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02a95a196f
This patch stops using VirtualRangeAllocator in AddressSpace and instead looks for holes in the region tree when allocating VM space. There are many benefits: - VirtualRangeAllocator is non-intrusive and would call kmalloc/kfree when used. This new solution is allocation-free. This was a source of unpleasant MM/kmalloc deadlocks. - We consolidate authority on what the address space looks like in a single place. Previously, we had both the range allocator *and* the region tree both being used to determine if an address was valid. Now there is only the region tree. - Deallocation of VM when splitting regions is no longer complicated, as we don't need to keep two separate trees in sync.
71 lines
1.9 KiB
C++
71 lines
1.9 KiB
C++
/*
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* Copyright (c) 2018-2021, Andreas Kling <kling@serenityos.org>
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* Copyright (c) 2021, Leon Albrecht <leon2002.la@gmail.com>
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*
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* SPDX-License-Identifier: BSD-2-Clause
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*/
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#pragma once
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#include <AK/Error.h>
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#include <Kernel/VirtualAddress.h>
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namespace Kernel::Memory {
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class VirtualRange {
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friend class VirtualRangeAllocator;
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public:
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VirtualRange() = delete;
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VirtualRange(VirtualAddress base, size_t size)
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: m_base(base)
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, m_size(size)
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{
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}
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VirtualAddress base() const { return m_base; }
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size_t size() const { return m_size; }
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bool is_valid() const { return !m_base.is_null(); }
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bool contains(VirtualAddress vaddr) const { return vaddr >= base() && vaddr < end(); }
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VirtualAddress end() const { return m_base.offset(m_size); }
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bool operator==(VirtualRange const& other) const
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{
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return m_base == other.m_base && m_size == other.m_size;
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}
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bool contains(VirtualAddress base, size_t size) const
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{
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if (base.offset(size) < base)
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return false;
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return base >= m_base && base.offset(size) <= end();
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}
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bool contains(VirtualRange const& other) const
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{
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return contains(other.base(), other.size());
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}
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Vector<VirtualRange, 2> carve(VirtualRange const&) const;
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VirtualRange intersect(VirtualRange const&) const;
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bool intersects(VirtualRange const&) const;
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static ErrorOr<VirtualRange> expand_to_page_boundaries(FlatPtr address, size_t size);
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private:
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VirtualAddress m_base;
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size_t m_size { 0 };
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};
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}
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template<>
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struct AK::Formatter<Kernel::Memory::VirtualRange> : Formatter<FormatString> {
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ErrorOr<void> format(FormatBuilder& builder, Kernel::Memory::VirtualRange value)
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{
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return Formatter<FormatString>::format(builder, "{} - {} (size {:p})", value.base().as_ptr(), value.base().offset(value.size() - 1).as_ptr(), value.size());
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}
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};
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