RE: Re: CMA in AMD IOMMU driver
Hi Christoph, Im able to reserve CMA memory during boot up in AMD. But how can i use/allocate that memory in my driver. I dont know if this is the right forum to ask such question. Any help will be appriciated. Thanks and regards, Sathya - Original Message - Sender : Christoph Hellwig Date : 2019-06-26 12:28 (GMT+5:30) Title : Re: CMA in AMD IOMMU driver To : Sathyavathi M CC : null Toms conversion of the AMD IOMMU driver to use dma-iommu adds CMA support :) Regards, Sathya ___ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
RE: RE: Re: CMA in AMD IOMMU driver
I tried to apply the patch (AMD IOMMU driver to use dma-iommu) to linux kerenl 5.1.15 but it gives me some errors. Downloaded the patch from https://patchwork.ozlabs.org/patch/1096015/ Is this the right way im doing? Please let me know. Thanks, Sathya - Original Message - Sender : Sathyavathi M Engineer/Host Software /SSIR/Samsung Electronics Date : 2019-06-26 15:21 (GMT+5:30) Title : RE: Re: CMA in AMD IOMMU driver To : null CC : null Dear Christoph, Thanks for the reply. can you please let me know which kernel has it? Thanks, Sathya - Original Message - Sender : Christoph Hellwig Date : 2019-06-26 12:28 (GMT+5:30) Title : Re: CMA in AMD IOMMU driver To : Sathyavathi M CC : null Toms conversion of the AMD IOMMU driver to use dma-iommu adds CMA support :) Regards, Sathya ___ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu Regards, Sathya ___ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
RE: Re: CMA in AMD IOMMU driver
Dear Christoph, Thanks for the reply. can you please let me know which kernel has it? Thanks, Sathya - Original Message - Sender : Christoph Hellwig Date : 2019-06-26 12:28 (GMT+5:30) Title : Re: CMA in AMD IOMMU driver To : Sathyavathi M CC : null Toms conversion of the AMD IOMMU driver to use dma-iommu adds CMA support :) Regards, Sathya ___ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
Re: CMA in AMD IOMMU driver
Toms conversion of the AMD IOMMU driver to use dma-iommu adds CMA support :) ___ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
CMA in AMD IOMMU driver
Dear All, This mail regarding the below communication about CMA in AMD IOMMU driver. On Mon, Feb 02, 2015 at 10:35:36AM -0700, Alex Williamson wrote: > [cc +joerg] > > On Mon, 2015-02-02 at 11:01 -0500, Mark Hounschell wrote: > > From what I understand of CMA, and it seems provable to me, is that > > dma_alloc_coherent allocates my 8MB buffer from CMA defined on the > > cmdline. Without CMA specified on the cmdline, dma_alloc_coherent > > definitely fails to allocate an 8MB contiguous buffer. From what I've > > read about it, it is supposed to transparently "just work" when > > dma_alloc_coherent is used? > > Yes, if you're running with the software iotlb (aka. bounce buffers), > then dma_ops->alloc is x86_swiotlb_alloc_coherent(), which calls > dma_generic_alloc_coherent(), which attempts to use CMA via > dma_alloc_from_contiguous(). > > If you look at the same path with AMD-Vi, dma_ops->alloc is > amd_iommu.c:alloc_coherent(), which simply uses __get_free_pages() to > allocate the buffer. I don't see any CMA integration along that path. > If you were using Intel VT-d, then the buffer is again allocated with > dma_alloc_from_contiguous() and should use CMA. This was added in > kernel v3.16, but no corresponding AMD-Vi change was added. Joerg, this > might be an easily fixed oversight. Right, CMA is not yet integrated in the AMD IOMMU driver, nobody asked fot it until now :) I will add that fall-back there for big allocations. Joerg Has CMA been added in AMD IOMMU driver, If yes which version of kernel has it. Thanks in Advance. Regards, Sathya ___ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
