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![Dan Williams](/assets/img/avatar_default.png)
Implement the base infrastructure for libnvdimm PFN devices. Similar to BTT devices they take a namespace as a backing device and layer functionality on top. In this case the functionality is reserving space for an array of 'struct page' entries to be handed out through pfn_to_page(). For now this is just the basic libnvdimm-device-model for configuring the base PFN device. As the namespace claiming mechanism for PFN devices is mostly identical to BTT devices drivers/nvdimm/claim.c is created to house the common bits. Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
201 lines
4.7 KiB
C
201 lines
4.7 KiB
C
/*
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* Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of version 2 of the GNU General Public License as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*/
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#include <linux/device.h>
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#include <linux/sizes.h>
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#include "nd-core.h"
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#include "pfn.h"
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#include "btt.h"
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#include "nd.h"
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void __nd_detach_ndns(struct device *dev, struct nd_namespace_common **_ndns)
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{
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struct nd_namespace_common *ndns = *_ndns;
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dev_WARN_ONCE(dev, !mutex_is_locked(&ndns->dev.mutex)
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|| ndns->claim != dev,
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"%s: invalid claim\n", __func__);
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ndns->claim = NULL;
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*_ndns = NULL;
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put_device(&ndns->dev);
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}
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void nd_detach_ndns(struct device *dev,
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struct nd_namespace_common **_ndns)
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{
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struct nd_namespace_common *ndns = *_ndns;
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if (!ndns)
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return;
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get_device(&ndns->dev);
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device_lock(&ndns->dev);
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__nd_detach_ndns(dev, _ndns);
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device_unlock(&ndns->dev);
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put_device(&ndns->dev);
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}
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bool __nd_attach_ndns(struct device *dev, struct nd_namespace_common *attach,
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struct nd_namespace_common **_ndns)
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{
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if (attach->claim)
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return false;
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dev_WARN_ONCE(dev, !mutex_is_locked(&attach->dev.mutex)
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|| *_ndns,
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"%s: invalid claim\n", __func__);
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attach->claim = dev;
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*_ndns = attach;
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get_device(&attach->dev);
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return true;
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}
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bool nd_attach_ndns(struct device *dev, struct nd_namespace_common *attach,
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struct nd_namespace_common **_ndns)
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{
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bool claimed;
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device_lock(&attach->dev);
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claimed = __nd_attach_ndns(dev, attach, _ndns);
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device_unlock(&attach->dev);
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return claimed;
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}
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static int namespace_match(struct device *dev, void *data)
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{
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char *name = data;
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return strcmp(name, dev_name(dev)) == 0;
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}
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static bool is_idle(struct device *dev, struct nd_namespace_common *ndns)
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{
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struct nd_region *nd_region = to_nd_region(dev->parent);
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struct device *seed = NULL;
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if (is_nd_btt(dev))
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seed = nd_region->btt_seed;
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else if (is_nd_pfn(dev))
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seed = nd_region->pfn_seed;
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if (seed == dev || ndns || dev->driver)
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return false;
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return true;
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}
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static void nd_detach_and_reset(struct device *dev,
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struct nd_namespace_common **_ndns)
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{
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/* detach the namespace and destroy / reset the device */
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nd_detach_ndns(dev, _ndns);
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if (is_idle(dev, *_ndns)) {
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nd_device_unregister(dev, ND_ASYNC);
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} else if (is_nd_btt(dev)) {
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struct nd_btt *nd_btt = to_nd_btt(dev);
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nd_btt->lbasize = 0;
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kfree(nd_btt->uuid);
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nd_btt->uuid = NULL;
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} else if (is_nd_pfn(dev)) {
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struct nd_pfn *nd_pfn = to_nd_pfn(dev);
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kfree(nd_pfn->uuid);
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nd_pfn->uuid = NULL;
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nd_pfn->mode = PFN_MODE_NONE;
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}
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}
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ssize_t nd_namespace_store(struct device *dev,
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struct nd_namespace_common **_ndns, const char *buf,
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size_t len)
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{
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struct nd_namespace_common *ndns;
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struct device *found;
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char *name;
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if (dev->driver) {
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dev_dbg(dev, "%s: -EBUSY\n", __func__);
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return -EBUSY;
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}
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name = kstrndup(buf, len, GFP_KERNEL);
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if (!name)
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return -ENOMEM;
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strim(name);
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if (strncmp(name, "namespace", 9) == 0 || strcmp(name, "") == 0)
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/* pass */;
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else {
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len = -EINVAL;
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goto out;
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}
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ndns = *_ndns;
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if (strcmp(name, "") == 0) {
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nd_detach_and_reset(dev, _ndns);
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goto out;
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} else if (ndns) {
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dev_dbg(dev, "namespace already set to: %s\n",
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dev_name(&ndns->dev));
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len = -EBUSY;
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goto out;
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}
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found = device_find_child(dev->parent, name, namespace_match);
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if (!found) {
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dev_dbg(dev, "'%s' not found under %s\n", name,
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dev_name(dev->parent));
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len = -ENODEV;
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goto out;
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}
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ndns = to_ndns(found);
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if (__nvdimm_namespace_capacity(ndns) < SZ_16M) {
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dev_dbg(dev, "%s too small to host\n", name);
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len = -ENXIO;
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goto out_attach;
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}
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WARN_ON_ONCE(!is_nvdimm_bus_locked(dev));
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if (!nd_attach_ndns(dev, ndns, _ndns)) {
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dev_dbg(dev, "%s already claimed\n",
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dev_name(&ndns->dev));
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len = -EBUSY;
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}
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out_attach:
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put_device(&ndns->dev); /* from device_find_child */
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out:
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kfree(name);
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return len;
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}
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/*
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* nd_sb_checksum: compute checksum for a generic info block
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*
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* Returns a fletcher64 checksum of everything in the given info block
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* except the last field (since that's where the checksum lives).
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*/
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u64 nd_sb_checksum(struct nd_gen_sb *nd_gen_sb)
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{
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u64 sum;
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__le64 sum_save;
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BUILD_BUG_ON(sizeof(struct btt_sb) != SZ_4K);
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BUILD_BUG_ON(sizeof(struct nd_pfn_sb) != SZ_4K);
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BUILD_BUG_ON(sizeof(struct nd_gen_sb) != SZ_4K);
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sum_save = nd_gen_sb->checksum;
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nd_gen_sb->checksum = 0;
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sum = nd_fletcher64(nd_gen_sb, sizeof(*nd_gen_sb), 1);
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nd_gen_sb->checksum = sum_save;
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return sum;
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}
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EXPORT_SYMBOL(nd_sb_checksum);
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