tree 24a97806c51050de37fcc26f7a242443c8463060
parent 4a8de7f80b9469e79c6ecf14f25050fa5982e803
author Juergen Gross <jgross@suse.com> 1638188159 +0100
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1638949504 +0100

xen/netfront: disentangle tx_skb_freelist

commit 21631d2d741a64a073e167c27769e73bc7844a2f upstream.

The tx_skb_freelist elements are in a single linked list with the
request id used as link reference. The per element link field is in a
union with the skb pointer of an in use request.

Move the link reference out of the union in order to enable a later
reuse of it for requests which need a populated skb pointer.

Rename add_id_to_freelist() and get_id_from_freelist() to
add_id_to_list() and get_id_from_list() in order to prepare using
those for other lists as well. Define ~0 as value to indicate the end
of a list and place that value into the link for a request not being
on the list.

When freeing a skb zero the skb pointer in the request. Use a NULL
value of the skb pointer instead of skb_entry_is_link() for deciding
whether a request has a skb linked to it.

Remove skb_entry_set_link() and open code it instead as it is really
trivial now.

Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>