POWER5 added popcntb, and POWER7 added popcntw and popcntd. As a first step
this patch does all the work out of line, but it would be nice to implement
them as inlines with an out of line fallback.
The performance issue with hweight was noticed when disabling SMT on a large
(192 thread) POWER7 box. The patch improves that testcase by about 8%.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
For performance reasons we are about to change ISYNC_ON_SMP to sometimes be
lwsync. Now that the macro name doesn't make sense, change it and LWSYNC_ON_SMP
to better explain what the barriers are doing.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This patch implements the lwarx/ldarx hint bit for bit locks.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The bitops.h functions that operate on a single bit in a bitfield are
implemented by operating on the corresponding word location. In all
cases the inner logic is valid if the mask being applied has more than
one bit set, so this patch exposes those inner operations. Indeed,
set_bits() was already available, but it duplicated code from
set_bit() (rather than making the latter a wrapper) - it was also
missing the PPC405_ERR77() workaround and the "volatile" address
qualifier present in other APIs. This corrects that, and exposes the
other multi-bit equivalents.
One advantage of these multi-bit forms is that they allow word-sized
variables to essentially be their own spinlocks, eg. very useful for
state machines where an atomic "flags" variable can obviate the need
for any additional locking.
Signed-off-by: Geoff Thorpe <geoff@geoffthorpe.net>
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>
Anton Blanchard
Geoff Thorpe
Stephen Rothwell