/*
* QEMU 64-bit address ranges
*
* Copyright (c) 2015-2016 Red Hat, Inc.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#ifndef QEMU_RANGE_H
#define QEMU_RANGE_H
/*
* Operations on 64 bit address ranges.
* Notes:
* - Ranges must not wrap around 0, but can include UINT64_MAX.
*/
struct Range {
/*
* Do not access members directly, use the functions!
* A non-empty range has @lob <= @upb.
* An empty range has @lob == @upb + 1.
*/
uint64_t lob; /* inclusive lower bound */
uint64_t upb; /* inclusive upper bound */
};
static inline void range_invariant(const Range *range)
{
assert(range->lob <= range->upb || range->lob == range->upb + 1);
}
/* Compound literal encoding the empty range */
#define range_empty ((Range){ .lob = 1, .upb = 0 })
/* Is @range empty? */
static inline bool range_is_empty(const Range *range)
{
range_invariant(range);
return range->lob > range->upb;
}
/* Does @range contain @val? */
static inline bool range_contains(const Range *range, uint64_t val)
{
return val >= range->lob && val <= range->upb;
}
/* Initialize @range to the empty range */
static inline void range_make_empty(Range *range)
{
*range = range_empty;
assert(range_is_empty(range));
}
/*
* Initialize @range to span the interval [@lob,@upb].
* Both bounds are inclusive.
* The interval must not be empty, i.e. @lob must be less than or
* equal @upb.
*/
static inline void range_set_bounds(Range *range, uint64_t lob, uint64_t upb)
{
range->lob = lob;
range->upb = upb;
assert(!range_is_empty(range));
}
/*
* Initialize @range to span the interval [@lob,@upb_plus1).
* The lower bound is inclusive, the upper bound is exclusive.
* Zero @upb_plus1 is special: if @lob is also zero, set @range to the
* empty range. Else, set @range to [@lob,UINT64_MAX].
*/
static inline void range_set_bounds1(Range *range,
uint64_t lob, uint64_t upb_plus1)
{
if (!lob && !upb_plus1) {
*range = range_empty;
} else {
range->lob = lob;
range->upb = upb_plus1 - 1;
}
range_invariant(range);
}
/* Return @range's lower bound. @range must not be empty. */
static inline uint64_t range_lob(Range *range)
{
assert(!range_is_empty(range));
return range->lob;
}
/* Return @range's upper bound. @range must not be empty. */
static inline uint64_t range_upb(Range *range)
{
assert(!range_is_empty(range));
return range->upb;
}
/*
* Initialize @range to span the interval [@lob,@lob + @size - 1].
* @size may be 0. If the range would overflow, returns -ERANGE, otherwise
* 0.
*/
static inline int QEMU_WARN_UNUSED_RESULT range_init(Range *range, uint64_t lob,
uint64_t size)
{
if (lob + size < lob) {
return -ERANGE;
}
range->lob = lob;
range->upb = lob + size - 1;
range_invariant(range);
return 0;
}
/*
* Initialize @range to span the interval [@lob,@lob + @size - 1].
* @size may be 0. Range must not overflow.
*/
static inline void range_init_nofail(Range *range, uint64_t lob, uint64_t size)
{
range->lob = lob;
range->upb = lob + size - 1;
range_invariant(range);
}
/*
* Get the size of @range.
*/
static inline uint64_t range_size(const Range *range)
{
return range->upb - range->lob + 1;
}
/*
* Check if @range1 overlaps with @range2. If one of the ranges is empty,
* the result is always "false".
*/
static inline bool range_overlaps_range(const Range *range1,
const Range *range2)
{
if (range_is_empty(range1) || range_is_empty(range2)) {
return false;
}
return !(range2->upb < range1->lob || range1->upb < range2->lob);
}
/*
* Check if @range1 contains @range2. If one of the ranges is empty,
* the result is always "false".
*/
static inline bool range_contains_range(const Range *range1,
const Range *range2)
{
if (range_is_empty(range1) || range_is_empty(range2)) {
return false;
}
return range1->lob <= range2->lob && range1->upb >= range2->upb;
}
/*
* Extend @range to the smallest interval that includes @extend_by, too.
*/
static inline void range_extend(Range *range, Range *extend_by)
{
if (range_is_empty(extend_by)) {
return;
}
if (range_is_empty(range)) {
*range = *extend_by;
return;
}
if (range->lob > extend_by->lob) {
range->lob = extend_by->lob;
}
if (range->upb < extend_by->upb) {
range->upb = extend_by->upb;
}
range_invariant(range);
}
/* 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);
}
GList *range_list_insert(GList *list, Range *data);
#endif
