[PATCH v2 0/2] accel: Add Arm Ethos-U NPU

[Rob Herring (Arm)]

The Arm Ethos-U65/85 NPUs are designed for edge AI inference 
applications[0].

The driver works with Mesa Teflon. A merge request for Ethos support is 
here[1]. The UAPI should also be compatible with the downstream (open 
source) driver stack[2] and Vela compiler though that has not been 
implemented.

Testing so far has been on i.MX93 boards with Ethos-U65. Support for U85 
is still todo. Only minor changes on driver side will be needed for U85 
support.

A git tree is here[3].

Rob

[0] https://www.arm.com/products/silicon-ip-cpu?families=ethos%20npus
[1] https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/36699/
[2] https://gitlab.arm.com/artificial-intelligence/ethos-u/
[3] git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux.git ethos-v2

Signed-off-by: Rob Herring (Arm) <robh at kernel.org>
---
Changes in v2:
- Rebase on v6.17-rc1 adapting to scheduler changes
- scheduler: Drop the reset workqueue. According to the scheduler docs,
  we don't need it since we have a single h/w queue.
- scheduler: Rework the timeout handling to continue running if we are
  making progress. Fixes timeouts on larger jobs.
- Reset the NPU on resume so it's in a known state
- Add error handling on clk_get() calls
- Fix drm_mm splat on module unload. We were missing a put on the
  cmdstream BO in the scheduler clean-up.
- Fix 0-day report needing explicit bitfield.h include
- Link to v1: https://lore.kernel.org/r/20250722-ethos-v1-0-cc1c5a0cbbfb@kernel.org

---
Rob Herring (Arm) (2):
      dt-bindings: npu: Add Arm Ethos-U65/U85
      accel: Add Arm Ethos-U NPU driver

 .../devicetree/bindings/npu/arm,ethos.yaml         |  79 +++
 MAINTAINERS                                        |   9 +
 drivers/accel/Kconfig                              |   1 +
 drivers/accel/Makefile                             |   1 +
 drivers/accel/ethos/Kconfig                        |  10 +
 drivers/accel/ethos/Makefile                       |   4 +
 drivers/accel/ethos/ethos_device.h                 | 181 ++++++
 drivers/accel/ethos/ethos_drv.c                    | 418 ++++++++++++
 drivers/accel/ethos/ethos_drv.h                    |  15 +
 drivers/accel/ethos/ethos_gem.c                    | 707 +++++++++++++++++++++
 drivers/accel/ethos/ethos_gem.h                    |  46 ++
 drivers/accel/ethos/ethos_job.c                    | 514 +++++++++++++++
 drivers/accel/ethos/ethos_job.h                    |  41 ++
 include/uapi/drm/ethos_accel.h                     | 262 ++++++++
 14 files changed, 2288 insertions(+)
---
base-commit: 8f5ae30d69d7543eee0d70083daf4de8fe15d585
change-id: 20250715-ethos-3fdd39ef6f19

Best regards,
--  
Rob Herring (Arm) <robh at kernel.org>