| Message ID | 20220722213214.1377835-5-jshargo@chromium.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/5] drm/vkms: Merge default_config and device | expand |
On Fri, Jul 22, 2022 at 05:32:12PM -0400, Jim Shargo wrote: > This change adds the basic scaffolding for ConfigFS, including setting > up the default directories. It does not allow for the registration of > configfs-backed devices, which is complex and provided in a follow-up > commit. > > This CL includes docs about using ConfigFS with VKMS, but I'll summarize > in brief here as well (assuming ConfigFS is mounted at /config/): > > To create a new configuration, you can do so via `mkdir > /config/vkms/my-device`. > > This will create a number of directories and files automatically: > > /config > `-- vkms > `-- my-device > |-- connectors > |-- crtcs > |-- encoders > |-- planes > `-- is_registered > > You can then configure objects by mkdir'ing in each of the directories. > > When you're satisfied, you can `echo 1 > /config/vkms/my-device/is_registered`. > This will create a new device according to your configuration. > > For now, this will fail, but the next change will add support for it. > > Signed-off-by: Jim Shargo <jshargo@chromium.org> > --- > Documentation/gpu/vkms.rst | 76 ++++ > drivers/gpu/drm/Kconfig | 1 + > drivers/gpu/drm/vkms/Makefile | 1 + > drivers/gpu/drm/vkms/vkms_configfs.c | 527 +++++++++++++++++++++++++++ > drivers/gpu/drm/vkms/vkms_drv.c | 28 +- > drivers/gpu/drm/vkms/vkms_drv.h | 75 +++- > drivers/gpu/drm/vkms/vkms_output.c | 11 +- > 7 files changed, 711 insertions(+), 8 deletions(-) > create mode 100644 drivers/gpu/drm/vkms/vkms_configfs.c > > diff --git a/Documentation/gpu/vkms.rst b/Documentation/gpu/vkms.rst > index 9c873c3912cc..f5f8ea0de5bc 100644 > --- a/Documentation/gpu/vkms.rst > +++ b/Documentation/gpu/vkms.rst > @@ -51,6 +51,82 @@ To disable the driver, use :: > > sudo modprobe -r vkms > > +Configuration With ConfigFS > +=========================== > + > +VKMS is instrumented with support for configuration via `ConfigFS`. With VKMS > +installed, you can mount ConfigFS at /config/ like so:: > + > + mkdir -p /config/ > + sudo mount -t configfs none /config > + > +This allows you to configure multiple virtual cards in addition to an immutable > +"default" card created by the driver at initialization time. Is the default for backwards compatibility? > + > +To set up a new card, create a new directory under the vkms configfs > +directory:: > + > + $ mkdir /config/vkms/test > + > +With your card created you'll find an new directory ready to be configured:: > + > + /config > + `-- vkms > + |-- default > + | `-- is_registered > + `-- test > + |-- connectors > + |-- crtcs > + |-- encoders > + |-- planes > + `-- is_registered > + > +Each directory you add within the connectors, crtcs, encoders, and planes > +directories will let you configure a new object of that type. Adding new > +objects will automatically create a set of default files and folders you can > +use to configure that object. > + > +For instance, we can set up a very basic driver like so:: > + > + DRM_PLANE_TYPE_PRIMARY=1 > + DRM_PLANE_TYPE_CURSOR=2 > + DRM_PLANE_TYPE_OVERLAY=0 > + > + mkdir /config/vkms/test/planes/primary > + echo $DRM_PLANE_TYPE_PRIMARY > /config/vkms/test/planes/primary/type > + > + mkdir /config/vkms/test/planes/other_primary > + echo $DRM_PLANE_TYPE_PRIMARY > /config/vkms/test/planes/other_primary/type > + > + mkdir /config/vkms/test/planes/cursor > + echo $DRM_PLANE_TYPE_CURSOR > /config/vkms/test/planes/cursor/type > + > + mkdir /config/vkms/test/planes/overlay > + echo $DRM_PLANE_TYPE_OVERLAY > /config/vkms/test/planes/overlay/type > + > + mkdir /config/vkms/test/crtcs/crtc > + mkdir /config/vkms/test/crtcs/crtc_other > + mkdir /config/vkms/test/encoders/encoder > + mkdir /config/vkms/test/connectors/connector > + > + ln -s /config/vkms/test/encoders/encoder /config/vkms/test/connectors/connector/possible_encoders > + ln -s /config/vkms/test/crtcs/crtc /config/vkms/test/encoders/encoder/possible_crtcs/ > + ln -s /config/vkms/test/crtcs/crtc /config/vkms/test/planes/primary/possible_crtcs/ > + ln -s /config/vkms/test/crtcs/crtc /config/vkms/test/planes/cursor/possible_crtcs/ > + ln -s /config/vkms/test/crtcs/crtc /config/vkms/test/planes/overlay/possible_crtcs/ > + ln -s /config/vkms/test/crtcs/crtc_other /config/vkms/test/planes/overlay/possible_crtcs/ > + > +You can see that specific attributes, such as `.../<plane>/type`, can be > +configured by writing into them. Associating objects together can be done via > +symlinks. > + > +Finally, to register your newly configured objects with DRM so you can use your > +virtual device, all you need to do is write `1` into the special file > +`/config/vkms/test/is_registered``, which will return non-zero on error. > + > +When you're done with the virtual card, all you need to do is `rmdir` the root > +directory. There seems to be some amount of overlap between this blurb and the one in vkms_configfs.c. IMO it'd be better to unify these in the source and link it here using: .. kernel-doc:: drivers/gpu/drm/vkms/vkms_configfs.c :doc: ConfigFS Support for VKMS > + > Testing With IGT > ================ > > diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig > index f1422bee3dcc..5c90c82fab6d 100644 > --- a/drivers/gpu/drm/Kconfig > +++ b/drivers/gpu/drm/Kconfig > @@ -307,6 +307,7 @@ config DRM_VKMS > depends on DRM && MMU > select DRM_KMS_HELPER > select DRM_GEM_SHMEM_HELPER > + select CONFIGFS_FS > select CRC32 > default n > help > diff --git a/drivers/gpu/drm/vkms/Makefile b/drivers/gpu/drm/vkms/Makefile > index 72f779cbfedd..3efb7b0f5319 100644 > --- a/drivers/gpu/drm/vkms/Makefile > +++ b/drivers/gpu/drm/vkms/Makefile > @@ -3,6 +3,7 @@ vkms-y := \ > vkms_drv.o \ > vkms_plane.o \ > vkms_output.o \ > + vkms_configfs.o \ > vkms_crtc.o \ > vkms_composer.o \ > vkms_writeback.o > diff --git a/drivers/gpu/drm/vkms/vkms_configfs.c b/drivers/gpu/drm/vkms/vkms_configfs.c > new file mode 100644 > index 000000000000..fa0d8700258e > --- /dev/null > +++ b/drivers/gpu/drm/vkms/vkms_configfs.c > @@ -0,0 +1,527 @@ > +// SPDX-License-Identifier: GPL-2.0+ > + > +#include <linux/configfs.h> > +#include <linux/kernel.h> Same comment re: kernel.h > +#include <linux/mutex.h> > + > +#include <drm/drm_plane.h> > +#include <drm/drm_print.h> > + > +#include "vkms_drv.h" > + > +/** > + * DOC: ConfigFS Support for VKMS > + * > + * When ConfigFS is mounted, say at /config/, we add a /config/vkms/ > + * directory. Each folder in this directory represents a different > + * virtual driver. Drivers can be "registered", meaning that they're > + * available to use as a DRM driver. Initially, this just contains a > + * registered "default" device. Nit: s/driver/device/ since the term drm device is much better specified than drm driver. > + * > + * Users can mkdir in this the VKMS directory to begin the process of > + * configuring a new device. Users can mkdir in the automatically > + * created "connectors", "crtcs", "encoders", and "planes" folders to > + * set up those objects. > + * > + * In order to create associations between objects, users can symlink > + * the object's directory. For instance, to make a plane work with a > + * CRTC, the user will add a symlink like so: > + * /config/vkms/card/planes/<plane>/possible_crtcs/<crtc_symlink> > + * > + * Objects may have files (in ConfigFS-speak, attributes) that allow > + * for additional configuration. For instance, a user can set the > + * plane type by writing the appropriate value to the "type" property > + * in the plane's directory. > + * > + * Once the driver is configured, the user can write a "1" to the > + * "is_registered" file/attribute in the driver's directory. Until a > + * virtual driver is registered, nothing DRM-related is set up. > + */ > + > +static struct config_item_type card_group_type; > +static struct config_item_type connectors_group_type; > +static struct config_item_type crtcs_group_type; > +static struct config_item_type encoders_group_type; > +static struct config_item_type planes_group_type; Could you reorder things to avoid these icky forward declarations? > + > +static void vkms_configfs_setup_default_groups(struct vkms_configfs *configfs, > + const char *name) > +{ > + config_group_init_type_name(&configfs->card_group, name, > + &card_group_type); > + > + config_group_init_type_name(&configfs->connectors_group, "connectors", > + &connectors_group_type); > + configfs_add_default_group(&configfs->connectors_group, > + &configfs->card_group); > + > + config_group_init_type_name(&configfs->crtcs_group, "crtcs", > + &crtcs_group_type); > + configfs_add_default_group(&configfs->crtcs_group, > + &configfs->card_group); > + > + config_group_init_type_name(&configfs->encoders_group, "encoders", > + &encoders_group_type); > + configfs_add_default_group(&configfs->encoders_group, > + &configfs->card_group); > + > + config_group_init_type_name(&configfs->planes_group, "planes", > + &planes_group_type); > + configfs_add_default_group(&configfs->planes_group, > + &configfs->card_group); > +} > + > +/* Root directory group and subsystem, e.g. /config/vkms/ */ > + > +static struct config_group *make_root_group(struct config_group *group, > + const char *name) > +{ > + struct vkms_configfs *configfs = > + kzalloc(sizeof(struct vkms_configfs), GFP_KERNEL); Nit: sizeof(*configfs) would be more compact. You could probably use devm_kzalloc if you passed in device to avoid the kfree in drop_root_group(). > + > + if (!configfs) > + return ERR_PTR(ENOMEM); > + > + vkms_configfs_setup_default_groups(configfs, name); > + > + return &configfs->card_group; > +} > + > +static void drop_root_group(struct config_group *group, > + struct config_item *item) > +{ > + struct vkms_configfs *configfs = item_to_configfs(item); > + > + if (configfs->card) > + vkms_card_destroy(configfs->card); > + > + kfree(configfs); > +} > + > +static struct configfs_group_operations root_group_ops = { > + .make_group = &make_root_group, > + .drop_item = &drop_root_group, > +}; > + > +static struct config_item_type vkms_type = { > + .ct_group_ops = &root_group_ops, > + .ct_owner = THIS_MODULE, > +}; > + > +static struct configfs_subsystem vkms_subsys = { > + .su_group = { > + .cg_item = { > + .ci_name = "vkms", > + .ci_type = &vkms_type, > + }, > + }, If you do the following you can remove the mutex_init() below: .su_mutex = __MUTEX_INITIALIZER(vkms_subsys.su_mutex), > +}; > + > +int vkms_init_configfs(void) > +{ > + config_group_init(&vkms_subsys.su_group); > + mutex_init(&vkms_subsys.su_mutex); > + return configfs_register_subsystem(&vkms_subsys); > +} > + > +void vkms_unregister_configfs(void) > +{ > + configfs_unregister_subsystem(&vkms_subsys); > +} > + > +/* > + * Common helpers (common sub-groups) > + */ > + > +/* Possible CRTCs, e.g. /config/vkms/card/<object>/possible_crtcs/<symlink> */ > + > +static struct config_item_type crtc_type; Nit: Same comment re: forward declaration (and below too, I'll stop mentioning it) > + > +static int possible_crtcs_allow_link(struct config_item *src, > + struct config_item *target) > +{ > + struct vkms_config_links *links = item_to_config_links(src); > + struct vkms_config_crtc *crtc; > + > + if (target->ci_type != &crtc_type) { > + DRM_ERROR("Unable to link non-CRTCs."); > + return -EINVAL; > + } > + > + crtc = item_to_config_crtc(target); > + > + if (links->linked_object_bitmap & (1 << crtc->crtc_config_idx)) { > + DRM_ERROR( > + "Tried to add two symlinks to the same CRTC from the same object"); > + return -EINVAL; > + } > + > + links->linked_object_bitmap |= 1 << crtc->crtc_config_idx; Nit: you can replace the shift with BIT(crtc->crtc_config_idx). Same comment elsewhere in the file. > + > + return 0; > +} > + > +static void possible_crtcs_drop_link(struct config_item *src, > + struct config_item *target) > +{ > + struct vkms_config_links *links = item_to_config_links(src); > + struct vkms_config_crtc *crtc = item_to_config_crtc(target); > + > + links->linked_object_bitmap &= ~(1 << crtc->crtc_config_idx); > +} > + > +static struct configfs_item_operations possible_crtcs_item_ops = { > + .allow_link = &possible_crtcs_allow_link, > + .drop_link = &possible_crtcs_drop_link, > +}; > + > +static struct config_item_type possible_crtcs_group_type = { > + .ct_item_ops = &possible_crtcs_item_ops, > + .ct_owner = THIS_MODULE, > +}; > + > +static void add_possible_crtcs(struct config_group *parent, > + struct config_group *possible_crtcs) > +{ > + config_group_init_type_name(possible_crtcs, "possible_crtcs", > + &possible_crtcs_group_type); > + configfs_add_default_group(possible_crtcs, parent); > +} > + > +/* Possible encoders, e.g. /config/vkms/card/connector/possible_encoders/<symlink> */ > + > +static struct config_item_type encoder_type; > + > +static int possible_encoders_allow_link(struct config_item *src, > + struct config_item *target) > +{ > + struct vkms_config_links *links = item_to_config_links(src); > + struct vkms_config_encoder *encoder; > + > + if (target->ci_type != &encoder_type) { > + DRM_ERROR("Unable to link non-encoders."); > + return -EINVAL; > + } > + > + encoder = item_to_config_encoder(target); > + > + if (links->linked_object_bitmap & (1 << encoder->encoder_config_idx)) { > + DRM_ERROR( > + "Tried to add two symlinks to the same encoder from the same object"); > + return -EINVAL; > + } > + > + links->linked_object_bitmap |= 1 << encoder->encoder_config_idx; > + > + return 0; > +} > + > +static void possible_encoders_drop_link(struct config_item *src, > + struct config_item *target) > +{ > + struct vkms_config_links *links = item_to_config_links(src); > + struct vkms_config_encoder *encoder = item_to_config_encoder(target); > + > + links->linked_object_bitmap &= ~(1 << encoder->encoder_config_idx); > +} > + > +static struct configfs_item_operations possible_encoders_item_ops = { > + .allow_link = &possible_encoders_allow_link, > + .drop_link = &possible_encoders_drop_link, > +}; > + > +static struct config_item_type possible_encoders_group_type = { > + .ct_item_ops = &possible_encoders_item_ops, > + .ct_owner = THIS_MODULE, > +}; > + > +static void add_possible_encoders(struct config_group *parent, > + struct config_group *possible_encoders) > +{ > + config_group_init_type_name(possible_encoders, "possible_encoders", > + &possible_encoders_group_type); > + configfs_add_default_group(possible_encoders, parent); > +} > + > +/* > + * Individual objects (connectors, crtcs, encoders, planes): > + */ > + > +/* Connector item, e.g. /config/vkms/card/connectors/ID */ > + > +static struct config_item_type connector_type = { > + .ct_owner = THIS_MODULE, > +}; > + > +/* Crtc item, e.g. /config/vkms/card/crtcs/ID */ > + > +static int crtc_allow_link(struct config_item *src, struct config_item *target) > +{ > + // TODO delete? Could you expand on this TODO? > + return 0; > +} > + > +static struct configfs_item_operations crtc_item_ops = { > + .allow_link = &crtc_allow_link, > +}; > + > +static struct config_item_type crtc_type = { > + .ct_item_ops = &crtc_item_ops, > + .ct_owner = THIS_MODULE, > +}; > + > +/* Encoder item, e.g. /config/vkms/card/encoder/ID */ > + > +static struct config_item_type encoder_type = { > + .ct_owner = THIS_MODULE, > +}; > + > +/* Plane item, e.g. /config/vkms/card/planes/ID */ > + > +static ssize_t plane_type_show(struct config_item *item, char *buf) > +{ > + struct vkms_config_plane *plane = item_to_config_plane(item); > + return sprintf(buf, "%u", plane->type); > +} > + > +static ssize_t plane_type_store(struct config_item *item, const char *buf, > + size_t len) > +{ > + struct vkms_config_plane *plane = item_to_config_plane(item); > + int val, ret; > + > + ret = kstrtouint(buf, 10, &val); > + if (ret) { > + return -ret; I think kstrtouint already returns negative errno. > + } Nit: Remove braces > + > + if (val != DRM_PLANE_TYPE_PRIMARY && val != DRM_PLANE_TYPE_CURSOR && > + val != DRM_PLANE_TYPE_OVERLAY) { > + return -EINVAL; > + } Nit: Here too > + > + plane->type = val; > + > + return len; > +} > + > +CONFIGFS_ATTR(plane_, type); > + > +static struct configfs_attribute *plane_attrs[] = { > + &plane_attr_type, > + NULL, > +}; > + > +static struct config_item_type plane_type = { > + .ct_attrs = plane_attrs, > + .ct_owner = THIS_MODULE, > +}; > + > +/* > + * Directory groups, e.g. /config/vkms/card/{planes, crtcs, ...} > + */ > + > +/* Connectors group: /config/vkms/card/connectors/ */ > + > +static struct config_group *connectors_group_make(struct config_group *group, > + const char *name) > +{ > + struct vkms_config_connector *connector = > + kzalloc(sizeof(struct vkms_config_connector), GFP_KERNEL); Nit: Add blank line here, use sizeof(*connector) and consider switching to devm_kzalloc. There might be other places I missed with this feedback. > + if (!connector) > + return ERR_PTR(ENOMEM); Can you please return negative errno? There are a few other places with positive ERR_PTR values which should be converted. > + > + config_group_init_type_name(&connector->config_group, name, > + &connector_type); > + add_possible_encoders(&connector->config_group, > + &connector->possible_encoders.group); > + > + return &connector->config_group; > +} > + > +static void connectors_group_drop(struct config_group *group, > + struct config_item *item) > +{ > + struct vkms_config_connector *connector = > + item_to_config_connector(item); Nit: Here too. > + kfree(connector); > +} > + > +static struct configfs_group_operations connectors_group_ops = { > + .make_group = &connectors_group_make, > + .drop_item = &connectors_group_drop, > +}; > + > +static struct config_item_type connectors_group_type = { > + .ct_group_ops = &connectors_group_ops, > + .ct_owner = THIS_MODULE, > +}; > + > +/* CRTCs group: /config/vkms/card/crtcs/ */ > + > +static struct config_group *crtcs_group_make(struct config_group *group, > + const char *name) > +{ > + struct vkms_configfs *configfs = > + container_of(group, struct vkms_configfs, crtcs_group); > + unsigned long next_idx = find_first_zero_bit(&configfs->allocated_crtcs, > + VKMS_MAX_OUTPUT_OBJECTS); > + struct vkms_config_crtc *crtc; > + > + if (next_idx == VKMS_MAX_OUTPUT_OBJECTS) { > + DRM_ERROR("Unable to allocate another CRTC."); > + return ERR_PTR(ENOMEM); > + } > + > + crtc = kzalloc(sizeof(struct vkms_config_crtc), GFP_KERNEL); > + if (!crtc) > + return ERR_PTR(ENOMEM); > + > + config_group_init_type_name(&crtc->config_group, name, &crtc_type); > + crtc->crtc_config_idx = next_idx; > + > + set_bit(next_idx, &configfs->allocated_crtcs); > + > + return &crtc->config_group; > +} > + > +static void crtcs_group_drop(struct config_group *group, > + struct config_item *item) > +{ > + struct vkms_config_crtc *crtc = item_to_config_crtc(item); > + kfree(crtc); > +} > + > +static struct configfs_group_operations crtcs_group_ops = { > + .make_group = &crtcs_group_make, > + .drop_item = &crtcs_group_drop, > +}; > + > +static struct config_item_type crtcs_group_type = { > + .ct_group_ops = &crtcs_group_ops, > + .ct_owner = THIS_MODULE, > +}; > + > +/* Encoders group: /config/vkms/card/encoders/ */ > + > +static struct config_group *encoders_group_make(struct config_group *group, > + const char *name) > +{ > + struct vkms_configfs *configfs = > + container_of(group, struct vkms_configfs, encoders_group); > + unsigned long next_idx = find_first_zero_bit( > + &configfs->allocated_encoders, VKMS_MAX_OUTPUT_OBJECTS); > + struct vkms_config_encoder *encoder; > + > + if (next_idx == VKMS_MAX_OUTPUT_OBJECTS) { > + DRM_ERROR("Unable to allocate another encoder."); > + return ERR_PTR(ENOMEM); > + } > + > + encoder = kzalloc(sizeof(struct vkms_config_encoder), GFP_KERNEL); > + if (!encoder) > + return ERR_PTR(ENOMEM); > + > + config_group_init_type_name(&encoder->config_group, name, > + &encoder_type); > + add_possible_crtcs(&encoder->config_group, > + &encoder->possible_crtcs.group); > + encoder->encoder_config_idx = next_idx; > + set_bit(next_idx, &configfs->allocated_encoders); > + > + return &encoder->config_group; > +} > + > +static void encoders_group_drop(struct config_group *group, > + struct config_item *item) > +{ > + struct vkms_config_encoder *encoder = item_to_config_encoder(item); > + kfree(encoder); > +} > + > +static struct configfs_group_operations encoders_group_ops = { > + .make_group = &encoders_group_make, > + .drop_item = &encoders_group_drop, > +}; > + > +static struct config_item_type encoders_group_type = { > + .ct_group_ops = &encoders_group_ops, > + .ct_owner = THIS_MODULE, > +}; > + > +/* Planes group: /config/vkms/card/planes/ */ > + > +static struct config_group *make_plane_group(struct config_group *group, > + const char *name) > +{ > + struct vkms_config_plane *plane = > + kzalloc(sizeof(struct vkms_config_plane), GFP_KERNEL); > + if (!plane) > + return ERR_PTR(ENOMEM); > + > + config_group_init_type_name(&plane->config_group, name, &plane_type); > + add_possible_crtcs(&plane->config_group, &plane->possible_crtcs.group); > + > + return &plane->config_group; > +} > + > +static void drop_plane_group(struct config_group *group, > + struct config_item *item) > +{ > + struct vkms_config_plane *plane = item_to_config_plane(item); > + kfree(plane); > +} > + > +static struct configfs_group_operations plane_group_ops = { > + .make_group = &make_plane_group, > + .drop_item = &drop_plane_group, > +}; > + > +static struct config_item_type planes_group_type = { > + .ct_group_ops = &plane_group_ops, > + .ct_owner = THIS_MODULE, > +}; > + > +/* Root directory group, e.g. /config/vkms/card */ > + > +static ssize_t card_is_registered_show(struct config_item *item, char *buf) > +{ > + struct vkms_configfs *configfs = item_to_configfs(item); > + return sprintf(buf, "%d", configfs->card != NULL); > +} > + > +static ssize_t card_is_registered_store(struct config_item *item, > + const char *buf, size_t len) > +{ > + struct vkms_configfs *configfs = item_to_configfs(item); > + struct vkms_card *card; > + int value, ret; > + > + ret = kstrtoint(buf, 0, &value); > + if (ret) > + return ret; > + > + if (value != 1) > + return -EINVAL; > + > + if (configfs->card) > + return len; > + > + card = vkms_card_init(item->ci_name, configfs); > + if (IS_ERR(card)) > + return -PTR_ERR(card); I just realized that vkms_card_init() returns a combination of positive and negative errnos (encoded as PTR). We'll probably want to convert all of those to negative errnos and return PTR_ERR(card) here. Generally speaking, everything should return negative errno on error. > + > + return len; > +} > + > +CONFIGFS_ATTR(card_, is_registered); > + > +static struct configfs_attribute *card_group_attrs[] = { > + &card_attr_is_registered, > + NULL, > +}; > + > +static struct config_item_type card_group_type = { > + .ct_attrs = card_group_attrs, > + .ct_owner = THIS_MODULE, > +}; > diff --git a/drivers/gpu/drm/vkms/vkms_drv.c b/drivers/gpu/drm/vkms/vkms_drv.c > index 266c9f643f70..37b95ca28672 100644 > --- a/drivers/gpu/drm/vkms/vkms_drv.c > +++ b/drivers/gpu/drm/vkms/vkms_drv.c > @@ -9,6 +9,9 @@ > * the GPU in DRM API tests. > */ > > +#include <linux/configfs.h> > +#include <linux/device.h> > +#include <linux/dma-mapping.h> > #include <linux/kernel.h> > #include <linux/module.h> > #include <linux/platform_device.h> > @@ -152,7 +155,7 @@ static int vkms_modeset_init(struct vkms_card *card) > dev->mode_config.preferred_depth = 0; > dev->mode_config.helper_private = &vkms_mode_config_helpers; > > - return card->is_default ? vkms_output_init_default(card, 0) : -ENOTSUPP; > + return card->is_default ? vkms_output_init_default(card, 0) : vkms_output_init(card, 0); > } > > static void vkms_device_destroy(void) > @@ -166,7 +169,7 @@ static void vkms_device_destroy(void) > memset(&vkms_device, 0, sizeof(struct vkms_device)); > } > > -struct vkms_card *vkms_card_init(const char *name, bool is_default) > +struct vkms_card *vkms_card_init(const char *name, struct vkms_configfs *configfs) > { > char unique_name[64] = { 0 }; > struct platform_device *pdev; > @@ -190,7 +193,7 @@ struct vkms_card *vkms_card_init(const char *name, bool is_default) > ret = ENOMEM; > goto out_platform_device; > } > - > + Nit: Trailing whitespace introduction? > card = devm_drm_dev_alloc(&pdev->dev, &vkms_driver, struct vkms_card, > drm); > if (IS_ERR(card)) { > @@ -202,7 +205,8 @@ struct vkms_card *vkms_card_init(const char *name, bool is_default) > card->platform = pdev; > card->drm.unique = card->name_buf; > card->vkms_device = &vkms_device; > - card->is_default = is_default; > + card->configfs = configfs; > + card->is_default = configfs == NULL; IMO we should get rid of is_default and just check !configfs if they're equivalent. > card->is_registered = false; > card->resource_group_id = grp; > > @@ -235,7 +239,10 @@ struct vkms_card *vkms_card_init(const char *name, bool is_default) > > devres_close_group(&pdev->dev, grp); > list_add_tail(&card->node, &vkms_device.cards); > - > + > + if (configfs) > + configfs->card = card; > + > return card; > > out_release_group: > @@ -260,16 +267,24 @@ void vkms_card_destroy(struct vkms_card *card) > static int __init vkms_init(void) > { > struct vkms_card *card; > + int ret; > > vkms_device.config.cursor = enable_cursor; > vkms_device.config.writeback = enable_writeback; > vkms_device.config.overlay = enable_overlay; > INIT_LIST_HEAD(&vkms_device.cards); > + > + ret = vkms_init_configfs(); > + if (ret) { > + DRM_ERROR("Unable to initialize configfs\n"); > + return ret; > + } > > card = vkms_card_init("default", /* configfs */ NULL); > if (IS_ERR(card)) { > - DRM_ERROR("Unable to init default card"); > + DRM_ERROR("Unable to init default card\n"); Does this belong in an earlier change? > vkms_device_destroy(); > + vkms_unregister_configfs(); vkms_unregister_configfs() always directly follows vkms_device_destroy(), seems like it could just be called from destroy? > return PTR_ERR(card); > } > > @@ -279,6 +294,7 @@ static int __init vkms_init(void) > static void __exit vkms_exit(void) > { > vkms_device_destroy(); > + vkms_unregister_configfs(); > } > > module_init(vkms_init); > diff --git a/drivers/gpu/drm/vkms/vkms_drv.h b/drivers/gpu/drm/vkms/vkms_drv.h > index 30ae06d7af71..f43e4c563863 100644 > --- a/drivers/gpu/drm/vkms/vkms_drv.h > +++ b/drivers/gpu/drm/vkms/vkms_drv.h > @@ -3,6 +3,7 @@ > #ifndef _VKMS_DRV_H_ > #define _VKMS_DRV_H_ > > +#include <linux/configfs.h> > #include <linux/hrtimer.h> > #include <linux/kernel.h> > > @@ -10,6 +11,7 @@ > #include <drm/drm_gem.h> > #include <drm/drm_gem_atomic_helper.h> > #include <drm/drm_encoder.h> > +#include <drm/drm_plane.h> > #include <drm/drm_writeback.h> > > #define XRES_MIN 20 > @@ -116,11 +118,59 @@ struct vkms_config { > bool overlay; > }; > > +struct vkms_config_links { > + struct config_group group; > + unsigned long linked_object_bitmap; > +}; > + > +struct vkms_config_connector { > + struct config_group config_group; > + struct vkms_config_links possible_encoders; > +}; > + > +struct vkms_config_crtc { > + struct config_group config_group; > + unsigned long crtc_config_idx; > +}; > + > +struct vkms_config_encoder { > + struct config_group config_group; > + struct vkms_config_links possible_crtcs; > + unsigned long encoder_config_idx; > +}; > + > +struct vkms_config_plane { > + struct config_group config_group; > + struct vkms_config_links possible_crtcs; > + enum drm_plane_type type; > +}; > + > +struct vkms_card; > + > +struct vkms_configfs { > + /* Directory group containing connector configs, e.g. /config/vkms/card/ */ > + struct config_group card_group; > + /* Directory group containing connector configs, e.g. /config/vkms/card/connectors/ */ > + struct config_group connectors_group; > + /* Directory group containing CRTC configs, e.g. /config/vkms/card/crtcs/ */ > + struct config_group crtcs_group; > + /* Directory group containing encoder configs, e.g. /config/vkms/card/encoders/ */ > + struct config_group encoders_group; > + /* Directory group containing plane configs, e.g. /config/vkms/card/planes/ */ > + struct config_group planes_group; > + > + unsigned long allocated_crtcs; > + unsigned long allocated_encoders; For bitmasks you probably want to explicitly specify their length by using u32/u64 types. This probably applies elsewhere too. > + > + struct vkms_card *card; > +}; > + > struct vkms_card { > struct platform_device *platform; > struct drm_device drm; > struct list_head node; > struct vkms_output output; > + struct vkms_configfs *configfs; > struct vkms_device *vkms_device; > /* storage for the value of drm->unique, giving this dev a unique busid */ > char name_buf[64]; > @@ -149,8 +199,27 @@ struct vkms_device { > #define to_vkms_plane_state(target)\ > container_of(target, struct vkms_plane_state, base.base) > > +#define item_to_configfs(item)\ > + container_of(to_config_group(item), struct vkms_configfs, card_group) > + > +#define item_to_config_connector(item)\ > + container_of(to_config_group(item), struct vkms_config_connector, config_group) > + > +#define item_to_config_crtc(item) \ > + container_of(to_config_group(item), struct vkms_config_crtc, config_group) > + > +#define item_to_config_encoder(item) \ > + container_of(to_config_group(item), struct vkms_config_encoder, config_group) > + > +#define item_to_config_plane(item) \ > + container_of(to_config_group(item), struct vkms_config_plane, config_group) > + > +#define item_to_config_links(item) \ > + container_of(to_config_group(item), struct vkms_config_links, group) > + > /* Cards */ > -struct vkms_card *vkms_card_init(const char *name, bool is_default); > +struct vkms_card *vkms_card_init(const char *name, > + struct vkms_configfs *configfs); > void vkms_card_destroy(struct vkms_card *card); > > /* CRTC */ > @@ -176,4 +245,8 @@ void vkms_set_composer(struct vkms_crtc *vkms_crtc, bool enabled); > /* Writeback */ > int vkms_enable_writeback_connector(struct vkms_card *card, struct vkms_crtc *vkms_crtc); > > +/* ConfigFS Support */ > +int vkms_init_configfs(void); > +void vkms_unregister_configfs(void); > + > #endif /* _VKMS_DRV_H_ */ > diff --git a/drivers/gpu/drm/vkms/vkms_output.c b/drivers/gpu/drm/vkms/vkms_output.c > index 2b72d8e763a8..e343a9c1f311 100644 > --- a/drivers/gpu/drm/vkms/vkms_output.c > +++ b/drivers/gpu/drm/vkms/vkms_output.c > @@ -1,10 +1,14 @@ > // SPDX-License-Identifier: GPL-2.0+ > > -#include "vkms_drv.h" > +#include <linux/configfs.h> > +#include <linux/kernel.h> > + > #include <drm/drm_atomic_helper.h> > #include <drm/drm_probe_helper.h> > #include <drm/drm_simple_kms_helper.h> > > +#include "vkms_drv.h" > + > static void vkms_connector_destroy(struct drm_connector *connector) > { > drm_connector_cleanup(connector); > @@ -171,3 +175,8 @@ int vkms_output_init_default(struct vkms_card *card, int index) > > return ret; > } > + > +int vkms_output_init(struct vkms_card *card, int index) > +{ > + return -ENOTSUPP; > +} I think you can drop this from the patch and introduce it when it's useful. > -- > 2.37.1.359.gd136c6c3e2-goog >
diff --git a/Documentation/gpu/vkms.rst b/Documentation/gpu/vkms.rst index 9c873c3912cc..f5f8ea0de5bc 100644 --- a/Documentation/gpu/vkms.rst +++ b/Documentation/gpu/vkms.rst @@ -51,6 +51,82 @@ To disable the driver, use :: sudo modprobe -r vkms +Configuration With ConfigFS +=========================== + +VKMS is instrumented with support for configuration via `ConfigFS`. With VKMS +installed, you can mount ConfigFS at /config/ like so:: + + mkdir -p /config/ + sudo mount -t configfs none /config + +This allows you to configure multiple virtual cards in addition to an immutable +"default" card created by the driver at initialization time. + +To set up a new card, create a new directory under the vkms configfs +directory:: + + $ mkdir /config/vkms/test + +With your card created you'll find an new directory ready to be configured:: + + /config + `-- vkms + |-- default + | `-- is_registered + `-- test + |-- connectors + |-- crtcs + |-- encoders + |-- planes + `-- is_registered + +Each directory you add within the connectors, crtcs, encoders, and planes +directories will let you configure a new object of that type. Adding new +objects will automatically create a set of default files and folders you can +use to configure that object. + +For instance, we can set up a very basic driver like so:: + + DRM_PLANE_TYPE_PRIMARY=1 + DRM_PLANE_TYPE_CURSOR=2 + DRM_PLANE_TYPE_OVERLAY=0 + + mkdir /config/vkms/test/planes/primary + echo $DRM_PLANE_TYPE_PRIMARY > /config/vkms/test/planes/primary/type + + mkdir /config/vkms/test/planes/other_primary + echo $DRM_PLANE_TYPE_PRIMARY > /config/vkms/test/planes/other_primary/type + + mkdir /config/vkms/test/planes/cursor + echo $DRM_PLANE_TYPE_CURSOR > /config/vkms/test/planes/cursor/type + + mkdir /config/vkms/test/planes/overlay + echo $DRM_PLANE_TYPE_OVERLAY > /config/vkms/test/planes/overlay/type + + mkdir /config/vkms/test/crtcs/crtc + mkdir /config/vkms/test/crtcs/crtc_other + mkdir /config/vkms/test/encoders/encoder + mkdir /config/vkms/test/connectors/connector + + ln -s /config/vkms/test/encoders/encoder /config/vkms/test/connectors/connector/possible_encoders + ln -s /config/vkms/test/crtcs/crtc /config/vkms/test/encoders/encoder/possible_crtcs/ + ln -s /config/vkms/test/crtcs/crtc /config/vkms/test/planes/primary/possible_crtcs/ + ln -s /config/vkms/test/crtcs/crtc /config/vkms/test/planes/cursor/possible_crtcs/ + ln -s /config/vkms/test/crtcs/crtc /config/vkms/test/planes/overlay/possible_crtcs/ + ln -s /config/vkms/test/crtcs/crtc_other /config/vkms/test/planes/overlay/possible_crtcs/ + +You can see that specific attributes, such as `.../<plane>/type`, can be +configured by writing into them. Associating objects together can be done via +symlinks. + +Finally, to register your newly configured objects with DRM so you can use your +virtual device, all you need to do is write `1` into the special file +`/config/vkms/test/is_registered``, which will return non-zero on error. + +When you're done with the virtual card, all you need to do is `rmdir` the root +directory. + Testing With IGT ================ diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig index f1422bee3dcc..5c90c82fab6d 100644 --- a/drivers/gpu/drm/Kconfig +++ b/drivers/gpu/drm/Kconfig @@ -307,6 +307,7 @@ config DRM_VKMS depends on DRM && MMU select DRM_KMS_HELPER select DRM_GEM_SHMEM_HELPER + select CONFIGFS_FS select CRC32 default n help diff --git a/drivers/gpu/drm/vkms/Makefile b/drivers/gpu/drm/vkms/Makefile index 72f779cbfedd..3efb7b0f5319 100644 --- a/drivers/gpu/drm/vkms/Makefile +++ b/drivers/gpu/drm/vkms/Makefile @@ -3,6 +3,7 @@ vkms-y := \ vkms_drv.o \ vkms_plane.o \ vkms_output.o \ + vkms_configfs.o \ vkms_crtc.o \ vkms_composer.o \ vkms_writeback.o diff --git a/drivers/gpu/drm/vkms/vkms_configfs.c b/drivers/gpu/drm/vkms/vkms_configfs.c new file mode 100644 index 000000000000..fa0d8700258e --- /dev/null +++ b/drivers/gpu/drm/vkms/vkms_configfs.c @@ -0,0 +1,527 @@ +// SPDX-License-Identifier: GPL-2.0+ + +#include <linux/configfs.h> +#include <linux/kernel.h> +#include <linux/mutex.h> + +#include <drm/drm_plane.h> +#include <drm/drm_print.h> + +#include "vkms_drv.h" + +/** + * DOC: ConfigFS Support for VKMS + * + * When ConfigFS is mounted, say at /config/, we add a /config/vkms/ + * directory. Each folder in this directory represents a different + * virtual driver. Drivers can be "registered", meaning that they're + * available to use as a DRM driver. Initially, this just contains a + * registered "default" device. + * + * Users can mkdir in this the VKMS directory to begin the process of + * configuring a new device. Users can mkdir in the automatically + * created "connectors", "crtcs", "encoders", and "planes" folders to + * set up those objects. + * + * In order to create associations between objects, users can symlink + * the object's directory. For instance, to make a plane work with a + * CRTC, the user will add a symlink like so: + * /config/vkms/card/planes/<plane>/possible_crtcs/<crtc_symlink> + * + * Objects may have files (in ConfigFS-speak, attributes) that allow + * for additional configuration. For instance, a user can set the + * plane type by writing the appropriate value to the "type" property + * in the plane's directory. + * + * Once the driver is configured, the user can write a "1" to the + * "is_registered" file/attribute in the driver's directory. Until a + * virtual driver is registered, nothing DRM-related is set up. + */ + +static struct config_item_type card_group_type; +static struct config_item_type connectors_group_type; +static struct config_item_type crtcs_group_type; +static struct config_item_type encoders_group_type; +static struct config_item_type planes_group_type; + +static void vkms_configfs_setup_default_groups(struct vkms_configfs *configfs, + const char *name) +{ + config_group_init_type_name(&configfs->card_group, name, + &card_group_type); + + config_group_init_type_name(&configfs->connectors_group, "connectors", + &connectors_group_type); + configfs_add_default_group(&configfs->connectors_group, + &configfs->card_group); + + config_group_init_type_name(&configfs->crtcs_group, "crtcs", + &crtcs_group_type); + configfs_add_default_group(&configfs->crtcs_group, + &configfs->card_group); + + config_group_init_type_name(&configfs->encoders_group, "encoders", + &encoders_group_type); + configfs_add_default_group(&configfs->encoders_group, + &configfs->card_group); + + config_group_init_type_name(&configfs->planes_group, "planes", + &planes_group_type); + configfs_add_default_group(&configfs->planes_group, + &configfs->card_group); +} + +/* Root directory group and subsystem, e.g. /config/vkms/ */ + +static struct config_group *make_root_group(struct config_group *group, + const char *name) +{ + struct vkms_configfs *configfs = + kzalloc(sizeof(struct vkms_configfs), GFP_KERNEL); + + if (!configfs) + return ERR_PTR(ENOMEM); + + vkms_configfs_setup_default_groups(configfs, name); + + return &configfs->card_group; +} + +static void drop_root_group(struct config_group *group, + struct config_item *item) +{ + struct vkms_configfs *configfs = item_to_configfs(item); + + if (configfs->card) + vkms_card_destroy(configfs->card); + + kfree(configfs); +} + +static struct configfs_group_operations root_group_ops = { + .make_group = &make_root_group, + .drop_item = &drop_root_group, +}; + +static struct config_item_type vkms_type = { + .ct_group_ops = &root_group_ops, + .ct_owner = THIS_MODULE, +}; + +static struct configfs_subsystem vkms_subsys = { + .su_group = { + .cg_item = { + .ci_name = "vkms", + .ci_type = &vkms_type, + }, + }, +}; + +int vkms_init_configfs(void) +{ + config_group_init(&vkms_subsys.su_group); + mutex_init(&vkms_subsys.su_mutex); + return configfs_register_subsystem(&vkms_subsys); +} + +void vkms_unregister_configfs(void) +{ + configfs_unregister_subsystem(&vkms_subsys); +} + +/* + * Common helpers (common sub-groups) + */ + +/* Possible CRTCs, e.g. /config/vkms/card/<object>/possible_crtcs/<symlink> */ + +static struct config_item_type crtc_type; + +static int possible_crtcs_allow_link(struct config_item *src, + struct config_item *target) +{ + struct vkms_config_links *links = item_to_config_links(src); + struct vkms_config_crtc *crtc; + + if (target->ci_type != &crtc_type) { + DRM_ERROR("Unable to link non-CRTCs."); + return -EINVAL; + } + + crtc = item_to_config_crtc(target); + + if (links->linked_object_bitmap & (1 << crtc->crtc_config_idx)) { + DRM_ERROR( + "Tried to add two symlinks to the same CRTC from the same object"); + return -EINVAL; + } + + links->linked_object_bitmap |= 1 << crtc->crtc_config_idx; + + return 0; +} + +static void possible_crtcs_drop_link(struct config_item *src, + struct config_item *target) +{ + struct vkms_config_links *links = item_to_config_links(src); + struct vkms_config_crtc *crtc = item_to_config_crtc(target); + + links->linked_object_bitmap &= ~(1 << crtc->crtc_config_idx); +} + +static struct configfs_item_operations possible_crtcs_item_ops = { + .allow_link = &possible_crtcs_allow_link, + .drop_link = &possible_crtcs_drop_link, +}; + +static struct config_item_type possible_crtcs_group_type = { + .ct_item_ops = &possible_crtcs_item_ops, + .ct_owner = THIS_MODULE, +}; + +static void add_possible_crtcs(struct config_group *parent, + struct config_group *possible_crtcs) +{ + config_group_init_type_name(possible_crtcs, "possible_crtcs", + &possible_crtcs_group_type); + configfs_add_default_group(possible_crtcs, parent); +} + +/* Possible encoders, e.g. /config/vkms/card/connector/possible_encoders/<symlink> */ + +static struct config_item_type encoder_type; + +static int possible_encoders_allow_link(struct config_item *src, + struct config_item *target) +{ + struct vkms_config_links *links = item_to_config_links(src); + struct vkms_config_encoder *encoder; + + if (target->ci_type != &encoder_type) { + DRM_ERROR("Unable to link non-encoders."); + return -EINVAL; + } + + encoder = item_to_config_encoder(target); + + if (links->linked_object_bitmap & (1 << encoder->encoder_config_idx)) { + DRM_ERROR( + "Tried to add two symlinks to the same encoder from the same object"); + return -EINVAL; + } + + links->linked_object_bitmap |= 1 << encoder->encoder_config_idx; + + return 0; +} + +static void possible_encoders_drop_link(struct config_item *src, + struct config_item *target) +{ + struct vkms_config_links *links = item_to_config_links(src); + struct vkms_config_encoder *encoder = item_to_config_encoder(target); + + links->linked_object_bitmap &= ~(1 << encoder->encoder_config_idx); +} + +static struct configfs_item_operations possible_encoders_item_ops = { + .allow_link = &possible_encoders_allow_link, + .drop_link = &possible_encoders_drop_link, +}; + +static struct config_item_type possible_encoders_group_type = { + .ct_item_ops = &possible_encoders_item_ops, + .ct_owner = THIS_MODULE, +}; + +static void add_possible_encoders(struct config_group *parent, + struct config_group *possible_encoders) +{ + config_group_init_type_name(possible_encoders, "possible_encoders", + &possible_encoders_group_type); + configfs_add_default_group(possible_encoders, parent); +} + +/* + * Individual objects (connectors, crtcs, encoders, planes): + */ + +/* Connector item, e.g. /config/vkms/card/connectors/ID */ + +static struct config_item_type connector_type = { + .ct_owner = THIS_MODULE, +}; + +/* Crtc item, e.g. /config/vkms/card/crtcs/ID */ + +static int crtc_allow_link(struct config_item *src, struct config_item *target) +{ + // TODO delete? + return 0; +} + +static struct configfs_item_operations crtc_item_ops = { + .allow_link = &crtc_allow_link, +}; + +static struct config_item_type crtc_type = { + .ct_item_ops = &crtc_item_ops, + .ct_owner = THIS_MODULE, +}; + +/* Encoder item, e.g. /config/vkms/card/encoder/ID */ + +static struct config_item_type encoder_type = { + .ct_owner = THIS_MODULE, +}; + +/* Plane item, e.g. /config/vkms/card/planes/ID */ + +static ssize_t plane_type_show(struct config_item *item, char *buf) +{ + struct vkms_config_plane *plane = item_to_config_plane(item); + return sprintf(buf, "%u", plane->type); +} + +static ssize_t plane_type_store(struct config_item *item, const char *buf, + size_t len) +{ + struct vkms_config_plane *plane = item_to_config_plane(item); + int val, ret; + + ret = kstrtouint(buf, 10, &val); + if (ret) { + return -ret; + } + + if (val != DRM_PLANE_TYPE_PRIMARY && val != DRM_PLANE_TYPE_CURSOR && + val != DRM_PLANE_TYPE_OVERLAY) { + return -EINVAL; + } + + plane->type = val; + + return len; +} + +CONFIGFS_ATTR(plane_, type); + +static struct configfs_attribute *plane_attrs[] = { + &plane_attr_type, + NULL, +}; + +static struct config_item_type plane_type = { + .ct_attrs = plane_attrs, + .ct_owner = THIS_MODULE, +}; + +/* + * Directory groups, e.g. /config/vkms/card/{planes, crtcs, ...} + */ + +/* Connectors group: /config/vkms/card/connectors/ */ + +static struct config_group *connectors_group_make(struct config_group *group, + const char *name) +{ + struct vkms_config_connector *connector = + kzalloc(sizeof(struct vkms_config_connector), GFP_KERNEL); + if (!connector) + return ERR_PTR(ENOMEM); + + config_group_init_type_name(&connector->config_group, name, + &connector_type); + add_possible_encoders(&connector->config_group, + &connector->possible_encoders.group); + + return &connector->config_group; +} + +static void connectors_group_drop(struct config_group *group, + struct config_item *item) +{ + struct vkms_config_connector *connector = + item_to_config_connector(item); + kfree(connector); +} + +static struct configfs_group_operations connectors_group_ops = { + .make_group = &connectors_group_make, + .drop_item = &connectors_group_drop, +}; + +static struct config_item_type connectors_group_type = { + .ct_group_ops = &connectors_group_ops, + .ct_owner = THIS_MODULE, +}; + +/* CRTCs group: /config/vkms/card/crtcs/ */ + +static struct config_group *crtcs_group_make(struct config_group *group, + const char *name) +{ + struct vkms_configfs *configfs = + container_of(group, struct vkms_configfs, crtcs_group); + unsigned long next_idx = find_first_zero_bit(&configfs->allocated_crtcs, + VKMS_MAX_OUTPUT_OBJECTS); + struct vkms_config_crtc *crtc; + + if (next_idx == VKMS_MAX_OUTPUT_OBJECTS) { + DRM_ERROR("Unable to allocate another CRTC."); + return ERR_PTR(ENOMEM); + } + + crtc = kzalloc(sizeof(struct vkms_config_crtc), GFP_KERNEL); + if (!crtc) + return ERR_PTR(ENOMEM); + + config_group_init_type_name(&crtc->config_group, name, &crtc_type); + crtc->crtc_config_idx = next_idx; + + set_bit(next_idx, &configfs->allocated_crtcs); + + return &crtc->config_group; +} + +static void crtcs_group_drop(struct config_group *group, + struct config_item *item) +{ + struct vkms_config_crtc *crtc = item_to_config_crtc(item); + kfree(crtc); +} + +static struct configfs_group_operations crtcs_group_ops = { + .make_group = &crtcs_group_make, + .drop_item = &crtcs_group_drop, +}; + +static struct config_item_type crtcs_group_type = { + .ct_group_ops = &crtcs_group_ops, + .ct_owner = THIS_MODULE, +}; + +/* Encoders group: /config/vkms/card/encoders/ */ + +static struct config_group *encoders_group_make(struct config_group *group, + const char *name) +{ + struct vkms_configfs *configfs = + container_of(group, struct vkms_configfs, encoders_group); + unsigned long next_idx = find_first_zero_bit( + &configfs->allocated_encoders, VKMS_MAX_OUTPUT_OBJECTS); + struct vkms_config_encoder *encoder; + + if (next_idx == VKMS_MAX_OUTPUT_OBJECTS) { + DRM_ERROR("Unable to allocate another encoder."); + return ERR_PTR(ENOMEM); + } + + encoder = kzalloc(sizeof(struct vkms_config_encoder), GFP_KERNEL); + if (!encoder) + return ERR_PTR(ENOMEM); + + config_group_init_type_name(&encoder->config_group, name, + &encoder_type); + add_possible_crtcs(&encoder->config_group, + &encoder->possible_crtcs.group); + encoder->encoder_config_idx = next_idx; + set_bit(next_idx, &configfs->allocated_encoders); + + return &encoder->config_group; +} + +static void encoders_group_drop(struct config_group *group, + struct config_item *item) +{ + struct vkms_config_encoder *encoder = item_to_config_encoder(item); + kfree(encoder); +} + +static struct configfs_group_operations encoders_group_ops = { + .make_group = &encoders_group_make, + .drop_item = &encoders_group_drop, +}; + +static struct config_item_type encoders_group_type = { + .ct_group_ops = &encoders_group_ops, + .ct_owner = THIS_MODULE, +}; + +/* Planes group: /config/vkms/card/planes/ */ + +static struct config_group *make_plane_group(struct config_group *group, + const char *name) +{ + struct vkms_config_plane *plane = + kzalloc(sizeof(struct vkms_config_plane), GFP_KERNEL); + if (!plane) + return ERR_PTR(ENOMEM); + + config_group_init_type_name(&plane->config_group, name, &plane_type); + add_possible_crtcs(&plane->config_group, &plane->possible_crtcs.group); + + return &plane->config_group; +} + +static void drop_plane_group(struct config_group *group, + struct config_item *item) +{ + struct vkms_config_plane *plane = item_to_config_plane(item); + kfree(plane); +} + +static struct configfs_group_operations plane_group_ops = { + .make_group = &make_plane_group, + .drop_item = &drop_plane_group, +}; + +static struct config_item_type planes_group_type = { + .ct_group_ops = &plane_group_ops, + .ct_owner = THIS_MODULE, +}; + +/* Root directory group, e.g. /config/vkms/card */ + +static ssize_t card_is_registered_show(struct config_item *item, char *buf) +{ + struct vkms_configfs *configfs = item_to_configfs(item); + return sprintf(buf, "%d", configfs->card != NULL); +} + +static ssize_t card_is_registered_store(struct config_item *item, + const char *buf, size_t len) +{ + struct vkms_configfs *configfs = item_to_configfs(item); + struct vkms_card *card; + int value, ret; + + ret = kstrtoint(buf, 0, &value); + if (ret) + return ret; + + if (value != 1) + return -EINVAL; + + if (configfs->card) + return len; + + card = vkms_card_init(item->ci_name, configfs); + if (IS_ERR(card)) + return -PTR_ERR(card); + + return len; +} + +CONFIGFS_ATTR(card_, is_registered); + +static struct configfs_attribute *card_group_attrs[] = { + &card_attr_is_registered, + NULL, +}; + +static struct config_item_type card_group_type = { + .ct_attrs = card_group_attrs, + .ct_owner = THIS_MODULE, +}; diff --git a/drivers/gpu/drm/vkms/vkms_drv.c b/drivers/gpu/drm/vkms/vkms_drv.c index 266c9f643f70..37b95ca28672 100644 --- a/drivers/gpu/drm/vkms/vkms_drv.c +++ b/drivers/gpu/drm/vkms/vkms_drv.c @@ -9,6 +9,9 @@ * the GPU in DRM API tests. */ +#include <linux/configfs.h> +#include <linux/device.h> +#include <linux/dma-mapping.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/platform_device.h> @@ -152,7 +155,7 @@ static int vkms_modeset_init(struct vkms_card *card) dev->mode_config.preferred_depth = 0; dev->mode_config.helper_private = &vkms_mode_config_helpers; - return card->is_default ? vkms_output_init_default(card, 0) : -ENOTSUPP; + return card->is_default ? vkms_output_init_default(card, 0) : vkms_output_init(card, 0); } static void vkms_device_destroy(void) @@ -166,7 +169,7 @@ static void vkms_device_destroy(void) memset(&vkms_device, 0, sizeof(struct vkms_device)); } -struct vkms_card *vkms_card_init(const char *name, bool is_default) +struct vkms_card *vkms_card_init(const char *name, struct vkms_configfs *configfs) { char unique_name[64] = { 0 }; struct platform_device *pdev; @@ -190,7 +193,7 @@ struct vkms_card *vkms_card_init(const char *name, bool is_default) ret = ENOMEM; goto out_platform_device; } - + card = devm_drm_dev_alloc(&pdev->dev, &vkms_driver, struct vkms_card, drm); if (IS_ERR(card)) { @@ -202,7 +205,8 @@ struct vkms_card *vkms_card_init(const char *name, bool is_default) card->platform = pdev; card->drm.unique = card->name_buf; card->vkms_device = &vkms_device; - card->is_default = is_default; + card->configfs = configfs; + card->is_default = configfs == NULL; card->is_registered = false; card->resource_group_id = grp; @@ -235,7 +239,10 @@ struct vkms_card *vkms_card_init(const char *name, bool is_default) devres_close_group(&pdev->dev, grp); list_add_tail(&card->node, &vkms_device.cards); - + + if (configfs) + configfs->card = card; + return card; out_release_group: @@ -260,16 +267,24 @@ void vkms_card_destroy(struct vkms_card *card) static int __init vkms_init(void) { struct vkms_card *card; + int ret; vkms_device.config.cursor = enable_cursor; vkms_device.config.writeback = enable_writeback; vkms_device.config.overlay = enable_overlay; INIT_LIST_HEAD(&vkms_device.cards); + + ret = vkms_init_configfs(); + if (ret) { + DRM_ERROR("Unable to initialize configfs\n"); + return ret; + } card = vkms_card_init("default", /* configfs */ NULL); if (IS_ERR(card)) { - DRM_ERROR("Unable to init default card"); + DRM_ERROR("Unable to init default card\n"); vkms_device_destroy(); + vkms_unregister_configfs(); return PTR_ERR(card); } @@ -279,6 +294,7 @@ static int __init vkms_init(void) static void __exit vkms_exit(void) { vkms_device_destroy(); + vkms_unregister_configfs(); } module_init(vkms_init); diff --git a/drivers/gpu/drm/vkms/vkms_drv.h b/drivers/gpu/drm/vkms/vkms_drv.h index 30ae06d7af71..f43e4c563863 100644 --- a/drivers/gpu/drm/vkms/vkms_drv.h +++ b/drivers/gpu/drm/vkms/vkms_drv.h @@ -3,6 +3,7 @@ #ifndef _VKMS_DRV_H_ #define _VKMS_DRV_H_ +#include <linux/configfs.h> #include <linux/hrtimer.h> #include <linux/kernel.h> @@ -10,6 +11,7 @@ #include <drm/drm_gem.h> #include <drm/drm_gem_atomic_helper.h> #include <drm/drm_encoder.h> +#include <drm/drm_plane.h> #include <drm/drm_writeback.h> #define XRES_MIN 20 @@ -116,11 +118,59 @@ struct vkms_config { bool overlay; }; +struct vkms_config_links { + struct config_group group; + unsigned long linked_object_bitmap; +}; + +struct vkms_config_connector { + struct config_group config_group; + struct vkms_config_links possible_encoders; +}; + +struct vkms_config_crtc { + struct config_group config_group; + unsigned long crtc_config_idx; +}; + +struct vkms_config_encoder { + struct config_group config_group; + struct vkms_config_links possible_crtcs; + unsigned long encoder_config_idx; +}; + +struct vkms_config_plane { + struct config_group config_group; + struct vkms_config_links possible_crtcs; + enum drm_plane_type type; +}; + +struct vkms_card; + +struct vkms_configfs { + /* Directory group containing connector configs, e.g. /config/vkms/card/ */ + struct config_group card_group; + /* Directory group containing connector configs, e.g. /config/vkms/card/connectors/ */ + struct config_group connectors_group; + /* Directory group containing CRTC configs, e.g. /config/vkms/card/crtcs/ */ + struct config_group crtcs_group; + /* Directory group containing encoder configs, e.g. /config/vkms/card/encoders/ */ + struct config_group encoders_group; + /* Directory group containing plane configs, e.g. /config/vkms/card/planes/ */ + struct config_group planes_group; + + unsigned long allocated_crtcs; + unsigned long allocated_encoders; + + struct vkms_card *card; +}; + struct vkms_card { struct platform_device *platform; struct drm_device drm; struct list_head node; struct vkms_output output; + struct vkms_configfs *configfs; struct vkms_device *vkms_device; /* storage for the value of drm->unique, giving this dev a unique busid */ char name_buf[64]; @@ -149,8 +199,27 @@ struct vkms_device { #define to_vkms_plane_state(target)\ container_of(target, struct vkms_plane_state, base.base) +#define item_to_configfs(item)\ + container_of(to_config_group(item), struct vkms_configfs, card_group) + +#define item_to_config_connector(item)\ + container_of(to_config_group(item), struct vkms_config_connector, config_group) + +#define item_to_config_crtc(item) \ + container_of(to_config_group(item), struct vkms_config_crtc, config_group) + +#define item_to_config_encoder(item) \ + container_of(to_config_group(item), struct vkms_config_encoder, config_group) + +#define item_to_config_plane(item) \ + container_of(to_config_group(item), struct vkms_config_plane, config_group) + +#define item_to_config_links(item) \ + container_of(to_config_group(item), struct vkms_config_links, group) + /* Cards */ -struct vkms_card *vkms_card_init(const char *name, bool is_default); +struct vkms_card *vkms_card_init(const char *name, + struct vkms_configfs *configfs); void vkms_card_destroy(struct vkms_card *card); /* CRTC */ @@ -176,4 +245,8 @@ void vkms_set_composer(struct vkms_crtc *vkms_crtc, bool enabled); /* Writeback */ int vkms_enable_writeback_connector(struct vkms_card *card, struct vkms_crtc *vkms_crtc); +/* ConfigFS Support */ +int vkms_init_configfs(void); +void vkms_unregister_configfs(void); + #endif /* _VKMS_DRV_H_ */ diff --git a/drivers/gpu/drm/vkms/vkms_output.c b/drivers/gpu/drm/vkms/vkms_output.c index 2b72d8e763a8..e343a9c1f311 100644 --- a/drivers/gpu/drm/vkms/vkms_output.c +++ b/drivers/gpu/drm/vkms/vkms_output.c @@ -1,10 +1,14 @@ // SPDX-License-Identifier: GPL-2.0+ -#include "vkms_drv.h" +#include <linux/configfs.h> +#include <linux/kernel.h> + #include <drm/drm_atomic_helper.h> #include <drm/drm_probe_helper.h> #include <drm/drm_simple_kms_helper.h> +#include "vkms_drv.h" + static void vkms_connector_destroy(struct drm_connector *connector) { drm_connector_cleanup(connector); @@ -171,3 +175,8 @@ int vkms_output_init_default(struct vkms_card *card, int index) return ret; } + +int vkms_output_init(struct vkms_card *card, int index) +{ + return -ENOTSUPP; +}
This change adds the basic scaffolding for ConfigFS, including setting up the default directories. It does not allow for the registration of configfs-backed devices, which is complex and provided in a follow-up commit. This CL includes docs about using ConfigFS with VKMS, but I'll summarize in brief here as well (assuming ConfigFS is mounted at /config/): To create a new configuration, you can do so via `mkdir /config/vkms/my-device`. This will create a number of directories and files automatically: /config `-- vkms `-- my-device |-- connectors |-- crtcs |-- encoders |-- planes `-- is_registered You can then configure objects by mkdir'ing in each of the directories. When you're satisfied, you can `echo 1 > /config/vkms/my-device/is_registered`. This will create a new device according to your configuration. For now, this will fail, but the next change will add support for it. Signed-off-by: Jim Shargo <jshargo@chromium.org> --- Documentation/gpu/vkms.rst | 76 ++++ drivers/gpu/drm/Kconfig | 1 + drivers/gpu/drm/vkms/Makefile | 1 + drivers/gpu/drm/vkms/vkms_configfs.c | 527 +++++++++++++++++++++++++++ drivers/gpu/drm/vkms/vkms_drv.c | 28 +- drivers/gpu/drm/vkms/vkms_drv.h | 75 +++- drivers/gpu/drm/vkms/vkms_output.c | 11 +- 7 files changed, 711 insertions(+), 8 deletions(-) create mode 100644 drivers/gpu/drm/vkms/vkms_configfs.c