x86/amd-iommu: Fix IOMMU-API initialization for iommu=pt

This patch moves the initialization of the iommu-api out of
the dma-ops initialization code. This ensures that the
iommu-api is initialized even with iommu=pt.

Cc: stable@kernel.org
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

arch/x86/include/asm/amd_iommu_proto.h

@@ -31,6 +31,7 @@ extern void amd_iommu_reset_cmd_buffer(struct amd_iommu *iommu);
 extern int amd_iommu_init_devices(void);
 extern void amd_iommu_uninit_devices(void);
 extern void amd_iommu_init_notifier(void);
+extern void amd_iommu_init_api(void);
 #ifndef CONFIG_AMD_IOMMU_STATS
 
 static inline void amd_iommu_stats_init(void) { }

arch/x86/kernel/amd_iommu.c

@@ -2221,6 +2221,12 @@ static struct dma_map_ops amd_iommu_dma_ops = {
 /*
  * The function which clues the AMD IOMMU driver into dma_ops.
  */
+
+void __init amd_iommu_init_api(void)
+{
+	register_iommu(&amd_iommu_ops);
+}
+
 int __init amd_iommu_init_dma_ops(void)
 {
 	struct amd_iommu *iommu;
@@ -2256,8 +2262,6 @@ int __init amd_iommu_init_dma_ops(void)
 	/* Make the driver finally visible to the drivers */
 	dma_ops = &amd_iommu_dma_ops;
 
-	register_iommu(&amd_iommu_ops);
-
 	amd_iommu_stats_init();
 
 	return 0;

arch/x86/kernel/amd_iommu_init.c

@@ -1292,9 +1292,12 @@ static int __init amd_iommu_init(void)
 		ret = amd_iommu_init_passthrough();
 	else
 		ret = amd_iommu_init_dma_ops();
+
 	if (ret)
 		goto free;
 
+	amd_iommu_init_api();
+
 	amd_iommu_init_notifier();
 
 	enable_iommus();