ACPI: VIOT: Initialize the correct IOMMU fwspec

When setting up DMA for a PCI device, we need to initialize its
iommu_fwspec with all possible alias RIDs (such as PCI bridges). To do
this we use pci_for_each_dma_alias() which calls
viot_pci_dev_iommu_init(). This function incorrectly initializes the
fwspec of the bridge instead of the device being configured. Fix it by
passing the original device as context to pci_for_each_dma_alias().

Fixes: 3cf4855 ("ACPI: Add driver for the VIOT table")
Link: https://lore.kernel.org/all/Y8qzOKm6kvhGWG1T@myrica
Reported-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Tested-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Author: Jean-Philippe Brucker

drivers/acpi/viot.c

@@ -328,6 +328,7 @@ static int viot_pci_dev_iommu_init(struct pci_dev *pdev, u16 dev_id, void *data)
 {
 	u32 epid;
 	struct viot_endpoint *ep;
+	struct device *aliased_dev = data;
 	u32 domain_nr = pci_domain_nr(pdev->bus);
 
 	list_for_each_entry(ep, &viot_pci_ranges, list) {
@@ -338,7 +339,7 @@ static int viot_pci_dev_iommu_init(struct pci_dev *pdev, u16 dev_id, void *data)
 			epid = ((domain_nr - ep->segment_start) << 16) +
 				dev_id - ep->bdf_start + ep->endpoint_id;
 
-			return viot_dev_iommu_init(&pdev->dev, ep->viommu,
+			return viot_dev_iommu_init(aliased_dev, ep->viommu,
 						   epid);
 		}
 	}
@@ -372,7 +373,7 @@ int viot_iommu_configure(struct device *dev)
 {
 	if (dev_is_pci(dev))
 		return pci_for_each_dma_alias(to_pci_dev(dev),
-					      viot_pci_dev_iommu_init, NULL);
+					      viot_pci_dev_iommu_init, dev);
 	else if (dev_is_platform(dev))
 		return viot_mmio_dev_iommu_init(to_platform_device(dev));
 	return -ENODEV;