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// 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 {
public:
/// The maximum VA that this AS can technically reach
static constexpr VaType VaMaximum{(1ULL << (AddressSpaceBits - 1)) +
((1ULL << (AddressSpaceBits - 1)) - 1)};
explicit FlatAddressSpaceMap(VaType va_limit,
std::function<void(VaType, VaType)> unmap_callback = {});
FlatAddressSpaceMap() = default;
void Map(VaType virt, PaType phys, VaType size, ExtraBlockInfo extra_info = {}) {
std::scoped_lock lock(block_mutex);
MapLocked(virt, phys, size, extra_info);
}
void Unmap(VaType virt, VaType size) {
std::scoped_lock lock(block_mutex);
UnmapLocked(virt, size);
}
VaType GetVALimit() const {
return va_limit;
}
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 {
/// VA of the block
VaType virt{UnmappedVa};
/// PA of the block, will increase 1-1 with VA until a new block is encountered
PaType phys{UnmappedPa};
[[no_unique_address]] ExtraBlockInfo extra_info;
Block() = default;
Block(VaType virt_, PaType phys_, ExtraBlockInfo extra_info_)
: virt(virt_), phys(phys_), extra_info(extra_info_) {}
bool Valid() const {
return virt != UnmappedVa;
}
bool Mapped() const {
return phys != UnmappedPa;
}
bool Unmapped() const {
return phys == UnmappedPa;
}
bool operator<(const VaType& p_virt) const {
return virt < p_virt;
}
};
/**
* @brief Maps a PA range into the given AS region
* @note block_mutex MUST be locked when calling this
*/
void MapLocked(VaType virt, PaType phys, VaType size, ExtraBlockInfo extra_info);
/**
* @brief Unmaps the given range and merges it with other unmapped regions
* @note block_mutex MUST be locked when calling this
*/
void UnmapLocked(VaType virt, VaType size);
std::mutex block_mutex;
std::vector<Block> blocks{Block{}};
/// a soft limit on the maximum VA of the AS
VaType va_limit{VaMaximum};
private:
/// Callback called when the mappings in an region have changed
std::function<void(VaType, VaType)> unmap_callback{};
};
/**
* @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>;
public:
explicit FlatAllocator(VaType virt_start, VaType va_limit = 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);
VaType GetVAStart() const {
return virt_start;
}
private:
/// The base VA of the allocator, no allocations will be below this
VaType virt_start;
/**
* The end address for the initial linear allocation pass
* Once this reaches the AS limit the slower allocation path will be used
*/
VaType current_linear_alloc_end;
};
} // namespace Common
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