[RFC PATCH 00/12] Ion cleanup in preparation for moving out of staging

Benjamin Gaignard
2017-03-03T12:54:07Z

2017-03-03 11:27 GMT+01:00 Daniel Vetter <daniel@ffwll.ch>:
> On Fri, Mar 03, 2017 at 11:04:33AM +0100, Daniel Vetter wrote:
>> On Thu, Mar 02, 2017 at 01:44:32PM -0800, Laura Abbott wrote:
>> > Hi,
>> >
>> > There's been some recent discussions[1] about Ion-like frameworks. There's
>> > apparently interest in just keeping Ion since it works reasonablly well.
>> > This series does what should be the final clean ups for it to possibly be
>> > moved out of staging.
>> >
>> > This includes the following:
>> > - Some general clean up and removal of features that never got a lot of use
>> > as far as I can tell.
>> > - Fixing up the caching. This is the series I proposed back in December[2]
>> > but never heard any feedback on. It will certainly break existing
>> > applications that rely on the implicit caching. I'd rather make an effort
>> > to move to a model that isn't going directly against the establishement
>> > though.
>> > - Fixing up the platform support. The devicetree approach was never well
>> > recieved by DT maintainers. The proposal here is to think of Ion less as
>> > specifying requirements and more of a framework for exposing memory to
>> > userspace.
>> > - CMA allocations now happen without the need of a dummy device structure.
>> > This fixes a bunch of the reasons why I attempted to add devicetree
>> > support before.
>> >
>> > I've had problems getting feedback in the past so if I don't hear any major
>> > objections I'm going to send out with the RFC dropped to be picked up.
>> > The only reason there isn't a patch to come out of staging is to discuss any
>> > other changes to the ABI people might want. Once this comes out of staging,
>> > I really don't want to mess with the ABI.
>> >
>> > Feedback appreciated.
>>
>> Imo looks all good. And I just realized that cross-checking with the TODO,
>> the 2 items about _CUSTOM and _IMPORT ioctls I noted are already there.
>
> One more for the todo: Add rst/sphinx documentation for ION. That's also
> always a good excuse to review the internal interfaces and exported
> symbols. But we can do that after destaging ...
> -Daniel

Removing alignment looks good for me but why not also remove it from
struct ion_allocation_data since the field become useless ?

Also does someone use ion_user_handle_t handle ? Can we directly export
a dma-buf file descriptor ?

Benjamin

>
>>
>> Otherwise I looked through the patches, looks all really reasonable.
>>
>> Wrt merging, my experience from destaging the android syncpt stuff was
>> that merging the patches through the staging tree lead to lots of
>> cross-tree issues with the gpu folks wanting to use that. Ion will
>> probably run into similar things, so I'd propose we pull these cleanup
>> patches and the eventual de-staging in throught drm. Yes that defacto
>> means I'm also volunteering myself a bit :-)
>>
>> In the end we could put it all into drivers/gpu/ion or something like
>> that.
>>
>> Thoughts? Greg?
>> -Daniel
>>
>>
>> >
>> > Thanks,
>> > Laura
>> >
>> > [1] https://marc.info/?l=linux-kernel&m=148699712602105&w=2
>> > [2] https://marc.info/?l=linaro-mm-sig&m=148176050802908&w=2
>> >
>> > Laura Abbott (12):
>> > staging: android: ion: Remove dmap_cnt
>> > staging: android: ion: Remove alignment from allocation field
>> > staging: android: ion: Duplicate sg_table
>> > staging: android: ion: Call dma_map_sg for syncing and mapping
>> > staging: android: ion: Remove page faulting support
>> > staging: android: ion: Remove crufty cache support
>> > staging: android: ion: Remove old platform support
>> > cma: Store a name in the cma structure
>> > cma: Introduce cma_for_each_area
>> > staging: android: ion: Use CMA APIs directly
>> > staging: android: ion: Make Ion heaps selectable
>> > staging; android: ion: Enumerate all available heaps
>> >
>> > drivers/base/dma-contiguous.c | 5 +-
>> > drivers/staging/android/ion/Kconfig | 51 ++--
>> > drivers/staging/android/ion/Makefile | 14 +-
>> > drivers/staging/android/ion/hisilicon/Kconfig | 5 -
>> > drivers/staging/android/ion/hisilicon/Makefile | 1 -
>> > drivers/staging/android/ion/hisilicon/hi6220_ion.c | 113 ---------
>> > drivers/staging/android/ion/ion-ioctl.c | 6 -
>> > drivers/staging/android/ion/ion.c | 282 ++++++---------------
>> > drivers/staging/android/ion/ion.h | 5 +-
>> > drivers/staging/android/ion/ion_carveout_heap.c | 16 +-
>> > drivers/staging/android/ion/ion_chunk_heap.c | 15 +-
>> > drivers/staging/android/ion/ion_cma_heap.c | 102 ++------
>> > drivers/staging/android/ion/ion_dummy_driver.c | 156 ------------
>> > drivers/staging/android/ion/ion_enumerate.c | 89 +++++++
>> > drivers/staging/android/ion/ion_of.c | 184 --------------
>> > drivers/staging/android/ion/ion_of.h | 37 ---
>> > drivers/staging/android/ion/ion_page_pool.c | 3 -
>> > drivers/staging/android/ion/ion_priv.h | 57 ++++-
>> > drivers/staging/android/ion/ion_system_heap.c | 14 +-
>> > drivers/staging/android/ion/tegra/Makefile | 1 -
>> > drivers/staging/android/ion/tegra/tegra_ion.c | 80 ------
>> > include/linux/cma.h | 6 +-
>> > mm/cma.c | 25 +-
>> > mm/cma.h | 1 +
>> > mm/cma_debug.c | 2 +-
>> > 25 files changed, 312 insertions(+), 958 deletions(-)
>> > delete mode 100644 drivers/staging/android/ion/hisilicon/Kconfig
>> > delete mode 100644 drivers/staging/android/ion/hisilicon/Makefile
>> > delete mode 100644 drivers/staging/android/ion/hisilicon/hi6220_ion.c
>> > delete mode 100644 drivers/staging/android/ion/ion_dummy_driver.c
>> > create mode 100644 drivers/staging/android/ion/ion_enumerate.c
>> > delete mode 100644 drivers/staging/android/ion/ion_of.c
>> > delete mode 100644 drivers/staging/android/ion/ion_of.h
>> > delete mode 100644 drivers/staging/android/ion/tegra/Makefile
>> > delete mode 100644 drivers/staging/android/ion/tegra/tegra_ion.c
>> >
>> > --
>> > 2.7.4
>> >
>> > --
>> > To unsubscribe, send a message with 'unsubscribe linux-mm' in
>> > the body to majordomo at kvack.org. For more info on Linux MM,
>> > see: http://www.linux-mm.org/ .
>> > Don't email: email at kvack.org
>>
>> --
>> Daniel Vetter
>> Software Engineer, Intel Corporation
>> http://blog.ffwll.ch
>
> --
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch