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