powerpc/spapr: vfio: Replace iommu_table with iommu_table_group

Modern IBM POWERPC systems support multiple (currently two) TCE tables
per IOMMU group (a.k.a. PE). This adds a iommu_table_group container
for TCE tables. Right now just one table is supported.

This defines iommu_table_group struct which stores pointers to
iommu_group and iommu_table(s). This replaces iommu_table with
iommu_table_group where iommu_table was used to identify a group:
- iommu_register_group();
- iommudata of generic iommu_group;

This removes @data from iommu_table as it_table_group provides
same access to pnv_ioda_pe.

For IODA, instead of embedding iommu_table, the new iommu_table_group
keeps pointers to those. The iommu_table structs are allocated
dynamically.

For P5IOC2, both iommu_table_group and iommu_table are embedded into
PE struct. As there is no EEH and SRIOV support for P5IOC2,
iommu_free_table() should not be called on iommu_table struct pointers
so we can keep it embedded in pnv_phb::p5ioc2.

For pSeries, this replaces multiple calls of kzalloc_node() with a new
iommu_pseries_alloc_group() helper and stores the table group struct
pointer into the pci_dn struct. For release, a iommu_table_free_group()
helper is added.

This moves iommu_table struct allocation from SR-IOV code to
the generic DMA initialization code in pnv_pci_ioda_setup_dma_pe and
pnv_pci_ioda2_setup_dma_pe as this is where DMA is actually initialized.
This change is here because those lines had to be changed anyway.

This should cause no behavioural change.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
[aw: for the vfio related changes]
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

1 files changed, 9 insertions, 8 deletions

diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
index c0e67e945c95..719f0485ec79 100644
--- a/arch/powerpc/kernel/iommu.c
+++ b/arch/powerpc/kernel/iommu.c
@@ -889,11 +889,12 @@ EXPORT_SYMBOL_GPL(iommu_direction_to_tce_perm);
  */
 static void group_release(void *iommu_data)
 {
-	struct iommu_table *tbl = iommu_data;
-	tbl->it_group = NULL;
+	struct iommu_table_group *table_group = iommu_data;
+
+	table_group->group = NULL;
 }
 
-void iommu_register_group(struct iommu_table *tbl,
+void iommu_register_group(struct iommu_table_group *table_group,
 		int pci_domain_number, unsigned long pe_num)
 {
 	struct iommu_group *grp;
@@ -905,8 +906,8 @@ void iommu_register_group(struct iommu_table *tbl,
 				PTR_ERR(grp));
 		return;
 	}
-	tbl->it_group = grp;
-	iommu_group_set_iommudata(grp, tbl, group_release);
+	table_group->group = grp;
+	iommu_group_set_iommudata(grp, table_group, group_release);
 	name = kasprintf(GFP_KERNEL, "domain%d-pe%lx",
 			pci_domain_number, pe_num);
 	if (!name)
@@ -1094,7 +1095,7 @@ int iommu_add_device(struct device *dev)
 	}
 
 	tbl = get_iommu_table_base(dev);
-	if (!tbl || !tbl->it_group) {
+	if (!tbl || !tbl->it_table_group || !tbl->it_table_group->group) {
 		pr_debug("%s: Skipping device %s with no tbl\n",
 			 __func__, dev_name(dev));
 		return 0;
@@ -1102,7 +1103,7 @@ int iommu_add_device(struct device *dev)
 
 	pr_debug("%s: Adding %s to iommu group %d\n",
 		 __func__, dev_name(dev),
-		 iommu_group_id(tbl->it_group));
+		 iommu_group_id(tbl->it_table_group->group));
 
 	if (PAGE_SIZE < IOMMU_PAGE_SIZE(tbl)) {
 		pr_err("%s: Invalid IOMMU page size %lx (%lx) on %s\n",
@@ -1111,7 +1112,7 @@ int iommu_add_device(struct device *dev)
 		return -EINVAL;
 	}
 
-	return iommu_group_add_device(tbl->it_group, dev);
+	return iommu_group_add_device(tbl->it_table_group->group, dev);
 }
 EXPORT_SYMBOL_GPL(iommu_add_device);