linux/drivers/cxl/Kconfig

# SPDX-License-Identifier: GPL-2.0-only
menuconfig CXL_BUS
	tristate "CXL (Compute Express Link) Devices Support"
	depends on PCI
	help
	  CXL is a bus that is electrically compatible with PCI Express, but
	  layers three protocols on that signalling (CXL.io, CXL.cache, and
	  CXL.mem). The CXL.cache protocol allows devices to hold cachelines
	  locally, the CXL.mem protocol allows devices to be fully coherent
	  memory targets, the CXL.io protocol is equivalent to PCI Express.
	  Say 'y' to enable support for the configuration and management of
	  devices supporting these protocols.

if CXL_BUS

config CXL_MEM
	tristate "CXL.mem: Memory Devices"
	help
	  The CXL.mem protocol allows a device to act as a provider of
	  "System RAM" and/or "Persistent Memory" that is fully coherent
	  as if the memory was attached to the typical CPU memory
	  controller.

	  Say 'y/m' to enable a driver (named "cxl_mem.ko" when built as
	  a module) that will attach to CXL.mem devices for
	  configuration, provisioning, and health monitoring. This
	  driver is required for dynamic provisioning of CXL.mem
	  attached memory which is a prerequisite for persistent memory
	  support. Typically volatile memory is mapped by platform
	  firmware and included in the platform memory map, but in some
	  cases the OS is responsible for mapping that memory. See
	  Chapter 2.3 Type 3 CXL Device in the CXL 2.0 specification.

	  If unsure say 'm'.

config CXL_MEM_RAW_COMMANDS
	bool "RAW Command Interface for Memory Devices"
	depends on CXL_MEM
	help
	  Enable CXL RAW command interface.

	  The CXL driver ioctl interface may assign a kernel ioctl command
	  number for each specification defined opcode. At any given point in
	  time the number of opcodes that the specification defines and a device
	  may implement may exceed the kernel's set of associated ioctl function
	  numbers. The mismatch is either by omission, specification is too new,
	  or by design. When prototyping new hardware, or developing / debugging
	  the driver it is useful to be able to submit any possible command to
	  the hardware, even commands that may crash the kernel due to their
	  potential impact to memory currently in use by the kernel.

	  If developing CXL hardware or the driver say Y, otherwise say N.
endif