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, 3 insertions, 1 deletions

diff --git a/arch/powerpc/include/asm/mmu-hash64.h b/arch/powerpc/include/asm/mmu-hash64.h
index 2102b214a87c..0e398cfee2c8 100644
--- a/arch/powerpc/include/asm/mmu-hash64.h
+++ b/arch/powerpc/include/asm/mmu-hash64.h
@@ -250,7 +250,9 @@ extern int hash_page(unsigned long ea, unsigned long access, unsigned long trap)
 int __hash_page_huge(unsigned long ea, unsigned long access, unsigned long vsid,
                      pte_t *ptep, unsigned long trap, int local, int ssize,
                      unsigned int shift, unsigned int mmu_psize);
-
+extern void hash_failure_debug(unsigned long ea, unsigned long access,
+                               unsigned long vsid, unsigned long trap,
+                               int ssize, int psize, unsigned long pte);
 extern int htab_bolt_mapping(unsigned long vstart, unsigned long vend,
                              unsigned long pstart, unsigned long prot,
                              int psize, int ssize);