sdk/fidl/fuchsia.sysmem2/usages.fidl

// Copyright 2020 The Fuchsia 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.sysmem2;

/// Describes how a client will access the contents of a buffer.
@available(added=19)
type BufferUsage = table {
    /// If the client sets this field, the client should not set any other
    /// fields in the same table instance. The only valid bit in this field is
    /// `NONE_USAGE` which must be set if this field is set. The point of this
    /// field and the one bit set in this field is to essentially prove that the
    /// client really means they aren't going to use the buffers, so don't need
    /// any VMOs (didn't just fail to fill out the table).
    1: none uint32;
    /// If set, holds CPU usage bits. See `CPU_USAGE_*` flags in usages.fidl.
    2: cpu uint32;
    /// If set, holds vulkan usage bits. See `VULKAN_IMAGE_*` and
    /// `VULKAN_BUFFER_*` bits in usages.fidl. The `VULKAN_USAGE_*` bit
    /// definitions/names are deprecated.
    3: vulkan uint32;
    /// If set, holds display usage bits. See `DISPLAY_USAGE_*` bits in
    /// usages.fidl.
    4: display uint32;
    /// If set, holds video usage bits. See `VIDEO_USAGE_*` bits in usages.fidl.
    5: video uint32;
};

// Flag for "none" usage.
//
// This bit indicates that there is no direct usage from the participant, and
// that the participant hasn't forgotten to set usage.
@available(added=19)
const NONE_USAGE uint32 = 1;

// Flags for "cpu" usage.
// The "often" variants prefer cacheable memory.
@available(added=19)
const CPU_USAGE_READ uint32 = 1;
@available(added=19)
const CPU_USAGE_READ_OFTEN uint32 = 2;
@available(added=19)
const CPU_USAGE_WRITE uint32 = 4;
@available(added=19)
const CPU_USAGE_WRITE_OFTEN uint32 = 8;

// Flags for "vulkan" usage.
// Based on https://www.khronos.org/registry/vulkan/specs/1.1-extensions/man/html/VkImageUsageFlagBits.html
@available(added=19)
const VULKAN_IMAGE_USAGE_TRANSFER_SRC uint32 = 0X0001;
@available(added=19)
const VULKAN_IMAGE_USAGE_TRANSFER_DST uint32 = 0X0002;
@available(added=19)
const VULKAN_IMAGE_USAGE_SAMPLED uint32 = 0X0004;
@available(added=19)
const VULKAN_IMAGE_USAGE_STORAGE uint32 = 0X0008;
@available(added=19)
const VULKAN_IMAGE_USAGE_COLOR_ATTACHMENT uint32 = 0X0010;
@available(added=19)
const VULKAN_IMAGE_USAGE_STENCIL_ATTACHMENT uint32 = 0X0020;
@available(added=19)
const VULKAN_IMAGE_USAGE_TRANSIENT_ATTACHMENT uint32 = 0X0040;
@available(added=19)
const VULKAN_IMAGE_USAGE_INPUT_ATTACHMENT uint32 = 0X0080;

// Vulkan buffer usage flags.
// Based on https://www.khronos.org/registry/vulkan/specs/1.2-extensions/man/html/VkBufferUsageFlagBits.html
@available(added=19)
const VULKAN_BUFFER_USAGE_TRANSFER_SRC uint32 = 0X00010000;
@available(added=19)
const VULKAN_BUFFER_USAGE_TRANSFER_DST uint32 = 0X00020000;
@available(added=19)
const VULKAN_BUFFER_USAGE_UNIFORM_TEXEL_BUFFER uint32 = 0X00040000;
@available(added=19)
const VULKAN_BUFFER_USAGE_STORAGE_TEXEL_BUFFER uint32 = 0X00080000;
@available(added=19)
const VULKAN_BUFFER_USAGE_UNIFORM_BUFFER uint32 = 0X00100000;
@available(added=19)
const VULKAN_BUFFER_USAGE_STORAGE_BUFFER uint32 = 0X00200000;
@available(added=19)
const VULKAN_BUFFER_USAGE_INDEX_BUFFER uint32 = 0X00400000;
@available(added=19)
const VULKAN_BUFFER_USAGE_VERTEX_BUFFER uint32 = 0X00800000;
@available(added=19)
const VULKAN_BUFFER_USAGE_INDIRECT_BUFFER uint32 = 0X01000000;

// Flags for "display" usage.
@available(added=19)
const DISPLAY_USAGE_LAYER uint32 = 1;
@available(added=19)
const DISPLAY_USAGE_CURSOR uint32 = 2;

// Flags for "video" usage.
// TODO(https://fxbug.dev/42107168): Add more specific HwDecoder flags if needed.
@available(added=19)
const VIDEO_USAGE_HW_DECODER uint32 = 1;
@available(added=19)
const VIDEO_USAGE_HW_ENCODER uint32 = 2;
@available(added=19)
const VIDEO_USAGE_CAPTURE uint32 = 8;
// VIDEO_USAGE_DECRYPTOR_OUTPUT is for the output of a decryptor; such buffers
// will contain decrypted compressed media data. The decryptor output may be in
// secure memory (controlled separately via secure_required). This bit can be
// used for any decryptor output, not just a video decryptor output.
@available(added=19)
const VIDEO_USAGE_DECRYPTOR_OUTPUT uint32 = 16;
// This usage is for a HW video decoder's internal buffers that aren't shared
// with other participants.
@available(added=19)
const VIDEO_USAGE_HW_DECODER_INTERNAL uint32 = 32;