drm/vkms: Add vkms_config type

Currently, data for the device instance is held by vkms_device.
Add a separate type, vkms_config to contain configuration details
for the device and various modes to be later used by configfs.
This config data stays constant once the device is created.

Accordingly, add vkms_create and vkms_destroy to initialize/destroy
device through configfs. Currently, they are being called from vkms_init
and vkms_exit, but will be evoked from configfs later on. When configfs
is added, device configuration will be tracked by configfs and only vkms
device lifetime will be handled by vkms_init and vkms_exit functions.

Modify usage of enable_cursor feature to reflect the changes in
relevant files.
Co-developed-by: Daniel Vetter <danvet.vetter@ffwl.ch>
Signed-off-by: Daniel Vetter <danvet.vetter@ffwl.ch>
Signed-off-by: Sumera Priyadarsini <sylphrenadin@gmail.com>
Reviewed-by: Melissa Wen <melissa.srw@gmail.com>
Signed-off-by: Melissa Wen <melissa.srw@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/a090ad29b826185df30f80c66932dd2173d7b060.1610391685.git.sylphrenadin@gmail.com

drivers/gpu/drm/vkms/vkms_drv.c

@@ -34,9 +34,9 @@
 #define DRIVER_MAJOR	1
 #define DRIVER_MINOR	0
 
-static struct vkms_device *vkms_device;
+static struct vkms_config *default_config;
 
-bool enable_cursor = true;
+static bool enable_cursor = true;
 module_param_named(enable_cursor, enable_cursor, bool, 0444);
 MODULE_PARM_DESC(enable_cursor, "Enable/Disable cursor support");
 
@@ -122,10 +122,11 @@ static int vkms_modeset_init(struct vkms_device *vkmsdev)
 	return vkms_output_init(vkmsdev, 0);
 }
 
-static int __init vkms_init(void)
+static int vkms_create(struct vkms_config *config)
 {
 	int ret;
 	struct platform_device *pdev;
+	struct vkms_device *vkms_device;
 
 	pdev = platform_device_register_simple(DRIVER_NAME, -1, NULL, 0);
 	if (IS_ERR(pdev))
@@ -143,6 +144,8 @@ static int __init vkms_init(void)
 		goto out_devres;
 	}
 	vkms_device->platform = pdev;
+	vkms_device->config = config;
+	config->dev = vkms_device;
 
 	ret = dma_coerce_mask_and_coherent(vkms_device->drm.dev,
 					   DMA_BIT_MASK(64));
@@ -179,21 +182,42 @@ static int __init vkms_init(void)
 	return ret;
 }
 
-static void __exit vkms_exit(void)
+static int __init vkms_init(void)
+{
+	struct vkms_config *config = kmalloc(sizeof(*config), GFP_KERNEL);
+
+	default_config = config;
+
+	config->cursor = enable_cursor;
+
+	return vkms_create(config);
+}
+
+static void vkms_destroy(struct vkms_config *config)
 {
 	struct platform_device *pdev;
 
-	if (!vkms_device) {
+	if (!config->dev) {
 		DRM_INFO("vkms_device is NULL.\n");
 		return;
 	}
 
-	pdev = vkms_device->platform;
+	pdev = config->dev->platform;
 
-	drm_dev_unregister(&vkms_device->drm);
-	drm_atomic_helper_shutdown(&vkms_device->drm);
+	drm_dev_unregister(&config->dev->drm);
+	drm_atomic_helper_shutdown(&config->dev->drm);
 	devres_release_group(&pdev->dev, NULL);
 	platform_device_unregister(pdev);
+
+	config->dev = NULL;
+}
+
+static void __exit vkms_exit(void)
+{
+	if (default_config->dev)
+		vkms_destroy(default_config);
+
+	kfree(default_config);
 }
 
 module_init(vkms_init);

drivers/gpu/drm/vkms/vkms_drv.h

@@ -19,8 +19,6 @@
 #define XRES_MAX  8192
 #define YRES_MAX  8192
 
-extern bool enable_cursor;
-
 struct vkms_composer {
 	struct drm_framebuffer fb;
 	struct drm_rect src, dst;
@@ -82,10 +80,19 @@ struct vkms_output {
 	spinlock_t composer_lock;
 };
 
+struct vkms_device;
+
+struct vkms_config {
+	bool cursor;
+	/* only set when instantiated */
+	struct vkms_device *dev;
+};
+
 struct vkms_device {
 	struct drm_device drm;
 	struct platform_device *platform;
 	struct vkms_output output;
+	const struct vkms_config *config;
 };
 
 #define drm_crtc_to_vkms_output(target) \

drivers/gpu/drm/vkms/vkms_output.c

@@ -46,7 +46,7 @@ int vkms_output_init(struct vkms_device *vkmsdev, int index)
 	if (IS_ERR(primary))
 		return PTR_ERR(primary);
 
-	if (enable_cursor) {
+	if (vkmsdev->config->cursor) {
 		cursor = vkms_plane_init(vkmsdev, DRM_PLANE_TYPE_CURSOR, index);
 		if (IS_ERR(cursor)) {
 			ret = PTR_ERR(cursor);
@@ -98,7 +98,7 @@ int vkms_output_init(struct vkms_device *vkmsdev, int index)
 	drm_crtc_cleanup(crtc);
 
 err_crtc:
-	if (enable_cursor)
+	if (vkmsdev->config->cursor)
 		drm_plane_cleanup(cursor);
 
 err_cursor: