diff mbox series

[v3,03/11] m68k: Add clear_bit_unlock_is_negative_byte implementation

Message ID 20200416220130.13343-4-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.  Someone who knows m68k assembly
can probably do better (the BFCLR instruction appears to set the N bit
appropriately).

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: linux-m68k@lists.linux-m68k.org
---
 arch/m68k/include/asm/bitops.h | 7 +++++++
 1 file changed, 7 insertions(+)
diff mbox series

Patch

diff --git a/arch/m68k/include/asm/bitops.h b/arch/m68k/include/asm/bitops.h
index 10133a968c8e..bfb34e0748fe 100644
--- a/arch/m68k/include/asm/bitops.h
+++ b/arch/m68k/include/asm/bitops.h
@@ -524,6 +524,13 @@  static inline int __fls(int x)
 #define clear_bit_unlock	clear_bit
 #define __clear_bit_unlock	clear_bit_unlock
 
+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);
+}
+
 #include <asm-generic/bitops/ext2-atomic.h>
 #include <asm-generic/bitops/le.h>
 #include <asm-generic/bitops/fls64.h>