* CMA in AMD IOMMU driver [not found] <CGME20190626043433epcms5p84b9b6580f6c6444e69b85525863460ea@epcms5p8> @ 2019-06-26 4:34 ` Sathyavathi M 2019-06-26 6:58 ` Christoph Hellwig 0 siblings, 1 reply; 5+ messages in thread From: Sathyavathi M @ 2019-06-26 4:34 UTC (permalink / raw) To: iommu@lists.linux-foundation.org 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 ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: CMA in AMD IOMMU driver 2019-06-26 4:34 ` CMA in AMD IOMMU driver Sathyavathi M @ 2019-06-26 6:58 ` Christoph Hellwig 2019-06-26 9:48 ` Sathyavathi M 2019-07-01 6:19 ` Sathyavathi M 0 siblings, 2 replies; 5+ messages in thread From: Christoph Hellwig @ 2019-06-26 6:58 UTC (permalink / raw) To: Sathyavathi M; +Cc: iommu@lists.linux-foundation.org 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 ^ permalink raw reply [flat|nested] 5+ messages in thread
* RE: Re: CMA in AMD IOMMU driver 2019-06-26 6:58 ` Christoph Hellwig @ 2019-06-26 9:48 ` Sathyavathi M 2019-06-27 5:55 ` Sathyavathi M 2019-07-01 6:19 ` Sathyavathi M 1 sibling, 1 reply; 5+ messages in thread From: Sathyavathi M @ 2019-06-26 9:48 UTC (permalink / raw) To: Christoph Hellwig; +Cc: iommu@lists.linux-foundation.org Dear Christoph, Thanks for the reply. can you please let me know which kernel has it? Thanks, Sathya --------- Original Message --------- Sender : Christoph Hellwig <hch@infradead.org> Date : 2019-06-26 12:28 (GMT+5:30) Title : Re: CMA in AMD IOMMU driver To : Sathyavathi M<sathya.m@samsung.com> CC : null<iommu@lists.linux-foundation.org> 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 ^ permalink raw reply [flat|nested] 5+ messages in thread
* RE: RE: Re: CMA in AMD IOMMU driver 2019-06-26 9:48 ` Sathyavathi M @ 2019-06-27 5:55 ` Sathyavathi M 0 siblings, 0 replies; 5+ messages in thread From: Sathyavathi M @ 2019-06-27 5:55 UTC (permalink / raw) To: Christoph Hellwig; +Cc: iommu@lists.linux-foundation.org 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 <sathya.m@samsung.com> 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<hch@infradead.org> CC : null<iommu@lists.linux-foundation.org> Dear Christoph, Thanks for the reply. can you please let me know which kernel has it? Thanks, Sathya --------- Original Message --------- Sender : Christoph Hellwig <hch@infradead.org> Date : 2019-06-26 12:28 (GMT+5:30) Title : Re: CMA in AMD IOMMU driver To : Sathyavathi M<sathya.m@samsung.com> CC : null<iommu@lists.linux-foundation.org> 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 ^ permalink raw reply [flat|nested] 5+ messages in thread
* RE: Re: CMA in AMD IOMMU driver 2019-06-26 6:58 ` Christoph Hellwig 2019-06-26 9:48 ` Sathyavathi M @ 2019-07-01 6:19 ` Sathyavathi M 1 sibling, 0 replies; 5+ messages in thread From: Sathyavathi M @ 2019-07-01 6:19 UTC (permalink / raw) To: Christoph Hellwig; +Cc: iommu@lists.linux-foundation.org [-- Attachment #1.1: Type: text/html, Size: 3222 bytes --] [-- Attachment #1.2: 201602111742151_N3WZA6X7.png --] [-- Type: image/png, Size: 33527 bytes --] [-- Attachment #2: Type: text/plain, Size: 156 bytes --] _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu ^ permalink raw reply [flat|nested] 5+ messages in thread
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2019-06-26 4:34 ` CMA in AMD IOMMU driver Sathyavathi M
2019-06-26 6:58 ` Christoph Hellwig
2019-06-26 9:48 ` Sathyavathi M
2019-06-27 5:55 ` Sathyavathi M
2019-07-01 6:19 ` Sathyavathi M
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