powerpc/mm: Add some debug output when hash insertion fails

This adds some debug output to our MMU hash code to print out some
useful debug data if the hypervisor refuses the insertion (which
should normally never happen).

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---

1 files changed, 2 insertions, 0 deletions

diff --git a/arch/powerpc/mm/hugetlbpage-hash64.c b/arch/powerpc/mm/hugetlbpage-hash64.c
index faae9ec4cb04..cc5c273086cf 100644
--- a/arch/powerpc/mm/hugetlbpage-hash64.c
+++ b/arch/powerpc/mm/hugetlbpage-hash64.c
@@ -127,6 +127,8 @@ repeat:
                  */
                 if (unlikely(slot == -2)) {
                         *ptep = __pte(old_pte);
+                        hash_failure_debug(ea, access, vsid, trap, ssize,
+                                           mmu_psize, old_pte);
                         return -1;
                 }