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 void kfd_topology_kobj_release(struct kobject *kobj)
 505 {
 506         kfree(kobj);
 507 }
 508
 509 static const struct sysfs_ops sysprops_ops = {
 510         .show = sysprops_show,
 511 };
 512
 513 static struct kobj_type sysprops_type = {
 514         .release = kfd_topology_kobj_release,
 515         .sysfs_ops = &sysprops_ops,
 516 };
 517
 518 static ssize_t iolink_show(struct kobject *kobj, struct attribute *attr,
 519                 char *buffer)
 520 {
 521         ssize_t ret;
 522         struct kfd_iolink_properties *iolink;
 523
 524         /* Making sure that the buffer is an empty string */
 525         buffer[0] = 0;
 526
 527         iolink = container_of(attr, struct kfd_iolink_properties, attr);
 528         sysfs_show_32bit_prop(buffer, "type", iolink->iolink_type);
 529         sysfs_show_32bit_prop(buffer, "version_major", iolink->ver_maj);
 530         sysfs_show_32bit_prop(buffer, "version_minor", iolink->ver_min);
 531         sysfs_show_32bit_prop(buffer, "node_from", iolink->node_from);
 532         sysfs_show_32bit_prop(buffer, "node_to", iolink->node_to);
 533         sysfs_show_32bit_prop(buffer, "weight", iolink->weight);
 534         sysfs_show_32bit_prop(buffer, "min_latency", iolink->min_latency);
 535         sysfs_show_32bit_prop(buffer, "max_latency", iolink->max_latency);
 536         sysfs_show_32bit_prop(buffer, "min_bandwidth", iolink->min_bandwidth);
 537         sysfs_show_32bit_prop(buffer, "max_bandwidth", iolink->max_bandwidth);
 538         sysfs_show_32bit_prop(buffer, "recommended_transfer_size",
 539                         iolink->rec_transfer_size);
 540         ret = sysfs_show_32bit_prop(buffer, "flags", iolink->flags);
 541
 542         return ret;
 543 }
 544
 545 static const struct sysfs_ops iolink_ops = {
 546         .show = iolink_show,
 547 };
 548
 549 static struct kobj_type iolink_type = {
 550         .release = kfd_topology_kobj_release,
 551         .sysfs_ops = &iolink_ops,
 552 };
 553
 554 static ssize_t mem_show(struct kobject *kobj, struct attribute *attr,
 555                 char *buffer)
 556 {
 557         ssize_t ret;
 558         struct kfd_mem_properties *mem;
 559
 560         /* Making sure that the buffer is an empty string */
 561         buffer[0] = 0;
 562
 563         mem = container_of(attr, struct kfd_mem_properties, attr);
 564         sysfs_show_32bit_prop(buffer, "heap_type", mem->heap_type);
 565         sysfs_show_64bit_prop(buffer, "size_in_bytes", mem->size_in_bytes);
 566         sysfs_show_32bit_prop(buffer, "flags", mem->flags);
 567         sysfs_show_32bit_prop(buffer, "width", mem->width);
 568         ret = sysfs_show_32bit_prop(buffer, "mem_clk_max", mem->mem_clk_max);
 569
 570         return ret;
 571 }
 572
 573 static const struct sysfs_ops mem_ops = {
 574         .show = mem_show,
 575 };
 576
 577 static struct kobj_type mem_type = {
 578         .release = kfd_topology_kobj_release,
 579         .sysfs_ops = &mem_ops,
 580 };
 581
 582 static ssize_t kfd_cache_show(struct kobject *kobj, struct attribute *attr,
 583                 char *buffer)
 584 {
 585         ssize_t ret;
 586         uint32_t i;
 587         struct kfd_cache_properties *cache;
 588
 589         /* Making sure that the buffer is an empty string */
 590         buffer[0] = 0;
 591
 592         cache = container_of(attr, struct kfd_cache_properties, attr);
 593         sysfs_show_32bit_prop(buffer, "processor_id_low",
 594                         cache->processor_id_low);
 595         sysfs_show_32bit_prop(buffer, "level", cache->cache_level);
 596         sysfs_show_32bit_prop(buffer, "size", cache->cache_size);
 597         sysfs_show_32bit_prop(buffer, "cache_line_size", cache->cacheline_size);
 598         sysfs_show_32bit_prop(buffer, "cache_lines_per_tag",
 599                         cache->cachelines_per_tag);
 600         sysfs_show_32bit_prop(buffer, "association", cache->cache_assoc);
 601         sysfs_show_32bit_prop(buffer, "latency", cache->cache_latency);
 602         sysfs_show_32bit_prop(buffer, "type", cache->cache_type);
 603         snprintf(buffer, PAGE_SIZE, "%ssibling_map ", buffer);
 604         for (i = 0; i < KFD_TOPOLOGY_CPU_SIBLINGS; i++)
 605                 ret = snprintf(buffer, PAGE_SIZE, "%s%d%s",
 606                                 buffer, cache->sibling_map[i],
 607                                 (i == KFD_TOPOLOGY_CPU_SIBLINGS-1) ?
 608                                                 "\n" : ",");
 609
 610         return ret;
 611 }
 612
 613 static const struct sysfs_ops cache_ops = {
 614         .show = kfd_cache_show,
 615 };
 616
 617 static struct kobj_type cache_type = {
 618         .release = kfd_topology_kobj_release,
 619         .sysfs_ops = &cache_ops,
 620 };
 621
 622 static ssize_t node_show(struct kobject *kobj, struct attribute *attr,
 623                 char *buffer)
 624 {
 625         struct kfd_topology_device *dev;
 626         char public_name[KFD_TOPOLOGY_PUBLIC_NAME_SIZE];
 627         uint32_t i;
 628         uint32_t log_max_watch_addr;
 629
 630         /* Making sure that the buffer is an empty string */
 631         buffer[0] = 0;
 632
 633         if (strcmp(attr->name, "gpu_id") == 0) {
 634                 dev = container_of(attr, struct kfd_topology_device,
 635                                 attr_gpuid);
 636                 return sysfs_show_32bit_val(buffer, dev->gpu_id);
 637         }
 638
 639         if (strcmp(attr->name, "name") == 0) {
 640                 dev = container_of(attr, struct kfd_topology_device,
 641                                 attr_name);
 642                 for (i = 0; i < KFD_TOPOLOGY_PUBLIC_NAME_SIZE; i++) {
 643                         public_name[i] =
 644                                         (char)dev->node_props.marketing_name[i];
 645                         if (dev->node_props.marketing_name[i] == 0)
 646                                 break;
 647                 }
 648                 public_name[KFD_TOPOLOGY_PUBLIC_NAME_SIZE-1] = 0x0;
 649                 return sysfs_show_str_val(buffer, public_name);
 650         }
 651
 652         dev = container_of(attr, struct kfd_topology_device,
 653                         attr_props);
 654         sysfs_show_32bit_prop(buffer, "cpu_cores_count",
 655                         dev->node_props.cpu_cores_count);
 656         sysfs_show_32bit_prop(buffer, "simd_count",
 657                         dev->node_props.simd_count);
 658
 659         if (dev->mem_bank_count < dev->node_props.mem_banks_count) {
 660                 pr_info_once("mem_banks_count truncated from %d to %d\n",
 661                                 dev->node_props.mem_banks_count,
 662                                 dev->mem_bank_count);
 663                 sysfs_show_32bit_prop(buffer, "mem_banks_count",
 664                                 dev->mem_bank_count);
 665         } else {
 666                 sysfs_show_32bit_prop(buffer, "mem_banks_count",
 667                                 dev->node_props.mem_banks_count);
 668         }
 669
 670         sysfs_show_32bit_prop(buffer, "caches_count",
 671                         dev->node_props.caches_count);
 672         sysfs_show_32bit_prop(buffer, "io_links_count",
 673                         dev->node_props.io_links_count);
 674         sysfs_show_32bit_prop(buffer, "cpu_core_id_base",
 675                         dev->node_props.cpu_core_id_base);
 676         sysfs_show_32bit_prop(buffer, "simd_id_base",
 677                         dev->node_props.simd_id_base);
 678         sysfs_show_32bit_prop(buffer, "max_waves_per_simd",
 679                         dev->node_props.max_waves_per_simd);
 680         sysfs_show_32bit_prop(buffer, "lds_size_in_kb",
 681                         dev->node_props.lds_size_in_kb);
 682         sysfs_show_32bit_prop(buffer, "gds_size_in_kb",
 683                         dev->node_props.gds_size_in_kb);
 684         sysfs_show_32bit_prop(buffer, "wave_front_size",
 685                         dev->node_props.wave_front_size);
 686         sysfs_show_32bit_prop(buffer, "array_count",
 687                         dev->node_props.array_count);
 688         sysfs_show_32bit_prop(buffer, "simd_arrays_per_engine",
 689                         dev->node_props.simd_arrays_per_engine);
 690         sysfs_show_32bit_prop(buffer, "cu_per_simd_array",
 691                         dev->node_props.cu_per_simd_array);
 692         sysfs_show_32bit_prop(buffer, "simd_per_cu",
 693                         dev->node_props.simd_per_cu);
 694         sysfs_show_32bit_prop(buffer, "max_slots_scratch_cu",
 695                         dev->node_props.max_slots_scratch_cu);
 696         sysfs_show_32bit_prop(buffer, "vendor_id",
 697                         dev->node_props.vendor_id);
 698         sysfs_show_32bit_prop(buffer, "device_id",
 699                         dev->node_props.device_id);
 700         sysfs_show_32bit_prop(buffer, "location_id",
 701                         dev->node_props.location_id);
 702
 703         if (dev->gpu) {
 704                 log_max_watch_addr =
 705                         __ilog2_u32(dev->gpu->device_info->num_of_watch_points);
 706
 707                 if (log_max_watch_addr) {
 708                         dev->node_props.capability |=
 709                                         HSA_CAP_WATCH_POINTS_SUPPORTED;
 710
 711                         dev->node_props.capability |=
 712                                 ((log_max_watch_addr <<
 713                                         HSA_CAP_WATCH_POINTS_TOTALBITS_SHIFT) &
 714                                 HSA_CAP_WATCH_POINTS_TOTALBITS_MASK);
 715                 }
 716
 717                 sysfs_show_32bit_prop(buffer, "max_engine_clk_fcompute",
 718                         dev->gpu->kfd2kgd->get_max_engine_clock_in_mhz(
 719                                         dev->gpu->kgd));
 720
 721                 sysfs_show_64bit_prop(buffer, "local_mem_size",
 722                                 (unsigned long long int) 0);
 723
 724                 sysfs_show_32bit_prop(buffer, "fw_version",
 725                         dev->gpu->kfd2kgd->get_fw_version(
 726                                                 dev->gpu->kgd,
 727                                                 KGD_ENGINE_MEC1));
 728                 sysfs_show_32bit_prop(buffer, "capability",
 729                                 dev->node_props.capability);
 730         }
 731
 732         return sysfs_show_32bit_prop(buffer, "max_engine_clk_ccompute",
 733                                         cpufreq_quick_get_max(0)/1000);
 734 }
 735
 736 static const struct sysfs_ops node_ops = {
 737         .show = node_show,
 738 };
 739
 740 static struct kobj_type node_type = {
 741         .release = kfd_topology_kobj_release,
 742         .sysfs_ops = &node_ops,
 743 };
 744
 745 static void kfd_remove_sysfs_file(struct kobject *kobj, struct attribute *attr)
 746 {
 747         sysfs_remove_file(kobj, attr);
 748         kobject_del(kobj);
 749         kobject_put(kobj);
 750 }
 751
 752 static void kfd_remove_sysfs_node_entry(struct kfd_topology_device *dev)
 753 {
 754         struct kfd_iolink_properties *iolink;
 755         struct kfd_cache_properties *cache;
 756         struct kfd_mem_properties *mem;
 757
 758         if (dev->kobj_iolink) {
 759                 list_for_each_entry(iolink, &dev->io_link_props, list)
 760                         if (iolink->kobj) {
 761                                 kfd_remove_sysfs_file(iolink->kobj,
 762                                                         &iolink->attr);
 763                                 iolink->kobj = NULL;
 764                         }
 765                 kobject_del(dev->kobj_iolink);
 766                 kobject_put(dev->kobj_iolink);
 767                 dev->kobj_iolink = NULL;
 768         }
 769
 770         if (dev->kobj_cache) {
 771                 list_for_each_entry(cache, &dev->cache_props, list)
 772                         if (cache->kobj) {
 773                                 kfd_remove_sysfs_file(cache->kobj,
 774                                                         &cache->attr);
 775                                 cache->kobj = NULL;
 776                         }
 777                 kobject_del(dev->kobj_cache);
 778                 kobject_put(dev->kobj_cache);
 779                 dev->kobj_cache = NULL;
 780         }
 781
 782         if (dev->kobj_mem) {
 783                 list_for_each_entry(mem, &dev->mem_props, list)
 784                         if (mem->kobj) {
 785                                 kfd_remove_sysfs_file(mem->kobj, &mem->attr);
 786                                 mem->kobj = NULL;
 787                         }
 788                 kobject_del(dev->kobj_mem);
 789                 kobject_put(dev->kobj_mem);
 790                 dev->kobj_mem = NULL;
 791         }
 792
 793         if (dev->kobj_node) {
 794                 sysfs_remove_file(dev->kobj_node, &dev->attr_gpuid);
 795                 sysfs_remove_file(dev->kobj_node, &dev->attr_name);
 796                 sysfs_remove_file(dev->kobj_node, &dev->attr_props);
 797                 kobject_del(dev->kobj_node);
 798                 kobject_put(dev->kobj_node);
 799                 dev->kobj_node = NULL;
 800         }
 801 }
 802
 803 static int kfd_build_sysfs_node_entry(struct kfd_topology_device *dev,
 804                 uint32_t id)
 805 {
 806         struct kfd_iolink_properties *iolink;
 807         struct kfd_cache_properties *cache;
 808         struct kfd_mem_properties *mem;
 809         int ret;
 810         uint32_t i;
 811
 812         if (WARN_ON(dev->kobj_node))
 813                 return -EEXIST;
 814
 815         /*
 816          * Creating the sysfs folders
 817          */
 818         dev->kobj_node = kfd_alloc_struct(dev->kobj_node);
 819         if (!dev->kobj_node)
 820                 return -ENOMEM;
 821
 822         ret = kobject_init_and_add(dev->kobj_node, &node_type,
 823                         sys_props.kobj_nodes, "%d", id);
 824         if (ret < 0) {
 825                 kobject_put(dev->kobj_node);
 826                 return ret;
 827         }
 828
 829         dev->kobj_mem = kobject_create_and_add("mem_banks", dev->kobj_node);
 830         if (!dev->kobj_mem)
 831                 return -ENOMEM;
 832
 833         dev->kobj_cache = kobject_create_and_add("caches", dev->kobj_node);
 834         if (!dev->kobj_cache)
 835                 return -ENOMEM;
 836
 837         dev->kobj_iolink = kobject_create_and_add("io_links", dev->kobj_node);
 838         if (!dev->kobj_iolink)
 839                 return -ENOMEM;
 840
 841         /*
 842          * Creating sysfs files for node properties
 843          */
 844         dev->attr_gpuid.name = "gpu_id";
 845         dev->attr_gpuid.mode = KFD_SYSFS_FILE_MODE;
 846         sysfs_attr_init(&dev->attr_gpuid);
 847         dev->attr_name.name = "name";
 848         dev->attr_name.mode = KFD_SYSFS_FILE_MODE;
 849         sysfs_attr_init(&dev->attr_name);
 850         dev->attr_props.name = "properties";
 851         dev->attr_props.mode = KFD_SYSFS_FILE_MODE;
 852         sysfs_attr_init(&dev->attr_props);
 853         ret = sysfs_create_file(dev->kobj_node, &dev->attr_gpuid);
 854         if (ret < 0)
 855                 return ret;
 856         ret = sysfs_create_file(dev->kobj_node, &dev->attr_name);
 857         if (ret < 0)
 858                 return ret;
 859         ret = sysfs_create_file(dev->kobj_node, &dev->attr_props);
 860         if (ret < 0)
 861                 return ret;
 862
 863         i = 0;
 864         list_for_each_entry(mem, &dev->mem_props, list) {
 865                 mem->kobj = kzalloc(sizeof(struct kobject), GFP_KERNEL);
 866                 if (!mem->kobj)
 867                         return -ENOMEM;
 868                 ret = kobject_init_and_add(mem->kobj, &mem_type,
 869                                 dev->kobj_mem, "%d", i);
 870                 if (ret < 0) {
 871                         kobject_put(mem->kobj);
 872                         return ret;
 873                 }
 874
 875                 mem->attr.name = "properties";
 876                 mem->attr.mode = KFD_SYSFS_FILE_MODE;
 877                 sysfs_attr_init(&mem->attr);
 878                 ret = sysfs_create_file(mem->kobj, &mem->attr);
 879                 if (ret < 0)
 880                         return ret;
 881                 i++;
 882         }
 883
 884         i = 0;
 885         list_for_each_entry(cache, &dev->cache_props, list) {
 886                 cache->kobj = kzalloc(sizeof(struct kobject), GFP_KERNEL);
 887                 if (!cache->kobj)
 888                         return -ENOMEM;
 889                 ret = kobject_init_and_add(cache->kobj, &cache_type,
 890                                 dev->kobj_cache, "%d", i);
 891                 if (ret < 0) {
 892                         kobject_put(cache->kobj);
 893                         return ret;
 894                 }
 895
 896                 cache->attr.name = "properties";
 897                 cache->attr.mode = KFD_SYSFS_FILE_MODE;
 898                 sysfs_attr_init(&cache->attr);
 899                 ret = sysfs_create_file(cache->kobj, &cache->attr);
 900                 if (ret < 0)
 901                         return ret;
 902                 i++;
 903         }
 904
 905         i = 0;
 906         list_for_each_entry(iolink, &dev->io_link_props, list) {
 907                 iolink->kobj = kzalloc(sizeof(struct kobject), GFP_KERNEL);
 908                 if (!iolink->kobj)
 909                         return -ENOMEM;
 910                 ret = kobject_init_and_add(iolink->kobj, &iolink_type,
 911                                 dev->kobj_iolink, "%d", i);
 912                 if (ret < 0) {
 913                         kobject_put(iolink->kobj);
 914                         return ret;
 915                 }
 916
 917                 iolink->attr.name = "properties";
 918                 iolink->attr.mode = KFD_SYSFS_FILE_MODE;
 919                 sysfs_attr_init(&iolink->attr);
 920                 ret = sysfs_create_file(iolink->kobj, &iolink->attr);
 921                 if (ret < 0)
 922                         return ret;
 923                 i++;
 924 }
 925
 926         return 0;
 927 }
 928
 929 static int kfd_build_sysfs_node_tree(void)
 930 {
 931         struct kfd_topology_device *dev;
 932         int ret;
 933         uint32_t i = 0;
 934
 935         list_for_each_entry(dev, &topology_device_list, list) {
 936                 ret = kfd_build_sysfs_node_entry(dev, i);
 937                 if (ret < 0)
 938                         return ret;
 939                 i++;
 940         }
 941
 942         return 0;
 943 }
 944
 945 static void kfd_remove_sysfs_node_tree(void)
 946 {
 947         struct kfd_topology_device *dev;
 948
 949         list_for_each_entry(dev, &topology_device_list, list)
 950                 kfd_remove_sysfs_node_entry(dev);
 951 }
 952
 953 static int kfd_topology_update_sysfs(void)
 954 {
 955         int ret;
 956
 957         pr_info("Creating topology SYSFS entries\n");
 958         if (!sys_props.kobj_topology) {
 959                 sys_props.kobj_topology =
 960                                 kfd_alloc_struct(sys_props.kobj_topology);
 961                 if (!sys_props.kobj_topology)
 962                         return -ENOMEM;
 963
 964                 ret = kobject_init_and_add(sys_props.kobj_topology,
 965                                 &sysprops_type,  &kfd_device->kobj,
 966                                 "topology");
 967                 if (ret < 0) {
 968                         kobject_put(sys_props.kobj_topology);
 969                         return ret;
 970                 }
 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         uint64_t local_mem_size;
1094         int i;
1095
1096         if (!gpu)
1097                 return 0;
1098
1099         local_mem_size = gpu->kfd2kgd->get_vmem_size(gpu->kgd);
1100
1101         buf[0] = gpu->pdev->devfn;
1102         buf[1] = gpu->pdev->subsystem_vendor;
1103         buf[2] = gpu->pdev->subsystem_device;
1104         buf[3] = gpu->pdev->device;
1105         buf[4] = gpu->pdev->bus->number;
1106         buf[5] = lower_32_bits(local_mem_size);
1107         buf[6] = upper_32_bits(local_mem_size);
1108
1109         for (i = 0, hashout = 0; i < 7; i++)
1110                 hashout ^= hash_32(buf[i], KFD_GPU_ID_HASH_WIDTH);
1111
1112         return hashout;
1113 }
1114
1115 static struct kfd_topology_device *kfd_assign_gpu(struct kfd_dev *gpu)
1116 {
1117         struct kfd_topology_device *dev;
1118         struct kfd_topology_device *out_dev = NULL;
1119
1120         list_for_each_entry(dev, &topology_device_list, list)
1121                 if (!dev->gpu && (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         gpu_id = kfd_generate_gpu_id(gpu);
1145
1146         pr_debug("Adding new GPU (ID: 0x%x) to topology\n", gpu_id);
1147
1148         down_write(&topology_lock);
1149         /*
1150          * Try to assign the GPU to existing topology device (generated from
1151          * CRAT table
1152          */
1153         dev = kfd_assign_gpu(gpu);
1154         if (!dev) {
1155                 pr_info("GPU was not found in the current topology. Extending.\n");
1156                 kfd_debug_print_topology();
1157                 dev = kfd_create_topology_device();
1158                 if (!dev) {
1159                         res = -ENOMEM;
1160                         goto err;
1161                 }
1162                 dev->gpu = gpu;
1163
1164                 /*
1165                  * TODO: Make a call to retrieve topology information from the
1166                  * GPU vBIOS
1167                  */
1168
1169                 /* Update the SYSFS tree, since we added another topology
1170                  * device
1171                  */
1172                 if (kfd_topology_update_sysfs() < 0)
1173                         kfd_topology_release_sysfs();
1174
1175         }
1176
1177         dev->gpu_id = gpu_id;
1178         gpu->id = gpu_id;
1179         dev->node_props.vendor_id = gpu->pdev->vendor;
1180         dev->node_props.device_id = gpu->pdev->device;
1181         dev->node_props.location_id = (gpu->pdev->bus->number << 24) +
1182                         (gpu->pdev->devfn & 0xffffff);
1183         /*
1184          * TODO: Retrieve max engine clock values from KGD
1185          */
1186
1187         if (dev->gpu->device_info->asic_family == CHIP_CARRIZO) {
1188                 dev->node_props.capability |= HSA_CAP_DOORBELL_PACKET_TYPE;
1189                 pr_info("Adding doorbell packet type capability\n");
1190         }
1191
1192         res = 0;
1193
1194 err:
1195         up_write(&topology_lock);
1196
1197         if (res == 0)
1198                 kfd_notify_gpu_change(gpu_id, 1);
1199
1200         return res;
1201 }
1202
1203 int kfd_topology_remove_device(struct kfd_dev *gpu)
1204 {
1205         struct kfd_topology_device *dev;
1206         uint32_t gpu_id;
1207         int res = -ENODEV;
1208
1209         down_write(&topology_lock);
1210
1211         list_for_each_entry(dev, &topology_device_list, list)
1212                 if (dev->gpu == gpu) {
1213                         gpu_id = dev->gpu_id;
1214                         kfd_remove_sysfs_node_entry(dev);
1215                         kfd_release_topology_device(dev);
1216                         res = 0;
1217                         if (kfd_topology_update_sysfs() < 0)
1218                                 kfd_topology_release_sysfs();
1219                         break;
1220                 }
1221
1222         up_write(&topology_lock);
1223
1224         if (res == 0)
1225                 kfd_notify_gpu_change(gpu_id, 0);
1226
1227         return res;
1228 }
1229
1230 /*
1231  * When idx is out of bounds, the function will return NULL
1232  */
1233 struct kfd_dev *kfd_topology_enum_kfd_devices(uint8_t idx)
1234 {
1235
1236         struct kfd_topology_device *top_dev;
1237         struct kfd_dev *device = NULL;
1238         uint8_t device_idx = 0;
1239
1240         down_read(&topology_lock);
1241
1242         list_for_each_entry(top_dev, &topology_device_list, list) {
1243                 if (device_idx == idx) {
1244                         device = top_dev->gpu;
1245                         break;
1246                 }
1247
1248                 device_idx++;
1249         }
1250
1251         up_read(&topology_lock);
1252
1253         return device;
1254
1255 }