[RFC 02/29] nvkm/vgpu: attach to nvkm as a nvkm client

[Zhi Wang <zhiw@xxxxxxxxxx>]

nvkm is a HW abstraction layer(HAL) that initializes the HW and
allows its clients to manipulate the GPU functions regardless of the
generations of GPU HW. On the top layer, it provides generic APIs for a
client to connect to NVKM, enumerate the GPU functions, and manipulate
the GPU HW.

To reach nvkm, the client needs to connect to NVKM layer by layer: driver
layer, client layer, and eventually, the device layer, which provides all
the access routines to GPU functions. After a client attaches to NVKM,
it initializes the HW and is able to serve the clients.

Attach to nvkm as a nvkm client.

Cc: Neo Jia <cjia@xxxxxxxxxx>
Signed-off-by: Zhi Wang <zhiw@xxxxxxxxxx>
---
 .../nouveau/include/nvkm/vgpu_mgr/vgpu_mgr.h  |  8 ++++
 .../gpu/drm/nouveau/nvkm/vgpu_mgr/vgpu_mgr.c  | 48 ++++++++++++++++++-
 2 files changed, 55 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/nouveau/include/nvkm/vgpu_mgr/vgpu_mgr.h b/drivers/gpu/drm/nouveau/include/nvkm/vgpu_mgr/vgpu_mgr.h
index 3163fff1085b..9e10e18306b0 100644
--- a/drivers/gpu/drm/nouveau/include/nvkm/vgpu_mgr/vgpu_mgr.h
+++ b/drivers/gpu/drm/nouveau/include/nvkm/vgpu_mgr/vgpu_mgr.h
@@ -7,6 +7,14 @@
 struct nvkm_vgpu_mgr {
 	bool enabled;
 	struct nvkm_device *nvkm_dev;
+
+	const struct nvif_driver *driver;
+
+	const struct nvif_client_impl *cli_impl;
+	struct nvif_client_priv *cli_priv;
+
+	const struct nvif_device_impl *dev_impl;
+	struct nvif_device_priv *dev_priv;
 };
 
 bool nvkm_vgpu_mgr_is_supported(struct nvkm_device *device);
diff --git a/drivers/gpu/drm/nouveau/nvkm/vgpu_mgr/vgpu_mgr.c b/drivers/gpu/drm/nouveau/nvkm/vgpu_mgr/vgpu_mgr.c
index a506414e5ba2..0639596f8a96 100644
--- a/drivers/gpu/drm/nouveau/nvkm/vgpu_mgr/vgpu_mgr.c
+++ b/drivers/gpu/drm/nouveau/nvkm/vgpu_mgr/vgpu_mgr.c
@@ -1,5 +1,7 @@
 /* SPDX-License-Identifier: MIT */
 #include <core/device.h>
+#include <core/driver.h>
+#include <nvif/driverif.h>
 #include <core/pci.h>
 #include <vgpu_mgr/vgpu_mgr.h>
 
@@ -42,6 +44,44 @@ bool nvkm_vgpu_mgr_is_enabled(struct nvkm_device *device)
 	return device->vgpu_mgr.enabled;
 }
 
+static void detach_nvkm(struct nvkm_vgpu_mgr *vgpu_mgr)
+{
+	if (vgpu_mgr->dev_impl) {
+		vgpu_mgr->dev_impl->del(vgpu_mgr->dev_priv);
+		vgpu_mgr->dev_impl = NULL;
+	}
+
+	if (vgpu_mgr->cli_impl) {
+		vgpu_mgr->cli_impl->del(vgpu_mgr->cli_priv);
+		vgpu_mgr->cli_impl = NULL;
+	}
+}
+
+static int attach_nvkm(struct nvkm_vgpu_mgr *vgpu_mgr)
+{
+	struct nvkm_device *device = vgpu_mgr->nvkm_dev;
+	int ret;
+
+	ret = nvkm_driver_ctor(device, &vgpu_mgr->driver,
+			       &vgpu_mgr->cli_impl, &vgpu_mgr->cli_priv);
+	if (ret)
+		return ret;
+
+	ret = vgpu_mgr->cli_impl->device.new(vgpu_mgr->cli_priv,
+					     &vgpu_mgr->dev_impl,
+					     &vgpu_mgr->dev_priv);
+	if (ret)
+		goto fail_device_new;
+
+	return 0;
+
+fail_device_new:
+	vgpu_mgr->cli_impl->del(vgpu_mgr->cli_priv);
+	vgpu_mgr->cli_impl = NULL;
+
+	return ret;
+}
+
 /**
  * nvkm_vgpu_mgr_init - Initialize the vGPU manager support
  * @device: the nvkm_device pointer
@@ -51,13 +91,18 @@ bool nvkm_vgpu_mgr_is_enabled(struct nvkm_device *device)
 int nvkm_vgpu_mgr_init(struct nvkm_device *device)
 {
 	struct nvkm_vgpu_mgr *vgpu_mgr = &device->vgpu_mgr;
+	int ret;
 
 	if (!nvkm_vgpu_mgr_is_supported(device))
 		return -ENODEV;
 
 	vgpu_mgr->nvkm_dev = device;
-	vgpu_mgr->enabled = true;
 
+	ret = attach_nvkm(vgpu_mgr);
+	if (ret)
+		return ret;
+
+	vgpu_mgr->enabled = true;
 	pci_info(nvkm_to_pdev(device),
 		 "NVIDIA vGPU mananger support is enabled.\n");
 
@@ -72,5 +117,6 @@ void nvkm_vgpu_mgr_fini(struct nvkm_device *device)
 {
 	struct nvkm_vgpu_mgr *vgpu_mgr = &device->vgpu_mgr;
 
+	detach_nvkm(vgpu_mgr);
 	vgpu_mgr->enabled = false;
 }
-- 
2.34.1