From mboxrd@z Thu Jan 1 00:00:00 1970 From: robin.murphy@arm.com (Robin Murphy) Date: Thu, 31 May 2018 18:52:48 +0100 Subject: [PATCH v4 1/2] ARM: dma-mapping: Set proper DMA ops in arm_iommu_detach_device() In-Reply-To: <20180530140625.21247-2-thierry.reding@gmail.com> References: <20180530140625.21247-1-thierry.reding@gmail.com> <20180530140625.21247-2-thierry.reding@gmail.com> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 30/05/18 15:06, Thierry Reding wrote: > From: Thierry Reding > > Instead of setting the DMA ops pointer to NULL, set the correct, > non-IOMMU ops depending on the device's coherency setting. It looks like it's probably been 4 or 5 years since that became subtly wrong by virtue of the landscape changing around it, but it's clearly not enough of a problem to consider stable backports :) Reviewed-by: Robin Murphy > Signed-off-by: Thierry Reding > --- > Changes in v4: > - new patch to fix existing arm_iommu_detach_device() to do what we need > > arch/arm/mm/dma-mapping.c | 12 ++++++------ > 1 file changed, 6 insertions(+), 6 deletions(-) > > diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c > index af27f1c22d93..87a0037574e4 100644 > --- a/arch/arm/mm/dma-mapping.c > +++ b/arch/arm/mm/dma-mapping.c > @@ -1151,6 +1151,11 @@ int arm_dma_supported(struct device *dev, u64 mask) > return __dma_supported(dev, mask, false); > } > > +static const struct dma_map_ops *arm_get_dma_map_ops(bool coherent) > +{ > + return coherent ? &arm_coherent_dma_ops : &arm_dma_ops; > +} > + > #ifdef CONFIG_ARM_DMA_USE_IOMMU > > static int __dma_info_to_prot(enum dma_data_direction dir, unsigned long attrs) > @@ -2296,7 +2301,7 @@ void arm_iommu_detach_device(struct device *dev) > iommu_detach_device(mapping->domain, dev); > kref_put(&mapping->kref, release_iommu_mapping); > to_dma_iommu_mapping(dev) = NULL; > - set_dma_ops(dev, NULL); > + set_dma_ops(dev, arm_get_dma_map_ops(dev->archdata.dma_coherent)); > > pr_debug("Detached IOMMU controller from %s device.\n", dev_name(dev)); > } > @@ -2357,11 +2362,6 @@ static void arm_teardown_iommu_dma_ops(struct device *dev) { } > > #endif /* CONFIG_ARM_DMA_USE_IOMMU */ > > -static const struct dma_map_ops *arm_get_dma_map_ops(bool coherent) > -{ > - return coherent ? &arm_coherent_dma_ops : &arm_dma_ops; > -} > - > void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size, > const struct iommu_ops *iommu, bool coherent) > { >