Currently the tiling parameters of buffer objects can only be set at
allocation time, and only a single tiled mode is supported. This new
DRM_TEGRA_GEM_SET_TILING IOCTL allows more modes to be set and also
allows the tiling mode to be changed after the allocation. This will
enable the Tegra DRM driver to import buffers from a GPU and directly
scan them out by configuring the display controller appropriately.
To complement this, the DRM_TEGRA_GEM_GET_TILING IOCTL can query the
current tiling mode of a buffer object. This is necessary when importing
buffers via handle (as is done in Mesa for example) so that userspace
can determine the proper parameters for the 2D or 3D engines.
Reviewed-by: Stéphane Marchesin <marcheu@chromium.org>
Tested-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
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* For the very latest on DRI development, please see: *
* http://dri.freedesktop.org/ *
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The Direct Rendering Manager (drm) is a device-independent kernel-level
device driver that provides support for the XFree86 Direct Rendering
Infrastructure (DRI).
The DRM supports the Direct Rendering Infrastructure (DRI) in four major
ways:
1. The DRM provides synchronized access to the graphics hardware via
the use of an optimized two-tiered lock.
2. The DRM enforces the DRI security policy for access to the graphics
hardware by only allowing authenticated X11 clients access to
restricted regions of memory.
3. The DRM provides a generic DMA engine, complete with multiple
queues and the ability to detect the need for an OpenGL context
switch.
4. The DRM is extensible via the use of small device-specific modules
that rely extensively on the API exported by the DRM module.
Documentation on the DRI is available from:
http://dri.freedesktop.org/wiki/Documentation
http://sourceforge.net/project/showfiles.php?group_id=387
http://dri.sourceforge.net/doc/
For specific information about kernel-level support, see:
The Direct Rendering Manager, Kernel Support for the Direct Rendering
Infrastructure
http://dri.sourceforge.net/doc/drm_low_level.html
Hardware Locking for the Direct Rendering Infrastructure
http://dri.sourceforge.net/doc/hardware_locking_low_level.html
A Security Analysis of the Direct Rendering Infrastructure
http://dri.sourceforge.net/doc/security_low_level.html
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