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With the current IOMMU-API the hardware TLBs have to be flushed in every iommu_ops->unmap() call-back. For unmapping large amounts of address space, like it happens when a KVM domain with assigned devices is destroyed, this causes thousands of unnecessary TLB flushes in the IOMMU hardware because the unmap call-back runs for every unmapped physical page. With the TLB Flush Interface and the new iommu_unmap_fast() function introduced here the need to clean the hardware TLBs is removed from the unmapping code-path. Users of iommu_unmap_fast() have to explicitly call the TLB-Flush functions to sync the page-table changes to the hardware. Three functions for TLB-Flushes are introduced: * iommu_flush_tlb_all() - Flushes all TLB entries associated with that domain. TLBs entries are flushed when this function returns. * iommu_tlb_range_add() - This will add a given range to the flush queue for this domain. * iommu_tlb_sync() - Flushes all queued ranges from the hardware TLBs. Returns when the flush is finished. The semantic of this interface is intentionally similar to the iommu_gather_ops from the io-pgtable code. Cc: Alex Williamson <alex.williamson@redhat.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Joerg Roedel <jroedel@suse.de>