highmem.c 875 B

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  1. /* highmem.c: arch-specific highmem stuff
  2. *
  3. * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
  4. * Written by David Howells (dhowells@redhat.com)
  5. *
  6. * This program is free software; you can redistribute it and/or
  7. * modify it under the terms of the GNU General Public License
  8. * as published by the Free Software Foundation; either version
  9. * 2 of the License, or (at your option) any later version.
  10. */
  11. #include <linux/highmem.h>
  12. #include <linux/module.h>
  13. void *kmap(struct page *page)
  14. {
  15. might_sleep();
  16. if (!PageHighMem(page))
  17. return page_address(page);
  18. return kmap_high(page);
  19. }
  20. EXPORT_SYMBOL(kmap);
  21. void kunmap(struct page *page)
  22. {
  23. if (in_interrupt())
  24. BUG();
  25. if (!PageHighMem(page))
  26. return;
  27. kunmap_high(page);
  28. }
  29. EXPORT_SYMBOL(kunmap);
  30. struct page *kmap_atomic_to_page(void *ptr)
  31. {
  32. return virt_to_page(ptr);
  33. }
  34. EXPORT_SYMBOL(kmap_atomic_to_page);