powerpc/iommu: Cleanup setting of DMA base/offset

Now that the table and the offset can co-exist, we no longer need to flip/flop, we can just establish both once at boot time.

Signed-off-by Benjamin Herrenschmidt <[email protected]>

---
  arch/powerpc/platforms/powernv/pci-ioda.c |  3 +--
  arch/powerpc/platforms/pseries/iommu.c    |  3 +--
  arch/powerpc/sysdev/dart_iommu.c          | 16 +++-------------
  3 files changed, 5 insertions(+), 17 deletions(-)

arch/powerpc/platforms/powernv/pci-ioda.c +0 -0

index 5738d31..2c286b57 100644

arch/powerpc/platforms/powernv/pci-ioda.c +1 -1

  	} 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->table_group.tables[0]);
  	}
  	*pdev->dev.dma_mask = dma_mask;
  	return 0;

@@ -1659,6 +1657,7 @@ static void pnv_ioda_setup_bus_dma(struct pnv_ioda_pe *pe,
 
  	list_for_each_entry(dev, &bus->devices, bus_list) {
  		set_iommu_table_base(&dev->dev, pe->table_group.tables[0]);
+		set_dma_offset(&dev->dev, pe->tce_bypass_base);
  		iommu_add_device(&dev->dev);
 
  		if ((pe->flags & PNV_IODA_PE_BUS_ALL) && dev->subordinate)

arch/powerpc/platforms/pseries/iommu.c +1 -2

index 10510de..0946b98 100644
@@ -1253,11 +1253,10 @@ static int dma_set_mask_pSeriesLP(struct device *dev, u64 dma_mask)
  		}
  	}
 
-	/* fall back on iommu ops, restore table pointer with ops */
+	/* fall back on iommu ops */
  	if (!ddw_enabled && get_dma_ops(dev) != &dma_iommu_ops) {
  		dev_info(dev, "Restoring 32-bit DMA via iommu\n");
  		set_dma_ops(dev, &dma_iommu_ops);
-		pci_dma_dev_setup_pSeriesLP(pdev);
  	}
 
  check_mask:

arch/powerpc/sysdev/dart_iommu.c +3 -13

index 90bcdfe..b734863 100644
@@ -313,20 +313,11 @@ static void iommu_table_dart_setup(void)
  	set_bit(iommu_table_dart.it_size - 1, iommu_table_dart.it_map);
  }
 
-static void dma_dev_setup_dart(struct device *dev)
-{
-	/* We only have one iommu table on the mac for now, which makes
-	 * things simple. Setup all PCI devices to point to this table
-	 */
-	if (get_dma_ops(dev) == &dma_direct_ops)
-		set_dma_offset(dev, DART_U4_BYPASS_BASE);
-	else
-		set_iommu_table_base(dev, &iommu_table_dart);
-}
-
  static void pci_dma_dev_setup_dart(struct pci_dev *dev)
  {
-	dma_dev_setup_dart(&dev->dev);
+	if (dart_is_u4)
+		set_dma_offset(&dev->dev, DART_U4_BYPASS_BASE);
+	set_iommu_table_base(&dev->dev, &iommu_table_dart);
  }
 
  static void pci_dma_bus_setup_dart(struct pci_bus *bus)

@@ -370,7 +361,6 @@ static int dart_dma_set_mask(struct device *dev, u64 dma_mask)
  		dev_info(dev, "Using 32-bit DMA via iommu\n");
  		set_dma_ops(dev, &dma_iommu_ops);
  	}
-	dma_dev_setup_dart(dev);
 
  	*dev->dma_mask = dma_mask;
  	return 0;

_______________________________________________
Linuxppc-dev mailing list
[email protected]
https://lists.ozlabs.org/listinfo/linuxppc-dev

Quoted 10 lines · Benjamin Herrenschmidt

Now that the table and the offset can co-exist, we no longer need to flip/flop, we can just establish both once at boot time.

Signed-off-by Benjamin Herrenschmidt <[email protected]>

---
  arch/powerpc/platforms/powernv/pci-ioda.c |  3 +--
  arch/powerpc/platforms/pseries/iommu.c    |  3 +--
  arch/powerpc/sysdev/dart_iommu.c          | 16 +++-------------
  3 files changed, 5 insertions(+), 17 deletions(-)

arch/powerpc/platforms/powernv/pci-ioda.c static int pnv_pci_ioda_dma_set_mask(struct pci_dev *pdev, u64 dma_mask) · line 1623

Quoted 9 lines

arch/powerpc/platforms/powernv/pci-ioda.c +0 -1

index 5738d31..2c286b57 100644
@@ -1620,11 +1620,9 @@ static int pnv_pci_ioda_dma_set_mask(struct pci_dev *pdev, u64 dma_mask)
  	if (bypass) {
  		dev_info(&pdev->dev, "Using 64-bit DMA iommu bypass\n");
  		set_dma_ops(&pdev->dev, &dma_direct_ops);
-		set_dma_offset(&pdev->dev, pe->tce_bypass_base);

This particular change breaks SRIOV. So some SRIOV code relies on that but I could not spot this place quickly.

Also, this specific patch in powerpc/next tree just does not compile because of "powerpc/iommu: Remove dma_data union" but this is another story :)