GPU: Implemented nvhost-as-gpu's UnmapBuffer ioctl.

It removes a mapping previously created with the MapBufferEx ioctl.

src/core/hle/service/nvdrv/devices/nvhost_as_gpu.cpp

@@ -26,6 +26,8 @@ u32 nvhost_as_gpu::ioctl(Ioctl command, const std::vector<u8>& input, std::vecto
         return BindChannel(input, output);
     case IoctlCommand::IocGetVaRegionsCommand:
         return GetVARegions(input, output);
+    case IoctlCommand::IocUnmapBufferCommand:
+        return UnmapBuffer(input, output);
     }
 
     if (static_cast<IoctlCommand>(command.cmd.Value()) == IoctlCommand::IocRemapCommand)
@@ -125,6 +127,37 @@ u32 nvhost_as_gpu::MapBufferEx(const std::vector<u8>& input, std::vector<u8>& ou
         params.offset = gpu.memory_manager->MapBufferEx(object->addr, object->size);
     }
 
+    // Create a new mapping entry for this operation.
+    ASSERT_MSG(buffer_mappings.find(params.offset) == buffer_mappings.end(),
+               "Offset is already mapped");
+
+    BufferMapping mapping{};
+    mapping.nvmap_handle = params.nvmap_handle;
+    mapping.offset = params.offset;
+    mapping.size = object->size;
+
+    buffer_mappings[params.offset] = mapping;
+
+    std::memcpy(output.data(), &params, output.size());
+    return 0;
+}
+
+u32 nvhost_as_gpu::UnmapBuffer(const std::vector<u8>& input, std::vector<u8>& output) {
+    IoctlUnmapBuffer params{};
+    std::memcpy(&params, input.data(), input.size());
+
+    NGLOG_DEBUG(Service_NVDRV, "called, offset=0x{:X}", params.offset);
+
+    auto& gpu = Core::System::GetInstance().GPU();
+
+    auto itr = buffer_mappings.find(params.offset);
+
+    ASSERT_MSG(itr != buffer_mappings.end(), "Tried to unmap invalid mapping");
+
+    params.offset = gpu.memory_manager->UnmapBuffer(params.offset, itr->second.size);
+
+    buffer_mappings.erase(itr->second.offset);
+
     std::memcpy(output.data(), &params, output.size());
     return 0;
 }

src/core/hle/service/nvdrv/devices/nvhost_as_gpu.h

@@ -5,6 +5,7 @@
 #pragma once
 
 #include <memory>
+#include <unordered_map>
 #include <utility>
 #include <vector>
 #include "common/common_types.h"
@@ -30,6 +31,7 @@ private:
         IocMapBufferExCommand = 0xC0284106,
         IocBindChannelCommand = 0x40044101,
         IocGetVaRegionsCommand = 0xC0404108,
+        IocUnmapBufferCommand = 0xC0084105,
     };
 
     struct IoctlInitalizeEx {
@@ -76,6 +78,11 @@ private:
     };
     static_assert(sizeof(IoctlMapBufferEx) == 40, "IoctlMapBufferEx is incorrect size");
 
+    struct IoctlUnmapBuffer {
+        u64_le offset;
+    };
+    static_assert(sizeof(IoctlUnmapBuffer) == 8, "IoctlUnmapBuffer is incorrect size");
+
     struct IoctlBindChannel {
         u32_le fd;
     };
@@ -98,12 +105,22 @@ private:
     static_assert(sizeof(IoctlGetVaRegions) == 16 + sizeof(IoctlVaRegion) * 2,
                   "IoctlGetVaRegions is incorrect size");
 
+    struct BufferMapping {
+        u64 offset;
+        u64 size;
+        u32 nvmap_handle;
+    };
+
+    /// Map containing the nvmap object mappings in GPU memory.
+    std::unordered_map<u64, BufferMapping> buffer_mappings;
+
     u32 channel{};
 
     u32 InitalizeEx(const std::vector<u8>& input, std::vector<u8>& output);
     u32 AllocateSpace(const std::vector<u8>& input, std::vector<u8>& output);
     u32 Remap(const std::vector<u8>& input, std::vector<u8>& output);
     u32 MapBufferEx(const std::vector<u8>& input, std::vector<u8>& output);
+    u32 UnmapBuffer(const std::vector<u8>& input, std::vector<u8>& output);
     u32 BindChannel(const std::vector<u8>& input, std::vector<u8>& output);
     u32 GetVARegions(const std::vector<u8>& input, std::vector<u8>& output);
 

src/video_core/memory_manager.cpp

@@ -58,6 +58,25 @@ GPUVAddr MemoryManager::MapBufferEx(VAddr cpu_addr, GPUVAddr gpu_addr, u64 size)
     return gpu_addr;
 }
 
+GPUVAddr MemoryManager::UnmapBuffer(GPUVAddr gpu_addr, u64 size) {
+    ASSERT((gpu_addr & PAGE_MASK) == 0);
+
+    for (u64 offset = 0; offset < size; offset += PAGE_SIZE) {
+        ASSERT(PageSlot(gpu_addr + offset) != static_cast<u64>(PageStatus::Allocated) &&
+               PageSlot(gpu_addr + offset) != static_cast<u64>(PageStatus::Unmapped));
+        PageSlot(gpu_addr + offset) = static_cast<u64>(PageStatus::Unmapped);
+    }
+
+    // Delete the region mappings that are contained within the unmapped region
+    mapped_regions.erase(std::remove_if(mapped_regions.begin(), mapped_regions.end(),
+                                        [&](const MappedRegion& region) {
+                                            return region.gpu_addr <= gpu_addr &&
+                                                   region.gpu_addr + region.size < gpu_addr + size;
+                                        }),
+                         mapped_regions.end());
+    return gpu_addr;
+}
+
 boost::optional<GPUVAddr> MemoryManager::FindFreeBlock(u64 size, u64 align) {
     GPUVAddr gpu_addr = 0;
     u64 free_space = 0;

src/video_core/memory_manager.h

@@ -25,6 +25,7 @@ public:
     GPUVAddr AllocateSpace(GPUVAddr gpu_addr, u64 size, u64 align);
     GPUVAddr MapBufferEx(VAddr cpu_addr, u64 size);
     GPUVAddr MapBufferEx(VAddr cpu_addr, GPUVAddr gpu_addr, u64 size);
+    GPUVAddr UnmapBuffer(GPUVAddr gpu_addr, u64 size);
     boost::optional<VAddr> GpuToCpuAddress(GPUVAddr gpu_addr);
     std::vector<GPUVAddr> CpuToGpuAddress(VAddr cpu_addr) const;