Le 13/08/24 - 12:44, José Expósito a écrit :
> Create a default subgroup at /config/vkms/encoders to allow to create as
> many encoders as required. When the encoder is created the
> possible_crtcs subgroup is created allowing to link encoders and CRTCs.
I did not test, but the issue about index for crtc are maybe the same for
encoders.
> Signed-off-by: José Expósito <jose.exposito89@xxxxxxxxx>
> ---
> Documentation/gpu/vkms.rst | 14 ++-
> drivers/gpu/drm/vkms/vkms_config.h | 3 +
> drivers/gpu/drm/vkms/vkms_configfs.c | 127 +++++++++++++++++++++++++--
> 3 files changed, 136 insertions(+), 8 deletions(-)
>
> diff --git a/Documentation/gpu/vkms.rst b/Documentation/gpu/vkms.rst
> index 0886349ad4a0..c69be063d3b4 100644
> --- a/Documentation/gpu/vkms.rst
> +++ b/Documentation/gpu/vkms.rst
> @@ -76,7 +76,8 @@ And directories are created for each configurable item of the display pipeline::
> tree /config/vkms/my-vkms
> /config/vkms/my-vkms
> ├── crtcs
> - └── enabled
> + ├── enabled
> + └── encoders
>
> To add items to the display pipeline, create one or more directories under the
> available paths.
> @@ -90,6 +91,15 @@ CRTCs have 2 configurable attributes:
> - cursor: Enable or disable cursor plane support
> - writeback: Enable or disable writeback connector support
>
> +Continue by creating one or more encoders::
> +
> + sudo mkdir /config/vkms/my-vkms/encoders/encoder0
> +
> +Encoders can be linked to CRTCs by creating a symbolic link under
> +``possible_crtcs``::
> +
> + sudo ln -s /config/vkms/my-vkms/crtcs/crtc0 /config/vkms/my-vkms/encoders/encoder0/possible_crtcs
> +
> Once you are done configuring the VKMS instance, enable it::
>
> echo "1" | sudo tee /config/vkms/my-vkms/enabled
> @@ -100,6 +110,8 @@ Finally, you can remove the VKMS instance disabling it::
>
> Or removing the top level directory and its subdirectories::
>
> + sudo rm /config/vkms/my-vkms/encoders/*/possible_crtcs/*
> + sudo rmdir /config/vkms/my-vkms/encoders/*
> sudo rmdir /config/vkms/my-vkms/crtcs/*
> sudo rmdir /config/vkms/my-vkms
Same comment as previously, I think we should forbid this way to delete an
instance.
> diff --git a/drivers/gpu/drm/vkms/vkms_config.h b/drivers/gpu/drm/vkms/vkms_config.h
> index f96a0456a3d7..f9423533a7f3 100644
> --- a/drivers/gpu/drm/vkms/vkms_config.h
> +++ b/drivers/gpu/drm/vkms/vkms_config.h
> @@ -29,6 +29,9 @@ struct vkms_config_encoder {
> struct list_head list;
> unsigned int index;
> uint32_t possible_crtcs;
> + /* only used if created from configfs */
> + struct config_group encoder_group;
> + struct config_group possible_crtcs_group;
Again, I don't like mixing configfs and vkms_config. Can we keep both
stuff splitted?
> };
>
> struct vkms_config_connector {
> diff --git a/drivers/gpu/drm/vkms/vkms_configfs.c b/drivers/gpu/drm/vkms/vkms_configfs.c
> index 04278a39cd3c..c0b62fb93dc0 100644
> --- a/drivers/gpu/drm/vkms/vkms_configfs.c
> +++ b/drivers/gpu/drm/vkms/vkms_configfs.c
> @@ -19,6 +19,8 @@ static bool is_configfs_registered;
> * Initialized when a new directory is created under "/config/vkms/"
> * @crtcs_group: Default subgroup of @device_group at "/config/vkms/crtcs".
> * Each of its items represent a CRTC
> + * @encoders_group: Default subgroup of @device_group at
> + * "/config/vkms/encoders". Each of its items represent a encoder
> * @lock: Lock used to project concurrent access to the configuration attributes
> * @enabled: Protected by @lock. The device is created or destroyed when this
> * option changes
> @@ -27,6 +29,7 @@ struct vkms_configfs {
> struct vkms_config *vkms_config;
> struct config_group device_group;
> struct config_group crtcs_group;
> + struct config_group encoders_group;
>
> /* protected by @lock */
> struct mutex lock;
> @@ -45,6 +48,15 @@ struct vkms_configfs {
> #define crtcs_item_to_vkms_config_crtc(item) \
> container_of(to_config_group(item), struct vkms_config_crtc, crtc_group)
>
> +#define encoders_group_to_vkms_configfs(group) \
> + container_of(group, struct vkms_configfs, encoders_group)
> +
> +#define encoders_item_to_vkms_config_encoder(item) \
> + container_of(to_config_group(item), struct vkms_config_encoder, encoder_group)
> +
> +#define encoder_possible_crtcs_item_to_vkms_config_encoder(item) \
> + container_of(to_config_group(item), struct vkms_config_encoder, possible_crtcs_group)
> +
> static ssize_t crtc_cursor_show(struct config_item *item, char *page)
> {
> struct vkms_config_crtc *crtc_cfg = crtcs_item_to_vkms_config_crtc(item);
> @@ -171,6 +183,110 @@ static struct config_item_type crtcs_group_type = {
> .ct_owner = THIS_MODULE,
> };
>
> +static int encoder_possible_crtcs_allow_link(struct config_item *src,
> + struct config_item *target)
> +{
> + struct vkms_config_encoder *encoder_cfg;
> + struct vkms_config_crtc *crtc_cfg;
> +
> + if (target->ci_type != &crtc_group_type)
> + return -EINVAL;
I also need to check on my implementation, be we also need to check if the
target is in the correct device, not only the correct type :)
> +
> + encoder_cfg = encoder_possible_crtcs_item_to_vkms_config_encoder(src);
> + crtc_cfg = crtcs_item_to_vkms_config_crtc(target);
> +
> + if (encoder_cfg->possible_crtcs & BIT(crtc_cfg->index))
> + return -EINVAL;
> +
> + encoder_cfg->possible_crtcs |= BIT(crtc_cfg->index);
> +
> + return 0;
> +}
> +
> +static void encoder_possible_crtcs_drop_link(struct config_item *src,
> + struct config_item *target)
> +{
> + struct vkms_config_encoder *encoder_cfg;
> + struct vkms_config_crtc *crtc_cfg;
> +
> + encoder_cfg = encoder_possible_crtcs_item_to_vkms_config_encoder(src);
> + crtc_cfg = crtcs_item_to_vkms_config_crtc(target);
> +
> + encoder_cfg->possible_crtcs &= ~BIT(crtc_cfg->index);
> +}
> +
> +static struct configfs_item_operations encoder_possible_crtcs_item_ops = {
> + .allow_link = &encoder_possible_crtcs_allow_link,
> + .drop_link = &encoder_possible_crtcs_drop_link,
> +};
> +
> +static struct config_item_type encoder_possible_crtcs_group_type = {
> + .ct_item_ops = &encoder_possible_crtcs_item_ops,
> + .ct_owner = THIS_MODULE,
> +};
> +
> +static const struct config_item_type encoder_group_type = {
> + .ct_owner = THIS_MODULE,
> +};
> +
> +static struct config_group *make_encoders_group(struct config_group *group,
> + const char *name)
> +{
> + struct vkms_configfs *configfs = encoders_group_to_vkms_configfs(group);
> + struct vkms_config_encoder *encoder_cfg;
> + int ret;
> +
> + mutex_lock(&configfs->lock);
> +
> + if (configfs->enabled) {
> + ret = -EINVAL;
> + goto err_unlock;
> + }
> +
> + encoder_cfg = vkms_config_add_encoder(configfs->vkms_config, 0);
> + if (IS_ERR(encoder_cfg)) {
> + ret = PTR_ERR(encoder_cfg);
> + goto err_unlock;
> + }
> +
> + config_group_init_type_name(&encoder_cfg->encoder_group, name,
> + &encoder_group_type);
> +
> + config_group_init_type_name(&encoder_cfg->possible_crtcs_group,
> + "possible_crtcs",
> + &encoder_possible_crtcs_group_type);
> + configfs_add_default_group(&encoder_cfg->possible_crtcs_group,
> + &encoder_cfg->encoder_group);
> +
> + mutex_unlock(&configfs->lock);
> +
> + return &encoder_cfg->encoder_group;
> +
> +err_unlock:
> + mutex_unlock(&configfs->lock);
> + return ERR_PTR(ret);
> +}
> +
> +static void drop_encoders_group(struct config_group *group,
> + struct config_item *item)
> +{
> + struct vkms_configfs *configfs = encoders_group_to_vkms_configfs(group);
> + struct vkms_config_encoder *encoder_cfg =
> + encoders_item_to_vkms_config_encoder(item);
> +
> + vkms_config_destroy_encoder(configfs->vkms_config, encoder_cfg);
> +}
Same, I think there should not be any free in drop.
> +
> +static struct configfs_group_operations encoders_group_ops = {
> + .make_group = &make_encoders_group,
> + .drop_item = &drop_encoders_group,
> +};
> +
> +static struct config_item_type encoders_group_type = {
> + .ct_group_ops = &encoders_group_ops,
> + .ct_owner = THIS_MODULE,
> +};
> +
> static ssize_t device_enabled_show(struct config_item *item, char *page)
> {
> struct vkms_configfs *configfs = config_item_to_vkms_configfs(item);
> @@ -225,7 +341,6 @@ static struct config_group *make_device_group(struct config_group *group,
> const char *name)
> {
> struct vkms_configfs *configfs;
> - struct vkms_config_encoder *encoder_cfg = NULL;
> struct vkms_config_connector *connector_cfg = NULL;
> char *config_name;
> int ret;
> @@ -252,11 +367,10 @@ static struct config_group *make_device_group(struct config_group *group,
> configfs_add_default_group(&configfs->crtcs_group,
> &configfs->device_group);
>
> - encoder_cfg = vkms_config_add_encoder(configfs->vkms_config, BIT(0));
> - if (IS_ERR(encoder_cfg)) {
> - ret = PTR_ERR(encoder_cfg);
> - goto err_kfree;
> - }
> + config_group_init_type_name(&configfs->encoders_group, "encoders",
> + &encoders_group_type);
> + configfs_add_default_group(&configfs->encoders_group,
> + &configfs->device_group);
>
> connector_cfg = vkms_config_add_connector(configfs->vkms_config, BIT(0),
> connector_status_connected);
> @@ -269,7 +383,6 @@ static struct config_group *make_device_group(struct config_group *group,
>
> err_kfree:
> kfree(configfs);
> - kfree(encoder_cfg);
> kfree(connector_cfg);
> return ERR_PTR(ret);
> }
> --
> 2.46.0
>
--
Louis Chauvet, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
