xref: /openbmc/linux/arch/arm/lib/copy_page.S (revision 22246614)
1/*
2 *  linux/arch/arm/lib/copypage.S
3 *
4 *  Copyright (C) 1995-1999 Russell King
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 *
10 *  ASM optimised string functions
11 */
12#include <linux/linkage.h>
13#include <asm/assembler.h>
14#include <asm/asm-offsets.h>
15
16#define COPY_COUNT (PAGE_SZ/64 PLD( -1 ))
17
18		.text
19		.align	5
20/*
21 * StrongARM optimised copy_page routine
22 * now 1.78bytes/cycle, was 1.60 bytes/cycle (50MHz bus -> 89MB/s)
23 * Note that we probably achieve closer to the 100MB/s target with
24 * the core clock switching.
25 */
26ENTRY(copy_page)
27		stmfd	sp!, {r4, lr}			@	2
28	PLD(	pld	[r1, #0]		)
29	PLD(	pld	[r1, #32]		)
30		mov	r2, #COPY_COUNT			@	1
31		ldmia	r1!, {r3, r4, ip, lr}		@	4+1
321:	PLD(	pld	[r1, #64]		)
33	PLD(	pld	[r1, #96]		)
342:		stmia	r0!, {r3, r4, ip, lr}		@	4
35		ldmia	r1!, {r3, r4, ip, lr}		@	4+1
36		stmia	r0!, {r3, r4, ip, lr}		@	4
37		ldmia	r1!, {r3, r4, ip, lr}		@	4+1
38		stmia	r0!, {r3, r4, ip, lr}		@	4
39		ldmia	r1!, {r3, r4, ip, lr}		@	4
40		subs	r2, r2, #1			@	1
41		stmia	r0!, {r3, r4, ip, lr}		@	4
42		ldmgtia	r1!, {r3, r4, ip, lr}		@	4
43		bgt	1b				@	1
44	PLD(	ldmeqia r1!, {r3, r4, ip, lr}	)
45	PLD(	beq	2b			)
46		ldmfd	sp!, {r4, pc}			@	3
47