diff --git a/arch/powerpc/oprofile/op_model_cell.c b/arch/powerpc/oprofile/op_model_cell.c
index 2eb15f388103..e08e1d7b3dc5 100644
--- a/arch/powerpc/oprofile/op_model_cell.c
+++ b/arch/powerpc/oprofile/op_model_cell.c
@@ -39,10 +39,17 @@
 #include "../platforms/cell/interrupt.h"
 
 #define PPU_CYCLES_EVENT_NUM 1	/*  event number for CYCLES */
+#define PPU_CYCLES_GRP_NUM   1  /* special group number for identifying
+                                 * PPU_CYCLES event
+                                 */
 #define CBE_COUNT_ALL_CYCLES 0x42800000	/* PPU cycle event specifier */
 
-#define NUM_THREADS 2
-#define VIRT_CNTR_SW_TIME_NS 100000000	// 0.5 seconds
+#define NUM_THREADS 2         /* number of physical threads in
+			       * physical processor
+			       */
+#define NUM_TRACE_BUS_WORDS 4
+#define NUM_INPUT_BUS_WORDS 2
+
 
 struct pmc_cntrl_data {
 	unsigned long vcntr;
@@ -58,7 +65,7 @@ struct pmc_cntrl_data {
 struct pm_signal {
 	u16 cpu;		/* Processor to modify */
 	u16 sub_unit;		/* hw subunit this applies to (if applicable) */
-	u16 signal_group;	/* Signal Group to Enable/Disable */
+	short int signal_group;	/* Signal Group to Enable/Disable */
 	u8 bus_word;		/* Enable/Disable on this Trace/Trigger/Event
 				 * Bus Word(s) (bitmask)
 				 */
@@ -93,7 +100,6 @@ static struct {
 	u32 pm07_cntrl[NR_PHYS_CTRS];
 } pm_regs;
 
-
 #define GET_SUB_UNIT(x) ((x & 0x0000f000) >> 12)
 #define GET_BUS_WORD(x) ((x & 0x000000f0) >> 4)
 #define GET_BUS_TYPE(x) ((x & 0x00000300) >> 8)
@@ -101,7 +107,6 @@ static struct {
 #define GET_COUNT_CYCLES(x) (x & 0x00000001)
 #define GET_INPUT_CONTROL(x) ((x & 0x00000004) >> 2)
 
-
 static DEFINE_PER_CPU(unsigned long[NR_PHYS_CTRS], pmc_values);
 
 static struct pmc_cntrl_data pmc_cntrl[NUM_THREADS][NR_PHYS_CTRS];
@@ -129,8 +134,8 @@ static spinlock_t virt_cntr_lock = SPIN_LOCK_UNLOCKED;
 
 static u32 ctr_enabled;
 
-static unsigned char trace_bus[4];
-static unsigned char input_bus[2];
+static unsigned char trace_bus[NUM_TRACE_BUS_WORDS];
+static unsigned char input_bus[NUM_INPUT_BUS_WORDS];
 
 /*
  * Firmware interface functions
@@ -177,25 +182,40 @@ static void pm_rtas_reset_signals(u32 node)
 static void pm_rtas_activate_signals(u32 node, u32 count)
 {
 	int ret;
-	int j;
+	int i, j;
 	struct pm_signal pm_signal_local[NR_PHYS_CTRS];
 
+	/* There is no debug setup required for the cycles event.
+	 * Note that only events in the same group can be used.
+	 * Otherwise, there will be conflicts in correctly routing
+	 * the signals on the debug bus.  It is the responsiblity
+	 * of the OProfile user tool to check the events are in
+	 * the same group.
+	 */
+	i = 0;
 	for (j = 0; j < count; j++) {
-		/* fw expects physical cpu # */
-		pm_signal_local[j].cpu = node;
-		pm_signal_local[j].signal_group = pm_signal[j].signal_group;
-		pm_signal_local[j].bus_word = pm_signal[j].bus_word;
-		pm_signal_local[j].sub_unit = pm_signal[j].sub_unit;
-		pm_signal_local[j].bit = pm_signal[j].bit;
+		if (pm_signal[j].signal_group != PPU_CYCLES_GRP_NUM) {
+
+			/* fw expects physical cpu # */
+			pm_signal_local[i].cpu = node;
+			pm_signal_local[i].signal_group
+				= pm_signal[j].signal_group;
+			pm_signal_local[i].bus_word = pm_signal[j].bus_word;
+			pm_signal_local[i].sub_unit = pm_signal[j].sub_unit;
+			pm_signal_local[i].bit = pm_signal[j].bit;
+			i++;
+		}
 	}
 
-	ret = rtas_ibm_cbe_perftools(SUBFUNC_ACTIVATE, PASSTHRU_ENABLE,
-				     pm_signal_local,
-				     count * sizeof(struct pm_signal));
+	if (i != 0) {
+		ret = rtas_ibm_cbe_perftools(SUBFUNC_ACTIVATE, PASSTHRU_ENABLE,
+					     pm_signal_local,
+					     i * sizeof(struct pm_signal));
 
-	if (ret)
-		printk(KERN_WARNING "%s: rtas returned: %d\n",
-		       __FUNCTION__, ret);
+		if (ret)
+			printk(KERN_WARNING "%s: rtas returned: %d\n",
+			       __FUNCTION__, ret);
+	}
 }
 
 /*
@@ -212,7 +232,7 @@ static void set_pm_event(u32 ctr, int event, u32 unit_mask)
 		/* Special Event: Count all cpu cycles */
 		pm_regs.pm07_cntrl[ctr] = CBE_COUNT_ALL_CYCLES;
 		p = &(pm_signal[ctr]);
-		p->signal_group = 21;
+		p->signal_group = PPU_CYCLES_GRP_NUM;
 		p->bus_word = 1;
 		p->sub_unit = 0;
 		p->bit = 0;
@@ -232,13 +252,21 @@ static void set_pm_event(u32 ctr, int event, u32 unit_mask)
 
 	p->signal_group = event / 100;
 	p->bus_word = bus_word;
-	p->sub_unit = unit_mask & 0x0000f000;
+	p->sub_unit = (unit_mask & 0x0000f000) >> 12;
 
 	pm_regs.pm07_cntrl[ctr] = 0;
 	pm_regs.pm07_cntrl[ctr] |= PM07_CTR_COUNT_CYCLES(count_cycles);
 	pm_regs.pm07_cntrl[ctr] |= PM07_CTR_POLARITY(polarity);
 	pm_regs.pm07_cntrl[ctr] |= PM07_CTR_INPUT_CONTROL(input_control);
 
+	/* Some of the islands signal selection is based on 64 bit words.
+	 * The debug bus words are 32 bits, the input words to the performance
+	 * counters are defined as 32 bits.  Need to convert the 64 bit island
+	 * specification to the appropriate 32 input bit and bus word for the
+	 * performance counter event selection.  See the CELL Performance
+	 * monitoring signals manual and the Perf cntr hardware descriptions
+	 * for the details.
+	 */
 	if (input_control == 0) {
 		if (signal_bit > 31) {
 			signal_bit -= 32;
@@ -259,12 +287,12 @@ static void set_pm_event(u32 ctr, int event, u32 unit_mask)
 		p->bit = signal_bit;
 	}
 
-	for (i = 0; i < 4; i++) {
+	for (i = 0; i < NUM_TRACE_BUS_WORDS; i++) {
 		if (bus_word & (1 << i)) {
 			pm_regs.debug_bus_control |=
 			    (bus_type << (31 - (2 * i) + 1));
 
-			for (j = 0; j < 2; j++) {
+			for (j = 0; j < NUM_INPUT_BUS_WORDS; j++) {
 				if (input_bus[j] == 0xff) {
 					input_bus[j] = i;
 					pm_regs.group_control |=
@@ -278,52 +306,58 @@ static void set_pm_event(u32 ctr, int event, u32 unit_mask)
 	;
 }
 
-static void write_pm_cntrl(int cpu, struct pm_cntrl *pm_cntrl)
+static void write_pm_cntrl(int cpu)
 {
-	/* Oprofile will use 32 bit counters, set bits 7:10 to 0 */
+	/* Oprofile will use 32 bit counters, set bits 7:10 to 0
+	 * pmregs.pm_cntrl is a global
+	 */
+
 	u32 val = 0;
-	if (pm_cntrl->enable == 1)
+	if (pm_regs.pm_cntrl.enable == 1)
 		val |= CBE_PM_ENABLE_PERF_MON;
 
-	if (pm_cntrl->stop_at_max == 1)
+	if (pm_regs.pm_cntrl.stop_at_max == 1)
 		val |= CBE_PM_STOP_AT_MAX;
 
-	if (pm_cntrl->trace_mode == 1)
-		val |= CBE_PM_TRACE_MODE_SET(pm_cntrl->trace_mode);
+	if (pm_regs.pm_cntrl.trace_mode == 1)
+		val |= CBE_PM_TRACE_MODE_SET(pm_regs.pm_cntrl.trace_mode);
 
-	if (pm_cntrl->freeze == 1)
+	if (pm_regs.pm_cntrl.freeze == 1)
 		val |= CBE_PM_FREEZE_ALL_CTRS;
 
 	/* Routine set_count_mode must be called previously to set
 	 * the count mode based on the user selection of user and kernel.
 	 */
-	val |= CBE_PM_COUNT_MODE_SET(pm_cntrl->count_mode);
+	val |= CBE_PM_COUNT_MODE_SET(pm_regs.pm_cntrl.count_mode);
 	cbe_write_pm(cpu, pm_control, val);
 }
 
 static inline void
-set_count_mode(u32 kernel, u32 user, struct pm_cntrl *pm_cntrl)
+set_count_mode(u32 kernel, u32 user)
 {
 	/* The user must specify user and kernel if they want them. If
-	 *  neither is specified, OProfile will count in hypervisor mode
+	 *  neither is specified, OProfile will count in hypervisor mode.
+	 *  pm_regs.pm_cntrl is a global
 	 */
 	if (kernel) {
 		if (user)
-			pm_cntrl->count_mode = CBE_COUNT_ALL_MODES;
+			pm_regs.pm_cntrl.count_mode = CBE_COUNT_ALL_MODES;
 		else
-			pm_cntrl->count_mode = CBE_COUNT_SUPERVISOR_MODE;
+			pm_regs.pm_cntrl.count_mode =
+				CBE_COUNT_SUPERVISOR_MODE;
 	} else {
 		if (user)
-			pm_cntrl->count_mode = CBE_COUNT_PROBLEM_MODE;
+			pm_regs.pm_cntrl.count_mode = CBE_COUNT_PROBLEM_MODE;
 		else
-			pm_cntrl->count_mode = CBE_COUNT_HYPERVISOR_MODE;
+			pm_regs.pm_cntrl.count_mode =
+				CBE_COUNT_HYPERVISOR_MODE;
 	}
 }
 
 static inline void enable_ctr(u32 cpu, u32 ctr, u32 * pm07_cntrl)
 {
 
-	pm07_cntrl[ctr] |= PM07_CTR_ENABLE(1);
+	pm07_cntrl[ctr] |= CBE_PM_CTR_ENABLE;
 	cbe_write_pm07_control(cpu, ctr, pm07_cntrl[ctr]);
 }
 
@@ -365,6 +399,14 @@ static void cell_virtual_cntr(unsigned long data)
 	hdw_thread = 1 ^ hdw_thread;
 	next_hdw_thread = hdw_thread;
 
+	for (i = 0; i < num_counters; i++)
+	/* There are some per thread events.  Must do the
+	 * set event, for the thread that is being started
+	 */
+		set_pm_event(i,
+			pmc_cntrl[next_hdw_thread][i].evnts,
+			pmc_cntrl[next_hdw_thread][i].masks);
+
 	/* The following is done only once per each node, but
 	 * we need cpu #, not node #, to pass to the cbe_xxx functions.
 	 */
@@ -385,12 +427,13 @@ static void cell_virtual_cntr(unsigned long data)
 			    == 0xFFFFFFFF)
 				/* If the cntr value is 0xffffffff, we must
 				 * reset that to 0xfffffff0 when the current
-				 * thread is restarted.  This will generate a new
-				 * interrupt and make sure that we never restore
-				 * the counters to the max value.  If the counters
-				 * were restored to the max value, they do not
-				 * increment and no interrupts are generated.  Hence
-				 * no more samples will be collected on that cpu.
+				 * thread is restarted.  This will generate a
+				 * new interrupt and make sure that we never
+				 * restore the counters to the max value.  If
+				 * the counters were restored to the max value,
+				 * they do not increment and no interrupts are
+				 * generated.  Hence no more samples will be
+				 * collected on that cpu.
 				 */
 				cbe_write_ctr(cpu, i, 0xFFFFFFF0);
 			else
@@ -410,9 +453,6 @@ static void cell_virtual_cntr(unsigned long data)
 				 * Must do the set event, enable_cntr
 				 * for each cpu.
 				 */
-				set_pm_event(i,
-				     pmc_cntrl[next_hdw_thread][i].evnts,
-				     pmc_cntrl[next_hdw_thread][i].masks);
 				enable_ctr(cpu, i,
 					   pm_regs.pm07_cntrl);
 			} else {
@@ -465,8 +505,7 @@ cell_reg_setup(struct op_counter_config *ctr,
 	pm_regs.pm_cntrl.trace_mode = 0;
 	pm_regs.pm_cntrl.freeze = 1;
 
-	set_count_mode(sys->enable_kernel, sys->enable_user,
-		       &pm_regs.pm_cntrl);
+	set_count_mode(sys->enable_kernel, sys->enable_user);
 
 	/* Setup the thread 0 events */
 	for (i = 0; i < num_ctrs; ++i) {
@@ -498,10 +537,10 @@ cell_reg_setup(struct op_counter_config *ctr,
 		pmc_cntrl[1][i].vcntr = i;
 	}
 
-	for (i = 0; i < 4; i++)
+	for (i = 0; i < NUM_TRACE_BUS_WORDS; i++)
 		trace_bus[i] = 0xff;
 
-	for (i = 0; i < 2; i++)
+	for (i = 0; i < NUM_INPUT_BUS_WORDS; i++)
 		input_bus[i] = 0xff;
 
 	/* Our counters count up, and "count" refers to
@@ -560,7 +599,7 @@ static void cell_cpu_setup(struct op_counter_config *cntr)
 	cbe_write_pm(cpu, pm_start_stop, 0);
 	cbe_write_pm(cpu, group_control, pm_regs.group_control);
 	cbe_write_pm(cpu, debug_bus_control, pm_regs.debug_bus_control);
-	write_pm_cntrl(cpu, &pm_regs.pm_cntrl);
+	write_pm_cntrl(cpu);
 
 	for (i = 0; i < num_counters; ++i) {
 		if (ctr_enabled & (1 << i)) {
@@ -602,7 +641,7 @@ static void cell_global_start(struct op_counter_config *ctr)
 			}
 		}
 
-		cbe_clear_pm_interrupts(cpu);
+		cbe_get_and_clear_pm_interrupts(cpu);
 		cbe_enable_pm_interrupts(cpu, hdw_thread, interrupt_mask);
 		cbe_enable_pm(cpu);
 	}
@@ -672,7 +711,7 @@ cell_handle_interrupt(struct pt_regs *regs, struct op_counter_config *ctr)
 
 	cbe_disable_pm(cpu);
 
-	interrupt_mask = cbe_clear_pm_interrupts(cpu);
+	interrupt_mask = cbe_get_and_clear_pm_interrupts(cpu);
 
 	/* If the interrupt mask has been cleared, then the virt cntr
 	 * has cleared the interrupt.  When the thread that generated
diff --git a/arch/powerpc/platforms/cell/pmu.c b/arch/powerpc/platforms/cell/pmu.c
index d04ae1671e6c..66ca4b5a1dbc 100644
--- a/arch/powerpc/platforms/cell/pmu.c
+++ b/arch/powerpc/platforms/cell/pmu.c
@@ -345,18 +345,12 @@ EXPORT_SYMBOL_GPL(cbe_read_trace_buffer);
  * Enabling/disabling interrupts for the entire performance monitoring unit.
  */
 
-u32 cbe_query_pm_interrupts(u32 cpu)
-{
-	return cbe_read_pm(cpu, pm_status);
-}
-EXPORT_SYMBOL_GPL(cbe_query_pm_interrupts);
-
-u32 cbe_clear_pm_interrupts(u32 cpu)
+u32 cbe_get_and_clear_pm_interrupts(u32 cpu)
 {
 	/* Reading pm_status clears the interrupt bits. */
-	return cbe_query_pm_interrupts(cpu);
+	return cbe_read_pm(cpu, pm_status);
 }
-EXPORT_SYMBOL_GPL(cbe_clear_pm_interrupts);
+EXPORT_SYMBOL_GPL(cbe_get_and_clear_pm_interrupts);
 
 void cbe_enable_pm_interrupts(u32 cpu, u32 thread, u32 mask)
 {
@@ -371,7 +365,7 @@ EXPORT_SYMBOL_GPL(cbe_enable_pm_interrupts);
 
 void cbe_disable_pm_interrupts(u32 cpu)
 {
-	cbe_clear_pm_interrupts(cpu);
+	cbe_get_and_clear_pm_interrupts(cpu);
 	cbe_write_pm(cpu, pm_status, 0);
 }
 EXPORT_SYMBOL_GPL(cbe_disable_pm_interrupts);
diff --git a/arch/powerpc/platforms/cell/spufs/context.c b/arch/powerpc/platforms/cell/spufs/context.c
index 28c718ca3b51..04ad2e364e97 100644
--- a/arch/powerpc/platforms/cell/spufs/context.c
+++ b/arch/powerpc/platforms/cell/spufs/context.c
@@ -42,7 +42,7 @@ struct spu_context *alloc_spu_context(struct spu_gang *gang)
 	}
 	spin_lock_init(&ctx->mmio_lock);
 	kref_init(&ctx->kref);
-	init_rwsem(&ctx->state_sema);
+	mutex_init(&ctx->state_mutex);
 	init_MUTEX(&ctx->run_sema);
 	init_waitqueue_head(&ctx->ibox_wq);
 	init_waitqueue_head(&ctx->wbox_wq);
@@ -53,6 +53,10 @@ struct spu_context *alloc_spu_context(struct spu_gang *gang)
 	ctx->owner = get_task_mm(current);
 	if (gang)
 		spu_gang_add_ctx(gang, ctx);
+	ctx->rt_priority = current->rt_priority;
+	ctx->policy = current->policy;
+	ctx->prio = current->prio;
+	INIT_DELAYED_WORK(&ctx->sched_work, spu_sched_tick);
 	goto out;
 out_free:
 	kfree(ctx);
@@ -65,9 +69,9 @@ void destroy_spu_context(struct kref *kref)
 {
 	struct spu_context *ctx;
 	ctx = container_of(kref, struct spu_context, kref);
-	down_write(&ctx->state_sema);
+	mutex_lock(&ctx->state_mutex);
 	spu_deactivate(ctx);
-	up_write(&ctx->state_sema);
+	mutex_unlock(&ctx->state_mutex);
 	spu_fini_csa(&ctx->csa);
 	if (ctx->gang)
 		spu_gang_remove_ctx(ctx->gang, ctx);
@@ -96,16 +100,6 @@ void spu_forget(struct spu_context *ctx)
 	spu_release(ctx);
 }
 
-void spu_acquire(struct spu_context *ctx)
-{
-	down_read(&ctx->state_sema);
-}
-
-void spu_release(struct spu_context *ctx)
-{
-	up_read(&ctx->state_sema);
-}
-
 void spu_unmap_mappings(struct spu_context *ctx)
 {
 	if (ctx->local_store)
@@ -124,83 +118,84 @@ void spu_unmap_mappings(struct spu_context *ctx)
 		unmap_mapping_range(ctx->psmap, 0, 0x20000, 1);
 }
 
+/**
+ * spu_acquire_exclusive - lock spu contex and protect against userspace access
+ * @ctx:	spu contex to lock
+ *
+ * Note:
+ *	Returns 0 and with the context locked on success
+ *	Returns negative error and with the context _unlocked_ on failure.
+ */
 int spu_acquire_exclusive(struct spu_context *ctx)
 {
-	int ret = 0;
+	int ret = -EINVAL;
 
-	down_write(&ctx->state_sema);
-	/* ctx is about to be freed, can't acquire any more */
-	if (!ctx->owner) {
-		ret = -EINVAL;
-		goto out;
-	}
+	spu_acquire(ctx);
+	/*
+	 * Context is about to be freed, so we can't acquire it anymore.
+	 */
+	if (!ctx->owner)
+		goto out_unlock;
 
 	if (ctx->state == SPU_STATE_SAVED) {
 		ret = spu_activate(ctx, 0);
 		if (ret)
-			goto out;
-		ctx->state = SPU_STATE_RUNNABLE;
+			goto out_unlock;
 	} else {
-		/* We need to exclude userspace access to the context. */
+		/*
+		 * We need to exclude userspace access to the context.
+		 *
+		 * To protect against memory access we invalidate all ptes
+		 * and make sure the pagefault handlers block on the mutex.
+		 */
 		spu_unmap_mappings(ctx);
 	}
 
-out:
-	if (ret)
-		up_write(&ctx->state_sema);
+	return 0;
+
+ out_unlock:
+	spu_release(ctx);
 	return ret;
 }
 
-int spu_acquire_runnable(struct spu_context *ctx)
+/**
+ * spu_acquire_runnable - lock spu contex and make sure it is in runnable state
+ * @ctx:	spu contex to lock
+ *
+ * Note:
+ *	Returns 0 and with the context locked on success
+ *	Returns negative error and with the context _unlocked_ on failure.
+ */
+int spu_acquire_runnable(struct spu_context *ctx, unsigned long flags)
 {
-	int ret = 0;
-
-	down_read(&ctx->state_sema);
-	if (ctx->state == SPU_STATE_RUNNABLE) {
-		ctx->spu->prio = current->prio;
-		return 0;
-	}
-	up_read(&ctx->state_sema);
-
-	down_write(&ctx->state_sema);
-	/* ctx is about to be freed, can't acquire any more */
-	if (!ctx->owner) {
-		ret = -EINVAL;
-		goto out;
-	}
+	int ret = -EINVAL;
 
+	spu_acquire(ctx);
 	if (ctx->state == SPU_STATE_SAVED) {
-		ret = spu_activate(ctx, 0);
+		/*
+		 * Context is about to be freed, so we can't acquire it anymore.
+		 */
+		if (!ctx->owner)
+			goto out_unlock;
+		ret = spu_activate(ctx, flags);
 		if (ret)
-			goto out;
-		ctx->state = SPU_STATE_RUNNABLE;
+			goto out_unlock;
 	}
 
-	downgrade_write(&ctx->state_sema);
-	/* On success, we return holding the lock */
-
-	return ret;
-out:
-	/* Release here, to simplify calling code. */
-	up_write(&ctx->state_sema);
+	return 0;
 
+ out_unlock:
+	spu_release(ctx);
 	return ret;
 }
 
+/**
+ * spu_acquire_saved - lock spu contex and make sure it is in saved state
+ * @ctx:	spu contex to lock
+ */
 void spu_acquire_saved(struct spu_context *ctx)
 {
-	down_read(&ctx->state_sema);
-
-	if (ctx->state == SPU_STATE_SAVED)
-		return;
-
-	up_read(&ctx->state_sema);
-	down_write(&ctx->state_sema);
-
-	if (ctx->state == SPU_STATE_RUNNABLE) {
+	spu_acquire(ctx);
+	if (ctx->state != SPU_STATE_SAVED)
 		spu_deactivate(ctx);
-		ctx->state = SPU_STATE_SAVED;
-	}
-
-	downgrade_write(&ctx->state_sema);
 }
diff --git a/arch/powerpc/platforms/cell/spufs/file.c b/arch/powerpc/platforms/cell/spufs/file.c
index a528020baa18..b00653d69c01 100644
--- a/arch/powerpc/platforms/cell/spufs/file.c
+++ b/arch/powerpc/platforms/cell/spufs/file.c
@@ -103,6 +103,9 @@ static unsigned long spufs_mem_mmap_nopfn(struct vm_area_struct *vma,
 
 	offset += vma->vm_pgoff << PAGE_SHIFT;
 
+	if (offset >= LS_SIZE)
+		return NOPFN_SIGBUS;
+
 	spu_acquire(ctx);
 
 	if (ctx->state == SPU_STATE_SAVED) {
@@ -164,7 +167,7 @@ static unsigned long spufs_ps_nopfn(struct vm_area_struct *vma,
 	/* error here usually means a signal.. we might want to test
 	 * the error code more precisely though
 	 */
-	ret = spu_acquire_runnable(ctx);
+	ret = spu_acquire_runnable(ctx, 0);
 	if (ret)
 		return NOPFN_REFAULT;
 
@@ -1306,7 +1309,7 @@ static ssize_t spufs_mfc_write(struct file *file, const char __user *buffer,
 	if (ret)
 		goto out;
 
-	spu_acquire_runnable(ctx);
+	spu_acquire_runnable(ctx, 0);
 	if (file->f_flags & O_NONBLOCK) {
 		ret = ctx->ops->send_mfc_command(ctx, &cmd);
 	} else {
diff --git a/arch/powerpc/platforms/cell/spufs/run.c b/arch/powerpc/platforms/cell/spufs/run.c
index 1acc2ffef8c8..353a8fa07ab8 100644
--- a/arch/powerpc/platforms/cell/spufs/run.c
+++ b/arch/powerpc/platforms/cell/spufs/run.c
@@ -133,7 +133,7 @@ static int spu_setup_isolated(struct spu_context *ctx)
 	spu_mfc_sr1_set(ctx->spu, sr1);
 
 out_unlock:
-	spu_release_exclusive(ctx);
+	spu_release(ctx);
 out:
 	return ret;
 }
@@ -143,7 +143,7 @@ static inline int spu_run_init(struct spu_context *ctx, u32 * npc)
 	int ret;
 	unsigned long runcntl = SPU_RUNCNTL_RUNNABLE;
 
-	ret = spu_acquire_runnable(ctx);
+	ret = spu_acquire_runnable(ctx, SPU_ACTIVATE_NOWAKE);
 	if (ret)
 		return ret;
 
@@ -155,7 +155,7 @@ static inline int spu_run_init(struct spu_context *ctx, u32 * npc)
 			spu_release(ctx);
 			ret = spu_setup_isolated(ctx);
 			if (!ret)
-				ret = spu_acquire_runnable(ctx);
+				ret = spu_acquire_runnable(ctx, SPU_ACTIVATE_NOWAKE);
 		}
 
 		/* if userspace has set the runcntrl register (eg, to issue an
@@ -164,8 +164,10 @@ static inline int spu_run_init(struct spu_context *ctx, u32 * npc)
 			(SPU_RUNCNTL_RUNNABLE | SPU_RUNCNTL_ISOLATE);
 		if (runcntl == 0)
 			runcntl = SPU_RUNCNTL_RUNNABLE;
-	} else
+	} else {
+		spu_start_tick(ctx);
 		ctx->ops->npc_write(ctx, *npc);
+	}
 
 	ctx->ops->runcntl_write(ctx, runcntl);
 	return ret;
@@ -176,6 +178,7 @@ static inline int spu_run_fini(struct spu_context *ctx, u32 * npc,
 {
 	int ret = 0;
 
+	spu_stop_tick(ctx);
 	*status = ctx->ops->status_read(ctx);
 	*npc = ctx->ops->npc_read(ctx);
 	spu_release(ctx);
@@ -329,8 +332,10 @@ long spufs_run_spu(struct file *file, struct spu_context *ctx,
 		}
 		if (unlikely(ctx->state != SPU_STATE_RUNNABLE)) {
 			ret = spu_reacquire_runnable(ctx, npc, &status);
-			if (ret)
+			if (ret) {
+				spu_stop_tick(ctx);
 				goto out2;
+			}
 			continue;
 		}
 		ret = spu_process_events(ctx);
@@ -361,4 +366,3 @@ long spufs_run_spu(struct file *file, struct spu_context *ctx,
 	up(&ctx->run_sema);
 	return ret;
 }
-
diff --git a/arch/powerpc/platforms/cell/spufs/sched.c b/arch/powerpc/platforms/cell/spufs/sched.c
index bd6fe4b7a84b..2f25e68b4bac 100644
--- a/arch/powerpc/platforms/cell/spufs/sched.c
+++ b/arch/powerpc/platforms/cell/spufs/sched.c
@@ -44,17 +44,18 @@
 #include <asm/spu_priv1.h>
 #include "spufs.h"
 
-#define SPU_MIN_TIMESLICE 	(100 * HZ / 1000)
+#define SPU_TIMESLICE	(HZ)
 
-#define SPU_BITMAP_SIZE (((MAX_PRIO+BITS_PER_LONG)/BITS_PER_LONG)+1)
 struct spu_prio_array {
-	unsigned long bitmap[SPU_BITMAP_SIZE];
-	wait_queue_head_t waitq[MAX_PRIO];
+	DECLARE_BITMAP(bitmap, MAX_PRIO);
+	struct list_head runq[MAX_PRIO];
+	spinlock_t runq_lock;
 	struct list_head active_list[MAX_NUMNODES];
 	struct mutex active_mutex[MAX_NUMNODES];
 };
 
 static struct spu_prio_array *spu_prio;
+static struct workqueue_struct *spu_sched_wq;
 
 static inline int node_allowed(int node)
 {
@@ -68,6 +69,64 @@ static inline int node_allowed(int node)
 	return 1;
 }
 
+void spu_start_tick(struct spu_context *ctx)
+{
+	if (ctx->policy == SCHED_RR)
+		queue_delayed_work(spu_sched_wq, &ctx->sched_work, SPU_TIMESLICE);
+}
+
+void spu_stop_tick(struct spu_context *ctx)
+{
+	if (ctx->policy == SCHED_RR)
+		cancel_delayed_work(&ctx->sched_work);
+}
+
+void spu_sched_tick(struct work_struct *work)
+{
+	struct spu_context *ctx =
+		container_of(work, struct spu_context, sched_work.work);
+	struct spu *spu;
+	int rearm = 1;
+
+	mutex_lock(&ctx->state_mutex);
+	spu = ctx->spu;
+	if (spu) {
+		int best = sched_find_first_bit(spu_prio->bitmap);
+		if (best <= ctx->prio) {
+			spu_deactivate(ctx);
+			rearm = 0;
+		}
+	}
+	mutex_unlock(&ctx->state_mutex);
+
+	if (rearm)
+		spu_start_tick(ctx);
+}
+
+/**
+ * spu_add_to_active_list - add spu to active list
+ * @spu:	spu to add to the active list
+ */
+static void spu_add_to_active_list(struct spu *spu)
+{
+	mutex_lock(&spu_prio->active_mutex[spu->node]);
+	list_add_tail(&spu->list, &spu_prio->active_list[spu->node]);
+	mutex_unlock(&spu_prio->active_mutex[spu->node]);
+}
+
+/**
+ * spu_remove_from_active_list - remove spu from active list
+ * @spu:       spu to remove from the active list
+ */
+static void spu_remove_from_active_list(struct spu *spu)
+{
+	int node = spu->node;
+
+	mutex_lock(&spu_prio->active_mutex[node]);
+	list_del_init(&spu->list);
+	mutex_unlock(&spu_prio->active_mutex[node]);
+}
+
 static inline void mm_needs_global_tlbie(struct mm_struct *mm)
 {
 	int nr = (NR_CPUS > 1) ? NR_CPUS : NR_CPUS + 1;
@@ -94,8 +153,12 @@ int spu_switch_event_unregister(struct notifier_block * n)
 	return blocking_notifier_chain_unregister(&spu_switch_notifier, n);
 }
 
-
-static inline void bind_context(struct spu *spu, struct spu_context *ctx)
+/**
+ * spu_bind_context - bind spu context to physical spu
+ * @spu:	physical spu to bind to
+ * @ctx:	context to bind
+ */
+static void spu_bind_context(struct spu *spu, struct spu_context *ctx)
 {
 	pr_debug("%s: pid=%d SPU=%d NODE=%d\n", __FUNCTION__, current->pid,
 		 spu->number, spu->node);
@@ -104,7 +167,6 @@ static inline void bind_context(struct spu *spu, struct spu_context *ctx)
 	ctx->spu = spu;
 	ctx->ops = &spu_hw_ops;
 	spu->pid = current->pid;
-	spu->prio = current->prio;
 	spu->mm = ctx->owner;
 	mm_needs_global_tlbie(spu->mm);
 	spu->ibox_callback = spufs_ibox_callback;
@@ -118,12 +180,21 @@ static inline void bind_context(struct spu *spu, struct spu_context *ctx)
 	spu->timestamp = jiffies;
 	spu_cpu_affinity_set(spu, raw_smp_processor_id());
 	spu_switch_notify(spu, ctx);
+	spu_add_to_active_list(spu);
+	ctx->state = SPU_STATE_RUNNABLE;
 }
 
-static inline void unbind_context(struct spu *spu, struct spu_context *ctx)
+/**
+ * spu_unbind_context - unbind spu context from physical spu
+ * @spu:	physical spu to unbind from
+ * @ctx:	context to unbind
+ */
+static void spu_unbind_context(struct spu *spu, struct spu_context *ctx)
 {
 	pr_debug("%s: unbind pid=%d SPU=%d NODE=%d\n", __FUNCTION__,
 		 spu->pid, spu->number, spu->node);
+
+	spu_remove_from_active_list(spu);
 	spu_switch_notify(spu, NULL);
 	spu_unmap_mappings(ctx);
 	spu_save(&ctx->csa, spu);
@@ -136,95 +207,98 @@ static inline void unbind_context(struct spu *spu, struct spu_context *ctx)
 	spu->dma_callback = NULL;
 	spu->mm = NULL;
 	spu->pid = 0;
-	spu->prio = MAX_PRIO;
 	ctx->ops = &spu_backing_ops;
 	ctx->spu = NULL;
 	spu->flags = 0;
 	spu->ctx = NULL;
 }
 
-static inline void spu_add_wq(wait_queue_head_t * wq, wait_queue_t * wait,
-			      int prio)
+/**
+ * spu_add_to_rq - add a context to the runqueue
+ * @ctx:       context to add
+ */
+static void spu_add_to_rq(struct spu_context *ctx)
 {
-	prepare_to_wait_exclusive(wq, wait, TASK_INTERRUPTIBLE);
-	set_bit(prio, spu_prio->bitmap);
+	spin_lock(&spu_prio->runq_lock);
+	list_add_tail(&ctx->rq, &spu_prio->runq[ctx->prio]);
+	set_bit(ctx->prio, spu_prio->bitmap);
+	spin_unlock(&spu_prio->runq_lock);
 }
 
-static inline void spu_del_wq(wait_queue_head_t * wq, wait_queue_t * wait,
-			      int prio)
+/**
+ * spu_del_from_rq - remove a context from the runqueue
+ * @ctx:       context to remove
+ */
+static void spu_del_from_rq(struct spu_context *ctx)
 {
-	u64 flags;
-
-	__set_current_state(TASK_RUNNING);
-
-	spin_lock_irqsave(&wq->lock, flags);
-
-	remove_wait_queue_locked(wq, wait);
-	if (list_empty(&wq->task_list))
-		clear_bit(prio, spu_prio->bitmap);
-
-	spin_unlock_irqrestore(&wq->lock, flags);
+	spin_lock(&spu_prio->runq_lock);
+	list_del_init(&ctx->rq);
+	if (list_empty(&spu_prio->runq[ctx->prio]))
+		clear_bit(ctx->prio, spu_prio->bitmap);
+	spin_unlock(&spu_prio->runq_lock);
 }
 
-static void spu_prio_wait(struct spu_context *ctx, u64 flags)
+/**
+ * spu_grab_context - remove one context from the runqueue
+ * @prio:      priority of the context to be removed
+ *
+ * This function removes one context from the runqueue for priority @prio.
+ * If there is more than one context with the given priority the first
+ * task on the runqueue will be taken.
+ *
+ * Returns the spu_context it just removed.
+ *
+ * Must be called with spu_prio->runq_lock held.
+ */
+static struct spu_context *spu_grab_context(int prio)
+{
+	struct list_head *rq = &spu_prio->runq[prio];
+
+	if (list_empty(rq))
+		return NULL;
+	return list_entry(rq->next, struct spu_context, rq);
+}
+
+static void spu_prio_wait(struct spu_context *ctx)
 {
-	int prio = current->prio;
-	wait_queue_head_t *wq = &spu_prio->waitq[prio];
 	DEFINE_WAIT(wait);
 
-	if (ctx->spu)
-		return;
-
-	spu_add_wq(wq, &wait, prio);
-
+	set_bit(SPU_SCHED_WAKE, &ctx->sched_flags);
+	prepare_to_wait_exclusive(&ctx->stop_wq, &wait, TASK_INTERRUPTIBLE);
 	if (!signal_pending(current)) {
-		up_write(&ctx->state_sema);
-		pr_debug("%s: pid=%d prio=%d\n", __FUNCTION__,
-			 current->pid, current->prio);
+		mutex_unlock(&ctx->state_mutex);
 		schedule();
-		down_write(&ctx->state_sema);
+		mutex_lock(&ctx->state_mutex);
 	}
-
-	spu_del_wq(wq, &wait, prio);
+	__set_current_state(TASK_RUNNING);
+	remove_wait_queue(&ctx->stop_wq, &wait);
+	clear_bit(SPU_SCHED_WAKE, &ctx->sched_flags);
 }
 
-static void spu_prio_wakeup(void)
+/**
+ * spu_reschedule - try to find a runnable context for a spu
+ * @spu:       spu available
+ *
+ * This function is called whenever a spu becomes idle.  It looks for the
+ * most suitable runnable spu context and schedules it for execution.
+ */
+static void spu_reschedule(struct spu *spu)
 {
-	int best = sched_find_first_bit(spu_prio->bitmap);
+	int best;
+
+	spu_free(spu);
+
+	spin_lock(&spu_prio->runq_lock);
+	best = sched_find_first_bit(spu_prio->bitmap);
 	if (best < MAX_PRIO) {
-		wait_queue_head_t *wq = &spu_prio->waitq[best];
-		wake_up_interruptible_nr(wq, 1);
+		struct spu_context *ctx = spu_grab_context(best);
+		if (ctx && test_bit(SPU_SCHED_WAKE, &ctx->sched_flags))
+			wake_up(&ctx->stop_wq);
 	}
+	spin_unlock(&spu_prio->runq_lock);
 }
 
-static int get_active_spu(struct spu *spu)
-{
-	int node = spu->node;
-	struct spu *tmp;
-	int rc = 0;
-
-	mutex_lock(&spu_prio->active_mutex[node]);
-	list_for_each_entry(tmp, &spu_prio->active_list[node], list) {
-		if (tmp == spu) {
-			list_del_init(&spu->list);
-			rc = 1;
-			break;
-		}
-	}
-	mutex_unlock(&spu_prio->active_mutex[node]);
-	return rc;
-}
-
-static void put_active_spu(struct spu *spu)
-{
-	int node = spu->node;
-
-	mutex_lock(&spu_prio->active_mutex[node]);
-	list_add_tail(&spu->list, &spu_prio->active_list[node]);
-	mutex_unlock(&spu_prio->active_mutex[node]);
-}
-
-static struct spu *spu_get_idle(struct spu_context *ctx, u64 flags)
+static struct spu *spu_get_idle(struct spu_context *ctx)
 {
 	struct spu *spu = NULL;
 	int node = cpu_to_node(raw_smp_processor_id());
@@ -241,87 +315,154 @@ static struct spu *spu_get_idle(struct spu_context *ctx, u64 flags)
 	return spu;
 }
 
-static inline struct spu *spu_get(struct spu_context *ctx, u64 flags)
-{
-	/* Future: spu_get_idle() if possible,
-	 * otherwise try to preempt an active
-	 * context.
-	 */
-	return spu_get_idle(ctx, flags);
-}
-
-/* The three externally callable interfaces
- * for the scheduler begin here.
+/**
+ * find_victim - find a lower priority context to preempt
+ * @ctx:	canidate context for running
  *
- *	spu_activate	- bind a context to SPU, waiting as needed.
- *	spu_deactivate	- unbind a context from its SPU.
- *	spu_yield	- yield an SPU if others are waiting.
+ * Returns the freed physical spu to run the new context on.
  */
-
-int spu_activate(struct spu_context *ctx, u64 flags)
+static struct spu *find_victim(struct spu_context *ctx)
 {
+	struct spu_context *victim = NULL;
 	struct spu *spu;
-	int ret = 0;
+	int node, n;
 
-	for (;;) {
-		if (ctx->spu)
-			return 0;
-		spu = spu_get(ctx, flags);
-		if (spu != NULL) {
-			if (ctx->spu != NULL) {
-				spu_free(spu);
-				spu_prio_wakeup();
-				break;
-			}
-			bind_context(spu, ctx);
-			put_active_spu(spu);
-			break;
+	/*
+	 * Look for a possible preemption candidate on the local node first.
+	 * If there is no candidate look at the other nodes.  This isn't
+	 * exactly fair, but so far the whole spu schedule tries to keep
+	 * a strong node affinity.  We might want to fine-tune this in
+	 * the future.
+	 */
+ restart:
+	node = cpu_to_node(raw_smp_processor_id());
+	for (n = 0; n < MAX_NUMNODES; n++, node++) {
+		node = (node < MAX_NUMNODES) ? node : 0;
+		if (!node_allowed(node))
+			continue;
+
+		mutex_lock(&spu_prio->active_mutex[node]);
+		list_for_each_entry(spu, &spu_prio->active_list[node], list) {
+			struct spu_context *tmp = spu->ctx;
+
+			if (tmp->rt_priority < ctx->rt_priority &&
+			    (!victim || tmp->rt_priority < victim->rt_priority))
+				victim = spu->ctx;
 		}
-		spu_prio_wait(ctx, flags);
-		if (signal_pending(current)) {
-			ret = -ERESTARTSYS;
-			spu_prio_wakeup();
-			break;
+		mutex_unlock(&spu_prio->active_mutex[node]);
+
+		if (victim) {
+			/*
+			 * This nests ctx->state_mutex, but we always lock
+			 * higher priority contexts before lower priority
+			 * ones, so this is safe until we introduce
+			 * priority inheritance schemes.
+			 */
+			if (!mutex_trylock(&victim->state_mutex)) {
+				victim = NULL;
+				goto restart;
+			}
+
+			spu = victim->spu;
+			if (!spu) {
+				/*
+				 * This race can happen because we've dropped
+				 * the active list mutex.  No a problem, just
+				 * restart the search.
+				 */
+				mutex_unlock(&victim->state_mutex);
+				victim = NULL;
+				goto restart;
+			}
+			spu_unbind_context(spu, victim);
+			mutex_unlock(&victim->state_mutex);
+			return spu;
 		}
 	}
-	return ret;
+
+	return NULL;
 }
 
+/**
+ * spu_activate - find a free spu for a context and execute it
+ * @ctx:	spu context to schedule
+ * @flags:	flags (currently ignored)
+ *
+ * Tries to find a free spu to run @ctx.  If no free spu is availble
+ * add the context to the runqueue so it gets woken up once an spu
+ * is available.
+ */
+int spu_activate(struct spu_context *ctx, unsigned long flags)
+{
+
+	if (ctx->spu)
+		return 0;
+
+	do {
+		struct spu *spu;
+
+		spu = spu_get_idle(ctx);
+		/*
+		 * If this is a realtime thread we try to get it running by
+		 * preempting a lower priority thread.
+		 */
+		if (!spu && ctx->rt_priority)
+			spu = find_victim(ctx);
+		if (spu) {
+			spu_bind_context(spu, ctx);
+			return 0;
+		}
+
+		spu_add_to_rq(ctx);
+		if (!(flags & SPU_ACTIVATE_NOWAKE))
+			spu_prio_wait(ctx);
+		spu_del_from_rq(ctx);
+	} while (!signal_pending(current));
+
+	return -ERESTARTSYS;
+}
+
+/**
+ * spu_deactivate - unbind a context from it's physical spu
+ * @ctx:	spu context to unbind
+ *
+ * Unbind @ctx from the physical spu it is running on and schedule
+ * the highest priority context to run on the freed physical spu.
+ */
 void spu_deactivate(struct spu_context *ctx)
 {
-	struct spu *spu;
-	int needs_idle;
+	struct spu *spu = ctx->spu;
 
-	spu = ctx->spu;
-	if (!spu)
-		return;
-	needs_idle = get_active_spu(spu);
-	unbind_context(spu, ctx);
-	if (needs_idle) {
-		spu_free(spu);
-		spu_prio_wakeup();
+	if (spu) {
+		spu_unbind_context(spu, ctx);
+		spu_reschedule(spu);
 	}
 }
 
+/**
+ * spu_yield -  yield a physical spu if others are waiting
+ * @ctx:	spu context to yield
+ *
+ * Check if there is a higher priority context waiting and if yes
+ * unbind @ctx from the physical spu and schedule the highest
+ * priority context to run on the freed physical spu instead.
+ */
 void spu_yield(struct spu_context *ctx)
 {
 	struct spu *spu;
 	int need_yield = 0;
 
-	if (down_write_trylock(&ctx->state_sema)) {
+	if (mutex_trylock(&ctx->state_mutex)) {
 		if ((spu = ctx->spu) != NULL) {
 			int best = sched_find_first_bit(spu_prio->bitmap);
 			if (best < MAX_PRIO) {
 				pr_debug("%s: yielding SPU %d NODE %d\n",
 					 __FUNCTION__, spu->number, spu->node);
 				spu_deactivate(ctx);
-				ctx->state = SPU_STATE_SAVED;
 				need_yield = 1;
-			} else {
-				spu->prio = MAX_PRIO;
 			}
 		}
-		up_write(&ctx->state_sema);
+		mutex_unlock(&ctx->state_mutex);
 	}
 	if (unlikely(need_yield))
 		yield();
@@ -331,14 +472,19 @@ int __init spu_sched_init(void)
 {
 	int i;
 
+	spu_sched_wq = create_singlethread_workqueue("spusched");
+	if (!spu_sched_wq)
+		return 1;
+
 	spu_prio = kzalloc(sizeof(struct spu_prio_array), GFP_KERNEL);
 	if (!spu_prio) {
 		printk(KERN_WARNING "%s: Unable to allocate priority queue.\n",
 		       __FUNCTION__);
+		       destroy_workqueue(spu_sched_wq);
 		return 1;
 	}
 	for (i = 0; i < MAX_PRIO; i++) {
-		init_waitqueue_head(&spu_prio->waitq[i]);
+		INIT_LIST_HEAD(&spu_prio->runq[i]);
 		__clear_bit(i, spu_prio->bitmap);
 	}
 	__set_bit(MAX_PRIO, spu_prio->bitmap);
@@ -346,6 +492,7 @@ int __init spu_sched_init(void)
 		mutex_init(&spu_prio->active_mutex[i]);
 		INIT_LIST_HEAD(&spu_prio->active_list[i]);
 	}
+	spin_lock_init(&spu_prio->runq_lock);
 	return 0;
 }
 
@@ -364,4 +511,5 @@ void __exit spu_sched_exit(void)
 		mutex_unlock(&spu_prio->active_mutex[node]);
 	}
 	kfree(spu_prio);
+	destroy_workqueue(spu_sched_wq);
 }
diff --git a/arch/powerpc/platforms/cell/spufs/spufs.h b/arch/powerpc/platforms/cell/spufs/spufs.h
index 0941c56df9b5..0c437891dfd5 100644
--- a/arch/powerpc/platforms/cell/spufs/spufs.h
+++ b/arch/powerpc/platforms/cell/spufs/spufs.h
@@ -23,7 +23,7 @@
 #define SPUFS_H
 
 #include <linux/kref.h>
-#include <linux/rwsem.h>
+#include <linux/mutex.h>
 #include <linux/spinlock.h>
 #include <linux/fs.h>
 
@@ -37,11 +37,13 @@ enum {
 };
 
 struct spu_context_ops;
-
-#define SPU_CONTEXT_PREEMPT          0UL
-
 struct spu_gang;
 
+/* ctx->sched_flags */
+enum {
+	SPU_SCHED_WAKE = 0,
+};
+
 struct spu_context {
 	struct spu *spu;		  /* pointer to a physical SPU */
 	struct spu_state csa;		  /* SPU context save area. */
@@ -56,7 +58,7 @@ struct spu_context {
 	u64 object_id;		   /* user space pointer for oprofile */
 
 	enum { SPU_STATE_RUNNABLE, SPU_STATE_SAVED } state;
-	struct rw_semaphore state_sema;
+	struct mutex state_mutex;
 	struct semaphore run_sema;
 
 	struct mm_struct *owner;
@@ -77,6 +79,14 @@ struct spu_context {
 
 	struct list_head gang_list;
 	struct spu_gang *gang;
+
+	/* scheduler fields */
+ 	struct list_head rq;
+	struct delayed_work sched_work;
+	unsigned long sched_flags;
+	unsigned long rt_priority;
+	int policy;
+	int prio;
 };
 
 struct spu_gang {
@@ -161,6 +171,16 @@ void spu_gang_remove_ctx(struct spu_gang *gang, struct spu_context *ctx);
 void spu_gang_add_ctx(struct spu_gang *gang, struct spu_context *ctx);
 
 /* context management */
+static inline void spu_acquire(struct spu_context *ctx)
+{
+	mutex_lock(&ctx->state_mutex);
+}
+
+static inline void spu_release(struct spu_context *ctx)
+{
+	mutex_unlock(&ctx->state_mutex);
+}
+
 struct spu_context * alloc_spu_context(struct spu_gang *gang);
 void destroy_spu_context(struct kref *kref);
 struct spu_context * get_spu_context(struct spu_context *ctx);
@@ -168,20 +188,18 @@ int put_spu_context(struct spu_context *ctx);
 void spu_unmap_mappings(struct spu_context *ctx);
 
 void spu_forget(struct spu_context *ctx);
-void spu_acquire(struct spu_context *ctx);
-void spu_release(struct spu_context *ctx);
-int spu_acquire_runnable(struct spu_context *ctx);
+int spu_acquire_runnable(struct spu_context *ctx, unsigned long flags);
 void spu_acquire_saved(struct spu_context *ctx);
 int spu_acquire_exclusive(struct spu_context *ctx);
-
-static inline void spu_release_exclusive(struct spu_context *ctx)
-{
-	up_write(&ctx->state_sema);
-}
-
-int spu_activate(struct spu_context *ctx, u64 flags);
+enum {
+	SPU_ACTIVATE_NOWAKE = 1,
+};
+int spu_activate(struct spu_context *ctx, unsigned long flags);
 void spu_deactivate(struct spu_context *ctx);
 void spu_yield(struct spu_context *ctx);
+void spu_start_tick(struct spu_context *ctx);
+void spu_stop_tick(struct spu_context *ctx);
+void spu_sched_tick(struct work_struct *work);
 int __init spu_sched_init(void);
 void __exit spu_sched_exit(void);
 
diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index 77540a2f7704..0183e5fbaf46 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -2811,7 +2811,6 @@ static void dump_spu_fields(struct spu *spu)
 	DUMP_FIELD(spu, "0x%lx", irqs[2]);
 	DUMP_FIELD(spu, "0x%x", slb_replace);
 	DUMP_FIELD(spu, "%d", pid);
-	DUMP_FIELD(spu, "%d", prio);
 	DUMP_FIELD(spu, "0x%p", mm);
 	DUMP_FIELD(spu, "0x%p", ctx);
 	DUMP_FIELD(spu, "0x%p", rq);
diff --git a/include/asm-powerpc/cell-pmu.h b/include/asm-powerpc/cell-pmu.h
index e8c2ebd3ddda..35b95773746c 100644
--- a/include/asm-powerpc/cell-pmu.h
+++ b/include/asm-powerpc/cell-pmu.h
@@ -53,6 +53,11 @@
 #define CBE_PM_CTR_POLARITY                0x01000000
 #define CBE_PM_CTR_COUNT_CYCLES            0x00800000
 #define CBE_PM_CTR_ENABLE                  0x00400000
+#define PM07_CTR_INPUT_MUX(x)              (((x) & 0x3F) << 26)
+#define PM07_CTR_INPUT_CONTROL(x)          (((x) & 1) << 25)
+#define PM07_CTR_POLARITY(x)               (((x) & 1) << 24)
+#define PM07_CTR_COUNT_CYCLES(x)           (((x) & 1) << 23)
+#define PM07_CTR_ENABLE(x)                 (((x) & 1) << 22)
 
 /* Macros for the pm_status register. */
 #define CBE_PM_CTR_OVERFLOW_INTR(ctr)      (1 << (31 - ((ctr) & 7)))
@@ -89,8 +94,7 @@ extern void cbe_read_trace_buffer(u32 cpu, u64 *buf);
 
 extern void cbe_enable_pm_interrupts(u32 cpu, u32 thread, u32 mask);
 extern void cbe_disable_pm_interrupts(u32 cpu);
-extern u32  cbe_query_pm_interrupts(u32 cpu);
-extern u32  cbe_clear_pm_interrupts(u32 cpu);
+extern u32  cbe_get_and_clear_pm_interrupts(u32 cpu);
 extern void cbe_sync_irq(int node);
 
 /* Utility functions, macros */
@@ -103,11 +107,4 @@ extern u32 cbe_get_hw_thread_id(int cpu);
 #define CBE_COUNT_PROBLEM_MODE          2
 #define CBE_COUNT_ALL_MODES             3
 
-/* Macros for the pm07_control registers. */
-#define PM07_CTR_INPUT_MUX(x)                    (((x) & 0x3F) << 26)
-#define PM07_CTR_INPUT_CONTROL(x)                (((x) & 1) << 25)
-#define PM07_CTR_POLARITY(x)                     (((x) & 1) << 24)
-#define PM07_CTR_COUNT_CYCLES(x)                 (((x) & 1) << 23)
-#define PM07_CTR_ENABLE(x)                       (((x) & 1) << 22)
-
 #endif /* __ASM_CELL_PMU_H__ */
diff --git a/include/asm-powerpc/spu.h b/include/asm-powerpc/spu.h
index b634e16575f2..0f9f2dd24a79 100644
--- a/include/asm-powerpc/spu.h
+++ b/include/asm-powerpc/spu.h
@@ -129,7 +129,6 @@ struct spu {
 	struct spu_runqueue *rq;
 	unsigned long long timestamp;
 	pid_t pid;
-	int prio;
 	int class_0_pending;
 	spinlock_t register_lock;