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	 c1006a3689
			
		
	
	
		c1006a3689
		
	
	
	
	
		
			
			By making sure the PhysicalPage instance is fully destructed the allocators will have a chance to reclaim the PhysicalPageEntry for free-list purposes. Just pass them the physical address of the page that was freed, which is enough to lookup the PhysicalPageEntry later.
		
			
				
	
	
		
			57 lines
		
	
	
	
		
			1.9 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			57 lines
		
	
	
	
		
			1.9 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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| 
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| #pragma once
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| 
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| #include <AK/Bitmap.h>
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| #include <AK/NonnullRefPtrVector.h>
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| #include <AK/Optional.h>
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| #include <AK/RefCounted.h>
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| #include <Kernel/VM/PhysicalPage.h>
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| 
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| namespace Kernel {
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| 
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| class PhysicalRegion : public RefCounted<PhysicalRegion> {
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|     AK_MAKE_ETERNAL
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| 
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| public:
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|     static NonnullRefPtr<PhysicalRegion> create(PhysicalAddress lower, PhysicalAddress upper);
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|     ~PhysicalRegion() = default;
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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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| 
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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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| 
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|     NonnullRefPtr<PhysicalRegion> take_pages_from_beginning(unsigned);
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| 
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|     RefPtr<PhysicalPage> take_free_page(bool supervisor);
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|     NonnullRefPtrVector<PhysicalPage> take_contiguous_free_pages(size_t count, bool supervisor, size_t physical_alignment = PAGE_SIZE);
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|     void return_page(PhysicalAddress);
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| 
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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 addr);
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| 
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|     PhysicalRegion(PhysicalAddress lower, PhysicalAddress upper);
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| 
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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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| }
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