linux/drivers/nvdimm/dax_devs.c
Dan Williams 4a0079bc7a nvdimm: Replace lockdep_mutex with local lock classes
In response to an attempt to expand dev->lockdep_mutex for device_lock()
validation [1], Peter points out [2] that the lockdep API already has
the ability to assign a dedicated lock class per subsystem device-type.

Use lockdep_set_class() to override the default device_lock()
'__lockdep_no_validate__' class for each NVDIMM subsystem device-type. This
enables lockdep to detect deadlocks and recursive locking within the
device-driver core and the subsystem.

Link: https://lore.kernel.org/r/164982968798.684294.15817853329823976469.stgit@dwillia2-desk3.amr.corp.intel.com [1]
Link: https://lore.kernel.org/r/Ylf0dewci8myLvoW@hirez.programming.kicks-ass.net [2]
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/165055520896.3745911.8021255583475547548.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-04-28 14:01:55 -07:00

127 lines
2.8 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright(c) 2013-2016 Intel Corporation. All rights reserved.
*/
#include <linux/device.h>
#include <linux/sizes.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include "nd-core.h"
#include "pfn.h"
#include "nd.h"
static void nd_dax_release(struct device *dev)
{
struct nd_region *nd_region = to_nd_region(dev->parent);
struct nd_dax *nd_dax = to_nd_dax(dev);
struct nd_pfn *nd_pfn = &nd_dax->nd_pfn;
dev_dbg(dev, "trace\n");
nd_detach_ndns(dev, &nd_pfn->ndns);
ida_simple_remove(&nd_region->dax_ida, nd_pfn->id);
kfree(nd_pfn->uuid);
kfree(nd_dax);
}
struct nd_dax *to_nd_dax(struct device *dev)
{
struct nd_dax *nd_dax = container_of(dev, struct nd_dax, nd_pfn.dev);
WARN_ON(!is_nd_dax(dev));
return nd_dax;
}
EXPORT_SYMBOL(to_nd_dax);
static const struct device_type nd_dax_device_type = {
.name = "nd_dax",
.release = nd_dax_release,
.groups = nd_pfn_attribute_groups,
};
bool is_nd_dax(struct device *dev)
{
return dev ? dev->type == &nd_dax_device_type : false;
}
EXPORT_SYMBOL(is_nd_dax);
static struct nd_dax *nd_dax_alloc(struct nd_region *nd_region)
{
struct nd_pfn *nd_pfn;
struct nd_dax *nd_dax;
struct device *dev;
nd_dax = kzalloc(sizeof(*nd_dax), GFP_KERNEL);
if (!nd_dax)
return NULL;
nd_pfn = &nd_dax->nd_pfn;
nd_pfn->id = ida_simple_get(&nd_region->dax_ida, 0, 0, GFP_KERNEL);
if (nd_pfn->id < 0) {
kfree(nd_dax);
return NULL;
}
dev = &nd_pfn->dev;
dev_set_name(dev, "dax%d.%d", nd_region->id, nd_pfn->id);
dev->type = &nd_dax_device_type;
dev->parent = &nd_region->dev;
return nd_dax;
}
struct device *nd_dax_create(struct nd_region *nd_region)
{
struct device *dev = NULL;
struct nd_dax *nd_dax;
if (!is_memory(&nd_region->dev))
return NULL;
nd_dax = nd_dax_alloc(nd_region);
if (nd_dax)
dev = nd_pfn_devinit(&nd_dax->nd_pfn, NULL);
nd_device_register(dev);
return dev;
}
int nd_dax_probe(struct device *dev, struct nd_namespace_common *ndns)
{
int rc;
struct nd_dax *nd_dax;
struct device *dax_dev;
struct nd_pfn *nd_pfn;
struct nd_pfn_sb *pfn_sb;
struct nd_region *nd_region = to_nd_region(ndns->dev.parent);
if (ndns->force_raw)
return -ENODEV;
switch (ndns->claim_class) {
case NVDIMM_CCLASS_NONE:
case NVDIMM_CCLASS_DAX:
break;
default:
return -ENODEV;
}
nvdimm_bus_lock(&ndns->dev);
nd_dax = nd_dax_alloc(nd_region);
nd_pfn = &nd_dax->nd_pfn;
dax_dev = nd_pfn_devinit(nd_pfn, ndns);
nvdimm_bus_unlock(&ndns->dev);
if (!dax_dev)
return -ENOMEM;
pfn_sb = devm_kmalloc(dev, sizeof(*pfn_sb), GFP_KERNEL);
nd_pfn->pfn_sb = pfn_sb;
rc = nd_pfn_validate(nd_pfn, DAX_SIG);
dev_dbg(dev, "dax: %s\n", rc == 0 ? dev_name(dax_dev) : "<none>");
if (rc < 0) {
nd_detach_ndns(dax_dev, &nd_pfn->ndns);
put_device(dax_dev);
} else
nd_device_register(dax_dev);
return rc;
}
EXPORT_SYMBOL(nd_dax_probe);