powerpc/iommu/powernv: Get rid of set_iommu_table_base_and_group

The set_iommu_table_base_and_group() name suggests that the function
sets table base and add a device to an IOMMU group.

The actual purpose for table base setting is to put some reference
into a device so later iommu_add_device() can get the IOMMU group
reference and the device to the group.

At the moment a group cannot be explicitly passed to iommu_add_device()
as we want it to work from the bus notifier, we can fix it later and
remove confusing calls of set_iommu_table_base().

This replaces set_iommu_table_base_and_group() with a couple of
set_iommu_table_base() + iommu_add_device() which makes reading the code
easier.

This adds few comments why set_iommu_table_base() and iommu_add_device()
are called where they are called.

For IODA1/2, this essentially removes iommu_add_device() call from
the pnv_pci_ioda_dma_dev_setup() as it will always fail at this particular
place:
- for physical PE, the device is already attached by iommu_add_device()
in pnv_pci_ioda_setup_dma_pe();
- for virtual PE, the sysfs entries are not ready to create all symlinks
so actual adding is happening in tce_iommu_bus_notifier.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

2 files changed, 25 insertions, 5 deletions

diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index 5491d2f0e192..fd594b28fce1 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -1598,7 +1598,13 @@ 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(&pdev->dev, pe->tce32_table);
+	/*
+	 * Note: iommu_add_device() will fail here as
+	 * for physical PE: the device is already added by now;
+	 * for virtual PE: sysfs entries are not ready yet and
+	 * tce_iommu_bus_notifier will add the device to a group later.
+	 */
 }
 
 static int pnv_pci_ioda_dma_set_mask(struct pci_dev *pdev, u64 dma_mask)
@@ -1660,7 +1666,8 @@ static void pnv_ioda_setup_bus_dma(struct pnv_ioda_pe *pe,
 	struct pci_dev *dev;
 
 	list_for_each_entry(dev, &bus->devices, bus_list) {
-		set_iommu_table_base_and_group(&dev->dev, pe->tce32_table);
+		set_iommu_table_base(&dev->dev, pe->tce32_table);
+		iommu_add_device(&dev->dev);
 
 		if (dev->subordinate)
 			pnv_ioda_setup_bus_dma(pe, dev->subordinate);
@@ -1836,7 +1843,13 @@ static void pnv_pci_ioda_setup_dma_pe(struct pnv_phb *phb,
 	if (pe->flags & PNV_IODA_PE_DEV) {
 		iommu_register_group(tbl, phb->hose->global_number,
 				     pe->pe_number);
-		set_iommu_table_base_and_group(&pe->pdev->dev, tbl);
+		/*
+		 * Setting table base here only for carrying iommu_group
+		 * further down to let iommu_add_device() do the job.
+		 * pnv_pci_ioda_dma_dev_setup will override it later anyway.
+		 */
+		set_iommu_table_base(&pe->pdev->dev, tbl);
+		iommu_add_device(&pe->pdev->dev);
 	} else if (pe->flags & (PNV_IODA_PE_BUS | PNV_IODA_PE_BUS_ALL)) {
 		iommu_register_group(tbl, phb->hose->global_number,
 				     pe->pe_number);
@@ -1964,7 +1977,13 @@ static void pnv_pci_ioda2_setup_dma_pe(struct pnv_phb *phb,
 	if (pe->flags & PNV_IODA_PE_DEV) {
 		iommu_register_group(tbl, phb->hose->global_number,
 				     pe->pe_number);
-		set_iommu_table_base_and_group(&pe->pdev->dev, tbl);
+		/*
+		 * Setting table base here only for carrying iommu_group
+		 * further down to let iommu_add_device() do the job.
+		 * pnv_pci_ioda_dma_dev_setup will override it later anyway.
+		 */
+		set_iommu_table_base(&pe->pdev->dev, tbl);
+		iommu_add_device(&pe->pdev->dev);
 	} else if (pe->flags & (PNV_IODA_PE_BUS | PNV_IODA_PE_BUS_ALL)) {
 		iommu_register_group(tbl, phb->hose->global_number,
 				     pe->pe_number);
diff --git a/arch/powerpc/platforms/powernv/pci-p5ioc2.c b/arch/powerpc/platforms/powernv/pci-p5ioc2.c
index 7f826e8cc1d4..61ae20aa9000 100644
--- a/arch/powerpc/platforms/powernv/pci-p5ioc2.c
+++ b/arch/powerpc/platforms/powernv/pci-p5ioc2.c
@@ -92,7 +92,8 @@ static void pnv_pci_p5ioc2_dma_dev_setup(struct pnv_phb *phb,
 				pci_domain_nr(phb->hose->bus), phb->opal_id);
 	}
 
-	set_iommu_table_base_and_group(&pdev->dev, &phb->p5ioc2.iommu_table);
+	set_iommu_table_base(&pdev->dev, &phb->p5ioc2.iommu_table);
+	iommu_add_device(&pdev->dev);
 }
 
 static const struct pci_controller_ops pnv_pci_p5ioc2_controller_ops = {