physaddr.c 2.3 KB

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  1. // SPDX-License-Identifier: GPL-2.0
  2. #include <linux/memblock.h>
  3. #include <linux/mmdebug.h>
  4. #include <linux/export.h>
  5. #include <linux/mm.h>
  6. #include <asm/page.h>
  7. #include <linux/vmalloc.h>
  8. #include "physaddr.h"
  9. #ifdef CONFIG_X86_64
  10. #ifdef CONFIG_DEBUG_VIRTUAL
  11. unsigned long __phys_addr(unsigned long x)
  12. {
  13. unsigned long y = x - __START_KERNEL_map;
  14. /* use the carry flag to determine if x was < __START_KERNEL_map */
  15. if (unlikely(x > y)) {
  16. x = y + phys_base;
  17. VIRTUAL_BUG_ON(y >= KERNEL_IMAGE_SIZE);
  18. } else {
  19. x = y + (__START_KERNEL_map - PAGE_OFFSET);
  20. /* carry flag will be set if starting x was >= PAGE_OFFSET */
  21. VIRTUAL_BUG_ON((x > y) || !phys_addr_valid(x));
  22. }
  23. return x;
  24. }
  25. EXPORT_SYMBOL(__phys_addr);
  26. unsigned long __phys_addr_symbol(unsigned long x)
  27. {
  28. unsigned long y = x - __START_KERNEL_map;
  29. /* only check upper bounds since lower bounds will trigger carry */
  30. VIRTUAL_BUG_ON(y >= KERNEL_IMAGE_SIZE);
  31. return y + phys_base;
  32. }
  33. EXPORT_SYMBOL(__phys_addr_symbol);
  34. #endif
  35. bool __virt_addr_valid(unsigned long x)
  36. {
  37. unsigned long y = x - __START_KERNEL_map;
  38. /* use the carry flag to determine if x was < __START_KERNEL_map */
  39. if (unlikely(x > y)) {
  40. x = y + phys_base;
  41. if (y >= KERNEL_IMAGE_SIZE)
  42. return false;
  43. } else {
  44. x = y + (__START_KERNEL_map - PAGE_OFFSET);
  45. /* carry flag will be set if starting x was >= PAGE_OFFSET */
  46. if ((x > y) || !phys_addr_valid(x))
  47. return false;
  48. }
  49. return pfn_valid(x >> PAGE_SHIFT);
  50. }
  51. EXPORT_SYMBOL(__virt_addr_valid);
  52. #else
  53. #ifdef CONFIG_DEBUG_VIRTUAL
  54. unsigned long __phys_addr(unsigned long x)
  55. {
  56. unsigned long phys_addr = x - PAGE_OFFSET;
  57. /* VMALLOC_* aren't constants */
  58. VIRTUAL_BUG_ON(x < PAGE_OFFSET);
  59. VIRTUAL_BUG_ON(__vmalloc_start_set && is_vmalloc_addr((void *) x));
  60. /* max_low_pfn is set early, but not _that_ early */
  61. if (max_low_pfn) {
  62. VIRTUAL_BUG_ON((phys_addr >> PAGE_SHIFT) > max_low_pfn);
  63. BUG_ON(slow_virt_to_phys((void *)x) != phys_addr);
  64. }
  65. return phys_addr;
  66. }
  67. EXPORT_SYMBOL(__phys_addr);
  68. #endif
  69. bool __virt_addr_valid(unsigned long x)
  70. {
  71. if (x < PAGE_OFFSET)
  72. return false;
  73. if (__vmalloc_start_set && is_vmalloc_addr((void *) x))
  74. return false;
  75. if (x >= FIXADDR_START)
  76. return false;
  77. return pfn_valid((x - PAGE_OFFSET) >> PAGE_SHIFT);
  78. }
  79. EXPORT_SYMBOL(__virt_addr_valid);
  80. #endif /* CONFIG_X86_64 */