From mboxrd@z Thu Jan 1 00:00:00 1970 From: Robin Murphy Subject: Re: [PATCH V5 3/5] iommu/dma-iommu: Handle deferred devices Date: Mon, 19 Aug 2019 19:26:08 +0100 Message-ID: <5a12defd-b68d-bd2d-da5a-16628a1f5b91@arm.com> References: <20190815110944.3579-1-murphyt7@tcd.ie> <20190815110944.3579-4-murphyt7@tcd.ie> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20190815110944.3579-4-murphyt7@tcd.ie> Content-Language: en-GB Sender: linux-kernel-owner@vger.kernel.org To: Tom Murphy , iommu@lists.linux-foundation.org Cc: Joerg Roedel , Will Deacon , Marek Szyprowski , Kukjin Kim , Krzysztof Kozlowski , David Woodhouse , Andy Gross , Matthias Brugger , Rob Clark , Heiko Stuebner , Gerald Schaefer , Thierry Reding , Jonathan Hunter , Jean-Philippe Brucker , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-mediatek@lists.infradead.org, linux-rockchip@lists.infradead.org, linux-s390@vger.kernel.o List-Id: linux-samsung-soc@vger.kernel.org On 15/08/2019 12:09, Tom Murphy wrote: > Handle devices which defer their attach to the iommu in the dma-iommu api Other than nitpicking the name (I'd lean towards something like iommu_dma_deferred_attach), Reviewed-by: Robin Murphy > Signed-off-by: Tom Murphy > --- > drivers/iommu/dma-iommu.c | 27 ++++++++++++++++++++++++++- > 1 file changed, 26 insertions(+), 1 deletion(-) > > diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c > index 2712fbc68b28..906b7fa14d3c 100644 > --- a/drivers/iommu/dma-iommu.c > +++ b/drivers/iommu/dma-iommu.c > @@ -22,6 +22,7 @@ > #include > #include > #include > +#include > > struct iommu_dma_msi_page { > struct list_head list; > @@ -351,6 +352,21 @@ static int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base, > return iova_reserve_iommu_regions(dev, domain); > } > > +static int handle_deferred_device(struct device *dev, > + struct iommu_domain *domain) > +{ > + const struct iommu_ops *ops = domain->ops; > + > + if (!is_kdump_kernel()) > + return 0; > + > + if (unlikely(ops->is_attach_deferred && > + ops->is_attach_deferred(domain, dev))) > + return iommu_attach_device(domain, dev); > + > + return 0; > +} > + > /** > * dma_info_to_prot - Translate DMA API directions and attributes to IOMMU API > * page flags. > @@ -463,6 +479,9 @@ static dma_addr_t __iommu_dma_map(struct device *dev, phys_addr_t phys, > size_t iova_off = iova_offset(iovad, phys); > dma_addr_t iova; > > + if (unlikely(handle_deferred_device(dev, domain))) > + return DMA_MAPPING_ERROR; > + > size = iova_align(iovad, size + iova_off); > > iova = iommu_dma_alloc_iova(domain, size, dma_get_mask(dev), dev); > @@ -581,6 +600,9 @@ static void *iommu_dma_alloc_remap(struct device *dev, size_t size, > > *dma_handle = DMA_MAPPING_ERROR; > > + if (unlikely(handle_deferred_device(dev, domain))) > + return NULL; > + > min_size = alloc_sizes & -alloc_sizes; > if (min_size < PAGE_SIZE) { > min_size = PAGE_SIZE; > @@ -713,7 +735,7 @@ static dma_addr_t iommu_dma_map_page(struct device *dev, struct page *page, > int prot = dma_info_to_prot(dir, coherent, attrs); > dma_addr_t dma_handle; > > - dma_handle =__iommu_dma_map(dev, phys, size, prot); > + dma_handle = __iommu_dma_map(dev, phys, size, prot); > if (!coherent && !(attrs & DMA_ATTR_SKIP_CPU_SYNC) && > dma_handle != DMA_MAPPING_ERROR) > arch_sync_dma_for_device(dev, phys, size, dir); > @@ -823,6 +845,9 @@ static int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg, > unsigned long mask = dma_get_seg_boundary(dev); > int i; > > + if (unlikely(handle_deferred_device(dev, domain))) > + return 0; > + > if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) > iommu_dma_sync_sg_for_device(dev, sg, nents, dir); > >