diff options
| author | Alexey Kardashevskiy <aik@ozlabs.ru> | 2023-03-06 18:30:20 +0100 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2023-03-14 13:36:27 +0100 |
| commit | 9d67c94335096311c0bc7556ad1022de7385790b (patch) | |
| tree | 818fb720dc6b4700345e0096fc09c85e8bc5d9fe /arch/powerpc/platforms/powernv/pci-ioda.c | |
| parent | Linux 6.3-rc2 (diff) | |
| download | linux-9d67c94335096311c0bc7556ad1022de7385790b.tar.xz linux-9d67c94335096311c0bc7556ad1022de7385790b.zip | |
powerpc/iommu: Add "borrowing" iommu_table_group_ops
PPC64 IOMMU API defines iommu_table_group_ops which handles DMA windows
for PEs: control the ownership, create/set/unset a table the hardware
for dynamic DMA windows (DDW). VFIO uses the API to implement support on
POWER.
So far only PowerNV IODA2 (POWER8 and newer machines) implemented this
and other cases (POWER7 or nested KVM) did not and instead reused
existing iommu_table structs. This means 1) no DDW 2) ownership transfer
is done directly in the VFIO SPAPR TCE driver.
Soon POWER is going to get its own iommu_ops and ownership control is
going to move there. This implements spapr_tce_table_group_ops which
borrows iommu_table tables. The upside is that VFIO needs to know less
about POWER.
The new ops returns the existing table from create_table() and only
checks if the same window is already set. This is only going to work if
the default DMA window starts table_group.tce32_start and as big as
pe->table_group.tce32_size (not the case for IODA2+ PowerNV).
This changes iommu_table_group_ops::take_ownership() to return an error
if borrowing a table failed.
This should not cause any visible change in behavior for PowerNV.
pSeries was not that well tested/supported anyway.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Timothy Pearson <tpearson@raptorengineering.com>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
[mpe: Fix CONFIG_IOMMU_API=n build (skiroot_defconfig), & formatting]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/525438831.16998517.1678123820075.JavaMail.zimbra@raptorengineeringinc.com
Diffstat (limited to 'arch/powerpc/platforms/powernv/pci-ioda.c')
| -rw-r--r-- | arch/powerpc/platforms/powernv/pci-ioda.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c index 4f6e20a35aa1..c8a5caedc4c5 100644 --- a/arch/powerpc/platforms/powernv/pci-ioda.c +++ b/arch/powerpc/platforms/powernv/pci-ioda.c @@ -1554,6 +1554,10 @@ found: if (WARN_ON(!tbl)) return; +#ifdef CONFIG_IOMMU_API + pe->table_group.ops = &spapr_tce_table_group_ops; + pe->table_group.pgsizes = SZ_4K; +#endif iommu_register_group(&pe->table_group, phb->hose->global_number, pe->pe_number); pnv_pci_link_table_and_group(phb->hose->node, 0, tbl, &pe->table_group); @@ -1888,7 +1892,7 @@ static void pnv_ioda_setup_bus_dma(struct pnv_ioda_pe *pe, struct pci_bus *bus) } } -static void pnv_ioda2_take_ownership(struct iommu_table_group *table_group) +static long pnv_ioda2_take_ownership(struct iommu_table_group *table_group) { struct pnv_ioda_pe *pe = container_of(table_group, struct pnv_ioda_pe, table_group); @@ -1902,6 +1906,8 @@ static void pnv_ioda2_take_ownership(struct iommu_table_group *table_group) else if (pe->pdev) set_iommu_table_base(&pe->pdev->dev, NULL); iommu_tce_table_put(tbl); + + return 0; } static void pnv_ioda2_release_ownership(struct iommu_table_group *table_group) |