[PATCH v4 0/9] Add new formats support to vkms

[Igor Torrente <igormtorrente@gmail.com>]

Summary
=======
This series of patches refactor some vkms components in order to introduce
new formats to the planes and writeback connector.

Now in the blend function, the plane's pixels are converted to ARGB16161616
and then blended together.

The CRC is calculated based on the ARGB1616161616 buffer. And if required,
this buffer is copied/converted to the writeback buffer format.

And to handle the pixel conversion, new functions were added to convert
from a specific format to ARGB16161616 (the reciprocal is also true).

Tests
=====
This patch series was tested using the following igt tests:
-t ".*kms_plane.*"
-t ".*kms_writeback.*"
-t ".*kms_cursor_crc*"
-t ".*kms_flip.*"

New tests passing
-------------------
- pipe-A-cursor-size-change
- pipe-A-cursor-alpha-transparent

Performance
-----------
Further optimizing the code, now it's running slightly faster than the V2.
And it consumes less memory than the current implementation in the common case
(more detail in the commit message).

Results running the IGT tests `kms_cursor_crc`:

|                             Frametime                                 |
|:---------------:|:---------:|:--------------:|:------------:|:-------:|
|  implmentation  |  Current  |  Per-pixel(V1) | Per-line(V2) |   V3    |
| frametime range |  8~22 ms  |    32~56 ms    |    6~19 ms   | 5~18 ms |
|     Average     |  10.0 ms  |     35.8 ms    |    8.6 ms    |  7.3 ms |

| Memory consumption (output dimensions) |
|:--------------------------------------:|
|       Current      |     This patch    |
|:------------------:|:-----------------:|
|   Width * Heigth   |     2 * Width     |

XRGB to ARGB behavior
=====================
During the development, I decided to always fill the alpha channel of
the output pixel whenever the conversion from a format without an alpha
channel to ARGB16161616 is necessary. Therefore, I ignore the value
received from the XRGB and overwrite the value with 0xFFFF.

---
Igor Torrente (9):
  drm: vkms: Replace the deprecated drm_mode_config_init
  drm: vkms: Alloc the compose frame using vzalloc
  drm: vkms: Replace hardcoded value of `vkms_composer.map` to
    DRM_FORMAT_MAX_PLANES
  drm: vkms: Rename `vkms_composer` to `vkms_frame_info`
  drm: vkms: Add fb information to `vkms_writeback_job`
  drm: drm_atomic_helper: Add a new helper to deal with the writeback
    connector validation
  drm: vkms: Refactor the plane composer to accept new formats
  drm: vkms: Adds XRGB_16161616 and ARGB_1616161616 formats
  drm: vkms: Add support to the RGB565 format

 drivers/gpu/drm/drm_atomic_helper.c   |  39 +++
 drivers/gpu/drm/vkms/Makefile         |   1 +
 drivers/gpu/drm/vkms/vkms_composer.c  | 336 +++++++++++++-------------
 drivers/gpu/drm/vkms/vkms_drv.c       |   6 +-
 drivers/gpu/drm/vkms/vkms_drv.h       |  20 +-
 drivers/gpu/drm/vkms/vkms_formats.c   | 279 +++++++++++++++++++++
 drivers/gpu/drm/vkms/vkms_formats.h   |  49 ++++
 drivers/gpu/drm/vkms/vkms_plane.c     |  47 ++--
 drivers/gpu/drm/vkms/vkms_writeback.c |  32 ++-
 include/drm/drm_atomic_helper.h       |   3 +
 10 files changed, 600 insertions(+), 212 deletions(-)
 create mode 100644 drivers/gpu/drm/vkms/vkms_formats.c
 create mode 100644 drivers/gpu/drm/vkms/vkms_formats.h

-- 
2.30.2