diff options
Diffstat (limited to 'arch/arm/lib/copy_page.S')
| -rw-r--r-- | arch/arm/lib/copy_page.S | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/arch/arm/lib/copy_page.S b/arch/arm/lib/copy_page.S new file mode 100644 index 000000000..5db1a8ee3 --- /dev/null +++ b/arch/arm/lib/copy_page.S @@ -0,0 +1,44 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * linux/arch/arm/lib/copypage.S + * + * Copyright (C) 1995-1999 Russell King + * + * ASM optimised string functions + */ +#include <linux/linkage.h> +#include <asm/assembler.h> +#include <asm/asm-offsets.h> +#include <asm/cache.h> + +#define COPY_COUNT (PAGE_SZ / (2 * L1_CACHE_BYTES) PLD( -1 )) + + .text + .align 5 +/* + * StrongARM optimised copy_page routine + * now 1.78bytes/cycle, was 1.60 bytes/cycle (50MHz bus -> 89MB/s) + * Note that we probably achieve closer to the 100MB/s target with + * the core clock switching. + */ +ENTRY(copy_page) + stmfd sp!, {r4, lr} @ 2 + PLD( pld [r1, #0] ) + PLD( pld [r1, #L1_CACHE_BYTES] ) + mov r2, #COPY_COUNT @ 1 + ldmia r1!, {r3, r4, ip, lr} @ 4+1 +1: PLD( pld [r1, #2 * L1_CACHE_BYTES]) + PLD( pld [r1, #3 * L1_CACHE_BYTES]) +2: + .rept (2 * L1_CACHE_BYTES / 16 - 1) + stmia r0!, {r3, r4, ip, lr} @ 4 + ldmia r1!, {r3, r4, ip, lr} @ 4 + .endr + subs r2, r2, #1 @ 1 + stmia r0!, {r3, r4, ip, lr} @ 4 + ldmiagt r1!, {r3, r4, ip, lr} @ 4 + bgt 1b @ 1 + PLD( ldmiaeq r1!, {r3, r4, ip, lr} ) + PLD( beq 2b ) + ldmfd sp!, {r4, pc} @ 3 +ENDPROC(copy_page) |