zircon/system/fidl/fuchsia-sysmem/usages.fidl

// Copyright 2018 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

library fuchsia.sysmem;

// Describes how a client will access the contents of a buffer.
// TODO(ZX-2260): change struct to table
struct BufferUsage {
    uint32 cpu;
    uint32 vulkan;
    uint32 display;
    uint32 video;
};

// Flags for "cpu" usage.
// The "often" variants prefer cacheable memory.
const uint32 cpuUsageRead = 1;
const uint32 cpuUsageReadOften = 2;
const uint32 cpuUsageWrite = 4;
const uint32 cpuUsageWriteOften = 8;

// Flags for "vulkan" usage.
// Based on https://www.khronos.org/registry/vulkan/specs/1.1-extensions/man/html/VkImageUsageFlagBits.html
const uint32 vulkanUsageTransferSrc = 0x0001;
const uint32 vulkanUsageTransferDst = 0x0002;
const uint32 vulkanUsageSampled = 0x0004;
const uint32 vulkanUsageStorage = 0x0008;
const uint32 vulkanUsageColorAttachment = 0x0010;
const uint32 vulkanUsageStencilAttachment = 0x0020;
const uint32 vulkanUsageTransientAttachment = 0x0040;
const uint32 vulkanUsageInputAttachment = 0x0080;

// Flags for "display" usage.
const uint32 displayUsageLayer = 1;
const uint32 displayUsageCursor = 2;

// Flags for "video" usage.
// TODO(ZX-2259): Add more specific HwDecoder flags if needed.
const uint32 videoUsageHwDecoder = 1;
const uint32 videoUsageHwEncoder = 2;
// TODO(dustingreen): This bit is likely redundant with secure_required and
// secure_permitted bool(s); this bit might be able to be removed.
const uint32 videoUsageHwProtected = 4;