From f87a88642e660edd8912ad39fe77848c6f9927a2 Mon Sep 17 00:00:00 2001 From: Alexey Kardashevskiy Date: Fri, 5 Jun 2015 16:35:10 +1000 Subject: vfio: powerpc/spapr/iommu/powernv/ioda2: Rework IOMMU ownership control This adds tce_iommu_take_ownership() and tce_iommu_release_ownership which call in a loop iommu_take_ownership()/iommu_release_ownership() for every table on the group. As there is just one now, no change in behaviour is expected. At the moment the iommu_table struct has a set_bypass() which enables/ disables DMA bypass on IODA2 PHB. This is exposed to POWERPC IOMMU code which calls this callback when external IOMMU users such as VFIO are about to get over a PHB. The set_bypass() callback is not really an iommu_table function but IOMMU/PE function. This introduces a iommu_table_group_ops struct and adds take_ownership()/release_ownership() callbacks to it which are called when an external user takes/releases control over the IOMMU. This replaces set_bypass() with ownership callbacks as it is not necessarily just bypass enabling, it can be something else/more so let's give it more generic name. The callbacks is implemented for IODA2 only. Other platforms (P5IOC2, IODA1) will use the old iommu_take_ownership/iommu_release_ownership API. The following patches will replace iommu_take_ownership/ iommu_release_ownership calls in IODA2 with full IOMMU table release/ create. As we here and touching bypass control, this removes pnv_pci_ioda2_setup_bypass_pe() as it does not do much more compared to pnv_pci_ioda2_set_bypass. This moves tce_bypass_base initialization to pnv_pci_ioda2_setup_dma_pe. Signed-off-by: Alexey Kardashevskiy [aw: for the vfio related changes] Acked-by: Alex Williamson Reviewed-by: Gavin Shan Reviewed-by: David Gibson Signed-off-by: Michael Ellerman --- arch/powerpc/kernel/iommu.c | 12 ------------ 1 file changed, 12 deletions(-) (limited to 'arch/powerpc/kernel') diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c index be258b2ecb10..e7f81b7399ba 100644 --- a/arch/powerpc/kernel/iommu.c +++ b/arch/powerpc/kernel/iommu.c @@ -1047,14 +1047,6 @@ int iommu_take_ownership(struct iommu_table *tbl) memset(tbl->it_map, 0xff, sz); - /* - * Disable iommu bypass, otherwise the user can DMA to all of - * our physical memory via the bypass window instead of just - * the pages that has been explicitly mapped into the iommu - */ - if (tbl->set_bypass) - tbl->set_bypass(tbl, false); - return 0; } EXPORT_SYMBOL_GPL(iommu_take_ownership); @@ -1068,10 +1060,6 @@ void iommu_release_ownership(struct iommu_table *tbl) /* Restore bit#0 set by iommu_init_table() */ if (tbl->it_offset == 0) set_bit(0, tbl->it_map); - - /* The kernel owns the device now, we can restore the iommu bypass */ - if (tbl->set_bypass) - tbl->set_bypass(tbl, true); } EXPORT_SYMBOL_GPL(iommu_release_ownership); -- cgit v1.2.3