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, "trace\n");
  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_size_select_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_size_select_store(dev, buf, &nd_btt->lbasize,
  76                         btt_lbasize_supported);
  77         dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
  78                         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, "result: %zd wrote: %s%s", rc, buf,
 105                         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, "result: %zd wrote: %s%s", rc, buf,
 135                         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 ssize_t size_show(struct device *dev,
 144                 struct device_attribute *attr, char *buf)
 145 {
 146         struct nd_btt *nd_btt = to_nd_btt(dev);
 147         ssize_t rc;
 148
 149         device_lock(dev);
 150         if (dev->driver)
 151                 rc = sprintf(buf, "%llu\n", nd_btt->size);
 152         else {
 153                 /* no size to convey if the btt instance is disabled */
 154                 rc = -ENXIO;
 155         }
 156         device_unlock(dev);
 157
 158         return rc;
 159 }
 160 static DEVICE_ATTR_RO(size);
 161
 162 static ssize_t log_zero_flags_show(struct device *dev,
 163                 struct device_attribute *attr, char *buf)
 164 {
 165         return sprintf(buf, "Y\n");
 166 }
 167 static DEVICE_ATTR_RO(log_zero_flags);
 168
 169 static struct attribute *nd_btt_attributes[] = {
 170         &dev_attr_sector_size.attr,
 171         &dev_attr_namespace.attr,
 172         &dev_attr_uuid.attr,
 173         &dev_attr_size.attr,
 174         &dev_attr_log_zero_flags.attr,
 175         NULL,
 176 };
 177
 178 static struct attribute_group nd_btt_attribute_group = {
 179         .attrs = nd_btt_attributes,
 180 };
 181
 182 static const struct attribute_group *nd_btt_attribute_groups[] = {
 183         &nd_btt_attribute_group,
 184         &nd_device_attribute_group,
 185         &nd_numa_attribute_group,
 186         NULL,
 187 };
 188
 189 static struct device *__nd_btt_create(struct nd_region *nd_region,
 190                 unsigned long lbasize, u8 *uuid,
 191                 struct nd_namespace_common *ndns)
 192 {
 193         struct nd_btt *nd_btt;
 194         struct device *dev;
 195
 196         nd_btt = kzalloc(sizeof(*nd_btt), GFP_KERNEL);
 197         if (!nd_btt)
 198                 return NULL;
 199
 200         nd_btt->id = ida_simple_get(&nd_region->btt_ida, 0, 0, GFP_KERNEL);
 201         if (nd_btt->id < 0)
 202                 goto out_nd_btt;
 203
 204         nd_btt->lbasize = lbasize;
 205         if (uuid) {
 206                 uuid = kmemdup(uuid, 16, GFP_KERNEL);
 207                 if (!uuid)
 208                         goto out_put_id;
 209         }
 210         nd_btt->uuid = uuid;
 211         dev = &nd_btt->dev;
 212         dev_set_name(dev, "btt%d.%d", nd_region->id, nd_btt->id);
 213         dev->parent = &nd_region->dev;
 214         dev->type = &nd_btt_device_type;
 215         dev->groups = nd_btt_attribute_groups;
 216         device_initialize(&nd_btt->dev);
 217         if (ndns && !__nd_attach_ndns(&nd_btt->dev, ndns, &nd_btt->ndns)) {
 218                 dev_dbg(&ndns->dev, "failed, already claimed by %s\n",
 219                                 dev_name(ndns->claim));
 220                 put_device(dev);
 221                 return NULL;
 222         }
 223         return dev;
 224
 225 out_put_id:
 226         ida_simple_remove(&nd_region->btt_ida, nd_btt->id);
 227
 228 out_nd_btt:
 229         kfree(nd_btt);
 230         return NULL;
 231 }
 232
 233 struct device *nd_btt_create(struct nd_region *nd_region)
 234 {
 235         struct device *dev = __nd_btt_create(nd_region, 0, NULL, NULL);
 236
 237         __nd_device_register(dev);
 238         return dev;
 239 }
 240
 241 /**
 242  * nd_btt_arena_is_valid - check if the metadata layout is valid
 243  * @nd_btt:     device with BTT geometry and backing device info
 244  * @super:      pointer to the arena's info block being tested
 245  *
 246  * Check consistency of the btt info block with itself by validating
 247  * the checksum, and with the parent namespace by verifying the
 248  * parent_uuid contained in the info block with the one supplied in.
 249  *
 250  * Returns:
 251  * false for an invalid info block, true for a valid one
 252  */
 253 bool nd_btt_arena_is_valid(struct nd_btt *nd_btt, struct btt_sb *super)
 254 {
 255         const u8 *parent_uuid = nd_dev_to_uuid(&nd_btt->ndns->dev);
 256         u64 checksum;
 257
 258         if (memcmp(super->signature, BTT_SIG, BTT_SIG_LEN) != 0)
 259                 return false;
 260
 261         if (!guid_is_null((guid_t *)&super->parent_uuid))
 262                 if (memcmp(super->parent_uuid, parent_uuid, 16) != 0)
 263                         return false;
 264
 265         checksum = le64_to_cpu(super->checksum);
 266         super->checksum = 0;
 267         if (checksum != nd_sb_checksum((struct nd_gen_sb *) super))
 268                 return false;
 269         super->checksum = cpu_to_le64(checksum);
 270
 271         /* TODO: figure out action for this */
 272         if ((le32_to_cpu(super->flags) & IB_FLAG_ERROR_MASK) != 0)
 273                 dev_info(&nd_btt->dev, "Found arena with an error flag\n");
 274
 275         return true;
 276 }
 277 EXPORT_SYMBOL(nd_btt_arena_is_valid);
 278
 279 int nd_btt_version(struct nd_btt *nd_btt, struct nd_namespace_common *ndns,
 280                 struct btt_sb *btt_sb)
 281 {
 282         if (ndns->claim_class == NVDIMM_CCLASS_BTT2) {
 283                 /* Probe/setup for BTT v2.0 */
 284                 nd_btt->initial_offset = 0;
 285                 nd_btt->version_major = 2;
 286                 nd_btt->version_minor = 0;
 287                 if (nvdimm_read_bytes(ndns, 0, btt_sb, sizeof(*btt_sb), 0))
 288                         return -ENXIO;
 289                 if (!nd_btt_arena_is_valid(nd_btt, btt_sb))
 290                         return -ENODEV;
 291                 if ((le16_to_cpu(btt_sb->version_major) != 2) ||
 292                                 (le16_to_cpu(btt_sb->version_minor) != 0))
 293                         return -ENODEV;
 294         } else {
 295                 /*
 296                  * Probe/setup for BTT v1.1 (NVDIMM_CCLASS_NONE or
 297                  * NVDIMM_CCLASS_BTT)
 298                  */
 299                 nd_btt->initial_offset = SZ_4K;
 300                 nd_btt->version_major = 1;
 301                 nd_btt->version_minor = 1;
 302                 if (nvdimm_read_bytes(ndns, SZ_4K, btt_sb, sizeof(*btt_sb), 0))
 303                         return -ENXIO;
 304                 if (!nd_btt_arena_is_valid(nd_btt, btt_sb))
 305                         return -ENODEV;
 306                 if ((le16_to_cpu(btt_sb->version_major) != 1) ||
 307                                 (le16_to_cpu(btt_sb->version_minor) != 1))
 308                         return -ENODEV;
 309         }
 310         return 0;
 311 }
 312 EXPORT_SYMBOL(nd_btt_version);
 313
 314 static int __nd_btt_probe(struct nd_btt *nd_btt,
 315                 struct nd_namespace_common *ndns, struct btt_sb *btt_sb)
 316 {
 317         int rc;
 318
 319         if (!btt_sb || !ndns || !nd_btt)
 320                 return -ENODEV;
 321
 322         if (nvdimm_namespace_capacity(ndns) < SZ_16M)
 323                 return -ENXIO;
 324
 325         rc = nd_btt_version(nd_btt, ndns, btt_sb);
 326         if (rc < 0)
 327                 return rc;
 328
 329         nd_btt->lbasize = le32_to_cpu(btt_sb->external_lbasize);
 330         nd_btt->uuid = kmemdup(btt_sb->uuid, 16, GFP_KERNEL);
 331         if (!nd_btt->uuid)
 332                 return -ENOMEM;
 333
 334         __nd_device_register(&nd_btt->dev);
 335
 336         return 0;
 337 }
 338
 339 int nd_btt_probe(struct device *dev, struct nd_namespace_common *ndns)
 340 {
 341         int rc;
 342         struct device *btt_dev;
 343         struct btt_sb *btt_sb;
 344         struct nd_region *nd_region = to_nd_region(ndns->dev.parent);
 345
 346         if (ndns->force_raw)
 347                 return -ENODEV;
 348
 349         switch (ndns->claim_class) {
 350         case NVDIMM_CCLASS_NONE:
 351         case NVDIMM_CCLASS_BTT:
 352         case NVDIMM_CCLASS_BTT2:
 353                 break;
 354         default:
 355                 return -ENODEV;
 356         }
 357
 358         nvdimm_bus_lock(&ndns->dev);
 359         btt_dev = __nd_btt_create(nd_region, 0, NULL, ndns);
 360         nvdimm_bus_unlock(&ndns->dev);
 361         if (!btt_dev)
 362                 return -ENOMEM;
 363         btt_sb = devm_kzalloc(dev, sizeof(*btt_sb), GFP_KERNEL);
 364         rc = __nd_btt_probe(to_nd_btt(btt_dev), ndns, btt_sb);
 365         dev_dbg(dev, "btt: %s\n", rc == 0 ? dev_name(btt_dev) : "<none>");
 366         if (rc < 0) {
 367                 struct nd_btt *nd_btt = to_nd_btt(btt_dev);
 368
 369                 nd_detach_ndns(btt_dev, &nd_btt->ndns);
 370                 put_device(btt_dev);
 371         }
 372
 373         return rc;
 374 }
 375 EXPORT_SYMBOL(nd_btt_probe);