diff options
author | Jean Delvare <jdelvare@suse.de> | 2007-04-26 07:44:22 (GMT) |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2007-04-26 07:44:22 (GMT) |
commit | eefa3906283a2b60a6d02a2cda593a7d7d7946c5 (patch) | |
tree | a4e1f3b8dca04b8dff3cd99dc43f771f798558fb /net/core/user_dma.c | |
parent | 28d8909bc790d936ce33f4402adf7577533bbd4b (diff) | |
download | linux-eefa3906283a2b60a6d02a2cda593a7d7d7946c5.tar.xz |
[NET]: Clean up sk_buff walkers.
I noticed recently that, in skb_checksum(), "offset" and "start" are
essentially the same thing and have the same value throughout the
function, despite being computed differently. Using a single variable
allows some cleanups and makes the skb_checksum() function smaller,
more readable, and presumably marginally faster.
We appear to have many other "sk_buff walker" functions built on the
exact same model, so the cleanup applies to them, too. Here is a list
of the functions I found to be affected:
net/appletalk/ddp.c:atalk_sum_skb()
net/core/datagram.c:skb_copy_datagram_iovec()
net/core/datagram.c:skb_copy_and_csum_datagram()
net/core/skbuff.c:skb_copy_bits()
net/core/skbuff.c:skb_store_bits()
net/core/skbuff.c:skb_checksum()
net/core/skbuff.c:skb_copy_and_csum_bit()
net/core/user_dma.c:dma_skb_copy_datagram_iovec()
net/xfrm/xfrm_algo.c:skb_icv_walk()
net/xfrm/xfrm_algo.c:skb_to_sgvec()
OTOH, I admit I'm a bit surprised, the cleanup is rather obvious so I'm
really wondering if I am missing something. Can anyone please comment
on this?
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core/user_dma.c')
-rw-r--r-- | net/core/user_dma.c | 25 |
1 files changed, 9 insertions, 16 deletions
diff --git a/net/core/user_dma.c b/net/core/user_dma.c index 0ad1cd5..89241cd 100644 --- a/net/core/user_dma.c +++ b/net/core/user_dma.c @@ -49,8 +49,8 @@ int dma_skb_copy_datagram_iovec(struct dma_chan *chan, struct sk_buff *skb, int offset, struct iovec *to, size_t len, struct dma_pinned_list *pinned_list) { - int start = skb_headlen(skb); - int i, copy = start - offset; + int end = skb_headlen(skb); + int i, copy = end - offset; dma_cookie_t cookie = 0; /* Copy header. */ @@ -69,11 +69,9 @@ int dma_skb_copy_datagram_iovec(struct dma_chan *chan, /* Copy paged appendix. Hmm... why does this look so complicated? */ for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { - int end; + BUG_TRAP(len >= 0); - BUG_TRAP(start <= offset + len); - - end = start + skb_shinfo(skb)->frags[i].size; + end = offset + skb_shinfo(skb)->frags[i].size; copy = end - offset; if ((copy = end - offset) > 0) { skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; @@ -82,8 +80,8 @@ int dma_skb_copy_datagram_iovec(struct dma_chan *chan, if (copy > len) copy = len; - cookie = dma_memcpy_pg_to_iovec(chan, to, pinned_list, page, - frag->page_offset + offset - start, copy); + cookie = dma_memcpy_pg_to_iovec(chan, to, pinned_list, + page, frag->page_offset, copy); if (cookie < 0) goto fault; len -= copy; @@ -91,25 +89,21 @@ int dma_skb_copy_datagram_iovec(struct dma_chan *chan, goto end; offset += copy; } - start = end; } if (skb_shinfo(skb)->frag_list) { struct sk_buff *list = skb_shinfo(skb)->frag_list; for (; list; list = list->next) { - int end; - - BUG_TRAP(start <= offset + len); + BUG_TRAP(len >= 0); - end = start + list->len; + end = offset + list->len; copy = end - offset; if (copy > 0) { if (copy > len) copy = len; cookie = dma_skb_copy_datagram_iovec(chan, list, - offset - start, to, copy, - pinned_list); + 0, to, copy, pinned_list); if (cookie < 0) goto fault; len -= copy; @@ -117,7 +111,6 @@ int dma_skb_copy_datagram_iovec(struct dma_chan *chan, goto end; offset += copy; } - start = end; } } |