kernel: memory: Improve implementation of device shared memory. (#3707)

* kernel: memory: Improve implementation of device shared memory.

* fixup! kernel: memory: Improve implementation of device shared memory.

* fixup! kernel: memory: Improve implementation of device shared memory.

src/core/hle/kernel/memory/memory_block.h

@@ -17,7 +17,7 @@ namespace Kernel::Memory {
 
 enum class MemoryState : u32 {
     None = 0,
-    Mask = 0xFFFFFFFF, // TODO(bunnei): This should probable be 0xFF
+    Mask = 0xFF,
     All = ~None,
 
     FlagCanReprotect = (1 << 8),
@@ -253,6 +253,23 @@ public:
         };
     }
 
+    void ShareToDevice(MemoryPermission /*new_perm*/) {
+        ASSERT((attribute & MemoryAttribute::DeviceShared) == MemoryAttribute::DeviceShared ||
+               device_use_count == 0);
+        attribute |= MemoryAttribute::DeviceShared;
+        const u16 new_use_count{++device_use_count};
+        ASSERT(new_use_count > 0);
+    }
+
+    void UnshareToDevice(MemoryPermission /*new_perm*/) {
+        ASSERT((attribute & MemoryAttribute::DeviceShared) == MemoryAttribute::DeviceShared);
+        const u16 prev_use_count{device_use_count--};
+        ASSERT(prev_use_count > 0);
+        if (prev_use_count == 1) {
+            attribute &= ~MemoryAttribute::DeviceShared;
+        }
+    }
+
 private:
     constexpr bool HasProperties(MemoryState s, MemoryPermission p, MemoryAttribute a) const {
         constexpr MemoryAttribute AttributeIgnoreMask{MemoryAttribute::DontCareMask |
@@ -287,9 +304,9 @@ private:
         state = new_state;
         perm = new_perm;
 
-        // TODO(bunnei): Is this right?
         attribute = static_cast<MemoryAttribute>(
-            new_attribute /*| (attribute & (MemoryAttribute::IpcLocked | MemoryAttribute::DeviceShared))*/);
+            new_attribute |
+            (attribute & (MemoryAttribute::IpcLocked | MemoryAttribute::DeviceShared)));
     }
 
     constexpr MemoryBlock Split(VAddr split_addr) {

src/core/hle/kernel/memory/memory_block_manager.cpp

@@ -143,6 +143,42 @@ void MemoryBlockManager::Update(VAddr addr, std::size_t num_pages, MemoryState s
     }
 }
 
+void MemoryBlockManager::UpdateLock(VAddr addr, std::size_t num_pages, LockFunc&& lock_func,
+                                    MemoryPermission perm) {
+    const std::size_t prev_count{memory_block_tree.size()};
+    const VAddr end_addr{addr + num_pages * PageSize};
+    iterator node{memory_block_tree.begin()};
+
+    while (node != memory_block_tree.end()) {
+        MemoryBlock* block{&(*node)};
+        iterator next_node{std::next(node)};
+        const VAddr cur_addr{block->GetAddress()};
+        const VAddr cur_end_addr{block->GetNumPages() * PageSize + cur_addr};
+
+        if (addr < cur_end_addr && cur_addr < end_addr) {
+            iterator new_node{node};
+
+            if (addr > cur_addr) {
+                memory_block_tree.insert(node, block->Split(addr));
+            }
+
+            if (end_addr < cur_end_addr) {
+                new_node = memory_block_tree.insert(node, block->Split(end_addr));
+            }
+
+            lock_func(new_node, perm);
+
+            MergeAdjacent(new_node, next_node);
+        }
+
+        if (cur_end_addr - 1 >= end_addr - 1) {
+            break;
+        }
+
+        node = next_node;
+    }
+}
+
 void MemoryBlockManager::IterateForRange(VAddr start, VAddr end, IterateFunc&& func) {
     const_iterator it{FindIterator(start)};
     MemoryInfo info{};

src/core/hle/kernel/memory/memory_block_manager.h

@@ -45,6 +45,9 @@ public:
                 MemoryPermission perm = MemoryPermission::None,
                 MemoryAttribute attribute = MemoryAttribute::None);
 
+    using LockFunc = std::function<void(iterator, MemoryPermission)>;
+    void UpdateLock(VAddr addr, std::size_t num_pages, LockFunc&& lock_func, MemoryPermission perm);
+
     using IterateFunc = std::function<void(const MemoryInfo&)>;
     void IterateForRange(VAddr start, VAddr end, IterateFunc&& func);
 

src/core/hle/kernel/memory/page_table.cpp

@@ -840,6 +840,50 @@ ResultVal<VAddr> PageTable::AllocateAndMapMemory(std::size_t needed_num_pages, s
     return MakeResult<VAddr>(addr);
 }
 
+ResultCode PageTable::LockForDeviceAddressSpace(VAddr addr, std::size_t size) {
+    std::lock_guard lock{page_table_lock};
+
+    MemoryPermission perm{};
+    if (const ResultCode result{CheckMemoryState(
+            nullptr, &perm, nullptr, addr, size, MemoryState::FlagCanChangeAttribute,
+            MemoryState::FlagCanChangeAttribute, MemoryPermission::None, MemoryPermission::None,
+            MemoryAttribute::LockedAndIpcLocked, MemoryAttribute::None,
+            MemoryAttribute::DeviceSharedAndUncached)};
+        result.IsError()) {
+        return result;
+    }
+
+    block_manager->UpdateLock(addr, size / PageSize,
+                              [perm](MemoryBlockManager::iterator block, MemoryPermission perm) {
+                                  block->ShareToDevice(perm);
+                              },
+                              perm);
+
+    return RESULT_SUCCESS;
+}
+
+ResultCode PageTable::UnlockForDeviceAddressSpace(VAddr addr, std::size_t size) {
+    std::lock_guard lock{page_table_lock};
+
+    MemoryPermission perm{};
+    if (const ResultCode result{CheckMemoryState(
+            nullptr, &perm, nullptr, addr, size, MemoryState::FlagCanChangeAttribute,
+            MemoryState::FlagCanChangeAttribute, MemoryPermission::None, MemoryPermission::None,
+            MemoryAttribute::LockedAndIpcLocked, MemoryAttribute::None,
+            MemoryAttribute::DeviceSharedAndUncached)};
+        result.IsError()) {
+        return result;
+    }
+
+    block_manager->UpdateLock(addr, size / PageSize,
+                              [perm](MemoryBlockManager::iterator block, MemoryPermission perm) {
+                                  block->UnshareToDevice(perm);
+                              },
+                              perm);
+
+    return RESULT_SUCCESS;
+}
+
 ResultCode PageTable::InitializeMemoryLayout(VAddr start, VAddr end) {
     block_manager = std::make_unique<MemoryBlockManager>(start, end);
 

src/core/hle/kernel/memory/page_table.h

@@ -53,6 +53,8 @@ public:
                                           bool is_map_only, VAddr region_start,
                                           std::size_t region_num_pages, MemoryState state,
                                           MemoryPermission perm, PAddr map_addr = 0);
+    ResultCode LockForDeviceAddressSpace(VAddr addr, std::size_t size);
+    ResultCode UnlockForDeviceAddressSpace(VAddr addr, std::size_t size);
 
     Common::PageTable& PageTableImpl() {
         return page_table_impl;

src/video_core/memory_manager.cpp

@@ -51,11 +51,8 @@ GPUVAddr MemoryManager::MapBufferEx(VAddr cpu_addr, u64 size) {
     const GPUVAddr gpu_addr{FindFreeRegion(address_space_base, aligned_size)};
 
     MapBackingMemory(gpu_addr, system.Memory().GetPointer(cpu_addr), aligned_size, cpu_addr);
-    ASSERT(system.CurrentProcess()
-               ->PageTable()
-               .SetMemoryAttribute(cpu_addr, size, Kernel::Memory::MemoryAttribute::DeviceShared,
-                                   Kernel::Memory::MemoryAttribute::DeviceShared)
-               .IsSuccess());
+    ASSERT(
+        system.CurrentProcess()->PageTable().LockForDeviceAddressSpace(cpu_addr, size).IsSuccess());
 
     return gpu_addr;
 }
@@ -66,11 +63,8 @@ GPUVAddr MemoryManager::MapBufferEx(VAddr cpu_addr, GPUVAddr gpu_addr, u64 size)
     const u64 aligned_size{Common::AlignUp(size, page_size)};
 
     MapBackingMemory(gpu_addr, system.Memory().GetPointer(cpu_addr), aligned_size, cpu_addr);
-    ASSERT(system.CurrentProcess()
-               ->PageTable()
-               .SetMemoryAttribute(cpu_addr, size, Kernel::Memory::MemoryAttribute::DeviceShared,
-                                   Kernel::Memory::MemoryAttribute::DeviceShared)
-               .IsSuccess());
+    ASSERT(
+        system.CurrentProcess()->PageTable().LockForDeviceAddressSpace(cpu_addr, size).IsSuccess());
     return gpu_addr;
 }
 
@@ -87,9 +81,7 @@ GPUVAddr MemoryManager::UnmapBuffer(GPUVAddr gpu_addr, u64 size) {
     UnmapRange(gpu_addr, aligned_size);
     ASSERT(system.CurrentProcess()
                ->PageTable()
-               .SetMemoryAttribute(cpu_addr.value(), size,
-                                   Kernel::Memory::MemoryAttribute::DeviceShared,
-                                   Kernel::Memory::MemoryAttribute::None)
+               .UnlockForDeviceAddressSpace(cpu_addr.value(), size)
                .IsSuccess());
 
     return gpu_addr;