[PATCH kernel v12.2] powerpc/powernv: Fix crash when CONFIG_IOMMU_API is off

[Alexey Kardashevskiy]

The code introduced in
"[PATCH kernel v12 17/34]
powerpc/spapr: vfio: Switch from iommu_table to new iommu_table_group"
checks if an IOMMU group was registered for the specific
table group which is not true when CONFIG_IOMMU_API is off as
iommu_register_group() is a stub in this case.

This replaces BUG_ON with WARN_ON and removes the check as it is a wrong
place for it anyway.

Signed-off-by: Alexey Kardashevskiy <aik at ozlabs.ru>
---
 arch/powerpc/platforms/powernv/pci.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/platforms/powernv/pci.c b/arch/powerpc/platforms/powernv/pci.c
index 4b4c583..429498e 100644
--- a/arch/powerpc/platforms/powernv/pci.c
+++ b/arch/powerpc/platforms/powernv/pci.c
@@ -622,9 +622,8 @@ long pnv_pci_link_table_and_group(int node, int num,
 {
 	struct iommu_table_group_link *tgl = NULL;
 
-	BUG_ON(!tbl);
-	BUG_ON(!table_group);
-	BUG_ON(!table_group->group);
+	if (WARN_ON(!tbl || !table_group))
+		return -EINVAL;
 
 	tgl = kzalloc_node(sizeof(struct iommu_table_group_link), GFP_KERNEL,
 			node);
-- 
2.4.0.rc3.8.gfb3e7d5