[PATCH v3 -next 0/9] CMA: generalize CMA reserved area management code

Marek Szyprowski
2014-06-16T09:11:35Z

Hello,

On 2014-06-16 07:40, Joonsoo Kim wrote:
> Currently, there are two users on CMA functionality, one is the DMA
> subsystem and the other is the KVM on powerpc. They have their own code
> to manage CMA reserved area even if they looks really similar.
> >From my guess, it is caused by some needs on bitmap management. Kvm side
> wants to maintain bitmap not for 1 page, but for more size. Eventually it
> use bitmap where one bit represents 64 pages.
>
> When I implement CMA related patches, I should change those two places
> to apply my change and it seem to be painful to me. I want to change
> this situation and reduce future code management overhead through
> this patch.
>
> This change could also help developer who want to use CMA in their
> new feature development, since they can use CMA easily without
> copying & pasting this reserved area management code.
>
> v3:
> - Simplify old patch 1(log format fix) and move it to the end of patchset.
> - Patch 2: Pass aligned base and size to dma_contiguous_early_fixup()
> - Patch 5: Add some accessor functions to pass aligned base and size to
> dma_contiguous_early_fixup() function
> - Patch 5: Move MAX_CMA_AREAS definition to cma.h
> - Patch 6: Add CMA region zeroing to PPC KVM's CMA alloc function
> - Patch 8: put 'base' ahead of 'size' in cma_declare_contiguous()
> - Remaining minor fixes are noted in commit description of each one
>
> v2:
> - Although this patchset looks very different with v1, the end result,
> that is, mm/cma.c is same with v1's one. So I carry Ack to patch 6-7.
>
> This patchset is based on linux-next 20140610.

Thanks for taking care of this. I will test it with my setup and if
everything goes well, I will take it to my -next tree. If any branch
is required for anyone to continue his works on top of those patches,
let me know, I will also prepare it.

> Patch 1-4 prepare some features to cover PPC KVM's requirements.
> Patch 5-6 generalize CMA reserved area management code and change users
> to use it.
> Patch 7-9 clean-up minor things.
>
> Joonsoo Kim (9):
> DMA, CMA: fix possible memory leak
> DMA, CMA: separate core CMA management codes from DMA APIs
> DMA, CMA: support alignment constraint on CMA region
> DMA, CMA: support arbitrary bitmap granularity
> CMA: generalize CMA reserved area management functionality
> PPC, KVM, CMA: use general CMA reserved area management framework
> mm, CMA: clean-up CMA allocation error path
> mm, CMA: change cma_declare_contiguous() to obey coding convention
> mm, CMA: clean-up log message
>
> arch/arm/mm/dma-mapping.c | 1 +
> arch/powerpc/kvm/book3s_64_mmu_hv.c | 4 +-
> arch/powerpc/kvm/book3s_hv_builtin.c | 19 +-
> arch/powerpc/kvm/book3s_hv_cma.c | 240 ------------------------
> arch/powerpc/kvm/book3s_hv_cma.h | 27 ---
> drivers/base/Kconfig | 10 -
> drivers/base/dma-contiguous.c | 210 ++-------------------
> include/linux/cma.h | 21 +++
> include/linux/dma-contiguous.h | 11 +-
> mm/Kconfig | 11 ++
> mm/Makefile | 1 +
> mm/cma.c | 335 ++++++++++++++++++++++++++++++++++
> 12 files changed, 397 insertions(+), 493 deletions(-)
> delete mode 100644 arch/powerpc/kvm/book3s_hv_cma.c
> delete mode 100644 arch/powerpc/kvm/book3s_hv_cma.h
> create mode 100644 include/linux/cma.h
> create mode 100644 mm/cma.c
>

Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland