|  | /* | 
|  | * 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) |