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
  16 #include <asm/plpar_wrappers.h>
  17
  18 #define BIND_ANY_ADDR (~0ul)
  19
  20 #define PAPR_SCM_DIMM_CMD_MASK \
  21         ((1ul << ND_CMD_GET_CONFIG_SIZE) | \
  22          (1ul << ND_CMD_GET_CONFIG_DATA) | \
  23          (1ul << ND_CMD_SET_CONFIG_DATA))
  24
  25 struct papr_scm_priv {
  26         struct platform_device *pdev;
  27         struct device_node *dn;
  28         uint32_t drc_index;
  29         uint64_t blocks;
  30         uint64_t block_size;
  31         int metadata_size;
  32         bool is_volatile;
  33
  34         uint64_t bound_addr;
  35
  36         struct nvdimm_bus_descriptor bus_desc;
  37         struct nvdimm_bus *bus;
  38         struct nvdimm *nvdimm;
  39         struct resource res;
  40         struct nd_region *region;
  41         struct nd_interleave_set nd_set;
  42 };
  43
  44 static int drc_pmem_bind(struct papr_scm_priv *p)
  45 {
  46         unsigned long ret[PLPAR_HCALL_BUFSIZE];
  47         uint64_t saved = 0;
  48         uint64_t token;
  49         int64_t rc;
  50
  51         /*
  52          * When the hypervisor cannot map all the requested memory in a single
  53          * hcall it returns H_BUSY and we call again with the token until
  54          * we get H_SUCCESS. Aborting the retry loop before getting H_SUCCESS
  55          * leave the system in an undefined state, so we wait.
  56          */
  57         token = 0;
  58
  59         do {
  60                 rc = plpar_hcall(H_SCM_BIND_MEM, ret, p->drc_index, 0,
  61                                 p->blocks, BIND_ANY_ADDR, token);
  62                 token = ret[0];
  63                 if (!saved)
  64                         saved = ret[1];
  65                 cond_resched();
  66         } while (rc == H_BUSY);
  67
  68         if (rc)
  69                 return rc;
  70
  71         p->bound_addr = saved;
  72         dev_dbg(&p->pdev->dev, "bound drc 0x%x to %pR\n", p->drc_index, &p->res);
  73         return rc;
  74 }
  75
  76 static void drc_pmem_unbind(struct papr_scm_priv *p)
  77 {
  78         unsigned long ret[PLPAR_HCALL_BUFSIZE];
  79         uint64_t token = 0;
  80         int64_t rc;
  81
  82         dev_dbg(&p->pdev->dev, "unbind drc 0x%x\n", p->drc_index);
  83
  84         /* NB: unbind has the same retry requirements as drc_pmem_bind() */
  85         do {
  86
  87                 /* Unbind of all SCM resources associated with drcIndex */
  88                 rc = plpar_hcall(H_SCM_UNBIND_ALL, ret, H_UNBIND_SCOPE_DRC,
  89                                  p->drc_index, token);
  90                 token = ret[0];
  91
  92                 /* Check if we are stalled for some time */
  93                 if (H_IS_LONG_BUSY(rc)) {
  94                         msleep(get_longbusy_msecs(rc));
  95                         rc = H_BUSY;
  96                 } else if (rc == H_BUSY) {
  97                         cond_resched();
  98                 }
  99
 100         } while (rc == H_BUSY);
 101
 102         if (rc)
 103                 dev_err(&p->pdev->dev, "unbind error: %lld\n", rc);
 104         else
 105                 dev_dbg(&p->pdev->dev, "unbind drc 0x%x complete\n",
 106                         p->drc_index);
 107
 108         return;
 109 }
 110
 111 static int drc_pmem_query_n_bind(struct papr_scm_priv *p)
 112 {
 113         unsigned long start_addr;
 114         unsigned long end_addr;
 115         unsigned long ret[PLPAR_HCALL_BUFSIZE];
 116         int64_t rc;
 117
 118
 119         rc = plpar_hcall(H_SCM_QUERY_BLOCK_MEM_BINDING, ret,
 120                          p->drc_index, 0);
 121         if (rc)
 122                 goto err_out;
 123         start_addr = ret[0];
 124
 125         /* Make sure the full region is bound. */
 126         rc = plpar_hcall(H_SCM_QUERY_BLOCK_MEM_BINDING, ret,
 127                          p->drc_index, p->blocks - 1);
 128         if (rc)
 129                 goto err_out;
 130         end_addr = ret[0];
 131
 132         if ((end_addr - start_addr) != ((p->blocks - 1) * p->block_size))
 133                 goto err_out;
 134
 135         p->bound_addr = start_addr;
 136         dev_dbg(&p->pdev->dev, "bound drc 0x%x to %pR\n", p->drc_index, &p->res);
 137         return rc;
 138
 139 err_out:
 140         dev_info(&p->pdev->dev,
 141                  "Failed to query, trying an unbind followed by bind");
 142         drc_pmem_unbind(p);
 143         return drc_pmem_bind(p);
 144 }
 145
 146
 147 static int papr_scm_meta_get(struct papr_scm_priv *p,
 148                              struct nd_cmd_get_config_data_hdr *hdr)
 149 {
 150         unsigned long data[PLPAR_HCALL_BUFSIZE];
 151         unsigned long offset, data_offset;
 152         int len, read;
 153         int64_t ret;
 154
 155         if ((hdr->in_offset + hdr->in_length) > p->metadata_size)
 156                 return -EINVAL;
 157
 158         for (len = hdr->in_length; len; len -= read) {
 159
 160                 data_offset = hdr->in_length - len;
 161                 offset = hdr->in_offset + data_offset;
 162
 163                 if (len >= 8)
 164                         read = 8;
 165                 else if (len >= 4)
 166                         read = 4;
 167                 else if (len >= 2)
 168                         read = 2;
 169                 else
 170                         read = 1;
 171
 172                 ret = plpar_hcall(H_SCM_READ_METADATA, data, p->drc_index,
 173                                   offset, read);
 174
 175                 if (ret == H_PARAMETER) /* bad DRC index */
 176                         return -ENODEV;
 177                 if (ret)
 178                         return -EINVAL; /* other invalid parameter */
 179
 180                 switch (read) {
 181                 case 8:
 182                         *(uint64_t *)(hdr->out_buf + data_offset) = be64_to_cpu(data[0]);
 183                         break;
 184                 case 4:
 185                         *(uint32_t *)(hdr->out_buf + data_offset) = be32_to_cpu(data[0] & 0xffffffff);
 186                         break;
 187
 188                 case 2:
 189                         *(uint16_t *)(hdr->out_buf + data_offset) = be16_to_cpu(data[0] & 0xffff);
 190                         break;
 191
 192                 case 1:
 193                         *(uint8_t *)(hdr->out_buf + data_offset) = (data[0] & 0xff);
 194                         break;
 195                 }
 196         }
 197         return 0;
 198 }
 199
 200 static int papr_scm_meta_set(struct papr_scm_priv *p,
 201                              struct nd_cmd_set_config_hdr *hdr)
 202 {
 203         unsigned long offset, data_offset;
 204         int len, wrote;
 205         unsigned long data;
 206         __be64 data_be;
 207         int64_t ret;
 208
 209         if ((hdr->in_offset + hdr->in_length) > p->metadata_size)
 210                 return -EINVAL;
 211
 212         for (len = hdr->in_length; len; len -= wrote) {
 213
 214                 data_offset = hdr->in_length - len;
 215                 offset = hdr->in_offset + data_offset;
 216
 217                 if (len >= 8) {
 218                         data = *(uint64_t *)(hdr->in_buf + data_offset);
 219                         data_be = cpu_to_be64(data);
 220                         wrote = 8;
 221                 } else if (len >= 4) {
 222                         data = *(uint32_t *)(hdr->in_buf + data_offset);
 223                         data &= 0xffffffff;
 224                         data_be = cpu_to_be32(data);
 225                         wrote = 4;
 226                 } else if (len >= 2) {
 227                         data = *(uint16_t *)(hdr->in_buf + data_offset);
 228                         data &= 0xffff;
 229                         data_be = cpu_to_be16(data);
 230                         wrote = 2;
 231                 } else {
 232                         data_be = *(uint8_t *)(hdr->in_buf + data_offset);
 233                         data_be &= 0xff;
 234                         wrote = 1;
 235                 }
 236
 237                 ret = plpar_hcall_norets(H_SCM_WRITE_METADATA, p->drc_index,
 238                                          offset, data_be, wrote);
 239                 if (ret == H_PARAMETER) /* bad DRC index */
 240                         return -ENODEV;
 241                 if (ret)
 242                         return -EINVAL; /* other invalid parameter */
 243         }
 244
 245         return 0;
 246 }
 247
 248 int papr_scm_ndctl(struct nvdimm_bus_descriptor *nd_desc, struct nvdimm *nvdimm,
 249                 unsigned int cmd, void *buf, unsigned int buf_len, int *cmd_rc)
 250 {
 251         struct nd_cmd_get_config_size *get_size_hdr;
 252         struct papr_scm_priv *p;
 253
 254         /* Only dimm-specific calls are supported atm */
 255         if (!nvdimm)
 256                 return -EINVAL;
 257
 258         p = nvdimm_provider_data(nvdimm);
 259
 260         switch (cmd) {
 261         case ND_CMD_GET_CONFIG_SIZE:
 262                 get_size_hdr = buf;
 263
 264                 get_size_hdr->status = 0;
 265                 get_size_hdr->max_xfer = 8;
 266                 get_size_hdr->config_size = p->metadata_size;
 267                 *cmd_rc = 0;
 268                 break;
 269
 270         case ND_CMD_GET_CONFIG_DATA:
 271                 *cmd_rc = papr_scm_meta_get(p, buf);
 272                 break;
 273
 274         case ND_CMD_SET_CONFIG_DATA:
 275                 *cmd_rc = papr_scm_meta_set(p, buf);
 276                 break;
 277
 278         default:
 279                 return -EINVAL;
 280         }
 281
 282         dev_dbg(&p->pdev->dev, "returned with cmd_rc = %d\n", *cmd_rc);
 283
 284         return 0;
 285 }
 286
 287 static const struct attribute_group *region_attr_groups[] = {
 288         &nd_region_attribute_group,
 289         &nd_device_attribute_group,
 290         &nd_mapping_attribute_group,
 291         &nd_numa_attribute_group,
 292         NULL,
 293 };
 294
 295 static const struct attribute_group *bus_attr_groups[] = {
 296         &nvdimm_bus_attribute_group,
 297         NULL,
 298 };
 299
 300 static const struct attribute_group *papr_scm_dimm_groups[] = {
 301         &nvdimm_attribute_group,
 302         &nd_device_attribute_group,
 303         NULL,
 304 };
 305
 306 static inline int papr_scm_node(int node)
 307 {
 308         int min_dist = INT_MAX, dist;
 309         int nid, min_node;
 310
 311         if ((node == NUMA_NO_NODE) || node_online(node))
 312                 return node;
 313
 314         min_node = first_online_node;
 315         for_each_online_node(nid) {
 316                 dist = node_distance(node, nid);
 317                 if (dist < min_dist) {
 318                         min_dist = dist;
 319                         min_node = nid;
 320                 }
 321         }
 322         return min_node;
 323 }
 324
 325 static int papr_scm_nvdimm_init(struct papr_scm_priv *p)
 326 {
 327         struct device *dev = &p->pdev->dev;
 328         struct nd_mapping_desc mapping;
 329         struct nd_region_desc ndr_desc;
 330         unsigned long dimm_flags;
 331         int target_nid, online_nid;
 332
 333         p->bus_desc.ndctl = papr_scm_ndctl;
 334         p->bus_desc.module = THIS_MODULE;
 335         p->bus_desc.of_node = p->pdev->dev.of_node;
 336         p->bus_desc.attr_groups = bus_attr_groups;
 337         p->bus_desc.provider_name = kstrdup(p->pdev->name, GFP_KERNEL);
 338
 339         if (!p->bus_desc.provider_name)
 340                 return -ENOMEM;
 341
 342         p->bus = nvdimm_bus_register(NULL, &p->bus_desc);
 343         if (!p->bus) {
 344                 dev_err(dev, "Error creating nvdimm bus %pOF\n", p->dn);
 345                 kfree(p->bus_desc.provider_name);
 346                 return -ENXIO;
 347         }
 348
 349         dimm_flags = 0;
 350         set_bit(NDD_ALIASING, &dimm_flags);
 351
 352         p->nvdimm = nvdimm_create(p->bus, p, papr_scm_dimm_groups,
 353                                 dimm_flags, PAPR_SCM_DIMM_CMD_MASK, 0, NULL);
 354         if (!p->nvdimm) {
 355                 dev_err(dev, "Error creating DIMM object for %pOF\n", p->dn);
 356                 goto err;
 357         }
 358
 359         if (nvdimm_bus_check_dimm_count(p->bus, 1))
 360                 goto err;
 361
 362         /* now add the region */
 363
 364         memset(&mapping, 0, sizeof(mapping));
 365         mapping.nvdimm = p->nvdimm;
 366         mapping.start = 0;
 367         mapping.size = p->blocks * p->block_size; // XXX: potential overflow?
 368
 369         memset(&ndr_desc, 0, sizeof(ndr_desc));
 370         ndr_desc.attr_groups = region_attr_groups;
 371         target_nid = dev_to_node(&p->pdev->dev);
 372         online_nid = papr_scm_node(target_nid);
 373         ndr_desc.numa_node = online_nid;
 374         ndr_desc.target_node = target_nid;
 375         ndr_desc.res = &p->res;
 376         ndr_desc.of_node = p->dn;
 377         ndr_desc.provider_data = p;
 378         ndr_desc.mapping = &mapping;
 379         ndr_desc.num_mappings = 1;
 380         ndr_desc.nd_set = &p->nd_set;
 381         set_bit(ND_REGION_PAGEMAP, &ndr_desc.flags);
 382
 383         if (p->is_volatile)
 384                 p->region = nvdimm_volatile_region_create(p->bus, &ndr_desc);
 385         else
 386                 p->region = nvdimm_pmem_region_create(p->bus, &ndr_desc);
 387         if (!p->region) {
 388                 dev_err(dev, "Error registering region %pR from %pOF\n",
 389                                 ndr_desc.res, p->dn);
 390                 goto err;
 391         }
 392         if (target_nid != online_nid)
 393                 dev_info(dev, "Region registered with target node %d and online node %d",
 394                          target_nid, online_nid);
 395
 396         return 0;
 397
 398 err:    nvdimm_bus_unregister(p->bus);
 399         kfree(p->bus_desc.provider_name);
 400         return -ENXIO;
 401 }
 402
 403 static int papr_scm_probe(struct platform_device *pdev)
 404 {
 405         struct device_node *dn = pdev->dev.of_node;
 406         u32 drc_index, metadata_size;
 407         u64 blocks, block_size;
 408         struct papr_scm_priv *p;
 409         const char *uuid_str;
 410         u64 uuid[2];
 411         int rc;
 412
 413         /* check we have all the required DT properties */
 414         if (of_property_read_u32(dn, "ibm,my-drc-index", &drc_index)) {
 415                 dev_err(&pdev->dev, "%pOF: missing drc-index!\n", dn);
 416                 return -ENODEV;
 417         }
 418
 419         if (of_property_read_u64(dn, "ibm,block-size", &block_size)) {
 420                 dev_err(&pdev->dev, "%pOF: missing block-size!\n", dn);
 421                 return -ENODEV;
 422         }
 423
 424         if (of_property_read_u64(dn, "ibm,number-of-blocks", &blocks)) {
 425                 dev_err(&pdev->dev, "%pOF: missing number-of-blocks!\n", dn);
 426                 return -ENODEV;
 427         }
 428
 429         if (of_property_read_string(dn, "ibm,unit-guid", &uuid_str)) {
 430                 dev_err(&pdev->dev, "%pOF: missing unit-guid!\n", dn);
 431                 return -ENODEV;
 432         }
 433
 434
 435         p = kzalloc(sizeof(*p), GFP_KERNEL);
 436         if (!p)
 437                 return -ENOMEM;
 438
 439         /* optional DT properties */
 440         of_property_read_u32(dn, "ibm,metadata-size", &metadata_size);
 441
 442         p->dn = dn;
 443         p->drc_index = drc_index;
 444         p->block_size = block_size;
 445         p->blocks = blocks;
 446         p->is_volatile = !of_property_read_bool(dn, "ibm,cache-flush-required");
 447
 448         /* We just need to ensure that set cookies are unique across */
 449         uuid_parse(uuid_str, (uuid_t *) uuid);
 450         /*
 451          * cookie1 and cookie2 are not really little endian
 452          * we store a little endian representation of the
 453          * uuid str so that we can compare this with the label
 454          * area cookie irrespective of the endian config with which
 455          * the kernel is built.
 456          */
 457         p->nd_set.cookie1 = cpu_to_le64(uuid[0]);
 458         p->nd_set.cookie2 = cpu_to_le64(uuid[1]);
 459
 460         /* might be zero */
 461         p->metadata_size = metadata_size;
 462         p->pdev = pdev;
 463
 464         /* request the hypervisor to bind this region to somewhere in memory */
 465         rc = drc_pmem_bind(p);
 466
 467         /* If phyp says drc memory still bound then force unbound and retry */
 468         if (rc == H_OVERLAP)
 469                 rc = drc_pmem_query_n_bind(p);
 470
 471         if (rc != H_SUCCESS) {
 472                 dev_err(&p->pdev->dev, "bind err: %d\n", rc);
 473                 rc = -ENXIO;
 474                 goto err;
 475         }
 476
 477         /* setup the resource for the newly bound range */
 478         p->res.start = p->bound_addr;
 479         p->res.end   = p->bound_addr + p->blocks * p->block_size - 1;
 480         p->res.name  = pdev->name;
 481         p->res.flags = IORESOURCE_MEM;
 482
 483         rc = papr_scm_nvdimm_init(p);
 484         if (rc)
 485                 goto err2;
 486
 487         platform_set_drvdata(pdev, p);
 488
 489         return 0;
 490
 491 err2:   drc_pmem_unbind(p);
 492 err:    kfree(p);
 493         return rc;
 494 }
 495
 496 static int papr_scm_remove(struct platform_device *pdev)
 497 {
 498         struct papr_scm_priv *p = platform_get_drvdata(pdev);
 499
 500         nvdimm_bus_unregister(p->bus);
 501         drc_pmem_unbind(p);
 502         kfree(p->bus_desc.provider_name);
 503         kfree(p);
 504
 505         return 0;
 506 }
 507
 508 static const struct of_device_id papr_scm_match[] = {
 509         { .compatible = "ibm,pmemory" },
 510         { },
 511 };
 512
 513 static struct platform_driver papr_scm_driver = {
 514         .probe = papr_scm_probe,
 515         .remove = papr_scm_remove,
 516         .driver = {
 517                 .name = "papr_scm",
 518                 .owner = THIS_MODULE,
 519                 .of_match_table = papr_scm_match,
 520         },
 521 };
 522
 523 module_platform_driver(papr_scm_driver);
 524 MODULE_DEVICE_TABLE(of, papr_scm_match);
 525 MODULE_LICENSE("GPL");
 526 MODULE_AUTHOR("IBM Corporation");