diff --git a/Documentation/gpu/drm-internals.rst b/Documentation/gpu/drm-internals.rst index 607f78f0f189..38afed24a75c 100644 --- a/Documentation/gpu/drm-internals.rst +++ b/Documentation/gpu/drm-internals.rst @@ -75,6 +75,12 @@ update it, its value is mostly useless. The DRM core prints it to the kernel log at initialization time and passes it to userspace through the DRM_IOCTL_VERSION ioctl. +Module Initialization +--------------------- + +.. kernel-doc:: include/drm/drm_module.h + :doc: overview + Managing Ownership of the Framebuffer Aperture ---------------------------------------------- diff --git a/include/drm/drm_module.h b/include/drm/drm_module.h new file mode 100644 index 000000000000..eb3fd7bcbec9 --- /dev/null +++ b/include/drm/drm_module.h @@ -0,0 +1,95 @@ +/* SPDX-License-Identifier: MIT */ + +#ifndef DRM_MODULE_H +#define DRM_MODULE_H + +#include + +#include + +/** + * DOC: overview + * + * This library provides helpers registering DRM drivers during module + * initialization and shutdown. The provided helpers act like bus-specific + * module helpers, such as module_pci_driver(), but respect additional + * parameters that control DRM driver registration. + * + * Below is an example of initializing a DRM driver for a device on the + * PCI bus. + * + * .. code-block:: c + * + * struct pci_driver my_pci_drv = { + * }; + * + * drm_module_pci_driver(my_pci_drv); + * + * The generated code will test if DRM drivers are enabled and register + * the PCI driver my_pci_drv. For more complex module initialization, you + * can still use module_init() and module_exit() in your driver. + */ + +/* + * PCI drivers + */ + +static inline int __init drm_pci_register_driver(struct pci_driver *pci_drv) +{ + if (drm_firmware_drivers_only()) + return -ENODEV; + + return pci_register_driver(pci_drv); +} + +/** + * drm_module_pci_driver - Register a DRM driver for PCI-based devices + * @__pci_drv: the PCI driver structure + * + * Registers a DRM driver for devices on the PCI bus. The helper + * macro behaves like module_pci_driver() but tests the state of + * drm_firmware_drivers_only(). For more complex module initialization, + * use module_init() and module_exit() directly. + * + * Each module may only use this macro once. Calling it replaces + * module_init() and module_exit(). + */ +#define drm_module_pci_driver(__pci_drv) \ + module_driver(__pci_drv, drm_pci_register_driver, pci_unregister_driver) + +static inline int __init +drm_pci_register_driver_if_modeset(struct pci_driver *pci_drv, int modeset) +{ + if (drm_firmware_drivers_only() && modeset == -1) + return -ENODEV; + if (modeset == 0) + return -ENODEV; + + return pci_register_driver(pci_drv); +} + +static inline void __exit +drm_pci_unregister_driver_if_modeset(struct pci_driver *pci_drv, int modeset) +{ + pci_unregister_driver(pci_drv); +} + +/** + * drm_module_pci_driver_if_modeset - Register a DRM driver for PCI-based devices + * @__pci_drv: the PCI driver structure + * @__modeset: an additional parameter that disables the driver + * + * This macro is deprecated and only provided for existing drivers. For + * new drivers, use drm_module_pci_driver(). + * + * Registers a DRM driver for devices on the PCI bus. The helper macro + * behaves like drm_module_pci_driver() with an additional driver-specific + * flag. If __modeset is 0, the driver has been disabled, if __modeset is + * -1 the driver state depends on the global DRM state. For all other + * values, the PCI driver has been enabled. The default should be -1. + */ +#define drm_module_pci_driver_if_modeset(__pci_drv, __modeset) \ + module_driver(__pci_drv, drm_pci_register_driver_if_modeset, \ + drm_pci_unregister_driver_if_modeset, __modeset) + +#endif