[CELL] spufs: rework list management and associated locking

This sorts out the various lists and related locks in the spu code.

In detail:

 - the per-node free_spus and active_list are gone.  Instead struct spu
   gained an alloc_state member telling whether the spu is free or not
 - the per-node spus array is now locked by a per-node mutex, which
   takes over from the global spu_lock and the per-node active_mutex
 - the spu_alloc* and spu_free function are gone as the state change is
   now done inline in the spufs code.  This allows some more sharing of
   code for the affinity vs normal case and more efficient locking
 - some little refactoring in the affinity code for this locking scheme

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>

arch/powerpc/platforms/cell/spu_base.c

@@ -409,7 +409,7 @@ static void spu_free_irqs(struct spu *spu)
 		free_irq(spu->irqs[2], spu);
 }
 
-static void spu_init_channels(struct spu *spu)
+void spu_init_channels(struct spu *spu)
 {
 	static const struct {
 		 unsigned channel;
@@ -442,66 +442,7 @@ static void spu_init_channels(struct spu *spu)
 		out_be64(&priv2->spu_chnlcnt_RW, count_list[i].count);
 	}
 }
-
-struct spu *spu_alloc_spu(struct spu *req_spu)
-{
-	struct spu *spu, *ret = NULL;
-
-	spin_lock(&spu_lock);
-	list_for_each_entry(spu, &cbe_spu_info[req_spu->node].free_spus, list) {
-		if (spu == req_spu) {
-			list_del_init(&spu->list);
-			pr_debug("Got SPU %d %d\n", spu->number, spu->node);
-			spu_init_channels(spu);
-			ret = spu;
-			break;
-		}
-	}
-	spin_unlock(&spu_lock);
-	return ret;
-}
-EXPORT_SYMBOL_GPL(spu_alloc_spu);
-
-struct spu *spu_alloc_node(int node)
-{
-	struct spu *spu = NULL;
-
-	spin_lock(&spu_lock);
-	if (!list_empty(&cbe_spu_info[node].free_spus)) {
-		spu = list_entry(cbe_spu_info[node].free_spus.next, struct spu,
-									list);
-		list_del_init(&spu->list);
-		pr_debug("Got SPU %d %d\n", spu->number, spu->node);
-	}
-	spin_unlock(&spu_lock);
-
-	if (spu)
-		spu_init_channels(spu);
-	return spu;
-}
-EXPORT_SYMBOL_GPL(spu_alloc_node);
-
-struct spu *spu_alloc(void)
-{
-	struct spu *spu = NULL;
-	int node;
-
-	for (node = 0; node < MAX_NUMNODES; node++) {
-		spu = spu_alloc_node(node);
-		if (spu)
-			break;
-	}
-
-	return spu;
-}
-
-void spu_free(struct spu *spu)
-{
-	spin_lock(&spu_lock);
-	list_add_tail(&spu->list, &cbe_spu_info[spu->node].free_spus);
-	spin_unlock(&spu_lock);
-}
-EXPORT_SYMBOL_GPL(spu_free);
+EXPORT_SYMBOL_GPL(spu_init_channels);
 
 static int spu_shutdown(struct sys_device *sysdev)
 {
@@ -597,6 +538,8 @@ static int __init create_spu(void *data)
 	if (!spu)
 		goto out;
 
+	spu->alloc_state = SPU_FREE;
+
 	spin_lock_init(&spu->register_lock);
 	spin_lock(&spu_lock);
 	spu->number = number++;
@@ -617,11 +560,10 @@ static int __init create_spu(void *data)
 	if (ret)
 		goto out_free_irqs;
 
-	spin_lock(&spu_lock);
-	list_add(&spu->list, &cbe_spu_info[spu->node].free_spus);
+	mutex_lock(&cbe_spu_info[spu->node].list_mutex);
 	list_add(&spu->cbe_list, &cbe_spu_info[spu->node].spus);
 	cbe_spu_info[spu->node].n_spus++;
-	spin_unlock(&spu_lock);
+	mutex_unlock(&cbe_spu_info[spu->node].list_mutex);
 
 	mutex_lock(&spu_full_list_mutex);
 	spin_lock_irqsave(&spu_full_list_lock, flags);
@@ -831,8 +773,8 @@ static int __init init_spu_base(void)
 	int i, ret = 0;
 
 	for (i = 0; i < MAX_NUMNODES; i++) {
+		mutex_init(&cbe_spu_info[i].list_mutex);
 		INIT_LIST_HEAD(&cbe_spu_info[i].spus);
-		INIT_LIST_HEAD(&cbe_spu_info[i].free_spus);
 	}
 
 	if (!spu_management_ops)