drivers/gpu/drm/amd/amdkfd/kfd_topology.c

   1 /*
   2  * Copyright 2014 Advanced Micro Devices, Inc.
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice shall be included in
  12  * all copies or substantial portions of the Software.
  13  *
  14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  17  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
  18  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  19  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  20  * OTHER DEALINGS IN THE SOFTWARE.
  21  */
  22
  23 #include <linux/types.h>
  24 #include <linux/kernel.h>
  25 #include <linux/pci.h>
  26 #include <linux/errno.h>
  27 #include <linux/acpi.h>
  28 #include <linux/hash.h>
  29 #include <linux/cpufreq.h>
  30 #include <linux/log2.h>
  31
  32 #include "kfd_priv.h"
  33 #include "kfd_crat.h"
  34 #include "kfd_topology.h"
  35
  36 static struct list_head topology_device_list;
  37 static int topology_crat_parsed;
  38 static struct kfd_system_properties sys_props;
  39
  40 static DECLARE_RWSEM(topology_lock);
  41
  42 struct kfd_dev *kfd_device_by_id(uint32_t gpu_id)
  43 {
  44         struct kfd_topology_device *top_dev;
  45         struct kfd_dev *device = NULL;
  46
  47         down_read(&topology_lock);
  48
  49         list_for_each_entry(top_dev, &topology_device_list, list)
  50                 if (top_dev->gpu_id == gpu_id) {
  51                         device = top_dev->gpu;
  52                         break;
  53                 }
  54
  55         up_read(&topology_lock);
  56
  57         return device;
  58 }
  59
  60 struct kfd_dev *kfd_device_by_pci_dev(const struct pci_dev *pdev)
  61 {
  62         struct kfd_topology_device *top_dev;
  63         struct kfd_dev *device = NULL;
  64
  65         down_read(&topology_lock);
  66
  67         list_for_each_entry(top_dev, &topology_device_list, list)
  68                 if (top_dev->gpu->pdev == pdev) {
  69                         device = top_dev->gpu;
  70                         break;
  71                 }
  72
  73         up_read(&topology_lock);
  74
  75         return device;
  76 }
  77
  78 static int kfd_topology_get_crat_acpi(void *crat_image, size_t *size)
  79 {
  80         struct acpi_table_header *crat_table;
  81         acpi_status status;
  82
  83         if (!size)
  84                 return -EINVAL;
  85
  86         /*
  87          * Fetch the CRAT table from ACPI
  88          */
  89         status = acpi_get_table(CRAT_SIGNATURE, 0, &crat_table);
  90         if (status == AE_NOT_FOUND) {
  91                 pr_warn("CRAT table not found\n");
  92                 return -ENODATA;
  93         } else if (ACPI_FAILURE(status)) {
  94                 const char *err = acpi_format_exception(status);
  95
  96                 pr_err("CRAT table error: %s\n", err);
  97                 return -EINVAL;
  98         }
  99
 100         if (*size >= crat_table->length && crat_image != NULL)
 101                 memcpy(crat_image, crat_table, crat_table->length);
 102
 103         *size = crat_table->length;
 104
 105         return 0;
 106 }
 107
 108 static void kfd_populated_cu_info_cpu(struct kfd_topology_device *dev,
 109                 struct crat_subtype_computeunit *cu)
 110 {
 111         dev->node_props.cpu_cores_count = cu->num_cpu_cores;
 112         dev->node_props.cpu_core_id_base = cu->processor_id_low;
 113         if (cu->hsa_capability & CRAT_CU_FLAGS_IOMMU_PRESENT)
 114                 dev->node_props.capability |= HSA_CAP_ATS_PRESENT;
 115
 116         pr_info("CU CPU: cores=%d id_base=%d\n", cu->num_cpu_cores,
 117                         cu->processor_id_low);
 118 }
 119
 120 static void kfd_populated_cu_info_gpu(struct kfd_topology_device *dev,
 121                 struct crat_subtype_computeunit *cu)
 122 {
 123         dev->node_props.simd_id_base = cu->processor_id_low;
 124         dev->node_props.simd_count = cu->num_simd_cores;
 125         dev->node_props.lds_size_in_kb = cu->lds_size_in_kb;
 126         dev->node_props.max_waves_per_simd = cu->max_waves_simd;
 127         dev->node_props.wave_front_size = cu->wave_front_size;
 128         dev->node_props.mem_banks_count = cu->num_banks;
 129         dev->node_props.array_count = cu->num_arrays;
 130         dev->node_props.cu_per_simd_array = cu->num_cu_per_array;
 131         dev->node_props.simd_per_cu = cu->num_simd_per_cu;
 132         dev->node_props.max_slots_scratch_cu = cu->max_slots_scatch_cu;
 133         if (cu->hsa_capability & CRAT_CU_FLAGS_HOT_PLUGGABLE)
 134                 dev->node_props.capability |= HSA_CAP_HOT_PLUGGABLE;
 135         pr_info("CU GPU: simds=%d id_base=%d\n", cu->num_simd_cores,
 136                                 cu->processor_id_low);
 137 }
 138
 139 /* kfd_parse_subtype_cu is called when the topology mutex is already acquired */
 140 static int kfd_parse_subtype_cu(struct crat_subtype_computeunit *cu)
 141 {
 142         struct kfd_topology_device *dev;
 143         int i = 0;
 144
 145         pr_info("Found CU entry in CRAT table with proximity_domain=%d caps=%x\n",
 146                         cu->proximity_domain, cu->hsa_capability);
 147         list_for_each_entry(dev, &topology_device_list, list) {
 148                 if (cu->proximity_domain == i) {
 149                         if (cu->flags & CRAT_CU_FLAGS_CPU_PRESENT)
 150                                 kfd_populated_cu_info_cpu(dev, cu);
 151
 152                         if (cu->flags & CRAT_CU_FLAGS_GPU_PRESENT)
 153                                 kfd_populated_cu_info_gpu(dev, cu);
 154                         break;
 155                 }
 156                 i++;
 157         }
 158
 159         return 0;
 160 }
 161
 162 /*
 163  * kfd_parse_subtype_mem is called when the topology mutex is
 164  * already acquired
 165  */
 166 static int kfd_parse_subtype_mem(struct crat_subtype_memory *mem)
 167 {
 168         struct kfd_mem_properties *props;
 169         struct kfd_topology_device *dev;
 170         int i = 0;
 171
 172         pr_info("Found memory entry in CRAT table with proximity_domain=%d\n",
 173                         mem->promixity_domain);
 174         list_for_each_entry(dev, &topology_device_list, list) {
 175                 if (mem->promixity_domain == i) {
 176                         props = kfd_alloc_struct(props);
 177                         if (props == NULL)
 178                                 return -ENOMEM;
 179
 180                         if (dev->node_props.cpu_cores_count == 0)
 181                                 props->heap_type = HSA_MEM_HEAP_TYPE_FB_PRIVATE;
 182                         else
 183                                 props->heap_type = HSA_MEM_HEAP_TYPE_SYSTEM;
 184
 185                         if (mem->flags & CRAT_MEM_FLAGS_HOT_PLUGGABLE)
 186                                 props->flags |= HSA_MEM_FLAGS_HOT_PLUGGABLE;
 187                         if (mem->flags & CRAT_MEM_FLAGS_NON_VOLATILE)
 188                                 props->flags |= HSA_MEM_FLAGS_NON_VOLATILE;
 189
 190                         props->size_in_bytes =
 191                                 ((uint64_t)mem->length_high << 32) +
 192                                                         mem->length_low;
 193                         props->width = mem->width;
 194
 195                         dev->mem_bank_count++;
 196                         list_add_tail(&props->list, &dev->mem_props);
 197
 198                         break;
 199                 }
 200                 i++;
 201         }
 202
 203         return 0;
 204 }
 205
 206 /*
 207  * kfd_parse_subtype_cache is called when the topology mutex
 208  * is already acquired
 209  */
 210 static int kfd_parse_subtype_cache(struct crat_subtype_cache *cache)
 211 {
 212         struct kfd_cache_properties *props;
 213         struct kfd_topology_device *dev;
 214         uint32_t id;
 215
 216         id = cache->processor_id_low;
 217
 218         pr_info("Found cache entry in CRAT table with processor_id=%d\n", id);
 219         list_for_each_entry(dev, &topology_device_list, list)
 220                 if (id == dev->node_props.cpu_core_id_base ||
 221                     id == dev->node_props.simd_id_base) {
 222                         props = kfd_alloc_struct(props);
 223                         if (props == NULL)
 224                                 return -ENOMEM;
 225
 226                         props->processor_id_low = id;
 227                         props->cache_level = cache->cache_level;
 228                         props->cache_size = cache->cache_size;
 229                         props->cacheline_size = cache->cache_line_size;
 230                         props->cachelines_per_tag = cache->lines_per_tag;
 231                         props->cache_assoc = cache->associativity;
 232                         props->cache_latency = cache->cache_latency;
 233
 234                         if (cache->flags & CRAT_CACHE_FLAGS_DATA_CACHE)
 235                                 props->cache_type |= HSA_CACHE_TYPE_DATA;
 236                         if (cache->flags & CRAT_CACHE_FLAGS_INST_CACHE)
 237                                 props->cache_type |= HSA_CACHE_TYPE_INSTRUCTION;
 238                         if (cache->flags & CRAT_CACHE_FLAGS_CPU_CACHE)
 239                                 props->cache_type |= HSA_CACHE_TYPE_CPU;
 240                         if (cache->flags & CRAT_CACHE_FLAGS_SIMD_CACHE)
 241                                 props->cache_type |= HSA_CACHE_TYPE_HSACU;
 242
 243                         dev->cache_count++;
 244                         dev->node_props.caches_count++;
 245                         list_add_tail(&props->list, &dev->cache_props);
 246
 247                         break;
 248                 }
 249
 250         return 0;
 251 }
 252
 253 /*
 254  * kfd_parse_subtype_iolink is called when the topology mutex
 255  * is already acquired
 256  */
 257 static int kfd_parse_subtype_iolink(struct crat_subtype_iolink *iolink)
 258 {
 259         struct kfd_iolink_properties *props;
 260         struct kfd_topology_device *dev;
 261         uint32_t i = 0;
 262         uint32_t id_from;
 263         uint32_t id_to;
 264
 265         id_from = iolink->proximity_domain_from;
 266         id_to = iolink->proximity_domain_to;
 267
 268         pr_info("Found IO link entry in CRAT table with id_from=%d\n", id_from);
 269         list_for_each_entry(dev, &topology_device_list, list) {
 270                 if (id_from == i) {
 271                         props = kfd_alloc_struct(props);
 272                         if (props == NULL)
 273                                 return -ENOMEM;
 274
 275                         props->node_from = id_from;
 276                         props->node_to = id_to;
 277                         props->ver_maj = iolink->version_major;
 278                         props->ver_min = iolink->version_minor;
 279
 280                         /*
 281                          * weight factor (derived from CDIR), currently always 1
 282                          */
 283                         props->weight = 1;
 284
 285                         props->min_latency = iolink->minimum_latency;
 286                         props->max_latency = iolink->maximum_latency;
 287                         props->min_bandwidth = iolink->minimum_bandwidth_mbs;
 288                         props->max_bandwidth = iolink->maximum_bandwidth_mbs;
 289                         props->rec_transfer_size =
 290                                         iolink->recommended_transfer_size;
 291
 292                         dev->io_link_count++;
 293                         dev->node_props.io_links_count++;
 294                         list_add_tail(&props->list, &dev->io_link_props);
 295
 296                         break;
 297                 }
 298                 i++;
 299         }
 300
 301         return 0;
 302 }
 303
 304 static int kfd_parse_subtype(struct crat_subtype_generic *sub_type_hdr)
 305 {
 306         struct crat_subtype_computeunit *cu;
 307         struct crat_subtype_memory *mem;
 308         struct crat_subtype_cache *cache;
 309         struct crat_subtype_iolink *iolink;
 310         int ret = 0;
 311
 312         switch (sub_type_hdr->type) {
 313         case CRAT_SUBTYPE_COMPUTEUNIT_AFFINITY:
 314                 cu = (struct crat_subtype_computeunit *)sub_type_hdr;
 315                 ret = kfd_parse_subtype_cu(cu);
 316                 break;
 317         case CRAT_SUBTYPE_MEMORY_AFFINITY:
 318                 mem = (struct crat_subtype_memory *)sub_type_hdr;
 319                 ret = kfd_parse_subtype_mem(mem);
 320                 break;
 321         case CRAT_SUBTYPE_CACHE_AFFINITY:
 322                 cache = (struct crat_subtype_cache *)sub_type_hdr;
 323                 ret = kfd_parse_subtype_cache(cache);
 324                 break;
 325         case CRAT_SUBTYPE_TLB_AFFINITY:
 326                 /*
 327                  * For now, nothing to do here
 328                  */
 329                 pr_info("Found TLB entry in CRAT table (not processing)\n");
 330                 break;
 331         case CRAT_SUBTYPE_CCOMPUTE_AFFINITY:
 332                 /*
 333                  * For now, nothing to do here
 334                  */
 335                 pr_info("Found CCOMPUTE entry in CRAT table (not processing)\n");
 336                 break;
 337         case CRAT_SUBTYPE_IOLINK_AFFINITY:
 338                 iolink = (struct crat_subtype_iolink *)sub_type_hdr;
 339                 ret = kfd_parse_subtype_iolink(iolink);
 340                 break;
 341         default:
 342                 pr_warn("Unknown subtype (%d) in CRAT\n",
 343                                 sub_type_hdr->type);
 344         }
 345
 346         return ret;
 347 }
 348
 349 static void kfd_release_topology_device(struct kfd_topology_device *dev)
 350 {
 351         struct kfd_mem_properties *mem;
 352         struct kfd_cache_properties *cache;
 353         struct kfd_iolink_properties *iolink;
 354
 355         list_del(&dev->list);
 356
 357         while (dev->mem_props.next != &dev->mem_props) {
 358                 mem = container_of(dev->mem_props.next,
 359                                 struct kfd_mem_properties, list);
 360                 list_del(&mem->list);
 361                 kfree(mem);
 362         }
 363
 364         while (dev->cache_props.next != &dev->cache_props) {
 365                 cache = container_of(dev->cache_props.next,
 366                                 struct kfd_cache_properties, list);
 367                 list_del(&cache->list);
 368                 kfree(cache);
 369         }
 370
 371         while (dev->io_link_props.next != &dev->io_link_props) {
 372                 iolink = container_of(dev->io_link_props.next,
 373                                 struct kfd_iolink_properties, list);
 374                 list_del(&iolink->list);
 375                 kfree(iolink);
 376         }
 377
 378         kfree(dev);
 379
 380         sys_props.num_devices--;
 381 }
 382
 383 static void kfd_release_live_view(void)
 384 {
 385         struct kfd_topology_device *dev;
 386
 387         while (topology_device_list.next != &topology_device_list) {
 388                 dev = container_of(topology_device_list.next,
 389                                  struct kfd_topology_device, list);
 390                 kfd_release_topology_device(dev);
 391 }
 392
 393         memset(&sys_props, 0, sizeof(sys_props));
 394 }
 395
 396 static struct kfd_topology_device *kfd_create_topology_device(void)
 397 {
 398         struct kfd_topology_device *dev;
 399
 400         dev = kfd_alloc_struct(dev);
 401         if (!dev) {
 402                 pr_err("No memory to allocate a topology device");
 403                 return NULL;
 404         }
 405
 406         INIT_LIST_HEAD(&dev->mem_props);
 407         INIT_LIST_HEAD(&dev->cache_props);
 408         INIT_LIST_HEAD(&dev->io_link_props);
 409
 410         list_add_tail(&dev->list, &topology_device_list);
 411         sys_props.num_devices++;
 412
 413         return dev;
 414 }
 415
 416 static int kfd_parse_crat_table(void *crat_image)
 417 {
 418         struct kfd_topology_device *top_dev;
 419         struct crat_subtype_generic *sub_type_hdr;
 420         uint16_t node_id;
 421         int ret;
 422         struct crat_header *crat_table = (struct crat_header *)crat_image;
 423         uint16_t num_nodes;
 424         uint32_t image_len;
 425
 426         if (!crat_image)
 427                 return -EINVAL;
 428
 429         num_nodes = crat_table->num_domains;
 430         image_len = crat_table->length;
 431
 432         pr_info("Parsing CRAT table with %d nodes\n", num_nodes);
 433
 434         for (node_id = 0; node_id < num_nodes; node_id++) {
 435                 top_dev = kfd_create_topology_device();
 436                 if (!top_dev) {
 437                         kfd_release_live_view();
 438                         return -ENOMEM;
 439                 }
 440         }
 441
 442         sys_props.platform_id =
 443                 (*((uint64_t *)crat_table->oem_id)) & CRAT_OEMID_64BIT_MASK;
 444         sys_props.platform_oem = *((uint64_t *)crat_table->oem_table_id);
 445         sys_props.platform_rev = crat_table->revision;
 446
 447         sub_type_hdr = (struct crat_subtype_generic *)(crat_table+1);
 448         while ((char *)sub_type_hdr + sizeof(struct crat_subtype_generic) <
 449                         ((char *)crat_image) + image_len) {
 450                 if (sub_type_hdr->flags & CRAT_SUBTYPE_FLAGS_ENABLED) {
 451                         ret = kfd_parse_subtype(sub_type_hdr);
 452                         if (ret != 0) {
 453                                 kfd_release_live_view();
 454                                 return ret;
 455                         }
 456                 }
 457
 458                 sub_type_hdr = (typeof(sub_type_hdr))((char *)sub_type_hdr +
 459                                 sub_type_hdr->length);
 460         }
 461
 462         sys_props.generation_count++;
 463         topology_crat_parsed = 1;
 464
 465         return 0;
 466 }
 467
 468
 469 #define sysfs_show_gen_prop(buffer, fmt, ...) \
 470                 snprintf(buffer, PAGE_SIZE, "%s"fmt, buffer, __VA_ARGS__)
 471 #define sysfs_show_32bit_prop(buffer, name, value) \
 472                 sysfs_show_gen_prop(buffer, "%s %u\n", name, value)
 473 #define sysfs_show_64bit_prop(buffer, name, value) \
 474                 sysfs_show_gen_prop(buffer, "%s %llu\n", name, value)
 475 #define sysfs_show_32bit_val(buffer, value) \
 476                 sysfs_show_gen_prop(buffer, "%u\n", value)
 477 #define sysfs_show_str_val(buffer, value) \
 478                 sysfs_show_gen_prop(buffer, "%s\n", value)
 479
 480 static ssize_t sysprops_show(struct kobject *kobj, struct attribute *attr,
 481                 char *buffer)
 482 {
 483         ssize_t ret;
 484
 485         /* Making sure that the buffer is an empty string */
 486         buffer[0] = 0;
 487
 488         if (attr == &sys_props.attr_genid) {
 489                 ret = sysfs_show_32bit_val(buffer, sys_props.generation_count);
 490         } else if (attr == &sys_props.attr_props) {
 491                 sysfs_show_64bit_prop(buffer, "platform_oem",
 492                                 sys_props.platform_oem);
 493                 sysfs_show_64bit_prop(buffer, "platform_id",
 494                                 sys_props.platform_id);
 495                 ret = sysfs_show_64bit_prop(buffer, "platform_rev",
 496                                 sys_props.platform_rev);
 497         } else {
 498                 ret = -EINVAL;
 499         }
 500
 501         return ret;
 502 }
 503
 504 static const struct sysfs_ops sysprops_ops = {
 505         .show = sysprops_show,
 506 };
 507
 508 static struct kobj_type sysprops_type = {
 509         .sysfs_ops = &sysprops_ops,
 510 };
 511
 512 static ssize_t iolink_show(struct kobject *kobj, struct attribute *attr,
 513                 char *buffer)
 514 {
 515         ssize_t ret;
 516         struct kfd_iolink_properties *iolink;
 517
 518         /* Making sure that the buffer is an empty string */
 519         buffer[0] = 0;
 520
 521         iolink = container_of(attr, struct kfd_iolink_properties, attr);
 522         sysfs_show_32bit_prop(buffer, "type", iolink->iolink_type);
 523         sysfs_show_32bit_prop(buffer, "version_major", iolink->ver_maj);
 524         sysfs_show_32bit_prop(buffer, "version_minor", iolink->ver_min);
 525         sysfs_show_32bit_prop(buffer, "node_from", iolink->node_from);
 526         sysfs_show_32bit_prop(buffer, "node_to", iolink->node_to);
 527         sysfs_show_32bit_prop(buffer, "weight", iolink->weight);
 528         sysfs_show_32bit_prop(buffer, "min_latency", iolink->min_latency);
 529         sysfs_show_32bit_prop(buffer, "max_latency", iolink->max_latency);
 530         sysfs_show_32bit_prop(buffer, "min_bandwidth", iolink->min_bandwidth);
 531         sysfs_show_32bit_prop(buffer, "max_bandwidth", iolink->max_bandwidth);
 532         sysfs_show_32bit_prop(buffer, "recommended_transfer_size",
 533                         iolink->rec_transfer_size);
 534         ret = sysfs_show_32bit_prop(buffer, "flags", iolink->flags);
 535
 536         return ret;
 537 }
 538
 539 static const struct sysfs_ops iolink_ops = {
 540         .show = iolink_show,
 541 };
 542
 543 static struct kobj_type iolink_type = {
 544         .sysfs_ops = &iolink_ops,
 545 };
 546
 547 static ssize_t mem_show(struct kobject *kobj, struct attribute *attr,
 548                 char *buffer)
 549 {
 550         ssize_t ret;
 551         struct kfd_mem_properties *mem;
 552
 553         /* Making sure that the buffer is an empty string */
 554         buffer[0] = 0;
 555
 556         mem = container_of(attr, struct kfd_mem_properties, attr);
 557         sysfs_show_32bit_prop(buffer, "heap_type", mem->heap_type);
 558         sysfs_show_64bit_prop(buffer, "size_in_bytes", mem->size_in_bytes);
 559         sysfs_show_32bit_prop(buffer, "flags", mem->flags);
 560         sysfs_show_32bit_prop(buffer, "width", mem->width);
 561         ret = sysfs_show_32bit_prop(buffer, "mem_clk_max", mem->mem_clk_max);
 562
 563         return ret;
 564 }
 565
 566 static const struct sysfs_ops mem_ops = {
 567         .show = mem_show,
 568 };
 569
 570 static struct kobj_type mem_type = {
 571         .sysfs_ops = &mem_ops,
 572 };
 573
 574 static ssize_t kfd_cache_show(struct kobject *kobj, struct attribute *attr,
 575                 char *buffer)
 576 {
 577         ssize_t ret;
 578         uint32_t i;
 579         struct kfd_cache_properties *cache;
 580
 581         /* Making sure that the buffer is an empty string */
 582         buffer[0] = 0;
 583
 584         cache = container_of(attr, struct kfd_cache_properties, attr);
 585         sysfs_show_32bit_prop(buffer, "processor_id_low",
 586                         cache->processor_id_low);
 587         sysfs_show_32bit_prop(buffer, "level", cache->cache_level);
 588         sysfs_show_32bit_prop(buffer, "size", cache->cache_size);
 589         sysfs_show_32bit_prop(buffer, "cache_line_size", cache->cacheline_size);
 590         sysfs_show_32bit_prop(buffer, "cache_lines_per_tag",
 591                         cache->cachelines_per_tag);
 592         sysfs_show_32bit_prop(buffer, "association", cache->cache_assoc);
 593         sysfs_show_32bit_prop(buffer, "latency", cache->cache_latency);
 594         sysfs_show_32bit_prop(buffer, "type", cache->cache_type);
 595         snprintf(buffer, PAGE_SIZE, "%ssibling_map ", buffer);
 596         for (i = 0; i < KFD_TOPOLOGY_CPU_SIBLINGS; i++)
 597                 ret = snprintf(buffer, PAGE_SIZE, "%s%d%s",
 598                                 buffer, cache->sibling_map[i],
 599                                 (i == KFD_TOPOLOGY_CPU_SIBLINGS-1) ?
 600                                                 "\n" : ",");
 601
 602         return ret;
 603 }
 604
 605 static const struct sysfs_ops cache_ops = {
 606         .show = kfd_cache_show,
 607 };
 608
 609 static struct kobj_type cache_type = {
 610         .sysfs_ops = &cache_ops,
 611 };
 612
 613 static ssize_t node_show(struct kobject *kobj, struct attribute *attr,
 614                 char *buffer)
 615 {
 616         struct kfd_topology_device *dev;
 617         char public_name[KFD_TOPOLOGY_PUBLIC_NAME_SIZE];
 618         uint32_t i;
 619         uint32_t log_max_watch_addr;
 620
 621         /* Making sure that the buffer is an empty string */
 622         buffer[0] = 0;
 623
 624         if (strcmp(attr->name, "gpu_id") == 0) {
 625                 dev = container_of(attr, struct kfd_topology_device,
 626                                 attr_gpuid);
 627                 return sysfs_show_32bit_val(buffer, dev->gpu_id);
 628         }
 629
 630         if (strcmp(attr->name, "name") == 0) {
 631                 dev = container_of(attr, struct kfd_topology_device,
 632                                 attr_name);
 633                 for (i = 0; i < KFD_TOPOLOGY_PUBLIC_NAME_SIZE; i++) {
 634                         public_name[i] =
 635                                         (char)dev->node_props.marketing_name[i];
 636                         if (dev->node_props.marketing_name[i] == 0)
 637                                 break;
 638                 }
 639                 public_name[KFD_TOPOLOGY_PUBLIC_NAME_SIZE-1] = 0x0;
 640                 return sysfs_show_str_val(buffer, public_name);
 641         }
 642
 643         dev = container_of(attr, struct kfd_topology_device,
 644                         attr_props);
 645         sysfs_show_32bit_prop(buffer, "cpu_cores_count",
 646                         dev->node_props.cpu_cores_count);
 647         sysfs_show_32bit_prop(buffer, "simd_count",
 648                         dev->node_props.simd_count);
 649
 650         if (dev->mem_bank_count < dev->node_props.mem_banks_count) {
 651                 pr_info_once("mem_banks_count truncated from %d to %d\n",
 652                                 dev->node_props.mem_banks_count,
 653                                 dev->mem_bank_count);
 654                 sysfs_show_32bit_prop(buffer, "mem_banks_count",
 655                                 dev->mem_bank_count);
 656         } else {
 657                 sysfs_show_32bit_prop(buffer, "mem_banks_count",
 658                                 dev->node_props.mem_banks_count);
 659         }
 660
 661         sysfs_show_32bit_prop(buffer, "caches_count",
 662                         dev->node_props.caches_count);
 663         sysfs_show_32bit_prop(buffer, "io_links_count",
 664                         dev->node_props.io_links_count);
 665         sysfs_show_32bit_prop(buffer, "cpu_core_id_base",
 666                         dev->node_props.cpu_core_id_base);
 667         sysfs_show_32bit_prop(buffer, "simd_id_base",
 668                         dev->node_props.simd_id_base);
 669         sysfs_show_32bit_prop(buffer, "max_waves_per_simd",
 670                         dev->node_props.max_waves_per_simd);
 671         sysfs_show_32bit_prop(buffer, "lds_size_in_kb",
 672                         dev->node_props.lds_size_in_kb);
 673         sysfs_show_32bit_prop(buffer, "gds_size_in_kb",
 674                         dev->node_props.gds_size_in_kb);
 675         sysfs_show_32bit_prop(buffer, "wave_front_size",
 676                         dev->node_props.wave_front_size);
 677         sysfs_show_32bit_prop(buffer, "array_count",
 678                         dev->node_props.array_count);
 679         sysfs_show_32bit_prop(buffer, "simd_arrays_per_engine",
 680                         dev->node_props.simd_arrays_per_engine);
 681         sysfs_show_32bit_prop(buffer, "cu_per_simd_array",
 682                         dev->node_props.cu_per_simd_array);
 683         sysfs_show_32bit_prop(buffer, "simd_per_cu",
 684                         dev->node_props.simd_per_cu);
 685         sysfs_show_32bit_prop(buffer, "max_slots_scratch_cu",
 686                         dev->node_props.max_slots_scratch_cu);
 687         sysfs_show_32bit_prop(buffer, "vendor_id",
 688                         dev->node_props.vendor_id);
 689         sysfs_show_32bit_prop(buffer, "device_id",
 690                         dev->node_props.device_id);
 691         sysfs_show_32bit_prop(buffer, "location_id",
 692                         dev->node_props.location_id);
 693
 694         if (dev->gpu) {
 695                 log_max_watch_addr =
 696                         __ilog2_u32(dev->gpu->device_info->num_of_watch_points);
 697
 698                 if (log_max_watch_addr) {
 699                         dev->node_props.capability |=
 700                                         HSA_CAP_WATCH_POINTS_SUPPORTED;
 701
 702                         dev->node_props.capability |=
 703                                 ((log_max_watch_addr <<
 704                                         HSA_CAP_WATCH_POINTS_TOTALBITS_SHIFT) &
 705                                 HSA_CAP_WATCH_POINTS_TOTALBITS_MASK);
 706                 }
 707
 708                 sysfs_show_32bit_prop(buffer, "max_engine_clk_fcompute",
 709                         dev->gpu->kfd2kgd->get_max_engine_clock_in_mhz(
 710                                         dev->gpu->kgd));
 711
 712                 sysfs_show_64bit_prop(buffer, "local_mem_size",
 713                                 (unsigned long long int) 0);
 714
 715                 sysfs_show_32bit_prop(buffer, "fw_version",
 716                         dev->gpu->kfd2kgd->get_fw_version(
 717                                                 dev->gpu->kgd,
 718                                                 KGD_ENGINE_MEC1));
 719                 sysfs_show_32bit_prop(buffer, "capability",
 720                                 dev->node_props.capability);
 721         }
 722
 723         return sysfs_show_32bit_prop(buffer, "max_engine_clk_ccompute",
 724                                         cpufreq_quick_get_max(0)/1000);
 725 }
 726
 727 static const struct sysfs_ops node_ops = {
 728         .show = node_show,
 729 };
 730
 731 static struct kobj_type node_type = {
 732         .sysfs_ops = &node_ops,
 733 };
 734
 735 static void kfd_remove_sysfs_file(struct kobject *kobj, struct attribute *attr)
 736 {
 737         sysfs_remove_file(kobj, attr);
 738         kobject_del(kobj);
 739         kobject_put(kobj);
 740 }
 741
 742 static void kfd_remove_sysfs_node_entry(struct kfd_topology_device *dev)
 743 {
 744         struct kfd_iolink_properties *iolink;
 745         struct kfd_cache_properties *cache;
 746         struct kfd_mem_properties *mem;
 747
 748         if (dev->kobj_iolink) {
 749                 list_for_each_entry(iolink, &dev->io_link_props, list)
 750                         if (iolink->kobj) {
 751                                 kfd_remove_sysfs_file(iolink->kobj,
 752                                                         &iolink->attr);
 753                                 iolink->kobj = NULL;
 754                         }
 755                 kobject_del(dev->kobj_iolink);
 756                 kobject_put(dev->kobj_iolink);
 757                 dev->kobj_iolink = NULL;
 758         }
 759
 760         if (dev->kobj_cache) {
 761                 list_for_each_entry(cache, &dev->cache_props, list)
 762                         if (cache->kobj) {
 763                                 kfd_remove_sysfs_file(cache->kobj,
 764                                                         &cache->attr);
 765                                 cache->kobj = NULL;
 766                         }
 767                 kobject_del(dev->kobj_cache);
 768                 kobject_put(dev->kobj_cache);
 769                 dev->kobj_cache = NULL;
 770         }
 771
 772         if (dev->kobj_mem) {
 773                 list_for_each_entry(mem, &dev->mem_props, list)
 774                         if (mem->kobj) {
 775                                 kfd_remove_sysfs_file(mem->kobj, &mem->attr);
 776                                 mem->kobj = NULL;
 777                         }
 778                 kobject_del(dev->kobj_mem);
 779                 kobject_put(dev->kobj_mem);
 780                 dev->kobj_mem = NULL;
 781         }
 782
 783         if (dev->kobj_node) {
 784                 sysfs_remove_file(dev->kobj_node, &dev->attr_gpuid);
 785                 sysfs_remove_file(dev->kobj_node, &dev->attr_name);
 786                 sysfs_remove_file(dev->kobj_node, &dev->attr_props);
 787                 kobject_del(dev->kobj_node);
 788                 kobject_put(dev->kobj_node);
 789                 dev->kobj_node = NULL;
 790         }
 791 }
 792
 793 static int kfd_build_sysfs_node_entry(struct kfd_topology_device *dev,
 794                 uint32_t id)
 795 {
 796         struct kfd_iolink_properties *iolink;
 797         struct kfd_cache_properties *cache;
 798         struct kfd_mem_properties *mem;
 799         int ret;
 800         uint32_t i;
 801
 802         if (WARN_ON(dev->kobj_node))
 803                 return -EEXIST;
 804
 805         /*
 806          * Creating the sysfs folders
 807          */
 808         dev->kobj_node = kfd_alloc_struct(dev->kobj_node);
 809         if (!dev->kobj_node)
 810                 return -ENOMEM;
 811
 812         ret = kobject_init_and_add(dev->kobj_node, &node_type,
 813                         sys_props.kobj_nodes, "%d", id);
 814         if (ret < 0)
 815                 return ret;
 816
 817         dev->kobj_mem = kobject_create_and_add("mem_banks", dev->kobj_node);
 818         if (!dev->kobj_mem)
 819                 return -ENOMEM;
 820
 821         dev->kobj_cache = kobject_create_and_add("caches", dev->kobj_node);
 822         if (!dev->kobj_cache)
 823                 return -ENOMEM;
 824
 825         dev->kobj_iolink = kobject_create_and_add("io_links", dev->kobj_node);
 826         if (!dev->kobj_iolink)
 827                 return -ENOMEM;
 828
 829         /*
 830          * Creating sysfs files for node properties
 831          */
 832         dev->attr_gpuid.name = "gpu_id";
 833         dev->attr_gpuid.mode = KFD_SYSFS_FILE_MODE;
 834         sysfs_attr_init(&dev->attr_gpuid);
 835         dev->attr_name.name = "name";
 836         dev->attr_name.mode = KFD_SYSFS_FILE_MODE;
 837         sysfs_attr_init(&dev->attr_name);
 838         dev->attr_props.name = "properties";
 839         dev->attr_props.mode = KFD_SYSFS_FILE_MODE;
 840         sysfs_attr_init(&dev->attr_props);
 841         ret = sysfs_create_file(dev->kobj_node, &dev->attr_gpuid);
 842         if (ret < 0)
 843                 return ret;
 844         ret = sysfs_create_file(dev->kobj_node, &dev->attr_name);
 845         if (ret < 0)
 846                 return ret;
 847         ret = sysfs_create_file(dev->kobj_node, &dev->attr_props);
 848         if (ret < 0)
 849                 return ret;
 850
 851         i = 0;
 852         list_for_each_entry(mem, &dev->mem_props, list) {
 853                 mem->kobj = kzalloc(sizeof(struct kobject), GFP_KERNEL);
 854                 if (!mem->kobj)
 855                         return -ENOMEM;
 856                 ret = kobject_init_and_add(mem->kobj, &mem_type,
 857                                 dev->kobj_mem, "%d", i);
 858                 if (ret < 0)
 859                         return ret;
 860
 861                 mem->attr.name = "properties";
 862                 mem->attr.mode = KFD_SYSFS_FILE_MODE;
 863                 sysfs_attr_init(&mem->attr);
 864                 ret = sysfs_create_file(mem->kobj, &mem->attr);
 865                 if (ret < 0)
 866                         return ret;
 867                 i++;
 868         }
 869
 870         i = 0;
 871         list_for_each_entry(cache, &dev->cache_props, list) {
 872                 cache->kobj = kzalloc(sizeof(struct kobject), GFP_KERNEL);
 873                 if (!cache->kobj)
 874                         return -ENOMEM;
 875                 ret = kobject_init_and_add(cache->kobj, &cache_type,
 876                                 dev->kobj_cache, "%d", i);
 877                 if (ret < 0)
 878                         return ret;
 879
 880                 cache->attr.name = "properties";
 881                 cache->attr.mode = KFD_SYSFS_FILE_MODE;
 882                 sysfs_attr_init(&cache->attr);
 883                 ret = sysfs_create_file(cache->kobj, &cache->attr);
 884                 if (ret < 0)
 885                         return ret;
 886                 i++;
 887         }
 888
 889         i = 0;
 890         list_for_each_entry(iolink, &dev->io_link_props, list) {
 891                 iolink->kobj = kzalloc(sizeof(struct kobject), GFP_KERNEL);
 892                 if (!iolink->kobj)
 893                         return -ENOMEM;
 894                 ret = kobject_init_and_add(iolink->kobj, &iolink_type,
 895                                 dev->kobj_iolink, "%d", i);
 896                 if (ret < 0)
 897                         return ret;
 898
 899                 iolink->attr.name = "properties";
 900                 iolink->attr.mode = KFD_SYSFS_FILE_MODE;
 901                 sysfs_attr_init(&iolink->attr);
 902                 ret = sysfs_create_file(iolink->kobj, &iolink->attr);
 903                 if (ret < 0)
 904                         return ret;
 905                 i++;
 906 }
 907
 908         return 0;
 909 }
 910
 911 static int kfd_build_sysfs_node_tree(void)
 912 {
 913         struct kfd_topology_device *dev;
 914         int ret;
 915         uint32_t i = 0;
 916
 917         list_for_each_entry(dev, &topology_device_list, list) {
 918                 ret = kfd_build_sysfs_node_entry(dev, i);
 919                 if (ret < 0)
 920                         return ret;
 921                 i++;
 922         }
 923
 924         return 0;
 925 }
 926
 927 static void kfd_remove_sysfs_node_tree(void)
 928 {
 929         struct kfd_topology_device *dev;
 930
 931         list_for_each_entry(dev, &topology_device_list, list)
 932                 kfd_remove_sysfs_node_entry(dev);
 933 }
 934
 935 static int kfd_topology_update_sysfs(void)
 936 {
 937         int ret;
 938
 939         pr_info("Creating topology SYSFS entries\n");
 940         if (!sys_props.kobj_topology) {
 941                 sys_props.kobj_topology =
 942                                 kfd_alloc_struct(sys_props.kobj_topology);
 943                 if (!sys_props.kobj_topology)
 944                         return -ENOMEM;
 945
 946                 ret = kobject_init_and_add(sys_props.kobj_topology,
 947                                 &sysprops_type,  &kfd_device->kobj,
 948                                 "topology");
 949                 if (ret < 0)
 950                         return ret;
 951
 952                 sys_props.kobj_nodes = kobject_create_and_add("nodes",
 953                                 sys_props.kobj_topology);
 954                 if (!sys_props.kobj_nodes)
 955                         return -ENOMEM;
 956
 957                 sys_props.attr_genid.name = "generation_id";
 958                 sys_props.attr_genid.mode = KFD_SYSFS_FILE_MODE;
 959                 sysfs_attr_init(&sys_props.attr_genid);
 960                 ret = sysfs_create_file(sys_props.kobj_topology,
 961                                 &sys_props.attr_genid);
 962                 if (ret < 0)
 963                         return ret;
 964
 965                 sys_props.attr_props.name = "system_properties";
 966                 sys_props.attr_props.mode = KFD_SYSFS_FILE_MODE;
 967                 sysfs_attr_init(&sys_props.attr_props);
 968                 ret = sysfs_create_file(sys_props.kobj_topology,
 969                                 &sys_props.attr_props);
 970                 if (ret < 0)
 971                         return ret;
 972         }
 973
 974         kfd_remove_sysfs_node_tree();
 975
 976         return kfd_build_sysfs_node_tree();
 977 }
 978
 979 static void kfd_topology_release_sysfs(void)
 980 {
 981         kfd_remove_sysfs_node_tree();
 982         if (sys_props.kobj_topology) {
 983                 sysfs_remove_file(sys_props.kobj_topology,
 984                                 &sys_props.attr_genid);
 985                 sysfs_remove_file(sys_props.kobj_topology,
 986                                 &sys_props.attr_props);
 987                 if (sys_props.kobj_nodes) {
 988                         kobject_del(sys_props.kobj_nodes);
 989                         kobject_put(sys_props.kobj_nodes);
 990                         sys_props.kobj_nodes = NULL;
 991                 }
 992                 kobject_del(sys_props.kobj_topology);
 993                 kobject_put(sys_props.kobj_topology);
 994                 sys_props.kobj_topology = NULL;
 995         }
 996 }
 997
 998 int kfd_topology_init(void)
 999 {
1000         void *crat_image = NULL;
1001         size_t image_size = 0;
1002         int ret;
1003
1004         /*
1005          * Initialize the head for the topology device list
1006          */
1007         INIT_LIST_HEAD(&topology_device_list);
1008         init_rwsem(&topology_lock);
1009         topology_crat_parsed = 0;
1010
1011         memset(&sys_props, 0, sizeof(sys_props));
1012
1013         /*
1014          * Get the CRAT image from the ACPI
1015          */
1016         ret = kfd_topology_get_crat_acpi(crat_image, &image_size);
1017         if (ret == 0 && image_size > 0) {
1018                 pr_info("Found CRAT image with size=%zd\n", image_size);
1019                 crat_image = kmalloc(image_size, GFP_KERNEL);
1020                 if (!crat_image) {
1021                         ret = -ENOMEM;
1022                         pr_err("No memory for allocating CRAT image\n");
1023                         goto err;
1024                 }
1025                 ret = kfd_topology_get_crat_acpi(crat_image, &image_size);
1026
1027                 if (ret == 0) {
1028                         down_write(&topology_lock);
1029                         ret = kfd_parse_crat_table(crat_image);
1030                         if (ret == 0)
1031                                 ret = kfd_topology_update_sysfs();
1032                         up_write(&topology_lock);
1033                 } else {
1034                         pr_err("Couldn't get CRAT table size from ACPI\n");
1035                 }
1036                 kfree(crat_image);
1037         } else if (ret == -ENODATA) {
1038                 ret = 0;
1039         } else {
1040                 pr_err("Couldn't get CRAT table size from ACPI\n");
1041         }
1042
1043 err:
1044         pr_info("Finished initializing topology ret=%d\n", ret);
1045         return ret;
1046 }
1047
1048 void kfd_topology_shutdown(void)
1049 {
1050         kfd_topology_release_sysfs();
1051         kfd_release_live_view();
1052 }
1053
1054 static void kfd_debug_print_topology(void)
1055 {
1056         struct kfd_topology_device *dev;
1057         uint32_t i = 0;
1058
1059         pr_info("DEBUG PRINT OF TOPOLOGY:");
1060         list_for_each_entry(dev, &topology_device_list, list) {
1061                 pr_info("Node: %d\n", i);
1062                 pr_info("\tGPU assigned: %s\n", (dev->gpu ? "yes" : "no"));
1063                 pr_info("\tCPU count: %d\n", dev->node_props.cpu_cores_count);
1064                 pr_info("\tSIMD count: %d", dev->node_props.simd_count);
1065                 i++;
1066         }
1067 }
1068
1069 static uint32_t kfd_generate_gpu_id(struct kfd_dev *gpu)
1070 {
1071         uint32_t hashout;
1072         uint32_t buf[7];
1073         uint64_t local_mem_size;
1074         int i;
1075
1076         if (!gpu)
1077                 return 0;
1078
1079         local_mem_size = gpu->kfd2kgd->get_vmem_size(gpu->kgd);
1080
1081         buf[0] = gpu->pdev->devfn;
1082         buf[1] = gpu->pdev->subsystem_vendor;
1083         buf[2] = gpu->pdev->subsystem_device;
1084         buf[3] = gpu->pdev->device;
1085         buf[4] = gpu->pdev->bus->number;
1086         buf[5] = lower_32_bits(local_mem_size);
1087         buf[6] = upper_32_bits(local_mem_size);
1088
1089         for (i = 0, hashout = 0; i < 7; i++)
1090                 hashout ^= hash_32(buf[i], KFD_GPU_ID_HASH_WIDTH);
1091
1092         return hashout;
1093 }
1094
1095 static struct kfd_topology_device *kfd_assign_gpu(struct kfd_dev *gpu)
1096 {
1097         struct kfd_topology_device *dev;
1098         struct kfd_topology_device *out_dev = NULL;
1099
1100         list_for_each_entry(dev, &topology_device_list, list)
1101                 if (!dev->gpu && (dev->node_props.simd_count > 0)) {
1102                         dev->gpu = gpu;
1103                         out_dev = dev;
1104                         break;
1105                 }
1106
1107         return out_dev;
1108 }
1109
1110 static void kfd_notify_gpu_change(uint32_t gpu_id, int arrival)
1111 {
1112         /*
1113          * TODO: Generate an event for thunk about the arrival/removal
1114          * of the GPU
1115          */
1116 }
1117
1118 int kfd_topology_add_device(struct kfd_dev *gpu)
1119 {
1120         uint32_t gpu_id;
1121         struct kfd_topology_device *dev;
1122         int res;
1123
1124         gpu_id = kfd_generate_gpu_id(gpu);
1125
1126         pr_debug("Adding new GPU (ID: 0x%x) to topology\n", gpu_id);
1127
1128         down_write(&topology_lock);
1129         /*
1130          * Try to assign the GPU to existing topology device (generated from
1131          * CRAT table
1132          */
1133         dev = kfd_assign_gpu(gpu);
1134         if (!dev) {
1135                 pr_info("GPU was not found in the current topology. Extending.\n");
1136                 kfd_debug_print_topology();
1137                 dev = kfd_create_topology_device();
1138                 if (!dev) {
1139                         res = -ENOMEM;
1140                         goto err;
1141                 }
1142                 dev->gpu = gpu;
1143
1144                 /*
1145                  * TODO: Make a call to retrieve topology information from the
1146                  * GPU vBIOS
1147                  */
1148
1149                 /* Update the SYSFS tree, since we added another topology
1150                  * device
1151                  */
1152                 if (kfd_topology_update_sysfs() < 0)
1153                         kfd_topology_release_sysfs();
1154
1155         }
1156
1157         dev->gpu_id = gpu_id;
1158         gpu->id = gpu_id;
1159         dev->node_props.vendor_id = gpu->pdev->vendor;
1160         dev->node_props.device_id = gpu->pdev->device;
1161         dev->node_props.location_id = (gpu->pdev->bus->number << 24) +
1162                         (gpu->pdev->devfn & 0xffffff);
1163         /*
1164          * TODO: Retrieve max engine clock values from KGD
1165          */
1166
1167         if (dev->gpu->device_info->asic_family == CHIP_CARRIZO) {
1168                 dev->node_props.capability |= HSA_CAP_DOORBELL_PACKET_TYPE;
1169                 pr_info("Adding doorbell packet type capability\n");
1170         }
1171
1172         res = 0;
1173
1174 err:
1175         up_write(&topology_lock);
1176
1177         if (res == 0)
1178                 kfd_notify_gpu_change(gpu_id, 1);
1179
1180         return res;
1181 }
1182
1183 int kfd_topology_remove_device(struct kfd_dev *gpu)
1184 {
1185         struct kfd_topology_device *dev;
1186         uint32_t gpu_id;
1187         int res = -ENODEV;
1188
1189         down_write(&topology_lock);
1190
1191         list_for_each_entry(dev, &topology_device_list, list)
1192                 if (dev->gpu == gpu) {
1193                         gpu_id = dev->gpu_id;
1194                         kfd_remove_sysfs_node_entry(dev);
1195                         kfd_release_topology_device(dev);
1196                         res = 0;
1197                         if (kfd_topology_update_sysfs() < 0)
1198                                 kfd_topology_release_sysfs();
1199                         break;
1200                 }
1201
1202         up_write(&topology_lock);
1203
1204         if (res == 0)
1205                 kfd_notify_gpu_change(gpu_id, 0);
1206
1207         return res;
1208 }
1209
1210 /*
1211  * When idx is out of bounds, the function will return NULL
1212  */
1213 struct kfd_dev *kfd_topology_enum_kfd_devices(uint8_t idx)
1214 {
1215
1216         struct kfd_topology_device *top_dev;
1217         struct kfd_dev *device = NULL;
1218         uint8_t device_idx = 0;
1219
1220         down_read(&topology_lock);
1221
1222         list_for_each_entry(top_dev, &topology_device_list, list) {
1223                 if (device_idx == idx) {
1224                         device = top_dev->gpu;
1225                         break;
1226                 }
1227
1228                 device_idx++;
1229         }
1230
1231         up_read(&topology_lock);
1232
1233         return device;
1234
1235 }