[v4,11/14] drm/vkms: Allow to configure multiple encoders

Commit Message

José Expósito Feb. 18, 2025, 10:12 a.m. UTC

Add a list of encoders to vkms_config and helper functions to add and
remove as many encoders as wanted.

For backwards compatibility, add one encoder to the default
configuration.

A future patch will allow to attach encoders and CRTCs, but for the
moment there are no changes in the way the output is configured.

Reviewed-by: Louis Chauvet <[e-mail]>
Co-developed-by: Louis Chauvet <[e-mail]>
Signed-off-by: Louis Chauvet <[e-mail]>
Signed-off-by: José Expósito <[e-mail]>
---
 .clang-format                                 |  1 +
 drivers/gpu/drm/vkms/tests/vkms_config_test.c | 94 +++++++++++++++++++
 drivers/gpu/drm/vkms/vkms_config.c            | 54 +++++++++++
 drivers/gpu/drm/vkms/vkms_config.h            | 46 +++++++++
 4 files changed, 195 insertions(+)

Patch

diff --git a/.clang-format b/.clang-format
index 6f944fa39841..c355a2f58eed 100644
--- a/.clang-format
+++ b/.clang-format
@@ -691,6 +691,7 @@  ForEachMacros:
   - 'v4l2_m2m_for_each_src_buf_safe'
   - 'virtio_device_for_each_vq'
   - 'vkms_config_for_each_crtc'
+  - 'vkms_config_for_each_encoder'
   - 'vkms_config_for_each_plane'
   - 'vkms_config_plane_for_each_possible_crtc'
   - 'while_for_each_ftrace_op'
diff --git a/drivers/gpu/drm/vkms/tests/vkms_config_test.c b/drivers/gpu/drm/vkms/tests/vkms_config_test.c
index 0997ea924ab7..fa8b4f23cb49 100644
--- a/drivers/gpu/drm/vkms/tests/vkms_config_test.c
+++ b/drivers/gpu/drm/vkms/tests/vkms_config_test.c
@@ -17,6 +17,17 @@  static size_t vkms_config_get_num_planes(struct vkms_config *config)
 	return count;
 }
 
+static size_t vkms_config_get_num_encoders(struct vkms_config *config)
+{
+	struct vkms_config_encoder *encoder_cfg;
+	size_t count = 0;
+
+	vkms_config_for_each_encoder(config, encoder_cfg)
+		count++;
+
+	return count;
+}
+
 static struct vkms_config_plane *get_first_plane(struct vkms_config *config)
 {
 	struct vkms_config_plane *plane_cfg;
@@ -37,6 +48,16 @@  static struct vkms_config_crtc *get_first_crtc(struct vkms_config *config)
 	return NULL;
 }
 
+static struct vkms_config_encoder *get_first_encoder(struct vkms_config *config)
+{
+	struct vkms_config_encoder *encoder_cfg;
+
+	vkms_config_for_each_encoder(config, encoder_cfg)
+		return encoder_cfg;
+
+	return NULL;
+}
+
 struct default_config_case {
 	bool enable_cursor;
 	bool enable_writeback;
@@ -57,6 +78,7 @@  static void vkms_config_test_empty_config(struct kunit *test)
 
 	KUNIT_EXPECT_EQ(test, vkms_config_get_num_planes(config), 0);
 	KUNIT_EXPECT_EQ(test, vkms_config_get_num_crtcs(config), 0);
+	KUNIT_EXPECT_EQ(test, vkms_config_get_num_encoders(config), 0);
 
 	KUNIT_EXPECT_FALSE(test, vkms_config_is_valid(config));
 
@@ -130,6 +152,9 @@  static void vkms_config_test_default_config(struct kunit *test)
 		KUNIT_EXPECT_EQ(test, n_possible_crtcs, 1);
 	}
 
+	/* Encoders */
+	KUNIT_EXPECT_EQ(test, vkms_config_get_num_encoders(config), 1);
+
 	KUNIT_EXPECT_TRUE(test, vkms_config_is_valid(config));
 
 	vkms_config_destroy(config);
@@ -215,6 +240,50 @@  static void vkms_config_test_get_crtcs(struct kunit *test)
 	vkms_config_destroy(config);
 }
 
+static void vkms_config_test_get_encoders(struct kunit *test)
+{
+	struct vkms_config *config;
+	struct vkms_config_encoder *encoder_cfg;
+	struct vkms_config_encoder *encoder_cfg1, *encoder_cfg2;
+	int n_encoders = 0;
+
+	config = vkms_config_create("test");
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, config);
+
+	vkms_config_for_each_encoder(config, encoder_cfg)
+		n_encoders++;
+	KUNIT_ASSERT_EQ(test, n_encoders, 0);
+
+	encoder_cfg1 = vkms_config_create_encoder(config);
+	vkms_config_for_each_encoder(config, encoder_cfg) {
+		n_encoders++;
+		if (encoder_cfg != encoder_cfg1)
+			KUNIT_FAIL(test, "Unexpected encoder");
+	}
+	KUNIT_ASSERT_EQ(test, n_encoders, 1);
+	n_encoders = 0;
+
+	encoder_cfg2 = vkms_config_create_encoder(config);
+	vkms_config_for_each_encoder(config, encoder_cfg) {
+		n_encoders++;
+		if (encoder_cfg != encoder_cfg1 && encoder_cfg != encoder_cfg2)
+			KUNIT_FAIL(test, "Unexpected encoder");
+	}
+	KUNIT_ASSERT_EQ(test, n_encoders, 2);
+	n_encoders = 0;
+
+	vkms_config_destroy_encoder(config, encoder_cfg2);
+	vkms_config_for_each_encoder(config, encoder_cfg) {
+		n_encoders++;
+		if (encoder_cfg != encoder_cfg1)
+			KUNIT_FAIL(test, "Unexpected encoder");
+	}
+	KUNIT_ASSERT_EQ(test, n_encoders, 1);
+	n_encoders = 0;
+
+	vkms_config_destroy(config);
+}
+
 static void vkms_config_test_invalid_plane_number(struct kunit *test)
 {
 	struct vkms_config *config;
@@ -350,6 +419,29 @@  static void vkms_config_test_invalid_crtc_number(struct kunit *test)
 	vkms_config_destroy(config);
 }
 
+static void vkms_config_test_invalid_encoder_number(struct kunit *test)
+{
+	struct vkms_config *config;
+	struct vkms_config_encoder *encoder_cfg;
+	int n;
+
+	config = vkms_config_default_create(false, false, false);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, config);
+
+	/* Invalid: No encoders */
+	encoder_cfg = get_first_encoder(config);
+	vkms_config_destroy_encoder(config, encoder_cfg);
+	KUNIT_EXPECT_FALSE(test, vkms_config_is_valid(config));
+
+	/* Invalid: Too many encoders */
+	for (n = 0; n <= 32; n++)
+		vkms_config_create_encoder(config);
+
+	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;
@@ -514,10 +606,12 @@  static struct kunit_case vkms_config_test_cases[] = {
 			 default_config_gen_params),
 	KUNIT_CASE(vkms_config_test_get_planes),
 	KUNIT_CASE(vkms_config_test_get_crtcs),
+	KUNIT_CASE(vkms_config_test_get_encoders),
 	KUNIT_CASE(vkms_config_test_invalid_plane_number),
 	KUNIT_CASE(vkms_config_test_valid_plane_type),
 	KUNIT_CASE(vkms_config_test_valid_plane_possible_crtcs),
 	KUNIT_CASE(vkms_config_test_invalid_crtc_number),
+	KUNIT_CASE(vkms_config_test_invalid_encoder_number),
 	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),
diff --git a/drivers/gpu/drm/vkms/vkms_config.c b/drivers/gpu/drm/vkms/vkms_config.c
index 458385413648..db8be054f6f4 100644
--- a/drivers/gpu/drm/vkms/vkms_config.c
+++ b/drivers/gpu/drm/vkms/vkms_config.c
@@ -24,6 +24,7 @@  struct vkms_config *vkms_config_create(const char *dev_name)
 
 	INIT_LIST_HEAD(&config->planes);
 	INIT_LIST_HEAD(&config->crtcs);
+	INIT_LIST_HEAD(&config->encoders);
 
 	return config;
 }
@@ -36,6 +37,7 @@  struct vkms_config *vkms_config_default_create(bool enable_cursor,
 	struct vkms_config *config;
 	struct vkms_config_plane *plane_cfg;
 	struct vkms_config_crtc *crtc_cfg;
+	struct vkms_config_encoder *encoder_cfg;
 	int n;
 
 	config = vkms_config_create(DEFAULT_DEVICE_NAME);
@@ -80,6 +82,10 @@  struct vkms_config *vkms_config_default_create(bool enable_cursor,
 			goto err_alloc;
 	}
 
+	encoder_cfg = vkms_config_create_encoder(config);
+	if (IS_ERR(encoder_cfg))
+		goto err_alloc;
+
 	return config;
 
 err_alloc:
@@ -92,6 +98,7 @@  void vkms_config_destroy(struct vkms_config *config)
 {
 	struct vkms_config_plane *plane_cfg, *plane_tmp;
 	struct vkms_config_crtc *crtc_cfg, *crtc_tmp;
+	struct vkms_config_encoder *encoder_cfg, *encoder_tmp;
 
 	list_for_each_entry_safe(plane_cfg, plane_tmp, &config->planes, link)
 		vkms_config_destroy_plane(plane_cfg);
@@ -99,6 +106,9 @@  void vkms_config_destroy(struct vkms_config *config)
 	list_for_each_entry_safe(crtc_cfg, crtc_tmp, &config->crtcs, link)
 		vkms_config_destroy_crtc(config, crtc_cfg);
 
+	list_for_each_entry_safe(encoder_cfg, encoder_tmp, &config->encoders, link)
+		vkms_config_destroy_encoder(config, encoder_cfg);
+
 	kfree_const(config->dev_name);
 	kfree(config);
 }
@@ -192,6 +202,20 @@  static bool valid_crtc_number(const struct vkms_config *config)
 	return true;
 }
 
+static bool valid_encoder_number(const struct vkms_config *config)
+{
+	struct drm_device *dev = config->dev ? &config->dev->drm : NULL;
+	size_t n_encoders;
+
+	n_encoders = list_count_nodes((struct list_head *)&config->encoders);
+	if (n_encoders <= 0 || n_encoders >= 32) {
+		drm_info(dev, "The number of encoders must be between 1 and 31\n");
+		return false;
+	}
+
+	return true;
+}
+
 bool vkms_config_is_valid(const struct vkms_config *config)
 {
 	struct vkms_config_crtc *crtc_cfg;
@@ -202,6 +226,9 @@  bool vkms_config_is_valid(const struct vkms_config *config)
 	if (!valid_crtc_number(config))
 		return false;
 
+	if (!valid_encoder_number(config))
+		return false;
+
 	if (!valid_plane_possible_crtcs(config))
 		return false;
 
@@ -222,6 +249,7 @@  static int vkms_config_show(struct seq_file *m, void *data)
 	const char *dev_name;
 	struct vkms_config_plane *plane_cfg;
 	struct vkms_config_crtc *crtc_cfg;
+	struct vkms_config_encoder *encoder_cfg;
 
 	dev_name = vkms_config_get_device_name((struct vkms_config *)vkmsdev->config);
 	seq_printf(m, "dev_name=%s\n", dev_name);
@@ -238,6 +266,9 @@  static int vkms_config_show(struct seq_file *m, void *data)
 			   vkms_config_crtc_get_writeback(crtc_cfg));
 	}
 
+	vkms_config_for_each_encoder(vkmsdev->config, encoder_cfg)
+		seq_puts(m, "encoder\n");
+
 	return 0;
 }
 
@@ -384,3 +415,26 @@  struct vkms_config_plane *vkms_config_crtc_cursor_plane(const struct vkms_config
 	return vkms_config_crtc_get_plane(config, crtc_cfg, DRM_PLANE_TYPE_CURSOR);
 }
 EXPORT_SYMBOL_IF_KUNIT(vkms_config_crtc_cursor_plane);
+
+struct vkms_config_encoder *vkms_config_create_encoder(struct vkms_config *config)
+{
+	struct vkms_config_encoder *encoder_cfg;
+
+	encoder_cfg = kzalloc(sizeof(*encoder_cfg), GFP_KERNEL);
+	if (!encoder_cfg)
+		return ERR_PTR(-ENOMEM);
+
+	encoder_cfg->config = config;
+	list_add_tail(&encoder_cfg->link, &config->encoders);
+
+	return encoder_cfg;
+}
+EXPORT_SYMBOL_IF_KUNIT(vkms_config_create_encoder);
+
+void vkms_config_destroy_encoder(struct vkms_config *config,
+				 struct vkms_config_encoder *encoder_cfg)
+{
+	list_del(&encoder_cfg->link);
+	kfree(encoder_cfg);
+}
+EXPORT_SYMBOL_IF_KUNIT(vkms_config_destroy_encoder);
diff --git a/drivers/gpu/drm/vkms/vkms_config.h b/drivers/gpu/drm/vkms/vkms_config.h
index ad303b34ee03..024cbed0e439 100644
--- a/drivers/gpu/drm/vkms/vkms_config.h
+++ b/drivers/gpu/drm/vkms/vkms_config.h
@@ -15,12 +15,14 @@ 
  * @dev_name: Name of the device
  * @planes: List of planes configured for the device
  * @crtcs: List of CRTCs configured for the device
+ * @encoders: List of encoders configured for the device
  * @dev: Used to store the current VKMS device. Only set when the device is instantiated.
  */
 struct vkms_config {
 	const char *dev_name;
 	struct list_head planes;
 	struct list_head crtcs;
+	struct list_head encoders;
 	struct vkms_device *dev;
 };
 
@@ -69,6 +71,24 @@  struct vkms_config_crtc {
 	struct vkms_output *crtc;
 };
 
+/**
+ * struct vkms_config_encoder
+ *
+ * @link: Link to the others encoders in vkms_config
+ * @config: The vkms_config this CRTC belongs to
+ * @encoder: Internal usage. This pointer should never be considered as valid.
+ *           It can be used to store a temporary reference to a VKMS encoder
+ *           during device creation. This pointer is not managed by the
+ *           configuration and must be managed by other means.
+ */
+struct vkms_config_encoder {
+	struct list_head link;
+	struct vkms_config *config;
+
+	/* Internal usage */
+	struct drm_encoder *encoder;
+};
+
 /**
  * vkms_config_for_each_plane - Iterate over the vkms_config planes
  * @config: &struct vkms_config pointer
@@ -85,6 +105,14 @@  struct vkms_config_crtc {
 #define vkms_config_for_each_crtc(config, crtc_cfg) \
 	list_for_each_entry((crtc_cfg), &(config)->crtcs, link)
 
+/**
+ * vkms_config_for_each_encoder - Iterate over the vkms_config encoders
+ * @config: &struct vkms_config pointer
+ * @encoder_cfg: &struct vkms_config_encoder pointer used as cursor
+ */
+#define vkms_config_for_each_encoder(config, encoder_cfg) \
+	list_for_each_entry((encoder_cfg), &(config)->encoders, link)
+
 /**
  * vkms_config_plane_for_each_possible_crtc - Iterate over the vkms_config_plane
  * possible CRTCs
@@ -286,4 +314,22 @@  struct vkms_config_plane *vkms_config_crtc_primary_plane(const struct vkms_confi
 struct vkms_config_plane *vkms_config_crtc_cursor_plane(const struct vkms_config *config,
 							struct vkms_config_crtc *crtc_cfg);
 
+/**
+ * vkms_config_create_encoder() - Add a new encoder configuration
+ * @config: Configuration to add the encoder to
+ *
+ * Returns:
+ * The new encoder configuration or an error. Call vkms_config_destroy_encoder()
+ * to free the returned encoder configuration.
+ */
+struct vkms_config_encoder *vkms_config_create_encoder(struct vkms_config *config);
+
+/**
+ * vkms_config_destroy_encoder() - Remove and free a encoder configuration
+ * @config: Configuration to remove the encoder from
+ * @encoder_cfg: Encoder configuration to destroy
+ */
+void vkms_config_destroy_encoder(struct vkms_config *config,
+				 struct vkms_config_encoder *encoder_cfg);
+
 #endif /* _VKMS_CONFIG_H_ */