diff --git a/arch/powerpc/include/asm/mmu-hash64.h b/arch/powerpc/include/asm/mmu-hash64.h
index 2102b214a87c9ab49b7540962c2faef15251f55c..0e398cfee2c82826b6abad1eb8ece6330df6b0b4 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);
diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
index 40847a9dd6db619dc1cece6fd65851885bfd8047..09dffe6efa46aeae84d62a922215f87fe0a8ca2d 100644
--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -871,6 +871,18 @@ static inline int subpage_protection(struct mm_struct *mm, unsigned long ea)
 }
 #endif
 
+void hash_failure_debug(unsigned long ea, unsigned long access,
+			unsigned long vsid, unsigned long trap,
+			int ssize, int psize, unsigned long pte)
+{
+	if (!printk_ratelimit())
+		return;
+	pr_info("mm: Hashing failure ! EA=0x%lx access=0x%lx current=%s\n",
+		ea, access, current->comm);
+	pr_info("    trap=0x%lx vsid=0x%lx ssize=%d psize=%d pte=0x%lx\n",
+		trap, vsid, ssize, psize, pte);
+}
+
 /* Result code is:
  *  0 - handled
  *  1 - normal page fault
@@ -1036,6 +1048,12 @@ int hash_page(unsigned long ea, unsigned long access, unsigned long trap)
 					    local, ssize, spp);
 	}
 
+	/* Dump some info in case of hash insertion failure, they should
+	 * never happen so it is really useful to know if/when they do
+	 */
+	if (rc == -1)
+		hash_failure_debug(ea, access, vsid, trap, ssize, psize,
+				   pte_val(*ptep));
 #ifndef CONFIG_PPC_64K_PAGES
 	DBG_LOW(" o-pte: %016lx\n", pte_val(*ptep));
 #else
@@ -1054,8 +1072,7 @@ void hash_preload(struct mm_struct *mm, unsigned long ea,
 	void *pgdir;
 	pte_t *ptep;
 	unsigned long flags;
-	int local = 0;
-	int ssize;
+	int rc, ssize, local = 0;
 
 	BUG_ON(REGION_ID(ea) != USER_REGION_ID);
 
@@ -1101,11 +1118,18 @@ void hash_preload(struct mm_struct *mm, unsigned long ea,
 	/* Hash it in */
 #ifdef CONFIG_PPC_HAS_HASH_64K
 	if (mm->context.user_psize == MMU_PAGE_64K)
-		__hash_page_64K(ea, access, vsid, ptep, trap, local, ssize);
+		rc = __hash_page_64K(ea, access, vsid, ptep, trap, local, ssize);
 	else
 #endif /* CONFIG_PPC_HAS_HASH_64K */
-		__hash_page_4K(ea, access, vsid, ptep, trap, local, ssize,
-			       subpage_protection(pgdir, ea));
+		rc = __hash_page_4K(ea, access, vsid, ptep, trap, local, ssize,
+				    subpage_protection(pgdir, ea));
+
+	/* Dump some info in case of hash insertion failure, they should
+	 * never happen so it is really useful to know if/when they do
+	 */
+	if (rc == -1)
+		hash_failure_debug(ea, access, vsid, trap, ssize,
+				   mm->context.user_psize, pte_val(*ptep));
 
 	local_irq_restore(flags);
 }
diff --git a/arch/powerpc/mm/hugetlbpage-hash64.c b/arch/powerpc/mm/hugetlbpage-hash64.c
index faae9ec4cb04fbb7d911bb11dc4d57d91f2a6a9c..cc5c273086cf833e28bc89a91bb814b09c16a4e4 100644
--- a/arch/powerpc/mm/hugetlbpage-hash64.c
+++ b/arch/powerpc/mm/hugetlbpage-hash64.c
@@ -127,6 +127,8 @@ int __hash_page_huge(unsigned long ea, unsigned long access, unsigned long vsid,
 		 */
 		if (unlikely(slot == -2)) {
 			*ptep = __pte(old_pte);
+			hash_failure_debug(ea, access, vsid, trap, ssize,
+					   mmu_psize, old_pte);
 			return -1;
 		}