[POWERPC] spufs: Add runcntrl read accessors

This change adds a read accessor for the SPE problem-state run control
register.

This is required for for applying (userspace) changes made to the run
control register while the SPE is stopped - simply asserting the master
run control bit is not sufficient. My next patch for isolated-mode
setup requires this.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
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 u32 spu_backing_runcntl_read(struct spu_context *ctx)
+{
+	return ctx->csa.prob.spu_runcntl_RW;
+}
+
 static void spu_backing_runcntl_write(struct spu_context *ctx, u32 val)
 {
 	spin_lock(&ctx->csa.register_lock);
@@ -363,6 +368,7 @@ 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,
+	.runcntl_read = spu_backing_runcntl_read,
 	.runcntl_write = spu_backing_runcntl_write,
 	.master_start = spu_backing_master_start,
 	.master_stop = spu_backing_master_stop,

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

@@ -207,6 +207,11 @@ static char *spu_hw_get_ls(struct spu_context *ctx)
 	return ctx->spu->local_store;
 }
 
+static u32 spu_hw_runcntl_read(struct spu_context *ctx)
+{
+	return in_be32(&ctx->spu->problem->spu_runcntl_RW);
+}
+
 static void spu_hw_runcntl_write(struct spu_context *ctx, u32 val)
 {
 	spin_lock_irq(&ctx->spu->register_lock);
@@ -307,6 +312,7 @@ 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,
+	.runcntl_read = spu_hw_runcntl_read,
 	.runcntl_write = spu_hw_runcntl_write,
 	.master_start = spu_hw_master_start,
 	.master_stop = spu_hw_master_stop,

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

@@ -115,6 +115,7 @@ 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);
+	 u32 (*runcntl_read) (struct spu_context * ctx);
 	void (*runcntl_write) (struct spu_context * ctx, u32 data);
 	void (*master_start) (struct spu_context * ctx);
 	void (*master_stop) (struct spu_context * ctx);