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"); 497