[PATCH]Add notification for active Cell SPU tasks

[Maynard Johnson <maynardj@us.ibm.com>]

Subject: Enable SPU switch notification to detect currently active SPU tasks.

From: Maynard Johnson <maynardj@us.ibm.com>

This patch adds to the capability of spu_switch_event_register to notify the
caller of currently active SPU tasks.  It also exports spu_switch_event_register
and spu_switch_event_unregister.

Signed-off-by: Maynard Johnson <mpjohn@us.ibm.com>


Index: linux-2.6.19-rc6-arnd1+patches/arch/powerpc/platforms/cell/spufs/sched.c
===================================================================
--- linux-2.6.19-rc6-arnd1+patches.orig/arch/powerpc/platforms/cell/spufs/sched.c	2006-11-24 11:34:44.884455680 -0600
+++ linux-2.6.19-rc6-arnd1+patches/arch/powerpc/platforms/cell/spufs/sched.c	2006-12-01 13:57:21.864583264 -0600
@@ -84,15 +84,37 @@
 			    ctx ? ctx->object_id : 0, spu);
 }
 
+static void notify_spus_active(void)
+{
+	int node;
+	for (node = 0; node < MAX_NUMNODES; node++) {
+		struct spu *spu;
+		mutex_lock(&spu_prio->active_mutex[node]);
+		list_for_each_entry(spu, &spu_prio->active_list[node], list) {
+	 			 struct spu_context *ctx = spu->ctx;
+	 			 blocking_notifier_call_chain(&spu_switch_notifier,
+	 		 			 ctx ? ctx->object_id : 0, spu);
+		}
+		mutex_unlock(&spu_prio->active_mutex[node]);
+	 }
+
+}
+
 int spu_switch_event_register(struct notifier_block * n)
 {
-	return blocking_notifier_chain_register(&spu_switch_notifier, n);
+	int ret;
+	ret = blocking_notifier_chain_register(&spu_switch_notifier, n);
+	if (!ret)
+		notify_spus_active();
+	return ret;
 }
+EXPORT_SYMBOL_GPL(spu_switch_event_register);
 
 int spu_switch_event_unregister(struct notifier_block * n)
 {
 	return blocking_notifier_chain_unregister(&spu_switch_notifier, n);
 }
+EXPORT_SYMBOL_GPL(spu_switch_event_unregister);
 
 
 static inline void bind_context(struct spu *spu, struct spu_context *ctx)