[Spice-devel] [PATCH 01/10] drm: Provide PCI module-init macros
Thomas Zimmermann
tzimmermann at suse.de
Fri Dec 17 14:46:06 UTC 2021
Provide helper macros to register PCI-based DRM drivers. The new
macros behave like module_pci_driver() with an additional test if
DRM modesetting has been enabled.
Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
---
Documentation/gpu/drm-internals.rst | 6 ++
include/drm/drm_module.h | 95 +++++++++++++++++++++++++++++
2 files changed, 101 insertions(+)
create mode 100644 include/drm/drm_module.h
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 <linux/pci.h>
+
+#include <drm/drm_drv.h>
+
+/**
+ * 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
--
2.34.1
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