diff options
Diffstat (limited to 'arch/arm/lib/bitops.S')
| -rw-r--r-- | arch/arm/lib/bitops.S | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/arch/arm/lib/bitops.S b/arch/arm/lib/bitops.S new file mode 100644 index 0000000000..29d1524634 --- /dev/null +++ b/arch/arm/lib/bitops.S @@ -0,0 +1,45 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2023 Sean Anderson <sean.anderson@seco.com> + * + * ARM bitops to call when using THUMB1, which doesn't have these instructions. + */ +#include <linux/linkage.h> +#include <asm/assembler.h> + +.pushsection .text.__fls +ENTRY(__fls) + clz r0, r0 + rsb r0, r0, #31 + ret lr +ENDPROC(__fls) +.popsection + +.pushsection .text.__ffs +ENTRY(__ffs) + rsb r3, r0, #0 + and r0, r0, r3 + clz r0, r0 + rsb r0, r0, #31 + ret lr +ENDPROC(__ffs) +.popsection + +.pushsection .text.fls +ENTRY(fls) + cmp r0, #0 + clzne r0, r0 + rsbne r0, r0, #32 + ret lr +ENDPROC(fls) +.popsection + +.pushsection .text.ffs +ENTRY(ffs) + rsb r3, r0, #0 + and r0, r0, r3 + clz r0, r0 + rsb r0, r0, #32 + ret lr +ENDPROC(ffs) +.popsection |