(was: drm/ast/mgag200: Place cursor BOs at VRAM high-end)
This patchset cleans up the memory management of HW cursors in mgag200. It further moves the allocated cursor BOs to the of the video RAM to reduce memory fragmentation.
The mgag200 driver manages cursor memory in dedicated GEM VRAM buffer objects. It uses a double-buffering scheme of alternating between two GEM BOs The code is convoluted and can lead to memory fragmentation if a BO is stored the middle of VRAM. This is especially a problem as mgag200 devices only contain a small amount of video memory (e.g., 16 MiB).
With this patchset, the cursor handling in mgag200 is first split up into separate functions for copying cursor images, managing buffer objects, setting scanout addresses, and moving and hiding the cursor. Furthermore, the driver dedicates a few KiB at the high end of a device's video memory to storing the cursor's buffer objects. This prevents memory fragmentation.
The patchset has been tested on mgag200 hardware.
v3: * split-off mgag200 patches into separate series v2: * remove VRAM buffers in favor of GEM BOs * manage BO placement with pin flag
Thomas Zimmermann (7): drm/mgag200: Rename cursor functions to use mgag200_ prefix drm/mgag200: Add init and fini functions for cursor handling drm/mgag200: Add separate move-cursor function drm/mgag200: Move cursor-image update to mgag200_show_cursor() drm/mgag200: Move cursor BO swapping into mgag200_show_cursor() drm/mgag200: Reserve video memory for cursor plane drm/mgag200: Allocate cursor BOs at high end of video memory
drivers/gpu/drm/mgag200/mgag200_cursor.c | 313 ++++++++++++++--------- drivers/gpu/drm/mgag200/mgag200_drv.h | 22 +- drivers/gpu/drm/mgag200/mgag200_main.c | 20 +- drivers/gpu/drm/mgag200/mgag200_mode.c | 6 +- drivers/gpu/drm/mgag200/mgag200_ttm.c | 4 + 5 files changed, 216 insertions(+), 149 deletions(-)
-- 2.23.0