Back when this was first written, dma_supported() was somewhat of a murky mess, with subtly different interpretations being relied upon in various places. The "does device X support DMA to address range Y?" uses assuming Y to be physical addresses, which motivated the current iommu_dma_supported() implementation and are alluded to in the comment therein, have since been cleaned up, leaving only the far less ambiguous "can device X drive address bits Y" usage internal to DMA API mask setting. As such, there is no reason to keep a slightly misleading callback which does nothing but duplicate the current default behaviour; we already constrain IOVA allocations to the iommu_domain aperture where necessary, so let's leave DMA mask business to architecture-specific code where it belongs.
Signed-off-by: Robin Murphy <[email protected]> --- Techincally an IOMMU patch, but could possibly go via arm64 I suppose. arch/arm64/mm/dma-mapping.c | 1 - drivers/iommu/dma-iommu.c | 10 ---------- include/linux/dma-iommu.h | 1 - 3 files changed, 12 deletions(-) diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c index 88493b0ebd5e..351f7595cb3e 100644 --- a/arch/arm64/mm/dma-mapping.c +++ b/arch/arm64/mm/dma-mapping.c @@ -810,7 +810,6 @@ static struct dma_map_ops iommu_dma_ops = { .sync_sg_for_device = __iommu_sync_sg_for_device, .map_resource = iommu_dma_map_resource, .unmap_resource = iommu_dma_unmap_resource, - .dma_supported = iommu_dma_supported, .mapping_error = iommu_dma_mapping_error, }; diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index 1c9ac26e3b68..48d36ce59efb 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -734,16 +734,6 @@ void iommu_dma_unmap_resource(struct device *dev, dma_addr_t handle, __iommu_dma_unmap(iommu_get_domain_for_dev(dev), handle); } -int iommu_dma_supported(struct device *dev, u64 mask) -{ - /* - * 'Special' IOMMUs which don't have the same addressing capability - * as the CPU will have to wait until we have some way to query that - * before they'll be able to use this framework. - */ - return 1; -} - int iommu_dma_mapping_error(struct device *dev, dma_addr_t dma_addr) { return dma_addr == DMA_ERROR_CODE; diff --git a/include/linux/dma-iommu.h b/include/linux/dma-iommu.h index 3a846f9ec0fd..5725c94b1f12 100644 --- a/include/linux/dma-iommu.h +++ b/include/linux/dma-iommu.h @@ -67,7 +67,6 @@ dma_addr_t iommu_dma_map_resource(struct device *dev, phys_addr_t phys, size_t size, enum dma_data_direction dir, unsigned long attrs); void iommu_dma_unmap_resource(struct device *dev, dma_addr_t handle, size_t size, enum dma_data_direction dir, unsigned long attrs); -int iommu_dma_supported(struct device *dev, u64 mask); int iommu_dma_mapping_error(struct device *dev, dma_addr_t dma_addr); /* The DMA API isn't _quite_ the whole story, though... */ -- 2.11.0.dirty _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
