drivers/gpu/drm/amd/amdkfd/kfd_chardev.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/device.h>
  24 #include <linux/export.h>
  25 #include <linux/err.h>
  26 #include <linux/fs.h>
  27 #include <linux/sched.h>
  28 #include <linux/slab.h>
  29 #include <linux/uaccess.h>
  30 #include <linux/compat.h>
  31 #include <uapi/linux/kfd_ioctl.h>
  32 #include <linux/time.h>
  33 #include <linux/mm.h>
  34 #include <linux/uaccess.h>
  35 #include <uapi/asm-generic/mman-common.h>
  36 #include <asm/processor.h>
  37 #include "kfd_priv.h"
  38 #include "kfd_device_queue_manager.h"
  39
  40 static long kfd_ioctl(struct file *, unsigned int, unsigned long);
  41 static int kfd_open(struct inode *, struct file *);
  42 static int kfd_mmap(struct file *, struct vm_area_struct *);
  43
  44 static const char kfd_dev_name[] = "kfd";
  45
  46 static const struct file_operations kfd_fops = {
  47         .owner = THIS_MODULE,
  48         .unlocked_ioctl = kfd_ioctl,
  49         .compat_ioctl = kfd_ioctl,
  50         .open = kfd_open,
  51         .mmap = kfd_mmap,
  52 };
  53
  54 static int kfd_char_dev_major = -1;
  55 static struct class *kfd_class;
  56 struct device *kfd_device;
  57
  58 int kfd_chardev_init(void)
  59 {
  60         int err = 0;
  61
  62         kfd_char_dev_major = register_chrdev(0, kfd_dev_name, &kfd_fops);
  63         err = kfd_char_dev_major;
  64         if (err < 0)
  65                 goto err_register_chrdev;
  66
  67         kfd_class = class_create(THIS_MODULE, kfd_dev_name);
  68         err = PTR_ERR(kfd_class);
  69         if (IS_ERR(kfd_class))
  70                 goto err_class_create;
  71
  72         kfd_device = device_create(kfd_class, NULL,
  73                                         MKDEV(kfd_char_dev_major, 0),
  74                                         NULL, kfd_dev_name);
  75         err = PTR_ERR(kfd_device);
  76         if (IS_ERR(kfd_device))
  77                 goto err_device_create;
  78
  79         return 0;
  80
  81 err_device_create:
  82         class_destroy(kfd_class);
  83 err_class_create:
  84         unregister_chrdev(kfd_char_dev_major, kfd_dev_name);
  85 err_register_chrdev:
  86         return err;
  87 }
  88
  89 void kfd_chardev_exit(void)
  90 {
  91         device_destroy(kfd_class, MKDEV(kfd_char_dev_major, 0));
  92         class_destroy(kfd_class);
  93         unregister_chrdev(kfd_char_dev_major, kfd_dev_name);
  94 }
  95
  96 struct device *kfd_chardev(void)
  97 {
  98         return kfd_device;
  99 }
 100
 101
 102 static int kfd_open(struct inode *inode, struct file *filep)
 103 {
 104         struct kfd_process *process;
 105         bool is_32bit_user_mode;
 106
 107         if (iminor(inode) != 0)
 108                 return -ENODEV;
 109
 110         is_32bit_user_mode = is_compat_task();
 111
 112         if (is_32bit_user_mode == true) {
 113                 dev_warn(kfd_device,
 114                         "Process %d (32-bit) failed to open /dev/kfd\n"
 115                         "32-bit processes are not supported by amdkfd\n",
 116                         current->pid);
 117                 return -EPERM;
 118         }
 119
 120         process = kfd_create_process(current);
 121         if (IS_ERR(process))
 122                 return PTR_ERR(process);
 123
 124         dev_dbg(kfd_device, "process %d opened, compat mode (32 bit) - %d\n",
 125                 process->pasid, process->is_32bit_user_mode);
 126
 127         return 0;
 128 }
 129
 130 static long kfd_ioctl_get_version(struct file *filep, struct kfd_process *p,
 131                                         void __user *arg)
 132 {
 133         struct kfd_ioctl_get_version_args args;
 134         int err = 0;
 135
 136         args.major_version = KFD_IOCTL_MAJOR_VERSION;
 137         args.minor_version = KFD_IOCTL_MINOR_VERSION;
 138
 139         if (copy_to_user(arg, &args, sizeof(args)))
 140                 err = -EFAULT;
 141
 142         return err;
 143 }
 144
 145 static int set_queue_properties_from_user(struct queue_properties *q_properties,
 146                                 struct kfd_ioctl_create_queue_args *args)
 147 {
 148         void *tmp;
 149
 150         if (args->queue_percentage > KFD_MAX_QUEUE_PERCENTAGE) {
 151                 pr_err("kfd: queue percentage must be between 0 to KFD_MAX_QUEUE_PERCENTAGE\n");
 152                 return -EINVAL;
 153         }
 154
 155         if (args->queue_priority > KFD_MAX_QUEUE_PRIORITY) {
 156                 pr_err("kfd: queue priority must be between 0 to KFD_MAX_QUEUE_PRIORITY\n");
 157                 return -EINVAL;
 158         }
 159
 160         if ((args->ring_base_address) &&
 161                 (!access_ok(VERIFY_WRITE,
 162                         (const void __user *) args->ring_base_address,
 163                         sizeof(uint64_t)))) {
 164                 pr_err("kfd: can't access ring base address\n");
 165                 return -EFAULT;
 166         }
 167
 168         if (!is_power_of_2(args->ring_size) && (args->ring_size != 0)) {
 169                 pr_err("kfd: ring size must be a power of 2 or 0\n");
 170                 return -EINVAL;
 171         }
 172
 173         if (!access_ok(VERIFY_WRITE,
 174                         (const void __user *) args->read_pointer_address,
 175                         sizeof(uint32_t))) {
 176                 pr_err("kfd: can't access read pointer\n");
 177                 return -EFAULT;
 178         }
 179
 180         if (!access_ok(VERIFY_WRITE,
 181                         (const void __user *) args->write_pointer_address,
 182                         sizeof(uint32_t))) {
 183                 pr_err("kfd: can't access write pointer\n");
 184                 return -EFAULT;
 185         }
 186
 187         tmp = (void *)(uintptr_t)args->eop_buffer_address;
 188         if (tmp != NULL &&
 189                 !access_ok(VERIFY_WRITE, tmp, sizeof(uint32_t))) {
 190                 pr_debug("kfd: can't access eop buffer");
 191                 return -EFAULT;
 192         }
 193
 194         tmp = (void *)(uintptr_t)args->ctx_save_restore_address;
 195         if (tmp != NULL &&
 196                 !access_ok(VERIFY_WRITE, tmp, sizeof(uint32_t))) {
 197                 pr_debug("kfd: can't access ctx save restore buffer");
 198                 return -EFAULT;
 199         }
 200
 201         q_properties->is_interop = false;
 202         q_properties->queue_percent = args->queue_percentage;
 203         q_properties->priority = args->queue_priority;
 204         q_properties->queue_address = args->ring_base_address;
 205         q_properties->queue_size = args->ring_size;
 206         q_properties->read_ptr = (uint32_t *) args->read_pointer_address;
 207         q_properties->write_ptr = (uint32_t *) args->write_pointer_address;
 208         q_properties->eop_ring_buffer_address = args->eop_buffer_address;
 209         q_properties->eop_ring_buffer_size = args->eop_buffer_size;
 210         q_properties->ctx_save_restore_area_address =
 211                         args->ctx_save_restore_address;
 212         q_properties->ctx_save_restore_area_size = args->ctx_save_restore_size;
 213         if (args->queue_type == KFD_IOC_QUEUE_TYPE_COMPUTE ||
 214                 args->queue_type == KFD_IOC_QUEUE_TYPE_COMPUTE_AQL)
 215                 q_properties->type = KFD_QUEUE_TYPE_COMPUTE;
 216         else if (args->queue_type == KFD_IOC_QUEUE_TYPE_SDMA)
 217                 q_properties->type = KFD_QUEUE_TYPE_SDMA;
 218         else
 219                 return -ENOTSUPP;
 220
 221         if (args->queue_type == KFD_IOC_QUEUE_TYPE_COMPUTE_AQL)
 222                 q_properties->format = KFD_QUEUE_FORMAT_AQL;
 223         else
 224                 q_properties->format = KFD_QUEUE_FORMAT_PM4;
 225
 226         pr_debug("Queue Percentage (%d, %d)\n",
 227                         q_properties->queue_percent, args->queue_percentage);
 228
 229         pr_debug("Queue Priority (%d, %d)\n",
 230                         q_properties->priority, args->queue_priority);
 231
 232         pr_debug("Queue Address (0x%llX, 0x%llX)\n",
 233                         q_properties->queue_address, args->ring_base_address);
 234
 235         pr_debug("Queue Size (0x%llX, %u)\n",
 236                         q_properties->queue_size, args->ring_size);
 237
 238         pr_debug("Queue r/w Pointers (0x%llX, 0x%llX)\n",
 239                         (uint64_t) q_properties->read_ptr,
 240                         (uint64_t) q_properties->write_ptr);
 241
 242         pr_debug("Queue Format (%d)\n", q_properties->format);
 243
 244         pr_debug("Queue EOP (0x%llX)\n", q_properties->eop_ring_buffer_address);
 245
 246         pr_debug("Queue CTX save arex (0x%llX)\n",
 247                         q_properties->ctx_save_restore_area_address);
 248
 249         return 0;
 250 }
 251
 252 static long kfd_ioctl_create_queue(struct file *filep, struct kfd_process *p,
 253                                         void __user *arg)
 254 {
 255         struct kfd_ioctl_create_queue_args args;
 256         struct kfd_dev *dev;
 257         int err = 0;
 258         unsigned int queue_id;
 259         struct kfd_process_device *pdd;
 260         struct queue_properties q_properties;
 261
 262         memset(&q_properties, 0, sizeof(struct queue_properties));
 263
 264         if (copy_from_user(&args, arg, sizeof(args)))
 265                 return -EFAULT;
 266
 267         pr_debug("kfd: creating queue ioctl\n");
 268
 269         err = set_queue_properties_from_user(&q_properties, &args);
 270         if (err)
 271                 return err;
 272
 273         pr_debug("kfd: looking for gpu id 0x%x\n", args.gpu_id);
 274         dev = kfd_device_by_id(args.gpu_id);
 275         if (dev == NULL) {
 276                 pr_debug("kfd: gpu id 0x%x was not found\n", args.gpu_id);
 277                 return -EINVAL;
 278         }
 279
 280         mutex_lock(&p->mutex);
 281
 282         pdd = kfd_bind_process_to_device(dev, p);
 283         if (IS_ERR(pdd)) {
 284                 err = PTR_ERR(pdd);
 285                 goto err_bind_process;
 286         }
 287
 288         pr_debug("kfd: creating queue for PASID %d on GPU 0x%x\n",
 289                         p->pasid,
 290                         dev->id);
 291
 292         err = pqm_create_queue(&p->pqm, dev, filep, &q_properties,
 293                                 0, q_properties.type, &queue_id);
 294         if (err != 0)
 295                 goto err_create_queue;
 296
 297         args.queue_id = queue_id;
 298
 299         /* Return gpu_id as doorbell offset for mmap usage */
 300         args.doorbell_offset = args.gpu_id << PAGE_SHIFT;
 301
 302         if (copy_to_user(arg, &args, sizeof(args))) {
 303                 err = -EFAULT;
 304                 goto err_copy_args_out;
 305         }
 306
 307         mutex_unlock(&p->mutex);
 308
 309         pr_debug("kfd: queue id %d was created successfully\n", args.queue_id);
 310
 311         pr_debug("ring buffer address == 0x%016llX\n",
 312                         args.ring_base_address);
 313
 314         pr_debug("read ptr address    == 0x%016llX\n",
 315                         args.read_pointer_address);
 316
 317         pr_debug("write ptr address   == 0x%016llX\n",
 318                         args.write_pointer_address);
 319
 320         return 0;
 321
 322 err_copy_args_out:
 323         pqm_destroy_queue(&p->pqm, queue_id);
 324 err_create_queue:
 325 err_bind_process:
 326         mutex_unlock(&p->mutex);
 327         return err;
 328 }
 329
 330 static int kfd_ioctl_destroy_queue(struct file *filp, struct kfd_process *p,
 331                                         void __user *arg)
 332 {
 333         int retval;
 334         struct kfd_ioctl_destroy_queue_args args;
 335
 336         if (copy_from_user(&args, arg, sizeof(args)))
 337                 return -EFAULT;
 338
 339         pr_debug("kfd: destroying queue id %d for PASID %d\n",
 340                                 args.queue_id,
 341                                 p->pasid);
 342
 343         mutex_lock(&p->mutex);
 344
 345         retval = pqm_destroy_queue(&p->pqm, args.queue_id);
 346
 347         mutex_unlock(&p->mutex);
 348         return retval;
 349 }
 350
 351 static int kfd_ioctl_update_queue(struct file *filp, struct kfd_process *p,
 352                                         void __user *arg)
 353 {
 354         int retval;
 355         struct kfd_ioctl_update_queue_args args;
 356         struct queue_properties properties;
 357
 358         if (copy_from_user(&args, arg, sizeof(args)))
 359                 return -EFAULT;
 360
 361         if (args.queue_percentage > KFD_MAX_QUEUE_PERCENTAGE) {
 362                 pr_err("kfd: queue percentage must be between 0 to KFD_MAX_QUEUE_PERCENTAGE\n");
 363                 return -EINVAL;
 364         }
 365
 366         if (args.queue_priority > KFD_MAX_QUEUE_PRIORITY) {
 367                 pr_err("kfd: queue priority must be between 0 to KFD_MAX_QUEUE_PRIORITY\n");
 368                 return -EINVAL;
 369         }
 370
 371         if ((args.ring_base_address) &&
 372                 (!access_ok(VERIFY_WRITE,
 373                         (const void __user *) args.ring_base_address,
 374                         sizeof(uint64_t)))) {
 375                 pr_err("kfd: can't access ring base address\n");
 376                 return -EFAULT;
 377         }
 378
 379         if (!is_power_of_2(args.ring_size) && (args.ring_size != 0)) {
 380                 pr_err("kfd: ring size must be a power of 2 or 0\n");
 381                 return -EINVAL;
 382         }
 383
 384         properties.queue_address = args.ring_base_address;
 385         properties.queue_size = args.ring_size;
 386         properties.queue_percent = args.queue_percentage;
 387         properties.priority = args.queue_priority;
 388
 389         pr_debug("kfd: updating queue id %d for PASID %d\n",
 390                         args.queue_id, p->pasid);
 391
 392         mutex_lock(&p->mutex);
 393
 394         retval = pqm_update_queue(&p->pqm, args.queue_id, &properties);
 395
 396         mutex_unlock(&p->mutex);
 397
 398         return retval;
 399 }
 400
 401 static long kfd_ioctl_set_memory_policy(struct file *filep,
 402                                 struct kfd_process *p, void __user *arg)
 403 {
 404         struct kfd_ioctl_set_memory_policy_args args;
 405         struct kfd_dev *dev;
 406         int err = 0;
 407         struct kfd_process_device *pdd;
 408         enum cache_policy default_policy, alternate_policy;
 409
 410         if (copy_from_user(&args, arg, sizeof(args)))
 411                 return -EFAULT;
 412
 413         if (args.default_policy != KFD_IOC_CACHE_POLICY_COHERENT
 414             && args.default_policy != KFD_IOC_CACHE_POLICY_NONCOHERENT) {
 415                 return -EINVAL;
 416         }
 417
 418         if (args.alternate_policy != KFD_IOC_CACHE_POLICY_COHERENT
 419             && args.alternate_policy != KFD_IOC_CACHE_POLICY_NONCOHERENT) {
 420                 return -EINVAL;
 421         }
 422
 423         dev = kfd_device_by_id(args.gpu_id);
 424         if (dev == NULL)
 425                 return -EINVAL;
 426
 427         mutex_lock(&p->mutex);
 428
 429         pdd = kfd_bind_process_to_device(dev, p);
 430         if (IS_ERR(pdd)) {
 431                 err = PTR_ERR(pdd);
 432                 goto out;
 433         }
 434
 435         default_policy = (args.default_policy == KFD_IOC_CACHE_POLICY_COHERENT)
 436                          ? cache_policy_coherent : cache_policy_noncoherent;
 437
 438         alternate_policy =
 439                 (args.alternate_policy == KFD_IOC_CACHE_POLICY_COHERENT)
 440                    ? cache_policy_coherent : cache_policy_noncoherent;
 441
 442         if (!dev->dqm->ops.set_cache_memory_policy(dev->dqm,
 443                                 &pdd->qpd,
 444                                 default_policy,
 445                                 alternate_policy,
 446                                 (void __user *)args.alternate_aperture_base,
 447                                 args.alternate_aperture_size))
 448                 err = -EINVAL;
 449
 450 out:
 451         mutex_unlock(&p->mutex);
 452
 453         return err;
 454 }
 455
 456 static long kfd_ioctl_get_clock_counters(struct file *filep,
 457                                 struct kfd_process *p, void __user *arg)
 458 {
 459         struct kfd_ioctl_get_clock_counters_args args;
 460         struct kfd_dev *dev;
 461         struct timespec time;
 462
 463         if (copy_from_user(&args, arg, sizeof(args)))
 464                 return -EFAULT;
 465
 466         dev = kfd_device_by_id(args.gpu_id);
 467         if (dev == NULL)
 468                 return -EINVAL;
 469
 470         /* Reading GPU clock counter from KGD */
 471         args.gpu_clock_counter = kfd2kgd->get_gpu_clock_counter(dev->kgd);
 472
 473         /* No access to rdtsc. Using raw monotonic time */
 474         getrawmonotonic(&time);
 475         args.cpu_clock_counter = (uint64_t)timespec_to_ns(&time);
 476
 477         get_monotonic_boottime(&time);
 478         args.system_clock_counter = (uint64_t)timespec_to_ns(&time);
 479
 480         /* Since the counter is in nano-seconds we use 1GHz frequency */
 481         args.system_clock_freq = 1000000000;
 482
 483         if (copy_to_user(arg, &args, sizeof(args)))
 484                 return -EFAULT;
 485
 486         return 0;
 487 }
 488
 489
 490 static int kfd_ioctl_get_process_apertures(struct file *filp,
 491                                 struct kfd_process *p, void __user *arg)
 492 {
 493         struct kfd_ioctl_get_process_apertures_args args;
 494         struct kfd_process_device_apertures *pAperture;
 495         struct kfd_process_device *pdd;
 496
 497         dev_dbg(kfd_device, "get apertures for PASID %d", p->pasid);
 498
 499         if (copy_from_user(&args, arg, sizeof(args)))
 500                 return -EFAULT;
 501
 502         args.num_of_nodes = 0;
 503
 504         mutex_lock(&p->mutex);
 505
 506         /*if the process-device list isn't empty*/
 507         if (kfd_has_process_device_data(p)) {
 508                 /* Run over all pdd of the process */
 509                 pdd = kfd_get_first_process_device_data(p);
 510                 do {
 511                         pAperture = &args.process_apertures[args.num_of_nodes];
 512                         pAperture->gpu_id = pdd->dev->id;
 513                         pAperture->lds_base = pdd->lds_base;
 514                         pAperture->lds_limit = pdd->lds_limit;
 515                         pAperture->gpuvm_base = pdd->gpuvm_base;
 516                         pAperture->gpuvm_limit = pdd->gpuvm_limit;
 517                         pAperture->scratch_base = pdd->scratch_base;
 518                         pAperture->scratch_limit = pdd->scratch_limit;
 519
 520                         dev_dbg(kfd_device,
 521                                 "node id %u\n", args.num_of_nodes);
 522                         dev_dbg(kfd_device,
 523                                 "gpu id %u\n", pdd->dev->id);
 524                         dev_dbg(kfd_device,
 525                                 "lds_base %llX\n", pdd->lds_base);
 526                         dev_dbg(kfd_device,
 527                                 "lds_limit %llX\n", pdd->lds_limit);
 528                         dev_dbg(kfd_device,
 529                                 "gpuvm_base %llX\n", pdd->gpuvm_base);
 530                         dev_dbg(kfd_device,
 531                                 "gpuvm_limit %llX\n", pdd->gpuvm_limit);
 532                         dev_dbg(kfd_device,
 533                                 "scratch_base %llX\n", pdd->scratch_base);
 534                         dev_dbg(kfd_device,
 535                                 "scratch_limit %llX\n", pdd->scratch_limit);
 536
 537                         args.num_of_nodes++;
 538                 } while ((pdd = kfd_get_next_process_device_data(p, pdd)) != NULL &&
 539                                 (args.num_of_nodes < NUM_OF_SUPPORTED_GPUS));
 540         }
 541
 542         mutex_unlock(&p->mutex);
 543
 544         if (copy_to_user(arg, &args, sizeof(args)))
 545                 return -EFAULT;
 546
 547         return 0;
 548 }
 549
 550 static long kfd_ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
 551 {
 552         struct kfd_process *process;
 553         long err = -EINVAL;
 554
 555         dev_dbg(kfd_device,
 556                 "ioctl cmd 0x%x (#%d), arg 0x%lx\n",
 557                 cmd, _IOC_NR(cmd), arg);
 558
 559         process = kfd_get_process(current);
 560         if (IS_ERR(process))
 561                 return PTR_ERR(process);
 562
 563         switch (cmd) {
 564         case KFD_IOC_GET_VERSION:
 565                 err = kfd_ioctl_get_version(filep, process, (void __user *)arg);
 566                 break;
 567         case KFD_IOC_CREATE_QUEUE:
 568                 err = kfd_ioctl_create_queue(filep, process,
 569                                                 (void __user *)arg);
 570                 break;
 571
 572         case KFD_IOC_DESTROY_QUEUE:
 573                 err = kfd_ioctl_destroy_queue(filep, process,
 574                                                 (void __user *)arg);
 575                 break;
 576
 577         case KFD_IOC_SET_MEMORY_POLICY:
 578                 err = kfd_ioctl_set_memory_policy(filep, process,
 579                                                 (void __user *)arg);
 580                 break;
 581
 582         case KFD_IOC_GET_CLOCK_COUNTERS:
 583                 err = kfd_ioctl_get_clock_counters(filep, process,
 584                                                 (void __user *)arg);
 585                 break;
 586
 587         case KFD_IOC_GET_PROCESS_APERTURES:
 588                 err = kfd_ioctl_get_process_apertures(filep, process,
 589                                                 (void __user *)arg);
 590                 break;
 591
 592         case KFD_IOC_UPDATE_QUEUE:
 593                 err = kfd_ioctl_update_queue(filep, process,
 594                                                 (void __user *)arg);
 595                 break;
 596
 597         default:
 598                 dev_err(kfd_device,
 599                         "unknown ioctl cmd 0x%x, arg 0x%lx)\n",
 600                         cmd, arg);
 601                 err = -EINVAL;
 602                 break;
 603         }
 604
 605         if (err < 0)
 606                 dev_err(kfd_device,
 607                         "ioctl error %ld for ioctl cmd 0x%x (#%d)\n",
 608                         err, cmd, _IOC_NR(cmd));
 609
 610         return err;
 611 }
 612
 613 static int kfd_mmap(struct file *filp, struct vm_area_struct *vma)
 614 {
 615         struct kfd_process *process;
 616
 617         process = kfd_get_process(current);
 618         if (IS_ERR(process))
 619                 return PTR_ERR(process);
 620
 621         return kfd_doorbell_mmap(process, vma);
 622 }