uncached.c 1.0 KB

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  1. #include <linux/init.h>
  2. #include <asm/sizes.h>
  3. #include <asm/page.h>
  4. #include <asm/addrspace.h>
  5. /*
  6. * This is the offset of the uncached section from its cached alias.
  7. *
  8. * Legacy platforms handle trivial transitions between cached and
  9. * uncached segments by making use of the 1:1 mapping relationship in
  10. * 512MB lowmem, others via a special uncached mapping.
  11. *
  12. * Default value only valid in 29 bit mode, in 32bit mode this will be
  13. * updated by the early PMB initialization code.
  14. */
  15. unsigned long cached_to_uncached = SZ_512M;
  16. unsigned long uncached_size = SZ_512M;
  17. unsigned long uncached_start, uncached_end;
  18. int virt_addr_uncached(unsigned long kaddr)
  19. {
  20. return (kaddr >= uncached_start) && (kaddr < uncached_end);
  21. }
  22. void __init uncached_init(void)
  23. {
  24. #ifdef CONFIG_29BIT
  25. uncached_start = P2SEG;
  26. #else
  27. uncached_start = memory_end;
  28. #endif
  29. uncached_end = uncached_start + uncached_size;
  30. }
  31. void __init uncached_resize(unsigned long size)
  32. {
  33. uncached_size = size;
  34. uncached_end = uncached_start + uncached_size;
  35. }