cxl/core: Move pmem functionality

Refactor the pmem / nvdimm-bridge functionality from core/bus.c to
core/pmem.c. Introduce drivers/core/core.h to communicate data
structures and helpers between the core bus and other functionality that
registers devices on the bus.

Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/162792538899.368511.3881663908293411300.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Documentation/driver-api/cxl/memory-devices.rst

@@ -39,6 +39,9 @@ CXL Core
 .. kernel-doc:: drivers/cxl/core/bus.c
    :doc: cxl core
 
+.. kernel-doc:: drivers/cxl/core/pmem.c
+   :internal:
+
 External Interfaces
 ===================
 

drivers/cxl/core/Makefile

@@ -3,3 +3,4 @@ obj-$(CONFIG_CXL_BUS) += cxl_core.o
 
 ccflags-y += -DDEFAULT_SYMBOL_NAMESPACE=CXL -I$(srctree)/drivers/cxl
 cxl_core-y := bus.o
+cxl_core-y += pmem.o

drivers/cxl/core/bus.c

@@ -8,6 +8,7 @@
 #include <linux/idr.h>
 #include <cxlmem.h>
 #include <cxl.h>
+#include "core.h"
 
 /**
  * DOC: cxl core
@@ -37,7 +38,7 @@ static struct attribute *cxl_base_attributes[] = {
 	NULL,
 };
 
-static struct attribute_group cxl_base_attribute_group = {
+struct attribute_group cxl_base_attribute_group = {
 	.attrs = cxl_base_attributes,
 };
 
@@ -514,11 +515,6 @@ err:
 	return ERR_PTR(rc);
 }
 
-static void unregister_dev(void *dev)
-{
-	device_unregister(dev);
-}
-
 struct cxl_decoder *
 devm_cxl_add_decoder(struct device *host, struct cxl_port *port, int nr_targets,
 		     resource_size_t base, resource_size_t len,
@@ -543,7 +539,7 @@ devm_cxl_add_decoder(struct device *host, struct cxl_port *port, int nr_targets,
 	if (rc)
 		goto err;
 
-	rc = devm_add_action_or_reset(host, unregister_dev, dev);
+	rc = devm_add_action_or_reset(host, unregister_cxl_dev, dev);
 	if (rc)
 		return ERR_PTR(rc);
 	return cxld;
@@ -626,201 +622,6 @@ void cxl_probe_component_regs(struct device *dev, void __iomem *base,
 }
 EXPORT_SYMBOL_GPL(cxl_probe_component_regs);
 
-static void cxl_nvdimm_bridge_release(struct device *dev)
-{
-	struct cxl_nvdimm_bridge *cxl_nvb = to_cxl_nvdimm_bridge(dev);
-
-	kfree(cxl_nvb);
-}
-
-static const struct attribute_group *cxl_nvdimm_bridge_attribute_groups[] = {
-	&cxl_base_attribute_group,
-	NULL,
-};
-
-static const struct device_type cxl_nvdimm_bridge_type = {
-	.name = "cxl_nvdimm_bridge",
-	.release = cxl_nvdimm_bridge_release,
-	.groups = cxl_nvdimm_bridge_attribute_groups,
-};
-
-struct cxl_nvdimm_bridge *to_cxl_nvdimm_bridge(struct device *dev)
-{
-	if (dev_WARN_ONCE(dev, dev->type != &cxl_nvdimm_bridge_type,
-			  "not a cxl_nvdimm_bridge device\n"))
-		return NULL;
-	return container_of(dev, struct cxl_nvdimm_bridge, dev);
-}
-EXPORT_SYMBOL_GPL(to_cxl_nvdimm_bridge);
-
-static struct cxl_nvdimm_bridge *
-cxl_nvdimm_bridge_alloc(struct cxl_port *port)
-{
-	struct cxl_nvdimm_bridge *cxl_nvb;
-	struct device *dev;
-
-	cxl_nvb = kzalloc(sizeof(*cxl_nvb), GFP_KERNEL);
-	if (!cxl_nvb)
-		return ERR_PTR(-ENOMEM);
-
-	dev = &cxl_nvb->dev;
-	cxl_nvb->port = port;
-	cxl_nvb->state = CXL_NVB_NEW;
-	device_initialize(dev);
-	device_set_pm_not_required(dev);
-	dev->parent = &port->dev;
-	dev->bus = &cxl_bus_type;
-	dev->type = &cxl_nvdimm_bridge_type;
-
-	return cxl_nvb;
-}
-
-static void unregister_nvb(void *_cxl_nvb)
-{
-	struct cxl_nvdimm_bridge *cxl_nvb = _cxl_nvb;
-	bool flush;
-
-	/*
-	 * If the bridge was ever activated then there might be in-flight state
-	 * work to flush. Once the state has been changed to 'dead' then no new
-	 * work can be queued by user-triggered bind.
-	 */
-	device_lock(&cxl_nvb->dev);
-	flush = cxl_nvb->state != CXL_NVB_NEW;
-	cxl_nvb->state = CXL_NVB_DEAD;
-	device_unlock(&cxl_nvb->dev);
-
-	/*
-	 * Even though the device core will trigger device_release_driver()
-	 * before the unregister, it does not know about the fact that
-	 * cxl_nvdimm_bridge_driver defers ->remove() work. So, do the driver
-	 * release not and flush it before tearing down the nvdimm device
-	 * hierarchy.
-	 */
-	device_release_driver(&cxl_nvb->dev);
-	if (flush)
-		flush_work(&cxl_nvb->state_work);
-	device_unregister(&cxl_nvb->dev);
-}
-
-struct cxl_nvdimm_bridge *devm_cxl_add_nvdimm_bridge(struct device *host,
-						     struct cxl_port *port)
-{
-	struct cxl_nvdimm_bridge *cxl_nvb;
-	struct device *dev;
-	int rc;
-
-	if (!IS_ENABLED(CONFIG_CXL_PMEM))
-		return ERR_PTR(-ENXIO);
-
-	cxl_nvb = cxl_nvdimm_bridge_alloc(port);
-	if (IS_ERR(cxl_nvb))
-		return cxl_nvb;
-
-	dev = &cxl_nvb->dev;
-	rc = dev_set_name(dev, "nvdimm-bridge");
-	if (rc)
-		goto err;
-
-	rc = device_add(dev);
-	if (rc)
-		goto err;
-
-	rc = devm_add_action_or_reset(host, unregister_nvb, cxl_nvb);
-	if (rc)
-		return ERR_PTR(rc);
-
-	return cxl_nvb;
-
-err:
-	put_device(dev);
-	return ERR_PTR(rc);
-}
-EXPORT_SYMBOL_GPL(devm_cxl_add_nvdimm_bridge);
-
-static void cxl_nvdimm_release(struct device *dev)
-{
-	struct cxl_nvdimm *cxl_nvd = to_cxl_nvdimm(dev);
-
-	kfree(cxl_nvd);
-}
-
-static const struct attribute_group *cxl_nvdimm_attribute_groups[] = {
-	&cxl_base_attribute_group,
-	NULL,
-};
-
-static const struct device_type cxl_nvdimm_type = {
-	.name = "cxl_nvdimm",
-	.release = cxl_nvdimm_release,
-	.groups = cxl_nvdimm_attribute_groups,
-};
-
-bool is_cxl_nvdimm(struct device *dev)
-{
-	return dev->type == &cxl_nvdimm_type;
-}
-EXPORT_SYMBOL_GPL(is_cxl_nvdimm);
-
-struct cxl_nvdimm *to_cxl_nvdimm(struct device *dev)
-{
-	if (dev_WARN_ONCE(dev, !is_cxl_nvdimm(dev),
-			  "not a cxl_nvdimm device\n"))
-		return NULL;
-	return container_of(dev, struct cxl_nvdimm, dev);
-}
-EXPORT_SYMBOL_GPL(to_cxl_nvdimm);
-
-static struct cxl_nvdimm *cxl_nvdimm_alloc(struct cxl_memdev *cxlmd)
-{
-	struct cxl_nvdimm *cxl_nvd;
-	struct device *dev;
-
-	cxl_nvd = kzalloc(sizeof(*cxl_nvd), GFP_KERNEL);
-	if (!cxl_nvd)
-		return ERR_PTR(-ENOMEM);
-
-	dev = &cxl_nvd->dev;
-	cxl_nvd->cxlmd = cxlmd;
-	device_initialize(dev);
-	device_set_pm_not_required(dev);
-	dev->parent = &cxlmd->dev;
-	dev->bus = &cxl_bus_type;
-	dev->type = &cxl_nvdimm_type;
-
-	return cxl_nvd;
-}
-
-int devm_cxl_add_nvdimm(struct device *host, struct cxl_memdev *cxlmd)
-{
-	struct cxl_nvdimm *cxl_nvd;
-	struct device *dev;
-	int rc;
-
-	cxl_nvd = cxl_nvdimm_alloc(cxlmd);
-	if (IS_ERR(cxl_nvd))
-		return PTR_ERR(cxl_nvd);
-
-	dev = &cxl_nvd->dev;
-	rc = dev_set_name(dev, "pmem%d", cxlmd->id);
-	if (rc)
-		goto err;
-
-	rc = device_add(dev);
-	if (rc)
-		goto err;
-
-	dev_dbg(host, "%s: register %s\n", dev_name(dev->parent),
-		dev_name(dev));
-
-	return devm_add_action_or_reset(host, unregister_dev, dev);
-
-err:
-	put_device(dev);
-	return rc;
-}
-EXPORT_SYMBOL_GPL(devm_cxl_add_nvdimm);
-
 /**
  * cxl_probe_device_regs() - Detect CXL Device register blocks
  * @dev: Host device of the @base mapping

drivers/cxl/core/core.h

@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* Copyright(c) 2020 Intel Corporation. */
+
+#ifndef __CXL_CORE_H__
+#define __CXL_CORE_H__
+
+extern const struct device_type cxl_nvdimm_bridge_type;
+extern const struct device_type cxl_nvdimm_type;
+
+extern struct attribute_group cxl_base_attribute_group;
+
+static inline void unregister_cxl_dev(void *dev)
+{
+	device_unregister(dev);
+}
+
+#endif /* __CXL_CORE_H__ */

drivers/cxl/core/pmem.c

@@ -0,0 +1,204 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright(c) 2020 Intel Corporation. */
+
+#include <linux/device.h>
+#include <linux/slab.h>
+#include <cxlmem.h>
+#include <cxl.h>
+
+#include "core.h"
+
+static void cxl_nvdimm_bridge_release(struct device *dev)
+{
+	struct cxl_nvdimm_bridge *cxl_nvb = to_cxl_nvdimm_bridge(dev);
+
+	kfree(cxl_nvb);
+}
+
+static const struct attribute_group *cxl_nvdimm_bridge_attribute_groups[] = {
+	&cxl_base_attribute_group,
+	NULL,
+};
+
+const struct device_type cxl_nvdimm_bridge_type = {
+	.name = "cxl_nvdimm_bridge",
+	.release = cxl_nvdimm_bridge_release,
+	.groups = cxl_nvdimm_bridge_attribute_groups,
+};
+
+struct cxl_nvdimm_bridge *to_cxl_nvdimm_bridge(struct device *dev)
+{
+	if (dev_WARN_ONCE(dev, dev->type != &cxl_nvdimm_bridge_type,
+			  "not a cxl_nvdimm_bridge device\n"))
+		return NULL;
+	return container_of(dev, struct cxl_nvdimm_bridge, dev);
+}
+EXPORT_SYMBOL_GPL(to_cxl_nvdimm_bridge);
+
+static struct cxl_nvdimm_bridge *
+cxl_nvdimm_bridge_alloc(struct cxl_port *port)
+{
+	struct cxl_nvdimm_bridge *cxl_nvb;
+	struct device *dev;
+
+	cxl_nvb = kzalloc(sizeof(*cxl_nvb), GFP_KERNEL);
+	if (!cxl_nvb)
+		return ERR_PTR(-ENOMEM);
+
+	dev = &cxl_nvb->dev;
+	cxl_nvb->port = port;
+	cxl_nvb->state = CXL_NVB_NEW;
+	device_initialize(dev);
+	device_set_pm_not_required(dev);
+	dev->parent = &port->dev;
+	dev->bus = &cxl_bus_type;
+	dev->type = &cxl_nvdimm_bridge_type;
+
+	return cxl_nvb;
+}
+
+static void unregister_nvb(void *_cxl_nvb)
+{
+	struct cxl_nvdimm_bridge *cxl_nvb = _cxl_nvb;
+	bool flush;
+
+	/*
+	 * If the bridge was ever activated then there might be in-flight state
+	 * work to flush. Once the state has been changed to 'dead' then no new
+	 * work can be queued by user-triggered bind.
+	 */
+	device_lock(&cxl_nvb->dev);
+	flush = cxl_nvb->state != CXL_NVB_NEW;
+	cxl_nvb->state = CXL_NVB_DEAD;
+	device_unlock(&cxl_nvb->dev);
+
+	/*
+	 * Even though the device core will trigger device_release_driver()
+	 * before the unregister, it does not know about the fact that
+	 * cxl_nvdimm_bridge_driver defers ->remove() work. So, do the driver
+	 * release not and flush it before tearing down the nvdimm device
+	 * hierarchy.
+	 */
+	device_release_driver(&cxl_nvb->dev);
+	if (flush)
+		flush_work(&cxl_nvb->state_work);
+	device_unregister(&cxl_nvb->dev);
+}
+
+struct cxl_nvdimm_bridge *devm_cxl_add_nvdimm_bridge(struct device *host,
+						     struct cxl_port *port)
+{
+	struct cxl_nvdimm_bridge *cxl_nvb;
+	struct device *dev;
+	int rc;
+
+	if (!IS_ENABLED(CONFIG_CXL_PMEM))
+		return ERR_PTR(-ENXIO);
+
+	cxl_nvb = cxl_nvdimm_bridge_alloc(port);
+	if (IS_ERR(cxl_nvb))
+		return cxl_nvb;
+
+	dev = &cxl_nvb->dev;
+	rc = dev_set_name(dev, "nvdimm-bridge");
+	if (rc)
+		goto err;
+
+	rc = device_add(dev);
+	if (rc)
+		goto err;
+
+	rc = devm_add_action_or_reset(host, unregister_nvb, cxl_nvb);
+	if (rc)
+		return ERR_PTR(rc);
+
+	return cxl_nvb;
+
+err:
+	put_device(dev);
+	return ERR_PTR(rc);
+}
+EXPORT_SYMBOL_GPL(devm_cxl_add_nvdimm_bridge);
+
+static void cxl_nvdimm_release(struct device *dev)
+{
+	struct cxl_nvdimm *cxl_nvd = to_cxl_nvdimm(dev);
+
+	kfree(cxl_nvd);
+}
+
+static const struct attribute_group *cxl_nvdimm_attribute_groups[] = {
+	&cxl_base_attribute_group,
+	NULL,
+};
+
+const struct device_type cxl_nvdimm_type = {
+	.name = "cxl_nvdimm",
+	.release = cxl_nvdimm_release,
+	.groups = cxl_nvdimm_attribute_groups,
+};
+
+bool is_cxl_nvdimm(struct device *dev)
+{
+	return dev->type == &cxl_nvdimm_type;
+}
+EXPORT_SYMBOL_GPL(is_cxl_nvdimm);
+
+struct cxl_nvdimm *to_cxl_nvdimm(struct device *dev)
+{
+	if (dev_WARN_ONCE(dev, !is_cxl_nvdimm(dev),
+			  "not a cxl_nvdimm device\n"))
+		return NULL;
+	return container_of(dev, struct cxl_nvdimm, dev);
+}
+EXPORT_SYMBOL_GPL(to_cxl_nvdimm);
+
+static struct cxl_nvdimm *cxl_nvdimm_alloc(struct cxl_memdev *cxlmd)
+{
+	struct cxl_nvdimm *cxl_nvd;
+	struct device *dev;
+
+	cxl_nvd = kzalloc(sizeof(*cxl_nvd), GFP_KERNEL);
+	if (!cxl_nvd)
+		return ERR_PTR(-ENOMEM);
+
+	dev = &cxl_nvd->dev;
+	cxl_nvd->cxlmd = cxlmd;
+	device_initialize(dev);
+	device_set_pm_not_required(dev);
+	dev->parent = &cxlmd->dev;
+	dev->bus = &cxl_bus_type;
+	dev->type = &cxl_nvdimm_type;
+
+	return cxl_nvd;
+}
+
+int devm_cxl_add_nvdimm(struct device *host, struct cxl_memdev *cxlmd)
+{
+	struct cxl_nvdimm *cxl_nvd;
+	struct device *dev;
+	int rc;
+
+	cxl_nvd = cxl_nvdimm_alloc(cxlmd);
+	if (IS_ERR(cxl_nvd))
+		return PTR_ERR(cxl_nvd);
+
+	dev = &cxl_nvd->dev;
+	rc = dev_set_name(dev, "pmem%d", cxlmd->id);
+	if (rc)
+		goto err;
+
+	rc = device_add(dev);
+	if (rc)
+		goto err;
+
+	dev_dbg(host, "%s: register %s\n", dev_name(dev->parent),
+		dev_name(dev));
+
+	return devm_add_action_or_reset(host, unregister_cxl_dev, dev);
+
+err:
+	put_device(dev);
+	return rc;
+}
+EXPORT_SYMBOL_GPL(devm_cxl_add_nvdimm);