Re: [PATCH v14 0/5] DMA-BUF Heaps (destaging ION)

From: Pekka Paalanen
Date: Mon Nov 04 2019 - 03:18:19 EST


On Fri, 1 Nov 2019 21:42:33 +0000
John Stultz <john.stultz@xxxxxxxxxx> wrote:

> This again? I know!
>
> Apologies to all who hoped I'd stop bothering them with this
> patch set, but I ran afoul of the DRM tree rules by not
> getting the userland patches properly reviewed prior to the
> patches landing (I mistakenly was waiting for the patches to
> land upstream before pushing the userland patches). Thus,
> these were correctly reverted from the drm-misc-next tree.

Hi John,

mind, you have to get userland patches reviewed and accepted but *not
pushed*.

You cannot push/merge userland patches before the kernel patches have
properly landed, that bit you got right. But the supposedly confusing
bit is that for kernel patches to land, the userspace patches must be
reviewed and accepted first.

I just wanted to clarify this since you wrote "before pushing the
userland patches" above.


Thanks,
pq

>
> My attempts to quickly fix the userland review issue didn't get
> very far, as the revert brought additional eyes to the patchset,
> and further interface changes were requested (comically, which
> is the exact reason I was waiting to push the userland changes
> :)
>
> So like groundhog day, here we are again, with v14:
>
> This 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 (and a GET_FEATURES interface to help
> with any future changes to the interface).
>
> 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, since any such
> accounting should be implemented by dma-buf core or the heaps
> themselves.
>
> New in v14:
> * Reworked ioctl handler to zero fill any difference in
> structure size, similar to what the DRM core does, as
> suggested by Dave Airlie
> * Removed now unnecessary reserved bits in allocate_data
> * Added get_features ioctl as suggested by Dave Airlie
> * Removed pr_warn_once messages as requested by Dave
> Airlie
> * Fix missing argment to WARN() in dma_heap_buffer_destroy()
> found and fixed by Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> * Add check in fault hanlder that pgoff isn't larger then
> pagecount, reported by Dan Carpenter
> * Fix "redundant assignment to variable ret" issue reported
> by Colin King and fixed by Andrew Davis
> * Fix a missing return value in kselftest
> * Add calls to test the GET_FEATURES ioctl in ksefltest
> * Build fix reported by kernel test robot <lkp@xxxxxxxxx>
> and fixed by Xiao Yang <ice_yangxiao@xxxxxxx> for kselftest
> * Minor kselftest Makefile cleanups
>
> Many thanks again to the folks above who found and submitted
> fixes to small issues while the patches were in -next! I've
> folded them in to the patch set here.
>
> The ioctl rework to avoid reserved fields, was mostly duplicated
> from the DRM core, but it does add some complexity to the ioctl
> handler so I'd appreciate extra review.
>
> It felt substantial enough that I've removed the previous reviewed
> by and acked-by tags, but please let me know if you'd like me to
> re-add yours back.
>
> Apologies again for my flub and the extra noise here!
> I really appreciate everyone's patience with with me.
>
> 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: Hridya Valsaraju <hridya@xxxxxxxxxx>
> Cc: Sandeep Patil <sspatil@xxxxxxxxxx>
> Cc: Hillf Danton <hdanton@xxxxxxxx>
> Cc: Dave Airlie <airlied@xxxxxxxxx>
> 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 | 11 +
> drivers/dma-buf/Makefile | 2 +
> drivers/dma-buf/dma-heap.c | 313 ++++++++++++++++++
> 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 | 271 +++++++++++++++
> 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 | 77 +++++
> tools/testing/selftests/dmabuf-heaps/Makefile | 6 +
> .../selftests/dmabuf-heaps/dmabuf-heap.c | 255 ++++++++++++++
> 14 files changed, 1387 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
>

Attachment: pgpriJk95HpZx.pgp
Description: OpenPGP digital signature