Merge tag 'cxl-for-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl

Pull compute express link (CXL) updates from Dave Jiang:
 "The additions of note are adding CXL region remove support for locked
  CXL decoders, adding unit testing support for XOR address translation,
  and adding unit testing support for extended linear cache.

  Misc:
   - Remove incorrect page-allocator quirk section in documentation
   - Remove unused devm_cxl_port_enumerate_dports() function
   - Fix typo in cdat.c code comment
   - Replace use of system_wq with system_percpu_wq
   - Add locked CXL decoder support for region removal
   - Return when generic target updated
   - Rename region_res_match_cxl_range() to spa_maps_hpa()
   - Clarify comment in spa_maps_hpa()

  Enable unit testing for XOR address translation of SPA to DPA and vice versa:
   - Refactor address translation funcs for testing in cxl_region
   - Make the XOR calculations available for testing
   - Add cxl_translate module for address translation testing in
     cxl_test

  Extended Linear Cache changes:
   - Add extended linear cache size sysfs attribute
   - Adjust failure emission of extended linear cache detection in
     cxl_acpi
   - Added extended linear cache unit testing support in cxl_test

  Preparation refactor patches for PRM translation support:
   - Simplify cxl_rd_ops allocation and handling
   - Group xor arithmetric setup code in a single block
   - Remove local variable @inc in cxl_port_setup_targets()"

* tag 'cxl-for-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl: (22 commits)
  cxl/test: Assign overflow_err_count from log->nr_overflow
  cxl/test: Remove ret_limit race condition in mock_get_event()
  cxl/test: remove unused mock function for cxl_rcd_component_reg_phys()
  cxl/test: Add support for acpi extended linear cache
  cxl/test: Add cxl_test CFMWS support for extended linear cache
  cxl/test: Standardize CXL auto region size
  cxl/region: Remove local variable @inc in cxl_port_setup_targets()
  cxl/acpi: Group xor arithmetric setup code in a single block
  cxl: Simplify cxl_rd_ops allocation and handling
  cxl: Clarify comment in spa_maps_hpa()
  cxl: Rename region_res_match_cxl_range() to spa_maps_hpa()
  acpi/hmat: Return when generic target is updated
  cxl: Add handling of locked CXL decoder
  cxl/region: Add support to indicate region has extended linear cache
  cxl: Adjust extended linear cache failure emission in cxl_acpi
  cxl/test: Add cxl_translate module for address translation testing
  cxl/acpi: Make the XOR calculations available for testing
  cxl/region: Refactor address translation funcs for testing
  cxl/pci: replace use of system_wq with system_percpu_wq
  cxl: fix typos in cdat.c comments
  ...

2 files changed, 10 insertions, 32 deletions

diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl
index 6b4e8c7a963d..c80a1b5a03db 100644
--- a/Documentation/ABI/testing/sysfs-bus-cxl
+++ b/Documentation/ABI/testing/sysfs-bus-cxl
@@ -496,8 +496,17 @@ Description:
 		changed, only freed by writing 0. The kernel makes no guarantees
 		that data is maintained over an address space freeing event, and
 		there is no guarantee that a free followed by an allocate
-		results in the same address being allocated.
+		results in the same address being allocated. If extended linear
+		cache is present, the size indicates extended linear cache size
+		plus the CXL region size.
 
+What:		/sys/bus/cxl/devices/regionZ/extended_linear_cache_size
+Date:		October, 2025
+KernelVersion:	v6.19
+Contact:	linux-cxl@vger.kernel.org
+Description:
+		(RO) The size of extended linear cache, if there is an extended
+		linear cache. Otherwise the attribute will not be visible.
 
 What:		/sys/bus/cxl/devices/regionZ/mode
 Date:		January, 2023
diff --git a/Documentation/driver-api/cxl/allocation/page-allocator.rst b/Documentation/driver-api/cxl/allocation/page-allocator.rst
index 7b8fe1b8d5bb..3fa584a248bd 100644
--- a/Documentation/driver-api/cxl/allocation/page-allocator.rst
+++ b/Documentation/driver-api/cxl/allocation/page-allocator.rst
@@ -41,37 +41,6 @@ To simplify this, the page allocator will prefer :code:`ZONE_MOVABLE` over
 will fallback to allocate from :code:`ZONE_NORMAL`.
 
 
-Zone and Node Quirks
-====================
-Let's consider a configuration where the local DRAM capacity is largely onlined
-into :code:`ZONE_NORMAL`, with no :code:`ZONE_MOVABLE` capacity present. The
-CXL capacity has the opposite configuration - all onlined in
-:code:`ZONE_MOVABLE`.
-
-Under the default allocation policy, the page allocator will completely skip
-:code:`ZONE_MOVABLE` as a valid allocation target.  This is because, as of
-Linux v6.15, the page allocator does (approximately) the following: ::
-
-  for (each zone in local_node):
-
-    for (each node in fallback_order):
-
-      attempt_allocation(gfp_flags);
-
-Because the local node does not have :code:`ZONE_MOVABLE`, the CXL node is
-functionally unreachable for direct allocation.  As a result, the only way
-for CXL capacity to be used is via `demotion` in the reclaim path.
-
-This configuration also means that if the DRAM ndoe has :code:`ZONE_MOVABLE`
-capacity - when that capacity is depleted, the page allocator will actually
-prefer CXL :code:`ZONE_MOVABLE` pages over DRAM :code:`ZONE_NORMAL` pages.
-
-We may wish to invert this priority in future Linux versions.
-
-If `demotion` and `swap` are disabled, Linux will begin to cause OOM crashes
-when the DRAM nodes are depleted. See the reclaim section for more details.
-
-
 CGroups and CPUSets
 ===================
 Finally, assuming CXL memory is reachable via the page allocation (i.e. onlined