powerpc/powernv: Allocate struct pnv_ioda_pe iommu_table dynamically

Previously the iommu_table had the same lifetime as a struct pnv_ioda_pe
and was embedded in it. The pnv_ioda_pe was assigned to a PE on the bootup
stage. Since PEs are based on the hardware layout which is static in the
system, they will never get released. This means the iommu_table in the
pnv_ioda_pe will never get released either.

This no longer works for VF PE. VF PEs are created and released dynamically
when VFs are created and released. So we need to assign pnv_ioda_pe to VF
PEs respectively when VFs are enabled and clean up those resources for VF
PE when VFs are disabled. And iommu_table is one of the resources we need
to handle dynamically.

Current iommu_table is a static field in pnv_ioda_pe, which will face a
problem when freeing it. During the disabling of a VF,
pnv_pci_ioda2_release_dma_pe will call iommu_free_table to release the
iommu_table for this PE. A static iommu_table will fail in
iommu_free_table.

According to these requirement, this patch allocates iommu_table
dynamically.

Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/include/asm/iommu.h

@@ -78,6 +78,9 @@ struct iommu_table {
 	struct iommu_group *it_group;
 #endif
 	void (*set_bypass)(struct iommu_table *tbl, bool enable);
+#ifdef CONFIG_PPC_POWERNV
+	void           *data;
+#endif
 };
 
 /* Pure 2^n version of get_order */

arch/powerpc/platforms/powernv/pci-ioda.c

@@ -916,6 +916,10 @@ static void pnv_ioda_setup_bus_PE(struct pci_bus *bus, int all)
 		return;
 	}
 
+	pe->tce32_table = kzalloc_node(sizeof(struct iommu_table),
+			GFP_KERNEL, hose->node);
+	pe->tce32_table->data = pe;
+
 	/* Associate it with all child devices */
 	pnv_ioda_setup_same_PE(bus, pe);
 
@@ -1005,7 +1009,7 @@ static void pnv_pci_ioda_dma_dev_setup(struct pnv_phb *phb, struct pci_dev *pdev
 
 	pe = &phb->ioda.pe_array[pdn->pe_number];
 	WARN_ON(get_dma_ops(&pdev->dev) != &dma_iommu_ops);
-	set_iommu_table_base_and_group(&pdev->dev, &pe->tce32_table);
+	set_iommu_table_base_and_group(&pdev->dev, pe->tce32_table);
 }
 
 static int pnv_pci_ioda_dma_set_mask(struct pnv_phb *phb,
@@ -1032,7 +1036,7 @@ static int pnv_pci_ioda_dma_set_mask(struct pnv_phb *phb,
 	} else {
 		dev_info(&pdev->dev, "Using 32-bit DMA via iommu\n");
 		set_dma_ops(&pdev->dev, &dma_iommu_ops);
-		set_iommu_table_base(&pdev->dev, &pe->tce32_table);
+		set_iommu_table_base(&pdev->dev, pe->tce32_table);
 	}
 	*pdev->dev.dma_mask = dma_mask;
 	return 0;
@@ -1069,9 +1073,9 @@ static void pnv_ioda_setup_bus_dma(struct pnv_ioda_pe *pe,
 	list_for_each_entry(dev, &bus->devices, bus_list) {
 		if (add_to_iommu_group)
 			set_iommu_table_base_and_group(&dev->dev,
-						       &pe->tce32_table);
+						       pe->tce32_table);
 		else
-			set_iommu_table_base(&dev->dev, &pe->tce32_table);
+			set_iommu_table_base(&dev->dev, pe->tce32_table);
 
 		if (dev->subordinate)
 			pnv_ioda_setup_bus_dma(pe, dev->subordinate,
@@ -1161,8 +1165,7 @@ static void pnv_pci_ioda2_tce_invalidate(struct pnv_ioda_pe *pe,
 void pnv_pci_ioda_tce_invalidate(struct iommu_table *tbl,
 				 __be64 *startp, __be64 *endp, bool rm)
 {
-	struct pnv_ioda_pe *pe = container_of(tbl, struct pnv_ioda_pe,
-					      tce32_table);
+	struct pnv_ioda_pe *pe = tbl->data;
 	struct pnv_phb *phb = pe->phb;
 
 	if (phb->type == PNV_PHB_IODA1)
@@ -1228,7 +1231,7 @@ static void pnv_pci_ioda_setup_dma_pe(struct pnv_phb *phb,
 	}
 
 	/* Setup linux iommu table */
-	tbl = &pe->tce32_table;
+	tbl = pe->tce32_table;
 	pnv_pci_setup_iommu_table(tbl, addr, TCE32_TABLE_SIZE * segs,
 				  base << 28, IOMMU_PAGE_SHIFT_4K);
 
@@ -1266,8 +1269,7 @@ static void pnv_pci_ioda_setup_dma_pe(struct pnv_phb *phb,
 
 static void pnv_pci_ioda2_set_bypass(struct iommu_table *tbl, bool enable)
 {
-	struct pnv_ioda_pe *pe = container_of(tbl, struct pnv_ioda_pe,
-					      tce32_table);
+	struct pnv_ioda_pe *pe = tbl->data;
 	uint16_t window_id = (pe->pe_number << 1 ) + 1;
 	int64_t rc;
 
@@ -1312,10 +1314,10 @@ static void pnv_pci_ioda2_setup_bypass_pe(struct pnv_phb *phb,
 	pe->tce_bypass_base = 1ull << 59;
 
 	/* Install set_bypass callback for VFIO */
-	pe->tce32_table.set_bypass = pnv_pci_ioda2_set_bypass;
+	pe->tce32_table->set_bypass = pnv_pci_ioda2_set_bypass;
 
 	/* Enable bypass by default */
-	pnv_pci_ioda2_set_bypass(&pe->tce32_table, true);
+	pnv_pci_ioda2_set_bypass(pe->tce32_table, true);
 }
 
 static void pnv_pci_ioda2_setup_dma_pe(struct pnv_phb *phb,
@@ -1363,7 +1365,7 @@ static void pnv_pci_ioda2_setup_dma_pe(struct pnv_phb *phb,
 	}
 
 	/* Setup linux iommu table */
-	tbl = &pe->tce32_table;
+	tbl = pe->tce32_table;
 	pnv_pci_setup_iommu_table(tbl, addr, tce_table_size, 0,
 			IOMMU_PAGE_SHIFT_4K);
 

arch/powerpc/platforms/powernv/pci.h

@@ -53,7 +53,7 @@ struct pnv_ioda_pe {
 	/* "Base" iommu table, ie, 4K TCEs, 32-bit DMA */
 	int			tce32_seg;
 	int			tce32_segcount;
-	struct iommu_table	tce32_table;
+	struct iommu_table	*tce32_table;
 	phys_addr_t		tce_inval_reg_phys;
 
 	/* 64-bit TCE bypass region */