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| author | Peter Zijlstra <peterz@infradead.org> | 2016-04-18 01:16:08 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-06-16 10:48:23 +0200 |
| commit | e87fc0ec070554e34812be68267a9450271868d6 (patch) | |
| tree | d99ccf1052722bd4e699414851673768f4004e8f /arch/blackfin/include | |
| parent | 1a6eafacd4811cdc1b138faee858527658eee4e1 (diff) | |
| download | lwn-e87fc0ec070554e34812be68267a9450271868d6.tar.gz lwn-e87fc0ec070554e34812be68267a9450271868d6.zip | |
locking/atomic, arch/blackfin: Implement atomic_fetch_{add,sub,and,or,xor}()
Implement FETCH-OP atomic primitives, these are very similar to the
existing OP-RETURN primitives we already have, except they return the
value of the atomic variable _before_ modification.
This is especially useful for irreversible operations -- such as
bitops (because it becomes impossible to reconstruct the state prior
to modification).
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Miao <realmz6@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: adi-buildroot-devel@lists.sourceforge.net
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/blackfin/include')
| -rw-r--r-- | arch/blackfin/include/asm/atomic.h | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/blackfin/include/asm/atomic.h b/arch/blackfin/include/asm/atomic.h index 1c1c42330c99..63c7deceeeb6 100644 --- a/arch/blackfin/include/asm/atomic.h +++ b/arch/blackfin/include/asm/atomic.h @@ -17,6 +17,7 @@ asmlinkage int __raw_uncached_fetch_asm(const volatile int *ptr); asmlinkage int __raw_atomic_add_asm(volatile int *ptr, int value); +asmlinkage int __raw_atomic_xadd_asm(volatile int *ptr, int value); asmlinkage int __raw_atomic_and_asm(volatile int *ptr, int value); asmlinkage int __raw_atomic_or_asm(volatile int *ptr, int value); @@ -28,10 +29,17 @@ asmlinkage int __raw_atomic_test_asm(const volatile int *ptr, int value); #define atomic_add_return(i, v) __raw_atomic_add_asm(&(v)->counter, i) #define atomic_sub_return(i, v) __raw_atomic_add_asm(&(v)->counter, -(i)) +#define atomic_fetch_add(i, v) __raw_atomic_xadd_asm(&(v)->counter, i) +#define atomic_fetch_sub(i, v) __raw_atomic_xadd_asm(&(v)->counter, -(i)) + #define atomic_or(i, v) (void)__raw_atomic_or_asm(&(v)->counter, i) #define atomic_and(i, v) (void)__raw_atomic_and_asm(&(v)->counter, i) #define atomic_xor(i, v) (void)__raw_atomic_xor_asm(&(v)->counter, i) +#define atomic_fetch_or(i, v) __raw_atomic_or_asm(&(v)->counter, i) +#define atomic_fetch_and(i, v) __raw_atomic_and_asm(&(v)->counter, i) +#define atomic_fetch_xor(i, v) __raw_atomic_xor_asm(&(v)->counter, i) + #endif #include <asm-generic/atomic.h> |