yuzu/src/common/page_table.h
Fernando Sahmkow 27cbb75e7c PageTable: move backing addresses to a children class as the CPU page table does not need them.
This PR aims to reduce the memory usage in the CPU page table by moving
GPU specific parameters into a child class. This saves 1Gb of Memory for
most games.
2020-03-14 09:43:57 -04:00

96 lines
2.7 KiB
C++

// Copyright 2019 yuzu Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#pragma once
#include <vector>
#include <boost/icl/interval_map.hpp>
#include "common/common_types.h"
#include "common/memory_hook.h"
namespace Common {
enum class PageType : u8 {
/// Page is unmapped and should cause an access error.
Unmapped,
/// Page is mapped to regular memory. This is the only type you can get pointers to.
Memory,
/// Page is mapped to regular memory, but also needs to check for rasterizer cache flushing and
/// invalidation
RasterizerCachedMemory,
/// Page is mapped to a I/O region. Writing and reading to this page is handled by functions.
Special,
/// Page is allocated for use.
Allocated,
};
struct SpecialRegion {
enum class Type {
DebugHook,
IODevice,
} type;
MemoryHookPointer handler;
bool operator<(const SpecialRegion& other) const {
return std::tie(type, handler) < std::tie(other.type, other.handler);
}
bool operator==(const SpecialRegion& other) const {
return std::tie(type, handler) == std::tie(other.type, other.handler);
}
};
/**
* A (reasonably) fast way of allowing switchable and remappable process address spaces. It loosely
* mimics the way a real CPU page table works.
*/
struct PageTable {
explicit PageTable(std::size_t page_size_in_bits);
~PageTable();
/**
* Resizes the page table to be able to accomodate enough pages within
* a given address space.
*
* @param address_space_width_in_bits The address size width in bits.
*/
void Resize(std::size_t address_space_width_in_bits);
/**
* Vector of memory pointers backing each page. An entry can only be non-null if the
* corresponding entry in the `attributes` vector is of type `Memory`.
*/
std::vector<u8*> pointers;
/**
* Contains MMIO handlers that back memory regions whose entries in the `attribute` vector is
* of type `Special`.
*/
boost::icl::interval_map<u64, std::set<SpecialRegion>> special_regions;
/**
* Vector of fine grained page attributes. If it is set to any value other than `Memory`, then
* the corresponding entry in `pointers` MUST be set to null.
*/
std::vector<PageType> attributes;
const std::size_t page_size_in_bits{};
};
/**
* A more advanced Page Table with the ability to save a backing address when using it
* depends on another MMU.
*/
struct BackingPageTable : PageTable {
explicit BackingPageTable(std::size_t page_size_in_bits);
~BackingPageTable();
void Resize(std::size_t address_space_width_in_bits);
std::vector<u64> backing_addr;
};
} // namespace Common