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Sometimes we need to pass ranges around, add a handy structure for this purpose. Note: memory.c defines its own concept of AddrRange structure for working with 128 addresses. It's necessary there for doing range math. This is not needed for most users: struct Range is much simpler, and is only used for passing the range around. Cc: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
46 lines
1.3 KiB
C
46 lines
1.3 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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/*
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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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typedef struct Range Range;
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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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