In preparation for removing volatile from the atomic_t definition, this
patch adds a volatile cast to all the atomic read functions.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The LL/SC and IRQ versions were using generic stubs while the GRB version
was just reimplementing what it already had for the standard cmpxchg()
code. As we have optimized cmpxchg() implementations that are decoupled
from the atomic code, simply falling back on the generic wrapper does the
right thing. With this in place the GRB case is unaffected while the
LL/SC case gets to use its optimized cmpxchg().
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
In the past these were simply wrapping to barrier() which was sufficient
on SH SMP platforms predating SH-4A. Unfortunately due to ll/sc semantics
an explicit synco is needed in these cases, which is sorted for us by
just switching these over to smp_mb(). smp_mb() also has the benefit of
being wrapped to barrier() in the UP and non-SH4A cases, so old behaviour
is maintained for those parts.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
The existing asm-generic/atomic.h only defines the
atomic_long type. This renames it to atomic-long.h
so we have a place to add a truly generic atomic.h
that can be used on all non-SMP systems.
Signed-off-by: Remis Lima Baima <remis.developer@googlemail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Ingo Molnar <mingo@elte.hu>
This fixes up a typo in the ll/sc based cmpxchg code which apparently
wasn't getting a lot of testing due to the swapped old/new pair. With
that fixed up, the ll/sc code also starts using it and provides its own
atomic_add_unless().
Signed-off-by: Aoi Shinkai <shinkoi2005@gmail.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>