1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * linux/arch/arm/lib/copypage.S
4 *
5 * Copyright (C) 1995-1999 Russell King
6 *
7 * ASM optimised string functions
8 */
9 #include <linux/linkage.h>
10 #include <asm/assembler.h>
11 #include <asm/asm-offsets.h>
12 #include <asm/cache.h>
13
14 #define COPY_COUNT (PAGE_SZ / (2 * L1_CACHE_BYTES) PLD( -1 ))
15
16 .text
17 .align 5
18 /*
19 * StrongARM optimised copy_page routine
20 * now 1.78bytes/cycle, was 1.60 bytes/cycle (50MHz bus -> 89MB/s)
21 * Note that we probably achieve closer to the 100MB/s target with
22 * the core clock switching.
23 */
24 ENTRY(copy_page)
25 stmfd sp!, {r4, lr} @ 2
26 PLD( pld [r1, #0] )
27 PLD( pld [r1, #L1_CACHE_BYTES] )
28 mov r2, #COPY_COUNT @ 1
29 ldmia r1!, {r3, r4, ip, lr} @ 4+1
30 1: PLD( pld [r1, #2 * L1_CACHE_BYTES])
31 PLD( pld [r1, #3 * L1_CACHE_BYTES])
32 2:
33 .rept (2 * L1_CACHE_BYTES / 16 - 1)
34 stmia r0!, {r3, r4, ip, lr} @ 4
35 ldmia r1!, {r3, r4, ip, lr} @ 4
36 .endr
37 subs r2, r2, #1 @ 1
38 stmia r0!, {r3, r4, ip, lr} @ 4
39 ldmiagt r1!, {r3, r4, ip, lr} @ 4
40 bgt 1b @ 1
41 PLD( ldmiaeq r1!, {r3, r4, ip, lr} )
42 PLD( beq 2b )
43 ldmfd sp!, {r4, pc} @ 3
44 ENDPROC(copy_page)
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