From mboxrd@z Thu Jan 1 00:00:00 1970 From: will.deacon@arm.com (Will Deacon) Date: Fri, 29 Aug 2014 16:54:23 +0100 Subject: [RFC PATCH 0/7] Introduce automatic DMA configuration for IOMMU masters Message-ID: <1409327670-3495-1-git-send-email-will.deacon@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi all, This patch series is an RFC to implement IOMMU master configuration into of_dma_configure. I haven't yet ported any IOMMU drivers to it, so it remains untested, but I wanted to get some early feedback to ensure that this doesn't end up going in the wrong direction. The idea comes out of my understanding following discussions with Arnd and David at Kernel Summit / LinuxCon in Chicago. Essentially: - Allow IOMMUs to be probed early and set up per-instance data on their of_node - Add a new callback to the iommu_ops structure for adding a device with a set of opaque IDs (e.g. Stream IDs or Requester IDs) - Add an of_iommu_configure function, called from of_dma_configure, which registers the master IDs with the correspond IOMMU before probing the master itself - Where applicable, create an IOMMU domain per device and swizzle the DMA ops for that device to use the IOMMU variants. I haven't bothered doing anything clever with the DMA masks yet, so I wouldn't be surprised if we end up chewing through tonnes of memory allocating IOMMU domains that are far too big at the moment. Again, this is just an RFC and I'd welcome comments on the general direction of the series. Cheers, Will --->8 Will Deacon (7): iommu: provide early initialisation hook for IOMMU drivers dma-mapping: replace set_arch_dma_coherent_ops with arch_setup_dma_ops iommu: add new iommu_ops callback for adding a device with a set of IDs iommu: provide helper function to configure an IOMMU for an of master dma-mapping: detect and configure IOMMU in of_dma_configure arm: call iommu_init before of_platform_populate arm: dma-mapping: plumb our iommu mapping ops into arch_setup_dma_ops arch/arm/include/asm/dma-mapping.h | 10 ++--- arch/arm/kernel/setup.c | 5 ++- arch/arm/mm/dma-mapping.c | 77 ++++++++++++++++++++++++++++++++++---- drivers/iommu/Kconfig | 2 +- drivers/iommu/of_iommu.c | 50 +++++++++++++++++++++++++ drivers/of/platform.c | 53 ++++++++++---------------- include/asm-generic/vmlinux.lds.h | 2 + include/linux/dma-mapping.h | 10 ++--- include/linux/iommu.h | 2 + include/linux/of_iommu.h | 27 +++++++++++++ 10 files changed, 184 insertions(+), 54 deletions(-) -- 2.1.0