[PATCH v12 0/5] DMA-BUF Heaps (destaging ION)

From: John Stultz
Date: Fri Oct 18 2019 - 01:23:30 EST

Andrew brought up a reasonable concern with the CMA heap
enumeration in the previous patch set, and I had a few other
minor cleanups to add, so here is yet 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

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:

And the userspace changes here:

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, since any such
accounting should be implemented by dma-buf core or the heaps

New in v12:
* To address Andrew's concern about adding all CMA areas, the
CMA heap only adds the default CMA region for now.
* Minor cleanups and prep for loading heaps from modules
* I have patches to add other specified CMA regions, as well as
loading heaps from modules in my WIP tree, which I will submit
once this set is queued, here:


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: Hridya Valsaraju <hridya@xxxxxxxxxx>
Cc: Hillf Danton <hdanton@xxxxxxxx>
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

drivers/dma-buf/Kconfig | 11 +
drivers/dma-buf/Makefile | 2 +
drivers/dma-buf/dma-heap.c | 271 ++++++++++++++++++
drivers/dma-buf/heaps/Kconfig | 14 +
drivers/dma-buf/heaps/Makefile | 4 +
drivers/dma-buf/heaps/cma_heap.c | 178 ++++++++++++
drivers/dma-buf/heaps/heap-helpers.c | 270 +++++++++++++++++
drivers/dma-buf/heaps/heap-helpers.h | 55 ++++
drivers/dma-buf/heaps/system_heap.c | 124 ++++++++
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 | 238 +++++++++++++++
14 files changed, 1308 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