arch/arm/lib/copy_page.S

   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/constants.h>
  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                 mov     r2, #PAGE_SZ/64                 @       1
  27                 ldmia   r1!, {r3, r4, ip, lr}           @       4+1
  28 1:              stmia   r0!, {r3, r4, ip, lr}           @       4
  29                 ldmia   r1!, {r3, r4, ip, lr}           @       4+1
  30                 stmia   r0!, {r3, r4, ip, lr}           @       4
  31                 ldmia   r1!, {r3, r4, ip, lr}           @       4+1
  32                 stmia   r0!, {r3, r4, ip, lr}           @       4
  33                 ldmia   r1!, {r3, r4, ip, lr}           @       4
  34                 subs    r2, r2, #1                      @       1
  35                 stmia   r0!, {r3, r4, ip, lr}           @       4
  36                 ldmneia r1!, {r3, r4, ip, lr}           @       4
  37                 bne     1b                              @       1
  38                 LOADREGS(fd, sp!, {r4, pc})             @       3