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/*
* Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of version 2 of the GNU General Public License as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*/
#include <linux/device.h>
#include <linux/sizes.h>
#include "nd-core.h"
#include "pfn.h"
#include "btt.h"
#include "nd.h"
void __nd_detach_ndns(struct device *dev, struct nd_namespace_common **_ndns)
{
struct nd_namespace_common *ndns = *_ndns;
dev_WARN_ONCE(dev, !mutex_is_locked(&ndns->dev.mutex)
|| ndns->claim != dev,
"%s: invalid claim\n", __func__);
ndns->claim = NULL;
*_ndns = NULL;
put_device(&ndns->dev);
}
void nd_detach_ndns(struct device *dev,
struct nd_namespace_common **_ndns)
{
struct nd_namespace_common *ndns = *_ndns;
if (!ndns)
return;
get_device(&ndns->dev);
device_lock(&ndns->dev);
__nd_detach_ndns(dev, _ndns);
device_unlock(&ndns->dev);
put_device(&ndns->dev);
}
bool __nd_attach_ndns(struct device *dev, struct nd_namespace_common *attach,
struct nd_namespace_common **_ndns)
{
if (attach->claim)
return false;
dev_WARN_ONCE(dev, !mutex_is_locked(&attach->dev.mutex)
|| *_ndns,
"%s: invalid claim\n", __func__);
attach->claim = dev;
*_ndns = attach;
get_device(&attach->dev);
return true;
}
bool nd_attach_ndns(struct device *dev, struct nd_namespace_common *attach,
struct nd_namespace_common **_ndns)
{
bool claimed;
device_lock(&attach->dev);
claimed = __nd_attach_ndns(dev, attach, _ndns);
device_unlock(&attach->dev);
return claimed;
}
static int namespace_match(struct device *dev, void *data)
{
char *name = data;
return strcmp(name, dev_name(dev)) == 0;
}
static bool is_idle(struct device *dev, struct nd_namespace_common *ndns)
{
struct nd_region *nd_region = to_nd_region(dev->parent);
struct device *seed = NULL;
if (is_nd_btt(dev))
seed = nd_region->btt_seed;
else if (is_nd_pfn(dev))
seed = nd_region->pfn_seed;
if (seed == dev || ndns || dev->driver)
return false;
return true;
}
static void nd_detach_and_reset(struct device *dev,
struct nd_namespace_common **_ndns)
{
/* detach the namespace and destroy / reset the device */
nd_detach_ndns(dev, _ndns);
if (is_idle(dev, *_ndns)) {
nd_device_unregister(dev, ND_ASYNC);
} else if (is_nd_btt(dev)) {
struct nd_btt *nd_btt = to_nd_btt(dev);
nd_btt->lbasize = 0;
kfree(nd_btt->uuid);
nd_btt->uuid = NULL;
} else if (is_nd_pfn(dev)) {
struct nd_pfn *nd_pfn = to_nd_pfn(dev);
kfree(nd_pfn->uuid);
nd_pfn->uuid = NULL;
nd_pfn->mode = PFN_MODE_NONE;
}
}
ssize_t nd_namespace_store(struct device *dev,
struct nd_namespace_common **_ndns, const char *buf,
size_t len)
{
struct nd_namespace_common *ndns;
struct device *found;
char *name;
if (dev->driver) {
dev_dbg(dev, "%s: -EBUSY\n", __func__);
return -EBUSY;
}
name = kstrndup(buf, len, GFP_KERNEL);
if (!name)
return -ENOMEM;
strim(name);
if (strncmp(name, "namespace", 9) == 0 || strcmp(name, "") == 0)
/* pass */;
else {
len = -EINVAL;
goto out;
}
ndns = *_ndns;
if (strcmp(name, "") == 0) {
nd_detach_and_reset(dev, _ndns);
goto out;
} else if (ndns) {
dev_dbg(dev, "namespace already set to: %s\n",
dev_name(&ndns->dev));
len = -EBUSY;
goto out;
}
found = device_find_child(dev->parent, name, namespace_match);
if (!found) {
dev_dbg(dev, "'%s' not found under %s\n", name,
dev_name(dev->parent));
len = -ENODEV;
goto out;
}
ndns = to_ndns(found);
if (__nvdimm_namespace_capacity(ndns) < SZ_16M) {
dev_dbg(dev, "%s too small to host\n", name);
len = -ENXIO;
goto out_attach;
}
WARN_ON_ONCE(!is_nvdimm_bus_locked(dev));
if (!nd_attach_ndns(dev, ndns, _ndns)) {
dev_dbg(dev, "%s already claimed\n",
dev_name(&ndns->dev));
len = -EBUSY;
}
out_attach:
put_device(&ndns->dev); /* from device_find_child */
out:
kfree(name);
return len;
}
/*
* nd_sb_checksum: compute checksum for a generic info block
*
* Returns a fletcher64 checksum of everything in the given info block
* except the last field (since that's where the checksum lives).
*/
u64 nd_sb_checksum(struct nd_gen_sb *nd_gen_sb)
{
u64 sum;
__le64 sum_save;
BUILD_BUG_ON(sizeof(struct btt_sb) != SZ_4K);
BUILD_BUG_ON(sizeof(struct nd_pfn_sb) != SZ_4K);
BUILD_BUG_ON(sizeof(struct nd_gen_sb) != SZ_4K);
sum_save = nd_gen_sb->checksum;
nd_gen_sb->checksum = 0;
sum = nd_fletcher64(nd_gen_sb, sizeof(*nd_gen_sb), 1);
nd_gen_sb->checksum = sum_save;
return sum;
}
EXPORT_SYMBOL(nd_sb_checksum);
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