From: Peter Gonda pgonda@google.com
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 pgonda@google.com Co-developed-by: Sean Christopherson seanjc@google.com Signed-off-by: Sean Christopherson seanjc@google.com --- tools/arch/x86/include/asm/atomic.h | 7 +++++++ tools/include/asm-generic/atomic-gcc.h | 12 ++++++++++++ 2 files changed, 19 insertions(+)
diff --git a/tools/arch/x86/include/asm/atomic.h b/tools/arch/x86/include/asm/atomic.h index 1f5e26aae9fc..01cc27ec4520 100644 --- a/tools/arch/x86/include/asm/atomic.h +++ b/tools/arch/x86/include/asm/atomic.h @@ -8,6 +8,7 @@
#define LOCK_PREFIX "\n\tlock; "
+#include <asm/asm.h> #include <asm/cmpxchg.h>
/* @@ -70,4 +71,10 @@ static __always_inline int atomic_cmpxchg(atomic_t *v, int old, int new) return cmpxchg(&v->counter, old, new); }
+static inline int atomic_test_and_set_bit(long nr, unsigned long *addr) +{ + GEN_BINARY_RMWcc(LOCK_PREFIX __ASM_SIZE(bts), *addr, "Ir", nr, "%0", "c"); + +} + #endif /* _TOOLS_LINUX_ASM_X86_ATOMIC_H */ 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 <linux/compiler.h> #include <linux/types.h> +#include <linux/bitops.h>
/* * 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 */