[POWERPC] cell: wrap master run control bit

Add platform specific SPU run control routines to the spufs.  The current
spufs implementation uses the SPU master run control bit (MFC_SR1[S]) to
control SPE execution, but the PS3 hypervisor does not support the use of
this feature.

This change adds the run control wrapper routies spu_enable_spu() and
spu_disable_spu().  The bare metal routines use the master run control
bit, and the PS3 specific routines use the priv2 run control register.

An outstanding enhancement for the PS3 would be to add a guard to check
for incorrect access to the spu problem state when the spu context is
disabled.  This check could be implemented with a flag added to the spu
context that would inhibit mapping problem state pages, and a routine
to unmap spu problem state pages.  When the spu is enabled with
ps3_enable_spu() the flag would be set allowing pages to be mapped,
and when the spu is disabled with ps3_disable_spu() the flag would be
cleared and mapped problem state pages would be unmapped.

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

4 files changed, 19 insertions, 2 deletions

diff --git a/arch/powerpc/platforms/cell/spufs/backing_ops.c b/arch/powerpc/platforms/cell/spufs/backing_ops.c
index ec01214e51e..a64a0044df9 100644
--- a/arch/powerpc/platforms/cell/spufs/backing_ops.c
+++ b/arch/powerpc/platforms/cell/spufs/backing_ops.c
@@ -285,6 +285,11 @@ static void spu_backing_runcntl_write(struct spu_context *ctx, u32 val)
 	spin_unlock(&ctx->csa.register_lock);
 }
 
+static void spu_backing_runcntl_stop(struct spu_context *ctx)
+{
+	spu_backing_runcntl_write(ctx, SPU_RUNCNTL_STOP);
+}
+
 static void spu_backing_master_start(struct spu_context *ctx)
 {
 	struct spu_state *csa = &ctx->csa;
@@ -381,6 +386,7 @@ struct spu_context_ops spu_backing_ops = {
 	.get_ls = spu_backing_get_ls,
 	.runcntl_read = spu_backing_runcntl_read,
 	.runcntl_write = spu_backing_runcntl_write,
+	.runcntl_stop = spu_backing_runcntl_stop,
 	.master_start = spu_backing_master_start,
 	.master_stop = spu_backing_master_stop,
 	.set_mfc_query = spu_backing_set_mfc_query,
diff --git a/arch/powerpc/platforms/cell/spufs/hw_ops.c b/arch/powerpc/platforms/cell/spufs/hw_ops.c
index fc4ed1ffbd4..e09616733c1 100644
--- a/arch/powerpc/platforms/cell/spufs/hw_ops.c
+++ b/arch/powerpc/platforms/cell/spufs/hw_ops.c
@@ -220,6 +220,15 @@ static void spu_hw_runcntl_write(struct spu_context *ctx, u32 val)
 	spin_unlock_irq(&ctx->spu->register_lock);
 }
 
+static void spu_hw_runcntl_stop(struct spu_context *ctx)
+{
+	spin_lock_irq(&ctx->spu->register_lock);
+	out_be32(&ctx->spu->problem->spu_runcntl_RW, SPU_RUNCNTL_STOP);
+	while (in_be32(&ctx->spu->problem->spu_status_R) & SPU_STATUS_RUNNING)
+		cpu_relax();
+	spin_unlock_irq(&ctx->spu->register_lock);
+}
+
 static void spu_hw_master_start(struct spu_context *ctx)
 {
 	struct spu *spu = ctx->spu;
@@ -321,6 +330,7 @@ struct spu_context_ops spu_hw_ops = {
 	.get_ls = spu_hw_get_ls,
 	.runcntl_read = spu_hw_runcntl_read,
 	.runcntl_write = spu_hw_runcntl_write,
+	.runcntl_stop = spu_hw_runcntl_stop,
 	.master_start = spu_hw_master_start,
 	.master_stop = spu_hw_master_stop,
 	.set_mfc_query = spu_hw_set_mfc_query,
diff --git a/arch/powerpc/platforms/cell/spufs/run.c b/arch/powerpc/platforms/cell/spufs/run.c
index 1ce5e22ea5f..aad163ff46f 100644
--- a/arch/powerpc/platforms/cell/spufs/run.c
+++ b/arch/powerpc/platforms/cell/spufs/run.c
@@ -302,7 +302,7 @@ long spufs_run_spu(struct spu_context *ctx, u32 *npc, u32 *event)
 	if (mutex_lock_interruptible(&ctx->run_mutex))
 		return -ERESTARTSYS;
 
-	ctx->ops->master_start(ctx);
+	spu_enable_spu(ctx);
 	ctx->event_return = 0;
 
 	spu_acquire(ctx);
@@ -376,7 +376,7 @@ long spufs_run_spu(struct spu_context *ctx, u32 *npc, u32 *event)
 		ctx->stats.libassist++;
 
 
-	ctx->ops->master_stop(ctx);
+	spu_disable_spu(ctx);
 	ret = spu_run_fini(ctx, npc, &status);
 	spu_yield(ctx);
 
diff --git a/arch/powerpc/platforms/cell/spufs/spufs.h b/arch/powerpc/platforms/cell/spufs/spufs.h
index ca47b991bda..5e92ad32cc9 100644
--- a/arch/powerpc/platforms/cell/spufs/spufs.h
+++ b/arch/powerpc/platforms/cell/spufs/spufs.h
@@ -170,6 +170,7 @@ struct spu_context_ops {
 	char*(*get_ls) (struct spu_context * ctx);
 	 u32 (*runcntl_read) (struct spu_context * ctx);
 	void (*runcntl_write) (struct spu_context * ctx, u32 data);
+	void (*runcntl_stop) (struct spu_context * ctx);
 	void (*master_start) (struct spu_context * ctx);
 	void (*master_stop) (struct spu_context * ctx);
 	int (*set_mfc_query)(struct spu_context * ctx, u32 mask, u32 mode);