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362063619c
We have two classes of framebuffer - Created by the driver (atm only for fbdev), and the driver holds onto the last reference count until destruction. - Created by userspace and associated with a given fd. These framebuffers will be reaped when their assoiciated fb is closed. Now these two cases are set up differently, the framebuffers are on different lists and hence destruction needs to clean up different things. Also, for userspace framebuffers we remove them from any current usage, whereas for internal framebuffers it is assumed that the driver has done this already. Long story short, we need two different ways to cleanup such drivers. Three functions are involved in total: - drm_framebuffer_remove: Convenience function which removes the fb from all active usage and then drops the passed-in reference. - drm_framebuffer_unregister_private: Will remove driver-private framebuffers from relevant lists and drop the corresponding references. Should be called for driver-private framebuffers before dropping the last reference (or like for a lot of the drivers where the fbdev is embedded someplace else, before doing the cleanup manually). - drm_framebuffer_cleanup: Final cleanup for both classes of fbs, should be called by the driver's ->destroy callback once the last reference is gone. This patch just rolls out the new interfaces and updates all drivers (by adding calls to drm_framebuffer_unregister_private at all the right places)- no functional changes yet. Follow-on patches will move drm core code around and update the lifetime management for framebuffers, so that we are no longer required to keep framebuffers alive by locking mode_config.mutex. I've also updated the kerneldoc already. vmwgfx seems to again be a bit special, at least I haven't figured out how the fbdev support in that driver works. It smells like it's external though. v2: The i915 driver creates another private framebuffer in the load-detect code. Adjust its cleanup code, too. Reviewed-by: Rob Clark <rob@ti.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
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* For the very latest on DRI development, please see: *
* http://dri.freedesktop.org/ *
************************************************************
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