The C version of csum_add() as defined in include/net/checksum.h gives
the following assembly in ppc32:
0: 7c 04 1a 14 add r0,r4,r3
4: 7c 64 00 10 subfc r3,r4,r0
8: 7c 63 19 10 subfe r3,r3,r3
c: 7c 63 00 50 subf r3,r3,r0
and the following in ppc64:
0xc000000000001af8 <+0>: add r3,r3,r4
0xc000000000001afc <+4>: cmplw cr7,r3,r4
0xc000000000001b00 <+8>: mfcr r4
0xc000000000001b04 <+12>: rlwinm r4,r4,29,31,31
0xc000000000001b08 <+16>: add r3,r4,r3
0xc000000000001b0c <+20>: clrldi r3,r3,32
0xc000000000001b10 <+24>: blr
include/net/checksum.h also offers the possibility to define an arch
specific function. This patch provides a specific csum_add() inline
function.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <scottwood@freescale.com>
csum_tcpudp_magic() is only a few instructions, and does modify
really few registers. So it is not worth having it as a separate
function and suffer function branching and saving of volatile
registers.
This patch makes it inline by use of the already existing
csum_tcpudp_nofold() function.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <scottwood@freescale.com>
We need to fix some endian issues in our checksum code. For now
just enable the generic checksum routines for little endian builds.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This adds the equivalent of csum_and_copy_from_user for the receive side so we
can copy and checksum in one pass. It is modelled on the generic checksum
routine.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
We use the same core loop as the new csum_partial, adding in the
stores and exception handling code. To keep things simple we do all the
exception fixup in csum_and_copy_from_user. This wrapper function is
modelled on the generic checksum code and is careful to always calculate
a complete checksum even if we only copied part of the data to userspace.
To test this I forced checksumming on over loopback and ran socklib (a
simple TCP benchmark). On a POWER6 575 throughput improved by 19% with
this patch. If I forced both the sender and receiver onto the same cpu
(with the hope of shifting the benchmark from being cache bandwidth limited
to cpu limited), adding this patch improved performance by 55%
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
from include/asm-powerpc. This is the result of a
mkdir arch/powerpc/include/asm
git mv include/asm-powerpc/* arch/powerpc/include/asm
Followed by a few documentation/comment fixups and a couple of places
where <asm-powepc/...> was being used explicitly. Of the latter only
one was outside the arch code and it is a driver only built for powerpc.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
