iommu/amd: Don't initialize IOMMUv2 resources when not required
Add a check to the init-path of the AMD IOMMUv2 driver if
the hardware is available in the system. Only allocate all
the resources if it is really available.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
diff --git a/drivers/iommu/amd_iommu_v2.c b/drivers/iommu/amd_iommu_v2.c
index 8add9f1..036fe9b 100644
--- a/drivers/iommu/amd_iommu_v2.c
+++ b/drivers/iommu/amd_iommu_v2.c
@@ -921,7 +921,16 @@
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 @@
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);