[POWERPC] spufs: allow isolated mode apps by starting the SPE loader

This patch adds general support for isolated mode SPE apps.

Isolated apps are started indirectly, by a dedicated loader "kernel".
This patch starts the loader when spe_create is invoked with the
ISOLATE flag. We do this at spe_create time to allow libspe to pass the
isolated app in before calling spe_run.

The loader is read from the device tree, at the location
"/spu-isolation/loader". If the loader is not present, an attempt to
start an isolated SPE binary will fail with -ENODEV.

Update: loader needs to be correctly aligned - copy to a kmalloced buf.
Update: remove workaround for systemsim/spurom 'L-bit' bug, which has
        been fixed.
Update: don't write to runcntl on spu_run_init: SPU is already running.
Update: do spu_setup_isolated earlier

Tested on systemsim.

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>

1 files changed, 7 insertions, 5 deletions

diff --git a/arch/powerpc/platforms/cell/spufs/run.c b/arch/powerpc/platforms/cell/spufs/run.c
index 0c03a04..a4a0080c 100644
--- a/arch/powerpc/platforms/cell/spufs/run.c
+++ b/arch/powerpc/platforms/cell/spufs/run.c
@@ -1,3 +1,5 @@
+#define DEBUG
+
 #include <linux/wait.h>
 #include <linux/ptrace.h>
 
@@ -56,12 +58,12 @@ static inline int spu_run_init(struct spu_context *ctx, u32 * npc)
 	if ((ret = spu_acquire_runnable(ctx)) != 0)
 		return ret;
 
-	if (ctx->flags & SPU_CREATE_ISOLATE)
-		runcntl |= SPU_RUNCNTL_ISOLATE;
-	else
+	/* if we're in isolated mode, we would have started the SPU
+	 * earlier, so don't do it again now. */
+	if (!(ctx->flags & SPU_CREATE_ISOLATE)) {
 		ctx->ops->npc_write(ctx, *npc);
-
-	ctx->ops->runcntl_write(ctx, runcntl);
+		ctx->ops->runcntl_write(ctx, runcntl);
+	}
 	return 0;
 }