drm/vmwgfx: Stop using raw ttm_buffer_object's

Various bits of the driver used raw ttm_buffer_object instead of the
driver specific vmw_bo object. All those places used to duplicate
the mapped bo caching policy of vmw_bo.

Instead of duplicating all of that code and special casing various
functions to work both with vmw_bo and raw ttm_buffer_object's unify
the buffer object handling code.

As part of that work fix the naming of bo's, e.g. insted of generic
backup use 'guest_memory' because that's what it really is.

All of it makes the driver easier to maintain and the code easier to
read. Saves 100+ loc as well.

Signed-off-by: Zack Rusin <zackr@vmware.com>
Reviewed-by: Martin Krastev <krastevm@vmware.com>
Reviewed-by: Maaz Mombasawala <mombasawalam@vmware.com>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20230131033542.953249-9-zack@kde.org

drm/vmwgfx: Abstract placement selection

Problem with explicit placement selection in vmwgfx is that by the time
the buffer object needs to be validated the information about which
placement was supposed to be used is lost. To workaround this the driver
had a bunch of state in various places e.g. as_mob or cpu_blit to
somehow convey the information on which placement was intended.

Fix it properly by allowing the buffer objects to hold their preferred
placement so it can be reused whenever needed. This makes the entire
validation pipeline a lot easier both to understand and maintain.

Signed-off-by: Zack Rusin <zackr@vmware.com>
Reviewed-by: Martin Krastev <krastevm@vmware.com>
Reviewed-by: Maaz Mombasawala <mombasawalam@vmware.com>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20230131033542.953249-8-zack@kde.org

drm/vmwgfx: Implement DRIVER_GEM

This is initial change adding support for DRIVER_GEM to vmwgfx. vmwgfx
was written before GEM and has always used TTM. Over the years the
TTM buffers started inherting from GEM objects but vmwgfx never
implemented GEM making it quite awkward. We were directly setting
variables in GEM objects to not make DRM crash.

This change brings vmwgfx inline with other DRM drivers and allows us
to use a lot of DRM helpers which have depended on drivers with GEM
support.

Due to historical reasons vmwgfx splits the idea of a buffer and surface
which makes it a littly tricky since either one can be used in most
of our ioctl's which take user space handles. For now our BO's are
GEM objects and our surfaces are opaque objects which are backed by
GEM objects. In the future I'd like to combine those into a single
BO but we don't want to break any of our existing ioctl's so it will
take time to do it in a non-destructive way.

Signed-off-by: Zack Rusin <zackr@vmware.com>
Reviewed-by: Martin Krastev <krastevm@vmware.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211206172620.3139754-5-zack@kde.org

drm/vmwgfx: add SPDX idenitifier and clarify license

This is dual licensed under GPL-2.0 or MIT.
vmwgfx_msg.h is the odd one out that is GPL-2.0+ or MIT.

Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Dirk Hohndel (VMware) <dirk@hohndel.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180506231626.115996-9-dirk@hohndel.org

drm/vmwgfx: Re-implement the stream resource as a simple resource.

Provide and document a reference implementation.

Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Sinclair Yeh <syeh@vmware.com>