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			75 lines
		
	
	
	
		
			3 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			75 lines
		
	
	
	
		
			3 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| /*
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|  * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
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|  * All rights reserved.
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|  *
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|  * Redistribution and use in source and binary forms, with or without
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|  * modification, are permitted provided that the following conditions are met:
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|  *
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|  * 1. Redistributions of source code must retain the above copyright notice, this
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|  *    list of conditions and the following disclaimer.
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|  *
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|  * 2. Redistributions in binary form must reproduce the above copyright notice,
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|  *    this list of conditions and the following disclaimer in the documentation
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|  *    and/or other materials provided with the distribution.
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|  *
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|  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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|  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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|  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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|  * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
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|  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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|  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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|  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
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|  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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|  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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|  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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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() { }
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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(const PhysicalPage& page) const { return page.paddr() >= m_lower && page.paddr() <= m_upper; }
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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);
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|     void return_page(const PhysicalPage& page);
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| 
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| private:
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|     unsigned find_contiguous_free_pages(size_t count);
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|     Optional<unsigned> find_and_allocate_contiguous_range(size_t count);
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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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