1# SPDX-License-Identifier: GPL-2.0-only 2menu "DMABUF options" 3 4config SYNC_FILE 5 bool "Explicit Synchronization Framework" 6 default n 7 select DMA_SHARED_BUFFER 8 help 9 The Sync File Framework adds explicit synchronization via 10 userspace. It enables send/receive 'struct dma_fence' objects to/from 11 userspace via Sync File fds for synchronization between drivers via 12 userspace components. It has been ported from Android. 13 14 The first and main user for this is graphics in which a fence is 15 associated with a buffer. When a job is submitted to the GPU a fence 16 is attached to the buffer and is transferred via userspace, using Sync 17 Files fds, to the DRM driver for example. More details at 18 Documentation/driver-api/sync_file.rst. 19 20config SW_SYNC 21 bool "Sync File Validation Framework" 22 default n 23 depends on SYNC_FILE 24 depends on DEBUG_FS 25 help 26 A sync object driver that uses a 32bit counter to coordinate 27 synchronization. Useful when there is no hardware primitive backing 28 the synchronization. 29 30 WARNING: improper use of this can result in deadlocking kernel 31 drivers from userspace. Intended for test and debug only. 32 33config UDMABUF 34 bool "userspace dmabuf misc driver" 35 default n 36 depends on DMA_SHARED_BUFFER 37 depends on MEMFD_CREATE || COMPILE_TEST 38 depends on MMU 39 select VMAP_PFN 40 help 41 A driver to let userspace turn memfd regions into dma-bufs. 42 Qemu can use this to create host dmabufs for guest framebuffers. 43 44config DMABUF_MOVE_NOTIFY 45 bool "Move notify between drivers (EXPERIMENTAL)" 46 default n 47 depends on DMA_SHARED_BUFFER 48 help 49 Don't pin buffers if the dynamic DMA-buf interface is available on 50 both the exporter as well as the importer. This fixes a security 51 problem where userspace is able to pin unrestricted amounts of memory 52 through DMA-buf. 53 This is marked experimental because we don't yet have a consistent 54 execution context and memory management between drivers. 55 56config DMABUF_DEBUG 57 bool "DMA-BUF debug checks" 58 depends on DMA_SHARED_BUFFER 59 default y if DMA_API_DEBUG 60 help 61 This option enables additional checks for DMA-BUF importers and 62 exporters. Specifically it validates that importers do not peek at the 63 underlying struct page when they import a buffer. 64 65config DMABUF_SELFTESTS 66 tristate "Selftests for the dma-buf interfaces" 67 default n 68 depends on DMA_SHARED_BUFFER 69 70menuconfig DMABUF_HEAPS 71 bool "DMA-BUF Userland Memory Heaps" 72 select DMA_SHARED_BUFFER 73 help 74 Choose this option to enable the DMA-BUF userland memory heaps. 75 This options creates per heap chardevs in /dev/dma_heap/ which 76 allows userspace to allocate dma-bufs that can be shared 77 between drivers. 78 79menuconfig DMABUF_SYSFS_STATS 80 bool "DMA-BUF sysfs statistics (DEPRECATED)" 81 depends on DMA_SHARED_BUFFER 82 help 83 Choose this option to enable DMA-BUF sysfs statistics 84 in location /sys/kernel/dmabuf/buffers. 85 86 /sys/kernel/dmabuf/buffers/<inode_number> will contain 87 statistics for the DMA-BUF with the unique inode number 88 <inode_number>. 89 90 This option is deprecated and should sooner or later be removed. 91 Android is the only user of this and it turned out that this resulted 92 in quite some performance problems. 93 94source "drivers/dma-buf/heaps/Kconfig" 95 96endmenu 97