0001 # SPDX-License-Identifier: GPL-2.0-only
0002 menu "DMABUF options"
0003
0004 config SYNC_FILE
0005 bool "Explicit Synchronization Framework"
0006 default n
0007 select DMA_SHARED_BUFFER
0008 help
0009 The Sync File Framework adds explicit synchronization via
0010 userspace. It enables send/receive 'struct dma_fence' objects to/from
0011 userspace via Sync File fds for synchronization between drivers via
0012 userspace components. It has been ported from Android.
0013
0014 The first and main user for this is graphics in which a fence is
0015 associated with a buffer. When a job is submitted to the GPU a fence
0016 is attached to the buffer and is transferred via userspace, using Sync
0017 Files fds, to the DRM driver for example. More details at
0018 Documentation/driver-api/sync_file.rst.
0019
0020 config SW_SYNC
0021 bool "Sync File Validation Framework"
0022 default n
0023 depends on SYNC_FILE
0024 depends on DEBUG_FS
0025 help
0026 A sync object driver that uses a 32bit counter to coordinate
0027 synchronization. Useful when there is no hardware primitive backing
0028 the synchronization.
0029
0030 WARNING: improper use of this can result in deadlocking kernel
0031 drivers from userspace. Intended for test and debug only.
0032
0033 config UDMABUF
0034 bool "userspace dmabuf misc driver"
0035 default n
0036 depends on DMA_SHARED_BUFFER
0037 depends on MEMFD_CREATE || COMPILE_TEST
0038 help
0039 A driver to let userspace turn memfd regions into dma-bufs.
0040 Qemu can use this to create host dmabufs for guest framebuffers.
0041
0042 config DMABUF_MOVE_NOTIFY
0043 bool "Move notify between drivers (EXPERIMENTAL)"
0044 default n
0045 depends on DMA_SHARED_BUFFER
0046 help
0047 Don't pin buffers if the dynamic DMA-buf interface is available on
0048 both the exporter as well as the importer. This fixes a security
0049 problem where userspace is able to pin unrestricted amounts of memory
0050 through DMA-buf.
0051 This is marked experimental because we don't yet have a consistent
0052 execution context and memory management between drivers.
0053
0054 config DMABUF_DEBUG
0055 bool "DMA-BUF debug checks"
0056 depends on DMA_SHARED_BUFFER
0057 default y if DMA_API_DEBUG
0058 help
0059 This option enables additional checks for DMA-BUF importers and
0060 exporters. Specifically it validates that importers do not peek at the
0061 underlying struct page when they import a buffer.
0062
0063 config DMABUF_SELFTESTS
0064 tristate "Selftests for the dma-buf interfaces"
0065 default n
0066 depends on DMA_SHARED_BUFFER
0067
0068 menuconfig DMABUF_HEAPS
0069 bool "DMA-BUF Userland Memory Heaps"
0070 select DMA_SHARED_BUFFER
0071 help
0072 Choose this option to enable the DMA-BUF userland memory heaps.
0073 This options creates per heap chardevs in /dev/dma_heap/ which
0074 allows userspace to allocate dma-bufs that can be shared
0075 between drivers.
0076
0077 menuconfig DMABUF_SYSFS_STATS
0078 bool "DMA-BUF sysfs statistics (DEPRECATED)"
0079 depends on DMA_SHARED_BUFFER
0080 help
0081 Choose this option to enable DMA-BUF sysfs statistics
0082 in location /sys/kernel/dmabuf/buffers.
0083
0084 /sys/kernel/dmabuf/buffers/<inode_number> will contain
0085 statistics for the DMA-BUF with the unique inode number
0086 <inode_number>.
0087
0088 This option is deprecated and should sooner or later be removed.
0089 Android is the only user of this and it turned out that this resulted
0090 in quite some performance problems.
0091
0092 source "drivers/dma-buf/heaps/Kconfig"
0093
0094 endmenu
