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Diffstat (limited to 'Documentation/gpu/drm-internals.rst')
| -rw-r--r-- | Documentation/gpu/drm-internals.rst | 159 |
1 files changed, 72 insertions, 87 deletions
diff --git a/Documentation/gpu/drm-internals.rst b/Documentation/gpu/drm-internals.rst index 5ee9674fb9e9..94f93fd3b8a0 100644 --- a/Documentation/gpu/drm-internals.rst +++ b/Documentation/gpu/drm-internals.rst @@ -24,9 +24,9 @@ Driver Initialization At the core of every DRM driver is a :c:type:`struct drm_driver <drm_driver>` structure. Drivers typically statically initialize a drm_driver structure, and then pass it to -:c:func:`drm_dev_alloc()` to allocate a device instance. After the +drm_dev_alloc() to allocate a device instance. After the device instance is fully initialized it can be registered (which makes -it accessible from userspace) using :c:func:`drm_dev_register()`. +it accessible from userspace) using drm_dev_register(). The :c:type:`struct drm_driver <drm_driver>` structure contains static information that describes the driver and features it @@ -39,68 +39,6 @@ sections. Driver Information ------------------ -Driver Features -~~~~~~~~~~~~~~~ - -Drivers inform the DRM core about their requirements and supported -features by setting appropriate flags in the driver_features field. -Since those flags influence the DRM core behaviour since registration -time, most of them must be set to registering the :c:type:`struct -drm_driver <drm_driver>` instance. - -u32 driver_features; - -DRIVER_USE_AGP - Driver uses AGP interface, the DRM core will manage AGP resources. - -DRIVER_LEGACY - Denote a legacy driver using shadow attach. Don't use. - -DRIVER_KMS_LEGACY_CONTEXT - Used only by nouveau for backwards compatibility with existing userspace. - Don't use. - -DRIVER_PCI_DMA - Driver is capable of PCI DMA, mapping of PCI DMA buffers to - userspace will be enabled. Deprecated. - -DRIVER_SG - Driver can perform scatter/gather DMA, allocation and mapping of - scatter/gather buffers will be enabled. Deprecated. - -DRIVER_HAVE_DMA - Driver supports DMA, the userspace DMA API will be supported. - Deprecated. - -DRIVER_HAVE_IRQ; DRIVER_IRQ_SHARED - DRIVER_HAVE_IRQ indicates whether the driver has an IRQ handler - managed by the DRM Core. The core will support simple IRQ handler - installation when the flag is set. The installation process is - described in ?. - - DRIVER_IRQ_SHARED indicates whether the device & handler support - shared IRQs (note that this is required of PCI drivers). - -DRIVER_GEM - Driver use the GEM memory manager. - -DRIVER_MODESET - Driver supports mode setting interfaces (KMS). - -DRIVER_PRIME - Driver implements DRM PRIME buffer sharing. - -DRIVER_RENDER - Driver supports dedicated render nodes. - -DRIVER_ATOMIC - Driver supports atomic properties. In this case the driver must - implement appropriate obj->atomic_get_property() vfuncs for any - modeset objects with driver specific properties. - -DRIVER_SYNCOBJ - Driver support drm sync objects. - Major, Minor and Patchlevel ~~~~~~~~~~~~~~~~~~~~~~~~~~~ @@ -119,8 +57,8 @@ is larger than the driver minor, the DRM_IOCTL_SET_VERSION call will return an error. Otherwise the driver's set_version() method will be called with the requested version. -Name, Description and Date -~~~~~~~~~~~~~~~~~~~~~~~~~~ +Name and Description +~~~~~~~~~~~~~~~~~~~~ char \*name; char \*desc; char \*date; The driver name is printed to the kernel log at initialization time, @@ -131,11 +69,11 @@ The driver description is a purely informative string passed to userspace through the DRM_IOCTL_VERSION ioctl and otherwise unused by the kernel. -The driver date, formatted as YYYYMMDD, is meant to identify the date of -the latest modification to the driver. However, as most drivers fail to -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 Device Instance and Driver Handling ----------------------------------- @@ -143,6 +81,9 @@ Device Instance and Driver Handling .. kernel-doc:: drivers/gpu/drm/drm_drv.c :doc: driver instance overview +.. kernel-doc:: include/drm/drm_device.h + :internal: + .. kernel-doc:: include/drm/drm_drv.h :internal: @@ -152,15 +93,11 @@ Device Instance and Driver Handling Driver Load ----------- +Component Helper Usage +~~~~~~~~~~~~~~~~~~~~~~ -IRQ Helper Library -~~~~~~~~~~~~~~~~~~ - -.. kernel-doc:: drivers/gpu/drm/drm_irq.c - :doc: irq helpers - -.. kernel-doc:: drivers/gpu/drm/drm_irq.c - :export: +.. kernel-doc:: drivers/gpu/drm/drm_drv.c + :doc: component helper usage recommendations Memory Manager Initialization ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ @@ -186,18 +123,18 @@ be unmapped; on many devices, the ROM address decoder is shared with other BARs, so leaving it mapped could cause undesired behaviour like hangs or memory corruption. -Bus-specific Device Registration and PCI Support ------------------------------------------------- +Managed Resources +----------------- -A number of functions are provided to help with device registration. The -functions deal with PCI and platform devices respectively and are only -provided for historical reasons. These are all deprecated and shouldn't -be used in new drivers. Besides that there's a few helpers for pci -drivers. +.. kernel-doc:: drivers/gpu/drm/drm_managed.c + :doc: managed resources -.. kernel-doc:: drivers/gpu/drm/drm_pci.c +.. kernel-doc:: drivers/gpu/drm/drm_managed.c :export: +.. kernel-doc:: include/drm/drm_managed.h + :internal: + Open/Close, File Operations and IOCTLs ====================================== @@ -230,6 +167,54 @@ Printer .. kernel-doc:: drivers/gpu/drm/drm_print.c :export: +Utilities +--------- + +.. kernel-doc:: include/drm/drm_util.h + :doc: drm utils + +.. kernel-doc:: include/drm/drm_util.h + :internal: + + +Unit testing +============ + +KUnit +----- + +KUnit (Kernel unit testing framework) provides a common framework for unit tests +within the Linux kernel. + +This section covers the specifics for the DRM subsystem. For general information +about KUnit, please refer to Documentation/dev-tools/kunit/start.rst. + +How to run the tests? +~~~~~~~~~~~~~~~~~~~~~ + +In order to facilitate running the test suite, a configuration file is present +in ``drivers/gpu/drm/tests/.kunitconfig``. It can be used by ``kunit.py`` as +follows: + +.. code-block:: bash + + $ ./tools/testing/kunit/kunit.py run --kunitconfig=drivers/gpu/drm/tests \ + --kconfig_add CONFIG_VIRTIO_UML=y \ + --kconfig_add CONFIG_UML_PCI_OVER_VIRTIO=y + +.. note:: + The configuration included in ``.kunitconfig`` should be as generic as + possible. + ``CONFIG_VIRTIO_UML`` and ``CONFIG_UML_PCI_OVER_VIRTIO`` are not + included in it because they are only required for User Mode Linux. + +KUnit Coverage Rules +~~~~~~~~~~~~~~~~~~~~ + +KUnit support is gradually added to the DRM framework and helpers. There's no +general requirement for the framework and helpers to have KUnit tests at the +moment. However, patches that are affecting a function or helper already +covered by KUnit tests must provide tests if the change calls for one. Legacy Support Code =================== |