93ed397011
This declaration specifies the "function" type and size for various assembly functions, mainly needed for generating the correct branch instructions in Thumb-2. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
127 lines
2.4 KiB
ArmAsm
127 lines
2.4 KiB
ArmAsm
/*
|
|
* linux/arch/arm/lib/memset.S
|
|
*
|
|
* Copyright (C) 1995-2000 Russell King
|
|
*
|
|
* 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.
|
|
*
|
|
* ASM optimised string functions
|
|
*/
|
|
#include <linux/linkage.h>
|
|
#include <asm/assembler.h>
|
|
|
|
.text
|
|
.align 5
|
|
.word 0
|
|
|
|
1: subs r2, r2, #4 @ 1 do we have enough
|
|
blt 5f @ 1 bytes to align with?
|
|
cmp r3, #2 @ 1
|
|
strltb r1, [r0], #1 @ 1
|
|
strleb r1, [r0], #1 @ 1
|
|
strb r1, [r0], #1 @ 1
|
|
add r2, r2, r3 @ 1 (r2 = r2 - (4 - r3))
|
|
/*
|
|
* The pointer is now aligned and the length is adjusted. Try doing the
|
|
* memzero again.
|
|
*/
|
|
|
|
ENTRY(memset)
|
|
ands r3, r0, #3 @ 1 unaligned?
|
|
bne 1b @ 1
|
|
/*
|
|
* we know that the pointer in r0 is aligned to a word boundary.
|
|
*/
|
|
orr r1, r1, r1, lsl #8
|
|
orr r1, r1, r1, lsl #16
|
|
mov r3, r1
|
|
cmp r2, #16
|
|
blt 4f
|
|
|
|
#if ! CALGN(1)+0
|
|
|
|
/*
|
|
* We need an extra register for this loop - save the return address and
|
|
* use the LR
|
|
*/
|
|
str lr, [sp, #-4]!
|
|
mov ip, r1
|
|
mov lr, r1
|
|
|
|
2: subs r2, r2, #64
|
|
stmgeia r0!, {r1, r3, ip, lr} @ 64 bytes at a time.
|
|
stmgeia r0!, {r1, r3, ip, lr}
|
|
stmgeia r0!, {r1, r3, ip, lr}
|
|
stmgeia r0!, {r1, r3, ip, lr}
|
|
bgt 2b
|
|
ldmeqfd sp!, {pc} @ Now <64 bytes to go.
|
|
/*
|
|
* No need to correct the count; we're only testing bits from now on
|
|
*/
|
|
tst r2, #32
|
|
stmneia r0!, {r1, r3, ip, lr}
|
|
stmneia r0!, {r1, r3, ip, lr}
|
|
tst r2, #16
|
|
stmneia r0!, {r1, r3, ip, lr}
|
|
ldr lr, [sp], #4
|
|
|
|
#else
|
|
|
|
/*
|
|
* This version aligns the destination pointer in order to write
|
|
* whole cache lines at once.
|
|
*/
|
|
|
|
stmfd sp!, {r4-r7, lr}
|
|
mov r4, r1
|
|
mov r5, r1
|
|
mov r6, r1
|
|
mov r7, r1
|
|
mov ip, r1
|
|
mov lr, r1
|
|
|
|
cmp r2, #96
|
|
tstgt r0, #31
|
|
ble 3f
|
|
|
|
and ip, r0, #31
|
|
rsb ip, ip, #32
|
|
sub r2, r2, ip
|
|
movs ip, ip, lsl #(32 - 4)
|
|
stmcsia r0!, {r4, r5, r6, r7}
|
|
stmmiia r0!, {r4, r5}
|
|
tst ip, #(1 << 30)
|
|
mov ip, r1
|
|
strne r1, [r0], #4
|
|
|
|
3: subs r2, r2, #64
|
|
stmgeia r0!, {r1, r3-r7, ip, lr}
|
|
stmgeia r0!, {r1, r3-r7, ip, lr}
|
|
bgt 3b
|
|
ldmeqfd sp!, {r4-r7, pc}
|
|
|
|
tst r2, #32
|
|
stmneia r0!, {r1, r3-r7, ip, lr}
|
|
tst r2, #16
|
|
stmneia r0!, {r4-r7}
|
|
ldmfd sp!, {r4-r7, lr}
|
|
|
|
#endif
|
|
|
|
4: tst r2, #8
|
|
stmneia r0!, {r1, r3}
|
|
tst r2, #4
|
|
strne r1, [r0], #4
|
|
/*
|
|
* When we get here, we've got less than 4 bytes to zero. We
|
|
* may have an unaligned pointer as well.
|
|
*/
|
|
5: tst r2, #2
|
|
strneb r1, [r0], #1
|
|
strneb r1, [r0], #1
|
|
tst r2, #1
|
|
strneb r1, [r0], #1
|
|
mov pc, lr
|
|
ENDPROC(memset)
|