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// SPDX-License-Identifier: GPL-2.0-only
/* Copyright(c) 2020 Intel Corporation. */
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/idr.h>
#include <cxlmem.h>
#include <cxl.h>
#include "core.h"
/**
* DOC: cxl pmem
*
* The core CXL PMEM infrastructure supports persistent memory
* provisioning and serves as a bridge to the LIBNVDIMM subsystem. A CXL
* 'bridge' device is added at the root of a CXL device topology if
* platform firmware advertises at least one persistent memory capable
* CXL window. That root-level bridge corresponds to a LIBNVDIMM 'bus'
* device. Then for each cxl_memdev in the CXL device topology a bridge
* device is added to host a LIBNVDIMM dimm object. When these bridges
* are registered native LIBNVDIMM uapis are translated to CXL
* operations, for example, namespace label access commands.
*/
static DEFINE_IDA(cxl_nvdimm_bridge_ida);
static void cxl_nvdimm_bridge_release(struct device *dev)
{
struct cxl_nvdimm_bridge *cxl_nvb = to_cxl_nvdimm_bridge(dev);
ida_free(&cxl_nvdimm_bridge_ida, cxl_nvb->id);
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_NS_GPL(to_cxl_nvdimm_bridge, CXL);
bool is_cxl_nvdimm_bridge(struct device *dev)
{
return dev->type == &cxl_nvdimm_bridge_type;
}
EXPORT_SYMBOL_NS_GPL(is_cxl_nvdimm_bridge, CXL);
static int match_nvdimm_bridge(struct device *dev, void *data)
{
return is_cxl_nvdimm_bridge(dev);
}
struct cxl_nvdimm_bridge *cxl_find_nvdimm_bridge(struct device *start)
{
struct cxl_port *port = find_cxl_root(start);
struct device *dev;
if (!port)
return NULL;
dev = device_find_child(&port->dev, NULL, match_nvdimm_bridge);
put_device(&port->dev);
if (!dev)
return NULL;
return to_cxl_nvdimm_bridge(dev);
}
EXPORT_SYMBOL_NS_GPL(cxl_find_nvdimm_bridge, CXL);
static struct lock_class_key cxl_nvdimm_bridge_key;
static struct cxl_nvdimm_bridge *cxl_nvdimm_bridge_alloc(struct cxl_port *port)
{
struct cxl_nvdimm_bridge *cxl_nvb;
struct device *dev;
int rc;
cxl_nvb = kzalloc(sizeof(*cxl_nvb), GFP_KERNEL);
if (!cxl_nvb)
return ERR_PTR(-ENOMEM);
rc = ida_alloc(&cxl_nvdimm_bridge_ida, GFP_KERNEL);
if (rc < 0)
goto err;
cxl_nvb->id = rc;
dev = &cxl_nvb->dev;
cxl_nvb->port = port;
cxl_nvb->state = CXL_NVB_NEW;
device_initialize(dev);
lockdep_set_class(&dev->mutex, &cxl_nvdimm_bridge_key);
device_set_pm_not_required(dev);
dev->parent = &port->dev;
dev->bus = &cxl_bus_type;
dev->type = &cxl_nvdimm_bridge_type;
return cxl_nvb;
err:
kfree(cxl_nvb);
return ERR_PTR(rc);
}
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);
}
/**
* devm_cxl_add_nvdimm_bridge() - add the root of a LIBNVDIMM topology
* @host: platform firmware root device
* @port: CXL port at the root of a CXL topology
*
* Return: bridge device that can host cxl_nvdimm objects
*/
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%d", cxl_nvb->id);
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_NS_GPL(devm_cxl_add_nvdimm_bridge, CXL);
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_NS_GPL(is_cxl_nvdimm, CXL);
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_NS_GPL(to_cxl_nvdimm, CXL);
static struct lock_class_key cxl_nvdimm_key;
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);
lockdep_set_class(&dev->mutex, &cxl_nvdimm_key);
device_set_pm_not_required(dev);
dev->parent = &cxlmd->dev;
dev->bus = &cxl_bus_type;
dev->type = &cxl_nvdimm_type;
return cxl_nvd;
}
static void cxl_nvd_unregister(void *dev)
{
device_unregister(dev);
}
/**
* devm_cxl_add_nvdimm() - add a bridge between a cxl_memdev and an nvdimm
* @host: same host as @cxlmd
* @cxlmd: cxl_memdev instance that will perform LIBNVDIMM operations
*
* Return: 0 on success negative error code on failure.
*/
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, cxl_nvd_unregister, dev);
err:
put_device(dev);
return rc;
}
EXPORT_SYMBOL_NS_GPL(devm_cxl_add_nvdimm, CXL);