drm/vkms: Allow to configure multiple CRTCs

Add a list of CRTCs to vkms_config and helper functions to add and remove as many CRTCs as wanted. For backwards compatibility, add one CRTC to the default configuration. A future patch will allow to attach planes and CRTCs, but for the moment there are no changes in the way the output is configured. 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/20250218101214.5790-10-jose.exposito89@gmail.com Signed-off-by: Maxime Ripard <mripard@kernel.org>
2025-09-04 20:19:47 +08:00 · 2025-02-18 11:12:09 +01:00 · 2025-02-18 11:12:09 +01:00 · 600df32dac
commit 600df32dac
parent bc5b0d5dcc
4 changed files with 222 additions and 5 deletions
--- a/.clang-format
+++ b/.clang-format
@ -690,6 +690,7 @@ ForEachMacros:
  - 'v4l2_m2m_for_each_src_buf'
  - 'v4l2_m2m_for_each_src_buf_safe'
  - 'virtio_device_for_each_vq'
+  - 'vkms_config_for_each_crtc'
  - 'vkms_config_for_each_plane'
  - 'while_for_each_ftrace_op'
  - 'xa_for_each'
--- a/drivers/gpu/drm/vkms/tests/vkms_config_test.c
+++ b/drivers/gpu/drm/vkms/tests/vkms_config_test.c
@ -27,6 +27,16 @@ static struct vkms_config_plane *get_first_plane(struct vkms_config *config)
 	return NULL;
 }

+static struct vkms_config_crtc *get_first_crtc(struct vkms_config *config)
+{
+	struct vkms_config_crtc *crtc_cfg;
+
+	vkms_config_for_each_crtc(config, crtc_cfg)
+		return crtc_cfg;
+
+	return NULL;
+}
+
 struct default_config_case {
 	bool enable_cursor;
 	bool enable_writeback;
@ -46,6 +56,7 @@ static void vkms_config_test_empty_config(struct kunit *test)
 	KUNIT_EXPECT_STREQ(test, vkms_config_get_device_name(config), "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_FALSE(test, vkms_config_is_valid(config));

@ -70,6 +81,7 @@ static void vkms_config_test_default_config(struct kunit *test)
 	const struct default_config_case *params = test->param_value;
 	struct vkms_config *config;
 	struct vkms_config_plane *plane_cfg;
+	struct vkms_config_crtc *crtc_cfg;
 	int n_primaries = 0;
 	int n_cursors = 0;
 	int n_overlays = 0;
@ -79,8 +91,6 @@ static void vkms_config_test_default_config(struct kunit *test)
 					    params->enable_overlay);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, config);

-	KUNIT_EXPECT_EQ(test, config->writeback, params->enable_writeback);
-
 	/* Planes */
 	vkms_config_for_each_plane(config, plane_cfg) {
 		switch (vkms_config_plane_get_type(plane_cfg)) {
@ -101,6 +111,13 @@ static void vkms_config_test_default_config(struct kunit *test)
 	KUNIT_EXPECT_EQ(test, n_cursors, params->enable_cursor ? 1 : 0);
 	KUNIT_EXPECT_EQ(test, n_overlays, params->enable_overlay ? 8 : 0);

+	/* CRTCs */
+	KUNIT_EXPECT_EQ(test, vkms_config_get_num_crtcs(config), 1);
+
+	crtc_cfg = get_first_crtc(config);
+	KUNIT_EXPECT_EQ(test, vkms_config_crtc_get_writeback(crtc_cfg),
+			params->enable_writeback);
+
 	KUNIT_EXPECT_TRUE(test, vkms_config_is_valid(config));

 	vkms_config_destroy(config);
@ -149,6 +166,43 @@ static void vkms_config_test_get_planes(struct kunit *test)
 	vkms_config_destroy(config);
 }

+static void vkms_config_test_get_crtcs(struct kunit *test)
+{
+	struct vkms_config *config;
+	struct vkms_config_crtc *crtc_cfg;
+	struct vkms_config_crtc *crtc_cfg1, *crtc_cfg2;
+
+	config = vkms_config_create("test");
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, config);
+
+	KUNIT_ASSERT_EQ(test, vkms_config_get_num_crtcs(config), 0);
+	vkms_config_for_each_crtc(config, crtc_cfg)
+		KUNIT_FAIL(test, "Unexpected CRTC");
+
+	crtc_cfg1 = vkms_config_create_crtc(config);
+	KUNIT_ASSERT_EQ(test, vkms_config_get_num_crtcs(config), 1);
+	vkms_config_for_each_crtc(config, crtc_cfg) {
+		if (crtc_cfg != crtc_cfg1)
+			KUNIT_FAIL(test, "Unexpected CRTC");
+	}
+
+	crtc_cfg2 = vkms_config_create_crtc(config);
+	KUNIT_ASSERT_EQ(test, vkms_config_get_num_crtcs(config), 2);
+	vkms_config_for_each_crtc(config, crtc_cfg) {
+		if (crtc_cfg != crtc_cfg1 && crtc_cfg != crtc_cfg2)
+			KUNIT_FAIL(test, "Unexpected CRTC");
+	}
+
+	vkms_config_destroy_crtc(config, crtc_cfg2);
+	KUNIT_ASSERT_EQ(test, vkms_config_get_num_crtcs(config), 1);
+	vkms_config_for_each_crtc(config, crtc_cfg) {
+		if (crtc_cfg != crtc_cfg1)
+			KUNIT_FAIL(test, "Unexpected CRTC");
+	}
+
+	vkms_config_destroy(config);
+}
+
 static void vkms_config_test_invalid_plane_number(struct kunit *test)
 {
 	struct vkms_config *config;
@ -213,13 +267,38 @@ static void vkms_config_test_valid_plane_type(struct kunit *test)
 	vkms_config_destroy(config);
 }

+static void vkms_config_test_invalid_crtc_number(struct kunit *test)
+{
+	struct vkms_config *config;
+	struct vkms_config_crtc *crtc_cfg;
+	int n;
+
+	config = vkms_config_default_create(false, false, false);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, config);
+
+	/* Invalid: No CRTCs */
+	crtc_cfg = get_first_crtc(config);
+	vkms_config_destroy_crtc(config, crtc_cfg);
+	KUNIT_EXPECT_FALSE(test, vkms_config_is_valid(config));
+
+	/* Invalid: Too many CRTCs */
+	for (n = 0; n <= 32; n++)
+		vkms_config_create_crtc(config);
+
+	KUNIT_EXPECT_FALSE(test, vkms_config_is_valid(config));
+
+	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,
 			 default_config_gen_params),
 	KUNIT_CASE(vkms_config_test_get_planes),
+	KUNIT_CASE(vkms_config_test_get_crtcs),
 	KUNIT_CASE(vkms_config_test_invalid_plane_number),
 	KUNIT_CASE(vkms_config_test_valid_plane_type),
+	KUNIT_CASE(vkms_config_test_invalid_crtc_number),
 	{}
 };

--- a/drivers/gpu/drm/vkms/vkms_config.c
+++ b/drivers/gpu/drm/vkms/vkms_config.c
@ -23,6 +23,7 @@ struct vkms_config *vkms_config_create(const char *dev_name)
 	}

 	INIT_LIST_HEAD(&config->planes);
+	INIT_LIST_HEAD(&config->crtcs);

 	return config;
 }
@ -34,19 +35,23 @@ 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;
 	int n;

 	config = vkms_config_create(DEFAULT_DEVICE_NAME);
 	if (IS_ERR(config))
 		return config;

-	config->writeback = enable_writeback;
-
 	plane_cfg = vkms_config_create_plane(config);
 	if (IS_ERR(plane_cfg))
 		goto err_alloc;
 	vkms_config_plane_set_type(plane_cfg, DRM_PLANE_TYPE_PRIMARY);

+	crtc_cfg = vkms_config_create_crtc(config);
+	if (IS_ERR(crtc_cfg))
+		goto err_alloc;
+	vkms_config_crtc_set_writeback(crtc_cfg, enable_writeback);
+
 	if (enable_overlay) {
 		for (n = 0; n < NUM_OVERLAY_PLANES; n++) {
 			plane_cfg = vkms_config_create_plane(config);
@ -75,10 +80,14 @@ EXPORT_SYMBOL_IF_KUNIT(vkms_config_default_create);
 void vkms_config_destroy(struct vkms_config *config)
 {
 	struct vkms_config_plane *plane_cfg, *plane_tmp;
+	struct vkms_config_crtc *crtc_cfg, *crtc_tmp;

 	list_for_each_entry_safe(plane_cfg, plane_tmp, &config->planes, link)
 		vkms_config_destroy_plane(plane_cfg);

+	list_for_each_entry_safe(crtc_cfg, crtc_tmp, &config->crtcs, link)
+		vkms_config_destroy_crtc(config, crtc_cfg);
+
 	kfree_const(config->dev_name);
 	kfree(config);
 }
@ -135,11 +144,28 @@ static bool valid_plane_type(const struct vkms_config *config)
 	return true;
 }

+static bool valid_crtc_number(const struct vkms_config *config)
+{
+	struct drm_device *dev = config->dev ? &config->dev->drm : NULL;
+	size_t n_crtcs;
+
+	n_crtcs = list_count_nodes((struct list_head *)&config->crtcs);
+	if (n_crtcs <= 0 || n_crtcs >= 32) {
+		drm_info(dev, "The number of CRTCs must be between 1 and 31\n");
+		return false;
+	}
+
+	return true;
+}
+
 bool vkms_config_is_valid(const struct vkms_config *config)
 {
 	if (!valid_plane_number(config))
 		return false;

+	if (!valid_crtc_number(config))
+		return false;
+
 	if (!valid_plane_type(config))
 		return false;

@ -154,10 +180,10 @@ static int vkms_config_show(struct seq_file *m, void *data)
 	struct vkms_device *vkmsdev = drm_device_to_vkms_device(dev);
 	const char *dev_name;
 	struct vkms_config_plane *plane_cfg;
+	struct vkms_config_crtc *crtc_cfg;

 	dev_name = vkms_config_get_device_name((struct vkms_config *)vkmsdev->config);
 	seq_printf(m, "dev_name=%s\n", dev_name);
-	seq_printf(m, "writeback=%d\n", vkmsdev->config->writeback);

 	vkms_config_for_each_plane(vkmsdev->config, plane_cfg) {
 		seq_puts(m, "plane:\n");
@ -165,6 +191,12 @@ static int vkms_config_show(struct seq_file *m, void *data)
 			   vkms_config_plane_get_type(plane_cfg));
 	}

+	vkms_config_for_each_crtc(vkmsdev->config, crtc_cfg) {
+		seq_puts(m, "crtc:\n");
+		seq_printf(m, "\twriteback=%d\n",
+			   vkms_config_crtc_get_writeback(crtc_cfg));
+	}
+
 	return 0;
 }

@ -201,3 +233,28 @@ void vkms_config_destroy_plane(struct vkms_config_plane *plane_cfg)
 	kfree(plane_cfg);
 }
 EXPORT_SYMBOL_IF_KUNIT(vkms_config_destroy_plane);
+
+struct vkms_config_crtc *vkms_config_create_crtc(struct vkms_config *config)
+{
+	struct vkms_config_crtc *crtc_cfg;
+
+	crtc_cfg = kzalloc(sizeof(*crtc_cfg), GFP_KERNEL);
+	if (!crtc_cfg)
+		return ERR_PTR(-ENOMEM);
+
+	crtc_cfg->config = config;
+	vkms_config_crtc_set_writeback(crtc_cfg, false);
+
+	list_add_tail(&crtc_cfg->link, &config->crtcs);
+
+	return crtc_cfg;
+}
+EXPORT_SYMBOL_IF_KUNIT(vkms_config_create_crtc);
+
+void vkms_config_destroy_crtc(struct vkms_config *config,
+			      struct vkms_config_crtc *crtc_cfg)
+{
+	list_del(&crtc_cfg->link);
+	kfree(crtc_cfg);
+}
+EXPORT_SYMBOL_IF_KUNIT(vkms_config_destroy_crtc);
--- a/drivers/gpu/drm/vkms/vkms_config.h
+++ b/drivers/gpu/drm/vkms/vkms_config.h
@ -14,12 +14,14 @@
 * @dev_name: Name of the device
 * @writeback: If true, a writeback buffer can be attached to the CRTC
 * @planes: List of planes configured for the device
+ * @crtcs: List of CRTCs 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;
 	bool writeback;
 	struct list_head planes;
+	struct list_head crtcs;
 	struct vkms_device *dev;
 };

@ -45,6 +47,27 @@ struct vkms_config_plane {
 	struct vkms_plane *plane;
 };

+/**
+ * struct vkms_config_crtc
+ *
+ * @link: Link to the others CRTCs in vkms_config
+ * @config: The vkms_config this CRTC belongs to
+ * @writeback: If true, a writeback buffer can be attached to the CRTC
+ * @crtc: Internal usage. This pointer should never be considered as valid.
+ *        It can be used to store a temporary reference to a VKMS CRTC during
+ *        device creation. This pointer is not managed by the configuration and
+ *        must be managed by other means.
+ */
+struct vkms_config_crtc {
+	struct list_head link;
+	struct vkms_config *config;
+
+	bool writeback;
+
+	/* Internal usage */
+	struct vkms_output *crtc;
+};
+
 /**
 * vkms_config_for_each_plane - Iterate over the vkms_config planes
 * @config: &struct vkms_config pointer
@ -53,6 +76,14 @@ struct vkms_config_plane {
 #define vkms_config_for_each_plane(config, plane_cfg) \
 	list_for_each_entry((plane_cfg), &(config)->planes, link)

+/**
+ * vkms_config_for_each_crtc - Iterate over the vkms_config CRTCs
+ * @config: &struct vkms_config pointer
+ * @crtc_cfg: &struct vkms_config_crtc pointer used as cursor
+ */
+#define vkms_config_for_each_crtc(config, crtc_cfg) \
+	list_for_each_entry((crtc_cfg), &(config)->crtcs, link)
+
 /**
 * vkms_config_create() - Create a new VKMS configuration
 * @dev_name: Name of the device
@ -96,6 +127,15 @@ vkms_config_get_device_name(struct vkms_config *config)
 	return config->dev_name;
 }

+/**
+ * vkms_config_get_num_crtcs() - Return the number of CRTCs in the configuration
+ * @config: Configuration to get the number of CRTCs from
+ */
+static inline size_t vkms_config_get_num_crtcs(struct vkms_config *config)
+{
+	return list_count_nodes(&config->crtcs);
+}
+
 /**
 * vkms_config_is_valid() - Validate a configuration
 * @config: Configuration to validate
@ -151,4 +191,44 @@ vkms_config_plane_set_type(struct vkms_config_plane *plane_cfg,
 	plane_cfg->type = type;
 }

+/**
+ * vkms_config_create_crtc() - Add a new CRTC configuration
+ * @config: Configuration to add the CRTC to
+ *
+ * Returns:
+ * The new CRTC configuration or an error. Call vkms_config_destroy_crtc() to
+ * free the returned CRTC configuration.
+ */
+struct vkms_config_crtc *vkms_config_create_crtc(struct vkms_config *config);
+
+/**
+ * vkms_config_destroy_crtc() - Remove and free a CRTC configuration
+ * @config: Configuration to remove the CRTC from
+ * @crtc_cfg: CRTC configuration to destroy
+ */
+void vkms_config_destroy_crtc(struct vkms_config *config,
+			      struct vkms_config_crtc *crtc_cfg);
+
+/**
+ * vkms_config_crtc_get_writeback() - If a writeback connector will be created
+ * @crtc_cfg: CRTC with or without a writeback connector
+ */
+static inline bool
+vkms_config_crtc_get_writeback(struct vkms_config_crtc *crtc_cfg)
+{
+	return crtc_cfg->writeback;
+}
+
+/**
+ * vkms_config_crtc_set_writeback() - If a writeback connector will be created
+ * @crtc_cfg: Target CRTC
+ * @writeback: Enable or disable the writeback connector
+ */
+static inline void
+vkms_config_crtc_set_writeback(struct vkms_config_crtc *crtc_cfg,
+			       bool writeback)
+{
+	crtc_cfg->writeback = writeback;
+}
+
 #endif /* _VKMS_CONFIG_H_ */