// SPDX-FileCopyrightText: 2021 Skyline Team and Contributors
// SPDX-License-Identifier: GPL-3.0-or-later
#pragma once
#include <concepts>
#include <functional>
#include <mutex>
#include <vector>
#include "common/common_types.h"
namespace Common {
template <typename VaType, size_t AddressSpaceBits>
concept AddressSpaceValid = std::is_unsigned_v<VaType> && sizeof(VaType) * 8 >= AddressSpaceBits;
struct EmptyStruct {};
/**
* @brief FlatAddressSpaceMap provides a generic VA->PA mapping implementation using a sorted vector
*/
template <typename VaType, VaType UnmappedVa, typename PaType, PaType UnmappedPa,
bool PaContigSplit, size_t AddressSpaceBits, typename ExtraBlockInfo = EmptyStruct>
requires AddressSpaceValid<VaType, AddressSpaceBits>
class FlatAddressSpaceMap {
private:
std::function<void(VaType, VaType)>
unmapCallback{}; //!< Callback called when the mappings in an region have changed
protected:
/**
* @brief Represents a block of memory in the AS, the physical mapping is contiguous until
* another block with a different phys address is hit
*/
struct Block {
VaType virt{UnmappedVa}; //!< VA of the block
PaType phys{UnmappedPa}; //!< PA of the block, will increase 1-1 with VA until a new block
//!< is encountered
[[no_unique_address]] ExtraBlockInfo extraInfo;
Block() = default;
Block(VaType virt_, PaType phys_, ExtraBlockInfo extraInfo_)
: virt(virt_), phys(phys_), extraInfo(extraInfo_) {}
constexpr bool Valid() {
return virt != UnmappedVa;
}
constexpr bool Mapped() {
return phys != UnmappedPa;
}
constexpr bool Unmapped() {
return phys == UnmappedPa;
}
bool operator<(const VaType& pVirt) const {
return virt < pVirt;
}
};
std::mutex blockMutex;
std::vector<Block> blocks{Block{}};
/**
* @brief Maps a PA range into the given AS region
* @note blockMutex MUST be locked when calling this
*/
void MapLocked(VaType virt, PaType phys, VaType size, ExtraBlockInfo extraInfo);
/**
* @brief Unmaps the given range and merges it with other unmapped regions
* @note blockMutex MUST be locked when calling this
*/
void UnmapLocked(VaType virt, VaType size);
public:
static constexpr VaType VaMaximum{(1ULL << (AddressSpaceBits - 1)) +
((1ULL << (AddressSpaceBits - 1)) -
1)}; //!< The maximum VA that this AS can technically reach
VaType vaLimit{VaMaximum}; //!< A soft limit on the maximum VA of the AS
FlatAddressSpaceMap(VaType vaLimit, std::function<void(VaType, VaType)> unmapCallback = {});
FlatAddressSpaceMap() = default;
void Map(VaType virt, PaType phys, VaType size, ExtraBlockInfo extraInfo = {}) {
std::scoped_lock lock(blockMutex);
MapLocked(virt, phys, size, extraInfo);
}
void Unmap(VaType virt, VaType size) {
std::scoped_lock lock(blockMutex);
UnmapLocked(virt, size);
}
};
/**
* @brief FlatMemoryManager specialises FlatAddressSpaceMap to work as an allocator, with an
* initial, fast linear pass and a subsequent slower pass that iterates until it finds a free block
*/
template <typename VaType, VaType UnmappedVa, size_t AddressSpaceBits>
requires AddressSpaceValid<VaType, AddressSpaceBits>
class FlatAllocator
: public FlatAddressSpaceMap<VaType, UnmappedVa, bool, false, false, AddressSpaceBits> {
private:
using Base = FlatAddressSpaceMap<VaType, UnmappedVa, bool, false, false, AddressSpaceBits>;
VaType currentLinearAllocEnd; //!< The end address for the initial linear allocation pass, once
//!< this reaches the AS limit the slower allocation path will be
//!< used
public:
VaType vaStart; //!< The base VA of the allocator, no allocations will be below this
FlatAllocator(VaType vaStart, VaType vaLimit = Base::VaMaximum);
/**
* @brief Allocates a region in the AS of the given size and returns its address
*/
VaType Allocate(VaType size);
/**
* @brief Marks the given region in the AS as allocated
*/
void AllocateFixed(VaType virt, VaType size);
/**
* @brief Frees an AS region so it can be used again
*/
void Free(VaType virt, VaType size);
};
} // namespace Common
