diff mbox series

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

Message ID 20200416220130.13343-6-willy@infradead.org (mailing list archive)
State New, archived
Headers show
Series Make PageWriteback use the PageLocked optimisation | expand

Commit Message

Matthew Wilcox April 16, 2020, 10:01 p.m. UTC 
From: "Matthew Wilcox (Oracle)" <willy@infradead.org>

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

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: linux-riscv@lists.infradead.org
---
 arch/riscv/include/asm/bitops.h | 7 +++++++
 1 file changed, 7 insertions(+)
diff mbox series

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