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authorPeter Zijlstra <peterz@infradead.org>2016-04-18 01:16:09 +0200
committerIngo Molnar <mingo@kernel.org>2016-06-16 10:48:21 +0200
commite490f9b1d3b40ba32ad07432b63b813ce3052d41 (patch)
tree2c088d9cf8e0c25b450f266112f7c19bd0af4b51 /arch/arm64/include/asm/atomic_ll_sc.h
parent6da068c1beba684b2a0dbf43a07b0529edd9e959 (diff)
downloadlinux-e490f9b1d3b40ba32ad07432b63b813ce3052d41.tar.bz2
locking/atomic, arch/arm64: Implement atomic{,64}_fetch_{add,sub,and,andnot,or,xor}{,_relaxed,_acquire,_release}()
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). [wildea01: compile fixes for ll/sc] Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steve Capper <steve.capper@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-arch@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/arm64/include/asm/atomic_ll_sc.h')
-rw-r--r--arch/arm64/include/asm/atomic_ll_sc.h110
1 files changed, 86 insertions, 24 deletions
diff --git a/arch/arm64/include/asm/atomic_ll_sc.h b/arch/arm64/include/asm/atomic_ll_sc.h
index f61c84f6ba02..f819fdcff1ac 100644
--- a/arch/arm64/include/asm/atomic_ll_sc.h
+++ b/arch/arm64/include/asm/atomic_ll_sc.h
@@ -77,26 +77,57 @@ __LL_SC_PREFIX(atomic_##op##_return##name(int i, atomic_t *v)) \
} \
__LL_SC_EXPORT(atomic_##op##_return##name);
+#define ATOMIC_FETCH_OP(name, mb, acq, rel, cl, op, asm_op) \
+__LL_SC_INLINE int \
+__LL_SC_PREFIX(atomic_fetch_##op##name(int i, atomic_t *v)) \
+{ \
+ unsigned long tmp; \
+ int val, result; \
+ \
+ asm volatile("// atomic_fetch_" #op #name "\n" \
+" prfm pstl1strm, %3\n" \
+"1: ld" #acq "xr %w0, %3\n" \
+" " #asm_op " %w1, %w0, %w4\n" \
+" st" #rel "xr %w2, %w1, %3\n" \
+" cbnz %w2, 1b\n" \
+" " #mb \
+ : "=&r" (result), "=&r" (val), "=&r" (tmp), "+Q" (v->counter) \
+ : "Ir" (i) \
+ : cl); \
+ \
+ return result; \
+} \
+__LL_SC_EXPORT(atomic_fetch_##op##name);
+
#define ATOMIC_OPS(...) \
ATOMIC_OP(__VA_ARGS__) \
- ATOMIC_OP_RETURN( , dmb ish, , l, "memory", __VA_ARGS__)
-
-#define ATOMIC_OPS_RLX(...) \
- ATOMIC_OPS(__VA_ARGS__) \
+ ATOMIC_OP_RETURN( , dmb ish, , l, "memory", __VA_ARGS__)\
ATOMIC_OP_RETURN(_relaxed, , , , , __VA_ARGS__)\
ATOMIC_OP_RETURN(_acquire, , a, , "memory", __VA_ARGS__)\
- ATOMIC_OP_RETURN(_release, , , l, "memory", __VA_ARGS__)
+ ATOMIC_OP_RETURN(_release, , , l, "memory", __VA_ARGS__)\
+ ATOMIC_FETCH_OP ( , dmb ish, , l, "memory", __VA_ARGS__)\
+ ATOMIC_FETCH_OP (_relaxed, , , , , __VA_ARGS__)\
+ ATOMIC_FETCH_OP (_acquire, , a, , "memory", __VA_ARGS__)\
+ ATOMIC_FETCH_OP (_release, , , l, "memory", __VA_ARGS__)
-ATOMIC_OPS_RLX(add, add)
-ATOMIC_OPS_RLX(sub, sub)
+ATOMIC_OPS(add, add)
+ATOMIC_OPS(sub, sub)
+
+#undef ATOMIC_OPS
+#define ATOMIC_OPS(...) \
+ ATOMIC_OP(__VA_ARGS__) \
+ ATOMIC_FETCH_OP ( , dmb ish, , l, "memory", __VA_ARGS__)\
+ ATOMIC_FETCH_OP (_relaxed, , , , , __VA_ARGS__)\
+ ATOMIC_FETCH_OP (_acquire, , a, , "memory", __VA_ARGS__)\
+ ATOMIC_FETCH_OP (_release, , , l, "memory", __VA_ARGS__)
-ATOMIC_OP(and, and)
-ATOMIC_OP(andnot, bic)
-ATOMIC_OP(or, orr)
-ATOMIC_OP(xor, eor)
+ATOMIC_OPS(and, and)
+ATOMIC_OPS(andnot, bic)
+ATOMIC_OPS(or, orr)
+ATOMIC_OPS(xor, eor)
-#undef ATOMIC_OPS_RLX
#undef ATOMIC_OPS
+#undef ATOMIC_FETCH_OP
#undef ATOMIC_OP_RETURN
#undef ATOMIC_OP
@@ -140,26 +171,57 @@ __LL_SC_PREFIX(atomic64_##op##_return##name(long i, atomic64_t *v)) \
} \
__LL_SC_EXPORT(atomic64_##op##_return##name);
+#define ATOMIC64_FETCH_OP(name, mb, acq, rel, cl, op, asm_op) \
+__LL_SC_INLINE long \
+__LL_SC_PREFIX(atomic64_fetch_##op##name(long i, atomic64_t *v)) \
+{ \
+ long result, val; \
+ unsigned long tmp; \
+ \
+ asm volatile("// atomic64_fetch_" #op #name "\n" \
+" prfm pstl1strm, %3\n" \
+"1: ld" #acq "xr %0, %3\n" \
+" " #asm_op " %1, %0, %4\n" \
+" st" #rel "xr %w2, %1, %3\n" \
+" cbnz %w2, 1b\n" \
+" " #mb \
+ : "=&r" (result), "=&r" (val), "=&r" (tmp), "+Q" (v->counter) \
+ : "Ir" (i) \
+ : cl); \
+ \
+ return result; \
+} \
+__LL_SC_EXPORT(atomic64_fetch_##op##name);
+
#define ATOMIC64_OPS(...) \
ATOMIC64_OP(__VA_ARGS__) \
- ATOMIC64_OP_RETURN(, dmb ish, , l, "memory", __VA_ARGS__)
-
-#define ATOMIC64_OPS_RLX(...) \
- ATOMIC64_OPS(__VA_ARGS__) \
+ ATOMIC64_OP_RETURN(, dmb ish, , l, "memory", __VA_ARGS__) \
ATOMIC64_OP_RETURN(_relaxed,, , , , __VA_ARGS__) \
ATOMIC64_OP_RETURN(_acquire,, a, , "memory", __VA_ARGS__) \
- ATOMIC64_OP_RETURN(_release,, , l, "memory", __VA_ARGS__)
+ ATOMIC64_OP_RETURN(_release,, , l, "memory", __VA_ARGS__) \
+ ATOMIC64_FETCH_OP (, dmb ish, , l, "memory", __VA_ARGS__) \
+ ATOMIC64_FETCH_OP (_relaxed,, , , , __VA_ARGS__) \
+ ATOMIC64_FETCH_OP (_acquire,, a, , "memory", __VA_ARGS__) \
+ ATOMIC64_FETCH_OP (_release,, , l, "memory", __VA_ARGS__)
-ATOMIC64_OPS_RLX(add, add)
-ATOMIC64_OPS_RLX(sub, sub)
+ATOMIC64_OPS(add, add)
+ATOMIC64_OPS(sub, sub)
+
+#undef ATOMIC64_OPS
+#define ATOMIC64_OPS(...) \
+ ATOMIC64_OP(__VA_ARGS__) \
+ ATOMIC64_FETCH_OP (, dmb ish, , l, "memory", __VA_ARGS__) \
+ ATOMIC64_FETCH_OP (_relaxed,, , , , __VA_ARGS__) \
+ ATOMIC64_FETCH_OP (_acquire,, a, , "memory", __VA_ARGS__) \
+ ATOMIC64_FETCH_OP (_release,, , l, "memory", __VA_ARGS__)
-ATOMIC64_OP(and, and)
-ATOMIC64_OP(andnot, bic)
-ATOMIC64_OP(or, orr)
-ATOMIC64_OP(xor, eor)
+ATOMIC64_OPS(and, and)
+ATOMIC64_OPS(andnot, bic)
+ATOMIC64_OPS(or, orr)
+ATOMIC64_OPS(xor, eor)
-#undef ATOMIC64_OPS_RLX
#undef ATOMIC64_OPS
+#undef ATOMIC64_FETCH_OP
#undef ATOMIC64_OP_RETURN
#undef ATOMIC64_OP