Merge tag 'iommu-updates-v3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu

Pull IOMMU updates from Joerg Roedel:
 "The IOMMU updates for this round are not very large patch-wise.  But
  they contain two new IOMMU drivers for the ARM Tegra 2 and 3
  platforms.  Besides that there are also a few patches for the AMD
  IOMMU which prepare the driver for adding intr-remapping support and a
  couple of fixes."

* tag 'iommu-updates-v3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
  iommu/amd: Fix section mismatch
  iommu/amd: Move interrupt setup code into seperate function
  iommu/amd: Make sure IOMMU interrupts are re-enabled on resume
  iommu/amd: Fix section warning for prealloc_protection_domains
  iommu/amd: Don't initialize IOMMUv2 resources when not required
  iommu/amd: Update git-tree in MAINTAINERS
  iommu/tegra-gart: fix spin_unlock in map failure path
  iommu/amd: Fix double free of mem-region in error-path
  iommu/amd: Split amd_iommu_init function
  ARM: IOMMU: Tegra30: Add iommu_ops for SMMU driver
  ARM: IOMMU: Tegra20: Add iommu_ops for GART driver

1 files changed, 13 insertions, 1 deletions

diff --git a/drivers/iommu/amd_iommu_v2.c b/drivers/iommu/amd_iommu_v2.c
index 8add9f125d3e..036fe9bf157e 100644
--- a/drivers/iommu/amd_iommu_v2.c
+++ b/drivers/iommu/amd_iommu_v2.c
@@ -921,7 +921,16 @@ static int __init amd_iommu_v2_init(void)
 	size_t state_table_size;
 	int ret;
 
-	pr_info("AMD IOMMUv2 driver by Joerg Roedel <joerg.roedel@amd.com>");
+	pr_info("AMD IOMMUv2 driver by Joerg Roedel <joerg.roedel@amd.com>\n");
+
+	if (!amd_iommu_v2_supported()) {
+		pr_info("AMD IOMMUv2 functionality not available on this sytem\n");
+		/*
+		 * Load anyway to provide the symbols to other modules
+		 * which may use AMD IOMMUv2 optionally.
+		 */
+		return 0;
+	}
 
 	spin_lock_init(&state_lock);
 
@@ -961,6 +970,9 @@ static void __exit amd_iommu_v2_exit(void)
 	size_t state_table_size;
 	int i;
 
+	if (!amd_iommu_v2_supported())
+		return;
+
 	profile_event_unregister(PROFILE_TASK_EXIT, &profile_nb);
 	amd_iommu_unregister_ppr_notifier(&ppr_nb);