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-rw-r--r--arch/x86/include/asm/bitops.h21
1 files changed, 21 insertions, 0 deletions
diff --git a/arch/x86/include/asm/bitops.h b/arch/x86/include/asm/bitops.h
index 973c6bd17f98..0fe9de58af31 100644
--- a/arch/x86/include/asm/bitops.h
+++ b/arch/x86/include/asm/bitops.h
@@ -207,6 +207,20 @@ static __always_inline bool constant_test_bit(long nr, const volatile unsigned l
(addr[nr >> _BITOPS_LONG_SHIFT])) != 0;
}
+static __always_inline bool constant_test_bit_acquire(long nr, const volatile unsigned long *addr)
+{
+ bool oldbit;
+
+ asm volatile("testb %2,%1"
+ CC_SET(nz)
+ : CC_OUT(nz) (oldbit)
+ : "m" (((unsigned char *)addr)[nr >> 3]),
+ "i" (1 << (nr & 7))
+ :"memory");
+
+ return oldbit;
+}
+
static __always_inline bool variable_test_bit(long nr, volatile const unsigned long *addr)
{
bool oldbit;
@@ -226,6 +240,13 @@ arch_test_bit(unsigned long nr, const volatile unsigned long *addr)
variable_test_bit(nr, addr);
}
+static __always_inline bool
+arch_test_bit_acquire(unsigned long nr, const volatile unsigned long *addr)
+{
+ return __builtin_constant_p(nr) ? constant_test_bit_acquire(nr, addr) :
+ variable_test_bit(nr, addr);
+}
+
/**
* __ffs - find first set bit in word
* @word: The word to search