forked from luck/tmp_suning_uos_patched
fd522a8dec
When compiling the kernel to Thumb-2, using a 16-bit NOP in the memmove() implementation causes the preceding ADD PC instruction to branch incorrectly in the middle of a 32-bit LDR or STR instruction. The memmove() code is now similar to the memcpy() template. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
200 lines
4.0 KiB
ArmAsm
200 lines
4.0 KiB
ArmAsm
/*
|
|
* linux/arch/arm/lib/memmove.S
|
|
*
|
|
* Author: Nicolas Pitre
|
|
* Created: Sep 28, 2005
|
|
* Copyright: (C) MontaVista Software Inc.
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*/
|
|
|
|
#include <linux/linkage.h>
|
|
#include <asm/assembler.h>
|
|
|
|
.text
|
|
|
|
/*
|
|
* Prototype: void *memmove(void *dest, const void *src, size_t n);
|
|
*
|
|
* Note:
|
|
*
|
|
* If the memory regions don't overlap, we simply branch to memcpy which is
|
|
* normally a bit faster. Otherwise the copy is done going downwards. This
|
|
* is a transposition of the code from copy_template.S but with the copy
|
|
* occurring in the opposite direction.
|
|
*/
|
|
|
|
ENTRY(memmove)
|
|
|
|
subs ip, r0, r1
|
|
cmphi r2, ip
|
|
bls memcpy
|
|
|
|
stmfd sp!, {r0, r4, lr}
|
|
add r1, r1, r2
|
|
add r0, r0, r2
|
|
subs r2, r2, #4
|
|
blt 8f
|
|
ands ip, r0, #3
|
|
PLD( pld [r1, #-4] )
|
|
bne 9f
|
|
ands ip, r1, #3
|
|
bne 10f
|
|
|
|
1: subs r2, r2, #(28)
|
|
stmfd sp!, {r5 - r8}
|
|
blt 5f
|
|
|
|
CALGN( ands ip, r0, #31 )
|
|
CALGN( sbcnes r4, ip, r2 ) @ C is always set here
|
|
CALGN( bcs 2f )
|
|
CALGN( adr r4, 6f )
|
|
CALGN( subs r2, r2, ip ) @ C is set here
|
|
CALGN( rsb ip, ip, #32 )
|
|
CALGN( add pc, r4, ip )
|
|
|
|
PLD( pld [r1, #-4] )
|
|
2: PLD( subs r2, r2, #96 )
|
|
PLD( pld [r1, #-32] )
|
|
PLD( blt 4f )
|
|
PLD( pld [r1, #-64] )
|
|
PLD( pld [r1, #-96] )
|
|
|
|
3: PLD( pld [r1, #-128] )
|
|
4: ldmdb r1!, {r3, r4, r5, r6, r7, r8, ip, lr}
|
|
subs r2, r2, #32
|
|
stmdb r0!, {r3, r4, r5, r6, r7, r8, ip, lr}
|
|
bge 3b
|
|
PLD( cmn r2, #96 )
|
|
PLD( bge 4b )
|
|
|
|
5: ands ip, r2, #28
|
|
rsb ip, ip, #32
|
|
addne pc, pc, ip @ C is always clear here
|
|
b 7f
|
|
6: W(nop)
|
|
W(ldr) r3, [r1, #-4]!
|
|
W(ldr) r4, [r1, #-4]!
|
|
W(ldr) r5, [r1, #-4]!
|
|
W(ldr) r6, [r1, #-4]!
|
|
W(ldr) r7, [r1, #-4]!
|
|
W(ldr) r8, [r1, #-4]!
|
|
W(ldr) lr, [r1, #-4]!
|
|
|
|
add pc, pc, ip
|
|
nop
|
|
W(nop)
|
|
W(str) r3, [r0, #-4]!
|
|
W(str) r4, [r0, #-4]!
|
|
W(str) r5, [r0, #-4]!
|
|
W(str) r6, [r0, #-4]!
|
|
W(str) r7, [r0, #-4]!
|
|
W(str) r8, [r0, #-4]!
|
|
W(str) lr, [r0, #-4]!
|
|
|
|
CALGN( bcs 2b )
|
|
|
|
7: ldmfd sp!, {r5 - r8}
|
|
|
|
8: movs r2, r2, lsl #31
|
|
ldrneb r3, [r1, #-1]!
|
|
ldrcsb r4, [r1, #-1]!
|
|
ldrcsb ip, [r1, #-1]
|
|
strneb r3, [r0, #-1]!
|
|
strcsb r4, [r0, #-1]!
|
|
strcsb ip, [r0, #-1]
|
|
ldmfd sp!, {r0, r4, pc}
|
|
|
|
9: cmp ip, #2
|
|
ldrgtb r3, [r1, #-1]!
|
|
ldrgeb r4, [r1, #-1]!
|
|
ldrb lr, [r1, #-1]!
|
|
strgtb r3, [r0, #-1]!
|
|
strgeb r4, [r0, #-1]!
|
|
subs r2, r2, ip
|
|
strb lr, [r0, #-1]!
|
|
blt 8b
|
|
ands ip, r1, #3
|
|
beq 1b
|
|
|
|
10: bic r1, r1, #3
|
|
cmp ip, #2
|
|
ldr r3, [r1, #0]
|
|
beq 17f
|
|
blt 18f
|
|
|
|
|
|
.macro backward_copy_shift push pull
|
|
|
|
subs r2, r2, #28
|
|
blt 14f
|
|
|
|
CALGN( ands ip, r0, #31 )
|
|
CALGN( sbcnes r4, ip, r2 ) @ C is always set here
|
|
CALGN( subcc r2, r2, ip )
|
|
CALGN( bcc 15f )
|
|
|
|
11: stmfd sp!, {r5 - r9}
|
|
|
|
PLD( pld [r1, #-4] )
|
|
PLD( subs r2, r2, #96 )
|
|
PLD( pld [r1, #-32] )
|
|
PLD( blt 13f )
|
|
PLD( pld [r1, #-64] )
|
|
PLD( pld [r1, #-96] )
|
|
|
|
12: PLD( pld [r1, #-128] )
|
|
13: ldmdb r1!, {r7, r8, r9, ip}
|
|
mov lr, r3, push #\push
|
|
subs r2, r2, #32
|
|
ldmdb r1!, {r3, r4, r5, r6}
|
|
orr lr, lr, ip, pull #\pull
|
|
mov ip, ip, push #\push
|
|
orr ip, ip, r9, pull #\pull
|
|
mov r9, r9, push #\push
|
|
orr r9, r9, r8, pull #\pull
|
|
mov r8, r8, push #\push
|
|
orr r8, r8, r7, pull #\pull
|
|
mov r7, r7, push #\push
|
|
orr r7, r7, r6, pull #\pull
|
|
mov r6, r6, push #\push
|
|
orr r6, r6, r5, pull #\pull
|
|
mov r5, r5, push #\push
|
|
orr r5, r5, r4, pull #\pull
|
|
mov r4, r4, push #\push
|
|
orr r4, r4, r3, pull #\pull
|
|
stmdb r0!, {r4 - r9, ip, lr}
|
|
bge 12b
|
|
PLD( cmn r2, #96 )
|
|
PLD( bge 13b )
|
|
|
|
ldmfd sp!, {r5 - r9}
|
|
|
|
14: ands ip, r2, #28
|
|
beq 16f
|
|
|
|
15: mov lr, r3, push #\push
|
|
ldr r3, [r1, #-4]!
|
|
subs ip, ip, #4
|
|
orr lr, lr, r3, pull #\pull
|
|
str lr, [r0, #-4]!
|
|
bgt 15b
|
|
CALGN( cmp r2, #0 )
|
|
CALGN( bge 11b )
|
|
|
|
16: add r1, r1, #(\pull / 8)
|
|
b 8b
|
|
|
|
.endm
|
|
|
|
|
|
backward_copy_shift push=8 pull=24
|
|
|
|
17: backward_copy_shift push=16 pull=16
|
|
|
|
18: backward_copy_shift push=24 pull=8
|
|
|
|
ENDPROC(memmove)
|