Commit ba4e7d97 authored by Committed by Dave AirlieBrowse files
drm: Add the TTM GPU memory manager subsystem.
TTM is a GPU memory manager subsystem designed for use with GPU devices with various memory types (On-card VRAM, AGP, PCI apertures etc.). It's essentially a helper library that assists the DRM driver in creating and managing persistent buffer objects. TTM manages placement of data and CPU map setup and teardown on data movement. It can also optionally manage synchronization of data on a per-buffer-object level. TTM takes care to provide an always valid virtual user-space address to a buffer object which makes user-space sub-allocation of big buffer objects feasible. TTM uses a fine-grained per buffer-object locking scheme, taking care to release all relevant locks when waiting for the GPU. Although this implies some locking overhead, it's probably a big win for devices with multiple command submission mechanisms, since the lock contention will be minimal. TTM can be used with whatever user-space interface the driver chooses, including GEM. It's used by the upcoming Radeon KMS DRM driver and is also the GPU memory management core of various new experimental DRM drivers. Signed-off-by: Thomas Hellstrom <firstname.lastname@example.org> Signed-off-by: Jerome Glisse <email@example.com> Signed-off-by: Dave Airlie <firstname.lastname@example.org>