/*
* OpenRISC string.S
*
* Linux architectural port borrowing liberally from similar works of
* others. All original copyrights apply as per the original source
* declaration.
*
* Modifications for the OpenRISC architecture:
* Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
* Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/linkage.h>
#include <asm/errno.h>
/*
* this can be optimized by doing gcc inline assemlby with
* proper constraints (no need to save args registers...)
*
*/
/*
*
* int __copy_tofrom_user(void *to, const void *from, unsigned long size);
*
* NOTE: it returns number of bytes NOT copied !!!
*
*/
.global __copy_tofrom_user
__copy_tofrom_user:
l.addi r1,r1,-12
l.sw 0(r1),r6
l.sw 4(r1),r4
l.sw 8(r1),r3
l.addi r11,r5,0
2: l.sfeq r11,r0
l.bf 1f
l.addi r11,r11,-1
8: l.lbz r6,0(r4)
9: l.sb 0(r3),r6
l.addi r3,r3,1
l.j 2b
l.addi r4,r4,1
1:
l.addi r11,r11,1 // r11 holds the return value
l.lwz r6,0(r1)
l.lwz r4,4(r1)
l.lwz r3,8(r1)
l.jr r9
l.addi r1,r1,12
.section .fixup, "ax"
99:
l.j 1b
l.nop
.previous
.section __ex_table, "a"
.long 8b, 99b // read fault
.long 9b, 99b // write fault
.previous
/*
* unsigned long clear_user(void *addr, unsigned long size) ;
*
* NOTE: it returns number of bytes NOT cleared !!!
*/
.global __clear_user
__clear_user:
l.addi r1,r1,-8
l.sw 0(r1),r4
l.sw 4(r1),r3
2: l.sfeq r4,r0
l.bf 1f
l.addi r4,r4,-1
9: l.sb 0(r3),r0
l.j 2b
l.addi r3,r3,1
1:
l.addi r11,r4,1
l.lwz r4,0(r1)
l.lwz r3,4(r1)
l.jr r9
l.addi r1,r1,8
.section .fixup, "ax"
99:
l.j 1b
l.nop
.previous
.section __ex_table, "a"
.long 9b, 99b // write fault
.previous
/*
* long strncpy_from_user(char *dst, const char *src, long count)
*
*
*/
.global __strncpy_from_user
__strncpy_from_user:
l.addi r1,r1,-16
l.sw 0(r1),r6
l.sw 4(r1),r5
l.sw 8(r1),r4
l.sw 12(r1),r3
l.addi r11,r5,0
2: l.sfeq r5,r0
l.bf 1f
l.addi r5,r5,-1
8: l.lbz r6,0(r4)
l.sfeq r6,r0
l.bf 1f
9: l.sb 0(r3),r6
l.addi r3,r3,1
l.j 2b
l.addi r4,r4,1
1:
l.lwz r6,0(r1)
l.addi r5,r5,1
l.sub r11,r11,r5 // r11 holds the return value
l.lwz r6,0(r1)
l.lwz r5,4(r1)
l.lwz r4,8(r1)
l.lwz r3,12(r1)
l.jr r9
l.addi r1,r1,16
.section .fixup, "ax"
99:
l.movhi r11,hi(-EFAULT)
l.ori r11,r11,lo(-EFAULT)
l.lwz r6,0(r1)
l.lwz r5,4(r1)
l.lwz r4,8(r1)
l.lwz r3,12(r1)
l.jr r9
l.addi r1,r1,16
.previous
.section __ex_table, "a"
.long 8b, 99b // read fault
.previous
/*
* extern int __strnlen_user(const char *str, long len, unsigned long top);
*
*
* RTRN: - length of a string including NUL termination character
* - on page fault 0
*/
.global __strnlen_user
__strnlen_user:
l.addi r1,r1,-8
l.sw 0(r1),r6
l.sw 4(r1),r3
l.addi r11,r0,0
2: l.sfeq r11,r4
l.bf 1f
l.addi r11,r11,1
8: l.lbz r6,0(r3)
l.sfeq r6,r0
l.bf 1f
l.sfgeu r3,r5 // are we over the top ?
l.bf 99f
l.j 2b
l.addi r3,r3,1
1:
l.lwz r6,0(r1)
l.lwz r3,4(r1)
l.jr r9
l.addi r1,r1,8
.section .fixup, "ax"
99:
l.addi r11,r0,0
l.lwz r6,0(r1)
l.lwz r3,4(r1)
l.jr r9
l.addi r1,r1,8
.previous
.section __ex_table, "a"
.long 8b, 99b // read fault
.previous
