Merge tag 'cxl-for-5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl

Pull CXL (Compute Express Link) updates from Dan Williams:
 "This subsystem is still in the build-out phase as the bulk of the
  update is improvements to enumeration and fleshing out the device
  model. In terms of new features, more mailbox commands have been added
  to the allowed-list in support of persistent memory provisioning
  support targeting v5.15.

  The critical update from an enumeration perspective is support for the
  CXL Fixed Memory Window Structure that indicates to Linux which system
  physical address ranges decode to the CXL Host Bridges in the system.
  This allows the driver to detect which address ranges have been mapped
  by firmware and what address ranges are available for future hotplug.

  So, again, mostly skeleton this round, with more meat targeting v5.15.

  Summary:

   - Add support for the CXL Fixed Memory Window Structure, a recent
     extension of the ACPI CEDT (CXL Early Discovery Table)

   - Add infrastructure for component registers

   - Add HDM (Host-managed device memory) decoder definitions

   - Define a device model for an HDM decoder tree

   - Bridge CXL persistent memory capabilities to an NVDIMM bus /
     device-model

   - Switch to fine grained mapping of CXL MMIO registers to allow
     different drivers / system software to own individual register
     blocks

   - Enable media provisioning commands, and publish the label storage
     area size in sysfs

   - Miscellaneous cleanups and fixes"

* tag 'cxl-for-5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl: (34 commits)
  cxl/pci: Rename CXL REGLOC ID
  cxl/acpi: Use the ACPI CFMWS to create static decoder objects
  cxl/acpi: Add the Host Bridge base address to CXL port objects
  cxl/pmem: Register 'pmem' / cxl_nvdimm devices
  libnvdimm: Drop unused device power management support
  libnvdimm: Export nvdimm shutdown helper, nvdimm_delete()
  cxl/pmem: Add initial infrastructure for pmem support
  cxl/core: Add cxl-bus driver infrastructure
  cxl/pci: Add media provisioning required commands
  cxl/component_regs: Fix offset
  cxl/hdm: Fix decoder count calculation
  cxl/acpi: Introduce cxl_decoder objects
  cxl/acpi: Enumerate host bridge root ports
  cxl/acpi: Add downstream port data to cxl_port instances
  cxl/Kconfig: Default drivers to CONFIG_CXL_BUS
  cxl/acpi: Introduce the root of a cxl_port topology
  cxl/pci: Fixup devm_cxl_iomap_block() to take a 'struct device *'
  cxl/pci: Add HDM decoder capabilities
  cxl/pci: Reserve individual register block regions
  cxl/pci: Map registers based on capabilities
  ...

1 files changed, 103 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl
index 2fe7490ad6a8..0b6a2e6e8fbb 100644
--- a/Documentation/ABI/testing/sysfs-bus-cxl
+++ b/Documentation/ABI/testing/sysfs-bus-cxl
@@ -24,3 +24,106 @@ Description:
 		(RO) "Persistent Only Capacity" as bytes. Represents the
 		identically named field in the Identify Memory Device Output
 		Payload in the CXL-2.0 specification.
+
+What:		/sys/bus/cxl/devices/*/devtype
+Date:		June, 2021
+KernelVersion:	v5.14
+Contact:	linux-cxl@vger.kernel.org
+Description:
+		CXL device objects export the devtype attribute which mirrors
+		the same value communicated in the DEVTYPE environment variable
+		for uevents for devices on the "cxl" bus.
+
+What:		/sys/bus/cxl/devices/portX/uport
+Date:		June, 2021
+KernelVersion:	v5.14
+Contact:	linux-cxl@vger.kernel.org
+Description:
+		CXL port objects are enumerated from either a platform firmware
+		device (ACPI0017 and ACPI0016) or PCIe switch upstream port with
+		CXL component registers. The 'uport' symlink connects the CXL
+		portX object to the device that published the CXL port
+		capability.
+
+What:		/sys/bus/cxl/devices/portX/dportY
+Date:		June, 2021
+KernelVersion:	v5.14
+Contact:	linux-cxl@vger.kernel.org
+Description:
+		CXL port objects are enumerated from either a platform firmware
+		device (ACPI0017 and ACPI0016) or PCIe switch upstream port with
+		CXL component registers. The 'dportY' symlink identifies one or
+		more downstream ports that the upstream port may target in its
+		decode of CXL memory resources.  The 'Y' integer reflects the
+		hardware port unique-id used in the hardware decoder target
+		list.
+
+What:		/sys/bus/cxl/devices/decoderX.Y
+Date:		June, 2021
+KernelVersion:	v5.14
+Contact:	linux-cxl@vger.kernel.org
+Description:
+		CXL decoder objects are enumerated from either a platform
+		firmware description, or a CXL HDM decoder register set in a
+		PCIe device (see CXL 2.0 section 8.2.5.12 CXL HDM Decoder
+		Capability Structure). The 'X' in decoderX.Y represents the
+		cxl_port container of this decoder, and 'Y' represents the
+		instance id of a given decoder resource.
+
+What:		/sys/bus/cxl/devices/decoderX.Y/{start,size}
+Date:		June, 2021
+KernelVersion:	v5.14
+Contact:	linux-cxl@vger.kernel.org
+Description:
+		The 'start' and 'size' attributes together convey the physical
+		address base and number of bytes mapped in the decoder's decode
+		window. For decoders of devtype "cxl_decoder_root" the address
+		range is fixed. For decoders of devtype "cxl_decoder_switch" the
+		address is bounded by the decode range of the cxl_port ancestor
+		of the decoder's cxl_port, and dynamically updates based on the
+		active memory regions in that address space.
+
+What:		/sys/bus/cxl/devices/decoderX.Y/locked
+Date:		June, 2021
+KernelVersion:	v5.14
+Contact:	linux-cxl@vger.kernel.org
+Description:
+		CXL HDM decoders have the capability to lock the configuration
+		until the next device reset. For decoders of devtype
+		"cxl_decoder_root" there is no standard facility to unlock them.
+		For decoders of devtype "cxl_decoder_switch" a secondary bus
+		reset, of the PCIe bridge that provides the bus for this
+		decoders uport, unlocks / resets the decoder.
+
+What:		/sys/bus/cxl/devices/decoderX.Y/target_list
+Date:		June, 2021
+KernelVersion:	v5.14
+Contact:	linux-cxl@vger.kernel.org
+Description:
+		Display a comma separated list of the current decoder target
+		configuration. The list is ordered by the current configured
+		interleave order of the decoder's dport instances. Each entry in
+		the list is a dport id.
+
+What:		/sys/bus/cxl/devices/decoderX.Y/cap_{pmem,ram,type2,type3}
+Date:		June, 2021
+KernelVersion:	v5.14
+Contact:	linux-cxl@vger.kernel.org
+Description:
+		When a CXL decoder is of devtype "cxl_decoder_root", it
+		represents a fixed memory window identified by platform
+		firmware. A fixed window may only support a subset of memory
+		types. The 'cap_*' attributes indicate whether persistent
+		memory, volatile memory, accelerator memory, and / or expander
+		memory may be mapped behind this decoder's memory window.
+
+What:		/sys/bus/cxl/devices/decoderX.Y/target_type
+Date:		June, 2021
+KernelVersion:	v5.14
+Contact:	linux-cxl@vger.kernel.org
+Description:
+		When a CXL decoder is of devtype "cxl_decoder_switch", it can
+		optionally decode either accelerator memory (type-2) or expander
+		memory (type-3). The 'target_type' attribute indicates the
+		current setting which may dynamically change based on what
+		memory regions are activated in this decode hierarchy.