1 files changed, 137 insertions, 72 deletions

diff --git a/src/video_core/texture_cache/texture_cache.h b/src/video_core/texture_cache/texture_cache.h
index 1dbe01bc0..2731aead0 100644
--- a/src/video_core/texture_cache/texture_cache.h
+++ b/src/video_core/texture_cache/texture_cache.h
@@ -7,6 +7,7 @@
 
 #include "common/alignment.h"
 #include "common/settings.h"
+#include "video_core/control/channel_state.h"
 #include "video_core/dirty_flags.h"
 #include "video_core/engines/kepler_compute.h"
 #include "video_core/texture_cache/image_view_base.h"
@@ -29,12 +30,8 @@ using VideoCore::Surface::SurfaceType;
 using namespace Common::Literals;
 
 template <class P>
-TextureCache<P>::TextureCache(Runtime& runtime_, VideoCore::RasterizerInterface& rasterizer_,
-                              Tegra::Engines::Maxwell3D& maxwell3d_,
-                              Tegra::Engines::KeplerCompute& kepler_compute_,
-                              Tegra::MemoryManager& gpu_memory_)
-    : runtime{runtime_}, rasterizer{rasterizer_}, maxwell3d{maxwell3d_},
-      kepler_compute{kepler_compute_}, gpu_memory{gpu_memory_} {
+TextureCache<P>::TextureCache(Runtime& runtime_, VideoCore::RasterizerInterface& rasterizer_)
+    : runtime{runtime_}, rasterizer{rasterizer_} {
     // Configure null sampler
     TSCEntry sampler_descriptor{};
     sampler_descriptor.min_filter.Assign(Tegra::Texture::TextureFilter::Linear);
@@ -42,6 +39,13 @@ TextureCache<P>::TextureCache(Runtime& runtime_, VideoCore::RasterizerInterface&
     sampler_descriptor.mipmap_filter.Assign(Tegra::Texture::TextureMipmapFilter::Linear);
     sampler_descriptor.cubemap_anisotropy.Assign(1);
 
+    // Setup channels
+    current_channel_id = UNSET_CHANNEL;
+    state = nullptr;
+    maxwell3d = nullptr;
+    kepler_compute = nullptr;
+    gpu_memory = nullptr;
+
     // Make sure the first index is reserved for the null resources
     // This way the null resource becomes a compile time constant
     void(slot_images.insert(NullImageParams{}));
@@ -93,7 +97,7 @@ void TextureCache<P>::RunGarbageCollector() {
             const auto copies = FullDownloadCopies(image.info);
             image.DownloadMemory(map, copies);
             runtime.Finish();
-            SwizzleImage(gpu_memory, image.gpu_addr, image.info, copies, map.mapped_span);
+            SwizzleImage(*gpu_memory, image.gpu_addr, image.info, copies, map.mapped_span);
         }
         if (True(image.flags & ImageFlagBits::Tracked)) {
             UntrackImage(image, image_id);
@@ -152,22 +156,23 @@ void TextureCache<P>::MarkModification(ImageId id) noexcept {
 template <class P>
 template <bool has_blacklists>
 void TextureCache<P>::FillGraphicsImageViews(std::span<ImageViewInOut> views) {
-    FillImageViews<has_blacklists>(graphics_image_table, graphics_image_view_ids, views);
+    FillImageViews<has_blacklists>(state->graphics_image_table, state->graphics_image_view_ids,
+                                   views);
 }
 
 template <class P>
 void TextureCache<P>::FillComputeImageViews(std::span<ImageViewInOut> views) {
-    FillImageViews<true>(compute_image_table, compute_image_view_ids, views);
+    FillImageViews<true>(state->compute_image_table, state->compute_image_view_ids, views);
 }
 
 template <class P>
 typename P::Sampler* TextureCache<P>::GetGraphicsSampler(u32 index) {
-    if (index > graphics_sampler_table.Limit()) {
+    if (index > state->graphics_sampler_table.Limit()) {
         LOG_DEBUG(HW_GPU, "Invalid sampler index={}", index);
         return &slot_samplers[NULL_SAMPLER_ID];
     }
-    const auto [descriptor, is_new] = graphics_sampler_table.Read(index);
-    SamplerId& id = graphics_sampler_ids[index];
+    const auto [descriptor, is_new] = state->graphics_sampler_table.Read(index);
+    SamplerId& id = state->graphics_sampler_ids[index];
     if (is_new) {
         id = FindSampler(descriptor);
     }
@@ -176,12 +181,12 @@ typename P::Sampler* TextureCache<P>::GetGraphicsSampler(u32 index) {
 
 template <class P>
 typename P::Sampler* TextureCache<P>::GetComputeSampler(u32 index) {
-    if (index > compute_sampler_table.Limit()) {
+    if (index > state->compute_sampler_table.Limit()) {
         LOG_DEBUG(HW_GPU, "Invalid sampler index={}", index);
         return &slot_samplers[NULL_SAMPLER_ID];
     }
-    const auto [descriptor, is_new] = compute_sampler_table.Read(index);
-    SamplerId& id = compute_sampler_ids[index];
+    const auto [descriptor, is_new] = state->compute_sampler_table.Read(index);
+    SamplerId& id = state->compute_sampler_ids[index];
     if (is_new) {
         id = FindSampler(descriptor);
     }
@@ -191,34 +196,34 @@ typename P::Sampler* TextureCache<P>::GetComputeSampler(u32 index) {
 template <class P>
 void TextureCache<P>::SynchronizeGraphicsDescriptors() {
     using SamplerIndex = Tegra::Engines::Maxwell3D::Regs::SamplerIndex;
-    const bool linked_tsc = maxwell3d.regs.sampler_index == SamplerIndex::ViaHeaderIndex;
-    const u32 tic_limit = maxwell3d.regs.tic.limit;
-    const u32 tsc_limit = linked_tsc ? tic_limit : maxwell3d.regs.tsc.limit;
-    if (graphics_sampler_table.Synchornize(maxwell3d.regs.tsc.Address(), tsc_limit)) {
-        graphics_sampler_ids.resize(tsc_limit + 1, CORRUPT_ID);
+    const bool linked_tsc = maxwell3d->regs.sampler_index == SamplerIndex::ViaHeaderIndex;
+    const u32 tic_limit = maxwell3d->regs.tic.limit;
+    const u32 tsc_limit = linked_tsc ? tic_limit : maxwell3d->regs.tsc.limit;
+    if (state->graphics_sampler_table.Synchornize(maxwell3d->regs.tsc.Address(), tsc_limit)) {
+        state->graphics_sampler_ids.resize(tsc_limit + 1, CORRUPT_ID);
     }
-    if (graphics_image_table.Synchornize(maxwell3d.regs.tic.Address(), tic_limit)) {
-        graphics_image_view_ids.resize(tic_limit + 1, CORRUPT_ID);
+    if (state->graphics_image_table.Synchornize(maxwell3d->regs.tic.Address(), tic_limit)) {
+        state->graphics_image_view_ids.resize(tic_limit + 1, CORRUPT_ID);
     }
 }
 
 template <class P>
 void TextureCache<P>::SynchronizeComputeDescriptors() {
-    const bool linked_tsc = kepler_compute.launch_description.linked_tsc;
-    const u32 tic_limit = kepler_compute.regs.tic.limit;
-    const u32 tsc_limit = linked_tsc ? tic_limit : kepler_compute.regs.tsc.limit;
-    const GPUVAddr tsc_gpu_addr = kepler_compute.regs.tsc.Address();
-    if (compute_sampler_table.Synchornize(tsc_gpu_addr, tsc_limit)) {
-        compute_sampler_ids.resize(tsc_limit + 1, CORRUPT_ID);
+    const bool linked_tsc = kepler_compute->launch_description.linked_tsc;
+    const u32 tic_limit = kepler_compute->regs.tic.limit;
+    const u32 tsc_limit = linked_tsc ? tic_limit : kepler_compute->regs.tsc.limit;
+    const GPUVAddr tsc_gpu_addr = kepler_compute->regs.tsc.Address();
+    if (state->compute_sampler_table.Synchornize(tsc_gpu_addr, tsc_limit)) {
+        state->compute_sampler_ids.resize(tsc_limit + 1, CORRUPT_ID);
     }
-    if (compute_image_table.Synchornize(kepler_compute.regs.tic.Address(), tic_limit)) {
-        compute_image_view_ids.resize(tic_limit + 1, CORRUPT_ID);
+    if (state->compute_image_table.Synchornize(kepler_compute->regs.tic.Address(), tic_limit)) {
+        state->compute_image_view_ids.resize(tic_limit + 1, CORRUPT_ID);
     }
 }
 
 template <class P>
 bool TextureCache<P>::RescaleRenderTargets(bool is_clear) {
-    auto& flags = maxwell3d.dirty.flags;
+    auto& flags = maxwell3d->dirty.flags;
     u32 scale_rating = 0;
     bool rescaled = false;
     std::array<ImageId, NUM_RT> tmp_color_images{};
@@ -315,7 +320,7 @@ bool TextureCache<P>::RescaleRenderTargets(bool is_clear) {
 template <class P>
 void TextureCache<P>::UpdateRenderTargets(bool is_clear) {
     using namespace VideoCommon::Dirty;
-    auto& flags = maxwell3d.dirty.flags;
+    auto& flags = maxwell3d->dirty.flags;
     if (!flags[Dirty::RenderTargets]) {
         for (size_t index = 0; index < NUM_RT; ++index) {
             ImageViewId& color_buffer_id = render_targets.color_buffer_ids[index];
@@ -342,7 +347,7 @@ void TextureCache<P>::UpdateRenderTargets(bool is_clear) {
     PrepareImageView(depth_buffer_id, true, is_clear && IsFullClear(depth_buffer_id));
 
     for (size_t index = 0; index < NUM_RT; ++index) {
-        render_targets.draw_buffers[index] = static_cast<u8>(maxwell3d.regs.rt_control.Map(index));
+        render_targets.draw_buffers[index] = static_cast<u8>(maxwell3d->regs.rt_control.Map(index));
     }
     u32 up_scale = 1;
     u32 down_shift = 0;
@@ -351,8 +356,8 @@ void TextureCache<P>::UpdateRenderTargets(bool is_clear) {
         down_shift = Settings::values.resolution_info.down_shift;
     }
     render_targets.size = Extent2D{
-        (maxwell3d.regs.render_area.width * up_scale) >> down_shift,
-        (maxwell3d.regs.render_area.height * up_scale) >> down_shift,
+        (maxwell3d->regs.render_area.width * up_scale) >> down_shift,
+        (maxwell3d->regs.render_area.height * up_scale) >> down_shift,
     };
 
     flags[Dirty::DepthBiasGlobal] = true;
@@ -458,7 +463,7 @@ void TextureCache<P>::DownloadMemory(VAddr cpu_addr, size_t size) {
         const auto copies = FullDownloadCopies(image.info);
         image.DownloadMemory(map, copies);
         runtime.Finish();
-        SwizzleImage(gpu_memory, image.gpu_addr, image.info, copies, map.mapped_span);
+        SwizzleImage(*gpu_memory, image.gpu_addr, image.info, copies, map.mapped_span);
     }
 }
 
@@ -655,7 +660,7 @@ void TextureCache<P>::PopAsyncFlushes() {
     for (const ImageId image_id : download_ids) {
         const ImageBase& image = slot_images[image_id];
         const auto copies = FullDownloadCopies(image.info);
-        SwizzleImage(gpu_memory, image.gpu_addr, image.info, copies, download_span);
+        SwizzleImage(*gpu_memory, image.gpu_addr, image.info, copies, download_span);
         download_map.offset += image.unswizzled_size_bytes;
         download_span = download_span.subspan(image.unswizzled_size_bytes);
     }
@@ -714,26 +719,26 @@ void TextureCache<P>::UploadImageContents(Image& image, StagingBuffer& staging)
     const GPUVAddr gpu_addr = image.gpu_addr;
 
     if (True(image.flags & ImageFlagBits::AcceleratedUpload)) {
-        gpu_memory.ReadBlockUnsafe(gpu_addr, mapped_span.data(), mapped_span.size_bytes());
+        gpu_memory->ReadBlockUnsafe(gpu_addr, mapped_span.data(), mapped_span.size_bytes());
         const auto uploads = FullUploadSwizzles(image.info);
         runtime.AccelerateImageUpload(image, staging, uploads);
     } else if (True(image.flags & ImageFlagBits::Converted)) {
         std::vector<u8> unswizzled_data(image.unswizzled_size_bytes);
-        auto copies = UnswizzleImage(gpu_memory, gpu_addr, image.info, unswizzled_data);
+        auto copies = UnswizzleImage(*gpu_memory, gpu_addr, image.info, unswizzled_data);
         ConvertImage(unswizzled_data, image.info, mapped_span, copies);
         image.UploadMemory(staging, copies);
     } else {
-        const auto copies = UnswizzleImage(gpu_memory, gpu_addr, image.info, mapped_span);
+        const auto copies = UnswizzleImage(*gpu_memory, gpu_addr, image.info, mapped_span);
         image.UploadMemory(staging, copies);
     }
 }
 
 template <class P>
 ImageViewId TextureCache<P>::FindImageView(const TICEntry& config) {
-    if (!IsValidEntry(gpu_memory, config)) {
+    if (!IsValidEntry(*gpu_memory, config)) {
         return NULL_IMAGE_VIEW_ID;
     }
-    const auto [pair, is_new] = image_views.try_emplace(config);
+    const auto [pair, is_new] = state->image_views.try_emplace(config);
     ImageViewId& image_view_id = pair->second;
     if (is_new) {
         image_view_id = CreateImageView(config);
@@ -777,9 +782,9 @@ ImageId TextureCache<P>::FindOrInsertImage(const ImageInfo& info, GPUVAddr gpu_a
 template <class P>
 ImageId TextureCache<P>::FindImage(const ImageInfo& info, GPUVAddr gpu_addr,
                                    RelaxedOptions options) {
-    std::optional<VAddr> cpu_addr = gpu_memory.GpuToCpuAddress(gpu_addr);
+    std::optional<VAddr> cpu_addr = gpu_memory->GpuToCpuAddress(gpu_addr);
     if (!cpu_addr) {
-        cpu_addr = gpu_memory.GpuToCpuAddress(gpu_addr, CalculateGuestSizeInBytes(info));
+        cpu_addr = gpu_memory->GpuToCpuAddress(gpu_addr, CalculateGuestSizeInBytes(info));
         if (!cpu_addr) {
             return ImageId{};
         }
@@ -860,7 +865,7 @@ void TextureCache<P>::InvalidateScale(Image& image) {
         image.scale_tick = frame_tick + 1;
     }
     const std::span<const ImageViewId> image_view_ids = image.image_view_ids;
-    auto& dirty = maxwell3d.dirty.flags;
+    auto& dirty = maxwell3d->dirty.flags;
     dirty[Dirty::RenderTargets] = true;
     dirty[Dirty::ZetaBuffer] = true;
     for (size_t rt = 0; rt < NUM_RT; ++rt) {
@@ -881,11 +886,11 @@ void TextureCache<P>::InvalidateScale(Image& image) {
     image.image_view_ids.clear();
     image.image_view_infos.clear();
     if constexpr (ENABLE_VALIDATION) {
-        std::ranges::fill(graphics_image_view_ids, CORRUPT_ID);
-        std::ranges::fill(compute_image_view_ids, CORRUPT_ID);
+        std::ranges::fill(state->graphics_image_view_ids, CORRUPT_ID);
+        std::ranges::fill(state->compute_image_view_ids, CORRUPT_ID);
     }
-    graphics_image_table.Invalidate();
-    compute_image_table.Invalidate();
+    state->graphics_image_table.Invalidate();
+    state->compute_image_table.Invalidate();
     has_deleted_images = true;
 }
 
@@ -929,10 +934,10 @@ bool TextureCache<P>::ScaleDown(Image& image) {
 template <class P>
 ImageId TextureCache<P>::InsertImage(const ImageInfo& info, GPUVAddr gpu_addr,
                                      RelaxedOptions options) {
-    std::optional<VAddr> cpu_addr = gpu_memory.GpuToCpuAddress(gpu_addr);
+    std::optional<VAddr> cpu_addr = gpu_memory->GpuToCpuAddress(gpu_addr);
     if (!cpu_addr) {
         const auto size = CalculateGuestSizeInBytes(info);
-        cpu_addr = gpu_memory.GpuToCpuAddress(gpu_addr, size);
+        cpu_addr = gpu_memory->GpuToCpuAddress(gpu_addr, size);
         if (!cpu_addr) {
             const VAddr fake_addr = ~(1ULL << 40ULL) + virtual_invalid_space;
             virtual_invalid_space += Common::AlignUp(size, 32);
@@ -1050,7 +1055,7 @@ ImageId TextureCache<P>::JoinImages(const ImageInfo& info, GPUVAddr gpu_addr, VA
     const ImageId new_image_id = slot_images.insert(runtime, new_info, gpu_addr, cpu_addr);
     Image& new_image = slot_images[new_image_id];
 
-    if (!gpu_memory.IsContinousRange(new_image.gpu_addr, new_image.guest_size_bytes)) {
+    if (!gpu_memory->IsContinousRange(new_image.gpu_addr, new_image.guest_size_bytes)) {
         new_image.flags |= ImageFlagBits::Sparse;
     }
 
@@ -1192,7 +1197,7 @@ SamplerId TextureCache<P>::FindSampler(const TSCEntry& config) {
     if (std::ranges::all_of(config.raw, [](u64 value) { return value == 0; })) {
         return NULL_SAMPLER_ID;
     }
-    const auto [pair, is_new] = samplers.try_emplace(config);
+    const auto [pair, is_new] = state->samplers.try_emplace(config);
     if (is_new) {
         pair->second = slot_samplers.insert(runtime, config);
     }
@@ -1201,7 +1206,7 @@ SamplerId TextureCache<P>::FindSampler(const TSCEntry& config) {
 
 template <class P>
 ImageViewId TextureCache<P>::FindColorBuffer(size_t index, bool is_clear) {
-    const auto& regs = maxwell3d.regs;
+    const auto& regs = maxwell3d->regs;
     if (index >= regs.rt_control.count) {
         return ImageViewId{};
     }
@@ -1219,7 +1224,7 @@ ImageViewId TextureCache<P>::FindColorBuffer(size_t index, bool is_clear) {
 
 template <class P>
 ImageViewId TextureCache<P>::FindDepthBuffer(bool is_clear) {
-    const auto& regs = maxwell3d.regs;
+    const auto& regs = maxwell3d->regs;
     if (!regs.zeta_enable) {
         return ImageViewId{};
     }
@@ -1321,8 +1326,8 @@ void TextureCache<P>::ForEachImageInRegionGPU(GPUVAddr gpu_addr, size_t size, Fu
     static constexpr bool BOOL_BREAK = std::is_same_v<FuncReturn, bool>;
     boost::container::small_vector<ImageId, 8> images;
     ForEachGPUPage(gpu_addr, size, [this, &images, gpu_addr, size, func](u64 page) {
-        const auto it = gpu_page_table.find(page);
-        if (it == gpu_page_table.end()) {
+        const auto it = state->gpu_page_table.find(page);
+        if (it == state->gpu_page_table.end()) {
             if constexpr (BOOL_BREAK) {
                 return false;
             } else {
@@ -1403,9 +1408,9 @@ template <typename Func>
 void TextureCache<P>::ForEachSparseSegment(ImageBase& image, Func&& func) {
     using FuncReturn = typename std::invoke_result<Func, GPUVAddr, VAddr, size_t>::type;
     static constexpr bool RETURNS_BOOL = std::is_same_v<FuncReturn, bool>;
-    const auto segments = gpu_memory.GetSubmappedRange(image.gpu_addr, image.guest_size_bytes);
+    const auto segments = gpu_memory->GetSubmappedRange(image.gpu_addr, image.guest_size_bytes);
     for (const auto& [gpu_addr, size] : segments) {
-        std::optional<VAddr> cpu_addr = gpu_memory.GpuToCpuAddress(gpu_addr);
+        std::optional<VAddr> cpu_addr = gpu_memory->GpuToCpuAddress(gpu_addr);
         ASSERT(cpu_addr);
         if constexpr (RETURNS_BOOL) {
             if (func(gpu_addr, *cpu_addr, size)) {
@@ -1449,7 +1454,7 @@ void TextureCache<P>::RegisterImage(ImageId image_id) {
     image.lru_index = lru_cache.Insert(image_id, frame_tick);
 
     ForEachGPUPage(image.gpu_addr, image.guest_size_bytes,
-                   [this, image_id](u64 page) { gpu_page_table[page].push_back(image_id); });
+                   [this, image_id](u64 page) { state->gpu_page_table[page].push_back(image_id); });
     if (False(image.flags & ImageFlagBits::Sparse)) {
         auto map_id =
             slot_map_views.insert(image.gpu_addr, image.cpu_addr, image.guest_size_bytes, image_id);
@@ -1497,8 +1502,9 @@ void TextureCache<P>::UnregisterImage(ImageId image_id) {
             }
             image_ids.erase(vector_it);
         };
-    ForEachGPUPage(image.gpu_addr, image.guest_size_bytes,
-                   [this, &clear_page_table](u64 page) { clear_page_table(page, gpu_page_table); });
+    ForEachGPUPage(image.gpu_addr, image.guest_size_bytes, [this, &clear_page_table](u64 page) {
+        clear_page_table(page, state->gpu_page_table);
+    });
     if (False(image.flags & ImageFlagBits::Sparse)) {
         const auto map_id = image.map_view_id;
         ForEachCPUPage(image.cpu_addr, image.guest_size_bytes, [this, map_id](u64 page) {
@@ -1631,7 +1637,7 @@ void TextureCache<P>::DeleteImage(ImageId image_id, bool immediate_delete) {
     ASSERT_MSG(False(image.flags & ImageFlagBits::Registered), "Image was not unregistered");
 
     // Mark render targets as dirty
-    auto& dirty = maxwell3d.dirty.flags;
+    auto& dirty = maxwell3d->dirty.flags;
     dirty[Dirty::RenderTargets] = true;
     dirty[Dirty::ZetaBuffer] = true;
     for (size_t rt = 0; rt < NUM_RT; ++rt) {
@@ -1681,22 +1687,24 @@ void TextureCache<P>::DeleteImage(ImageId image_id, bool immediate_delete) {
     if (alloc_images.empty()) {
         image_allocs_table.erase(alloc_it);
     }
-    if constexpr (ENABLE_VALIDATION) {
-        std::ranges::fill(graphics_image_view_ids, CORRUPT_ID);
-        std::ranges::fill(compute_image_view_ids, CORRUPT_ID);
+    for (auto& this_state : channel_storage) {
+        if constexpr (ENABLE_VALIDATION) {
+            std::ranges::fill(this_state.graphics_image_view_ids, CORRUPT_ID);
+            std::ranges::fill(this_state.compute_image_view_ids, CORRUPT_ID);
+        }
+        this_state.graphics_image_table.Invalidate();
+        this_state.compute_image_table.Invalidate();
     }
-    graphics_image_table.Invalidate();
-    compute_image_table.Invalidate();
     has_deleted_images = true;
 }
 
 template <class P>
 void TextureCache<P>::RemoveImageViewReferences(std::span<const ImageViewId> removed_views) {
-    auto it = image_views.begin();
-    while (it != image_views.end()) {
+    auto it = state->image_views.begin();
+    while (it != state->image_views.end()) {
         const auto found = std::ranges::find(removed_views, it->second);
         if (found != removed_views.end()) {
-            it = image_views.erase(it);
+            it = state->image_views.erase(it);
         } else {
             ++it;
         }
@@ -1943,7 +1951,7 @@ bool TextureCache<P>::IsFullClear(ImageViewId id) {
     const ImageViewBase& image_view = slot_image_views[id];
     const ImageBase& image = slot_images[image_view.image_id];
     const Extent3D size = image_view.size;
-    const auto& regs = maxwell3d.regs;
+    const auto& regs = maxwell3d->regs;
     const auto& scissor = regs.scissor_test[0];
     if (image.info.resources.levels > 1 || image.info.resources.layers > 1) {
         // Images with multiple resources can't be cleared in a single call
@@ -1958,4 +1966,61 @@ bool TextureCache<P>::IsFullClear(ImageViewId id) {
            scissor.max_y >= size.height;
 }
 
+template <class P>
+TextureCache<P>::ChannelInfo::ChannelInfo(Tegra::Control::ChannelState& state) noexcept
+    : maxwell3d{*state.maxwell_3d}, kepler_compute{*state.kepler_compute},
+      gpu_memory{*state.memory_manager}, graphics_image_table{gpu_memory},
+      graphics_sampler_table{gpu_memory}, compute_image_table{gpu_memory}, compute_sampler_table{
+                                                                               gpu_memory} {}
+
+template <class P>
+void TextureCache<P>::CreateChannel(struct Tegra::Control::ChannelState& channel) {
+    ASSERT(channel_map.find(channel.bind_id) == channel_map.end() && channel.bind_id >= 0);
+    auto new_id = [this, &channel]() {
+        if (!free_channel_ids.empty()) {
+            auto id = free_channel_ids.front();
+            free_channel_ids.pop_front();
+            new (&channel_storage[id]) ChannelInfo(channel);
+            return id;
+        }
+        channel_storage.emplace_back(channel);
+        return channel_storage.size() - 1;
+    }();
+    channel_map.emplace(channel.bind_id, new_id);
+    if (current_channel_id != UNSET_CHANNEL) {
+        state = &channel_storage[current_channel_id];
+    }
+}
+
+/// Bind a channel for execution.
+template <class P>
+void TextureCache<P>::BindToChannel(s32 id) {
+    auto it = channel_map.find(id);
+    ASSERT(it != channel_map.end() && id >= 0);
+    current_channel_id = it->second;
+    state = &channel_storage[current_channel_id];
+    maxwell3d = &state->maxwell3d;
+    kepler_compute = &state->kepler_compute;
+    gpu_memory = &state->gpu_memory;
+}
+
+/// Erase channel's state.
+template <class P>
+void TextureCache<P>::EraseChannel(s32 id) {
+    const auto it = channel_map.find(id);
+    ASSERT(it != channel_map.end() && id >= 0);
+    const auto this_id = it->second;
+    free_channel_ids.push_back(this_id);
+    channel_map.erase(it);
+    if (this_id == current_channel_id) {
+        current_channel_id = UNSET_CHANNEL;
+        state = nullptr;
+        maxwell3d = nullptr;
+        kepler_compute = nullptr;
+        gpu_memory = nullptr;
+    } else if (current_channel_id != UNSET_CHANNEL) {
+        state = &channel_storage[current_channel_id];
+    }
+}
+
 } // namespace VideoCommon