[POWERPC] spufs: Update SPU_Status[CISHP] in backing runcntl write

Currently, the kernel may fail to restart a SPE context which
has stopped and been swapped out.

This changes spu_backing_runcntl_write to emulate the real
SPU_Status register exactly.  When the SPU Run Control register
is written with SPU_RunCntl[Run] set to '1', the physical SPU
automatically sets SPU_Status[R] and clears SPU_Status[CISHP].

Signed-off-by: Masato Noguchi <Masato.Noguchi@jp.sony.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

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

@@ -288,6 +288,12 @@ static void spu_backing_runcntl_write(struct spu_context *ctx, u32 val)
 	spin_lock(&ctx->csa.register_lock);
 	ctx->csa.prob.spu_runcntl_RW = val;
 	if (val & SPU_RUNCNTL_RUNNABLE) {
+		ctx->csa.prob.spu_status_R &=
+			~SPU_STATUS_STOPPED_BY_STOP &
+			~SPU_STATUS_STOPPED_BY_HALT &
+			~SPU_STATUS_SINGLE_STEP &
+			~SPU_STATUS_INVALID_INSTR &
+			~SPU_STATUS_INVALID_CH;
 		ctx->csa.prob.spu_status_R |= SPU_STATUS_RUNNING;
 	} else {
 		ctx->csa.prob.spu_status_R &= ~SPU_STATUS_RUNNING;