delay.c 1022 B

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  1. // SPDX-License-Identifier: GPL-2.0-only
  2. /*
  3. * Copyright (C) 2011 Richard Weinberger <richrd@nod.at>
  4. * Mostly copied from arch/x86/lib/delay.c
  5. */
  6. #include <linux/export.h>
  7. #include <linux/kernel.h>
  8. #include <linux/delay.h>
  9. #include <asm/param.h>
  10. void __delay(unsigned long loops)
  11. {
  12. asm volatile(
  13. "test %0,%0\n"
  14. "jz 3f\n"
  15. "jmp 1f\n"
  16. ".align 16\n"
  17. "1: jmp 2f\n"
  18. ".align 16\n"
  19. "2: dec %0\n"
  20. " jnz 2b\n"
  21. "3: dec %0\n"
  22. : /* we don't need output */
  23. : "a" (loops)
  24. );
  25. }
  26. EXPORT_SYMBOL(__delay);
  27. inline void __const_udelay(unsigned long xloops)
  28. {
  29. int d0;
  30. xloops *= 4;
  31. asm("mull %%edx"
  32. : "=d" (xloops), "=&a" (d0)
  33. : "1" (xloops), "0"
  34. (loops_per_jiffy * (HZ/4)));
  35. __delay(++xloops);
  36. }
  37. EXPORT_SYMBOL(__const_udelay);
  38. void __udelay(unsigned long usecs)
  39. {
  40. __const_udelay(usecs * 0x000010c7); /* 2**32 / 1000000 (rounded up) */
  41. }
  42. EXPORT_SYMBOL(__udelay);
  43. void __ndelay(unsigned long nsecs)
  44. {
  45. __const_udelay(nsecs * 0x00005); /* 2**32 / 1000000000 (rounded up) */
  46. }
  47. EXPORT_SYMBOL(__ndelay);