copy_page.S 1.3 KB

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  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/asm-offsets.h>
  15. #define COPY_COUNT (PAGE_SZ/64 PLD( -1 ))
  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, #32] )
  28. mov r2, #COPY_COUNT @ 1
  29. ldmia r1!, {r3, r4, ip, lr} @ 4+1
  30. 1: PLD( pld [r1, #64] )
  31. PLD( pld [r1, #96] )
  32. 2: stmia r0!, {r3, r4, ip, lr} @ 4
  33. ldmia r1!, {r3, r4, ip, lr} @ 4+1
  34. stmia r0!, {r3, r4, ip, lr} @ 4
  35. ldmia r1!, {r3, r4, ip, lr} @ 4+1
  36. stmia r0!, {r3, r4, ip, lr} @ 4
  37. ldmia r1!, {r3, r4, ip, lr} @ 4
  38. subs r2, r2, #1 @ 1
  39. stmia r0!, {r3, r4, ip, lr} @ 4
  40. ldmgtia r1!, {r3, r4, ip, lr} @ 4
  41. bgt 1b @ 1
  42. PLD( ldmeqia r1!, {r3, r4, ip, lr} )
  43. PLD( beq 2b )
  44. ldmfd sp!, {r4, pc} @ 3