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 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>