diff --git a/include/linux/mempolicy.h b/include/linux/mempolicy.h
index b8b3da7..389a06e8 100644
--- a/include/linux/mempolicy.h
+++ b/include/linux/mempolicy.h
@@ -9,12 +9,13 @@
  */
 
 /* Policies */
-#define MPOL_DEFAULT	0
-#define MPOL_PREFERRED	1
-#define MPOL_BIND	2
-#define MPOL_INTERLEAVE	3
-
-#define MPOL_MAX MPOL_INTERLEAVE
+enum {
+	MPOL_DEFAULT,
+	MPOL_PREFERRED,
+	MPOL_BIND,
+	MPOL_INTERLEAVE,
+	MPOL_MAX,	/* always last member of enum */
+};
 
 /* Flags for get_mem_policy */
 #define MPOL_F_NODE	(1<<0)	/* return next IL mode instead of node mask */
@@ -64,7 +65,7 @@
  */
 struct mempolicy {
 	atomic_t refcnt;
-	short policy; 	/* See MPOL_* above */
+	unsigned short policy; 	/* See MPOL_* above */
 	union {
 		short 		 preferred_node; /* preferred */
 		nodemask_t	 nodes;		/* interleave/bind */
@@ -134,7 +135,7 @@
 	spinlock_t lock;
 };
 
-void mpol_shared_policy_init(struct shared_policy *info, int policy,
+void mpol_shared_policy_init(struct shared_policy *info, unsigned short policy,
 				nodemask_t *nodes);
 int mpol_set_shared_policy(struct shared_policy *info,
 				struct vm_area_struct *vma,
@@ -202,7 +203,7 @@
 }
 
 static inline void mpol_shared_policy_init(struct shared_policy *info,
-					int policy, nodemask_t *nodes)
+				unsigned short policy, nodemask_t *nodes)
 {
 }
 
diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h
index 8d5fb36..639a407 100644
--- a/include/linux/shmem_fs.h
+++ b/include/linux/shmem_fs.h
@@ -34,7 +34,7 @@
 	uid_t uid;		    /* Mount uid for root directory */
 	gid_t gid;		    /* Mount gid for root directory */
 	mode_t mode;		    /* Mount mode for root directory */
-	int policy;		    /* Default NUMA memory alloc policy */
+	unsigned short policy;	    /* Default NUMA memory alloc policy */
 	nodemask_t policy_nodes;    /* nodemask for preferred and bind */
 };
 
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index acb5ee3..1311dc4 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -114,7 +114,7 @@
                                const nodemask_t *newmask);
 
 /* Do sanity checking on a policy */
-static int mpol_check_policy(int mode, nodemask_t *nodes)
+static int mpol_check_policy(unsigned short mode, nodemask_t *nodes)
 {
 	int was_empty, is_empty;
 
@@ -159,6 +159,8 @@
 		if (!was_empty && is_empty)
 			return -EINVAL;
 		break;
+	default:
+		BUG();
 	}
 	return 0;
 }
@@ -185,7 +187,7 @@
 }
 
 /* Create a new policy */
-static struct mempolicy *mpol_new(int mode, nodemask_t *nodes)
+static struct mempolicy *mpol_new(unsigned short mode, nodemask_t *nodes)
 {
 	struct mempolicy *policy;
 
@@ -218,6 +220,8 @@
 		}
 		policy->v.nodes = *nodes;
 		break;
+	default:
+		BUG();
 	}
 	policy->policy = mode;
 	policy->cpuset_mems_allowed = cpuset_mems_allowed(current);
@@ -462,7 +466,7 @@
 }
 
 /* Set the process memory policy */
-static long do_set_mempolicy(int mode, nodemask_t *nodes)
+static long do_set_mempolicy(unsigned short mode, nodemask_t *nodes)
 {
 	struct mempolicy *new;
 
@@ -759,7 +763,7 @@
 #endif
 
 static long do_mbind(unsigned long start, unsigned long len,
-		     unsigned long mode, nodemask_t *nmask,
+		     unsigned short mode, nodemask_t *nmask,
 		     unsigned long flags)
 {
 	struct vm_area_struct *vma;
@@ -769,9 +773,8 @@
 	int err;
 	LIST_HEAD(pagelist);
 
-	if ((flags & ~(unsigned long)(MPOL_MF_STRICT |
-				      MPOL_MF_MOVE | MPOL_MF_MOVE_ALL))
-	    || mode > MPOL_MAX)
+	if (flags & ~(unsigned long)(MPOL_MF_STRICT |
+				     MPOL_MF_MOVE | MPOL_MF_MOVE_ALL))
 		return -EINVAL;
 	if ((flags & MPOL_MF_MOVE_ALL) && !capable(CAP_SYS_NICE))
 		return -EPERM;
@@ -804,7 +807,7 @@
 	if (!new)
 		flags |= MPOL_MF_DISCONTIG_OK;
 
-	pr_debug("mbind %lx-%lx mode:%ld nodes:%lx\n",start,start+len,
+	pr_debug("mbind %lx-%lx mode:%d nodes:%lx\n", start, start + len,
 		 mode, nmask ? nodes_addr(*nmask)[0] : -1);
 
 	down_write(&mm->mmap_sem);
@@ -905,6 +908,8 @@
 	nodemask_t nodes;
 	int err;
 
+	if (mode >= MPOL_MAX)
+		return -EINVAL;
 	err = get_nodes(&nodes, nmask, maxnode);
 	if (err)
 		return err;
@@ -918,7 +923,7 @@
 	int err;
 	nodemask_t nodes;
 
-	if (mode < 0 || mode > MPOL_MAX)
+	if (mode < 0 || mode >= MPOL_MAX)
 		return -EINVAL;
 	err = get_nodes(&nodes, nmask, maxnode);
 	if (err)
@@ -1201,7 +1206,7 @@
  */
 unsigned slab_node(struct mempolicy *policy)
 {
-	int pol = policy ? policy->policy : MPOL_DEFAULT;
+	unsigned short pol = policy ? policy->policy : MPOL_DEFAULT;
 
 	switch (pol) {
 	case MPOL_INTERLEAVE:
@@ -1635,7 +1640,7 @@
 	return 0;
 }
 
-void mpol_shared_policy_init(struct shared_policy *info, int policy,
+void mpol_shared_policy_init(struct shared_policy *info, unsigned short policy,
 				nodemask_t *policy_nodes)
 {
 	info->root = RB_ROOT;
@@ -1830,7 +1835,7 @@
 	char *p = buffer;
 	int l;
 	nodemask_t nodes;
-	int mode = pol ? pol->policy : MPOL_DEFAULT;
+	unsigned short mode = pol ? pol->policy : MPOL_DEFAULT;
 
 	switch (mode) {
 	case MPOL_DEFAULT:
diff --git a/mm/shmem.c b/mm/shmem.c
index f514dd39..d8ef7ba 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1079,7 +1079,8 @@
 
 #ifdef CONFIG_NUMA
 #ifdef CONFIG_TMPFS
-static int shmem_parse_mpol(char *value, int *policy, nodemask_t *policy_nodes)
+static int shmem_parse_mpol(char *value, unsigned short *policy,
+			    nodemask_t *policy_nodes)
 {
 	char *nodelist = strchr(value, ':');
 	int err = 1;
@@ -1128,7 +1129,7 @@
 	return err;
 }
 
-static void shmem_show_mpol(struct seq_file *seq, int policy,
+static void shmem_show_mpol(struct seq_file *seq, unsigned short policy,
 			    const nodemask_t policy_nodes)
 {
 	char *policy_string;
@@ -1197,13 +1198,13 @@
 }
 #else /* !CONFIG_NUMA */
 #ifdef CONFIG_TMPFS
-static inline int shmem_parse_mpol(char *value, int *policy,
+static inline int shmem_parse_mpol(char *value, unsigned short *policy,
 						nodemask_t *policy_nodes)
 {
 	return 1;
 }
 
-static inline void shmem_show_mpol(struct seq_file *seq, int policy,
+static inline void shmem_show_mpol(struct seq_file *seq, unsigned short policy,
 			    const nodemask_t policy_nodes)
 {
 }