[POWERPC] spufs: make state_mutex interruptible

Make most places that use spu_acquire/spu_acquire_saved interruptible,
this allows getting out of the spufs code when e.g. pressing ctrl+c.
There are a few places where we get called e.g. from spufs teardown
routines were we can't simply err out so these are left with a comment.
For now I've also not touched the poll routines because it's open what
libspe would expect in terms of interrupted system calls.

Acked-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 8 insertions, 3 deletions

diff --git a/arch/powerpc/platforms/cell/spufs/sched.c b/arch/powerpc/platforms/cell/spufs/sched.c
index 2775c1652ba..eee7cef28f1 100644
--- a/arch/powerpc/platforms/cell/spufs/sched.c
+++ b/arch/powerpc/platforms/cell/spufs/sched.c
@@ -705,7 +705,9 @@ static void __spu_schedule(struct spu *spu, struct spu_context *ctx)
 
 static void spu_schedule(struct spu *spu, struct spu_context *ctx)
 {
-	spu_acquire(ctx);
+	/* not a candidate for interruptible because it's called either
+	   from the scheduler thread or from spu_deactivate */
+	mutex_lock(&ctx->state_mutex);
 	__spu_schedule(spu, ctx);
 	spu_release(ctx);
 }
@@ -823,7 +825,9 @@ static int __spu_deactivate(struct spu_context *ctx, int force, int max_prio)
 				else {
 					spu_release(ctx);
 					spu_schedule(spu, new);
-					spu_acquire(ctx);
+					/* this one can't easily be made
+					   interruptible */
+					mutex_lock(&ctx->state_mutex);
 				}
 			}
 		}
@@ -867,7 +871,8 @@ static noinline void spusched_tick(struct spu_context *ctx)
 	struct spu *spu = NULL;
 	u32 status;
 
-	spu_acquire(ctx);
+	if (spu_acquire(ctx))
+		BUG();	/* a kernel thread never has signals pending */
 
 	if (ctx->state != SPU_STATE_RUNNABLE)
 		goto out;