64 lines
1.8 KiB
C
64 lines
1.8 KiB
C
#ifndef QEMU_RANGE_H
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#define QEMU_RANGE_H
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#include <inttypes.h>
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#include <qemu/typedefs.h>
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/*
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* Operations on 64 bit address ranges.
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* Notes:
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* - ranges must not wrap around 0, but can include the last byte ~0x0LL.
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* - this can not represent a full 0 to ~0x0LL range.
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*/
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/* A structure representing a range of addresses. */
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struct Range {
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uint64_t begin; /* First byte of the range, or 0 if empty. */
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uint64_t end; /* 1 + the last byte. 0 if range empty or ends at ~0x0LL. */
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};
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static inline void range_extend(Range *range, Range *extend_by)
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{
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if (!extend_by->begin && !extend_by->end) {
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return;
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}
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if (!range->begin && !range->end) {
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*range = *extend_by;
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return;
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}
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if (range->begin > extend_by->begin) {
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range->begin = extend_by->begin;
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}
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/* Compare last byte in case region ends at ~0x0LL */
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if (range->end - 1 < extend_by->end - 1) {
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range->end = extend_by->end;
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}
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}
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/* Get last byte of a range from offset + length.
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* Undefined for ranges that wrap around 0. */
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static inline uint64_t range_get_last(uint64_t offset, uint64_t len)
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{
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return offset + len - 1;
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}
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/* Check whether a given range covers a given byte. */
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static inline int range_covers_byte(uint64_t offset, uint64_t len,
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uint64_t byte)
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{
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return offset <= byte && byte <= range_get_last(offset, len);
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}
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/* Check whether 2 given ranges overlap.
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* Undefined if ranges that wrap around 0. */
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static inline int ranges_overlap(uint64_t first1, uint64_t len1,
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uint64_t first2, uint64_t len2)
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{
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uint64_t last1 = range_get_last(first1, len1);
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uint64_t last2 = range_get_last(first2, len2);
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return !(last2 < first1 || last1 < first2);
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}
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#endif
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