1 files changed, 27 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/cell/spufs/context.c b/arch/powerpc/platforms/cell/spufs/context.c
index 034cf6af53a..0870009f56d 100644
--- a/arch/powerpc/platforms/cell/spufs/context.c
+++ b/arch/powerpc/platforms/cell/spufs/context.c
@@ -120,6 +120,33 @@ void spu_unmap_mappings(struct spu_context *ctx)
 		unmap_mapping_range(ctx->signal2, 0, 0x4000, 1);
 }
 
+int spu_acquire_exclusive(struct spu_context *ctx)
+{
+	int ret = 0;
+
+	down_write(&ctx->state_sema);
+	/* ctx is about to be freed, can't acquire any more */
+	if (!ctx->owner) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (ctx->state == SPU_STATE_SAVED) {
+		ret = spu_activate(ctx, 0);
+		if (ret)
+			goto out;
+		ctx->state = SPU_STATE_RUNNABLE;
+	} else {
+		/* We need to exclude userspace access to the context. */
+		spu_unmap_mappings(ctx);
+	}
+
+out:
+	if (ret)
+		up_write(&ctx->state_sema);
+	return ret;
+}
+
 int spu_acquire_runnable(struct spu_context *ctx)
 {
 	int ret = 0;