linux/drivers/nvdimm/core.c
Dan Williams 87a30e1f05 driver-core, libnvdimm: Let device subsystems add local lockdep coverage
For good reason, the standard device_lock() is marked
lockdep_set_novalidate_class() because there is simply no sane way to
describe the myriad ways the device_lock() ordered with other locks.
However, that leaves subsystems that know their own local device_lock()
ordering rules to find lock ordering mistakes manually. Instead,
introduce an optional / additional lockdep-enabled lock that a subsystem
can acquire in all the same paths that the device_lock() is acquired.

A conversion of the NFIT driver and NVDIMM subsystem to a
lockdep-validate device_lock() scheme is included. The
debug_nvdimm_lock() implementation implements the correct lock-class and
stacking order for the libnvdimm device topology hierarchy.

Yes, this is a hack, but hopefully it is a useful hack for other
subsystems device_lock() debug sessions. Quoting Greg:

    "Yeah, it feels a bit hacky but it's really up to a subsystem to mess up
     using it as much as anything else, so user beware :)

     I don't object to it if it makes things easier for you to debug."

Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/156341210661.292348.7014034644265455704.stgit@dwillia2-desk3.amr.corp.intel.com
2019-07-18 16:23:27 -07:00

466 lines
10 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
*/
#include <linux/libnvdimm.h>
#include <linux/badblocks.h>
#include <linux/export.h>
#include <linux/module.h>
#include <linux/blkdev.h>
#include <linux/device.h>
#include <linux/ctype.h>
#include <linux/ndctl.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <linux/io.h>
#include "nd-core.h"
#include "nd.h"
LIST_HEAD(nvdimm_bus_list);
DEFINE_MUTEX(nvdimm_bus_list_mutex);
void nvdimm_bus_lock(struct device *dev)
{
struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
if (!nvdimm_bus)
return;
mutex_lock(&nvdimm_bus->reconfig_mutex);
}
EXPORT_SYMBOL(nvdimm_bus_lock);
void nvdimm_bus_unlock(struct device *dev)
{
struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
if (!nvdimm_bus)
return;
mutex_unlock(&nvdimm_bus->reconfig_mutex);
}
EXPORT_SYMBOL(nvdimm_bus_unlock);
bool is_nvdimm_bus_locked(struct device *dev)
{
struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
if (!nvdimm_bus)
return false;
return mutex_is_locked(&nvdimm_bus->reconfig_mutex);
}
EXPORT_SYMBOL(is_nvdimm_bus_locked);
struct nvdimm_map {
struct nvdimm_bus *nvdimm_bus;
struct list_head list;
resource_size_t offset;
unsigned long flags;
size_t size;
union {
void *mem;
void __iomem *iomem;
};
struct kref kref;
};
static struct nvdimm_map *find_nvdimm_map(struct device *dev,
resource_size_t offset)
{
struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
struct nvdimm_map *nvdimm_map;
list_for_each_entry(nvdimm_map, &nvdimm_bus->mapping_list, list)
if (nvdimm_map->offset == offset)
return nvdimm_map;
return NULL;
}
static struct nvdimm_map *alloc_nvdimm_map(struct device *dev,
resource_size_t offset, size_t size, unsigned long flags)
{
struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
struct nvdimm_map *nvdimm_map;
nvdimm_map = kzalloc(sizeof(*nvdimm_map), GFP_KERNEL);
if (!nvdimm_map)
return NULL;
INIT_LIST_HEAD(&nvdimm_map->list);
nvdimm_map->nvdimm_bus = nvdimm_bus;
nvdimm_map->offset = offset;
nvdimm_map->flags = flags;
nvdimm_map->size = size;
kref_init(&nvdimm_map->kref);
if (!request_mem_region(offset, size, dev_name(&nvdimm_bus->dev))) {
dev_err(&nvdimm_bus->dev, "failed to request %pa + %zd for %s\n",
&offset, size, dev_name(dev));
goto err_request_region;
}
if (flags)
nvdimm_map->mem = memremap(offset, size, flags);
else
nvdimm_map->iomem = ioremap(offset, size);
if (!nvdimm_map->mem)
goto err_map;
dev_WARN_ONCE(dev, !is_nvdimm_bus_locked(dev), "%s: bus unlocked!",
__func__);
list_add(&nvdimm_map->list, &nvdimm_bus->mapping_list);
return nvdimm_map;
err_map:
release_mem_region(offset, size);
err_request_region:
kfree(nvdimm_map);
return NULL;
}
static void nvdimm_map_release(struct kref *kref)
{
struct nvdimm_bus *nvdimm_bus;
struct nvdimm_map *nvdimm_map;
nvdimm_map = container_of(kref, struct nvdimm_map, kref);
nvdimm_bus = nvdimm_map->nvdimm_bus;
dev_dbg(&nvdimm_bus->dev, "%pa\n", &nvdimm_map->offset);
list_del(&nvdimm_map->list);
if (nvdimm_map->flags)
memunmap(nvdimm_map->mem);
else
iounmap(nvdimm_map->iomem);
release_mem_region(nvdimm_map->offset, nvdimm_map->size);
kfree(nvdimm_map);
}
static void nvdimm_map_put(void *data)
{
struct nvdimm_map *nvdimm_map = data;
struct nvdimm_bus *nvdimm_bus = nvdimm_map->nvdimm_bus;
nvdimm_bus_lock(&nvdimm_bus->dev);
kref_put(&nvdimm_map->kref, nvdimm_map_release);
nvdimm_bus_unlock(&nvdimm_bus->dev);
}
/**
* devm_nvdimm_memremap - map a resource that is shared across regions
* @dev: device that will own a reference to the shared mapping
* @offset: physical base address of the mapping
* @size: mapping size
* @flags: memremap flags, or, if zero, perform an ioremap instead
*/
void *devm_nvdimm_memremap(struct device *dev, resource_size_t offset,
size_t size, unsigned long flags)
{
struct nvdimm_map *nvdimm_map;
nvdimm_bus_lock(dev);
nvdimm_map = find_nvdimm_map(dev, offset);
if (!nvdimm_map)
nvdimm_map = alloc_nvdimm_map(dev, offset, size, flags);
else
kref_get(&nvdimm_map->kref);
nvdimm_bus_unlock(dev);
if (!nvdimm_map)
return NULL;
if (devm_add_action_or_reset(dev, nvdimm_map_put, nvdimm_map))
return NULL;
return nvdimm_map->mem;
}
EXPORT_SYMBOL_GPL(devm_nvdimm_memremap);
u64 nd_fletcher64(void *addr, size_t len, bool le)
{
u32 *buf = addr;
u32 lo32 = 0;
u64 hi32 = 0;
int i;
for (i = 0; i < len / sizeof(u32); i++) {
lo32 += le ? le32_to_cpu((__le32) buf[i]) : buf[i];
hi32 += lo32;
}
return hi32 << 32 | lo32;
}
EXPORT_SYMBOL_GPL(nd_fletcher64);
struct nvdimm_bus_descriptor *to_nd_desc(struct nvdimm_bus *nvdimm_bus)
{
/* struct nvdimm_bus definition is private to libnvdimm */
return nvdimm_bus->nd_desc;
}
EXPORT_SYMBOL_GPL(to_nd_desc);
struct device *to_nvdimm_bus_dev(struct nvdimm_bus *nvdimm_bus)
{
/* struct nvdimm_bus definition is private to libnvdimm */
return &nvdimm_bus->dev;
}
EXPORT_SYMBOL_GPL(to_nvdimm_bus_dev);
static bool is_uuid_sep(char sep)
{
if (sep == '\n' || sep == '-' || sep == ':' || sep == '\0')
return true;
return false;
}
static int nd_uuid_parse(struct device *dev, u8 *uuid_out, const char *buf,
size_t len)
{
const char *str = buf;
u8 uuid[16];
int i;
for (i = 0; i < 16; i++) {
if (!isxdigit(str[0]) || !isxdigit(str[1])) {
dev_dbg(dev, "pos: %d buf[%zd]: %c buf[%zd]: %c\n",
i, str - buf, str[0],
str + 1 - buf, str[1]);
return -EINVAL;
}
uuid[i] = (hex_to_bin(str[0]) << 4) | hex_to_bin(str[1]);
str += 2;
if (is_uuid_sep(*str))
str++;
}
memcpy(uuid_out, uuid, sizeof(uuid));
return 0;
}
/**
* nd_uuid_store: common implementation for writing 'uuid' sysfs attributes
* @dev: container device for the uuid property
* @uuid_out: uuid buffer to replace
* @buf: raw sysfs buffer to parse
*
* Enforce that uuids can only be changed while the device is disabled
* (driver detached)
* LOCKING: expects nd_device_lock() is held on entry
*/
int nd_uuid_store(struct device *dev, u8 **uuid_out, const char *buf,
size_t len)
{
u8 uuid[16];
int rc;
if (dev->driver)
return -EBUSY;
rc = nd_uuid_parse(dev, uuid, buf, len);
if (rc)
return rc;
kfree(*uuid_out);
*uuid_out = kmemdup(uuid, sizeof(uuid), GFP_KERNEL);
if (!(*uuid_out))
return -ENOMEM;
return 0;
}
ssize_t nd_size_select_show(unsigned long current_size,
const unsigned long *supported, char *buf)
{
ssize_t len = 0;
int i;
for (i = 0; supported[i]; i++)
if (current_size == supported[i])
len += sprintf(buf + len, "[%ld] ", supported[i]);
else
len += sprintf(buf + len, "%ld ", supported[i]);
len += sprintf(buf + len, "\n");
return len;
}
ssize_t nd_size_select_store(struct device *dev, const char *buf,
unsigned long *current_size, const unsigned long *supported)
{
unsigned long lbasize;
int rc, i;
if (dev->driver)
return -EBUSY;
rc = kstrtoul(buf, 0, &lbasize);
if (rc)
return rc;
for (i = 0; supported[i]; i++)
if (lbasize == supported[i])
break;
if (supported[i]) {
*current_size = lbasize;
return 0;
} else {
return -EINVAL;
}
}
static ssize_t commands_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
int cmd, len = 0;
struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
for_each_set_bit(cmd, &nd_desc->cmd_mask, BITS_PER_LONG)
len += sprintf(buf + len, "%s ", nvdimm_bus_cmd_name(cmd));
len += sprintf(buf + len, "\n");
return len;
}
static DEVICE_ATTR_RO(commands);
static const char *nvdimm_bus_provider(struct nvdimm_bus *nvdimm_bus)
{
struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
struct device *parent = nvdimm_bus->dev.parent;
if (nd_desc->provider_name)
return nd_desc->provider_name;
else if (parent)
return dev_name(parent);
else
return "unknown";
}
static ssize_t provider_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
return sprintf(buf, "%s\n", nvdimm_bus_provider(nvdimm_bus));
}
static DEVICE_ATTR_RO(provider);
static int flush_namespaces(struct device *dev, void *data)
{
nd_device_lock(dev);
nd_device_unlock(dev);
return 0;
}
static int flush_regions_dimms(struct device *dev, void *data)
{
nd_device_lock(dev);
nd_device_unlock(dev);
device_for_each_child(dev, NULL, flush_namespaces);
return 0;
}
static ssize_t wait_probe_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
int rc;
if (nd_desc->flush_probe) {
rc = nd_desc->flush_probe(nd_desc);
if (rc)
return rc;
}
nd_synchronize();
device_for_each_child(dev, NULL, flush_regions_dimms);
return sprintf(buf, "1\n");
}
static DEVICE_ATTR_RO(wait_probe);
static struct attribute *nvdimm_bus_attributes[] = {
&dev_attr_commands.attr,
&dev_attr_wait_probe.attr,
&dev_attr_provider.attr,
NULL,
};
struct attribute_group nvdimm_bus_attribute_group = {
.attrs = nvdimm_bus_attributes,
};
EXPORT_SYMBOL_GPL(nvdimm_bus_attribute_group);
int nvdimm_bus_add_badrange(struct nvdimm_bus *nvdimm_bus, u64 addr, u64 length)
{
return badrange_add(&nvdimm_bus->badrange, addr, length);
}
EXPORT_SYMBOL_GPL(nvdimm_bus_add_badrange);
#ifdef CONFIG_BLK_DEV_INTEGRITY
int nd_integrity_init(struct gendisk *disk, unsigned long meta_size)
{
struct blk_integrity bi;
if (meta_size == 0)
return 0;
memset(&bi, 0, sizeof(bi));
bi.tuple_size = meta_size;
bi.tag_size = meta_size;
blk_integrity_register(disk, &bi);
blk_queue_max_integrity_segments(disk->queue, 1);
return 0;
}
EXPORT_SYMBOL(nd_integrity_init);
#else /* CONFIG_BLK_DEV_INTEGRITY */
int nd_integrity_init(struct gendisk *disk, unsigned long meta_size)
{
return 0;
}
EXPORT_SYMBOL(nd_integrity_init);
#endif
static __init int libnvdimm_init(void)
{
int rc;
rc = nvdimm_bus_init();
if (rc)
return rc;
rc = nvdimm_init();
if (rc)
goto err_dimm;
rc = nd_region_init();
if (rc)
goto err_region;
nd_label_init();
return 0;
err_region:
nvdimm_exit();
err_dimm:
nvdimm_bus_exit();
return rc;
}
static __exit void libnvdimm_exit(void)
{
WARN_ON(!list_empty(&nvdimm_bus_list));
nd_region_exit();
nvdimm_exit();
nvdimm_bus_exit();
nd_region_devs_exit();
nvdimm_devs_exit();
}
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Intel Corporation");
subsys_initcall(libnvdimm_init);
module_exit(libnvdimm_exit);