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| author | Peter Zijlstra <peterz@infradead.org> | 2014-02-06 21:16:07 +0400 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2014-04-18 13:40:30 +0400 |
| commit | febdbfe8a91ce0d11939d4940b592eb0dba8d663 (patch) | |
| tree | 5651dc5030d3cc43a0e852f60ca2627835ef194f /include/linux/bitops.h | |
| parent | 2ab08ee9f0a4eba27c7c4ce0b6d5118e8a18554b (diff) | |
| download | linux-febdbfe8a91ce0d11939d4940b592eb0dba8d663.tar.xz | |
arch: Prepare for smp_mb__{before,after}_atomic()
Since the smp_mb__{before,after}*() ops are fundamentally dependent on
how an arch can implement atomics it doesn't make sense to have 3
variants of them. They must all be the same.
Furthermore, the 3 variants suggest they're only valid for those 3
atomic ops, while we have many more where they could be applied.
So move away from
smp_mb__{before,after}_{atomic,clear}_{dec,inc,bit}() and reduce the
interface to just the two: smp_mb__{before,after}_atomic().
This patch prepares the way by introducing default implementations in
asm-generic/barrier.h that default to a full barrier and providing
__deprecated inlines for the previous 6 barriers if they're not
provided by the arch.
This should allow for a mostly painless transition (lots of deprecated
warns in the interim).
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/n/tip-wr59327qdyi9mbzn6x937s4e@git.kernel.org
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "Chen, Gong" <gong.chen@linux.intel.com>
Cc: John Sullivan <jsrhbz@kanargh.force9.co.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mauro Carvalho Chehab <m.chehab@samsung.com>
Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include/linux/bitops.h')
| -rw-r--r-- | include/linux/bitops.h | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/include/linux/bitops.h b/include/linux/bitops.h index be5fd38bd5a0..cbc5833fb221 100644 --- a/include/linux/bitops.h +++ b/include/linux/bitops.h @@ -32,6 +32,26 @@ extern unsigned long __sw_hweight64(__u64 w); */ #include <asm/bitops.h> +/* + * Provide __deprecated wrappers for the new interface, avoid flag day changes. + * We need the ugly external functions to break header recursion hell. + */ +#ifndef smp_mb__before_clear_bit +static inline void __deprecated smp_mb__before_clear_bit(void) +{ + extern void __smp_mb__before_atomic(void); + __smp_mb__before_atomic(); +} +#endif + +#ifndef smp_mb__after_clear_bit +static inline void __deprecated smp_mb__after_clear_bit(void) +{ + extern void __smp_mb__after_atomic(void); + __smp_mb__after_atomic(); +} +#endif + #define for_each_set_bit(bit, addr, size) \ for ((bit) = find_first_bit((addr), (size)); \ (bit) < (size); \ |