yuzu-early/src/common/page_table.cpp
2022-02-19 10:01:45 +01:00

75 lines
2.1 KiB
C++
Executable File

// Copyright 2019 yuzu Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#include "common/page_table.h"
namespace Common {
PageTable::PageTable() = default;
PageTable::~PageTable() noexcept = default;
bool PageTable::BeginTraversal(TraversalEntry* out_entry, TraversalContext* out_context,
u64 address) const {
// Setup invalid defaults.
out_entry->phys_addr = 0;
out_entry->block_size = page_size;
out_context->next_page = 0;
// Validate that we can read the actual entry.
const auto page = address / page_size;
if (page >= backing_addr.size()) {
return false;
}
// Validate that the entry is mapped.
const auto phys_addr = backing_addr[page];
if (phys_addr == 0) {
return false;
}
// Populate the results.
out_entry->phys_addr = phys_addr + address;
out_context->next_page = page + 1;
out_context->next_offset = address + page_size;
return true;
}
bool PageTable::ContinueTraversal(TraversalEntry* out_entry, TraversalContext* context) const {
// Setup invalid defaults.
out_entry->phys_addr = 0;
out_entry->block_size = page_size;
// Validate that we can read the actual entry.
const auto page = context->next_page;
if (page >= backing_addr.size()) {
return false;
}
// Validate that the entry is mapped.
const auto phys_addr = backing_addr[page];
if (phys_addr == 0) {
return false;
}
// Populate the results.
out_entry->phys_addr = phys_addr + context->next_offset;
context->next_page = page + 1;
context->next_offset += page_size;
return true;
}
void PageTable::Resize(std::size_t address_space_width_in_bits, std::size_t page_size_in_bits) {
const std::size_t num_page_table_entries{1ULL
<< (address_space_width_in_bits - page_size_in_bits)};
pointers.resize(num_page_table_entries);
backing_addr.resize(num_page_table_entries);
current_address_space_width_in_bits = address_space_width_in_bits;
page_size = 1ULL << page_size_in_bits;
}
} // namespace Common