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linux-next/arch/powerpc/boot/string.S
Mike Ditto 59fd6b8cc0 powerpc: Fix boot wrapper memcmp() called with zero length argument
I noticed, when trying to use, e.g.,
node = find_node_by_prop_value(prev, "booleanprop", "", 0))
to search for all nodes with a certain boolean property, that memcmp()
returns garbage when comparing zero bytes.  It should return zero.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-10-21 15:17:48 +11:00

270 lines
3.7 KiB
ArmAsm

/*
* Copyright (C) Paul Mackerras 1997.
*
* 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.
*
* NOTE: this code runs in 32 bit mode and is packaged as ELF32.
*/
#include "ppc_asm.h"
.text
.globl strcpy
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
.globl strncpy
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 */
blr
.globl strcat
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
.globl strchr
strchr:
addi r3,r3,-1
1: lbzu r0,1(r3)
cmpw 0,r0,r4
beqlr
cmpwi 0,r0,0
bne 1b
li r3,0
blr
.globl strcmp
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
.globl strncmp
strncmp:
mtctr r5
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
bdnzt eq,1b
blr
.globl strlen
strlen:
addi r4,r3,-1
1: lbzu r0,1(r4)
cmpwi 0,r0,0
bne 1b
subf r3,r3,r4
blr
.globl memset
memset:
rlwimi r4,r4,8,16,23
rlwimi r4,r4,16,0,15
addi r6,r3,-4
cmplwi 0,r5,4
blt 7f
stwu r4,4(r6)
beqlr
andi. r0,r6,3
add r5,r0,r5
subf r6,r0,r6
rlwinm r0,r5,32-2,2,31
mtctr r0
bdz 6f
1: stwu r4,4(r6)
bdnz 1b
6: andi. r5,r5,3
7: cmpwi 0,r5,0
beqlr
mtctr r5
addi r6,r6,3
8: stbu r4,1(r6)
bdnz 8b
blr
.globl memmove
memmove:
cmplw 0,r3,r4
bgt backwards_memcpy
/* fall through */
.globl memcpy
memcpy:
rlwinm. r7,r5,32-3,3,31 /* r7 = r5 >> 3 */
addi r6,r3,-4
addi r4,r4,-4
beq 3f /* if less than 8 bytes to do */
andi. r0,r6,3 /* get dest word aligned */
mtctr r7
bne 5f
andi. r0,r4,3 /* check src word aligned too */
bne 3f
1: lwz r7,4(r4)
lwzu r8,8(r4)
stw r7,4(r6)
stwu r8,8(r6)
bdnz 1b
andi. r5,r5,7
2: cmplwi 0,r5,4
blt 3f
lwzu r0,4(r4)
addi r5,r5,-4
stwu r0,4(r6)
3: cmpwi 0,r5,0
beqlr
mtctr r5
addi r4,r4,3
addi r6,r6,3
4: lbzu r0,1(r4)
stbu r0,1(r6)
bdnz 4b
blr
5: subfic r0,r0,4
cmpw cr1,r0,r5
add r7,r0,r4
andi. r7,r7,3 /* will source be word-aligned too? */
ble cr1,3b
bne 3b /* do byte-by-byte if not */
mtctr r0
6: lbz r7,4(r4)
addi r4,r4,1
stb r7,4(r6)
addi r6,r6,1
bdnz 6b
subf r5,r0,r5
rlwinm. r7,r5,32-3,3,31
beq 2b
mtctr r7
b 1b
.globl backwards_memcpy
backwards_memcpy:
rlwinm. r7,r5,32-3,3,31 /* r7 = r5 >> 3 */
add r6,r3,r5
add r4,r4,r5
beq 3f
andi. r0,r6,3
mtctr r7
bne 5f
andi. r0,r4,3
bne 3f
1: lwz r7,-4(r4)
lwzu r8,-8(r4)
stw r7,-4(r6)
stwu r8,-8(r6)
bdnz 1b
andi. r5,r5,7
2: cmplwi 0,r5,4
blt 3f
lwzu r0,-4(r4)
subi r5,r5,4
stwu r0,-4(r6)
3: cmpwi 0,r5,0
beqlr
mtctr r5
4: lbzu r0,-1(r4)
stbu r0,-1(r6)
bdnz 4b
blr
5: cmpw cr1,r0,r5
subf r7,r0,r4
andi. r7,r7,3
ble cr1,3b
bne 3b
mtctr r0
6: lbzu r7,-1(r4)
stbu r7,-1(r6)
bdnz 6b
subf r5,r0,r5
rlwinm. r7,r5,32-3,3,31
beq 2b
mtctr r7
b 1b
.globl memchr
memchr:
cmpwi 0,r5,0
blelr
mtctr r5
addi r3,r3,-1
1: lbzu r0,1(r3)
cmpw r0,r4
beqlr
bdnz 1b
li r3,0
blr
.globl memcmp
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
/*
* Flush the dcache and invalidate the icache for a range of addresses.
*
* flush_cache(addr, len)
*/
.global flush_cache
flush_cache:
addi 4,4,0x1f /* len = (len + 0x1f) / 0x20 */
rlwinm. 4,4,27,5,31
mtctr 4
beqlr
1: dcbf 0,3
icbi 0,3
addi 3,3,0x20
bdnz 1b
sync
isync
blr