[PATCH 0/8] AMDGPU usermode queues

Shashank Sharma shashank.sharma at amd.com
Fri Feb 3 21:54:01 UTC 2023

From: Shashank Sharma <contactshashanksharma at gmail.com>

This patch series introduces AMDGPU usermode graphics queues.
User queues is a method of GPU workload submission into the graphics
hardware without any interaction with kernel/DRM schedulers. In this
method, a userspace graphics application can create its own workqueue
and submit it directly in the GPU HW.

The general idea of how this is supposed to work:
- The application creates the following GPU objetcs:
  - A queue object to hold the workload packets.
  - A read pointer object.
  - A write pointer object.
  - A doorbell page.
- Kernel picks any 32-bit offset in the doorbell page for this queue.
- The application uses the usermode_queue_create IOCTL introduced in
  this patch, by passing the the GPU addresses of these objects (read
  ptr, write ptr, queue base address and doorbell address)
- The kernel creates the queue and maps it in the HW.
- The application can start submitting the data in the queue as soon as
  the kernel IOCTL returns.
- Once the data is filled in the queue, the app must write the number of
  dwords in the doorbell offset, and the GPU will start fetching the data.

libDRM changes for this series and a sample DRM test program can be found
in the MESA merge request here:

The RFC patch series and previous discussion can be seen here:

This patch series needs the doorbell re-design changes, which are being
reviewed here:

In absence of the doorbell patches, this patch series uses a hack patch
to test the functionality. That hack patch is also published here at the
end of the series, just for reference.

Alex Deucher (1):
  drm/amdgpu: UAPI for user queue management

Arvind Yadav (1):
  drm/amdgpu: DO-NOT-MERGE add busy-waiting delay

Shashank Sharma (6):
  drm/amdgpu: add usermode queues
  drm/amdgpu: introduce userqueue MQD handlers
  drm/amdgpu: Add V11 graphics MQD functions
  drm/amdgpu: Create context for usermode queue
  drm/amdgpu: Map userqueue into HW
  drm/amdgpu: DO-NOT-MERGE doorbell hack

 drivers/gpu/drm/amd/amdgpu/Makefile           |   3 +
 drivers/gpu/drm/amd/amdgpu/amdgpu.h           |   2 +
 drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c       |   2 +
 drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c       |   5 +
 drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.c | 365 ++++++++++++++++++
 .../amd/amdgpu/amdgpu_userqueue_mqd_gfx_v11.c | 300 ++++++++++++++
 .../gpu/drm/amd/include/amdgpu_userqueue.h    |  93 +++++
 drivers/gpu/drm/amd/include/v11_structs.h     |  16 +-
 include/uapi/drm/amdgpu_drm.h                 |  59 +++
 9 files changed, 837 insertions(+), 8 deletions(-)
 create mode 100644 drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.c
 create mode 100644 drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue_mqd_gfx_v11.c
 create mode 100644 drivers/gpu/drm/amd/include/amdgpu_userqueue.h


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