From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
Copy and paste the clear_bit_unlock() implementation, and test the old
variable to see if it has bit 7 set.
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Tony Luck <tony.luck@xxxxxxxxx>
Cc: Fenghua Yu <fenghua.yu@xxxxxxxxx>
Cc: linux-ia64@xxxxxxxxxxxxxxx
---
arch/ia64/include/asm/bitops.h | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)
diff --git a/arch/ia64/include/asm/bitops.h b/arch/ia64/include/asm/bitops.h
index 2f24ee6459d2..ba92ca44731b 100644
--- a/arch/ia64/include/asm/bitops.h
+++ b/arch/ia64/include/asm/bitops.h
@@ -117,6 +117,26 @@ clear_bit_unlock (int nr, volatile void *addr)
} while (cmpxchg_rel(m, old, new) != old);
}
+static inline bool clear_bit_unlock_is_negative_byte(unsigned int nr,
+ volatile unsigned long *p)
+{
+ __u32 mask, old, new;
+ volatile __u32 *m;
+ CMPXCHG_BUGCHECK_DECL
+
+ m = (volatile __u32 *) addr + (nr >> 5);
+ mask = ~(1 << (nr & 31));
+ do {
+ CMPXCHG_BUGCHECK(m);
+ old = *m;
+ new = old & mask;
+ } while (cmpxchg_rel(m, old, new) != old);
+
+ return old & (1 << 7);
+}
+#define clear_bit_unlock_is_negative_byte \
+ clear_bit_unlock_is_negative_byte
+
/**
* __clear_bit_unlock - Non-atomically clears a bit in memory with release
* @nr: Bit to clear
--
2.25.1
