drm/vkms: Switch to dynamic allocation for CRTC

A specific allocation for the CRTC is not strictly necessary at this
point, but in order to implement dynamic configuration of VKMS (configFS),
it will be easier to have one allocation per CRTC.

Reviewed-by: Maxime Ripard <mripard@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20250117-b4-vkms-allocated-v4-3-8ec8fd21aaf6@bootlin.com
Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com>

4 files changed, 45 insertions, 40 deletions

diff --git a/drivers/gpu/drm/vkms/vkms_crtc.c b/drivers/gpu/drm/vkms/vkms_crtc.c
index 434c35d5e947..cf229aec71c3 100644
--- a/drivers/gpu/drm/vkms/vkms_crtc.c
+++ b/drivers/gpu/drm/vkms/vkms_crtc.c
@@ -84,9 +84,7 @@ static bool vkms_get_vblank_timestamp(struct drm_crtc *crtc,
 				      int *max_error, ktime_t *vblank_time,
 				      bool in_vblank_irq)
 {
-	struct drm_device *dev = crtc->dev;
-	struct vkms_device *vkmsdev = drm_device_to_vkms_device(dev);
-	struct vkms_output *output = &vkmsdev->output;
+	struct vkms_output *output = drm_crtc_to_vkms_output(crtc);
 	struct drm_vblank_crtc *vblank = drm_crtc_vblank_crtc(crtc);
 
 	if (!READ_ONCE(vblank->enabled)) {
@@ -271,25 +269,29 @@ static const struct drm_crtc_helper_funcs vkms_crtc_helper_funcs = {
 	.atomic_disable	= vkms_crtc_atomic_disable,
 };
 
-int vkms_crtc_init(struct drm_device *dev, struct drm_crtc *crtc,
-		   struct drm_plane *primary, struct drm_plane *cursor)
+struct vkms_output *vkms_crtc_init(struct drm_device *dev, struct drm_plane *primary,
+				   struct drm_plane *cursor)
 {
-	struct vkms_output *vkms_out = drm_crtc_to_vkms_output(crtc);
+	struct vkms_output *vkms_out;
+	struct drm_crtc *crtc;
 	int ret;
 
-	ret = drmm_crtc_init_with_planes(dev, crtc, primary, cursor,
-					 &vkms_crtc_funcs, NULL);
-	if (ret) {
-		DRM_ERROR("Failed to init CRTC\n");
-		return ret;
+	vkms_out = drmm_crtc_alloc_with_planes(dev, struct vkms_output, crtc,
+					       primary, cursor,
+					       &vkms_crtc_funcs, NULL);
+	if (IS_ERR(vkms_out)) {
+		DRM_DEV_ERROR(dev->dev, "Failed to init CRTC\n");
+		return vkms_out;
 	}
 
+	crtc = &vkms_out->crtc;
+
 	drm_crtc_helper_add(crtc, &vkms_crtc_helper_funcs);
 
 	ret = drm_mode_crtc_set_gamma_size(crtc, VKMS_LUT_SIZE);
 	if (ret) {
 		DRM_ERROR("Failed to set gamma size\n");
-		return ret;
+		return ERR_PTR(ret);
 	}
 
 	drm_crtc_enable_color_mgmt(crtc, 0, false, VKMS_LUT_SIZE);
@@ -299,9 +301,9 @@ int vkms_crtc_init(struct drm_device *dev, struct drm_crtc *crtc,
 
 	vkms_out->composer_workq = drmm_alloc_ordered_workqueue(dev, "vkms_composer", 0);
 	if (IS_ERR(vkms_out->composer_workq))
-		return PTR_ERR(vkms_out->composer_workq);
+		return ERR_CAST(vkms_out->composer_workq);
 	if (!vkms_out->composer_workq)
-		return -ENOMEM;
+		return ERR_PTR(-ENOMEM);
 
-	return ret;
+	return vkms_out;
 }
diff --git a/drivers/gpu/drm/vkms/vkms_drv.h b/drivers/gpu/drm/vkms/vkms_drv.h
index 333983bcf8d4..abbb652be2b5 100644
--- a/drivers/gpu/drm/vkms/vkms_drv.h
+++ b/drivers/gpu/drm/vkms/vkms_drv.h
@@ -215,7 +215,6 @@ struct vkms_config {
 struct vkms_device {
 	struct drm_device drm;
 	struct platform_device *platform;
-	struct vkms_output output;
 	const struct vkms_config *config;
 };
 
@@ -242,8 +241,9 @@ struct vkms_device {
  * @primary: primary plane to attach to the CRTC
  * @cursor: plane to attach to the CRTC
  */
-int vkms_crtc_init(struct drm_device *dev, struct drm_crtc *crtc,
-		   struct drm_plane *primary, struct drm_plane *cursor);
+struct vkms_output *vkms_crtc_init(struct drm_device *dev,
+				   struct drm_plane *primary,
+				   struct drm_plane *cursor);
 
 /**
  * vkms_output_init() - Initialize all sub-components needed for a VKMS device.
@@ -274,6 +274,6 @@ void vkms_set_composer(struct vkms_output *out, bool enabled);
 void vkms_writeback_row(struct vkms_writeback_job *wb, const struct line_buffer *src_buffer, int y);
 
 /* Writeback */
-int vkms_enable_writeback_connector(struct vkms_device *vkmsdev, struct drm_crtc *crtc);
+int vkms_enable_writeback_connector(struct vkms_device *vkmsdev, struct vkms_output *vkms_out);
 
 #endif /* _VKMS_DRV_H_ */
diff --git a/drivers/gpu/drm/vkms/vkms_output.c b/drivers/gpu/drm/vkms/vkms_output.c
index 21ca975e424d..22f0d678af3a 100644
--- a/drivers/gpu/drm/vkms/vkms_output.c
+++ b/drivers/gpu/drm/vkms/vkms_output.c
@@ -30,11 +30,10 @@ static const struct drm_connector_helper_funcs vkms_conn_helper_funcs = {
 
 int vkms_output_init(struct vkms_device *vkmsdev)
 {
-	struct vkms_output *output = &vkmsdev->output;
 	struct drm_device *dev = &vkmsdev->drm;
 	struct drm_connector *connector;
 	struct drm_encoder *encoder;
-	struct drm_crtc *crtc = &output->crtc;
+	struct vkms_output *output;
 	struct vkms_plane *primary, *overlay, *cursor = NULL;
 	int ret;
 	int writeback;
@@ -56,9 +55,12 @@ int vkms_output_init(struct vkms_device *vkmsdev)
 			return PTR_ERR(cursor);
 	}
 
-	ret = vkms_crtc_init(dev, crtc, &primary->base, &cursor->base);
-	if (ret)
-		return ret;
+	output = vkms_crtc_init(dev, &primary->base,
+				cursor ? &cursor->base : NULL);
+	if (IS_ERR(output)) {
+		DRM_ERROR("Failed to allocate CRTC\n");
+		return PTR_ERR(output);
+	}
 
 	if (vkmsdev->config->overlay) {
 		for (n = 0; n < NUM_OVERLAY_PLANES; n++) {
@@ -67,7 +69,7 @@ int vkms_output_init(struct vkms_device *vkmsdev)
 				DRM_DEV_ERROR(dev->dev, "Failed to init vkms plane\n");
 				return PTR_ERR(overlay);
 			}
-			overlay->base.possible_crtcs = drm_crtc_mask(crtc);
+			overlay->base.possible_crtcs = drm_crtc_mask(&output->crtc);
 		}
 	}
 
@@ -97,23 +99,23 @@ int vkms_output_init(struct vkms_device *vkmsdev)
 		DRM_ERROR("Failed to init encoder\n");
 		return ret;
 	}
-	encoder->possible_crtcs = drm_crtc_mask(crtc);
+	encoder->possible_crtcs = drm_crtc_mask(&output->crtc);
 
+	/* Attach the encoder and the connector */
 	ret = drm_connector_attach_encoder(connector, encoder);
 	if (ret) {
 		DRM_ERROR("Failed to attach connector to encoder\n");
 		return ret;
 	}
 
+	/* Initialize the writeback component */
 	if (vkmsdev->config->writeback) {
-		writeback = vkms_enable_writeback_connector(vkmsdev, crtc);
+		writeback = vkms_enable_writeback_connector(vkmsdev, output);
 		if (writeback)
 			DRM_ERROR("Failed to init writeback connector\n");
 	}
 
 	drm_mode_config_reset(dev);
 
-	return 0;
-
 	return ret;
 }
diff --git a/drivers/gpu/drm/vkms/vkms_writeback.c b/drivers/gpu/drm/vkms/vkms_writeback.c
index 981975c2b0a0..e9b5c74d7c58 100644
--- a/drivers/gpu/drm/vkms/vkms_writeback.c
+++ b/drivers/gpu/drm/vkms/vkms_writeback.c
@@ -105,7 +105,9 @@ static void vkms_wb_cleanup_job(struct drm_writeback_connector *connector,
 				struct drm_writeback_job *job)
 {
 	struct vkms_writeback_job *vkmsjob = job->priv;
-	struct vkms_device *vkmsdev;
+	struct vkms_output *vkms_output = container_of(connector,
+						       struct vkms_output,
+						       wb_connector);
 
 	if (!job->fb)
 		return;
@@ -114,8 +116,7 @@ static void vkms_wb_cleanup_job(struct drm_writeback_connector *connector,
 
 	drm_framebuffer_put(vkmsjob->wb_frame_info.fb);
 
-	vkmsdev = drm_device_to_vkms_device(job->fb->dev);
-	vkms_set_composer(&vkmsdev->output, false);
+	vkms_set_composer(vkms_output, false);
 	kfree(vkmsjob);
 }
 
@@ -124,8 +125,7 @@ static void vkms_wb_atomic_commit(struct drm_connector *conn,
 {
 	struct drm_connector_state *connector_state = drm_atomic_get_new_connector_state(state,
 											 conn);
-	struct vkms_device *vkmsdev = drm_device_to_vkms_device(conn->dev);
-	struct vkms_output *output = &vkmsdev->output;
+	struct vkms_output *output = drm_crtc_to_vkms_output(connector_state->crtc);
 	struct drm_writeback_connector *wb_conn = &output->wb_connector;
 	struct drm_connector_state *conn_state = wb_conn->base.state;
 	struct vkms_crtc_state *crtc_state = output->composer_state;
@@ -139,7 +139,7 @@ static void vkms_wb_atomic_commit(struct drm_connector *conn,
 	if (!conn_state)
 		return;
 
-	vkms_set_composer(&vkmsdev->output, true);
+	vkms_set_composer(output, true);
 
 	active_wb = conn_state->writeback_job->priv;
 	wb_frame_info = &active_wb->wb_frame_info;
@@ -162,22 +162,23 @@ static const struct drm_connector_helper_funcs vkms_wb_conn_helper_funcs = {
 	.atomic_check = vkms_wb_atomic_check,
 };
 
-int vkms_enable_writeback_connector(struct vkms_device *vkmsdev, struct drm_crtc *crtc)
+int vkms_enable_writeback_connector(struct vkms_device *vkmsdev,
+				    struct vkms_output *vkms_output)
 {
-	struct drm_writeback_connector *wb = &vkmsdev->output.wb_connector;
+	struct drm_writeback_connector *wb = &vkms_output->wb_connector;
 	int ret;
 
-	ret = drmm_encoder_init(&vkmsdev->drm, &vkmsdev->output.wb_encoder,
+	ret = drmm_encoder_init(&vkmsdev->drm, &vkms_output->wb_encoder,
 				NULL, DRM_MODE_ENCODER_VIRTUAL, NULL);
 	if (ret)
 		return ret;
-	vkmsdev->output.wb_encoder.possible_crtcs |= drm_crtc_mask(crtc);
+	vkms_output->wb_encoder.possible_crtcs |= drm_crtc_mask(&vkms_output->crtc);
 
 	drm_connector_helper_add(&wb->base, &vkms_wb_conn_helper_funcs);
 
 	return drmm_writeback_connector_init(&vkmsdev->drm, wb,
 					     &vkms_wb_connector_funcs,
-					     &vkmsdev->output.wb_encoder,
+					     &vkms_output->wb_encoder,
 					     vkms_wb_formats,
 					     ARRAY_SIZE(vkms_wb_formats));
 }