2 files changed, 26 insertions, 10 deletions

diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c
index fa5a1474cd18..0d20286d78c6 100644
--- a/arch/x86/kernel/amd_iommu.c
+++ b/arch/x86/kernel/amd_iommu.c
@@ -1487,6 +1487,7 @@ static int __attach_device(struct device *dev,
                            struct protection_domain *domain)
 {
         struct iommu_dev_data *dev_data, *alias_data;
+        int ret;
 
         dev_data   = get_dev_data(dev);
         alias_data = get_dev_data(dev_data->alias);
@@ -1498,13 +1499,14 @@ static int __attach_device(struct device *dev,
         spin_lock(&domain->lock);
 
         /* Some sanity checks */
+        ret = -EBUSY;
         if (alias_data->domain != NULL &&
             alias_data->domain != domain)
-                return -EBUSY;
+                goto out_unlock;
 
         if (dev_data->domain != NULL &&
             dev_data->domain != domain)
-                return -EBUSY;
+                goto out_unlock;
 
         /* Do real assignment */
         if (dev_data->alias != dev) {
@@ -1520,10 +1522,14 @@ static int __attach_device(struct device *dev,
 
         atomic_inc(&dev_data->bind);
 
+        ret = 0;
+
+out_unlock:
+
         /* ready */
         spin_unlock(&domain->lock);
 
-        return 0;
+        return ret;
 }
 
 /*
@@ -2324,10 +2330,6 @@ int __init amd_iommu_init_dma_ops(void)
 
         iommu_detected = 1;
         swiotlb = 0;
-#ifdef CONFIG_GART_IOMMU
-        gart_iommu_aperture_disabled = 1;
-        gart_iommu_aperture = 0;
-#endif
 
         /* Make the driver finally visible to the drivers */
         dma_ops = &amd_iommu_dma_ops;
diff --git a/arch/x86/kernel/amd_iommu_init.c b/arch/x86/kernel/amd_iommu_init.c
index 3bacb4d0844c..3cc63e2b8dd4 100644
--- a/arch/x86/kernel/amd_iommu_init.c
+++ b/arch/x86/kernel/amd_iommu_init.c
@@ -287,8 +287,12 @@ static u8 * __init iommu_map_mmio_space(u64 address)
 {
         u8 *ret;
 
-        if (!request_mem_region(address, MMIO_REGION_LENGTH, "amd_iommu"))
+        if (!request_mem_region(address, MMIO_REGION_LENGTH, "amd_iommu")) {
+                pr_err("AMD-Vi: Can not reserve memory region %llx for mmio\n",
+                        address);
+                pr_err("AMD-Vi: This is a BIOS bug. Please contact your hardware vendor\n");
                 return NULL;
+        }
 
         ret = ioremap_nocache(address, MMIO_REGION_LENGTH);
         if (ret != NULL)
@@ -1314,7 +1318,7 @@ static int __init amd_iommu_init(void)
                 ret = amd_iommu_init_dma_ops();
 
         if (ret)
-                goto free;
+                goto free_disable;
 
         amd_iommu_init_api();
 
@@ -1332,9 +1336,10 @@ static int __init amd_iommu_init(void)
 out:
         return ret;
 
-free:
+free_disable:
         disable_iommus();
 
+free:
         amd_iommu_uninit_devices();
 
         free_pages((unsigned long)amd_iommu_pd_alloc_bitmap,
@@ -1353,6 +1358,15 @@ free:
 
         free_unity_maps();
 
+#ifdef CONFIG_GART_IOMMU
+        /*
+         * We failed to initialize the AMD IOMMU - try fallback to GART
+         * if possible.
+         */
+        gart_iommu_init();
+
+#endif
+
         goto out;
 }