[POWERPC] spufs: Fix SPE single-step mode

Currently we only catch debug events through the 0x3fff status;
spufs_run_spu doesn't handle single-step SPE events.

This change adds a handler for conditions where the SPE is stopped due
to single-step-mode.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

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

@@ -410,8 +410,11 @@ long spufs_run_spu(struct spu_context *ctx, u32 *npc, u32 *event)
 	 * since we have TIF_SINGLESTEP set, thus the kernel will do
 	 * it upon return from the syscall anyawy
 	 */
-	if ((status & SPU_STATUS_STOPPED_BY_STOP)
-	    && (status >> SPU_STOP_STATUS_SHIFT) == 0x3fff) {
+	if (unlikely(status & SPU_STATUS_SINGLE_STEP))
+		ret = -ERESTARTSYS;
+
+	else if (unlikely((status & SPU_STATUS_STOPPED_BY_STOP)
+	    && (status >> SPU_STOP_STATUS_SHIFT) == 0x3fff)) {
 		force_sig(SIGTRAP, current);
 		ret = -ERESTARTSYS;
 	}