Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (c) 1996, 1998, 1999, 2004 by Ralf Baechle
 * Copyright (c) 1999 Silicon Graphics, Inc.
 */
#include <asm/asm.h>
#include <asm/asm-offsets.h>
#include <asm/regdef.h>

#define EX(insn,reg,addr,handler)                       \
9:      insn    reg, addr;                              \
        .section __ex_table,"a";                        \
        PTR     9b, handler;                            \
        .previous

/*
 * Return the size of a string including the ending NUL character upto a
 * maximum of a1 or 0 in case of error.
 *
 * Note: for performance reasons we deliberately accept that a user may
 *       make strlen_user and strnlen_user access the first few KSEG0
 *       bytes.  There's nothing secret there.  On 64-bit accessing beyond
 *       the maximum is a tad hairier ...
 */
LEAF(__strnlen_user_asm)
        LONG_L          v0, TI_ADDR_LIMIT($28)  # pointer ok?
        and             v0, a0
        bnez            v0, fault

FEXPORT(__strnlen_user_nocheck_asm)
        move            v0, a0
        PTR_ADDU        a1, a0                  # stop pointer
1:      beq             v0, a1, 1f              # limit reached?
        EX(lb, t0, (v0), fault)
        PTR_ADDU        v0, 1
        bnez            t0, 1b
1:      PTR_SUBU        v0, a0
        jr              ra
        END(__strnlen_user_asm)

fault:  move            v0, zero
        jr              ra