xref: /kernel/linux/linux-6.6/drivers/dma-buf/Kconfig

# SPDX-License-Identifier: GPL-2.0-only
menu "DMABUF options"

config SYNC_FILE
	bool "Explicit Synchronization Framework"
	default n
	select DMA_SHARED_BUFFER
	help
	  The Sync File Framework adds explicit synchronization via
	  userspace. It enables send/receive 'struct dma_fence' objects to/from
	  userspace via Sync File fds for synchronization between drivers via
	  userspace components. It has been ported from Android.

	  The first and main user for this is graphics in which a fence is
	  associated with a buffer. When a job is submitted to the GPU a fence
	  is attached to the buffer and is transferred via userspace, using Sync
	  Files fds, to the DRM driver for example. More details at
	  Documentation/driver-api/sync_file.rst.

config SW_SYNC
	bool "Sync File Validation Framework"
	default n
	depends on SYNC_FILE
	depends on DEBUG_FS
	help
	  A sync object driver that uses a 32bit counter to coordinate
	  synchronization.  Useful when there is no hardware primitive backing
	  the synchronization.

	  WARNING: improper use of this can result in deadlocking kernel
	  drivers from userspace. Intended for test and debug only.

config UDMABUF
	bool "userspace dmabuf misc driver"
	default n
	depends on DMA_SHARED_BUFFER
	depends on MEMFD_CREATE || COMPILE_TEST
	help
	  A driver to let userspace turn memfd regions into dma-bufs.
	  Qemu can use this to create host dmabufs for guest framebuffers.

config DMABUF_MOVE_NOTIFY
	bool "Move notify between drivers (EXPERIMENTAL)"
	default n
	depends on DMA_SHARED_BUFFER
	help
	  Don't pin buffers if the dynamic DMA-buf interface is available on
	  both the exporter as well as the importer. This fixes a security
	  problem where userspace is able to pin unrestricted amounts of memory
	  through DMA-buf.
	  This is marked experimental because we don't yet have a consistent
	  execution context and memory management between drivers.

config DMABUF_DEBUG
	bool "DMA-BUF debug checks"
	depends on DMA_SHARED_BUFFER
	default y if DMA_API_DEBUG
	help
	  This option enables additional checks for DMA-BUF importers and
	  exporters. Specifically it validates that importers do not peek at the
	  underlying struct page when they import a buffer.

config DMABUF_SELFTESTS
	tristate "Selftests for the dma-buf interfaces"
	default n
	depends on DMA_SHARED_BUFFER

config DMABUF_PROCESS_INFO
	bool "Show dmabuf usage of all processes"
	default n
	depends on DMA_SHARED_BUFFER
	depends on PROC_FS || DEBUG_FS
	help
	  Choose this option to show dmabuf objects usage of all processes.
	  Firstly, with this option, when a process creates a dmabuf object,
	  its pid and task_comm will be recorded in the dmabuf.
	  Secondly, this option creates dma_buf/process_bufinfo file in
	  debugfs (if DEBUG_FS enabled) and process_dmabuf_info file in procfs
	  (if PROC_FS enabled) to show dmabuf objects usage of all processes.

menuconfig DMABUF_HEAPS
	bool "DMA-BUF Userland Memory Heaps"
	select DMA_SHARED_BUFFER
	help
	  Choose this option to enable the DMA-BUF userland memory heaps.
	  This options creates per heap chardevs in /dev/dma_heap/ which
	  allows userspace to allocate dma-bufs that can be shared
	  between drivers.

menuconfig DMABUF_SYSFS_STATS
	bool "DMA-BUF sysfs statistics (DEPRECATED)"
	depends on DMA_SHARED_BUFFER
	help
	   Choose this option to enable DMA-BUF sysfs statistics
	   in location /sys/kernel/dmabuf/buffers.

	   /sys/kernel/dmabuf/buffers/<inode_number> will contain
	   statistics for the DMA-BUF with the unique inode number
	   <inode_number>.

	   This option is deprecated and should sooner or later be removed.
	   Android is the only user of this and it turned out that this resulted
	   in quite some performance problems.

source "drivers/dma-buf/heaps/Kconfig"

endmenu