From: Mike Travis <travis@sgi.com>
Date: Fri, 10 Aug 2012 11:37:48 +0000 (-0700)
Subject: x86 PCI: Fix identity mapping for sandy bridge
X-Git-Tag: v2.6.39-400.9.0~425^2~7
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=ca22abadba4d686f44572a2edf590cfcd1590e12;p=users%2Fjedix%2Flinux-maple.git

x86 PCI: Fix identity mapping for sandy bridge

With SandyBridge, Intel has changed these Socket PCI devices to have a class
type of "System Peripheral" & "Performance counter", rather than "HostBridge".
So instead of using a "special" case to detect which devices will not be
doing DMA, use the fact that a device that is not associated with an IOMMU,
will not need an identity map.

Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Mike Habeck <habeck@sgi.com>
---

diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c
index 0ec8930f31b8..96dc1bf0c923 100644
--- a/drivers/pci/intel-iommu.c
+++ b/drivers/pci/intel-iommu.c
@@ -47,8 +47,6 @@
 #define ROOT_SIZE		VTD_PAGE_SIZE
 #define CONTEXT_SIZE		VTD_PAGE_SIZE
 
-#define IS_BRIDGE_HOST_DEVICE(pdev) \
-			    ((pdev->class >> 8) == PCI_CLASS_BRIDGE_HOST)
 #define IS_GFX_DEVICE(pdev) ((pdev->class >> 16) == PCI_BASE_CLASS_DISPLAY)
 #define IS_ISA_DEVICE(pdev) ((pdev->class >> 8) == PCI_CLASS_BRIDGE_ISA)
 #define IS_AZALIA(pdev) ((pdev)->vendor == 0x8086 && (pdev)->device == 0x3a3e)
@@ -2350,18 +2348,18 @@ static int __init iommu_prepare_static_identity_mapping(int hw)
 		return -EFAULT;
 
 	for_each_pci_dev(pdev) {
-		/* Skip Host/PCI Bridge devices */
-		if (IS_BRIDGE_HOST_DEVICE(pdev))
-			continue;
 		if (iommu_should_identity_map(pdev, 1)) {
-			printk(KERN_INFO "IOMMU: %s identity mapping for device %s\n",
-			       hw ? "hardware" : "software", pci_name(pdev));
-
 			ret = domain_add_dev_info(si_domain, pdev,
-						     hw ? CONTEXT_TT_PASS_THROUGH :
-						     CONTEXT_TT_MULTI_LEVEL);
-			if (ret)
+					     hw ? CONTEXT_TT_PASS_THROUGH :
+						  CONTEXT_TT_MULTI_LEVEL);
+			if (ret) {
+				/* device not associated with an iommu */
+				if (ret == -ENODEV)
+					continue;
 				return ret;
+			}
+			pr_info("IOMMU: %s identity mapping for device %s\n",
+				hw ? "hardware" : "software", pci_name(pdev));
 		}
 	}