[PATCH v3 0/9] drm/amdgpu: Add MMIO-remap Singleton BO for HDP flush v3

[Srinivasan Shanmugam]

This series introduces a kernel-managed singleton BO representing the MMIO-remap (HDP flush) page and exposes it to userspace through a new GEM domain.

Design
------
- A tiny (1-page) TTM bucket is introduced for AMDGPU_PL_MMIO_REMAP
  (mirroring doorbells).
- A singleton BO is created during amdgpu_ttm_init() and freed at
  fini().
- The BO is kernel-owned and never evicted.
- amdgpu_gem_create_ioctl() recognizes the new GEM domain bit
  (AMDGPU_GEM_DOMAIN_MMIO_REMAP) and returns a handle to the pre-created singleton BO, enforcing size/alignment checks.
- Userspace thus gets a stable GEM handle and can mmap it to issue HDP
  flushes.

v2: Updated review comments from v1. (Alex/Christian)

v3: Updated review comments from v2. (Alex/Christian)
[RFC,v2,1/8] drm/amdgpu/uapi: Introduce AMDGPU_GEM_DOMAIN_MMIO_REMAP | https://patchwork.freedesktop.org/patch/670410/
[RFC,v2,2/8] drm/amdgpu/ttm: Add New AMDGPU_PL_MMIO_REMAP Placement | https://patchwork.freedesktop.org/patch/670411/
[RFC,v2,3/8] drm/amdgpu: Wire up MMIO_REMAP placement and User-visible strings | https://patchwork.freedesktop.org/patch/670412/
[RFC,v2,4/8] drm/amdgpu: Add mmio_remap bookkeeping to amdgpu_device | https://patchwork.freedesktop.org/patch/670415/
[RFC,v2,5/8] drm/amdgpu: Implement TTM handling for MMIO_REMAP placement | https://patchwork.freedesktop.org/patch/670413/
[RFC,v2,6/8] drm/amdgpu/ttm: Initialize AMDGPU_PL_MMIO_REMAP Heap | https://patchwork.freedesktop.org/patch/670414/
[RFC,v2,7/8] drm/amdgpu/ttm: Allocate/Free 4K MMIO_REMAP Singleton BO | https://patchwork.freedesktop.org/patch/670417/
[RFC,v2,8/8] drm/amdgpu/gem: Return Handle to MMIO_REMAP Singleton in GEM_CREATE | https://patchwork.freedesktop.org/patch/670416/ 

* Only compilation tested so far (x86_64, defconfig + amdgpu enabled).

Cc: Christian König <christian.koenig at amd.com>
Cc: Alex Deucher <alexander.deucher at amd.com>

Srinivasan Shanmugam (9):
  drm/amdgpu/uapi: Introduce AMDGPU_GEM_DOMAIN_MMIO_REMAP
  drm/ttm: Bump TTM_NUM_MEM_TYPES to 9 (Prep for AMDGPU_PL_MMIO_REMAP)
  drm/amdgpu/ttm: Add New AMDGPU_PL_MMIO_REMAP Placement
  drm/amdgpu: Wire up MMIO_REMAP placement and User-visible strings
  drm/amdgpu: Add mmio_remap bookkeeping to amdgpu_device
  drm/amdgpu: Implement TTM handling for MMIO_REMAP placement
  drm/amdgpu/ttm: Initialize AMDGPU_PL_MMIO_REMAP Heap
  drm/amdgpu/ttm: Allocate/Free 4K MMIO_REMAP Singleton BO
  drm/amdgpu/gem: Return Handle to MMIO_REMAP Singleton in GEM_CREATE

 drivers/gpu/drm/amd/amdgpu/amdgpu.h           |  1 +
 drivers/gpu/drm/amd/amdgpu/amdgpu_fdinfo.c    |  1 +
 drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c       | 62 +++++++++++++
 drivers/gpu/drm/amd/amdgpu/amdgpu_object.c    | 13 +++
 drivers/gpu/drm/amd/amdgpu/amdgpu_object.h    |  2 +
 .../gpu/drm/amd/amdgpu/amdgpu_res_cursor.h    |  2 +
 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c       | 87 ++++++++++++++++++-
 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h       |  3 +-
 include/drm/ttm/ttm_resource.h                |  2 +-
 include/uapi/drm/amdgpu_drm.h                 |  8 +-
 10 files changed, 174 insertions(+), 7 deletions(-)


base-commit: 6b70b6008d812a9a210455dd55459a21279bad1e
-- 
2.34.1