Book a Demo!
CoCalc Logo Icon
StoreFeaturesDocsShareSupportNewsAboutPoliciesSign UpSign In
awilliam
GitHub Repository: awilliam/linux-vfio
 Path: blob/master/arch/arm/lib/copy_page.S
10817 views
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
#include <asm/cache.h>

16


17
#define COPY_COUNT (PAGE_SZ / (2 * L1_CACHE_BYTES) PLD( -1 ))

18


19
		.text

20
		.align	5

21
/*

22
 * StrongARM optimised copy_page routine

23
 * now 1.78bytes/cycle, was 1.60 bytes/cycle (50MHz bus -> 89MB/s)

24
 * Note that we probably achieve closer to the 100MB/s target with

25
 * the core clock switching.

26
 */

27
ENTRY(copy_page)

28
		stmfd	sp!, {r4, lr}			@	2

29
	PLD(	pld	[r1, #0]		)

30
	PLD(	pld	[r1, #L1_CACHE_BYTES]		)

31
		mov	r2, #COPY_COUNT			@	1

32
		ldmia	r1!, {r3, r4, ip, lr}		@	4+1

33
1:	PLD(	pld	[r1, #2 * L1_CACHE_BYTES])

34
	PLD(	pld	[r1, #3 * L1_CACHE_BYTES])

35
2:

36
	.rept	(2 * L1_CACHE_BYTES / 16 - 1)

37
		stmia	r0!, {r3, r4, ip, lr}		@	4

38
		ldmia	r1!, {r3, r4, ip, lr}		@	4

39
	.endr

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
ENDPROC(copy_page)

48


49