/*
* String handling functions for PowerPC.
*
* Copyright (C) 1996 Paul Mackerras.
*
* 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/config.h>
#include <asm/processor.h>
#include <asm/errno.h>
#include <asm/ppc_asm.h>
.section __ex_table,"a"
#ifdef CONFIG_PPC64
.align 3
#define EXTBL .llong
#else
.align 2
#define EXTBL .long
#endif
.text
_GLOBAL(strcpy)
addi r5,r3,-1
addi r4,r4,-1
1: lbzu r0,1(r4)
cmpwi 0,r0,0
stbu r0,1(r5)
bne 1b
blr
/* This clears out any unused part of the destination buffer,
just as the libc version does. -- paulus */
_GLOBAL(strncpy)
cmpwi 0,r5,0
beqlr
mtctr r5
addi r6,r3,-1
addi r4,r4,-1
1: lbzu r0,1(r4)
cmpwi 0,r0,0
stbu r0,1(r6)
bdnzf 2,1b /* dec ctr, branch if ctr != 0 && !cr0.eq */
bnelr /* if we didn't hit a null char, we're done */
mfctr r5
cmpwi 0,r5,0 /* any space left in destination buffer? */
beqlr /* we know r0 == 0 here */
2: stbu r0,1(r6) /* clear it out if so */
bdnz 2b
blr
_GLOBAL(strcat)
addi r5,r3,-1
addi r4,r4,-1
1: lbzu r0,1(r5)
cmpwi 0,r0,0
bne 1b
addi r5,r5,-1
1: lbzu r0,1(r4)
cmpwi 0,r0,0
stbu r0,1(r5)
bne 1b
blr
_GLOBAL(strcmp)
addi r5,r3,-1
addi r4,r4,-1
1: lbzu r3,1(r5)
cmpwi 1,r3,0
lbzu r0,1(r4)
subf. r3,r0,r3
beqlr 1
beq 1b
blr
_GLOBAL(strlen)
addi r4,r3,-1
1: lbzu r0,1(r4)
cmpwi 0,r0,0
bne 1b
subf r3,r3,r4
blr
_GLOBAL(memcmp)
cmpwi 0,r5,0
ble- 2f
mtctr r5
addi r6,r3,-1
addi r4,r4,-1
1: lbzu r3,1(r6)
lbzu r0,1(r4)
subf. r3,r0,r3
bdnzt 2,1b
blr
2: li r3,0
blr
_GLOBAL(memchr)
cmpwi 0,r5,0
ble- 2f
mtctr r5
addi r3,r3,-1
1: lbzu r0,1(r3)
cmpw 0,r0,r4
bdnzf 2,1b
beqlr
2: li r3,0
blr
_GLOBAL(__clear_user)
addi r6,r3,-4
li r3,0
li r5,0
cmplwi 0,r4,4
blt 7f
/* clear a single word */
11: stwu r5,4(r6)
beqlr
/* clear word sized chunks */
andi. r0,r6,3
add r4,r0,r4
subf r6,r0,r6
srwi r0,r4,2
andi. r4,r4,3
mtctr r0
bdz 7f
1: stwu r5,4(r6)
bdnz 1b
/* clear byte sized chunks */
7: cmpwi 0,r4,0
beqlr
mtctr r4
addi r6,r6,3
8: stbu r5,1(r6)
bdnz 8b
blr
90: mr r3,r4
blr
91: mfctr r3
slwi r3,r3,2
add r3,r3,r4
blr
92: mfctr r3
blr
.section __ex_table,"a"
EXTBL 11b,90b
EXTBL 1b,91b
EXTBL 8b,92b
.text
_GLOBAL(__strncpy_from_user)
addi r6,r3,-1
addi r4,r4,-1
cmpwi 0,r5,0
beq 2f
mtctr r5
1: lbzu r0,1(r4)
cmpwi 0,r0,0
stbu r0,1(r6)
bdnzf 2,1b /* dec ctr, branch if ctr != 0 && !cr0.eq */
beq 3f
2: addi r6,r6,1
3: subf r3,r3,r6
blr
99: li r3,-EFAULT
blr
.section __ex_table,"a"
EXTBL 1b,99b
.text
/* r3 = str, r4 = len (> 0), r5 = top (highest addr) */
_GLOBAL(__strnlen_user)
addi r7,r3,-1
subf r6,r7,r5 /* top+1 - str */
cmplw 0,r4,r6
bge 0f
mr r6,r4
0: mtctr r6 /* ctr = min(len, top - str) */
1: lbzu r0,1(r7) /* get next byte */
cmpwi 0,r0,0
bdnzf 2,1b /* loop if --ctr != 0 && byte != 0 */
addi r7,r7,1
subf r3,r3,r7 /* number of bytes we have looked at */
beqlr /* return if we found a 0 byte */
cmpw 0,r3,r4 /* did we look at all len bytes? */
blt 99f /* if not, must have hit top */
addi r3,r4,1 /* return len + 1 to indicate no null found */
blr
99: li r3,0 /* bad address, return 0 */
blr
.section __ex_table,"a"
EXTBL 1b,99b
