Improve __csum_partial by interleaving loads and adds.
On a 8xx, it brings neither improvement nor degradation.
On a 83xx, it brings a 25% improvement.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This macro is taken from s390, and allows more flexibility in
changing exception table format.
mpe: Put it in ppc_asm.h and only define one version using
stringinfy_in_c(). Add some empty definitions and headers to keep the
selftests happy.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Pull kbuild updates from Michal Marek:
- EXPORT_SYMBOL for asm source by Al Viro.
This does bring a regression, because genksyms no longer generates
checksums for these symbols (CONFIG_MODVERSIONS). Nick Piggin is
working on a patch to fix this.
Plus, we are talking about functions like strcpy(), which rarely
change prototypes.
- Fixes for PPC fallout of the above by Stephen Rothwell and Nick
Piggin
- fixdep speedup by Alexey Dobriyan.
- preparatory work by Nick Piggin to allow architectures to build with
-ffunction-sections, -fdata-sections and --gc-sections
- CONFIG_THIN_ARCHIVES support by Stephen Rothwell
- fix for filenames with colons in the initramfs source by me.
* 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild: (22 commits)
initramfs: Escape colons in depfile
ppc: there is no clear_pages to export
powerpc/64: whitelist unresolved modversions CRCs
kbuild: -ffunction-sections fix for archs with conflicting sections
kbuild: add arch specific post-link Makefile
kbuild: allow archs to select link dead code/data elimination
kbuild: allow architectures to use thin archives instead of ld -r
kbuild: Regenerate genksyms lexer
kbuild: genksyms fix for typeof handling
fixdep: faster CONFIG_ search
ia64: move exports to definitions
sparc32: debride memcpy.S a bit
[sparc] unify 32bit and 64bit string.h
sparc: move exports to definitions
ppc: move exports to definitions
arm: move exports to definitions
s390: move exports to definitions
m68k: move exports to definitions
alpha: move exports to actual definitions
x86: move exports to actual definitions
...
Commit 7aef413656 ("powerpc32: rewrite csum_partial_copy_generic()
based on copy_tofrom_user()") introduced a bug when destination address
is odd and len is lower than cacheline size.
In that case the resulting csum value doesn't have to be rotated one
byte because the cache-aligned copy part is skipped so no alignment
is performed.
Fixes: 7aef413656 ("powerpc32: rewrite csum_partial_copy_generic() based on copy_tofrom_user()")
Cc: stable@vger.kernel.org # v4.6+
Reported-by: Alessio Igor Bogani <alessio.bogani@elettra.eu>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Tested-by: Alessio Igor Bogani <alessio.bogani@elettra.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Commit 7aef413656 ("powerpc32: rewrite csum_partial_copy_generic()
based on copy_tofrom_user()") introduced a bug when destination
address is odd and initial csum is not null
In that (rare) case the initial csum value has to be rotated one byte
as well as the resulting value is
This patch also fixes related comments
Fixes: 7aef413656 ("powerpc32: rewrite csum_partial_copy_generic() based on copy_tofrom_user()")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
csum_partial is often called for small fixed length packets
for which it is suboptimal to use the generic csum_partial()
function.
For instance, in my configuration, I got:
* One place calling it with constant len 4
* Seven places calling it with constant len 8
* Three places calling it with constant len 14
* One place calling it with constant len 20
* One place calling it with constant len 24
* One place calling it with constant len 32
This patch renames csum_partial() to __csum_partial() and
implements csum_partial() as a wrapper inline function which
* uses csum_add() for small 16bits multiple constant length
* uses ip_fast_csum() for other 32bits multiple constant
* uses __csum_partial() in all other cases
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <oss@buserror.net>
On the 8xx, load latency is 2 cycles and taking branches also takes
2 cycles. So let's unroll the loop.
This patch improves csum_partial() speed by around 10% on both:
* 8xx (single issue processor with parallel execution)
* 83xx (superscalar 6xx processor with dual instruction fetch
and parallel execution)
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <oss@buserror.net>
r5 does contain the value to be updated, so lets use r5 all way long
for that. It makes the code more readable.
To avoid confusion, it is better to use adde instead of addc
The first addition is useless. Its only purpose is to clear carry.
As r4 is a signed int that is always positive, this can be done by
using srawi instead of srwi
Let's also remove the comment about bdnz having no overhead as it
is not correct on all powerpc, at least on MPC8xx
In the last part, in our situation, the remaining quantity of bytes
to be proceeded is between 0 and 3. Therefore, we can base that part
on the value of bit 31 and bit 30 of r4 instead of anding r4 with 3
then proceding on comparisons and substractions.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <oss@buserror.net>
csum_partial_copy_generic() does the same as copy_tofrom_user and also
calculates the checksum during the copy. Unlike copy_tofrom_user(),
the existing version of csum_partial_copy_generic() doesn't take
benefit of the cache.
This patch is a rewrite of csum_partial_copy_generic() based on
copy_tofrom_user().
The previous version of csum_partial_copy_generic() was handling
errors. Now we have the checksum wrapper functions to handle the error
case like in powerpc64 so we can make the error case simple:
just return -EFAULT.
copy_tofrom_user() only has r12 available => we use it for the
checksum r7 and r8 which contains pointers to error feedback are used,
so we stack them.
On a TCP benchmark using socklib on the loopback interface on which
checksum offload and scatter/gather have been deactivated, we get
about 20% performance increase.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <oss@buserror.net>
In several architectures, ip_fast_csum() is inlined
There are functions like ip_send_check() which do nothing
much more than calling ip_fast_csum().
Inlining ip_fast_csum() allows the compiler to optimise better
Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
[scottwood: whitespace and cast fixes]
Signed-off-by: Scott Wood <oss@buserror.net>
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>
This doesn't change any code, just renames things so we consistently
have foo_32.c and foo_64.c where we have separate 32- and 64-bit
versions.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Christophe Leroy
Nicholas Piggin
Linus Torvalds
Al Viro
Paul Mackerras