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// 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_flex(*cxlr_pmem, mapping, p->nr_targets);
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;
}
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