X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=qemu%2Finclude%2Fqemu%2Frange.h;fp=qemu%2Finclude%2Fqemu%2Frange.h;h=cfa021fd48ae4125ed0f3cd6cfbb66d4df0fb8d8;hb=e44e3482bdb4d0ebde2d8b41830ac2cdb07948fb;hp=0000000000000000000000000000000000000000;hpb=9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00;p=kvmfornfv.git diff --git a/qemu/include/qemu/range.h b/qemu/include/qemu/range.h new file mode 100644 index 000000000..cfa021fd4 --- /dev/null +++ b/qemu/include/qemu/range.h @@ -0,0 +1,135 @@ +#ifndef QEMU_RANGE_H +#define QEMU_RANGE_H + +#include +#include +#include "qemu/queue.h" + +/* + * Operations on 64 bit address ranges. + * Notes: + * - ranges must not wrap around 0, but can include the last byte ~0x0LL. + * - this can not represent a full 0 to ~0x0LL range. + */ + +/* A structure representing a range of addresses. */ +struct Range { + uint64_t begin; /* First byte of the range, or 0 if empty. */ + uint64_t end; /* 1 + the last byte. 0 if range empty or ends at ~0x0LL. */ +}; + +static inline void range_extend(Range *range, Range *extend_by) +{ + if (!extend_by->begin && !extend_by->end) { + return; + } + if (!range->begin && !range->end) { + *range = *extend_by; + return; + } + if (range->begin > extend_by->begin) { + range->begin = extend_by->begin; + } + /* Compare last byte in case region ends at ~0x0LL */ + if (range->end - 1 < extend_by->end - 1) { + range->end = extend_by->end; + } +} + +/* Get last byte of a range from offset + length. + * Undefined for ranges that wrap around 0. */ +static inline uint64_t range_get_last(uint64_t offset, uint64_t len) +{ + return offset + len - 1; +} + +/* Check whether a given range covers a given byte. */ +static inline int range_covers_byte(uint64_t offset, uint64_t len, + uint64_t byte) +{ + return offset <= byte && byte <= range_get_last(offset, len); +} + +/* Check whether 2 given ranges overlap. + * Undefined if ranges that wrap around 0. */ +static inline int ranges_overlap(uint64_t first1, uint64_t len1, + uint64_t first2, uint64_t len2) +{ + uint64_t last1 = range_get_last(first1, len1); + uint64_t last2 = range_get_last(first2, len2); + + return !(last2 < first1 || last1 < first2); +} + +/* 0,1 can merge with 1,2 but don't overlap */ +static inline bool ranges_can_merge(Range *range1, Range *range2) +{ + return !(range1->end < range2->begin || range2->end < range1->begin); +} + +static inline int range_merge(Range *range1, Range *range2) +{ + if (ranges_can_merge(range1, range2)) { + if (range1->end < range2->end) { + range1->end = range2->end; + } + if (range1->begin > range2->begin) { + range1->begin = range2->begin; + } + return 0; + } + + return -1; +} + +static inline GList *g_list_insert_sorted_merged(GList *list, + gpointer data, + GCompareFunc func) +{ + GList *l, *next = NULL; + Range *r, *nextr; + + if (!list) { + list = g_list_insert_sorted(list, data, func); + return list; + } + + nextr = data; + l = list; + while (l && l != next && nextr) { + r = l->data; + if (ranges_can_merge(r, nextr)) { + range_merge(r, nextr); + l = g_list_remove_link(l, next); + next = g_list_next(l); + if (next) { + nextr = next->data; + } else { + nextr = NULL; + } + } else { + l = g_list_next(l); + } + } + + if (!l) { + list = g_list_insert_sorted(list, data, func); + } + + return list; +} + +static inline gint range_compare(gconstpointer a, gconstpointer b) +{ + Range *ra = (Range *)a, *rb = (Range *)b; + if (ra->begin == rb->begin && ra->end == rb->end) { + return 0; + } else if (range_get_last(ra->begin, ra->end) < + range_get_last(rb->begin, rb->end)) { + return -1; + } else { + return 1; + } +} + +#endif