drm/nouveau/device: implement a generic method to query device-specific properties

We have a need to fetch data from GPU-specific sub-devices that is not
tied to any particular engine object.

This commit provides the framework to support such queries.

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

3 files changed, 69 insertions, 1 deletions

diff --git a/drivers/gpu/drm/nouveau/nvkm/core/engine.c b/drivers/gpu/drm/nouveau/nvkm/core/engine.c
index 657231c3c098..d0322ce85172 100644
--- a/drivers/gpu/drm/nouveau/nvkm/core/engine.c
+++ b/drivers/gpu/drm/nouveau/nvkm/core/engine.c
@@ -83,6 +83,20 @@ nvkm_engine_intr(struct nvkm_subdev *subdev)
 }
 
 static int
+nvkm_engine_info(struct nvkm_subdev *subdev, u64 mthd, u64 *data)
+{
+	struct nvkm_engine *engine = nvkm_engine(subdev);
+	if (engine->func->info) {
+		if ((engine = nvkm_engine_ref(engine))) {
+			int ret = engine->func->info(engine, mthd, data);
+			nvkm_engine_unref(&engine);
+			return ret;
+		}
+	}
+	return -ENOSYS;
+}
+
+static int
 nvkm_engine_fini(struct nvkm_subdev *subdev, bool suspend)
 {
 	struct nvkm_engine *engine = nvkm_engine(subdev);
@@ -150,6 +164,7 @@ nvkm_engine_func = {
 	.preinit = nvkm_engine_preinit,
 	.init = nvkm_engine_init,
 	.fini = nvkm_engine_fini,
+	.info = nvkm_engine_info,
 	.intr = nvkm_engine_intr,
 };
 
diff --git a/drivers/gpu/drm/nouveau/nvkm/core/subdev.c b/drivers/gpu/drm/nouveau/nvkm/core/subdev.c
index c707306ac286..b96f9e2f237a 100644
--- a/drivers/gpu/drm/nouveau/nvkm/core/subdev.c
+++ b/drivers/gpu/drm/nouveau/nvkm/core/subdev.c
@@ -93,6 +93,14 @@ nvkm_subdev_intr(struct nvkm_subdev *subdev)
 }
 
 int
+nvkm_subdev_info(struct nvkm_subdev *subdev, u64 mthd, u64 *data)
+{
+	if (subdev->func->info)
+		return subdev->func->info(subdev, mthd, data);
+	return -ENOSYS;
+}
+
+int
 nvkm_subdev_fini(struct nvkm_subdev *subdev, bool suspend)
 {
 	struct nvkm_device *device = subdev->device;
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/device/user.c b/drivers/gpu/drm/nouveau/nvkm/engine/device/user.c
index 17adcb4e8854..3526516765f8 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/device/user.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/device/user.c
@@ -40,6 +40,40 @@ struct nvkm_udevice {
 };
 
 static int
+nvkm_udevice_info_subdev(struct nvkm_device *device, u64 mthd, u64 *data)
+{
+	struct nvkm_subdev *subdev;
+	enum nvkm_devidx subidx;
+
+	switch (mthd & NV_DEVICE_INFO_UNIT) {
+	default:
+		return -EINVAL;
+	}
+
+	subdev = nvkm_device_subdev(device, subidx);
+	if (subdev)
+		return nvkm_subdev_info(subdev, mthd, data);
+	return -ENODEV;
+}
+
+static void
+nvkm_udevice_info_v1(struct nvkm_device *device,
+		     struct nv_device_info_v1_data *args)
+{
+	if (args->mthd & NV_DEVICE_INFO_UNIT) {
+		if (nvkm_udevice_info_subdev(device, args->mthd, &args->data))
+			args->mthd = NV_DEVICE_INFO_INVALID;
+		return;
+	}
+
+	switch (args->mthd) {
+	default:
+		args->mthd = NV_DEVICE_INFO_INVALID;
+		break;
+	}
+}
+
+static int
 nvkm_udevice_info(struct nvkm_udevice *udev, void *data, u32 size)
 {
 	struct nvkm_object *object = &udev->object;
@@ -48,10 +82,21 @@ nvkm_udevice_info(struct nvkm_udevice *udev, void *data, u32 size)
 	struct nvkm_instmem *imem = device->imem;
 	union {
 		struct nv_device_info_v0 v0;
+		struct nv_device_info_v1 v1;
 	} *args = data;
-	int ret = -ENOSYS;
+	int ret = -ENOSYS, i;
 
 	nvif_ioctl(object, "device info size %d\n", size);
+	if (!(ret = nvif_unpack(ret, &data, &size, args->v1, 1, 1, true))) {
+		nvif_ioctl(object, "device info vers %d count %d\n",
+			   args->v1.version, args->v1.count);
+		if (args->v1.count * sizeof(args->v1.data[0]) == size) {
+			for (i = 0; i < args->v1.count; i++)
+				nvkm_udevice_info_v1(device, &args->v1.data[i]);
+			return 0;
+		}
+		return -EINVAL;
+	} else
 	if (!(ret = nvif_unpack(ret, &data, &size, args->v0, 0, 0, false))) {
 		nvif_ioctl(object, "device info vers %d\n", args->v0.version);
 	} else