include/qemu/range.h

   1 #ifndef QEMU_RANGE_H
   2 #define QEMU_RANGE_H
   3
   4 #include <inttypes.h>
   5
   6 /*
   7  * Operations on 64 bit address ranges.
   8  * Notes:
   9  *   - ranges must not wrap around 0, but can include the last byte ~0x0LL.
  10  *   - this can not represent a full 0 to ~0x0LL range.
  11  */
  12
  13 /* A structure representing a range of addresses. */
  14 struct Range {
  15     uint64_t begin; /* First byte of the range, or 0 if empty. */
  16     uint64_t end;   /* 1 + the last byte. 0 if range empty or ends at ~0x0LL. */
  17 };
  18 typedef struct Range Range;
  19
  20 /* Get last byte of a range from offset + length.
  21  * Undefined for ranges that wrap around 0. */
  22 static inline uint64_t range_get_last(uint64_t offset, uint64_t len)
  23 {
  24     return offset + len - 1;
  25 }
  26
  27 /* Check whether a given range covers a given byte. */
  28 static inline int range_covers_byte(uint64_t offset, uint64_t len,
  29                                     uint64_t byte)
  30 {
  31     return offset <= byte && byte <= range_get_last(offset, len);
  32 }
  33
  34 /* Check whether 2 given ranges overlap.
  35  * Undefined if ranges that wrap around 0. */
  36 static inline int ranges_overlap(uint64_t first1, uint64_t len1,
  37                                  uint64_t first2, uint64_t len2)
  38 {
  39     uint64_t last1 = range_get_last(first1, len1);
  40     uint64_t last2 = range_get_last(first2, len2);
  41
  42     return !(last2 < first1 || last1 < first2);
  43 }
  44
  45 #endif