diff --git a/arch/powerpc/include/asm/mmu-hash64.h b/arch/powerpc/include/asm/mmu-hash64.h
index b537903b9fca..bebe31c2e907 100644
--- a/arch/powerpc/include/asm/mmu-hash64.h
+++ b/arch/powerpc/include/asm/mmu-hash64.h
@@ -41,6 +41,7 @@ extern char initial_stab[];
 
 #define SLB_NUM_BOLTED		3
 #define SLB_CACHE_ENTRIES	8
+#define SLB_MIN_SIZE		32
 
 /* Bits in the SLB ESID word */
 #define SLB_ESID_V		ASM_CONST(0x0000000008000000) /* valid */
@@ -276,6 +277,7 @@ extern void slb_flush_and_rebolt(void);
 extern void stab_initialize(unsigned long stab);
 
 extern void slb_vmalloc_update(void);
+extern void slb_set_size(u16 size);
 #endif /* __ASSEMBLY__ */
 
 /*
diff --git a/arch/powerpc/kernel/lparcfg.c b/arch/powerpc/kernel/lparcfg.c
index 2419cc706ff1..ed0ac4e4b8d8 100644
--- a/arch/powerpc/kernel/lparcfg.c
+++ b/arch/powerpc/kernel/lparcfg.c
@@ -35,6 +35,7 @@
 #include <asm/prom.h>
 #include <asm/vdso_datapage.h>
 #include <asm/vio.h>
+#include <asm/mmu.h>
 
 #define MODULE_VERS "1.8"
 #define MODULE_NAME "lparcfg"
@@ -537,6 +538,8 @@ static int pseries_lparcfg_data(struct seq_file *m, void *v)
 
 	seq_printf(m, "shared_processor_mode=%d\n", lppaca[0].shared_proc);
 
+	seq_printf(m, "slb_size=%d\n", mmu_slb_size);
+
 	return 0;
 }
 
diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c
index c434823b8c83..bf90361bb70f 100644
--- a/arch/powerpc/kernel/rtas.c
+++ b/arch/powerpc/kernel/rtas.c
@@ -39,6 +39,7 @@
 #include <asm/smp.h>
 #include <asm/atomic.h>
 #include <asm/time.h>
+#include <asm/mmu.h>
 
 struct rtas_t rtas = {
 	.lock = __RAW_SPIN_LOCK_UNLOCKED
@@ -713,6 +714,7 @@ static void rtas_percpu_suspend_me(void *info)
 {
 	long rc = H_SUCCESS;
 	unsigned long msr_save;
+	u16 slb_size = mmu_slb_size;
 	int cpu;
 	struct rtas_suspend_me_data *data =
 		(struct rtas_suspend_me_data *)info;
@@ -735,13 +737,16 @@ static void rtas_percpu_suspend_me(void *info)
 		/* All other cpus are in H_JOIN, this cpu does
 		 * the suspend.
 		 */
+		slb_set_size(SLB_MIN_SIZE);
 		printk(KERN_DEBUG "calling ibm,suspend-me on cpu %i\n",
 		       smp_processor_id());
 		data->error = rtas_call(data->token, 0, 1, NULL);
 
-		if (data->error)
+		if (data->error) {
 			printk(KERN_DEBUG "ibm,suspend-me returned %d\n",
 			       data->error);
+			slb_set_size(slb_size);
+		}
 	} else {
 		printk(KERN_ERR "H_JOIN on cpu %i failed with rc = %ld\n",
 		       smp_processor_id(), rc);
diff --git a/arch/powerpc/mm/slb.c b/arch/powerpc/mm/slb.c
index 07961c5c169e..1d98ecc8eecd 100644
--- a/arch/powerpc/mm/slb.c
+++ b/arch/powerpc/mm/slb.c
@@ -249,14 +249,22 @@ void switch_slb(struct task_struct *tsk, struct mm_struct *mm)
 static inline void patch_slb_encoding(unsigned int *insn_addr,
 				      unsigned int immed)
 {
-	/* Assume the instruction had a "0" immediate value, just
-	 * "or" in the new value
-	 */
-	*insn_addr |= immed;
+	*insn_addr = (*insn_addr & 0xffff0000) | immed;
 	flush_icache_range((unsigned long)insn_addr, 4+
 			   (unsigned long)insn_addr);
 }
 
+void slb_set_size(u16 size)
+{
+	extern unsigned int *slb_compare_rr_to_size;
+
+	if (mmu_slb_size == size)
+		return;
+
+	mmu_slb_size = size;
+	patch_slb_encoding(slb_compare_rr_to_size, mmu_slb_size);
+}
+
 void slb_initialize(void)
 {
 	unsigned long linear_llp, vmalloc_llp, io_llp;
diff --git a/arch/powerpc/platforms/pseries/reconfig.c b/arch/powerpc/platforms/pseries/reconfig.c
index b6f1b137d427..2e2bbe120b90 100644
--- a/arch/powerpc/platforms/pseries/reconfig.c
+++ b/arch/powerpc/platforms/pseries/reconfig.c
@@ -20,6 +20,7 @@
 #include <asm/machdep.h>
 #include <asm/uaccess.h>
 #include <asm/pSeries_reconfig.h>
+#include <asm/mmu.h>
 
 
 
@@ -439,9 +440,15 @@ static int do_update_property(char *buf, size_t bufsize)
 	if (!newprop)
 		return -ENOMEM;
 
+	if (!strcmp(name, "slb-size") || !strcmp(name, "ibm,slb-size"))
+		slb_set_size(*(int *)value);
+
 	oldprop = of_find_property(np, name,NULL);
-	if (!oldprop)
+	if (!oldprop) {
+		if (strlen(name))
+			return prom_add_property(np, newprop);
 		return -ENODEV;
+	}
 
 	rc = prom_update_property(np, newprop, oldprop);
 	if (rc)