aboutsummaryrefslogtreecommitdiff
path: root/arch/arm/lib/clearbit.S
diff options
context:
space:
mode:
Diffstat (limited to 'arch/arm/lib/clearbit.S')
-rw-r--r--arch/arm/lib/clearbit.S31
1 files changed, 31 insertions, 0 deletions
diff --git a/arch/arm/lib/clearbit.S b/arch/arm/lib/clearbit.S
new file mode 100644
index 000000000000..069a2ce413f0
--- /dev/null
+++ b/arch/arm/lib/clearbit.S
@@ -0,0 +1,31 @@
+/*
+ * linux/arch/arm/lib/clearbit.S
+ *
+ * Copyright (C) 1995-1996 Russell King
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+ .text
+
+/*
+ * Purpose : Function to clear a bit
+ * Prototype: int clear_bit(int bit, void *addr)
+ */
+ENTRY(_clear_bit_be)
+ eor r0, r0, #0x18 @ big endian byte ordering
+ENTRY(_clear_bit_le)
+ and r2, r0, #7
+ mov r3, #1
+ mov r3, r3, lsl r2
+ save_and_disable_irqs ip, r2
+ ldrb r2, [r1, r0, lsr #3]
+ bic r2, r2, r3
+ strb r2, [r1, r0, lsr #3]
+ restore_irqs ip
+ RETINSTR(mov,pc,lr)
+
+