drivers/nvdimm/btt_devs.c

   1 /*
   2  * Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of version 2 of the GNU General Public License as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful, but
   9  * WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  */
  13 #include <linux/blkdev.h>
  14 #include <linux/device.h>
  15 #include <linux/genhd.h>
  16 #include <linux/sizes.h>
  17 #include <linux/slab.h>
  18 #include <linux/fs.h>
  19 #include <linux/mm.h>
  20 #include "nd-core.h"
  21 #include "btt.h"
  22 #include "nd.h"
  23
  24 static void nd_btt_release(struct device *dev)
  25 {
  26         struct nd_region *nd_region = to_nd_region(dev->parent);
  27         struct nd_btt *nd_btt = to_nd_btt(dev);
  28
  29         dev_dbg(dev, "%s\n", __func__);
  30         nd_detach_ndns(&nd_btt->dev, &nd_btt->ndns);
  31         ida_simple_remove(&nd_region->btt_ida, nd_btt->id);
  32         kfree(nd_btt->uuid);
  33         kfree(nd_btt);
  34 }
  35
  36 static struct device_type nd_btt_device_type = {
  37         .name = "nd_btt",
  38         .release = nd_btt_release,
  39 };
  40
  41 bool is_nd_btt(struct device *dev)
  42 {
  43         return dev->type == &nd_btt_device_type;
  44 }
  45 EXPORT_SYMBOL(is_nd_btt);
  46
  47 struct nd_btt *to_nd_btt(struct device *dev)
  48 {
  49         struct nd_btt *nd_btt = container_of(dev, struct nd_btt, dev);
  50
  51         WARN_ON(!is_nd_btt(dev));
  52         return nd_btt;
  53 }
  54 EXPORT_SYMBOL(to_nd_btt);
  55
  56 static const unsigned long btt_lbasize_supported[] = { 512, 520, 528,
  57         4096, 4104, 4160, 4224, 0 };
  58
  59 static ssize_t sector_size_show(struct device *dev,
  60                 struct device_attribute *attr, char *buf)
  61 {
  62         struct nd_btt *nd_btt = to_nd_btt(dev);
  63
  64         return nd_sector_size_show(nd_btt->lbasize, btt_lbasize_supported, buf);
  65 }
  66
  67 static ssize_t sector_size_store(struct device *dev,
  68                 struct device_attribute *attr, const char *buf, size_t len)
  69 {
  70         struct nd_btt *nd_btt = to_nd_btt(dev);
  71         ssize_t rc;
  72
  73         device_lock(dev);
  74         nvdimm_bus_lock(dev);
  75         rc = nd_sector_size_store(dev, buf, &nd_btt->lbasize,
  76                         btt_lbasize_supported);
  77         dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
  78                         rc, buf, buf[len - 1] == '\n' ? "" : "\n");
  79         nvdimm_bus_unlock(dev);
  80         device_unlock(dev);
  81
  82         return rc ? rc : len;
  83 }
  84 static DEVICE_ATTR_RW(sector_size);
  85
  86 static ssize_t uuid_show(struct device *dev,
  87                 struct device_attribute *attr, char *buf)
  88 {
  89         struct nd_btt *nd_btt = to_nd_btt(dev);
  90
  91         if (nd_btt->uuid)
  92                 return sprintf(buf, "%pUb\n", nd_btt->uuid);
  93         return sprintf(buf, "\n");
  94 }
  95
  96 static ssize_t uuid_store(struct device *dev,
  97                 struct device_attribute *attr, const char *buf, size_t len)
  98 {
  99         struct nd_btt *nd_btt = to_nd_btt(dev);
 100         ssize_t rc;
 101
 102         device_lock(dev);
 103         rc = nd_uuid_store(dev, &nd_btt->uuid, buf, len);
 104         dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
 105                         rc, buf, buf[len - 1] == '\n' ? "" : "\n");
 106         device_unlock(dev);
 107
 108         return rc ? rc : len;
 109 }
 110 static DEVICE_ATTR_RW(uuid);
 111
 112 static ssize_t namespace_show(struct device *dev,
 113                 struct device_attribute *attr, char *buf)
 114 {
 115         struct nd_btt *nd_btt = to_nd_btt(dev);
 116         ssize_t rc;
 117
 118         nvdimm_bus_lock(dev);
 119         rc = sprintf(buf, "%s\n", nd_btt->ndns
 120                         ? dev_name(&nd_btt->ndns->dev) : "");
 121         nvdimm_bus_unlock(dev);
 122         return rc;
 123 }
 124
 125 static ssize_t namespace_store(struct device *dev,
 126                 struct device_attribute *attr, const char *buf, size_t len)
 127 {
 128         struct nd_btt *nd_btt = to_nd_btt(dev);
 129         ssize_t rc;
 130
 131         device_lock(dev);
 132         nvdimm_bus_lock(dev);
 133         rc = nd_namespace_store(dev, &nd_btt->ndns, buf, len);
 134         dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
 135                         rc, buf, buf[len - 1] == '\n' ? "" : "\n");
 136         nvdimm_bus_unlock(dev);
 137         device_unlock(dev);
 138
 139         return rc;
 140 }
 141 static DEVICE_ATTR_RW(namespace);
 142
 143 static struct attribute *nd_btt_attributes[] = {
 144         &dev_attr_sector_size.attr,
 145         &dev_attr_namespace.attr,
 146         &dev_attr_uuid.attr,
 147         NULL,
 148 };
 149
 150 static struct attribute_group nd_btt_attribute_group = {
 151         .attrs = nd_btt_attributes,
 152 };
 153
 154 static const struct attribute_group *nd_btt_attribute_groups[] = {
 155         &nd_btt_attribute_group,
 156         &nd_device_attribute_group,
 157         &nd_numa_attribute_group,
 158         NULL,
 159 };
 160
 161 static struct device *__nd_btt_create(struct nd_region *nd_region,
 162                 unsigned long lbasize, u8 *uuid,
 163                 struct nd_namespace_common *ndns)
 164 {
 165         struct nd_btt *nd_btt;
 166         struct device *dev;
 167
 168         nd_btt = kzalloc(sizeof(*nd_btt), GFP_KERNEL);
 169         if (!nd_btt)
 170                 return NULL;
 171
 172         nd_btt->id = ida_simple_get(&nd_region->btt_ida, 0, 0, GFP_KERNEL);
 173         if (nd_btt->id < 0) {
 174                 kfree(nd_btt);
 175                 return NULL;
 176         }
 177
 178         nd_btt->lbasize = lbasize;
 179         if (uuid)
 180                 uuid = kmemdup(uuid, 16, GFP_KERNEL);
 181         nd_btt->uuid = uuid;
 182         dev = &nd_btt->dev;
 183         dev_set_name(dev, "btt%d.%d", nd_region->id, nd_btt->id);
 184         dev->parent = &nd_region->dev;
 185         dev->type = &nd_btt_device_type;
 186         dev->groups = nd_btt_attribute_groups;
 187         device_initialize(&nd_btt->dev);
 188         if (ndns && !__nd_attach_ndns(&nd_btt->dev, ndns, &nd_btt->ndns)) {
 189                 dev_dbg(&ndns->dev, "%s failed, already claimed by %s\n",
 190                                 __func__, dev_name(ndns->claim));
 191                 put_device(dev);
 192                 return NULL;
 193         }
 194         return dev;
 195 }
 196
 197 struct device *nd_btt_create(struct nd_region *nd_region)
 198 {
 199         struct device *dev = __nd_btt_create(nd_region, 0, NULL, NULL);
 200
 201         if (dev)
 202                 __nd_device_register(dev);
 203         return dev;
 204 }
 205
 206 static bool uuid_is_null(u8 *uuid)
 207 {
 208         static const u8 null_uuid[16];
 209
 210         return (memcmp(uuid, null_uuid, 16) == 0);
 211 }
 212
 213 /**
 214  * nd_btt_arena_is_valid - check if the metadata layout is valid
 215  * @nd_btt:     device with BTT geometry and backing device info
 216  * @super:      pointer to the arena's info block being tested
 217  *
 218  * Check consistency of the btt info block with itself by validating
 219  * the checksum, and with the parent namespace by verifying the
 220  * parent_uuid contained in the info block with the one supplied in.
 221  *
 222  * Returns:
 223  * false for an invalid info block, true for a valid one
 224  */
 225 bool nd_btt_arena_is_valid(struct nd_btt *nd_btt, struct btt_sb *super)
 226 {
 227         const u8 *parent_uuid = nd_dev_to_uuid(&nd_btt->ndns->dev);
 228         u64 checksum;
 229
 230         if (memcmp(super->signature, BTT_SIG, BTT_SIG_LEN) != 0)
 231                 return false;
 232
 233         if (!uuid_is_null(super->parent_uuid))
 234                 if (memcmp(super->parent_uuid, parent_uuid, 16) != 0)
 235                         return false;
 236
 237         checksum = le64_to_cpu(super->checksum);
 238         super->checksum = 0;
 239         if (checksum != nd_sb_checksum((struct nd_gen_sb *) super))
 240                 return false;
 241         super->checksum = cpu_to_le64(checksum);
 242
 243         /* TODO: figure out action for this */
 244         if ((le32_to_cpu(super->flags) & IB_FLAG_ERROR_MASK) != 0)
 245                 dev_info(&nd_btt->dev, "Found arena with an error flag\n");
 246
 247         return true;
 248 }
 249 EXPORT_SYMBOL(nd_btt_arena_is_valid);
 250
 251 static int __nd_btt_probe(struct nd_btt *nd_btt,
 252                 struct nd_namespace_common *ndns, struct btt_sb *btt_sb)
 253 {
 254         if (!btt_sb || !ndns || !nd_btt)
 255                 return -ENODEV;
 256
 257         if (nvdimm_read_bytes(ndns, SZ_4K, btt_sb, sizeof(*btt_sb)))
 258                 return -ENXIO;
 259
 260         if (nvdimm_namespace_capacity(ndns) < SZ_16M)
 261                 return -ENXIO;
 262
 263         if (!nd_btt_arena_is_valid(nd_btt, btt_sb))
 264                 return -ENODEV;
 265
 266         nd_btt->lbasize = le32_to_cpu(btt_sb->external_lbasize);
 267         nd_btt->uuid = kmemdup(btt_sb->uuid, 16, GFP_KERNEL);
 268         if (!nd_btt->uuid)
 269                 return -ENOMEM;
 270
 271         __nd_device_register(&nd_btt->dev);
 272
 273         return 0;
 274 }
 275
 276 int nd_btt_probe(struct nd_namespace_common *ndns, void *drvdata)
 277 {
 278         int rc;
 279         struct device *dev;
 280         struct btt_sb *btt_sb;
 281         struct nd_region *nd_region = to_nd_region(ndns->dev.parent);
 282
 283         if (ndns->force_raw)
 284                 return -ENODEV;
 285
 286         nvdimm_bus_lock(&ndns->dev);
 287         dev = __nd_btt_create(nd_region, 0, NULL, ndns);
 288         nvdimm_bus_unlock(&ndns->dev);
 289         if (!dev)
 290                 return -ENOMEM;
 291         dev_set_drvdata(dev, drvdata);
 292         btt_sb = kzalloc(sizeof(*btt_sb), GFP_KERNEL);
 293         rc = __nd_btt_probe(to_nd_btt(dev), ndns, btt_sb);
 294         kfree(btt_sb);
 295         dev_dbg(&ndns->dev, "%s: btt: %s\n", __func__,
 296                         rc == 0 ? dev_name(dev) : "<none>");
 297         if (rc < 0) {
 298                 struct nd_btt *nd_btt = to_nd_btt(dev);
 299
 300                 __nd_detach_ndns(dev, &nd_btt->ndns);
 301                 put_device(dev);
 302         }
 303
 304         return rc;
 305 }
 306 EXPORT_SYMBOL(nd_btt_probe);