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-rw-r--r--Documentation/ABI/testing/sysfs-bus-cxl26
-rw-r--r--Documentation/driver-api/cxl/index.rst12
-rw-r--r--Documentation/driver-api/cxl/memory-devices.rst46
-rw-r--r--Documentation/driver-api/index.rst1
-rw-r--r--Documentation/userspace-api/ioctl/ioctl-number.rst1
5 files changed, 86 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl
new file mode 100644
index 000000000000..2fe7490ad6a8
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-cxl
@@ -0,0 +1,26 @@
+What: /sys/bus/cxl/devices/memX/firmware_version
+Date: December, 2020
+KernelVersion: v5.12
+Contact: linux-cxl@vger.kernel.org
+Description:
+ (RO) "FW Revision" string as reported by the Identify
+ Memory Device Output Payload in the CXL-2.0
+ specification.
+
+What: /sys/bus/cxl/devices/memX/ram/size
+Date: December, 2020
+KernelVersion: v5.12
+Contact: linux-cxl@vger.kernel.org
+Description:
+ (RO) "Volatile 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/memX/pmem/size
+Date: December, 2020
+KernelVersion: v5.12
+Contact: linux-cxl@vger.kernel.org
+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.
diff --git a/Documentation/driver-api/cxl/index.rst b/Documentation/driver-api/cxl/index.rst
new file mode 100644
index 000000000000..036e49553542
--- /dev/null
+++ b/Documentation/driver-api/cxl/index.rst
@@ -0,0 +1,12 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+====================
+Compute Express Link
+====================
+
+.. toctree::
+ :maxdepth: 1
+
+ memory-devices
+
+.. only:: subproject and html
diff --git a/Documentation/driver-api/cxl/memory-devices.rst b/Documentation/driver-api/cxl/memory-devices.rst
new file mode 100644
index 000000000000..1bad466f9167
--- /dev/null
+++ b/Documentation/driver-api/cxl/memory-devices.rst
@@ -0,0 +1,46 @@
+.. SPDX-License-Identifier: GPL-2.0
+.. include:: <isonum.txt>
+
+===================================
+Compute Express Link Memory Devices
+===================================
+
+A Compute Express Link Memory Device is a CXL component that implements the
+CXL.mem protocol. It contains some amount of volatile memory, persistent memory,
+or both. It is enumerated as a PCI device for configuration and passing
+messages over an MMIO mailbox. Its contribution to the System Physical
+Address space is handled via HDM (Host Managed Device Memory) decoders
+that optionally define a device's contribution to an interleaved address
+range across multiple devices underneath a host-bridge or interleaved
+across host-bridges.
+
+Driver Infrastructure
+=====================
+
+This section covers the driver infrastructure for a CXL memory device.
+
+CXL Memory Device
+-----------------
+
+.. kernel-doc:: drivers/cxl/mem.c
+ :doc: cxl mem
+
+.. kernel-doc:: drivers/cxl/mem.c
+ :internal:
+
+CXL Bus
+-------
+.. kernel-doc:: drivers/cxl/bus.c
+ :doc: cxl bus
+
+External Interfaces
+===================
+
+CXL IOCTL Interface
+-------------------
+
+.. kernel-doc:: include/uapi/linux/cxl_mem.h
+ :doc: UAPI
+
+.. kernel-doc:: include/uapi/linux/cxl_mem.h
+ :internal:
diff --git a/Documentation/driver-api/index.rst b/Documentation/driver-api/index.rst
index 9d9af54d68c5..9ba74e86751b 100644
--- a/Documentation/driver-api/index.rst
+++ b/Documentation/driver-api/index.rst
@@ -35,6 +35,7 @@ available subsections can be seen below.
usb/index
firewire
pci/index
+ cxl/index
spi
i2c
ipmb
diff --git a/Documentation/userspace-api/ioctl/ioctl-number.rst b/Documentation/userspace-api/ioctl/ioctl-number.rst
index d02ba2f67df8..2fe16fb8c3af 100644
--- a/Documentation/userspace-api/ioctl/ioctl-number.rst
+++ b/Documentation/userspace-api/ioctl/ioctl-number.rst
@@ -353,6 +353,7 @@ Code Seq# Include File Comments
<mailto:michael.klein@puffin.lb.shuttle.de>
0xCC 00-0F drivers/misc/ibmvmc.h pseries VMC driver
0xCD 01 linux/reiserfs_fs.h
+0xCE 01-02 uapi/linux/cxl_mem.h Compute Express Link Memory Devices
0xCF 02 fs/cifs/ioctl.c
0xDB 00-0F drivers/char/mwave/mwavepub.h
0xDD 00-3F ZFCP device driver see drivers/s390/scsi/