diff options
Diffstat (limited to 'arch/riscv/lib/strrchr.S')
| -rw-r--r-- | arch/riscv/lib/strrchr.S | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/arch/riscv/lib/strrchr.S b/arch/riscv/lib/strrchr.S new file mode 100644 index 000000000..ac58b20ca --- /dev/null +++ b/arch/riscv/lib/strrchr.S @@ -0,0 +1,37 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +/* + * Copyright (C) 2025 Feng Jiang <jiangfeng@kylinos.cn> + */ + +#include <linux/linkage.h> +#include <asm/asm.h> + +/* char *strrchr(const char *s, int c) */ +SYM_FUNC_START(strrchr) + /* + * Parameters + * a0 - The string to be searched + * a1 - The character to seaerch for + * + * Returns + * a0 - Address of last occurrence of 'c' or 0 + * + * Clobbers + * t0, t1 + */ + andi a1, a1, 0xff + mv t1, a0 + li a0, 0 +1: + lbu t0, 0(t1) + bne t0, a1, 2f + mv a0, t1 +2: + addi t1, t1, 1 + bnez t0, 1b + ret +SYM_FUNC_END(strrchr) + +SYM_FUNC_ALIAS_WEAK(__pi_strrchr, strrchr) +EXPORT_SYMBOL(strrchr) |