drivers/gpu/drm/amd/amdkfd/kfd_events.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/mm_types.h>
  24 #include <linux/slab.h>
  25 #include <linux/types.h>
  26 #include <linux/sched.h>
  27 #include <linux/uaccess.h>
  28 #include <linux/mm.h>
  29 #include <linux/mman.h>
  30 #include <linux/memory.h>
  31 #include "kfd_priv.h"
  32 #include "kfd_events.h"
  33 #include <linux/device.h>
  34
  35 /*
  36  * A task can only be on a single wait_queue at a time, but we need to support
  37  * waiting on multiple events (any/all).
  38  * Instead of each event simply having a wait_queue with sleeping tasks, it
  39  * has a singly-linked list of tasks.
  40  * A thread that wants to sleep creates an array of these, one for each event
  41  * and adds one to each event's waiter chain.
  42  */
  43 struct kfd_event_waiter {
  44         struct list_head waiters;
  45         struct task_struct *sleeping_task;
  46
  47         /* Transitions to true when the event this belongs to is signaled. */
  48         bool activated;
  49
  50         /* Event */
  51         struct kfd_event *event;
  52         uint32_t input_index;
  53 };
  54
  55 /*
  56  * Over-complicated pooled allocator for event notification slots.
  57  *
  58  * Each signal event needs a 64-bit signal slot where the signaler will write
  59  * a 1 before sending an interrupt.l (This is needed because some interrupts
  60  * do not contain enough spare data bits to identify an event.)
  61  * We get whole pages from vmalloc and map them to the process VA.
  62  * Individual signal events are then allocated a slot in a page.
  63  */
  64
  65 struct signal_page {
  66         struct list_head event_pages;   /* kfd_process.signal_event_pages */
  67         uint64_t *kernel_address;
  68         uint64_t __user *user_address;
  69         uint32_t page_index;            /* Index into the mmap aperture. */
  70         unsigned int free_slots;
  71         unsigned long used_slot_bitmap[0];
  72 };
  73
  74 #define SLOTS_PER_PAGE KFD_SIGNAL_EVENT_LIMIT
  75 #define SLOT_BITMAP_SIZE BITS_TO_LONGS(SLOTS_PER_PAGE)
  76 #define BITS_PER_PAGE (ilog2(SLOTS_PER_PAGE)+1)
  77 #define SIGNAL_PAGE_SIZE (sizeof(struct signal_page) + \
  78                                 SLOT_BITMAP_SIZE * sizeof(long))
  79
  80 /*
  81  * For signal events, the event ID is used as the interrupt user data.
  82  * For SQ s_sendmsg interrupts, this is limited to 8 bits.
  83  */
  84
  85 #define INTERRUPT_DATA_BITS 8
  86 #define SIGNAL_EVENT_ID_SLOT_SHIFT 0
  87
  88 static uint64_t *page_slots(struct signal_page *page)
  89 {
  90         return page->kernel_address;
  91 }
  92
  93 static bool allocate_free_slot(struct kfd_process *process,
  94                                 struct signal_page **out_page,
  95                                 unsigned int *out_slot_index)
  96 {
  97         struct signal_page *page;
  98
  99         list_for_each_entry(page, &process->signal_event_pages, event_pages) {
 100                 if (page->free_slots > 0) {
 101                         unsigned int slot =
 102                                 find_first_zero_bit(page->used_slot_bitmap,
 103                                                         SLOTS_PER_PAGE);
 104
 105                         __set_bit(slot, page->used_slot_bitmap);
 106                         page->free_slots--;
 107
 108                         page_slots(page)[slot] = UNSIGNALED_EVENT_SLOT;
 109
 110                         *out_page = page;
 111                         *out_slot_index = slot;
 112
 113                         pr_debug("allocated event signal slot in page %p, slot %d\n",
 114                                         page, slot);
 115
 116                         return true;
 117                 }
 118         }
 119
 120         pr_debug("No free event signal slots were found for process %p\n",
 121                         process);
 122
 123         return false;
 124 }
 125
 126 #define list_tail_entry(head, type, member) \
 127         list_entry((head)->prev, type, member)
 128
 129 static bool allocate_signal_page(struct file *devkfd, struct kfd_process *p)
 130 {
 131         void *backing_store;
 132         struct signal_page *page;
 133
 134         page = kzalloc(SIGNAL_PAGE_SIZE, GFP_KERNEL);
 135         if (!page)
 136                 goto fail_alloc_signal_page;
 137
 138         page->free_slots = SLOTS_PER_PAGE;
 139
 140         backing_store = (void *) __get_free_pages(GFP_KERNEL | __GFP_ZERO,
 141                                         get_order(KFD_SIGNAL_EVENT_LIMIT * 8));
 142         if (!backing_store)
 143                 goto fail_alloc_signal_store;
 144
 145         /* prevent user-mode info leaks */
 146         memset(backing_store, (uint8_t) UNSIGNALED_EVENT_SLOT,
 147                 KFD_SIGNAL_EVENT_LIMIT * 8);
 148
 149         page->kernel_address = backing_store;
 150
 151         if (list_empty(&p->signal_event_pages))
 152                 page->page_index = 0;
 153         else
 154                 page->page_index = list_tail_entry(&p->signal_event_pages,
 155                                                    struct signal_page,
 156                                                    event_pages)->page_index + 1;
 157
 158         pr_debug("allocated new event signal page at %p, for process %p\n",
 159                         page, p);
 160         pr_debug("page index is %d\n", page->page_index);
 161
 162         list_add(&page->event_pages, &p->signal_event_pages);
 163
 164         return true;
 165
 166 fail_alloc_signal_store:
 167         kfree(page);
 168 fail_alloc_signal_page:
 169         return false;
 170 }
 171
 172 static bool allocate_event_notification_slot(struct file *devkfd,
 173                                         struct kfd_process *p,
 174                                         struct signal_page **page,
 175                                         unsigned int *signal_slot_index)
 176 {
 177         bool ret;
 178
 179         ret = allocate_free_slot(p, page, signal_slot_index);
 180         if (ret == false) {
 181                 ret = allocate_signal_page(devkfd, p);
 182                 if (ret == true)
 183                         ret = allocate_free_slot(p, page, signal_slot_index);
 184         }
 185
 186         return ret;
 187 }
 188
 189 /* Assumes that the process's event_mutex is locked. */
 190 static void release_event_notification_slot(struct signal_page *page,
 191                                                 size_t slot_index)
 192 {
 193         __clear_bit(slot_index, page->used_slot_bitmap);
 194         page->free_slots++;
 195
 196         /* We don't free signal pages, they are retained by the process
 197          * and reused until it exits. */
 198 }
 199
 200 static struct signal_page *lookup_signal_page_by_index(struct kfd_process *p,
 201                                                 unsigned int page_index)
 202 {
 203         struct signal_page *page;
 204
 205         /*
 206          * This is safe because we don't delete signal pages until the
 207          * process exits.
 208          */
 209         list_for_each_entry(page, &p->signal_event_pages, event_pages)
 210                 if (page->page_index == page_index)
 211                         return page;
 212
 213         return NULL;
 214 }
 215
 216 /*
 217  * Assumes that p->event_mutex is held and of course that p is not going
 218  * away (current or locked).
 219  */
 220 static struct kfd_event *lookup_event_by_id(struct kfd_process *p, uint32_t id)
 221 {
 222         struct kfd_event *ev;
 223
 224         hash_for_each_possible(p->events, ev, events, id)
 225                 if (ev->event_id == id)
 226                         return ev;
 227
 228         return NULL;
 229 }
 230
 231 static u32 make_signal_event_id(struct signal_page *page,
 232                                          unsigned int signal_slot_index)
 233 {
 234         return page->page_index |
 235                         (signal_slot_index << SIGNAL_EVENT_ID_SLOT_SHIFT);
 236 }
 237
 238 /*
 239  * Produce a kfd event id for a nonsignal event.
 240  * These are arbitrary numbers, so we do a sequential search through
 241  * the hash table for an unused number.
 242  */
 243 static u32 make_nonsignal_event_id(struct kfd_process *p)
 244 {
 245         u32 id;
 246
 247         for (id = p->next_nonsignal_event_id;
 248                 id < KFD_LAST_NONSIGNAL_EVENT_ID &&
 249                 lookup_event_by_id(p, id) != NULL;
 250                 id++)
 251                 ;
 252
 253         if (id < KFD_LAST_NONSIGNAL_EVENT_ID) {
 254
 255                 /*
 256                  * What if id == LAST_NONSIGNAL_EVENT_ID - 1?
 257                  * Then next_nonsignal_event_id = LAST_NONSIGNAL_EVENT_ID so
 258                  * the first loop fails immediately and we proceed with the
 259                  * wraparound loop below.
 260                  */
 261                 p->next_nonsignal_event_id = id + 1;
 262
 263                 return id;
 264         }
 265
 266         for (id = KFD_FIRST_NONSIGNAL_EVENT_ID;
 267                 id < KFD_LAST_NONSIGNAL_EVENT_ID &&
 268                 lookup_event_by_id(p, id) != NULL;
 269                 id++)
 270                 ;
 271
 272
 273         if (id < KFD_LAST_NONSIGNAL_EVENT_ID) {
 274                 p->next_nonsignal_event_id = id + 1;
 275                 return id;
 276         }
 277
 278         p->next_nonsignal_event_id = KFD_FIRST_NONSIGNAL_EVENT_ID;
 279         return 0;
 280 }
 281
 282 static struct kfd_event *lookup_event_by_page_slot(struct kfd_process *p,
 283                                                 struct signal_page *page,
 284                                                 unsigned int signal_slot)
 285 {
 286         return lookup_event_by_id(p, make_signal_event_id(page, signal_slot));
 287 }
 288
 289 static int create_signal_event(struct file *devkfd,
 290                                 struct kfd_process *p,
 291                                 struct kfd_event *ev)
 292 {
 293         if (p->signal_event_count == KFD_SIGNAL_EVENT_LIMIT) {
 294                 pr_warn("amdkfd: Signal event wasn't created because limit was reached\n");
 295                 return -ENOMEM;
 296         }
 297
 298         if (!allocate_event_notification_slot(devkfd, p, &ev->signal_page,
 299                                                 &ev->signal_slot_index)) {
 300                 pr_warn("amdkfd: Signal event wasn't created because out of kernel memory\n");
 301                 return -ENOMEM;
 302         }
 303
 304         p->signal_event_count++;
 305
 306         ev->user_signal_address =
 307                         &ev->signal_page->user_address[ev->signal_slot_index];
 308
 309         ev->event_id = make_signal_event_id(ev->signal_page,
 310                                                 ev->signal_slot_index);
 311
 312         pr_debug("signal event number %zu created with id %d, address %p\n",
 313                         p->signal_event_count, ev->event_id,
 314                         ev->user_signal_address);
 315
 316         pr_debug("signal event number %zu created with id %d, address %p\n",
 317                         p->signal_event_count, ev->event_id,
 318                         ev->user_signal_address);
 319
 320         return 0;
 321 }
 322
 323 /*
 324  * No non-signal events are supported yet.
 325  * We create them as events that never signal.
 326  * Set event calls from user-mode are failed.
 327  */
 328 static int create_other_event(struct kfd_process *p, struct kfd_event *ev)
 329 {
 330         ev->event_id = make_nonsignal_event_id(p);
 331         if (ev->event_id == 0)
 332                 return -ENOMEM;
 333
 334         return 0;
 335 }
 336
 337 void kfd_event_init_process(struct kfd_process *p)
 338 {
 339         mutex_init(&p->event_mutex);
 340         hash_init(p->events);
 341         INIT_LIST_HEAD(&p->signal_event_pages);
 342         p->next_nonsignal_event_id = KFD_FIRST_NONSIGNAL_EVENT_ID;
 343         p->signal_event_count = 0;
 344 }
 345
 346 static void destroy_event(struct kfd_process *p, struct kfd_event *ev)
 347 {
 348         if (ev->signal_page != NULL) {
 349                 release_event_notification_slot(ev->signal_page,
 350                                                 ev->signal_slot_index);
 351                 p->signal_event_count--;
 352         }
 353
 354         /*
 355          * Abandon the list of waiters. Individual waiting threads will
 356          * clean up their own data.
 357          */
 358         list_del(&ev->waiters);
 359
 360         hash_del(&ev->events);
 361         kfree(ev);
 362 }
 363
 364 static void destroy_events(struct kfd_process *p)
 365 {
 366         struct kfd_event *ev;
 367         struct hlist_node *tmp;
 368         unsigned int hash_bkt;
 369
 370         hash_for_each_safe(p->events, hash_bkt, tmp, ev, events)
 371                 destroy_event(p, ev);
 372 }
 373
 374 /*
 375  * We assume that the process is being destroyed and there is no need to
 376  * unmap the pages or keep bookkeeping data in order.
 377  */
 378 static void shutdown_signal_pages(struct kfd_process *p)
 379 {
 380         struct signal_page *page, *tmp;
 381
 382         list_for_each_entry_safe(page, tmp, &p->signal_event_pages,
 383                                         event_pages) {
 384                 free_pages((unsigned long)page->kernel_address,
 385                                 get_order(KFD_SIGNAL_EVENT_LIMIT * 8));
 386                 kfree(page);
 387         }
 388 }
 389
 390 void kfd_event_free_process(struct kfd_process *p)
 391 {
 392         destroy_events(p);
 393         shutdown_signal_pages(p);
 394 }
 395
 396 static bool event_can_be_gpu_signaled(const struct kfd_event *ev)
 397 {
 398         return ev->type == KFD_EVENT_TYPE_SIGNAL ||
 399                                         ev->type == KFD_EVENT_TYPE_DEBUG;
 400 }
 401
 402 static bool event_can_be_cpu_signaled(const struct kfd_event *ev)
 403 {
 404         return ev->type == KFD_EVENT_TYPE_SIGNAL;
 405 }
 406
 407 int kfd_event_create(struct file *devkfd, struct kfd_process *p,
 408                      uint32_t event_type, bool auto_reset, uint32_t node_id,
 409                      uint32_t *event_id, uint32_t *event_trigger_data,
 410                      uint64_t *event_page_offset, uint32_t *event_slot_index)
 411 {
 412         int ret = 0;
 413         struct kfd_event *ev = kzalloc(sizeof(*ev), GFP_KERNEL);
 414
 415         if (!ev)
 416                 return -ENOMEM;
 417
 418         ev->type = event_type;
 419         ev->auto_reset = auto_reset;
 420         ev->signaled = false;
 421
 422         INIT_LIST_HEAD(&ev->waiters);
 423
 424         *event_page_offset = 0;
 425
 426         mutex_lock(&p->event_mutex);
 427
 428         switch (event_type) {
 429         case KFD_EVENT_TYPE_SIGNAL:
 430         case KFD_EVENT_TYPE_DEBUG:
 431                 ret = create_signal_event(devkfd, p, ev);
 432                 if (!ret) {
 433                         *event_page_offset = (ev->signal_page->page_index |
 434                                         KFD_MMAP_EVENTS_MASK);
 435                         *event_page_offset <<= PAGE_SHIFT;
 436                         *event_slot_index = ev->signal_slot_index;
 437                 }
 438                 break;
 439         default:
 440                 ret = create_other_event(p, ev);
 441                 break;
 442         }
 443
 444         if (!ret) {
 445                 hash_add(p->events, &ev->events, ev->event_id);
 446
 447                 *event_id = ev->event_id;
 448                 *event_trigger_data = ev->event_id;
 449         } else {
 450                 kfree(ev);
 451         }
 452
 453         mutex_unlock(&p->event_mutex);
 454
 455         return ret;
 456 }
 457
 458 /* Assumes that p is current. */
 459 int kfd_event_destroy(struct kfd_process *p, uint32_t event_id)
 460 {
 461         struct kfd_event *ev;
 462         int ret = 0;
 463
 464         mutex_lock(&p->event_mutex);
 465
 466         ev = lookup_event_by_id(p, event_id);
 467
 468         if (ev)
 469                 destroy_event(p, ev);
 470         else
 471                 ret = -EINVAL;
 472
 473         mutex_unlock(&p->event_mutex);
 474         return ret;
 475 }
 476
 477 static void set_event(struct kfd_event *ev)
 478 {
 479         struct kfd_event_waiter *waiter;
 480         struct kfd_event_waiter *next;
 481
 482         /* Auto reset if the list is non-empty and we're waking someone. */
 483         ev->signaled = !ev->auto_reset || list_empty(&ev->waiters);
 484
 485         list_for_each_entry_safe(waiter, next, &ev->waiters, waiters) {
 486                 waiter->activated = true;
 487
 488                 /* _init because free_waiters will call list_del */
 489                 list_del_init(&waiter->waiters);
 490
 491                 wake_up_process(waiter->sleeping_task);
 492         }
 493 }
 494
 495 /* Assumes that p is current. */
 496 int kfd_set_event(struct kfd_process *p, uint32_t event_id)
 497 {
 498         int ret = 0;
 499         struct kfd_event *ev;
 500
 501         mutex_lock(&p->event_mutex);
 502
 503         ev = lookup_event_by_id(p, event_id);
 504
 505         if (ev && event_can_be_cpu_signaled(ev))
 506                 set_event(ev);
 507         else
 508                 ret = -EINVAL;
 509
 510         mutex_unlock(&p->event_mutex);
 511         return ret;
 512 }
 513
 514 static void reset_event(struct kfd_event *ev)
 515 {
 516         ev->signaled = false;
 517 }
 518
 519 /* Assumes that p is current. */
 520 int kfd_reset_event(struct kfd_process *p, uint32_t event_id)
 521 {
 522         int ret = 0;
 523         struct kfd_event *ev;
 524
 525         mutex_lock(&p->event_mutex);
 526
 527         ev = lookup_event_by_id(p, event_id);
 528
 529         if (ev && event_can_be_cpu_signaled(ev))
 530                 reset_event(ev);
 531         else
 532                 ret = -EINVAL;
 533
 534         mutex_unlock(&p->event_mutex);
 535         return ret;
 536
 537 }
 538
 539 static void acknowledge_signal(struct kfd_process *p, struct kfd_event *ev)
 540 {
 541         page_slots(ev->signal_page)[ev->signal_slot_index] =
 542                                                 UNSIGNALED_EVENT_SLOT;
 543 }
 544
 545 static bool is_slot_signaled(struct signal_page *page, unsigned int index)
 546 {
 547         return page_slots(page)[index] != UNSIGNALED_EVENT_SLOT;
 548 }
 549
 550 static void set_event_from_interrupt(struct kfd_process *p,
 551                                         struct kfd_event *ev)
 552 {
 553         if (ev && event_can_be_gpu_signaled(ev)) {
 554                 acknowledge_signal(p, ev);
 555                 set_event(ev);
 556         }
 557 }
 558
 559 void kfd_signal_event_interrupt(unsigned int pasid, uint32_t partial_id,
 560                                 uint32_t valid_id_bits)
 561 {
 562         struct kfd_event *ev;
 563
 564         /*
 565          * Because we are called from arbitrary context (workqueue) as opposed
 566          * to process context, kfd_process could attempt to exit while we are
 567          * running so the lookup function returns a locked process.
 568          */
 569         struct kfd_process *p = kfd_lookup_process_by_pasid(pasid);
 570
 571         if (!p)
 572                 return; /* Presumably process exited. */
 573
 574         mutex_lock(&p->event_mutex);
 575
 576         if (valid_id_bits >= INTERRUPT_DATA_BITS) {
 577                 /* Partial ID is a full ID. */
 578                 ev = lookup_event_by_id(p, partial_id);
 579                 set_event_from_interrupt(p, ev);
 580         } else {
 581                 /*
 582                  * Partial ID is in fact partial. For now we completely
 583                  * ignore it, but we could use any bits we did receive to
 584                  * search faster.
 585                  */
 586                 struct signal_page *page;
 587                 unsigned i;
 588
 589                 list_for_each_entry(page, &p->signal_event_pages, event_pages)
 590                         for (i = 0; i < SLOTS_PER_PAGE; i++)
 591                                 if (is_slot_signaled(page, i)) {
 592                                         ev = lookup_event_by_page_slot(p,
 593                                                                 page, i);
 594                                         set_event_from_interrupt(p, ev);
 595                                 }
 596         }
 597
 598         mutex_unlock(&p->event_mutex);
 599         mutex_unlock(&p->mutex);
 600 }
 601
 602 static struct kfd_event_waiter *alloc_event_waiters(uint32_t num_events)
 603 {
 604         struct kfd_event_waiter *event_waiters;
 605         uint32_t i;
 606
 607         event_waiters = kmalloc_array(num_events,
 608                                         sizeof(struct kfd_event_waiter),
 609                                         GFP_KERNEL);
 610
 611         for (i = 0; (event_waiters) && (i < num_events) ; i++) {
 612                 INIT_LIST_HEAD(&event_waiters[i].waiters);
 613                 event_waiters[i].sleeping_task = current;
 614                 event_waiters[i].activated = false;
 615         }
 616
 617         return event_waiters;
 618 }
 619
 620 static int init_event_waiter(struct kfd_process *p,
 621                 struct kfd_event_waiter *waiter,
 622                 uint32_t event_id,
 623                 uint32_t input_index)
 624 {
 625         struct kfd_event *ev = lookup_event_by_id(p, event_id);
 626
 627         if (!ev)
 628                 return -EINVAL;
 629
 630         waiter->event = ev;
 631         waiter->input_index = input_index;
 632         waiter->activated = ev->signaled;
 633         ev->signaled = ev->signaled && !ev->auto_reset;
 634
 635         list_add(&waiter->waiters, &ev->waiters);
 636
 637         return 0;
 638 }
 639
 640 static bool test_event_condition(bool all, uint32_t num_events,
 641                                 struct kfd_event_waiter *event_waiters)
 642 {
 643         uint32_t i;
 644         uint32_t activated_count = 0;
 645
 646         for (i = 0; i < num_events; i++) {
 647                 if (event_waiters[i].activated) {
 648                         if (!all)
 649                                 return true;
 650
 651                         activated_count++;
 652                 }
 653         }
 654
 655         return activated_count == num_events;
 656 }
 657
 658 /*
 659  * Copy event specific data, if defined.
 660  * Currently only memory exception events have additional data to copy to user
 661  */
 662 static bool copy_signaled_event_data(uint32_t num_events,
 663                 struct kfd_event_waiter *event_waiters,
 664                 struct kfd_event_data __user *data)
 665 {
 666         struct kfd_hsa_memory_exception_data *src;
 667         struct kfd_hsa_memory_exception_data __user *dst;
 668         struct kfd_event_waiter *waiter;
 669         struct kfd_event *event;
 670         uint32_t i;
 671
 672         for (i = 0; i < num_events; i++) {
 673                 waiter = &event_waiters[i];
 674                 event = waiter->event;
 675                 if (waiter->activated && event->type == KFD_EVENT_TYPE_MEMORY) {
 676                         dst = &data[waiter->input_index].memory_exception_data;
 677                         src = &event->memory_exception_data;
 678                         if (copy_to_user(dst, src,
 679                                 sizeof(struct kfd_hsa_memory_exception_data)))
 680                                 return false;
 681                 }
 682         }
 683
 684         return true;
 685
 686 }
 687
 688
 689
 690 static long user_timeout_to_jiffies(uint32_t user_timeout_ms)
 691 {
 692         if (user_timeout_ms == KFD_EVENT_TIMEOUT_IMMEDIATE)
 693                 return 0;
 694
 695         if (user_timeout_ms == KFD_EVENT_TIMEOUT_INFINITE)
 696                 return MAX_SCHEDULE_TIMEOUT;
 697
 698         /*
 699          * msecs_to_jiffies interprets all values above 2^31-1 as infinite,
 700          * but we consider them finite.
 701          * This hack is wrong, but nobody is likely to notice.
 702          */
 703         user_timeout_ms = min_t(uint32_t, user_timeout_ms, 0x7FFFFFFF);
 704
 705         return msecs_to_jiffies(user_timeout_ms) + 1;
 706 }
 707
 708 static void free_waiters(uint32_t num_events, struct kfd_event_waiter *waiters)
 709 {
 710         uint32_t i;
 711
 712         for (i = 0; i < num_events; i++)
 713                 list_del(&waiters[i].waiters);
 714
 715         kfree(waiters);
 716 }
 717
 718 int kfd_wait_on_events(struct kfd_process *p,
 719                        uint32_t num_events, void __user *data,
 720                        bool all, uint32_t user_timeout_ms,
 721                        enum kfd_event_wait_result *wait_result)
 722 {
 723         struct kfd_event_data __user *events =
 724                         (struct kfd_event_data __user *) data;
 725         uint32_t i;
 726         int ret = 0;
 727         struct kfd_event_waiter *event_waiters = NULL;
 728         long timeout = user_timeout_to_jiffies(user_timeout_ms);
 729
 730         mutex_lock(&p->event_mutex);
 731
 732         event_waiters = alloc_event_waiters(num_events);
 733         if (!event_waiters) {
 734                 ret = -ENOMEM;
 735                 goto fail;
 736         }
 737
 738         for (i = 0; i < num_events; i++) {
 739                 struct kfd_event_data event_data;
 740
 741                 if (copy_from_user(&event_data, &events[i],
 742                                 sizeof(struct kfd_event_data)))
 743                         goto fail;
 744
 745                 ret = init_event_waiter(p, &event_waiters[i],
 746                                 event_data.event_id, i);
 747                 if (ret)
 748                         goto fail;
 749         }
 750
 751         mutex_unlock(&p->event_mutex);
 752
 753         while (true) {
 754                 if (fatal_signal_pending(current)) {
 755                         ret = -EINTR;
 756                         break;
 757                 }
 758
 759                 if (signal_pending(current)) {
 760                         /*
 761                          * This is wrong when a nonzero, non-infinite timeout
 762                          * is specified. We need to use
 763                          * ERESTARTSYS_RESTARTBLOCK, but struct restart_block
 764                          * contains a union with data for each user and it's
 765                          * in generic kernel code that I don't want to
 766                          * touch yet.
 767                          */
 768                         ret = -ERESTARTSYS;
 769                         break;
 770                 }
 771
 772                 if (test_event_condition(all, num_events, event_waiters)) {
 773                         if (copy_signaled_event_data(num_events,
 774                                         event_waiters, events))
 775                                 *wait_result = KFD_WAIT_COMPLETE;
 776                         else
 777                                 *wait_result = KFD_WAIT_ERROR;
 778                         break;
 779                 }
 780
 781                 if (timeout <= 0) {
 782                         *wait_result = KFD_WAIT_TIMEOUT;
 783                         break;
 784                 }
 785
 786                 timeout = schedule_timeout_interruptible(timeout);
 787         }
 788         __set_current_state(TASK_RUNNING);
 789
 790         mutex_lock(&p->event_mutex);
 791         free_waiters(num_events, event_waiters);
 792         mutex_unlock(&p->event_mutex);
 793
 794         return ret;
 795
 796 fail:
 797         if (event_waiters)
 798                 free_waiters(num_events, event_waiters);
 799
 800         mutex_unlock(&p->event_mutex);
 801
 802         *wait_result = KFD_WAIT_ERROR;
 803
 804         return ret;
 805 }
 806
 807 int kfd_event_mmap(struct kfd_process *p, struct vm_area_struct *vma)
 808 {
 809
 810         unsigned int page_index;
 811         unsigned long pfn;
 812         struct signal_page *page;
 813
 814         /* check required size is logical */
 815         if (get_order(KFD_SIGNAL_EVENT_LIMIT * 8) !=
 816                         get_order(vma->vm_end - vma->vm_start)) {
 817                 pr_err("amdkfd: event page mmap requested illegal size\n");
 818                 return -EINVAL;
 819         }
 820
 821         page_index = vma->vm_pgoff;
 822
 823         page = lookup_signal_page_by_index(p, page_index);
 824         if (!page) {
 825                 /* Probably KFD bug, but mmap is user-accessible. */
 826                 pr_debug("signal page could not be found for page_index %u\n",
 827                                 page_index);
 828                 return -EINVAL;
 829         }
 830
 831         pfn = __pa(page->kernel_address);
 832         pfn >>= PAGE_SHIFT;
 833
 834         vma->vm_flags |= VM_IO | VM_DONTCOPY | VM_DONTEXPAND | VM_NORESERVE
 835                        | VM_DONTDUMP | VM_PFNMAP;
 836
 837         pr_debug("mapping signal page\n");
 838         pr_debug("     start user address  == 0x%08lx\n", vma->vm_start);
 839         pr_debug("     end user address    == 0x%08lx\n", vma->vm_end);
 840         pr_debug("     pfn                 == 0x%016lX\n", pfn);
 841         pr_debug("     vm_flags            == 0x%08lX\n", vma->vm_flags);
 842         pr_debug("     size                == 0x%08lX\n",
 843                         vma->vm_end - vma->vm_start);
 844
 845         page->user_address = (uint64_t __user *)vma->vm_start;
 846
 847         /* mapping the page to user process */
 848         return remap_pfn_range(vma, vma->vm_start, pfn,
 849                         vma->vm_end - vma->vm_start, vma->vm_page_prot);
 850 }
 851
 852 /*
 853  * Assumes that p->event_mutex is held and of course
 854  * that p is not going away (current or locked).
 855  */
 856 static void lookup_events_by_type_and_signal(struct kfd_process *p,
 857                 int type, void *event_data)
 858 {
 859         struct kfd_hsa_memory_exception_data *ev_data;
 860         struct kfd_event *ev;
 861         int bkt;
 862         bool send_signal = true;
 863
 864         ev_data = (struct kfd_hsa_memory_exception_data *) event_data;
 865
 866         hash_for_each(p->events, bkt, ev, events)
 867                 if (ev->type == type) {
 868                         send_signal = false;
 869                         dev_dbg(kfd_device,
 870                                         "Event found: id %X type %d",
 871                                         ev->event_id, ev->type);
 872                         set_event(ev);
 873                         if (ev->type == KFD_EVENT_TYPE_MEMORY && ev_data)
 874                                 ev->memory_exception_data = *ev_data;
 875                 }
 876
 877         /* Send SIGTERM no event of type "type" has been found*/
 878         if (send_signal) {
 879                 if (send_sigterm) {
 880                         dev_warn(kfd_device,
 881                                 "Sending SIGTERM to HSA Process with PID %d ",
 882                                         p->lead_thread->pid);
 883                         send_sig(SIGTERM, p->lead_thread, 0);
 884                 } else {
 885                         dev_err(kfd_device,
 886                                 "HSA Process (PID %d) got unhandled exception",
 887                                 p->lead_thread->pid);
 888                 }
 889         }
 890 }
 891
 892 void kfd_signal_iommu_event(struct kfd_dev *dev, unsigned int pasid,
 893                 unsigned long address, bool is_write_requested,
 894                 bool is_execute_requested)
 895 {
 896         struct kfd_hsa_memory_exception_data memory_exception_data;
 897         struct vm_area_struct *vma;
 898
 899         /*
 900          * Because we are called from arbitrary context (workqueue) as opposed
 901          * to process context, kfd_process could attempt to exit while we are
 902          * running so the lookup function returns a locked process.
 903          */
 904         struct kfd_process *p = kfd_lookup_process_by_pasid(pasid);
 905
 906         if (!p)
 907                 return; /* Presumably process exited. */
 908
 909         memset(&memory_exception_data, 0, sizeof(memory_exception_data));
 910
 911         down_read(&p->mm->mmap_sem);
 912         vma = find_vma(p->mm, address);
 913
 914         memory_exception_data.gpu_id = dev->id;
 915         memory_exception_data.va = address;
 916         /* Set failure reason */
 917         memory_exception_data.failure.NotPresent = 1;
 918         memory_exception_data.failure.NoExecute = 0;
 919         memory_exception_data.failure.ReadOnly = 0;
 920         if (vma) {
 921                 if (vma->vm_start > address) {
 922                         memory_exception_data.failure.NotPresent = 1;
 923                         memory_exception_data.failure.NoExecute = 0;
 924                         memory_exception_data.failure.ReadOnly = 0;
 925                 } else {
 926                         memory_exception_data.failure.NotPresent = 0;
 927                         if (is_write_requested && !(vma->vm_flags & VM_WRITE))
 928                                 memory_exception_data.failure.ReadOnly = 1;
 929                         else
 930                                 memory_exception_data.failure.ReadOnly = 0;
 931                         if (is_execute_requested && !(vma->vm_flags & VM_EXEC))
 932                                 memory_exception_data.failure.NoExecute = 1;
 933                         else
 934                                 memory_exception_data.failure.NoExecute = 0;
 935                 }
 936         }
 937
 938         up_read(&p->mm->mmap_sem);
 939
 940         mutex_lock(&p->event_mutex);
 941
 942         /* Lookup events by type and signal them */
 943         lookup_events_by_type_and_signal(p, KFD_EVENT_TYPE_MEMORY,
 944                         &memory_exception_data);
 945
 946         mutex_unlock(&p->event_mutex);
 947         mutex_unlock(&p->mutex);
 948 }
 949
 950 void kfd_signal_hw_exception_event(unsigned int pasid)
 951 {
 952         /*
 953          * Because we are called from arbitrary context (workqueue) as opposed
 954          * to process context, kfd_process could attempt to exit while we are
 955          * running so the lookup function returns a locked process.
 956          */
 957         struct kfd_process *p = kfd_lookup_process_by_pasid(pasid);
 958
 959         if (!p)
 960                 return; /* Presumably process exited. */
 961
 962         mutex_lock(&p->event_mutex);
 963
 964         /* Lookup events by type and signal them */
 965         lookup_events_by_type_and_signal(p, KFD_EVENT_TYPE_HW_EXCEPTION, NULL);
 966
 967         mutex_unlock(&p->event_mutex);
 968         mutex_unlock(&p->mutex);
 969 }