# SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note # # (C) COPYRIGHT 2012-2013, 2020-2021 ARM Limited. All rights reserved. # # This program is free software and is provided to you under the terms of the # GNU General Public License version 2 as published by the Free Software # Foundation, and any use by you of this program is subject to the terms # of such GNU license. # # This program is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU General Public License for more details. # # You should have received a copy of the GNU General Public License # along with this program; if not, you can access it online at # http://www.gnu.org/licenses/gpl-2.0.html. # # ===================== dma-buf-test-exporter ===================== Overview -------- The dma-buf-test-exporter is a simple exporter of dma_buf objects. It has a private API to allocate and manipulate the buffers which are represented as dma_buf fds. The private API allows: * simple allocation of physically non-contiguous buffers * simple allocation of physically contiguous buffers * query kernel side API usage stats (number of attachments, number of mappings, mmaps) * failure mode configuration (fail attach, mapping, mmap) * kernel side memset of buffers The buffers support all of the dma_buf API, including mmap. It supports being compiled as a module both in-tree and out-of-tree. See include/linux/dma-buf-test-exporter.h for the ioctl interface. See Documentation/dma-buf-sharing.txt for details on dma_buf.