Commit fad1138b authored by Louis Chauvet's avatar Louis Chauvet Committed by Luca Ceresoli
Browse files

drm/vkms: Allow to attach encoders and CRTCs via configfs 



Create a default subgroup at
/config/vkms/encoders/encoder/possible_crtcs that will contain symbolic
links to the possible CRTCs for the encoder.

Tested-by: default avatarMark Yacoub <markyacoub@google.com>
Reviewed-by: default avatarLouis Chauvet <louis.chauvet@bootlin.com>
Reviewed-by: default avatarHarry Wentland <harry.wentland@amd.com>
Reviewed-by: default avatarLuca Ceresoli <luca.ceresoli@bootlin.com>
Signed-off-by: default avatarLouis Chauvet <louis.chauvet@bootlin.com>
Co-developed-by: default avatarJosé Expósito <jose.exposito89@gmail.com>
Signed-off-by: default avatarJosé Expósito <jose.exposito89@gmail.com>
Link: https://lore.kernel.org/r/20251016175618.10051-10-jose.exposito89@gmail.com


Signed-off-by: default avatarLuca Ceresoli <luca.ceresoli@bootlin.com>
parent 67d8cf92

Documentation/gpu/vkms.rst

+2 −0
Original line number Diff line number Diff line
@@ -106,6 +106,7 @@ Next, create one or more encoders:: 
To finish the configuration, link the different pipeline items::



  sudo ln -s /config/vkms/my-vkms/crtcs/crtc0 /config/vkms/my-vkms/planes/plane0/possible_crtcs

  sudo ln -s /config/vkms/my-vkms/crtcs/crtc0 /config/vkms/my-vkms/encoders/encoder0/possible_crtcs



Since at least one primary plane is required, make sure to set the right type::
@@ -122,6 +123,7 @@ Finally, you can remove the VKMS instance disabling it:: 
And removing the top level directory and its subdirectories::



  sudo rm /config/vkms/my-vkms/planes/*/possible_crtcs/*

  sudo rm /config/vkms/my-vkms/encoders/*/possible_crtcs/*

  sudo rmdir /config/vkms/my-vkms/planes/*

  sudo rmdir /config/vkms/my-vkms/crtcs/*

  sudo rmdir /config/vkms/my-vkms/encoders/*

drivers/gpu/drm/vkms/vkms_configfs.c

+58 −0
Original line number Diff line number Diff line
@@ -70,11 +70,13 @@ struct vkms_configfs_crtc { 
 *

 * @group: Top level configuration group that represents a encoder.

 * Initialized when a new directory is created under "/config/vkms/encoders"

 * @possible_crtcs_group: Default subgroup of @group at "encoder/possible_crtcs"

 * @dev: The vkms_configfs_device this encoder belongs to

 * @config: Configuration of the VKMS encoder

 */

struct vkms_configfs_encoder {

	struct config_group group;

	struct config_group possible_crtcs_group;

	struct vkms_configfs_device *dev;

	struct vkms_config_encoder *config;

};
@@ -100,6 +102,10 @@ struct vkms_configfs_encoder { 
	container_of(to_config_group((item)), struct vkms_configfs_encoder, \

		     group)



#define encoder_possible_crtcs_item_to_vkms_configfs_encoder(item) \

	container_of(to_config_group((item)), struct vkms_configfs_encoder, \

		     possible_crtcs_group)



static ssize_t crtc_writeback_show(struct config_item *item, char *page)

{

	struct vkms_configfs_crtc *crtc;
@@ -364,6 +370,52 @@ static const struct config_item_type plane_group_type = { 
	.ct_owner	= THIS_MODULE,

};



static int encoder_possible_crtcs_allow_link(struct config_item *src,

					     struct config_item *target)

{

	struct vkms_configfs_encoder *encoder;

	struct vkms_configfs_crtc *crtc;

	int ret;



	if (target->ci_type != &crtc_item_type)

		return -EINVAL;



	encoder = encoder_possible_crtcs_item_to_vkms_configfs_encoder(src);

	crtc = crtc_item_to_vkms_configfs_crtc(target);



	scoped_guard(mutex, &encoder->dev->lock) {

		if (encoder->dev->enabled)

			return -EBUSY;



		ret = vkms_config_encoder_attach_crtc(encoder->config, crtc->config);

	}



	return ret;

}



static void encoder_possible_crtcs_drop_link(struct config_item *src,

					     struct config_item *target)

{

	struct vkms_configfs_encoder *encoder;

	struct vkms_configfs_crtc *crtc;



	encoder = encoder_possible_crtcs_item_to_vkms_configfs_encoder(src);

	crtc = crtc_item_to_vkms_configfs_crtc(target);



	scoped_guard(mutex, &encoder->dev->lock)

		vkms_config_encoder_detach_crtc(encoder->config, crtc->config);

}



static struct configfs_item_operations encoder_possible_crtcs_item_operations = {

	.allow_link	= encoder_possible_crtcs_allow_link,

	.drop_link	= encoder_possible_crtcs_drop_link,

};



static const struct config_item_type encoder_possible_crtcs_group_type = {

	.ct_item_ops	= &encoder_possible_crtcs_item_operations,

	.ct_owner	= THIS_MODULE,

};



static void encoder_release(struct config_item *item)

{

	struct vkms_configfs_encoder *encoder;
@@ -413,6 +465,12 @@ static struct config_group *make_encoder_group(struct config_group *group, 


		config_group_init_type_name(&encoder->group, name,

					    &encoder_item_type);



		config_group_init_type_name(&encoder->possible_crtcs_group,

					    "possible_crtcs",

					    &encoder_possible_crtcs_group_type);

		configfs_add_default_group(&encoder->possible_crtcs_group,

					   &encoder->group);

	}



	return &encoder->group;