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Diffstat (limited to 'kernel/arch/arm64/lib/strchr.S')
| -rw-r--r-- | kernel/arch/arm64/lib/strchr.S | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/kernel/arch/arm64/lib/strchr.S b/kernel/arch/arm64/lib/strchr.S new file mode 100644 index 000000000..dae0cf559 --- /dev/null +++ b/kernel/arch/arm64/lib/strchr.S @@ -0,0 +1,42 @@ +/* + * Based on arch/arm/lib/strchr.S + * + * Copyright (C) 1995-2000 Russell King + * Copyright (C) 2013 ARM Ltd. + * + * 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. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <linux/linkage.h> +#include <asm/assembler.h> + +/* + * Find the first occurrence of a character in a string. + * + * Parameters: + * x0 - str + * x1 - c + * Returns: + * x0 - address of first occurrence of 'c' or 0 + */ +ENTRY(strchr) + and w1, w1, #0xff +1: ldrb w2, [x0], #1 + cmp w2, w1 + ccmp w2, wzr, #4, ne + b.ne 1b + sub x0, x0, #1 + cmp w2, w1 + csel x0, x0, xzr, eq + ret +ENDPROC(strchr) |