[v3,05/11] riscv: Add clear_bit_unlock_is_negative_byte implementation

Commit Message

Matthew Wilcox April 16, 2020, 10:01 p.m. UTC

From: "Matthew Wilcox (Oracle)" <[e-mail]>

This is the generic implementation.  I can't figure out an optimised
implementation for riscv.

Signed-off-by: Matthew Wilcox (Oracle) <[e-mail]>
Cc: Paul Walmsley <[e-mail]>
Cc: Palmer Dabbelt <[e-mail]>
Cc: Albert Ou <[e-mail]>
Cc: [e-mail]
---
 arch/riscv/include/asm/bitops.h | 7 +++++++
 1 file changed, 7 insertions(+)

Patch

diff --git a/arch/riscv/include/asm/bitops.h b/arch/riscv/include/asm/bitops.h
index 396a3303c537..f2060c126a34 100644
--- a/arch/riscv/include/asm/bitops.h
+++ b/arch/riscv/include/asm/bitops.h
@@ -171,6 +171,13 @@  static inline void clear_bit_unlock(
 	__op_bit_ord(and, __NOT, nr, addr, .rl);
 }
 
+static inline bool clear_bit_unlock_is_negative_byte(unsigned int nr,
+						volatile unsigned long *p)
+{
+	clear_bit_unlock(nr, p);
+	return test_bit(7, p);
+}
+
 /**
  * __clear_bit_unlock - Clear a bit in memory, for unlock
  * @nr: the bit to set