[PATCH kernel 3/4] powerpc/mm/iommu: Make mm_iommu_new() fail on existing regions

[Alexey Kardashevskiy]

Since we are going to have 2 different preregistering helpers, let's
make it clear that mm_iommu_new() is only for the normal (i.e. not device)
memory and for existing areas mm_iommu_get() should be used instead.

Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru>
---
 arch/powerpc/mm/mmu_context_iommu.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/powerpc/mm/mmu_context_iommu.c 
b/arch/powerpc/mm/mmu_context_iommu.c
index a8c4a3c..839dbce 100644
--- a/arch/powerpc/mm/mmu_context_iommu.c
+++ b/arch/powerpc/mm/mmu_context_iommu.c
@@ -141,8 +141,7 @@ long mm_iommu_new(struct mm_struct *mm, unsigned long ua, 
unsigned long entries,
        list_for_each_entry_rcu(mem, &mm->context.iommu_group_mem_list,
                        next) {
                if ((mem->ua == ua) && (mem->entries == entries)) {
-                       ++mem->used;
-                       *pmem = mem;
+                       ret = -EBUSY;
                        goto unlock_exit;
                }
 
-- 
2.11.0