range.c 3.0 KB

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  1. // SPDX-License-Identifier: GPL-2.0
  2. /*
  3. * Range add and subtract
  4. */
  5. #include <linux/init.h>
  6. #include <linux/minmax.h>
  7. #include <linux/printk.h>
  8. #include <linux/sort.h>
  9. #include <linux/string.h>
  10. #include <linux/range.h>
  11. int add_range(struct range *range, int az, int nr_range, u64 start, u64 end)
  12. {
  13. if (start >= end)
  14. return nr_range;
  15. /* Out of slots: */
  16. if (nr_range >= az)
  17. return nr_range;
  18. range[nr_range].start = start;
  19. range[nr_range].end = end;
  20. nr_range++;
  21. return nr_range;
  22. }
  23. int add_range_with_merge(struct range *range, int az, int nr_range,
  24. u64 start, u64 end)
  25. {
  26. int i;
  27. if (start >= end)
  28. return nr_range;
  29. /* get new start/end: */
  30. for (i = 0; i < nr_range; i++) {
  31. u64 common_start, common_end;
  32. if (!range[i].end)
  33. continue;
  34. common_start = max(range[i].start, start);
  35. common_end = min(range[i].end, end);
  36. if (common_start > common_end)
  37. continue;
  38. /* new start/end, will add it back at last */
  39. start = min(range[i].start, start);
  40. end = max(range[i].end, end);
  41. memmove(&range[i], &range[i + 1],
  42. (nr_range - (i + 1)) * sizeof(range[i]));
  43. range[nr_range - 1].start = 0;
  44. range[nr_range - 1].end = 0;
  45. nr_range--;
  46. i--;
  47. }
  48. /* Need to add it: */
  49. return add_range(range, az, nr_range, start, end);
  50. }
  51. void subtract_range(struct range *range, int az, u64 start, u64 end)
  52. {
  53. int i, j;
  54. if (start >= end)
  55. return;
  56. for (j = 0; j < az; j++) {
  57. if (!range[j].end)
  58. continue;
  59. if (start <= range[j].start && end >= range[j].end) {
  60. range[j].start = 0;
  61. range[j].end = 0;
  62. continue;
  63. }
  64. if (start <= range[j].start && end < range[j].end &&
  65. range[j].start < end) {
  66. range[j].start = end;
  67. continue;
  68. }
  69. if (start > range[j].start && end >= range[j].end &&
  70. range[j].end > start) {
  71. range[j].end = start;
  72. continue;
  73. }
  74. if (start > range[j].start && end < range[j].end) {
  75. /* Find the new spare: */
  76. for (i = 0; i < az; i++) {
  77. if (range[i].end == 0)
  78. break;
  79. }
  80. if (i < az) {
  81. range[i].end = range[j].end;
  82. range[i].start = end;
  83. } else {
  84. pr_err("%s: run out of slot in ranges\n",
  85. __func__);
  86. }
  87. range[j].end = start;
  88. continue;
  89. }
  90. }
  91. }
  92. static int cmp_range(const void *x1, const void *x2)
  93. {
  94. const struct range *r1 = x1;
  95. const struct range *r2 = x2;
  96. if (r1->start < r2->start)
  97. return -1;
  98. if (r1->start > r2->start)
  99. return 1;
  100. return 0;
  101. }
  102. int clean_sort_range(struct range *range, int az)
  103. {
  104. int i, j, k = az - 1, nr_range = az;
  105. for (i = 0; i < k; i++) {
  106. if (range[i].end)
  107. continue;
  108. for (j = k; j > i; j--) {
  109. if (range[j].end) {
  110. k = j;
  111. break;
  112. }
  113. }
  114. if (j == i)
  115. break;
  116. range[i].start = range[k].start;
  117. range[i].end = range[k].end;
  118. range[k].start = 0;
  119. range[k].end = 0;
  120. k--;
  121. }
  122. /* count it */
  123. for (i = 0; i < az; i++) {
  124. if (!range[i].end) {
  125. nr_range = i;
  126. break;
  127. }
  128. }
  129. /* sort them */
  130. sort(range, nr_range, sizeof(struct range), cmp_range, NULL);
  131. return nr_range;
  132. }
  133. void sort_range(struct range *range, int nr_range)
  134. {
  135. /* sort them */
  136. sort(range, nr_range, sizeof(struct range), cmp_range, NULL);
  137. }