As a preparation work for introducing writeback to vkms, this patch
renames the file vkms_crc.c into vkms_composer.c. Accordingly, it also
adjusts the functions and data structures to match the changes.

No functional change.

Signed-off-by: Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/dea62063077ebf5cc1dfce8876e56788d15367e6.1561491964.git.rodrigosiqueiramelo@gmail.com

Add SPDX license identifiers to all Make/Kconfig files which:

 - Have no license information of any form

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

  GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch implement the necessary functions to compute and add CRCs
entries:

- Implement the set_crc_source() callback.
- Compute CRC using crc32 on the visible part of the framebuffer.
- Use ordered workqueue per output to compute and add CRC at the end
  of a vblank.
- Use appropriate synchronization methods since the CRC computation must
  be atomic wrt the generated vblank event for a given atomic update, by
  using spinlock across atomic_begin/atomic_flush to wrap the event
  handling code completely and match the flip event with the CRC.

Since vkms_crc_work_handle() can sleep, spinlock can't be acquired
while accessing vkms_output->primary_crc to compute CRC.
To make sure the data is updated and released without conflict with
the vkms_crc_work_handle(), the work_struct is flushed @crtc_destroy
and the data is updated before scheduling the work handle again, as
follow:

* CRC data update:
1- store vkms_crc_data {fb, src} per plane_state
2- @plane_duplicate_state -> allocate vkms_crc_data
3- during atomic commit (@atomic_update) ->
	a) copy {fb, src} to plane_state->crc_data
	b) get reference to fb,
3- @plane_destroy_state -> a) if (fb refcount) remove reference to fb
			   b) deallocate crc_data

* Atomic Commit:
1- vkms_plane_atomic_check
2- vkms_prepare_fb -> vmap vkms_gem_obj->vaddr
3- atomic_begin -> hold crc spinlock
4- atomic_plane_update -> a) update vkms_output->primary_crc
			  b) get reference to fb
5- atomic_flush -> a) send vblank event while holding event_lock
		   b) release crc spinlock

* hrtimer regular callback:
1- hold crc spinlock
2- drm_crtc_handle_vblank()
3- queue vkms_crc_work_handle
4- release crc spinlock

* cleanup:
1- @cleanup_fb ->vunmap vkms_gem_obj->vaddr
2- @crtc_destroy -> flush work struct
3- @plane_destroy -> a) if (fb refcount) remove reference to fb
		     b) deallocate crc_data

Signed-off-by: Haneen Mohammed <hamohammed.sa@gmail.com>
[seanpaul fixed typo in vkms_crtc s/vblamk/vblank/]
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/b948327f48c3e70ab232b4a0848ee6d033b26484.1533171495.git.hamohammed.sa@gmail.com

VKMS currently does not handle dumb data, and as a consequence, it does
not provide mechanisms for handling gem. This commit adds the necessary
support for gem object/handler and the dumb functions.

Changes since V1:
 Daniel Vetter:
 - Add dumb buffer support to the same patchset
Changes since V2:
 Haneen:
 - Add missing gem_free_object_unlocked callback to fix the warning
   "Memory manager not clean during takedown"

Signed-off-by: Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/70b7becc91c6a323dbc15cb5fc912cbdfe4ef7d9.1531359228.git.rodrigosiqueiramelo@gmail.com

This commit adds the essential infrastructure for around CRTCs which
is composed of: a new data struct for output data information, a
function for creating planes, and a simple encoder attached to the
connector. Finally, due to the introduction of a new initialization
function, connectors were moved from vkms_drv.c to vkms_display.c.

Signed-off-by: Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>
Reviewed-by: Haneen Mohammed <hamohammed.sa@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/b6e27bc6a54f5cb340658fa5969f7b48fbfbf1b7.1526514457.git.rodrigosiqueiramelo@gmail.com

This patch introduces Virtual Kernel Mode-Setting (VKMS) driver. It
creates a very basic kms driver with 1 crtc/encoder/connector/plane.

VKMS driver would be useful for testing, or for running X (or similar)
on headless machines and be able to still use the GPU. Thus it enables
a virtual display without the need for hardware display capability.

Signed-off-by: Haneen Mohammed <hamohammed.sa@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180514143346.GA21695@haneen-vb