[PATCH v3 0/3] drm/vkms: Switch to allocated for drm objects

[PATCH v3 0/3] drm/vkms: Switch to allocated for drm objects

[Louis Chauvet]

Specific allocations for each DRM object is not strictly needed in VKMS
right now, but in order to implement dynamic configuration of VKMS
(configFS), it will be easier to have one allocation per DRM object.

There is no need for a dynamic allocation for the writeback connector as
there can only be one per CRTC

No functionnal changes are intented in this series.

This series requires [1] to switch vkms objects to drm-managed objects.

[1]:https://lore.kernel.org/all/20241122-google-vkms-managed-v5-0-1ab60403e960@bootlin.com/

Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com>
---
Changes in v3:
- Add R-by
- Fix bug reported by José
- Remove patch to rename vkms_output to vkms_crtc
- Link to v2: https://lore.kernel.org/r/20241122-b4-vkms-allocated-v2-0-ff7bddbf0bfb@bootlin.com

Changes in v2:
- Rebased on drm-misc-next
- Apply comments from Jose
- Link to v1: https://lore.kernel.org/r/20240912-b4-vkms-allocated-v1-0-29abbaa14af9@bootlin.com

---
Louis Chauvet (3):
      drm/vkms: Switch to dynamic allocation for connector
      drm/vkms: Switch to dynamic allocation for encoder
      drm/vkms: Switch to dynamic allocation for CRTC

 drivers/gpu/drm/vkms/vkms_crtc.c      | 32 ++++++++++++++++--------------
 drivers/gpu/drm/vkms/vkms_drv.h       | 11 +++++------
 drivers/gpu/drm/vkms/vkms_output.c    | 37 +++++++++++++++++++++++------------
 drivers/gpu/drm/vkms/vkms_writeback.c | 17 ++++++++--------
 4 files changed, 56 insertions(+), 41 deletions(-)
---
base-commit: f8a2397baf041a5cee408b082334bb09c7e161df
change-id: 20240909-b4-vkms-allocated-9f5508f4444a
prerequisite-message-id: 20241230-google-vkms-managed-v6-0-15c7d65cd63b@bootlin.com
prerequisite-patch-id: b608594ad493a41000ee703792eac4b23f9e35dc
prerequisite-patch-id: 5697aa87c44bbf3eda8a1ba424465dc792545d4c
prerequisite-patch-id: 223d59c407ce28dacf3f563b5c0148d2398303f1
prerequisite-patch-id: 852b8a54fb933d66592df19aadc551827f719029
prerequisite-patch-id: 8763b3f1494bcb5fddf298f1df429293f2838806
prerequisite-patch-id: 5ab0f908802d3977c60b03e7c5f2631163b4e15e
prerequisite-patch-id: 7f411c316bee613498134279d6b6aa87b58df531
prerequisite-patch-id: 30a1e033fa43241ca6a43006fd4f29f8e9217224

Best regards,
-- 
Louis Chauvet <louis.chauvet@bootlin.com>

[PATCH v3 1/3] drm/vkms: Switch to dynamic allocation for connector

[Louis Chauvet]

A specific allocation for the connector 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
connector.

Reviewed-by: Maxime Ripard <mripard@kernel.org>
Reviewed-by: José Expósito <jose.exposito89@gmail.com>
Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com>
---
 drivers/gpu/drm/vkms/vkms_drv.h    | 1 -
 drivers/gpu/drm/vkms/vkms_output.c | 8 +++++++-
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/vkms/vkms_drv.h b/drivers/gpu/drm/vkms/vkms_drv.h
index 00541eff3d1b0aa4b374fb94c8fe34932df31509..820e7899cb049b45d8bdbe5a0dc7be08eee6db69 100644
--- a/drivers/gpu/drm/vkms/vkms_drv.h
+++ b/drivers/gpu/drm/vkms/vkms_drv.h
@@ -177,7 +177,6 @@ struct vkms_crtc_state {
 struct vkms_output {
 	struct drm_crtc crtc;
 	struct drm_encoder encoder;
-	struct drm_connector connector;
 	struct drm_writeback_connector wb_connector;
 	struct hrtimer vblank_hrtimer;
 	ktime_t period_ns;
diff --git a/drivers/gpu/drm/vkms/vkms_output.c b/drivers/gpu/drm/vkms/vkms_output.c
index ab9affa75b66ce9f00fe025052439405206144ec..ec3545730ef79af0db51d8ec605b9cdfff52c2a3 100644
--- a/drivers/gpu/drm/vkms/vkms_output.c
+++ b/drivers/gpu/drm/vkms/vkms_output.c
@@ -32,7 +32,7 @@ int vkms_output_init(struct vkms_device *vkmsdev)
 {
 	struct vkms_output *output = &vkmsdev->output;
 	struct drm_device *dev = &vkmsdev->drm;
-	struct drm_connector *connector = &output->connector;
+	struct drm_connector *connector;
 	struct drm_encoder *encoder = &output->encoder;
 	struct drm_crtc *crtc = &output->crtc;
 	struct vkms_plane *primary, *overlay, *cursor = NULL;
@@ -71,6 +71,12 @@ int vkms_output_init(struct vkms_device *vkmsdev)
 		}
 	}
 
+	connector = drmm_kzalloc(dev, sizeof(*connector), GFP_KERNEL);
+	if (!connector) {
+		DRM_ERROR("Failed to allocate connector\n");
+		return -ENOMEM;
+	}
+
 	ret = drmm_connector_init(dev, connector, &vkms_connector_funcs,
 				  DRM_MODE_CONNECTOR_VIRTUAL, NULL);
 	if (ret) {

-- 
2.47.1

[PATCH v3 2/3] drm/vkms: Switch to dynamic allocation for encoder

[Louis Chauvet]

A specific allocation for the encoder 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 encoder.

Reviewed-by: Maxime Ripard <mripard@kernel.org>
Reviewed-by: José Expósito <jose.exposito89@gmail.com>
Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com>
---
 drivers/gpu/drm/vkms/vkms_drv.h    | 1 -
 drivers/gpu/drm/vkms/vkms_output.c | 7 ++++++-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/vkms/vkms_drv.h b/drivers/gpu/drm/vkms/vkms_drv.h
index 820e7899cb049b45d8bdbe5a0dc7be08eee6db69..19fd99b8e506c4454d7878b67f692a0441c22665 100644
--- a/drivers/gpu/drm/vkms/vkms_drv.h
+++ b/drivers/gpu/drm/vkms/vkms_drv.h
@@ -176,7 +176,6 @@ struct vkms_crtc_state {
  */
 struct vkms_output {
 	struct drm_crtc crtc;
-	struct drm_encoder encoder;
 	struct drm_writeback_connector wb_connector;
 	struct hrtimer vblank_hrtimer;
 	ktime_t period_ns;
diff --git a/drivers/gpu/drm/vkms/vkms_output.c b/drivers/gpu/drm/vkms/vkms_output.c
index ec3545730ef79af0db51d8ec605b9cdfff52c2a3..102b6ad466cb4f7c6704f30cea669e5d7f81540a 100644
--- a/drivers/gpu/drm/vkms/vkms_output.c
+++ b/drivers/gpu/drm/vkms/vkms_output.c
@@ -33,7 +33,7 @@ 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 = &output->encoder;
+	struct drm_encoder *encoder;
 	struct drm_crtc *crtc = &output->crtc;
 	struct vkms_plane *primary, *overlay, *cursor = NULL;
 	int ret;
@@ -86,6 +86,11 @@ int vkms_output_init(struct vkms_device *vkmsdev)
 
 	drm_connector_helper_add(connector, &vkms_conn_helper_funcs);
 
+	encoder = drmm_kzalloc(dev, sizeof(*encoder), GFP_KERNEL);
+	if (!encoder) {
+		DRM_ERROR("Failed to allocate encoder\n");
+		return -ENOMEM;
+	}
 	ret = drmm_encoder_init(dev, encoder, NULL,
 				DRM_MODE_ENCODER_VIRTUAL, NULL);
 	if (ret) {

-- 
2.47.1

[PATCH v3 3/3] drm/vkms: Switch to dynamic allocation for CRTC

[Louis Chauvet]

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.

Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com>
---
 drivers/gpu/drm/vkms/vkms_crtc.c      | 32 +++++++++++++++++---------------
 drivers/gpu/drm/vkms/vkms_drv.h       |  9 +++++----
 drivers/gpu/drm/vkms/vkms_output.c    | 22 ++++++++++++----------
 drivers/gpu/drm/vkms/vkms_writeback.c | 17 +++++++++--------
 4 files changed, 43 insertions(+), 37 deletions(-)

diff --git a/drivers/gpu/drm/vkms/vkms_crtc.c b/drivers/gpu/drm/vkms/vkms_crtc.c
index ace8d293f7da611110c1e117b6cf2f3c9e9b4381..d014dec117e7d4ec7e9e38037a4a4cb4bc6be4ca 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)) {
@@ -279,25 +277,29 @@ static void vkms_crtc_destroy_workqueue(struct drm_device *dev,
 	destroy_workqueue(vkms_out->composer_workq);
 }
 
-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);
@@ -307,12 +309,12 @@ int vkms_crtc_init(struct drm_device *dev, struct drm_crtc *crtc,
 
 	vkms_out->composer_workq = alloc_ordered_workqueue("vkms_composer", 0);
 	if (!vkms_out->composer_workq)
-		return -ENOMEM;
+		return ERR_PTR(-ENOMEM);
 
 	ret = drmm_add_action_or_reset(dev, vkms_crtc_destroy_workqueue,
 				       vkms_out);
 	if (ret)
-		return ret;
+		return ERR_PTR(ret);
 
-	return ret;
+	return vkms_out;
 }
diff --git a/drivers/gpu/drm/vkms/vkms_drv.h b/drivers/gpu/drm/vkms/vkms_drv.h
index 19fd99b8e506c4454d7878b67f692a0441c22665..fbe7de67fb9c6a6a6964d71b452b9a3ce573e0f8 100644
--- a/drivers/gpu/drm/vkms/vkms_drv.h
+++ b/drivers/gpu/drm/vkms/vkms_drv.h
@@ -214,7 +214,6 @@ struct vkms_config {
 struct vkms_device {
 	struct drm_device drm;
 	struct platform_device *platform;
-	struct vkms_output output;
 	const struct vkms_config *config;
 };
 
@@ -241,8 +240,9 @@ 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.
@@ -273,6 +273,7 @@ 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);
+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 102b6ad466cb4f7c6704f30cea669e5d7f81540a..22f0d678af3ac8177e43c4ea730af3f2109de5f3 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);
+		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 f12417b2d24803a33e4ff56108cc89704a500faf..c9b6e161fa8698491f20082dfe0b713f27bcb918 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;
@@ -162,9 +162,10 @@ 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)
+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;
 
 	drm_connector_helper_add(&wb->base, &vkms_wb_conn_helper_funcs);
 

-- 
2.47.1

Re: [PATCH v3 3/3] drm/vkms: Switch to dynamic allocation for CRTC

[Maxime Ripard]

On Mon, 30 Dec 2024 19:39:46 +0100, Louis Chauvet wrote:
> 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.
> 
> Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com>
> 
> [ ... ]

Reviewed-by: Maxime Ripard <mripard@kernel.org>

Thanks!
Maxime