diff --git a/Documentation/gpu/vkms.rst b/Documentation/gpu/vkms.rst index 8a8b1002931f..73521b9ff0c3 100644 --- a/Documentation/gpu/vkms.rst +++ b/Documentation/gpu/vkms.rst @@ -51,6 +51,38 @@ To disable the driver, use :: sudo modprobe -r vkms +Configuring With Configfs +========================= + +It is possible to create and configure multiple VKMS instances via configfs. + +Start by mounting configfs and loading VKMS:: + + sudo mount -t configfs none /config + sudo modprobe vkms + +Once VKMS is loaded, ``/config/vkms`` is created automatically. Each directory +under ``/config/vkms`` represents a VKMS instance, create a new one:: + + sudo mkdir /config/vkms/my-vkms + +By default, the instance is disabled:: + + cat /config/vkms/my-vkms/enabled + 0 + +Once you are done configuring the VKMS instance, enable it:: + + echo "1" | sudo tee /config/vkms/my-vkms/enabled + +Finally, you can remove the VKMS instance disabling it:: + + echo "0" | sudo tee /config/vkms/my-vkms/enabled + +And removing the top level directory:: + + sudo rmdir /config/vkms/my-vkms + Testing With IGT ================ diff --git a/drivers/gpu/drm/vkms/Kconfig b/drivers/gpu/drm/vkms/Kconfig index 3c02f928ffe6..3977bbb99f7d 100644 --- a/drivers/gpu/drm/vkms/Kconfig +++ b/drivers/gpu/drm/vkms/Kconfig @@ -7,6 +7,7 @@ config DRM_VKMS select DRM_KMS_HELPER select DRM_GEM_SHMEM_HELPER select CRC32 + select CONFIGFS_FS default n help Virtual Kernel Mode-Setting (VKMS) is used for testing or for diff --git a/drivers/gpu/drm/vkms/Makefile b/drivers/gpu/drm/vkms/Makefile index d657865e573f..939991fc8233 100644 --- a/drivers/gpu/drm/vkms/Makefile +++ b/drivers/gpu/drm/vkms/Makefile @@ -8,7 +8,8 @@ vkms-y := \ vkms_composer.o \ vkms_writeback.o \ vkms_connector.o \ - vkms_config.o + vkms_config.o \ + vkms_configfs.o obj-$(CONFIG_DRM_VKMS) += vkms.o obj-$(CONFIG_DRM_VKMS_KUNIT_TEST) += tests/ diff --git a/drivers/gpu/drm/vkms/vkms_configfs.c b/drivers/gpu/drm/vkms/vkms_configfs.c new file mode 100644 index 000000000000..ee186952971b --- /dev/null +++ b/drivers/gpu/drm/vkms/vkms_configfs.c @@ -0,0 +1,172 @@ +// SPDX-License-Identifier: GPL-2.0+ +#include +#include +#include +#include + +#include "vkms_drv.h" +#include "vkms_config.h" +#include "vkms_configfs.h" + +/* To avoid registering configfs more than once or unregistering on error */ +static bool is_configfs_registered; + +/** + * struct vkms_configfs_device - Configfs representation of a VKMS device + * + * @group: Top level configuration group that represents a VKMS device. + * Initialized when a new directory is created under "/config/vkms/" + * @lock: Lock used to project concurrent access to the configuration attributes + * @config: Protected by @lock. Configuration of the VKMS device + * @enabled: Protected by @lock. The device is created or destroyed when this + * option changes + */ +struct vkms_configfs_device { + struct config_group group; + + struct mutex lock; + struct vkms_config *config; + bool enabled; +}; + +#define device_item_to_vkms_configfs_device(item) \ + container_of(to_config_group((item)), struct vkms_configfs_device, \ + group) + +static ssize_t device_enabled_show(struct config_item *item, char *page) +{ + struct vkms_configfs_device *dev; + bool enabled; + + dev = device_item_to_vkms_configfs_device(item); + + scoped_guard(mutex, &dev->lock) + enabled = dev->enabled; + + return sprintf(page, "%d\n", enabled); +} + +static ssize_t device_enabled_store(struct config_item *item, const char *page, + size_t count) +{ + struct vkms_configfs_device *dev; + bool enabled; + int ret = 0; + + dev = device_item_to_vkms_configfs_device(item); + + if (kstrtobool(page, &enabled)) + return -EINVAL; + + scoped_guard(mutex, &dev->lock) { + if (!dev->enabled && enabled) { + if (!vkms_config_is_valid(dev->config)) + return -EINVAL; + + ret = vkms_create(dev->config); + if (ret) + return ret; + } else if (dev->enabled && !enabled) { + vkms_destroy(dev->config); + } + + dev->enabled = enabled; + } + + return (ssize_t)count; +} + +CONFIGFS_ATTR(device_, enabled); + +static struct configfs_attribute *device_item_attrs[] = { + &device_attr_enabled, + NULL, +}; + +static void device_release(struct config_item *item) +{ + struct vkms_configfs_device *dev; + + dev = device_item_to_vkms_configfs_device(item); + + if (dev->enabled) + vkms_destroy(dev->config); + + mutex_destroy(&dev->lock); + vkms_config_destroy(dev->config); + kfree(dev); +} + +static struct configfs_item_operations device_item_operations = { + .release = &device_release, +}; + +static const struct config_item_type device_item_type = { + .ct_attrs = device_item_attrs, + .ct_item_ops = &device_item_operations, + .ct_owner = THIS_MODULE, +}; + +static struct config_group *make_device_group(struct config_group *group, + const char *name) +{ + struct vkms_configfs_device *dev; + + if (strcmp(name, DEFAULT_DEVICE_NAME) == 0) + return ERR_PTR(-EINVAL); + + dev = kzalloc(sizeof(*dev), GFP_KERNEL); + if (!dev) + return ERR_PTR(-ENOMEM); + + dev->config = vkms_config_create(name); + if (IS_ERR(dev->config)) { + kfree(dev); + return ERR_CAST(dev->config); + } + + config_group_init_type_name(&dev->group, name, &device_item_type); + mutex_init(&dev->lock); + + return &dev->group; +} + +static struct configfs_group_operations device_group_ops = { + .make_group = &make_device_group, +}; + +static const struct config_item_type device_group_type = { + .ct_group_ops = &device_group_ops, + .ct_owner = THIS_MODULE, +}; + +static struct configfs_subsystem vkms_subsys = { + .su_group = { + .cg_item = { + .ci_name = "vkms", + .ci_type = &device_group_type, + }, + }, + .su_mutex = __MUTEX_INITIALIZER(vkms_subsys.su_mutex), +}; + +int vkms_configfs_register(void) +{ + int ret; + + if (is_configfs_registered) + return 0; + + config_group_init(&vkms_subsys.su_group); + ret = configfs_register_subsystem(&vkms_subsys); + + is_configfs_registered = ret == 0; + + return ret; +} + +void vkms_configfs_unregister(void) +{ + if (is_configfs_registered) + configfs_unregister_subsystem(&vkms_subsys); +} diff --git a/drivers/gpu/drm/vkms/vkms_configfs.h b/drivers/gpu/drm/vkms/vkms_configfs.h new file mode 100644 index 000000000000..e9020b0043db --- /dev/null +++ b/drivers/gpu/drm/vkms/vkms_configfs.h @@ -0,0 +1,8 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +#ifndef _VKMS_CONFIGFS_H_ +#define _VKMS_CONFIGFS_H_ + +int vkms_configfs_register(void); +void vkms_configfs_unregister(void); + +#endif /* _VKMS_CONFIGFS_H_ */ diff --git a/drivers/gpu/drm/vkms/vkms_drv.c b/drivers/gpu/drm/vkms/vkms_drv.c index 78af37c7bd83..c1f23e6a4b07 100644 --- a/drivers/gpu/drm/vkms/vkms_drv.c +++ b/drivers/gpu/drm/vkms/vkms_drv.c @@ -28,6 +28,7 @@ #include #include "vkms_config.h" +#include "vkms_configfs.h" #include "vkms_drv.h" #define DRIVER_NAME "vkms" @@ -214,6 +215,10 @@ static int __init vkms_init(void) int ret; struct vkms_config *config; + ret = vkms_configfs_register(); + if (ret) + return ret; + config = vkms_config_default_create(enable_cursor, enable_writeback, enable_overlay); if (IS_ERR(config)) return PTR_ERR(config); @@ -250,6 +255,8 @@ void vkms_destroy(struct vkms_config *config) static void __exit vkms_exit(void) { + vkms_configfs_unregister(); + if (!default_config) return;