From 0c05a3b7d0b39872db66c9b6af12261242c713e8 Mon Sep 17 00:00:00 2001
From: Alex Williamson <alex.williamson@redhat.com>
Date: Fri, 21 Oct 2011 15:56:11 -0400
Subject: [PATCH] --- yaml --- r: 282801 b: refs/heads/master c:
 70ae6f0d55bd216b2f773fa5fa5018c0490a9e50 h: refs/heads/master i:   282799:
 767c14f5b8643e5c7a2d3371eafb03fcc0c88fc1 v: v3

---
 [refs]                            |  2 +-
 trunk/drivers/iommu/intel-iommu.c | 46 +++++++++++++++++++++++++++++++
 2 files changed, 47 insertions(+), 1 deletion(-)

diff --git a/[refs] b/[refs]
index 54cddacead6e..ec37e79d1305 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 1460432cb513f0c16136ed132c20ecfbf8ccf942
+refs/heads/master: 70ae6f0d55bd216b2f773fa5fa5018c0490a9e50
diff --git a/trunk/drivers/iommu/intel-iommu.c b/trunk/drivers/iommu/intel-iommu.c
index c0c7820d4c46..39ca6bb17e13 100644
--- a/trunk/drivers/iommu/intel-iommu.c
+++ b/trunk/drivers/iommu/intel-iommu.c
@@ -4060,6 +4060,51 @@ static int intel_iommu_domain_has_cap(struct iommu_domain *domain,
 	return 0;
 }
 
+/*
+ * Group numbers are arbitrary.  Device with the same group number
+ * indicate the iommu cannot differentiate between them.  To avoid
+ * tracking used groups we just use the seg|bus|devfn of the lowest
+ * level we're able to differentiate devices
+ */
+static int intel_iommu_device_group(struct device *dev, unsigned int *groupid)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	struct pci_dev *bridge;
+	union {
+		struct {
+			u8 devfn;
+			u8 bus;
+			u16 segment;
+		} pci;
+		u32 group;
+	} id;
+
+	if (iommu_no_mapping(dev))
+		return -ENODEV;
+
+	id.pci.segment = pci_domain_nr(pdev->bus);
+	id.pci.bus = pdev->bus->number;
+	id.pci.devfn = pdev->devfn;
+
+	if (!device_to_iommu(id.pci.segment, id.pci.bus, id.pci.devfn))
+		return -ENODEV;
+
+	bridge = pci_find_upstream_pcie_bridge(pdev);
+	if (bridge) {
+		if (pci_is_pcie(bridge)) {
+			id.pci.bus = bridge->subordinate->number;
+			id.pci.devfn = 0;
+		} else {
+			id.pci.bus = bridge->bus->number;
+			id.pci.devfn = bridge->devfn;
+		}
+	}
+
+	*groupid = id.group;
+
+	return 0;
+}
+
 static struct iommu_ops intel_iommu_ops = {
 	.domain_init	= intel_iommu_domain_init,
 	.domain_destroy = intel_iommu_domain_destroy,
@@ -4069,6 +4114,7 @@ static struct iommu_ops intel_iommu_ops = {
 	.unmap		= intel_iommu_unmap,
 	.iova_to_phys	= intel_iommu_iova_to_phys,
 	.domain_has_cap = intel_iommu_domain_has_cap,
+	.device_group	= intel_iommu_device_group,
 };
 
 static void __devinit quirk_iommu_rwbf(struct pci_dev *dev)