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/*
* 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>
#include <asm/page.h>
/* Loop unrolling for __copy_tofrom_user */
#define COPY(offset) \
1: lwi r4 , r6, 0x0000 + offset; \
2: lwi r19, r6, 0x0004 + offset; \
3: lwi r20, r6, 0x0008 + offset; \
4: lwi r21, r6, 0x000C + offset; \
5: lwi r22, r6, 0x0010 + offset; \
6: lwi r23, r6, 0x0014 + offset; \
7: lwi r24, r6, 0x0018 + offset; \
8: lwi r25, r6, 0x001C + offset; \
9: swi r4 , r5, 0x0000 + offset; \
10: swi r19, r5, 0x0004 + offset; \
11: swi r20, r5, 0x0008 + offset; \
12: swi r21, r5, 0x000C + offset; \
13: swi r22, r5, 0x0010 + offset; \
14: swi r23, r5, 0x0014 + offset; \
15: swi r24, r5, 0x0018 + offset; \
16: swi r25, r5, 0x001C + offset; \
.section __ex_table,"a"; \
.word 1b, 33f; \
.word 2b, 33f; \
.word 3b, 33f; \
.word 4b, 33f; \
.word 5b, 33f; \
.word 6b, 33f; \
.word 7b, 33f; \
.word 8b, 33f; \
.word 9b, 33f; \
.word 10b, 33f; \
.word 11b, 33f; \
.word 12b, 33f; \
.word 13b, 33f; \
.word 14b, 33f; \
.word 15b, 33f; \
.word 16b, 33f; \
.text
#define COPY_80(offset) \
COPY(0x00 + offset);\
COPY(0x20 + offset);\
COPY(0x40 + offset);\
COPY(0x60 + offset);
/*
* 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, 0f /* zero size is not likely */
or r3, r5, r6 /* find if is any to/from unaligned */
or r3, r3, r7 /* find if count is unaligned */
andi r3, r3, 0x3 /* mask last 3 bits */
bneid r3, bu1 /* if r3 is not zero then byte copying */
or r3, r0, r0
rsubi r3, r7, PAGE_SIZE /* detect PAGE_SIZE */
beqid r3, page;
or r3, r0, r0
w1: lw r4, r6, r3 /* at least one 4 byte copy */
w2: sw r4, r5, r3
addik r7, r7, -4
bneid r7, w1
addik r3, r3, 4
addik r3, r7, 0
rtsd r15, 8
nop
.section __ex_table,"a"
.word w1, 0f;
.word w2, 0f;
.text
.align 4 /* Alignment is important to keep icache happy */
page: /* Create room on stack and save registers for storing values */
addik r1, r1, -40
swi r5, r1, 0
swi r6, r1, 4
swi r7, r1, 8
swi r19, r1, 12
swi r20, r1, 16
swi r21, r1, 20
swi r22, r1, 24
swi r23, r1, 28
swi r24, r1, 32
swi r25, r1, 36
loop: /* r4, r19, r20, r21, r22, r23, r24, r25 are used for storing values */
/* Loop unrolling to get performance boost */
COPY_80(0x000);
COPY_80(0x080);
COPY_80(0x100);
COPY_80(0x180);
/* copy loop */
addik r6, r6, 0x200
addik r7, r7, -0x200
bneid r7, loop
addik r5, r5, 0x200
/* Restore register content */
lwi r5, r1, 0
lwi r6, r1, 4
lwi r7, r1, 8
lwi r19, r1, 12
lwi r20, r1, 16
lwi r21, r1, 20
lwi r22, r1, 24
lwi r23, r1, 28
lwi r24, r1, 32
lwi r25, r1, 36
addik r1, r1, 40
/* return back */
addik r3, r0, 0
rtsd r15, 8
nop
/* Fault case - return temp count */
33:
addik r3, r7, 0
/* Restore register content */
lwi r5, r1, 0
lwi r6, r1, 4
lwi r7, r1, 8
lwi r19, r1, 12
lwi r20, r1, 16
lwi r21, r1, 20
lwi r22, r1, 24
lwi r23, r1, 28
lwi r24, r1, 32
lwi r25, r1, 36
addik r1, r1, 40
/* return back */
rtsd r15, 8
nop
.align 4 /* Alignment is important to keep icache happy */
bu1: lbu r4,r6,r3
bu2: sb r4,r5,r3
addik r7,r7,-1
bneid r7,bu1
addik r3,r3,1 /* delay slot */
0:
addik r3,r7,0
rtsd r15,8
nop
.size __copy_tofrom_user, . - __copy_tofrom_user
.section __ex_table,"a"
.word bu1, 0b;
.word bu2, 0b;
.text
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