[PATCH v2 3/7] amd_iommu: Support IOMMU groups

[Alex Williamson <alex.williamson-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>]

Add IOMMU group support to AMD-Vi device init and uninit code.
Existing notifiers make sure this gets called for each device.

Signed-off-by: Alex Williamson <alex.williamson-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
---

 drivers/iommu/amd_iommu.c |   24 +++++++++++++++++++++++-
 1 file changed, 23 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 0ad46f1..e072bd1 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -256,9 +256,11 @@ static bool check_device(struct device *dev)
 
 static int iommu_init_device(struct device *dev)
 {
-	struct pci_dev *pdev = to_pci_dev(dev);
+	struct pci_dev *dma_pdev, *pdev = to_pci_dev(dev);
 	struct iommu_dev_data *dev_data;
+	struct iommu_group *group;
 	u16 alias;
+	int ret;
 
 	if (dev->archdata.iommu)
 		return 0;
@@ -279,8 +281,26 @@ static int iommu_init_device(struct device *dev)
 			return -ENOTSUPP;
 		}
 		dev_data->alias_data = alias_data;
+
+		dma_pdev = pci_get_bus_and_slot(alias >> 8, alias & 0xff);
+	} else
+		dma_pdev = pci_dev_get(pdev);
+
+	group = iommu_group_get(&dma_pdev->dev);
+	pci_dev_put(dma_pdev);
+	if (!group) {
+		group = iommu_group_alloc();
+		if (IS_ERR(group))
+			return PTR_ERR(group);
 	}
 
+	ret = iommu_group_add_device(group, dev);
+
+	iommu_group_put(group);
+
+	if (ret)
+		return ret;
+
 	if (pci_iommuv2_capable(pdev)) {
 		struct amd_iommu *iommu;
 
@@ -309,6 +329,8 @@ static void iommu_ignore_device(struct device *dev)
 
 static void iommu_uninit_device(struct device *dev)
 {
+	iommu_group_remove_device(dev);
+
 	/*
 	 * Nothing to do here - we keep dev_data around for unplugged devices
 	 * and reuse it when the device is re-plugged - not doing so would