[POWERPC] spufs: don't (ab)use SCHED_IDLE

commit 4ef11014 introduced a usage of SCHED_IDLE to detect when
a context is within spu_run.

Instead of SCHED_IDLE (which has other meaning), add a flag to
sched_flags to tell if a context should be running.
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>

arch/powerpc/platforms/cell/spufs/run.c

@@ -220,6 +220,7 @@ static int spu_run_init(struct spu_context *ctx, u32 *npc)
 		}
 	}
 
+	set_bit(SPU_SCHED_SPU_RUN, &ctx->sched_flags);
 	return 0;
 }
 
@@ -234,7 +235,7 @@ static int spu_run_fini(struct spu_context *ctx, u32 *npc,
 	*npc = ctx->ops->npc_read(ctx);
 
 	spuctx_switch_state(ctx, SPU_UTIL_IDLE_LOADED);
-	ctx->policy = SCHED_IDLE;
+	clear_bit(SPU_SCHED_SPU_RUN, &ctx->sched_flags);
 	spu_release(ctx);
 
 	if (signal_pending(current))

arch/powerpc/platforms/cell/spufs/sched.c

@@ -867,7 +867,7 @@ static noinline void spusched_tick(struct spu_context *ctx)
 	if (ctx->policy == SCHED_FIFO)
 		goto out;
 
-	if (--ctx->time_slice && ctx->policy != SCHED_IDLE)
+	if (--ctx->time_slice && test_bit(SPU_SCHED_SPU_RUN, &ctx->sched_flags))
 		goto out;
 
 	spu = ctx->spu;
@@ -877,7 +877,7 @@ static noinline void spusched_tick(struct spu_context *ctx)
 	new = grab_runnable_context(ctx->prio + 1, spu->node);
 	if (new) {
 		spu_unschedule(spu, ctx);
-		if (ctx->policy != SCHED_IDLE)
+		if (test_bit(SPU_SCHED_SPU_RUN, &ctx->sched_flags))
 			spu_add_to_rq(ctx);
 	} else {
 		spu_context_nospu_trace(spusched_tick__newslice, ctx);

arch/powerpc/platforms/cell/spufs/spufs.h

@@ -44,6 +44,7 @@ struct spu_gang;
 enum {
 	SPU_SCHED_NOTIFY_ACTIVE,
 	SPU_SCHED_WAS_ACTIVE,	/* was active upon spu_acquire_saved()  */
+	SPU_SCHED_SPU_RUN,	/* context is within spu_run */
 };
 
 struct spu_context {