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>

2 files changed, 12 insertions, 9 deletions

diff --git a/arch/powerpc/include/asm/iommu.h b/arch/powerpc/include/asm/iommu.h
index e2a45c37dba8..5a7267f47bdb 100644
--- a/arch/powerpc/include/asm/iommu.h
+++ b/arch/powerpc/include/asm/iommu.h
@@ -91,14 +91,9 @@ struct iommu_table {
 	struct iommu_pool pools[IOMMU_NR_POOLS];
 	unsigned long *it_map;       /* A simple allocation bitmap for now */
 	unsigned long  it_page_shift;/* table iommu page size */
-#ifdef CONFIG_IOMMU_API
-	struct iommu_group *it_group;
-#endif
+	struct iommu_table_group *it_table_group;
 	struct iommu_table_ops *it_ops;
 	void (*set_bypass)(struct iommu_table *tbl, bool enable);
-#ifdef CONFIG_PPC_POWERNV
-	void           *data;
-#endif
 };
 
 /* Pure 2^n version of get_order */
@@ -129,14 +124,22 @@ extern void iommu_free_table(struct iommu_table *tbl, const char *node_name);
  */
 extern struct iommu_table *iommu_init_table(struct iommu_table * tbl,
 					    int nid);
+#define IOMMU_TABLE_GROUP_MAX_TABLES	1
+
+struct iommu_table_group {
+	struct iommu_group *group;
+	struct iommu_table *tables[IOMMU_TABLE_GROUP_MAX_TABLES];
+};
+
 #ifdef CONFIG_IOMMU_API
-extern void iommu_register_group(struct iommu_table *tbl,
+
+extern void iommu_register_group(struct iommu_table_group *table_group,
 				 int pci_domain_number, unsigned long pe_num);
 extern int iommu_add_device(struct device *dev);
 extern void iommu_del_device(struct device *dev);
 extern int __init tce_iommu_bus_notifier_init(void);
 #else
-static inline void iommu_register_group(struct iommu_table *tbl,
+static inline void iommu_register_group(struct iommu_table_group *table_group,
 					int pci_domain_number,
 					unsigned long pe_num)
 {
diff --git a/arch/powerpc/include/asm/pci-bridge.h b/arch/powerpc/include/asm/pci-bridge.h
index b76cd5682a8c..712add590445 100644
--- a/arch/powerpc/include/asm/pci-bridge.h
+++ b/arch/powerpc/include/asm/pci-bridge.h
@@ -199,7 +199,7 @@ struct pci_dn {
 
 	struct  pci_dn *parent;
 	struct  pci_controller *phb;	/* for pci devices */
-	struct	iommu_table *iommu_table;	/* for phb's or bridges */
+	struct	iommu_table_group *table_group;	/* for phb's or bridges */
 	struct	device_node *node;	/* back-pointer to the device_node */
 
 	int	pci_ext_config_space;	/* for pci devices */