> @@ -3631,35 +3607,30 @@ static int iommu_no_mapping(struct device *dev) > if (iommu_dummy(dev)) > return 1; > > - if (!iommu_identity_mapping) > - return 0; > -
FYI, iommu_no_mapping has been refactored in for-next: https://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu.git/commit/?h=x86/vt-d&id=48b2c937ea37a3bece0094b46450ed5267525289 > found = identity_mapping(dev); > if (found) { > + /* > + * If the device's dma_mask is less than the system's memory > + * size then this is not a candidate for identity mapping. > + */ > + u64 dma_mask = *dev->dma_mask; > + > + if (dev->coherent_dma_mask && > + dev->coherent_dma_mask < dma_mask) > + dma_mask = dev->coherent_dma_mask; > + > + if (dma_mask < dma_get_required_mask(dev)) { I know this is mostly existing code moved around, but it really needs some fixing. For one dma_get_required_mask is supposed to return the required to not bounce mask for the given device. E.g. for a device behind an iommu it should always just return 32-bit. If you really want to check vs system memory please call dma_direct_get_required_mask without the dma_ops indirection. Second I don't even think we need to check the coherent_dma_mask, dma_direct is pretty good at always finding memory even without an iommu. Third this doesn't take take the bus_dma_mask into account. This probably should just be: if (min(*dev->dma_mask, dev->bus_dma_mask) < dma_direct_get_required_mask(dev)) { _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
