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