ladybird/Kernel/PhysicalAddress.h
Tom 87dc4c3d2c Kernel: Move PhysicalPage classes out of the heap into an array
By moving the PhysicalPage classes out of the kernel heap into a static
array, one for each physical page, we can avoid the added overhead and
easily find them by indexing into an array.

This also wraps the PhysicalPage into a PhysicalPageEntry, which allows
us to re-use each slot with information where to find the next free
page.
2021-07-08 11:43:34 +02:00

66 lines
2.5 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/Format.h>
#include <AK/Types.h>
typedef u64 PhysicalPtr;
typedef u64 PhysicalSize;
class PhysicalAddress {
public:
ALWAYS_INLINE static PhysicalPtr physical_page_base(PhysicalPtr page_address) { return page_address & ~(PhysicalPtr)0xfff; }
ALWAYS_INLINE static size_t physical_page_index(PhysicalPtr page_address)
{
auto page_index = page_address >> 12;
if constexpr (sizeof(size_t) < sizeof(PhysicalPtr))
VERIFY(!(page_index & ~(PhysicalPtr)((size_t)-1)));
return (size_t)(page_index);
}
PhysicalAddress() = default;
explicit PhysicalAddress(PhysicalPtr address)
: m_address(address)
{
}
[[nodiscard]] PhysicalAddress offset(PhysicalPtr o) const { return PhysicalAddress(m_address + o); }
[[nodiscard]] PhysicalPtr get() const { return m_address; }
void set(PhysicalPtr address) { m_address = address; }
void mask(PhysicalPtr m) { m_address &= m; }
[[nodiscard]] bool is_null() const { return m_address == 0; }
[[nodiscard]] u8* as_ptr() { return reinterpret_cast<u8*>(m_address); }
[[nodiscard]] const u8* as_ptr() const { return reinterpret_cast<const u8*>(m_address); }
[[nodiscard]] PhysicalAddress page_base() const { return PhysicalAddress(physical_page_base(m_address)); }
[[nodiscard]] PhysicalPtr offset_in_page() const { return PhysicalAddress(m_address & 0xfff).get(); }
bool operator==(const PhysicalAddress& other) const { return m_address == other.m_address; }
bool operator!=(const PhysicalAddress& other) const { return m_address != other.m_address; }
bool operator>(const PhysicalAddress& other) const { return m_address > other.m_address; }
bool operator>=(const PhysicalAddress& other) const { return m_address >= other.m_address; }
bool operator<(const PhysicalAddress& other) const { return m_address < other.m_address; }
bool operator<=(const PhysicalAddress& other) const { return m_address <= other.m_address; }
private:
PhysicalPtr m_address { 0 };
};
template<>
struct AK::Formatter<PhysicalAddress> : AK::Formatter<FormatString> {
void format(FormatBuilder& builder, PhysicalAddress value)
{
if constexpr (sizeof(PhysicalPtr) == sizeof(u64))
return AK::Formatter<FormatString>::format(builder, "P{:016x}", value.get());
else
return AK::Formatter<FormatString>::format(builder, "P{}", value.as_ptr());
}
};