[CELL] spufs: make sure context are scheduled again after spu_acquire_saved

Currently a process is removed from the physical spu when spu_acquire_saved
is saved but never put back.  This patch adds a new spu_release_saved
that is to be paired with spu_acquire_saved and put the process back if
it has been in RUNNABLE state before.

Niether Jeremy not be are entirely happy about this exact patch because
it adds another spu_activate call outside of the owner thread, but I
feel this is the best short-term fix we can come up with.

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

1 files changed, 17 insertions, 1 deletions

diff --git a/arch/powerpc/platforms/cell/spufs/context.c b/arch/powerpc/platforms/cell/spufs/context.c
index 0e5e55f53c8..6b091ea1d19 100644
--- a/arch/powerpc/platforms/cell/spufs/context.c
+++ b/arch/powerpc/platforms/cell/spufs/context.c
@@ -165,6 +165,22 @@ int spu_acquire_runnable(struct spu_context *ctx, unsigned long flags)
 void spu_acquire_saved(struct spu_context *ctx)
 {
 	spu_acquire(ctx);
-	if (ctx->state != SPU_STATE_SAVED)
+	if (ctx->state != SPU_STATE_SAVED) {
+		set_bit(SPU_SCHED_WAS_ACTIVE, &ctx->sched_flags);
 		spu_deactivate(ctx);
+	}
+}
+
+/**
+ * spu_release_saved - unlock spu context and return it to the runqueue
+ * @ctx:	context to unlock
+ */
+void spu_release_saved(struct spu_context *ctx)
+{
+	BUG_ON(ctx->state != SPU_STATE_SAVED);
+
+	if (test_and_clear_bit(SPU_SCHED_WAS_ACTIVE, &ctx->sched_flags))
+		spu_activate(ctx, 0);
+
+	spu_release(ctx);
 }