drm/nouveau/top: add function to lookup interrupt mask for a given device

Signed-off-by: NBen Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/include/nvkm/subdev/top.h

@@ -10,6 +10,7 @@ struct nvkm_top {
 
 u32 nvkm_top_reset(struct nvkm_device *, enum nvkm_devidx);
 u32 nvkm_top_intr(struct nvkm_device *, u32 intr, u64 *subdevs);
+u32 nvkm_top_intr_mask(struct nvkm_device *, enum nvkm_devidx);
 enum nvkm_devidx nvkm_top_fault(struct nvkm_device *, int fault);
 enum nvkm_devidx nvkm_top_engine(struct nvkm_device *, int, int *runl, int *engn);
 

drivers/gpu/drm/nouveau/nvkm/subdev/top/base.c

@@ -56,6 +56,22 @@ nvkm_top_reset(struct nvkm_device *device, enum nvkm_devidx index)
 	return 0;
 }
 
+u32
+nvkm_top_intr_mask(struct nvkm_device *device, enum nvkm_devidx devidx)
+{
+	struct nvkm_top *top = device->top;
+	struct nvkm_top_device *info;
+
+	if (top) {
+		list_for_each_entry(info, &top->device, head) {
+			if (info->index == devidx && info->intr >= 0)
+				return BIT(info->intr);
+		}
+	}
+
+	return 0;
+}
+
 u32
 nvkm_top_intr(struct nvkm_device *device, u32 intr, u64 *psubdevs)
 {