[PATCH v3 0/3] pull region-specific logic into new files

[PATCH v3 0/3] pull region-specific logic into new files

[Gregory Price]

cxl/core/region.c presently contains logic to handle cxl_region,
cxl_pmem_region, and cxl_dax_region.  The cxl_pmem_region and
cxl_dax_region management code deserves new files to make it clear
that this logic applies to a specific types of regions.

This also breaks up development space so fewer conflicts can occur, and
it becomes clear where changes are actually happening.

I snuck in a cleanup.h fixup for devm_cxl_add_dax_region to tidy up some
of the existing functions.

v2 -> v3:  renamed from x_region to region_x because it's prettier
           added cleanup.h
           small nits asked for by Jonathan (commas)

Gregory Price (3):
  cxl/core/region: move pmem region driver logic into region_pmem.c
  cxl/core/region: move dax region device logic into region_dax.c
  cxl/core: use cleanup.h for devm_cxl_add_dax_region

 drivers/cxl/core/Makefile      |   2 +
 drivers/cxl/core/core.h        |   2 +
 drivers/cxl/core/region.c      | 283 ---------------------------------
 drivers/cxl/core/region_dax.c  | 104 ++++++++++++
 drivers/cxl/core/region_pmem.c | 189 ++++++++++++++++++++++
 drivers/cxl/cxl.h              |   1 +
 6 files changed, 298 insertions(+), 283 deletions(-)
 create mode 100644 drivers/cxl/core/region_dax.c
 create mode 100644 drivers/cxl/core/region_pmem.c

-- 
2.47.3

[PATCH v3 1/3] cxl/core/region: move pmem region driver logic into region_pmem.c

[Gregory Price]

core/region.c is overloaded with per-region control logic (pmem, dax).
Move pmem region logic from region.c into region_pmem.c to make it
clear that this code only applies to pmem regions.

No functional changes.

Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Fabio M. De Francesco <fabio.m.de.francesco@linux.intel.com>
Signed-off-by: Gregory Price <gourry@gourry.net>
---
 drivers/cxl/core/Makefile      |   1 +
 drivers/cxl/core/core.h        |   1 +
 drivers/cxl/core/region.c      | 184 --------------------------------
 drivers/cxl/core/region_pmem.c | 189 +++++++++++++++++++++++++++++++++
 4 files changed, 191 insertions(+), 184 deletions(-)
 create mode 100644 drivers/cxl/core/region_pmem.c

diff --git a/drivers/cxl/core/Makefile b/drivers/cxl/core/Makefile
index a639a9499972..d1484a0e5eb4 100644
--- a/drivers/cxl/core/Makefile
+++ b/drivers/cxl/core/Makefile
@@ -16,6 +16,7 @@ cxl_core-y += pmu.o
 cxl_core-y += cdat.o
 cxl_core-$(CONFIG_TRACING) += trace.o
 cxl_core-$(CONFIG_CXL_REGION) += region.o
+cxl_core-$(CONFIG_CXL_REGION) += region_pmem.o
 cxl_core-$(CONFIG_CXL_MCE) += mce.o
 cxl_core-$(CONFIG_CXL_FEATURES) += features.o
 cxl_core-$(CONFIG_CXL_EDAC_MEM_FEATURES) += edac.o
diff --git a/drivers/cxl/core/core.h b/drivers/cxl/core/core.h
index 007b8aff0238..ced65a779a09 100644
--- a/drivers/cxl/core/core.h
+++ b/drivers/cxl/core/core.h
@@ -50,6 +50,7 @@ int cxl_get_poison_by_endpoint(struct cxl_port *port);
 struct cxl_region *cxl_dpa_to_region(const struct cxl_memdev *cxlmd, u64 dpa);
 u64 cxl_dpa_to_hpa(struct cxl_region *cxlr, const struct cxl_memdev *cxlmd,
 		   u64 dpa);
+int devm_cxl_add_pmem_region(struct cxl_region *cxlr);
 
 #else
 static inline u64 cxl_dpa_to_hpa(struct cxl_region *cxlr,
diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
index bd4c4a4a27da..1c322318d70e 100644
--- a/drivers/cxl/core/region.c
+++ b/drivers/cxl/core/region.c
@@ -2757,46 +2757,6 @@ static ssize_t delete_region_store(struct device *dev,
 }
 DEVICE_ATTR_WO(delete_region);
 
-static void cxl_pmem_region_release(struct device *dev)
-{
-	struct cxl_pmem_region *cxlr_pmem = to_cxl_pmem_region(dev);
-	int i;
-
-	for (i = 0; i < cxlr_pmem->nr_mappings; i++) {
-		struct cxl_memdev *cxlmd = cxlr_pmem->mapping[i].cxlmd;
-
-		put_device(&cxlmd->dev);
-	}
-
-	kfree(cxlr_pmem);
-}
-
-static const struct attribute_group *cxl_pmem_region_attribute_groups[] = {
-	&cxl_base_attribute_group,
-	NULL,
-};
-
-const struct device_type cxl_pmem_region_type = {
-	.name = "cxl_pmem_region",
-	.release = cxl_pmem_region_release,
-	.groups = cxl_pmem_region_attribute_groups,
-};
-
-bool is_cxl_pmem_region(struct device *dev)
-{
-	return dev->type == &cxl_pmem_region_type;
-}
-EXPORT_SYMBOL_NS_GPL(is_cxl_pmem_region, "CXL");
-
-struct cxl_pmem_region *to_cxl_pmem_region(struct device *dev)
-{
-	if (dev_WARN_ONCE(dev, !is_cxl_pmem_region(dev),
-			  "not a cxl_pmem_region device\n"))
-		return NULL;
-	return container_of(dev, struct cxl_pmem_region, dev);
-}
-EXPORT_SYMBOL_NS_GPL(to_cxl_pmem_region, "CXL");
-
 struct cxl_poison_context {
 	struct cxl_port *port;
 	int part;
@@ -3432,64 +3392,6 @@ static int region_offset_to_dpa_result(struct cxl_region *cxlr, u64 offset,
 	return -ENXIO;
 }
 
-static struct lock_class_key cxl_pmem_region_key;
-
-static int cxl_pmem_region_alloc(struct cxl_region *cxlr)
-{
-	struct cxl_region_params *p = &cxlr->params;
-	struct cxl_nvdimm_bridge *cxl_nvb;
-	struct device *dev;
-	int i;
-
-	guard(rwsem_read)(&cxl_rwsem.region);
-	if (p->state != CXL_CONFIG_COMMIT)
-		return -ENXIO;
-
-	struct cxl_pmem_region *cxlr_pmem __free(kfree) =
-		kzalloc(struct_size(cxlr_pmem, mapping, p->nr_targets), GFP_KERNEL);
-	if (!cxlr_pmem)
-		return -ENOMEM;
-
-	cxlr_pmem->hpa_range.start = p->res->start;
-	cxlr_pmem->hpa_range.end = p->res->end;
-
-	/* Snapshot the region configuration underneath the cxl_rwsem.region */
-	cxlr_pmem->nr_mappings = p->nr_targets;
-	for (i = 0; i < p->nr_targets; i++) {
-		struct cxl_endpoint_decoder *cxled = p->targets[i];
-		struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
-		struct cxl_pmem_region_mapping *m = &cxlr_pmem->mapping[i];
-
-		/*
-		 * Regions never span CXL root devices, so by definition the
-		 * bridge for one device is the same for all.
-		 */
-		if (i == 0) {
-			cxl_nvb = cxl_find_nvdimm_bridge(cxlmd->endpoint);
-			if (!cxl_nvb)
-				return -ENODEV;
-			cxlr->cxl_nvb = cxl_nvb;
-		}
-		m->cxlmd = cxlmd;
-		get_device(&cxlmd->dev);
-		m->start = cxled->dpa_res->start;
-		m->size = resource_size(cxled->dpa_res);
-		m->position = i;
-	}
-
-	dev = &cxlr_pmem->dev;
-	device_initialize(dev);
-	lockdep_set_class(&dev->mutex, &cxl_pmem_region_key);
-	device_set_pm_not_required(dev);
-	dev->parent = &cxlr->dev;
-	dev->bus = &cxl_bus_type;
-	dev->type = &cxl_pmem_region_type;
-	cxlr_pmem->cxlr = cxlr;
-	cxlr->cxlr_pmem = no_free_ptr(cxlr_pmem);
-
-	return 0;
-}
-
 static void cxl_dax_region_release(struct device *dev)
 {
 	struct cxl_dax_region *cxlr_dax = to_cxl_dax_region(dev);
@@ -3553,92 +3455,6 @@ static struct cxl_dax_region *cxl_dax_region_alloc(struct cxl_region *cxlr)
 	return cxlr_dax;
 }
 
-static void cxlr_pmem_unregister(void *_cxlr_pmem)
-{
-	struct cxl_pmem_region *cxlr_pmem = _cxlr_pmem;
-	struct cxl_region *cxlr = cxlr_pmem->cxlr;
-	struct cxl_nvdimm_bridge *cxl_nvb = cxlr->cxl_nvb;
-
-	/*
-	 * Either the bridge is in ->remove() context under the device_lock(),
-	 * or cxlr_release_nvdimm() is cancelling the bridge's release action
-	 * for @cxlr_pmem and doing it itself (while manually holding the bridge
-	 * lock).
-	 */
-	device_lock_assert(&cxl_nvb->dev);
-	cxlr->cxlr_pmem = NULL;
-	cxlr_pmem->cxlr = NULL;
-	device_unregister(&cxlr_pmem->dev);
-}
-
-static void cxlr_release_nvdimm(void *_cxlr)
-{
-	struct cxl_region *cxlr = _cxlr;
-	struct cxl_nvdimm_bridge *cxl_nvb = cxlr->cxl_nvb;
-
-	scoped_guard(device, &cxl_nvb->dev) {
-		if (cxlr->cxlr_pmem)
-			devm_release_action(&cxl_nvb->dev, cxlr_pmem_unregister,
-					    cxlr->cxlr_pmem);
-	}
-	cxlr->cxl_nvb = NULL;
-	put_device(&cxl_nvb->dev);
-}
-
-/**
- * devm_cxl_add_pmem_region() - add a cxl_region-to-nd_region bridge
- * @cxlr: parent CXL region for this pmem region bridge device
- *
- * Return: 0 on success negative error code on failure.
- */
-static int devm_cxl_add_pmem_region(struct cxl_region *cxlr)
-{
-	struct cxl_pmem_region *cxlr_pmem;
-	struct cxl_nvdimm_bridge *cxl_nvb;
-	struct device *dev;
-	int rc;
-
-	rc = cxl_pmem_region_alloc(cxlr);
-	if (rc)
-		return rc;
-	cxlr_pmem = cxlr->cxlr_pmem;
-	cxl_nvb = cxlr->cxl_nvb;
-
-	dev = &cxlr_pmem->dev;
-	rc = dev_set_name(dev, "pmem_region%d", cxlr->id);
-	if (rc)
-		goto err;
-
-	rc = device_add(dev);
-	if (rc)
-		goto err;
-
-	dev_dbg(&cxlr->dev, "%s: register %s\n", dev_name(dev->parent),
-		dev_name(dev));
-
-	scoped_guard(device, &cxl_nvb->dev) {
-		if (cxl_nvb->dev.driver)
-			rc = devm_add_action_or_reset(&cxl_nvb->dev,
-						      cxlr_pmem_unregister,
-						      cxlr_pmem);
-		else
-			rc = -ENXIO;
-	}
-
-	if (rc)
-		goto err_bridge;
-
-	/* @cxlr carries a reference on @cxl_nvb until cxlr_release_nvdimm */
-	return devm_add_action_or_reset(&cxlr->dev, cxlr_release_nvdimm, cxlr);
-
-err:
-	put_device(dev);
-err_bridge:
-	put_device(&cxl_nvb->dev);
-	cxlr->cxl_nvb = NULL;
-	return rc;
-}
-
 static void cxlr_dax_unregister(void *_cxlr_dax)
 {
 	struct cxl_dax_region *cxlr_dax = _cxlr_dax;
diff --git a/drivers/cxl/core/region_pmem.c b/drivers/cxl/core/region_pmem.c
new file mode 100644
index 000000000000..f800407566d3
--- /dev/null
+++ b/drivers/cxl/core/region_pmem.c
@@ -0,0 +1,189 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright(c) 2022 Intel Corporation. All rights reserved. */
+#include <linux/device.h>
+#include <linux/slab.h>
+#include <cxlmem.h>
+#include <cxl.h>
+#include "core.h"
+
+static void cxl_pmem_region_release(struct device *dev)
+{
+	struct cxl_pmem_region *cxlr_pmem = to_cxl_pmem_region(dev);
+	int i;
+
+	for (i = 0; i < cxlr_pmem->nr_mappings; i++) {
+		struct cxl_memdev *cxlmd = cxlr_pmem->mapping[i].cxlmd;
+
+		put_device(&cxlmd->dev);
+	}
+
+	kfree(cxlr_pmem);
+}
+
+static const struct attribute_group *cxl_pmem_region_attribute_groups[] = {
+	&cxl_base_attribute_group,
+	NULL
+};
+
+const struct device_type cxl_pmem_region_type = {
+	.name = "cxl_pmem_region",
+	.release = cxl_pmem_region_release,
+	.groups = cxl_pmem_region_attribute_groups,
+};
+bool is_cxl_pmem_region(struct device *dev)
+{
+	return dev->type == &cxl_pmem_region_type;
+}
+EXPORT_SYMBOL_NS_GPL(is_cxl_pmem_region, "CXL");
+
+struct cxl_pmem_region *to_cxl_pmem_region(struct device *dev)
+{
+	if (dev_WARN_ONCE(dev, !is_cxl_pmem_region(dev),
+				"not a cxl_pmem_region device\n"))
+		return NULL;
+	return container_of(dev, struct cxl_pmem_region, dev);
+}
+EXPORT_SYMBOL_NS_GPL(to_cxl_pmem_region, "CXL");
+static struct lock_class_key cxl_pmem_region_key;
+
+static int cxl_pmem_region_alloc(struct cxl_region *cxlr)
+{
+	struct cxl_region_params *p = &cxlr->params;
+	struct cxl_nvdimm_bridge *cxl_nvb;
+	struct device *dev;
+	int i;
+
+	guard(rwsem_read)(&cxl_rwsem.region);
+	if (p->state != CXL_CONFIG_COMMIT)
+		return -ENXIO;
+
+	struct cxl_pmem_region *cxlr_pmem __free(kfree) =
+		kzalloc(struct_size(cxlr_pmem, mapping, p->nr_targets), GFP_KERNEL);
+	if (!cxlr_pmem)
+		return -ENOMEM;
+
+	cxlr_pmem->hpa_range.start = p->res->start;
+	cxlr_pmem->hpa_range.end = p->res->end;
+
+	/* Snapshot the region configuration underneath the cxl_rwsem.region */
+	cxlr_pmem->nr_mappings = p->nr_targets;
+	for (i = 0; i < p->nr_targets; i++) {
+		struct cxl_endpoint_decoder *cxled = p->targets[i];
+		struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
+		struct cxl_pmem_region_mapping *m = &cxlr_pmem->mapping[i];
+
+		/*
+		 * Regions never span CXL root devices, so by definition the
+		 * bridge for one device is the same for all.
+		 */
+		if (i == 0) {
+			cxl_nvb = cxl_find_nvdimm_bridge(cxlmd->endpoint);
+			if (!cxl_nvb)
+				return -ENODEV;
+			cxlr->cxl_nvb = cxl_nvb;
+		}
+		m->cxlmd = cxlmd;
+		get_device(&cxlmd->dev);
+		m->start = cxled->dpa_res->start;
+		m->size = resource_size(cxled->dpa_res);
+		m->position = i;
+	}
+
+	dev = &cxlr_pmem->dev;
+	device_initialize(dev);
+	lockdep_set_class(&dev->mutex, &cxl_pmem_region_key);
+	device_set_pm_not_required(dev);
+	dev->parent = &cxlr->dev;
+	dev->bus = &cxl_bus_type;
+	dev->type = &cxl_pmem_region_type;
+	cxlr_pmem->cxlr = cxlr;
+	cxlr->cxlr_pmem = no_free_ptr(cxlr_pmem);
+
+	return 0;
+}
+
+static void cxlr_pmem_unregister(void *_cxlr_pmem)
+{
+	struct cxl_pmem_region *cxlr_pmem = _cxlr_pmem;
+	struct cxl_region *cxlr = cxlr_pmem->cxlr;
+	struct cxl_nvdimm_bridge *cxl_nvb = cxlr->cxl_nvb;
+
+	/*
+	 * Either the bridge is in ->remove() context under the device_lock(),
+	 * or cxlr_release_nvdimm() is cancelling the bridge's release action
+	 * for @cxlr_pmem and doing it itself (while manually holding the bridge
+	 * lock).
+	 */
+	device_lock_assert(&cxl_nvb->dev);
+	cxlr->cxlr_pmem = NULL;
+	cxlr_pmem->cxlr = NULL;
+	device_unregister(&cxlr_pmem->dev);
+}
+
+static void cxlr_release_nvdimm(void *_cxlr)
+{
+	struct cxl_region *cxlr = _cxlr;
+	struct cxl_nvdimm_bridge *cxl_nvb = cxlr->cxl_nvb;
+
+	scoped_guard(device, &cxl_nvb->dev) {
+		if (cxlr->cxlr_pmem)
+			devm_release_action(&cxl_nvb->dev, cxlr_pmem_unregister,
+					cxlr->cxlr_pmem);
+	}
+	cxlr->cxl_nvb = NULL;
+	put_device(&cxl_nvb->dev);
+}
+
+/**
+ * devm_cxl_add_pmem_region() - add a cxl_region-to-nd_region bridge
+ * @cxlr: parent CXL region for this pmem region bridge device
+ *
+ * Return: 0 on success negative error code on failure.
+ */
+int devm_cxl_add_pmem_region(struct cxl_region *cxlr)
+{
+	struct cxl_pmem_region *cxlr_pmem;
+	struct cxl_nvdimm_bridge *cxl_nvb;
+	struct device *dev;
+	int rc;
+
+	rc = cxl_pmem_region_alloc(cxlr);
+	if (rc)
+		return rc;
+	cxlr_pmem = cxlr->cxlr_pmem;
+	cxl_nvb = cxlr->cxl_nvb;
+
+	dev = &cxlr_pmem->dev;
+	rc = dev_set_name(dev, "pmem_region%d", cxlr->id);
+	if (rc)
+		goto err;
+
+	rc = device_add(dev);
+	if (rc)
+		goto err;
+
+	dev_dbg(&cxlr->dev, "%s: register %s\n", dev_name(dev->parent),
+			dev_name(dev));
+
+	scoped_guard(device, &cxl_nvb->dev) {
+		if (cxl_nvb->dev.driver)
+			rc = devm_add_action_or_reset(&cxl_nvb->dev,
+					cxlr_pmem_unregister,
+					cxlr_pmem);
+		else
+			rc = -ENXIO;
+	}
+
+	if (rc)
+		goto err_bridge;
+
+	/* @cxlr carries a reference on @cxl_nvb until cxlr_release_nvdimm */
+	return devm_add_action_or_reset(&cxlr->dev, cxlr_release_nvdimm, cxlr);
+
+err:
+	put_device(dev);
+err_bridge:
+	put_device(&cxl_nvb->dev);
+	cxlr->cxl_nvb = NULL;
+	return rc;
+}
-- 
2.47.3

[PATCH v3 2/3] cxl/core/region: move dax region device logic into region_dax.c

[Gregory Price]

core/region.c is overloaded with per-region control logic (pmem, dax).
Move CXL DAX region device logic from region.c into region_dax.c.

No functional changes.

Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Fabio M. De Francesco <fabio.m.de.francesco@linux.intel.com>
Acked-by: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Gregory Price <gourry@gourry.net>
---
 drivers/cxl/core/Makefile     |   1 +
 drivers/cxl/core/core.h       |   1 +
 drivers/cxl/core/region.c     |  99 ------------------------------
 drivers/cxl/core/region_dax.c | 109 ++++++++++++++++++++++++++++++++++
 4 files changed, 111 insertions(+), 99 deletions(-)
 create mode 100644 drivers/cxl/core/region_dax.c

diff --git a/drivers/cxl/core/Makefile b/drivers/cxl/core/Makefile
index d1484a0e5eb4..d3ec8aea64c5 100644
--- a/drivers/cxl/core/Makefile
+++ b/drivers/cxl/core/Makefile
@@ -16,6 +16,7 @@ cxl_core-y += pmu.o
 cxl_core-y += cdat.o
 cxl_core-$(CONFIG_TRACING) += trace.o
 cxl_core-$(CONFIG_CXL_REGION) += region.o
+cxl_core-$(CONFIG_CXL_REGION) += region_dax.o
 cxl_core-$(CONFIG_CXL_REGION) += region_pmem.o
 cxl_core-$(CONFIG_CXL_MCE) += mce.o
 cxl_core-$(CONFIG_CXL_FEATURES) += features.o
diff --git a/drivers/cxl/core/core.h b/drivers/cxl/core/core.h
index ced65a779a09..a89e0d6d9e7b 100644
--- a/drivers/cxl/core/core.h
+++ b/drivers/cxl/core/core.h
@@ -50,6 +50,7 @@ int cxl_get_poison_by_endpoint(struct cxl_port *port);
 struct cxl_region *cxl_dpa_to_region(const struct cxl_memdev *cxlmd, u64 dpa);
 u64 cxl_dpa_to_hpa(struct cxl_region *cxlr, const struct cxl_memdev *cxlmd,
 		   u64 dpa);
+int devm_cxl_add_dax_region(struct cxl_region *cxlr);
 int devm_cxl_add_pmem_region(struct cxl_region *cxlr);
 
 #else
diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
index 1c322318d70e..0c37caa60f2a 100644
--- a/drivers/cxl/core/region.c
+++ b/drivers/cxl/core/region.c
@@ -3392,105 +3392,6 @@ static int region_offset_to_dpa_result(struct cxl_region *cxlr, u64 offset,
 	return -ENXIO;
 }
 
-static void cxl_dax_region_release(struct device *dev)
-{
-	struct cxl_dax_region *cxlr_dax = to_cxl_dax_region(dev);
-
-	kfree(cxlr_dax);
-}
-
-static const struct attribute_group *cxl_dax_region_attribute_groups[] = {
-	&cxl_base_attribute_group,
-	NULL,
-};
-
-const struct device_type cxl_dax_region_type = {
-	.name = "cxl_dax_region",
-	.release = cxl_dax_region_release,
-	.groups = cxl_dax_region_attribute_groups,
-};
-
-static bool is_cxl_dax_region(struct device *dev)
-{
-	return dev->type == &cxl_dax_region_type;
-}
-
-struct cxl_dax_region *to_cxl_dax_region(struct device *dev)
-{
-	if (dev_WARN_ONCE(dev, !is_cxl_dax_region(dev),
-			  "not a cxl_dax_region device\n"))
-		return NULL;
-	return container_of(dev, struct cxl_dax_region, dev);
-}
-EXPORT_SYMBOL_NS_GPL(to_cxl_dax_region, "CXL");
-
-static struct lock_class_key cxl_dax_region_key;
-
-static struct cxl_dax_region *cxl_dax_region_alloc(struct cxl_region *cxlr)
-{
-	struct cxl_region_params *p = &cxlr->params;
-	struct cxl_dax_region *cxlr_dax;
-	struct device *dev;
-
-	guard(rwsem_read)(&cxl_rwsem.region);
-	if (p->state != CXL_CONFIG_COMMIT)
-		return ERR_PTR(-ENXIO);
-
-	cxlr_dax = kzalloc(sizeof(*cxlr_dax), GFP_KERNEL);
-	if (!cxlr_dax)
-		return ERR_PTR(-ENOMEM);
-
-	cxlr_dax->hpa_range.start = p->res->start;
-	cxlr_dax->hpa_range.end = p->res->end;
-
-	dev = &cxlr_dax->dev;
-	cxlr_dax->cxlr = cxlr;
-	device_initialize(dev);
-	lockdep_set_class(&dev->mutex, &cxl_dax_region_key);
-	device_set_pm_not_required(dev);
-	dev->parent = &cxlr->dev;
-	dev->bus = &cxl_bus_type;
-	dev->type = &cxl_dax_region_type;
-
-	return cxlr_dax;
-}
-
-static void cxlr_dax_unregister(void *_cxlr_dax)
-{
-	struct cxl_dax_region *cxlr_dax = _cxlr_dax;
-
-	device_unregister(&cxlr_dax->dev);
-}
-
-static int devm_cxl_add_dax_region(struct cxl_region *cxlr)
-{
-	struct cxl_dax_region *cxlr_dax;
-	struct device *dev;
-	int rc;
-
-	cxlr_dax = cxl_dax_region_alloc(cxlr);
-	if (IS_ERR(cxlr_dax))
-		return PTR_ERR(cxlr_dax);
-
-	dev = &cxlr_dax->dev;
-	rc = dev_set_name(dev, "dax_region%d", cxlr->id);
-	if (rc)
-		goto err;
-
-	rc = device_add(dev);
-	if (rc)
-		goto err;
-
-	dev_dbg(&cxlr->dev, "%s: register %s\n", dev_name(dev->parent),
-		dev_name(dev));
-
-	return devm_add_action_or_reset(&cxlr->dev, cxlr_dax_unregister,
-					cxlr_dax);
-err:
-	put_device(dev);
-	return rc;
-}
-
 static int match_root_decoder(struct device *dev, const void *data)
 {
 	const struct range *r1, *r2 = data;
diff --git a/drivers/cxl/core/region_dax.c b/drivers/cxl/core/region_dax.c
new file mode 100644
index 000000000000..c8dd2bd1d9b9
--- /dev/null
+++ b/drivers/cxl/core/region_dax.c
@@ -0,0 +1,109 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright(c) 2022 Intel Corporation. All rights reserved.
+ * Copyright(c) 2026 Meta Technologies Inc. All rights reserved.
+ */
+#include <linux/device.h>
+#include <linux/slab.h>
+#include <cxlmem.h>
+#include <cxl.h>
+#include "core.h"
+
+static void cxl_dax_region_release(struct device *dev)
+{
+	struct cxl_dax_region *cxlr_dax = to_cxl_dax_region(dev);
+
+	kfree(cxlr_dax);
+}
+
+static const struct attribute_group *cxl_dax_region_attribute_groups[] = {
+	&cxl_base_attribute_group,
+	NULL
+};
+
+const struct device_type cxl_dax_region_type = {
+	.name = "cxl_dax_region",
+	.release = cxl_dax_region_release,
+	.groups = cxl_dax_region_attribute_groups,
+};
+
+static bool is_cxl_dax_region(struct device *dev)
+{
+	return dev->type == &cxl_dax_region_type;
+}
+
+struct cxl_dax_region *to_cxl_dax_region(struct device *dev)
+{
+	if (dev_WARN_ONCE(dev, !is_cxl_dax_region(dev),
+			  "not a cxl_dax_region device\n"))
+		return NULL;
+	return container_of(dev, struct cxl_dax_region, dev);
+}
+EXPORT_SYMBOL_NS_GPL(to_cxl_dax_region, "CXL");
+
+static struct lock_class_key cxl_dax_region_key;
+
+static struct cxl_dax_region *cxl_dax_region_alloc(struct cxl_region *cxlr)
+{
+	struct cxl_region_params *p = &cxlr->params;
+	struct cxl_dax_region *cxlr_dax;
+	struct device *dev;
+
+	guard(rwsem_read)(&cxl_rwsem.region);
+	if (p->state != CXL_CONFIG_COMMIT)
+		return ERR_PTR(-ENXIO);
+
+	cxlr_dax = kzalloc(sizeof(*cxlr_dax), GFP_KERNEL);
+	if (!cxlr_dax)
+		return ERR_PTR(-ENOMEM);
+
+	cxlr_dax->hpa_range.start = p->res->start;
+	cxlr_dax->hpa_range.end = p->res->end;
+
+	dev = &cxlr_dax->dev;
+	cxlr_dax->cxlr = cxlr;
+	device_initialize(dev);
+	lockdep_set_class(&dev->mutex, &cxl_dax_region_key);
+	device_set_pm_not_required(dev);
+	dev->parent = &cxlr->dev;
+	dev->bus = &cxl_bus_type;
+	dev->type = &cxl_dax_region_type;
+
+	return cxlr_dax;
+}
+
+static void cxlr_dax_unregister(void *_cxlr_dax)
+{
+	struct cxl_dax_region *cxlr_dax = _cxlr_dax;
+
+	device_unregister(&cxlr_dax->dev);
+}
+
+int devm_cxl_add_dax_region(struct cxl_region *cxlr)
+{
+	struct cxl_dax_region *cxlr_dax;
+	struct device *dev;
+	int rc;
+
+	cxlr_dax = cxl_dax_region_alloc(cxlr);
+	if (IS_ERR(cxlr_dax))
+		return PTR_ERR(cxlr_dax);
+
+	dev = &cxlr_dax->dev;
+	rc = dev_set_name(dev, "dax_region%d", cxlr->id);
+	if (rc)
+		goto err;
+
+	rc = device_add(dev);
+	if (rc)
+		goto err;
+
+	dev_dbg(&cxlr->dev, "%s: register %s\n", dev_name(dev->parent),
+		dev_name(dev));
+
+	return devm_add_action_or_reset(&cxlr->dev, cxlr_dax_unregister,
+					cxlr_dax);
+err:
+	put_device(dev);
+	return rc;
+}
-- 
2.47.3

[PATCH v3 3/3] cxl/core: use cleanup.h for devm_cxl_add_dax_region

[Gregory Price]

Cleanup the gotos in the function.

No functional change intended.

Signed-off-by: Gregory Price <gourry@gourry.net>
---
 drivers/cxl/core/region_dax.c | 21 ++++++++-------------
 drivers/cxl/cxl.h             |  1 +
 2 files changed, 9 insertions(+), 13 deletions(-)

diff --git a/drivers/cxl/core/region_dax.c b/drivers/cxl/core/region_dax.c
index c8dd2bd1d9b9..49907c6c7620 100644
--- a/drivers/cxl/core/region_dax.c
+++ b/drivers/cxl/core/region_dax.c
@@ -81,29 +81,24 @@ static void cxlr_dax_unregister(void *_cxlr_dax)
 
 int devm_cxl_add_dax_region(struct cxl_region *cxlr)
 {
-	struct cxl_dax_region *cxlr_dax;
-	struct device *dev;
+	struct cxl_dax_region *cxlr_dax __free(put_cxl_dax_region) = NULL;
 	int rc;
 
 	cxlr_dax = cxl_dax_region_alloc(cxlr);
 	if (IS_ERR(cxlr_dax))
 		return PTR_ERR(cxlr_dax);
 
-	dev = &cxlr_dax->dev;
-	rc = dev_set_name(dev, "dax_region%d", cxlr->id);
+	rc = dev_set_name(&cxlr_dax->dev, "dax_region%d", cxlr->id);
 	if (rc)
-		goto err;
+		return rc;
 
-	rc = device_add(dev);
+	rc = device_add(&cxlr_dax->dev);
 	if (rc)
-		goto err;
+		return rc;
 
-	dev_dbg(&cxlr->dev, "%s: register %s\n", dev_name(dev->parent),
-		dev_name(dev));
+	dev_dbg(&cxlr->dev, "%s: register %s\n", dev_name(cxlr_dax->dev.parent),
+		dev_name(&cxlr_dax->dev));
 
 	return devm_add_action_or_reset(&cxlr->dev, cxlr_dax_unregister,
-					cxlr_dax);
-err:
-	put_device(dev);
-	return rc;
+					no_free_ptr(cxlr_dax));
 }
diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
index 04c673e7cdb0..0b59008ea45a 100644
--- a/drivers/cxl/cxl.h
+++ b/drivers/cxl/cxl.h
@@ -803,6 +803,7 @@ DEFINE_FREE(put_cxl_root, struct cxl_root *, if (_T) put_device(&_T->port.dev))
 DEFINE_FREE(put_cxl_port, struct cxl_port *, if (!IS_ERR_OR_NULL(_T)) put_device(&_T->dev))
 DEFINE_FREE(put_cxl_root_decoder, struct cxl_root_decoder *, if (!IS_ERR_OR_NULL(_T)) put_device(&_T->cxlsd.cxld.dev))
 DEFINE_FREE(put_cxl_region, struct cxl_region *, if (!IS_ERR_OR_NULL(_T)) put_device(&_T->dev))
+DEFINE_FREE(put_cxl_dax_region, struct cxl_dax_region *, if (!IS_ERR_OR_NULL(_T)) put_device(&_T->dev))
 
 int devm_cxl_enumerate_ports(struct cxl_memdev *cxlmd);
 void cxl_bus_rescan(void);
-- 
2.47.3

Re: [PATCH v3 3/3] cxl/core: use cleanup.h for devm_cxl_add_dax_region

[Dave Jiang]

On 2/11/26 1:42 PM, Gregory Price wrote:
> Cleanup the gotos in the function.
> 
> No functional change intended.
> 
> Signed-off-by: Gregory Price <gourry@gourry.net>
> ---
>  drivers/cxl/core/region_dax.c | 21 ++++++++-------------
>  drivers/cxl/cxl.h             |  1 +
>  2 files changed, 9 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/cxl/core/region_dax.c b/drivers/cxl/core/region_dax.c
> index c8dd2bd1d9b9..49907c6c7620 100644
> --- a/drivers/cxl/core/region_dax.c
> +++ b/drivers/cxl/core/region_dax.c
> @@ -81,29 +81,24 @@ static void cxlr_dax_unregister(void *_cxlr_dax)
>  
>  int devm_cxl_add_dax_region(struct cxl_region *cxlr)
>  {
> -	struct cxl_dax_region *cxlr_dax;
> -	struct device *dev;
> +	struct cxl_dax_region *cxlr_dax __free(put_cxl_dax_region) = NULL;
>  	int rc;
>  
>  	cxlr_dax = cxl_dax_region_alloc(cxlr);

The typical __cleanup() pattern is to move the variable declaration here in order to minimize unintended issues between declare and check.

>  	if (IS_ERR(cxlr_dax))
>  		return PTR_ERR(cxlr_dax);
>  
> -	dev = &cxlr_dax->dev;

Given that this local var is used multiple times, maybe we should keep it?

DJ

> -	rc = dev_set_name(dev, "dax_region%d", cxlr->id);
> +	rc = dev_set_name(&cxlr_dax->dev, "dax_region%d", cxlr->id);
>  	if (rc)
> -		goto err;
> +		return rc;
>  
> -	rc = device_add(dev);
> +	rc = device_add(&cxlr_dax->dev);
>  	if (rc)
> -		goto err;
> +		return rc;
>  
> -	dev_dbg(&cxlr->dev, "%s: register %s\n", dev_name(dev->parent),
> -		dev_name(dev));
> +	dev_dbg(&cxlr->dev, "%s: register %s\n", dev_name(cxlr_dax->dev.parent),
> +		dev_name(&cxlr_dax->dev));
>  
>  	return devm_add_action_or_reset(&cxlr->dev, cxlr_dax_unregister,
> -					cxlr_dax);
> -err:
> -	put_device(dev);
> -	return rc;
> +					no_free_ptr(cxlr_dax));
>  }
> diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
> index 04c673e7cdb0..0b59008ea45a 100644
> --- a/drivers/cxl/cxl.h
> +++ b/drivers/cxl/cxl.h
> @@ -803,6 +803,7 @@ DEFINE_FREE(put_cxl_root, struct cxl_root *, if (_T) put_device(&_T->port.dev))
>  DEFINE_FREE(put_cxl_port, struct cxl_port *, if (!IS_ERR_OR_NULL(_T)) put_device(&_T->dev))
>  DEFINE_FREE(put_cxl_root_decoder, struct cxl_root_decoder *, if (!IS_ERR_OR_NULL(_T)) put_device(&_T->cxlsd.cxld.dev))
>  DEFINE_FREE(put_cxl_region, struct cxl_region *, if (!IS_ERR_OR_NULL(_T)) put_device(&_T->dev))
> +DEFINE_FREE(put_cxl_dax_region, struct cxl_dax_region *, if (!IS_ERR_OR_NULL(_T)) put_device(&_T->dev))
>  
>  int devm_cxl_enumerate_ports(struct cxl_memdev *cxlmd);
>  void cxl_bus_rescan(void);

Re: [PATCH v3 3/3] cxl/core: use cleanup.h for devm_cxl_add_dax_region

[Gregory Price]

On Tue, Feb 17, 2026 at 04:55:13PM -0700, Dave Jiang wrote:
> 
> 
> On 2/11/26 1:42 PM, Gregory Price wrote:
> > Cleanup the gotos in the function.
> > 
> > No functional change intended.
> > 
> > Signed-off-by: Gregory Price <gourry@gourry.net>
> > ---
> >  drivers/cxl/core/region_dax.c | 21 ++++++++-------------
> >  drivers/cxl/cxl.h             |  1 +
> >  2 files changed, 9 insertions(+), 13 deletions(-)
> > 
> > diff --git a/drivers/cxl/core/region_dax.c b/drivers/cxl/core/region_dax.c
> > index c8dd2bd1d9b9..49907c6c7620 100644
> > --- a/drivers/cxl/core/region_dax.c
> > +++ b/drivers/cxl/core/region_dax.c
> > @@ -81,29 +81,24 @@ static void cxlr_dax_unregister(void *_cxlr_dax)
> >  
> >  int devm_cxl_add_dax_region(struct cxl_region *cxlr)
> >  {
> > -	struct cxl_dax_region *cxlr_dax;
> > -	struct device *dev;
> > +	struct cxl_dax_region *cxlr_dax __free(put_cxl_dax_region) = NULL;
> >  	int rc;
> >  
> >  	cxlr_dax = cxl_dax_region_alloc(cxlr);
> 
> The typical __cleanup() pattern is to move the variable declaration here in order to minimize unintended issues between declare and check.
>

Ah, relatively new pattern for me, i'll clean it up

> >  	if (IS_ERR(cxlr_dax))
> >  		return PTR_ERR(cxlr_dax);
> >  
> > -	dev = &cxlr_dax->dev;
> 
> Given that this local var is used multiple times, maybe we should keep it?
> 

Fair, will re-spin claned up

~Gregory