cxl: update documentation structure in prep for new docs

Restructure the cxl folder to make adding docs per-page cleaner.

Signed-off-by: Gregory Price <gourry@gourry.net>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://patch.msgid.link/20250512162134.3596150-2-gourry@gourry.net
Signed-off-by: Dave Jiang <dave.jiang@intel.com>

Documentation/driver-api/cxl/index.rst

@@ -4,12 +4,22 @@
 Compute Express Link
 ====================
 
+CXL device configuration has a complex handoff between platform (Hardware,
+BIOS, EFI), OS (early boot, core kernel, driver), and user policy decisions
+that have impacts on each other.  The docs here break up configurations steps.
+
 .. toctree::
-   :maxdepth: 1
-
-   memory-devices
-   access-coordinates
+   :maxdepth: 2
+   :caption: Overview
 
+   theory-of-operation
    maturity-map
 
+.. toctree::
+   :maxdepth: 1
+   :caption: Linux Kernel Configuration
+
+   linux/access-coordinates
+
+
 .. only::  subproject and html

Documentation/driver-api/cxl/theory-of-operation.rst

@@ -1,9 +1,9 @@
 .. SPDX-License-Identifier: GPL-2.0
 .. include:: <isonum.txt>
 
-===================================
-Compute Express Link Memory Devices
-===================================
+===============================================
+Compute Express Link Driver Theory of Operation
+===============================================
 
 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,
@@ -14,8 +14,8 @@ that optionally define a device's contribution to an interleaved address
 range across multiple devices underneath a host-bridge or interleaved
 across host-bridges.
 
-CXL Bus: Theory of Operation
-============================
+The CXL Bus
+===========
 Similar to how a RAID driver takes disk objects and assembles them into a new
 logical device, the CXL subsystem is tasked to take PCIe and ACPI objects and
 assemble them into a CXL.mem decode topology. The need for runtime configuration