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dma-buf: Add dma-buf heaps framework

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This framework allows a unified userspace interface for dma-buf
exporters, allowing userland to allocate specific types of memory
for use in dma-buf sharing.

Each heap is given its own device node, which a user can allocate
a dma-buf fd from using the DMA_HEAP_IOC_ALLOC.

This code is an evoluiton of the Android ION implementation,
and a big thanks is due to its authors/maintainers over time
for their effort:
  Rebecca Schultz Zavin, Colin Cross, Benjamin Gaignard,
  Laura Abbott, and many other contributors!

Cc: Laura Abbott <labbott@redhat.com>
Cc: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Liam Mark <lmark@codeaurora.org>
Cc: Pratik Patel <pratikp@codeaurora.org>
Cc: Brian Starkey <Brian.Starkey@arm.com>
Cc: Vincent Donnefort <Vincent.Donnefort@arm.com>
Cc: Sudipto Paul <Sudipto.Paul@arm.com>
Cc: Andrew F. Davis <afd@ti.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Chenbo Feng <fengc@google.com>
Cc: Alistair Strachan <astrachan@google.com>
Cc: Hridya Valsaraju <hridya@google.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Reviewed-by: Brian Starkey <brian.starkey@arm.com>
Acked-by: Laura Abbott <labbott@redhat.com>
Tested-by: Ayan Kumar Halder <ayan.halder@arm.com>
Signed-off-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20191021190310.85221-2-john.stultz@linaro.org
This commit is contained in:
Andrew F. Davis
2019-10-21 19:03:06 +00:00
committed by Sumit Semwal
parent ea7d8c675e
commit a69b0e855d
6 changed files with 411 additions and 0 deletions
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55
include/uapi/linux/dma-heap.h Normal file
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/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
/*
* DMABUF Heaps Userspace API
*
* Copyright (C) 2011 Google, Inc.
* Copyright (C) 2019 Linaro Ltd.
*/
#ifndef _UAPI_LINUX_DMABUF_POOL_H
#define _UAPI_LINUX_DMABUF_POOL_H
#include <linux/ioctl.h>
#include <linux/types.h>
/**
* DOC: DMABUF Heaps Userspace API
*/
/* Valid FD_FLAGS are O_CLOEXEC, O_RDONLY, O_WRONLY, O_RDWR */
#define DMA_HEAP_VALID_FD_FLAGS (O_CLOEXEC | O_ACCMODE)
/* Currently no heap flags */
#define DMA_HEAP_VALID_HEAP_FLAGS (0)
/**
* struct dma_heap_allocation_data - metadata passed from userspace for
* allocations
* @len: size of the allocation
* @fd: will be populated with a fd which provdes the
* handle to the allocated dma-buf
* @fd_flags: file descriptor flags used when allocating
* @heap_flags: flags passed to heap
*
* Provided by userspace as an argument to the ioctl
*/
struct dma_heap_allocation_data {
__u64 len;
__u32 fd;
__u32 fd_flags;
__u64 heap_flags;
__u32 reserved0;
__u32 reserved1;
};
#define DMA_HEAP_IOC_MAGIC 'H'
/**
* DOC: DMA_HEAP_IOC_ALLOC - allocate memory from pool
*
* Takes an dma_heap_allocation_data struct and returns it with the fd field
* populated with the dmabuf handle of the allocation.
*/
#define DMA_HEAP_IOC_ALLOC _IOWR(DMA_HEAP_IOC_MAGIC, 0, \
struct dma_heap_allocation_data)
#endif /* _UAPI_LINUX_DMABUF_POOL_H */