Commit 2959ab24 authored Mar 13, 2023 by Nipun Gupta Committed by Greg Kroah-Hartman Mar 29, 2023

cdx: add the cdx bus driver



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@amd.com>
Reviewed-by: Pieter Jansen van Vuuren <pieter.jansen-van-vuuren@amd.com>
Tested-by: Nikhil Agarwal <nikhil.agarwal@amd.com>
Link: https://lore.kernel.org/r/20230313132636.31850-2-nipun.gupta@amd.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 71d74aaa

Documentation/ABI/testing/sysfs-bus-cdx

0 → 100644

+12 −0

Original line number	Diff line number	Diff line
		What: /sys/bus/cdx/rescan
		Date: March 2023
		Contact: nipun.gupta@amd.com
		Description:
		Writing y/1/on to this file will cause rescan of the bus
		and devices on the CDX bus. Any new devices are scanned and
		added to the list of Linux devices and any devices removed are
		also deleted from Linux.

		For example::

		# echo 1 > /sys/bus/cdx/rescan

MAINTAINERS

+7 −0

Original line number	Diff line number	Diff line
		@@ -964,6 +964,13 @@ Q: https://patchwork.kernel.org/project/linux-rdma/list/
		F: drivers/infiniband/hw/efa/
		F: include/uapi/rdma/efa-abi.h

		AMD CDX BUS DRIVER
		M: Nipun Gupta <nipun.gupta@amd.com>
		M: Nikhil Agarwal <nikhil.agarwal@amd.com>
		S: Maintained
		F: drivers/cdx/*
		F: include/linux/cdx/*

		AMD CRYPTOGRAPHIC COPROCESSOR (CCP) DRIVER
		M: Tom Lendacky <thomas.lendacky@amd.com>
		M: John Allen <john.allen@amd.com>

drivers/Kconfig

+2 −0

Original line number	Diff line number	Diff line
		@@ -241,4 +241,6 @@ source "drivers/peci/Kconfig"

		source "drivers/hte/Kconfig"

		source "drivers/cdx/Kconfig"

		endmenu

drivers/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -194,3 +194,4 @@ obj-$(CONFIG_MOST) += most/
		obj-$(CONFIG_PECI) += peci/
		obj-$(CONFIG_HTE) += hte/
		obj-$(CONFIG_DRM_ACCEL) += accel/
		obj-$(CONFIG_CDX_BUS) += cdx/

drivers/cdx/Kconfig

0 → 100644

+17 −0

Original line number	Diff line number	Diff line
		# SPDX-License-Identifier: GPL-2.0
		#
		# CDX bus configuration
		#
		# Copyright (C) 2022-2023, Advanced Micro Devices, Inc.
		#

		config CDX_BUS
		bool "CDX Bus driver"
		depends on OF && ARM64
		help
		Driver to enable Composable DMA Transfer(CDX) Bus. CDX bus
		exposes Fabric devices which uses composable DMA IP to the
		APU. 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 these CDX devices.