jcs.org
Serenity Operating System
1/*
2 * Copyright (c) 2018-2021, Andreas Kling <kling@serenityos.org>
3 * Copyright (c) 2021, Leon Albrecht <leon2002.la@gmail.com>
4 *
5 * SPDX-License-Identifier: BSD-2-Clause
6 */
7
8#include <AK/Vector.h>
9#include <Kernel/Memory/MemoryManager.h>
10#include <Kernel/Memory/VirtualRange.h>
11
12namespace Kernel::Memory {
13
14Vector<VirtualRange, 2> VirtualRange::carve(VirtualRange const& taken) const
15{
16 VERIFY((taken.size() % PAGE_SIZE) == 0);
17
18 Vector<VirtualRange, 2> parts;
19 if (taken == *this)
20 return {};
21 if (taken.base() > base())
22 parts.append({ base(), taken.base().get() - base().get() });
23 if (taken.end() < end())
24 parts.append({ taken.end(), end().get() - taken.end().get() });
25 return parts;
26}
27
28bool VirtualRange::intersects(VirtualRange const& other) const
29{
30 auto a = *this;
31 auto b = other;
32
33 if (a.base() > b.base())
34 swap(a, b);
35
36 return a.base() < b.end() && b.base() < a.end();
37}
38
39VirtualRange VirtualRange::intersect(VirtualRange const& other) const
40{
41 if (*this == other) {
42 return *this;
43 }
44 auto new_base = max(base(), other.base());
45 auto new_end = min(end(), other.end());
46 VERIFY(new_base < new_end);
47 return VirtualRange(new_base, (new_end - new_base).get());
48}
49
50ErrorOr<VirtualRange> VirtualRange::expand_to_page_boundaries(FlatPtr address, size_t size)
51{
52 if ((address + size) < address)
53 return EINVAL;
54
55 auto base = VirtualAddress { address }.page_base();
56 auto end = TRY(page_round_up(address + size));
57 return VirtualRange { base, end - base.get() };
58}
59
60}