fixmap.h 2.5 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. * Copyright (C) 2013 Mark Salter <msalter@redhat.com>
  10. *
  11. * Adapted from arch/x86 version.
  12. *
  13. */
  14. #ifndef _ASM_ARM64_FIXMAP_H
  15. #define _ASM_ARM64_FIXMAP_H
  16. #ifndef __ASSEMBLY__
  17. #include <linux/kernel.h>
  18. #include <linux/sizes.h>
  19. #include <asm/boot.h>
  20. #include <asm/page.h>
  21. #include <asm/pgtable-prot.h>
  22. /*
  23. * Here we define all the compile-time 'special' virtual
  24. * addresses. The point is to have a constant address at
  25. * compile time, but to set the physical address only
  26. * in the boot process.
  27. *
  28. * These 'compile-time allocated' memory buffers are
  29. * page-sized. Use set_fixmap(idx,phys) to associate
  30. * physical memory with fixmap indices.
  31. *
  32. */
  33. enum fixed_addresses {
  34. FIX_HOLE,
  35. /*
  36. * Reserve a virtual window for the FDT that is 2 MB larger than the
  37. * maximum supported size, and put it at the top of the fixmap region.
  38. * The additional space ensures that any FDT that does not exceed
  39. * MAX_FDT_SIZE can be mapped regardless of whether it crosses any
  40. * 2 MB alignment boundaries.
  41. *
  42. * Keep this at the top so it remains 2 MB aligned.
  43. */
  44. #define FIX_FDT_SIZE (MAX_FDT_SIZE + SZ_2M)
  45. FIX_FDT_END,
  46. FIX_FDT = FIX_FDT_END + FIX_FDT_SIZE / PAGE_SIZE - 1,
  47. FIX_EARLYCON_MEM_BASE,
  48. FIX_TEXT_POKE0,
  49. __end_of_permanent_fixed_addresses,
  50. /*
  51. * Temporary boot-time mappings, used by early_ioremap(),
  52. * before ioremap() is functional.
  53. */
  54. #define NR_FIX_BTMAPS (SZ_256K / PAGE_SIZE)
  55. #define FIX_BTMAPS_SLOTS 7
  56. #define TOTAL_FIX_BTMAPS (NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS)
  57. FIX_BTMAP_END = __end_of_permanent_fixed_addresses,
  58. FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1,
  59. /*
  60. * Used for kernel page table creation, so unmapped memory may be used
  61. * for tables.
  62. */
  63. FIX_PTE,
  64. FIX_PMD,
  65. FIX_PUD,
  66. FIX_PGD,
  67. __end_of_fixed_addresses
  68. };
  69. #define FIXADDR_SIZE (__end_of_permanent_fixed_addresses << PAGE_SHIFT)
  70. #define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE)
  71. #define FIXMAP_PAGE_IO __pgprot(PROT_DEVICE_nGnRE)
  72. void __init early_fixmap_init(void);
  73. #define __early_set_fixmap __set_fixmap
  74. #define __late_set_fixmap __set_fixmap
  75. #define __late_clear_fixmap(idx) __set_fixmap((idx), 0, FIXMAP_PAGE_CLEAR)
  76. extern void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot);
  77. #include <asm-generic/fixmap.h>
  78. #endif /* !__ASSEMBLY__ */
  79. #endif /* _ASM_ARM64_FIXMAP_H */