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) 45