copy_page.S
上传用户:lgb322
上传日期:2013-02-24
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- /*
- * linux/arch/arm/lib/copypage.S
- *
- * Copyright (C) 1995-1999 Russell King
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * ASM optimised string functions
- */
- #include <linux/linkage.h>
- #include <asm/assembler.h>
- #include <asm/constants.h>
- .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
- mov r2, #PAGE_SZ/64 @ 1
- ldmia r1!, {r3, r4, ip, lr} @ 4+1
- 1: stmia r0!, {r3, r4, ip, lr} @ 4
- ldmia r1!, {r3, r4, ip, lr} @ 4+1
- stmia r0!, {r3, r4, ip, lr} @ 4
- ldmia r1!, {r3, r4, ip, lr} @ 4+1
- stmia r0!, {r3, r4, ip, lr} @ 4
- ldmia r1!, {r3, r4, ip, lr} @ 4
- subs r2, r2, #1 @ 1
- stmia r0!, {r3, r4, ip, lr} @ 4
- ldmneia r1!, {r3, r4, ip, lr} @ 4
- bne 1b @ 1
- LOADREGS(fd, sp!, {r4, pc}) @ 3