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| author | Peter Zijlstra <peterz@infradead.org> | 2016-04-18 02:16:06 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-06-16 11:48:26 +0300 |
| commit | e898eb27ffd8b0ad6f4fd0b631559bc877c85444 (patch) | |
| tree | b9ee91a96640d1c139d43b3cb1cc8c226efcb938 | |
| parent | e39d88ea3ce4a471cd0202f4f2c8f5ee0f8d7f53 (diff) | |
| download | linux-e898eb27ffd8b0ad6f4fd0b631559bc877c85444.tar.xz | |
locking/atomic, arch/metag: 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>
Acked-by: James Hogan <james.hogan@imgtec.com>
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: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-metag@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
| -rw-r--r-- | arch/metag/include/asm/atomic.h | 2 | ||||
| -rw-r--r-- | arch/metag/include/asm/atomic_lnkget.h | 36 | ||||
| -rw-r--r-- | arch/metag/include/asm/atomic_lock1.h | 33 |
3 files changed, 63 insertions, 8 deletions
diff --git a/arch/metag/include/asm/atomic.h b/arch/metag/include/asm/atomic.h index 470e365f04ea..6ca210de8a7d 100644 --- a/arch/metag/include/asm/atomic.h +++ b/arch/metag/include/asm/atomic.h @@ -17,6 +17,8 @@ #include <asm/atomic_lnkget.h> #endif +#define atomic_fetch_or atomic_fetch_or + #define atomic_add_negative(a, v) (atomic_add_return((a), (v)) < 0) #define atomic_dec_return(v) atomic_sub_return(1, (v)) diff --git a/arch/metag/include/asm/atomic_lnkget.h b/arch/metag/include/asm/atomic_lnkget.h index 88fa25fae8bd..def2c642f053 100644 --- a/arch/metag/include/asm/atomic_lnkget.h +++ b/arch/metag/include/asm/atomic_lnkget.h @@ -69,16 +69,44 @@ static inline int atomic_##op##_return(int i, atomic_t *v) \ return result; \ } -#define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_OP_RETURN(op) +#define ATOMIC_FETCH_OP(op) \ +static inline int atomic_fetch_##op(int i, atomic_t *v) \ +{ \ + int result, temp; \ + \ + smp_mb(); \ + \ + asm volatile ( \ + "1: LNKGETD %1, [%2]\n" \ + " " #op " %0, %1, %3\n" \ + " LNKSETD [%2], %0\n" \ + " DEFR %0, TXSTAT\n" \ + " ANDT %0, %0, #HI(0x3f000000)\n" \ + " CMPT %0, #HI(0x02000000)\n" \ + " BNZ 1b\n" \ + : "=&d" (temp), "=&d" (result) \ + : "da" (&v->counter), "bd" (i) \ + : "cc"); \ + \ + smp_mb(); \ + \ + return result; \ +} + +#define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_OP_RETURN(op) ATOMIC_FETCH_OP(op) ATOMIC_OPS(add) ATOMIC_OPS(sub) -ATOMIC_OP(and) -ATOMIC_OP(or) -ATOMIC_OP(xor) +#undef ATOMIC_OPS +#define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_FETCH_OP(op) + +ATOMIC_OPS(and) +ATOMIC_OPS(or) +ATOMIC_OPS(xor) #undef ATOMIC_OPS +#undef ATOMIC_FETCH_OP #undef ATOMIC_OP_RETURN #undef ATOMIC_OP diff --git a/arch/metag/include/asm/atomic_lock1.h b/arch/metag/include/asm/atomic_lock1.h index 0295d9b8d5bf..6c1380a8a0d4 100644 --- a/arch/metag/include/asm/atomic_lock1.h +++ b/arch/metag/include/asm/atomic_lock1.h @@ -64,15 +64,40 @@ static inline int atomic_##op##_return(int i, atomic_t *v) \ return result; \ } -#define ATOMIC_OPS(op, c_op) ATOMIC_OP(op, c_op) ATOMIC_OP_RETURN(op, c_op) +#define ATOMIC_FETCH_OP(op, c_op) \ +static inline int atomic_fetch_##op(int i, atomic_t *v) \ +{ \ + unsigned long result; \ + unsigned long flags; \ + \ + __global_lock1(flags); \ + result = v->counter; \ + fence(); \ + v->counter c_op i; \ + __global_unlock1(flags); \ + \ + return result; \ +} + +#define ATOMIC_OPS(op, c_op) \ + ATOMIC_OP(op, c_op) \ + ATOMIC_OP_RETURN(op, c_op) \ + ATOMIC_FETCH_OP(op, c_op) ATOMIC_OPS(add, +=) ATOMIC_OPS(sub, -=) -ATOMIC_OP(and, &=) -ATOMIC_OP(or, |=) -ATOMIC_OP(xor, ^=) #undef ATOMIC_OPS +#define ATOMIC_OPS(op, c_op) \ + ATOMIC_OP(op, c_op) \ + ATOMIC_FETCH_OP(op, c_op) + +ATOMIC_OPS(and, &=) +ATOMIC_OPS(or, |=) +ATOMIC_OPS(xor, ^=) + +#undef ATOMIC_OPS +#undef ATOMIC_FETCH_OP #undef ATOMIC_OP_RETURN #undef ATOMIC_OP |