54 lines
2.2 KiB
Plaintext
54 lines
2.2 KiB
Plaintext
# SPDX-License-Identifier: GPL-2.0-only
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menuconfig CXL_BUS
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tristate "CXL (Compute Express Link) Devices Support"
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depends on PCI
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help
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CXL is a bus that is electrically compatible with PCI Express, but
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layers three protocols on that signalling (CXL.io, CXL.cache, and
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CXL.mem). The CXL.cache protocol allows devices to hold cachelines
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locally, the CXL.mem protocol allows devices to be fully coherent
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memory targets, the CXL.io protocol is equivalent to PCI Express.
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Say 'y' to enable support for the configuration and management of
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devices supporting these protocols.
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if CXL_BUS
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config CXL_MEM
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tristate "CXL.mem: Memory Devices"
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help
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The CXL.mem protocol allows a device to act as a provider of
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"System RAM" and/or "Persistent Memory" that is fully coherent
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as if the memory was attached to the typical CPU memory
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controller.
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Say 'y/m' to enable a driver (named "cxl_mem.ko" when built as
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a module) that will attach to CXL.mem devices for
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configuration, provisioning, and health monitoring. This
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driver is required for dynamic provisioning of CXL.mem
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attached memory which is a prerequisite for persistent memory
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support. Typically volatile memory is mapped by platform
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firmware and included in the platform memory map, but in some
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cases the OS is responsible for mapping that memory. See
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Chapter 2.3 Type 3 CXL Device in the CXL 2.0 specification.
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If unsure say 'm'.
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config CXL_MEM_RAW_COMMANDS
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bool "RAW Command Interface for Memory Devices"
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depends on CXL_MEM
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help
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Enable CXL RAW command interface.
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The CXL driver ioctl interface may assign a kernel ioctl command
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number for each specification defined opcode. At any given point in
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time the number of opcodes that the specification defines and a device
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may implement may exceed the kernel's set of associated ioctl function
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numbers. The mismatch is either by omission, specification is too new,
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or by design. When prototyping new hardware, or developing / debugging
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the driver it is useful to be able to submit any possible command to
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the hardware, even commands that may crash the kernel due to their
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potential impact to memory currently in use by the kernel.
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If developing CXL hardware or the driver say Y, otherwise say N.
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endif
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