On 30/05/18 15:06, Thierry Reding wrote:
From: Thierry Reding treding@nvidia.com
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 robin.murphy@arm.com
Signed-off-by: Thierry Reding treding@nvidia.com
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) {