drm/vkms: Allow to attach connectors and encoders

Add a list of possible encoders to the connector configuration and
helpers to attach and detach them.

Now that the default configuration has its connector and encoder
correctly, configure the output following the configuration.

Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
Co-developed-by: Louis Chauvet <louis.chauvet@bootlin.com>
Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com>
Signed-off-by: José Expósito <jose.exposito89@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250218101214.5790-15-jose.exposito89@gmail.com
Signed-off-by: Maxime Ripard <mripard@kernel.org>

.clang-format

@@ -694,6 +694,7 @@ ForEachMacros:
   - 'vkms_config_for_each_crtc'
   - 'vkms_config_for_each_encoder'
   - 'vkms_config_for_each_plane'
+  - 'vkms_config_connector_for_each_possible_encoder'
   - 'vkms_config_encoder_for_each_possible_crtc'
   - 'vkms_config_plane_for_each_possible_crtc'
   - 'while_for_each_ftrace_op'

drivers/gpu/drm/vkms/tests/vkms_config_test.c

@@ -584,12 +584,32 @@ static void vkms_config_test_invalid_connector_number(struct kunit *test)
 	vkms_config_destroy(config);
 }
 
+static void vkms_config_test_valid_connector_possible_encoders(struct kunit *test)
+{
+	struct vkms_config *config;
+	struct vkms_config_encoder *encoder_cfg;
+	struct vkms_config_connector *connector_cfg;
+
+	config = vkms_config_default_create(false, false, false);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, config);
+
+	encoder_cfg = get_first_encoder(config);
+	connector_cfg = get_first_connector(config);
+
+	/* Invalid: Connector without a possible encoder */
+	vkms_config_connector_detach_encoder(connector_cfg, encoder_cfg);
+	KUNIT_EXPECT_FALSE(test, vkms_config_is_valid(config));
+
+	vkms_config_destroy(config);
+}
+
 static void vkms_config_test_attach_different_configs(struct kunit *test)
 {
 	struct vkms_config *config1, *config2;
 	struct vkms_config_plane *plane_cfg1, *plane_cfg2;
 	struct vkms_config_crtc *crtc_cfg1, *crtc_cfg2;
 	struct vkms_config_encoder *encoder_cfg1, *encoder_cfg2;
+	struct vkms_config_connector *connector_cfg1, *connector_cfg2;
 	int err;
 
 	config1 = vkms_config_create("test1");
@@ -601,10 +621,12 @@ static void vkms_config_test_attach_different_configs(struct kunit *test)
 	plane_cfg1 = vkms_config_create_plane(config1);
 	crtc_cfg1 = vkms_config_create_crtc(config1);
 	encoder_cfg1 = vkms_config_create_encoder(config1);
+	connector_cfg1 = vkms_config_create_connector(config1);
 
 	plane_cfg2 = vkms_config_create_plane(config2);
 	crtc_cfg2 = vkms_config_create_crtc(config2);
 	encoder_cfg2 = vkms_config_create_encoder(config2);
+	connector_cfg2 = vkms_config_create_connector(config2);
 
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, plane_cfg1);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, plane_cfg2);
@@ -612,6 +634,8 @@ static void vkms_config_test_attach_different_configs(struct kunit *test)
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, crtc_cfg2);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, encoder_cfg1);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, encoder_cfg2);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, connector_cfg1);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, connector_cfg2);
 
 	err = vkms_config_plane_attach_crtc(plane_cfg1, crtc_cfg2);
 	KUNIT_EXPECT_NE(test, err, 0);
@@ -623,6 +647,11 @@ static void vkms_config_test_attach_different_configs(struct kunit *test)
 	err = vkms_config_encoder_attach_crtc(encoder_cfg2, crtc_cfg1);
 	KUNIT_EXPECT_NE(test, err, 0);
 
+	err = vkms_config_connector_attach_encoder(connector_cfg1, encoder_cfg2);
+	KUNIT_EXPECT_NE(test, err, 0);
+	err = vkms_config_connector_attach_encoder(connector_cfg2, encoder_cfg1);
+	KUNIT_EXPECT_NE(test, err, 0);
+
 	vkms_config_destroy(config1);
 	vkms_config_destroy(config2);
 }
@@ -816,6 +845,77 @@ static void vkms_config_test_encoder_get_possible_crtcs(struct kunit *test)
 	vkms_config_destroy(config);
 }
 
+static void vkms_config_test_connector_get_possible_encoders(struct kunit *test)
+{
+	struct vkms_config *config;
+	struct vkms_config_connector *connector_cfg1, *connector_cfg2;
+	struct vkms_config_encoder *encoder_cfg1, *encoder_cfg2;
+	struct vkms_config_encoder *possible_encoder;
+	unsigned long idx = 0;
+	int n_encoders = 0;
+	int err;
+
+	config = vkms_config_create("test");
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, config);
+
+	connector_cfg1 = vkms_config_create_connector(config);
+	connector_cfg2 = vkms_config_create_connector(config);
+	encoder_cfg1 = vkms_config_create_encoder(config);
+	encoder_cfg2 = vkms_config_create_encoder(config);
+
+	/* No possible encoders */
+	vkms_config_connector_for_each_possible_encoder(connector_cfg1, idx,
+							possible_encoder)
+		KUNIT_FAIL(test, "Unexpected possible encoder");
+
+	vkms_config_connector_for_each_possible_encoder(connector_cfg2, idx,
+							possible_encoder)
+		KUNIT_FAIL(test, "Unexpected possible encoder");
+
+	/* Connector 1 attached to encoders 1 and 2 */
+	err = vkms_config_connector_attach_encoder(connector_cfg1, encoder_cfg1);
+	KUNIT_EXPECT_EQ(test, err, 0);
+	err = vkms_config_connector_attach_encoder(connector_cfg1, encoder_cfg2);
+	KUNIT_EXPECT_EQ(test, err, 0);
+
+	vkms_config_connector_for_each_possible_encoder(connector_cfg1, idx,
+							possible_encoder) {
+		n_encoders++;
+		if (possible_encoder != encoder_cfg1 &&
+		    possible_encoder != encoder_cfg2)
+			KUNIT_FAIL(test, "Unexpected possible encoder");
+	}
+	KUNIT_ASSERT_EQ(test, n_encoders, 2);
+	n_encoders = 0;
+
+	vkms_config_connector_for_each_possible_encoder(connector_cfg2, idx,
+							possible_encoder)
+		KUNIT_FAIL(test, "Unexpected possible encoder");
+
+	/* Connector 1 attached to encoder 1 and connector 2 to encoder 2 */
+	vkms_config_connector_detach_encoder(connector_cfg1, encoder_cfg2);
+	vkms_config_connector_for_each_possible_encoder(connector_cfg1, idx,
+							possible_encoder) {
+		n_encoders++;
+		if (possible_encoder != encoder_cfg1)
+			KUNIT_FAIL(test, "Unexpected possible encoder");
+	}
+	KUNIT_ASSERT_EQ(test, n_encoders, 1);
+	n_encoders = 0;
+
+	err = vkms_config_connector_attach_encoder(connector_cfg2, encoder_cfg2);
+	KUNIT_EXPECT_EQ(test, err, 0);
+	vkms_config_connector_for_each_possible_encoder(connector_cfg2, idx,
+							possible_encoder) {
+		n_encoders++;
+		if (possible_encoder != encoder_cfg2)
+			KUNIT_FAIL(test, "Unexpected possible encoder");
+	}
+	KUNIT_ASSERT_EQ(test, n_encoders, 1);
+
+	vkms_config_destroy(config);
+}
+
 static struct kunit_case vkms_config_test_cases[] = {
 	KUNIT_CASE(vkms_config_test_empty_config),
 	KUNIT_CASE_PARAM(vkms_config_test_default_config,
@@ -831,10 +931,12 @@ static struct kunit_case vkms_config_test_cases[] = {
 	KUNIT_CASE(vkms_config_test_invalid_encoder_number),
 	KUNIT_CASE(vkms_config_test_valid_encoder_possible_crtcs),
 	KUNIT_CASE(vkms_config_test_invalid_connector_number),
+	KUNIT_CASE(vkms_config_test_valid_connector_possible_encoders),
 	KUNIT_CASE(vkms_config_test_attach_different_configs),
 	KUNIT_CASE(vkms_config_test_plane_attach_crtc),
 	KUNIT_CASE(vkms_config_test_plane_get_possible_crtcs),
 	KUNIT_CASE(vkms_config_test_encoder_get_possible_crtcs),
+	KUNIT_CASE(vkms_config_test_connector_get_possible_encoders),
 	{}
 };
 

drivers/gpu/drm/vkms/vkms_config.c

@@ -95,6 +95,9 @@ struct vkms_config *vkms_config_default_create(bool enable_cursor,
 	if (IS_ERR(connector_cfg))
 		goto err_alloc;
 
+	if (vkms_config_connector_attach_encoder(connector_cfg, encoder_cfg))
+		goto err_alloc;
+
 	return config;
 
 err_alloc:
@@ -279,6 +282,22 @@ static bool valid_connector_number(const struct vkms_config *config)
 	return true;
 }
 
+static bool valid_connector_possible_encoders(const struct vkms_config *config)
+{
+	struct drm_device *dev = config->dev ? &config->dev->drm : NULL;
+	struct vkms_config_connector *connector_cfg;
+
+	vkms_config_for_each_connector(config, connector_cfg) {
+		if (xa_empty(&connector_cfg->possible_encoders)) {
+			drm_info(dev,
+				 "All connectors must have at least one possible encoder\n");
+			return false;
+		}
+	}
+
+	return true;
+}
+
 bool vkms_config_is_valid(const struct vkms_config *config)
 {
 	struct vkms_config_crtc *crtc_cfg;
@@ -306,6 +325,9 @@ bool vkms_config_is_valid(const struct vkms_config *config)
 	if (!valid_encoder_possible_crtcs(config))
 		return false;
 
+	if (!valid_connector_possible_encoders(config))
+		return false;
+
 	return true;
 }
 EXPORT_SYMBOL_IF_KUNIT(vkms_config_is_valid);
@@ -513,6 +535,11 @@ EXPORT_SYMBOL_IF_KUNIT(vkms_config_create_encoder);
 void vkms_config_destroy_encoder(struct vkms_config *config,
 				 struct vkms_config_encoder *encoder_cfg)
 {
+	struct vkms_config_connector *connector_cfg;
+
+	vkms_config_for_each_connector(config, connector_cfg)
+		vkms_config_connector_detach_encoder(connector_cfg, encoder_cfg);
+
 	xa_destroy(&encoder_cfg->possible_crtcs);
 	list_del(&encoder_cfg->link);
 	kfree(encoder_cfg);
@@ -561,6 +588,7 @@ struct vkms_config_connector *vkms_config_create_connector(struct vkms_config *c
 		return ERR_PTR(-ENOMEM);
 
 	connector_cfg->config = config;
+	xa_init_flags(&connector_cfg->possible_encoders, XA_FLAGS_ALLOC);
 
 	list_add_tail(&connector_cfg->link, &config->connectors);
 
@@ -570,7 +598,43 @@ EXPORT_SYMBOL_IF_KUNIT(vkms_config_create_connector);
 
 void vkms_config_destroy_connector(struct vkms_config_connector *connector_cfg)
 {
+	xa_destroy(&connector_cfg->possible_encoders);
 	list_del(&connector_cfg->link);
 	kfree(connector_cfg);
 }
 EXPORT_SYMBOL_IF_KUNIT(vkms_config_destroy_connector);
+
+int __must_check vkms_config_connector_attach_encoder(struct vkms_config_connector *connector_cfg,
+						      struct vkms_config_encoder *encoder_cfg)
+{
+	struct vkms_config_encoder *possible_encoder;
+	unsigned long idx = 0;
+	u32 encoder_idx = 0;
+
+	if (connector_cfg->config != encoder_cfg->config)
+		return -EINVAL;
+
+	vkms_config_connector_for_each_possible_encoder(connector_cfg, idx,
+							possible_encoder) {
+		if (possible_encoder == encoder_cfg)
+			return -EEXIST;
+	}
+
+	return xa_alloc(&connector_cfg->possible_encoders, &encoder_idx,
+			encoder_cfg, xa_limit_32b, GFP_KERNEL);
+}
+EXPORT_SYMBOL_IF_KUNIT(vkms_config_connector_attach_encoder);
+
+void vkms_config_connector_detach_encoder(struct vkms_config_connector *connector_cfg,
+					  struct vkms_config_encoder *encoder_cfg)
+{
+	struct vkms_config_encoder *possible_encoder;
+	unsigned long idx = 0;
+
+	vkms_config_connector_for_each_possible_encoder(connector_cfg, idx,
+							possible_encoder) {
+		if (possible_encoder == encoder_cfg)
+			xa_erase(&connector_cfg->possible_encoders, idx);
+	}
+}
+EXPORT_SYMBOL_IF_KUNIT(vkms_config_connector_detach_encoder);

drivers/gpu/drm/vkms/vkms_config.h

@@ -99,6 +99,7 @@ struct vkms_config_encoder {
  *
  * @link: Link to the others connector in vkms_config
  * @config: The vkms_config this connector belongs to
+ * @possible_encoders: Array of encoders that can be used with this connector
  * @connector: Internal usage. This pointer should never be considered as valid.
  *             It can be used to store a temporary reference to a VKMS connector
  *             during device creation. This pointer is not managed by the
@@ -108,6 +109,8 @@ struct vkms_config_connector {
 	struct list_head link;
 	struct vkms_config *config;
 
+	struct xarray possible_encoders;
+
 	/* Internal usage */
 	struct vkms_connector *connector;
 };
@@ -164,6 +167,16 @@ struct vkms_config_connector {
 #define vkms_config_encoder_for_each_possible_crtc(encoder_cfg, idx, possible_crtc) \
 	xa_for_each(&(encoder_cfg)->possible_crtcs, idx, (possible_crtc))
 
+/**
+ * vkms_config_connector_for_each_possible_encoder - Iterate over the
+ * vkms_config_connector possible encoders
+ * @connector_cfg: &struct vkms_config_connector pointer
+ * @idx: Index of the cursor
+ * @possible_encoder: &struct vkms_config_encoder pointer used as cursor
+ */
+#define vkms_config_connector_for_each_possible_encoder(connector_cfg, idx, possible_encoder) \
+	xa_for_each(&(connector_cfg)->possible_encoders, idx, (possible_encoder))
+
 /**
  * vkms_config_create() - Create a new VKMS configuration
  * @dev_name: Name of the device
@@ -405,4 +418,20 @@ struct vkms_config_connector *vkms_config_create_connector(struct vkms_config *c
  */
 void vkms_config_destroy_connector(struct vkms_config_connector *connector_cfg);
 
+/**
+ * vkms_config_connector_attach_encoder - Attach a connector to an encoder
+ * @connector_cfg: Connector to attach
+ * @encoder_cfg: Encoder to attach @connector_cfg to
+ */
+int __must_check vkms_config_connector_attach_encoder(struct vkms_config_connector *connector_cfg,
+						      struct vkms_config_encoder *encoder_cfg);
+
+/**
+ * vkms_config_connector_detach_encoder - Detach a connector from an encoder
+ * @connector_cfg: Connector to detach
+ * @encoder_cfg: Encoder to detach @connector_cfg from
+ */
+void vkms_config_connector_detach_encoder(struct vkms_config_connector *connector_cfg,
+					  struct vkms_config_encoder *encoder_cfg);
+
 #endif /* _VKMS_CONFIG_H_ */

drivers/gpu/drm/vkms/vkms_output.c

@@ -8,10 +8,10 @@
 int vkms_output_init(struct vkms_device *vkmsdev)
 {
 	struct drm_device *dev = &vkmsdev->drm;
-	struct vkms_connector *connector;
 	struct vkms_config_plane *plane_cfg;
 	struct vkms_config_crtc *crtc_cfg;
 	struct vkms_config_encoder *encoder_cfg;
+	struct vkms_config_connector *connector_cfg;
 	int ret;
 	int writeback;
 
@@ -83,22 +83,29 @@ int vkms_output_init(struct vkms_device *vkmsdev)
 		}
 	}
 
-	connector = vkms_connector_init(vkmsdev);
-	if (IS_ERR(connector)) {
-		DRM_ERROR("Failed to init connector\n");
-		return PTR_ERR(connector);
-	}
+	vkms_config_for_each_connector(vkmsdev->config, connector_cfg) {
+		struct vkms_config_encoder *possible_encoder;
+		unsigned long idx = 0;
 
-	/* Attach the encoder and the connector */
-	vkms_config_for_each_encoder(vkmsdev->config, encoder_cfg) {
-		ret = drm_connector_attach_encoder(&connector->base, encoder_cfg->encoder);
-		if (ret) {
-			DRM_ERROR("Failed to attach connector to encoder\n");
-			return ret;
+		connector_cfg->connector = vkms_connector_init(vkmsdev);
+		if (IS_ERR(connector_cfg->connector)) {
+			DRM_ERROR("Failed to init connector\n");
+			return PTR_ERR(connector_cfg->connector);
+		}
+
+		vkms_config_connector_for_each_possible_encoder(connector_cfg,
+								idx,
+								possible_encoder) {
+			ret = drm_connector_attach_encoder(&connector_cfg->connector->base,
+							   possible_encoder->encoder);
+			if (ret) {
+				DRM_ERROR("Failed to attach connector to encoder\n");
+				return ret;
+			}
 		}
 	}
 
 	drm_mode_config_reset(dev);
 
-	return ret;
+	return 0;
 }