Merge tag 'cxl-for-5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull initial support for CXL (Compute Express Link) from Dan Williams:
 "Introduce an initial driver for CXL 2.0 Type-3 Memory Devices.

  CXL is Compute Express Link which released the 2.0 specification in
  November. The Linux relevant changes in CXL 2.0 are support for an OS
  to dynamically assign address space to memory devices, support for
  switches, persistent memory, and hotplug.

  A Type-3 Memory Device is a PCI enumerated device presenting the CXL
  Memory Device Class Code and implementing the CXL.mem protocol.
  CXL.mem allows device to advertise CPU and I/O coherent memory to the
  system, i.e. typical "System RAM" and "Persistent Memory" in Linux
  /proc/iomem terms.

  In addition to the CXL.mem fast path there is an administrative
  command hardware mailbox interface for maintenance and provisioning.
  It is this command interface that is the focus of the initial driver.
  With this driver a CXL device that is mapped by the BIOS can be
  administered by Linux.

  Linux support for CXL PMEM and dynamic CXL address space management
  are to be implemented post v5.12"

Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
  4cdadfd5e0a7 ("cxl/mem: Introduce a driver for CXL-2.0-Type-3 endpoints")
  13237183c735 ("cxl/mem: Add a "RAW" send command")
  472b1ce6e9d6 ("cxl/mem: Enable commands via CEL")
  57ee605b976c ("cxl/mem: Add set of informational commands")

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
  8adaf747c9f0 ("cxl/mem: Find device capabilities")
  b39cb1052a5c ("cxl/mem: Register CXL memX devices")

* tag 'cxl-for-5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  cxl/mem: Fix potential memory leak
  cxl/mem: Return -EFAULT if copy_to_user() fails
  MAINTAINERS: Add maintainers of the CXL driver
  cxl/mem: Add set of informational commands
  cxl/mem: Enable commands via CEL
  cxl/mem: Add a "RAW" send command
  cxl/mem: Add basic IOCTL interface
  cxl/mem: Register CXL memX devices
  cxl/mem: Find device capabilities
  cxl/mem: Introduce a driver for CXL-2.0-Type-3 endpoints