Merge branch 'for-6.19/cxl-addr-xlat' into cxl-for-next

Enable unit testing for XOR address translation of SPA to DPA and vice versa.

drivers/cxl/acpi.c

@@ -11,25 +11,36 @@
 #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
@@ -60,6 +71,14 @@ static u64 cxl_apply_xor_maps(struct cxl_root_decoder *cxlrd, u64 addr)
 
 	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 {
 	struct device *dev;

drivers/cxl/core/region.c

@@ -2953,28 +2953,119 @@ 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)
+#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)
 {
-	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;
+	int ways, gran;
 
-	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
@@ -2986,9 +3077,6 @@ u64 cxl_dpa_to_hpa(struct cxl_region *cxlr, const struct cxl_memdev *cxlmd,
 	 * 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);
 
 	if (eiw < 8) {
@@ -3003,6 +3091,37 @@ u64 cxl_dpa_to_hpa(struct cxl_region *cxlr, const struct cxl_memdev *cxlmd,
 	/* 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;
 
@@ -3035,8 +3154,6 @@ static int region_offset_to_dpa_result(struct cxl_region *cxlr, u64 offset,
 	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;
@@ -3058,50 +3175,15 @@ static int region_offset_to_dpa_result(struct cxl_region *cxlr, u64 offset,
 	} 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++) {

drivers/cxl/cxl.h

@@ -746,6 +746,25 @@ static inline bool is_cxl_root(struct cxl_port *port)
 	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);
 struct cxl_port *to_cxl_port(const struct device *dev);

tools/testing/cxl/test/Kbuild

@@ -4,6 +4,7 @@ ccflags-y := -I$(srctree)/drivers/cxl/ -I$(srctree)/drivers/cxl/core
 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_translate.c

@@ -0,0 +1,445 @@
+// 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);