iommu/vt-d: fix bug in handling multiple RMRRs for the same PCI device

Function dmar_iommu_notify_scope_dev() makes a wrong assumption that
there's one RMRR for each PCI device at most, which causes DMA failure
on some HP platforms. So enhance dmar_iommu_notify_scope_dev() to
handle multiple RMRRs for the same PCI device.

Fixbug: https://bugzilla.novell.com/show_bug.cgi?id=879482

Cc: <stable@vger.kernel.org> # 3.15
Reported-by: Tom Mingarelli <thomas.mingarelli@hp.com>
Tested-by: Linda Knippers <linda.knippers@hp.com>
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

1 files changed, 3 insertions, 6 deletions

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 6bb32773c3ac..51b6b77dc3e5 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -3816,14 +3816,11 @@ int dmar_iommu_notify_scope_dev(struct dmar_pci_notify_info *info)
                                 ((void *)rmrr) + rmrr->header.length,
                                 rmrr->segment, rmrru->devices,
                                 rmrru->devices_cnt);
-                        if (ret > 0)
-                                break;
-                        else if(ret < 0)
+                        if(ret < 0)
                                 return ret;
                 } else if (info->event == BUS_NOTIFY_DEL_DEVICE) {
-                        if (dmar_remove_dev_scope(info, rmrr->segment,
-                                rmrru->devices, rmrru->devices_cnt))
-                                break;
+                        dmar_remove_dev_scope(info, rmrr->segment,
+                                rmrru->devices, rmrru->devices_cnt);
                 }
         }