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

From: Randy Dunlap
Date: Tue Jan 17 2023 - 12:24:17 EST


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@xxxxxxx>
> Signed-off-by: Tarak Reddy <tarak.reddy@xxxxxxx>
> ---
> 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