diff options
Diffstat (limited to 'arch/loongarch/lib/copy_user.S')
| -rw-r--r-- | arch/loongarch/lib/copy_user.S | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/arch/loongarch/lib/copy_user.S b/arch/loongarch/lib/copy_user.S new file mode 100644 index 000000000..97d20327a --- /dev/null +++ b/arch/loongarch/lib/copy_user.S @@ -0,0 +1,47 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2020-2022 Loongson Technology Corporation Limited + */ + +#include <asm/asm.h> +#include <asm/asmmacro.h> +#include <asm/export.h> +#include <asm/regdef.h> + +.macro fixup_ex from, to, offset, fix +.if \fix + .section .fixup, "ax" +\to: addi.d a0, a2, \offset + jr ra + .previous +.endif + .section __ex_table, "a" + PTR \from\()b, \to\()b + .previous +.endm + +/* + * unsigned long __copy_user(void *to, const void *from, size_t n) + * + * a0: to + * a1: from + * a2: n + */ +SYM_FUNC_START(__copy_user) + beqz a2, 3f + +1: ld.b t0, a1, 0 +2: st.b t0, a0, 0 + addi.d a0, a0, 1 + addi.d a1, a1, 1 + addi.d a2, a2, -1 + bgtz a2, 1b + +3: move a0, a2 + jr ra + + fixup_ex 1, 4, 0, 1 + fixup_ex 2, 4, 0, 0 +SYM_FUNC_END(__copy_user) + +EXPORT_SYMBOL(__copy_user) |