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| author |   Peter Zijlstra <peterz@infradead.org> | 2016-04-18 01:16:06 +0200 |
|---|---|---|
| committer |   Ingo Molnar <mingo@kernel.org> | 2016-06-16 10:48:27 +0200 |
| commit | 4edac529eb629ccd598e2236c61762537f16e883 (patch) | |
| tree | 51404e266d10636af9d919a7110126ed97afbfd8 /arch/mips/include/asm/atomic.h | |
| parent | locking/atomic, arch/metag: Implement atomic_fetch_{add,sub,and,or,xor}() (diff) | |
| download | linux-dev-4edac529eb629ccd598e2236c61762537f16e883.tar.xz linux-dev-4edac529eb629ccd598e2236c61762537f16e883.zip | |
locking/atomic, arch/mips: Implement atomic{,64}_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: Ralf Baechle <ralf@linux-mips.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/mips/include/asm/atomic.h')
| -rw-r--r-- | arch/mips/include/asm/atomic.h | 138 |
1 files changed, 129 insertions, 9 deletions
diff --git a/arch/mips/include/asm/atomic.h b/arch/mips/include/asm/atomic.h index 835b402e4574..431079f8e483 100644 --- a/arch/mips/include/asm/atomic.h +++ b/arch/mips/include/asm/atomic.h @@ -66,7 +66,7 @@ static __inline__ void atomic_##op(int i, atomic_t * v) \ " " #asm_op " %0, %2 \n" \ " sc %0, %1 \n" \ " .set mips0 \n" \ - : "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (v->counter) \ + : "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (v->counter) \ : "Ir" (i)); \ } while (unlikely(!temp)); \ } else { \ @@ -130,18 +130,78 @@ static __inline__ int atomic_##op##_return(int i, atomic_t * v) \ return result; \ } +#define ATOMIC_FETCH_OP(op, c_op, asm_op) \ +static __inline__ int atomic_fetch_##op(int i, atomic_t * v) \ +{ \ + int result; \ + \ + smp_mb__before_llsc(); \ + \ + if (kernel_uses_llsc && R10000_LLSC_WAR) { \ + int temp; \ + \ + __asm__ __volatile__( \ + " .set arch=r4000 \n" \ + "1: ll %1, %2 # atomic_fetch_" #op " \n" \ + " " #asm_op " %0, %1, %3 \n" \ + " sc %0, %2 \n" \ + " beqzl %0, 1b \n" \ + " move %0, %1 \n" \ + " .set mips0 \n" \ + : "=&r" (result), "=&r" (temp), \ + "+" GCC_OFF_SMALL_ASM() (v->counter) \ + : "Ir" (i)); \ + } else if (kernel_uses_llsc) { \ + int temp; \ + \ + do { \ + __asm__ __volatile__( \ + " .set "MIPS_ISA_LEVEL" \n" \ + " ll %1, %2 # atomic_fetch_" #op " \n" \ + " " #asm_op " %0, %1, %3 \n" \ + " sc %0, %2 \n" \ + " .set mips0 \n" \ + : "=&r" (result), "=&r" (temp), \ + "+" GCC_OFF_SMALL_ASM() (v->counter) \ + : "Ir" (i)); \ + } while (unlikely(!result)); \ + \ + result = temp; \ + } else { \ + unsigned long flags; \ + \ + raw_local_irq_save(flags); \ + result = v->counter; \ + v->counter c_op i; \ + raw_local_irq_restore(flags); \ + } \ + \ + smp_llsc_mb(); \ + \ + return result; \ +} + #define ATOMIC_OPS(op, c_op, asm_op) \ ATOMIC_OP(op, c_op, asm_op) \ - ATOMIC_OP_RETURN(op, c_op, asm_op) + ATOMIC_OP_RETURN(op, c_op, asm_op) \ + ATOMIC_FETCH_OP(op, c_op, asm_op) ATOMIC_OPS(add, +=, addu) ATOMIC_OPS(sub, -=, subu) -ATOMIC_OP(and, &=, and) -ATOMIC_OP(or, |=, or) -ATOMIC_OP(xor, ^=, xor) +#undef ATOMIC_OPS +#define ATOMIC_OPS(op, c_op, asm_op) \ + ATOMIC_OP(op, c_op, asm_op) \ + ATOMIC_FETCH_OP(op, c_op, asm_op) + +#define atomic_fetch_or atomic_fetch_or + +ATOMIC_OPS(and, &=, and) +ATOMIC_OPS(or, |=, or) +ATOMIC_OPS(xor, ^=, xor) #undef ATOMIC_OPS +#undef ATOMIC_FETCH_OP #undef ATOMIC_OP_RETURN #undef ATOMIC_OP @@ -414,17 +474,77 @@ static __inline__ long atomic64_##op##_return(long i, atomic64_t * v) \ return result; \ } +#define ATOMIC64_FETCH_OP(op, c_op, asm_op) \ +static __inline__ long atomic64_fetch_##op(long i, atomic64_t * v) \ +{ \ + long result; \ + \ + smp_mb__before_llsc(); \ + \ + if (kernel_uses_llsc && R10000_LLSC_WAR) { \ + long temp; \ + \ + __asm__ __volatile__( \ + " .set arch=r4000 \n" \ + "1: lld %1, %2 # atomic64_fetch_" #op "\n" \ + " " #asm_op " %0, %1, %3 \n" \ + " scd %0, %2 \n" \ + " beqzl %0, 1b \n" \ + " move %0, %1 \n" \ + " .set mips0 \n" \ + : "=&r" (result), "=&r" (temp), \ + "+" GCC_OFF_SMALL_ASM() (v->counter) \ + : "Ir" (i)); \ + } else if (kernel_uses_llsc) { \ + long temp; \ + \ + do { \ + __asm__ __volatile__( \ + " .set "MIPS_ISA_LEVEL" \n" \ + " lld %1, %2 # atomic64_fetch_" #op "\n" \ + " " #asm_op " %0, %1, %3 \n" \ + " scd %0, %2 \n" \ + " .set mips0 \n" \ + : "=&r" (result), "=&r" (temp), \ + "=" GCC_OFF_SMALL_ASM() (v->counter) \ + : "Ir" (i), GCC_OFF_SMALL_ASM() (v->counter) \ + : "memory"); \ + } while (unlikely(!result)); \ + \ + result = temp; \ + } else { \ + unsigned long flags; \ + \ + raw_local_irq_save(flags); \ + result = v->counter; \ + v->counter c_op i; \ + raw_local_irq_restore(flags); \ + } \ + \ + smp_llsc_mb(); \ + \ + return result; \ +} + #define ATOMIC64_OPS(op, c_op, asm_op) \ ATOMIC64_OP(op, c_op, asm_op) \ - ATOMIC64_OP_RETURN(op, c_op, asm_op) + ATOMIC64_OP_RETURN(op, c_op, asm_op) \ + ATOMIC64_FETCH_OP(op, c_op, asm_op) ATOMIC64_OPS(add, +=, daddu) ATOMIC64_OPS(sub, -=, dsubu) -ATOMIC64_OP(and, &=, and) -ATOMIC64_OP(or, |=, or) -ATOMIC64_OP(xor, ^=, xor) #undef ATOMIC64_OPS +#define ATOMIC64_OPS(op, c_op, asm_op) \ + ATOMIC64_OP(op, c_op, asm_op) \ + ATOMIC64_FETCH_OP(op, c_op, asm_op) + +ATOMIC64_OPS(and, &=, and) +ATOMIC64_OPS(or, |=, or) +ATOMIC64_OPS(xor, ^=, xor) + +#undef ATOMIC64_OPS +#undef ATOMIC64_FETCH_OP #undef ATOMIC64_OP_RETURN #undef ATOMIC64_OP |