[PATCH v6 0/5] DMA-BUF Heaps (destaging ION)

[John Stultz]

Here is another pass at the dma-buf heaps patchset Andrew and I
have been working on which tries to destage a fair chunk of ION
functionality.

The patchset implements per-heap devices which can be opened
directly and then an ioctl is used to allocate a dmabuf from the
heap.

The interface is similar, but much simpler then IONs, only
providing an ALLOC ioctl.

Also, I've provided relatively simple system and cma heaps.

I've booted and tested these patches with AOSP on the HiKey960
using the kernel tree here:
  https://git.linaro.org/people/john.stultz/android-dev.git/log/?h=dev/dma-buf-heap

And the userspace changes here:
  https://android-review.googlesource.com/c/device/linaro/hikey/+/909436

Compared to ION, this patchset is missing the system-contig,
carveout and chunk heaps, as I don't have a device that uses
those, so I'm unable to do much useful validation there.
Additionally we have no upstream users of chunk or carveout,
and the system-contig has been deprecated in the common/andoid-*
kernels, so this should be ok.

I've also removed the stats accounting for now, since any such
accounting should be implemented by dma-buf core or the heaps
themselves.


New in v6:
* Number of cleanups and error path fixes suggested by Brian Starkey,
  many thanks for his close review and suggestions!


Outstanding concerns:
* Need to better understand various secure heap implementations.
  Some concern that heap private flags will be needed, but its
  also possible that dma-buf heaps can't solve everyone's needs,
  in which case, a vendor's secure buffer driver can implement
  their own dma-buf exporter. So I'm not too worried here.

Thoughts and feedback would be greatly appreciated!

thanks
-john

Cc: Laura Abbott <labbott@xxxxxxxxxx>
Cc: Benjamin Gaignard <benjamin.gaignard@xxxxxxxxxx>
Cc: Sumit Semwal <sumit.semwal@xxxxxxxxxx>
Cc: Liam Mark <lmark@xxxxxxxxxxxxxx>
Cc: Pratik Patel <pratikp@xxxxxxxxxxxxxx>
Cc: Brian Starkey <Brian.Starkey@xxxxxxx>
Cc: Vincent Donnefort <Vincent.Donnefort@xxxxxxx>
Cc: Sudipto Paul <Sudipto.Paul@xxxxxxx>
Cc: Andrew F. Davis <afd@xxxxxx>
Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx>
Cc: Chenbo Feng <fengc@xxxxxxxxxx>
Cc: Alistair Strachan <astrachan@xxxxxxxxxx>
Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx

Andrew F. Davis (1):
  dma-buf: Add dma-buf heaps framework

John Stultz (4):
  dma-buf: heaps: Add heap helpers
  dma-buf: heaps: Add system heap to dmabuf heaps
  dma-buf: heaps: Add CMA heap to dmabuf heaps
  kselftests: Add dma-heap test

 MAINTAINERS                                   |  18 ++
 drivers/dma-buf/Kconfig                       |  10 +
 drivers/dma-buf/Makefile                      |   2 +
 drivers/dma-buf/dma-heap.c                    | 249 +++++++++++++++++
 drivers/dma-buf/heaps/Kconfig                 |  14 +
 drivers/dma-buf/heaps/Makefile                |   4 +
 drivers/dma-buf/heaps/cma_heap.c              | 169 +++++++++++
 drivers/dma-buf/heaps/heap-helpers.c          | 262 ++++++++++++++++++
 drivers/dma-buf/heaps/heap-helpers.h          |  54 ++++
 drivers/dma-buf/heaps/system_heap.c           | 121 ++++++++
 include/linux/dma-heap.h                      |  59 ++++
 include/uapi/linux/dma-heap.h                 |  55 ++++
 tools/testing/selftests/dmabuf-heaps/Makefile |   9 +
 .../selftests/dmabuf-heaps/dmabuf-heap.c      | 234 ++++++++++++++++
 14 files changed, 1260 insertions(+)
 create mode 100644 drivers/dma-buf/dma-heap.c
 create mode 100644 drivers/dma-buf/heaps/Kconfig
 create mode 100644 drivers/dma-buf/heaps/Makefile
 create mode 100644 drivers/dma-buf/heaps/cma_heap.c
 create mode 100644 drivers/dma-buf/heaps/heap-helpers.c
 create mode 100644 drivers/dma-buf/heaps/heap-helpers.h
 create mode 100644 drivers/dma-buf/heaps/system_heap.c
 create mode 100644 include/linux/dma-heap.h
 create mode 100644 include/uapi/linux/dma-heap.h
 create mode 100644 tools/testing/selftests/dmabuf-heaps/Makefile
 create mode 100644 tools/testing/selftests/dmabuf-heaps/dmabuf-heap.c

-- 
2.17.1