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         BUG_ON(!dev);
 112         BUG_ON(!cu);
 113
 114         dev->node_props.cpu_cores_count = cu->num_cpu_cores;
 115         dev->node_props.cpu_core_id_base = cu->processor_id_low;
 116         if (cu->hsa_capability & CRAT_CU_FLAGS_IOMMU_PRESENT)
 117                 dev->node_props.capability |= HSA_CAP_ATS_PRESENT;
 118
 119         pr_info("CU CPU: cores=%d id_base=%d\n", cu->num_cpu_cores,
 120                         cu->processor_id_low);
 121 }
 122
 123 static void kfd_populated_cu_info_gpu(struct kfd_topology_device *dev,
 124                 struct crat_subtype_computeunit *cu)
 125 {
 126         BUG_ON(!dev);
 127         BUG_ON(!cu);
 128
 129         dev->node_props.simd_id_base = cu->processor_id_low;
 130         dev->node_props.simd_count = cu->num_simd_cores;
 131         dev->node_props.lds_size_in_kb = cu->lds_size_in_kb;
 132         dev->node_props.max_waves_per_simd = cu->max_waves_simd;
 133         dev->node_props.wave_front_size = cu->wave_front_size;
 134         dev->node_props.mem_banks_count = cu->num_banks;
 135         dev->node_props.array_count = cu->num_arrays;
 136         dev->node_props.cu_per_simd_array = cu->num_cu_per_array;
 137         dev->node_props.simd_per_cu = cu->num_simd_per_cu;
 138         dev->node_props.max_slots_scratch_cu = cu->max_slots_scatch_cu;
 139         if (cu->hsa_capability & CRAT_CU_FLAGS_HOT_PLUGGABLE)
 140                 dev->node_props.capability |= HSA_CAP_HOT_PLUGGABLE;
 141         pr_info("CU GPU: simds=%d id_base=%d\n", cu->num_simd_cores,
 142                                 cu->processor_id_low);
 143 }
 144
 145 /* kfd_parse_subtype_cu is called when the topology mutex is already acquired */
 146 static int kfd_parse_subtype_cu(struct crat_subtype_computeunit *cu)
 147 {
 148         struct kfd_topology_device *dev;
 149         int i = 0;
 150
 151         BUG_ON(!cu);
 152
 153         pr_info("Found CU entry in CRAT table with proximity_domain=%d caps=%x\n",
 154                         cu->proximity_domain, cu->hsa_capability);
 155         list_for_each_entry(dev, &topology_device_list, list) {
 156                 if (cu->proximity_domain == i) {
 157                         if (cu->flags & CRAT_CU_FLAGS_CPU_PRESENT)
 158                                 kfd_populated_cu_info_cpu(dev, cu);
 159
 160                         if (cu->flags & CRAT_CU_FLAGS_GPU_PRESENT)
 161                                 kfd_populated_cu_info_gpu(dev, cu);
 162                         break;
 163                 }
 164                 i++;
 165         }
 166
 167         return 0;
 168 }
 169
 170 /*
 171  * kfd_parse_subtype_mem is called when the topology mutex is
 172  * already acquired
 173  */
 174 static int kfd_parse_subtype_mem(struct crat_subtype_memory *mem)
 175 {
 176         struct kfd_mem_properties *props;
 177         struct kfd_topology_device *dev;
 178         int i = 0;
 179
 180         BUG_ON(!mem);
 181
 182         pr_info("Found memory entry in CRAT table with proximity_domain=%d\n",
 183                         mem->promixity_domain);
 184         list_for_each_entry(dev, &topology_device_list, list) {
 185                 if (mem->promixity_domain == i) {
 186                         props = kfd_alloc_struct(props);
 187                         if (props == NULL)
 188                                 return -ENOMEM;
 189
 190                         if (dev->node_props.cpu_cores_count == 0)
 191                                 props->heap_type = HSA_MEM_HEAP_TYPE_FB_PRIVATE;
 192                         else
 193                                 props->heap_type = HSA_MEM_HEAP_TYPE_SYSTEM;
 194
 195                         if (mem->flags & CRAT_MEM_FLAGS_HOT_PLUGGABLE)
 196                                 props->flags |= HSA_MEM_FLAGS_HOT_PLUGGABLE;
 197                         if (mem->flags & CRAT_MEM_FLAGS_NON_VOLATILE)
 198                                 props->flags |= HSA_MEM_FLAGS_NON_VOLATILE;
 199
 200                         props->size_in_bytes =
 201                                 ((uint64_t)mem->length_high << 32) +
 202                                                         mem->length_low;
 203                         props->width = mem->width;
 204
 205                         dev->mem_bank_count++;
 206                         list_add_tail(&props->list, &dev->mem_props);
 207
 208                         break;
 209                 }
 210                 i++;
 211         }
 212
 213         return 0;
 214 }
 215
 216 /*
 217  * kfd_parse_subtype_cache is called when the topology mutex
 218  * is already acquired
 219  */
 220 static int kfd_parse_subtype_cache(struct crat_subtype_cache *cache)
 221 {
 222         struct kfd_cache_properties *props;
 223         struct kfd_topology_device *dev;
 224         uint32_t id;
 225
 226         BUG_ON(!cache);
 227
 228         id = cache->processor_id_low;
 229
 230         pr_info("Found cache entry in CRAT table with processor_id=%d\n", id);
 231         list_for_each_entry(dev, &topology_device_list, list)
 232                 if (id == dev->node_props.cpu_core_id_base ||
 233                     id == dev->node_props.simd_id_base) {
 234                         props = kfd_alloc_struct(props);
 235                         if (props == NULL)
 236                                 return -ENOMEM;
 237
 238                         props->processor_id_low = id;
 239                         props->cache_level = cache->cache_level;
 240                         props->cache_size = cache->cache_size;
 241                         props->cacheline_size = cache->cache_line_size;
 242                         props->cachelines_per_tag = cache->lines_per_tag;
 243                         props->cache_assoc = cache->associativity;
 244                         props->cache_latency = cache->cache_latency;
 245
 246                         if (cache->flags & CRAT_CACHE_FLAGS_DATA_CACHE)
 247                                 props->cache_type |= HSA_CACHE_TYPE_DATA;
 248                         if (cache->flags & CRAT_CACHE_FLAGS_INST_CACHE)
 249                                 props->cache_type |= HSA_CACHE_TYPE_INSTRUCTION;
 250                         if (cache->flags & CRAT_CACHE_FLAGS_CPU_CACHE)
 251                                 props->cache_type |= HSA_CACHE_TYPE_CPU;
 252                         if (cache->flags & CRAT_CACHE_FLAGS_SIMD_CACHE)
 253                                 props->cache_type |= HSA_CACHE_TYPE_HSACU;
 254
 255                         dev->cache_count++;
 256                         dev->node_props.caches_count++;
 257                         list_add_tail(&props->list, &dev->cache_props);
 258
 259                         break;
 260                 }
 261
 262         return 0;
 263 }
 264
 265 /*
 266  * kfd_parse_subtype_iolink is called when the topology mutex
 267  * is already acquired
 268  */
 269 static int kfd_parse_subtype_iolink(struct crat_subtype_iolink *iolink)
 270 {
 271         struct kfd_iolink_properties *props;
 272         struct kfd_topology_device *dev;
 273         uint32_t i = 0;
 274         uint32_t id_from;
 275         uint32_t id_to;
 276
 277         BUG_ON(!iolink);
 278
 279         id_from = iolink->proximity_domain_from;
 280         id_to = iolink->proximity_domain_to;
 281
 282         pr_info("Found IO link entry in CRAT table with id_from=%d\n", id_from);
 283         list_for_each_entry(dev, &topology_device_list, list) {
 284                 if (id_from == i) {
 285                         props = kfd_alloc_struct(props);
 286                         if (props == NULL)
 287                                 return -ENOMEM;
 288
 289                         props->node_from = id_from;
 290                         props->node_to = id_to;
 291                         props->ver_maj = iolink->version_major;
 292                         props->ver_min = iolink->version_minor;
 293
 294                         /*
 295                          * weight factor (derived from CDIR), currently always 1
 296                          */
 297                         props->weight = 1;
 298
 299                         props->min_latency = iolink->minimum_latency;
 300                         props->max_latency = iolink->maximum_latency;
 301                         props->min_bandwidth = iolink->minimum_bandwidth_mbs;
 302                         props->max_bandwidth = iolink->maximum_bandwidth_mbs;
 303                         props->rec_transfer_size =
 304                                         iolink->recommended_transfer_size;
 305
 306                         dev->io_link_count++;
 307                         dev->node_props.io_links_count++;
 308                         list_add_tail(&props->list, &dev->io_link_props);
 309
 310                         break;
 311                 }
 312                 i++;
 313         }
 314
 315         return 0;
 316 }
 317
 318 static int kfd_parse_subtype(struct crat_subtype_generic *sub_type_hdr)
 319 {
 320         struct crat_subtype_computeunit *cu;
 321         struct crat_subtype_memory *mem;
 322         struct crat_subtype_cache *cache;
 323         struct crat_subtype_iolink *iolink;
 324         int ret = 0;
 325
 326         BUG_ON(!sub_type_hdr);
 327
 328         switch (sub_type_hdr->type) {
 329         case CRAT_SUBTYPE_COMPUTEUNIT_AFFINITY:
 330                 cu = (struct crat_subtype_computeunit *)sub_type_hdr;
 331                 ret = kfd_parse_subtype_cu(cu);
 332                 break;
 333         case CRAT_SUBTYPE_MEMORY_AFFINITY:
 334                 mem = (struct crat_subtype_memory *)sub_type_hdr;
 335                 ret = kfd_parse_subtype_mem(mem);
 336                 break;
 337         case CRAT_SUBTYPE_CACHE_AFFINITY:
 338                 cache = (struct crat_subtype_cache *)sub_type_hdr;
 339                 ret = kfd_parse_subtype_cache(cache);
 340                 break;
 341         case CRAT_SUBTYPE_TLB_AFFINITY:
 342                 /*
 343                  * For now, nothing to do here
 344                  */
 345                 pr_info("Found TLB entry in CRAT table (not processing)\n");
 346                 break;
 347         case CRAT_SUBTYPE_CCOMPUTE_AFFINITY:
 348                 /*
 349                  * For now, nothing to do here
 350                  */
 351                 pr_info("Found CCOMPUTE entry in CRAT table (not processing)\n");
 352                 break;
 353         case CRAT_SUBTYPE_IOLINK_AFFINITY:
 354                 iolink = (struct crat_subtype_iolink *)sub_type_hdr;
 355                 ret = kfd_parse_subtype_iolink(iolink);
 356                 break;
 357         default:
 358                 pr_warn("Unknown subtype (%d) in CRAT\n",
 359                                 sub_type_hdr->type);
 360         }
 361
 362         return ret;
 363 }
 364
 365 static void kfd_release_topology_device(struct kfd_topology_device *dev)
 366 {
 367         struct kfd_mem_properties *mem;
 368         struct kfd_cache_properties *cache;
 369         struct kfd_iolink_properties *iolink;
 370
 371         BUG_ON(!dev);
 372
 373         list_del(&dev->list);
 374
 375         while (dev->mem_props.next != &dev->mem_props) {
 376                 mem = container_of(dev->mem_props.next,
 377                                 struct kfd_mem_properties, list);
 378                 list_del(&mem->list);
 379                 kfree(mem);
 380         }
 381
 382         while (dev->cache_props.next != &dev->cache_props) {
 383                 cache = container_of(dev->cache_props.next,
 384                                 struct kfd_cache_properties, list);
 385                 list_del(&cache->list);
 386                 kfree(cache);
 387         }
 388
 389         while (dev->io_link_props.next != &dev->io_link_props) {
 390                 iolink = container_of(dev->io_link_props.next,
 391                                 struct kfd_iolink_properties, list);
 392                 list_del(&iolink->list);
 393                 kfree(iolink);
 394         }
 395
 396         kfree(dev);
 397
 398         sys_props.num_devices--;
 399 }
 400
 401 static void kfd_release_live_view(void)
 402 {
 403         struct kfd_topology_device *dev;
 404
 405         while (topology_device_list.next != &topology_device_list) {
 406                 dev = container_of(topology_device_list.next,
 407                                  struct kfd_topology_device, list);
 408                 kfd_release_topology_device(dev);
 409 }
 410
 411         memset(&sys_props, 0, sizeof(sys_props));
 412 }
 413
 414 static struct kfd_topology_device *kfd_create_topology_device(void)
 415 {
 416         struct kfd_topology_device *dev;
 417
 418         dev = kfd_alloc_struct(dev);
 419         if (dev == NULL) {
 420                 pr_err("No memory to allocate a topology device");
 421                 return NULL;
 422         }
 423
 424         INIT_LIST_HEAD(&dev->mem_props);
 425         INIT_LIST_HEAD(&dev->cache_props);
 426         INIT_LIST_HEAD(&dev->io_link_props);
 427
 428         list_add_tail(&dev->list, &topology_device_list);
 429         sys_props.num_devices++;
 430
 431         return dev;
 432 }
 433
 434 static int kfd_parse_crat_table(void *crat_image)
 435 {
 436         struct kfd_topology_device *top_dev;
 437         struct crat_subtype_generic *sub_type_hdr;
 438         uint16_t node_id;
 439         int ret;
 440         struct crat_header *crat_table = (struct crat_header *)crat_image;
 441         uint16_t num_nodes;
 442         uint32_t image_len;
 443
 444         if (!crat_image)
 445                 return -EINVAL;
 446
 447         num_nodes = crat_table->num_domains;
 448         image_len = crat_table->length;
 449
 450         pr_info("Parsing CRAT table with %d nodes\n", num_nodes);
 451
 452         for (node_id = 0; node_id < num_nodes; node_id++) {
 453                 top_dev = kfd_create_topology_device();
 454                 if (!top_dev) {
 455                         kfd_release_live_view();
 456                         return -ENOMEM;
 457                 }
 458         }
 459
 460         sys_props.platform_id =
 461                 (*((uint64_t *)crat_table->oem_id)) & CRAT_OEMID_64BIT_MASK;
 462         sys_props.platform_oem = *((uint64_t *)crat_table->oem_table_id);
 463         sys_props.platform_rev = crat_table->revision;
 464
 465         sub_type_hdr = (struct crat_subtype_generic *)(crat_table+1);
 466         while ((char *)sub_type_hdr + sizeof(struct crat_subtype_generic) <
 467                         ((char *)crat_image) + image_len) {
 468                 if (sub_type_hdr->flags & CRAT_SUBTYPE_FLAGS_ENABLED) {
 469                         ret = kfd_parse_subtype(sub_type_hdr);
 470                         if (ret != 0) {
 471                                 kfd_release_live_view();
 472                                 return ret;
 473                         }
 474                 }
 475
 476                 sub_type_hdr = (typeof(sub_type_hdr))((char *)sub_type_hdr +
 477                                 sub_type_hdr->length);
 478         }
 479
 480         sys_props.generation_count++;
 481         topology_crat_parsed = 1;
 482
 483         return 0;
 484 }
 485
 486
 487 #define sysfs_show_gen_prop(buffer, fmt, ...) \
 488                 snprintf(buffer, PAGE_SIZE, "%s"fmt, buffer, __VA_ARGS__)
 489 #define sysfs_show_32bit_prop(buffer, name, value) \
 490                 sysfs_show_gen_prop(buffer, "%s %u\n", name, value)
 491 #define sysfs_show_64bit_prop(buffer, name, value) \
 492                 sysfs_show_gen_prop(buffer, "%s %llu\n", name, value)
 493 #define sysfs_show_32bit_val(buffer, value) \
 494                 sysfs_show_gen_prop(buffer, "%u\n", value)
 495 #define sysfs_show_str_val(buffer, value) \
 496                 sysfs_show_gen_prop(buffer, "%s\n", value)
 497
 498 static ssize_t sysprops_show(struct kobject *kobj, struct attribute *attr,
 499                 char *buffer)
 500 {
 501         ssize_t ret;
 502
 503         /* Making sure that the buffer is an empty string */
 504         buffer[0] = 0;
 505
 506         if (attr == &sys_props.attr_genid) {
 507                 ret = sysfs_show_32bit_val(buffer, sys_props.generation_count);
 508         } else if (attr == &sys_props.attr_props) {
 509                 sysfs_show_64bit_prop(buffer, "platform_oem",
 510                                 sys_props.platform_oem);
 511                 sysfs_show_64bit_prop(buffer, "platform_id",
 512                                 sys_props.platform_id);
 513                 ret = sysfs_show_64bit_prop(buffer, "platform_rev",
 514                                 sys_props.platform_rev);
 515         } else {
 516                 ret = -EINVAL;
 517         }
 518
 519         return ret;
 520 }
 521
 522 static const struct sysfs_ops sysprops_ops = {
 523         .show = sysprops_show,
 524 };
 525
 526 static struct kobj_type sysprops_type = {
 527         .sysfs_ops = &sysprops_ops,
 528 };
 529
 530 static ssize_t iolink_show(struct kobject *kobj, struct attribute *attr,
 531                 char *buffer)
 532 {
 533         ssize_t ret;
 534         struct kfd_iolink_properties *iolink;
 535
 536         /* Making sure that the buffer is an empty string */
 537         buffer[0] = 0;
 538
 539         iolink = container_of(attr, struct kfd_iolink_properties, attr);
 540         sysfs_show_32bit_prop(buffer, "type", iolink->iolink_type);
 541         sysfs_show_32bit_prop(buffer, "version_major", iolink->ver_maj);
 542         sysfs_show_32bit_prop(buffer, "version_minor", iolink->ver_min);
 543         sysfs_show_32bit_prop(buffer, "node_from", iolink->node_from);
 544         sysfs_show_32bit_prop(buffer, "node_to", iolink->node_to);
 545         sysfs_show_32bit_prop(buffer, "weight", iolink->weight);
 546         sysfs_show_32bit_prop(buffer, "min_latency", iolink->min_latency);
 547         sysfs_show_32bit_prop(buffer, "max_latency", iolink->max_latency);
 548         sysfs_show_32bit_prop(buffer, "min_bandwidth", iolink->min_bandwidth);
 549         sysfs_show_32bit_prop(buffer, "max_bandwidth", iolink->max_bandwidth);
 550         sysfs_show_32bit_prop(buffer, "recommended_transfer_size",
 551                         iolink->rec_transfer_size);
 552         ret = sysfs_show_32bit_prop(buffer, "flags", iolink->flags);
 553
 554         return ret;
 555 }
 556
 557 static const struct sysfs_ops iolink_ops = {
 558         .show = iolink_show,
 559 };
 560
 561 static struct kobj_type iolink_type = {
 562         .sysfs_ops = &iolink_ops,
 563 };
 564
 565 static ssize_t mem_show(struct kobject *kobj, struct attribute *attr,
 566                 char *buffer)
 567 {
 568         ssize_t ret;
 569         struct kfd_mem_properties *mem;
 570
 571         /* Making sure that the buffer is an empty string */
 572         buffer[0] = 0;
 573
 574         mem = container_of(attr, struct kfd_mem_properties, attr);
 575         sysfs_show_32bit_prop(buffer, "heap_type", mem->heap_type);
 576         sysfs_show_64bit_prop(buffer, "size_in_bytes", mem->size_in_bytes);
 577         sysfs_show_32bit_prop(buffer, "flags", mem->flags);
 578         sysfs_show_32bit_prop(buffer, "width", mem->width);
 579         ret = sysfs_show_32bit_prop(buffer, "mem_clk_max", mem->mem_clk_max);
 580
 581         return ret;
 582 }
 583
 584 static const struct sysfs_ops mem_ops = {
 585         .show = mem_show,
 586 };
 587
 588 static struct kobj_type mem_type = {
 589         .sysfs_ops = &mem_ops,
 590 };
 591
 592 static ssize_t kfd_cache_show(struct kobject *kobj, struct attribute *attr,
 593                 char *buffer)
 594 {
 595         ssize_t ret;
 596         uint32_t i;
 597         struct kfd_cache_properties *cache;
 598
 599         /* Making sure that the buffer is an empty string */
 600         buffer[0] = 0;
 601
 602         cache = container_of(attr, struct kfd_cache_properties, attr);
 603         sysfs_show_32bit_prop(buffer, "processor_id_low",
 604                         cache->processor_id_low);
 605         sysfs_show_32bit_prop(buffer, "level", cache->cache_level);
 606         sysfs_show_32bit_prop(buffer, "size", cache->cache_size);
 607         sysfs_show_32bit_prop(buffer, "cache_line_size", cache->cacheline_size);
 608         sysfs_show_32bit_prop(buffer, "cache_lines_per_tag",
 609                         cache->cachelines_per_tag);
 610         sysfs_show_32bit_prop(buffer, "association", cache->cache_assoc);
 611         sysfs_show_32bit_prop(buffer, "latency", cache->cache_latency);
 612         sysfs_show_32bit_prop(buffer, "type", cache->cache_type);
 613         snprintf(buffer, PAGE_SIZE, "%ssibling_map ", buffer);
 614         for (i = 0; i < KFD_TOPOLOGY_CPU_SIBLINGS; i++)
 615                 ret = snprintf(buffer, PAGE_SIZE, "%s%d%s",
 616                                 buffer, cache->sibling_map[i],
 617                                 (i == KFD_TOPOLOGY_CPU_SIBLINGS-1) ?
 618                                                 "\n" : ",");
 619
 620         return ret;
 621 }
 622
 623 static const struct sysfs_ops cache_ops = {
 624         .show = kfd_cache_show,
 625 };
 626
 627 static struct kobj_type cache_type = {
 628         .sysfs_ops = &cache_ops,
 629 };
 630
 631 static ssize_t node_show(struct kobject *kobj, struct attribute *attr,
 632                 char *buffer)
 633 {
 634         struct kfd_topology_device *dev;
 635         char public_name[KFD_TOPOLOGY_PUBLIC_NAME_SIZE];
 636         uint32_t i;
 637         uint32_t log_max_watch_addr;
 638
 639         /* Making sure that the buffer is an empty string */
 640         buffer[0] = 0;
 641
 642         if (strcmp(attr->name, "gpu_id") == 0) {
 643                 dev = container_of(attr, struct kfd_topology_device,
 644                                 attr_gpuid);
 645                 return sysfs_show_32bit_val(buffer, dev->gpu_id);
 646         }
 647
 648         if (strcmp(attr->name, "name") == 0) {
 649                 dev = container_of(attr, struct kfd_topology_device,
 650                                 attr_name);
 651                 for (i = 0; i < KFD_TOPOLOGY_PUBLIC_NAME_SIZE; i++) {
 652                         public_name[i] =
 653                                         (char)dev->node_props.marketing_name[i];
 654                         if (dev->node_props.marketing_name[i] == 0)
 655                                 break;
 656                 }
 657                 public_name[KFD_TOPOLOGY_PUBLIC_NAME_SIZE-1] = 0x0;
 658                 return sysfs_show_str_val(buffer, public_name);
 659         }
 660
 661         dev = container_of(attr, struct kfd_topology_device,
 662                         attr_props);
 663         sysfs_show_32bit_prop(buffer, "cpu_cores_count",
 664                         dev->node_props.cpu_cores_count);
 665         sysfs_show_32bit_prop(buffer, "simd_count",
 666                         dev->node_props.simd_count);
 667
 668         if (dev->mem_bank_count < dev->node_props.mem_banks_count) {
 669                 pr_info_once("kfd: mem_banks_count truncated from %d to %d\n",
 670                                 dev->node_props.mem_banks_count,
 671                                 dev->mem_bank_count);
 672                 sysfs_show_32bit_prop(buffer, "mem_banks_count",
 673                                 dev->mem_bank_count);
 674         } else {
 675                 sysfs_show_32bit_prop(buffer, "mem_banks_count",
 676                                 dev->node_props.mem_banks_count);
 677         }
 678
 679         sysfs_show_32bit_prop(buffer, "caches_count",
 680                         dev->node_props.caches_count);
 681         sysfs_show_32bit_prop(buffer, "io_links_count",
 682                         dev->node_props.io_links_count);
 683         sysfs_show_32bit_prop(buffer, "cpu_core_id_base",
 684                         dev->node_props.cpu_core_id_base);
 685         sysfs_show_32bit_prop(buffer, "simd_id_base",
 686                         dev->node_props.simd_id_base);
 687         sysfs_show_32bit_prop(buffer, "max_waves_per_simd",
 688                         dev->node_props.max_waves_per_simd);
 689         sysfs_show_32bit_prop(buffer, "lds_size_in_kb",
 690                         dev->node_props.lds_size_in_kb);
 691         sysfs_show_32bit_prop(buffer, "gds_size_in_kb",
 692                         dev->node_props.gds_size_in_kb);
 693         sysfs_show_32bit_prop(buffer, "wave_front_size",
 694                         dev->node_props.wave_front_size);
 695         sysfs_show_32bit_prop(buffer, "array_count",
 696                         dev->node_props.array_count);
 697         sysfs_show_32bit_prop(buffer, "simd_arrays_per_engine",
 698                         dev->node_props.simd_arrays_per_engine);
 699         sysfs_show_32bit_prop(buffer, "cu_per_simd_array",
 700                         dev->node_props.cu_per_simd_array);
 701         sysfs_show_32bit_prop(buffer, "simd_per_cu",
 702                         dev->node_props.simd_per_cu);
 703         sysfs_show_32bit_prop(buffer, "max_slots_scratch_cu",
 704                         dev->node_props.max_slots_scratch_cu);
 705         sysfs_show_32bit_prop(buffer, "vendor_id",
 706                         dev->node_props.vendor_id);
 707         sysfs_show_32bit_prop(buffer, "device_id",
 708                         dev->node_props.device_id);
 709         sysfs_show_32bit_prop(buffer, "location_id",
 710                         dev->node_props.location_id);
 711
 712         if (dev->gpu) {
 713                 log_max_watch_addr =
 714                         __ilog2_u32(dev->gpu->device_info->num_of_watch_points);
 715
 716                 if (log_max_watch_addr) {
 717                         dev->node_props.capability |=
 718                                         HSA_CAP_WATCH_POINTS_SUPPORTED;
 719
 720                         dev->node_props.capability |=
 721                                 ((log_max_watch_addr <<
 722                                         HSA_CAP_WATCH_POINTS_TOTALBITS_SHIFT) &
 723                                 HSA_CAP_WATCH_POINTS_TOTALBITS_MASK);
 724                 }
 725
 726                 sysfs_show_32bit_prop(buffer, "max_engine_clk_fcompute",
 727                         dev->gpu->kfd2kgd->get_max_engine_clock_in_mhz(
 728                                         dev->gpu->kgd));
 729
 730                 sysfs_show_64bit_prop(buffer, "local_mem_size",
 731                                 (unsigned long long int) 0);
 732
 733                 sysfs_show_32bit_prop(buffer, "fw_version",
 734                         dev->gpu->kfd2kgd->get_fw_version(
 735                                                 dev->gpu->kgd,
 736                                                 KGD_ENGINE_MEC1));
 737                 sysfs_show_32bit_prop(buffer, "capability",
 738                                 dev->node_props.capability);
 739         }
 740
 741         return sysfs_show_32bit_prop(buffer, "max_engine_clk_ccompute",
 742                                         cpufreq_quick_get_max(0)/1000);
 743 }
 744
 745 static const struct sysfs_ops node_ops = {
 746         .show = node_show,
 747 };
 748
 749 static struct kobj_type node_type = {
 750         .sysfs_ops = &node_ops,
 751 };
 752
 753 static void kfd_remove_sysfs_file(struct kobject *kobj, struct attribute *attr)
 754 {
 755         sysfs_remove_file(kobj, attr);
 756         kobject_del(kobj);
 757         kobject_put(kobj);
 758 }
 759
 760 static void kfd_remove_sysfs_node_entry(struct kfd_topology_device *dev)
 761 {
 762         struct kfd_iolink_properties *iolink;
 763         struct kfd_cache_properties *cache;
 764         struct kfd_mem_properties *mem;
 765
 766         BUG_ON(!dev);
 767
 768         if (dev->kobj_iolink) {
 769                 list_for_each_entry(iolink, &dev->io_link_props, list)
 770                         if (iolink->kobj) {
 771                                 kfd_remove_sysfs_file(iolink->kobj,
 772                                                         &iolink->attr);
 773                                 iolink->kobj = NULL;
 774                         }
 775                 kobject_del(dev->kobj_iolink);
 776                 kobject_put(dev->kobj_iolink);
 777                 dev->kobj_iolink = NULL;
 778         }
 779
 780         if (dev->kobj_cache) {
 781                 list_for_each_entry(cache, &dev->cache_props, list)
 782                         if (cache->kobj) {
 783                                 kfd_remove_sysfs_file(cache->kobj,
 784                                                         &cache->attr);
 785                                 cache->kobj = NULL;
 786                         }
 787                 kobject_del(dev->kobj_cache);
 788                 kobject_put(dev->kobj_cache);
 789                 dev->kobj_cache = NULL;
 790         }
 791
 792         if (dev->kobj_mem) {
 793                 list_for_each_entry(mem, &dev->mem_props, list)
 794                         if (mem->kobj) {
 795                                 kfd_remove_sysfs_file(mem->kobj, &mem->attr);
 796                                 mem->kobj = NULL;
 797                         }
 798                 kobject_del(dev->kobj_mem);
 799                 kobject_put(dev->kobj_mem);
 800                 dev->kobj_mem = NULL;
 801         }
 802
 803         if (dev->kobj_node) {
 804                 sysfs_remove_file(dev->kobj_node, &dev->attr_gpuid);
 805                 sysfs_remove_file(dev->kobj_node, &dev->attr_name);
 806                 sysfs_remove_file(dev->kobj_node, &dev->attr_props);
 807                 kobject_del(dev->kobj_node);
 808                 kobject_put(dev->kobj_node);
 809                 dev->kobj_node = NULL;
 810         }
 811 }
 812
 813 static int kfd_build_sysfs_node_entry(struct kfd_topology_device *dev,
 814                 uint32_t id)
 815 {
 816         struct kfd_iolink_properties *iolink;
 817         struct kfd_cache_properties *cache;
 818         struct kfd_mem_properties *mem;
 819         int ret;
 820         uint32_t i;
 821
 822         BUG_ON(!dev);
 823
 824         /*
 825          * Creating the sysfs folders
 826          */
 827         BUG_ON(dev->kobj_node);
 828         dev->kobj_node = kfd_alloc_struct(dev->kobj_node);
 829         if (!dev->kobj_node)
 830                 return -ENOMEM;
 831
 832         ret = kobject_init_and_add(dev->kobj_node, &node_type,
 833                         sys_props.kobj_nodes, "%d", id);
 834         if (ret < 0)
 835                 return ret;
 836
 837         dev->kobj_mem = kobject_create_and_add("mem_banks", dev->kobj_node);
 838         if (!dev->kobj_mem)
 839                 return -ENOMEM;
 840
 841         dev->kobj_cache = kobject_create_and_add("caches", dev->kobj_node);
 842         if (!dev->kobj_cache)
 843                 return -ENOMEM;
 844
 845         dev->kobj_iolink = kobject_create_and_add("io_links", dev->kobj_node);
 846         if (!dev->kobj_iolink)
 847                 return -ENOMEM;
 848
 849         /*
 850          * Creating sysfs files for node properties
 851          */
 852         dev->attr_gpuid.name = "gpu_id";
 853         dev->attr_gpuid.mode = KFD_SYSFS_FILE_MODE;
 854         sysfs_attr_init(&dev->attr_gpuid);
 855         dev->attr_name.name = "name";
 856         dev->attr_name.mode = KFD_SYSFS_FILE_MODE;
 857         sysfs_attr_init(&dev->attr_name);
 858         dev->attr_props.name = "properties";
 859         dev->attr_props.mode = KFD_SYSFS_FILE_MODE;
 860         sysfs_attr_init(&dev->attr_props);
 861         ret = sysfs_create_file(dev->kobj_node, &dev->attr_gpuid);
 862         if (ret < 0)
 863                 return ret;
 864         ret = sysfs_create_file(dev->kobj_node, &dev->attr_name);
 865         if (ret < 0)
 866                 return ret;
 867         ret = sysfs_create_file(dev->kobj_node, &dev->attr_props);
 868         if (ret < 0)
 869                 return ret;
 870
 871         i = 0;
 872         list_for_each_entry(mem, &dev->mem_props, list) {
 873                 mem->kobj = kzalloc(sizeof(struct kobject), GFP_KERNEL);
 874                 if (!mem->kobj)
 875                         return -ENOMEM;
 876                 ret = kobject_init_and_add(mem->kobj, &mem_type,
 877                                 dev->kobj_mem, "%d", i);
 878                 if (ret < 0)
 879                         return ret;
 880
 881                 mem->attr.name = "properties";
 882                 mem->attr.mode = KFD_SYSFS_FILE_MODE;
 883                 sysfs_attr_init(&mem->attr);
 884                 ret = sysfs_create_file(mem->kobj, &mem->attr);
 885                 if (ret < 0)
 886                         return ret;
 887                 i++;
 888         }
 889
 890         i = 0;
 891         list_for_each_entry(cache, &dev->cache_props, list) {
 892                 cache->kobj = kzalloc(sizeof(struct kobject), GFP_KERNEL);
 893                 if (!cache->kobj)
 894                         return -ENOMEM;
 895                 ret = kobject_init_and_add(cache->kobj, &cache_type,
 896                                 dev->kobj_cache, "%d", i);
 897                 if (ret < 0)
 898                         return ret;
 899
 900                 cache->attr.name = "properties";
 901                 cache->attr.mode = KFD_SYSFS_FILE_MODE;
 902                 sysfs_attr_init(&cache->attr);
 903                 ret = sysfs_create_file(cache->kobj, &cache->attr);
 904                 if (ret < 0)
 905                         return ret;
 906                 i++;
 907         }
 908
 909         i = 0;
 910         list_for_each_entry(iolink, &dev->io_link_props, list) {
 911                 iolink->kobj = kzalloc(sizeof(struct kobject), GFP_KERNEL);
 912                 if (!iolink->kobj)
 913                         return -ENOMEM;
 914                 ret = kobject_init_and_add(iolink->kobj, &iolink_type,
 915                                 dev->kobj_iolink, "%d", i);
 916                 if (ret < 0)
 917                         return ret;
 918
 919                 iolink->attr.name = "properties";
 920                 iolink->attr.mode = KFD_SYSFS_FILE_MODE;
 921                 sysfs_attr_init(&iolink->attr);
 922                 ret = sysfs_create_file(iolink->kobj, &iolink->attr);
 923                 if (ret < 0)
 924                         return ret;
 925                 i++;
 926 }
 927
 928         return 0;
 929 }
 930
 931 static int kfd_build_sysfs_node_tree(void)
 932 {
 933         struct kfd_topology_device *dev;
 934         int ret;
 935         uint32_t i = 0;
 936
 937         list_for_each_entry(dev, &topology_device_list, list) {
 938                 ret = kfd_build_sysfs_node_entry(dev, i);
 939                 if (ret < 0)
 940                         return ret;
 941                 i++;
 942         }
 943
 944         return 0;
 945 }
 946
 947 static void kfd_remove_sysfs_node_tree(void)
 948 {
 949         struct kfd_topology_device *dev;
 950
 951         list_for_each_entry(dev, &topology_device_list, list)
 952                 kfd_remove_sysfs_node_entry(dev);
 953 }
 954
 955 static int kfd_topology_update_sysfs(void)
 956 {
 957         int ret;
 958
 959         pr_info("Creating topology SYSFS entries\n");
 960         if (sys_props.kobj_topology == NULL) {
 961                 sys_props.kobj_topology =
 962                                 kfd_alloc_struct(sys_props.kobj_topology);
 963                 if (!sys_props.kobj_topology)
 964                         return -ENOMEM;
 965
 966                 ret = kobject_init_and_add(sys_props.kobj_topology,
 967                                 &sysprops_type,  &kfd_device->kobj,
 968                                 "topology");
 969                 if (ret < 0)
 970                         return ret;
 971
 972                 sys_props.kobj_nodes = kobject_create_and_add("nodes",
 973                                 sys_props.kobj_topology);
 974                 if (!sys_props.kobj_nodes)
 975                         return -ENOMEM;
 976
 977                 sys_props.attr_genid.name = "generation_id";
 978                 sys_props.attr_genid.mode = KFD_SYSFS_FILE_MODE;
 979                 sysfs_attr_init(&sys_props.attr_genid);
 980                 ret = sysfs_create_file(sys_props.kobj_topology,
 981                                 &sys_props.attr_genid);
 982                 if (ret < 0)
 983                         return ret;
 984
 985                 sys_props.attr_props.name = "system_properties";
 986                 sys_props.attr_props.mode = KFD_SYSFS_FILE_MODE;
 987                 sysfs_attr_init(&sys_props.attr_props);
 988                 ret = sysfs_create_file(sys_props.kobj_topology,
 989                                 &sys_props.attr_props);
 990                 if (ret < 0)
 991                         return ret;
 992         }
 993
 994         kfd_remove_sysfs_node_tree();
 995
 996         return kfd_build_sysfs_node_tree();
 997 }
 998
 999 static void kfd_topology_release_sysfs(void)
1000 {
1001         kfd_remove_sysfs_node_tree();
1002         if (sys_props.kobj_topology) {
1003                 sysfs_remove_file(sys_props.kobj_topology,
1004                                 &sys_props.attr_genid);
1005                 sysfs_remove_file(sys_props.kobj_topology,
1006                                 &sys_props.attr_props);
1007                 if (sys_props.kobj_nodes) {
1008                         kobject_del(sys_props.kobj_nodes);
1009                         kobject_put(sys_props.kobj_nodes);
1010                         sys_props.kobj_nodes = NULL;
1011                 }
1012                 kobject_del(sys_props.kobj_topology);
1013                 kobject_put(sys_props.kobj_topology);
1014                 sys_props.kobj_topology = NULL;
1015         }
1016 }
1017
1018 int kfd_topology_init(void)
1019 {
1020         void *crat_image = NULL;
1021         size_t image_size = 0;
1022         int ret;
1023
1024         /*
1025          * Initialize the head for the topology device list
1026          */
1027         INIT_LIST_HEAD(&topology_device_list);
1028         init_rwsem(&topology_lock);
1029         topology_crat_parsed = 0;
1030
1031         memset(&sys_props, 0, sizeof(sys_props));
1032
1033         /*
1034          * Get the CRAT image from the ACPI
1035          */
1036         ret = kfd_topology_get_crat_acpi(crat_image, &image_size);
1037         if (ret == 0 && image_size > 0) {
1038                 pr_info("Found CRAT image with size=%zd\n", image_size);
1039                 crat_image = kmalloc(image_size, GFP_KERNEL);
1040                 if (!crat_image) {
1041                         ret = -ENOMEM;
1042                         pr_err("No memory for allocating CRAT image\n");
1043                         goto err;
1044                 }
1045                 ret = kfd_topology_get_crat_acpi(crat_image, &image_size);
1046
1047                 if (ret == 0) {
1048                         down_write(&topology_lock);
1049                         ret = kfd_parse_crat_table(crat_image);
1050                         if (ret == 0)
1051                                 ret = kfd_topology_update_sysfs();
1052                         up_write(&topology_lock);
1053                 } else {
1054                         pr_err("Couldn't get CRAT table size from ACPI\n");
1055                 }
1056                 kfree(crat_image);
1057         } else if (ret == -ENODATA) {
1058                 ret = 0;
1059         } else {
1060                 pr_err("Couldn't get CRAT table size from ACPI\n");
1061         }
1062
1063 err:
1064         pr_info("Finished initializing topology ret=%d\n", ret);
1065         return ret;
1066 }
1067
1068 void kfd_topology_shutdown(void)
1069 {
1070         kfd_topology_release_sysfs();
1071         kfd_release_live_view();
1072 }
1073
1074 static void kfd_debug_print_topology(void)
1075 {
1076         struct kfd_topology_device *dev;
1077         uint32_t i = 0;
1078
1079         pr_info("DEBUG PRINT OF TOPOLOGY:");
1080         list_for_each_entry(dev, &topology_device_list, list) {
1081                 pr_info("Node: %d\n", i);
1082                 pr_info("\tGPU assigned: %s\n", (dev->gpu ? "yes" : "no"));
1083                 pr_info("\tCPU count: %d\n", dev->node_props.cpu_cores_count);
1084                 pr_info("\tSIMD count: %d", dev->node_props.simd_count);
1085                 i++;
1086         }
1087 }
1088
1089 static uint32_t kfd_generate_gpu_id(struct kfd_dev *gpu)
1090 {
1091         uint32_t hashout;
1092         uint32_t buf[7];
1093         int i;
1094
1095         if (!gpu)
1096                 return 0;
1097
1098         buf[0] = gpu->pdev->devfn;
1099         buf[1] = gpu->pdev->subsystem_vendor;
1100         buf[2] = gpu->pdev->subsystem_device;
1101         buf[3] = gpu->pdev->device;
1102         buf[4] = gpu->pdev->bus->number;
1103         buf[5] = (uint32_t)(gpu->kfd2kgd->get_vmem_size(gpu->kgd)
1104                         & 0xffffffff);
1105         buf[6] = (uint32_t)(gpu->kfd2kgd->get_vmem_size(gpu->kgd) >> 32);
1106
1107         for (i = 0, hashout = 0; i < 7; i++)
1108                 hashout ^= hash_32(buf[i], KFD_GPU_ID_HASH_WIDTH);
1109
1110         return hashout;
1111 }
1112
1113 static struct kfd_topology_device *kfd_assign_gpu(struct kfd_dev *gpu)
1114 {
1115         struct kfd_topology_device *dev;
1116         struct kfd_topology_device *out_dev = NULL;
1117
1118         BUG_ON(!gpu);
1119
1120         list_for_each_entry(dev, &topology_device_list, list)
1121                 if (dev->gpu == NULL && dev->node_props.simd_count > 0) {
1122                         dev->gpu = gpu;
1123                         out_dev = dev;
1124                         break;
1125                 }
1126
1127         return out_dev;
1128 }
1129
1130 static void kfd_notify_gpu_change(uint32_t gpu_id, int arrival)
1131 {
1132         /*
1133          * TODO: Generate an event for thunk about the arrival/removal
1134          * of the GPU
1135          */
1136 }
1137
1138 int kfd_topology_add_device(struct kfd_dev *gpu)
1139 {
1140         uint32_t gpu_id;
1141         struct kfd_topology_device *dev;
1142         int res;
1143
1144         BUG_ON(!gpu);
1145
1146         gpu_id = kfd_generate_gpu_id(gpu);
1147
1148         pr_debug("kfd: Adding new GPU (ID: 0x%x) to topology\n", gpu_id);
1149
1150         down_write(&topology_lock);
1151         /*
1152          * Try to assign the GPU to existing topology device (generated from
1153          * CRAT table
1154          */
1155         dev = kfd_assign_gpu(gpu);
1156         if (!dev) {
1157                 pr_info("GPU was not found in the current topology. Extending.\n");
1158                 kfd_debug_print_topology();
1159                 dev = kfd_create_topology_device();
1160                 if (!dev) {
1161                         res = -ENOMEM;
1162                         goto err;
1163                 }
1164                 dev->gpu = gpu;
1165
1166                 /*
1167                  * TODO: Make a call to retrieve topology information from the
1168                  * GPU vBIOS
1169                  */
1170
1171                 /*
1172                  * Update the SYSFS tree, since we added another topology device
1173                  */
1174                 if (kfd_topology_update_sysfs() < 0)
1175                         kfd_topology_release_sysfs();
1176
1177         }
1178
1179         dev->gpu_id = gpu_id;
1180         gpu->id = gpu_id;
1181         dev->node_props.vendor_id = gpu->pdev->vendor;
1182         dev->node_props.device_id = gpu->pdev->device;
1183         dev->node_props.location_id = (gpu->pdev->bus->number << 24) +
1184                         (gpu->pdev->devfn & 0xffffff);
1185         /*
1186          * TODO: Retrieve max engine clock values from KGD
1187          */
1188
1189         if (dev->gpu->device_info->asic_family == CHIP_CARRIZO) {
1190                 dev->node_props.capability |= HSA_CAP_DOORBELL_PACKET_TYPE;
1191                 pr_info("amdkfd: adding doorbell packet type capability\n");
1192         }
1193
1194         res = 0;
1195
1196 err:
1197         up_write(&topology_lock);
1198
1199         if (res == 0)
1200                 kfd_notify_gpu_change(gpu_id, 1);
1201
1202         return res;
1203 }
1204
1205 int kfd_topology_remove_device(struct kfd_dev *gpu)
1206 {
1207         struct kfd_topology_device *dev;
1208         uint32_t gpu_id;
1209         int res = -ENODEV;
1210
1211         BUG_ON(!gpu);
1212
1213         down_write(&topology_lock);
1214
1215         list_for_each_entry(dev, &topology_device_list, list)
1216                 if (dev->gpu == gpu) {
1217                         gpu_id = dev->gpu_id;
1218                         kfd_remove_sysfs_node_entry(dev);
1219                         kfd_release_topology_device(dev);
1220                         res = 0;
1221                         if (kfd_topology_update_sysfs() < 0)
1222                                 kfd_topology_release_sysfs();
1223                         break;
1224                 }
1225
1226         up_write(&topology_lock);
1227
1228         if (res == 0)
1229                 kfd_notify_gpu_change(gpu_id, 0);
1230
1231         return res;
1232 }
1233
1234 /*
1235  * When idx is out of bounds, the function will return NULL
1236  */
1237 struct kfd_dev *kfd_topology_enum_kfd_devices(uint8_t idx)
1238 {
1239
1240         struct kfd_topology_device *top_dev;
1241         struct kfd_dev *device = NULL;
1242         uint8_t device_idx = 0;
1243
1244         down_read(&topology_lock);
1245
1246         list_for_each_entry(top_dev, &topology_device_list, list) {
1247                 if (device_idx == idx) {
1248                         device = top_dev->gpu;
1249                         break;
1250                 }
1251
1252                 device_idx++;
1253         }
1254
1255         up_read(&topology_lock);
1256
1257         return device;
1258
1259 }