LXR linux/arch/mips/lib/strlen

   1/*
   2 * This file is subject to the terms and conditions of the GNU General Public
   3 * License.  See the file "COPYING" in the main directory of this archive
   4 * for more details.
   5 *
   6 * Copyright (c) 1996, 1998, 1999, 2004 by Ralf Baechle
   7 * Copyright (c) 1999 Silicon Graphics, Inc.
   8 */
   9#include <asm/asm.h>
  10#include <asm/asm-offsets.h>
  11#include <asm/regdef.h>
  12
  13#define EX(insn,reg,addr,handler)                       \
  149:      insn    reg, addr;                              \
  15        .section __ex_table,"a";                        \
  16        PTR     9b, handler;                            \
  17        .previous
  18
  19/*
  20 * Return the size of a string (including the ending 0)
  21 *
  22 * Return 0 for error
  23 */
  24LEAF(__strlen_user_asm)
  25        LONG_L          v0, TI_ADDR_LIMIT($28)  # pointer ok?
  26        and             v0, a0
  27        bnez            v0, .Lfault
  28
  29FEXPORT(__strlen_user_nocheck_asm)
  30        move            v0, a0
  311:      EX(lb, t0, (v0), .Lfault)
  32        PTR_ADDIU       v0, 1
  33        bnez            t0, 1b
  34        PTR_SUBU        v0, a0
  35        jr              ra
  36        END(__strlen_user_asm)
  37
  38.Lfault:        move            v0, zero
  39        jr              ra
  40