[PATCH 10/13] drm/vkms: Allow to configure multiple encoders

José Expósito
2025-01-29T11:01:18Z

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.

Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com>
Signed-off-by: José Expósito <jose.exposito89@gmail.com>
---
drivers/gpu/drm/vkms/tests/vkms_config_test.c | 65 ++++++++++++++++
drivers/gpu/drm/vkms/vkms_config.c | 78 +++++++++++++++++++
drivers/gpu/drm/vkms/vkms_config.h | 49 ++++++++++++
3 files changed, 192 insertions(+)

diff --git a/drivers/gpu/drm/vkms/tests/vkms_config_test.c b/drivers/gpu/drm/vkms/tests/vkms_config_test.c
index 5e698616491a..6c09363d9a96 100644
--- a/drivers/gpu/drm/vkms/tests/vkms_config_test.c
+++ b/drivers/gpu/drm/vkms/tests/vkms_config_test.c
@@ -26,6 +26,7 @@ static void vkms_config_test_empty_config(struct kunit *test)

KUNIT_EXPECT_TRUE(test, list_empty(&config->planes));
KUNIT_EXPECT_TRUE(test, list_empty(&config->crtcs));
+ KUNIT_EXPECT_TRUE(test, list_empty(&config->encoders));

KUNIT_EXPECT_FALSE(test, vkms_config_is_valid(config));

@@ -99,6 +100,9 @@ static void vkms_config_test_default_config(struct kunit *test)
KUNIT_EXPECT_EQ(test, n_possible_crtcs, 1);
}

+ /* Encoders */
+ KUNIT_EXPECT_EQ(test, list_count_nodes(&config->encoders), 1);
+
KUNIT_EXPECT_TRUE(test, vkms_config_is_valid(config));

vkms_config_destroy(config);
@@ -176,6 +180,42 @@ 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_cfg1, *encoder_cfg2;
+ struct vkms_config_encoder **array;
+ size_t length;
+
+ config = vkms_config_create("test");
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, config);
+
+ array = vkms_config_get_encoders(config, &length);
+ KUNIT_ASSERT_EQ(test, length, 0);
+ KUNIT_ASSERT_NULL(test, array);
+
+ encoder_cfg1 = vkms_config_add_encoder(config);
+ array = vkms_config_get_encoders(config, &length);
+ KUNIT_ASSERT_EQ(test, length, 1);
+ KUNIT_ASSERT_PTR_EQ(test, array[0], encoder_cfg1);
+ kfree(array);
+
+ encoder_cfg2 = vkms_config_add_encoder(config);
+ array = vkms_config_get_encoders(config, &length);
+ KUNIT_ASSERT_EQ(test, length, 2);
+ KUNIT_ASSERT_PTR_EQ(test, array[0], encoder_cfg1);
+ KUNIT_ASSERT_PTR_EQ(test, array[1], encoder_cfg2);
+ kfree(array);
+
+ vkms_config_destroy_encoder(config, encoder_cfg2);
+ array = vkms_config_get_encoders(config, &length);
+ KUNIT_ASSERT_EQ(test, length, 1);
+ KUNIT_ASSERT_PTR_EQ(test, array[0], encoder_cfg1);
+ kfree(array);
+
+ vkms_config_destroy(config);
+}
+
static void vkms_config_test_valid_plane_number(struct kunit *test)
{
struct vkms_config *config;
@@ -311,6 +351,29 @@ static void vkms_config_test_valid_crtc_number(struct kunit *test)
vkms_config_destroy(config);
}

+static void vkms_config_test_valid_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 = list_first_entry(&config->encoders, typeof(*encoder_cfg), link);
+ 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_add_encoder(config);
+
+ KUNIT_EXPECT_FALSE(test, vkms_config_is_valid(config));
+
+ vkms_config_destroy(config);
+}
+
static void vkms_config_test_plane_attach_crtc(struct kunit *test)
{
struct vkms_config *config;
@@ -439,10 +502,12 @@ 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_valid_plane_number),
KUNIT_CASE(vkms_config_test_valid_plane_type),
KUNIT_CASE(vkms_config_test_valid_plane_possible_crtcs),
KUNIT_CASE(vkms_config_test_valid_crtc_number),
+ KUNIT_CASE(vkms_config_test_valid_encoder_number),
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 a2ce4905589b..75e72f9b5972 100644
--- 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);
+ INIT_LIST_HEAD(&config->encoders);

return config;
}
@@ -34,6 +35,7 @@ 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);
@@ -78,6 +80,10 @@ struct vkms_config *vkms_config_default_create(bool enable_cursor,
goto err_alloc;
}

+ encoder_cfg = vkms_config_add_encoder(config);
+ if (IS_ERR(encoder_cfg))
+ goto err_alloc;
+
return config;

err_alloc:
@@ -89,6 +95,7 @@ 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);
@@ -96,6 +103,9 @@ 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);
}
@@ -154,6 +164,33 @@ struct vkms_config_crtc **vkms_config_get_crtcs(const struct vkms_config *config
return array;
}

+struct vkms_config_encoder **vkms_config_get_encoders(const struct vkms_config *config,
+ size_t *out_length)
+{
+ struct vkms_config_encoder **array;
+ struct vkms_config_encoder *encoder_cfg;
+ size_t length;
+ int n = 0;
+
+ length = list_count_nodes((struct list_head *)&config->encoders);
+ if (length == 0) {
+ *out_length = length;
+ return NULL;
+ }
+
+ array = kmalloc_array(length, sizeof(*array), GFP_KERNEL);
+ if (!array)
+ return ERR_PTR(-ENOMEM);
+
+ list_for_each_entry(encoder_cfg, &config->encoders, link) {
+ array[n] = encoder_cfg;
+ n++;
+ }
+
+ *out_length = length;
+ return array;
+}
+
static bool valid_plane_number(struct vkms_config *config)
{
size_t n_planes;
@@ -238,6 +275,19 @@ static bool valid_crtc_number(struct vkms_config *config)
return true;
}

+static bool valid_encoder_number(struct vkms_config *config)
+{
+ size_t n_encoders;
+
+ n_encoders = list_count_nodes(&config->encoders);
+ if (n_encoders <= 0 || n_encoders >= 32) {
+ pr_err("The number of encoders must be between 1 and 31\n");
+ return false;
+ }
+
+ return true;
+}
+
bool vkms_config_is_valid(struct vkms_config *config)
{
struct vkms_config_crtc *crtc_cfg;
@@ -248,6 +298,9 @@ bool vkms_config_is_valid(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;

@@ -267,6 +320,7 @@ 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);
@@ -283,6 +337,10 @@ static int vkms_config_show(struct seq_file *m, void *data)
vkms_config_crtc_get_writeback(crtc_cfg));
}

+ list_for_each_entry(encoder_cfg, &vkmsdev->config->encoders, link) {
+ seq_puts(m, "encoder\n");
+ }
+
return 0;
}

@@ -436,3 +494,23 @@ 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);
}
+
+struct vkms_config_encoder *vkms_config_add_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);
+
+ list_add_tail(&encoder_cfg->link, &config->encoders);
+
+ return encoder_cfg;
+}
+
+void vkms_config_destroy_encoder(struct vkms_config *config,
+ struct vkms_config_encoder *encoder_cfg)
+{
+ list_del(&encoder_cfg->link);
+ kfree(encoder_cfg);
+}
diff --git a/drivers/gpu/drm/vkms/vkms_config.h b/drivers/gpu/drm/vkms/vkms_config.h
index 1f2e6c485d08..40774d0daeac 100644
--- 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
* @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;
};

@@ -64,6 +66,22 @@ struct vkms_config_crtc {
struct vkms_output *crtc;
};

+/**
+ * struct vkms_config_encoder
+ *
+ * @link: Link to the others encoders in vkms_config
+ * @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;
+
+ /* Internal usage */
+ struct drm_encoder *encoder;
+};
+
/**
* vkms_config_create() - Create a new VKMS configuration
* @dev_name: Name of the device
@@ -139,6 +157,19 @@ static inline size_t vkms_config_get_num_crtcs(struct vkms_config *config)
struct vkms_config_crtc **vkms_config_get_crtcs(const struct vkms_config *config,
size_t *out_length);

+/**
+ * vkms_config_get_encoders() - Return the array of encoders of the device
+ * @config: Configuration to get the encoders from
+ * @out_length: Length of the returned array
+ *
+ * Returns:
+ * A list of pointers to the configurations. On success, the caller is
+ * responsible to free the returned array, but not its contents. On error,
+ * it returns an error and @out_length is invalid.
+ */
+struct vkms_config_encoder **vkms_config_get_encoders(const struct vkms_config *config,
+ size_t *out_length);
+
/**
* vkms_config_is_valid() - Validate a configuration
* @config: Configuration to validate
@@ -285,4 +316,22 @@ 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_add_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_add_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_ */
--
2.48.1