1 #ifndef QEMU_RANGE_H 2 #define QEMU_RANGE_H 3 4 #include <inttypes.h> 5 #include <qemu/typedefs.h> 6 7 /* 8 * Operations on 64 bit address ranges. 9 * Notes: 10 * - ranges must not wrap around 0, but can include the last byte ~0x0LL. 11 * - this can not represent a full 0 to ~0x0LL range. 12 */ 13 14 /* A structure representing a range of addresses. */ 15 struct Range { 16 uint64_t begin; /* First byte of the range, or 0 if empty. */ 17 uint64_t end; /* 1 + the last byte. 0 if range empty or ends at ~0x0LL. */ 18 }; 19 20 static inline void range_extend(Range *range, Range *extend_by) 21 { 22 if (!extend_by->begin && !extend_by->end) { 23 return; 24 } 25 if (!range->begin && !range->end) { 26 *range = *extend_by; 27 return; 28 } 29 if (range->begin > extend_by->begin) { 30 range->begin = extend_by->begin; 31 } 32 /* Compare last byte in case region ends at ~0x0LL */ 33 if (range->end - 1 < extend_by->end - 1) { 34 range->end = extend_by->end; 35 } 36 } 37 38 /* Get last byte of a range from offset + length. 39 * Undefined for ranges that wrap around 0. */ 40 static inline uint64_t range_get_last(uint64_t offset, uint64_t len) 41 { 42 return offset + len - 1; 43 } 44 45 /* Check whether a given range covers a given byte. */ 46 static inline int range_covers_byte(uint64_t offset, uint64_t len, 47 uint64_t byte) 48 { 49 return offset <= byte && byte <= range_get_last(offset, len); 50 } 51 52 /* Check whether 2 given ranges overlap. 53 * Undefined if ranges that wrap around 0. */ 54 static inline int ranges_overlap(uint64_t first1, uint64_t len1, 55 uint64_t first2, uint64_t len2) 56 { 57 uint64_t last1 = range_get_last(first1, len1); 58 uint64_t last2 = range_get_last(first2, len2); 59 60 return !(last2 < first1 || last1 < first2); 61 } 62 63 #endif 64
