| 115 | } |
| 116 | |
| 117 | auto VirtualMemory::UnmapPage(void* page_dir, void* virtual_addr) |
| 118 | -> Expected<void> { |
| 119 | assert(page_dir != nullptr && "UnmapPage: page_dir is null"); |
| 120 | |
| 121 | auto pte_result = FindPageTableEntry(page_dir, virtual_addr, false); |
| 122 | if (!pte_result.has_value()) { |
| 123 | return std::unexpected(Error(ErrorCode::kVmPageNotMapped)); |
| 124 | } |
| 125 | |
| 126 | auto pte = pte_result.value(); |
| 127 | |
| 128 | if (!cpu_io::virtual_memory::IsPageTableEntryValid(*pte)) { |
| 129 | return std::unexpected(Error(ErrorCode::kVmPageNotMapped)); |
| 130 | } |
| 131 | |
| 132 | // 清除页表项 |
| 133 | *pte = 0; |
| 134 | |
| 135 | // 刷新 TLB |
| 136 | cpu_io::virtual_memory::FlushTLBAll(); |
| 137 | |
| 138 | return {}; |
| 139 | } |
| 140 | |
| 141 | auto VirtualMemory::GetMapping(void* page_dir, void* virtual_addr) |
| 142 | -> Expected<void*> { |