arch/powerpc/platforms/pseries/papr_scm.c

   1 // SPDX-License-Identifier: GPL-2.0
   2
   3 #define pr_fmt(fmt)     "papr-scm: " fmt
   4
   5 #include <linux/of.h>
   6 #include <linux/kernel.h>
   7 #include <linux/module.h>
   8 #include <linux/ioport.h>
   9 #include <linux/slab.h>
  10 #include <linux/ndctl.h>
  11 #include <linux/sched.h>
  12 #include <linux/libnvdimm.h>
  13 #include <linux/platform_device.h>
  14 #include <linux/delay.h>
  15 #include <linux/seq_buf.h>
  16
  17 #include <asm/plpar_wrappers.h>
  18
  19 #define BIND_ANY_ADDR (~0ul)
  20
  21 #define PAPR_SCM_DIMM_CMD_MASK \
  22         ((1ul << ND_CMD_GET_CONFIG_SIZE) | \
  23          (1ul << ND_CMD_GET_CONFIG_DATA) | \
  24          (1ul << ND_CMD_SET_CONFIG_DATA))
  25
  26 /* DIMM health bitmap bitmap indicators */
  27 /* SCM device is unable to persist memory contents */
  28 #define PAPR_PMEM_UNARMED                   (1ULL << (63 - 0))
  29 /* SCM device failed to persist memory contents */
  30 #define PAPR_PMEM_SHUTDOWN_DIRTY            (1ULL << (63 - 1))
  31 /* SCM device contents are persisted from previous IPL */
  32 #define PAPR_PMEM_SHUTDOWN_CLEAN            (1ULL << (63 - 2))
  33 /* SCM device contents are not persisted from previous IPL */
  34 #define PAPR_PMEM_EMPTY                     (1ULL << (63 - 3))
  35 /* SCM device memory life remaining is critically low */
  36 #define PAPR_PMEM_HEALTH_CRITICAL           (1ULL << (63 - 4))
  37 /* SCM device will be garded off next IPL due to failure */
  38 #define PAPR_PMEM_HEALTH_FATAL              (1ULL << (63 - 5))
  39 /* SCM contents cannot persist due to current platform health status */
  40 #define PAPR_PMEM_HEALTH_UNHEALTHY          (1ULL << (63 - 6))
  41 /* SCM device is unable to persist memory contents in certain conditions */
  42 #define PAPR_PMEM_HEALTH_NON_CRITICAL       (1ULL << (63 - 7))
  43 /* SCM device is encrypted */
  44 #define PAPR_PMEM_ENCRYPTED                 (1ULL << (63 - 8))
  45 /* SCM device has been scrubbed and locked */
  46 #define PAPR_PMEM_SCRUBBED_AND_LOCKED       (1ULL << (63 - 9))
  47
  48 /* Bits status indicators for health bitmap indicating unarmed dimm */
  49 #define PAPR_PMEM_UNARMED_MASK (PAPR_PMEM_UNARMED |             \
  50                                 PAPR_PMEM_HEALTH_UNHEALTHY)
  51
  52 /* Bits status indicators for health bitmap indicating unflushed dimm */
  53 #define PAPR_PMEM_BAD_SHUTDOWN_MASK (PAPR_PMEM_SHUTDOWN_DIRTY)
  54
  55 /* Bits status indicators for health bitmap indicating unrestored dimm */
  56 #define PAPR_PMEM_BAD_RESTORE_MASK  (PAPR_PMEM_EMPTY)
  57
  58 /* Bit status indicators for smart event notification */
  59 #define PAPR_PMEM_SMART_EVENT_MASK (PAPR_PMEM_HEALTH_CRITICAL | \
  60                                     PAPR_PMEM_HEALTH_FATAL |    \
  61                                     PAPR_PMEM_HEALTH_UNHEALTHY)
  62
  63 /* private struct associated with each region */
  64 struct papr_scm_priv {
  65         struct platform_device *pdev;
  66         struct device_node *dn;
  67         uint32_t drc_index;
  68         uint64_t blocks;
  69         uint64_t block_size;
  70         int metadata_size;
  71         bool is_volatile;
  72
  73         uint64_t bound_addr;
  74
  75         struct nvdimm_bus_descriptor bus_desc;
  76         struct nvdimm_bus *bus;
  77         struct nvdimm *nvdimm;
  78         struct resource res;
  79         struct nd_region *region;
  80         struct nd_interleave_set nd_set;
  81
  82         /* Protect dimm health data from concurrent read/writes */
  83         struct mutex health_mutex;
  84
  85         /* Last time the health information of the dimm was updated */
  86         unsigned long lasthealth_jiffies;
  87
  88         /* Health information for the dimm */
  89         u64 health_bitmap;
  90 };
  91
  92 static int drc_pmem_bind(struct papr_scm_priv *p)
  93 {
  94         unsigned long ret[PLPAR_HCALL_BUFSIZE];
  95         uint64_t saved = 0;
  96         uint64_t token;
  97         int64_t rc;
  98
  99         /*
 100          * When the hypervisor cannot map all the requested memory in a single
 101          * hcall it returns H_BUSY and we call again with the token until
 102          * we get H_SUCCESS. Aborting the retry loop before getting H_SUCCESS
 103          * leave the system in an undefined state, so we wait.
 104          */
 105         token = 0;
 106
 107         do {
 108                 rc = plpar_hcall(H_SCM_BIND_MEM, ret, p->drc_index, 0,
 109                                 p->blocks, BIND_ANY_ADDR, token);
 110                 token = ret[0];
 111                 if (!saved)
 112                         saved = ret[1];
 113                 cond_resched();
 114         } while (rc == H_BUSY);
 115
 116         if (rc)
 117                 return rc;
 118
 119         p->bound_addr = saved;
 120         dev_dbg(&p->pdev->dev, "bound drc 0x%x to 0x%lx\n",
 121                 p->drc_index, (unsigned long)saved);
 122         return rc;
 123 }
 124
 125 static void drc_pmem_unbind(struct papr_scm_priv *p)
 126 {
 127         unsigned long ret[PLPAR_HCALL_BUFSIZE];
 128         uint64_t token = 0;
 129         int64_t rc;
 130
 131         dev_dbg(&p->pdev->dev, "unbind drc 0x%x\n", p->drc_index);
 132
 133         /* NB: unbind has the same retry requirements as drc_pmem_bind() */
 134         do {
 135
 136                 /* Unbind of all SCM resources associated with drcIndex */
 137                 rc = plpar_hcall(H_SCM_UNBIND_ALL, ret, H_UNBIND_SCOPE_DRC,
 138                                  p->drc_index, token);
 139                 token = ret[0];
 140
 141                 /* Check if we are stalled for some time */
 142                 if (H_IS_LONG_BUSY(rc)) {
 143                         msleep(get_longbusy_msecs(rc));
 144                         rc = H_BUSY;
 145                 } else if (rc == H_BUSY) {
 146                         cond_resched();
 147                 }
 148
 149         } while (rc == H_BUSY);
 150
 151         if (rc)
 152                 dev_err(&p->pdev->dev, "unbind error: %lld\n", rc);
 153         else
 154                 dev_dbg(&p->pdev->dev, "unbind drc 0x%x complete\n",
 155                         p->drc_index);
 156
 157         return;
 158 }
 159
 160 static int drc_pmem_query_n_bind(struct papr_scm_priv *p)
 161 {
 162         unsigned long start_addr;
 163         unsigned long end_addr;
 164         unsigned long ret[PLPAR_HCALL_BUFSIZE];
 165         int64_t rc;
 166
 167
 168         rc = plpar_hcall(H_SCM_QUERY_BLOCK_MEM_BINDING, ret,
 169                          p->drc_index, 0);
 170         if (rc)
 171                 goto err_out;
 172         start_addr = ret[0];
 173
 174         /* Make sure the full region is bound. */
 175         rc = plpar_hcall(H_SCM_QUERY_BLOCK_MEM_BINDING, ret,
 176                          p->drc_index, p->blocks - 1);
 177         if (rc)
 178                 goto err_out;
 179         end_addr = ret[0];
 180
 181         if ((end_addr - start_addr) != ((p->blocks - 1) * p->block_size))
 182                 goto err_out;
 183
 184         p->bound_addr = start_addr;
 185         dev_dbg(&p->pdev->dev, "bound drc 0x%x to 0x%lx\n", p->drc_index, start_addr);
 186         return rc;
 187
 188 err_out:
 189         dev_info(&p->pdev->dev,
 190                  "Failed to query, trying an unbind followed by bind");
 191         drc_pmem_unbind(p);
 192         return drc_pmem_bind(p);
 193 }
 194
 195 /*
 196  * Issue hcall to retrieve dimm health info and populate papr_scm_priv with the
 197  * health information.
 198  */
 199 static int __drc_pmem_query_health(struct papr_scm_priv *p)
 200 {
 201         unsigned long ret[PLPAR_HCALL_BUFSIZE];
 202         long rc;
 203
 204         /* issue the hcall */
 205         rc = plpar_hcall(H_SCM_HEALTH, ret, p->drc_index);
 206         if (rc != H_SUCCESS) {
 207                 dev_err(&p->pdev->dev,
 208                         "Failed to query health information, Err:%ld\n", rc);
 209                 return -ENXIO;
 210         }
 211
 212         p->lasthealth_jiffies = jiffies;
 213         p->health_bitmap = ret[0] & ret[1];
 214
 215         dev_dbg(&p->pdev->dev,
 216                 "Queried dimm health info. Bitmap:0x%016lx Mask:0x%016lx\n",
 217                 ret[0], ret[1]);
 218
 219         return 0;
 220 }
 221
 222 /* Min interval in seconds for assuming stable dimm health */
 223 #define MIN_HEALTH_QUERY_INTERVAL 60
 224
 225 /* Query cached health info and if needed call drc_pmem_query_health */
 226 static int drc_pmem_query_health(struct papr_scm_priv *p)
 227 {
 228         unsigned long cache_timeout;
 229         int rc;
 230
 231         /* Protect concurrent modifications to papr_scm_priv */
 232         rc = mutex_lock_interruptible(&p->health_mutex);
 233         if (rc)
 234                 return rc;
 235
 236         /* Jiffies offset for which the health data is assumed to be same */
 237         cache_timeout = p->lasthealth_jiffies +
 238                 msecs_to_jiffies(MIN_HEALTH_QUERY_INTERVAL * 1000);
 239
 240         /* Fetch new health info is its older than MIN_HEALTH_QUERY_INTERVAL */
 241         if (time_after(jiffies, cache_timeout))
 242                 rc = __drc_pmem_query_health(p);
 243         else
 244                 /* Assume cached health data is valid */
 245                 rc = 0;
 246
 247         mutex_unlock(&p->health_mutex);
 248         return rc;
 249 }
 250
 251 static int papr_scm_meta_get(struct papr_scm_priv *p,
 252                              struct nd_cmd_get_config_data_hdr *hdr)
 253 {
 254         unsigned long data[PLPAR_HCALL_BUFSIZE];
 255         unsigned long offset, data_offset;
 256         int len, read;
 257         int64_t ret;
 258
 259         if ((hdr->in_offset + hdr->in_length) > p->metadata_size)
 260                 return -EINVAL;
 261
 262         for (len = hdr->in_length; len; len -= read) {
 263
 264                 data_offset = hdr->in_length - len;
 265                 offset = hdr->in_offset + data_offset;
 266
 267                 if (len >= 8)
 268                         read = 8;
 269                 else if (len >= 4)
 270                         read = 4;
 271                 else if (len >= 2)
 272                         read = 2;
 273                 else
 274                         read = 1;
 275
 276                 ret = plpar_hcall(H_SCM_READ_METADATA, data, p->drc_index,
 277                                   offset, read);
 278
 279                 if (ret == H_PARAMETER) /* bad DRC index */
 280                         return -ENODEV;
 281                 if (ret)
 282                         return -EINVAL; /* other invalid parameter */
 283
 284                 switch (read) {
 285                 case 8:
 286                         *(uint64_t *)(hdr->out_buf + data_offset) = be64_to_cpu(data[0]);
 287                         break;
 288                 case 4:
 289                         *(uint32_t *)(hdr->out_buf + data_offset) = be32_to_cpu(data[0] & 0xffffffff);
 290                         break;
 291
 292                 case 2:
 293                         *(uint16_t *)(hdr->out_buf + data_offset) = be16_to_cpu(data[0] & 0xffff);
 294                         break;
 295
 296                 case 1:
 297                         *(uint8_t *)(hdr->out_buf + data_offset) = (data[0] & 0xff);
 298                         break;
 299                 }
 300         }
 301         return 0;
 302 }
 303
 304 static int papr_scm_meta_set(struct papr_scm_priv *p,
 305                              struct nd_cmd_set_config_hdr *hdr)
 306 {
 307         unsigned long offset, data_offset;
 308         int len, wrote;
 309         unsigned long data;
 310         __be64 data_be;
 311         int64_t ret;
 312
 313         if ((hdr->in_offset + hdr->in_length) > p->metadata_size)
 314                 return -EINVAL;
 315
 316         for (len = hdr->in_length; len; len -= wrote) {
 317
 318                 data_offset = hdr->in_length - len;
 319                 offset = hdr->in_offset + data_offset;
 320
 321                 if (len >= 8) {
 322                         data = *(uint64_t *)(hdr->in_buf + data_offset);
 323                         data_be = cpu_to_be64(data);
 324                         wrote = 8;
 325                 } else if (len >= 4) {
 326                         data = *(uint32_t *)(hdr->in_buf + data_offset);
 327                         data &= 0xffffffff;
 328                         data_be = cpu_to_be32(data);
 329                         wrote = 4;
 330                 } else if (len >= 2) {
 331                         data = *(uint16_t *)(hdr->in_buf + data_offset);
 332                         data &= 0xffff;
 333                         data_be = cpu_to_be16(data);
 334                         wrote = 2;
 335                 } else {
 336                         data_be = *(uint8_t *)(hdr->in_buf + data_offset);
 337                         data_be &= 0xff;
 338                         wrote = 1;
 339                 }
 340
 341                 ret = plpar_hcall_norets(H_SCM_WRITE_METADATA, p->drc_index,
 342                                          offset, data_be, wrote);
 343                 if (ret == H_PARAMETER) /* bad DRC index */
 344                         return -ENODEV;
 345                 if (ret)
 346                         return -EINVAL; /* other invalid parameter */
 347         }
 348
 349         return 0;
 350 }
 351
 352 static int papr_scm_ndctl(struct nvdimm_bus_descriptor *nd_desc,
 353                           struct nvdimm *nvdimm, unsigned int cmd, void *buf,
 354                           unsigned int buf_len, int *cmd_rc)
 355 {
 356         struct nd_cmd_get_config_size *get_size_hdr;
 357         struct papr_scm_priv *p;
 358
 359         /* Only dimm-specific calls are supported atm */
 360         if (!nvdimm)
 361                 return -EINVAL;
 362
 363         p = nvdimm_provider_data(nvdimm);
 364
 365         switch (cmd) {
 366         case ND_CMD_GET_CONFIG_SIZE:
 367                 get_size_hdr = buf;
 368
 369                 get_size_hdr->status = 0;
 370                 get_size_hdr->max_xfer = 8;
 371                 get_size_hdr->config_size = p->metadata_size;
 372                 *cmd_rc = 0;
 373                 break;
 374
 375         case ND_CMD_GET_CONFIG_DATA:
 376                 *cmd_rc = papr_scm_meta_get(p, buf);
 377                 break;
 378
 379         case ND_CMD_SET_CONFIG_DATA:
 380                 *cmd_rc = papr_scm_meta_set(p, buf);
 381                 break;
 382
 383         default:
 384                 return -EINVAL;
 385         }
 386
 387         dev_dbg(&p->pdev->dev, "returned with cmd_rc = %d\n", *cmd_rc);
 388
 389         return 0;
 390 }
 391
 392 static ssize_t flags_show(struct device *dev,
 393                           struct device_attribute *attr, char *buf)
 394 {
 395         struct nvdimm *dimm = to_nvdimm(dev);
 396         struct papr_scm_priv *p = nvdimm_provider_data(dimm);
 397         struct seq_buf s;
 398         u64 health;
 399         int rc;
 400
 401         rc = drc_pmem_query_health(p);
 402         if (rc)
 403                 return rc;
 404
 405         /* Copy health_bitmap locally, check masks & update out buffer */
 406         health = READ_ONCE(p->health_bitmap);
 407
 408         seq_buf_init(&s, buf, PAGE_SIZE);
 409         if (health & PAPR_PMEM_UNARMED_MASK)
 410                 seq_buf_printf(&s, "not_armed ");
 411
 412         if (health & PAPR_PMEM_BAD_SHUTDOWN_MASK)
 413                 seq_buf_printf(&s, "flush_fail ");
 414
 415         if (health & PAPR_PMEM_BAD_RESTORE_MASK)
 416                 seq_buf_printf(&s, "restore_fail ");
 417
 418         if (health & PAPR_PMEM_ENCRYPTED)
 419                 seq_buf_printf(&s, "encrypted ");
 420
 421         if (health & PAPR_PMEM_SMART_EVENT_MASK)
 422                 seq_buf_printf(&s, "smart_notify ");
 423
 424         if (health & PAPR_PMEM_SCRUBBED_AND_LOCKED)
 425                 seq_buf_printf(&s, "scrubbed locked ");
 426
 427         if (seq_buf_used(&s))
 428                 seq_buf_printf(&s, "\n");
 429
 430         return seq_buf_used(&s);
 431 }
 432 DEVICE_ATTR_RO(flags);
 433
 434 /* papr_scm specific dimm attributes */
 435 static struct attribute *papr_nd_attributes[] = {
 436         &dev_attr_flags.attr,
 437         NULL,
 438 };
 439
 440 static struct attribute_group papr_nd_attribute_group = {
 441         .name = "papr",
 442         .attrs = papr_nd_attributes,
 443 };
 444
 445 static const struct attribute_group *papr_nd_attr_groups[] = {
 446         &papr_nd_attribute_group,
 447         NULL,
 448 };
 449
 450 static int papr_scm_nvdimm_init(struct papr_scm_priv *p)
 451 {
 452         struct device *dev = &p->pdev->dev;
 453         struct nd_mapping_desc mapping;
 454         struct nd_region_desc ndr_desc;
 455         unsigned long dimm_flags;
 456         int target_nid, online_nid;
 457
 458         p->bus_desc.ndctl = papr_scm_ndctl;
 459         p->bus_desc.module = THIS_MODULE;
 460         p->bus_desc.of_node = p->pdev->dev.of_node;
 461         p->bus_desc.provider_name = kstrdup(p->pdev->name, GFP_KERNEL);
 462
 463         if (!p->bus_desc.provider_name)
 464                 return -ENOMEM;
 465
 466         p->bus = nvdimm_bus_register(NULL, &p->bus_desc);
 467         if (!p->bus) {
 468                 dev_err(dev, "Error creating nvdimm bus %pOF\n", p->dn);
 469                 kfree(p->bus_desc.provider_name);
 470                 return -ENXIO;
 471         }
 472
 473         dimm_flags = 0;
 474         set_bit(NDD_LABELING, &dimm_flags);
 475
 476         p->nvdimm = nvdimm_create(p->bus, p, papr_nd_attr_groups,
 477                                   dimm_flags, PAPR_SCM_DIMM_CMD_MASK, 0, NULL);
 478         if (!p->nvdimm) {
 479                 dev_err(dev, "Error creating DIMM object for %pOF\n", p->dn);
 480                 goto err;
 481         }
 482
 483         if (nvdimm_bus_check_dimm_count(p->bus, 1))
 484                 goto err;
 485
 486         /* now add the region */
 487
 488         memset(&mapping, 0, sizeof(mapping));
 489         mapping.nvdimm = p->nvdimm;
 490         mapping.start = 0;
 491         mapping.size = p->blocks * p->block_size; // XXX: potential overflow?
 492
 493         memset(&ndr_desc, 0, sizeof(ndr_desc));
 494         target_nid = dev_to_node(&p->pdev->dev);
 495         online_nid = numa_map_to_online_node(target_nid);
 496         ndr_desc.numa_node = online_nid;
 497         ndr_desc.target_node = target_nid;
 498         ndr_desc.res = &p->res;
 499         ndr_desc.of_node = p->dn;
 500         ndr_desc.provider_data = p;
 501         ndr_desc.mapping = &mapping;
 502         ndr_desc.num_mappings = 1;
 503         ndr_desc.nd_set = &p->nd_set;
 504
 505         if (p->is_volatile)
 506                 p->region = nvdimm_volatile_region_create(p->bus, &ndr_desc);
 507         else {
 508                 set_bit(ND_REGION_PERSIST_MEMCTRL, &ndr_desc.flags);
 509                 p->region = nvdimm_pmem_region_create(p->bus, &ndr_desc);
 510         }
 511         if (!p->region) {
 512                 dev_err(dev, "Error registering region %pR from %pOF\n",
 513                                 ndr_desc.res, p->dn);
 514                 goto err;
 515         }
 516         if (target_nid != online_nid)
 517                 dev_info(dev, "Region registered with target node %d and online node %d",
 518                          target_nid, online_nid);
 519
 520         return 0;
 521
 522 err:    nvdimm_bus_unregister(p->bus);
 523         kfree(p->bus_desc.provider_name);
 524         return -ENXIO;
 525 }
 526
 527 static int papr_scm_probe(struct platform_device *pdev)
 528 {
 529         struct device_node *dn = pdev->dev.of_node;
 530         u32 drc_index, metadata_size;
 531         u64 blocks, block_size;
 532         struct papr_scm_priv *p;
 533         const char *uuid_str;
 534         u64 uuid[2];
 535         int rc;
 536
 537         /* check we have all the required DT properties */
 538         if (of_property_read_u32(dn, "ibm,my-drc-index", &drc_index)) {
 539                 dev_err(&pdev->dev, "%pOF: missing drc-index!\n", dn);
 540                 return -ENODEV;
 541         }
 542
 543         if (of_property_read_u64(dn, "ibm,block-size", &block_size)) {
 544                 dev_err(&pdev->dev, "%pOF: missing block-size!\n", dn);
 545                 return -ENODEV;
 546         }
 547
 548         if (of_property_read_u64(dn, "ibm,number-of-blocks", &blocks)) {
 549                 dev_err(&pdev->dev, "%pOF: missing number-of-blocks!\n", dn);
 550                 return -ENODEV;
 551         }
 552
 553         if (of_property_read_string(dn, "ibm,unit-guid", &uuid_str)) {
 554                 dev_err(&pdev->dev, "%pOF: missing unit-guid!\n", dn);
 555                 return -ENODEV;
 556         }
 557
 558
 559         p = kzalloc(sizeof(*p), GFP_KERNEL);
 560         if (!p)
 561                 return -ENOMEM;
 562
 563         /* Initialize the dimm mutex */
 564         mutex_init(&p->health_mutex);
 565
 566         /* optional DT properties */
 567         of_property_read_u32(dn, "ibm,metadata-size", &metadata_size);
 568
 569         p->dn = dn;
 570         p->drc_index = drc_index;
 571         p->block_size = block_size;
 572         p->blocks = blocks;
 573         p->is_volatile = !of_property_read_bool(dn, "ibm,cache-flush-required");
 574
 575         /* We just need to ensure that set cookies are unique across */
 576         uuid_parse(uuid_str, (uuid_t *) uuid);
 577         /*
 578          * cookie1 and cookie2 are not really little endian
 579          * we store a little endian representation of the
 580          * uuid str so that we can compare this with the label
 581          * area cookie irrespective of the endian config with which
 582          * the kernel is built.
 583          */
 584         p->nd_set.cookie1 = cpu_to_le64(uuid[0]);
 585         p->nd_set.cookie2 = cpu_to_le64(uuid[1]);
 586
 587         /* might be zero */
 588         p->metadata_size = metadata_size;
 589         p->pdev = pdev;
 590
 591         /* request the hypervisor to bind this region to somewhere in memory */
 592         rc = drc_pmem_bind(p);
 593
 594         /* If phyp says drc memory still bound then force unbound and retry */
 595         if (rc == H_OVERLAP)
 596                 rc = drc_pmem_query_n_bind(p);
 597
 598         if (rc != H_SUCCESS) {
 599                 dev_err(&p->pdev->dev, "bind err: %d\n", rc);
 600                 rc = -ENXIO;
 601                 goto err;
 602         }
 603
 604         /* setup the resource for the newly bound range */
 605         p->res.start = p->bound_addr;
 606         p->res.end   = p->bound_addr + p->blocks * p->block_size - 1;
 607         p->res.name  = pdev->name;
 608         p->res.flags = IORESOURCE_MEM;
 609
 610         rc = papr_scm_nvdimm_init(p);
 611         if (rc)
 612                 goto err2;
 613
 614         platform_set_drvdata(pdev, p);
 615
 616         return 0;
 617
 618 err2:   drc_pmem_unbind(p);
 619 err:    kfree(p);
 620         return rc;
 621 }
 622
 623 static int papr_scm_remove(struct platform_device *pdev)
 624 {
 625         struct papr_scm_priv *p = platform_get_drvdata(pdev);
 626
 627         nvdimm_bus_unregister(p->bus);
 628         drc_pmem_unbind(p);
 629         kfree(p->bus_desc.provider_name);
 630         kfree(p);
 631
 632         return 0;
 633 }
 634
 635 static const struct of_device_id papr_scm_match[] = {
 636         { .compatible = "ibm,pmemory" },
 637         { },
 638 };
 639
 640 static struct platform_driver papr_scm_driver = {
 641         .probe = papr_scm_probe,
 642         .remove = papr_scm_remove,
 643         .driver = {
 644                 .name = "papr_scm",
 645                 .of_match_table = papr_scm_match,
 646         },
 647 };
 648
 649 module_platform_driver(papr_scm_driver);
 650 MODULE_DEVICE_TABLE(of, papr_scm_match);
 651 MODULE_LICENSE("GPL");
 652 MODULE_AUTHOR("IBM Corporation");