[PATCH 01/19] bus/cdx: add the cdx bus driver

Randy Dunlap rdunlap at infradead.org
Tue Jan 17 09:21:48 PST 2023


Hi--

On 1/17/23 05:41, Nipun Gupta wrote:
> Introduce AMD CDX bus, which provides a mechanism for scanning
> and probing CDX devices. These devices are memory mapped on
> system bus for Application Processors(APUs).
> 
> CDX devices can be changed dynamically in the Fabric and CDX
> bus interacts with CDX controller to rescan the bus and
> rediscover the devices.
> 
> Signed-off-by: Nipun Gupta <nipun.gupta at amd.com>
> Signed-off-by: Tarak Reddy <tarak.reddy at amd.com>
> ---
>  Documentation/ABI/testing/sysfs-bus-cdx |  12 +
>  MAINTAINERS                             |   7 +
>  drivers/bus/Kconfig                     |   1 +
>  drivers/bus/Makefile                    |   2 +
>  drivers/bus/cdx/Kconfig                 |  14 +
>  drivers/bus/cdx/Makefile                |   8 +
>  drivers/bus/cdx/cdx.c                   | 433 ++++++++++++++++++++++++
>  drivers/bus/cdx/cdx.h                   |  62 ++++
>  include/linux/cdx/cdx_bus.h             | 153 +++++++++
>  include/linux/mod_devicetable.h         |  15 +
>  scripts/mod/devicetable-offsets.c       |   4 +
>  scripts/mod/file2alias.c                |  12 +
>  12 files changed, 723 insertions(+)
>  create mode 100644 Documentation/ABI/testing/sysfs-bus-cdx
>  create mode 100644 drivers/bus/cdx/Kconfig
>  create mode 100644 drivers/bus/cdx/Makefile
>  create mode 100644 drivers/bus/cdx/cdx.c
>  create mode 100644 drivers/bus/cdx/cdx.h
>  create mode 100644 include/linux/cdx/cdx_bus.h
> 

> diff --git a/drivers/bus/cdx/Kconfig b/drivers/bus/cdx/Kconfig
> new file mode 100644
> index 000000000000..54e0623ebcff
> --- /dev/null
> +++ b/drivers/bus/cdx/Kconfig
> @@ -0,0 +1,14 @@
> +# SPDX-License-Identifier: GPL-2.0
> +#
> +# CDX bus configuration
> +#
> +# Copyright (C) 2022-2023, Advanced Micro Devices, Inc.
> +#
> +
> +config CDX_BUS
> +	bool "CDX Bus driver"
> +	help
> +	  Driver to enable CDX Bus. CDX bus provides a mechanism for
> +	  scanning and probing of CDX devices. CDX devices are memory
> +	  mapped on system bus for embedded CPUs. CDX bus uses CDX
> +	  controller and firmware to scan the CDX devices.

Would you mind telling people who use 'make *config' what CDX means,
either in the bool prompt string or in the help text?


> +/**
> + * cdx_unregister_device - Unregister a CDX device
> + * @dev: CDX device
> + * @data: This is always passed as NULL, and is not used in this API,
> + *	  but is required here as the bus_for_each_dev() API expects
> + *	  the passed function (cdx_unregister_device) to have this
> + *	  as an argument.
> + *
> + * @return: -errno on failure, 0 on success.

The syntax (or spelling) for a function's return value in kernel-doc is just:
 * Return: -errno on failure, 0 on success.

That should be changed in many places throughout.

Thanks.

-- 
~Randy



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