Re: [PATCH 00/13] New driver to support OpenCAPI devices on POWER9

From: Andrew Donnellan
Date: Mon Dec 18 2017 - 19:23:10 EST

On 19/12/17 02:21, Frederic Barrat wrote:
This series adds support for Open Coherent Accelerator (ocxl) devices
on POWER9 processor. OpenCAPI is a consortium developing the
specifications for an interface between processors and accelerators,
allowing sharing the host memory with the accelerators, using virtual

The OpenCAPI device can also have its own local memory and provide
access to the host, though it is not supported by that series.

The OpenCAPI specification is processor agnostic, but this series adds
support specifically for powerpc.

Even though the underlying transport is not PCI, the firmware
abstracts the hardware like a PCI host bridge and Linux sees the
OpenCAPI devices as PCI devices. So a lot of existing infrastructure
and commands can be reused.

Patches 1-5: add the platform-specific services needed by the driver
Patches 6-10: driver code
Patch 11: small correction to existing cxl driver
Patch 12: documentation

Current limitations, that will be addressed in later patches:
- no capability to trigger a reset of the opencapi adapter
- no support for the 'wake_host_thread' command
- no support for adapters with a dual-link connection (none exists yet)
- no access to the adapter-local memory

Many people contributed directly or indirectly, from the software,
hardware and bringup teams. In particular Andrew Donnellan and
Alastair D'Silva, who are developing the related firmware and library.

Feedback welcome!

[+ linux-accelerators]

The corresponding patch series for skiboot/OPAL can be found at:


Andrew Donnellan OzLabs, ADL Canberra
andrew.donnellan@xxxxxxxxxxx IBM Australia Limited