drm/nouveau/falcon: better detection of debug register

Not all falcons have a debug register, and it is not always found at the
same offset.
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/nvkm/falcon/base.c

@@ -170,6 +170,7 @@ nvkm_falcon_ctor(const struct nvkm_falcon_func *func,
 		 struct nvkm_subdev *subdev, const char *name, u32 addr,
 		 struct nvkm_falcon *falcon)
 {
+	u32 debug_reg;
 	u32 reg;
 
 	falcon->func = func;
@@ -189,8 +190,30 @@ nvkm_falcon_ctor(const struct nvkm_falcon_func *func,
 	falcon->code.limit = (reg & 0x1ff) << 8;
 	falcon->data.limit = (reg & 0x3fe00) >> 1;
 
-	reg = nvkm_falcon_rd32(falcon, 0xc08);
-	falcon->debug = (reg >> 20) & 0x1;
+	switch (subdev->index) {
+	case NVKM_ENGINE_GR:
+		debug_reg = 0x0;
+		break;
+	case NVKM_SUBDEV_PMU:
+		debug_reg = 0xc08;
+		break;
+	case NVKM_ENGINE_NVDEC:
+		debug_reg = 0xd00;
+		break;
+	case NVKM_ENGINE_SEC2:
+		debug_reg = 0x408;
+		break;
+	default:
+		nvkm_warn(subdev, "unsupported falcon %s!\n",
+			  nvkm_subdev_name[subdev->index]);
+		debug_reg = 0;
+		break;
+	}
+
+	if (debug_reg) {
+		u32 val = nvkm_falcon_rd32(falcon, debug_reg);
+		falcon->debug = (val >> 20) & 0x1;
+	}
 }
 
 void