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c2792212f4
Instead of each PhysicalPage knowing whether it comes from the supervisor pages or from the user pages, we can just check in both sets when freeing a page. It's just a handful of pointer range checks, nothing expensive.
56 lines
1.7 KiB
C++
56 lines
1.7 KiB
C++
/*
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* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
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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/Bitmap.h>
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#include <AK/Optional.h>
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#include <Kernel/VM/PhysicalPage.h>
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namespace Kernel {
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class PhysicalRegion {
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public:
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static PhysicalRegion create(PhysicalAddress lower, PhysicalAddress upper)
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{
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return { lower, upper };
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}
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void expand(PhysicalAddress lower, PhysicalAddress upper);
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unsigned finalize_capacity();
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PhysicalAddress lower() const { return m_lower; }
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PhysicalAddress upper() const { return m_upper; }
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unsigned size() const { return m_pages; }
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unsigned used() const { return m_used - m_recently_returned.size(); }
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unsigned free() const { return m_pages - m_used + m_recently_returned.size(); }
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bool contains(PhysicalAddress paddr) const { return paddr >= m_lower && paddr <= m_upper; }
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PhysicalRegion take_pages_from_beginning(unsigned);
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RefPtr<PhysicalPage> take_free_page();
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NonnullRefPtrVector<PhysicalPage> take_contiguous_free_pages(size_t count, size_t physical_alignment = PAGE_SIZE);
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void return_page(PhysicalAddress);
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private:
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unsigned find_contiguous_free_pages(size_t count, size_t physical_alignment = PAGE_SIZE);
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Optional<unsigned> find_and_allocate_contiguous_range(size_t count, unsigned alignment = 1);
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Optional<unsigned> find_one_free_page();
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void free_page_at(PhysicalAddress);
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PhysicalRegion(PhysicalAddress lower, PhysicalAddress upper);
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PhysicalAddress m_lower;
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PhysicalAddress m_upper;
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unsigned m_pages { 0 };
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unsigned m_used { 0 };
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Bitmap m_bitmap;
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size_t m_free_hint { 0 };
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Vector<PhysicalAddress, 256> m_recently_returned;
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};
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}
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