drivers/nvdimm/pfn_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 "pfn.h"
  22 #include "nd.h"
  23
  24 static void nd_pfn_release(struct device *dev)
  25 {
  26         struct nd_region *nd_region = to_nd_region(dev->parent);
  27         struct nd_pfn *nd_pfn = to_nd_pfn(dev);
  28
  29         dev_dbg(dev, "%s\n", __func__);
  30         nd_detach_ndns(&nd_pfn->dev, &nd_pfn->ndns);
  31         ida_simple_remove(&nd_region->pfn_ida, nd_pfn->id);
  32         kfree(nd_pfn->uuid);
  33         kfree(nd_pfn);
  34 }
  35
  36 static struct device_type nd_pfn_device_type = {
  37         .name = "nd_pfn",
  38         .release = nd_pfn_release,
  39 };
  40
  41 bool is_nd_pfn(struct device *dev)
  42 {
  43         return dev ? dev->type == &nd_pfn_device_type : false;
  44 }
  45 EXPORT_SYMBOL(is_nd_pfn);
  46
  47 struct nd_pfn *to_nd_pfn(struct device *dev)
  48 {
  49         struct nd_pfn *nd_pfn = container_of(dev, struct nd_pfn, dev);
  50
  51         WARN_ON(!is_nd_pfn(dev));
  52         return nd_pfn;
  53 }
  54 EXPORT_SYMBOL(to_nd_pfn);
  55
  56 static ssize_t mode_show(struct device *dev,
  57                 struct device_attribute *attr, char *buf)
  58 {
  59         struct nd_pfn *nd_pfn = to_nd_pfn(dev);
  60
  61         switch (nd_pfn->mode) {
  62         case PFN_MODE_RAM:
  63                 return sprintf(buf, "ram\n");
  64         case PFN_MODE_PMEM:
  65                 return sprintf(buf, "pmem\n");
  66         default:
  67                 return sprintf(buf, "none\n");
  68         }
  69 }
  70
  71 static ssize_t mode_store(struct device *dev,
  72                 struct device_attribute *attr, const char *buf, size_t len)
  73 {
  74         struct nd_pfn *nd_pfn = to_nd_pfn(dev);
  75         ssize_t rc = 0;
  76
  77         device_lock(dev);
  78         nvdimm_bus_lock(dev);
  79         if (dev->driver)
  80                 rc = -EBUSY;
  81         else {
  82                 size_t n = len - 1;
  83
  84                 if (strncmp(buf, "pmem\n", n) == 0
  85                                 || strncmp(buf, "pmem", n) == 0) {
  86                         /* TODO: allocate from PMEM support */
  87                         rc = -ENOTTY;
  88                 } else if (strncmp(buf, "ram\n", n) == 0
  89                                 || strncmp(buf, "ram", n) == 0)
  90                         nd_pfn->mode = PFN_MODE_RAM;
  91                 else if (strncmp(buf, "none\n", n) == 0
  92                                 || strncmp(buf, "none", n) == 0)
  93                         nd_pfn->mode = PFN_MODE_NONE;
  94                 else
  95                         rc = -EINVAL;
  96         }
  97         dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
  98                         rc, buf, buf[len - 1] == '\n' ? "" : "\n");
  99         nvdimm_bus_unlock(dev);
 100         device_unlock(dev);
 101
 102         return rc ? rc : len;
 103 }
 104 static DEVICE_ATTR_RW(mode);
 105
 106 static ssize_t align_show(struct device *dev,
 107                 struct device_attribute *attr, char *buf)
 108 {
 109         struct nd_pfn *nd_pfn = to_nd_pfn(dev);
 110
 111         return sprintf(buf, "%lx\n", nd_pfn->align);
 112 }
 113
 114 static ssize_t __align_store(struct nd_pfn *nd_pfn, const char *buf)
 115 {
 116         unsigned long val;
 117         int rc;
 118
 119         rc = kstrtoul(buf, 0, &val);
 120         if (rc)
 121                 return rc;
 122
 123         if (!is_power_of_2(val) || val < PAGE_SIZE || val > SZ_1G)
 124                 return -EINVAL;
 125
 126         if (nd_pfn->dev.driver)
 127                 return -EBUSY;
 128         else
 129                 nd_pfn->align = val;
 130
 131         return 0;
 132 }
 133
 134 static ssize_t align_store(struct device *dev,
 135                 struct device_attribute *attr, const char *buf, size_t len)
 136 {
 137         struct nd_pfn *nd_pfn = to_nd_pfn(dev);
 138         ssize_t rc;
 139
 140         device_lock(dev);
 141         nvdimm_bus_lock(dev);
 142         rc = __align_store(nd_pfn, buf);
 143         dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
 144                         rc, buf, buf[len - 1] == '\n' ? "" : "\n");
 145         nvdimm_bus_unlock(dev);
 146         device_unlock(dev);
 147
 148         return rc ? rc : len;
 149 }
 150 static DEVICE_ATTR_RW(align);
 151
 152 static ssize_t uuid_show(struct device *dev,
 153                 struct device_attribute *attr, char *buf)
 154 {
 155         struct nd_pfn *nd_pfn = to_nd_pfn(dev);
 156
 157         if (nd_pfn->uuid)
 158                 return sprintf(buf, "%pUb\n", nd_pfn->uuid);
 159         return sprintf(buf, "\n");
 160 }
 161
 162 static ssize_t uuid_store(struct device *dev,
 163                 struct device_attribute *attr, const char *buf, size_t len)
 164 {
 165         struct nd_pfn *nd_pfn = to_nd_pfn(dev);
 166         ssize_t rc;
 167
 168         device_lock(dev);
 169         rc = nd_uuid_store(dev, &nd_pfn->uuid, buf, len);
 170         dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
 171                         rc, buf, buf[len - 1] == '\n' ? "" : "\n");
 172         device_unlock(dev);
 173
 174         return rc ? rc : len;
 175 }
 176 static DEVICE_ATTR_RW(uuid);
 177
 178 static ssize_t namespace_show(struct device *dev,
 179                 struct device_attribute *attr, char *buf)
 180 {
 181         struct nd_pfn *nd_pfn = to_nd_pfn(dev);
 182         ssize_t rc;
 183
 184         nvdimm_bus_lock(dev);
 185         rc = sprintf(buf, "%s\n", nd_pfn->ndns
 186                         ? dev_name(&nd_pfn->ndns->dev) : "");
 187         nvdimm_bus_unlock(dev);
 188         return rc;
 189 }
 190
 191 static ssize_t namespace_store(struct device *dev,
 192                 struct device_attribute *attr, const char *buf, size_t len)
 193 {
 194         struct nd_pfn *nd_pfn = to_nd_pfn(dev);
 195         ssize_t rc;
 196
 197         device_lock(dev);
 198         nvdimm_bus_lock(dev);
 199         rc = nd_namespace_store(dev, &nd_pfn->ndns, buf, len);
 200         dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
 201                         rc, buf, buf[len - 1] == '\n' ? "" : "\n");
 202         nvdimm_bus_unlock(dev);
 203         device_unlock(dev);
 204
 205         return rc;
 206 }
 207 static DEVICE_ATTR_RW(namespace);
 208
 209 static struct attribute *nd_pfn_attributes[] = {
 210         &dev_attr_mode.attr,
 211         &dev_attr_namespace.attr,
 212         &dev_attr_uuid.attr,
 213         &dev_attr_align.attr,
 214         NULL,
 215 };
 216
 217 static struct attribute_group nd_pfn_attribute_group = {
 218         .attrs = nd_pfn_attributes,
 219 };
 220
 221 static const struct attribute_group *nd_pfn_attribute_groups[] = {
 222         &nd_pfn_attribute_group,
 223         &nd_device_attribute_group,
 224         &nd_numa_attribute_group,
 225         NULL,
 226 };
 227
 228 static struct device *__nd_pfn_create(struct nd_region *nd_region,
 229                 struct nd_namespace_common *ndns)
 230 {
 231         struct nd_pfn *nd_pfn;
 232         struct device *dev;
 233
 234         /* we can only create pages for contiguous ranged of pmem */
 235         if (!is_nd_pmem(&nd_region->dev))
 236                 return NULL;
 237
 238         nd_pfn = kzalloc(sizeof(*nd_pfn), GFP_KERNEL);
 239         if (!nd_pfn)
 240                 return NULL;
 241
 242         nd_pfn->id = ida_simple_get(&nd_region->pfn_ida, 0, 0, GFP_KERNEL);
 243         if (nd_pfn->id < 0) {
 244                 kfree(nd_pfn);
 245                 return NULL;
 246         }
 247
 248         nd_pfn->mode = PFN_MODE_NONE;
 249         nd_pfn->align = HPAGE_SIZE;
 250         dev = &nd_pfn->dev;
 251         dev_set_name(dev, "pfn%d.%d", nd_region->id, nd_pfn->id);
 252         dev->parent = &nd_region->dev;
 253         dev->type = &nd_pfn_device_type;
 254         dev->groups = nd_pfn_attribute_groups;
 255         device_initialize(&nd_pfn->dev);
 256         if (ndns && !__nd_attach_ndns(&nd_pfn->dev, ndns, &nd_pfn->ndns)) {
 257                 dev_dbg(&ndns->dev, "%s failed, already claimed by %s\n",
 258                                 __func__, dev_name(ndns->claim));
 259                 put_device(dev);
 260                 return NULL;
 261         }
 262         return dev;
 263 }
 264
 265 struct device *nd_pfn_create(struct nd_region *nd_region)
 266 {
 267         struct device *dev = __nd_pfn_create(nd_region, NULL);
 268
 269         if (dev)
 270                 __nd_device_register(dev);
 271         return dev;
 272 }
 273
 274 int nd_pfn_validate(struct nd_pfn *nd_pfn)
 275 {
 276         u64 checksum, offset;
 277         struct nd_namespace_io *nsio;
 278         struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
 279         struct nd_namespace_common *ndns = nd_pfn->ndns;
 280         const u8 *parent_uuid = nd_dev_to_uuid(&ndns->dev);
 281
 282         if (!pfn_sb || !ndns)
 283                 return -ENODEV;
 284
 285         if (!is_nd_pmem(nd_pfn->dev.parent))
 286                 return -ENODEV;
 287
 288         if (nvdimm_read_bytes(ndns, SZ_4K, pfn_sb, sizeof(*pfn_sb)))
 289                 return -ENXIO;
 290
 291         if (memcmp(pfn_sb->signature, PFN_SIG, PFN_SIG_LEN) != 0)
 292                 return -ENODEV;
 293
 294         checksum = le64_to_cpu(pfn_sb->checksum);
 295         pfn_sb->checksum = 0;
 296         if (checksum != nd_sb_checksum((struct nd_gen_sb *) pfn_sb))
 297                 return -ENODEV;
 298         pfn_sb->checksum = cpu_to_le64(checksum);
 299
 300         if (memcmp(pfn_sb->parent_uuid, parent_uuid, 16) != 0)
 301                 return -ENODEV;
 302
 303         switch (le32_to_cpu(pfn_sb->mode)) {
 304         case PFN_MODE_RAM:
 305                 break;
 306         case PFN_MODE_PMEM:
 307                 /* TODO: allocate from PMEM support */
 308                 return -ENOTTY;
 309         default:
 310                 return -ENXIO;
 311         }
 312
 313         if (!nd_pfn->uuid) {
 314                 /* from probe we allocate */
 315                 nd_pfn->uuid = kmemdup(pfn_sb->uuid, 16, GFP_KERNEL);
 316                 if (!nd_pfn->uuid)
 317                         return -ENOMEM;
 318         } else {
 319                 /* from init we validate */
 320                 if (memcmp(nd_pfn->uuid, pfn_sb->uuid, 16) != 0)
 321                         return -EINVAL;
 322         }
 323
 324         if (nd_pfn->align > nvdimm_namespace_capacity(ndns)) {
 325                 dev_err(&nd_pfn->dev, "alignment: %lx exceeds capacity %llx\n",
 326                                 nd_pfn->align, nvdimm_namespace_capacity(ndns));
 327                 return -EINVAL;
 328         }
 329
 330         /*
 331          * These warnings are verbose because they can only trigger in
 332          * the case where the physical address alignment of the
 333          * namespace has changed since the pfn superblock was
 334          * established.
 335          */
 336         offset = le64_to_cpu(pfn_sb->dataoff);
 337         nsio = to_nd_namespace_io(&ndns->dev);
 338         if (offset >= resource_size(&nsio->res)) {
 339                 dev_err(&nd_pfn->dev, "pfn array size exceeds capacity of %s\n",
 340                                 dev_name(&ndns->dev));
 341                 return -EBUSY;
 342         }
 343
 344         nd_pfn->align = 1UL << ilog2(offset);
 345         if (!is_power_of_2(offset) || offset < PAGE_SIZE) {
 346                 dev_err(&nd_pfn->dev, "bad offset: %#llx dax disabled\n",
 347                                 offset);
 348                 return -ENXIO;
 349         }
 350
 351         return 0;
 352 }
 353 EXPORT_SYMBOL(nd_pfn_validate);
 354
 355 int nd_pfn_probe(struct nd_namespace_common *ndns, void *drvdata)
 356 {
 357         int rc;
 358         struct device *dev;
 359         struct nd_pfn *nd_pfn;
 360         struct nd_pfn_sb *pfn_sb;
 361         struct nd_region *nd_region = to_nd_region(ndns->dev.parent);
 362
 363         if (ndns->force_raw)
 364                 return -ENODEV;
 365
 366         nvdimm_bus_lock(&ndns->dev);
 367         dev = __nd_pfn_create(nd_region, ndns);
 368         nvdimm_bus_unlock(&ndns->dev);
 369         if (!dev)
 370                 return -ENOMEM;
 371         dev_set_drvdata(dev, drvdata);
 372         pfn_sb = kzalloc(sizeof(*pfn_sb), GFP_KERNEL);
 373         nd_pfn = to_nd_pfn(dev);
 374         nd_pfn->pfn_sb = pfn_sb;
 375         rc = nd_pfn_validate(nd_pfn);
 376         nd_pfn->pfn_sb = NULL;
 377         kfree(pfn_sb);
 378         dev_dbg(&ndns->dev, "%s: pfn: %s\n", __func__,
 379                         rc == 0 ? dev_name(dev) : "<none>");
 380         if (rc < 0) {
 381                 __nd_detach_ndns(dev, &nd_pfn->ndns);
 382                 put_device(dev);
 383         } else
 384                 __nd_device_register(&nd_pfn->dev);
 385
 386         return rc;
 387 }
 388 EXPORT_SYMBOL(nd_pfn_probe);