fixmap.h 2.0 KB

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  1. /*
  2. * fixmap.h: compile-time virtual memory allocation
  3. *
  4. * This file is subject to the terms and conditions of the GNU General Public
  5. * License. See the file "COPYING" in the main directory of this archive
  6. * for more details.
  7. *
  8. * Copyright (C) 1998 Ingo Molnar
  9. *
  10. * Copyright 2008 Freescale Semiconductor Inc.
  11. * Port to powerpc added by Kumar Gala
  12. *
  13. * Copyright 2011 Michal Simek <monstr@monstr.eu>
  14. * Copyright 2011 PetaLogix Qld Pty Ltd
  15. * Port to Microblaze
  16. */
  17. #ifndef _ASM_FIXMAP_H
  18. #define _ASM_FIXMAP_H
  19. #ifndef __ASSEMBLY__
  20. #include <linux/kernel.h>
  21. #include <asm/page.h>
  22. #ifdef CONFIG_HIGHMEM
  23. #include <linux/threads.h>
  24. #include <asm/kmap_types.h>
  25. #endif
  26. #define FIXADDR_TOP ((unsigned long)(-PAGE_SIZE))
  27. /*
  28. * Here we define all the compile-time 'special' virtual
  29. * addresses. The point is to have a constant address at
  30. * compile time, but to set the physical address only
  31. * in the boot process. We allocate these special addresses
  32. * from the end of virtual memory (0xfffff000) backwards.
  33. * Also this lets us do fail-safe vmalloc(), we
  34. * can guarantee that these special addresses and
  35. * vmalloc()-ed addresses never overlap.
  36. *
  37. * these 'compile-time allocated' memory buffers are
  38. * fixed-size 4k pages. (or larger if used with an increment
  39. * highger than 1) use fixmap_set(idx,phys) to associate
  40. * physical memory with fixmap indices.
  41. *
  42. * TLB entries of such buffers will not be flushed across
  43. * task switches.
  44. */
  45. enum fixed_addresses {
  46. FIX_HOLE,
  47. #ifdef CONFIG_HIGHMEM
  48. FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */
  49. FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_TYPE_NR * num_possible_cpus()) - 1,
  50. #endif
  51. __end_of_fixed_addresses
  52. };
  53. extern void __set_fixmap(enum fixed_addresses idx,
  54. phys_addr_t phys, pgprot_t flags);
  55. #define __FIXADDR_SIZE (__end_of_fixed_addresses << PAGE_SHIFT)
  56. #define FIXADDR_START (FIXADDR_TOP - __FIXADDR_SIZE)
  57. #define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_CI
  58. #include <asm-generic/fixmap.h>
  59. #endif /* !__ASSEMBLY__ */
  60. #endif