drm/nouveau/fifo/gf100: fix race condition when updating engine runlists

Similar in spirit to the gk104 fix with a similar title.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/nvkm/engine/fifo/gf100.c

@@ -47,7 +47,7 @@ gf100_fifo_uevent_fini(struct nvkm_fifo *fifo)
 }
 
 void
-gf100_fifo_runlist_update(struct gf100_fifo *fifo)
+gf100_fifo_runlist_commit(struct gf100_fifo *fifo)
 {
 	struct gf100_fifo_chan *chan;
 	struct nvkm_subdev *subdev = &fifo->base.engine.subdev;
@@ -77,6 +77,22 @@ gf100_fifo_runlist_update(struct gf100_fifo *fifo)
 	mutex_unlock(&subdev->mutex);
 }
 
+void
+gf100_fifo_runlist_remove(struct gf100_fifo *fifo, struct gf100_fifo_chan *chan)
+{
+	mutex_lock(&fifo->base.engine.subdev.mutex);
+	list_del_init(&chan->head);
+	mutex_unlock(&fifo->base.engine.subdev.mutex);
+}
+
+void
+gf100_fifo_runlist_insert(struct gf100_fifo *fifo, struct gf100_fifo_chan *chan)
+{
+	mutex_lock(&fifo->base.engine.subdev.mutex);
+	list_add_tail(&chan->head, &fifo->chan);
+	mutex_unlock(&fifo->base.engine.subdev.mutex);
+}
+
 static inline int
 gf100_fifo_engidx(struct gf100_fifo *fifo, u32 engn)
 {
@@ -139,7 +155,7 @@ gf100_fifo_recover_work(struct work_struct *work)
 		}
 	}
 
-	gf100_fifo_runlist_update(fifo);
+	gf100_fifo_runlist_commit(fifo);
 	nvkm_wr32(device, 0x00262c, engm);
 	nvkm_mask(device, 0x002630, engm, 0x00000000);
 }

drivers/gpu/drm/nouveau/nvkm/engine/fifo/gf100.h

@@ -5,6 +5,7 @@
 
 #include <subdev/mmu.h>
 
+struct gf100_fifo_chan;
 struct gf100_fifo {
 	struct nvkm_fifo base;
 
@@ -27,5 +28,7 @@ struct gf100_fifo {
 };
 
 void gf100_fifo_intr_engine(struct gf100_fifo *);
-void gf100_fifo_runlist_update(struct gf100_fifo *);
+void gf100_fifo_runlist_insert(struct gf100_fifo *, struct gf100_fifo_chan *);
+void gf100_fifo_runlist_remove(struct gf100_fifo *, struct gf100_fifo_chan *);
+void gf100_fifo_runlist_commit(struct gf100_fifo *);
 #endif

drivers/gpu/drm/nouveau/nvkm/engine/fifo/gpfifogf100.c

@@ -138,9 +138,9 @@ gf100_fifo_gpfifo_fini(struct nvkm_fifo_chan *base)
 	u32 coff = chan->base.chid * 8;
 
 	if (!list_empty(&chan->head) && !chan->killed) {
-		list_del_init(&chan->head);
+		gf100_fifo_runlist_remove(fifo, chan);
 		nvkm_mask(device, 0x003004 + coff, 0x00000001, 0x00000000);
-		gf100_fifo_runlist_update(fifo);
+		gf100_fifo_runlist_commit(fifo);
 	}
 
 	gf100_fifo_intr_engine(fifo);
@@ -160,9 +160,9 @@ gf100_fifo_gpfifo_init(struct nvkm_fifo_chan *base)
 	nvkm_wr32(device, 0x003000 + coff, 0xc0000000 | addr);
 
 	if (list_empty(&chan->head) && !chan->killed) {
-		list_add_tail(&chan->head, &fifo->chan);
+		gf100_fifo_runlist_insert(fifo, chan);
 		nvkm_wr32(device, 0x003004 + coff, 0x001f0001);
-		gf100_fifo_runlist_update(fifo);
+		gf100_fifo_runlist_commit(fifo);
 	}
 }