Re: [PATCH v2 1/5] drivers/accel: Introduce subsystem

From: Randy Dunlap
Date: Sat Jan 26 2019 - 12:09:28 EST


Hi,

Please see a few corrections inline...

On 1/25/19 1:13 PM, Olof Johansson wrote:
>
> Documentation/accelerators/README.rst | 42 +++++++++++++++++++++++++++++++++++
> MAINTAINERS | 8 +++++++
> drivers/Kconfig | 2 ++
> drivers/Makefile | 1 +
> drivers/accel/Kconfig | 16 +++++++++++++
> drivers/accel/Makefile | 5 +++++
> 6 files changed, 74 insertions(+)
> create mode 100644 Documentation/accelerators/README.rst
> create mode 100644 drivers/accel/Kconfig
> create mode 100644 drivers/accel/Makefile
>
> diff --git a/Documentation/accelerators/README.rst b/Documentation/accelerators/README.rst
> new file mode 100644
> index 0000000000000..79049ff99e93e
> --- /dev/null
> +++ b/Documentation/accelerators/README.rst
> @@ -0,0 +1,42 @@
> +.. _readme:
> +
> +Hardware offload accelerator subsystem
> +======================================
> +
> +This is a brief overview of the subsystem (grouping) of hardware
> +accelerators kept under drivers/accel
> +
> +Types of hardware supported
> +---------------------------
> +
> + The general types of hardware supported are hardware devices that has

that have

> + general interactions of sending commands and buffers to the hardware,
> + returning completions and possible filled buffers back, together
> + with the usual driver pieces around hardware control, setup, error
> + handling, etc.
> +
> + Drivers that fit into other subsystems are expected to be merged
> + there, and use the appropriate userspace interfaces of said functional
> + areas. We don't expect to see drivers for network, storage, graphics
> + and similar hardware implemented by drivers here.
> +
> +Expectations for contributions
> +------------------------------
> +
> + - Platforms and hardware that has fully open stacks, from Firmware to

that have

> + Userspace, are always going to be given preferential treatment. These
> + platforms give the best insight for behavior and interaction of all
> + layers, including ability to improve implementation across the stack
> + over time.
> +
> + - If a platform is partially proprietary, it is still expected that the
> + portions that interact the driver can be shared in a form that allows

that interact with the driver

> + for exercising the hardware/driver and evolution of the interface over
> + time. This could be separated into a shared library and test/sample
> + programs, for example.
> +
> + - Over time, there is an expectation to converge drivers over to shared
> + frameworks and interfaces. Until then, the general rule is that no
> + more than one driver per vendor will be acceptable. For vendors that
> + aren't participating in the work towards shared frameworks over time,
> + we reserve the right to phase out support for the hardware.

> diff --git a/drivers/accel/Kconfig b/drivers/accel/Kconfig
> new file mode 100644
> index 0000000000000..13b36c0398895
> --- /dev/null
> +++ b/drivers/accel/Kconfig
> @@ -0,0 +1,16 @@
> +#
> +# Drivers for hardware offload accelerators
> +# See Documentation/accel/README.rst for more details
> +#
> +
> +menuconfig ACCEL
> + bool "Hardware offload accelerator support"
> + help

Use tab instead of spaces above.

> + HW offload accelerators are used for high-bandwidth workloads
> + where a higher-level kernel/userspace interface isn't suitable.
> +
> +if ACCEL
> +
> +comment "HW Accellerator drivers"
> +
> +endif


--
~Randy