linux/arch/microblaze/lib/uaccess_old.S
Michal Simek ca3865bae5 microblaze: Support word copying in copy_tofrom_user
Word copying is used only for aligned addresses.
Here is space for improving to use any better copying technique.
Look at memcpy implementation.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-04-01 08:38:25 +02:00

153 lines
2.8 KiB
ArmAsm

/*
* Copyright (C) 2009 Michal Simek <monstr@monstr.eu>
* Copyright (C) 2009 PetaLogix
* Copyright (C) 2007 LynuxWorks, Inc.
*
* 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.
*/
#include <linux/errno.h>
#include <linux/linkage.h>
/*
* int __strncpy_user(char *to, char *from, int len);
*
* Returns:
* -EFAULT for an exception
* len if we hit the buffer limit
* bytes copied
*/
.text
.globl __strncpy_user;
.type __strncpy_user, @function
.align 4;
__strncpy_user:
/*
* r5 - to
* r6 - from
* r7 - len
* r3 - temp count
* r4 - temp val
*/
addik r3,r7,0 /* temp_count = len */
beqi r3,3f
1:
lbu r4,r6,r0
sb r4,r5,r0
addik r3,r3,-1
beqi r3,2f /* break on len */
addik r5,r5,1
bneid r4,1b
addik r6,r6,1 /* delay slot */
addik r3,r3,1 /* undo "temp_count--" */
2:
rsubk r3,r3,r7 /* temp_count = len - temp_count */
3:
rtsd r15,8
nop
.size __strncpy_user, . - __strncpy_user
.section .fixup, "ax"
.align 2
4:
brid 3b
addik r3,r0, -EFAULT
.section __ex_table, "a"
.word 1b,4b
/*
* int __strnlen_user(char __user *str, int maxlen);
*
* Returns:
* 0 on error
* maxlen + 1 if no NUL byte found within maxlen bytes
* size of the string (including NUL byte)
*/
.text
.globl __strnlen_user;
.type __strnlen_user, @function
.align 4;
__strnlen_user:
addik r3,r6,0
beqi r3,3f
1:
lbu r4,r5,r0
beqid r4,2f /* break on NUL */
addik r3,r3,-1 /* delay slot */
bneid r3,1b
addik r5,r5,1 /* delay slot */
addik r3,r3,-1 /* for break on len */
2:
rsubk r3,r3,r6
3:
rtsd r15,8
nop
.size __strnlen_user, . - __strnlen_user
.section .fixup,"ax"
4:
brid 3b
addk r3,r0,r0
.section __ex_table,"a"
.word 1b,4b
/*
* int __copy_tofrom_user(char *to, char *from, int len)
* Return:
* 0 on success
* number of not copied bytes on error
*/
.text
.globl __copy_tofrom_user;
.type __copy_tofrom_user, @function
.align 4;
__copy_tofrom_user:
/*
* r5 - to
* r6 - from
* r7, r3 - count
* r4 - tempval
*/
beqid r7, 3f /* zero size is not likely */
andi r3, r7, 0x3 /* filter add count */
bneid r3, 4f /* if is odd value then byte copying */
or r3, r5, r6 /* find if is any to/from unaligned */
andi r3, r3, 0x3 /* mask unaligned */
bneid r3, 1f /* it is unaligned -> then jump */
or r3, r0, r0
/* at least one 4 byte copy */
5: lw r4, r6, r3
6: sw r4, r5, r3
addik r7, r7, -4
bneid r7, 5b
addik r3, r3, 4
addik r3, r7, 0
rtsd r15, 8
nop
4: or r3, r0, r0
1: lbu r4,r6,r3
2: sb r4,r5,r3
addik r7,r7,-1
bneid r7,1b
addik r3,r3,1 /* delay slot */
3:
addik r3,r7,0
rtsd r15,8
nop
.size __copy_tofrom_user, . - __copy_tofrom_user
.section __ex_table,"a"
.word 1b,3b,2b,3b,5b,3b,6b,3b