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 inline int papr_scm_node(int node)
 288 {
 289         int min_dist = INT_MAX, dist;
 290         int nid, min_node;
 291
 292         if ((node == NUMA_NO_NODE) || node_online(node))
 293                 return node;
 294
 295         min_node = first_online_node;
 296         for_each_online_node(nid) {
 297                 dist = node_distance(node, nid);
 298                 if (dist < min_dist) {
 299                         min_dist = dist;
 300                         min_node = nid;
 301                 }
 302         }
 303         return min_node;
 304 }
 305
 306 static int papr_scm_nvdimm_init(struct papr_scm_priv *p)
 307 {
 308         struct device *dev = &p->pdev->dev;
 309         struct nd_mapping_desc mapping;
 310         struct nd_region_desc ndr_desc;
 311         unsigned long dimm_flags;
 312         int target_nid, online_nid;
 313
 314         p->bus_desc.ndctl = papr_scm_ndctl;
 315         p->bus_desc.module = THIS_MODULE;
 316         p->bus_desc.of_node = p->pdev->dev.of_node;
 317         p->bus_desc.provider_name = kstrdup(p->pdev->name, GFP_KERNEL);
 318
 319         if (!p->bus_desc.provider_name)
 320                 return -ENOMEM;
 321
 322         p->bus = nvdimm_bus_register(NULL, &p->bus_desc);
 323         if (!p->bus) {
 324                 dev_err(dev, "Error creating nvdimm bus %pOF\n", p->dn);
 325                 return -ENXIO;
 326         }
 327
 328         dimm_flags = 0;
 329         set_bit(NDD_ALIASING, &dimm_flags);
 330
 331         p->nvdimm = nvdimm_create(p->bus, p, NULL, dimm_flags,
 332                                   PAPR_SCM_DIMM_CMD_MASK, 0, NULL);
 333         if (!p->nvdimm) {
 334                 dev_err(dev, "Error creating DIMM object for %pOF\n", p->dn);
 335                 goto err;
 336         }
 337
 338         if (nvdimm_bus_check_dimm_count(p->bus, 1))
 339                 goto err;
 340
 341         /* now add the region */
 342
 343         memset(&mapping, 0, sizeof(mapping));
 344         mapping.nvdimm = p->nvdimm;
 345         mapping.start = 0;
 346         mapping.size = p->blocks * p->block_size; // XXX: potential overflow?
 347
 348         memset(&ndr_desc, 0, sizeof(ndr_desc));
 349         target_nid = dev_to_node(&p->pdev->dev);
 350         online_nid = papr_scm_node(target_nid);
 351         ndr_desc.numa_node = online_nid;
 352         ndr_desc.target_node = target_nid;
 353         ndr_desc.res = &p->res;
 354         ndr_desc.of_node = p->dn;
 355         ndr_desc.provider_data = p;
 356         ndr_desc.mapping = &mapping;
 357         ndr_desc.num_mappings = 1;
 358         ndr_desc.nd_set = &p->nd_set;
 359         set_bit(ND_REGION_PAGEMAP, &ndr_desc.flags);
 360
 361         if (p->is_volatile)
 362                 p->region = nvdimm_volatile_region_create(p->bus, &ndr_desc);
 363         else
 364                 p->region = nvdimm_pmem_region_create(p->bus, &ndr_desc);
 365         if (!p->region) {
 366                 dev_err(dev, "Error registering region %pR from %pOF\n",
 367                                 ndr_desc.res, p->dn);
 368                 goto err;
 369         }
 370         if (target_nid != online_nid)
 371                 dev_info(dev, "Region registered with target node %d and online node %d",
 372                          target_nid, online_nid);
 373
 374         return 0;
 375
 376 err:    nvdimm_bus_unregister(p->bus);
 377         kfree(p->bus_desc.provider_name);
 378         return -ENXIO;
 379 }
 380
 381 static int papr_scm_probe(struct platform_device *pdev)
 382 {
 383         struct device_node *dn = pdev->dev.of_node;
 384         u32 drc_index, metadata_size;
 385         u64 blocks, block_size;
 386         struct papr_scm_priv *p;
 387         const char *uuid_str;
 388         u64 uuid[2];
 389         int rc;
 390
 391         /* check we have all the required DT properties */
 392         if (of_property_read_u32(dn, "ibm,my-drc-index", &drc_index)) {
 393                 dev_err(&pdev->dev, "%pOF: missing drc-index!\n", dn);
 394                 return -ENODEV;
 395         }
 396
 397         if (of_property_read_u64(dn, "ibm,block-size", &block_size)) {
 398                 dev_err(&pdev->dev, "%pOF: missing block-size!\n", dn);
 399                 return -ENODEV;
 400         }
 401
 402         if (of_property_read_u64(dn, "ibm,number-of-blocks", &blocks)) {
 403                 dev_err(&pdev->dev, "%pOF: missing number-of-blocks!\n", dn);
 404                 return -ENODEV;
 405         }
 406
 407         if (of_property_read_string(dn, "ibm,unit-guid", &uuid_str)) {
 408                 dev_err(&pdev->dev, "%pOF: missing unit-guid!\n", dn);
 409                 return -ENODEV;
 410         }
 411
 412
 413         p = kzalloc(sizeof(*p), GFP_KERNEL);
 414         if (!p)
 415                 return -ENOMEM;
 416
 417         /* optional DT properties */
 418         of_property_read_u32(dn, "ibm,metadata-size", &metadata_size);
 419
 420         p->dn = dn;
 421         p->drc_index = drc_index;
 422         p->block_size = block_size;
 423         p->blocks = blocks;
 424         p->is_volatile = !of_property_read_bool(dn, "ibm,cache-flush-required");
 425
 426         /* We just need to ensure that set cookies are unique across */
 427         uuid_parse(uuid_str, (uuid_t *) uuid);
 428         /*
 429          * cookie1 and cookie2 are not really little endian
 430          * we store a little endian representation of the
 431          * uuid str so that we can compare this with the label
 432          * area cookie irrespective of the endian config with which
 433          * the kernel is built.
 434          */
 435         p->nd_set.cookie1 = cpu_to_le64(uuid[0]);
 436         p->nd_set.cookie2 = cpu_to_le64(uuid[1]);
 437
 438         /* might be zero */
 439         p->metadata_size = metadata_size;
 440         p->pdev = pdev;
 441
 442         /* request the hypervisor to bind this region to somewhere in memory */
 443         rc = drc_pmem_bind(p);
 444
 445         /* If phyp says drc memory still bound then force unbound and retry */
 446         if (rc == H_OVERLAP)
 447                 rc = drc_pmem_query_n_bind(p);
 448
 449         if (rc != H_SUCCESS) {
 450                 dev_err(&p->pdev->dev, "bind err: %d\n", rc);
 451                 rc = -ENXIO;
 452                 goto err;
 453         }
 454
 455         /* setup the resource for the newly bound range */
 456         p->res.start = p->bound_addr;
 457         p->res.end   = p->bound_addr + p->blocks * p->block_size - 1;
 458         p->res.name  = pdev->name;
 459         p->res.flags = IORESOURCE_MEM;
 460
 461         rc = papr_scm_nvdimm_init(p);
 462         if (rc)
 463                 goto err2;
 464
 465         platform_set_drvdata(pdev, p);
 466
 467         return 0;
 468
 469 err2:   drc_pmem_unbind(p);
 470 err:    kfree(p);
 471         return rc;
 472 }
 473
 474 static int papr_scm_remove(struct platform_device *pdev)
 475 {
 476         struct papr_scm_priv *p = platform_get_drvdata(pdev);
 477
 478         nvdimm_bus_unregister(p->bus);
 479         drc_pmem_unbind(p);
 480         kfree(p);
 481
 482         return 0;
 483 }
 484
 485 static const struct of_device_id papr_scm_match[] = {
 486         { .compatible = "ibm,pmemory" },
 487         { },
 488 };
 489
 490 static struct platform_driver papr_scm_driver = {
 491         .probe = papr_scm_probe,
 492         .remove = papr_scm_remove,
 493         .driver = {
 494                 .name = "papr_scm",
 495                 .of_match_table = papr_scm_match,
 496         },
 497 };
 498
 499 module_platform_driver(papr_scm_driver);
 500 MODULE_DEVICE_TABLE(of, papr_scm_match);
 501 MODULE_LICENSE("GPL");
 502 MODULE_AUTHOR("IBM Corporation");