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
...

Documentation/ABI/testing/sysfs-bus-cxl

···
 		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:	[e-mail]
+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

Documentation/driver-api/cxl/allocation/page-allocator.rst

···
 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

drivers/acpi/numa/hmat.c

···
 	 * Register generic port perf numbers. The nid may not be
 	 * initialized and is still NUMA_NO_NODE.
 	 */
-	mutex_lock(&target_lock);
-	if (*(u16 *)target->gen_port_device_handle) {
-		hmat_update_generic_target(target);
-		target->registered = true;
+	scoped_guard(mutex, &target_lock) {
+		if (*(u16 *)target->gen_port_device_handle) {
+			hmat_update_generic_target(target);
+			target->registered = true;
+			return;
+		}
 	}
-	mutex_unlock(&target_lock);
 
 	hmat_hotplug_target(target);
 }

drivers/cxl/acpi.c

···
 #include "cxlpci.h"
 #include "cxl.h"
 
-struct cxl_cxims_data {
-	int nr_maps;
-	u64 xormaps[] __counted_by(nr_maps);
-};
-
 static const guid_t acpi_cxl_qtg_id_guid =
 	GUID_INIT(0xF365F9A6, 0xA7DE, 0x4071,
 		  0xA6, 0x6A, 0xB4, 0x0C, 0x0B, 0x4F, 0x8E, 0x52);
 
-static u64 cxl_apply_xor_maps(struct cxl_root_decoder *cxlrd, u64 addr)
+#define HBIW_TO_NR_MAPS_SIZE (CXL_DECODER_MAX_INTERLEAVE + 1)
+static const int hbiw_to_nr_maps[HBIW_TO_NR_MAPS_SIZE] = {
+	[1] = 0, [2] = 1, [3] = 0, [4] = 2, [6] = 1, [8] = 3, [12] = 2, [16] = 4
+};
+
+static const int valid_hbiw[] = { 1, 2, 3, 4, 6, 8, 12, 16 };
+
+u64 cxl_do_xormap_calc(struct cxl_cxims_data *cximsd, u64 addr, int hbiw)
 {
-	struct cxl_cxims_data *cximsd = cxlrd->platform_data;
-	int hbiw = cxlrd->cxlsd.nr_targets;
+	int nr_maps_to_apply = -1;
 	u64 val;
 	int pos;
 
-	/* No xormaps for host bridge interleave ways of 1 or 3 */
-	if (hbiw == 1 || hbiw == 3)
-		return addr;
+	/*
+	 * Strictly validate hbiw since this function is used for testing and
+	 * that nullifies any expectation of trusted parameters from the CXL
+	 * Region Driver.
+	 */
+	for (int i = 0; i < ARRAY_SIZE(valid_hbiw); i++) {
+		if (valid_hbiw[i] == hbiw) {
+			nr_maps_to_apply = hbiw_to_nr_maps[hbiw];
+			break;
+		}
+	}
+	if (nr_maps_to_apply == -1 || nr_maps_to_apply > cximsd->nr_maps)
+		return ULLONG_MAX;
 
 	/*
 	 * In regions using XOR interleave arithmetic the CXL HPA may not
···
 	}
 
 	return addr;
+}
+EXPORT_SYMBOL_FOR_MODULES(cxl_do_xormap_calc, "cxl_translate");
+
+static u64 cxl_apply_xor_maps(struct cxl_root_decoder *cxlrd, u64 addr)
+{
+	struct cxl_cxims_data *cximsd = cxlrd->platform_data;
+
+	return cxl_do_xormap_calc(cximsd, addr, cxlrd->cxlsd.nr_targets);
 }
 
 struct cxl_cxims_context {
···
 
 	rc = hmat_get_extended_linear_cache_size(&res, nid, &cache_size);
 	if (rc)
-		return rc;
+		return 0;
 
 	/*
 	 * The cache range is expected to be within the CFMWS.
···
 	int rc;
 
 	rc = cxl_acpi_set_cache_size(cxlrd);
-	if (!rc)
-		return;
-
-	if (rc != -EOPNOTSUPP) {
+	if (rc) {
 		/*
-		 * Failing to support extended linear cache region resize does not
+		 * Failing to retrieve extended linear cache region resize does not
 		 * prevent the region from functioning. Only causes cxl list showing
 		 * incorrect region size.
 		 */
 		dev_warn(cxlrd->cxlsd.cxld.dev.parent,
-			 "Extended linear cache calculation failed rc:%d\n", rc);
-	}
+			 "Extended linear cache retrieval failed rc:%d\n", rc);
 
-	/* Ignoring return code */
-	cxlrd->cache_size = 0;
+		/* Ignoring return code */
+		cxlrd->cache_size = 0;
+	}
 }
 
 DEFINE_FREE(put_cxlrd, struct cxl_root_decoder *,
···
 		ig = CXL_DECODER_MIN_GRANULARITY;
 	cxld->interleave_granularity = ig;
 
-	cxl_setup_extended_linear_cache(cxlrd);
-
 	if (cfmws->interleave_arithmetic == ACPI_CEDT_CFMWS_ARITHMETIC_XOR) {
 		if (ways != 1 && ways != 3) {
 			cxims_ctx = (struct cxl_cxims_context) {
···
 				return -EINVAL;
 			}
 		}
+		cxlrd->ops.hpa_to_spa = cxl_apply_xor_maps;
+		cxlrd->ops.spa_to_hpa = cxl_apply_xor_maps;
 	}
+
+	cxl_setup_extended_linear_cache(cxlrd);
 
 	cxlrd->qos_class = cfmws->qtg_id;
-
-	if (cfmws->interleave_arithmetic == ACPI_CEDT_CFMWS_ARITHMETIC_XOR) {
-		cxlrd->ops = kzalloc(sizeof(*cxlrd->ops), GFP_KERNEL);
-		if (!cxlrd->ops)
-			return -ENOMEM;
-
-		cxlrd->ops->hpa_to_spa = cxl_apply_xor_maps;
-		cxlrd->ops->spa_to_hpa = cxl_apply_xor_maps;
-	}
 
 	rc = cxl_decoder_add(cxld);
 	if (rc)

drivers/cxl/core/cdat.c

···
 		cxl_coordinates_combine(coords, coords, ctx->coord);
 
 		/*
-		 * Take the min of the calculated bandwdith and the upstream
+		 * Take the min of the calculated bandwidth and the upstream
 		 * switch SSLBIS bandwidth if there's a parent switch
 		 */
 		if (!is_root)
···
 /**
  * cxl_region_update_bandwidth - Update the bandwidth access coordinates of a region
  * @cxlr: The region being operated on
- * @input_xa: xarray holds cxl_perf_ctx wht calculated bandwidth per ACPI0017 instance
+ * @input_xa: xarray holds cxl_perf_ctx with calculated bandwidth per ACPI0017 instance
  */
 static void cxl_region_update_bandwidth(struct cxl_region *cxlr,
 					struct xarray *input_xa)

drivers/cxl/core/hdm.c

···
 	if ((cxld->flags & CXL_DECODER_F_ENABLE) == 0)
 		return;
 
+	if (test_bit(CXL_DECODER_F_LOCK, &cxld->flags))
+		return;
+
 	if (port->commit_end == id)
 		cxl_port_commit_reap(cxld);
 	else

drivers/cxl/core/pci.c

···
 }
 EXPORT_SYMBOL_NS_GPL(__devm_cxl_add_dport_by_dev, "CXL");
 
-struct cxl_walk_context {
-	struct pci_bus *bus;
-	struct cxl_port *port;
-	int type;
-	int error;
-	int count;
-};
-
-static int match_add_dports(struct pci_dev *pdev, void *data)
-{
-	struct cxl_walk_context *ctx = data;
-	struct cxl_port *port = ctx->port;
-	int type = pci_pcie_type(pdev);
-	struct cxl_register_map map;
-	struct cxl_dport *dport;
-	u32 lnkcap, port_num;
-	int rc;
-
-	if (pdev->bus != ctx->bus)
-		return 0;
-	if (!pci_is_pcie(pdev))
-		return 0;
-	if (type != ctx->type)
-		return 0;
-	if (pci_read_config_dword(pdev, pci_pcie_cap(pdev) + PCI_EXP_LNKCAP,
-				  &lnkcap))
-		return 0;
-
-	rc = cxl_find_regblock(pdev, CXL_REGLOC_RBI_COMPONENT, &map);
-	if (rc)
-		dev_dbg(&port->dev, "failed to find component registers\n");
-
-	port_num = FIELD_GET(PCI_EXP_LNKCAP_PN, lnkcap);
-	dport = devm_cxl_add_dport(port, &pdev->dev, port_num, map.resource);
-	if (IS_ERR(dport)) {
-		ctx->error = PTR_ERR(dport);
-		return PTR_ERR(dport);
-	}
-	ctx->count++;
-
-	return 0;
-}
-
-/**
- * devm_cxl_port_enumerate_dports - enumerate downstream ports of the upstream port
- * @port: cxl_port whose ->uport_dev is the upstream of dports to be enumerated
- *
- * Returns a positive number of dports enumerated or a negative error
- * code.
- */
-int devm_cxl_port_enumerate_dports(struct cxl_port *port)
-{
-	struct pci_bus *bus = cxl_port_to_pci_bus(port);
-	struct cxl_walk_context ctx;
-	int type;
-
-	if (!bus)
-		return -ENXIO;
-
-	if (pci_is_root_bus(bus))
-		type = PCI_EXP_TYPE_ROOT_PORT;
-	else
-		type = PCI_EXP_TYPE_DOWNSTREAM;
-
-	ctx = (struct cxl_walk_context) {
-		.port = port,
-		.bus = bus,
-		.type = type,
-	};
-	pci_walk_bus(bus, match_add_dports, &ctx);
-
-	if (ctx.count == 0)
-		return -ENODEV;
-	if (ctx.error)
-		return ctx.error;
-	return ctx.count;
-}
-EXPORT_SYMBOL_NS_GPL(devm_cxl_port_enumerate_dports, "CXL");
-
 static int cxl_dvsec_mem_range_valid(struct cxl_dev_state *cxlds, int id)
 {
 	struct pci_dev *pdev = to_pci_dev(cxlds->dev);
···
 
 	return 0;
 }
+
+struct cxl_walk_context {
+	struct pci_bus *bus;
+	struct cxl_port *port;
+	int type;
+	int error;
+	int count;
+};
 
 static int count_dports(struct pci_dev *pdev, void *data)
 {

drivers/cxl/core/port.c

···
 	if (atomic_read(&cxlrd->region_id) >= 0)
 		memregion_free(atomic_read(&cxlrd->region_id));
 	__cxl_decoder_release(&cxlrd->cxlsd.cxld);
-	kfree(cxlrd->ops);
 	kfree(cxlrd);
 }
 

drivers/cxl/core/region.c

···
 	struct cxl_region_params *p = &cxlr->params;
 	int i;
 
+	if (test_bit(CXL_REGION_F_LOCK, &cxlr->flags))
+		return;
+
 	/*
 	 * Before region teardown attempt to flush, evict any data cached for
 	 * this region, or scream loudly about missing arch / platform support
···
 		return len;
 	}
 
+	if (test_bit(CXL_REGION_F_LOCK, &cxlr->flags))
+		return -EPERM;
+
 	rc = queue_reset(cxlr);
 	if (rc)
 		return rc;
···
 	return sysfs_emit(buf, "%d\n", p->state >= CXL_CONFIG_COMMIT);
 }
 static DEVICE_ATTR_RW(commit);
-
-static umode_t cxl_region_visible(struct kobject *kobj, struct attribute *a,
-				  int n)
-{
-	struct device *dev = kobj_to_dev(kobj);
-	struct cxl_region *cxlr = to_cxl_region(dev);
-
-	/*
-	 * Support tooling that expects to find a 'uuid' attribute for all
-	 * regions regardless of mode.
-	 */
-	if (a == &dev_attr_uuid.attr && cxlr->mode != CXL_PARTMODE_PMEM)
-		return 0444;
-	return a->mode;
-}
 
 static ssize_t interleave_ways_show(struct device *dev,
 				    struct device_attribute *attr, char *buf)
···
 }
 static DEVICE_ATTR_RW(size);
 
+static ssize_t extended_linear_cache_size_show(struct device *dev,
+					       struct device_attribute *attr,
+					       char *buf)
+{
+	struct cxl_region *cxlr = to_cxl_region(dev);
+	struct cxl_region_params *p = &cxlr->params;
+	ssize_t rc;
+
+	ACQUIRE(rwsem_read_intr, rwsem)(&cxl_rwsem.region);
+	if ((rc = ACQUIRE_ERR(rwsem_read_intr, &rwsem)))
+		return rc;
+	return sysfs_emit(buf, "%#llx\n", p->cache_size);
+}
+static DEVICE_ATTR_RO(extended_linear_cache_size);
+
 static struct attribute *cxl_region_attrs[] = {
 	&dev_attr_uuid.attr,
 	&dev_attr_commit.attr,
···
 	&dev_attr_resource.attr,
 	&dev_attr_size.attr,
 	&dev_attr_mode.attr,
+	&dev_attr_extended_linear_cache_size.attr,
 	NULL,
 };
+
+static umode_t cxl_region_visible(struct kobject *kobj, struct attribute *a,
+				  int n)
+{
+	struct device *dev = kobj_to_dev(kobj);
+	struct cxl_region *cxlr = to_cxl_region(dev);
+
+	/*
+	 * Support tooling that expects to find a 'uuid' attribute for all
+	 * regions regardless of mode.
+	 */
+	if (a == &dev_attr_uuid.attr && cxlr->mode != CXL_PARTMODE_PMEM)
+		return 0444;
+
+	/*
+	 * Don't display extended linear cache attribute if there is no
+	 * extended linear cache.
+	 */
+	if (a == &dev_attr_extended_linear_cache_size.attr &&
+	    cxlr->params.cache_size == 0)
+		return 0;
+
+	return a->mode;
+}
 
 static const struct attribute_group cxl_region_group = {
 	.attrs = cxl_region_attrs,
···
 	return 1;
 }
 
-static bool region_res_match_cxl_range(const struct cxl_region_params *p,
-				       const struct range *range)
+static bool spa_maps_hpa(const struct cxl_region_params *p,
+			 const struct range *range)
 {
 	if (!p->res)
 		return false;
 
 	/*
-	 * If an extended linear cache region then the CXL range is assumed
-	 * to be fronted by the DRAM range in current known implementation.
-	 * This assumption will be made until a variant implementation exists.
+	 * The extended linear cache region is constructed by a 1:1 ratio
+	 * where the SPA maps equal amounts of DRAM and CXL HPA capacity with
+	 * CXL decoders at the high end of the SPA range.
 	 */
 	return p->res->start + p->cache_size == range->start &&
 		p->res->end == range->end;
···
 	cxld = to_cxl_decoder(dev);
 	r = &cxld->hpa_range;
 
-	if (region_res_match_cxl_range(p, r))
+	if (spa_maps_hpa(p, r))
 		return 1;
 
 	return 0;
···
 	return 0;
 }
 
+static void cxl_region_set_lock(struct cxl_region *cxlr,
+				struct cxl_decoder *cxld)
+{
+	if (!test_bit(CXL_DECODER_F_LOCK, &cxld->flags))
+		return;
+
+	set_bit(CXL_REGION_F_LOCK, &cxlr->flags);
+	clear_bit(CXL_REGION_F_NEEDS_RESET, &cxlr->flags);
+}
+
 /**
  * cxl_port_attach_region() - track a region's interest in a port by endpoint
  * @port: port to add a new region reference 'struct cxl_region_ref'
···
 			goto out_erase;
 		}
 	}
+
+	cxl_region_set_lock(cxlr, cxld);
 
 	rc = cxl_rr_ep_add(cxl_rr, cxled);
 	if (rc) {
···
 				  struct cxl_endpoint_decoder *cxled)
 {
 	struct cxl_root_decoder *cxlrd = to_cxl_root_decoder(cxlr->dev.parent);
-	int parent_iw, parent_ig, ig, iw, rc, inc = 0, pos = cxled->pos;
+	int parent_iw, parent_ig, ig, iw, rc, pos = cxled->pos;
 	struct cxl_port *parent_port = to_cxl_port(port->dev.parent);
 	struct cxl_region_ref *cxl_rr = cxl_rr_load(port, cxlr);
 	struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
···
 	if (test_bit(CXL_REGION_F_AUTO, &cxlr->flags)) {
 		if (cxld->interleave_ways != iw ||
 		    (iw > 1 && cxld->interleave_granularity != ig) ||
-		    !region_res_match_cxl_range(p, &cxld->hpa_range) ||
+		    !spa_maps_hpa(p, &cxld->hpa_range) ||
 		    ((cxld->flags & CXL_DECODER_F_ENABLE) == 0)) {
 			dev_err(&cxlr->dev,
 				"%s:%s %s expected iw: %d ig: %d %pr\n",
···
 		cxlsd->target[cxl_rr->nr_targets_set] = ep->dport;
 		cxlsd->cxld.target_map[cxl_rr->nr_targets_set] = ep->dport->port_id;
 	}
-	inc = 1;
+	cxl_rr->nr_targets_set++;
 out_target_set:
-	cxl_rr->nr_targets_set += inc;
 	dev_dbg(&cxlr->dev, "%s:%s target[%d] = %s for %s:%s @ %d\n",
 		dev_name(port->uport_dev), dev_name(&port->dev),
 		cxl_rr->nr_targets_set - 1, dev_name(ep->dport->dport_dev),
···
 	dev->bus = &cxl_bus_type;
 	dev->type = &cxl_region_type;
 	cxlr->id = id;
+	cxl_region_set_lock(cxlr, &cxlrd->cxlsd.cxld);
 
 	return cxlr;
 }
···
 	return false;
 }
 
-static bool has_hpa_to_spa(struct cxl_root_decoder *cxlrd)
+#define CXL_POS_ZERO 0
+/**
+ * cxl_validate_translation_params
+ * @eiw: encoded interleave ways
+ * @eig: encoded interleave granularity
+ * @pos: position in interleave
+ *
+ * Callers pass CXL_POS_ZERO when no position parameter needs validating.
+ *
+ * Returns: 0 on success, -EINVAL on first invalid parameter
+ */
+int cxl_validate_translation_params(u8 eiw, u16 eig, int pos)
 {
-	return cxlrd->ops && cxlrd->ops->hpa_to_spa;
-}
+	int ways, gran;
 
-static bool has_spa_to_hpa(struct cxl_root_decoder *cxlrd)
-{
-	return cxlrd->ops && cxlrd->ops->spa_to_hpa;
-}
-
-u64 cxl_dpa_to_hpa(struct cxl_region *cxlr, const struct cxl_memdev *cxlmd,
-		   u64 dpa)
-{
-	struct cxl_root_decoder *cxlrd = to_cxl_root_decoder(cxlr->dev.parent);
-	u64 dpa_offset, hpa_offset, bits_upper, mask_upper, hpa;
-	struct cxl_region_params *p = &cxlr->params;
-	struct cxl_endpoint_decoder *cxled = NULL;
-	u16 eig = 0;
-	u8 eiw = 0;
-	int pos;
-
-	for (int i = 0; i < p->nr_targets; i++) {
-		cxled = p->targets[i];
-		if (cxlmd == cxled_to_memdev(cxled))
-			break;
+	if (eiw_to_ways(eiw, &ways)) {
+		pr_debug("%s: invalid eiw=%u\n", __func__, eiw);
+		return -EINVAL;
 	}
-	if (!cxled || cxlmd != cxled_to_memdev(cxled))
+	if (eig_to_granularity(eig, &gran)) {
+		pr_debug("%s: invalid eig=%u\n", __func__, eig);
+		return -EINVAL;
+	}
+	if (pos < 0 || pos >= ways) {
+		pr_debug("%s: invalid pos=%d for ways=%u\n", __func__, pos,
+			 ways);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_FOR_MODULES(cxl_validate_translation_params, "cxl_translate");
+
+u64 cxl_calculate_dpa_offset(u64 hpa_offset, u8 eiw, u16 eig)
+{
+	u64 dpa_offset, bits_lower, bits_upper, temp;
+	int ret;
+
+	ret = cxl_validate_translation_params(eiw, eig, CXL_POS_ZERO);
+	if (ret)
 		return ULLONG_MAX;
 
-	pos = cxled->pos;
-	ways_to_eiw(p->interleave_ways, &eiw);
-	granularity_to_eig(p->interleave_granularity, &eig);
+	/*
+	 * DPA offset: CXL Spec 3.2 Section 8.2.4.20.13
+	 * Lower bits [IG+7:0] pass through unchanged
+	 * (eiw < 8)
+	 *	Per spec: DPAOffset[51:IG+8] = (HPAOffset[51:IG+IW+8] >> IW)
+	 *	Clear the position bits to isolate upper section, then
+	 *	reverse the left shift by eiw that occurred during DPA->HPA
+	 * (eiw >= 8)
+	 *	Per spec: DPAOffset[51:IG+8] = HPAOffset[51:IG+IW] / 3
+	 *	Extract upper bits from the correct bit range and divide by 3
+	 *	to recover the original DPA upper bits
+	 */
+	bits_lower = hpa_offset & GENMASK_ULL(eig + 7, 0);
+	if (eiw < 8) {
+		temp = hpa_offset &= ~GENMASK_ULL(eig + eiw + 8 - 1, 0);
+		dpa_offset = temp >> eiw;
+	} else {
+		bits_upper = div64_u64(hpa_offset >> (eig + eiw), 3);
+		dpa_offset = bits_upper << (eig + 8);
+	}
+	dpa_offset |= bits_lower;
+
+	return dpa_offset;
+}
+EXPORT_SYMBOL_FOR_MODULES(cxl_calculate_dpa_offset, "cxl_translate");
+
+int cxl_calculate_position(u64 hpa_offset, u8 eiw, u16 eig)
+{
+	unsigned int ways = 0;
+	u64 shifted, rem;
+	int pos, ret;
+
+	ret = cxl_validate_translation_params(eiw, eig, CXL_POS_ZERO);
+	if (ret)
+		return ret;
+
+	if (!eiw)
+		/* position is 0 if no interleaving */
+		return 0;
+
+	/*
+	 * Interleave position: CXL Spec 3.2 Section 8.2.4.20.13
+	 * eiw < 8
+	 *	Position is in the IW bits at HPA_OFFSET[IG+8+IW-1:IG+8].
+	 *	Per spec "remove IW bits starting with bit position IG+8"
+	 * eiw >= 8
+	 *	Position is not explicitly stored in HPA_OFFSET bits. It is
+	 *	derived from the modulo operation of the upper bits using
+	 *	the total number of interleave ways.
+	 */
+	if (eiw < 8) {
+		pos = (hpa_offset >> (eig + 8)) & GENMASK(eiw - 1, 0);
+	} else {
+		shifted = hpa_offset >> (eig + 8);
+		eiw_to_ways(eiw, &ways);
+		div64_u64_rem(shifted, ways, &rem);
+		pos = rem;
+	}
+
+	return pos;
+}
+EXPORT_SYMBOL_FOR_MODULES(cxl_calculate_position, "cxl_translate");
+
+u64 cxl_calculate_hpa_offset(u64 dpa_offset, int pos, u8 eiw, u16 eig)
+{
+	u64 mask_upper, hpa_offset, bits_upper;
+	int ret;
+
+	ret = cxl_validate_translation_params(eiw, eig, pos);
+	if (ret)
+		return ULLONG_MAX;
 
 	/*
 	 * The device position in the region interleave set was removed
···
 	 * ways and granularity and is defined in the CXL Spec 3.0 Section
 	 * 8.2.4.19.13 Implementation Note: Device Decode Logic
 	 */
-
-	/* Remove the dpa base */
-	dpa_offset = dpa - cxl_dpa_resource_start(cxled);
 
 	mask_upper = GENMASK_ULL(51, eig + 8);
 
···
 	/* The lower bits remain unchanged */
 	hpa_offset |= dpa_offset & GENMASK_ULL(eig + 7, 0);
 
+	return hpa_offset;
+}
+EXPORT_SYMBOL_FOR_MODULES(cxl_calculate_hpa_offset, "cxl_translate");
+
+u64 cxl_dpa_to_hpa(struct cxl_region *cxlr, const struct cxl_memdev *cxlmd,
+		   u64 dpa)
+{
+	struct cxl_root_decoder *cxlrd = to_cxl_root_decoder(cxlr->dev.parent);
+	struct cxl_region_params *p = &cxlr->params;
+	struct cxl_endpoint_decoder *cxled = NULL;
+	u64 dpa_offset, hpa_offset, hpa;
+	u16 eig = 0;
+	u8 eiw = 0;
+	int pos;
+
+	for (int i = 0; i < p->nr_targets; i++) {
+		if (cxlmd == cxled_to_memdev(p->targets[i])) {
+			cxled = p->targets[i];
+			break;
+		}
+	}
+	if (!cxled)
+		return ULLONG_MAX;
+
+	pos = cxled->pos;
+	ways_to_eiw(p->interleave_ways, &eiw);
+	granularity_to_eig(p->interleave_granularity, &eig);
+
+	dpa_offset = dpa - cxl_dpa_resource_start(cxled);
+	hpa_offset = cxl_calculate_hpa_offset(dpa_offset, pos, eiw, eig);
+
 	/* Apply the hpa_offset to the region base address */
 	hpa = hpa_offset + p->res->start + p->cache_size;
 
 	/* Root decoder translation overrides typical modulo decode */
-	if (has_hpa_to_spa(cxlrd))
-		hpa = cxlrd->ops->hpa_to_spa(cxlrd, hpa);
+	if (cxlrd->ops.hpa_to_spa)
+		hpa = cxlrd->ops.hpa_to_spa(cxlrd, hpa);
 
 	if (!cxl_resource_contains_addr(p->res, hpa)) {
 		dev_dbg(&cxlr->dev,
···
 	}
 
 	/* Simple chunk check, by pos & gran, only applies to modulo decodes */
-	if (!has_hpa_to_spa(cxlrd) && (!cxl_is_hpa_in_chunk(hpa, cxlr, pos)))
+	if (!cxlrd->ops.hpa_to_spa && !cxl_is_hpa_in_chunk(hpa, cxlr, pos))
 		return ULLONG_MAX;
 
 	return hpa;
···
 	struct cxl_root_decoder *cxlrd = to_cxl_root_decoder(cxlr->dev.parent);
 	struct cxl_endpoint_decoder *cxled;
 	u64 hpa, hpa_offset, dpa_offset;
-	u64 bits_upper, bits_lower;
-	u64 shifted, rem, temp;
 	u16 eig = 0;
 	u8 eiw = 0;
 	int pos;
···
 	 * If the root decoder has SPA to CXL HPA callback, use it. Otherwise
 	 * CXL HPA is assumed to equal SPA.
 	 */
-	if (has_spa_to_hpa(cxlrd)) {
-		hpa = cxlrd->ops->spa_to_hpa(cxlrd, p->res->start + offset);
+	if (cxlrd->ops.spa_to_hpa) {
+		hpa = cxlrd->ops.spa_to_hpa(cxlrd, p->res->start + offset);
 		hpa_offset = hpa - p->res->start;
 	} else {
 		hpa_offset = offset;
 	}
-	/*
-	 * Interleave position: CXL Spec 3.2 Section 8.2.4.20.13
-	 * eiw < 8
-	 *	Position is in the IW bits at HPA_OFFSET[IG+8+IW-1:IG+8].
-	 *	Per spec "remove IW bits starting with bit position IG+8"
-	 * eiw >= 8
-	 *	Position is not explicitly stored in HPA_OFFSET bits. It is
-	 *	derived from the modulo operation of the upper bits using
-	 *	the total number of interleave ways.
-	 */
-	if (eiw < 8) {
-		pos = (hpa_offset >> (eig + 8)) & GENMASK(eiw - 1, 0);
-	} else {
-		shifted = hpa_offset >> (eig + 8);
-		div64_u64_rem(shifted, p->interleave_ways, &rem);
-		pos = rem;
-	}
+
+	pos = cxl_calculate_position(hpa_offset, eiw, eig);
 	if (pos < 0 || pos >= p->nr_targets) {
 		dev_dbg(&cxlr->dev, "Invalid position %d for %d targets\n",
 			pos, p->nr_targets);
 		return -ENXIO;
 	}
 
-	/*
-	 * DPA offset: CXL Spec 3.2 Section 8.2.4.20.13
-	 * Lower bits [IG+7:0] pass through unchanged
-	 * (eiw < 8)
-	 *	Per spec: DPAOffset[51:IG+8] = (HPAOffset[51:IG+IW+8] >> IW)
-	 *	Clear the position bits to isolate upper section, then
-	 *	reverse the left shift by eiw that occurred during DPA->HPA
-	 * (eiw >= 8)
-	 *	Per spec: DPAOffset[51:IG+8] = HPAOffset[51:IG+IW] / 3
-	 *	Extract upper bits from the correct bit range and divide by 3
-	 *	to recover the original DPA upper bits
-	 */
-	bits_lower = hpa_offset & GENMASK_ULL(eig + 7, 0);
-	if (eiw < 8) {
-		temp = hpa_offset &= ~((u64)GENMASK(eig + eiw + 8 - 1, 0));
-		dpa_offset = temp >> eiw;
-	} else {
-		bits_upper = div64_u64(hpa_offset >> (eig + eiw), 3);
-		dpa_offset = bits_upper << (eig + 8);
-	}
-	dpa_offset |= bits_lower;
+	dpa_offset = cxl_calculate_dpa_offset(hpa_offset, eiw, eig);
 
 	/* Look-up and return the result: a memdev and a DPA */
 	for (int i = 0; i < p->nr_targets; i++) {
···
 	p = &cxlr->params;
 
 	guard(rwsem_read)(&cxl_rwsem.region);
-	return region_res_match_cxl_range(p, r);
+	return spa_maps_hpa(p, r);
 }
 
 static int cxl_extended_linear_cache_resize(struct cxl_region *cxlr,
···
 		dev_warn(cxlmd->dev.parent,
 			 "Extended linear cache calculation failed rc:%d\n", rc);
 	}
+
+	rc = sysfs_update_group(&cxlr->dev.kobj, &cxl_region_group);
+	if (rc)
+		return rc;
 
 	rc = insert_resource(cxlrd->res, res);
 	if (rc) {

drivers/cxl/cxl.h

···
 	void *platform_data;
 	struct mutex range_lock;
 	int qos_class;
-	struct cxl_rd_ops *ops;
+	struct cxl_rd_ops ops;
 	struct cxl_switch_decoder cxlsd;
 };
 
···
  * but blocks cxl_region_probe().
  */
 #define CXL_REGION_F_NEEDS_RESET 1
+
+/*
+ * Indicate whether this region is locked due to 1 or more decoders that have
+ * been locked. The approach of all or nothing is taken with regard to the
+ * locked attribute. CXL_REGION_F_NEEDS_RESET should not be set if this flag is
+ * set.
+ */
+#define CXL_REGION_F_LOCK 2
 
 /**
  * struct cxl_region - CXL region
···
 {
 	return port->uport_dev == port->dev.parent;
 }
+
+/* Address translation functions exported to cxl_translate test module only */
+int cxl_validate_translation_params(u8 eiw, u16 eig, int pos);
+u64 cxl_calculate_hpa_offset(u64 dpa_offset, int pos, u8 eiw, u16 eig);
+u64 cxl_calculate_dpa_offset(u64 hpa_offset, u8 eiw, u16 eig);
+int cxl_calculate_position(u64 hpa_offset, u8 eiw, u16 eig);
+struct cxl_cxims_data {
+	int nr_maps;
+	u64 xormaps[] __counted_by(nr_maps);
+};
+
+#if IS_ENABLED(CONFIG_CXL_ACPI)
+u64 cxl_do_xormap_calc(struct cxl_cxims_data *cximsd, u64 addr, int hbiw);
+#else
+static inline u64 cxl_do_xormap_calc(struct cxl_cxims_data *cximsd, u64 addr, int hbiw)
+{
+	return ULLONG_MAX;
+}
+#endif
 
 int cxl_num_decoders_committed(struct cxl_port *port);
 bool is_cxl_port(const struct device *dev);

drivers/cxl/cxlpci.h

···
 	return lnksta2 & PCI_EXP_LNKSTA2_FLIT;
 }
 
-int devm_cxl_port_enumerate_dports(struct cxl_port *port);
 struct cxl_dev_state;
 void read_cdat_data(struct cxl_port *port);
 void cxl_cor_error_detected(struct pci_dev *pdev);

drivers/cxl/pci.c

···
 	if (opcode == CXL_MBOX_OP_SANITIZE) {
 		mutex_lock(&cxl_mbox->mbox_mutex);
 		if (mds->security.sanitize_node)
-			mod_delayed_work(system_wq, &mds->security.poll_dwork, 0);
+			mod_delayed_work(system_percpu_wq, &mds->security.poll_dwork, 0);
 		mutex_unlock(&cxl_mbox->mbox_mutex);
 	} else {
 		/* short-circuit the wait in __cxl_pci_mbox_send_cmd() */

tools/testing/cxl/Kbuild

···
 ldflags-y += --wrap=acpi_evaluate_integer
 ldflags-y += --wrap=acpi_pci_find_root
 ldflags-y += --wrap=nvdimm_bus_register
-ldflags-y += --wrap=devm_cxl_port_enumerate_dports
 ldflags-y += --wrap=cxl_await_media_ready
 ldflags-y += --wrap=devm_cxl_add_rch_dport
-ldflags-y += --wrap=cxl_rcd_component_reg_phys
 ldflags-y += --wrap=cxl_endpoint_parse_cdat
 ldflags-y += --wrap=cxl_dport_init_ras_reporting
 ldflags-y += --wrap=devm_cxl_endpoint_decoders_setup
+ldflags-y += --wrap=hmat_get_extended_linear_cache_size
 
 DRIVERS := ../../../drivers
 CXL_SRC := $(DRIVERS)/cxl

tools/testing/cxl/test/Kbuild

···
 obj-m += cxl_test.o
 obj-m += cxl_mock.o
 obj-m += cxl_mock_mem.o
+obj-m += cxl_translate.o
 
 cxl_test-y := cxl.o
 cxl_mock-y := mock.o

tools/testing/cxl/test/cxl.c

···
 #include "mock.h"
 
 static int interleave_arithmetic;
+static bool extended_linear_cache;
 
 #define FAKE_QTG_ID	42
 
···
 #define NR_CXL_SWITCH_PORTS 2
 #define NR_CXL_PORT_DECODERS 8
 #define NR_BRIDGES (NR_CXL_HOST_BRIDGES + NR_CXL_SINGLE_HOST + NR_CXL_RCH)
+
+#define MOCK_AUTO_REGION_SIZE_DEFAULT SZ_512M
+static int mock_auto_region_size = MOCK_AUTO_REGION_SIZE_DEFAULT;
 
 static struct platform_device *cxl_acpi;
 static struct platform_device *cxl_host_bridge[NR_CXL_HOST_BRIDGES];
···
 	return res;
 }
 
+/* Only update CFMWS0 as this is used by the auto region. */
+static void cfmws_elc_update(struct acpi_cedt_cfmws *window, int index)
+{
+	if (!extended_linear_cache)
+		return;
+
+	if (index != 0)
+		return;
+
+	/*
+	 * The window size should be 2x of the CXL region size where half is
+	 * DRAM and half is CXL
+	 */
+	window->window_size = mock_auto_region_size * 2;
+}
+
 static int populate_cedt(void)
 {
 	struct cxl_mock_res *res;
···
 	for (i = cfmws_start; i <= cfmws_end; i++) {
 		struct acpi_cedt_cfmws *window = mock_cfmws[i];
 
+		cfmws_elc_update(window, i);
 		res = alloc_mock_res(window->window_size, SZ_256M);
 		if (!res)
 			return -ENOMEM;
···
 
 	*data = host_bridge_index(adev);
 	return AE_OK;
+}
+
+static int
+mock_hmat_get_extended_linear_cache_size(struct resource *backing_res,
+					 int nid, resource_size_t *cache_size)
+{
+	struct acpi_cedt_cfmws *window = mock_cfmws[0];
+	struct resource cfmws0_res =
+		DEFINE_RES_MEM(window->base_hpa, window->window_size);
+
+	if (!extended_linear_cache ||
+	    !resource_contains(&cfmws0_res, backing_res)) {
+		return hmat_get_extended_linear_cache_size(backing_res,
+							   nid, cache_size);
+	}
+
+	*cache_size = mock_auto_region_size;
+
+	return 0;
 }
 
 static struct pci_bus mock_pci_bus[NR_BRIDGES];
···
 	struct cxl_endpoint_decoder *cxled;
 	struct cxl_switch_decoder *cxlsd;
 	struct cxl_port *port, *iter;
-	const int size = SZ_512M;
 	struct cxl_memdev *cxlmd;
 	struct cxl_dport *dport;
 	struct device *dev;
···
 	}
 
 	base = window->base_hpa;
+	if (extended_linear_cache)
+		base += mock_auto_region_size;
 	cxld->hpa_range = (struct range) {
 		.start = base,
-		.end = base + size - 1,
+		.end = base + mock_auto_region_size - 1,
 	};
 
 	cxld->interleave_ways = 2;
···
 	cxld->flags = CXL_DECODER_F_ENABLE;
 	cxled->state = CXL_DECODER_STATE_AUTO;
 	port->commit_end = cxld->id;
-	devm_cxl_dpa_reserve(cxled, 0, size / cxld->interleave_ways, 0);
+	devm_cxl_dpa_reserve(cxled, 0,
+			     mock_auto_region_size / cxld->interleave_ways, 0);
 	cxld->commit = mock_decoder_commit;
 	cxld->reset = mock_decoder_reset;
 
···
 		cxld->interleave_granularity = 4096;
 		cxld->hpa_range = (struct range) {
 			.start = base,
-			.end = base + size - 1,
+			.end = base + mock_auto_region_size - 1,
 		};
 		put_device(dev);
 	}
···
 	return 0;
 }
 
-static int mock_cxl_port_enumerate_dports(struct cxl_port *port)
-{
-	struct platform_device **array;
-	int i, array_size;
-	int rc;
-
-	rc = get_port_array(port, &array, &array_size);
-	if (rc)
-		return rc;
-
-	for (i = 0; i < array_size; i++) {
-		struct platform_device *pdev = array[i];
-		struct cxl_dport *dport;
-
-		if (pdev->dev.parent != port->uport_dev) {
-			dev_dbg(&port->dev, "%s: mismatch parent %s\n",
-				dev_name(port->uport_dev),
-				dev_name(pdev->dev.parent));
-			continue;
-		}
-
-		dport = devm_cxl_add_dport(port, &pdev->dev, pdev->id,
-					   CXL_RESOURCE_NONE);
-
-		if (IS_ERR(dport))
-			return PTR_ERR(dport);
-	}
-
-	return 0;
-}
-
 static struct cxl_dport *mock_cxl_add_dport_by_dev(struct cxl_port *port,
 						   struct device *dport_dev)
 {
···
 	.acpi_pci_find_root = mock_acpi_pci_find_root,
 	.devm_cxl_switch_port_decoders_setup = mock_cxl_switch_port_decoders_setup,
 	.devm_cxl_endpoint_decoders_setup = mock_cxl_endpoint_decoders_setup,
-	.devm_cxl_port_enumerate_dports = mock_cxl_port_enumerate_dports,
 	.cxl_endpoint_parse_cdat = mock_cxl_endpoint_parse_cdat,
 	.devm_cxl_add_dport_by_dev = mock_cxl_add_dport_by_dev,
+	.hmat_get_extended_linear_cache_size =
+		mock_hmat_get_extended_linear_cache_size,
 	.list = LIST_HEAD_INIT(cxl_mock_ops.list),
 };
 
···
 
 module_param(interleave_arithmetic, int, 0444);
 MODULE_PARM_DESC(interleave_arithmetic, "Modulo:0, XOR:1");
+module_param(extended_linear_cache, bool, 0444);
+MODULE_PARM_DESC(extended_linear_cache, "Enable extended linear cache support");
 module_init(cxl_test_init);
 module_exit(cxl_test_exit);
 MODULE_LICENSE("GPL v2");

tools/testing/cxl/test/cxl_translate.c

···
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright(c) 2025 Intel Corporation. All rights reserved.
+
+/* Preface all log entries with "cxl_translate" */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/moduleparam.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/acpi.h>
+#include <cxlmem.h>
+#include <cxl.h>
+
+/* Maximum number of test vectors and entry length */
+#define MAX_TABLE_ENTRIES 128
+#define MAX_ENTRY_LEN 128
+
+/* Expected number of parameters in each test vector */
+#define EXPECTED_PARAMS 7
+
+/* Module parameters for test vectors */
+static char *table[MAX_TABLE_ENTRIES];
+static int table_num;
+
+/* Interleave Arithmetic */
+#define MODULO_MATH 0
+#define XOR_MATH 1
+
+/*
+ * XOR mapping configuration
+ * The test data sets all use the same set of xormaps. When additional
+ * data sets arrive for validation, this static setup will need to
+ * be changed to accept xormaps as additional parameters.
+ */
+struct cxl_cxims_data *cximsd;
+static u64 xormaps[] = {
+	0x2020900,
+	0x4041200,
+	0x1010400,
+	0x800,
+};
+
+static int nr_maps = ARRAY_SIZE(xormaps);
+
+#define HBIW_TO_NR_MAPS_SIZE (CXL_DECODER_MAX_INTERLEAVE + 1)
+static const int hbiw_to_nr_maps[HBIW_TO_NR_MAPS_SIZE] = {
+	[1] = 0, [2] = 1, [3] = 0, [4] = 2, [6] = 1, [8] = 3, [12] = 2, [16] = 4
+};
+
+/**
+ * to_hpa - calculate an HPA offset from a DPA offset and position
+ *
+ * dpa_offset: device physical address offset
+ * pos: devices position in interleave
+ * r_eiw: region encoded interleave ways
+ * r_eig: region encoded interleave granularity
+ * hb_ways: host bridge interleave ways
+ * math: interleave arithmetic (MODULO_MATH or XOR_MATH)
+ *
+ * Returns: host physical address offset
+ */
+static u64 to_hpa(u64 dpa_offset, int pos, u8 r_eiw, u16 r_eig, u8 hb_ways,
+		  u8 math)
+{
+	u64 hpa_offset;
+
+	/* Calculate base HPA offset from DPA and position */
+	hpa_offset = cxl_calculate_hpa_offset(dpa_offset, pos, r_eiw, r_eig);
+
+	if (math == XOR_MATH) {
+		cximsd->nr_maps = hbiw_to_nr_maps[hb_ways];
+		if (cximsd->nr_maps)
+			return cxl_do_xormap_calc(cximsd, hpa_offset, hb_ways);
+	}
+	return hpa_offset;
+}
+
+/**
+ * to_dpa - translate an HPA offset to DPA offset
+ *
+ * hpa_offset: host physical address offset
+ * r_eiw: region encoded interleave ways
+ * r_eig: region encoded interleave granularity
+ * hb_ways: host bridge interleave ways
+ * math: interleave arithmetic (MODULO_MATH or XOR_MATH)
+ *
+ * Returns: device physical address offset
+ */
+static u64 to_dpa(u64 hpa_offset, u8 r_eiw, u16 r_eig, u8 hb_ways, u8 math)
+{
+	u64 offset = hpa_offset;
+
+	if (math == XOR_MATH) {
+		cximsd->nr_maps = hbiw_to_nr_maps[hb_ways];
+		if (cximsd->nr_maps)
+			offset =
+				cxl_do_xormap_calc(cximsd, hpa_offset, hb_ways);
+	}
+	return cxl_calculate_dpa_offset(offset, r_eiw, r_eig);
+}
+
+/**
+ * to_pos - extract an interleave position from an HPA offset
+ *
+ * hpa_offset: host physical address offset
+ * r_eiw: region encoded interleave ways
+ * r_eig: region encoded interleave granularity
+ * hb_ways: host bridge interleave ways
+ * math: interleave arithmetic (MODULO_MATH or XOR_MATH)
+ *
+ * Returns: devices position in region interleave
+ */
+static u64 to_pos(u64 hpa_offset, u8 r_eiw, u16 r_eig, u8 hb_ways, u8 math)
+{
+	u64 offset = hpa_offset;
+
+	/* Reverse XOR mapping if specified */
+	if (math == XOR_MATH)
+		offset = cxl_do_xormap_calc(cximsd, hpa_offset, hb_ways);
+
+	return cxl_calculate_position(offset, r_eiw, r_eig);
+}
+
+/**
+ * run_translation_test - execute forward and reverse translations
+ *
+ * @dpa: device physical address
+ * @pos: expected position in region interleave
+ * @r_eiw: region encoded interleave ways
+ * @r_eig: region encoded interleave granularity
+ * @hb_ways: host bridge interleave ways
+ * @math: interleave arithmetic (MODULO_MATH or XOR_MATH)
+ * @expect_spa: expected system physical address
+ *
+ * Returns: 0 on success, -1 on failure
+ */
+static int run_translation_test(u64 dpa, int pos, u8 r_eiw, u16 r_eig,
+				u8 hb_ways, int math, u64 expect_hpa)
+{
+	u64 translated_spa, reverse_dpa;
+	int reverse_pos;
+
+	/* Test Device to Host translation: DPA + POS -> SPA */
+	translated_spa = to_hpa(dpa, pos, r_eiw, r_eig, hb_ways, math);
+	if (translated_spa != expect_hpa) {
+		pr_err("Device to host failed: expected HPA %llu, got %llu\n",
+		       expect_hpa, translated_spa);
+		return -1;
+	}
+
+	/* Test Host to Device DPA translation: SPA -> DPA */
+	reverse_dpa = to_dpa(translated_spa, r_eiw, r_eig, hb_ways, math);
+	if (reverse_dpa != dpa) {
+		pr_err("Host to Device DPA failed: expected %llu, got %llu\n",
+		       dpa, reverse_dpa);
+		return -1;
+	}
+
+	/* Test Host to Device Position translation: SPA -> POS */
+	reverse_pos = to_pos(translated_spa, r_eiw, r_eig, hb_ways, math);
+	if (reverse_pos != pos) {
+		pr_err("Position lookup failed: expected %d, got %d\n", pos,
+		       reverse_pos);
+		return -1;
+	}
+
+	return 0;
+}
+
+/**
+ * parse_test_vector - parse a single test vector string
+ *
+ * entry: test vector string to parse
+ * dpa: device physical address
+ * pos: expected position in region interleave
+ * r_eiw: region encoded interleave ways
+ * r_eig: region encoded interleave granularity
+ * hb_ways: host bridge interleave ways
+ * math: interleave arithmetic (MODULO_MATH or XOR_MATH)
+ * expect_spa: expected system physical address
+ *
+ * Returns: 0 on success, negative error code on failure
+ */
+static int parse_test_vector(const char *entry, u64 *dpa, int *pos, u8 *r_eiw,
+			     u16 *r_eig, u8 *hb_ways, int *math,
+			     u64 *expect_hpa)
+{
+	unsigned int tmp_r_eiw, tmp_r_eig, tmp_hb_ways;
+	int parsed;
+
+	parsed = sscanf(entry, "%llu %d %u %u %u %d %llu", dpa, pos, &tmp_r_eiw,
+			&tmp_r_eig, &tmp_hb_ways, math, expect_hpa);
+
+	if (parsed != EXPECTED_PARAMS) {
+		pr_err("Parse error: expected %d parameters, got %d in '%s'\n",
+		       EXPECTED_PARAMS, parsed, entry);
+		return -EINVAL;
+	}
+	if (tmp_r_eiw > U8_MAX || tmp_r_eig > U16_MAX || tmp_hb_ways > U8_MAX) {
+		pr_err("Parameter overflow in entry: '%s'\n", entry);
+		return -ERANGE;
+	}
+	if (*math != MODULO_MATH && *math != XOR_MATH) {
+		pr_err("Invalid math type %d in entry: '%s'\n", *math, entry);
+		return -EINVAL;
+	}
+	*r_eiw = tmp_r_eiw;
+	*r_eig = tmp_r_eig;
+	*hb_ways = tmp_hb_ways;
+
+	return 0;
+}
+
+/*
+ * setup_xor_mapping - Initialize XOR mapping data structure
+ *
+ * The test data sets all use the same HBIG so we can use one set
+ * of xormaps, and set the number to apply based on HBIW before
+ * calling cxl_do_xormap_calc().
+ *
+ * When additional data sets arrive for validation with different
+ * HBIG's this static setup will need to be updated.
+ *
+ * Returns: 0 on success, negative error code on failure
+ */
+static int setup_xor_mapping(void)
+{
+	if (nr_maps <= 0)
+		return -EINVAL;
+
+	cximsd = kzalloc(struct_size(cximsd, xormaps, nr_maps), GFP_KERNEL);
+	if (!cximsd)
+		return -ENOMEM;
+
+	memcpy(cximsd->xormaps, xormaps, nr_maps * sizeof(*cximsd->xormaps));
+	cximsd->nr_maps = nr_maps;
+
+	return 0;
+}
+
+static int test_random_params(void)
+{
+	u8 valid_eiws[] = { 0, 1, 2, 3, 4, 8, 9, 10 };
+	u16 valid_eigs[] = { 0, 1, 2, 3, 4, 5, 6 };
+	int i, ways, pos, reverse_pos;
+	u64 dpa, hpa, reverse_dpa;
+	int iterations = 10000;
+	int failures = 0;
+
+	for (i = 0; i < iterations; i++) {
+		/* Generate valid random parameters for eiw, eig, pos, dpa */
+		u8 eiw = valid_eiws[get_random_u32() % ARRAY_SIZE(valid_eiws)];
+		u16 eig = valid_eigs[get_random_u32() % ARRAY_SIZE(valid_eigs)];
+
+		eiw_to_ways(eiw, &ways);
+		pos = get_random_u32() % ways;
+		dpa = get_random_u64() >> 12;
+
+		hpa = cxl_calculate_hpa_offset(dpa, pos, eiw, eig);
+		reverse_dpa = cxl_calculate_dpa_offset(hpa, eiw, eig);
+		reverse_pos = cxl_calculate_position(hpa, eiw, eig);
+
+		if (reverse_dpa != dpa || reverse_pos != pos) {
+			pr_err("test random iter %d FAIL hpa=%llu, dpa=%llu reverse_dpa=%llu, pos=%d reverse_pos=%d eiw=%u eig=%u\n",
+			       i, hpa, dpa, reverse_dpa, pos, reverse_pos, eiw,
+			       eig);
+
+			if (failures++ > 10) {
+				pr_err("test random too many failures, stop\n");
+				break;
+			}
+		}
+	}
+	pr_info("..... test random: PASS %d FAIL %d\n", i - failures, failures);
+
+	if (failures)
+		return -EINVAL;
+
+	return 0;
+}
+
+struct param_test {
+	u8 eiw;
+	u16 eig;
+	int pos;
+	bool expect; /* true: expect pass, false: expect fail */
+	const char *desc;
+};
+
+static struct param_test param_tests[] = {
+	{ 0x0, 0, 0, true, "1-way, min eig=0, pos=0" },
+	{ 0x0, 3, 0, true, "1-way, mid eig=3, pos=0" },
+	{ 0x0, 6, 0, true, "1-way, max eig=6, pos=0" },
+	{ 0x1, 0, 0, true, "2-way, eig=0, pos=0" },
+	{ 0x1, 3, 1, true, "2-way, eig=3, max pos=1" },
+	{ 0x1, 6, 1, true, "2-way, eig=6, max pos=1" },
+	{ 0x2, 0, 0, true, "4-way, eig=0, pos=0" },
+	{ 0x2, 3, 3, true, "4-way, eig=3, max pos=3" },
+	{ 0x2, 6, 3, true, "4-way, eig=6, max pos=3" },
+	{ 0x3, 0, 0, true, "8-way, eig=0, pos=0" },
+	{ 0x3, 3, 7, true, "8-way, eig=3, max pos=7" },
+	{ 0x3, 6, 7, true, "8-way, eig=6, max pos=7" },
+	{ 0x4, 0, 0, true, "16-way, eig=0, pos=0" },
+	{ 0x4, 3, 15, true, "16-way, eig=3, max pos=15" },
+	{ 0x4, 6, 15, true, "16-way, eig=6, max pos=15" },
+	{ 0x8, 0, 0, true, "3-way, eig=0, pos=0" },
+	{ 0x8, 3, 2, true, "3-way, eig=3, max pos=2" },
+	{ 0x8, 6, 2, true, "3-way, eig=6, max pos=2" },
+	{ 0x9, 0, 0, true, "6-way, eig=0, pos=0" },
+	{ 0x9, 3, 5, true, "6-way, eig=3, max pos=5" },
+	{ 0x9, 6, 5, true, "6-way, eig=6, max pos=5" },
+	{ 0xA, 0, 0, true, "12-way, eig=0, pos=0" },
+	{ 0xA, 3, 11, true, "12-way, eig=3, max pos=11" },
+	{ 0xA, 6, 11, true, "12-way, eig=6, max pos=11" },
+	{ 0x5, 0, 0, false, "invalid eiw=5" },
+	{ 0x7, 0, 0, false, "invalid eiw=7" },
+	{ 0xB, 0, 0, false, "invalid eiw=0xB" },
+	{ 0xFF, 0, 0, false, "invalid eiw=0xFF" },
+	{ 0x1, 7, 0, false, "invalid eig=7 (out of range)" },
+	{ 0x2, 0x10, 0, false, "invalid eig=0x10" },
+	{ 0x3, 0xFFFF, 0, false, "invalid eig=0xFFFF" },
+	{ 0x1, 0, -1, false, "pos < 0" },
+	{ 0x1, 0, 2, false, "2-way, pos=2 (>= ways)" },
+	{ 0x2, 0, 4, false, "4-way, pos=4 (>= ways)" },
+	{ 0x3, 0, 8, false, "8-way, pos=8 (>= ways)" },
+	{ 0x4, 0, 16, false, "16-way, pos=16 (>= ways)" },
+	{ 0x8, 0, 3, false, "3-way, pos=3 (>= ways)" },
+	{ 0x9, 0, 6, false, "6-way, pos=6 (>= ways)" },
+	{ 0xA, 0, 12, false, "12-way, pos=12 (>= ways)" },
+};
+
+static int test_cxl_validate_translation_params(void)
+{
+	int i, rc, failures = 0;
+	bool valid;
+
+	for (i = 0; i < ARRAY_SIZE(param_tests); i++) {
+		struct param_test *t = &param_tests[i];
+
+		rc = cxl_validate_translation_params(t->eiw, t->eig, t->pos);
+		valid = (rc == 0);
+
+		if (valid != t->expect) {
+			pr_err("test params failed: %s\n", t->desc);
+			failures++;
+		}
+	}
+	pr_info("..... test params: PASS %d FAIL %d\n", i - failures, failures);
+
+	if (failures)
+		return -EINVAL;
+
+	return 0;
+}
+
+/*
+ * cxl_translate_init
+ *
+ * Run the internal validation tests when no params are passed.
+ * Otherwise, parse the parameters (test vectors), and kick off
+ * the translation test.
+ *
+ * Returns: 0 on success, negative error code on failure
+ */
+static int __init cxl_translate_init(void)
+{
+	int rc, i;
+
+	/* If no tables are passed, validate module params only */
+	if (table_num == 0) {
+		pr_info("Internal validation test start...\n");
+		rc = test_cxl_validate_translation_params();
+		if (rc)
+			return rc;
+
+		rc = test_random_params();
+		if (rc)
+			return rc;
+
+		pr_info("Internal validation test completed successfully\n");
+
+		return 0;
+	}
+
+	pr_info("CXL translate test module loaded with %d test vectors\n",
+		table_num);
+
+	rc = setup_xor_mapping();
+	if (rc)
+		return rc;
+
+	/* Process each test vector */
+	for (i = 0; i < table_num; i++) {
+		u64 dpa, expect_spa;
+		int pos, math;
+		u8 r_eiw, hb_ways;
+		u16 r_eig;
+
+		pr_debug("Processing test vector %d: '%s'\n", i, table[i]);
+
+		/* Parse the test vector */
+		rc = parse_test_vector(table[i], &dpa, &pos, &r_eiw, &r_eig,
+				       &hb_ways, &math, &expect_spa);
+		if (rc) {
+			pr_err("CXL Translate Test %d: FAIL\n"
+			       "    Failed to parse test vector '%s'\n",
+			       i, table[i]);
+			continue;
+		}
+		/* Run the translation test */
+		rc = run_translation_test(dpa, pos, r_eiw, r_eig, hb_ways, math,
+					  expect_spa);
+		if (rc) {
+			pr_err("CXL Translate Test %d: FAIL\n"
+			       "    dpa=%llu pos=%d r_eiw=%u r_eig=%u hb_ways=%u math=%s expect_spa=%llu\n",
+			       i, dpa, pos, r_eiw, r_eig, hb_ways,
+			       (math == XOR_MATH) ? "XOR" : "MODULO",
+			       expect_spa);
+		} else {
+			pr_info("CXL Translate Test %d: PASS\n", i);
+		}
+	}
+
+	kfree(cximsd);
+	pr_info("CXL translate test completed\n");
+
+	return 0;
+}
+
+static void __exit cxl_translate_exit(void)
+{
+	pr_info("CXL translate test module unloaded\n");
+}
+
+module_param_array(table, charp, &table_num, 0444);
+MODULE_PARM_DESC(table, "Test vectors as space-separated decimal strings");
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("cxl_test: cxl address translation test module");
+MODULE_IMPORT_NS("CXL");
+
+module_init(cxl_translate_init);
+module_exit(cxl_translate_exit);

tools/testing/cxl/test/mem.c

···
  * Vary the number of events returned to simulate events occuring while the
  * logs are being read.
  */
-static int ret_limit = 0;
+static atomic_t event_counter = ATOMIC_INIT(0);
 
 static int mock_get_event(struct device *dev, struct cxl_mbox_cmd *cmd)
 {
 	struct cxl_get_event_payload *pl;
 	struct mock_event_log *log;
-	u16 nr_overflow;
+	int ret_limit;
 	u8 log_type;
 	int i;
 
 	if (cmd->size_in != sizeof(log_type))
 		return -EINVAL;
 
-	ret_limit = (ret_limit + 1) % CXL_TEST_EVENT_RET_MAX;
-	if (!ret_limit)
-		ret_limit = 1;
+	/* Vary return limit from 1 to CXL_TEST_EVENT_RET_MAX */
+	ret_limit = (atomic_inc_return(&event_counter) % CXL_TEST_EVENT_RET_MAX) + 1;
 
 	if (cmd->size_out < struct_size(pl, records, ret_limit))
 		return -EINVAL;
···
 		u64 ns;
 
 		pl->flags |= CXL_GET_EVENT_FLAG_OVERFLOW;
-		pl->overflow_err_count = cpu_to_le16(nr_overflow);
+		pl->overflow_err_count = cpu_to_le16(log->nr_overflow);
 		ns = ktime_get_real_ns();
 		ns -= 5000000000; /* 5s ago */
 		pl->first_overflow_timestamp = cpu_to_le64(ns);

tools/testing/cxl/test/mock.c

···
 }
 EXPORT_SYMBOL(__wrap_acpi_evaluate_integer);
 
+int __wrap_hmat_get_extended_linear_cache_size(struct resource *backing_res,
+					       int nid,
+					       resource_size_t *cache_size)
+{
+	int index, rc;
+	struct cxl_mock_ops *ops = get_cxl_mock_ops(&index);
+
+	if (ops)
+		rc = ops->hmat_get_extended_linear_cache_size(backing_res, nid,
+							      cache_size);
+	else
+		rc = hmat_get_extended_linear_cache_size(backing_res, nid,
+							 cache_size);
+
+	put_cxl_mock_ops(index);
+
+	return rc;
+}
+EXPORT_SYMBOL_GPL(__wrap_hmat_get_extended_linear_cache_size);
+
 struct acpi_pci_root *__wrap_acpi_pci_find_root(acpi_handle handle)
 {
 	int index;
···
 }
 EXPORT_SYMBOL_NS_GPL(__wrap_devm_cxl_endpoint_decoders_setup, "CXL");
 
-int __wrap_devm_cxl_port_enumerate_dports(struct cxl_port *port)
-{
-	int rc, index;
-	struct cxl_mock_ops *ops = get_cxl_mock_ops(&index);
-
-	if (ops && ops->is_mock_port(port->uport_dev))
-		rc = ops->devm_cxl_port_enumerate_dports(port);
-	else
-		rc = devm_cxl_port_enumerate_dports(port);
-	put_cxl_mock_ops(index);
-
-	return rc;
-}
-EXPORT_SYMBOL_NS_GPL(__wrap_devm_cxl_port_enumerate_dports, "CXL");
-
 int __wrap_cxl_await_media_ready(struct cxl_dev_state *cxlds)
 {
 	int rc, index;
···
 	return dport;
 }
 EXPORT_SYMBOL_NS_GPL(__wrap_devm_cxl_add_rch_dport, "CXL");
-
-resource_size_t __wrap_cxl_rcd_component_reg_phys(struct device *dev,
-						  struct cxl_dport *dport)
-{
-	int index;
-	resource_size_t component_reg_phys;
-	struct cxl_mock_ops *ops = get_cxl_mock_ops(&index);
-
-	if (ops && ops->is_mock_port(dev))
-		component_reg_phys = CXL_RESOURCE_NONE;
-	else
-		component_reg_phys = cxl_rcd_component_reg_phys(dev, dport);
-	put_cxl_mock_ops(index);
-
-	return component_reg_phys;
-}
-EXPORT_SYMBOL_NS_GPL(__wrap_cxl_rcd_component_reg_phys, "CXL");
 
 void __wrap_cxl_endpoint_parse_cdat(struct cxl_port *port)
 {

tools/testing/cxl/test/mock.h

···
 	bool (*is_mock_bus)(struct pci_bus *bus);
 	bool (*is_mock_port)(struct device *dev);
 	bool (*is_mock_dev)(struct device *dev);
-	int (*devm_cxl_port_enumerate_dports)(struct cxl_port *port);
 	int (*devm_cxl_switch_port_decoders_setup)(struct cxl_port *port);
 	int (*devm_cxl_endpoint_decoders_setup)(struct cxl_port *port);
 	void (*cxl_endpoint_parse_cdat)(struct cxl_port *port);
 	struct cxl_dport *(*devm_cxl_add_dport_by_dev)(struct cxl_port *port,
 						       struct device *dport_dev);
+	int (*hmat_get_extended_linear_cache_size)(struct resource *backing_res,
+						   int nid,
+						   resource_size_t *cache_size);
 };
 
 void register_cxl_mock_ops(struct cxl_mock_ops *ops);