[POWERPC] spufs: add backing ops for privcntl register

This change encapsulates the spu_privcntl_RW register so that it can
be written through backing ops.  This is necessary so that spu contexts
can be initialized and queued to the scheduler in spufs_run_spu.

Signed-off-by: Luke Browning <lukebr@linux.vnet.ibm.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

@@ -268,6 +268,11 @@ static char *spu_backing_get_ls(struct spu_context *ctx)
 	return ctx->csa.lscsa->ls;
 }
 
+static void spu_backing_privcntl_write(struct spu_context *ctx, u64 val)
+{
+	ctx->csa.priv2.spu_privcntl_RW = val;
+}
+
 static u32 spu_backing_runcntl_read(struct spu_context *ctx)
 {
 	return ctx->csa.prob.spu_runcntl_RW;
@@ -384,6 +389,7 @@ struct spu_context_ops spu_backing_ops = {
 	.npc_write = spu_backing_npc_write,
 	.status_read = spu_backing_status_read,
 	.get_ls = spu_backing_get_ls,
+	.privcntl_write = spu_backing_privcntl_write,
 	.runcntl_read = spu_backing_runcntl_read,
 	.runcntl_write = spu_backing_runcntl_write,
 	.runcntl_stop = spu_backing_runcntl_stop,

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

@@ -206,6 +206,11 @@ static char *spu_hw_get_ls(struct spu_context *ctx)
 	return ctx->spu->local_store;
 }
 
+static void spu_hw_privcntl_write(struct spu_context *ctx, u64 val)
+{
+	out_be64(&ctx->spu->priv2->spu_privcntl_RW, val);
+}
+
 static u32 spu_hw_runcntl_read(struct spu_context *ctx)
 {
 	return in_be32(&ctx->spu->problem->spu_runcntl_RW);
@@ -215,7 +220,8 @@ static void spu_hw_runcntl_write(struct spu_context *ctx, u32 val)
 {
 	spin_lock_irq(&ctx->spu->register_lock);
 	if (val & SPU_RUNCNTL_ISOLATE)
-		out_be64(&ctx->spu->priv2->spu_privcntl_RW, 4LL);
+		spu_hw_privcntl_write(ctx,
+			SPU_PRIVCNT_LOAD_REQUEST_ENABLE_MASK);
 	out_be32(&ctx->spu->problem->spu_runcntl_RW, val);
 	spin_unlock_irq(&ctx->spu->register_lock);
 }
@@ -328,6 +334,7 @@ struct spu_context_ops spu_hw_ops = {
 	.npc_write = spu_hw_npc_write,
 	.status_read = spu_hw_status_read,
 	.get_ls = spu_hw_get_ls,
+	.privcntl_write = spu_hw_privcntl_write,
 	.runcntl_read = spu_hw_runcntl_read,
 	.runcntl_write = spu_hw_runcntl_write,
 	.runcntl_stop = spu_hw_runcntl_stop,

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

@@ -128,10 +128,11 @@ out:
 
 static int spu_run_init(struct spu_context *ctx, u32 *npc)
 {
+	unsigned long runcntl;
+
 	spuctx_switch_state(ctx, SPU_UTIL_SYSTEM);
 
 	if (ctx->flags & SPU_CREATE_ISOLATE) {
-		unsigned long runcntl;
 
 		if (!(ctx->ops->status_read(ctx) & SPU_STATUS_ISOLATED_STATE)) {
 			int ret = spu_setup_isolated(ctx);
@@ -145,16 +146,21 @@ static int spu_run_init(struct spu_context *ctx, u32 *npc)
 			(SPU_RUNCNTL_RUNNABLE | SPU_RUNCNTL_ISOLATE);
 		if (runcntl == 0)
 			runcntl = SPU_RUNCNTL_RUNNABLE;
-		ctx->ops->runcntl_write(ctx, runcntl);
 	} else {
-		unsigned long mode = SPU_PRIVCNTL_MODE_NORMAL;
-		ctx->ops->npc_write(ctx, *npc);
+		unsigned long privcntl;
+
 		if (test_thread_flag(TIF_SINGLESTEP))
-			mode = SPU_PRIVCNTL_MODE_SINGLE_STEP;
-		out_be64(&ctx->spu->priv2->spu_privcntl_RW, mode);
-		ctx->ops->runcntl_write(ctx, SPU_RUNCNTL_RUNNABLE);
+			privcntl = SPU_PRIVCNTL_MODE_SINGLE_STEP;
+		else
+			privcntl = SPU_PRIVCNTL_MODE_NORMAL;
+		runcntl = SPU_RUNCNTL_RUNNABLE;
+
+		ctx->ops->npc_write(ctx, *npc);
+		ctx->ops->privcntl_write(ctx, privcntl);
 	}
 
+	ctx->ops->runcntl_write(ctx, runcntl);
+
 	spuctx_switch_state(ctx, SPU_UTIL_USER);
 
 	return 0;

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

@@ -169,6 +169,7 @@ struct spu_context_ops {
 	void (*npc_write) (struct spu_context * ctx, u32 data);
 	 u32(*status_read) (struct spu_context * ctx);
 	char*(*get_ls) (struct spu_context * ctx);
+	void (*privcntl_write) (struct spu_context *ctx, u64 data);
 	 u32 (*runcntl_read) (struct spu_context * ctx);
 	void (*runcntl_write) (struct spu_context * ctx, u32 data);
 	void (*runcntl_stop) (struct spu_context * ctx);