x86/iommu/intel: 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>
Cc: Jack Steiner <steiner@sgi.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Daniel Rahn <drahn@suse.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/n/tip-018fywmjs3lmzfyzjlktg8dx@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 9 insertions, 11 deletions

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index c9c6053198d4..8aa580dc3033 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -48,8 +48,6 @@
 #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)
@@ -2369,18 +2367,18 @@ 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));
                 }
         }