and 48 deletions

View file

@ -25,53 +25,6 @@ struct virtqueue {
void *priv;
};
/**
* operations for virtqueue
* virtqueue_add_buf: expose buffer to other end
* vq: the struct virtqueue we're talking about.
* sg: the description of the buffer(s).
* out_num: the number of sg readable by other side
* in_num: the number of sg which are writable (after readable ones)
* data: the token identifying the buffer.
* gfp: how to do memory allocations (if necessary).
* Returns remaining capacity of queue (sg segments) or a negative error.
* virtqueue_kick: update after add_buf
* vq: the struct virtqueue
* After one or more add_buf calls, invoke this to kick the other side.
* virtqueue_get_buf: get the next used buffer
* vq: the struct virtqueue we're talking about.
* len: the length written into the buffer
* Returns NULL or the "data" token handed to add_buf.
* virtqueue_disable_cb: disable callbacks
* vq: the struct virtqueue we're talking about.
* Note that this is not necessarily synchronous, hence unreliable and only
* useful as an optimization.
* virtqueue_enable_cb: restart callbacks after disable_cb.
* vq: the struct virtqueue we're talking about.
* This re-enables callbacks; it returns "false" if there are pending
* buffers in the queue, to detect a possible race between the driver
* checking for more work, and enabling callbacks.
* virtqueue_enable_cb_delayed: restart callbacks after disable_cb.
* vq: the struct virtqueue we're talking about.
* This re-enables callbacks but hints to the other side to delay
* interrupts until most of the available buffers have been processed;
* it returns "false" if there are many pending buffers in the queue,
* to detect a possible race between the driver checking for more work,
* and enabling callbacks.
* virtqueue_detach_unused_buf: detach first unused buffer
* vq: the struct virtqueue we're talking about.
* Returns NULL or the "data" token handed to add_buf
* virtqueue_get_vring_size: return the size of the virtqueue's vring
* vq: the struct virtqueue containing the vring of interest.
* Returns the size of the vring.
*
* Locking rules are straightforward: the driver is responsible for
* locking. No two operations may be invoked simultaneously, with the exception
* of virtqueue_disable_cb.
*
* All operations can be called in any context.
*/
int virtqueue_add_buf_gfp(struct virtqueue *vq,
struct scatterlist sg[],
unsigned int out_num,