LXR linux/arch/openrisc/lib/string.S

   1/*
   2 * OpenRISC string.S
   3 *
   4 * Linux architectural port borrowing liberally from similar works of
   5 * others.  All original copyrights apply as per the original source
   6 * declaration.
   7 *
   8 * Modifications for the OpenRISC architecture:
   9 * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
  10 * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
  11 *
  12 *      This program is free software; you can redistribute it and/or
  13 *      modify it under the terms of the GNU General Public License
  14 *      as published by the Free Software Foundation; either version
  15 *      2 of the License, or (at your option) any later version.
  16 */
  17
  18#include <linux/linkage.h>
  19#include <asm/errno.h>
  20
  21        /*
  22         * this can be optimized by doing gcc inline assemlby with
  23         * proper constraints (no need to save args registers...)
  24         *
  25         */
  26
  27
  28/*
  29 *
  30 * int __copy_tofrom_user(void *to, const void *from, unsigned long size);
  31 *
  32 * NOTE: it returns number of bytes NOT copied !!!
  33 *
  34 */
  35        .global __copy_tofrom_user
  36__copy_tofrom_user:
  37        l.addi  r1,r1,-12
  38        l.sw    0(r1),r6
  39        l.sw    4(r1),r4
  40        l.sw    8(r1),r3
  41
  42        l.addi  r11,r5,0
  432:      l.sfeq  r11,r0
  44        l.bf    1f
  45        l.addi  r11,r11,-1
  468:      l.lbz   r6,0(r4)
  479:      l.sb    0(r3),r6
  48        l.addi  r3,r3,1
  49        l.j     2b
  50        l.addi  r4,r4,1
  511:
  52        l.addi  r11,r11,1               // r11 holds the return value
  53
  54        l.lwz   r6,0(r1)
  55        l.lwz   r4,4(r1)
  56        l.lwz   r3,8(r1)
  57        l.jr    r9
  58        l.addi  r1,r1,12
  59
  60        .section .fixup, "ax"
  6199:
  62                l.j     1b
  63                l.nop
  64        .previous
  65
  66        .section __ex_table, "a"
  67                .long 8b, 99b           // read fault
  68                .long 9b, 99b           // write fault
  69        .previous
  70
  71/*
  72 * unsigned long clear_user(void *addr, unsigned long size) ;
  73 *
  74 * NOTE: it returns number of bytes NOT cleared !!!
  75 */
  76        .global __clear_user
  77__clear_user:
  78        l.addi  r1,r1,-8
  79        l.sw    0(r1),r4
  80        l.sw    4(r1),r3
  81
  822:      l.sfeq  r4,r0
  83        l.bf    1f
  84        l.addi  r4,r4,-1
  859:      l.sb    0(r3),r0
  86        l.j     2b
  87        l.addi  r3,r3,1
  88
  891:
  90        l.addi  r11,r4,1
  91
  92        l.lwz   r4,0(r1)
  93        l.lwz   r3,4(r1)
  94        l.jr    r9
  95        l.addi  r1,r1,8
  96
  97        .section .fixup, "ax"
  9899:
  99                l.j     1b
 100                l.nop
 101        .previous
 102
 103        .section __ex_table, "a"
 104                .long 9b, 99b           // write fault
 105        .previous
 106