First of all it is unnecessary to allocate a new skb in skb_pad since
the existing one is not shared. More importantly, our hard_start_xmit
interface does not allow a new skb to be allocated since that breaks
requeueing.
This patch uses pskb_expand_head to expand the existing skb and linearize
it if needed. Actually, someone should sift through every instance of
skb_pad on a non-linear skb as they do not fit the reasons why this was
originally created.
Incidentally, this fixes a minor bug when the skb is cloned (tcpdump,
TCP, etc.). As it is skb_pad will simply write over a cloned skb. Because
of the position of the write it is unlikely to cause problems but still
it's best if we don't do it.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
The purpose of this patch:
- Adopt the DMA API (jazzsonic, macsonic & core driver).
- Adopt the driver model (macsonic).
This part was cribbed from jazzsonic. As a consequence, macsonic once
again works as a module. Driver model is also used by the DMA calls.
- Support 16 bit cards (macsonic & core driver, also affects jazzsonic)
This code was adapted from the mac68k linux 2.2 kernel, where it has
languished for a long time.
- Support more 32-bit mac cards (macsonic)
Also from mac68k repo.
- Zero-copy buffer handling (core driver)
Provides a nice performance improvement. The new algorithm incidentally
helped to replace the old Jazz DMA code.
The patch was tested on a variety of macs (several 32-bit quadra built-in
NICs, a 16-bit LC PDS NIC and a 16-bit comm-slot NIC), and also on MIPS
Jazz.
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Jeff Garzik
Herbert Xu
Finn Thain
Linus Torvalds