From cf4694be2b2cf74945e50d39a02ea2307c4495f4 Mon Sep 17 00:00:00 2001 From: Peter Gonda Date: Thu, 6 Oct 2022 00:34:06 +0000 Subject: tools: Add atomic_test_and_set_bit() Add x86 and generic implementations of atomic_test_and_set_bit() to allow KVM selftests to atomically manage bitmaps. Note, the generic version is taken from arch_test_and_set_bit() as of commit 415d83249709 ("locking/atomic: Make test_and_*_bit() ordered on failure"). Signed-off-by: Peter Gonda Co-developed-by: Sean Christopherson Signed-off-by: Sean Christopherson Link: https://lore.kernel.org/r/20221006003409.649993-5-seanjc@google.com --- tools/include/asm-generic/atomic-gcc.h | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'tools/include/asm-generic') diff --git a/tools/include/asm-generic/atomic-gcc.h b/tools/include/asm-generic/atomic-gcc.h index 4c1966f7c77a..6daa68bf5b9e 100644 --- a/tools/include/asm-generic/atomic-gcc.h +++ b/tools/include/asm-generic/atomic-gcc.h @@ -4,6 +4,7 @@ #include #include +#include /* * Atomic operations that C can't guarantee us. Useful for @@ -69,4 +70,15 @@ static inline int atomic_cmpxchg(atomic_t *v, int oldval, int newval) return cmpxchg(&(v)->counter, oldval, newval); } +static inline int atomic_test_and_set_bit(long nr, unsigned long *addr) +{ + unsigned long mask = BIT_MASK(nr); + long old; + + addr += BIT_WORD(nr); + + old = __sync_fetch_and_or(addr, mask); + return !!(old & mask); +} + #endif /* __TOOLS_ASM_GENERIC_ATOMIC_H */ -- cgit v1.2.3