drm/nouveau/subdev: store subdevs in list

This is somewhat nicer to read.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>

drivers/gpu/drm/nouveau/include/nvkm/core/device.h

@@ -178,6 +178,8 @@ struct nvkm_device {
 	struct nvkm_sw *sw;
 	struct nvkm_engine *vic;
 	struct nvkm_engine *vp;
+
+	struct list_head subdev;
 };
 
 struct nvkm_subdev *nvkm_device_subdev(struct nvkm_device *, int index);

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

@@ -8,6 +8,7 @@ struct nvkm_subdev {
 	struct nvkm_device *device;
 	enum nvkm_devidx index;
 	u32 debug;
+	struct list_head head;
 
 	bool oneinit;
 };

drivers/gpu/drm/nouveau/nvkm/core/subdev.c

@@ -197,6 +197,7 @@ nvkm_subdev_del(struct nvkm_subdev **psubdev)
 	if (subdev && !WARN_ON(!subdev->func)) {
 		nvkm_trace(subdev, "destroy running...\n");
 		time = ktime_to_us(ktime_get());
+		list_del(&subdev->head);
 		if (subdev->func->dtor)
 			*psubdev = subdev->func->dtor(subdev);
 		time = ktime_to_us(ktime_get()) - time;
@@ -216,6 +217,7 @@ nvkm_subdev_ctor(const struct nvkm_subdev_func *func,
 	subdev->device = device;
 	subdev->index = index;
 	subdev->debug = nvkm_dbgopt(device->dbgopt, name);
+	list_add_tail(&subdev->head, &device->subdev);
 }
 
 int

drivers/gpu/drm/nouveau/nvkm/engine/device/base.c

@@ -2825,7 +2825,7 @@ nvkm_device_fini(struct nvkm_device *device, bool suspend)
 {
 	const char *action = suspend ? "suspend" : "fini";
 	struct nvkm_subdev *subdev;
-	int ret, i;
+	int ret;
 	s64 time;
 
 	nvdev_trace(device, "%s running...\n", action);
@@ -2833,12 +2833,10 @@ nvkm_device_fini(struct nvkm_device *device, bool suspend)
 
 	nvkm_acpi_fini(device);
 
-	for (i = NVKM_SUBDEV_NR - 1; i >= 0; i--) {
-		if ((subdev = nvkm_device_subdev(device, i))) {
-			ret = nvkm_subdev_fini(subdev, suspend);
-			if (ret && suspend)
-				goto fail;
-		}
+	list_for_each_entry_reverse(subdev, &device->subdev, head) {
+		ret = nvkm_subdev_fini(subdev, suspend);
+		if (ret && suspend)
+			goto fail;
 	}
 
 	nvkm_therm_clkgate_fini(device->therm, suspend);
@@ -2851,13 +2849,11 @@ nvkm_device_fini(struct nvkm_device *device, bool suspend)
 	return 0;
 
 fail:
-	do {
-		if ((subdev = nvkm_device_subdev(device, i))) {
-			int rret = nvkm_subdev_init(subdev);
-			if (rret)
-				nvkm_fatal(subdev, "failed restart, %d\n", ret);
-		}
-	} while (++i < NVKM_SUBDEV_NR);
+	list_for_each_entry_from(subdev, &device->subdev, head) {
+		int rret = nvkm_subdev_init(subdev);
+		if (rret)
+			nvkm_fatal(subdev, "failed restart, %d\n", ret);
+	}
 
 	nvdev_trace(device, "%s failed with %d\n", action, ret);
 	return ret;
@@ -2867,7 +2863,7 @@ static int
 nvkm_device_preinit(struct nvkm_device *device)
 {
 	struct nvkm_subdev *subdev;
-	int ret, i;
+	int ret;
 	s64 time;
 
 	nvdev_trace(device, "preinit running...\n");
@@ -2879,12 +2875,10 @@ nvkm_device_preinit(struct nvkm_device *device)
 			goto fail;
 	}
 
-	for (i = 0; i < NVKM_SUBDEV_NR; i++) {
-		if ((subdev = nvkm_device_subdev(device, i))) {
-			ret = nvkm_subdev_preinit(subdev);
-			if (ret)
-				goto fail;
-		}
+	list_for_each_entry(subdev, &device->subdev, head) {
+		ret = nvkm_subdev_preinit(subdev);
+		if (ret)
+			goto fail;
 	}
 
 	ret = nvkm_devinit_post(device->devinit, &device->disable_mask);
@@ -2904,7 +2898,7 @@ int
 nvkm_device_init(struct nvkm_device *device)
 {
 	struct nvkm_subdev *subdev;
-	int ret, i;
+	int ret;
 	s64 time;
 
 	ret = nvkm_device_preinit(device);
@@ -2922,12 +2916,10 @@ nvkm_device_init(struct nvkm_device *device)
 			goto fail;
 	}
 
-	for (i = 0; i < NVKM_SUBDEV_NR; i++) {
-		if ((subdev = nvkm_device_subdev(device, i))) {
-			ret = nvkm_subdev_init(subdev);
-			if (ret)
-				goto fail_subdev;
-		}
+	list_for_each_entry(subdev, &device->subdev, head) {
+		ret = nvkm_subdev_init(subdev);
+		if (ret)
+			goto fail_subdev;
 	}
 
 	nvkm_acpi_init(device);
@@ -2938,11 +2930,8 @@ nvkm_device_init(struct nvkm_device *device)
 	return 0;
 
 fail_subdev:
-	do {
-		if ((subdev = nvkm_device_subdev(device, i)))
-			nvkm_subdev_fini(subdev, false);
-	} while (--i >= 0);
-
+	list_for_each_entry_from(subdev, &device->subdev, head)
+		nvkm_subdev_fini(subdev, false);
 fail:
 	nvkm_device_fini(device, false);
 
@@ -2954,15 +2943,13 @@ void
 nvkm_device_del(struct nvkm_device **pdevice)
 {
 	struct nvkm_device *device = *pdevice;
-	int i;
+	struct nvkm_subdev *subdev, *subtmp;
 	if (device) {
 		mutex_lock(&nv_devices_mutex);
 		device->disable_mask = 0;
-		for (i = NVKM_SUBDEV_NR - 1; i >= 0; i--) {
-			struct nvkm_subdev *subdev =
-				nvkm_device_subdev(device, i);
+
+		list_for_each_entry_safe_reverse(subdev, subtmp, &device->subdev, head)
 			nvkm_subdev_del(&subdev);
-		}
 
 		nvkm_event_fini(&device->event);
 
@@ -3038,6 +3025,7 @@ nvkm_device_ctor(const struct nvkm_device_func *func,
 	device->name = name;
 	list_add_tail(&device->head, &nv_devices);
 	device->debug = nvkm_dbgopt(device->dbgopt, "device");
+	INIT_LIST_HEAD(&device->subdev);
 
 	ret = nvkm_event_init(&nvkm_device_event_func, 1, 1, &device->event);
 	if (ret)