[PATCH 0/2] Provide init/release functions for struct ttm_bo_global

[Thomas Zimmermann]

TTM uses global memory and BO for backing graphics buffers. These are
represented by struct ttm_mem_global and struct ttm_bo_global.

Currently, struct ttm_bo_global can only be initialized and released through
struct ttm_bo_global_ref. This is a workaround for passing an instance of
ttm_mem_global to the BO global initialization code.

The use of struct ttm_bo_global_ref makes driver code unnecessary hard to
understand. At the same time drivers can use any combination of memory and
BO for initializing the global instances. This can result in subtle bugs
when the order of initializing and releasing drivers changes.

As a first step for resolving these problems, the provided patch set
separates initialization and release of struct ttm_bo_global from
struct ttm_bo_global_ref.

The first patch only renames ttm_bo_global_{init/release}. Hopefully this
change can be applied at once for all drivers.

Future directions: All TTM-based drivers follow the same pattern for setting
up the TTM. In a follow-up patch, this code can be moved into a single place
and shared among drivers.

Thomas Zimmermann (2):
  drm/ttm: Rename ttm_bo_global_{init,release}() to
    ttm_bo_global_ref_*()
  drm/ttm: Provide ttm_bo_global_{init/release}() for struct
    ttm_bo_global

 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c     |  4 +-
 drivers/gpu/drm/ast/ast_ttm.c               |  4 +-
 drivers/gpu/drm/bochs/bochs_mm.c            |  4 +-
 drivers/gpu/drm/cirrus/cirrus_ttm.c         |  4 +-
 drivers/gpu/drm/hisilicon/hibmc/hibmc_ttm.c |  4 +-
 drivers/gpu/drm/mgag200/mgag200_ttm.c       |  4 +-
 drivers/gpu/drm/nouveau/nouveau_ttm.c       |  4 +-
 drivers/gpu/drm/qxl/qxl_ttm.c               |  4 +-
 drivers/gpu/drm/radeon/radeon_ttm.c         |  4 +-
 drivers/gpu/drm/ttm/ttm_bo.c                | 12 ++---
 drivers/gpu/drm/virtio/virtgpu_ttm.c        |  4 +-
 drivers/gpu/drm/vmwgfx/vmwgfx_ttm_glue.c    |  4 +-
 drivers/staging/vboxvideo/vbox_ttm.c        |  4 +-
 include/drm/ttm/ttm_bo_driver.h             | 53 ++++++++++++++++-----
 14 files changed, 70 insertions(+), 43 deletions(-)

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2.18.0